Bag filter is a widely used dust removal equipment, which can remove all kinds of industrial dust with high dust removal efficiency. In the process of using bag filter, we should pay attention to cleaning the dust regularly, so as not to affect the use effect of dust removal equipment. Generally speaking, the cleaning methods adopted by bag filter are as follows:
1, knock on the door manually
Tap each filter bag of the bag filter by manpower to shake off the dust, so as to remove the accumulated dust on the filter bag. Although this method of cleaning ash is simple and convenient, it wastes manpower and time, and it is easy to vibrate unevenly, causing damage to the filter bag, which has been gradually eliminated at present.
2, pulse blowing ash
The perforated plate (flower plate) for fixing the filter bags is arranged at the upper part of the box, and there is a blowpipe above each row of filter bags. The blowpipe is provided with a compressed air injection hole (nozzle) towards the center of each filter bag, and the other end of the blowpipe is connected with a pulse control system consisting of a pulse valve, a control valve and a compressed air storage tank. According to the automatic control program, the dust is cleaned by pulse injection according to the specified time or resistance value.
The pulse dust removal effect is strong and good. However, the pulse blowing device needs compressed air as energy source. In cold areas, water vapor in compressed air is easy to condense, which affects the blowing effect. Therefore, it is not suitable for outdoor use, and corresponding technical measures should be taken to prevent condensation or freezing.
3, vibration cleaning
The vibration or shaking of the mechanical device makes the filter bag in the equipment vibrate, resulting in dust falling. Usually, vibration is applied at the top to make the filter bag vibrate in the horizontal or vertical direction, or both directions at the same time.
This cleaning method is simple and reliable, but the cleaning effect is not very strong, which is more suitable for textile filter bags.
4, blowing
Industrial dust removal equipment also often adopts reverse blowing dust removal method, which can also be called reverse blowing airflow. This method often adopts the working system of compartments, and then the air flow in each compartment is reversed through the automatic adjustment of valves. More often, it acts on the internal filter screen, and the huge vibration can make the dust fall off.
The dust removal effect of this method is not very good, even weaker than the vibration dust removal method, but the damage to the filter cloth is much smaller, so this method can be used more when cleaning the dust on the glass fiber filter cloth.
5. Combined cleaning with back blowing and vibration
Back-blowing vibration combined dust cleaning method refers to the combined dust cleaning method combined with weak vibration when dust cannot be completely removed by only back-blowing dust cleaning method. In fact, high-temperature glass fiber filter bags often use this combined dust removal method.
6. Pulse cleaning of bellows
This cleaning method is to divide the filter bag into several parts, and then divide the filter bag into several sub-chambers in the clean bellows above the filter bag. The actual dust removal is carried out one by one according to the sequence of each space, and the exhaust valve is closed at the same time, and then the pulse airflow is sprayed to the upper part of each compartment from the other side, and finally the dust is removed according to the pulse.
7, gas ring blowing dust
Air ring reverse blowing is to set a hollow ring with a slit on the belt surface outside the circular filter bag. This ring is not fixed, it can move up and down. At the same time, it is connected to the pipeline of high-pressure fan, which injects high-speed gas into the interior through the ring, and then removes all the dust accumulated around the filter bag. The gas ring back blowing in industrial dust removal equipment is rarely used in actual operation because of its complex structure and easy damage of filter bags.
8, pulse jet cleaning
Pulse back-blowing ash cleaning method is an ash cleaning method that gives pulsation to the reverse airflow of the above-mentioned back-blowing ash cleaning method. The ash cleaning effect is strong, but it needs a mechanical structure that can produce pulsation. Because of the strong cleaning effect, if some filter bags are cleaned one by one, there is no need for compartment structure.
9, sonic cleaning
This dust removal method mainly uses acoustic wave dust collector to vibrate the dust removal bag to achieve the purpose of dust removal. This dust cleaning method has low power consumption, low loss of dust removal equipment and high cost.
Second, what are the precautions in the process of cleaning the bag filter?
Dust removal is a necessary step to ensure the normal work of bag filter, and poor dust removal effect will affect the dust removal effect. In the process of dust removal, matters that should be paid attention to mainly include:
1. According to the cleaning method adopted and the nature of the object to be treated, determine the appropriate cleaning cycle and cleaning time, so that the cleaning cycle is as long as possible and the cleaning time is as short as possible, so that it can run under the resistance condition of economical dust removal equipment.
2. When the bag filter works normally, the ash discharging device cannot stop working, otherwise the ash hopper will soon be full of dust and overflow into the bag room, forcing the bag filter to stop working.
3. After the dust removal equipment stops working, it is necessary to continue the dust removal process for two cycles to avoid the combination of moisture in the air and dust on the surface of the bag, resulting in caking and bag paste.
4. If backwashing and pulse cleaning methods are used, ensure that the medium gas is clean to avoid polluting the bag filter.