Plate heat exchangers are indispensable equipment in any production facility. After all, the cooling and heating of working media are the main factors in the process. So what is a plate heat exchanger? Let's take a closer look.
A plate heat exchanger is a special equipment designed to cool or heat a working medium by transferring heat from a hot coolant to a cold one through corrugated plates (stainless steel, titanium, graphite and other materials) that are interconnected. The plates are assembled in such a way that the hot and cold media do not mix with each other, but move on different sides of the plate. The set of plates and their number depends on the process and the media involved.
How it works
The first modern heat exchanger was assembled by the founder of APV (Richard Seligman) in 1923, but other available data suggests that the "father" of the modern heat exchanger is Gustave de Laval, who produced the first pasteurisation unit in 1938.
The heat exchanger plate is the main structural element. They are produced by cold stamping from corrosion-resistant alloys. At the same time, they can withstand a thickness of 0.4-1.0 mm. There are 4 holes on the plate, 2 of which are designed to supply cold and hot media, the other 2 are additionally sealed with contour gaskets to prevent the media from mixing with each other (special drainage grooves are also provided for this purpose). Since the movement in the channels does not occur in a straight line, the flow of the working medium moves turbulently. Add to this the counterflow of two media (hot and cold) and we get an increased temperature head, which in turn intensifies the heat exchange process. This also has a positive effect on the surface of the plates - the scale layer is reduced.
Why heat exchangers are needed
Heat exchangers are essential for these functions:
- use of residual heat resulting from the use of electrical energy;
- control of chemical processes necessary to maintain normal temperature conditions.
The new models are simple and safe to use. In the food industry, they are used for pasteurisation, and in metallurgy, they act as coolers. In shipbuilding, they are needed to maintain the engine cooling system. In the oil industry, they are used for cracking.
Types of heat exchangers
- Shell and tube
Advantages:
- High pressure
- Extreme temperature differences
- Ultra-high performance
Disadvantages:
- Dimensions
- Complexity of maintenance
- Difficulty of cleaning
2. Two-pipe heat exchanger
3. Brazed heat exchanger
4. Capacitors/evaporators
5. Capacitors
Interesting to know
If there is a large difference in flow rates or a minimal difference in final temperatures, multiple heat exchange is possible. This is achieved by directing the flows through a "loop". Such heat exchangers are additionally equipped with nozzles for supplying the working media, with the media moving in the same direction along the baffle plates.
The number of corrugated plates and their design depend directly on the process medium and the process. This also applies to the material of the plates: they can be made of either ordinary stainless steel or special alloys that can be used for handling very aggressive liquids. The material of the seals depends on these parameters and is selected in accordance with the physical, chemical and technological characteristics of the process.
- Working pressure (maximum): 1.6 MPa
- Operating temperature (maximum): 160 oC (200 oC)
- Heat exchange surface (maximum): 1500 м2
- Plates: stainless steel AISI316, titanium, etc.
- Seals: various types of rubber (EPDM, VITON, NBR)
- Frames: stainless steel AISI304 and AISI316, carbon steel, etc.
- Tubing: stainless steel AISI304 and AISI316, titanium, etc.
The process of selecting a heat exchanger is a rather painstaking and time-consuming process, because the materials must be selected correctly, otherwise the heat exchange equipment will fail or operate incorrectly, because for many technological processes, a difference of a few degrees disrupts the entire process and makes it impossible to obtain a product with the specified parameters.
Our experts will help you with the selection and answer any questions you may have.
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