Cleaning method of plate heat exchanger soot blowing cleaning and water spray cleaning

The mechanical cleaning, soot blowing cleaning and water spray cleaning methods of plate heat exchanger are introduced as follows:

Soot blowing cleaning

Soot blowing cleaning of soot blower has a good effect on removing particle dirt. The soot blower uses high-pressure air and high-pressure steam to spray directly onto the heat exchange surface through the nozzle. Steam should not be used if it corrodes heat exchange surfaces. There are many types of soot blowers. For example, rotary soot blowers are usually used to remove particulate deposits that do not adhere to walls; Telescopic soot blower, which is usually used to remove particles adhering to the wall. In order to remove the serious scaling surface without shutdown, the soot blowing pipe driven by motor can be used; Manual pipe blowing can also be used for small heat exchangers.

Spray cleaning

The method is suitable for carbide scale or hard scale that cannot be removed by chemical cleaning. The 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 on-line cleaning, such as spiral plate heat exchanger. During water spray cleaning, the selection of water pressure is very important, and the general pressure is between 50-70mpa. Practice has proved that the cleaning effect is poor if the pressure is too low, and the equipment will be damaged if the pressure is too high. Therefore, the preliminary test shall be conducted before operation and the construction shall be carried out after obtaining experience. In some occasions with a large number of heat exchangers, some special equipment can be designed to facilitate water spray cleaning. When spraying water, if the water is not recycled, it will not only waste valuable water resources, but also pollute the environment. By designing some equipment, water can be recycled after sedimentation and treatment. In order to facilitate use, the water spraying equipment can be designed to move automatically according to needs, and the length and angle of the nozzle can be adjusted to meet different water spraying requirements; Water spray cleaning can not only clean the inside of the pipeline, but also clean the outside of the pipeline and even the inner wall of the shell. It has been applied to the cleaning of plate fin heat exchanger and plate heat exchanger, and satisfactory results have been obtained.

Adding an appropriate amount of fine sand to the water usually helps to enhance the cleaning effect. However, if there is some coating on the heat exchange surface, sand shall not be mixed, and the water pressure shall be selected carefully. Because the water pressure is very high, do not point the nozzle to the site personnel to avoid accidents. In addition, when the water pressure is high, prevent the nozzle and pipe from bursting and hurting people. In addition, large recoil force will be generated during operation, and the operator should be prepared for this.