Plate heat exchanger

A plate heat exchanger is composed of multiple,thin, slightly separated plates that have very large surface areasand fluid flow passages for heat transfer. This stacked-platearrangement can be more effective, in a given space, than the shelland tube heat exchanger. Advancesin gasket and brazing technology have made theplate-type heat exchanger increasingly practical.In HVAC applications, large heat exchangers of this typeare called plate-and-frame; when used in open loops, theseheat exchangers are normally of the gasket type to allow periodicdisassembly, cleaning, and inspection. There are many types ofpermanently bonded plate heat exchangers, such as dip-brazed,vacuum-brazed, and welded plate varieties, and they are oftenspecified for closed-loop applications such as refrigeration.Plate heat exchangers also differ in the types of plates that areused, and in the configurations of those plates. Some plates may bestamped with "chevron", dimpled, or other patterns, where othersmay have machined fins and/or grooves. 

A plate heat exchanger is a typeof heat exchanger that uses metal plates totransfer heat between two fluids. This has a majoradvantage over a conventional heat exchanger in that the fluids areexposed to a much larger surface area because the fluidsspread out over the plates. This facilitates the transfer of heat,and greatly increases the speed ofthe temperature change. Plate heat exchangers are nowcommon and very small brazed versions are used in thehot-water sections of millions of combination boilers. The highheat transfer efficiency for such a small physical size hasincreased the domestic hot water (DHW) flowrate of combinationboilers. The small plate heat exchanger has made a great impact indomestic heating and hot-water. Larger commercial versionsusegaskets between the plates, smaller version tend to bebrazed.

Plate heat exchanger