Method for Manufacturing a Plate Heat Exchanger

A method for manufacturing a plate heat exchanger, comprising the steps of:

• punching plates, in each of which at least one projection having the form of a hollow truncated cone is provided;
• composing a plate assembly by consecutively mounting the projection of one plate into corresponding opening of an adjacent plate, wherein a predetermined gap between adjacent surfaces of the plates is maintained and a channel for passing a heat carrier is formed;
• preparing a soldering paste solution based on copper hydrocarbonate and nickel salts, into which the plate assembly is immersed;
• and
• placing the plate assembly with the applied soldering paste solution into a high-temperature through-type conveyor furnace in which soldering and covering the plate assembly with a copper-based alloy are performed during movement of the plate assembly,
• characterized by comprising the following:
• cleaning surfaces of each plate prior to composing the plate assembly;
• drying the applied soldering paste solution prior to placing the plate assembly into the high-temperature through-type conveyor furnace;
• providing a protective medium containing free hydrogen in the high-temperature through-type conveyor furnace;
• and
• providing two temperature zones along the way of movement of the plate assembly, wherein annealing the plate assembly is performed in the first temperature zone, and soldering and covering the plate assembly with the copper-based alloy are performed in the second temperature zone.