Maintenance of plate heat exchanger
Plate heat exchangers are an important part of heat exchange technology in process industry equipment. The elastic gasket that seals between each plate heat sink is a vulnerable part, and it is also a part that is easy to age under natural conditions. Its service life has an important impact on the service life of the plate heat exchanger. If these seals heat harden and lose their original elasticity, this can cause the heat exchanger to fail to function properly.
The following factors have a significant impact on the service life of elastomeric gaskets:
- How the heat exchanger works (continuous or discontinuous)
- Corrosiveness of heat dissipation media and cleaning agents used
- Maximum operating temperature
- maximum working pressure
- High stress on elastic gaskets due to excessive pressure and uneven pressure
- Natural aging.
The softening of the elastic gasket is related to pressure and temperature. When the gasket loses its elasticity, the heat exchanger will leak. In some products, in order to solve the dripping phenomenon caused by the aging of the gasket, it is allowed to adjust the sealing performance of the heat exchanger, that is, tighten the bolts of the combined plate heat exchanger again, and adjust the elastic gasket between each heat exchanger The compression force solves the problem of dripping. On the nameplate of the heat exchanger with this function, the allowable maximum and minimum stress are generally given. For new heat exchanger plate packs, the minimum allowable stress should be used for connection fixation. Depending on the number of fins in each group, the tightening force of the heat exchanger can be adjusted one or more times. When tightening each time, the nut can be screwed in 3mm, and the stress of the adjusting fins should always be paid attention to during the tightening process, and , it is only allowed to adjust the tightening force at room temperature for heat exchangers without working pressure to prevent dripping.
For plate heat exchangers that do not specify the stress adjustment range on the nameplate, the stress value is generally given in the part drawing. When tightening this type of plate heat exchanger, the tightening torque should not be lower than the value specified in the drawing in any case. Because it is related to the assembly quality and assembly deformation of the plate heat exchanger. When the tightening torque reaches the specified value, the elastic gasket can be replaced in a planned way. For plate heat exchangers used in important production equipment and corrosive media, it is recommended to have a spare set of seals. When the warehouse temperature is 18°C, the seals of the plate heat exchanger can be stored for about 3 to 5 years in transparent plastic packaging.