Abstract: In a heat exchanger comprising a plurality of plates arranged adjacent to each other and defining between them passages for heat exchanging fluids, the plates are provided at their corner portions with openings, the fluids being conveyed to and from the passages via said openings. The openings for one of the fluids are located at one side of the plates and the openings for the other fluid are located at the other side of the plates. The plates are provided with a corrugation pattern which varies in a direction transverse to the flow direction in such way that the passages are narrower shallower at the side of the plates at which the inlet and outlet openings of the respective passages are provided and wider deeper at the opposite side.

Abstract: A heat exchanger comprising a plurality of plates arranged adjacent to each other, whereby passages for two mutually heat exchanging fluids are formed between the plates. The plates comprise corrugations or ridges, whereby the corrugations form an angle with the longitudinal rim of the plate. In the first type of plates the corrugations form a first angle with said rim and in the second type of plates the corrugations form a second angle with the rim. The plates are combined in order to form two types of passages having different thermal length. The first type of passage is obtained by combining a first plate and a second plate and the second type of passage is formed by combining a first plate and a second plate, wherein one of the plates is turned 180.degree. in its own plane. Thus, two types of passages having different thermal lengths are obtained. The two types of passages can be combined for each heat exchanging fluid in order to provide the desired thermal length for that fluid.

Abstract: In a heat exchanger comprising a plurality of plates arranged adjacent to each other and provided with turbulence-generating corrugations, sealed passages for two heat exchanging media are enclosed between the plates, and two heat exchanging media flow through the passages in mutually inclined flow directions. In order to provide different thermal properties of the passages for the two media, the corrugations on an average extend at a wider angle relative to the flow direction of one of the media than to that of the other medium.

Abstract: In a plate heat exchanger, in which the plates are provided with a turbulence generating pattern of grooves and ridges which also form supporting points for plates disposed adjacent to each other, the thermal treatment of a medium will be different in different parts of one and the same passage due to the different length of different flow paths within the passage. In order to equalize the differences of thermal treatment within one and the same passage and/or to provide mutually different treatment of the heat exchanging media, each passage is formed by plates corrugated in a pattern which is unsymmetrical with regard to the central plane of the plates, the ridges and grooves of plates disposed adjacent to each other extending in mutually different directions relative to the longitudinal axis of the plates.

Abstract: In a plate heat exchanger in which the flow rates of the two heat exchanging fluids are different, it is possible to obtain an adjustment to differing proportions of the fluid flows, the pressure drops being given. To this end, the heat exchanger is provided with at least two sections of heat exchanging passages, in at least one of said sections the passages for the two respective fluids having essentially different flow resistances. Furthermore, the proportion of the flow resistances of the passages for the respective fluids in one section differs essentially from the corresponding proportion in at least one other section.

Abstract: In a plate heat exchanger having a large number of heat exchanging passages connected in parallel, the distribution of the flow between the passages will be unequal in that a larger flow passes through passages which are close to the inlets and outlets than through passages far away therefrom. To eliminate this problem, the passages are provided with means for regulating the flow resistance, said means being arranged so that passages which are situated farther away from the inlets and outlets have lower flow resistance than passages closer to said inlets and outlets.