In the production process of asphalt mixture, there are often some factors that affect its production quality. For example, the bag dust collector of the asphalt commercial concrete station will cause the emission to fail to meet the emission standards due to a large amount of high-temperature gas and dust. Therefore, the dust collector must be treated reasonably and effectively to ensure its normal operation and meet the emission requirements. Bag dust collectors have great advantages, such as strong adaptability, simple structure and stable operation, so they are widely used in the treatment of emissions. However, there are still many shortcomings in bag dust collectors, and effective measures must be taken to maintain them reasonably to ensure their efficient operation.

[1]. Analysis of the characteristics, working principle and influencing factors of bag dust collectors
Bag dust collectors are equipment used to effectively clean up emissions in the production process of asphalt mixtures. They are usually bulk and consist of a base, a shell, an inlet and outlet air chamber, a bag and a pulse combination.
1. Characteristics of bag dust collector. Dust collectors are often used in the domestic transportation production industry, not only because of the independent production and extended service life of dust collectors, but more importantly, they have other advantages. The specific advantages are: One of the advantages of bag dust collectors is that they have high dust removal efficiency, especially for the treatment of submicron dust. Because the requirements for its treatment object are not very high, the flue gas content and dust content do not have a great impact on the dust collector, so bag dust collectors can be widely used. In addition, the maintenance and repair of bag dust collectors are simple, and the operation is also simple and easy.
2. Working principle of bag dust collector. The working principle of bag dust collector is simple. Usually, the dust in the flue gas can be effectively treated with its own bag. This treatment method has mechanical controllability, so while intercepting dust, clean air will be discharged, and the intercepted dust will be collected in the funnel and then discharged through the system pipeline. Bag dust collectors are simple to operate and easy to disassemble and maintain, so they are widely used in the treatment of organic waste gas emissions.
3. Factors affecting bag-type dust collectors. Bag-type dust collectors have a limited service life, and in order to extend the service life of the dust collector, faults must be eliminated in a timely manner. There are two factors that often affect the normal use of bag-type dust collectors, namely the frequency of dust cleaning and bag management. The frequency of dust removal will affect the service life of the bag-type dust collector. Excessive frequency will cause damage to the bag of the dust collector. Usually, a layer of filter bed is applied to the filter bag of the dust collector to extend the service life of the filter bag. Insufficient daily care of the bag will also affect the service life of the bag-type dust collector. Usually, certain preventive measures should be taken, such as preventing the bag from getting wet, preventing the bag from being exposed to direct sunlight, and preventing the bag from deteriorating. In addition, during the operation of the bag, the exhaust temperature must reach the normal standard. Only in this way can the efficient operation of the bag-type dust collector be ensured and its service life be extended.

[2]. Common problems in the use of bag dust collectors
1. The pressure difference in the bag is very high but its dust removal capacity is very low.
(1) Hydrocarbon pollutants remaining in the bag. The source of the bag pollution does not need to be determined in time, and the influencing factor may be the fuel problem. If the fuel in the bag is oil, various problems are likely to occur, especially for heavy oil or waste oil. The viscosity of the oil often increases due to the low combustion temperature, which eventually leads to the inability of the fuel to burn fully, thereby contaminating the bag, causing a series of problems such as blockage and deterioration, affecting the service life of the bag, and not conducive to improving the working efficiency of the bag dust collector.
(2) The cleaning strength of the bag is not enough. In normal dust removal work, the dust collector bags should be cleaned frequently to prevent the pressure difference from increasing due to inadequate cleaning. For example, in the initial setting, the normal pulse duration is 0.25s, the normal pulse interval is 15s, and the normal air pressure should be controlled between 0.5 and 0.6Mpa, while the new system sets 3 different pulse intervals of 10s, 15s or 20s. However, inadequate cleaning of the bags will directly affect the pulse pressure and cycle, resulting in bag wear, shortening the service life of the bag dust collector, affecting the normal production of asphalt mixture, and reducing the efficiency and level of highway construction.
2. Dust will be emitted during the cleaning process of the pulse in the bag.
(1) Excessive cleaning of the bag pulse. Because of excessive cleaning of the dust on the bag pulse, it is not easy to form dust blocks on the bag surface, which affects the normal operation of the bag pulse, causing the pressure difference of the bag to fluctuate and reducing the service life of the bag dust collector. The cleaning of the bag pulse should be appropriately reduced to ensure that the pressure difference is stable between 747 and 1245Pa.
(2) The bag is not replaced in time and is seriously aged. The service life of the bag is limited. There may be problems with the use of the bag due to various reasons, affecting the normal operation of the bag dust collector, such as excessive temperature, chemical corrosion, bag wear, etc. The aging of the bag will directly affect the efficiency and quality of the treatment of emissions. Therefore, the bag must be inspected regularly and the aged bag must be replaced in time to ensure the normal production of the bag dust collector and improve its working quality.
3. Corrosion of bags.
(1) Chemical corrosion often occurs during the operation of bag filters, such as sulfur in the fuel. Excessive sulfur concentration will easily corrode the bags of the dust collector, causing rapid aging of the bags, thereby reducing the service life of the bag filters. Therefore, the temperature of the bag filters must be controlled to effectively avoid the condensation of water in them, because the sulfur dioxide produced during the combustion of the fuel and the condensed water will form sulfuric acid, resulting in an increase in the concentration of sulfuric acid in the fuel. At the same time, fuel containing low concentrations of sulfur can also be used directly.
(2) The temperature of the bag filters is too low. Because the bag filters will easily condense water when the temperature is too low, and the formed water will cause the parts in the bag filters to rust, causing rapid aging of the dust collector. At the same time, the chemical corrosion components remaining in the bag filters will become stronger due to the condensed water, greatly damaging the components of the bag filters and reducing the service life of the bag filters.

[3]. Maintain the problems that often occur during the operation of the bag filter
1. Effectively deal with the hydrocarbon pollutants that often appear in the bag. Because the temperature of the fuel is too low, the fuel is not fully burned, and a large amount of hydrocarbon pollutants remain, which affects the normal operation of the bag filter. Therefore, the fuel should be properly preheated to make its viscosity reach 90SSU or lower, and then the next step of combustion is carried out.
2. Deal with the problem of insufficient bag cleaning. Due to insufficient cleaning of the bag, the pulse pressure and cycle of the bag are deviated. Therefore, the pulse interval can be reduced first. If the air pressure needs to be increased, it should be ensured that the air pressure does not exceed 10Mpa, thereby reducing the wear of the bag and extending its service life.
3. Deal with the problem of excessive cleaning of the bag pulse. Because excessive cleaning of the pulse will affect the normal operation of the bag filter, it is necessary to timely reduce the number of pulse cleanings, reduce the cleaning intensity, and ensure that the pulse pressure difference is controlled within the range of 747~1245Pa, thereby reducing the dust emission of the bag pulse.
4. Deal with the problem of bag aging in a timely manner. Because the bags are easily affected by residual chemical pollutants, and the high temperature during operation will accelerate the wear of the dust collector bags, the bags should be strictly inspected and repaired regularly, and replaced in time when necessary to ensure the normal operation of the dust collector bags.
5. Effectively control the concentration of the chemical components of the fuel in the bags. Excessive concentration of chemical components will directly cause a large amount of corrosion to the bags and accelerate the aging of the bag components. Therefore, to avoid the increase in chemical concentration, it is necessary to effectively control the condensation of water and operate by increasing the temperature of the bag dust collector.
6. Deal with the problem of confusion in the differential pressure gauge in the bag dust collector. Because there is often moisture in the differential pressure pipe in the bag dust collector, in order to reduce leakage, the differential pressure pipe of the domestic sewage treatment device must be protected and a more solid and reliable differential pressure pipe must be used.