PREPARATION AND ORGANISATION FOR THE RESISTANCE OF A CONTROLLED ATMOSPHERE

摘要

1511973 Controlled gas atmospheres S Z VASILIEV I I MAERGOIZ L A MIKHAILOV and L I PUSHKAREV 1 July 1976 [1 July 1975 3 July 1975] 27541/76 Heading C5E Controlled gas atmospheres are produced by supplying a starting product on to a catalyst heated externally by the combustion products of a hydrocarbon gas, the starting product being a mixture of an additionally fed hydrocarbon gas and at least a portion of the combustion products of the hydrocarbon gas employed for heating the catalyst. The process may be conducted in an apparatus of the type shown in Fig. 1 which comprises an airtight lined casing 1 provided with a wall-mounted burner 2 for combustion of a hydrocarbon gas. Preparation of an air-gas mixture is effected in a gas-mixing unit including an air filter 3, an air flow meter 4, a hydrocarbon gas flow meter 5, a controller 6 for adjusting the ratios between the air and hydrocarbon gas flow rates and valves 7 and 8 setting these ratios. Air and hydrocarbon gas are supplied in the directions indicated by arrows A and B respectively. Upstream of the burner 2 there are successively mounted along the air-gas mixture path, a gas blower 9, a control valve 10 and a fire screen 11. The hydrocarbon gas combustion products are removed from the pipe 12 in the direction of arrow C. The catalyst 14 is contained in bucket 13 which bucket has a perforated bottom 15 connected with an outlet pipe 16 for the obtained controlled atmosphere. Inlet pipe 18 is for supplying the hydrocarbon gas on to the catalyst in the direction of the arrow D. A cooler 19 for the controlled atmosphere communicates with outlet pipe 16, the resulting controlled atmosphere being evacuated in the direction of arrow E. Thermocouple 20 is provided in the heating space 17 to measure the process temperature. The controlled atmospheres are of particular use in the heat treatment of metals and alloys.