TANGENTIALLY GAS-FIRED MUFFLE

摘要

A tangentially gas fired muffle comprises a hinged annular housing defining inner and outer annular chambers divided by a ring of heat resistant perforate or expanded material. The outer annular chamber has inlets in the form of immersion tubes each locating an atmospheric burner, and outlet ports for discharging the products of the previous burner or burners. The perforate or expended metal ring contains the combustion process in the outer annular chamber and also acts as a radiant for dissipating heat on a circumferential weld of two pipe section. The gas burners are connected to a control console for supplying the burners continuously with gas at respective high and low flow rates. Solenoid valves, connected to temperature controllers, provide the burners continuously with gas at respective high and low flow rates. Energy regulators control the rate of heating. A self-holding relay and a gas pressure responsive switch provide a safety feature for isolating the electrical and gas supplies in the event of a supply failure.