Plate heat exchanger cleaning method in place

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1. Overview There are currently two common cleaning methods for plate heat exchangers.: Manual cleaning and low-level cleaning, if conditions permit, the cleaning-in-place system should be used as much as possible. Because the cleaning-in-place system can use a pump to transport water into the interior of the device, there is no need to disassemble the heat exchanger. If the cleaning-in-place system is not practical for the manufacturer, the equipment can be cleaned by manual cleaning. The following is a brief discussion of the cleaning-in-place steps. 2. Precautions for plate cleaning 1. Do not use hydrochloric acid or chloride with a concentration exceeding 300 * Wash the stainless steel plates with 10-6% water. 2. Do not use various acids to clean titanium plates. 3. Usually the concentration of the cleaning solution should be less than 4%, and the temperature of the cleaning solution should not exceed 60°C. 3. Cleaning in place Cleaning in place is an important way to clean the plates, especially when the process liquid on the device is corrosive. After completing a work cycle, the remaining liquid should be drained through the drain pipe to avoid corrosion of the plates. When cleaning the heat exchanger, follow these steps:: 1. Drain all the liquid from the discharge pipes on both sides of the heat exchanger. If it cannot be drained, water can be used to force out the process liquid. 2. Rinse both sides of the heat exchanger with warm water of approximately 43°C until the outgoing water becomes clear and contains no process liquid. 3. Drain the flushing water from the heat exchanger and connect the cleaning-in-place pump. 4. To clean thoroughly, the cleaning-in-place solution must flow from the bottom to the top of the plate to ensure that all plate surfaces are wetted with the cleaning solution. When cleaning a multi-process heat exchanger, the cleaning fluid must flow in reverse direction for at least 12 hours of cleaning time to ensure that the surfaces of all multi-process plates are wetted. 5. A good cleaning solution is: Use a clean-in-place solution to achieve high flow rates or a clean-in-place nozzle diameter that allows for flow rates. If the in-place cleaning operation can be carried out according to the designated regular cleaning plan before complete contamination, the cleaning effect will be better. 6. After cleaning with the cleaning-in-place solution, rinse thoroughly with clean water. If the heat exchanger uses salt water as the cooling medium, before starting the cleaning operation, the salt water should be drained as much as possible, and then the heat exchanger should be rinsed with cold water. If all the salt water is thoroughly cleaned before cleaning both sides of the heat exchanger with hot cleaning-in-place solution, the corrosion to the equipment will be minimal. 4. Principles of cleaning in place 1. Never open the heat exchanger when it is still hot, under pressure, carrying liquid or in operation. 2. Always use clean water for flushing operations. 3. If steam is used as the sterilization medium, the temperature of the gasket should not exceed 132°C. 4. If chlorine-containing solution is used as cleaning medium, a solution with a small concentration should be used at low temperature as much as possible. The time required to clean the plates with this solution should be kept as short as possible. The chlorine concentration of the solution should not exceed 100 * 10-6. The temperature needs to be lower than 37°C, and the contact time between the plate and the solution cannot exceed 10 minutes. The following are recommendations on concentration, temperature and time. 5. Concentrated cleaning solutions must be added before water circulates through the device. Do not inject these solutions during water circulation. 6. A centrifugal pump must be used to keep the cleaning solution circulating. 7. Do not use hydrochloric acid to clean the plates. 8. After cleaning the plate with any type of chemical solution, you can use clean water to rinse the plate thoroughly.