How to maintain and maintain the waterproof vent system

1. Preservation of waterproof vents:

When the membrane is stored for a long time, it must maintain good performance and external energy has use value, so the life of the waterproof vent is an important issue. Therefore, special attention should be paid to the actual preservation. The preservation of waterproof and breathable microfiltration membranes is divided into wet preservation and dry preservation. Either way, the purpose is to prevent hydrolysis of the membrane, growth and erosion of microorganisms, shrinkage and deformation of the membrane, and the like.

1. Wet preservation

The key to wet preservation is to always keep the membrane surface with preservation solution in a moist state. The preservation solution can be formulated as follows: water: glycerol: formaldehyde = 79.5: 20 : 0.5. The function of formaldehyde in the waterproof vent material is to prevent the growth and reproduction of microorganisms on the surface of the membrane, and to prevent the erosion of the membrane. The purpose of adding glycerin is to reduce the freezing point of the preservation solution and prevent the membrane from being damaged by freezing. The formaldehyde in the formula can also be replaced by copper sulfate and other fungicides that are not harmful to the membrane. The storage requirements of cellulose acetate film are temperature 5~40℃, PH= 4.5~5, while the storage temperature and pH of non-cellulose acetate film can be wider.

2. Dry preservation:

Waterproof vents are often marketed as dry membranes, as this facilitates storage and transport. In addition, if the wet film is to be replaced by a dry method, the film must also be treated by the following methods before proceeding. The specific method is as follows: the cellulose acetate membrane can be soaked in 50% glycerol aqueous solution or 0.1% sodium dodecyl sulfonate aqueous solution for 5-6 days, and then dried at a relative humidity of 88%. Polysulfone membranes can be dried at room temperature with 10% glycerol, sulfonated oil, polyethylene glycol and other solutions as dehydrating agents. In addition, the surfactant also has a good effect on the deformation of the protective film pores.

Second, the maintenance and maintenance of the waterproof vent system should pay attention to the following issues:

1. According to the different membranes, special attention should be paid to the environment of use, especially the temperature, pH value of the feed liquid, and even the chlorine content in the feed liquid.

2. When the membrane system is stopped for a short time, attention should be paid to the moisturizing of the membrane, because once the membrane surface loses water and there is no remedial measure, the waterproof vent hole will shrink and deform, which will reduce the membrane performance.

3. When stopping, avoid contact with high-concentration feed liquid.

4. Regularly wash and maintain the membrane with maintenance solution to reduce membrane pollution.

5. In use, operate according to the operating conditions that the membrane system can withstand, and avoid overloading for long-term operation, so as to avoid irreversible damage to the membrane.