Maintenance of Plate Heat Exchanger

Even the plate heat exchanger will have problems in the course of use in one year, which needs to be repaired, especially its seal, to see if it is loose. This article introduces the precautions for maintenance of plate heat exchanger.

A plate heat exchanger is an important part of heat exchange technology in process industry equipment. The elastic gasket which is used to seal the heat sink is a kind of wearing part, and it is also a kind of ageing part under the natural condition. Its service life has an important impact on the service life of plate heat exchanger. If these seals harden and lose their elasticity, the heat exchanger will not work properly.

The following factors have an important influence on the service life of the elastic gasket plate heat exchanger: the working model of the heat exchanger (continuous or discontinuous) - the medium for heat dissipation and the corrosiveness of the cleaning agent used - the maximum working temperature - the maximum working pressure - the stress of the elastic gasket is large due to the excessive pressure and unbalanced pressure - natural ageing

The softening of the elastic gasket is related to pressure and temperature. When the gasket loses elasticity, the heat exchanger will leak. In some products, in order to solve the leakage caused by the ageing 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, adjust the compression force of the elastic gasket between each heat exchanger, and solve the leakage problem. The maximum and minimum allowable stresses are generally given on the nameplate of a heat exchanger with this function. For the new heat exchanger, the minimum allowable stress shall be used for connection and fixation.

Depending on the number of heat exchanger pieces in each group, the tightening force of the heat exchanger can be adjusted once or several times. When tightening each time, the nut can be screwed in 3mm, and the stress of the adjusting piece shall be paid attention to all the time during the tightening process. Moreover, only the heat exchanger without working pressure is allowed to adjust the tightening force at room temperature to prevent leakage.

For the plate heat exchanger which does not give the stress adjustment range in the nameplate, the stress value is generally given in the part drawing. When tightening such plate heat exchanger, the tightening torque shall 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 plate heat exchanger. When the tightening torque reaches the specified value, the elastic gasket can be replaced in a planned way. For plate heat exchanger used in important production equipment and corrosive media, it is recommended to have a set of spare seals. When the warehouse temperature is 18 ℃, the seal of the plate heat exchanger can be kept for about 3 years in transparent plastic packaging.