Selection and application of dust collector filter bag in asphalt mixing station/mills/plant
The working conditions of the dust collector in asphalt mixing station are very complex, so the filter bag is faced with the test of high temperature and high concentration dust environment. If the selection of the asphalt mixing filter bag is not suitable, it can not only make the equipment not produce normally, but also cause great economic loss to the users. Now SIIC team introduces the filter bag selection of the draining mixing station:
The SIIC aramid/nomex filter bag is the first choice for the asphalt mixing station/mills/plant.
Filter cloth must have suitable pores, allowing air to pass smoothly and blocking small dust from entering the filter cloth. Once the particles of fine particles enter the interior of the filter cloth, they can not be removed, resulting in a great decrease in the permeability of the filter cloth, the increase of the resistance of the dust, and even the filter bag that can not be used again. This is why the filter diameter of filter bag is finer and the filter cloth is denser. Although the price of filter cloth made of finer fiber is higher, the filtration resistance is larger when it is first used, but it has a stable service life and a long service life.
Of course, there are new materials to prevent dust entering into the filter cloth and the air permeability is not reduced, for example, spraying or covering a layer of ultra-thin fluorinated resin microporous membrane on the touch surface of the filter bag and dust. The inert resin is completely hydrophobic, the smooth surface not only does not stick to the dust, but also will greatly reduce the adhesive pouch phenomenon for the high water content dust. It can also be used to spray the filter bag surface with special powder to form a very thin cake on the surface to make the porosity more uniform and smaller.
The same process can be achieved by special processing such as calender or sintering on the surface of filter cloth. Three resistances (oil, waterproof, anti static) filter cloth has been widely applied in the dust removal industry of building materials enterprises. In short, when selecting dust filter bag materials, it is best to refer to relevant materials or consult professional production plants and experts. Now there are many filter bag factories, and the difference between them is large and the price difference is great. When choosing filter bags, the price, service life and physical properties of materials should be considered comprehensively. Especially when buying dust collector bag house system, we must not only consider the price, but also consider its configuration and material. Some filter bags are effective for certain kinds of dusts, but they may not be the best for other dusts. Filter fabric can be felt or woven. Most felt products absorb moisture due to capillary action between fibers. However, some special felt products, such as glass fiber needle punched felt, can damp moisture to a certain extent. The fibers of the felt products are irregular in arrangement and even in pores. Meanwhile, in order to ensure their strength, the thickness of the filter bags is thicker, and the dust removal efficiency is higher. In some important occasions or with dust and fine materials, especially the filter bag with high surface air velocity, the felt fabric is often used. Woven fabric is made of yarn. There are various patterns of holes in the spun yarn, and the surface is bright and clean. It is easy to design filter cloth that can be kept or separated from filter cake. In order to further improve the surface properties, silicone resin can be sprayed to obtain the wear-resistant surface, improve the capacity of filter cakes falling off from the filter bag surface and reduce the moisture absorption ability of the filter bag. For all kinds of chemicals with low melting point and high adhesion, it is better to use woven fiber filter bags. The SIIC aramid/nomex filter bag is the first choice for the asphalt mixing station/mills/plant.
There is also a great of knowledge about the setting up of filter rate in the dust removal station, because its impact on the life of the bag is too great.
The filtration speed (V) of the bag filter is the ratio of the filtered gas flow rate (m3/min) and the filter fabric area (M2). The filtration speed is an important parameter to determine the performance of the dust collector. The size of the filter directly affects the one-time investment, operation cost and dust removal efficiency of the bag filter. Too high filtration speed will cause too much pressure loss, reduce the efficiency of dust removal, clog the filter bag and cause rapid damage. However, increasing filtration speed can reduce the filter area and treat the same flow of gas with smaller devices. The low filtration speed will increase the efficiency of dust removal and prolong the service life of the filter bag, but it will cause too much dust collector and increase investment at once. At present, there is no available theoretical formula to calculate the filtration rate, which is mainly determined by experience. But in qualitative terms, it is related to dust properties, gas concentration, filter material and cleaning methods. Generally, if the dust concentration is high and the dust particles are small, the filtration rate should be small, on the other hand, the high value is taken.
