As heat treating facilities strive for energy efficiency and reliability, investing in power improvements can move a company toward sustainable operations. In this Controls Cornerinstallment, Brian K. Turner of RoMan Manufacturing, Inc. compares real power factor and displacement power factor in the efficiency and electrical performance of vacuum furnaces.
En el contexto de los hornos de vacío, el factor de potencia real y el factor de potencia de desplazamiento son conceptos claves en relación a la eficiencia y el comportamiento tanto de la fuente de energía eléctrica como de la carga del horno. A continuación, una comparación entre los dos factores.
1. El factor de potencia real (PF, por sus siglas en inglés)
Definición: El factor de potencia real es la relación entre la potencia real (potencia activa, P, medida en vatios) y la potencia aparente (S, medida en voltamperios). Da cuenta tanto del desplazamiento de fase como de la distorsión armónica.
Relevancia para hornos de vacío:
Los hornos de vacío, en particular los que funcionan con calentamiento por inducción, con frecuencia generan cargas no lineales debido a la operación de la electrónica de potencia.
Las cargas no lineales conllevan armónicos que distorsionan la forma de onda de la corriente generando una disminución en el factor de potencia real.
Un bajo factor de potencia real es indicador de ineficiencia ya que el sistema se ve obligado a aumentar el consumo de potencia aparente para generar la potencia real que se requiere.
2. El factor de potencia de desplazamiento (DPF, por sus siglas en inglés)
Definición: El factor de potencia de desplazamiento es el coseno del ángulo (ϕ) entre dos componentes fundamentales: el voltaje y las formas de onda de la corriente.
Relevancia para hornos de vacío
En los hornos de vacío la esencia inductiva de los componentes (p.ej., los transformadores y las cargas inductivas) genera un factor de potencia de retardo que se ve reflejado en el DPF.
Un bajo factor de potencia de desplazamiento (es decir, con retardo importante) implica demandas significativas para el sistema en cuanto a potencia reactiva, lo que a su vez afecta el tamaño de los transformadores y del equipo de distribución de energía.
Tabla superior: DPF – Condiciones ideales
La forma de onda sinusoidal verde representa la corriente en un escenario con factor de desplazamiento de potencia ideal en el que interviene únicamente el desplazamiento de fase (ϕ) entre el voltaje (curva azul) y la corriente.
Las formas de onda se ven limpias y sinusoidales, indicando la ausencia de distorsión armónica.
Tabla inferior: PF — Con distorsión armónica
La forma de onda roja representa la corriente con la intervención de la distorsión armónica, situación típica de sistemas con cargas no lineales, caso de los hornos de vacío.
Esta distorsión genera una disminución en el factor de potencia real frente al factor de potencia de desplazamiento, aún cuando no se haya modificado la relación en la fase fundamental.
Formas de onda que permiten visualizar el DPF vs. el PF en relación a voltaje y corriente
Efecto sobre el tamaño de transformadores y transformadores de distribución
Aumento en la demanda de potencia aparente
Un factor de potencia real disminuido (debido a los armónicos) implica que el transformador deberá manejar una mayor potencia aparente (S) sin importar que la potencia real (P) no haya cambiado. Esto puede aumentar los costos de capital al requerir transformadores más grandes.
Estrés térmico
Los armónicos llevan a pérdidas adicionales (por las corrientes inducidas y la histéresis) generando el sobrecalentamiento de los transformadores y disminuyendo la eficiencia y duración de los mismos.
Regulación de voltaje
Los armónicos distorsionan la forma de onda del voltaje, lo que podría afectar los equipos sensibles y obligar al uso de transformadores capaces de regular de manera más precisa el voltaje.
Penalización por consumo energético
Los proveedores del servicio de energía muchas veces aplican sanciones por un bajo factor de potencia real, con lo que buscan incentivar a los usuarios a mejorar la calidad de la potencia mediante el uso de filtros armónicos o corrección del factor de potencia.
Conclusión
La revisión del factor de potencia en los hornos de vacío es de crítica importancia para lograr una mayor eficiencia y la reducción de los costos operativos. En su avance hacia la eficiencia y la fiabilidad energética, invertir en estas mejoras permitirá a las plantas de tratamiento térmico acercarse un paso más a la operatividad sostenible.
Traducido por: Shawna Blair
About the Author:
Brian Turner Sales Applications Engineer 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.
As heat treating facilities strive for energy efficiency and reliability, investing in power improvements can move a company toward sustainable operations. In this Controls Cornerinstallment, Brian K. Turner of RoMan Manufacturing, Inc. compares real power factor and displacement power factor in the efficiency and electrical performance of vacuum furnaces.
In the context of vacuum furnaces, real power factor and displacement power factor are key concepts related to the efficiency and electrical performance of the furnace’s power supply and load. Here’s a comparison:
1. Real Power Factor (PF)
Definition: Real power factor is the ratio of real power (active power, P, measured in watts) to apparent power (S, measured in volt-amperes). It considers both the phase displacement and harmonic distortion.
Relevance to Vacuum Furnaces:
Vacuum furnaces, especially those using induction heating, often generate nonlinear loads due to the operation of power electronics.
Nonlinear loads introduce harmonics, which distort the current waveform, reducing the real power factor.
A low real power factor indicates inefficiency, as the system draws more apparent power for a given amount of real power.
2. Displacement Power Factor (DPF)
Definition: Displacement power factor is the cosine of the angle (ϕ) between the fundamental components of voltage and current waveforms. It ignores harmonic distortion and considers only the phase displacement caused by inductive or capacitive loads.
Relevance to Vacuum Furnaces
In vacuum furnaces, the inductive nature of components (e.g., transformers and inductive loads) causes a lagging power factor, which is reflected in the DPF.
A poor displacement power factor (e.g., heavily lagging) means the system has significant reactive power demands, affecting the sizing of transformers and power distribution equipment.
The above waveforms illustrate the difference between displacement power factor (DPF) and real power factor (PF) as they relate to current and voltage:
Top Chart: DPF — Ideal Conditions
The green sinusoidal waveform represents the current in an ideal displacement power factor scenario, where only phase displacement (ϕ) exists between the voltage (blue curve) and current.
The waveforms are clean and sinusoidal, indicating no harmonic distortion.
Bottom Chart: PF — With Harmonic Distortion
The red waveform represents the current with added harmonic distortion, typical in systems with nonlinear loads, like vacuum furnaces.
This distortion causes the real power factor to drop compared to the displacement power factor, even if the fundamental phase relationship is the same.
Waveforms that illustrate DPF vs. PF as it relates to voltage and current
Effects on Transformer and Utility Transformer Sizing
Increased Apparent Power Demand
A lower real power factor (due to harmonics) means the transformer must handle higher apparent power (S), even if the real power (P) is unchanged.
This can necessitate larger transformers, increasing capital costs.
Thermal Stress
Harmonics lead to additional losses (eddy currents and hysteresis), causing transformers to overheat and reducing their efficiency and lifespan.
Voltage Regulation Issues
Harmonics distort the voltage waveform, which can affect sensitive equipment and require transformers with tighter voltage regulation capabilities.
Utility Penalties
Utilities often impose penalties for low real power factor, incentivizing users to improve power quality through harmonic filters or power factor correction.
Conclusion
Addressing power factor in vacuum furnaces is crucial for improving efficiency and reducing operational costs. As heat treating facilities strive for energy efficiency and reliability, investing in these improvements is a step toward sustainable operations.
About the Author:
Brian Turner Sales Applications Engineer 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.
For more information: Contact Brian at bturner@romanmfg.com.
Processes that utilize electric-powered industrial heaters instead of fossil fuels will necessitate improved power consumption management. Therefore, advanced technologies in power management systems are critical, as in-house operations think about cost savings and electric power requirement compliance.
Janelle Coponen, senior product marketing program strategist, and Christian Schaffarra, director of research and development — Power Control Solutions’ Engineering Team, both of Advanced Energy, address the key to the discussion, SCRs and VSC, in this Technical Tuesday.Read more to understand how the reduction of harmonics allows operations to better manage energy consumption.
This informative piece was first released inHeat Treat Today’sJanuary 2025 Technologies To Watch in Heat Treating print edition.
Processes are increasingly converting to electric-powered industrial heaters instead of fossil fuels to improve process control and comply with the latest energy policies. This transition enables greater operational efficiencies but necessitates improved power consumption management by companies and their heat treat operations.
The integration of advanced technologies in power management systems is critical for both cost savings and to comply with electric power requirements. Among these technologies, silicon-controlled rectifiers (SCRs) and voltage sequence control (VSC) play a pivotal role in optimizing energy consumption. This article explores the significance of the reduction of harmonics by using a special energy-efficient mode to allow facilities to better manage and reduce their energy consumption.
What Are SCR Power Controllers?
Figure 1. SCR power controller
SCR power controllers regulate the power delivered to resistive or inductive loads. Unlike traditional mechanical switches, SCRs offer faster switching times and greater reliability. They are commonly used in applications requiring heating, melting, or bending such as heating elements, motors, and lighting systems.
These devices control electrical power, current, or voltage with high precision and reproducibility. They adjust the phase angle of the AC supply, allowing for finer control over the amount of power sent to the load. This reduces energy consumption and minimizes wear on the equipment, thereby extending its lifespan. Phase-angle firing is designed for high dynamic loads with small thermal inertia and allows for high control dynamic, soft and bump-less loading, and exact current-limit setting.
SCR power controllers produce high manufacturing quality and efficiency through:
Energy efficiency of approximately 99.6%
Power density of approx. 18 W/in3 (for 3-step VSC SCR)
High accuracy up to 1% for output power, 0.5% output voltage
Flexibility
EtherCAT Interface
Traditional SCR operation can be inefficient, especially under partial loads. An energy-efficient mode optimizes the SCR firing angle based on load requirements, reducing energy waste. By adapting to varying loads, these controllers improve system efficiency, lower energy costs, and reduce environmental impact.
Figure 2. Phas-angle firing control mode
Understanding Power Factor
Power factor (PF) is a critical component, representing the ratio of real load power (kW, the actual power consumed) to apparent load power (kVA, the total power supplied). It is a measure of how effectively electrical power is being converted into useful work output. A power factor of 1 (or 100%) indicates maximum efficiency, while lower values indicate wasted energy due to reactive power.
In many industrial settings, a low power factor can lead to higher electricity bills and additional charges from utility companies. Utilities must generate more power to compensate for the inefficiencies caused by reactive power, which does not perform useful work.
Benefits of Improved Power Factor and Reduced Harmonics
One significant advantage of using SCR power controllers is the ability to minimize harmonic distortion. Harmonics are voltage or current waveforms that deviate from the ideal sinusoidal wave, often caused by non-linear loads like electronic devices. These distortions can lead to overheating, equipment damage, and inefficiencies within the electrical system.
Figure 3. Power triangle
Reducing harmonics improves the overall efficiency of power systems and smoother equipment operation, which can prevent costly downtime. Additionally, improving power factor can result in financial savings by reducing energy loss, lowering demand charges, and increasing the capacity of existing electrical infrastructure.
This results in lower energy bills, less wasted energy, and better system reliability. Improved power factor can also help meet regulatory standards requiring specific power factor levels.
Special Energy-Efficient Mode, Voltage Sequence Control (VSC)
VSC complements SCR technology to enhance power system performance by managing voltage levels more effectively. It systematically sequences voltage application to loads, which improves power quality and extends the lifespan of equipment.
VSC is particularly beneficial for applications with inductive loads, where voltage management can significantly reduce inrush currents and mitigate harmonics. By integrating VSC with SCR technology, industries can harness the benefits of both systems, ensuring a stable and efficient power supply.
Combined Advantages of SCRs with Voltage Sequence Control
Improved energy efficiency: By optimizing firing angles and managing voltage sequences, facilities can achieve substantial reductions in energy consumption.
Cost savings: Lower energy usage translates directly into reduced operational costs, making these technologies economically attractive for businesses.
Enhanced equipment longevity: By reducing stress on electrical components through better voltage management, both SCRs and VSC can prolong the operational lifespan of machinery.
Environmental impact: Energy-efficient systems contribute to lower greenhouse gas emissions, aligning with global sustainability goals and regulatory standards.
Figure 4. Comparison phase-angle firing versus VSC
Advantages and Disadvantages of Using SCR in Voltage Sequence Control Mode
Here are several of the advantages:
Improved stability: Helps maintain voltage stability across the system, reducing the risk of voltage fluctuations and outages.
Enhanced performance: Optimizes the performance of electrical equipment by ensuring they operate within their rated voltage range, improving efficiency.
Protection against voltage imbalances: Monitors and adjusts for voltage imbalances in three-phase systems, which can prevent equipment damage and reduce wear.
Energy efficiency: By maintaining optimal voltage levels, VSC can lead to energy savings and lower operational costs.
Automated control: Often incorporates automation, allowing for real-time adjustments without manual intervention, thus improving response times.
Lowest level of harmonics: VSCs can help minimize harmonic distortion in electrical systems.
Lowest level of reactive power: The specific control design of the VSC can significantly impact the minimum achievable reactive power level, even in a weak grid.
Figure 5a. Standard circuit VAR (phase angle) / Figure 5b. VSC circuit
Compare with a few disadvantages:
Large footprint: Larger power controller footprint versus standard SCR power control system.
Initial cost: The initial investment in VSC systems and related technology can be higher, but payback time is less than a year.
Conclusion
Figure 6. Power factor over outpower in VAR (phase angle) blue line vs. VSC red line
In-house heat treat operations aiming for greater efficiency and cost reduction can benefit from VSC, the energy-efficient mode for SCR power controllers. By enhancing power factor and reducing harmonics, these devices optimize energy use and support sustainable, cost-effective operations. Adopting such technologies leads to significant improvements in industrial power consumption and enhanced savings for end users.
About the Author:
Janelle Coponen Senior Product Marketing Program Strategist Advanced Energy
With more than 21 years of experience in the industrial and energy sectors, Janelle Coponen bridges the gap between technical solutions and market needs. At Advanced Energy, she works alongside engineering teams to translate complex technologies into market ready strategies ensuring alignment between engineering innovations and business objectives.
Christian Schaffarra Director of Research and Development Power Control Solutions’ Engineering Team Advanced Energy
With more than 30 years of experience, Christian Schaffarra leads a research team dedicated to developing and advancing innovative power control technologies, ensuring optimal performance and reliability. He has a deep understanding of both the technical and marketing requirements that drive successful product development and engineered solutions.
If you work in a standards-driven industry, you may already feel the imperative of digitalization. In today’s Technical Tuesday, Mike Loepke, head of Nitrex Software & Digitalization, posits how, even if you aren’t necessitated to track compliance digitally, you are probably looking to synthesize and leverage the strengths of multiple advanced operations — furnace and process record-keeping, knowledge of furnace past operations, juggling different new equipment capabilities — across just one platform. In other words, you are looking to bring digitalization system management to your operations.
This informative piece was first released inHeat Treat Today’sDecember 2024 Medical & Energy Heat Treat print edition.
The Future of Heat Treatment Relies on Digitalization
The ultimate goal for heat treaters, whether commercial or captive, is to uphold the quality of their product and meet client expectations while remaining profitable. Digitalization supports these efforts as it synthesizes and presents detailed, transparent, and accessible data that allows heat treaters to better manage their equipment, processes, and product quality. In addition, the collection of detailed information can serve as a database of knowledge to be used by the next generation of heat treaters, supporting future viability and advancement in the field.
There are necessary steps to take to establish a digital solution and essential components to look for when choosing a software platform that assists heat treaters in optimizing equipment and processes, effectively creating the digitalization of the heat treat operations. Let’s explore these now.
How Digitalization Optimizes Heat Treatment Processes
Digitalization in the heat treatment industry relies on the integration of industrial internet of things (IIoT) technologies with traditional and modern heat treatment processes. Using enabling devices such as sensors, modern connectivity methods, analytics, machine learning, and IIoT software platforms, it is possible for heat treaters to collect and process data that, after analysis, drives informed decisions to optimize equipment, processes, and product quality. To put a finer point on it, digitalization occurs when a manufacturing system is digitally integrated to capture and preserve human experience and knowledge, forming a holistic virtual representation of heat treat operations.
Figure 1. QMULUS Shop Layout enables visual inspection of the current production status, the
location of goods and parts, as well as the real-time status of assets and their ongoing processes. Source: Nitrex
While digitalization varies from industry to industry and plant to plant, there are some common ways in which heat treaters can employ digital technologies to build such a system. Firstly, digitally integrated solutions can optimize process management and control. For example, when a sensor detects a temperature anomaly during a heat treatment process, the integrated software platform picks up that reading, analyzes it in real time, recognizes it as an error based on historical data or programmed parameters, and alerts the operator.
This integration also facilitates predictive, condition-based maintenance. For example, if collected data and analysis suggests that a furnace is behaving abnormally, the system can automatically generate a work order along with a list of potential failure causes, so that a technician can troubleshoot, identify, and correct small issues — such as a failing thermocouple — before they impact quality or result in equipment failure. By addressing these proactively, heat treaters can avoid extended periods of costly unplanned downtime and ensure continuous operation.
Secondly, artificial intelligence through machine learning plays a crucial role in optimizing quality control in a digitalized system. By analyzing data collected during heat treating processes, it learns to detect patterns and identify anomalies. As in the examples above, this capability enables the system to identify deviations from the desired outcomes, allowing heat treaters to quickly rectify any issues before they impact quality.
Figure 2. The heart of the IIoT data platform needs to be thoughtfully planned and designed. Illustrated are 5
steps to follow to ensure the cloud data system properly engages with the data generated from your specific
heat treat operations, ultimately delivering actionable insights. Step 1 depicts the various data sources;
Step 2 shows the data transformation, integration, and processing stages; Step 3 highlights the central
QMULUS database where data is indexed and organized; and Steps 4 and 5 demonstrate how data is further
processed, distributed, and accessed by different end-users. Source: Nitrex
Thirdly, algorithms can be programmed into a comprehensive management system to identify the most energy-efficient operating conditions for the heat treating process, helping heat treaters reduce their carbon footprint, minimize energy costs, and comply with sustainability goals.
In addition to these types of operational advantages, digitalization technologies can also be used to create a database of knowledge before experienced operators and experts leave the workforce. Traditionally, a handful of experts in the plant oversee the furnaces and equipment and understand how to best control and maintain them based on experience. However, passing down this knowledge to the next generation of heat treaters can take years, which may not be possible due to a company’s workflow demands and cost pressures. Digitalization addresses this challenge by creating a streamlined and accessible database of knowledge, offering less experienced operators and technicians immediate access to detailed information about what may be happening in the equipment or process for an issue at hand. This ensures that essential insights are not lost and enables quicker problem-solving and decision-making on the shop floor.
Making the Digitalization Transformation
While digitalization presents obvious advantages, the heat treatment industry, often conservative in its approach to technology, has some initial work and investment required before realizing the full benefits.
Going “paperless” in order to unlock the full potential of the available data is an important first step. All reports, histories, drawings, and other paperwork associated with equipment, processes, maintenance activities, product quality, and other relevant information should be digitized to provide a comprehensive view of both historical and current data.
Connectivity and integration between machine and higher-level systems are essential for effective data acquisition, monitoring, and remote control. SCADA systems, Manufacturing Execution Systems (MES), and other higher-level systems are rich sources of machine and process data. Gathering and analyzing this data can provide actionable insights that operators can use to make smarter decisions about the control and maintenance of equipment and processes.
Figure 3. A comprehensive overview displays all detected control loop anomalies, indicating possible root causes as well as recommended actions. Incorporating feedback from the responsible maintenance personnel further improves accuracy and delivers more effective recommendations for future
occurrences. Source: Nitrex
Finally, just having data is not enough. The data must be accessible, transparent, and relevant to be valuable. Achieving a complete picture of all the collected data, known as data consolidation, is necessary.
To build an IIoT platform with a well-architectured data engine, heat treaters should begin by identifying and understanding the different sources of data provided by sensors and high-level systems. This involves integrating the data through interfaces adapted to the data type and source, as well as documenting the integrated data sources, data fields, and data streams. Next, a “data lake” should be created to store the collected raw data. From this foundation, a data warehouse can be established to store enriched or analyzed data, derived values, data models, and forecasts in an organized way. For heat treaters, this type of contextualized data might be grouped by parts, loads, or orders.
Once the data engine is in place, the information stored in the data warehouse must be presented in a way that makes sense to operators and technicians for them to make informed decisions for heat treatment processes. To facilitate this, a universal data interface should be considered.
Building from this well-architectured data engine, the IIoT platform can then be expanded with statistical analytics, remote monitoring, KPI tracking, machine learning, artificial intelligence, and other applications to optimize processes and increase profitability.
What Heat Treaters Need in a Digitalization Solution
Harnessing modern technologies tomake digitalization a reality presents heat treaters with the opportunity to implement a solution based on a complete and well documented data system. It also means that the solution creates a holistic solution to data analysis, interpretation, reporting, and action that supports the real-world actions of heat treaters on the plant floor and in the office.
For this reason, a digitalization solution that has cloud and on-premises allows real-time access to analysis and alert messages for operators on the floor as well as managers who are away from the plant, ensuring quick problem-solving and maximum uptime in the event of process or machine issues.
Additionally, heat treaters should look for a solution that offers the freedom to integrate all the various platforms and equipment from which data are gathered from. These may include relevant machinery and production data from the shop floor as well as third-party and custom controllers. This flexibility to synthesize information from multiple sources will ensure the digitalization efforts lead to a comprehensive solution with actionable process overviews, recipe control, batch tracking, and other customization options.
To further this intent of a holistic solution, heat treaters should consider various data capabilities with different portal views, such as a manufacturer portal, a plant portal, and a client portal. However, considering the historic value of a comprehensive software solution, it may be worthwhile to consider how each user could transfer direct feedback and add new rules into the system, creating a repository of knowledge that bridges the knowledge of outgoing generations to future heat treaters.
Finally, any platform that directs the digitalization of a plant must prioritize robust security measures. Several features to look for are:
enhanced encryption standards to keep data confidential and tamper-proof during transmission and storage;
secure protocols based on industry best practices to safeguard data integrity;
a granular access control system (ACS) to allow IT administrators to define and manage user permissions of authorized personnel, thereby minimizing the risk of data breaches and unauthorized data manipulation; and
intrusion detection and prevention systems to continuously monitor network and system activities, enabling instant identification and mitigation of suspicious behavior. This serves as an additional layer of defense against potential cyber threats.
Beyond the software setup, be sure to use best practices by conducting regular security audits to assess the platform’s vulnerabilities and ensure compliance with evolving cybersecurity standards. While digitalization of heat treat operations may seem like a task for the next generation to complete, secure software options that integrate the hard work of digitizing plant activities can make this endeavor just a step away.
About the Author:
Mike Loepke Head of Nitrex Software & Digitalization Nitrex
Drawing from a background in Mathematics and Physics, coupled with extensive R&D experience and metallurgical modeling, Mike Loepke specializes in AI and process prediction. He has led Nitrex’s initiative in developing QMULUS, a pioneering IIoT cloud-based platform. Mike’s relentless pursuit of knowledge keeps him at the forefront of evolving technology.
In this installment of the Controls Corner, we are addressing inductance in a furnace heating system, and the critical role it plays in various industrial systems, including furnace load systems. Impedance acts as a measure of how much a circuit resists the flow of AC current. In this guest column, Brian Turner, sales applications engineer at RoMan Manufacturing, Inc., explains how impedance applies in electrical circuits.
Inductance is a fundamental concept in electrical engineering, and it plays a critical role in various industrial systems, including furnace load systems. In furnaces used for heating, inductance is a key factor influencing the system’s electrical performance, energy efficiency, and overall operational behavior.
To talk about inductance, let’s first address impedance and how it applies:
In electrical circuits, impedance refers to the total opposition to the flow of alternating current (AC), which is a combination of both resistance (from resistors) and reactance (from inductors), essentially acting as a measure of how much a circuit resists the flow of AC current, taking into account both the resistive component (like a resistor) and the reactive component (like an inductor at a specific frequency) within the circuit.
Load configuration, power source (IGBT, VRT, ERT) to the furnace feedthrough Source: RoMan Manufacturing Inc.
Inductance
Inductance is the property of an electrical conductor that opposes a change in the current flowing through it. It arises from the magnetic field generated around the conductor when an electric current passes through it. The unit of inductance is the Henry (H).
In an AC circuit, inductance creates a phenomenon known as inductive reactance, which resists the flow of current. Inductive reactance (XL) is given by the formula:
XL= 2πƒL
Where: • XL is the inductive reactance (in ohms) • f is the frequency of the AC supply (in hertz) • L is the inductance (in Henrys)
This reactance influences how the current behaves in the system, which is particularly important in furnace load systems where high current flows are common.
Resistance
Electrical resistance is the opposition that a material offers to the flow of electric current. It is measured in ohms (Ω) and depends on factors such as the material’s properties, its temperature, and the geometry of the conductor (length, cross-sectional area). In heating systems like vacuum furnaces, resistance is harnessed to convert electrical energy into heat through Joule heating (also known as resistive heating).
The relationship between electrical power, voltage, current, and resistance is governed by Ohm’s law:
V = IR
Where: • V is the voltage across the heating element(in volts) • I is the current through the element (inamperes) • R is the electrical resistance of theelement (in ohms)
The heat generated by the furnace’s heating elements is a function of the power dissipated in the resistance, given by the equation:
P = I2 x R
This shows that the heat produced is directly proportional to the resistance and the square of the current flowing through the heating elements
Close Couple
Reducing the material in the secondary* reduces resistance (HEAT = I2 x R)
Reducing the area in the secondary reduces inductive reactance increasing power factor
To be most efficient, use the shortest amount of conductor material from the electrical system secondary to the furnace feedthrough. Additionally, keep the distance between those conductors as small as possible.
Power Factor and Efficiency
Inductance in a furnace load system causes the current and voltage to be out of phase. This phase difference results in a lower power factor, which is a measure of how effectively the system converts electrical power into useful work. A lower power factor means that more apparent power (the combination of real power and reactive power) is required to achieve the same level of heating.
In practical terms, a furnace with a high inductive load will draw more current from the power supply for a given amount of heating, leading to increased energy losses and inefficiency.
In practical terms, a furnace with a high inductive load will draw more current from the power supply for a given amount of heating, leading to increased energy losses and inefficiency. Power factor correction techniques, such as the use of capacitors, are often employed to counteract the effects of inductance and improve system efficiency.
Conclusion
Inductance is a fundamental factor in the operation of furnace load systems, influencing everything from heating performance to energy efficiency and power quality. By understanding and managing inductance, furnace operators can optimize their systems for maximum performance while minimizing energy losses and operational costs. Controlling inductance is essential for ensuring that furnace load systems operate reliably and efficiently in demanding industrial environments.
*The connection from a vacuum power source to the furnace’s feedthroughs, this connection can be made using air-cooled cables, water-cooled cables, or copper bus.
About the Author:
Brian Turner Sales Applications Engineer 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.
Maintaining clear communication for high precision processing, critical with medical component heat treating, requires sophisticated operations. In today’s Technical Tuesday, Mike Grande, vice president of Sales at Wisconsin Oven Corporation, provides an overview of how the industrial internet of things (IIoT) advances heat treat performance capabilities and ensures accurate, repeatable results.
This informative piece was first released inHeat Treat Today’sDecember 2024 Medical & Energy Heat Treat print edition.
Today’s technology is evolving at an exponential rate. Over the last several years, digital technology has provided more and more connectivity between devices and processes. One of the most impactful is IoT technology. From smartphones to virtual assistants, touchscreen refrigerators to thermostats and interconnected home management systems, these products are quickly changing the way people interact and connect.
In addition to consumer products, the industrial world is also seeing increased reliance on this technology to improve throughput, decrease energy use, and increase equipment longevity by capturing and analyzing the data generated by their machines.
What Is IoT and IIoT Technology?
IoT (internet of things) refers to everyday items that have been equipped with sensors that transfer data over a network. Refrigerators, lights, thermostats, smart speakers, and entire homes are now available with IoT technology. Devices equipped with IoT options provide conveniences like remote monitoring, advanced programming, and smart learning, which make daily and household tasks easier. What seemed like science fiction just a few years ago has become reality.
This impressive technology does not only apply to the consumer world. The application of IoT to the manufacturing sector is even more impactful. Industrial internet of things (IIoT) is the term used to describe the application of connected IoT technology to industrial machinery. These systems collect and analyze data, learn from that data (“machine learning”), perform predictive maintenance, and then share that information with personnel, manufacturers, including manufacturers of the machines being monitored, and even other devices. This type of data collection and analysis gives valuable insight into the facilities, processes, and equipment to ensure that everything from energy usage in a facility to equipment performance for a process is optimized.
Figure 1. The IoT gateway collects the data from oven-mounted sensors and wirelessly transmits it to the cloud. Source: Wisconsin Oven Corporation
How Is IIoT Used in Industrial Ovens and Furnaces?
IIoT technology tracks the performance and health of the most critical components and conditions in the ovens and furnaces they are monitoring. The system utilizes an IoT gateway (Figure 1), which collects information from predictive maintenance sensors that gathers performance data and stores it over time. The gateway also wirelessly transmits the data to a cloud platform where it can be displayed in dashboards, designed for easy viewing and monitoring. Thresholds are set at warning or alarm conditions. When exceeded, the system alerts the user or the oven manufacturer that there is a problem. This type of system predicts component failures before they occur, allowing time to schedule maintenance and minimize unplanned downtime.
Figure 2: An example of a dashboard used on an oven IIoT system Source: Wisconsin Oven Corporation
The data is displayed in a dashboard format (Figure 2) which permits visual analysis of the information, and intuitive understanding of the process being performed in the oven. In the example of an oven used to process parts in an inert atmosphere, the x-axis represents the elapsed time, which can be expanded or collapsed by the user in order to provide a more (or less) detailed view of the process. The y-axis tracks variables such as temperature, pressure, oxygen level, nitrogen flow rate, and humidity level.
A few examples of the oven data gathered and analyzed by an IIoT system are as follows:
The output of the temperature controller is monitored. If, for example, the controller output is normally running at 30% for a specific oven (meaning the oven is using 30% of its full heat capacity), and for no apparent reason it increases to 60% output, this indicates either an exhaust damper is stuck open and causing the oven to exhaust too much of its heat, there is a heater failure, or a door is not closing fully, or something else.
Vibration sensors installed on recirculation blowers can monitor the health of the oven. Since blowers are rotating machines, they have a predictable vibration frequency and amplitude. As the blower bearings wear over time, these vibration parameters change. The IIoT system uses proprietary algorithms to determine acceptable vibration levels at different temperatures and RPMs. As the vibration values change over time, the system can predict when blower failure is likely, prior to it occurring. This allows replacement parts to be ordered before a “hair on fire” situation where the equipment suddenly stops working, interrupting production and workflow.
In order to monitor the burners on gas-fired ovens, the flame safety system is wired to the IIoT system. This allows remote evaluation of the flame sensor, purge timer, and other components that are critical to safe and proper burner operation. On older ovens, nuisance shutdowns can occur due to a dirty combustion blower, dirty flame rod, faulty airflow switch, or other reasons. An IIoT system allows the oven manufacturer to remotely diagnose this type of issue without ever sending a service technician to the job site, saving time and money.
An oven IIoT system is often used to measure the oven chamber pressure. Ovens can be intentionally operated at a neutral pressure, a slightly negative, or slightly positive pressure, for various process-related reasons. A pressure sensor measures this value and, via the IIoT gateway, delivers it to the dashboard in real time. If the chamber pressure strays outside of a predetermined range, this indicates a failure such as an improper damper setting or a malfunctioning exhaust blower.
The Benefits of IIoT Technology
Predictive maintenance is one of the most important benefits of IIoT. The ability to prevent potential equipment breakdowns and resulting process bottlenecks is invaluable. Not only does IIoT allow plant managers and operators to schedule maintenance ahead of time, it also reduces maintenance hours by knowing exactly what the issue is that needs to be serviced. This reduction in unplanned downtime increases productivity, which translates to higher profits.
The quantity of detailed, relevant data available (real time and retroactive) via the IIoT system exceeds the information a service technician can gather oven side, especially if the oven has stopped working. Using IIoT to remotely gain information to service the equipment, the problem can often be resolved the same day.
Perhaps the most impressive benefit of IIoT is remote diagnostics. Whether a furnace or oven is experiencing occasional unexplained shutdowns, or is completely out of commission, it typically takes days or weeks to schedule a service technician to inspect the equipment and diagnose the problem. However, if the oven is equipped with IIoT, a call can be made to the oven manufacturer who can remotely log into the system dashboard. They will be able to view and analyze the data gathered by all the sensors going back over time, without sending a service technician to the job site. Also, the quantity of detailed, relevant data available (real time and retroactive) via the IIoT system exceeds the information a service technician can gather oven-side, especially if the oven has stopped working. Using IIoT to remotely gain information to service the equipment, the problem can often be resolved the same day. Further, the IIoT system gathers and records the data going back in time for months, which is invaluable when trying to diagnose a chronic or intermittent failure.
Another use of IIoT technology is energy management. Through IIoT monitoring, facilities and equipment can be set to optimize energy efficiency. By ensuring the oven uses only the amount of heat energy necessary, and no more, its energy consumption is minimized. The system can reveal, for example, that a second shift oven operator opens the oven doors for five minutes to unload the parts and then load the next batch, while the first shift operator takes ten minutes to do the same process, wasting a great deal of energy as heated air spills out of the oven for an extra five minutes with every batch.
Data Security
IIoT devices use encryption to protect against unauthorized access to the oven operational data. Data transmitted between IIoT devices and the cloud is encrypted using protocols like Transport Layer Security (TLS). This provides confidence that only approved parties can access the information, safeguarding it from those with malicious intent. This ensures that even if data is intercepted, it will appear as jumbled information that cannot be read without the decryption key.
Because the data collected relates to the oven or furnace being monitored, and is not descriptive of the parts being processed, it would be of limited use to anyone who gained unauthorized access. If a malicious actor discovered, for example, the vibration levels, temperature controller output, or the status of the burner system while the oven is processing a load, it would be of limited proprietary value and would not directly reveal information about the parts being processed since no information about the load is included in the data.
In considering the security risk of an IIoT system collecting and transmitting data to the cloud, it must be compared to the alternative, which is bringing a service technician to the job site to perform the required maintenance or troubleshooting. When a service technician is invited on site, they have the opportunity to view the parts being processed, which temperature profiles apply to which parts, material handling methods, ancillary processes performed before or after heating, and even unrelated proprietary processes performed in the facility. This level of intrusion is much greater than simply sending the oven IIoT data to the cloud and avoiding the service technician entirely.
The Future of IIoT
Since the introduction of IIoT to the industrial oven market, it has gained acceptance by a wide range of manufacturers, and it is expected to continue to grow. Artificial intelligence (AI) is becoming a part of IIoT, as it can optimize the algorithms used in predictive maintenance. Also, IIoT can incorporate AI’s cognitive capabilities to better be able to learn at what thresholds of vibration, pressure, etc., to send alert notifications.
To Summarize
Consider purchasing an IIoT system with your next industrial oven. The successful implementation and use of IIoT provides a competitive advantage to the owner of the equipment. In today’s world of “doing more with less,” IIoT can increase productivity, reduce maintenance costs and unplanned downtime, and decrease energy use, all at minimal cost, and with no additional personnel required.
About the Author:
Mike Grande Vice President of Sales Wisconsin Oven Corporation
Mike Grande has a 30+ year background in the heat processing industry, including ovens, furnaces, and infrared equipment. He has a BS in Mechanical Engineering from University of Wisconsin-Milwaukee and received his certification as an Energy Manager (CEM) from the Association of Energy Engineers in 2009. Mike is the vice president of Sales at Wisconsin Oven Corporation.
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.
This informative piece was first released inHeat Treat Today’sSeptember 2024 People of Heat Treat print edition.
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.
This informative piece was first released in Heat Treat Today’s June 2024 Buyers’ Guide print edition.
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.
