Plate heat exchanger and method for manufacturing a plate heat exchanger

Abstract

The invention relates to a plate heat exchanger, which comprises a plate pack formed by corrugated heat exchange plates with openings for the flow of a first and a second heat exchange medium. The outer shell of the plate heat exchanger (1) has been formed by arranging separate strips (9, 9′) in the outer edge of the plate pack (2) so that the outer surfaces of the strips (9, 9′) are substantially in the same plane with the outer edges of the heat exchange plates (6, 6′), and by welding the strips (9, 9′) and the outer edges of the heat exchange plates (6, 6′) to each other.

Description

TECHNICAL FIELD OF THE INVENTION[0001]The invention relates to a plate heat exchanger and a method for manufacturing a plate heat exchanger according to the preambles of the independent claims presented below.BACKGROUND OF THE INVENTION[0002]In a typical prior art plate heat exchanger several rectangular heat exchange plates have been fastened on top of each other, the plates thus forming a plate pack. The plates of a plate heat exchanger are usually corrugated. The corrugation, i.e. the grooves and the ridges between them, aims to improve heat exchange properties and to cause a turbulent flow, which improves heat transfer coefficients. Typically, the plate pack is sealed with rubber sealing or the like, the sealings having been arranged in every plate space. Typically, the plate pack has been formed of heat exchange plates with openings, which openings form flow channels in the plate pack. The openings of the plate heat exchanger have been sealed in every other plate space, wherein...

AI Technical Summary

Benefits of technology

The invention is a heat exchanger with improved heat exchange properties compared to brazed heat exchangers. The heat exchange plates are clear from additional materials, which strengthen heat exchange properties. The manufacturing method of the heat exchanger involves welding all elements tightly to each other, eliminating the need for separate fastenings, gaskets, or sealings. The completely welded structure of the heat exchanger is compact, pressure-proof, and formed by arranging separate strips in the outer edge of the plate pack and welding them to the outer edges of the heat exchange plates. The separate strips circulate the whole outer edge of the plate pack for forming a uniform outer surface of the plate pack. The structure of the heat exchanger is simple and efficient to manufacture.

Problems solved by technology

A disadvantage in plate heat exchangers equipped with sealings has been their poor resistance especially to pressure, but also to temperature and corrosion.

The brazed structure withstands pressure quite well, but by reason of properties of the filler metal the brazed structures do not withstand high temperatures.

However, the heat exchange properties of the circular heat exchangers are not as good as the rectangular heat exchangers.

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