1. Isolate the equipment system and drain all water from the heat exchanger.
2. After cleaning the pipes with high-pressure water to remove sludge, algae, and other impurities, seal the system.
3. Install ball valves (not less than 1 inch = 2.54 cm) between the isolation valve and the heat exchanger; these should be installed at both the inlet and outlet.
4. Connect the transfer pump and connecting pipes to pump the cleaning agent in from the bottom of the heat exchanger and out from the top.
5. Begin pumping the required amount of cleaning agent into the heat exchanger (the ratio can be adjusted according to specific circumstances).
6. Repeatedly circulate the cleaning agent for the recommended cleaning time. As circulation progresses and deposits dissolve, the amount of gas produced during the reaction will increase; excess air should be released through the vent valve as needed. As air is released, the space inside the heat exchanger will increase; add an appropriate amount of water as needed, but do not inject a large amount of water at the beginning, as this may cause overflow.
7. Regularly check the effectiveness of the cleaning agent during circulation; pH test strips can be used for measurement. If the solution maintains a pH of 2-3, the cleaning agent remains effective. If the pH reaches 5-6, more cleaning agent needs to be added. The cleaning effect is achieved when the final solution's pH remains at 2-3 for 30 minutes without significant change. Note: The cleaning agent can be recycled and reused; discharging it would be wasteful.
8. After the cleaning time is reached, recover the cleaning solution. Rinse the exchanger repeatedly with clean water until it is clean and neutral. Measure the pH using pH paper to ensure it is 6-7.
9. After cleaning, the machine can be started. A pressure test can also be performed to check for leaks. If leaks are found, they can be repaired and protected using high-polymer composite materials, which can significantly extend the equipment's lifespan.
10. After the equipment stabilizes, record the current medium flow rate, operating pressure, heat exchange efficiency, and other data.
11. By comparing the changes in values before and after cleaning, the hourly savings in electricity and coal costs, as well as the increased work efficiency, can be calculated. This represents the value compensation of the technology applied by the enterprise.
12. The same operating method can also be used for cleaning condensers and frame-type heat exchangers.
⒔ If the company requires passivation pre-filming treatment of the equipment, the following procedure can be followed: Pump the passivation pre-filming agent into the equipment according to the recommended dilution ratio (while suspending test pieces in the circulation tank); circulate and soak for the recommended time; test the pre-filming effect (red dot method or blue dot method); discharge; rinse thoroughly with water until neutral (measure the pH value to 6-7 using pH test paper).
⒕ After the passivation pre-filming is completed, it is best to use ventilation equipment such as fans to dry the system, which can ensure and improve the passivation pre-filming effect.
