Performance of bag filter dust collector
The performance of the dust collector bag house (bag filters) is mainly related to the filtration velocity, dust removal efficiency, filtration resistance and cleaning methods.
Filtration rate is one of the main factors that affect the performance of the filter precipitator.
The filtering speed is calculated in the following form:
v=Q/60×A, in the form,
v: filtration velocity(superficial gas velocity), m/min
Q: treated air flow of bag filters, m3/hour
A: filtration area of filter material used in dust collector bag house, m2
Generally, the real filtration speed which gas goes through the filtration layer is vp:
vp=v/εp, in the form,
vp: real filtration speed which gas goes through the filtration layer, m/min
εp: Average voidage of dust layer, normally is 0.8～0.95.
In the actual operation process, the filtration rate is determined by the type of filter material, the particle size of dust, the physical and chemical properties and the way of ash removal. The filtration rate is large, the pressure difference on both sides of the filter material will be increased, and the fine dust attached to the filter material is squeezed past, so that the filtration efficiency can be reduced to the single fiber of the prescribed emission value or the worn filter material, especially the glass fiber filter material is accelerated to damage. If the filtration speed is small, it will increase the volume of the dust collector and increase investment.
The reference value of filter rate design for bag filter is as following table:
|
Type of dust |
Dust cleaning mode |
||
|
Combination of shaking and reverse air flow |
Pulse jet |
Reverse air blowing |
|
|
Talcum powder, coal, sandblasting dust, fly ash, ceramic dust, carbon black, pigment, kaolin, limestone, sand dust, stannite, cement (from cooler), enamel |
0.7～0.8 |
2.0～3.0 |
0.6～0.9 |
|
The sublimation of ferroalloy, cast dust, alumina, cement from ball mill, sublimation of carbonization furnace, lime, corundum, Anfu powder and other fertilizer, plastic and starch |
0.5～0.75 |
1.5～2.5 |
0.45～0.55 |
|
The sublimation of carbon black, silicon oxide, tin and zinc, and other aerosols, make-up powder, decontamination powder, powdered milk, activated charcoal, cement, etc. in gas due to condensation and chemical reaction |
0.45～0.5 |
0.8～2.0 |
0.33～0.45 |
|
Tobacco, leather powder, mixed feed, wood processing dust, coarse plant fiber (hemp, jute, etc.) |
0.9～2.0 |
2.56～0.6 |
|
|
Dust from asbestos, fiber dust, gypsum, pearlescent stone, rubber, dust, salt, flour and grinding process. |
0.3～1.1 |
2.5～4.5 |
|