dust collector filter bag materials selection

As one filter bag manufacturer, Shanghai Indro Industry Co., Ltd is very glad to introduce you tips of dust collector filter bag materials selection as following three parts: part 1, according to moisture and adhesive property of dust particles; part 2, according to flammability and electric charge of dust particle; part 3, according to flowability and friction of dust particles.

Dust collector filter bag materials selection-Part 1

According to moisture and adhesive property of dust particles:

Moisture and damp of dust particles is formed through capillary action between dusts, it has relationship with the atomic chain of dust, surface state and surface tension of liquid and other factors, which can be express by wetting angle. Generally speaking, hydrophilic is less than 60 degrees, and hydrophobicity is greater than 90 degrees. When the moisture content of hygroscopic dust increases, the aggregation force and the cohesive force of particles increase, and the fluidity and electric charge decrease, dust will adhere to surface of dust collector filter bags, gradually, dust cleaning will failure and dust cake is harden. Some dust such as CaO, CaCl, KCl, MgCl2, NaCO3 etc., after moisture further absorption and chemical reaction will occur, its properties and morphology change, this is called deliquescence. After the deliquescence, the surface of dust collector bag house filter bags will be blocked by dust, this is the most taboo.

Solutions of dust collector baghouse filter bag material selection:

For the dust with wettability, deliquescence, in the filter media/material selection, should pay attention to the smooth, not brushed and hydrophobicity, the ptfe laminated filter fabric is the best choice.

The strong wetting dust has very strong adhesive forces, and there is an inseparable relation between wet and sticky. For the dust collector bag filter (bag house), if the adhesive force is too small, it will lose the ability to capture dust, while the excessive adhesion will cause dust condensation and ash cleaning difficulties. For strong adhesion of dust, we shall select filament and not brushed filter materials, or the needle punched felt with the surface treatments of singeing (glazed), calendering, and heat set. Shall make full use of technology of impregnated(bathing), coated, ptfe lamination(membrane). From the material of filter media, nylon and glass fiber are superior to other varieties.

Dust collector filter bag materials selection-Part 2

According to flammability and electric charge of dust particle:

Some dust will burn or blast when meet sparks in the air in a particular concentration state. The flammability of dust is related to its particle size, composition, concentration, combustion heat and combustion speed. The smaller the particle size is, the larger the specific surface area is, and the easier ignition is. An important condition of dust explosion is a confined space, in this space, the explosion concentration limit is generally tens to hundreds of grams / m3, dust combustion heat of combustion speed is high, the greater the power of the explosion. Dust combustion or explosion source is usually caused by friction sparks, electrostatic sparks, hot particles and so on, in which the charging is the most harmful. This is because the fiber filter is usually easy to charge, and if the dust with charge as well, it will be easy to make sparks, so for flammable and easy charged dust such as coal, coke powder, alumina powder and magnesium powder, should select a flame retardant filter fabric and conductive filter materials.

Solutions of dust collector baghouse filter bag material selection:

Generally it is believed that the materials whose oxygen index more than 30 is safe, such as PPS, P84 and PTEF filter materials and filter rolls.

And for filter materials whose oxygen index is less than 30 of the fiber, such as polypropylene, polyester, can be treated by flame retardant bathing.

Another anti static filter material is using static elimination method.

This anti static filter media means that the conductive fiber is mixed into the filter fiber, so that the filter material has conductive property in the direction or weft direction, so that the resistance is less than 109 ohms. The commonly used conductive fibers are stainless steel fiber and modified (carburizing) chemical fiber. Compared with each other, the conductivity of the former is stable and reliable, and the latter tends to decline after a certain period of time. The blending amount of conductive fiber is about 2% - 5% of the basic fiber.

For dust with flammability and electric charge, the best solution is using anti static baghouse filter bags made of Shanghai INDRO anti static filter materials.

Dust collector filter bag materials selection: Some dust will burn or blast when meet sparks in the air in a particular concentration state. For such dust, we shall use anti static baghouse filter bags.

Dust collector filter bag materials selection-Part 3

According to flowability and friction of dust particles:

When flowability and friction of dust are strong, it will wear baghouse filter bags directly, make using life lower. The friction between rough and rhombic particles is more than 10 times larger than that of smooth spherical particles. The dust particle in size of approx 90 um is with the largest abrasiveness, while when the particle size is reduced to 5 - 10um the abrasiveness is very weak. The abrasiveness will be larger when air flow is higher and dust particle size is larger, so the flow velocity and its uniformity of dust size must be strictly controlled.

Solutions of dust collector baghouse filter bag material selection:

Among the common dusts, aluminum powder, silicon powder, coke powder, carbon powder and sintered ore powder are high abrasion dusts. For abrasive dust, it is better to select the filter material with good wear resistance. Wear parts and form of filter bag materials are many and varied, according to the experiences, most of dust collector filter bags wear in the bottom or lower part, this is because at the top of the filter bag filtration rate is low, gas dust concentration is small.

For abrasive dusts, following 3 points should be paid attention to when selecting bag filter material:

1) chemical fiber is superior to glass fiber, expanded/textured glass fiber is superior to ordinary glass fiber, fine, short, rolled fiber is better than coarse, long, smooth fiber.

2) In the felt material, it is better to use acupuncture to strengthen the intersection of fibers; in the woven fabric, satin fabric is the best, the fabric surface is brushed to improve wear resistance; But felt material, satin fabric and fleece filter will increase the resistance value.

3) For ordinary filter materials, surface coating, calendering and other finish treatment can also improve the wear resistance. For glass fiber filter material, silicone oil, graphite, PTFE treatment can improve wear resistance and bending resistance. But when the membrane filter material is used in the condition of strong abrasion, the film will be worn out prematurely and lose the film covering function.

Dust collector filter bag materials selection: According to flowability and friction of dust particles, when dust is with high flow and friction, shall select filter felt or fabric with good resistance. Needle punched felt shall be first selection, textured fiberglass fabric are second selection.