1、 The structural form of the shell of the bag dust collector: 1. Plate shell structure of the bag dust collector: The dust collector shell is surrounded by flat components, assembled with temporary bolts at the construction site, and then welded and sealed at the joints. The plate structure of bag filter is usually in the height direction. If the length of the bag is less than 6 meters, it can be divided into one piece to the top. If a 10 meter long bag is used, it can be divided into two sections, and then support should be added inside the bag filter box. 2. Bag filter skeleton shell structure: The filter bag chamber box of this type of structure is composed of columns and beams, with columns set around the box and multiple beams connected between the columns, and then attached to the beams and columns with wall panels to form a closed box enclosure. The advantage of this upper box structure is that there is no support inside the box, and more filter bags can be arranged. The clearance between the filter bags is large, the breathability is good, and the inspection is also convenient. The box of the entire bag filter is relatively sturdy and rigid, but the disadvantage is that it consumes a lot of steel and increases the weight of the equipment. Bag filter As an economical dust removal equipment, it has been widely used in various industries. However, due to the different properties of flue gas, especially the chemical corrosiveness, bag filter work is adversely affected. The research on the acid resistance and properties of bag filters mainly manifests in two aspects. Firstly, before the dust enters the dust collector, appropriate methods are used to weaken the acidity and corrosiveness of the dust, and even form a combination system of acid removal and dust removal to improve the treatment effect of the filter on acidic and corrosive dust gases. The second is to enhance the acid resistance and performance of the dust collector itself. These two methods have been applied in many domestic enterprises and have made some research progress. 2、 The main indicators for measuring the operational performance of a bag filter include the dust concentration of the outlet airflow and the operating resistance of the bag filter. The failure of the bag filter in a bag filter refers to the loss of its designed function. Therefore, if the concentration at the outlet of the dust collector exceeds the standard, the bag filter will not meet the design requirements and the dust collector will fail. In addition, the operating resistance of the bag filter is directly related to the energy consumption of the bag filter. According to regulations, when the operating resistance of the bag filter is below 1000Pa, it belongs to the normal operating state; When the operating resistance of the dust collector reaches over 1500Pa, replace the filter bag. Through investigation and analysis of the actual operation of the bag filter, it was found that the flue gas temperature and operating resistance content have an impact on the properties of the filter bag, the cleaning method, the oxygen content and energy of the flue gas. In addition, defects in the structure of the bag filter equipment can also cause the failure of the filter bag. The main factors causing the failure of the bag filter equipment include the air inlet method, air flow distribution, structural parameters, cleaning device, manufacturing and installation quality, operation and maintenance standards, etc. Many scholars have used numerical simulation and experimental methods to analyze the operating conditions of bag filters, and found that the uneven distribution of dust laden airflow, changes in pressure drop during operation, and unstable operation during dust cleaning all have an impact on the performance of filter bags. 3、 Analysis of the causes of bag filter bag failure: 1. The main reason for bag filter bag failure is that the operating resistance caused by dust cleaning failure is too high. After calculating the dust cleaning flow field of the bag filter bag using the method, it was found that the pressure peak on the surface of the bag increases along the length direction of the bag during the dust cleaning condition, and then the dust cleaning pressure decays, finally stabilizing at around 400Pa. This indicates that the dust cleaning structure of the dust collector cannot achieve the ideal dust cleaning effect at the bottom of the bag filter. The conclusion based on the fault tree method to analyze the failure of the bag filter bag is reliable, which proves that this method is feasible in analyzing bag filter bag failure. 2. The cleaning structure of the bag filter has been improved by adding a Venturi tube at the filter bag mouth and numerically simulating its cleaning flow field. The results show that the peak cleaning pressure at the upper part of the filter bag increases along the length direction of the filter bag and gradually stabilizes at around 2000Pa. This cleaning pressure distribution can achieve the ideal cleaning effect. 4、 The role of flower board in bag filter Flower board is an important component of bag filter. The deviation between the installation position and the theoretical position of the flower plate hole of the bag filter after processing should be less than 1.5mm, and the flatness deviation should not exceed 3/1000 of the length of the dust collector flower plate. The dust collector flower board not only needs to withstand the negative pressure of the system, but also the weight of the filter bag, dust layer, and bag cage. If the dust collector flower board deforms, it may affect the straightness of the filter bag and the sealing effect at the bag mouth. Therefore, reinforcement treatment should be carried out at the lower part of the bag filter flower board during design. The inside of the flower board of the bag filter is smooth and flat, reducing water consumption to 2/3 of the original and lowering operating costs. Both imports and exports are equipped with flanges and provided with flange dimensions. During installation, asbestos ropes are used to fill the joints at the flange joints to prevent air leakage and affect the dust removal effect. 5、 The current market situation of bag filter in China has a huge demand for bag filter materials, especially fiber filter materials, which have broad market development prospects. The 12th Five Year Plan of our country has put forward high demands for environmental protection, and filter materials will be widely used for water, gas, sound, and slag. The market prospects of the filter material industry are promising. Among them, in the treatment of smoke and dust, bag type dust removal is increasingly widely used due to its ability to remove dust, avoid secondary pollution, and facilitate the recovery of dry materials, accounting for 80% of the dust removal equipment used.
