How to choose the appropriate dust bag and the precautions in use
As the core part of the bag type dust collector, the filter material can not adapt to the temperature of the flue gas very important.
For example, needle punching filter bag has the same pore size and dust particle size. During the filtration process, the dust needs to form a porous layer on the surface of the filter material. The first is to understand the components of the flue gas: by understanding these decisions, the cleaning way of the dust collector, the post-processing method of filter material and the filtration speed. Generally speaking, pulse bag filter is usually used for large dust and light and light dust. Filtration speed is mostly controlled by 1.2m/min or less than 1m/min under a few working conditions. The other, depending on the situation, can use the high pressure back blowing dust collector and the cyclone dust collector. The post-processing methods of filter material usually have microporous film covering, water repellent and oil proof, anti static electricity easy to clean ash and other treatment, according to the situation. The components of the flue gas include the content of dust, the specific gravity, the size of the particle, the viscosity of the dust, the water content of the smoke and so on.
Second, understand the amount of flue gas to be treated: the handling air volume of the dust collector is usually combined with the system air leakage coefficient (10%-15%). Knowing the handling air volume of the dust collector and the wind speed of the filter can pass through the formula: the total area of the S=Q/60V is obtained. S: total area; Q: system handling air volume; V: filter wind speed.
Three, understand the flue gas temperature to be processed: for example, the normal usage temperature of filter material is too much outside the flue gas temperature, and the investment of equipment will increase due to the high cost of filter material. If the normal use temperature of the filter material is lower than the temperature of the flue gas, it is possible to cause the cloth bag to burn down and cause a great positive loss. So how do you choose the filter material at the temperature of the flue gas? According to the use temperature, the filter material is divided into 130 C at normal temperature, medium temperature filter material at 130 -180 C, and high temperature filter material at 180 C -280 C. When the temperature of the flue gas and the temperature of the filter material are known, the suitable filter material can be selected.
How to prolong the use of dust bag after the filter bag is used：The selection of needle felt dust bag material is directly related to the performance of bag filter, and the filter bag is the core of bag filter. The cost of the bag bag type dust collector in high temperature waste disposal equipment interest accounted for a large proportion of bag dust collector, which belongs to consumables, prolong the service life of the dust bag dust collector equipment manufacturing cost, have great influence on operating costs and maintain the interest and interest of cement production.
1. the suitable filter material is selected according to the different working conditions. The selection of filter media should be based on factors such as gas temperature, humidity, chemical characteristics, particle size, weight, shape, whether there is polish and dust concentration, filtration speed, cleaning way, emission concentration and working principle of bag filter. In general, the bag filter or the mechanical vibrator bag filter is used for weaving. As well as dew point temperature caused by dust blockage or chemical components corrosion damage and so on. The deformation of the bag cage and the abnormal flow of flue gas in the bag can also cause the damage of the filter bag. In addition, the reasons for the damage of filter bags include dust binding on filter surface, large temperature change of flue gas, large resistance to operation and frequency of dust blowing.
2. the dust layer is formed in the appearance of the filter bag in advance, and the filter bag should be precoated before the dust collector is put into operation. The dust layer can pre wrap and block the oil mist and acid, prevent oil mist, calculate the direct contact with the surface of the filter bag, prevent oil mist from blockage, and expose the phenomenon of paste bag.
3. the reasonable ash cleaning pressure, the ash clearing period and the dust control mode are set up, and the appropriate form of the ash cleaning structure is selected. In order to ensure that dust removal is relatively thorough and prevent dust blockage, special attention is paid to excessive cleaning and undesirable. This is because excessive cleaning will affect the service life and filtration performance of filter bags.
4. prevent the uneven load of the load and make the local filter bag run over the load. The exhaust gas at the inlet of the dust collector should be evenly distributed to the filter bags.
5. the inner diameter of the general filter bag can be larger than the filter cage 5mm, for example, the diameter of the bag and the filter bag, which can be reasonably matched with the 130mm filter bag. For synthetic fiber felt filter material. The outer diameter of the filter basket is generally designed to be 125mm, and for the glass fiber filter, the difference between the two diameters should be reduced to 23mm. There is a certain frictional resistance in the device, rather than very easy to put it down. The glass fiber at 280 DEG C under the environment of the shrinkage rate was 0, and the filter bag size is very stable, there is a certain cage in the heat expansion work bag can tightly attached to the bag cage, when cleaning the ash is mainly bending vibration effect of cleaning, collision does not occur in the bag between the bag cage wire, and thus minimize the friction.
6. airflow should have a drainage device for a longer filter bag. To ensure that high pressure airflow is aimed at the middle of the filter bag instead of directly impacting the filter bag, it will cause damage to the filter bag. At the same time, the size of the different diameter of the blowpipe should be different with the distance of the gas bag, so that the kinetic energy of the filter bag in different positions is basically equal.
7. we must strictly guard against overheating for a long time and operate for a long time. If the filter material is to be used at a certain temperature and affect the service life of the filter bags, we should take effective and effective measures to control the inlet temperature of the controller.