The material for dust collector bags is synthetic, natural or glass fibre woven into cloth or felt. The cloth or felt is then sewn into cylindrical or flat filter bags as required. Depending on the nature of the flue gas, the filter media is selected to suit the application conditions. Usually, in the case of flue gas temperature below 120°C, the filter media is required to have acid resistance and durability, often using polyester fleece and polyester needle felt; in dealing with high temperature flue gas (<250°C), the main choice is graphitised glass fibre cloth; in some special cases, the choice of carbon fibre filter media, etc. It is important to control the speed of the flue gas through the filter media (called filtration speed) in the operation of the bag filter. Generally the filtration speed is 0.5-2m/min, for particles larger than 0.1μm the efficiency can be more than 99%, the equipment resistance loss is about 980-I470Pa.

Dust collector bags are made of textile filter cloth and non-textile felt, using the filtering effect of fibre fabric to filter dust-containing gases.

According to the temperature material

A, room temperature cloth bag: room temperature cloth bag is mainly made of polyester, polypropylene, acrylic and other fibers by non-woven, textile process, with good air permeability, smooth surface, good dimensional stability, easy to strip dust and other excellent performance. Mainly used in general industrial enterprises with dust pollution industry dust removal and room temperature flue gas treatment and other fields.

Second, medium-temperature bags: as the country attaches greater importance to environmental protection, especially in recent years, the rapid development of bag-type dust removal technology industry, China began to use imported synthetic fibers developed can adapt to the more severe working conditions, ultra-long service life of high-performance filter materials. At present the more common medium-temperature filter materials are aramid fibers, PPS series fibers through the dip-tie, waterproof, oil-proof, anti-corrosion process treatment, so as to achieve the desired effect;.

Third, high-temperature bags: high-temperature bags are mainly made of P84, expanded glass fiber, ultra-fine glass fiber and other high-temperature resistant fibers through the textile, non-woven process, with good thermal stability, high filtration efficiency, long service life and other characteristics. It is mainly used for dust removal under various high temperature flue gas conditions.

Detailed description

The dust bag/filter bag is the heart of the bag-type dust collector in operation, usually cylindrical pulse-type filter bags are hung vertically in the dust collector, the dust-containing gas enters the dust collector from the air inlet and passes through the flow guide of the dust hopper, so that some of the large particles of dust in the gas are separated by inertia force and fall directly into the dust hopper. Most of the dust is collected on the outer surface of the filter bag, while the clean gas enters the inner part of the filter bag through the filter material, and the purified gas enters the upper box through the filter bag opening and is discharged through the air outlet. The cage inside the filter bag is used to support the bag and prevent it from collapsing, while it facilitates the removal and redistribution of the dust cake.

The fabric and design of the dust bag should be as efficient as possible, easy to remove and durable. The selection of dust bags is crucial, it directly affects the dust removal effect of the dust collector, the selection of dust bags is chosen from the following aspects: gas temperature, humidity and chemical properties, particle size, dust concentration, filter air speed, dust cleaning methods and other factors.

Dust bags are generally divided into pulse type dust filter bags, vibrating type dust bags and back-blowing type dust bags according to the different dust cleaning methods.

Depending on the shape, there are also round bag type, flat bag type and envelope type.

There are also different designs of bag mouth and bag bottom.