Combustion method and apparatus

In a combustion method wherein carbonaceous fuel and air are passed through an oxidation catalyst body to provide an effluent which traverses a downstream zone adjacent to and downstream of said body, the improvement comprising:

• directing jets of burning gaseous fuel into said downstream zone from a multiplicity of points distributed within or alongside said downstream zone to obtain combustion of said gaseous fuel in said jets substantially throughout a cross section of said downstream zone.

In a combustion method wherein carbonaceous fuel and air are passed through an oxidation catalyst body to provide an effluent which traverses a downstream zone adjacent to and downstream of said body, the improvement comprising:

• directing jets of burning gaseous fuel into said downstream zone from a multiplicity of points distributed within or alongside said downstream zone to effect coalescing of said jets and intermixing thereof in said downstream zone with substantially all of said effluent from the catalyst body.

In a method for catalytically-supported, thermal combustion wherein upon attainment of sustained operating conditions carbonaceous fuel and air in intimate admixture are combusted in an oxidation catalyst body the operating temperature of which is substantially above the instantaneous auto-ignition temperature of said fuel-air admixture but below a temperature that would result in any substantial formation of oxides of nitrogen, the improvement comprising:

• passing a mixture of said carbonaceous fuel and air in contact with said catalyst body to provide an effluent which traverses a downstream zone adjacent to and downstream of said body;
• and
• directing jets of burning gaseous fuel into said downstream zone from a multiplicity of points distributed within or alongside said downstream zone to effect coalescing of said jets and intermixing thereof in said downstream zone with substantially all of said effluent from the catalyst body.

In a method for catalytically-supported, thermal combustion wherein upon attainment of sustained operating conditions carbonaceus fuel and air in intimate admixture are combusted under essentially adiabatic conditions in an oxidation catalyst body the operating temperature of which is substantially above the instantaneous auto-ignition temperature of said fuel-air admixture but below a temperature that would result in any substantial formation of oxides of nitrogen, the improvement comprising:

• passing a mixture of said carbonaceous fuel and air in contact with said catalyst body over a period of time, said period including an interval prior to attainment of sustained operating conditions during which said catalyst body is at a temperature below said operating temperature such that the effluent traversing a downstream zone adjacent to and downstream of said body contains substantial proportions of incompletely combusted carbonaceous fuel;
• and
• at least during said interval directing jets of burning gaseous fuel into said downstream zone from a multiplicity of points distributed within or alongside said downstream zone to effect coalescing of said jets and intermixing thereof in said downstream zone with substantially all of said effluent from the catalyst body, for assisting the combustion of said incompletely combusted carbonaceous fuel.