1.Traditional Bag Filter:
The traditional bag filter is a dry dust filter. It is suitable for catching fine, dry and non fibrous dust. The filter bag is made of textile filter cloth or non-woven felt. The filtering effect of fiber fabric is used to filter the dusty gas. When the dusty gas enters the bag filter, the dust with large particles and large specific gravity will settle down due to the effect of gravity and fall into the ash hopper. When the gas containing fine dust passes through the filter material, the dust will be retained to purify the gas.
The traditional bag filter is a dry dust filter. It is suitable for catching fine, dry and non fibrous dust.
At present, it is widely used in coal-fired power plants, steel, building materials, non-ferrous metals, machinery, chemical industry, grain, agriculture and many other fields in China. A little obvious, but also accompanied by many shortcomings:
1. Some flue gases contain more moisture, or the dust carried has strong moisture absorption, which often leads to the adhesion of the filter bag of the bag filter and the blockage of the filter material. In order to ensure the normal operation of bag filter, necessary drying or thermal insulation measures must be taken to ensure that the moisture in the gas will not condense.
2. The filter bag of bag filter has a certain limit of temperature bearing capacity. When the temperature of the filter material is higher than that of the cotton fabric, the temperature of the filter material must be reduced to 80-260 ℃, and the temperature resistance of the filter material to the flue gas must be reduced when the temperature of the filter material is higher than that of the cotton fabric.
As the domestic environmental protection policy tends to be strict, further denitration of nitrogen oxides needs to be done while dedusting. At present, SNCR and SCR technologies are more mature for denitration. SCR is more favored because of its higher denitration efficiency and back-end governance. Because the traditional bag dust removal can not withstand the higher exhaust temperature, the temperature entering the back-end denitration is too low to carry out efficient denitration.
The denitration efficiency and treatment cost of medium and high temperature catalyst are more mature and economical than low temperature denitration. The market calls for an integrated scheme of high-temperature dust removal and denitration without cooling. Therefore, GRVNES has developed high-temperature metal bag, which can remove dust and denitration at 500 ℃.。
Working Curves of Three Catalysts
2. Metal High Temperature Bag Filter Technology Suitable for High Temperature Flue Gas Emission Control.
Metal high-temperature bag filter is a micro filter element made of very fine metal fiber and metal powder, which is formed by non-woven paving, stacking, static pressure and other processes, and then sintered at high temperature. High filtration precision, good air permeability, high mechanical strength, corrosion resistance and long service life. It is suitable for high-temperature use. It is widely used in high-temperature dust removal in cement kilns, glass kilns, ceramic kilns, chemical plants and other industries. Combined with the denitration catalyst products developed by our company, it realizes the integrated application of dust removal and denitration.
3. Technical Advantages and Characteristics
3.1 Wide application environment
It can be used continuously under 500 ℃ and in acid-base environment.
3.2 High performance
High filtration accuracy (1-50um), which can meet the needs of ultra clean discharge below 5mg / Nm3, and the dust removal efficiency is as high as 99.9%. The denitration efficiency is high. When combined with the dust collector, the denitration rate can reach more than 99%, realizing the requirement of nearly zero emission.
3.3 Low resistance
Good air permeability, small pressure loss, easy back blowing, easy dust removal, strong regeneration ability, simple maintenance and long service life.
3.4 High strength and processing performance
It has extremely high mechanical strength and compressive strength, adjustable length, convenient processing, welding and assembly, splicing processing can reach 6m or even longer, and the floor area is smaller.
4. Integrated Solution of High Temperature Dust Removal and Denitration
4.1 Pollution control and comprehensive energy utilization in the whole process of environmental protection Island
Subvert the traditional process route of denitration before dust removal and then desulfurization, adopt high-temperature dust removal before treatment of gas pollutants and comprehensive utilization of waste heat. After dust removal, the whole environmental protection system operates under the working condition of low dust, improve energy utilization efficiency, reduce the failure rate of environmental protection equipment, reduce the volume of equipment, and greatly reduce the investment cost and floor area.
4.2 High temperature bag filtration and catalysis
The best use temperature of catalytic materials is more than 300 ℃, and the general use temperature of traditional filter bag materials is no more than 300 "C, which limits the use of catalytic materials. While the use temperature range of metal high-temperature filter bag perfectly solves this problem, and cooperates with the use of catalytic materials to give full play to the best performance of catalytic materials.
4.3 Synergistic efficiency and long life
GRVNES catalytic filtration system can efficiently treat PM and NOx, with dust removal efficiency of more than 99.9% and denitration efficiency of more than 99% (specific values vary according to specific projects). Since the flue gas is filtered first and then reaches the catalyst layer for reaction, it can effectively prevent the influence of impurity ions in the dust on the service life of the catalyst, so it can greatly prolong the service life of the catalyst.
In addition, the catalytic filtration system can also cooperate with other catalytic technologies to deal with VOC, dioxin, Co, etc., with strong expansion performance.
Post time: May-07-2022