• English

    7 Measures to improve PTFE filter bag efficiency
     Jun 08, 2021|View:552

    Factors affecting PTFE filter bag efficiency

    1. The selection and application of filter bag material is the core technology of bag type dust collector, which plays a decisive role in the performance of the dust collector. Due to the environment of each PTFE filter bag point, the nature, temperature and technical requirements of dust treatment are different. Different filter materials should be selected according to different conditions, and corresponding technical protection measures should be taken. The requirements for filter bag materials include the following technical properties: filter bag materials are suitable for different temperatures, good peeling performance, easy ash cleaning, good air permeability, low resistance, high filtration efficiency, high strength, able to withstand high-strength ash cleaning, long service life and suitable price.

    2. The performance of the dust collector is determined by the filtration wind speed and the filtration speed. A very important parameter is also an important parameter to measure the advanced nature of bag precipitator. The filtration velocity is closely related to the dust concentration, particle size, application situation, viscosity, gas temperature, moisture content and ash cleaning method. When the particle size of dust is fine, the temperature and humidity are high, the concentration is high, and the viscosity is large, the filtering wind speed should be lower, otherwise, the high value can be selected. If the filtration speed is too high, the load of the filter bag will be increased, the filtration resistance will be increased, and the service life of the filter bag will be short and the efficiency will be low.

    3. Air leakage directly affects the PTFE filter bag effect and service life of the dust collector, and the air leakage rate is required to be less than 3%. The bag type dust collector generally operates under negative pressure, and it is easy to form a small circuit short circuit if there is air leakage. The air volume of PTFE filter bag system is not enough, resulting in positive pressure dust. Air leakage will also reduce the temperature of the system, easily form damp and paste the bag, increase the PTFE filter bag resistance and reduce the PTFE filter bag effect

    4. Thermal insulation is also a must for bag dust collector_ Off. The purpose of heat preservation is to keep the gas and avoid dampness. Most of the filter bags are smeared and blocked, which is caused by low dust temperature and high humidity

    5. The dust cleaning interval is too long, the dust attached to the filter bag can not be eliminated in time, resulting in the increase of system resistance. Generally, the injection interval is about 4S (which can be adjusted according to the actual production situation), the injection time is 0.25 ~ 0.35, and the time interval between chambers is about 30s.

    6. The cone of the ash hopper can not discharge the ash smoothly, and there is too much ash in the hopper, which will block the air inlet and cause poor ventilation.

    7. There is serious air leakage in the leaf part and surrounding walls of the leakage dust collector. When it rains, water will enter into the dust collector, resulting in bag pasting, or wet materials forming lumps to block the ash outlet of the cone part.

    7 Measures to improve PTFE filter bag efficiency 

    Measures to improve PTFE filter bag efficiency

    1. Strengthen management dust collector is a main equipment in the cement process circulation system, its operation directly affects the output and quality of the kiln, mill, dryer and other main equipment. The synchronous operation rate and intact rate of equipment system and dust collector must be ensured.

    2. To strengthen the sealing, the PTFE filter bag system mainly includes the dust collector body and other equipment of the PTFE filter bag system, such as steel impeller feeder, inlet and outlet valve, conveying equipment and pipeline, inspection door, etc. Strengthen the sealing of all inspection holes and doors. The inspection door * is easy to use double door, and the sealing around the door should use heat-resistant silicone rubber. The sealing of conveying equipment should also be strengthened to reduce and eliminate leakage. All joints of the shell shall be continuously welded, and there shall be no leakage and opening (air leakage is easy at the door hole and ash cleaning and blanking place). Therefore, it is necessary to strengthen the inspection and spot inspection of the PTFE filter bag system, check the integrity and sealing of the dust collector's air pipe, shell, upper pattern plate and other parts, and repair welding in time when the worn parts are found.

    3. Reduce the times of startup, shutdown and inspection, and the dust collector shall not be abnormal or shut down for a long time. Generally, the inspection door shall not be opened for maintenance. Every time the dust collector is opened, the temperature drops sharply and dews during the startup or maintenance period, which seriously affects the service life of the dust collector.

    4. The thickness of the insulation layer of the dust collector should be reasonably selected according to the temperature, and some better protective layers such as thin steel plate should be selected on the outer surface to extend the service life and insulation effect of the insulation layer. If the dust collector adopts external insulation measures, the heat loss of the shell will be reduced, especially before starting up in winter, the heating system of the dust collector should be turned on first, and the filter bag should be preheated for more than one hour, Then normal production can be carried out

    5. Strengthen the dust management. When the production system is transformed, the supporting PTFE filter bag system should be considered. In the design of matching, the inlet concentration, temperature and wind speed of the dust collector have certain technical requirements. When the production system is reformed, it may be necessary to increase the wind speed and the amount of dust. At this time, it is necessary to consider the capacity of the dust collector and the possible consequences, and try to match each other.

    6. Reduce the damage of cloth bag. First of all, the air outlet end of cloth bag is easy to be damaged. During the installation, maintenance and replacement of the cloth bag, the center line of the injection port and the center line of the filter bag must be kept coincident, otherwise the outlet of the filter bag will be damaged. Secondly, the bottom of the filter bag is easy to be damaged. The main reasons for this phenomenon are: the skeleton is too long, not fixed well, the lower part shakes greatly, and the friction between the filter bag and the filter bag is caused. Therefore, the filter bag is about 50 mm to 100 mm longer than the skeleton

    7. Reduce the dust concentration of flue gas. In the slag heating system, before the flue gas enters the bag type dust collector, the pre PTFE filter bag of flue gas (* *) and downward air inlet should be used as far as possible to capture the high temperature and large particles of flue gas, so as to reduce the dust concentration of flue gas. In particular, the high temperature flue gas directly enters into the filter bag, which reduces the frequency of dust cleaning and back blowing of the filter bag and prolongs the service life of the filter bag. The downward air inlet can make the large particle dust deposit naturally without passing through the filter bag. The unpowered settling chamber should be reserved in the PTFE filter bag transformation. It is a kind of unpowered operation equipment with no energy consumption, and is an ideal way of cooperation.

    • No.68 Gongyuan Road, Xuebu Industrial Park, Jintan, Changzhou, Jiangsu, China
    • info@czwayon.com