Plate heat exchanger

#This invention relates to a plate heat exchanger comprising a plurality of layers of at least partially corrugated sheet metal arranged parallel to one another, forming a plurality of heat-exchange passages, and at least one header that creates a flow connection among at least some of the heat-exchange passages.

#Plate heat exchangers are built from several corrugated sheets (hereinafter referred to as “fins”) that are stacked over one another and that ate separated from one another in each case by flat metal partitions. The fins and partitions are connected tightly to one another in such a way that a heat-exchanger block is produced, thereby forming a plurality of heat-exchange passages for streams to be brought into heat exchange with one another. To introduce and withdraw the streams, headers with supports used for attaching the incoming or outgoing pipelines are mounted via the inlet or outlet openings of the heat-exchange passages.

#All components of the plate heat exchangers are made from the same material, often from aluminum of aluminum alloys. Aluminum plate-fin heat exchangers are described in a brochure of Linde AG. Processing Engineering and Contracting Division entitled “Aluminum plate-fin heat exchangers”. Description of other plate heat exchangers are found in the literature, e.g. Chemical Engineers' Handbook, Perry & Chilton, 5th edition, McGraw-Hill, New York, 1973 pages 11-22 and 11-23.

#The invention as well as other details of the invention are explained in more detail below based on the embodiments that are depicted in the drawings, wherein:

#FIG. 1 diagrammatically depicts the structure of a plate heat exchanger according to the invention;

#FIG. 1A is an enlarged portion of the heat exchanger of FIG. 1 showing corrugated heat exchanger plates; and

#A heat exchanger block comprises a housing 1 containing corrugated and flat aluminum sheets conventionally soldered together in a soldering furnace. The heat-exchange passages formed between the sheets are closed to the outside by cover strips forming the housing. An area 2 is used as an intake opening to the heat-exchange passages. A header 3, which is provided with a connecting piece 4, creates a flow connection between the supply line for one of the fluids that is to undergo heat exchange, not shown, through the connecting piece 4, to the heat-exchange passages. As is seen in FIG. 1A the heat exchanger may have corrugated heat exchanger plates 10.

#A frame 5 is welded to header 3, and the thus prepared header is then welded gastight to intake opening 2. In order to be gastight, the intake opening 2 of the housing 1 has a selected area, and the header 2 has a corresponding outlet area with the frame 5 forming an intermediate piece disposed therebetween also enclosing the corresponding area. Frame 5 is depicted more precisely in FIG. 2. Frame 5 consists essentially of an aluminum layer 6 and a steel sheet 7, which are connected to one another using an explosive plating process. The thus produced plate heat exchange is distinguished by high strength and is preferably used in high-pressure applications. For further details of the explosive plating process, reference is made to the literature, for example, the attached brochure by Dynamit Nobel entitled ADynaplat Verbindungen durch Sprengstoff.

#In the specification and the following claims, Cr—Ni steel is any steel alloyed with chromium and nickel; low temperature steel is any steel alloyed for low temperature application; and C-steel is any unalloyed steel.