Plate heat exchangers are ideal equipment for liquid-liquid and liquid-vapor heat exchange. It has the characteristics of high heat exchange efficiency, low heat loss, compact and lightweight structure, small footprint, wide application and long service life. After the plate heat exchanger is used for 1-2 years, it needs to undergo necessary disassembly, inspection, cleaning, and pressure testing according to the actual operating conditions. The deformed or perforated plates need to be replaced in time. During this process, the assembly of the plate heat exchanger plates must be arranged in strict accordance with the flowchart. How to properly clamp the plate heat exchanger after disassembly and repair?
(1) After the plate heat exchanger is disassembled and inspected, the plates need to be clamped again as required. If additional plates are required to further improve the heat exchange capacity, the deformation strength of the fixed pressure plate and the movable pressure plate should be fully considered, and the same test pressure. The number of plates increases and the pre-tightening force of the bolts also needs to be increased. When the elastic deformation of the pressure plates on both sides exceeds the allowable range, the plane compression of the seal will cause radial sliding and misalignment. The failure of the seal causes the two media to leak outside or to flow through each other internally, and they cannot be used normally.
(2) For heat exchangers that have not been put into use for a long time, the tension of the bolts should usually be properly relaxed. The plates and gaskets lose their necessary elasticity after being compressed for a long time, and the sealing is easy to fail. The compression bolts of the heat exchanger are evenly distributed, and the plates need to be clamped diagonally before installation, and the inner distance of the two compression plates should be measured in real time to ensure that the two compression plates are basically parallel. The parallelism deviation of the four corners is less than 2%, and the bolts are pre-tightened in order.