Bag Dust Collector

A bag filter is a type of bag collector. It relies on filter bags made of fibre media, and mainly purifies the gas through the dust layer formed on the surface of the filter bag. Its dust removal efficiency can reach more than 99. This equipment is developed on the basis of absorbing the experience of the same type of equipment and combining with the specific conditions.

   Bag filter is a kind of bag dust collector, is a kind of dry type dust filtering 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-type dust removing equipment, the dust with large particles and large specific gravity settles down due to gravity and falls into the ash hopper, and when the gas containing finer dust passes through the filter material, the dust is blocked, so as to purify the gas. The equipment has few mechanical action parts, small maintenance workload, and convenient bag change. It is easy to change the bag. Adopting separate room to clean the dust, it can be operated for a long time, and the dust collection rate reaches above. It can be widely used in cement, electric power, metallurgy, chemical industry, coking, boiler, cement mill, raw mill, mine crushing, material lifting, transport and other dust collection points can be used.

The air inlet arrangement of the bag type dust removal equipment has two ways: upper air inlet and lower air inlet. Used more is the lower air inlet, it has the advantages of stable airflow, easy to install and adjust the filter bag, etc., but the direction of airflow and dust falling in the opposite direction, after the dust will make the fine dust re-accumulation in the filter bag, the effect of dust cleaning deteriorated, the pressure loss increased. Upper air intake form can avoid the above shortcomings, but due to the addition of the upper flower plate and the upper air intake distribution room, so that the height of the dust collector increases, the filter bag installation and adjustment is more complicated, the upper flower plate is easy to accumulate dust.

According to the gas pressure inside the dust collector, there are two types: positive pressure type and negative pressure type. Positive pressure type (also known as pressure type) dust collector internal gas pressure is higher than atmospheric pressure, generally located in the ventilator out of the air section; the reverse is inhaled. Positive pressure type bag filter is characterised by a simple shell structure, lightweight, tightness requirements are not high, and even in the treatment of room temperature gas can be open, only need to protect the filter bag from wind and rain can be, and compact layout, easy maintenance, but the fan is susceptible to wear and tear. The outstanding advantage of negative pressure bag filter is that it can make the fan free from the wear and tear of dust, but it requires high structural strength and tightness of the shell.

   There are various forms of bag filter. From the filter bag cross-section shape, there are two kinds of cylindrical and flat filter bag. Round bags are more widely used, the diameter is generally 120-300mm, not more than 600mm, the length of the bag is generally 2-6m, some up to 12m or more. Diameter length ratio is generally 16-40, the value of which is related to the way of ash removal. For large and medium-sized bag filter, generally divided into a number of rooms, the number of bags in each room is as few as 8-15, as many as 200, the number of dust collector rooms per unit, as few as 3-4 rooms, as many as 16 rooms or more.

According to the direction of the dust gas flow filter bag points, there are two types of internal and external filtration. The inner filter means that the dust gas flows into the inner filter bag, the dust is blocked on the inner side of the bag, and the clean gas escapes through the filter material to the outer side of the bag; on the contrary, it is the outer filter. External filtration of the bag is usually equipped with internal support skeleton (bag cage), the bag is easy to wear, maintenance difficulties.

   Bag filter efficiency, pressure loss, filtration speed, and bag life are related to the way of ash removal, so most of the actual way of ash removal according to the bag filter classification and naming.