After the screen changer has been used for a long time, it needs to be cleaned, so how to improve its cleaning effect is particularly important. The cleaning of the screen changer is divided into three steps: TEG cleaning, high-pressure water gun cleaning and ultrasonic cleaning.

After using the steam blowback filter element to undergo ultrasonic cleaning, a part of the filter impurities are removed, but a part of it remains inside the filter. In order to remove this part of impurities, after demonstration, a 1.6MPa steam back-blowing production line was added for filter element back-blowing to remove internal impurities to a greater extent. Practice has proved that its effect is remarkable.

Extend the cooking time of TEG TEG, namely triethylene glycol, is a colorless and transparent neutral oily liquid with a boiling point of 276°C. It has alcoholysis and dissolution effects on polyester under heating [2]. TEG cleaning is to dissolve the polyester melt on the screen changer after heating and cooking under the action of TEG solvent. The melt filter element that has just been removed is wrapped in polyester melt. It must be cooked in a TEG cooking tank and taken out at a constant temperature of 285°C for 4 hours. After removing the filter element, it is found that some of the melt has not been completely dissolved. For this reason, the constant temperature time is increased from 4h to more than 6h, so that all the melt adhered to the filter element is dissolved; at the same time, the method of secondary TEG cooking is adopted, that is, the removed filter element is put into the hanging basket for the second cooking. , To further increase the effect of cooking and cleaning.

Strengthen the high-pressure water gun to rinse the TEG steamed filter element. Because it is dirty, it must be rinsed with a high-pressure water gun. With the external filter type screen changer, the impurities remain in the outer layer of the filter. To this end, a special high-pressure water gun is used to flush from the inside to the outside to flush out the impurities. At the same time, the protective cover outside the filter element is removed to enhance the cleaning effect. In order to clean the filter element to a greater extent, randomly take out 10 from a set of filter elements, and then randomly remove 5 of the outer iron covers, then use a high-pressure water gun to clean the filter element, and then use ultrasonic cleaning for 2h, do a bubble point test, compare The results are shown in Table 2. It can be seen that it is easier to clean the filter element by removing the outer iron cover of the filter element during the high-pressure water gun flushing and ultrasonic cleaning stages.