Maintenance of the Plate Heat Exchanger

Even a plate heat exchanger can have problems during the course of a year and require maintenance, especially its seals, to see if it has loosened.

Here is the content list:

• Secondary adjusutment precautions

• Gasket bonding

• Repair and replacement

Secondary adjustment precautions

A plate heat exchanger is an important component of heat exchange technology in process industry equipment. The elastic gasket that seals between the individual plate heat sinks is a wearable part and one that is prone to deterioration under natural conditions. If these seals harden thermally and lose their original elasticity, the heat exchanger can not work properly. The softening of the elastic gasket is related to pressure and temperature, and when the gasket loses its elasticity, the heat exchanger can drip. In some products, in order to solve the drip phenomenon caused by the aging of the gasket, the heat exchanger is allowed to adjust the sealing performance, that is, tighten the bolts of the combined plate heat exchanger again to adjust the pressure of the elastic gasket between each heat exchanger to solve the drip problem.

Gasket bonding

According to the purpose of gasket use and sealing quality requirements, different manufacturers' blended sealant and non-blended sealant can be used. Before bonding, it should be thoroughly removed using steam airflow. Residual adhesive and residual gasket on the bonding surface. For blended sealant bonding, residual adhesive and gasket residues on the bonding surface of the plate heat exchanger must be removed by fire. In the case of high-volume bonding, a pool of liquid nitrogen should be prepared to freeze the seals, a heating oven should be prepared to dry the plate heat exchanger with a gasket at 160°C, and if available, the plate heat exchanger should be chemically cleaned to ensure complete removal of the gasket residue from the bonded parts in the plate heat exchanger bonding surface.

Repair and replacement

Usually, one finds heat exchanger seal failure by dripping during cold movement of the process equipment or during stopping and cooling. Some plate heat exchangers have a secondary adjustment feature that allows the heat exchanger sheet set to be tightened again in the event of a small drip. This increases the stress between the individual gaskets and solves the dripping phenomenon in a short time. In a newly assembled heat exchanger, a larger combination length size can be used, and when dripping occurs, the groups of plate heat exchangers can be tightened again, using a longer combination length size. The maximum combined length size and the minimum combined length size can generally be seen in the nameplate of the heat exchanger. It is important to note that the minimum combination length size cannot be smaller. When the combined heat exchanger reaches the minimum combined length size and still drips, it means that the gasket must be replaced.

These are the maintenance tips for plate heat exchangers, especially regarding the knowledge of flexible gaskets. With the popularity of heat exchangers, these are no longer just the work of engineers, but skills that each of us needs to master. This way we can greatly reduce the trouble encountered during the use of heat exchangers.