Semi-make and heat regenerative process and apparatus

Claim 1

A CYCLIC PROCESS FOR THE PRODUCTION OF UNSATURATED HYDROCARBONS FROM SUITABLE HYDROCARBON STARTING MATERIAL WHICH COMPRISES PASSING A NON-FLAMMABLE FIRST MIXTURE OF A HYDROCARBON STARTING MATERIAL AND A FREE-OXYGENCONTAINING GAS THROUGH A PLURALITY OF STRAIGHT FLUES, UNINTERRUPTED THROUGHOUT THIER LENGTH, OF A FIRST REGENERATIVE ZONE FROM THE COOLER TO THE HOTTER END THEREOF, SAID FIRST REGENERATIVE ZONE HAVING PREVIOUSLY BEEN SO HEATED THAT THE TEMPERATURE OF THE HOTTER END THEREOF, SAID FIRST INITIATE THERMAL ALTERATION OF SAID STARTING MATERIAL, THEREBY EFFECTING INCIPIENT ENDOTHERMAL ALTERATION OF SAID STARTING MATERIAL TO PRODUCE A SECOND FLAMMABLE MIXTURE, PASSING SAID SECOND FLAMMABLE MIXTURE INTO AN EXOTHERMICCOMBUSTION AND ENDOTHERMIC ALTERATION ZONE WHEREIN PART OF SAID SECOND MIXTURE IS SUBJECTED TO EXOTHERMIC COMBUSTION AND SUBSTANTIALLY THE REMAINDER OF THE HYDROCARBON STARTING MATERIAL IS SUBJECTED TO ENDOTHERMIC ALTERATION, PASSING THE EXOTHERMIC COMBUSTION AND ENDOTHERMIC ALTERATION PRODUCTS THROUGH A PLURALITY OF STRAIGHT FLUES, UNINTERRUPTED THROUGHOUT THEIR LENGTH, OF A SECOND REGENERATIVE ZONE FROM THE HOTTER TO THE COOLER END THEREOF, INTERRUPTING THE FLOW OF SAID NON-FLAMMABLE FIRST MIXTURE WHEN THE TEMPERATURE OF THE HOTTER END OF SAID FIRST REGENERATIVE ZONE FALLS BELOW THE ENDOTHERMAL ALTERATION TEMPERATURE OF SAID HYDROCARBON STARTING MATERIAL AND RE-