Method of producing heat treatment atmosphere

Claim 1

A method of producing a gaseous composition suitable for use as an atmosphere in heat treating metals, said composition being produced by a partial oxidation reaction between air and ethanol, said method comprising reacting a gaseous mixture consisting essentially of air and ethanol, the weight ratio of air to ethanol being between 1.0 and 3.0, said mixture being heated at a temperature between 1400° F. and 1850° F. in a bed of particles providing a surface conducive to said reaction, said reaction being for a period of time to form a substantially soot-free gaseous product containing substantially no oxygen and comprising hydrogen, carbon monoxide, carbon dioxide, methane, and water, said product containing at least 5 percent by volume methane and at least 3 percent by volume carbon dioxide, cooling the product gas to a temperature below 100° F. to minimize soot formation, and removing any water that condenses and introducing said product gas into a furnace containing metal to be treated and maintained at a temperature at which metal is suitably heat treated, whereby said product gas undergoes further reaction within said furnace that lowers the methane and carbon dioxide concentrations to produce a nonoxidizing atmosphere suitable for heat treating said metal.

Claim 2

A method of producing a gaseous composition suitable for use as an atmosphere in heat treating metals, said composition being produced by a partial oxidation reaction between air and ethanol, said method comprising reacting a gaseous mixture consisting essentially of air and ethanol, the weight ratio of air to ethanol being between 1.0 and 3.0, said mixture being heated at a temperature between 1400° F. and 1850° F. in a bed of particles providing a surface conducive to said reaction, said reaction being for a period of time to form a substantially soot-free gaseous product containing substantially no oxygen and comprising hydrogen, carbon monoxide, carbon dioxide, methane, and water, said product containing at least 5 percent by volume methane and at least 3 percent by volume carbon dioxide, cooling the product gas to a temperature below 100° F. to minimize soot formation, and removing any water that condenses and introducing said product gas into a furnace containing metal to be treated and maintained at a temperature at which metal is suitably heat treated, whereby said product gas undergoes further reaction within said furnace that lowers the methane and carbon dioxide concentrations to produce a nonoxidizing atmosphere suitable for heat treating said metal.

Claim 3

A method of producing a gaseous composition for use as an atmosphere for carburizing, said composition being produced by a partial oxidation reaction between air and ethanol, said method comprising reacting a gaseous mixture consisting of air and ethanol, the weight ratio of air to ethanol being less than about 2, said mixture being heated at a temperature between 1400° F. and 1850° F. in a bed of particles providing a surface conducive to the reaction, said reaction being for a period of time to form a substantially soot-free gaseous product containing substantially no oxygen and comprising hydrogen, nitrogen, carbon monoxide, carbon dioxide, methane, and water, said product containing at least 5 percent by volume methane and at least 3 percent by volume of carbon dioxide, cooling the product gas to a temperature of about 40° F. or lower to minimize soot formation and removing any water that condenses out, and introducing said product gas into a furnace containing metal to be treated and maintained at a temperature at which metal is suitably heat treated, whereby said gaseous product undergoes further reaction within said furnace that lowers the methane and carbon dioxide concentrations to produce an atmosphere suitable for carburizing said metal.

Claim 4

A method of producing a gaseous composition for use as an atmosphere for carburizing, said composition being produced by a partial oxidation reaction between air and ethanol, said method comprising reacting a gaseous mixture consisting of air and ethanol, the weight ratio of air to ethanol being less than about 2, said mixture being heated at a temperature between 1400° F. and 1850° F. in a bed of particles providing a surface conducive to the reaction, said reaction being for a period of time to form a substantially soot-free gaseous product containing substantially no oxygen and comprising hydrogen, nitrogen, carbon monoxide, carbon dioxide, methane, and water, said product containing at least 5 percent by volume methane and at least 3 percent by volume of carbon dioxide, cooling the product gas to a temperature of about 40° F. or lower to minimize soot formation and removing any water that condenses out, and introducing said product gas into a furnace containing metal to be treated and maintained at a temperature at which metal is suitably heat treated, whereby said gaseous product undergoes further reaction within said furnace that lowers the methane and carbon dioxide concentrations to produce an atmosphere suitable for carburizing said metal.

Claim 5

The method of producing a gaseous composition by a partial oxidation reaction between air and ethanol, said composition being suitable for use as an atmosphere in heat treating metals, said method comprising the steps of reacting a mixture consisting of air and ethanol in a proportion of ethanol-to-air greater than that which is stoichiometrically capable of complete combustion, the reaction being carried out at a temperature greater than 1300° F. in an externally heated bed of particles providing a surface conducive to the reaction and for a period of time sufficient to form a product gas comprising predominately unreacted nitrogen, hydrogen and carbon monoxide and containing at least 5 percent by volume methane, at least 3 percent by volume carbon dioxide, and water; but containing substantially no oxygen and substantially no soot, and introducing the product gas into a furnace containing metal for treatment and maintained at a suitable temperature therefor, said product gas undergoing further reaction within said furnace that lowers the methane and carbon dioxide to suitable heat treatment level and thereby providing a nonoxidizing atmosphere conducive to said heat treatment.

Claim 6

The method of producing a gaseous composition by a partial oxidation reaction between air and ethanol, said composition being suitable for use as an atmosphere in heat treating metals, said method comprising the steps of reacting a mixture consisting of air and ethanol in a proportion of ethanol-to-air greater than that which is stoichiometrically capable of complete combustion, the reaction being carried out at a temperature greater than 1300° F. in an externally heated bed of particles providing a surface conducive to the reaction and for a period of time sufficient to form a product gas comprising predominately unreacted nitrogen, hydrogen and carbon monoxide and containing at least 5 percent by volume methane, at least 3 percent by volume carbon dioxide, and water; but containing substantially no oxygen and substantially no soot, and introducing the product gas into a furnace containing metal for treatment and maintained at a suitable temperature therefor, said product gas undergoing further reaction within said furnace that lowers the methane and carbon dioxide to suitable heat treatment level and thereby providing a nonoxidizing atmosphere conducive to said heat treatment.

Claim 7

The method of producing a gaseous composition by a partial oxidation reaction between air and ethanol, said composition being suitable for use as an atmosphere in heat treating metals, said method comprising the steps of reacting a mixture consisting of air and ethanol in a proportion of ethanol-to-air greater than that which is stoichiometrically capable of complete combustion, the reaction being carried out at a temperature greater than 1400° F. but less than 1850° F. in an externally heated bed of particles providing a surface conducive to the reaction and for a period of time sufficient to form a product gas comprising predominately unreacted nitrogen, hydrogen and carbon monoxide, and containing at least 5 percent by volume methane, at least 3 percent by volume carbon dioxide, and water; but containing substantially no oxygen and substantially no soot, cooling the product gas to minimize soot formation and removing water as necessary to reduce the dew point of the product gas to below 100° F. and introducing the cooled product gas into a furnace containing metal for treatment and maintained at a suitable temperature therefor, said product gas undergoing further reaction within said furnace that lowers the methane and carbon dioxide to suitable heat treatment level and thereby providing a nonoxidizing atmosphere conducive to said heat treatment.

Claim 8

The method of producing a gaseous composition by a partial oxidation reaction between air and ethanol, said composition being suitable for use as an atmosphere in heat treating metals, said method comprising the steps of reacting a mixture consisting of air and ethanol in a proportion of ethanol-to-air greater than that which is stoichiometrically capable of complete combustion, the reaction being carried out at a temperature greater than 1400° F. but less than 1850° F. in an externally heated bed of particles providing a surface conducive to the reaction and for a period of time sufficient to form a product gas comprising predominately unreacted nitrogen, hydrogen and carbon monoxide, and containing at least 5 percent by volume methane, at least 3 percent by volume carbon dioxide, and water; but containing substantially no oxygen and substantially no soot, cooling the product gas to minimize soot formation and removing water as necessary to reduce the dew point of the product gas to below 100° F. and introducing the cooled product gas into a furnace containing metal for treatment and maintained at a suitable temperature therefor, said product gas undergoing further reaction within said furnace that lowers the methane and carbon dioxide to suitable heat treatment level and thereby providing a nonoxidizing atmosphere conducive to said heat treatment.