Fluidized bed oxidation of waste liquors resulting from the digestion of cellulosic materials for paper making

Claim 1

A PROCESS OF TREATING WASTE PULPING LIQUOR CONTAINING ORGANIC AND INORGANIC MATERIALS IN A REACTING VESSEL CONTAINING A LOWER FLUIDIZED BED OF SOLID PARTICLES CONSISTING SUBSTANTIALLY ENTIRELY OF RESIDUAL INORGANIC MATERIALS DERIVED FROM THE WASTE PULPING LIQUOR, WITH THE VESSEL HAVING AN UPPPER FREEBOARD AREA, SAID PROCESS COMPRISING: (A) CONCENTRATING SAID WASTE PULPING LIQUOR BY EVAPORATION UNTIL THE SOLIDS PORTION OF THE LIQUOR, AS DISTINGUISHED FROM THE LIQUID PORTION OF THE LIQUOR, IS APPROXIMATELY 20 TO 45 PERCENT AND HAS A COMBUSTIBLE CONTENT OF HEATING VALUE SUFFICIENT TO SUPPORT AUTOGENOUS COMBUSTION; (B) SPRAYING SAID CONCENTRATED LIQUOR INTO THE FREEBOARD AREA OF SAID VESSEL IN AN ATOMIZED FORM SUCH THAT SUBSTANTIAL EVAPORATION OF THE LIQUOR IS ACHIEVED IN THE FREEBOARD AREA OF THE VESSEL AND THE REAMINING ATOMIZED ADDITIONALLY CONCENTRATED LIQUOR SPRAY FLOWS INTO THE FLUIDIZED BED AREA; (C) MAINTAINING SAID BED FLUIDIZED BY INTRODUCING INTO THE FLUIDIZED BED AREA OF SAID VESSEL, AT A LINEAR VELOCITY OF APPROXIMATELY 1 TO 5 FEET PER SECOND, FLUIDIZING GAS CONTAINING OXYGEN SUFFICIENT TO EFFECT SUBSTANTIALLY COMPLETE ELIMINATION OF THE ORGANIC MATERIALS OF SAID LIQUOR AS GASEOUS PRODUCTS BY SUBSTANTIALLY TOTAL OXIDATIVE AUTOGENOUS COMBUSTION BETWEEN THE OXYGEN AND THE ORGANIC MATERIALS IN THE LIQUOR, SAID COMBUSTION BEING EFFECTED PRIMARILY IN THE FLUIDIZED-BED AREA WITH LITTLE COMBUSTION IN THE FREEBOARD AREA; (D) MAINTAINING SAID FLUIDIZED BED AT A NONSMELTING TEMPERATURE BELOW THE EUTECTIC TEMPERATURE OF THE RESIDUAL CHEMICAL MIXTURE OF THE BED BUT IN THE TEMPERATURE RANGE OF APPROXIMATELY 1,000* TO 1,800*F. DURING SAID SPRAYING AND COMBUSTION TO FORM IN THE FLUIDIZED BED, FROM THE RESIDUAL INORGANIC MATERIALS OF SAID LIQUOR, AGGLOMERATES HAVING SUFFICIENT WEIGHT TO PREVENT SUBSTANTIAL ENTRAINMENT THEREOF IN THE FLUIDIZING GAS AND GASEOUS PRODUCTS OF COMBUSTION ABOVE THE FLUIDIZED BED; (E) DISCHARGING SAID AGGLOMERATES DIRECTLY FROM THE FLUIDIZED-BED AREA OF THE VESSEL; AND (F) DISCHARGING SAID GASEOUS PRODUCTS OF COMBUSTION DIRECTLY FROM THE FREEBOARD AREA OF THE VESSEL.