Compact heat source and heat exchanger

Claim 1

A HEAT EXCHANGER COMPRISING A VERTICALLY ELONGATED PRESSURE VESSEL, A CONTAINING VESSEL DISPOSED WITHIN AND SPACED FROM SAID PRESSURE VESSEL FORMING AN ANNULAR SPACE THEREBETWEEN, A HEAT SOURCE LOCATED WITHIN SAID CONTAINING VESSEL FOR HEATING A FIRST FLUID, A PLURALITY OF TUBE BANKS DISPOSED WITHIN SAID ANNULAR SPACED FOR FLOW THROUGH THE TUBES OF SAID TUBE BANKS OF A SECOND FLUID IN INDIRECT HEAT TRANSFER RELATIONSHIP WITH SAID FIRST FLUID WHICH FLOWS UPWARDLY THROUGH SAID CONTAINING VESSEL AND DOWNWARDLY THROUGH SAID ANNULAR SPACE OVER SAID TUBE BANKS, EACH OF SAID TUBE BANKS COMPRISING A MUILTIPLICITY OF PARALLEL SINUOUS TUBES OF SIMILAR SHAPE AND LENGTH AND EACH FORMED BY A NUMBER OF HORIZONTALLY ARRANGED TUBE LIMBS INTERCONNECTED BY RETURN BENDS, EACH OF SAID TUBE LIMBS BEING ARCUATE IN FORM AND HAVING SUBSTANTIALLY THE SAME RADIUS OF CURVATURE AS THE ADJACENT WALL OF SAID PRESSURE VESSEL, SAID SINUOUS TUBES IN EACH TUBE BANK ARRANGED IN A NUMBER OF VERTICALLY EXTENDING HORIZONTALLY SPACED PLATENS WITH THE TUBE LIMBS IN A SINGLE PLATEN SPACED APART AND THE TUBE LIMBS IN ADJACENT PLATENS DISPOSED IN STAGGERED RELATIONSHIP, THE RETURN BENDS INTERCONNECTING SAID AD-