Thread Content
Whether the plate heat exchanger is fouled can be judged through daily performance observation and professional testing, combined with multiple indicators. There are mainly the following mature methods:: 1. Daily operation indicator monitoring (most commonly used, no need to disassemble the machine) Pressure drop (inlet and outlet pressure difference) judgment: Compare the initial pressure drop ΔP₀ after the equipment is put into use/just cleaned. If the actual pressure drop reaches ΔP ≥ 1.3×ΔP₀, it means that obvious fouling and blockage have occurred. ； When it reaches 1.5×ΔP₀, it is serious scaling and must be cleaned in time. Note that when the flow rate fluctuates greatly, it needs to be converted into the pressure drop at the rated flow rate and then compared. Heat exchange efficiency/temperature judgment: Under stable working conditions with the same load and flow rate, if the secondary side outlet temperature is 3~5°C lower than the normal value, or the heat exchanger heat transfer efficiency drops by more than 15% from the initial value, it can basically be determined that scaling has affected heat transfer. Preliminary judgment of appearance: Uneven color changes or obvious signs of scale or rust on the surface of the heat exchanger indicate that there is a high probability of scaling inside. 2. Disassemble the machine for direct inspection (the most intuitive and accurate). After the machine is shut down, disassemble the plate heat exchanger and directly observe the scaling of the plates.: If a uniform layer of white or yellow scale has appeared on the surface of the plate and the thickness exceeds 0.5mm, cleaning needs to be arranged. ； When the thickness of the scale layer reaches 1mm, the heat transfer efficiency has dropped by 30% to 40%, and it must be dealt with as soon as possible. 3. Professional equipment-assisted testing For plate heat exchangers that cannot be disassembled, professional equipment can be used for testing.: Use ultrasonic measuring instruments, infrared thermometers and other equipment to detect the scale thickness and temperature distribution inside the plates to accurately determine hidden scaling problems. ； You can also collect water samples from the inlet and outlet of the heat exchanger, and indirectly infer the internal scaling trend by analyzing changes in suspended solids and hardness.