Bag material selection of bag filter
The selection of bag material is the first consideration of bag filter. The selection of filter bag material will directly affect the filtering effect. The wrong material of the filter bag will lead to the pollution of the material and the reduction of the filtering effect. The material selection of bag filter mainly considers the compatibility of filter bag and operating medium. Generally, through the characteristics of the operating medium, design temperature, design pressure, pH and operating conditions (such as whether it is necessary to withstand steam, hot water or sterilization chemicals), Evaluate and eliminate the unsuitable filter materials one by one, that is, select the available filter materials initially. The use is also an important consideration. For example, the filter materials used for drugs, food or cosmetics must be the materials approved by FDA; for ultra-pure water, select the filter materials that are pure and do not contain substances that will affect the specific impedance; for filtered gas, select the hydrophobic materials and whether the design of "sanitary filtration" is required.
Select appropriate filter bag aperture according to the intercepted particle size proposed by the process and the efficiency curve of the filter bag provided by the manufacturer. Although the filtration efficiency of many filter bags has reached more than 98% at the filtration accuracy, about 2% of the particles that need to be intercepted still need to be considered. If the process requires a high retention rate of particles to be intercepted, it is feasible to select a higher precision filter bag. With the increasing strength of China's textile industry, filter bags have also been sold abroad in large quantities and have occupied a place in the international market. Due to the lack of relevant international and domestic standards for filter bags and technical means of production, the quality of filter bags is uneven, which brings difficulties to selection.