The plate heat exchanger is a high-efficiency heat exchanger made up of a series of metal sheets with a certain corrugated shape. Plate heat exchangers are ideal equipment for liquid-liquid and liquid-vapor heat exchange. After the plate heat exchanger is used for a long time, various problems of large and small failures will occur. So what are the problems that often occur in plate heat exchangers in use?
1. Fouling will reduce the heat transfer coefficient of the heat transfer equipment and block the plate passages. The plates of the plate heat exchanger are designed with a large number of support points, which are designed to turbulent flow and pressure support for the medium. It is a place where solid debris and fibers tend to gather. The side effect is that the fluid forms a local stagnation to generate dirt accumulations. After calcium and magnesium ions in the medium precipitate at a suitable temperature, it is easy to adhere to the accumulations to form honeycomb-like scales.
(1) Plate heat exchangers are not suitable for use in dirty or fouling environments (unless other measures are added).
(2) When using unsoftened cooling water as the cooling medium, the operating temperature should be controlled at about 50°C or lower to avoid the precipitation temperature of calcium and magnesium ions in the medium.
2. Pressure influence. When the disassembled plate heat exchanger is used within the rated working pressure, the leakage is mainly related to the abnormal impact load in the system (water hammer, air hammer), in addition to the quality factors of the equipment in the manufacturing and assembly. The pressure peak caused by the impact is often 1 to 3 times higher than the normal working pressure, which causes the rubber gasket in the equipment to shift and cause the seal to fail.