HEAT EXCHANGER AND A METHOD FOR A LIQUID-TIGHT MOUNTING OF AN END PLATE TO AN ARRAY OF HEAT EXCHANGING ELEMENTS OF THE HEAT EXCHANGER

摘要

Disclosed is a heat exchanger assembled of a pluralityof oval heat exchanging pipes whose end portions aremounted in a leakage proof manner in oval openings of topand bottom plates. The ratio of major and minor diametersof intermediate portions of the pipes is 2.5 : 1 through8 : 1 whereas the ratio of the major and minor diameters ofthe oval openings in the end plates is 1.2 : 1 through3 : 1. A method of mounting the pipe end portions in theoval openings is based on a preliminary shaping of the endportions by the application of pressure from the outsidetoward the center axis of the end portions in the directionof their major diameter. The preshaped end portions areinserted into sealing collars surrounding the edges ofrespective plate openings. Thereafter the end portions areexpanded by means of mandrels to sealingly close theopenings.