How to clean a plate heat exchanger?

- Jun 06, 2018-

The process of cleaning a plate heat exchanger:

1. Isolate the equipment system and drain the water from the heat exchanger.

2. Use high-pressure water to clean the sludge, algae, and other contaminants remaining in the pipeline and close the system.

3. A ball valve (not less than 1 inch = 2.54 cm) is installed between the isolation valve and the exchanger. The inlet and outlet ports should be installed.

4. Connect the transfer pump and connecting pipe to pump the cleaning agent from the bottom of the heat exchanger and out the top.

5. Start pumping the required cleaning agent into the heat exchanger (the ratio can be adjusted according to the specific situation).

6. Repeated cycle cleaning to the recommended cleaning time. As the circulation progresses and the sediment dissolves, the gases generated during the reaction increase, and excess air should be discharged through the purge valve at any time. With the discharge of air, the space inside the heat exchanger will increase, and appropriate water can be added. Do not inject large amounts of water at the beginning, which may cause water to overflow.

7. Periodically check the effectiveness of the cleaning agent, you can use PH test strips to determine. If the solution is maintained at a pH of 2-3, the cleaning agent is still effective. If the pH of the cleaning agent reaches 5-6, a suitable amount of cleaning agent must be added. The pH of the final solution remained unchanged for 30 minutes at 2‐3, demonstrating that the cleaning effect was achieved. Note: The cleaning agent can be reused after recycling, and waste will be wasted.

8. After the cleaning time is reached, the cleaning solution is recovered. Rinse the exchanger repeatedly with clean water until it is flushed to neutrality. Use a pH test paper to measure the pH 6~7.

9. After the cleaning is completed, it can be turned on. You can also press the test to see if there is a leak. If there is leakage, polymer composite materials can be used for repair and protection, and the service life of the equipment can be greatly extended.

10. After the equipment is stable, note the current media over flow, working pressure, heat transfer efficiency and other data.

11. Comparing the changes in values, before and after cleaning, it is possible to calculate the electricity costs, coal costs, and other production costs saved by the company per hour, and to increase the work efficiency. This is precisely the value compensation that companies use for technology applications.

12. The same operation method can also be used for condenser and frame type heat exchanger cleaning.

13. If the company needs equipment for passivation pre-film treatment, it can be operated according to the following process: Pass the passivation pre-filming agent into the equipment according to the recommended dilution ratio (while hanging the test piece in the circulating tank); cycle according to the recommended time, soaking Detection of pre-film effect (red dot method or blue dot method); discharge; rinse with water to neutrality (pH value of 6 to 7 with pH test paper).

14. After the passivation of the prefilming is completed, it is best to dry the system with a ventilating device such as a fan to ensure and enhance the passivation prefilming effect.

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