energy technical content

A Welcome Diversion: Smart Pump System Revolution for Self-Cleaning Furnaces

/ AEROSPACE HEAT TREAT TECHNICAL CONTENT, VACUUM FURNACES TECHNICAL CONTENT, VACUUM PUMPS GAUGES VALVES TECHNICAL CONTENT

What if your vacuum furnace could clean itself? In this Technical Tuesday installment, Bob Hill, FASM, president of Solar Atmospheres of Western PA and Michigan, explores a revolutionary dual roughing pump configuration that eliminates the need for solvents, foil wrapping, and manual pre-cleaning.

This informative piece was first released in Heat Treat Today’s December 2025 Annual Medical & Energy Heat Treat print edition.

Para leer el artículo en español, haga clic aquí.

Introduction

Vacuum furnaces require an exceptionally clean environment to process critical components, from medical devices to aerospace. But laborious, time-consuming component cleaning to ensure purity of the furnace and parts does not necessarily need to be done by people. With the right pumps, your vacuum furnace can clean itself. Explore what a fully integrated, vacuum-based cleaning cycle could look like by leveraging an innovative dual roughing pump configuration.

In the vacuum heat treating world, where critical components are often near-net-shape with minimal to zero stock removal, the surface aesthetics of the final product are critical to the end user. Across industries like aerospace, medical devices, and power generation, vacuum processing has become increasingly valued — not only for its precision, but also for its ability to eliminate downstream operations, ultimately saving cost and time.

Given these benefits, clients are frequently willing to pay a premium for bright, clean work. To achieve these pristine results, vacuum heat treaters insist that incoming parts must be clean and oil-free. However, what qualifies as “clean” in a manufacturing environment rarely meets the exacting standards required for vacuum thermal processing. As a result, many commercial heat treaters adopt secondary cleaning measures to ensure part cleanliness and to protect their vacuum furnaces from contamination by machining oils, lubricants, Dykem, oxidation, or polishing compounds.

Figure 1. Vacuum degreasing furnace. Source: Solar Atmospheres

Pre-Heat Treatment Cleaning: Traditional Challenges

Before any vacuum heat treatment, components must be thoroughly cleaned to remove organic and inorganic contaminants. Common practices include solvent immersion, drying, and vapor degreasing. This cleaning step is designed to eliminate residues that can volatilize and redeposit within the vacuum furnace, potentially compromising part quality and damaging the vacuum furnace hot zone and cold wall.

However, commonly used cleaning agents are often flammable, toxic, environmentally regulated, and costly to dispose of when spent.

Figure 2. (Left) Vapor degreaser and solvent cleaning and (right) foil wrapping station. Source: Solar Atmospheres
Figure 3. As a defensive measure to prevent furnace damage from potential upstream sourced contaminants, parts ready for heating are wrapped in stainless steel foil. Source: Solar Atmospheres

Given that commercial heat treaters process parts from thousands of upstream operations, each introducing its own set of contaminants, cross-contamination becomes a significant risk. Stainless steel foil wrapping is often used as a defensive measure, isolating parts from the furnace environment. While wrapping is often effective, it can be labor-intensive, expensive, and even potentially hazardous. Even with the proper PPE, the foil edges are razor-sharp. Foil wrapping continues to be a top health and safety concern for employees.

The MIM Furnace: A Catalyst for Innovation

Five years ago, Solar Atmospheres of Western Pennsylvania was tasked with sintering pre-sintered metal injection molding (MIM) parts at 2200°F. The binders present in these firearm parts volatilized during processing and heavily contaminated the vacuum furnace, resulting in extensive downtime and maintenance.

Figure 4. Bright, clean 17-4PH stainless steel parts post heat treatment in a vacuum degreasing furnace. Source: Solar Atmospheres

Instead of constructing a traditional “cold trap” to capture volatiles, CEO William Jones developed a more innovative solution: a “hot trap” designed to divert and capture contaminants before they could deposit inside the furnace. This proactive adaptation has proven to drastically improve part quality while eliminating the laborious and frequent cleaning of hot zones and cold walls.

After that MIM job ended, the underutilized furnace prompted experimentation. This adapted furnace proved to perform well on unwanted binders. So, we set out to test how this same system could be adapted to remove impurities from everyday production parts. After extensive trials using noncritical PH-grade stainless steel components, a fully integrated, vacuum-based cleaning and aging cycle was perfected. This development has since replaced traditional expensive pre-cleaning methods and dangerous foil wrapping, producing consistently clean and bright 17-4 PH aerospace components.

The Self-Cleaning Vacuum Furnace: How It Works

The key innovation lies in a dual roughing pump configuration.

(Left) Figure 5. Two-stage pumping system. (Right) Figure 6. Heated exit port on Pumping System #1.
Source: Solar Atmospheres

Pumping System #1 — Initial Pump-Down and Contaminant Removal:

  • Components are loaded into the furnace unwrapped and uncleaned.
  • Only Roughing Pump #1 is activated during the initial pump-down.
  • A slow temperature ramp allows contaminants to vaporize and exit the hot zone through a heated port into Pump #1.
  • Contaminants are safely trapped in the pump’s oil — the “hot trap.”

Pumping System #2 — Transition to Heat Treatment:

  • After off gassing is complete, Pump #1 is isolated.
  • Pump #2 system, which includes a roughing pump, booster, diffusion, and holding pump, takes over.
  • The chamber is then brought to 1 x 10⁻⁵ Torr and the standard vacuum thermal cycle proceeds.

This two-stage pumping sequence cleans both the parts and the chamber prior to heat treatment without ever opening the furnace door.

Results and Benefits

This newly developed vacuum furnace and process produces the following:

  • Cleaner parts: Vacuum cleaning penetrates blind holes, threads, and keyways more effectively than traditional solvent or vapor degreasing methods.
  • Injury reduction: The process eliminates the need for hazardous foil wrapping, significantly improving employee safety.
  • Environmental and cost advantages: The process reduces or eliminates chemical solvent use, cuts labor associated with pre-cleaning and wrapping, and reduces hazardous waste and disposal costs.
  • Furnace maintenance improvements: Hot zones and cold walls remain pristine — no weekly teardowns. Pump #1 oil is changed biweekly, eliminating roughing pump seizure concerns due to contaminated oil.

Conclusion: A Breakthrough in Vacuum Processing

Historically, part cleanliness in vacuum heat treating has been a persistent challenge — one often addressed through costly labor, chemicals, and dangerous stainless steel or titanium foil wrapping. Solar Atmospheres’ innovative dual-pump vacuum cleaning system, integrated seamlessly with a standard vacuum heat treatment cycle, redefines industry best practices.

This “self-cleaning furnace” concept not only delivers superior part finishes but also enhances safety, reduces environmental impact, and cuts operating costs. In a world where precision, cleanliness, and sustainability matter more than ever, this advancement may very well create a revolution in clean vacuum processing.

About The Author:

RObert (Bob) Hill PresidentSolar Atmospheres Michigan Source: Solar Atmospheres
Robert (Bob) Hill, FASM
President
Solar Atmospheres of Western PA and Michigan
Source: Solar Atmospheres

Bob Hill, FASM, president of Solar Atmospheres of Western PA and Michigan, began his career with Solar Atmospheres in 1995 at the headquarters plant located in Souderton, Pennsylvania. In 2000, Mr. Hill was assigned the responsibility of starting Solar Atmospheres’ second plant, Solar Atmospheres of Western PA, in Hermitage, Pennsylvania, where he has specialized in the development of large furnace technology and titanium processing capabilities. Additionally, he was awarded the prestigious Titanium Achievement Award in 2009 by the International Titanium Association. In 2022, Bob became president of his second plant, Solar Atmospheres of Michigan.

For more information: Contact Solar Atmospheres or visit www.solaratm.com.

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Un Giro Bienvenido: Autolimpieza en Hornos revolucionado por Sistema de Bombas Inteligentes

/ AEROSPACE HEAT TREAT TECHNICAL CONTENT, VACUUM FURNACES TECHNICAL CONTENT, VACUUM PUMPS GAUGES VALVES TECHNICAL CONTENT

¿Y si su horno de vacío pudiera limpiarse automáticamente? En esta entrega de Technical Tuesday, Bob Hill, FASM, presidente de Solar Atmospheres of Western PA and Michigan, explora una revolucionaria configuración de bomba de vacío doble que elimina la necesidad de disolventes, envoltura con lámina metálica y prelimpieza manual.

Este artículo informativo se publicó por primera vez en Heat Treat Today’s December 2025 Annual Medical & Energy Heat Treat print edition. Traducido por Víctor Zacarías.

To read this article in English, click here.

Introducción

Los hornos de vacío requieren un entorno excepcionalmente limpio para procesar componentes críticos, desde dispositivos médicos hasta componentes aeroespaciales. Sin embargo, la limpieza de componentes, laboriosa y que consume mucho tiempo para garantizar la pulcritud del horno y las piezas, no tiene por qué ser necesariamente realizada por personas. Con las bombas adecuadas, su horno de vacío puede limpiarse automáticamente. Descubra cómo sería un ciclo de limpieza al vacío totalmente integrado mediante una innovadora configuración de doble bomba de vacío primario.

En el ámbito del tratamiento térmico al vacío, donde los componentes críticos suelen tener una forma casi final con una mínima o nula eliminación de material, la estética superficial del producto final es fundamental para el usuario final. En sectores como el aeroespacial, el de dispositivos médicos y el de generación de energía, el procesamiento al vacío se ha vuelto cada vez más valioso, no solo por su precisión, sino también por su capacidad para eliminar operaciones posteriores, lo que en última instancia ahorra tiempo y dinero.

Dadas estas ventajas, los clientes suelen estar dispuestos a pagar un precio premium por un trabajo limpio y brillante. Para lograr estos resultados perfectos, las empresas de tratamiento térmico al vacío exigen que las piezas recibidas estén limpias y libres de aceite. Sin embargo, lo que se considera “limpio” en un entorno de fabricación rara vez cumple con los exigentes estándares requeridos para el procesamiento térmico al vacío. Por ello, muchos tratadores térmicos adoptan medidas de limpieza secundarias para garantizar la limpieza de las piezas y proteger sus hornos de vacío de la contaminación por aceites de maquinado, lubricantes, tintas, oxidación o compuestos de pulido.

Figura 1. Horno de desengrasado al vacio. Fuente: Solar Atmospheres

Limpieza previa al tratamiento térmico: desafíos tradicionales

Antes de cualquier tratamiento térmico al vacío, los componentes deben limpiarse a fondo para eliminar contaminantes orgánicos e inorgánicos. Las prácticas habituales incluyen inmersión en disolvente, secado y desengrasado por vapor. Esta limpieza tiene como objetivo eliminar los residuos que pueden volatilizarse y depositarse dentro del horno de vacío, lo que podría comprometer la calidad de la pieza y dañar la zona caliente y la pared fría del horno.

Sin embargo, los productos de limpieza de uso común suelen ser inflamables, tóxicos, estar sujetos a regulaciones ambientales y su eliminación resulta costosa una vez empleados.

Figura 2. (Izquierda) Desengrasante de vapor y limpieza con solvente y (derecha) estación de envoltura con papel aluminio. Fuente: Solar Atmospheres
Figura 3. Como medida de protección para evitar daños en el horno por posibles contaminantes procedentes de fuentes anteriores, las piezas listas para el tratamiento térmico se envuelven en papel de aluminio. Fuente: Solar Atmospheres

Dado que las plantas de tratamiento térmico comerciales procesan piezas procedentes de miles de operaciones previas, cada una con su propio conjunto de contaminantes, la contaminación cruzada representa un riesgo significativo. El embalaje con lámina de acero inoxidable se utiliza a menudo como medida de protección, aislando las piezas del ambiente del horno. Si bien el empaque suele ser eficaz, puede ser laborioso, costoso e incluso potencialmente peligroso. Aun con el equipo de protección personal adecuado, los bordes de la lámina son extremadamente filosos. El embalaje con lámina sigue siendo una de las principales preocupaciones en materia de salud y seguridad para los empleados.

El horno para MIM: el catalizador para la innovación

Hace cinco años, Solar Atmospheres, con sede en el oeste de Pensilvania, recibió el encargo de sinterizar piezas pre-sinterizadas mediante moldeo por inyección de metal (MIM) a 1200 °C. Los aglutinantes presentes en estas piezas de armas de fuego se volatilizaron durante el proceso y contaminaron gravemente el horno de vacío, lo que ocasionó largos periodos de inactividad y mantenimiento.

Figura 4. Piezas de acero inoxidable 17-4PH brillantes y limpias tras el tratamiento térmico en un horno de desengrasado al vacío. Fuente: Solar Atmospheres

En lugar de construir una trampa fría tradicional para capturar los volátiles, el director ejecutivo, William Jones, desarrolló una solución más innovadora: una trampa caliente diseñada para desviar y capturar los contaminantes antes de que se depositaran dentro del horno. Esta adaptación proactiva ha demostrado mejorar drásticamente la calidad de las piezas, eliminando la laboriosa y frecuente limpieza de las zonas calientes y las paredes frías.

Tras finalizar ese trabajo de MIM, el horno subutilizado impulsó la experimentación. Este horno adaptado demostró un buen rendimiento con aglutinantes no deseados. Así pues, nos propusimos probar cómo adaptar este mismo sistema para eliminar impurezas de piezas de producción diaria. Tras exhaustivas pruebas con componentes no críticos de acero inoxidable grado PH, se perfeccionó un ciclo de limpieza y envejecimiento totalmente integrado, basado en vacío. Este desarrollo ha sustituido desde entonces a los costosos métodos tradicionales de prelavado y al peligroso envoltorio en aluminio, produciendo componentes aeroespaciales 17-4 PH consistentemente limpios y brillantes.

Horno de vacío autolimpiante: Cómo funciona

La innovación clave reside en una configuración de doble bomba de vacío primario.

(Izquierda) Figura 5. Sistema de bombeo de dos etapas.
(Derecha) Figura 6. Salida calefactada del sistema de bombeo n.° 1.
Fuente: Solar Atmospheres

Sistema de bombeo n.° 1: Bombeo inicial y eliminación de contaminantes:

  • Los componentes se cargan en el horno sin envolver ni limpiar.
  • Durante el bombeo inicial, solo se activa la bomba de vacío primario n.° 1.
  • Un aumento gradual de la temperatura permite que los contaminantes se vaporicen y salgan de la zona caliente a través de un puerto calefactado hacia la bomba n.° 1.
  • Los contaminantes quedan atrapados de forma segura en el aceite de la bomba, la «trampa caliente».

Sistema de bombeo n.° 2: Transición al tratamiento térmico:

  • Una vez completado el bombeo, se aísla la bomba n.° 1.
  • El sistema de bombeo n.° 2, que incluye una bomba de vacío primario, una bomba de refuerzo, una bomba de difusión y una bomba de mantenimiento, entra en funcionamiento.
  • A continuación, la cámara se lleva a 1 x 10⁻⁵ Torr y se inicia el ciclo térmico de vacío estándar.

Esta secuencia de bombeo en dos etapas limpia tanto las piezas como la cámara antes del tratamiento térmico sin necesidad de abrir la puerta del horno.

Resultados y beneficios

Este horno de vacío y proceso recientemente desarrollados producen lo siguiente:

  • Piezas más limpias: La limpieza por vacío penetra en barrenos ciegos, roscas y chaveteros con mayor eficacia que los métodos tradicionales de desengrase con solventes o vapor.
  • Reducción de lesiones: El proceso elimina la necesidad de envolver con lámina metálica, lo que mejora significativamente la seguridad de los empleados.
  • Ventajas ambientales y económicas: El proceso reduce o elimina el uso de solventes químicos, disminuye la mano de obra asociada con la limpieza previa y el embalaje, y reduce los costos de disposición de residuos peligrosos.
  • Mejoras en el mantenimiento del horno: Las zonas calientes y las paredes frías se mantienen impecables, sin necesidad de desmontajes semanales. El aceite de la bomba n.° 1 se cambia cada dos semanas, lo que elimina los problemas de bloqueo de la bomba de vacío debido a la contaminación del aceite.

Conclusión: Un avance revolucionario en el procesamiento al vacío

Históricamente, la limpieza de las piezas en el tratamiento térmico al vacío ha sido un desafío constante, a menudo abordado con mano de obra costosa, productos químicos y el peligroso uso de lámina de acero inoxidable o titanio para su envoltura. El innovador sistema de limpieza al vacío de doble bomba de Solar Atmospheres, integrado a la perfección con un ciclo estándar de tratamiento térmico al vacío, redefine las mejores prácticas de la industria.

Este concepto de “horno autolimpiante” no solo ofrece acabados superiores en las piezas, sino que también mejora la seguridad, reduce el impacto ambiental y disminuye los costos operativos. En un mundo donde la precisión, la limpieza y la sostenibilidad son más importantes que nunca, este avance podría crear una revolución en el procesamiento al vacío limpio.

Acerca del autor:

RObert (Bob) Hill PresidentSolar Atmospheres Michigan Source: Solar Atmospheres
Robert (Bob) Hill, FASM
Presidente
Solar Atmospheres de Western Pensilvania y Michigan
Fuente: Solar Atmospheres

Bob Hill, FASM, presidente de Solar Atmospheres de Western Pensilvania y Michigan, comenzó su carrera en Solar Atmospheres en 1995 en la planta principal ubicada en Souderton, Pensilvania. En 2000, el Sr. Hill fue designado para la puesta en marcha de la segunda planta de Solar Atmospheres, Solar Atmospheres of Western PA, en Hermitage, Pensilvania, donde se especializó en el desarrollo de tecnología de hornos de gran tamaño y procesamiento de titanio. Además, en 2009 recibió el prestigioso Titanium Achievement Award de la International Titanium Association. En 2022, Bob asumió la presidencia de su segunda planta, Solar Atmospheres de Michigan.

Para más información: Contacte con Solar Atmospheres o visite www.solaratm.com.

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Harnessing the Sun: A Heat Treat Case Study with General Atomics

/ ENERGY HEAT TREAT, ENERGY HEAT TREAT TECHNICAL CONTENT, FEATURED NEWS, VACUUM FURNACES TECHNICAL CONTENT

OC Imagine this: A huge lab facility nestled in the south of France . . . teams of scientists and technicians striving to bring carbon-free energy solutions to the world . . . “replicating the high-energy fusion reaction that powers the sun and stars.” To complete the project, what heat treat solution is needed? Read more in this Technical Tuesday to find out.

This article by Rafal Walczak, product manager at SECO/VACUUM, will be published in Heat Treat Today’s December 2022 Medical & Energy print edition.

Introduction

For this case study, we will discuss how SECO/VACUUM built a highly specialized custom heat treating furnace used in the construction of the central component of a large, multinational science experiment.

The Experiment

ITER (standing for International Thermonuclear Experimental Reactor and meaning “the way” in Latin) is the largest high-energy science experiment ever conducted. At a giant lab facility in southern France 35 countries, hundreds of vendors, and thousands of scientists and technicians are collaborating on a device to demonstrate the feasibility of clean, safe, carbon-free energy production by replicating the high-energy fusion reaction that powers the sun and stars.

Figure 1. ITER Laboratory at the Cadarache research center in southern France
Source: ITER Organization

There are no solid materials that can touch, much less contain, such a high-energy reaction without immediately vaporizing. Instead, this super-hot cloud of plasma must be contained by a special configuration of magnets called a tokamak, which can trap charged particles in a toroidal or donut-shape cloud. This tokamak has 10 times more plasma containment volume than any other tokamak ever built.

The term “tokamak” comes to us from a Russian acronym that stands for “toroidal chamber with magnetic coils” (тороидальная камера с магнитными катушками).

The Magnet

Figure 2. ITER central solenoid and one isolated solenoid module
Source: General Atomics ITER Manufacturing

General Atomics’ Magnet Technologies Center near San Diego, CA was contracted to build the ITER tokamak’s large central magnet, the most powerful superconducting magnet ever built, strong enough to lift an aircraft carrier. Other magnets in the tokamak serve to contain the plasma. The central solenoid is an oscillating magnet responsible for inducing current in the plasma cloud similar to how an induction stove heats a pan, except it is heating the plasma to 15 times the temperature of the surface of the sun. Far too large to be constructed and transported in one piece, the 12-meter-tall, 4-meter-wide coil of wires must be built in six 2-meter-tall modules to be joined once they are all on site at the lab. A seventh module will be built as a spare.

Kenneth Khumthong, technical lead for final testing and fabrication certification for ITER Central Solenoid at GA, described the tests on each module of the magnet, saying, “We run a battery of tests on each and every module subjecting them to voltages as high as 30,000 volts and powering them with as much current as 40,000 amps. This is done to ensure that every module meets all of ITER’s specifications prior to shipping them out to France.”

Embrittlement vs. Field Strength Tradeoff

Other superconducting electromagnets in the ITER tokamak will be made using coils of relatively durable niobium-titanium alloy. Past experiments have demonstrated that magnetic fields greater than 12 Tesla disrupt the superconducting properties of Nb3Ti. The ITER central solenoid, however, must sustain magnetic field strengths above 13 Tesla. For this reason, the central solenoid coils must instead use niobium-tin as its superconducting wire, which more reliably maintains superconducting properties in such high magnetic fields but is also more brittle and too fragile to bend after reaction to Nb3Sn. In order to accommodate for the brittle wire, General Atomics had to first coil the wire and jacket into their final shape before heat treating the metals into their superconducting, albeit brittle, alloy Nb3Sn.

The Wire 

Figure 3. A dissection of the central solenoid conductor strands, central spiral, and structural jacket
Source: ITER Organization
  • Niobium-tin wire strands react to become Nb3
  • Copper strands serve as traditional conductors to safely dissipate stored energy when the superconductivity experiences a disruption. The copper strands do not react with the niobium-tin.
  • A central spiral maintains a hollow channel to circulate liquid helium to chill the Nb3Sn wires to 4°K, below their superconducting temperature of 12°
  • Creating such strong magnetic fields inside a coil of wire will also tear apart the coil of wire itself if that wire is not supported inside a high strength jacket. The ITER central solenoid wire bundle is about 38.5 mm diameter, housed inside a 50 x 50 mm stainless steel jacket.
  • Total maximum current in the superconductor wire is 48,000 amps.
  • Worldwide niobium production increased six-fold for several years just to meet the niobium demands of the ITER project.

The Heat Treating Furnace

Figure 4. Technicians ensure proper placement before lowering heat treat furnace
Source: General Atomics ITER Manufacturing

In order to convert the niobium-tin metal conductors into superconductors, each of these 4 meter by 2 meter 110 ton solenoid sections must be heat treated for five weeks, exceeding 1200°F (650°C) at its peak. The heat treatment serves to alloy the niobium and tin together into Nb3Sn, which becomes a superconductor when chilled with liquid helium to 4°Kelvin. No such heat treating furnaces existed, so General Atomics turned to SECO/VACUUM to build a custom heat treating furnace large enough to fit these solenoids and packed with all the technology needed to meet the strict quality control standards of this monumental experiment.

Five inch wide metal band heaters ring around the walls of the furnace with nearly 900kW of heating power. Covering 50% of the walls, they provide a very uniform heat. This is brought about by the following seven steps.

The Heat Treating Sequence

In addition to alloying the niobium-tin wires, the furnace also serves to remove the stresses in the stainless steel jacket housing the superconducting wire and to bake off any residual contaminants prior to reaching reaction temperature.

1. Complete a quality control test: Vacuum seal the untreated solenoid coil in the room temperature furnace and charge the inside of the conductor jacket with 30 bar high pressure helium to test for leaks after forming and welding.

  • Monitor furnace atmosphere with ultra-high sensitivity mass-spectrometer helium detectors.

2. Purge with argon gas while slowly ramping up heat.

  • This drives off hydrocarbons and oxygen before system reaches reaction temperatures.
  • Monitor furnace atmosphere with gas chromatograph to find impurities from residual oils and lubricants leftover from manufacturing process.
  • Monitor and control argon circulation and exchange with mass flow sensors and circulation blowers that penetrate the furnace lid with ferrofluidic feedthrough seals around the blower motor shafts.

3. Maintain at 1058°F (570°C) for about 10 days. Confirm stabilized temperature and pure atmosphere.

4. Proceed to 1202°F (650°C) for four days. This is the actual reaction phase that achieves the primary objective of converting the niobium-tin into the superconducting alloy Nb3

5. Very slowly and uniformly ramp back down to room temperature to avoid additional stresses in the coil.

6. Complete another quality control test: Evacuate the argon and once again vacuum seal the solenoid coil in the room temperature furnace and recharge with 30 bar high pressure helium to test for leaks after heat treating. Monitor atmosphere for the presence of helium, which would indicate a leak in the coil.

7. Only then is it ready for the post-heat treating stages of wrapping with insulation and encasing in epoxy resin for rigidity.

Options, Upgrades, Special Features

Figure 5. Cutaway illustration showing the furnace construction
Source: SECO/VACUUM

There was no room for error. SECO/VACUUM collaborated with the engineers at General Atomic to create a heat treat furnace that can assure temperature variation within the coil never varies by more than 18°F (10°C) anywhere in the furnace at any time in the five-week cycle and achieves near-perfect repeatability for all seven modules.

They accomplished this with quadruple-redundant control thermocouples and feeding temperature data from 150 points in the coil into the control computers. To shield against impurities, the furnace is first evacuated to a vacuum pressure of 0.001 Torr, and then purged with pure argon to drive out any residual oxygen or hydrocarbons that could contaminate the purity of the superconductor. Monitoring the argon atmosphere for impurities are redundant mass spectrometers. The argon is circulated by seven convection fans to heat the solenoid assembly evenly. Each of these fans must be driven through ferrofluidic feedthrough seals which allow the rotating shafts to operate through the furnace walls without compromising the vacuum seal of the furnace.

Consult, Collaborate, and Partner with SECO/VISORY

General Atomics first began discussing this project with Rafał Walczak, the product manager at SECO/VACUUM, in early 2010. Both teams spent over two years on conceptual discussions, preliminary designs, and process simulations before SECO was even awarded the contract. Once SECO was on board, it took another two years of design, fabrication, and installation before the furnace could be put into operation. SECO/VACUUM built it to handle a lifetime of use without error so they could be sure that it would work flawlessly for the seven cycles that it actually had to run.

The SECO/VISORY Heat Treat Advisory Council is a team of SECO/VACUUM heat treat experts and consultants with diverse thermal experience and process knowledge who are available to help companies solve their specific heat treat equipment challenges.

Rafal Walczak
Product Manager
SECO/VACUUM
Source: Rafal Walczak

About the Author: Rafal Walczak is the product manager at SECO/VACUUM. Rafal joined SECO/WARWICK Group as a service engineer in Vacuum Furnaces Division soon after graduation from Technical University of Zielona Góra in 2002. Since 2008, he has been involved in vacuum furnace sales in Europe and the USA. The combination of his technical background and field service experience help him provide outstanding support to his SECO/VACUUM customers. For more information, contact Rafal at Rafal.Walczak@SecoVacUSA.com.

Find heat treating products and services when you search on Heat Treat Buyers Guide.com

 

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