Dust bags

Bag filter, also known as filter dust collector, is a kind of dry dust collector, it is the use of fibre fabric made of bag filter element to capture solid particles in the dusty gas dust removal device. The principle of action is that the dust particles around the filter fabric fibres due to inertial force and fibre collision and be intercepted.

Dust bag fabric and design should try to pursue the filtration, easy dust stripping and effect. Dust bag selection is critical, it directly affects the dust removal effect of the dust collector, the selection of dust bag from the following aspects of selection: gas temperature, humidity and chemical properties, particle size, dust concentration, filtering wind speed, dust removal methods and other factors.

Dust bag is called the heart of the bag filter. Generally known as dust bag or filter bag, dust bag is the key part of the bag filter operation process, usually cylindrical filter bag hanging vertically in the dust collector.

A dust collector or dust removal equipment is a device that separates dust from flue gas. A bag filter, also known as a filter dust collector, is a dry dust collector, which is a dust collector that uses bag filter elements made of fibre compositions to capture solid particles in dusty gases. The principle of action is that dust particles are intercepted when they collide with the fibres around the filter cloth fibres due to inertial force.

In pulse and air box pulse dust collector, dust is attached to the outer surface of the filter bag. When the dusty gas passes through the dust collector, the dust is trapped on the outer surface of the filter bag, while the clean gas passes through the filter media to the inside of the filter bag. The cage inside the filter bag is used to support the bag and prevent it from collapsing, and it helps in dust cake and redistribution.

The fabric and design of the dust bag should be designed to maximise filtration, ease of dust stripping and effectiveness. The selection of dust bag is very important, it directly affects the dust removal effect of the dust collector, the selection of dust bag is selected from the following aspects: gas temperature, humidity and chemical properties, particle size, dust concentration, filtration air speed, dust removal method and other factors.

Working principle of bag

Bag filter is a kind of dry dust removal device. It is suitable for capturing fine, dry non-fibrous dust. The filter bag is made of textile filter cloth or non-textile felt, using the filtering effect of the fibre fabric to filter the dusty gas, when the dusty gas enters the bag filter, the particles of large, large dust, due to the effect of gravity, fall into the dust hopper, the gas containing fine dust is blocked when it passes through the filter media, so that the gas is purified. Generally the dust removal efficiency of new filter media is not high enough. After a period of time after the use of filter media, due to screening, collision, retention, diffusion, static electricity and other effects, the surface of the filter bag has accumulated a layer of dust, this layer of dust is called the initial layer, in the subsequent movement process, the initial layer of the filter media has become the main filtration layer, relying on the role of the initial layer of the filter media with larger holes to obtain a higher filtration efficiency. With the accumulation of dust on the surface of the filter media, the efficiency and resistance of the dust collector increase accordingly, when the pressure difference between the two sides of the filter media is very large, some of the fine dust particles that have been attached to the filter media will be squeezed, so that the efficiency of the dust collector decreases. In addition, the high resistance of dust collector will make the air volume of the dust collector system drop significantly. Therefore, when the resistance of dust collector reaches the value, it is necessary to clear the dust in time. When clearing soot, the initial layer should not be destroyed, so as to avoid efficiency loss. The structure of bag filter mainly consists of upper box, middle box, lower box (ash hopper), ash cleaning system and ash discharge mechanism and other parts.

The performance of the bag filter is good or bad, in addition to the correct choice of filter bag material, ash removal system plays a decisive role in the bag filter. For this reason, the method of clearing dust is one of the characteristics of the bag filter, but also an important part of the operation of the bag filter.