Little knowledge about filter bags

The filter bag has excellent chemical performance stability and heat resistance and is often made of needled felt.

How to use the filter bag:

Filter airtight filtration: The filter bag and the matching filter are used at the same time, using the system fluid pressure to squeeze the liquid through the filter bag to achieve the purpose of filtration. It has the advantages of fast flow rate, large processing capacity, and long service life of the filter bag, and is especially suitable for occasions where large flow requires closed filtration.

Self-flow open filtration: The filter bag is directly connected to the pipeline through a suitable joint, and the filtration must be carried out by the gravity pressure difference of the fluid. Its notable feature is that it does not need equipment investment, and the filtration is simple and feasible, especially suitable for small-scale, various, and intermittent economical liquid filtration.

A bag filter is a dry dust filter. It is suitable for capturing fine, dry, non-fibrous dust. The filter bag is made of woven filter cloth or non-woven felt, and the dust-containing gas is filtered by the filtering effect of the fiber fabric. The action settles down and falls into the ash hopper. When the gas containing finer dust passes through the filter material, the dust is blocked and the gas is purified. Generally, the dust removal efficiency of the new filter material is not high enough. After the filter, the material is used for a period of time, due to the effects of sieving, collision, retention, diffusion, and static electricity, a layer of dust accumulates on the surface of the filter bag. This layer of dust is called the primary layer. The main filter layer of the filter material depends on the role of the primary layer, and the filter material with a larger mesh can also obtain higher filtration efficiency. With the accumulation of dust on the surface of the filter material, the efficiency and resistance of the dust collector will increase accordingly. When the pressure difference between the two sides of the filter material is large, some fine dust particles that have been attached to the filter material will be squeezed. Reduce the efficiency of the dust collector. In addition, the high resistance of the dust collector will significantly reduce the air volume of the dust removal system. Therefore, after the resistance of the dust collector reaches a certain value, the dust should be cleaned in time. The primary layer should not be damaged when cleaning, so as to avoid a drop in efficiency.

The structure of the bag filter is mainly composed of an upper box, middle box, lower box (ash hopper), ash cleaning system, and ash discharge mechanism

The performance of the bag filter is good or bad, in addition to the correct selection of the filter bag material, the cleaning system plays a decisive role in the bag filter. For this reason, the cleaning method is one of the characteristics that distinguish the bag filter, and it is also an important part of the operation of the bag filter.

Classification of filter bags:

1. According to the shape of the cross-section of the filter bag, it is divided into a flat bag (trapezoid and flat) and a round bag (cylindrical).

2. The way of air inlet and outlet is divided into the lower air inlet and upper air outlet, upper air inlet and lower air outlet, and direct current type (limited to plate flat bags).

3. According to the filtering method of the filter bag, it is divided into external filter type and internal filter type.

4. According to the use environment and temperature resistance procedure of the filter bag, it is divided into normal temperature, medium-temperature, and high temperature.

Fibers for filter media include cotton fiber, wool fiber, synthetic fiber and glass fiber, etc. The filter media woven from different fibers have different properties. The commonly used filter materials are 208 or 901 polyester flannel, the use temperature is generally not more than 120 ° C, the glass fiber filter bag treated with silicon resin is generally not more than 250 ° C, and the cotton wool fabric is generally suitable for non-corrosive; Dusty gas below 80-90℃.

The most commonly used cleaning methods are:

1. Gas cleaning: Gas cleaning is done by means of high-pressure gas or external atmosphere blowing back the filter bag to remove the dust on the filter bag. Gas cleaning includes pulse jet cleaning, reverse blowing, and reverse suction.

2. Mechanical vibrating dust removal: divided into top vibrating dust removal and middle vibrating dust removal (both for filter bags), by means of a mechanical vibrating device periodically vibrating each row of filter bags, in turn, to remove filter Ash on the bag.

3. Manual beating: Manually beat each filter bag to remove the dust on the filter bag.

Wuxi Lenge Purification Equipment Co. Ltd. is a professional purification equipment manufacturer. Suitable for pharmaceuticals, laboratory food, beverages, etc. If you are interested in purification equipment, please feel free to contact us! You can call 86-510-85189266. Or send an email to export@wxljjh.com.