Electrophoretic paint bath liquid computer automatic maintenance system

Abstract

The invention discloses a computer automatic maintenance system for an electrophoretic coating bath, an auxiliary bath on an electrophoresis bath is sequentially connected with a coating inlet valve, an ultrafiltration pump, an ultrafiltration check valve and a stainless steel bag filter through a pipeline, a filter pressure gauge is arranged at the upper part of the stainless steel bag filter, a blowdown valve is arranged on one side of a coating outlet at the lower part of the stainless steel bag filter through a tee joint, an ultrafiltration reverse coating feeding electromagnetic valve and an ultrafiltration forward coating feeding electromagnetic valve are connected to the other side of the coating outlet at the lower part of the stainless steel bag filter through a coating feeding tee joint, the ultrafiltration forward coating feeding electromagnetic valve is sequentially connected with an inlet spiral-wound membrane ultrafiltration pipe, an ultrafiltration forward coating discharging electromagnetic valve, a coating discharging tee joint and the electrophoresis bath through a pipeline, the ultrafiltration forward coating feeding electromagnetic valve is sequentially connected with the inlet spiral-wound membrane ultrafiltration pipe, an ultrafiltration reverse coating discharging electromagnetic valve, the coating discharging tee joint and the electrophoresis bath through a pipeline; the PH value and the electrical conductivity of the electrophoresis bath are monitored online, the control of the electrical conductivity is automatically realized under the condition that the ultrafiltration water is not discharged, the stability of a bath solution is strengthened, the quality of an electrophoresis product is improved, the waste is avoided, and the pollution discharge is reduced.

Description

technical field [0001] The invention relates to a paint tank device, in particular to a computer automatic maintenance system for electrophoretic paint tank liquid. Background technique [0002] Due to its resin structure, cathodic electrophoretic paint cannot remove impurity ions in the bath liquid through ion exchange resin like anodic electrophoretic paint. The existing maintenance method is that the bath liquid passes through the ultrafiltration membrane to remove the water and acid containing impurity ions. , organic solvents and additives are separated from the electrophoretic paint resin, the electrophoretic paint resin is returned to the electrophoresis tank, and the water, acid, organic solvent and additives containing impurity ions are discharged as waste water. This maintenance method has the following defects: 1. Effective waste Organic solvents, additives and some small molecule electrophoresis resins. In the original ultrafiltration process, although the impur...

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Problems solved by technology

[0002] Due to its resin structure, cathodic electrophoretic paint cannot remove impurity ions in the bath liquid through ion exchange resin like anodic electrophoretic paint. The existing maintenance method is that the bath liquid passes through the ultrafiltration membrane to remove the water and acid containing impurity ions. , organic solvents and additives are separated from the electrophoretic paint resin, the electrophoretic paint resin is returned to the electrophoresis tank, and the water, acid, organic solvent and additives containing impurity ions are discharged as waste water. This maintenance method has the following defects: 1. Effective waste Organic solvents, additives and some small molecule electrophoretic resins

In the original ultrafiltration process, although the impurity ions are discharged and the conductivity is reduced, at the same time, some active ingredients in the electrophoresis bath are discharged at the same time, causing unnecessary waste and environmental pollution, such as solvents, additives and small molecule electrophoresis resins. It plays a key role in the process of electrophoresis. In order to make a good product, it is generally necessary to add a large amount of solvent to the bath after ultrafiltration to maintain the balance of the electrophoresis tank, which will increase the production cost accordingly.

The types and proportions of solvents and additives in the original paint formula are very complicated, and the types and proportions of solvents and additives added after ultrafiltration are relatively simple, and the addition amount cannot be controlled, which will easily cause the instability of the bath solution and affect the electrophoresis product. quality

2. The PH value is not well controlled

Since the cathodic electrophoretic paint is weakly acidic, when the pH of the electrophoretic tank solution rises, it is necessary to add neutralizing acid to adjust it. However, the conductance of the neutralizing acid is very high, and the overall conductance of the tank solution increases rapidly after adding more, and the film on the electrophoretic paint The speed is slow, the leveling of the paint film is poor and prone to shrinkage and many other problems, the overall addition amount is difficult to grasp, and it is easy to cause the instability of the bath solution, which will affect the quality of the electrophoresis product

3. Environmental protection is not up to standard

As mentioned above, because the ultrafiltration water contains a large amount of organic solvents, additives and small molecule electrophoresis resins, the COD index is very high and cannot be discharged directly. Biochemical treatment equipment is required to treat this kind of sewage. The equipment is expensive and the treatment process is complicated. Increase the production cost of the product

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