Apparatus for maintaining a carburizing atmosphere during heat treatment

Claim 1

A SYSTEM FOR MAINTAINING A CARBURIZING ATMOSPHERE FOR WORK UNDERGOING HEAT TREATMENT AND FOR CARBURIZING WORK UP TO AT LEAST 1.2% CARBON WITHOUT SOOT DEPOSITION COMPRISING: A FURNACE PROVIDED WITH HEAT-GENERATING MEANS AND A TREATING CHAMBER HEATED BY SAID HEAT-GENERATING MEANS AND ADAPTED TO RECEIVE WORK TO BE HEAT TREATED UNDER A PROTECTIVE ATMOSPHERE OF THE CARBURIZING TYPE, A FAN DISPOSED WITHIN SAID TREATING CHAMBER ADJACENT A WALL THEREOF, DRIVING MEANS FOR SAID FAN FOR PRODUCING VIOLENT AGITATION AND CIRCULATION OF THE GASES FORMING THE FURNACE ATMOSPHERRE WITHIN SAID TREATING CHAMBER AT HIGH RATES OF FLOW TO ESTABLISH THERMAL EQUILIBRIUM THROUGHOUT SAID WORK CHAMBER AND TO MAINTAIN CHEMICAL EQUILIBRIA BETWEEN THE CONSTITUENTS OF SAID ATMOSPHERE AND THE SURFACE OF THE WORK, CONDUIT MEANS HAVING BOTH AN INLET AND AN OUTLET IN COMMUNICATION WITH SAID TREATING CHAMBER AND FORMING A CLOSED EXTERNAL RECIRCULATION PATH FOR WITHDRAWAL AND RETURN OF ATMOSPHERE TO AND FROM THE TREATING CHAMBER, MEANS INCLUDING A GAS COMPRESSOR IN SAID CONDUIT MEANS HAVING ITS INLET CONNECTED TO SAID OUTLET FROM SAID TREATING CHAMBER AND ITS OUTLET CONNECTED TO SAID INLET TO SAID TREATING CHAMBER FOR MOVEMENT OF FURNACE ATMOSPHERE THROUGH SAID CLOSED EXTERNAL RECIRCULATION PATH, VALVE MEANS ASSOCIATED WITH SAID CONDUIT MEANS FOR REGULATING THE RATE OF FLOW OF THE STREAM OF FURNACE ATMOSPHERE TO BE RECIRCULATED, MEANS FOR COOLING SAID STREAM PRIOR TO ITS ARRIVAL AT SAID GAS COMPRESSOR, FILTERING MEANS INCLUDED IN SAID CONDUIT MEANS FOR REMOVING FROM SAID STREAM, AFTER COOLING THEREOF, SOLID AND LIQUID MATERIALS,

Claim 2

A SYSTEM FOR MAINTAINING A CARBURIZING ATMOSPHERE FOR WORK UNDERGOING HEAT TREATMENT AND FOR CARBURIZING WORK UP TO AT LEAST 1.2% CARBON WITHOUT SOOT DEPOSITION COMPRISING: A FURNACE PROVIDED WITH HEAT-GENERATING MEANS AND A TREATING CHAMBER HEATED BY SAID HEAT-GENERATING MEANS AND ADAPTED TO RECEIVE WORK TO BE HEAT TREATED UNDER A PROTECTIVE ATMOSPHERE OF THE CARBURIZING TYPE, A FAN DISPOSED WITHIN SAID TREATING CHAMBER ADJACENT A WALL THEREOF, DRIVING MEANS FOR SAID FAN FOR PRODUCING VIOLENT AGITATION AND CIRCULATION OF THE GASES FORMING THE FURNACE ATMOSPHERRE WITHIN SAID TREATING CHAMBER AT HIGH RATES OF FLOW TO ESTABLISH THERMAL EQUILIBRIUM THROUGHOUT SAID WORK CHAMBER AND TO MAINTAIN CHEMICAL EQUILIBRIA BETWEEN THE CONSTITUENTS OF SAID ATMOSPHERE AND THE SURFACE OF THE WORK, CONDUIT MEANS HAVING BOTH AN INLET AND AN OUTLET IN COMMUNICATION WITH SAID TREATING CHAMBER AND FORMING A CLOSED EXTERNAL RECIRCULATION PATH FOR WITHDRAWAL AND RETURN OF ATMOSPHERE TO AND FROM THE TREATING CHAMBER, MEANS INCLUDING A GAS COMPRESSOR IN SAID CONDUIT MEANS HAVING ITS INLET CONNECTED TO SAID OUTLET FROM SAID TREATING CHAMBER AND ITS OUTLET CONNECTED TO SAID INLET TO SAID TREATING CHAMBER FOR MOVEMENT OF FURNACE ATMOSPHERE THROUGH SAID CLOSED EXTERNAL RECIRCULATION PATH, VALVE MEANS ASSOCIATED WITH SAID CONDUIT MEANS FOR REGULATING THE RATE OF FLOW OF THE STREAM OF FURNACE ATMOSPHERE TO BE RECIRCULATED, MEANS FOR COOLING SAID STREAM PRIOR TO ITS ARRIVAL AT SAID GAS COMPRESSOR, FILTERING MEANS INCLUDED IN SAID CONDUIT MEANS FOR REMOVING FROM SAID STREAM, AFTER COOLING THEREOF, SOLID AND LIQUID MATERIALS,