Filter is used to prevent dust pollution, protect the environment, from the role of the dust collector, the higher the level of the efficiency of dust collector, the better.    

Compared with general boiler, asphalt mixing equipment production, not only produce smoke, dust and emissions. So, to increase the dust removal ability, generally USES two levels of dust removal. If the bitumen mixture equipments with the two-stage filter using high dust removal efficiency, under the current situation in our country, is likely to affect the mineral aggregate gradation, namely may affect the quality of the asphalt mixture. The following is the analysis of working condition of asphalt mixing equipment filter and advice. There are three kinds of asphalt mixture using the mineral aggregate, the coarse aggregate (gravel size more than 4.75 mm), fine aggregate (sand particle size of 4.75 mm to 4.75 mm) and packing (powder particle size of 0.075 mm below), each material has certain specifications. Also must be clean, dry, without impurities. Of coarse, fine, powder, three kinds of aggregate and strict gradation design, to make the highest strength of asphalt mixture, meet the requirements of the road traffic. If mixing all kinds of original aggregate of asphalt mixture is very clean, no dirt, or for mechanisms gravel, sand, dust filter at all levels of dust can be recycled, neither destroy grading, also does not affect the intensity of mixture. In this case, the efficiency of the dust collector at all levels, the higher the better.

However, at present our country highway construction, especially the serious problem is: aggregate yard from the society, more material is dirty, clay content, grading is not specifications. In the process of mixing asphalt mixture, abound in the filter in addition to the dust under the soil dust, soil dust can damage the strength of the mixture, therefore cannot be recycled. In most cases the dust filter are abandoned. Yet again in the dust filter contains a lot of fine aggregate parts, namely the particle size of 4.75 mm to 4.75 mm rocky ingredients, this is an important component of the mixture, scrap, this part will destroy the mineral aggregate gradation design. In the face of such social reality, the best way is to fully effect of the secondary filter points with asphalt mixing equipment, primary filter filter the coarse dust, only to remove all the dust is greater than 0.075 mm or more ingredients, dirt, not contain all can recycling, ensure the gradation design unchanged in the fine aggregate composition. All less than 0.075 mm below the dust by the secondary filter to filter down. Because of the high concentration of dust, so all as waste powder scrap. After discarded, new mineral supplements are available, and can guarantee the mineral aggregate gradation design not to undermine, mixture with high intensity. The bitumen mixture equipments factory both at home and abroad, according to the dedusting efficiency is higher, the more good ideas to make dust catcher, some foreign primary filter, dust removal efficiency can reach above 85%. Coarse and fine aggregate used in foreign countries are after washing, do not contain clay, so in addition to the dust under the full recovery. But in China the situation is changed, aggregate without water washing, in addition to the primary filter dust is greater than 0.075 mm of ingredients and ingredients are mixed together, is less than 0.075 mm in China under the reality of invalid, the amount is too large, also damage grading. Recycling, tainted with dust, affect the quality of mixture. Aimed at the reality of China suggest developing new level filters, in addition to the thick dust, only put interloper dust, in addition to the dust excluding 0.075 mm the following ingredients, all can be recycled. Ensure the mineral aggregate gradation, and make the heated fine aggregate is not lost.