The design of the plates determines the technical characteristics of the heat exchanger
Of shapes, sizes and design features of the PEX heat transfer plates depend on the intensity of heat transfer, reliability, staff, technology in production and labor for maintenance and repairs.
Corrugated plates are made by cold forming sheet metal, have increased stiffness compared to flat plates. On the wafer surface due to the presence of corrugation are slotted between plates winding channels of complex shape in which a relatively low flow rates is achieved by turbulence moving environments. In its position in the apparatus of the plate usually have different working fluid pressure on both sides, which can cause its deflection towards the lower pressure. To prevent such strains on each plate has vertical rows of remote (reference) projections, which create many points of mutual support between the plates. With full contact support protrusions between the plates of the assembled unit will hold a gap less than 4.5 mm.
Fluid after exiting the corner holes in between plates channel widening spreads on the input side, and then moves along the plate on a broad winding gap between them. During the washing liquid surface exposed to the turbulence which is caused by frequent rotations of the flow in the channels formed by corrugations.
Plates belonging to the same unit, also differ from each other constructively, which is due to their particular assignment and the relative position of the package. Multiples in the form of the plate at their destination in the apparatus is divided into three types: ordinary, boundary and limit.
Ordinary plate characterized by having a total number of holes in the corners, that is, each of which has four openings. Plates with these holes in the assembly apparatus form longitudinal collector channels. Ordinary plates make up the majority of plates in the apparatus. In each apparatus ordinary plate work in parallel in the same thermal and hydraulic conditions.
Boundary plates have an incomplete number of holes in the corners (at least four). Plates of this type are installed in locations where flow direction changes and, therefore, define the boundaries of packages.
End plates are placed at the ends of sections and directly adjacent to a fixed or pressure plate. End plates do not bear the heat load, as the working medium is washed on one side only.
In gasketed plate heat exchangers are used plate systems TL and VT. Brazed plate heat exchangers, as a special case of a fully collapsible, are collected based on laser-welded modules consisting of pairs of plates of TL.
