With the rapid increase in the consumption of various types of civil and industrial textiles, especially the demand for various textiles such as interior decoration, the fires caused by textiles have also been increasing. 1960s, Japan, Europe and the United States and other countries put forward the requirements for flame retardant finishing of textiles, and formulated various types of textile flame retardant standards. According to the International Organization for Standardization, flame retardancy (or flame-resistance) refers to the properties possessed by a material that slows, terminates, or prevents flaming combustion. It can be an inherent property of the material or it can be given to the material by certain treatments. Textile flame retardant technology is based on the latter theory of applied research. Modern combustion mechanism research shows that fabric combustion is a closed chain reaction process, and the purpose of positive combustion is to break the chain reaction, namely: in the exothermic phase, flame retardants are strong absorbers; in the thermal cracking phase, flame retardants act as catalysts to change the way of thermal degradation of fibers, so that they react in the direction of the reduction of combustible gases and increase of solids; in the flame zone, flame retardants are used to cut off the chain reaction by releasing free radicals of blocking agents, trapping agent to cut off the chain reaction, so that the active free radicals are blunted to achieve the purpose of flame retardant. Currently, flame-retardant fabrics are generally made from fabrics that have been post-treated with flame retardants. Dip-rollin method The process flow is dip-rolling, pre-drying, baking, washing and post-treatment. Dyeing method It is generally used for hydrophobic synthetic fabrics and requires affinity between flame retardant and fiber. Coating method The coating method is a finishing method in which the flame retardant is mixed into the cross-linking agent or binder to fix it on the fabric. Organic solvent method The organic solvent method can directly use non-water-soluble flame retardants, which has the advantages of short flame retardant finishing process time and low energy consumption, but requires solvent recovery devices and attention to the toxicity of solvents. Spraying method Spraying method has two kinds of manual spraying and mechanical continuous spraying, for some surface fluffy with pattern, tufting or pile head pile fabric, generally can be used continuous spraying method. As a kind of textile, in the actual operation of the filter bag, when the flue gas temperature is too large, or the presence of sparks, it will lead to the burning and breaking of the filter bag, thus affecting the filtration efficiency, for the flame retardant filter bag, the R & D department of Yuanchen Technology has been working on the flame retardant filter bag research, combined with graft copolymerization, sol-gel and supercritical dryi...

(Yuanchen Technology) In recent years, China's industrial restructuring has further deepened, and the structure of the power market has also undergone significant changes, constantly deepening the difficulty of peaking in the national grid; the state has also continued to introduce various peaking policies to encourage thermal power plants, especially large coal-fired power plants, to actively participate in grid peaking; while the existing thermal power units are facing increasingly serious overcapacity, the decline in annual generation hours available, the continued high price of coal, the further development of renewable energy and the promotion of power market reform, all making thermal power units face the new norm of becoming peaking units. At present, most power plants are retrofitted with SCR denitrification systems, but for the low load (mostly 30~40% load) operation of the units in deep peaking, the flue gas flow decreases and the flue gas temperature decreases, the conventional power SCR denitrification catalysts are not applicable, which in turn causes problems such as excessive NOx emissions and increased ammonia escape, bringing negative impacts to the enterprises. In response to the new normal of deep peaking in power industry, Yuanchen Technology Research Institute has successfully developed YC-CHJ-18DL250S and YC-CHJ-20DL250S wide temperature difference denitrification catalysts in the laboratory for half a year, which can effectively adapt to the special working conditions of deep peaking of power units with lower flue gas flow and lower temperature. The performance of this product has been verified by the full-size device of Anhui Kanfir Testing Technology Co., Ltd. to meet the requirements of flue gas NOx removal in both high and low load operation, with high activity, low ammonia escape rate (<3ppm) and small SO2/SO3 conversion rate (less than 1%) in the range of 250-400°c. The product will undergo long-term performance verification in the field working conditions at Wanergy Group Hefei Power Generation Co., Ltd. The future application of this product will provide power plant customers with a solution to the problem of substandard flue gas NOx and other pollutant emissions in the process of deep conditioning. Compared with conventional power catalysts, the application of this product can avoid the reheating of flue gas to ensure the catalyst performance, which can effectively achieve energy saving and emission reduction for customers. The promotion and application of Yuanchen Technology's power wide temperature difference denitrification catalyst will add a colorful touch to the power industry's goal of achieving carbon peak and carbon neutrality.

1. Preface With the continuous promotion of national strategies such as energy conservation and emission reduction, the flue gas denitrification technology of coal-fired power plants has gradually matured. The proportion of non-electric power industries in atmospheric treatment is gradually increasing, and some of them emit flue gas with low temperature, such as coking, cement, glass, industrial boilers, waste incineration, etc. Therefore, the research of efficient low-temperature denitrification technology is an important direction of the current denitrification process.    The current commercial catalysts are mainly V2O5-WO3, MoO3 /TiO2, with TiO2 as the carrier, V2O5 as the active component and WO3 or MoO3 as the active additive. The addition of the active additive improves the high and low temperature activity of the catalyst and effectively inhibits the occurrence of side reactions. However, the catalyst is a medium-high temperature catalyst with an active temperature window of 300-400°C. Below or above this temperature range, the denitrification activity of the catalyst starts to decline and reversible/irreversible poisoning deactivation occurs, which cannot meet the needs of industries with flue gas emission temperatures below 300°C. If the flue gas reheating followed by denitrification process is used, it will lead to increased energy consumption. Using low-temperature SCR denitrification can place the denitrification process after the dust removal or desulfurization process to reduce the wear and poisoning effect of soot on the catalyst, avoid flue gas reheating, and thus improve energy efficiency and save operating costs. Therefore, it is very important to study the performance of efficient low temperature denitrification catalysts for the low temperature denitrification industry. 2.Low temperature catalyst R&D direction Difficulties of low-temperature denitrification catalysts. (1) Low denitrification activity: denitrification catalyst activity generally decreases as the flue gas temperature decreases, and when the temperature is below 200℃, the existing low temperature catalyst activity is low, which will cause the denitrification efficiency to be substandard, and also lead to secondary pollution problems such as ammonia escape over the standard; (2) Poor anti-sulfur poisoning performance: SO2 and SO3 in the flue gas will react with the active bits of the catalyst, resulting in the reduction of the number of active bits and the degradation of denitrification performance. (3) Serious blockage poisoning: SO2 in flue gas formed by oxidation of SO3 will react with NH3 to produce sulfur ammonium salts, which will adhere to the catalyst surface, causing the catalyst active site to be covered, and the sulfur ammonium salts will further adsorb fly ash in the flue gas, aggravating the blockage and leading to rapid catalyst deactivation. (4) Poor water vapor tolerance: During low-temperature SCR denitrification, the water vapor pr...

Among the many VOCs organic waste gas treatment methods, Regenerative Catalytic Oxidation, referred to as RCO, is one of the most commonly used and effective technologies. Although regenerative catalytic oxidation treatment of organic waste gas is also a thermal oxidation technology, it differs from the RTO process in that its starting ignition temperature is usually 260-400°C, which is mainly due to the involvement of precious metal catalysts in the reaction. Therefore, precious metal catalyst is also the core unit of catalytic combustion method to treat organic waste gas. And catalyst poisoning is one of the most common problems. 1. Definition of catalyst poisoning Catalyst poisoning is a phenomenon in which the activity and selectivity of a catalyst are significantly reduced or lost by trace impurities contained in the reaction material. The essence of the poisoning phenomenon is some kind of chemical interaction between the trace impurities and the active center of the catalyst, forming an inactive substance. In gas-solid multiphase catalytic reactions are formed by adsorption complexes. One type of poisoning is called reversible poisoning or temporary poisoning if the poison acts weakly with the active component and the activity can be restored by simple methods. The other category is irreversible poisoning, it is impossible to restore the activity by simple methods. In order to reduce the activity of the side reaction, it is sometimes necessary to selectively poison the catalyst. 2. RCO precious metal catalyst poisoning judgment method (1) The degradation and removal rate decreases, catalytic combustion equipment has good removal rate for VOCs, if at a certain moment, the removal rate shows a large decrease, it is likely that there is poisoning of precious metal catalyst. (2) The temperature inside the furnace needs to be increased to achieve the standard of the exhaust gas. Depending on the composition of the exhaust gas, the normal furnace temperature is 200-400°C. For example, the normal starting combustion temperature of toluene is 190°C, and 99% removal can be achieved at 230°C. Once its reaction temperature is too high, the catalyst needs to be checked. 3. Types of catalyst poisoning (1) Recoverable poisoning: Toxic substances adsorb or chemically combine with active components such as platinum and palladium in the precious metal catalysts, thus creating chemical bonds with weak strength, which can be removed by physical or chemical means and regenerated in reverse to make the catalysts recover their activity. This is also the mildest form of poisoning. (2) Selective poisoning: We call it selective poisoning of the catalyst when the toxicant causes the precious metal catalyst to have no catalytic effect on some or specific components. (3) Permanent poisoning: The toxic substance interacts with the active components such as platinum and palladium in the precious metal catalyst and forms a strong and stable new chemical bond. 4. Ca...

What are the specifications of dust filter bag? The common specifications are 120~160mm in diameter and 2~6mm in length. For example, round bag Φ125*1000, Φ125*1500, Φ125*2000, Φ125*2500, etc., Φ133*1000, Φ133*1500, Φ133*2000, Φ133*2500, etc. First of all, the length of the filter bag, with the same volume of flue gas, filtration speed and diameter of the dust bag, can reduce the number of bags by increasing the length of the dust bag, thus reducing the floor space, reducing the solenoid valve, pulse valve, blowing tube and other parts of the dust cleaning system, saving investment and shortening the dust cleaning cycle. But on the other hand, the bag is longer, the dust collector box should also be extended upwards, the strength of its components will have to be increased, so that the equipment costs increase; from the pulse blowing point of view, to make the dust bag full length to get effective dust cleaning, must be applied in the blowing end of a large enough energy. The longer the dust bag, the greater the energy required, the more likely to damage the end of the filter bag blowing; dust bag longer, supported by the weight of the filter material increased, the tension also increased, if the top of the bag tension is too large, may be pulled through the seam; online cleaning, the longer the bag, the greater the possibility of dust from the bag to return to the bag; if offline cleaning, the longer the dust bag, the longer the time to pause after cleaning, cleaning the dust In addition, the bag is too long, then installation, maintenance, inspection will be inconvenient; dust collector if installed indoors, dust bag length is also limited by the building height. 1. Reduce the number of dust bag, the equipment covers an area of small: In the case of the same air volume, filtering wind speed and bag diameter, the increase of dust bag length will increase the filtration area of single dust bag, then the number of filter bags can be reduced and the footprint can be reduced:. 2. The number of dust bag is reduced, then the solenoid valve, pulse valve, blowing tube and other components of dust cleaning system will be reduced, saving investment, and can shorten the dust cleaning cycle of dust collector. 3. Room temperature bag dust collector dust bag length is too long will add the production cost: industrial dust collector box height to add, upward extension will make the component strength needs to increase, so the equipment production cost cost will add. 4. Poor dust removal: industrial dust collector online dust removal, the longer the dust bag, the dust blown out of the dust bag is re-absorbed from the bag, the greater the possibility of the bag, assuming offline dust removal, the longer the dust bag, the greater the energy required, the more easily damaged the filter bag blowing end; dust bag longer, the weight supported by the filter media increased, the tension also increased, if the top tension of the bag is too large, may be pulled through t...

Dust bag will directly affect the efficiency of dust removal, how to use and maintain the dust bag is very important. The temperature is too high or too low in the corresponding case will also bring impact to the dust bag, dust bag usually in use to prevent the internal gas cooling to below the dew point, especially in the negative pressure working bag dust collector. As air often leaks in from its shell, causing the temperature of the bag chamber to decrease, making the internal gas temperature below the dew point, the dust bag will be subject to moisture, the dust will not show fluffy, but stick to the dust bag, blocking the fabric holes, causing the dust cleaning failure, the pressure drop of the dust collector will become large, too much pressure can not continue to run, part of it will also produce dust bag paste bag can not remove dust. To prevent dew, it is necessary to keep the temperature of the gas in the dust collector and its system everywhere higher than its dew point 25~35℃ (such as the dew point temperature of the kiln mill machine 58℃, the running temperature should be above 90℃) to ensure the good use of dust bag. Take appropriate heating measures. Such as setting far-infrared electric heater, electric heater in the dust collector, or adding heater in the bag chamber, which can appropriately increase the flue gas temperature of the main machine and strengthen the temperature monitoring of the dust collector and dust removal system in order to grasp the use conditions of the bag dust collector and prevent the generation of condensation. Reduce air leakage. The leakage of air from some crevices of dust collector body, the leakage of dust bag body should be controlled below 3.5%, the leakage of air from process equipment in dust collector system such as the airtight ash discharge valve at the discharge port of ball mill, the leakage of airtight ash discharge valve under dust collector, the pipe flange connection, etc.. These are often overlooked by maintenance managers, thus, increasing the amount of unwanted air leakage and deteriorating the operating conditions of the baghouse. Additional raw material pile shed. In the cement production of various raw materials, fuel and mixed materials with different water content, if placed in a fixed pile shed to prevent rain can greatly reduce the water content of the material, which is a measure to reduce the material moisture, in China's southern cement plant this situation is more common, but some of the material pile shed is too small, some are not, therefore, to the use of the bag filter caused by the corresponding difficulties. Do a good job of insulation and rainproofing of dust collector, pipelines and other relevant places, practice has proved that good insulation measures can make the difference between the inlet and outlet temperature of bag filter very small, which is a measure to prevent condensation, dust-containing gas should be evenly distributed in the dust collector to preven...