Advantage of large bag filter in cement enterprise

With the implementation of new environmental protection standards, the kiln tail smoke dust concentration is required to be less than or equal to 50mg/m3. The coastal economically developed areas even require the kiln tail smoke dust concentration to be less than or equal to 10mg/m3. Therefore, the bag type dust collector is the kiln head and kiln. The inevitable trend of tail dust removal development. There are also many cement plants that have converted the electrostatic precipitators that fail to meet the standards into bag-type dust collectors according to the company's own equipment and funds. It has also achieved good results. Since the adaptability of the bag filter is stronger than that of the electric precipitator, more and more bag type dust removers are used at the kiln head and the kiln end, and the development momentum is rapid. This paper gives a detailed introduction to the application of large bag filter in cement enterprises, and believes that it can inspire the environmental protection of cement companies.
With the adjustment of industrial policies in China's cement industry, cement production is becoming more and more large. These large cement production lines have more than 50 dust collectors per line. Dust removal at the end of the kiln is the key to environmental protection. In the kiln dust removal of large cement plants, electrostatic precipitators have been used in the past. Because of the sensitivity of the electrostatic precipitator and its dust removal mechanism, the concentration of soot emissions is relatively high, generally above 100mg/m3.
The production process of the new dry process cement plant generally has more than 50 sets of dust collectors. In addition to the removal of rotary kiln exhaust gas treatment and kiln head coolers, most companies use electrostatic precipitators. With the development of environmental protection and the advancement of bag filter technology, almost all bag cement can be used in the whole process of cement production.
The large-scale high-efficiency bag filter is one of the signs of the development of modern dust removal technology. It has high dust removal efficiency, especially for capturing fine dust. In recent years, the improvement of filter material of bag filter and the optimization of cleaning control and structural performance have provided technical guarantee for the development of bag filter. The baghouse filter for large dry cement kiln tail gas treatment Has gradually become a trend.
The technical characteristics of the bag filter: the adaptability to the changes of the kiln condition is objective and objective. Whether it is an electrostatic precipitator or a bag filter, it has a high dust-collecting effect, as long as the design is selected correctly and the product quality is excellent. The maintenance operation is reasonable and can guarantee the emission standards set by the state. In comparison, due to the different structure of the equipment and the mechanism of dust removal and cleaning, when the kiln condition is unstable and the thermal parameters deviate from the original design index, the adaptability of the bag filter is stronger.
In actual production, when the amount of exhaust gas or dust concentration entering the electrostatic precipitator exceeds the original design value, the dust removal efficiency will decrease. The kiln exhaust gas cannot always remain within the design specifications. When the amount of feed (coal) and the leakage of the system exceed the design specifications, it is possible to make the amount of kiln exhaust gas exceed the standard, so that the dust removal efficiency of the dust collector is lowered and the discharge concentration exceeds the standard. For example, when the amount of exhaust gas entering the electrostatic precipitator is 5%~10% higher than the design index, the dust removal efficiency will be reduced from 99.875% of the original design to 99.83%~99.77%. In this case, if the original design discharge concentration is ≤100mg /m3, the actual emission concentration will rise to 137mg/m3~184mg/m3. Similarly, when the air leakage in the preheater exceeds 2%, the separation efficiency of the preheater is obviously reduced, and the dust concentration of the exhaust gas may increase. This will also cause the dust removal efficiency of the dust collector to decrease and the exhaust gas emission concentration to exceed the standard.
In order to solve the problem that the amount of exhaust gas or dust concentration entering the electrostatic precipitator increases and the dust removal efficiency decreases and the discharge exceeds the standard, it is necessary to increase the plate to increase the area of the sediment plate, which is very difficult for the electrostatic precipitator being used. . The bag filter determines the filter bag filter area according to the selected filter wind speed, and the filter bag filter area is basically not affected by the amount of exhaust gas or the dust concentration. When the amount of exhaust gas entering the bag filter increases, the filtration wind speed increases and the resistance rise speed increases. At this time, only the filter bag cleaning cycle is shortened and the number of cleaning times is increased to meet the dust removal requirement, and the dust removal efficiency is not affected. of.
In addition, in comparison, changes in the temperature and humidity (ie, the nature of the flue gas) entering the precipitator exhaust gas have a greater impact on the electrostatic precipitator. Generally, the temperature of the flue gas entering the electrostatic precipitator is 120 ° C ~ 150 ° C, the humidity is 10% ~ 15%, and the dew point is 50 ° C ~ 60 ° C. Too high or too low are unfavorable to the operation of the electrostatic precipitator. If the temperature is too high and the humidity is too low, the dust will increase in specific resistance, which may cause frequent spark discharge of the electric field, increase of corona current, and decrease of dust removal efficiency. If the temperature is too low and the humidity is too high, it may cause dust to be on the plate and electricity. Adhesion occurs on the halo line, making it difficult to vibrate the ash, which will affect the normal operation of the precipitator. With the implementation of new environmental protection standards, the kiln tail smoke dust concentration is required to be less than or equal to 50mg/m3. The coastal economically developed areas even require the kiln tail smoke dust concentration to be less than or equal to 10mg/m3. Therefore, the bag type dust collector is the kiln head and kiln. The inevitable trend of tail dust removal development. There are also many cement plants that have converted the electrostatic precipitators that fail to meet the standards into bag-type dust collectors according to the company's own equipment and funds. It has also achieved good results. Since the adaptability of the bag filter is stronger than that of the electric precipitator, more and more bag type dust removers are used at the kiln head and the kiln end, and the development momentum is rapid. This paper gives a detailed introduction to the application of large bag filter in cement enterprises, and believes that it can inspire the environmental protection of cement companies.
The large-scale high-efficiency bag filter is one of the signs of the development of modern dust removal technology. It has high dust removal efficiency, especially for capturing fine dust. In recent years, the improvement of filter material of bag filter and the optimization of cleaning control and structural performance have provided technical guarantee for the development of bag filter. The baghouse filter for large dry cement kiln tail gas treatment Has gradually become a trend.
The technical characteristics of the bag filter: the adaptability to the changes of the kiln condition is objective and objective. Whether it is an electrostatic precipitator or a bag filter, it has a high dust-collecting effect, as long as the design is selected correctly and the product quality is excellent. The maintenance operation is reasonable and can guarantee the emission standards set by the state. In comparison, due to the different structure of the equipment and the mechanism of dust removal and cleaning, when the kiln condition is unstable and the thermal parameters deviate from the original design index, the adaptability of the bag filter is stronger.
In actual production, when the amount of exhaust gas or dust concentration entering the electrostatic precipitator exceeds the original design value, the dust removal efficiency will decrease. The kiln exhaust gas cannot always remain within the design specifications. When the amount of feed (coal) and the leakage of the system exceed the design specifications, it is possible to make the amount of kiln exhaust gas exceed the standard, so that the dust removal efficiency of the dust collector is lowered and the discharge concentration exceeds the standard. For example, when the amount of exhaust gas entering the electrostatic precipitator is 5%~10% higher than the design index, the dust removal efficiency will be reduced from 99.875% of the original design to 99.83%~99.77%. In this case, if the original design discharge concentration is ≤100mg /m3, the actual emission concentration will rise to 137mg/m3~184mg/m3. Similarly, when the air leakage in the preheater exceeds 2%, the separation efficiency of the preheater is obviously reduced, and the dust concentration of the exhaust gas may increase. This will also cause the dust removal efficiency of the dust collector to decrease and the exhaust gas emission concentration to exceed the standard.
In order to solve the problem that the amount of exhaust gas or dust concentration entering the electrostatic precipitator increases and the dust removal efficiency decreases and the discharge exceeds the standard, it is necessary to increase the plate to increase the area of the sediment plate, which is very difficult for the electrostatic precipitator being used. . The bag filter determines the filter bag filter area according to the selected filter wind speed, and the filter bag filter area is basically not affected by the amount of exhaust gas or the dust concentration. When the amount of exhaust gas entering the bag filter increases, the filtration wind speed increases and the resistance rise speed increases. At this time, only the filter bag cleaning cycle is shortened and the number of cleaning times is increased to meet the dust removal requirement, and the dust removal efficiency is not affected. of.
In addition, in comparison, changes in the temperature and humidity (ie, the nature of the flue gas) entering the precipitator exhaust gas have a greater impact on the electrostatic precipitator. Generally, the temperature of the flue gas entering the electrostatic precipitator is 120 ° C ~ 150 ° C, the humidity is 10% ~ 15%, and the dew point is 50 ° C ~ 60 ° C. Too high or too low are unfavorable to the operation of the electrostatic precipitator. If the temperature is too high and the humidity is too low, the dust will increase in specific resistance, which may cause frequent spark discharge of the electric field, increase of corona current, and decrease of dust removal efficiency. If the temperature is too low and the humidity is too high, it may cause dust to be on the plate and electricity. Adhesion occurs on the halo line, making it difficult to vibrate the ash, which will affect the normal operation of the precipitator.
Bag dust collector dust bag