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

2. Use high-pressure water to clean the sludge, algae and other impurities left in the pipeline, and then close the system.

3. Install ball valve between isolation valve and exchanger, and install water inlet and return ports

4. Connect the delivery pump and connecting conduit to pump the cleaning agent in from the bottom of the heat exchanger and out from the top.

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

6. Repeatedly cycle cleaning to the recommended cleaning time. With the development of circulation and the dissolution of sediment, the gas produced during the reaction will increase, and excess air should be discharged at any time through the vent valve. As the air is discharged, the space in the heat exchanger will increase. Appropriate water can be added. Do not inject a large amount of water at the beginning, which may cause water overflow.

7. The effectiveness of cleaning agent shall be checked regularly during circulation, and pH test paper can be used for determination. If the solution is kept at pH 2 ‐ 3, the cleaning agent is still effective. If the pH value of the cleaning agent reaches 5 ‐ 6, an appropriate amount of cleaning agent needs to be added. The pH value of the final solution remained unchanged for 30 minutes at 2 ‐ 3, which proved that the cleaning effect was achieved. Note: the cleaning agent can be recycled and reused, and the discharge will cause waste.

8. After reaching the cleaning time, recover the cleaning solution. Wash the exchanger repeatedly with clear water until it is washed clean to neutral, and measure the pH value 6-7 with pH test paper.

9. The machine can be started after cleaning. Pressure test can also be carried out to see if there is leakage. In case of 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, record the current medium over flow, working pressure, heat exchange efficiency and other data.

⒒ by comparing the changes of the values before and after cleaning, we can calculate the production costs such as electricity cost and coal cost saved per hour and the improved work efficiency of the enterprise, which is the value compensation for the application of technology.

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

If the enterprise needs equipment for passivation pre film treatment, it can operate according to the following process: pump the passivation pre film agent into the equipment according to the recommended dilution ratio (hang the test piece in the circulation tank at the same time); cycle and soak according to the recommended time; test the pre film effect (red point method or blue point method); discharge; wash the water to neutral (measure pH value 6-7 with pH test paper).

14. After the completion of passivation pre film, it is better to use fans and other ventilation equipment to blow the system dry, so as to ensure and improve the effect of passivation pre film.