Flocked Swab production line 1. Maintenance of the main […]
1. Maintenance of the main tank circulation system
In order to ensure the smooth circulation of the electrophoresis main tank, you must pay attention to the usual maintenance and maintenance:
(1) A low circulation rate must be guaranteed: 4 times the tank liquid volume/hr. Insufficient circulation may cause deposition on the bottom of the tank and on the surface of the workpiece.
(2) Low surface velocity must be guaranteed: low surface velocity may cause deposition on the surface of the workpiece.
(3) The liquid level drop of the main and auxiliary tanks must be guaranteed.
(4) It must be ensured that there is no dead angle at the bottom of the tank: the fall of the glass fiber reinforced plastic lining in the tank may cause repeated deposition and dissolution of the paint, corrosion of the tank wall, and threat to personal safety.
(5) Proper filtration accuracy must be ensured: good filtration is an important measure to ensure that the coating film is free of particles.
(6) A good temperature control heat exchange system must be guaranteed: circulation and electrophoresis heat exchange, it is essential to control the bath temperature. The electrophoresis bath requires constant temperature during the production process, so the circulating bath must have a heat exchange system and sufficient heat exchange capacity. The temperature of the heat exchange medium is required: cooling: 5 ～ 15℃, heating: <50℃. Recommended bath temperature control during long-term shutdown: 20～25℃
(7) It is necessary to consider the recovery of the accumulated paint in the filter tank to improve the utilization rate of the electrophoretic paint.
Two maintenance of the ultrafiltration system
The ultrafiltration system has two main functions: it supplies sufficient ultrafiltrate for the effective closed-circuit flushing system and purifies the water-soluble impurities in the paint, and improves the utilization rate of the electrophoretic paint. The key point of the ultrafiltration system management is the ultrafiltration fluid permeation volume. It is necessary to check and record the ultrafiltration system flow rate every day. If abnormalities are found, corresponding measures will be taken immediately to deal with it. When the permeation volume drops by 30%, cleaning must be organized. The reasons for the low permeability are roughly divided into the following aspects:
1) The low flow rate of the tank liquid in the ultrafiltration equipment, the change of pressure setting, the lack of coarse filtration, and the frequent equipment stagnation (the equipment stops running for more than 1 hour) will reduce the permeation rate and may even cause the membrane (ultrafiltration membrane) to be damaged;
2) The temperature of the bath liquid is too high;
3) Failure of the activation layer of the ultrafiltration membrane: The activation layer converts the polarity of the charged material to the same polarity as the bath itself. Its effect is limited by time, and its durability can reach several months under conditions. After the activation layer fails, cleaning must be used to restore its function. When cleaning, the cleaning solution must be configured in strict accordance with the formula and ratio, and the cleaning procedure must be carefully followed. Otherwise, the ultrafiltration membrane will become invalid or scrapped.
Three maintenance of EDRO system
The environmental protection design of the electrophoresis line to achieve zero emissions is due to the application of the EDRO system, which turns the ultrafiltrate into pure water to spray the car body. The main point of its management is also the pure water permeation rate. The reasons for the low pure water amount usually include:
1) Improper maintenance during shutdown: the correct method is to flush the reverse osmosis system with pure water once a day when the shutdown time does not exceed 72 hours, and stop after 30 minutes of operation to prevent the components from losing water or growing microorganisms; the system is shut down If the time exceeds 72 hours, it must be preserved with chemicals.
2) Improper selection of cleaning agent and method: The correct method is to check the sediment on the inlet end of the membrane element or the sediment on the filter element before cleaning, determine the nature of the blockage on the membrane surface, select the appropriate cleaning agent, and pay attention to the pH value of the cleaning solution And temperature control.