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FAQs: Atmosphere Envelope Furnaces

FAQs: Atmosphere Envelope Furnaces


What exactly is an atmosphere envelope furnace?

The furnace features a gas tight working chamber that can be operated at up to .022 atmospheric pressure. Glands seal the electrodes and thermocouples, and the door is sealed with silicone or viton material. The result is a sealed envelope that allows processing in inert gases or mixtures with up to 5 percent hydrogen.

What models can be supplied with atmosphere envelopes?

Deltech atmosphere envelope furnaces are available with several “door” choices: front load, bottom load, and top hat. Sizes range from bench top to production scale, with operating temperatures to 1800 degrees Celsius.


How is the atmosphere regulated?

Use the following procedure: Purge the furnace workspace for 20 minutes at 5 liters per minute (lpm). Start the furnace and lower the flow to 0.5 liters per minute to maintain a 150-200 mm/H2O pressure in the workspace. The furnace is fully sealed, so the gas could be turned off and the inlet closed. However, this presents the risk of aspiration during cool down after the gas has condensed.


Are the gases that form in the process continuously expelled with the flow of gas?

The gases are continuously expelled if operated in the manner described above.


How is the chamber filled and emptied?

There is a gas inlet that has a ceramic lead into the working chamber. The exhaust is at the top of the furnace. Both have pipe fittings for any desired connections; for example to an exhaust system.


Is the thermal process programmable?

Yes. And the gas flow is also programmable provided you purchase a gas mixing system with the furnace. Our gas mixing systems include mass flow controllers (0-1 standard liters per minute), a software driven digital control system with optional communications,


Does the gas mixing system include a fluid distribution header?

Fluid distribution headers are optional. They are customizable 316L manifolds with your choice of port interfaces and ball valves. Thay are particularly useful when dealing with pipe greater than one inch in diameter or if you have several different interfaces.

Contact our  engineering team to explore the best options for your application.


FAQs: Atmosphere Envelope Furnaces

Picture of atmosphere envelope furnace

Front load atmosphere envelope furnace

All Deltech furnace systems are designed and manufactured in the U.S.A, and shipped and installed worldwide.