Bag filter is the development focus and direction of boiler dust removal
As early as in the 1980s, China installed a bag filter on the flue gas treatment of some power plant boilers. Due to the problems of the quality of the filter media, the backwardness of the leak detection methods, the inappropriateness of the backflushing method, and the lack of operation and management experience, these dusts were caused. All operations failed. In the 1990s, almost all electrostatic precipitators were used for boiler dust removal in domestic power plants. However, a small bag filter was used in the power plant's coal transportation system and ash removal system. In recent years, due to the increasingly stringent environmental protection standards in China, the development of industrial dust collector technology has been promoted. The filter bag performance of industrial dust collectors has been fully adapted to the characteristics of power plant boiler flue gas, and the leak detection methods have become more advanced. The purge system has become more reasonable. . At present, polyphenylene sulfide is used as the filter material of industrial dust collectors in thermal power plants in China. This type of filter material (also known as PPS) is a surface-type filter material, which completely removes dust and reduces the possibility of dust forming on the surface of the filter bag. . The kind of filter material has high strength and temperature resistance up to 190 (the exhaust temperature of normal operating conditions of the burning power plant is about 150), and the corrosion resistance and wear resistance are very strong. The disadvantage of polyphenylene sulfide is that when the oxygen content of the flue gas is greater than 15%, the oxygen resistance is poor, and the service life can reach 30,000 hours under normal operating conditions. The filter material PPS used in the domestic bag filter factory mainly depends on the import. The finished product bag is processed in the domestic market, which greatly reduces the price of the bag and reduces the operating cost of the equipment. The most successful operation of industrial dust collectors in domestic power plants is the two 200 MW units of Inner Mongolia Fengtai Co., Ltd. Since the original four units of the power plant used electrostatic precipitators, the dust removal efficiency was much lower than the design efficiency. Although the electrostatic precipitator was reformed several times and measures such as increasing the number of electric fields or expanding the circulation area were adopted, the dust removal effect was still unsatisfactory, and the dust emission concentration was still excessive. After analysis, it was considered that the reason for the low efficiency of the electrostatic precipitator was that the specific resistance of the coal was high. The content of S iO2 and Al2O3 in the ash component was high, and the sum of the two items was as high as 90. 54%, while the Na 2 O content. Only 0. 01%. The two 200MW units expanded by the plant were put into operation in 2002. The bag filter was operating normally, the dust removal efficiency reached 99.9%, and the dust emission concentration was below 28mg/Nm3. The plant's original 50 MW unit electrostatic precipitator has now been transformed into a bag filter (using the original electrostatic precipitator housing and bracket), and the operation effect is good. Domestic industrial dust collector factories have also installed bag dust collectors in several power plants and heat stations successively, such as two 130 t/h fluidized bed furnaces in the thermal power plant in Zhangjiagang Free Trade Zone and three 75 t/h cycles in the No. 5 heat source plant in Tianjin Development Zone. Fluidized bed furnaces and two 29MW hot water boilers in Beiyuan Thermal Power Station of Inner Mongolia Fufeng Thermal Power Co., Ltd. performed well. Nowadays, bag filter has been installed and used on large units, which is the focus and direction of boiler dust removal.
CNC lathe is a machine tool for machining metals and other materials, which controls the movement of the table and tools by a computer or other digital device to achieve high precision and efficiency. Compared with traditional lathes.
Cnc Vertical Lathes,Vertical Turning Lathe,Cnc Vertical Turret Lathe,Vertical Cnc Lathe Machine Ningbo Yien Machinery Co., Ltd , https://www.nbyienmachinery.com
Structural characteristics of CNC vertical lathe:
CNC vertical lathe is a CNC vertical lathe whose main structure is base and single column type structure with table, fixed beam, square ram and single tool holder structure, which is an economic CNC vertical lathe with high rigidity and high cost performance. The casting process of CNC vertical lathe is large in volume and complex in structure, the amount of iron liquid poured is large, the cooling time of the casting is long, and casting defects such as shrinkage, shrinkage, pore, crack and substandard mechanical properties are easy to appear, and it is difficult to control the production process. The base, column and beam of CNC vertical lathe are made of high-strength cast iron with good shock absorption; the large span hardened guide rail has good wear resistance and long-lasting precision maintenance. Symmetrical box structure can carry heavy cutting with high torque. The ram adopts square structure, with good precision. Fixed cross beam, good rigidity and high precision. CNC vertical lathe single tool block structure, stable and reliable precision. Centralized machine operation panel â—‡Makes the operation more convenient and quick. It can process various internal and external cylindrical surfaces, conical surfaces, circular curved surfaces, etc. CNC vertical lathe is suitable for processing parts such as motor shells, large and medium-sized disk sets and covers. It is suitable for electromechanical, automobile, wind power, engineering machinery and other industries.