When planning large filter bags in power plants, first of all, we should put the high reliability and high quality development required by the high continuity and high importance of the production of electric power enterprises in the first place, to ensure that the design of bag dust removal system can work safely and economically for a long time, and maintain the flow of electricity. The bag filter is divided into flat bags (trapezoidal and flat) and round bags (cylindrical) according to the shape of the filter bag cross-section. 2. According to the way of air inlet and outlet, it is divided into: lower air inlet and upper air outlet, upper air inlet and lower air outlet, and direct current type (only limited to flat bag). The core filter can be divided into external filter and internal filter according to the filtering method of the filter bag. The fiber used for filter material includes cotton fiber, wool fiber, synthetic fiber and glass fiber. The filter material woven from different fibers has different properties. The commonly used filter materials are 208 or 901 polyester flannelette, and the service temperature is generally not more than 120 ° C. The service temperature of glass fiber filter bags treated with silicone resin is generally not more than 250 ° C. Cotton wool fabrics are generally suitable for non-corrosive; Dusty gas with temperature below 80-90 ° C. Filter bag gas dust removal: gas dust removal is to purge the filter bag with the help of high-pressure gas or external atmosphere to remove the dust on the filter bag. Gas cleaning includes pulse jet cleaning, reverse blowing cleaning and reverse suction cleaning. In the whole thermal system, the main engine should be an important organic whole. It is necessary to coordinate the comprehensive cost of operation and control its own ability, so as to truly realize the power industry production with high quality, high yield and low consumption. In particular, it is necessary to select the appropriate bag dust removal technology according to the students, and also take the following information security maintenance methods:
1. Bag activity monitoring and active control procedure: detect pressure bag dust collection bag, adjustment, overpressure alarm, gray appearance of scraping condition, control status, flue gas temperature detection, overtemperature alarm, adjustment and other parameters.
2. Maintenance of dust removal bag: when the air preheating bag or incineration technology equipment fails, the ambient temperature of flue gas will suddenly fluctuate and rise sharply, and the dust removal bag may burn. When the temperature data of flue gas treatment reaches the upper limit, the alarm shall be given and the cooling management measures shall be activated actively, such as spraying water on the outer wall of the product at the outlet of the flue of the Chinese air preheating bag or spraying water on the outer wall of the pipe at the inlet of the dust removal bag. It can also activate the bypass flue, and even consider closing the furnace for students. It is considered that the oxidation resistance of some filter media is poor, and it is not recommended to add cold air to cool the temperature unless absolutely necessary.
In order to avoid the influence of the dust in the furnace on the filter cloth bag, the pre-coating of the ash system equipment should play a role.
All kinds of controlled coal are rich in certain moisture. No matter which moisture is selected for incineration, it can be separated through transpiration and differentiation to make the flue gas moist. The connotation and water and crystal water management will not change basically. However, in the process of data mining, transportation and storage, the external water, such as groundwater, surface water and rainwater, has a great development and change. When the water vapor content in the flue gas is high and the flue gas treatment temperature is relatively low, the most serious situation is that when the flue gas temperature is lower than the water dew point and the acid dew point together, condensation will occur on the dust removal bag, seriously endangering the safe and effective operation of the filter bag and the life of the bag. Therefore, it is necessary to consider anti-dewing methods for filter bags. The design of the filter bag shell body adopts students’ good thermal insulation technology to effectively prevent condensation. When necessary, enterprises should also actively consider means such as heating.
3. Research method of air flow velocity distribution: different dust-containing air flow in the main area of the box, different use of filter cloth bags in some areas of the same box, and different functional parts of the same filter cloth bag should be uniformly distributed as far as possible, which is necessary for us to keep the filter cloth bag free from the influence of air flow and prolong the life of the filter cloth bag. What is more important is the large bag type dust bag. Increasing the duty ratio (i.e. increasing the bag spacing) can greatly improve the uniformity of the internal airflow dispersion. At the same time, the uniformity of dusty air flow can be improved by setting a guide plate at the air inlet. In addition, increasing the space design dimension of the inlet and outlet air duct of the dust bag is also conducive to the uniform dispersion of the dust-laden air flow, which is called the concept of pressure equalization zone.