What is Bag Filter?
A Bag Filter is an air pollution controlling industrial equipment, used prominently in a Steam Boiler House Assembly. It is used to control the levels of sulfur dioxide and others.
There are different types of Bag Filters such as Shakers, Reverse Air and Pulse Jet type, with Pulse jet type being the most promising one of outstanding results.
A Pulse Jet type Bag Filter consists of a Four-sided hollow metallic body which is conical at the downside. Also, a vertical squirrel cage type arrangement is there for supporting and holding the filter bags. These squirrel type cages are covered by filter bag material. After covering these cages with Filter Bags, it appears as a Pipe like geometry Downside of this cage is blind while the other side is open for the flue gases exit and pressurized air inlet.
During the operation of a Steam Boiler, the flue gases leaving the Boiler enters the Bag filter body. Now, these flue gases come in contact with the outer surface of the Filter bags ( pipe-like). As the ID Fan creates a continuous suction effect, these flue gases try to enter the cage. So the, bigger size dust particles get collected at the surface of the Filter and flue gases leaves Bag filter through the outlet.
Now, these dust particles which are attached to the surface of the Filter Bag are separated by the Pressurized air supplied by the Pulse Jet system installed at the top of the Bag Filter. This pressurized air enters through the opening from where the Flue gases leave the Filter Bag and this air being pressurized hits the inner surface of the Filter Bag.The dust particles being at rest gets separated thereby justifying the law of inertia. These dust particles, thus separated, gets collected at the bottom bit of the Bag Filter with the help of a Rotary Air-Lock valve. Thereby, completing the operation.
We, at Thermodyne, have successfully installed and commissioned Bag filters at various sites and has helped in protecting the environment.