Burners for use in bore holes in the ground

Claim 1

A BURNER FOR HEATING A SUB-SURFACE DEPOSIT FOR RECOVERY OF VALUABLE PRODUCTS AND CONSTITUTED OF A BURNER TUBE ADAPTED TO BE LOWERED INTO A VERTICAL HOLE FORMED IN THE GROUND AND PENETRATING FROM THE SURFACE INTO THE DEPOSIT, SAID BURNER TUBE COMPRISING A FEEDER PORTION CONNECTABLE WITH ITS UPPER END TO A SOURCE OF A MIXTURE CONTAINING FUEL AND OXYGEN AND MERGING AT ITS LOWER END INTO A DOWNWARDLY CONICALLY TAPERING PORTION CONSTITUTING THE ZONE OF COMBUSTION OF SAID MIXTURE DURING NORMAL OPERATION OF THE BURNER, AND AN EXHAUST PORTION HAVING A CONTINUOUSLY EQUAL CROSS-SECTIONAL AREA OF THE SAME SIZE AS, AND CONNECTED TO THE WIDEST CROSS-SECTIONAL AREA OF THE CONICALLY TAPERING PORTION, THE EXHAUST PORTION CONSTITUTING A PASSAGE OF FLOW IN A DOWNWARD DIRECTION FOR THE FLUE GASES PRODUCED IN THE CONICALLY TAPERING PORTION BY THE COMBUSTION OF SAID MIXTURE, A CASING SURROUNDING SAID EXHAUST PORTION AND FEEDER PORTION, AND AT ITS BASE IN OPEN COMMUNICATION WITH THE OPEN BASE OF THE EXHAUST PORTION TO CONSTITUTE A FLOW PASSAGE IN AN UPWARD DIRECTION TO AND ABOVE THE SURFACE OF THE GROUND FOR THE FLUE GASES LEAVING THE OPEN BASE END OF THE EXHAUST PORTION, SAID CASING CONTAINING A BODY OF SOLID GRANULAR PARTICLES PROVIDING PARTICLES BETWEEN THE LOWER PART THEREOF AND THE LOWER PART OF THE BURNER TUBE IN FLOATING CONDITION BY UPWARDLY MOVING FLUE GASES WITHIN A ZONE SUBSTANTIALLY COINCIDING WITH THAT PART OF THE DEPOSIT TO BE HEATED, CHARACTERIZED BY SAID EXHAUST PORTION BEING SUBDIVIDED AT A SLIGHT DISTANCE FROM THE CONICALLY TAPERING PORTION INTO TWO INDIVIDUAL END-TO-END COMMUNICATING PARTS OF WHICH A FIRST PART IS INTEGRAL WITH SAID CONICALLY TAPERING PORTION AND A SECOND PART FORMED AS A SEPARATE MEMBER, MEANS TO KEEP SAID TWO PARTS OF THE EXHAUST PORTION IN END-TO-END ABUTTING AND SEALING CONNECTION WITH ONE ANOTHER AND TO LIFT THE FIRST PART TOGETHER WITH THE CONICALLY TAPERING PORTION AND THE FEEDER PORTION DURING THE OPERATION OF IGNITING SAID FUEL AND OXYGEN MIXTURE WITH THE SECOND PART REMAINING IN ITS LOCATION WITHIN THE HOLE.