Spiral tube heat exchanger

Claim 1

A HEAT EXCHANGER COMPRISING, IN COMBINATION, A PLURALITY OF INNER TUBES IN PARALLEL SPIRAL CONFIGURATION; A PLURALITY OF OUTER TUBES IN PARALLE SPRIAL CONFIGURATION; A TUBULAR WALL INTERPOSED BETWEEN SAID INNER TUBES AND SAID OUTER TUBES; SPIRAL INSULATING WALL MEANS BETWEEN EACH ADJACENT PAIR OF SAID INNER TUBES AND FORMING SEPARATE SPIRALLY EXTENDING ANNULAR PASSAGES FOR CONDUCTING RETURN FLOWS OF FLUID IN HEAT EXCHANGE RELATIONSHIP WITH THE OUTER SURFACES OF SASID INNER TUBES; SPRIAL INSULATING WALL MEANS BETWEEN EACH ADJACENT PAIR OF SAID OUTER TUBES AND FORMING SEPARATE SPIRALLY EXTENDING ANNULAR PASSAGES FOR CONDUCTING A RETURN FLOW OF FLUID IN HEAT EXCHANGE RELATIONSHIP WITH THE OUTER SURFACES OF SAID OUTER TUBES; A FIRST MANIFOLD OPERATIVELY CONNECTED TO SAID INNER AND OUTER SPIRAL TUBES FOR DISTRIBUTING FLUID TO SAID INNER AND OUTER SPIRAL TUBES; A SECOND MANIFOLD OPERATIVELY CONNECTED TO SAID INNER AND OUTER SPIRAL TUBES FOR COLLECTING THE FLOWS FROM SAID INNER AND OUTER SPIRAL TUBES; A FIRST CHAMBER OPEN TO ONE END OF SAID ANNULAR PASSAGES FOR DISTRIBUTING FLUID TO SAID ANNULAR PASSAGES; AND A SECOND CHAMBER OPEN TO THE OPPOSITE END OF SAID ANNULAR PASSAGES FOR COLLECTING FLUID FROM SAID ANNULAR PASSAGES EACH OF SAID SPIRAL INSULATING WAALL MEANS BEING FORMED BY TWO COEXTENSIVE FLEXIBLE FILLER STRIPS DISPOSED IN CONFRONTING EDGE TO EDGE RELATIONSHIP.