초록 ▼

A process for producing low-cost atmospheres suitable for annealing, brazing, and sintering non-ferrous metals and alloys from non-cryogenically produced nitrogen containing up to 5%, residual oxygen is disclosed. According to the process, suitable atmospheres are produced by 1) pre-heating the non-

A process for producing low-cost atmospheres suitable for annealing, brazing, and sintering non-ferrous metals and alloys from non-cryogenically produced nitrogen containing up to 5%, residual oxygen is disclosed. According to the process, suitable atmospheres are produced by 1) pre-heating the non-cryogenically produced nitrogen stream containing residual oxygen to a desired temperature, 2) mixing it with more than a stoichiometric amount a hydrocarbon gas, 3) passing it through a reactor packed with a platinum group of metal catalyst to reduce the residual oxygen to very low levels and convert it to a mixture of moisture and carbon dioxide, and 4) using the reactor effluent stream for annealing, brazing, and sintering non-ferrous metals and alloys in a furnace. The key features of the disclosed process include 1) pre-heating the non-cryogenically produced nitrogen containing residual oxygen to a certain minimum temperature, 2) adding more than a stoichiometric amount of a hydrocarbon gas to the pre-heated nitrogen stream, and 3) using a platinum group of metal catalyst to initiate and sustain the reaction between oxygen and the hydrocarbon gas.

대표청구항 ▼

A process for generating an atmosphere for use in a heat treating furnace used for annealing, brazing, or sintering non-ferrous metals and alloys comprising the steps of: pre-heating a non-cryogenically produced nitrogen stream containing up to 5% by volume residual oxygen to a temperature between 2

A process for generating an atmosphere for use in a heat treating furnace used for annealing, brazing, or sintering non-ferrous metals and alloys comprising the steps of: pre-heating a non-cryogenically produced nitrogen stream containing up to 5% by volume residual oxygen to a temperature between 200°C. and 400°C.; mixing the pre-heated non-cryogenically produced nitrogen stream with a hydrocarbon gas said hydrocarbon gas present in an amount in excess of that required for stoichiometric conversion of oxygen contained in said nitrogen stream; passing said mixture over a platinum group metal catalyst contained in a reactor; recovery from said reactor an effluent consisting essentially of nitrogen containing carbon dioxide, moisture, unreacted hydrocarbons and less than 10 ppm oxygen; and introducing said effluent into the furnace used to heat treat metals and alloys where the presence of unreacted hydrocarbons, carbon dioxide and moisture in the nitrogen will not affect inerting properties of the nitrogen.