How to improve the temperature resistance of plate heat exchanger gaskets
Users who know the plate heat exchanger know that the gaskets of the plate heat exchanger and the plates of the plate heat exchanger are important parts of the plate heat exchanger, which have a profound influence on the use effect of the plate heat exchanger. Here will introduce how to improve the temperature resistance of plate heat exchanger gaskets.
The working temperature of the plate heat exchanger is essentially the temperature that the gasket can withstand. The working pressure of the plate heat exchanger is also limited by the gasket. According to analysis, the length (m) of the heat exchanger gasket is 6-8 times the heat exchange area (m2). The plates of the heat exchanger are very thin and have poor rigidity. Only elastic materials can be used to make the gasket, but the heat exchange The temperature that the gasket can withstand is not high. The seal of the heat exchanger gasket should ensure the amount of compression, and the amount of compression should ensure that the groove does not deform.
Ⅰ. Non-adhesive heat exchanger gaskets, compared with traditional adhesive heat exchanger gaskets, are complicated in process, time-consuming and material-consuming, inconvenient to assemble and disassemble, and may even affect human health due to harmful components in adhesives and cleaning agents. And cause corrosion and cracking of the gasket groove of the heat exchanger plate. Therefore, the application of non-adhesive heat exchanger gaskets has become more and more extensive, and local adhesion methods can also be used in some cases. Generally, it only takes a few minutes to install (replace) a gasket, which saves 80%-95% and 70% of time and labor compared with pasted gaskets. It is especially convenient for on-site replacement and greatly reduces maintenance costs and downtime losses. The non-adhesive gasket and the corresponding parts of the plate have special structural shapes. The two are connected by mechanical methods. There are many varieties. They can be roughly divided into two types: "embedded" and "clip type". The applicable temperature reaches 165℃. , The pressure is 2.5MPa. Companies such as ALFA-LAVAL, APV, GEA, ITT and HISAKA of the United States all have their own products.
Ⅱ. Reliable heat exchanger plate positioning system In order to make the heat exchanger plate and the heat exchanger gasket seal position accurate and reliable, prevent up and down or left and right slippage, and extend the life of the heat exchanger gasket, ALFA-LAVAL, APV, GEA, and SONDEX have adopted different plate positioning structures.
Ⅲ. Plate heat exchanger gasket material and performance evaluation The weak link of PHE is the gasket. Over the years, it has been the focus of public attention and exploration, and some progress has been made in temperature resistance and corrosion resistance materials and their performance evaluation.
1. Nitrile rubber (NBR) is generally suitable for working conditions below 110°C. The newly developed high-temperature NBR can reach 120°C, and the hydrogenated NBR can reach 140°C; EPDM was only used at 150°C in the past. , High temperature EPDM has been increased to 160℃; Fluoro-propylene rubber (FPM) can be used at 175℃; graphite laminated gaskets can be used at temperatures up to 400℃, which can well replace compressed asbestos fiber gaskets.
2. With the development of non-adhesive heat exchanger gaskets, the formulation of the gasket materials for non-adhesive heat exchangers must have subtle changes, requiring more stable performance, more durability and better tear resistance.
The quality and service life of the plate heat exchanger largely depend on the quality and service life of the heat exchanger gasket. For a large number of plate heat exchangers, the plate heat exchanger will not be damaged, and the heat exchanger gasket is easy to age and cause leakage. Therefore, the quality of the plate heat exchanger gasket determines the quality and service life of the heat exchanger. Therefore, improving the temperature resistance of plate heat exchanger gaskets has important practical significance.
