The filtration performance of the dust
filter is mainly reflected in the filtration efficiency, dust capacity, air permeability and resistance, and service life.
The performance of the four-side dust filter element is briefly analyzed:
1, filter filter efficiency
On the one hand, the filtration efficiency of the filter element is related to the filter material structure, on the other hand, it also depends on the dust layer formed on the filter material. From the filter material structure, the filtration efficiency of short fiber is higher than that of long fiber, and the felt filter material is higher than that of fabric filter material. From the formation of the dust layer, for thin filter material, after cleaning, the dust layer is destroyed and the efficiency is reduced a lot, while for thick filter material, after cleaning, a part of the dust can be retained in the filter material to avoid excessive cleaning. Generally speaking, the highest efficiency can be achieved when the filter material is not broken, so as long as the design parameters are properly selected, the dust removal effect of the filter element should be no problem.
2, filter dust capacity
Dust capacity, also known as dust load, refers to the dust accumulated on the filter material per unit area when the given resistance value is reached (kg/m2). The dust content of the filter element affects the resistance of the filter material and the cleaning period. In order to avoid a lot of cleaning and extend the life of the filter element, it is generally required that the dust storage of the filter element is maximum. The dust capacity is related to the porosity and permeability of the filter material, and the dust capacity of felt filter material is larger than that of fabric filter material.
3, filter permeability and resistance
Ventilation filtration 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 a constant pressure difference value for calibration of air permeability, the value is different in different countries. Nichiki, the United States take 127Pa, Sweden take 100Pa, Germany take 200Pa, so the size of the selection of air permeability to consider the pressure difference taken during the experiment. The permeability depends on the fiber fineness, the type of fiber pile and the weaving method. According to Swedish data, the permeability of filament fiber filter material is 200-800 cubic meters /(square meter ·h), the permeability of short fiber travel material is 300-1000 cubic meters /(square meter ·h), and the permeability of felt filter material is 400-800 cubic meters /(square meter ·h). The higher the air permeability, the greater the air volume (specific load) allowed per unit area.
Air permeability generally refers to the air permeability of clean filter material. When there is dust on the filter cloth, the air permeability should be reduced. Depending on the nature of the dust, the general air permeability is only 20%-40% of the initial air permeability (the air permeability of the clean filter material), and for fine dust, even only 10%-20%. The ventilation string is reduced, the dust removal efficiency is improved, and the resistance is greatly increased.
4, filter life
The life of the filter element refers to the time of bursting under the normal conditions of use of the filter element, and the life of the filter element depends on the quality of the filter itself (material, weaving method, post-treatment process, etc.) and the conditions of use (temperature, humidity, dust properties, gray mode, etc.). Under the same conditions, good dust removal process design can also extend the service life of the filter element.
