Function of brazed plate heat exchangers

Learn everything about how braze plate heat exchnagers work, the production steps in how they are made to material combinations and various plates and channel types.

How brazed plate heat exchangers work

The brazed plate heat exchanger is in principle constructed as a package of corrugated channel plates between front and rear cover-plate packages. The cover-plate packages consist of sealing plates, blind rings and cover plates. Connections are mounted on the cover plates and can be customized to meet specific market and application requirements. During the vacuum-brazing process, a brazed joint is formed at every contact point between the base and the filler material. This design creates a heat exchanger that consists of two separate channels or circuits.

Production steps in how brazed plate heat exchangers are made

Sealing plates are used to seal off the space between the cover plate and the first and last channel plates. The number of cover plates varies, for example with the type and size of the brazed plate heat exchangersand its pressure rating. Some brazed plate heat exchangers have a blind ring to seal off the space between the channel plate and the cover plate. In others the blind rings are integrated in the cover plate and first/last channel plates.

Watch this short video showing the production steps in how brazed plate heat exchangers are made, from pressing plates, stacking and brazing to final testing and labeling. 

Plates and channel types for brazed plate heat exchangers

Certain brazed plate heat exchangers are available with different types of channel plates where the herringbone pattern varies. The benefit of different herringbone patterns is that the hydraulic and thermal characteristics of the brazed plate heat exchangers can be modified. For example, two brazed plate heat exchangerscan have the same pressure drop on both sides despite different flow rates.

The fluids can pass through the heat exchanger in different ways. For parallel flow brazed plate heat exchangers, there are two different flow configurations: co-current or counter-current (click on the images for more explanation).

  • Co-current flow
  • Counter-current flow

There are several different versions of the channel plate packages. Examples include:

  • Dual-circuit brazed plate heat exchangers
  • Two-pass brazed plate heat exchangers, which corresponds to two units connected in series.
  • Dual-over-two-pass brazed plate heat exchangers

Material combinations for brazed plate heat exchangers

There are different brazed plate heat exchangers product categories depending on material combinations and design pressures. The standard plate materials are AISI 316 stainless steel, S, vacuum-brazed with a pure copper filler, C, or a nickel-based filler, N. For demanding applications, the plates can be made of SMO 254, a stainless steel with a higher content of molybdenum.

 

FAQ´s about brazed plate heat exchangers

To view our most frequently asked questions and answers, please visit our FAQ page.

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