Swep International Ab

Niclas Bornegård

Tomas Dahlberg

Sven Andersson

Hans Andre

Hans AndrÉ

A method for brazing a plate heat exchanger () having a stack of heat exchanger plates with depressions and elevations forming interplate flow channels and port openings being in selective fluid communication with said interplate flow channels, the method comprising the steps of placing the stack of heat exchanger plates in a heating chamber () of a furnace (), conducting a gas for changing the temperature of the stack of heat exchanger plates through a plurality of nozzles () inside the heating chamber (), and conducting gas from at least one of said nozzles () into at least one of the port openings (O-O) of the stack of heat exchanger plates. Disclosed is also a system for brazing a plate heat exchanger ().

Method and a system for brazing a plate heat exchanger

The present application relates to a stencil device () for simultaneous stencil printing of brazing material onto elevations, areas surrounding port openings, and a circumferential skirt () of a heat exchanger plate () wherein the stencil device () comprises an upper stencil having openings for applying brazing material to elevations and areas surrounding port openings of the heat exchanger plate () and a lower stencil printing stencil () having a large opening () for receiving the heat exchanger plate () and contacting an outer perimeter of the circumferential skirt () of the heat exchanger plate (), wherein an inner surface () of the large opening () comprises brazing material exits () for applying brazing material to the circumferential skirts (). Disclosed is also a method of such stencil printing and also the use of a stencil device for applying heat exchanger plates () with a brazing material.

Stencil device and method for stencil printing of brazing material onto a heat exchanger plate and use thereof

A brazing material for brazing a brazed plate heat exchanger comprising a number of heat exchanger plates being provided with a pressed pattern of ridges and grooves adapted to provide contact points between neighbouring heat exchanger plates, such that the heat exchanger plates are kept on a distance from one another and such that interplate flow channels for media to exchange heat are formed between the heat exchanger plates comprises a brazing alloy comprising at least one melting point depressing element and metals resembling the composition of the heat exchanger plates. The brazing material comprises a mixture between grains of a melting brazing material having solidus and liquidus temperatures lower than a brazing temperature and a non-melting brazing material having solidus and liquidus temperatures above the brazing temperature. The ratio between the melting and non-melting brazing materials is such that an alloy formed by the melting and non-melting brazing materials has a solidus temperature lower than the brazing temperature and a liquidus temperature higher than the brazing temperature.

Brazing material

A method for producing a brazed plate heat exchanger comprising a stack of heat exchanger plates provided with a pressed pattern adapted to provide contact points between neighboring heat exchanger plates, such that the heat exchanger plates are kept on a distance from one another under formation of interplate flow channels for media to exchange heat, wherein the interplate flow channels are in selective communication with port openings for the media to exchange heat and circumferentially sealed along an outer periphery in order to avoid external leakage, comprises the following method steps: a. Calculating the position of the contact points between neighboring plates; b. Calculating a force that must be transferred by each contact point when the heat exchanger is in use; c. Based on the method steps above, calculating a necessary amount of brazing material for each contact point; d. Providing a screen for screen printing the brazing material onto the heat exchanger plates, wherein the screen is provided with openings, the size, position, plate thickness and shape of which being adapted to provide the necessary amount of brazing material to each contact point; e. Screen printing the heat exchanger plates with brazing material using the screen; f. Stacking the heat exchanger plates in a stack; and g. Brazing the stack of the heat exchanger plates in order to join the plates together to form the heat exchanger.

Method for producing a brazed plate heat exchanger

A method for brazing a plate heat exchanger comprising a stack of heat exchanger plates () is provided with a pressed pattern of ridges (R) and grooves (G) adapted to form contact points between the plates () and provide for interplate flow channels for media to exchange heat is provided. The interplate flow channels are in selective fluid communications with port openings () provided near corners of the heat exchanger plates (). The method comprises the following steps:

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Bjärred, Sweden

Niclas Bornegård