(1) The minimum circulating amount must be 4 times/hour of the bath liquid volume, and insufficient circulating amount may cause deposition on the bath bottom and workpiece surface.
(2) Minimum surface speed must be guaranteed: low surface speed may cause deposition on the surface of the workpiece.
(3) The liquid level difference between the main tank and the auxiliary tank must be ensured.
(4) There should be no injection dead angle at the bottom of the tank: the falling off of the glass fiber reinforced plastic lining in the tank body may cause repeated deposition and dissolution of paint, corrosion of the tank wall and electric leakage, threatening personal safety.
(5) Proper filtration accuracy must be ensured: Good filtration is an important measure to ensure the coating is particle-free.
(6) To ensure a good temperature control heat exchange system: circulation and electrophoresis heat exchange, it is essential to control the tank temperature. The electrophoresis tank requires constant temperature in the production process, so the circulating tank should have a heat exchange system and sufficient heat exchange capacity. Temperature requirements of heat exchange medium: cooling: 5 ~ 15℃, heating:
(7) It is necessary to test the recovery of paint accumulated in inverted cans in order to improve the utilization rate of electrophoretic paint. Ultrafiltration system has two main functions: providing sufficient ultrafiltrate for effective closed-circuit washing system, purifying water-soluble impurities in paint and improving the utilization rate of electrophoretic paint. The key of ultrafiltration system management is the permeability of ultrafiltrate. The flow of ultrafiltration system must be checked and recorded every day, and corresponding measures should be taken to deal with any abnormality. When the permeability drops by 30%, tissue cleaning is needed. The reasons for low light transmittance can be roughly divided into the following aspects:
1) In the ultrafiltration equipment, the low flow rate of the tank liquid, the change of the set pressure, the insufficient coarse filtration and the frequent stagnation of the equipment (the equipment stops running for more than 1 hour) will reduce the permeability and even cause damage to the diaphragm (ultrafiltration membrane);
2) The bath temperature is too high;
3) Failure of the activation layer of ultrafiltration membrane: the activation layer changes the polarity of charged substances to be the same as that of the bath itself, and its function is limited by time, and its durability can reach several months under the best conditions. After the activation layer fails, it must be cleaned to restore its function. When cleaning, the cleaning solution should be prepared in strict accordance with the formula and proportion, and the cleaning procedure should be carefully followed, otherwise the ultrafiltration membrane will be invalid or scrapped. The environmental protection design of electrophoresis line to achieve zero emission benefits from the application of EDRO system, which turns ultrafiltrate into pure water spray body. The focus of its management is also the amount of pure water, and the reasons for the low amount of pure water are usually:
1) Improper maintenance during shutdown: The correct method is to wash the reverse osmosis system with pure water once a day when the shutdown time is less than 72 hours, and stop it after 30 minutes of operation to prevent the components from losing water or breeding microorganisms; The system has been out of production for more than 72 hours and must be protected by chemicals.
2) Improper selection of cleaning agent and method: The correct method is to check the deposits at the water inlet end of the membrane element or on the filter element before cleaning, so as to judge the nature of membrane surface blockage, select the appropriate cleaning agent, and pay attention to controlling the PH value and temperature of the cleaning solution. The following table is the configuration method of cleaning solution, and the actual operation should be selected according to different situations.