Definition of bag filter:
The bag filter is a device that uses a bag-like filter element made of fabric to trap solid particles in a dust-containing gas.
With the advent of new filter materials and automatic cleaning methods, this type of dust removal equipment, which has a history of more than one hundred years, has become increasingly sophisticated and widely used in modern industry.
Classification of bag filter:
According to the national standard of “Classification of Bag Filters and Specification Performance Specification”, bag filter is divided into five categories.
Ash removal method is the main sign of the classification of bag filter
(1) Mechanical vibration
Bag filter with mechanical device (including manual, electromagnetic or pneumatic device) to make the filter bag vibrate and cleaned. There are bag-type dust collectors which are suitable for gap work and non-segmented structures and sub-chamber structures suitable for continuous operation. .
(2) Room reverse blowing
Take the structure of the sub-chamber, use the valve to switch air flow from room to room, and force the filter bag to collapse or bulge and dust bag filter under the effect of reverse air flow.
(3) nozzle backflush
The blowback air flow is provided by a high-pressure blower or a compressor, and a blower is used to blow back the air through the moving nozzle, so that the filter bag is deformed and shaken, and the baghouse dust-removing filter is penetrated by the filter material (all of which are non-subdivision structures).
(4) Vibration, backflushing and use
Mechanical baggage (including electromagnetic vibration or pneumatic vibration) and backflushing baghouse dust collectors (both of which are compartmental structures).
(5) Pulse jetting
Compressed air is used as cleaning power, and the compressed air is released within a moment by the pulse blowing mechanism. Several times of the secondary air is induced into the filter bag at high speed, and the filter bag rapidly bulges. The dust is removed by impact vibration and reverse airflow. Baghouse.
Bag filter structure
According to different structural characteristics, bag filter has the following forms
(1) Upper intake type and lower intake type
The upper air inlet type means that the dust-containing air flow inlet is located in the upper part of the bag room, and the air flow is in the same direction as the settlement of the dust.
The downwind wind type is where the dust-laden airflow inlet is located in the lower part of the bag room, and the direction of the airflow and the dust fall are opposite.
If the outside view is under the air, but the bag room is equipped with a deflector to introduce the dust-containing airflow into the upper part of the bag room. It should belong to the upper air type.
(2) round filter and flat filter
Circular filter means that the filter bag is cylindrical.
The flat filter type refers to a trapezoidal, wedge-shaped and non-cylindrical shape of the filter bag in the form of a flat plate (envelope).
(3) Suction type and press-in type
Inhalation means that the fan is located behind a bag filter and the bag filter is operated under negative pressure.
Press-in type means that the fan is located before the bag filter and the bag filter is working under positive pressure.
(4) Inlet and Outer Filters
The inner filter type refers to the dust-containing air flow from the bag to the outside of the bag, and the dust is collected on the inner side of the filter bag.
Outer filtration refers to the flow of dust-laden air from outside the bag to the outside of the bag to trap dust.