Bag filter

Description

The  bag filter adopts filtering mode of external type, consisting of upper box, intermediate box, dust hopper, filtering bag components, blowing devices, lifting valves, dust discharging valve, pulse valves as well as test and control system.
      Under working condition, the flue gas enters each dust hopper from under part of intermediate box via the inlet pipe. The large particles will directly drop into the dust hopper due to inertial impaction and gravity effects, while the residual dust will follow the gas stream entering the filtering area in the intermediate box, where the dust will adhere to the outer surface of filtering bag. After filtering, the clean gas will be discharged via upper box, lifting valve and discharging pipe.

With operating continuously, the dust amount adhered to the outer surface of the filtering bag will be increased gradually, which will make the resistance of the dust filter gradually increased, too. When the dust on the bag surface is accumulated to a certain amount, the control devices (differential pressure control, time control or manual control) will give out signals. Firstly, close the lifting valve of one bag chamber to cut off the gas stream, and then open the electromagnetic pulse valve, the compressed air will make the filtering bag rapid expansion and shocking, so that the dust accumulated on the outer surface of bag will drop. Take full account of the dust settling time (to ensure that the dust stripped from the filtering bag will drop into the dust hopper effectively and avoid it adhere to the adjacent filtering bag following the airflow, so that make the filtering bag a thorough cleaning), then open the lifting valve to get this bag chamber to recover filter function. Meantime the next chamber will start dust clean. The dust cleaning cycle will not be completed until the last bag cabin finishes the dust cleaning process. The bag filter is composed of many independent bag chambers, and the dust cleaning process is carried out in sequence without disturbing ofeach other, which will realize a continuous operation of the equipment.