Filtration efficiency
On the one hand, the filtration efficiency of the dust filter element is related to the structure of the filter material, and on the other hand, it also depends on the dust layer formed on the filter material. From the perspective of the filter material structure, the filtration efficiency of short fibers is higher than that of long fibers, and felt filter materials are better than fabrics. The filter material is high. From the perspective of the formation of the dust layer, for thin filter materials, after cleaning, the dust layer will be destroyed, and the efficiency will be greatly reduced. For thick filter materials, part of the dust can remain in the filter material after cleaning to avoid excessive cleaning. Generally speaking, the highest efficiency can be achieved when the filter material is not broken. Therefore, as long as the design parameters are selected properly, the dust removal effect of the filter element should be no problem.
Dust holding capacity
Dust holding capacity, also known as dust load, refers to the dust accumulated on the filter material per unit area when a given resistance value is reached (kg/m2). The dust holding capacity of the filter element affects the resistance of the filter material and the cleaning cycle. In order to avoid complicated dust cleaning and prolong the life of the filter element, it is generally required that the filter element has the largest dust holding capacity. The dust holding capacity is related to the porosity and air permeability of the filter material, and the felt filter material has a larger dust holding capacity than the fabric filter material.
Air permeability and resistance
Air permeability refers to the amount of gas passing through the filter material per unit area under a certain pressure difference. The resistance of the filter element is directly related to the air permeability. As the value of constant pressure difference for calibrated air flow, the value varies from country to country. Japan and the United States take 127Pa, Sweden takes 100Pa, and Germany takes 200Pa. Therefore, when choosing the air permeability, the pressure difference taken during the experiment should be considered. The air permeability depends on the fiber fineness, the type of fiber pile and the weaving method. According to Swedish data, the air permeability of filament fiber filter material is 200--800 cubic meters/(square meter ˙h), and the air permeability of short filament fiber travel material is 300-1000 cubic meters/(square meter ˙h). The air permeability of the felt filter material is 400-800 cubic meters/(square meter ˙h). The higher the air permeability, the greater the allowable air volume (specific load) per unit area.
The air permeability generally refers to the air permeability of the clean filter material. When dust accumulates on the filter cloth, the air permeability will decrease. According to the different properties of the dust, the general air permeability is only 20%-40% of the initial air permeability (air permeability when the filter material is clean), and for fine dust, it is even only 10%-20%. The ventilation string is reduced, and the dust removal efficiency is improved, but the resistance is greatly increased.
Service life
The life of the filter element refers to the time when the filter element explodes under normal use conditions. The life of the filter element depends on the quality of the filter element itself (material, weaving method, post-treatment process, etc.) two factors. Under the same conditions, a good dust removal process design can also prolong the service life of the filter element.
