The blowing pressure of the bag filter refers to the compressed air pressure of the pulse jet. The greater the injection pressure, the more induced secondary air flow, the greater the backflush gas velocity formed, the better the cleaning effect, and the more obvious the pressure drop of the bag filter. After the bag filter pressure drop is limited, the higher the injection pressure, the greater the processing capacity. In the case where the injection interval and the injection time are constant, the injection pressure increases, allowing the inlet dust concentration to be correspondingly increased. However, if the injection pressure is too high, over-ashing will also occur, which will affect the purification efficiency, that is, the phenomenon of “ash ashing” occurs instantaneously in the bag filter. At the same time, the consumption of gas increases and energy is wasted. It can be seen that too low or high injection pressure will affect the filtration effect.
A considerable part of the pressure of the compressed air is consumed to overcome the resistance of the blowing system itself, and its value can reach more than 0.2 MPa, in which the resistance of the pulse valve occupies a large part. In recent years, there have been several types of low-impedance pulse valves, such as direct pulse valves and double-diaphragm low-pressure pulse valves. As the internal resistance is reduced much, the injection pressure is also reduced accordingly, and the injection pressure can be as low as 0.2-0.3 MPa.
In addition, the injection pressure can be reduced by adding the diameter of the atmospheric package and the injection pipe to the nozzle instead of the injection hole. The DMF-T direct electromagnetic pulse valve is a low pressure pulse valve, and the DMF-Z angle pulse valve is a high pressure pulse valve. The pressure loss of the DMF-T is different and the injection pressure should be different. In addition to considering the impulse valve resistance, the injection pressure should also consider the length of the filter bag. The short filter bag uses a low injection pressure, and the long filter bag injection pressure should be increased accordingly. For the filter bag length of 2m, low pressure direct pulse valve, injection pressure is generally not more than 0.45 ~ 0.55MPa. Flat bag filter most high-pressure angle pulse valve, injection pressure can be properly increased to 0.6MPa.
