Does your dust collector often have such troubles? The dust collector has a small processing capacity and a large area; the operation is unstable, and there are abnormal noises and noises during the operation of the dust collector; the pipe dust is clogged and the dust removal device leaks the powder; the dust around the workbench is flying; it is not easy to install and replace; the filter bag replacement frequency is high 3. High maintenance cost … That ’s because you did n’t choose the right dust collector! The correct selection of the dust collector is an important link to ensure the normal operation of the dust removal system and achieve the predetermined treatment effect, and also a key measure to obtain the best filter bag life.
- Master the original data
(1) Dust-containing gas characteristics, including gas chemical composition, temperature, moisture content, corrosivity, flammability and explosiveness, dust concentration
(2) The physical and chemical characteristics of dust, including the particle size, dispersion degree, corrosivity, polishability, viscosity, flammability and explosiveness of the dust, etc.
(3) The air volume of the dust collector, the air volume and air pressure of the main fan of the system
(4) Requirements for emission concentration
(5) Requirements for the service life of the dust collector
(6) Location and site area of dust collector installation site
- Select the form of dust collector
There are many types of dust collectors, including pulse injection, mechanical vibration, nozzle back blowing and dust removal units.
At present, most of them use pulse spraying. The main feature of pulse spraying dust collectors is the use of compressed air pulse spraying to clean the dust, which has a high cleaning strength. The layers can be cleaned; the pressure of the bottom of the bag on the filter bag with a length of 6-8mm can reach more than 1500-2000Pa.
The cleaning intensity can be adjusted, there are high and low pressure pulse cleaning, online and offline pulse cleaning, the cleaning type is diverse, the effect is good, the structure of the pulse dust collector is diverse, there are down inlet type, up inlet type, end face Side wind. The filter bags are mainly round bags, as well as various flat bags.
- Select the filter material
The filter material is the core of the dust collector. Whether it is selected correctly or not determines the selection steps of the dust collector. The efficiency of the dust collector, the discharge concentration and the resistance and life of the filter bag are selected. The physical and chemical characteristics of the dust and gas in the gas and the dust removal form of the dust collector are analyzed and selected. The main considerations are to ensure the required filtered emission concentration and long filter bag life, and the lowest cost must be considered.
- Determine the filtering air speed
The filter speed of the dust collector can be selected according to experience, or can be calculated according to the allowable resistance, or a combination of experience and calculation. The size of the filter wind speed depends on the dust characteristics and concentration, gas characteristics, filter material type and cleaning method .
For the filtration of fine particles, large concentration, strong viscosity, strong sculpting dust, and high temperature and high humidity gas, the filtering air speed should take a small value, and vice versa. For the filter material, the resistance of the woven fabric is large, and the filter wind speed takes a small value. The needle punching felt has a large opening rate and the resistance is small. It can take a large value.
For the cleaning method, such as the mechanical blow-off chamber reverse blowing cleaning, the strength is weak, and the filtering air speed is a small value; the pulse blowing cleaning power is large, and the filtering air speed can be selected. If the filtering area of the filter material required for the gas is small, the dust collector takes a large value.
- Determine the cleaning system
The dust-cleaning cycle of the dust collector is related to the dust-cleaning method of the dust collector, the characteristics of flue gas and dust, the type of filter material, the filter air speed, and the pressure loss. Like the resistance of the equipment, the cleaning cycle is usually determined based on various factors and with reference to similar dust removal processes, and then adjusted according to the actual operating conditions.
If the constant pressure cleaning control method is adopted, the cleaning cycle is not artificially determined, but is adjusted automatically according to the operating conditions during operation. For the pulse dust collector, the cleaning system mainly includes the blowing cycle and pulse interval. Stop blowing and blowing (online or offline); for the sub-room backflushing dust collector, it mainly includes the duration and times of the three states of backflushing, filtration and settling.
- Determine the specifications of the dust collector
Determine the specification, model and quantity of the air compressor according to the air consumption. The oil and water in the compressed air are not cleanly separated. The air with moisture and oil sprayed into the bag will undoubtedly cause the filter bag to be clogged, which will increase the resistance of the dust collector. If the air volume is large, the processing air volume will be reduced, which will eventually lead to the inability of the dust collector to operate.
In addition, the large moisture in the air will also accelerate the corrosion of the spring in the pulse valve, and the pulse valve fails in a short period of time. In order to ensure that compressed air can meet the requirements of pulse valve performance, for the selection of compressed air dryer, when the temperature of the dust collector in the plant is below 10 ℃, a freeze dryer should be used. When the dust collector installed outside the factory reaches the freezing temperature without heat preservation facilities, the dryer with regenerated desiccant can be used. Under normal working conditions indoors, a dryer is generally not required.