Why does the gasket of the plate heat exchanger leak? _
Why does the gasket of the plate heat exchanger leak?
Why does the gasket of the 820 plate heat exchanger leak? Leakage occurs when the detachable plate heat exchanger is in use. In addition to the corrosion of the plate, the failure of the gasket material is also an important factor. The main reasons for the leakage of plate heat exchanger gaskets are as follows: When the rubber gasket material is in contact with fluid, when a fluid component penetrates into the rubber, the soluble substances in it can sometimes be extracted, resulting in the formation of rubber gaskets. Swelling; the presence of halogen and the action of ozone make the gasket soften or cause stress corrosion cracking. Under certain conditions, especially at high temperatures, elastic materials will decompose and release chemical substances, and these substances themselves will corrode the plate material, such as FPM rubber will release oxygen. After disassembling the plate heat exchanger, it was found that the surface of the cold fluid end of the plate was bright, with a small amount of black dirt in some parts, the number of corrosion pits was small and did not penetrate, and there were black deposits in the corrosion pits, so it can be inferred to be a gasket Sheet corrosion exists. Fluid pressure-the detachable plate heat exchanger leaks when used within the rated working pressure. In addition to the quality factors of the equipment in manufacturing and assembly, it is mainly related to the abnormal impact load of water hammer and air hammer in the system. This is a phenomenon that is not easy to observe during use. The instantaneous pressure peak caused by the impact is often 1-3 times higher than the normal working pressure, which displaces the rubber gasket installed in the plate heat exchanger, resulting in seal failure. The heat transfer element of this type of equipment uses stainless steel thin plates. Manufactured (with a thickness of 0.5-1.0mm), its sealing rigidity is relatively poor and the sealing periphery is very long, so the impact pressure resistance is much lower than that of the shell and tube heat exchanger. This abnormal impact of the plate heat exchanger can be judged based on the equipment that provides the conveying medium for it. When the alkali pump that transports the lye to the plate heat exchanger is overhauled, it is found that there are a small amount of honeycombs in the pump casing, indicating that the pump is in operation There is cavitation; at the same time, because of the leakage around the plate in the early stage, it can be inferred that the change of fluid pressure is also a possible factor of leakage.