How to Choose Dust Collector for Evaporative Air Cooler


1. Selection according to the amount of treated gas &nb […]

1. Selection according to the amount of treated gas


The most decisive factor to decide the size and type of dust collector is the amount of gas to be treated. For the amount of air, it is necessary to select a dust collector capable of handling the amount of air. It is often uneconomical to use multiple dust collectors to deal with the small amount of air in parallel. For the smaller amount of air, it is more economical to compare which type of dust collector is the most economical and easiest to meet the environmental requirements of dust source control and dust emission.

Since it is not easy to predict that the dust collector will be affected by the operation and environmental conditions after it enters the actual operation, it is necessary to ensure a certain margin or reserve some space which may increase the capacity of the equipment when deciding on the capacity of the equipment.



2. Selection according to the dispersion and density of dust


Dust dispersion has a great influence on the performance of dust collector, but the dust dispersion is the same, because the operating conditions are different. Therefore, when choosing the type of dust collector, the first thing is to accurately grasp the dispersion of dust, such as when the particle size is more than 10_m, the cyclone dust collector can be selected. When the particle size is less than several microns, the electrostatic precipitator and bag-type precipitator should be selected. The specific selection can be made according to the dispersion and other requirements, referring to the type and performance table of common precipitators, and then according to other conditions and the types and performance of the precipitators introduced.

The dust density also has a great influence on the dust removal performance of the dust collector. The most obvious effects are gravity, inertia and centrifugal dust collectors. One common feature of all dust collectors is that the smaller the stacking density is, the more difficult it is to separate and collect dust particles, and the more serious the dust is flying twice. Therefore, special measures should be taken in operation and equipment structure.



3. Selection according to the concentration of dust in gas


For nutation force, inertia and cyclone dust collector. Generally speaking, the higher the import dust concentration is, the higher the dust removal efficiency is, but this will increase the export dust concentration. Therefore, the dust treatment effect can not be generally considered as good only from the high dust removal efficiency. For wet dust collectors such as Venturi tube washer and jet scrubber, the initial dust concentration is less than 10 g/m; for bag filter, the lower the dust concentration is, the better the performance of the dust removal is. OK, at a higher initial concentration. Continuous ash removal, pressure loss and emission concentration can also meet environmental requirements. The initial concentration of ESP is below 30g/m3, which can be used without pre-precipitator.



4. Effect of Dust Adhesiveness on Type Selection


The adhesion mechanism between dust and wall is closely related to the specific surface area and moisture content of dust. The smaller the particle size d, the larger the specific surface area, the more water content, and the greater the adhesion.

In cyclone dust collector, the dust adhering to the wall by centrifugal force is dangerous of blockage, while the dust adhering to bag dust collector is easy to block the channel of the filter bag, and the discharge electrode and dust collector are easy to accumulate dust in the electrostatic precipitator.


5. Effect of Dust Specific Resistance on Type Selection


The dust specific resistance of ESP should be in the range of 104-10n cm. The specific resistance of dust varies greatly with the temperature and humidity of dusty gas. For the same kind of dust, the specific resistance is the largest between 100 and 200 C. If the dusty gas is quenched and tempered with sulfur, the specific resistance decreases. Therefore, the specific resistance of dust should be mastered beforehand when selecting ESP, and the selection of temperature of dusty gas and the adjustment of properties of dusty gas should be fully considered.