Several common problems with filter bags

Q: The depth of the filter material cannot measure the aperture. How is the accuracy determined?

Answer: The surface filter screen material can directly measure the obtained pore size value, which is the precision of the filter material. However, deep filtration is impossible to determine the exact value, so the conventional calibration method is to calibrate a class of materials with corresponding gram weight, thickness and diafiltration to a certain rated accuracy. The standards held by each material supplier are different, but each batch of materials should have strict industrial characteristics and complete test data. Therefore, when the filter bag provided by your filter bag supplier is calibrated to 5um, it should be possible to clarify the basis and test data of the accuracy calibration.

Q: The same nominal accuracy, but why is the filtering result different?

A: In fact, the nominal accuracy is only the nominal accuracy of the material in the strict sense. It is different from the accuracy in the real sense and can only be used as a reference for the classification. When choosing a filter bag, you should ask clearly what the filtration efficiency is at the nominal accuracy. This is crucial, and this is ignored by most users. Therefore, the same nominal 1um material, the filtration efficiency may be very different, the effect of use is of course very different.

Q: My filter bag has a short life and why is the same accuracy different?

A: It is necessary to know that the service life of the filter material is inseparable from the gas permeability of the material. The low gas permeability of the material is small, the original pressure difference used in the filter bag is small, the pressure is slow, and the life of the natural filter bag is long. The opposite is true. In addition, the process control of the surface treatment also affects the life of the filter bag. The liquid felt is subjected to a strict singeing process on the surface. If the surface finish is excessively pursued, the melted fiber will block the filter channel when it is over-burned, which will naturally reduce the liquid passage and increase the pressure drop of the filter material. The life of the bag.

Q: Why use a hot melt seam filter bag?

Answer: The experiment shows that the seam filter bag is pressed by the pressure at the initial stage of use, and a small amount of unfiltered liquid will be short-circuited by the extrusion filter bag, which reduces the final filtration efficiency of the filter bag. The hot melt seam filter bag is seamed with advanced ultrasonic hot melt technology. The joint has no pinholes and high strength, which can improve the overall filtration efficiency of the filter bag.

Q: What kind of surface treatment is just right?

Answer: The surface treatment is designed to lock the residual fiber on the surface, avoiding the filter felt being washed by the high-speed liquid, and taking out the fine fibers on the surface of the filter bag, causing secondary contamination of the filtrate. The quality of the surface treatment directly affects the availability of the filter material, and the control of the process is the key to the material. If the burn is over, there will be a blocked channel of the melting, and under-burning will result in poor retention of the residual fiber. A good and rigorous process should control the sintering of the fiber along the root without melting. Many manufacturers in the market use the common air filter felt as a liquid filter bag, and the two are completely different in surface treatment. The alternative use will definitely affect the usability of the filter bag.

Q: Is the filter bag broken? Is it a problem with the filter bag?

A: The answer is not necessarily. Before making a correct conclusion, Zui is good to check if your filter bag fits well with the existing filter built-in filter basket. As is known to all, the filter bag is a non-woven fabric, which cannot be pressed under its own pressure. It should be used in conjunction with the filter basket and fit tightly with it. If the size of the filter bag does not match, the filter bag is not well fitted or suspended. If the pressure is not effectively transmitted to the filter basket, the filter bag will be damaged soon. In addition, you should also check if the filter bag has not been replaced for a long time. The increased pressure difference will also cause damage to the filter bag, and even worse, it will swell the filter basket.