Views:1 Author:Site Editor Publish Time: 2020-03-24 Origin:Site
Plate heat exchanger gasket is one of the important components of plate heat exchanger, a ring made of material that can produce plastic deformation and has a certain strength. Most gaskets are cut from non-metallic plates, or made by professional factories in specified sizes. The materials are asbestos rubber plates, asbestos plates, polyethylene plates, etc, asbestos can also be thin metal plates (steel sheet, stainless steel). Metal-clad gaskets made of other non-metal materials; ordinary rubber gaskets are suitable for occasions where the temperature is below 120 ° C; asbestos rubber gaskets are suitable for water vapor temperature below 450 ° C and oil temperature below 350 When the pressure is lower than 5 MPa at ℃, the acid-resistant asbestos board is the most commonly used for general corrosive media. In high pressure equipment and pipelines, lens type or other shape metal gaskets made of copper, aluminum, 10 steel, stainless steel are used. The contact width between the high-pressure gasket and the sealing surface is very narrow (line contact), and the processing finish of the sealing surface and the gasket is high.
Gasket structure characteristics
Plate heat exchanger plates are divided into unilateral flow and diagonal flow according to the flow form of the heat transfer medium. Correspondingly, plate heat exchanger gaskets are divided into unilateral flow and diagonal flow according to the flow form of the heat exchange medium. Stream 2 kinds.
Unilateral flow refers to the heat exchange medium flowing in from the right corner hole of the heat exchange plate and finally flowing out from the right corner hole. Similarly, the heat exchange medium flowing in from the left corner hole finally flows out from the left corner hole. Diagonal flow means that the heat exchange fluid flows from the right corner hole and then flows out from the left corner hole, or the fluid flowing in from the left corner hole flows out from the right corner hole, showing a diagonal flow pattern. In terms of heat transfer efficiency, the diagonal flow method is better than the unilateral flow, but the cost of using the unilateral flow method is relatively low. Therefore, when the heat transfer efficiency can be satisfied, the unilateral flow method is generally used.
Plate heat exchanger sealing gasket can be divided into 3 types according to the installation method on the heat exchange plate:
(1) Direct paste type, that is, after the sealant is applied to the gasket, it is directly adhered to the installation groove of the heat exchange plate.
(2) Plastic nail inlay type, that is, a mounting hole is designed on the heat exchange plate, a rubber nail is designed on the side of the gasket, and the rubber nail is embedded in the mounting hole after the gasket is placed in the installation groove.
(3) Buckle type, that is, a buckle is designed on the side of the gasket, and the gasket is buckled on the heat exchange plate with the buckle.
For the above three methods, the paste type sealing gasket has a simple structure and is the easiest to process, but it is relatively troublesome to install and remove. Inlaid and snap-on gaskets have complex structures and are cumbersome to process, but are relatively easy to install and remove. Plate heat exchanger gaskets are divided into symmetrical and asymmetrical shapes according to the cross-sectional shape of the product. Symmetric shapes are generally used for diagonal flow plates. The upper and lower sealing surfaces are flat, symmetrical along the horizontal plane, and can be installed in front and back. The asymmetric ground is a flat surface, and the upper sealing surface may be a flat surface, a curved surface, an inclined surface, or the like.
Gasket material and temperature resistance
Use temperature ℃
Suitable for fluids
Nitrile rubber (NBR)
-15 ～ + 135
Water, seawater, mineral oil, brine
-25 ～ + 180
Hot water, steam, acid, alkali
-55 ～ + 230
Acid, alkali, fluid
0 ～ + 160
Concentrated acid, alkali, high temperature oil, steam