Abstract: A plate evaporator comprises several heat exchange plates arranged substantially vertically in spaced face-to-face relationship to define between the plates evaporation passages alternating with heating medium passages. An increasing cross-sectional area and a decreasing perimeter of the evaporation passages are achieved by so arranging the two heat transfer surfaces of adjacent plates defining an evaporation passage that they diverge from each other in the flow direction of the medium to be evaporated and by decreasing the width of said heat transfer surfaces in said direction.

Abstract: In a heat exchanger of falling film type comprising heat exchange plates with area enlarging corrugation forming ridges and valleys extending in the falling film direction, repeated redistribution of the falling film is brought about by having the ridges and the valleys extending continuously within each of a number of zones formed one after the other in the falling direction, whereas the ridges and the valleys with regard to two consecutive zones are laterally displaced in relation to each other such that the ridges and the valleys, respectively, in one zone extend in alignment with the valleys and the ridges, respectively, in a consecutive zone.

Abstract: In a plate evaporator, a tube (8) is removably inserted through aligned openings in the heat exchange plates (3). The interior of the tube (8) communicates with an inlet (4) for evaporation liquid, situated at one side of the plate package, and also communicates with every second plate interspace by way of distribution holes (10) in the tube wall. The tube may contain a piston (15-16) movable to adjust the capacity of the evaporator.

Abstract: A device for changing the number of part streams of a flowing medium comprises a tube (7) with a plurality of holes (11) through the tube wall and a piston (12) displaceable in the tube (7). By means of said piston (12) the interior of the tube can be divided such that a desirable number of holes (11) communicate with a first compartment (13) in the tube intended to be through-flowed by a medium. Through a second compartment (14) in the tube there is extending a piston rod (15) connected with the piston (12). For the change of the number of holes (7) communicating with said first compartment (13), at least one of a determined number of sleeve members (19-21), which are removably applied around the piston rod (15), is arranged to change place on the piston rod between a position within the tube (7) and a position axially outside the tube (7).

Abstract: A plate evaporator of the rising film type and/or the falling film type comprises several heat exchange plates essentially vertically arranged in spaced face-to-face relationship to define evaporation passages alternating with heating medium passages. Evaporation passages with increasing cross-sectioned area and decreasing perimeter in the flow direction of the feed liquid are formed by providing adjacent plates encompassing one evaporation passage with bulges (for example, ridges) which bulges, compared with imaginary planar plates, entail reduced volume of the evaporation passages. The size of said bulges (that is, the volume-reducing effect of said bulges) is gradually reduced in the flow direction of the medium to be evaporated. Thus, the cross-sectional area of the evaporation passages is increased while their perimeter is reduced in said direction.

Abstract: A heat exchanger comprises a plurality of first plates clamped in a frame-work. The plates are generally rectangular and have an opening at each of their corners, said opening forming together with corresponding openings of adjacent plates a first manifold duct for a heat exchanging fluid. A plurality of second plates have a recess at one or more of their corners, said recess corresponding to said openings of the first plates. A connection piece connected to said first manifold duct is clamped in the space formed by the recesses. All the plates have an additional opening forming a second manifold duct through which said first manifold duct is connected to the heat exchanging passages.