Gas Injection System optimizes heat treatment furnaces.

Press Release Summary:

Designed to maximize productivity of heat treatment furnaces without use of circulation fans, CARBOJET® is suited for upgrading roller hearth, pusher, rotary-retort, and pit furnaces. Ultra-high-speed injection of gas or gas mixture through special CARBOJET lances optimizes gas and atmosphere flows and circulation. To satisfy NFPA safety requirements, nitrogen supply system for CARBOJET system can be equipped with safety solution used to purge flammable atmosphere furnaces.

Original Press Release:

New CARBOJET® Technology Improves Heat Treatment Furnace Efficiency and Productivity

Murray Hill & New Providence, N.J., U.S., – Patented CARBOJET® gas injection technology that can improve the productivity of heat treatment furnaces without the use of circulation fans will be introduced by Linde LLC for the first time at Heat Treat 2015, booth #248.

The gas mixing technology is ideal for upgrading a variety of furnaces including roller hearth, pusher, rotary-retort and pit furnaces. Ultra-high-speed injection of a gas or gas mixture through special CARBOJET lances improves gas and atmosphere flows and circulation. This includes both the better mixing of the injected gases with the furnace atmosphere, and better movement of gas flows within the furnace.

“CARBOJET® technology has already proven successful in many heat treatment operations in Europe because rapid gas injection and homogenous mixing are hallmarks of process efficiency and product quality.”

– Grzegorz Moroz, program manager, heat treatment and atmospheres, Linde LLC

Specific advantages will depend on the type of heat treatment furnace. In continuous furnaces, for example, CARBOJET gas-injection technology offers a variety of benefits including: improved carbon transfer and homogenization, more intensive heat transfer with improved convection, better residue burn off at front of furnace, reduced soot formation, better cooling zone performance and quicker conditioning when switching atmospheres.

Benefits at a Glance

  • For roller hearth furnaces:  With lances positioned at the inlet, improved heat transfer offers potential to increase productivity by 10 percent. Minimizes soot formation, improves reproducibility of gas analysis.  Potential to increase productivity in cooling zone up to 35 percent.

  • For rotary-retort furnaces:  Better atmosphere mixing, minimizes formation of soft spots, increases throughput, longer retort life. Offers potential to increase output of bulk goods by about 20 percent.  

  • For pit furnaces:  Atmosphere circulation fan could be eliminated, uniform heating and more uniform carburizing, annealing, nitriding leads to up to 20 percent more efficient use of furnace space and productivity gain; can eliminate vibration damage to heating elements, furnace lid design extends lid life up to three times longer.

The nitrogen supply system for the CARBOJET system can also be equipped with a Linde-designed safety solution used to purge flammable atmosphere furnaces to satisfy National Fire Protection Association (NFPA) safety requirements for furnaces (NFPA 86).

Linde offers decades of experience in heat treatment across all common furnace types from continuous to batch type furnaces, including roller hearth, pusher, pit or rotary-retort. Expertise spans all typical protective atmospheres -- from pure nitrogen, pure hydrogen, nitrogen/hydrogen, nitrogen/hydrocarbon type atmospheres to endothermic gas, exothermic gas and monogas atmospheres.

Linde, a leading global industrial gases company, provides industry-leading portfolio solutions for the ferrous and non-ferrous metallurgy industries, ranging from gases and equipment to process consulting and services. For more information, contact Linde North America (, 800-755-9277.  

About Linde in North America

Linde LLC is a member of The Linde Group. In the 2014 financial year, The Linde Group generated revenue of  USD 17.9 bn (EUR 17.047 bn), making it the largest gases and engineering company in the world with approximately 65,500 employees working in more than 100 countries worldwide. The strategy of The Linde Group is geared towards long-term profitable growth and focuses on the expansion of its international business with forward-looking products and services. Linde acts responsibly towards its shareholders, business partners, employees, society and the environment – in every one of its business areas, regions and locations across the globe. The company is committed to technologies and products that unite the goals of customer value and sustainable development.

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Linde Contact:

Amy Ficon

Corporate Communications

908-771-1491, Fax 908-771-1460

Vinita Abraham

Corporate Communications


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