The advantages and disadvantages of dust collector dust removal and a variety of factors, but mainly depends on the filter material. The filter material of the bag filter is synthetic fabric, natural fiber or glass fiber woven cloth or felt. Depending on the nature of the flue gas, filter media suitable for the application conditions are selected. In general, when the flue gas temperature is lower than 120°C and the filter material is required to have acid resistance and durability, polyester fleece and polyester needle felt are often used; when high-temperature flue gas (<250°C) is processed, graphitization is mainly used. Glass cloth; in some special circumstances, the use of carbon fiber filters.
Since the bag filter is so important to our life, how can we choose which type of dust collector, or that type of dust collector is more suitable for their own family, what type of dust remover will be better, and what are the precautions? Here are just a few factors that need to be considered when selecting the type of dust collector from eight convenient and simple introductions.
1, the use of temperature For the bag filter, the use of temperature depends on two factors, the first is the maximum temperature of the filter material, and the second is the gas temperature must be above the dew point temperature. For bag filter, the relationship between using temperature and dust removal efficiency is not obvious. This is different from electric dust removal. For electrostatic precipitators, temperature change will affect the specific resistance of dust and other effects of dust removal efficiency.
2. Dust concentration at the inlet For bag filter, the inlet dust concentration will directly affect the following factors: Pressure loss and cleaning cycle. As the inlet concentration increases, the ash deposition speed on the same filter area increases and the pressure loss increases. As a result, the number of cleaning operations has to be increased. Filter bag and box wear. In the case where dust has strong abrasiveness, the amount of wear can be considered to be proportional to the dust concentration. It is not necessary to collect dust in advance. Pre-collecting dust is to add a dust-removing equipment before the entrance of the dust collector, also called pre-dusting. Ash discharge capacity of the ash discharge device. The ash discharging capacity of the ash discharging device shall be based on the ability to discharge all received dust, and the amount of dust is equal to the inlet dust concentration times the treated air volume. Operation method. Bag filter is divided into positive pressure and negative pressure operation modes. In order to reduce fan wear, it is not advisable to adopt positive pressure operation mode for large inlet concentration.
3.Excluding dust concentration at the outlet The dust concentration at the outlet refers to the discharge concentration of the dust collector. The indication method is the same as the inlet dust concentration. The size of the export dust concentration should be based on the local environmental protection requirements or the user’s requirements. The discharge concentration of the bag filter Generally can reach 50 g/Nm3 or less.
4. Handling air volume The processing air volume refers to the volume of gas that the dust removal equipment can purify in unit time. Units are cubic meters per hour (m3/h) or standard cubic meters per hour (Nm3/h). It is one of the most important factors in the design of bag filter. When the bag filter is designed or selected according to the air volume, the filter cannot generally be operated under the condition of exceeding the specified air volume. Otherwise, the filter bag is easily clogged, the service life is shortened, the pressure loss is greatly increased, and the dust removal efficiency is also reduced; however, it is not possible. If the air volume is too large, it will increase equipment investment and floor space. Reasonable choice of processing air volume is often determined based on process conditions and experience.
5. Pressure The operating pressure of the bag filter is determined according to the static pressure value and installation position of the device before and after the dust collector and the fan, and is also the designed pressure resistance value of the bag filter.
6, the filter speed The filter speed is an important factor in the design and selection of bag filter, it is defined as the speed of the filter gas through the filter, or through the filter air flow rate and filter area ratio. In order to improve the cleaning effect and the ability to work continuously, the bag filter is divided into several chambers (or zones) in the design. Each chamber has a main valve to control whether the chamber is in the filter state or the stop filter state (online or Offline status).
