Common faults and treatment methods in the maintenance process of plate heat exchanger_
Common faults and treatment methods in the maintenance process of plate heat exchanger
Common faults and treatment methods in the maintenance process of 733 plate heat exchanger (1) Common faults of plate heat exchanger 1. External leakage is mainly manifested as leakage (small amount, discontinuous water droplets) and leakage (large amount, Water droplets are continuous). The main parts where leakage occurs are the seal between the plate and the plate, the part of the second sealing leakage groove of the plate, and the inner side of the end plate and the compression plate. 2. The heating temperature cannot meet the requirements. The main feature is that the outlet temperature is low, which fails to meet the design requirements. (2) Cause analysis and treatment methods 1. Leakage (1) Causes The clamping size is not in place, the size is uneven everywhere (the size deviation should not be greater than 3 mm) or the clamping bolt is loose. Part of the gasket is out of the sealing groove, the main sealing surface of the gasket is dirty, the gasket is damaged or the gasket is aging. The plate is deformed, and the assembly misalignment causes the running pad. There are cracks in the plate sealing groove or the second sealing area. Example: Many thermal stations in Beijing, Qinghai, Xinjiang and other places use saturated steam as the primary heat source for heating. Due to the high steam temperature, when the system is unstable at the initial stage of equipment operation, the rubber gasket fails at high temperature, causing Steam leaks. (2) Treatment method In the no-pressure state, re-clamp the equipment according to the clamping size provided by the manufacturer. The size should be uniform, and the deviation of the compacted size should not exceed ±0.2N (mm) (N. The total number of plates) ), the parallelism between the two compression plates should be kept within 2 mm. Mark the leaking parts, then disassemble the heat exchanger and investigate and solve them one by one, reassemble or replace the gaskets and plates. Disassemble the open heat exchanger, repair the deformed parts of the plate or replace the plate. When there is no spare part for the plate, the plate at the deformed part can be temporarily removed and then reassembled for use. When reassembling the disassembled plates, clean the plate surface to prevent dirt from adhering to the gasket sealing surface. 2. The heating temperature cannot meet the requirements (1) Causes of insufficient medium flow on the primary side, resulting in a large temperature difference on the hot side and a small pressure drop. The cold side has a low temperature, and the cold and hot ends have low temperatures. The flow distribution of multiple plate heat exchangers operating in parallel is uneven. The internal fouling of the heat exchanger is serious. (2) Treatment method Increase the flow rate of the heat source or increase the diameter of the heat source medium pipeline. Balance the flow of multiple plate heat exchangers operating in parallel. ③ Disassemble the plate heat exchanger to clean the surface of the plate fouling.