Control method and system for downhole gas-air heater

Claim 1

THE METHOD OF CONTROLLING THE FLOW OF AIR AND GAS TO A BURNER LOCATED IN A BOREHOLE COMPRISING FLOWING A PREDETERMINED RATION OF AIR AND GAS TO A COMMON SURFACE MIXING CONDUIT TO FORM A COMBUSTILE MIXTURE THEREIN, FLOWING SAID COMBUSTIBLE MIXTURE TO SAID BURNER LOCATED IN SAID BOREHOLE, IGNITING SAID COMBUSTIBLE MIXTURE AT SAID BURNER TO CAUSE COMBUSTION THEREIN, CONTINUING THE FLOW OF THE COMBUSTIBLE MIXTURE TO SAID BURNER TO ELEVATE THE TEMPERATURE IN SAID BURNER TO ABOVE A PREDETERMINED MINIMUM, AFTER THEREAFTER STOPPING THE FLOW OF AIR TO SAID COMMIN SURFACE MIXING CONDUIT WHEN SAID TEMPERATURE IN SAID BURNER FALLS BELOW SAID PREDETERMINED MIMIMUM, AND SUBSTANTIALLY STOPPING THE FLOW OF SAID GAS TO SAID COMMON SURFACE CONDUIT IN RESPONSE TO THE STOPPING OF SAID AIR FLOW.