Brief description of cleaning methods for plate heat exchangers, including soot blowing and water spraying cleaning　

The mechanical cleaning, soot blowing cleaning, and water spraying cleaning methods for plate heat exchangers are introduced as follows:

Blow ash cleaning

The soot blower has a good effect on removing particle dirt during soot cleaning. The soot blower uses high-pressure air and high-pressure steam to be directly sprayed onto the heat exchange surface through a nozzle. If steam corrodes the heat exchange surface, it should not be used. There are various types of soot blowers. For example, rotary soot blowers are commonly used to remove particulate deposits that do not adhere to walls; A telescopic soot blower is typically used to remove particles adhering to walls. To remove severe scaling surfaces without stopping the machine, a motor-driven soot blowing pipe can be used; Manual blowing can also be used for small heat exchangers.

Spray cleaning

This method is suitable for removing carbide scale or hard scale that cannot be removed by chemical cleaning. Its advantage is that the wear rate of the equipment is very low, but the disadvantage is that the heat exchange equipment must be disassembled, which is not very convenient for online cleaning, such as spiral plate heat exchangers. When spraying water for cleaning, the choice of water pressure is very important, generally between 50-70mpa. Practice has proven that low pressure results in poor cleaning effectiveness, while high pressure can damage equipment. Therefore, preliminary tests should be conducted before operation, and construction should be carried out after gaining experience. In some cases where there are a large number of heat exchangers, special equipment can be designed to facilitate water spray cleaning. When spraying water, if the water is not recycled, it will not only waste precious water resources, but also pollute the environment. By designing some equipment, water can be recycled and reused after sedimentation and treatment. For convenience of use, the water spraying equipment can be designed to automatically move according to needs, and the length and angle of the nozzle can be adjusted to meet different water spraying requirements; Spray cleaning can not only clean the inside of pipelines, but also the outside of pipelines and even the inner walls of shells. It has been applied to the cleaning of plate fin heat exchangers and plate heat exchangers, achieving satisfactory results.

Adding an appropriate amount of fine sand to water usually helps enhance the cleaning effect. However, if there is some kind of coating on the heat exchange surface, sand should not be mixed, and the choice of water pressure should also be cautious. Due to the high water pressure, do not point the nozzle at the on-site personnel to avoid accidents. In addition, when the water pressure is high, precautions should be taken to prevent the nozzle and pipeline from bursting and injuring people. In addition, there will be significant recoil during the operation process, and the operator should be prepared for this.