Abstract: A spiral heat exchanger composed of two separate pipe systems, wherein each heat exchange medium runs in its own pipe system. The heat-emitting and the heat-absorbing pipe sytems are arranged in a tight, intermeshing fashion, in order to improve the heat exchange between the separate spirals, these are interconnected by employing a medium metal. The medium metal is applied by soldering, by dipping the heat exchanger into molten metal or by casting the molten metal on top of the exchanger.

Abstract: A pipe spiral bundle for a heat exchanger is produced by using pre-fabricated pipe spirals of the same shape, each pipe spirals having pipe loops essentially in one plane and at distances inside each other, such spirals being arranged concentrically and directly on top of each other and then tightly attached to each other so as to form a continuous spiral-shaped contact line between adjacent spirals, and a mutual branch pipe being connected to one end of each pipe spiral and a mutual collector pipe being connected to the opposite end of each pipe spiral. The pipe spirals may be heat welded to each other or connected to each other by mechanical binding members, such as metal bands.