Method for multiple zone treating of waste gas streams

Claim 1

IN THE DISCHARGE TO THE ATMOSPHERE OF A WASTE GAS STREAM CONTAINING OXIDAZABLE GASEOUS COMPOUNDS, THE METHOD WHICH COMPRISES PASSING SAID STREAM THROUGH A BED OF SOLID OXIDIZING CATALYST AND THEREIN BURNING AT LEAST A PORTION OF SAID OXIDIZALE COMPOUNDS, THEREBY GENERATING HEAT, PASSING THE RESULTANT HOT COMBUSTION PRODUCTS THROUGH A SECOND BED OF RELATIVELY INERT SOLID MATERIAL TO HEAT THE LATTER, CONTAINING THE PASSAGE OF THE WASTE GAS STREAM THROUGH THE CATALYST BED AND THE PASSAGE OF HOT COMBUSTION PRODUCTS FROM THE CATALYST BED THROUGH SAID SECOND BED UNTIL THE SECOND BED HAS BEEN HEATED BY THE COMBUSTION PRODUCTS TO A TEMPERATURE SUFFICIENT TO SUSTAIN NON-CATALYTIC COMBUSTION OF SAID OXIDIZABLE COMPOUNDS, THEN DISCONTINUING THE PASSAGE OF THE WASTE GAS STREAM THROUGH SAID CATALYST BED AND INTRODUCING THE SAME, WITHOUT SUBSTANTIAL BEATING THEREOF, TO SAID SECOND BED, PASSING THE THUS DIVERTED WASTE GAS STREAM THROUGH THE SECOND BED AND THEREIN BURNING OXIDIZABLE COMPONENTS THEREOF BY THE HEAT IMPORTED TO SAID SECOND BED FROM SAID HOT COMBUSTION PRODUCTS AND WITHOUT THE APPLICATION OF EXTRANEOUS HEAT TO THE DIVERTED GAS STREAM, THE FLOW OF THE WASTE GAS STREAM BEING DIVERTED GAS STREAM, THE FLOW OF TO SAID SECOND BED AND FROM THE SECOND BED TO THE CATALYST BED IN RESPONSE TO TEMPERATURE VARIATIONS IN THE SECOND BED.