Circulation of air or gas in heat treatment furnace - by pumping in cooled gas which is heated by outflowing gas

摘要

In order to maintain a uniform temp. throughout a heat treatment furnace it is necessary to circulate the air inside the furnace. This is usually done by means of a fan but it is extremely difficult to operate fans at heat treatment temps. of 1200 degrees C. Problem is solved by extracting the air or other gas forming the furnace atmosphere at the outlets and passing this gas through a heat exchanger to heat the incoming gas. The incoming gas is delivered by a pump which draws its supply from the gas which has passed through the cooler.