Guest Column

Is It Stuffy in Here? Exhaust Systems

/ ATMOSPHERE AIR FURNACES TECHNICAL CONTENT, BURNERS & COMBUSTION SYSTEMS TECHNICAL CONTENT, GUEST COLUMN, Manufacturing Heat Treat Technical Content, OP-ED

In each installment of Combustion Corner, Jim Roberts, president of U.S. Ignition, reinforces the goal of the series: providing informative content to “furnace guys” about the world of combustion. The previous column examined the air supply inlet — the inhale, and this month, Jim is examining the exhaust system — the exhale, and how to inspect it, maintain it, and manage it.

This informative piece was first released in Heat Treat Today’s March 2025 Aerospace print edition.

A guy walks into a room full of furnace guys and says, “Is it just me, or is it a tad stuffy in here?”

We have all been able to imagine that it is hard to focus and do your job in an environment where it seems like it’s hard to breathe. Well, our hard workin’ buddy, the furnace, is continually stuck in a cycle of trying to breathe in, breathe out — and then somewhere in between, the magic of combustion and heat happens! We talked last month about the “breathe in” part of the combustion process. This month, we are going to remind you that if you take a really good, productive, inhaled, life giving breath, you are probably going to want to exhale at some point, too!

Tip 2: Ensure Exhaust Systems Are Properly Functioning and Clean

Inhale, exhale. It makes sense that if we were earlier having issues with the air supply inlet, the exhaust should also be checked. Today’s combustion equipment is sophisticated and sensitive to pressure fluctuations. If the exhaust is restricted, the burners will struggle to get the proper input to the process. I used to use the example of trying to spit into a soda bottle. Try it. It’s tough to do and invariably will not leave you happy. Clean exhaust also minimizes any chance of fire. Read on for three examples.

A. Check the Flues and Exhausts for Soot

If you are responsible for burners that are delivering indirect heat (in other words, radiant tubes), you have a relatively easy task ahead to check the flues/exhausts. Each burner usually has its own exhaust, and one can see if the burners are running with fuel-rich condition (soot/carbon). Soot is not a sign of properly running burners and will signal trouble ahead. Soot can degrade the alloys at a chemical level. Soot can catch fire and create a hot spot in the tubes. Soot obviously signals you are using more fuel than needed (or your combustion blower is blocked, see the first column in this series).

As a furnace operator or floor person, it should be normal operating procedure to look for leakage around door seals.

Here’s a sub tip: If you cannot see the exhaust outlets directly, look around the floor and on the roof of the furnace up by the exhaust outlets. Light chunks of black stuff is what is being ejected into the room when it breaks free from the burner guts (if it can). That will tell you it’s time to tune those burners. If you do not have a good oxygen/flue gas analyzer, get one. It can be pricey, but it will pay for itself in a matter of months in both maintenance and fuel savings.

B. Seriously … Check the Flues and Leakage Around Door Seals

If you are running direct-fired furnace equipment, or furnaces that have the flue gases mixed from multiple burners, it gets a little trickier. All the same rules apply for not wanting soot. Only now, it can actually get exposure to your product, it can saturate your refractory, and it can clog a flue to the point that furnace pressure is affected. An increase in furnace pressure can test the integrity of your door seals. It can back up into the burners and put undue and untimely wear and tear on burner nozzles, ignitors, flame safety equipment, etc. As a furnace operator or floor person, it should be normal operating procedure to look for leakage around door seals.

C. Utilize Combustion Service Companies

Ask the wizards. Combustion service companies can usually help you diagnose and verify flue issues if you suspect they exist. It’s always a great idea to set a baseline for your combustion settings. Service companies can help you establish the optimum running conditions. Again, money well spent to optimize the performance of your furnaces. I’m sure you already have a combustion service team; some are listed in this publication. Otherwise, consult the trade groups like MTI and IHEA for recommended suppliers of that valuable service.

Check flues monthly. It should be a regular walk around maintenance check.

Don’t let the next headline be your plant. See you next issue.

About The Author:

Jim Roberts
President
US Ignition

Jim Roberts, president at US Ignition, began his 45-year career in the burner and heat recovery industry directed for heat treating specifically in 1979. He worked for and helped start up WB Combustion in Hales Corners, Wisconsin. In 1985 he joined Eclipse Engineering in Rockford, IL, specializing in heat treating-related combustion equipment/burners. Inducted into the American Gas Association’s Hall of Flame for service in training gas company field managers, Jim is a former president of MTI and has contributed to countless seminars on fuel reduction and combustion-related practices.

Contact Jim Roberts at jim@usignition.com.

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Most SMBs Unprepared for CMMC 2.0, Risk Losing Contracts 

/ CYBERSECURITY, GUEST COLUMN, OP-ED

“The Cybersecurity Maturity Model Certification (CMMC) 2.0 aims to improve cybersecurity across the defense industrial base (DIB), but many small to mid-sized businesses (SMBs) struggle to meet the standards, putting them at risk of losing crucial contracts.” In this Cybersecurity Desk column, Joe Coleman, cybersecurity officer at Bluestreak Compliance, a division of Bluestreak | Bright AM™, raises the alarm if small to mid-sized heat treaters neglect compliance standards and guides companies through the minefield of cyber threats facing all SMBs.

Read more Cybersecurity Desk columns in previous Heat Treat Today’s issues here.

Despite an increasing cyber threat landscape, many small to mid-sized businesses (SMBs) in the Department of Defense (DoD) supply chain remain unprepared for compliance with NIST SP 800-171 R2 and CMMC 2.0. The Cybersecurity Maturity Model Certification (CMMC) 2.0 aims to improve cybersecurity across the defense industrial base (DIB), but many SMBs struggle to meet the standards, putting them at risk of losing crucial contracts. Surveys suggest that nearly 70% of SMBs are unready for the new requirements, and the real figure could be even higher due to some businesses inaccurately reporting compliance by inflating their assessment scores. 

Understanding CMMC 2.0 

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CMMC 2.0 simplifies the original five-tier framework into three levels: 

  • Level 1: Basic cyber hygiene for contractors handling Federal Contract Information (FCI). 
  • Level 2: Advanced practices for those working with Controlled Unclassified Information (CUI). 
  • Level 3: Stringent requirements for contractors involved in national security projects. 

Compliance is mandatory for any contractor bidding on DoD contracts, including those working indirectly for federal contractors and subcontractors. SMBs should anticipate customers clients inquiring to inquire about their compliance as these standards will soon impact their business relationships. Achieving compliance is a lengthy process, typically taking 12 to 18 months. 

Low Readiness and Risks 

The lack of readiness among SMBs threatens both business continuity and national security. Many smaller contractors lack the resources and expertise to meet CMMC 2.0’s standards. Given the defense sector’s reliance on a wide variety of contractors, this gap could create widespread repercussions. 

Financial Implications of Non-Compliance 

Irreversible consequences from waiting to comply

Compliance with CMMC 2.0 can be financially burdensome. Implementing measures such as multi-factor authentication, encryption and continuous monitoring can be costly, especially for businesses with limited resources. The lack of in-house cybersecurity expertise compounds this issue, requiring companies to hire or train specialized personnel, further increasing costs. 

Failing to comply with CMMC 2.0 could result in losing valuable DoD contracts, which can be a significant portion of SMB revenue. Such losses could lead to layoffs, revenue declines or even business closures. 

Challenges to Compliance 

Several challenges contribute to the widespread unpreparedness among SMBs: 

  • Unclear timelines: Uncertainty surrounding DoD’s compliance timelines complicates planning and prioritization for SMBs. 
  • Complexity of requirements: While CMMC 2.0 simplifies the original framework, its specific requirements remain difficult to interpret for many SMBs, particularly in identifying necessary security measures. 
  • Resource limitations: The cost of achieving and maintaining compliance strains smaller businesses, which often lack the budgets for the required technology and expertise. 
  • Lack of cybersecurity expertise: A shortage of qualified personnel poses a significant obstacle, as demand for cybersecurity professionals is high across industries. 

Government Support Initiatives 

To help SMBs, the DoD has introduced various programs, including training, grants and educational resources. A phased implementation timeline also provides additional preparation time. However, industry experts suggest that further support, such as tax credits or subsidies, could help SMBs offset the costs of compliance. Clearer guidance from the DoD would also be beneficial in helping businesses navigate the certification process. 

Path Forward for SMBs 

Click image to download a list of cybersecurity acronyms and definitions.

To secure future contracts, SMBs must prioritize cybersecurity. This involves conducting internal risk assessments, identifying vulnerabilities, and creating compliance plans. Partnering with cybersecurity experts or managed service providers can help SMBs develop cost-effective strategies. Additionally, leveraging government resources and adopting critical security measures early will better position SMBs for CMMC 2.0 certification. 

Conclusion 

The widespread lack of preparedness for CMMC 2.0 poses significant risks to both SMBs and the defense supply chain. As deadlines approach, proactive measures from both businesses and the government are necessary to close the readiness gap and ensure the continued participation of SMBs in the defense sector. 

About the Author

Joe Coleman
Cyber Security Officer
Bluestreak Consulting
Source: Bluestreak Consulting

Joe Coleman is the cybersecurity officer at Bluestreak Compliance, which is a division of Bluestreak | Bright AM™. Joe has over 35 years of diverse manufacturing and engineering experience. His background includes extensive training in cybersecurity, a career as a machinist, machining manager and an early additive manufacturing (AM) pioneer. Joe presented at the Furnaces North America (FNA 2024) convention on DFARS, NIST 800-171, and CMMC 2.0.

For more information: Contact Joe at joe.coleman@go-throughput.com.

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Understanding Inductance in a Furnace Heating System

/ CONTROLS TECHNICAL CONTENT, Manufacturing Heat Treat Technical Content, OP-ED, VACUUM FURNACES TECHNICAL CONTENT

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.

This informative piece was first released in Heat Treat Today’s November 2024 Vacuum Heat Treat print edition.

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.

For more information: Contact Brian at bturner@romanmfg.com.

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Maintenance Message: Extending the Service Life of Refractory Linings

/ ALUMINUM PROCESSING TECHNICAL CONTENT, GUEST COLUMN, MANUFACTURING HEAT TREAT TECH

Heat treating aluminum presents a unique concern due to the operating conditions of high temperature, chemical corrosion, mechanical abrasion, and temperature variation. Guest columnist Roger M. Smith, director of technical services at Plibrico Company, LLC, examines the critical role the refractory lining plays in the success of manufacturing aluminum, why a refractory is susceptible to cracking under extreme conditions, and how to select and prepare refractory linings to achieve a longer service life.

This informative piece was first released in Heat Treat Today’s August 2024 Automotive print edition.

A significant concern when manufacturing aluminum metal is the practical service life of the furnace. The service life is driven by the refractory lining’s ability to resist the various operating conditions within the furnace, such as high temperature, temperature variation, chemical corrosion, and mechanical abrasion. Ideally, a single refractory composition would be capable of withstanding all these conditions and readily available at a low price.
Unfortunately, this is rarely the case.

Proper refractory selection is often about finding the best balance between price, properties, and performance for the given application and operating conditions. A refractory capable of high strength and abrasion resistance is often susceptible to cracking caused by extreme temperature variations, commonly referred to as thermal shock. However, a material capable of withstanding thermal shock without catastrophic cracking may be vulnerable
to chemical corrosion. Finding the best balance of material properties for each zone in each furnace is important for maximizing the service life of a furnace.

Figure 1. Schematic showing refractory lining in an aluminum furnace

Refractory Under Attack — Requirements for Melting Aluminum

The refractory lining in an aluminum furnace (Figure 1) must endure various chemical reactions that occur while the furnace is in operation. There are three separate regions to consider: above, below, and at the melt line. Above the melt line, the refractory must withstand attack from various alkali vapors. Alkali vapors can be produced from flux used in the aluminum and from the combustion products used to heat the furnace. Below the melt line, the refractory must withstand molten aluminum. At the melt line, the region commonly referred to as the bellyband area, there is a triple point where the refractory, atmosphere, and aluminum interact.

The refractory below the melt line comes in direct contact with liquid aluminum when the furnace is in operation. This contact can create a chemical reaction zone where oxides on the surface of the refractory can be reduced, such as silica (SiO2) to form silicon. Conversely, aluminum can penetrate into the refractory lining either through the same redox reactions or through infiltration due to capillary forces.

Aluminum forms corundum (Al2O3) when it oxidizes. This results in a change of the crystal structure from face-centered cubic to hexagonal, which causes a significant volume expansion. When corundum is formed inside the refractory lining, the change in volume creates cracks, which lead to more infiltration and more cracks until the refractory lining ultimately fails.

Wetting the Refractory

One method for reducing the reaction zone is to prevent the aluminum from “wetting” the refractory (see Figure 2). A liquid’s ability to “wet” a surface is defined by the contact angle of the liquid. When the contact angle between the liquid and the surface is greater than 90 degrees, then the liquid is said to wet the surface. When the contact angle is less than 90 degrees, the liquid does not wet the surface. A liquid that does not wet the surface is analogous to water beading on a car that has been freshly waxed. When aluminum does not wet a refractory, it is not able to react with the refractory and is not able to penetrate the lining.

Figure 2. Contact angle of the liquid demonstrating wetting vs. non-wetting

Various additives can be used to reduce aluminum’s tendency to wet a refractory. Some of the most used additives include barium, boron, or fluoride. They modify the surface chemistry of the refractory and reduce aluminum’s ability to react and penetrate. Using additives such as these greatly extends the effective service life of a refractory lining.

While non-wetting additives can be beneficial to extending the service life in areas where there is contact with molten aluminum, there are no benefits when not in aluminum contact. They do not protect from alkali attacks above the melt line. They do not enhance the abrasion resistance of the material. They do not improve the thermal shock resistance of the material. Furthermore, these additives are volatile. When exposed to temperatures above 1700°F (927°C), they begin to lose their effectiveness because they chemically react with other materials in the refractory and change. The additives can also be costly, which raises the price of the refractory compared to one with the same composition but without the additive.

The presence of non-wetting additives can have some negative effects on a refractory. Tests have shown that a 1% addition of a fluoride additive in a conventional castable can reduce the hot modulus of rupture (HMOR) by as much as 30% at 2000°F (1093°C). The effect can be even more significant in a low-cement castable. The loss in hot strength is likely attributed to the formation of a glassy phase induced by the additive. Fluoride and boron are both well-known glass formers and will form a glassy phase at the grain boundaries at high temperatures, which reduces the bond strength between individual grains and the overall strength of the bulk material.

Figure 3. Refractory lining

Balancing Refractory Properties

The advantages and disadvantages of a refractory material should be considered when selecting materials for an aluminum furnace. The sidewalls of a furnace all come in direct contact with molten aluminum.

The upper sidewalls must be scraped to remove aluminum that splashes up to prevent corundum growth. The refractory selected for its sidewalls should be abrasion resistant to protect from mechanical scraping and non-wetting to protect from corundum growth. The hearth and well are submerged in aluminum, but they do not see the same level of abrasion as the sidewalls. The sub-hearth may see some molten aluminum but must also provide support, so a strong, non-wetting refractory should be used.

The door and sill will experience temperature fluctuations every time the door is opened, and they will be exposed to abrasion as the furnace is charged. Materials that are resistant to thermal shock and abrasion should be selected. The roof and superstructure need to be strong and resistant to alkali vapors. Backup insulation should be selected to reduce heat loss, but it should be of a composition that has moderate resistance to molten aluminum in case of refractory failure at the hot face.

In all these zones, the operating conditions of the specific furnace must be considered, and the balance of properties must be adjusted case-by-case. The primary failure modes must be identified, and materials should then be adjusted accordingly.

The Key to Refractory Selection

The operating conditions in an aluminum furnace require a refractory lining with different benefits in different zones. At the furnace door, the refractory can experience drastic fluctuations in temperature that can cause cracking. The upper sidewalls will develop scale that has to be scraped off, so the refractory needs to be abrasion resistant.

The lower sidewalls come in direct contact with molten aluminum and need to resist chemical attacks and aluminum penetration to avoid corundum growth. Finding a cost-effective refractory that can meet all these requirements is very difficult, but it can be done with sufficient research. Careful material selection that considers the needs and operating conditions of a particular furnace is important for maximizing the service life of a refractory lining.

About the Author:

Roger M. Smith
Director of Technical Services
Plibrico Company, LLC
Source: Plibrico

Roger Smith is a seasoned professional in the refractory industry. With a master’s degree in Ceramic Engineering from the University of Missouri – Rolla, Roger has over 15 years of experience in the processing, development, and quality assurance of both traditional and advanced ceramics. He has a proven track record in developing innovative ceramic formulations, scaling up processes for commercial production, and optimizing manufacturing operations.

For more information: Visit www.plibrico.com.

This article was initially published in Industrial Heating. All content here presented is original from the author.

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Dual Chamber Vacuum Furnaces vs. Single Chamber Vacuum Furnaces — An Energy Perspective

/ FEATURED NEWS, GUEST COLUMN, Manufacturing Heat Treat Technical Content, OP-ED, VACUUM FURNACES TECHNICAL CONTENT

The need to understand how certain furnace designs operate comes at a time when heat treaters are weighing each energy cost and benefit of their systems and processes. Read on for a quick summary on how dual chamber furnaces preserve energy.

On April 17-19, 2024, TAV VACUUM FURNACES provided a speaker at the 4th MCHTSE (Mediterranean Conference on Heat Treatment and Surface Engineering). The speech focused on the energy aspects of vacuum heat treatment, a subject towards which all of us within the industry need to pay attention for reducing the carbon emissions aiming at a zero net emissions future.

We have already analyzed the essential role that vacuum furnaces will play in this transition, with a focus on the optimization of energy consumption in our previous article. With this new presentation, we wanted to emphasize how selecting the right vacuum furnace configuration for specific processes may impact the energy required to perform such process. For doing so, we compared two different furnace designs — single chamber vs. dual chamber vacuum furnaces — detailing all of the components’ energy consumption for a specific process.

TAV DC4, dual chamber vacuum furnace for low pressure carburizing and gas quenching
Source: TAV VACUUM FURNACES

As a sneak peek into our presentation, we will summarize below how the main features of the two vacuum furnaces design are affecting their energy performance.

Let’s start by introducing the protagonist of our comparison: a single chamber, graphite insulated vacuum furnace, model TAV H4, and a dual chamber furnace TAV DC4, both having useful volume 400 x 400 x 600 mm (16” x 16” x 24”) (w x h x d).

In a single chamber vacuum furnace, like the TAV H4, the entire process is carried out with the load inside the furnace hot zone. This represents a highly flexible configuration that can perform complex heat treatment recipes with a multiple sequence of heating and cooling stages and to precisely control the temperature gradients at each stage.

Configuration of the TAV DC4 dual chamber vacuum furnace
Source: TAV VACUUM FURNACES

Alternatively, a dual chamber vacuum furnace, like the TAV DC4, is equipped with a cold chamber, separated from the hot zone, dedicated for quenching. Despite the greater complexity of this type of vacuum furnace, the dual chamber configuration allows for several benefits.

First, in dual chamber furnaces, the graphite insulated hot chamber is never exposed to ambient air during loading and unloading of the furnace; for this reason, the hot chamber may be pre-heated at the treatment temperature (or at a lower temperature, to control the heating gradient). But in single chamber vacuum furnaces, the hot zone must always be loaded and unloaded at room temperature to avoid damages due to heat exposure of graphite to oxygen.

Because dual chamber furnaces have more controlled heating, this will result in both faster heating cycles and lower energy consumption, as a substantial amount of energy is required to heat up the furnace hot zone. This advantage obviously will be more relevant in terms of energy savings the shorter the time is between subsequent heat treatments.

View of the cold chamber of the TAV DC4 dual chamber vacuum furnace
Source: TAV VACUUM FURNACES

Secondly, since the quenching phase is performed in a separated chamber, the hot zone insulation can be improved in dual chamber vacuum furnaces by increasing the thickness of the graphite board without compromising cooling performance. This translates into a significantly lower heat dissipation, to the extent that at 2012°F (1100°C) the power dissipation per surface unit (kW/m2) is reduced by 25% compared to an equivalent single chamber vacuum furnace.

Additionally, quenching in a dedicated cold chamber allows to obtain higher heat transfer coefficients and higher cooling rates compared to a single chamber vacuum furnace. Since the cold chamber is dedicated solely to the quenching phase, it can be designed for optimizing the cooling gas flow only without the need to accommodate all the components required for heating. All things considered, the heat transfer coefficient achievable in the TAV DC4 can be, all other things being equal, even 50% higher compared to a single chamber vacuum furnace. Secondly, since the cold chamber remains at room temperature throughout the whole process, only the load and loading fixtures need to be cooled down; as a result, the amount of heat that needs to be dissipated is significantly less compared to the single chamber counterpart.

CFD simulation showing a study on the cooling gas speed in a section of the cooling chamber for the TAV DC4 dual chamber vacuum furnace
Source: TAV VACUUM FURNACES

For heat treatments requiring high cooling rates, it is possible to process significantly higher loads on the dual chamber furnace compared to the single chamber model; translated into numbers, the dual chamber model can effectively quench as much as double processable in a single chamber furnace, depending on the alloy grade, load configuration and overall process. The savings in terms of energy consumption per unit load (kWh/kg) achievable in the dual chamber furnace for such processes can be as high as 50% compared to the single chamber furnace.

In the end, the aim of the speech was to highlight how the energy efficiency of vacuum furnaces is highly dependent on the machine-process combination. Choosing the right vacuum furnace configuration for a specific application, instead of relying solely on standardised solutions, will improve significantly the energy efficiency of the heat treatment process and drive the return on investment.

About the Author

Giorgio Valseccchi
R&D Manager
TAV VACUUM FURNACES

Giogio Valsecchi has been with the company TAV VACUUM FURNACES for nearly 4 years, after having studied mechanical engineering at Politecnico di Milano. 

For more information: Contact Giorgio at info@tav-vacuumfurnaces.com.

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