Research and Design of Dust Removal Program for Bag-Type Pulse Dust Collector
The design of the dust removal program is of utmost importance and is based on various factors such as the principle of back-blowing dust removal, filter bag bulging and shrinking time, filter bag size, dust specific gravity, and more.
Impact of Program Execution and Design:
If the program's execution time and cleaning status design are unreasonable, it can adversely affect the cleaning effectiveness and overall performance of the dust collector. Currently, the most commonly used cleaning procedures are "two-state" (filtration ~ cleaning ~ filtration), and "three-state" (filtration ~ cleaning, static sedimentation ~ filtration) is also utilized. However, both of these cleaning states have their limitations. For instance, the "three-state" cleaning may lack sufficient cleaning force, thereby affecting the cleaning effectiveness. On the other hand, the "two-state" cleaning process does not provide enough time for dust to settle, resulting in phenomena such as "secondary dust" and "dust reattachment." When "dust reattachment" occurs extensively, it can lead to an "out of control" situation, causing equipment failure.
To address the issues encountered in the "two-state" and "three-state" cleaning methods, a new "combined state" cleaning method has been researched and designed. This method combines the advantages of both "two-state" and "three-state" cleaning. It incorporates the strength of "two-state" cleaning, the static settlement process of "three-state" cleaning, and introduces a unique filter bag shaking process. The cleaning process in the "combined state" is as follows:
Turn on the counter blower and open the shut-off valve in front of it to close the air outlet. The reverse blower blows the reverse ash cleaning airflow into the small bag chamber, changing the pressure difference inside and outside the filter bag. This causes the filter bag to transition from the "expanded" state to the "shrunken" state, effectively peeling off the dust layer on the surface of the filter bag.
After the cleaning time, close the shut-off valve and open the air outlet. The dust-laden gas re-enters the small bag chamber, causing the filter bag to expand sharply and shake, resulting in further cleaning.
Close the air outlet and open the reverse air outlet. The pouch chamber is sealed, creating an airless state. This allows the dust suspended in the filter bag to settle.
Open the air outlet and close the reverse air outlet. The jet filter bag "expands" again and returns to the filtering state. The transition between various states is facilitated by the lift switch valve and stop valve.
The duration of "stop cleaning, dust-free sedimentation time" depends on the length of the filter bag, volume and mass of dust, and the direction of the back-blow cleaning airflow. Generally, dust settles within 40s to 90s. As the blow-back airflow generated by our designed dust removal mechanism aligns with the free sedimentation of dust, the dust sedimentation time can be shortened. The back-blowing and cleaning time are determined by the filter bag length and the speed of back-blowing.
The pulse cleaning control principle diagram adopts a row and column matrix control structure. The electromagnetic pulse valve is connected between the row and column lines. Through the connection of the row and column lines, the injection control of the corresponding pulse valve is achieved. The pulse cleaning control operates in two modes: "automatic" and "on-site." In the "automatic" mode, the PLC controls the on and off of the row selection switch and column selection switch to realize the injection control of the electromagnetic pulse valve.
