Treatment gas and system for its generation

Claim 1

A PROCESS FOR PREPARING A GASEOUS COMPOSITION FOR THE TREATMENT OF FOOD PRODUCTS, COMPRISING INTERMIXING A HYDROCARBON FUEL WAS SELECTED FROM THE GROUP CONSISTING OF NATURAL GAS, PROPANE AND BUTANE AND MIXTURES THEREOF, WITH FROM 85% TO 95% OF THE AMOUNT OF AIR REQUIRED FOR COMPLETE COMBUSTION OF SAID FUEL GAS, BURNING SAID FUEL GAS IN A COMBUSTION ZONE AT A TEMPERATURE BETWEEN ABOUT 1250*F. AND 1700*F. IN CONTACT WITH THE INNER SURFACE OF A SURROUNDING REFRACTORY MATERIAL, SAID FUEL GAS BEING RETAINED IN SAID COMBUSTION ZONE UNTIL THE GASEOUS PRODUCT OF COMBUSTION IS FREE OF HYDROCARBONS, COOLING SAID HYDROCARBON-FREE GASEOUS PRODUCT OUTSIDE OF SAID COMBUSTION ZONE WITH A COOLING MEDIUM AND CONTACTING THE OUTER SURFACE OF SAID REFRACTORY MATERIAL WITH SAID COOLED HYDROCARB ON-FREE GASEOUS PRODUCT WHEREBY SUBSTANTIALLY THE ENTIRE INNER SURFACE OF SAID REFRACTORY IS MAINTAINED AT A TEMPERATURE BETWEEN ABOUT 1250*F. AND 1700*F. DURING BURNING OF SAID FUEL GAS.