Absorption refrigeration apparatus

Claim 1

IN ABSORPTION REFRIGERATION APPARATUS, AN UPRIGHT SHELL HAVING AN UPSTANDING SIDE WALL AND A TOP AND BOTTOM AND INSULATION THEREIN, A VAPOR-EXPULSION UNIT EMBEDDED IN THE INSULATION, SAID VAPOR-EXPULSION UNIT HAVING AT LEAST ONE PART IN WHICH VAPOR IS EXPELLED FROM SOLUTION BY HEATING, AN UPRIGHT HEATING TUBE WHICH EXTENDS THROUGH SAID INSULATION BETWEEN THE TOP AND BOTTOM OF SAID SHELL, THE TOP AND BOTTOM OF SAID SHELL HAVING OPENINGS COMMUNICATING WITH THE UPPER AND LOWER ENDS OF SAID HEATING TUBE, MEANS HEAT CONDUCTIVELY CONNECTING THE EXTERIOR SURFACES OF SAID TUBE AND SAID PART ALONG A ZONE WHICH EXTENDS LENGTHWISE OF SAID TUBE, SAID HEATING TUBE BEING HOLLOW, AN ELECTRICAL HEATING ELEMENT, MEANS FOR REMOVABLY POSITIONING SAID HEATING ELEMENT IN SAID TUBE THROUGH ITS UPPER OPEN END TO LOCATE SAID HEATING ELEMENT VERTICALLY AT SAID ZONE FOR OPERATING THE APPARATUS ELECTRICALLY, MEANS INCLUDING A FLUID FUEL BURNER POSITIONED AT THE LOWER END OF SAID HEATING TUBE FOR OPERATING THE APPARATUS WITH A COMBUSTIBLE FUEL MIXTURE, THE PART OF SAID HEATING TUBE AT SAID ZONE HAVING ITS INNER SURFACE IN THE PATH OF FLOW OF COMBUSTION GASES PRODUCED DURING OPERATION OF THE BURNER, AND CONTROL MEANS FOR RENDERING SAID ELECTRICAL HEATING ELEMENT OPERABLE TO HEAT SAID HEATING TUBE AND FOR RENDERING SAID FLUID FUEL BURNER OPERABLE TO HEAT SAID HEATING TUBE, SAID ELECTRICAL HEATING ELEMENT BEING REMOVED FROM SAID HEATING TUBE AT ITS UPPER END WHEN SAID FLUID FUEL BURNER IS RENDERED OPERABLE TO HEAT SAID HEATING TUBE, SAID CONTROL MEANS INCLUDING STRUCTURE FOR BLOCKING SAID HEATING TUBE TO PREVENT THE INSERTION OF SAID ELECTRICAL HEATING ELEMENT THEREIN RESPONSIVE TO RENDERING SAID FLUID FUEL BURNER OPERABLE TO HEAT SAID HEATING TUBE.