1、Close the valves

Close the outlet valve of the hot medium and the inlet and outlet valves of the cold medium. Drain the liquid inside the pipe and heat exchanger, and place the cleaning agent into the heat exchanger from the water inlet port. The outlet port of cold side is the cleaning agent outlet port. The sequence is: heating medium inlet - heating medium outlet - cold medium inlet - cooling medium outlet.

2、Cleaning with chemical agent

Fill the cleaning tank with water, check the system circulation, add cleaning agent when the circulation is stable, then start operation. Measure the cleaning agent concentration (in the range of 0.1-0.15mol/L) every one hour, and add the cleaning agent according to the measured value.

Heat exchangers that are not disassembled take a little longer to clean. Using the combination of circulation and soaking, water injection valves are installed inside the inlet and outlet valves of the secondary network of the heat exchanger. Inject the 3%~5% oxalic acid solution in the water tank into the heat exchanger, and use the circulating pump to force the oxalic acid solution to circulate between the heat exchanger and the water tank to achieve the purpose of cleaning.

3、Rinse the heat exchanger

Because the circulation port inside the heat exchanger is relatively small, there will be dirt residues attached to the plate after cleaning, which needs to be repeatedly washed with a circulating pump to discharge the waste water in the cleaning tank. Fill the heat exchanger with clean water, and then use the circulating pump to clean and observe until the drainage is clean.