Method for controlling the temperature of exothermic reactions such as the gasification of carbonaceous solids

Claim 1

IN THE HIGH-TEMPERATURE TREATMENT OF SUBDIVIDED SOLIDS WITH GASES REACTING EXOTHERMICALLY WITH SAID SOLIDS TO FORM A PRODUCT GAS AND A SOLID REACTION PRODUCT IN A REACTION ZONE WHEREIN SAID SOLIDS ARE MAINTAINED IN THE FORM OF A DENSE, TURBULENT MASS FLUIDIZED BY UPWARDLY FLOWING GASES, PRODUCT GAS CONTAINING A SUBSTANTIAL PROPORTION OF SOLIDS ENTRAINED IS WITHDRAWN UPWARDLY FROM SAID MASS AND PASSED UPWARDLY THROUGH A SECOND FLUIDIZED SOLIDS MASS MAINTAINED AT A TEMPERATURE SUBSTANTIALLY BELOW SAID HIGH TEMPERATURE BY MEANS OF HEAT EXCHANGE WITH A COOLING AGENT AND SOLIDS ARE RETURNED FROM SAID SECOND MASS TO SAID REACTION ZONE, THE IMPROVEMENT WHICH COMPRISES FEEDING FRESH SOLIDS TO SAID FIRST NAMED MASS RETURNING SOLIDS AT SAID LOWER TEMPERATURE FROM SAID SECOND MASS TO SAID FIRST NAMED MEANS AT A RATE CONTROLLED TO LIMIT SAID HIGH TEMPERATURE AT A DESIRED MAXIMUM LEVEL BY A DIRECT HEAT EXCHANGE BETWEEN SAID RETURNED SOLIDS AND SAID FIRST NAMED MASS, WITHDRAWING PRODUCT GAS UPWARDLY FROM SAID SECOND MASS AND RECOVERING SOLID REACTION PRODUCT FROM SAID SECOND MASS INDEPENDENTLY OF SAID PRODUCT GAS.