In this installment of the Controls Corner, we are addressing load configurations in a furnace. An industrial furnace is made up of multiple zones for the heating of the load. These zones are strategically placed to minimize heat losses and to give the best heat profile for the application (minimize hot and cold spots in the vessel). In this Technical Tuesday installment, guest columnist Stanley Rutkowski III, senior applications engineer at RoMan Manufacturing, Inc., highlights the differences between power controls based on voltage and current.
The utility company transmits power to the electrical grid in terms of “voltage” and “current.” Voltage is the pressure to push the current through the wires. The amount of voltage required is a function of the losses in the system (resistance, reactance, and impedance). Utility companies transmit this via the highest voltage available to minimize the current. By minimizing the current, the cross section of the conductors to transmit gets smaller and less costly to run over long distances. At an industrial facility, a step down transformer (distribution type) is used to change the high voltage from the utility company to plant voltage (and by the same ratio increase the current from low to high).
In the operations of a furnace, the term commonly used is power, which is a multiplication of two variables, voltage and current.
In the operations of a furnace, the term commonly used is power, which is a multiplication of two variables, voltage and current. The utility company transmits power in a three-phase configuration with 120 degrees difference between phases (typically labeled A-B, B-C, and C-A). Let’s take a brief look at four major load configurations.
Single-Phase Load
A single-phase load uses one of the three legs of the system in operation. This type of system is best used in three zone applications to try to balance the power of each zone to the utility. A single-phase load allows for the most control of a zone in a furnace as it is individually controlled, but potentially causes the most disturbances to the utility company.
Two-Phase Load (Scott-T)
A Scott-T system is a way to balance load a three-phase system but allow for two loads in operation. In a five zone furnace, you could configure a three-phase system for the middle three zones and a Scott-T system for the first and last zones (front and back). A Scott-T system has a single point of control for the two zones to have the least disturbances to the utility company.
Three-Phase Load
A three-phase load can be in different configurations, the most common being Delta and Wye. The differences between them are the vectors of the voltage and current. A Wye system has less voltage and more current while a Delta system has less current and higher voltage. Care needs to be taken to minimize potential circulating currents that can be created by the vectors of three-phase systems. The three-phase system is a single point of control for the loads and causes less disturbances to the utility company. Mixing of three-phase systems inside a furnace (Delta and Wye) can help further minimize disturbances to the utility company.
IGBT (Insulated-Gate Bipolar Transistor)
An IGBT (Insulated-Gate Bipolar Transistor) system is a hybrid system that uses a three-phase primary to create a single-phase load. This allows for the highest level of control while minimizing the disturbances to the utility company. This system also allows the usage of higher frequencies to shrink the footprint of the transformers, allowing the use of rectification to minimize inductance and minimize the high current runs to the load(s).
About the Author:
Stanley F. Rutkowski III Senior Applications Engineer RoMan Manufacturing, Inc.
Stanley F. Rutkowski III is the senior applications engineer at RoMan Manufacturing, Inc., working on electrical energy savings in resistance heating applications. Stanley has worked at the company for 33 years with experience in welding, glass and furnace industries from R&D, design, and application standpoints. For more than 15 years, his focus has been on energy savings applications in industrial heating applications.
Like most power systems, power control dates back to vacuum tube technology. Like radios, amplifiers, and other industrial equipment, the furnace market started using transistors as the technology evolved. Vacuum tubes were not generally balanced and contained poisonous elements and were phased out of usage in almost all industries. In this Technical Tuesday installment, guest columnist Stanley Rutkowski III, senior applications engineer at RoMan Manufacturing, Inc., distinguishes the different methods used to regulate power input to furnaces.
An ERT/SCR power control Source: RoMan Manufacturing, Inc.
In today’s furnace market, there are generally three primary types of control systems: VRT, SCR, and IGBT. Each of these control technologies employs different methods to regulate the power input to the furnace, which in turn generates the required heat. These control systems transfer the power from the plant power system to a transformer in line with the load (heating elements). Power is delivered to a plant in a three-phase system from the utility company. The least costly and highest power factor systems have a balanced load across the three phases during the operation of any furnace.
VRT (Variable Reactance Transformer)
A VRT incorporates a feedback mechanism to either increase or decrease the amount of DC injected into the controlling reactor in the system. This increases or decreases the amount of current in the system to control the heat in the furnace by comparing it to the scheduled setpoint. A VRT system can have the following configurations:
Single-phase power controller for single load applications
Scott-T three-phase power controller (this is a system that allows all three phases of the incoming power system to be utilized in a two-phase load application)
Three-phase power controller (in either a Delta or Wye configuration) for three zone load applications
SCR (Silicon Controlled Rectifier)
An SCR control system uses a pair of thyristors (gated diodes) to control the amount of power applied to the primary of a transformer. The SCR control delays the start of the waveform, and the control point is reset when the waveform crosses the zero line. An SCR system can have the following configurations:
Single-phase, phase-angle controlled for single load applications
Single-phase, zero-cross controlled for single load applications
Single-phase, on-load, tap-changing controlled (this incorporates multiple pairs of the thyristors together to lessen the losses of the SCR system)
Scott-T three-phase power controlled (this is a system that allows all three phases of the incoming power system to be utilized in a two-phase load application)
Three-phase, phase-angle controlled (in either a Delta or Wye configuration) for three zone load applications
Three-phase, zero-cross controlled (in either a Delta or Wye configuration) for three zone load applications
IGBT (Insulated-Gate Bipolar Transistor)
An IGBT power control Source: RoMan Manufacturing, Inc.
An IGBT uses a diode bridge, capacitor, and switching transistors to control the amount of power applied to the primary of a transformer. The input frequency to the transformer is controlled by the switching transistors. The diode bridge is connected to the three-phase system allowing single, Scott-T (two zone), or three zone systems all to pull a balanced load across the three phases of the plant power system. A line reactor is incorporated to maximize the power factor in the system, minimizing the total power usage of the furnace. The IGBT system also uses a square wave into the transformer and a rectifier after the transformer to remove inductance out of the power delivery system to reduce costs of cables, breakers, and other components in the total package.
About the Author:
Stanley F. Rutkowski III Senior Applications Engineer RoMan Manufacturing, Inc.
Stanley F. Rutkowski III is the senior applications engineer at RoMan Manufacturing, Inc., working on electrical energy savings in resistance heating applications. Stanley has worked at the company for 33 years with experience in welding, glass and furnace industries from R&D, design, and application standpoints. For more than 15 years, his focus has been on energy savings applications in industrial heating applications.
What are advanced management systems and how does deep integrative system management software help automotive heat treaters improve processes while saving on time and unnecessary expenses? Explore the future of software technology for the management of heat treating operations in this Technical Tuesday by Sefi Grossman, founder and CEO of CombustionOS.
The heat treating industry is on the brink of a technological transformation. Just as the momentous adoption of websites and emails transformed the nature of work for manufacturers, the advanced software systems are thrusting us into a new era of simplicity, automation, and deep integrations.
This article explores how advanced systems — an application of ERP (enterprise resource planning) and MES (manufacturing execution systems) combined with the power of AI — is revolutionizing facility operations, enhancing quality, efficiency, and profitability.
What Are Advanced Systems?
Advanced systems simplify, streamline, and automate operations by lifting the data burden off of plant personnel. While most existing systems focus on the part inventory workflow, more advanced systems go beyond by directly integrating into the heat treat process to track at bin/tray/tree level.
This requires real-time scheduling control, barcode scanning, digitizing recipe and process (no more paper), and direct sensor/PLC integration. Because of its critical nature, an advanced system is most likely an on-premise and cloud “hybrid solution” that is not crippled by internet connectivity issues. This allows it to still utilize rapidly evolving cloud systems that provide external services like messaging, big data storage, and AI to name a few.
Precise Processing
Figure 1. CombustionOS developers spend extensive time with operators and plant managers to create interfaces that are intuitive and easy to use. Pictured is access to job data stats from a mobile device being used outside of the manufacturing plant.
Repeatable, accurate methods to ensure optimal time, temperature, and atmosphere of the decided heat treatment processes are possible with advanced systems.
Utilizing existing sensors and hardware interfaces, data is collected in short intervals, transformed into meaningful data formats, and stored in a database. Network technologies such as HTTP, Modbus, and other analog to AI technologies make this possible with minimum additional hardware. The data is managed locally on the facility network, and synchronized with cloud services for further processing, analysis, and long-term history storage.
With a close monitoring of all these variables, facilities can tighten acceptable specification ranges. Deep integration with equipment ensures that data flows seamlessly from sensors and devices to the central system.
This real-time data collection and processing enables facilities to monitor operations continuously and make informed decisions quickly. For example, integrating data from temperature sensors, pressure gauges, and other monitoring devices ensures that all critical parameters are tracked and managed effectively. Additionally, if a temperature reading deviates from the acceptable range, the system can immediately alert the relevant personnel, allowing them to take corrective action before it becomes a critical issue.
In addition to quality assurance, integrated artificial intelligence tools optimize job scheduling. Unlike traditional date/time calendar methods, AI systems predict job completion times based on real-time process data. This is particularly useful for roller furnace setups, where continuous processing occurs, but it is also beneficial for batch furnaces. Optimized scheduling improves resource allocation and operational efficiency, ensuring that jobs are completed on time and to the required specifications. The difference between a “calculation algorithm” and AI is that, with AI, you do not have to pre-program it. It automatically learns and adjusts for known variability in your hardware and even the personnel that are operating the equipment.
Finally, the automation of these systems captures and records all necessary information accurately. This reduces the risk of non-compliance, improving the overall quality of the final product. For example, a Detroit-based heat treating facility reported that accessing real time data to ensure compliance with industry standards has allowed them to spend 40% less time on documentation tasks.
Figure 2. Having increased control over the process gives more peace of mind to operators that components perform as needed.
Alleviating Burden on Maintenance and Inventory
Predictive maintenance is one of the most significant applications of AI in the heat treating industry. Traditional maintenance schedules are often based on fixed intervals, which can lead to unnecessary downtime or unexpected failures. AI driven predictive maintenance, on the other hand, uses real-time data to determine the optimal times for maintenance activities. This approach not only reduces downtime but also extends the lifespan of equipment.
A Detroit-based heat treating facility implemented an AI-driven predictive maintenance system (PMs) and saw a 25% reduction in equipment downtime. By analyzing data from critical parts, inventory, process tracking history, and various sensors, the AI system could predict when components were likely to fail, allowing the maintenance team to inspect and address issues proactively beyond their standard PMs. This not only improved operational efficiency, but also saved significant costs associated with emergency repairs and unplanned downtime.
Additionally, the integration of QR codes for inventory and process tracking enables quick and accurate data entry compared to manual logging. For instance, when racking parts out of bins, operators can simply scan QR codes, which automatically update the system with the relevant information. This not only speeds up the process but also minimizes the chances of human error.
Reducing Operational Costs
The adoption of advanced ERP and MES systems has led to substantial cost savings for many facilities. These systems reduce operational costs through the implicit automated integrations that technologies like CombustionOS bring. Here are just a few ways that operational costs have been cut:
Decreasing shipping and receiving management from three to just one employee
Minimizing rework costs by timely process alerts
Reducing personnel by replacing constant manual oversight with accurate, digital tracking systems
Lowering administrative costs by utilizing a more efficient and accurate invoice automation platform
Case Study: A client reported comprehensive cost savings, including a 20% reduction in shipping and receiving time, fewer logistics and furnace operators needed, a 33% decrease in rework costs, a 15% savings in maintenance costs, and a 25% reduction in accounting overhead. These efficiencies translate into substantial payroll savings and improved profitability.
How To Implement
Figure 3. When racking parts out of bins, operators can simply scan QR codes, which automatically update the system with the relevant information.
One of the most significant advancements in heat treating technology is the deep integration with various equipment types. Unlike traditional ERP systems, which often lack true integration, advanced systems work backwards from equipment data, building ERP functionalities around this integration to ensure seamless and accurate data flow.
First, there are advanced systems that can handle data from both digital and analog sensors. So, for heat treaters who are juggling a variety of sensors and systems, looking for an integrative advanced system that has adaptability will ensure compatibility with existing equipment while keeping an eye on cost. Facilities can continue using their current equipment while benefiting from advanced monitoring and control capabilities.
Second, advanced ERP/MES systems can take collaboration with multiple vendors. Rather than uproot current systems and relationships, work with an advanced systems provider who is able to collaborate with other software and systems. Advanced ERP/MES systems provide comprehensive solutions that include deep equipment integration and full ERP functionalities. This approach reduces the complexity and cost of integration, ensuring that all components work together seamlessly.
Key Applications
Most operations in a heat treat department will benefit from advanced systems due to the time-saving automations that the system integrates. But many heat treaters are looking to adapt and integrate older systems and often more complex designs, like roller hearth furnaces. Here are some steps that experts will take to guide you through to make the digital integration smooth and effective:
First, it is important to understand you don’t need to boil the ocean. Starting with a more advanced inventory tracking system that employs barcodes can set the underpinnings for a more integrated system while providing immediate benefits to your logistics.
Then, it is also key to get a deep understanding of your current process and map out your operational workflow. Using a flowchart program helps visualize the process to make sure all stakeholders are on the same page.
Some aspects of your current process are probably outdated (perhaps created by someone who is no longer at the company), while others are key to the core of how you operate. Understanding the difference is crucial to make sure you unlock potential automation without disturbing your core process and flow.
You’ll then need to prepare every required form, document, chart etc. that you use in the operation. For process control, recipes, and lab testing, provide many parts/iterations to capture the complexity.
Finally, take inventory of any existing digital systems you have adopted, like inventory tracking, spreadsheets, or custom software. The existing system network, including servers, Wi-Fi setup, and hardware (PCs, printers, scanners, etc.) will be utilized as much as possible in the transition to reduce the need to purchase and set up different equipment.
The future will require constant innovations and thoughtful leveraging of increasingly advanced systems. Unlike static, homegrown, or “pieced together” solutions, the most advanced systems are constantly updated with new features, ensuring they remain at the cutting edge of technology. Engaging directly with plant personnel to understand their needs and challenges allows systems like CombustionOS to evolve and improve continuously.
The heat treating industry is on the cusp of a technological transformation, driven by advancements in ERP, MES, and AI. These technologies offer the potential to enhance quality, efficiency, and profitability, making them essential for the future of manufacturing. By embracing automation, integrating advanced AI capabilities, and committing to continuous innovation, the industry can achieve new levels of operational excellence.
About the Author:
Sefi Grossman Founder & CEO CombustionOS Source: Author
Sefi Grossman has been at the forefront of technology revolutions for the past two decades and has been leading the technology company CombustionOS for nearly seven years.
Ever wish you had a map to follow when navigating your power source? In the following Technical Tuesday article, Brian Turner, sales applications engineer at RoMan Manufacturing, Inc., charts the route that power takes from the source to the load and back again in a vacuum furnace.
In a vacuum furnace, the journey from the load (the material being heat treated) to the incoming power involves a complex arrangement of components that deliver, control, and monitor electrical energy. Here’s a breakdown of the path from the source to the load and back to the source of incoming power of a vacuum furnace:
Load
The material — either an item or batch of items — that is undergoing heat treatment; can be metals, ceramics, or composites.
Heating Elements
Common materials for heating elements include graphite, molybdenum, or tungsten, depending on the temperature range and application.
Electrical Feedthrough
These are used to transmit electrical power or signals through the vacuum chamber wall. They often contain insulated conductors and connectors to ensure safe transmission without leaking air into the vacuum environment.
Conductors
The most common methods to connect power from a vacuum power source to the furnace’s feedthrough include air-cooled cables, water-cooled cables, and copper bus bar. Power efficiency can be improved when selecting the length, size, and area between conductors. This can be achieved by close coupling the power system to the electrical feedthroughs, reducing resistance and inductive reactance, and improving the power factor.
Machined Copper Bar Source: RoMan Manufacturing, Inc.
Controlled Power Distribution Systems
The furnace market today generally relies on three primary types of control power distribution systems: VRT, SCR, and IGBT. Each of these technologies employs different methods to regulate the power input to the furnace, which in turn generates the required heat.
VRT (Variable Reactance Transformer)
The VRT controls AC voltage to the load, this is accomplished by a DC power controller that injects DC current into the reactor within the transformer.
The SCR controls the AC output voltage and can be paired with a transformer to step the voltage up or down and close couple to the furnace feedthroughs.
IGBT (Insulated-Gate Bipolar Transistor)
Balanced three-phase voltage is rectified through a bridge circuit to charge a capacitor in the DC bus. The IGBT network switches the DC bus at 1000Hz to control the AC output voltage to a Medium Frequency Direct Current (MFDC) power supply.
MFDC power supply transforms the AC voltage to a practical level and rectifies the secondary voltage (DC) to the heating circuit.
A line reactor on the incoming three-phase line mitigates harmonic content.
Control Systems
These systems manage the furnace’s operation, including driving the setpoint of the power system, temperature control, vacuum levels, and timing. They often consist of programmable logic controllers (PLCs), human-machine interfaces (HMIs), sensors, and other automation components.
Incoming Power
This is the origin of the furnace’s electrical energy, typically from a utility grid. It provides alternating current (AC), which is distributed and transformed within the furnace system to power all necessary components. In industrial settings, power companies usually charge for electricity based on several factors that reflect both the amount of electricity used and how it’s used. Some common charges/penalties are energy consumption (kWh), demand charges (kW), power factor penalties, and time-of-use (TOU) reactive power.
Conclusion
The careful arrangement of heating elements, electrical feedthroughs, conductors, and controlled power distribution systems allows for precise temperature control, ultimately impacting the quality of the processed material. Understanding the role of various control systems, such as VRT, SCR, IGBTs, and transformers is crucial for optimizing furnace performance and managing energy costs
About the Author:
Brian Turner Sales Applications Engineer RoMan Manufacturing, Inc. Source: RoMan Manufacturing, Inc.
Brian K. Turner has been with RoMan Manufacturing, Inc., for more than 12 years. Most of that time has been spent managing the R&D Lab. In recent years, he has taken on the role as applications engineer, working with customers and their applications.
What is the path forward for thermal loop systems, and how is “sustainability” at the forefront of this technology? The following article is co-authored by Peter Sherwin, global business development manager of Heat Treatment, and Thomas Ruecker, senior development manager, at Watlow. They examine four scopes to take into consideration when assessing thermal loop systems in the context of greenhouse gas emissions and their environmental impact.
Heat treatment thermal loop solutions provide several sustainability benefits, including reduced energy consumption and waste. The power controller regulates the power output to minimize energy waste, and the possible integration with renewable energy sources and circular economy principles provides a complete power solution that spans from element design to recycling and renewables. The thermal loop solutions, in combination with insulation design and materials, provide energy-efficient solutions that contribute to sustainability and reduce the environmental impact of heat treatment processes.
When discussing these systems in the context of greenhouse gas emissions and their environmental impact, it is essential to consider Scopes 1, 2, and 3, as well as the less common Scope 4:
Scope 1 (Direct Emissions): Heat treatment processes often involve the combustion of fossil fuels like natural gas, propane, or oil to generate heat. These direct emissions are attributed to the equipment used in the heat treatment process, such as furnaces and ovens. Efforts to reduce Scope 1 emissions include upgrading to more efficient equipment or adopting alternative heating technologies, like induction or electric heating systems.
Scope 2 (Indirect Emissions from Energy): In heat treatment processes and thermal loop systems, electricity is often used to power various components, such as pumps, fans, and control systems. The emissions associated with generating this electricity are considered Scope 2 emissions. To reduce Scope 2 emissions, companies can improve energy efficiency, invest in renewable energy sources, or purchase green energy from their utility provider.
Scope 3 (Other Indirect Emissions): These emissions are associated with activities throughout the value chain of heat treatment applications and thermal loop systems, such as the manufacturing and transporting of raw materials, equipment, and waste management. Companies can work to reduce Scope 3 emissions by collaborating with suppliers to improve the environmental performance of their products and services, optimizing transportation and logistics, and implementing waste reduction strategies.
Scope 4 (Avoided Emissions): In heat treatment applications and thermal loop systems, avoided emissions may come from implementing energy-efficient technologies, waste heat recovery systems, or other innovative solutions that reduce overall energy consumption and associated emissions. By quantifying these avoided emissions, companies can showcase the positive impact of their sustainability efforts on reducing their carbon footprint. Avoided emissions can also be highlighted when subcontracting heat treatment requirements to a more energy-efficient source rather than running an in-house operation. In this approach, the heat treatment process is outsourced to an external, specialized heat treatment service provider, especially if the in-house equipment is due to be lightly utilized. These service providers operate independent heat treatment facilities and offer services to multiple clients across various industries and generally run 24/7 with high utilization.
At the component level, energy savings can be realized using current technology. Advanced SCRs provide predictive load management functions and hybrid firing algorithms and contribute to sustainability by optimizing the energy usage of heat treatment processes. These SCRs offer real-time monitoring and control of energy consumption, while predictive load management systems use specific algorithms to manage peak power loads and adjust to optimize for local conditions (load shedding or load sharing). Hybrid firing systems use a combination of firing methods to control power factors and reduce the negative impact on the electrical infrastructure.
Heater design is also essential. Switching time impacts heater life with fast, modern switching modes (hybrid firing) significantly extending heater life compared to slower switching from conventional mechanical contactors.
Systems can be rapidly tested, simulated, and modeled through computational engineering. Several thermal loop systems today have improved temperature uniformity due to these methods.
Adaptive thermal system (ATS) solutions are the next frontier of thermal loop solutions. Rather than selecting the best-of-breed components — sometimes with overlapping functionality and kitting a complete solution — ATS provides a merged design between heater and control systems. ATS is already in place in several semiconductor applications, and this type of technology is looking to scale into heat treatment applications shortly.
Figure 2. Watlow Adaptive Thermal Systems ATSTM Source: Watlow
Challenges and Limitations
The initial investment in heat treatment thermal loop solutions can sometimes be higher than in traditional methods. However, this investment often leads to a significantly lower total cost of ownership and improved return on investment due to the thermal loop solutions’ increased efficiency, improved quality control, and extended life.
Ensuring regulatory compliance is complex and time-consuming, requiring organizations to have the right people, processes, and equipment.
Future Trends
As Industry 4.0 and digital transformation continue to gain momentum and Industry 5.0 practices are implemented, heat treatment thermal loop solutions will become increasingly important. Integrating digital technology and machine learning algorithms will provide even greater control, traceability, and transparency, enabling organizations to make informed decisions based on real-time data and predictive analytics. In addition, as new materials and manufacturing processes are developed, adaptive and flexible heat treatment thermal loop solutions will need to evolve to meet these challenges and provide the necessary level of control and efficiency for these new applications.
Conclusion
Heat treatment thermal loop solutions provide several benefits over traditional heat treatment methods, including improved temperature control, increased efficiency, and improved sustainability outcomes. The integration with Industry 4.0 and data management systems, as well as the use of FMEA and OEE metrics, further help enhance the performance of heat treatment processes. As Industry 4.0 digital transformation and Industry 5.0 practices continue to evolve, heat treatment thermal loop solutions will play an increasingly important role in the future of heat treatment.
About the Authors:
Peter Sherwin Global Business Development Manager of Heat Treatment WatlowThomas Ruecker Senior Business Development Manager of Heat Treatment Eurotherm, a Watlow company
Peter Sherwin, global business development manager of Heat Treatment at Watlow, is passionate about offering best-in-class solutions to the heat treatment industry. He is a chartered engineer and a recognized expert in heat treatment control and data solutions.
Thomas Ruecker is the business development manager of Heat Treatment at Eurotherm Germany, a Watlow company. His expertise includes concept development for the automation of heat treatment plants, with a focus on aerospace and automotive industry according to existing regulations (AMS2750, CQI-9).
“Communication is key.” As heat treating equipment and processes evolve, it becomes critical that the accompanying control systems also develop to maintain “communication.” In this Technical Tuesday installment, guest columnist Stanley Rutkowski III, senior applications engineer at RoMan Manufacturing, Inc., discusses how digital control system communications have improved to increase energy efficiency for manufacturers with in-house heat treat operations.
This informative piece was first released inHeat Treat Today’sMay 2024 Sustainability Heat Treat print edition.
Industrial furnace applications that rely on resistive heating will consume large amounts of electrical energy when processing their loads. Utilizing digital controls technologies to maximize this type of heating allows for a cleaner-and thus greener-approach to energy demands.
Typically, heat treat processes have a long duration (hours to days in length), and each load can have its own unique recipe in the amount of power required. With unique recipes, there tends to be a ramp-up phase (getting the vessel to temperature), followed by a soak phase (which demands more control over the power system), and then a cool-down phase (an even more controlled state). As the power is controlled through the furnace system, disturbances occur with different technologies. This starts with “tube technology,” then variable reactance transformer (VRT) technology, then silicon controlled rectifier (SCR) technology, and finally IGBT (insulated-gate bipolar transistor) technology. As these technologies have evolved, their ability to communicate information digitally has allowed for less disturbance in the power system and allowing both a less expensive energy bill and a cleaner energy usage for the process.
Definitions
Electrical Power
Power losses in an electrical system are defined by five aspects (Figure 1):
Resistance (R): a function of the material cross section and the length of an electrical conductor.
Reactance (XL): a function of the area in a circuit and is a vector 90 degrees offset from resistance.
Capacitance (XC): a vector 180 degrees offset from reactance. In inductive circuits, capacitance can be added for power factor correction.
Impedance (Z): the vector sum of resistance, reactance, and capacitance.
Power Factor [cos(F)]: the ratio of resistance to impedance. In industrial applications, displacement power factor (DPF), the offset of the current to voltage waveforms, is used in the billing of electrical power.
There are five unique aspects that define electrical power usage (Figure 2):
Real power (kW): the amount of power that is generated.
Reactive power (kVAR): the amount of power that is wasted.
Total power (kVA): the rate at which power is consumed. This is also referred to as apparent power.
Power factor (cos(F)): the ratio of real power to total power. In industrial applications, the displacement power factor (DPF) is the offset of the current to voltage waveforms and is used to bill for electrical power.
Peak demand: the capacity required when the power grid experiences the highest power demand in a specified period of time.
3 Most Popular Types of Control Systems
For the most part, today’s furnace manufacturers use three main types of control systems: VRT, SCR, and IGBT. Each operates with slightly different methods to control how power goes into the heat treat furnace and creates heat.
VRT Control System
One traditional resistance heating setup uses a VRT control system that incorporates a saturable reactor, which controls the power applied to the transformer in the system (Figure 3). The control transformer on the output side of the transformer feeds back to the reactor to set the limit on the input power to the transformer.
Figure 3. VRT Control and Transformer Schematic (CT=control transformer); Source: RoMan Manufacturing, Inc.
SCR Control System
Figure 4. SCR Control and Transformer Schematic; Source: RoMan Manufacturing, Inc.
Another traditional resistance heating setup uses an SCR control system that includes dual thyristors (gated diodes) to control the amount of power applied to the primary of a transformer.
The SCR control delays the start of the waveform, and the control point is reset when the waveform crosses the zero line.
Figure 5. Comparison of Sine Waves; Source: RoMan Manufacturing, Inc.
IGBT Control System
Finally, an IGBT control system uses a diode bridge, capacitor, and switching transistors to control the amount of power applied to the primary (i.e., main power input of a transformer). The input frequency to the transformer is controlled by the switching transistors. Since the IGBT control system utilizes all three phases of the power system, the IGBT control can be set to a particular phase for the zero cross (for phase orientation in the application, synchronous mode) or left floating (non-synchronous mode), as is demonstrated in Figure 6. The input voltage to the transformer is increased by the operation of the IGBT control. As such, potential energy savings may be had with these types of controls as compared to tradition controls (such as on-off contractors, time proportioning controls, or other types of current proportioning control systems).
Figure 6. IGBT Control and Transformer Schematic; Source: RoMan Manufacturing, Inc.
Synchronization with the IGBT can be to the incoming lines (A, B, or C phase) and can be offset from each of the phases. The ability to offset from a phase allows for traditional arrangements (Single Phase, Scott-T, Delta and Wye) as well as unique offsets allowing for additional vector heating in the application with AC outputs. The unique arrangements beyond the traditional systems could allow for more uniform heating of the part and less energy being consumed during the process.
Advantages of Utilizing Communications
As technology for controlling heating systems has evolved, and with an emphasis on clean energy sources, the ability to communicate with the control system has increased as well. This communication allows for more precise control of the run for the load, improved power usage (better power factors and less peak power usage as well as less total power usage), and inputs into a preventive maintenance program.
Table A. Analog vs. Digital IGBT Systems
With an IGBT system, both analogue and digital control communications are available today. See Table A for a comparison on how each control option works.
In addition to the EIP defined pieces, there is the ability to access the FPGA system for graphical outputs that can be downloaded into another system in your process for storage, comparisons, or general record keeping for a part run. The FPGA is an internal processor in the control that allows for more data, charting, and diagnostics to be captured and used by the system for both energy consumption and possible preventative maintenance purposes.
Why does this matter? Let’s turn to some possible ways of using the data generated from digital controls systems:
Evaluate average, minimum, and maximum DC bus voltages to plan for the best time and day to run heat treat jobs. For high power draw jobs, planning ahead can minimize power costs; similarly, knowing power trends can be helpful to plan jobs requiring sensitive control of the heating.
Evaluate transformer output voltage to allow the system to detect any shorts in the process. If the controller output and transformer output diverge from the known turns ratio, a change has occurred in the system. This could be corroborated if controller on time and output power do not trend.
Track furnace run records with EIP communications and FPGA data. This will be most helpful in processing lots of data, as is the case for Milspec records.
Evaluate changes in power factor to monitor any loose cables, and so avoid reactive power losses.
Evaluate the current versus the voltage to monitor the resistance of the system. If there is an increase in the resistance, you could project the trends in wear of the heating elements, therefore predicting future required maintenance.
Evaluate the critical control temperatures of the system to know if it is being run close to, or above, its ratings or if there is a disturbance in the cooling systems.
Use knowledge of power usages and power stability to update recipes for load runs so they use less power over the total run; this allows for a less costly power-savings solution. With less power usage, more output of the total facility can be had as each station contributes less to energy consumption
Even more benefits can be realized when users and builders of furnace systems and component manufacturers collaborate in the design of the total system. Such dialogues lead to the creation of more interactive and intuitive solutions that minimize power consumption, minimize downtime, and maximize outputs. These practical benefits are the foundation of a greener system.
About the Author:
Stanley F. Rutkowski III Senior Applications Engineer RoMan Manufacturing, Inc.
Stanley F. Rutkowski III is the senior applications engineer at RoMan Manufacturing, Inc., working on electrical energy savings in resistance heating applications. Stanley has worked at the company for 33 years with experience in welding, glass and furnace industries from R&D, design, and application standpoints. For more than 15 years, his focus has been on energy savings applications in industrial heating applications.
The future of heat treating requires new manufacturing solutions like robotics that can work with modular design. Yet so also does temperature monitoring need to be seamless to know how effectively your components are being heat treated — especially through being quenched.In this Technical Tuesday,learn more abouttemperature monitoring through the quench process.
Gas Carburization
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Carburizing has rapidly become one of the most critical heat treatment processes employed in the manufacture of automotive components. Also referred to as case hardening, it provides necessary surface resistance to wear, while maintaining toughness and core strength essential for hardworking automotive parts.
Figure 1. Typical carburizing heat treat temperature profile showing the critical temperature/time steps: (i) carburization, (ii) quench, and (iii) temper. (Source: PhoenixTM)
The carburizing process is achieved by heat treating the product in a carbon rich environment (Figure 1), typically at a temperature of 1562°F–1922°F (850°C–1050°C). The temperature and process time significantly influence the depth of carbon diffusion and other related surface characteristics. Critical to the process is a rapid quenching of the product following the diffusion in which the temperature is rapidly decreased to generate the microstructure, giving the enhanced surface hardness while maintaining a soft and tough product core.
The outer surface becomes hard via the transformation from austenite to martensite while the core remains soft and tough as a ferritic and/or pearlitic microstructure. Normally, carburized microstructures following quench are further tempered at temperatures of about 356°F (180°C) to transform some of the brittle martensite into tempered martensite to enhance ductility and grindability.
Critical Process Temperature Control
As discussed, the success of carburization is dependent on accurate, repeatable control of the product temperature and time at that temperature through the complete heat treatment process. Important to the whole operation is the quench, in which the rate of cooling (product temperature change) is critical to achieve the desired changes in microstructure, creating the surface hardness. It is interesting that the success of the whole heat treat process can rest on a process step which is so short (minutes), in terms of the complete heat teat process (hours). Getting the quench correct is not only essential to achieve the desired metal microstructure, but also to ensure that the physical dimensions and shape of the product are maintained (no distortion/warping) and issues such as quench cracking are eliminated.
Obviously, as the quench is so critical to the whole heat treat process, the correct quench selection needs to be made to achieve the optimum properties with acceptable levels of dimensional change. Many different quenchants can be applied with differing quenching performances. The rate of heat transfer (quench rate) of quench media in general follows this order from slowest to quickest: air, salt, polymer, oil, caustic, and water.
Technology Challenges for Temperature Monitoring
When considering carburization from an industry standpoint, furnace heat treat technology generally falls into one of two camps, embracing either air quench (low pressure carburization) or oil quench (sealed gas carburization/LPC with integral or vacuum oil quench). Although each achieves the same end goal, the heat treat mechanisms and technologies employed are very different, as are the temperature monitoring challenges.
To achieve the desired carburized product, it is necessary to control and hence monitor the product temperature through the three phases of the heat treat process. Conventionally, product temperature monitoring would be attempted using the traditional trailing thermocouple method. For many modern heat treat processes including carburization, the trailing thermocouple method is difficult and often practically impossible.1 The movement of the product or product basket from stage to stage, often from one independent sealed chamber to another (lateral or vertical movement), makes the monitoring of the complete process a significant challenge.
With the industry driving toward fully automated manufacturing, furnace manufacturers are now offering the complete package with full robotic product loading that includes shuttle transfer systems and modular heat treat phases to process both complete product baskets and single piece operations. Although trailing thermocouples may allow individual stages in the process to be measured, they cannot provide monitoring of the complete heat treat journey. Testing is therefore not under true normal production conditions, and therefore is not an accurate record of what happens in normal day to day operation.
Figure 2 shows schematic diagrams of two typical carburizing furnace configurations that would not be possible to monitor using trailing thermocouples. The first shows a modular batch furnace system where the product basket is transferred between each static heat treat operation (preheat, carburizing furnace, cooling station, quench, quench wash, temper furnace) via a charge transfer cart. The second shows the same heat treat operation but performed in a continuous indexed pusher furnace configuration where the product basket moves sequentially through each heat treat operation in a semi-continuous flow.
Thru-process temperature monitoring as a technique overcomes such technical restrictions. The data logger is protected by a specially designed thermal barrier, therefore, can travel with the product through each stage of the process measuring the product/process temperature with short, localized thermocouples that will not hinder travel. The careful design and construction of the monitoring system is important to address the specific challenges that different heat treat technology brings including modular batch and continuous pusher furnace designs (Figure 2).2
The following section will focus specifically on monitoring challenges of the sealed gas carburizing process with integral oil quench. Technical challenges of the alternative low pressure carburizing technology with high pressure gas quench have previously been discussed in an earlier publication.3
Monitoring Challenges of Sealed Gas Carburization — Oil Quench
Figure 3. “Thru-process” temperature monitoring system for use in a sealed carburizing furnace with integral oil quench — (3.1) Monitoring system entering furnace with thermocouple fixed to automotive gears, product test pieces (3.2) System exiting oil quench tank (3.3) System inserted into wash tank with product basket (Source: PhoenixTM)
Presently, the most common traditional method of gas carburizing for automotive steels is often referred to as sealed gas carburizing. In this method, the parts are surrounded by an endothermic gas atmosphere. Carbon is generated by the Boudouard reaction during the carburization process, typically at 1562°F–1832°F (850°C –1000°C). Despite the dramatic appearance of a sealed gas carburizing furnace, with its characteristic belching flames (Figure 3), from a monitoring perspective, the most challenging aspect of the process is not the heating, but the oil quench cooling. For such furnace technology, the historic limitation of “thru-process” temperature profiling has been the need to bypass the oil quench and wash stations, missing a critical process step from the monitoring operation. Obviously, passing a conventional hot barrier through an oil quench creates potential risk of both system damage from oil ingress and barrier distortion, as well as general process safety. However, the need to bypass the quench in certain furnace configurations by removing the hot system from the confined furnace space could create significant operational challenges, from an access and safety perspective.
Monitoring of the quench is important as ageing of the oil results in decomposition (thermal cracking), oxidation, and contamination (e.g. water) of the oil, all of which degrade the viscosity, heat transfer characteristics, and quench efficiency. Control of physical oil temperature and agitation rates is also key to oil quench performance. Quench monitoring allows economic oil replacement schedules to be set, without risk to process performance and product quality.
Figure 4. “Thru-process” temperature monitoring system oil quench compatible thermal barrier design: (1) Robust outer structural frame keeping insulation and inner barrier secure; (2) Internal thermal barrier — completely sealed with integral microporous insulation protecting data logger; (3) Mineral insulated thermocouples sealed in internal thermal barrier with oil tight compression fitting; (4) Multi-channel high temperature data logger; and (5) Sacrificial insulation blocks replaced after each run.
(Source: PhoenixTM)
To address the process challenges, a unique thermal barrier design has been developed that both protects the data logger in the furnace (typically three hours at 1697°F/925°C) and also protects during transfer through the oil quench (typically 15 mins) and final wash station (Figure 3). The key to the barrier design is the encasement of a sealed inner barrier with its own thermal protection with blocks of high-grade sacrificial insulation contained in a robust outer structural frame (Figure 4).
Quench Cooling Phases
Monitoring the oil quench in carburization gives the operator a unique insight into the product’s specific cooling characteristics, which can be critical to allow optimal product loading and process understanding and optimization. From a scientific perspective, the quench temperature profile trace, although only a couple of minutes in duration, is complex and unique. From a zoomed in quench trace (Figure 5) taken from a complete carburizing profile run, the three unique heat transfer phases making up the oil quench cool curve can be clearly identified:
Figure 5. Oil quench temperature profile for different locations on an automotive gear test piece shows the three distinct heat transfer phases: (1) film boiling “vapor blanket”, (2) nucleate boiling, and (3) convective heat transfer. (Source: PhoenixTM)
Film boiling “vapor Blanket”: The oil quenchant creates a layer of vapor (Leidenfrost phenomenon) covering the metal surface. Cooling in this stage is a function of conduction through the vapor envelope. Slow cool rate since the vapor blanket acts as an insulator.
Nucleate boiling: As the part cools, the vapor blanket collapses and nucleate boiling results. Heat transfer is fastest during this phase, typically two orders of magnitude higher than in film boiling.
Convective heat transfer: When the part temperature drops below the oil boiling point. the cooling rate slows significantly. The cooling rate is exponentially dependent on the oil’s viscosity.
From a heat treat perspective, the quench step relative to the whole process (hours) is quick (seconds), but it is probably the most critical to the performance of the metallurgical phase transitions and achieving the desired core microstructure of the product without risk of distortion. By being able to monitor the quench step, the process can be validated for different products with differing size, form, and thermal mass. As shown in Figure 6, the quench curve profile over the three heat transfer phases is very different for two different automotive gear sizes.
Figure 6. Oil quench temperature profile for different automotive gear sizes (20MnCr5 case hardening steel) with different thermal masses: Passenger Car Gear (2.2 lbs) and Commercial Vehicle Gear (17.6 lbs) (Source: PhoenixTM)
Summary
As discussed in this article, one of the key process performance factors associated with gas carburization is the control and monitoring of the product quench step. Employing an oil quench, the measurement of such operation is now very feasible as part of heat treat monitoring. Innovations in thru-process temperature profiling technology offer specific system designs to meet the respective application challenges.
References
[1] Dr. Steve Offley, “The light at the end of the tunnel – Monitoring Mesh Belt Furnaces,” Heat Treat Today, February 2022, https://www.heattreattoday.com/processes/brazing/brazing-technical-content/the-light-at-the-end-of-the-tunnel-monitoring-mesh-belt-furnaces/.
[2] Michael Mouilleseaux, “Heat Treat Radio #102: Lunch & Learn, Batch IQ Vs. Continuous Pusher, Part 1,” interviewed by Doug Glenn, Heat Treat Radio, October 26, 2023, audio, https://www.heattreattoday.com/media-category/heat-treat-radio/heat-treat-radio-102-102-lunch-learn-batch-iq-vs-continuous-pusher-part-1/.
[3] Dr. Steve Offley, “Discover the DNA of Automotive Heat Treat: Thru-process Temperature Monitoring,” Heat Treat Today, August 2023, https://www.heattreattoday.com/discover-the-dna-of-automotive-heat-treat-thru-process-temperature-monitoring/.
About the Author
Dr Steve Offley (“Dr O”), Product Marketing Manager, PhoenixTM
Dr. Steve Offley, “Dr. O,” has been the product marketing manager at PhoenixTM for the last five years after a career of over 25 years in temperature monitoring focusing on the heat treatment, paint, and general manufacturing industries. A key aspect of his role is the product management of the innovative PhoenixTM range of thru-process temperature and optical profiling and TUS monitoring system solutions.
How often do you think about the intelligent designs controlling the thermal loop system behind your heat treat operations? With ever-advancing abilities to integrate and manage data for temperature measurement and power usage, the ability of heat treat operations to make practical, efficient, and energy-conscious change is stronger than ever. In part 1, understand several benefits of thermal loop systems and how they are leveraged to comply with industry regulations, like Nadcap.
This Technical Tuesday article by Peter Sherwin, global business development manager – Heat Treatment, and Thomas Ruecker, senior business development manager, at Watlowwas originally published inHeat Treat Today’sJanuary/February 2024 Air & Atmosphere Heat Treat print edition.
Introduction
Heat treatment processes are a crucial component of many manufacturing industries, and thermal loop solutions have become increasingly popular for achieving improved temperature control and consistent outcomes.
A thermal loop solution is a closed loop system with several essential components, including an electrical power supply, power controller, heating element, temperature sensor, and process controller. The electrical power supply provides the energy needed for heating, the power controller regulates the power output to the heating element, the heating element heats the material, and the temperature sensor measures the temperature. Finally, the process controller adjusts the power output to maintain the desired temperature for the specified duration, providing better temperature control and consistent outcomes.
Performance Benefits
Heat treatment thermal loop solutions offer several advantages over traditional heat treatment methods, including improved temperature control and increased efficiency. The thermal loop system provides precise temperature control, enabling faster heating and cooling and optimized soak times. In addition, the complete design of modern thermal loop solutions includes energy-efficient heating and overall ease of use.
Figure 1. Watlow Industry 4.0 solution (Source: Watlow)
Heat treatment thermal loop solutions are integrated with Industry 4.0 frameworks and data management systems to provide real-time information on performance. Combining artificial intelligence and machine learning algorithms can also provide additional performance benefits, such as the ability to analyze data and identify patterns for further optimization. Ongoing performance losses in a heat treatment system typically come from process drift s. Industry 4.0 solutions can explore these drift s and provide opportunities to minimize these deviations.
Heat treatment thermal loop solutions can be optimized using Failure Mode and Effects Analysis (FMEA). FMEA is a proactive approach to identifying potential failure modes and their effects, allowing organizations to minimize the risk of process disruptions and improve the overall efficiency of their heat treatment processes. Historically, this was a tabletop exercise conducted once per year with a diverse team from across the organization. Updates to this static document were infrequent and were primarily based on organization memory rather than being automatically populated in real time with actual data. There is a potential to produce “live” FMEAs utilizing today’s technology and leveraging insights for continuous improvement.
Th e effectiveness of heat treatment thermal loop solutions can be measured using metrics such as overall equipment effectiveness (OEE). OEE combines metrics for availability, performance, and quality to provide a comprehensive view of the efficiency of a manufacturing process. By tracking OEE and contextual data, organizations can evaluate the effectiveness of their heat treatment thermal loop solutions and make informed decisions about optimizing their operations.
Regulatory Compliance
Nadcap (National Aerospace and Defense Contractors Accreditation Program) is an industry-driven program that provides accreditation for special processes in the aerospace and defense industries. Heat treatment is considered a “special process” under Nadcap because it has specific characteristics crucial to aerospace and defense components’ quality, safety, and performance. Th ese characteristics include:
Process sensitivity: Heat treatment processes involve precise control of temperature, time, and atmosphere to achieve the desired material properties. Minor variations in these parameters can significantly change the mechanical and metallurgical properties of the treated components. This sensitivity makes heat treatment a critical process in the aerospace and defense industries.
Limited traceability: Heat treatment processes typically result in changes to the material’s microstructure, which are not easily detectable through visual inspection or non-destructive testing methods. Th is limited traceability makes it crucial to have strict process controls to ensure the desired outcome is achieved consistently.
Critical performance requirements: Aerospace and defense components often have strict performance requirements due to the extreme conditions in which they operate, such as high temperatures, high loads, or corrosive environments. The heat treatment process ensures that these components meet the specifications and can withstand these demanding conditions.
High risk: The failure of a critical component in the aerospace or defense sector can result in catastrophic consequences, including loss of life, significant financial loss, and reputational damage. Ensuring that heat treatment processes meet stringent quality and safety standards is essential to mitigate these risks.
Nadcap heat treatment accreditation ensures suppliers meet industry standards January/February and best practices for heat treatment processes. The accreditation process includes rigorous audits, thorough documentation, and ongoing process control monitoring to maintain high quality, safety, and performance levels.
The aerospace industry’s AMS2750G pyrometry specification and the automotive industry’s CQI-9 4th Edition regulations are crucial for ensuring consistent and high-quality heat treated components. Adherence to these regulations is essential for meeting the stringent quality requirements of the aerospace and automotive industries and other industries with demanding specifications.
Temperature uniformity is a crucial requirement of both AMS2750G and CQI-9 4th Edition, mandating specific temperature uniformity requirements for heat treating furnaces to ensure the desired mechanical properties are achieved throughout the treated components. AMS2750G class 1 furnaces with strict uniformity requirements +/-5°F (+/-3°C) provide both quality output and predictable energy use. However, maintaining this uniformity requires significant maintenance oversight due to all the components involved in the thermal loop.
Calibration and testing procedures are specified in the standards to help ensure the accuracy and reliability of the temperature control systems used in heat treat processes.
Detailed process documentation is required by AMS2750G and CQI-9 4th Edition, including temperature uniformity surveys, calibration records, and furnace classifications. This documentation ensures traceability, enabling manufacturers to verify that the heat treat process is consistently controlled and meets the required specifications.
Figure 2. Eurotherm data reviewer (Source: Watlow)
Modern data platforms enable the efficient collection of secure raw data (tamper-evident) and provide the replay and reporting necessary to meet the standards.
Th e newer platforms also off er the latest industry communication protocols – like MQTT and OPC UA (Open Platform Communications Unifi ed Architecture) – to ease data transfer across enterprise systems.
MQTT is a lightweight, publish-subscribe- based messaging protocol for resource-constrained devices and low-bandwidth, high-latency, or unreliable networks. IBM developed it in the late 1990s, and it has become a popular choice for IoT applications due to its simplicity and efficiency. MQTT uses a central broker to manage the communication between devices, which publish data to “topics,” and subscribe to topics that they want to receive updates on.
OPC UA is a platform-independent, service-oriented architecture (SOA) developed by the OPC Foundation. It provides a unified framework for industrial automation and facilitates secure, reliable, and efficient communication between devices, controllers, and software applications. OPC UA is designed to be interoperable across multiple platforms and operating systems, allowing for seamless integration of devices and systems from different vendors.
The importance of personnel and training is emphasized by CQI-9 4th Edition, which requires manufacturers to establish training programs and maintain records of personnel qualifications to ensure that individuals responsible for heat treat processes are knowledgeable and competent. With touchscreen and mobile integration, a significant development in process controls has occurred over the
last decade.
Figure 3. Watlow F4T® touchscreen and Watlow PM PLUS™ EZ-LINK®
mobile application
By integrating these regulations into a precision control loop, heat treatment thermal loop solutions can provide the necessary level of control and ensure compliance with AMS2750G and CQI-9 4th Edition, leading to the production of high-quality heat treated components that meet performance requirements and safety standards.
Continuous improvement is also emphasized by both AMS2750G and CQI-9 4th Edition, requiring manufacturers to establish a system for monitoring, measuring, and analyzing the performance of their heat treatment systems. This development enables manufacturers to identify areas for improvement and implement corrective actions, ensuring that heat treat processes are continuously improving and meeting the necessary performance and safety standards.
To Be Continued in Part 2
In part 2 of this article, we’ll consider the improved sustainability outcomes, potential challenges and limitations, and the promising future this technology offers to the heat treat industry.
About the Authors
Peter Sherwin, Global Business Development Manager – Heat Treatment, WatlowThomas Ruecker, Senior Business Development Manager, Watlow
Peter Sherwin is a global business development manager of Heat Treatment for Watlow and is passionate about offering best-in-class solutions to the heat treatment industry. He is a chartered engineer and a recognized expert in heat treatment control and data solutions.
Thomas Ruecker is the business development manager of Heat Treatment at Eurotherm Germany, a Watlow company. His expertise includes concept development for the automation of heat treatment plants, with a focus on aerospace and automotive industry according to existing regulations (AMS2750, CQI-9).
For more information: Contact peter.sherwin@watlow.com or thomas.ruecker@watlow.com.
This article content is used with the permission of heat processing, which published this article in 2023.
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Our readers and Heat Treat Radiolisteners will remember a recent episode entitled "Heat Treat Radio #102: Lunch & Learn, Batch IQ Vs. Continuous Pusher, Part 1." Today's Technical Tuesday article is a continuation of this dialog, with Michael Mouilleseaux, a boot-on-the-ground North American heat treat expert from Erie Steel here to answer your questions on the maintenance of batch and continuous pusher furnace systems.
Doug Glenn, Heat TreatToday's publisher,Karen Gantzer, associate publisher/editor-in-chief, join in this Technical Tuesday article.
Stay tuned for a Part 2 continuation of the Lunch and LearnHeat Treat Radio episode, coming to Heat Treat Radio in a couple weeks.
Below, you can watch the video or read from an edited transcript.
Michael Mouilleseaux
General Manager at Erie Steel, Ltd.
Sourced from the author
Introduction to Maintenance
Doug Glenn: We would like to move on to maintenance of the batch furnace and the continuous furnace. What is the cost of maintaining and operating these furnaces?
Michael Mouilleseaux: When they are utilized in a carburizing environment, there is always excess carbon that falls out or precipitates out of the atmosphere, and it ends up as elemental carbon in the bottom of the furnace.
What do you do with that? In furnaces that are using a carburizing environment, the burnout of the furnace is easily the single most important piece of preventative maintenance that you can perform. How is that performed? First, the furnace is vacated; there is no product in the furnace, the temperature is reduced — typically, you want it down around 1500°F or 1550°F — and you introduce room air into the furnace. The room air ignites the carbon. It’s a very primitive operation.
So, what temperature does carbon burn at? It burns at 3000°F.
You need to be very careful. It’s a controlled burn because you can actually damage the furnace through refractory, through the alloy that’s in the furnace, or it can get away. How do you do control it? On one level, you’re just looking at the temperature control. If you have it set at 1550, you’re going to say, “I’m only going to put air as long as the temperature of the furnace does not go up more than 25°F or 50°F.” It’s somewhat dependent upon the piece of equipment and is one of those things that you learn empirically; there is not a hard and fast rule for it.
Then, you can shut off the air. If there is no oxygen, then the source for combustion is taken away and you stop that operation. If you need to do it more rapidly than that, you may need to flood the furnace with nitrogen. Typically, if you have to flood the furnace with nitrogen to do it, you’ve been a little too aggressive in your burnout.
How long do you perform that? The great thing with oxygen probes is that you can utilize your oxygen probe to help you learn when you have burnt out the furnace. You’re not getting an actual carbon atmosphere, but what you do get is a readout from the probe. What you can do is perform the burnout operation until you attain that level and then you know that you’ve done a sufficient job in burning it out. That’s the single most important piece of preventative maintenance that’s done on a furnace used for carburizing.
Doug Glenn: Is that both in batch and in continuous?
Michael Mouilleseaux: Identical, yes.
Doug Glenn: I’ve got a couple other questions about furnace burnouts as someone who’s not a furnace operator. You said that there’s “carbon dropout” in the furnace. I know that in some furnaces, parts of the atmosphere may precipitate onto the coolest part of the furnace. Is that what is happening, or are we talking about carbon powder at the bottom of a furnace?
Michael Mouilleseaux: It is carbon powder, and it becomes more egregious. The powder then begins to accumulate into pebbles, nuggets, and larger size pieces. That’s more problematic. When it is in a powdered form, that is the best.
The question will be: How often do you have to do this? As with everything, the answer is — it depends. It depends on what you’re doing; it depends on how aggressive you are in your carburizing.
In the boost phase, we talked about carburizing at upwards of 1%. As soon as you exceed the saturation level of carbon, you’re going to precipitate out the excess carbon. What is that number? It’s different for every temperature. At 1500°F, it’s .9 or .85; at 1750°F, it’s 1.25. But to attain that, you’re actually putting natural gas into the furnace, and the amount of natural gas that you put into the furnace and its dissociation rate — the rate that it breaks down — can then subsequently be diffused into the parts; all of that comes into play.
With saturation levels of carburizing, there is always some residual carbon that’s in the furnace.
Doug Glenn: You mentioned that carbon burns at around 3,000 degrees. Are you taking the furnace up to that temperature?
The great thing with oxygen probes is that you can utilize your oxygen probe to help you learn when you have burnt out the furnace. You’re not getting an actual carbon atmosphere, but what you do get is a readout from the probe. What you can do is perform the burnout operation until you attain that level and then you know that you’ve done a sufficient job in burning it out. That’s the single most important piece of preventative maintenance that’s done on a furnace used for carburizing
Michael Mouilleseaux: No. The burnout cycle is at 1500 or 1550. You raise that carbon to that level and introduce oxygen, and what you want is a slow burn.
We next think about the systems involved in the furnace. First there is the heating system. In a gas-fired furnace, some critical things to consider are burner recovery, burner adjustment, and the amount of excess air that results in that burner adjustment. That’s a preventative maintenance operation that needs to be performed on a regular basis. It probably doesn’t need to be done daily, but monthly is optimal. If everything is very steady, including the barometric pressure, then you don’t need to do all of those adjustments.
Now, electric furnaces have SCRs that fire the elements, and you have to pay attention to the tuning of those things to make sure that they’re operating at optimum performance. One of the ways that you can do that, in a batch furnace, is if you look at the recovery time.
For example, if you have a load that weighs 4000 lbs. and you put it in the furnace and you know that it takes an hour and a half for the furnace to recover to temperature, but then all of a sudden, it takes an hour and 45 minutes, or an hour and 50 minutes, or two hours, obviously the burners are not producing the same amount of heat. The burners are not pumping the requisite amount of BTUs to achieve that recovery time. Could that be related furnace circulation? Could it be related to the insulation in the furnace? At an extreme, it could. Typically, though, it’s related to burner or SCR tuning.
Those are the kinds of things that are very easy to pay attention to.
"Electric furnaces have SCRs that fire the elements, and you have to pay attention to the tuning of those things to make sure that they’re operating at optimum performance. One of the ways that you can do that, in a batch furnace, is if you look at the recovery time."
Setting up PM Through Controls System
The control schemes in the PLC are typically very robust. So, you can establish a program and the PLC is going to say, “I want to heat it at this rate, I want the carbon potential to be .4%, I want to hold this at two hours at temperature, and then I want to initiate a quenching cycle.” Typically, PLCs are quite robust.
The thing you have to be careful with is obviously not just power outages, but brownouts. Brownouts are when you don’t quite lose all voltage, but you lose some of it. If you don’t have some kind of a filter on the power you can mitigate with, or have an uninterruptable power supply for the PLC, you can damage those things, resulting in some major work on the PLC.
The other part of that is the furnace circulation. We’ve got fans in these furnaces, and we circulate the atmosphere. The primary stages of heating in the furnace are convection, until we get to 1200 degrees. How do we convect the heat? We have the atmosphere in the furnace, the fan circulates, it washes the atmosphere down the radiant tubes, it heats up the atmosphere, the atmosphere comes into contact with the components, and we’re convection-heating the parts.
Once we get to 1200 degrees or more, then the primary method of heating becomes radiant heating. That’s where the radiant tubes are then the primary means of transferring energy. But the fans become very important. Are they balanced? Is the RPM correct? Is the amp reading on the fan? Those are areas to look at.
You have to understand how the furnace operates when it’s healthy — the furnace manufacturer can help you and/or you just learn empirically. For instance, what would it mean if, all of a sudden, I’m drawing much fewer amps on a circulating fan and it’s running very rough? Quite possibly, we’ve lost a fan blade.
Then there is the atmosphere control system. All that we just described is applicable to both continuous and batch furnaces. The furnace needs to be sealed and you want a couple inches of water column pressure — excess pressure — in the furnace relative to atmosphere pressure, since safety is the number one concern.
The atmosphere that we’re talking about in most of these furnaces is endothermic atmosphere. It’s a reducing atmosphere, meaning that it’s combustible. If, of course, we have combustion in a closed vessel, that’s called an explosion.
The reducing atmosphere, in and of itself, is if you look in a furnace that is at anything above 1200 degrees where it’s red, up to 1700–1800 degrees where it’s going to be yellow to white — and there is no flame . . . . People are absolutely amazed when they look in an atmosphere furnace and they see no flame. What you should see is everything in a relative, uniform color. The parts should be a uniform color. If you look at the tubes, they should be a little lighter because the tubes will always be somewhat above the temperature of the parts . . . .
Back to the atmosphere: We want to be sure that the atmosphere stays in the furnace and that we maintain that pressure in the furnace. So, what would be a cause to lower the pressure in the furnace? A door leak or a leak in a fan. It could be, if you have a mechanical handling system, a leak through that system. Those are all places to look.
The PM on that? For maintaining the level of lubrication in the fan bearings, see that they’re cooled so that the outlet temperature of the coolant — be it air or water — should be higher than the inlet temperature; that shows that they’re being cooled.
I can’t tell you an absolute number, but I can say that for the equipment that we have, we have numbers that we’ve developed; we know that if the outlet temperature of the water is 20 degrees higher than it is going in, we’re doing a good job of cooling the bearings.
The door seals in furnaces, typically, are brick on brick. Typically, they use a wedge system to seal the doors in the furnace. But, of necessity, these are wear items. Therefore, in preventative maintenance, you might notice a burnout around a door where you hadn’t had one before. That tells you that atmosphere is leaking out of that door and so a repair is needed in the near future.
An interesting thing about a batch furnace: Most of them only have one door. So, it’s quite easy — you can open the vestibule and, in a maintenance operation, if you gassed up the furnace, you could see.There is always going to be some atmosphere coming around the door because that’s where the atmosphere goes into the vestibule, but it should be at the top; it shouldn’t be around the sides, and it definitely shouldn’t be at the bottom. It should be very consistent.
That’s one of those things that, again, you empirically learn. You look at it — it’s a visual operation to say what you’re doing.
There are two other systems: First, the quench system. We talked about how critical the quench system is. The RPMs of the prop, the amp draw of the motors for the props — those things should be very consistent. I think they should be monitor and data logged. The reason for that is you want to know when you quench a load that the RPMs of those props are what you have set it for. When you introduce a load into the quench, the amp draw is, of necessity, going to increase. That’s because you’ve put something in the path of the quenchant so, in order to maintain that flow, you’ve increased the amount of work that it takes to rotate those props.
That’s the kind of thing that you want to monitor. If the amp draw is changing, that means that there’s something in the quench system. Could it be the bearings? Could it be the motor? Those are some things that you’d need to take a look at and be certain of. Obviously, the props need to be in balance; you don’t want any vibration in them.
Doug Glenn: This is also true on the continuous furnace. You’ve got three or four green props in the batch furnace, and it would be the same in the continuous furnace.
Source: Erie Steel, Ltd
Maintenance of Quenchant
Michael Mouilleseaux: Also, there is the maintenance of the quenchant. I’m of the belief that the quench should be continuously filtered. I’m not a fan of batch filtering. I’ve been doing this long enough that I’ve done that, and it just isn’t successful. Quite possibly there are operations that allow it.
If you’re carburizing, you’re going to have particulate in the quenchant because that same atmosphere precipitation of carbon finds its way into the quench. It’s going to be on the parts, it’s going to be on the trays, it’s going to be dragged in there. So, you have this particulate carbon in the quench and it acts as a catalyst to break down the oil.
One way to extend the life of the oil is to make sure that you’re continuously filtering that out. People say 50 microns or 100 microns or 25 microns. Experientially, I’m going to say that it’s going to be 25 microns. If you have a 100-micron filter, that’s great for getting the pebbles out of the quench or the scale, if that were to be an issue with your customer’s parts, but that’s not sufficient to filter out the particulate that’s going to be of the size that’s going to catalyze the breakdown of your quenchant.
Doug Glenn: I assume that if you’re providing for some sort of continuous filtering of your quench, that’s built into the quench structure. The quench tank is built for that, right, and you’re continually flowing it through this filter?
Michael Mouilleseaux: I’m not going to say that no manufacturers offer sufficient quench filtering, but I am not aware of anyone that offers a quench filtration system that’s sufficient. Most of these things end up being standalone. You want to draw the quenchant from the bottom of the tank in one quarter, you want to put it through a series of filters, and you want to put it back into the furnace at the opposite end of the quench tank.
I can say with certainty, that a batch furnace which has not been filtered well, if you remove the quenchant from the furnace after six months — definitely after 12 months — of using it in daily carburizing, you’re going to take 55-gallon drums of sludge out of the furnace, and the sludge is essentially carbon that’s mixed in with the oil.
For that same furnace, with a sufficient quench filtration system, there will be little pockets in the four corners of the quench tank, but that’s about it.
CQI-9, Nadcap and all of those standards have a requirement for monitoring of quenchant. One of the monitors should be particulate because that lets you know how good a job you’re doing in filtering.
Having done it properly, one can say, “Well, I have to replace my quench oil,” — fill in the blank — “once a year, once every six months, once every two years.” Properly maintained and filtered, the quenchant does not have to be replaced very often.
You’re going to drag out a little oil on every load. You want to let the load drip so that you’re not taking that precious quench oil and just putting it in the wash and washing it off. But in a batch furnace, you could have a couple hundred gallons a month to four hundred gallons, depending on the size of the furnace, of add-back that you’re putting in there. Is that sufficient to maintain all of the additives that are in the quenchant? Is that something that you need to monitor? Typically, the manufacturer can do that for you. You get monitoring and you see what the quench speed is, what is the viscosity, flash – all of those important pieces of information.
Now, it doesn’t come for free. A filtration system is costly, and the filters are costly. A year’s worth of quenchant is five years’ worth of filters. In my mind, that’s a good tradeoff.
Karen Gantzer: So, Michael, when the process is filtering the quench, does this happen during production downtime?
Karen Gantzer
Associate Publisher/ Editor in Chief
Heat Treat Today
Michael Mouilleseaux: No, it’s done continuously. Even when the furnace is not running on the weekend, you’re still filtering the oil. You’re going to be taking 20-50 gallons out of the quench tank but you’re putting it right back in. It just passes through filters.
Some people have utilized centrifuges. It’s a very successful way of filtering out carbon particles in oil. The caveat on that is you don’t want the oil above 140 degrees. If you get the oil above 140 degrees and for every 20 degrees you go up, you start doubling the oxidation rate of the oil.
In high-temperature oil, we do a fair amount of modified marquenching. We do it in closed canisters. The seals must be temperature-tolerant, but it is very successful.
The last part is going to be the quench heating and cooling. Typically, at the first part of the week when you’re starting up the furnace or if you’re going from operation A to operation B and it requires a higher temperature quenchant, you’re going to use either gas or electric elements that are going to heat it. Those things need to be monitored so that they’re available when you need them. The last thing that you want to do is start out the week and find out that the quench heaters don’t work; then, you’re trying to find a couple of dummy loads that you can heat up to put into the quench to heat up the quenchant before proceeding with operations.
Then, of great, importance is quench cooling. In petroleum-based quenchants, you’ve got a flashpoint of 400 degrees plus or minus — could be 350, could be 450, depending upon the quenchant that you’re using. You don’t want the temperature of that oil to approach that flashpoint. You do that by using a quench-cooling system. It’s a big radiator. You’ve got a pump, and you set it when you want the pump to go on. You pump the oil out to the quench coolant, and when it comes back, once you’ve attained what your temperature is, then you stop.
Doug Glenn: I’ve got a couple quick questions on this. First, is the quench heater an immersion tube?
Michael Mouilleseaux: Yes. Gas-fired tubes and gas-fired units are very small u-tubes that go into the quench tank. Electrical units have got elements that are tolerant to that.
Doug Glenn: Typically, you’re using those because you’re actually using the quenchant and always putting hot things into it, so once the quench fluid is up to temperature, it’s not a problem. You’re using that quench heater just to get the thing up to temperature. So after that, most of the time, you’re using the cooler to keep it cool, correct?
Michael Mouilleseaux: Absolutely. That’s a control scheme. The last thing that you want to do is set the quench heater so that it’s within five degrees of setpoint and set the quench cooling so that it’s within five degrees of setpoint — then, the temperature just sits there, with heating and cooling fighting each other. You’re heating and cooling oil unnecessarily. You want to give yourself some bandwidth on that.
Material Handling System
Last is going to be the material handling system. In the batch furnace, many have what we call a “rear handler.” We saw the cart and it would push the load into the vestibule, the inner door would open, and it would push the load into the furnace. It’s always preferable to push hot loads, not to pull on them. The reason is that the base trays are alloy and the compressive strength is much higher than the tensile strength is. If you’re pulling on loads, you’re going to break trays.
Once the load is in the furnace, you would have a rear handler so when the cycle is terminated and the inner door opens, you would have a mechanism — it may have a flat bar that’s half the width of the tray — that actually pushes the load into the quench vestibule.
There it’s pushed by the charge car and the inner door is open. That same handler, from the charge car, pushes it into the furnace. Now, when the cycle is terminated, there is a handler in the rear of the furnace that pushes it into the vestibule for quenching.
The exception is right here: When it’s taken out of the vestibule, typically the charge car goes in and grabs it and pulls it out. But, at that point, you’re at 100 or 200 degrees so, at that temperature, you have no material effect upon the strength of the alloy.
Doug Glenn: Okay, the motion it took it from the tray on the left inside is going to push it in and then the next step it’s also going to push it into this “hot zone,” correct?
Michael Mouilleseaux: Yes.
Doug Glenn: But what you’re saying is, when it’s coming out of the hot zone, there’s probably a mechanism on the far righthand side of the hot zone that’s going to push it back. Nothing is going in to pull it out because it’s hot.
Michael Mouilleseaux: Extended reach cars put the load into the vestibule and then put it into the hot zone.
There are some rear handlers that, rather than being a simple push function, have a dog mechanism that allows them to go and get the load in the vestibule and pull it into the furnace. Personally, I am not a fan of that; I like the extended reach car because when you’re pushing something, it is very easy to determine if you’ve put it in the right location. If you grab a load and pull it, you could lose the attachment on that load and then it’s not put exactly where you want it to be.
You can put amp meters on these things so that the amount of force that the motors require to pull in or push out a load. The one thing you need to be cognizant of is that it’s going to take more power — a higher amp draw — to push a 4000-pound load than it is a 2000-pound load. Once you understand what that is, you can monitor these furnaces and then they start making sense to you.
Watlow®, a designer and manufacturer of complete industrial thermal systems, has recently completed its acquisition of Eurotherm®, a provider of controls, systems, software, and services for industrial markets around the world. How did the acquisition happen, what future technologies can we expect, and what should heat treaters know about this change?
Joining Doug Glenn, Heat Treat Today publisher and Heat Treat Radiohost, is Watlow CEO Rob Gilmore to answer all your questions.
Below, you can watch the video, listen to the podcast by clicking on the audio play button, or read an edited transcript.
The following transcript has been edited for your reading enjoyment.
Who Is Rob Gilmore? (00:43)
Contact us with your Reader Feedback!Rob Gilmore CEO Watlow Source: Watlow
Doug Glenn: Welcome everyone. Doug Glenn here, with Heat Treat Today. I have the great privilege of talking with Rob Gilmore, CEO of Watlow. I’m excited to talk with you, Rob. We’ve got quite a bit to cover today, so let me just jump in.
First off, I want to talk about you to give our listeners a sense of you and your background. I wasn’t stalking you, but I was doing a little bit of research, and I was pretty impressed.
I’ve got a list of titles here of things you’ve done at Watlow for the last 35 years: co-op student intern — that’s where you started, which is crazy — and then R&D, product development, manufacturing, engineer, design, development manager, operations product manager, semiconductor business group manager — where you spent a good bit of time — and VP and chief. So, tell us all about your experience at Watlow.
Robert Gilmore: Yes, I’ve had an exciting journey at Watlow and was fortunate enough to get started early in my career and figure out that I wanted to be in engineering. When I first started in engineering, I wasn’t too sure that was what I wanted to do, but when I started with Watlow, it definitely validated that this was it.
I was fortunate enough to get in the R&D group and learn a lot about both thermal applications and how to apply electric heat. It just continued to draw me to it. After I got into developing a lot of products, I entered into the manufacturing side to make sure I knew how we built those products. Then I really got to spend a lot of time with customers and customers’ applications to provide good solutions and solid solutions to our customers.
Doug Glenn: We’re going to get into a little bit of the Watlow company history here. Most recently, in 2021, you became CEO of Watlow, worldwide, correct?
Robert Gilmore: That is correct. We were fortunate to get partnered with a company called to really help us really accelerate and advance our strategy in the business.
About 10–12 years ago, we really knew that the thermal loop coming together was really going to help us optimize our customers’ applications around process heating and heat treat. We’ve seen a lot of success in that arena, and we knew that we wanted to invest much more capital into the business and help our customers be successful in those applications.
Doug Glenn: I want to talk a little bit more about Tinicum in a minute, but I think I heard that you, at one point in time, worked with or for Lindberg.
Robert Gilmore: Actually, it was early in my career, right after college. Lindberg was a very important customer of ours that was dealing with heat treat and furnaces, and they challenged us with some key applications.
My boss — this is a little bit of history of how I learned a lot about heat treat — said, “They’ve (Lindberg) got some significant thermal challenges and I’m going to drop you off here and don’t come back until you figure out how to solve those thermal challenges.”
I’ve always had a passion for heat treat and heat treat applications because they are the most challenging. I learned a lot about the application and how to optimize it.
Doug Glenn: And that was Lindberg rg, the commercial heat treat company, yes?
Robert Gilmore: I think it was actually their equipment manufacturing company.
They definitely did a lot in the auto industry, and there were really some challenging applications.
Doug Glenn: You have a decent amount of heat treat experience if you’ve been working with companies like Lindberg. That’s really good.
And, by the way, I just wanted to make one other comment: I think you’re in a rare class as somebody who has worked for the company for 35 years. That’s just really unheard of.
Robert Gilmore: Yes, it’s been a great company. We’ve been fortunate enough that the family atmosphere, the opportunity to do a lot of different things in the organization, and the ability learn a lot in the organization made it attractive. And it’s not only me; we’ve got a lot of talent in the business with years of service, application knowledge, and capabilities. It’s just been a great experience.
Doug Glenn: I think it speaks to the man, somebody who sticks around that long, as well as the company culture.
Meet Watlow (06:05)
Let’s talk about Watlow for a while.
I know a lot of people in our industry know Eurotherm and a lot of people know Watlow. Watlow hasn’t been as “core,” let’s say, to the heat treat, high temperature, thermal processing market as Eurotherm might have been.
Watlow’s company logo
Robert Gilmore: The headquarters are in St. Louis, but we’ve quickly become a pretty global organization organization over the past five years. That’s why we made some of the decisions that we did; our customers are global — they’re expecting to be supported globally.
So, we’re in headquarters. But that being said, I like to tell people it used to be 75% of our employees were in the Midwest, but now, 75% are outside the U.S., looking at the growth and the acquisitions that we’ve made in business.
Doug Glenn: I saw that the company was founded in 1922. So, just last year, you guys celebrated 100 years.
Robert Gilmore: That’s correct. It’s been a great journey for the company. It’s a great, rich history of solving thermal problems over the years. It’s a fun organization, from that perspective.
Doug Glenn : It was very impressive. I know now, it’s said there are at least 14 different sites around the globe — manufacturing, development, sales, service, etc.
Robert Gilmore: At least 14 different manufacturing sites, and then probably additional sales offices and development offices across the globe.
Doug Glenn: And Watlow, the core business encapsulates heaters, temperature controls, temperature sensors. How would you describe the core business of Watlow?
Robert Gilmore: Yes, I would say we look at it as a complete electric thermal loop. So, if you look at heaters, sensors, power devices, power management devices, along with temperature controls. That is the context of that thermal loop.
Doug Glenn: Gotcha. And then we did mention earlier, it was a family-owned business up until 2021, right?
Robert Gilmore: 2021, yes, is when we partnered with Tinicum.
Doug Glenn: Which is a private equity firm.
Robert Gilmore: Tinicum is more family oriented and it’s one of the reasons we partnered with them. But many of the family stayed in the business, just in a minority, shareholder position.
As Watlow started to advance its strategy, really around 2010, the goal was to bring the thermal loop together.
So, there was an acquisition in 2013 called Semiconductor Tooling Services (STS) and then there was the acquisition of Yarbrough that happened in 2018, and then CRC Inc. happened in 2020.
Doug Glenn: And there were a lot of product introductions. I was very impressed, looking down through the Watlow history on your website, seeing the amount of new products and services and acquisitions and expansions into various countries.
The bottom line is you are a global presence.
Robert Gilmore: We pride ourselves in being able to solve complicated thermal problems. We’ve got a very rich history of having solid technical and engineering talent, so usually if somebody can’t figure it out, they call us and we help them figure it out and work with them through that.
Key Markets (11:14)
Doug Glenn: Rob, if you don’t mind, could you just hit on some of the key markets? I know, obviously, you’re not all heat treat. I know you’re doing semiconductors.
In fact, I found it very interesting, by the way, as I was looking at your history, that you started out with shoes, some sort of a shoe heater.
Robert Gilmore: Yes, if you look at the history, the founder of the business recognized there was a way to mold leather more efficiently with an electric heater, and he created the electric heater (versus steam heating) in those applications. That’s how the business took off.
Over the years, we have continued to develop new products and new solutions as electric became more of an attractive solution. We pride ourselves in bringing the together.
Doug Glenn: Let’s talk about Watlow, not Eurotherm quite yet. Are there any major initiatives that you’ve got going on now?
Robert Gilmore: Yes. As Watlow was growing up as an organization, we were very product-centric, so we sold our components into a lot industries. Ten years ago, we decided that if we brought the thermal loop together to our customers, and targeted applications that had thermal challenges in there, we could bring a better solution to their process or their equipment in those applications.
That got us started on more of a market and application focus, starting with semiconductors.
That’s been the mantra. As we find that thermal is important in these different applications, we focus on those applications and provide those solutions.
“The semiconductor has definitely been attractive.”
So, the semiconductor has definitely been attractive. When you look at refrigerated transport and some of these markets looking for a cleaner, more efficient, alternative (what I would call “the diesel engine market”), we find that in cases where we have the opportunity to use the thermal system to increase fuel efficiency or make the engine burn much cleaner, that we’re helping our customers solve such problems.
There has been a big initiative to move from fossil fuel solutions to electric solutions. We see a lot of opportunities where we can help customers come up with more advanced heat exchanger solutions to optimize and provide a more efficient thermal solution to those applications. So, we’re helping many customers solve those applications.
We’re in medical. We’re in a lot of food processing, food equipment, as you might guess.
But we try to focus on those challenging applications where thermal is critical to the process or to the equipment, and help those customers optimize those solutions.
Green Initiatives and the Electric Thermal Loop (14:36)
Doug Glenn: You hit on one thing that I was going to ask you about: the green initiative, and if that’s really played well for you guys. Would you say yes to that?
Robert Gilmore: Absolutely. When you think about emissions reductions or clean energy, thermal is critical in those applications, and that is driving a lot of our products, solutions, and technologies. We’re helping customers solve those problems day in and day out.
Doug Glenn: Could you give our listeners any sense of magnitude or size of Watlow, whether it be total number of employees, annual sales, or profit margin — just kidding on that last one.
Robert Gilmore: We have around 4,000 employees, plus or minus, at any one time, and growing fast. I probably got that number wrong. We’re probably approaching a billion dollars in revenue. I might have to think about whether I want to share that or not, but it kind of gives you a relative size of the organization. We’re invested heavily in a lot of the products and technologies and supporting our customers, right now, to try to scale the business globally.
An illustration of the electric thermal loop.
Doug Glenn: Returning to the “green” topic I asked you about, there was a term you continually mentioned. It may be a term that you’re using there at Watlow that some of our readers and I might not understand: the concept of the “electric thermal loop.” Can you address that? What do you mean by that?
Robert Gilmore: Electric has been prevailing for a number of years, but when we look at the electric thermal loop, it is descriptive of the heater engine, the sensing device, the power management system, and the control system. That’s what I call that loop.
The industry (whether OEMs or end-users) addresses thermal loop from a component mindset: somebody is providing the electric heater, somebody is providing the control system, somebody is providing the sensor.
But we really find where we specialize is optimizing for the customer’s process or for the equipment to be optimized. That’s what we focus on. That’s why I call it the thermal loop. It’s, How do I optimize process performance or application performance by focusing on ? Am I getting a real sense of management process temperature or safety limits that we have to control, because we’ve got a volatile gas or something of that nature? So, we try to optimize that thermal loop; that’s the job that we do.
Doug Glenn: That makes sense. And, also, I can see how there would be value there to your engineer-based clients in that they can come to one place and you can say, “Okay, listen, we can help create the heat, we can apply the heat, we can measure and control it.”
Robert Gilmore: That’s correct, yes.
What the Acquisition of Eurotherm Offers Heat Treaters (18:40)
Doug Glenn : Let’s jump to Eurotherm. The acquisition of Eurotherm happened in 2022, which was just last year. It seemed like a long time ago, but it wasn’t all that long ago.
Robert Gilmore: Yes, it’s gone by fast, and we’re coming up on a one-year anniversary.
Doug Glenn: So, if you can take yourself back a year or maybe even two, when you first started looking at that acquisition, at the time, Eurotherm was part of Schneider Electric, which is a huge international conglomerate. What was appealing to you guys and where did you think you were going to take this thing?
Robert Gilmore: Eurotherm had been on Watlow’s radar for a number of years. We valued them as a market leader and a competitor in the marketplace, especially when it comes to the controls and the power management space. We always viewed them as being a leader on many fronts, from the product and technology side.
As we got closer, we also acknowledged that they were in some attractive adjacent markets that we thought we could use to complement their technology and capability to help us grow in scale in the business. Then, as we got to know them a little bit better, we recognized the talent and the capability that they had.
Watlow serves a lot of OEMs. OEMs are probably the majority of our business. Eurotherm leans more towards what we would call “the end-user market.” They’re really knowledgeable about these key applications and markets. They know what customers are doing in those applications. We found that very attractive, and when we were able to acquire them, we got a wealth of talent and knowledge around markets and applications, as well as the products that we were attracted to as well.
“Eurotherm had been on Watlow’s radar for a number of years. We valued them as a market leader and a competitor in the marketplace, especially when it comes to the controls and the power management space.”
Also, it increases our presence in Europe and Asia. It’s a good complement from that perspective.
We’re pretty excited about having them on board. We’re finding opportunities, all the time, to help our customers solve these applications. Now that those team members have access to our heating and sensing technology, that really gives them the full thermal loop to help support their customers. It’s a great complement to the business.
Doug Glenn: Yes. That’s very interesting. Before the acquisition of Eurotherm, Watlow was doing thermal controls of some sort?
Robert Gilmore: Yes. We’ve been in the controls business and power business for quite some time. When you look at the thermal loop, the way I phrase it is “the brains” of the thermal loop are in the control and power management side of the business. I’d like to say that’s the tip of the spear of what we’re doing for our customers, and our strategy is to bring that together.
Doug Glenn: I know that Eurotherm (and I’m wondering if this is another one of the reasons why you found them attractive) has systemwide, companywide-type controls and data acquisition, data management, and that type of thing. Did that capability play into the decision?
Robert Gilmore: Absolutely. That’s probably a really solid strength that they have around the data management acquisition side of their business. As we continue to make this thermal loop much more intelligent, access to data, data/data management, and data processing really becomes a really key value driver for us in the business.
It’s really very complementary to what we would say is on our roadmap: helping people implement Industry 4.0 and having that thermal loop intelligence in the system is really critical for where we’re going and how we’re helping our customers.
Integrating Industry 4.0 Technologies for Clients (23:07)
Doug Glenn : Can you speak to 4.0, either from the Watlow side or in combination with Eurotherm, along with things that might be coming up?
Robert Gilmore: When you look at our continued advancement and our bringing more advanced thermal loop and thermal processes together, data/data management/real-time data acquisition, and allowing that thermal loop to be more intelligent, real-time, feed the process
We actually have a portfolio of what we would call I-40 technologies that are helping our customers manage their systems and process more effectively. We’re in a lot of alpha and beta testing right now, with several of our customers, to help them advance their systems and solutions, as well.
Obstacles and Initiatives (24:03)
Doug Glenn: I assume the acquisition/integration of Eurotherm has gone relatively smoothly.
Robert Gilmore: It’s gone perfectly.
Doug Glenn: Never a misstep, I know!
Robert Gilmore: It’s been a great learning experience with the team. We’re coming together and figuring out how to work together. We’re trying to focus on our customers and our opportunities and then we’ll find it easier to work together. But I’m actually very happy with how things are going, with how the teams are working and really seizing the opportunity.
Doug Glenn: Good, good. Well, you know, in the years that I’ve been in the business, I’ve developed a decent knowledge of some of the people at Eurotherm, and I will second what you’re saying — you’ve got some good people and some good talent there.
So Rob, how about market obstacles, at this point? What are the things keeping you up at night?
Robert Gilmore: I think there are always going to be some of these challenges that are in front of us, with a business that’s growing like ours. We just continue to make sure that we’re developing and bringing on new talent and developing them to support the business and our customers. I think that’s always going to be a challenge.
In terms of these initiatives and where those opportunities are and which ones to focus on, a challenge is that different parts of the world are regulating differently, which makes us support faster. Predicting how those outcomes are going to happen and seeing what we should focus on first is always a challenge. We do not lack opportunity for business and growth opportunities.
But, you know, as much as those are obstacles, I look at those as great opportunities that are in front of us, as well.
Doug Glenn: Right. We had a team meeting here the other day with our team and somebody brought up the saying that Billie Jean King used to say, “Pressure is a privilege.” So, you know, you’ve got a lot of stuff going on and it’s a nice problem to have, to be able to say, “Well, which one of these is the best one to take?” and have to make that decision.
Learn what Watlow says about making combustion more sustainable through monitoring. Click the image above to read their article contribution!
We’re coming towards the end here, Rob. How about any specific initiatives with Eurotherm into either the heat treat market specifically or Eurotherm generally, that our listeners might want to know about?
Robert Gilmore: Yes, we’re continuing to advance the strategies in these different markets. Definitely in the heat treat market, we are coming together and really having specific strategies around that, and how we can optimize the thermal loop and those applications.
But really what I’m probably most excited about is the continued investment we have in technologies and products. We see a next generation of control and power management devices along with data acquisitions that you will start to see come out in 2024 and 2025.
We continue to invest in technology platforms, in what we would call the I-40 technologies platforms. We also have some, what I would call “advanced adaptive thermal systems,” that really allow the thermal loop to be intelligent.
We’ve been launching different products over the last probably five years, and more to come from that perspective.
And I’m pretty excited about some of the heater and sensing technologies that we’re developing, which include higher temp capabilities. The temperatures are going to continue to increase in some of these applications and become more demanding, and we’ve got some interesting technologies that we will be advancing there.
I think a big thing we’re also launching in a lot of alpha and beta applications, right now, has to do with “medium voltage technology.” As you continue to see this movement from fossil fuels to electric, the low voltage solutions don’t generate enough power, and we are introducing what we will call a medium voltage technology and heater technology. So, the ability to move from 480 to 600 volts to 4200 or 7200 volts is really going to give our customers the capability to handle going to those megawatt solutions that we can help them do.
I’m pretty excited about those technologies. We’ve been introducing some of those neat technologies that are going to help our customers be successful in many of these applications. It’s some pretty exciting stuff, at least for a lonely old engineer like myself.
Doug Glenn: For electric thermal loop geeks, this is great stuff.
Robert Gilmore: Absolutely.
Doug Glenn: I will tell you, And the whole green initiative seems to be global now. We were at THERMPROCESS over in GIFA in Düsseldorf, and it was all about green initiatives.
These are interesting times and I think you guys, with your business strategy, seem to be very, very well positioned to reap the benefits.
Robert Gilmore: We are definitely excited about what we’re doing today and what we’ll be doing tomorrow. These are exciting times for Watlow.
Doug Glenn: I have one other question for you: Are you guys doing anything with AI that you’re able to talk about?
Robert Gilmore: We definitely see opportunities from that perspective. We definitely believe it’s going to help — and it is helping — support our business. I would say probably we’re in the throws of really the ability to leverage the wealth of knowledge that we have and be able to get that through our business and our team members.
Again, I can’t even imagine the number of years of talent and technology and industry leaders in our business, and I want to make sure that knowledge gets transferred on to the next generation. I think we are looking at AI, in many ways, as to how to accelerate that ability. That’s probably the only nugget I’m going to give away from that perspective.
Doug Glenn: Fair enough.
Robert Gilmore: I appreciate the time and the opportunity. I’m definitely excited that we’re going to continue to have more presence in the heat treat market; you’re going to see our name more and more.
We’re pretty excited about the future and looking forward to talking to you some more.
Doug Glenn: If people want to keep up with you guys — what’s going on, what is the latest news out on you guys — is there any direction you want to steer? Is there anything you would recommend customers or prospects do?
Robert Gilmore: We’re continuing to advance and develop our website, and that’s a good place to start, if you want to reach out. Bob, or even myself sometimes, is always interested in what customers are thinking about or what help they need, as well.
Doug Glenn: Good, very good. Rob, thank you very much.
About the expert: Rob Gilmore has been with Watlow for nearly 35 years. Throughout his career Rob has gained broad experiences in engineering, manufacturing, product management, operations and general management. As a result, he has developed a keen understanding of the application of Watlow products, services, and solutions across a broad range of industries (including industrial ovens and furnaces). Prior to becoming CEO, Rob served as COO and general manager of the semiconductor processing business unit, growing this division to Watlow’s largest market segment. Shortly after Tinicum L.P. acquired a controlling interest in Watlow in March of 2021, he was promoted to Watlow’s CEO. Most recently, Rob has led the organization through the acquisition of Eurotherm from Schneider Electric in November of 2022.
