How to Deal with the Leakage of Plate Heat Exchanger?

The plate heat exchanger is a new type of high-efficiency heat exchanger made of metal sheets with certain corrugated shapes stacked on top of each other. A thin rectangular channel is formed between the various plates, and heat is exchanged through the plates. The plate heat exchanger is an ideal equipment for liquid-to-liquid and liquid-to-vapor heat exchange. It has the characteristics of a high heat exchanger coefficient, small pressure drop, compact structure, lightweight, small space occupation, easy installation and cleaning, easy combination of area and process, strong versatility of parts, long service life, a wide choice of materials and easy to achieve large-scale production. Among them, external leakage is the most common failure of plate heat exchangers.

Here is the content list:

• Failure performance

• Causes of external leakage

• Treatment of external leakage

Failure performance

External leakage is mainly manifested as leakage (small amount, discontinuous water drops) and leakage (larger amount, continuous water drops). The main parts of the external leakage are the seal between the plate and the plate, the second seal leakage slot of the plate and the inside of the end plate, and the compression plate.

Causes of external leakage

The causes of external leakage are as follows. The seal size of the plate heat exchanger is not in place, the size of each place is not uniform (the size deviation of each place should meet the standard) or the clamping bolt is loose. The gasket of the plate heat exchanger is out of the sealing groove, the main sealing surface of the gasket is dirty, the gasket is damaged or the gasket is aging can also cause external leakage. Deformation of the plate occurs and misalignment of the assembly causes a running gasket. Cracks in the sealing groove area of the plate or the second sealing area are all causes of the failure of the plate heat exchanger.

Treatment of external leakage

The treatment of external leakage caused by different reasons is also different and should be combined with the type of plate heat exchanger to solve the problem. In the state of no pressure, re-clamp the equipment according to the clamping dimensions provided by the manufacturer, the dimensions should be uniform and consistent, and the deviation of the clamping dimensions should be within the specified range. The parallelism of the two clamping plates should be kept within 2mm. If the specific cause of external leakage cannot be determined within a short period of time, the external leakage part of the plate heat exchanger can be marked, and then disassemble the heat exchanger one by one to investigate and solve the problem, reassemble or replace the gasket and plate. The heat exchanger will be disassembled, and the plate deformation parts to repair or replace the plate is the most basic measure. In the absence of plate spare parts, the deformed part of the plate can be temporarily removed and reassembled for use. When reassembling the disassembled plates, the plate surface should be cleaned to prevent dirt from adhering to the gasket sealing surface. These are the common troubleshooting methods for plate heat exchangers.

This paper analyzes and summarizes the most common and easily ignored problem in the operation of plate heat exchangers - external leakage. And the treatment methods are summarized. It is hoped that it will be of some significance to the designers and users of plate heat exchangers.