Working mode of bag filter in Shandong Province
The equipment to separate the industrial dust from the flue gas is called industrial dust remover or bag dust remover. Nowadays, the equipment mainly used for dust treatment are bag dust remover, filter cartridge dust remover and electrostatic precipitator. Let's talk about how it works.
Bag dust removal
The dust remover is mainly composed of a dust hopper, a filter chamber, a clean air chamber, a bracket, a lifting valve, an injection and cleaning device, etc. during operation, the dust containing gas enters the ash hopper from the air duct. Due to the effect of gravity, the large particles of dust fall directly into the bottom of the ash hopper, and the smaller dust flows upward with the air into the filter chamber and is blocked on the outer surface of the filter bag. The purified flue gas enters the bag and flows through the filter bag mouth and The clean air chamber enters, and finally the clean air is discharged through the function of fan.
With the continuous increase of working time of the equipment, more and more dust passes through the filter bag, so the resistance load of the filter bag also rises. At this time, the dust attached to the filter bag is blown out by pulse back blow.
Such cycle alternation keeps the working efficiency of the filter bag unchanged, so that the dust passing through the precipitator can reach the emission standard.
In a way, the working principle of the filter drum dust remover and the bag dust remover is the same. The only difference is three. (1) the filtering accuracy is different, and the filtering accuracy of the cloth bag is generally within 0.5-1um. The filtering accuracy of the filter cartridge can reach 0.2um at least. (2) the equipment maintenance is different. The maintenance of the filter cartridge is much easier than that of the cloth bag. Generally, if the dust removal equipment with the same air volume needs 1 day for the maintenance of the filter cartridge, the cloth bag needs at least 3 days.
The working principle of electrostatic precipitator is: the dust containing gas is separated by electricity when passing through the high-voltage electrostatic field, the dust particles and negative ions combine with negative electricity, and tend to discharge on the anode surface and deposit. In metallurgy, chemistry and other industries, it is used to purify gas or recover useful dust particles. It is a dust collection method that uses electrostatic field to ionize gas so that dust particles can be charged and adsorbed on the electrode. In strong electric field, air molecules are ionized into positive ions and electrons. When electrons rush to the positive electrode, they encounter dust particles, so that dust particles can be negatively adsorbed on the positive electrode and collected. It is commonly used in factories and power stations that use coal as fuel to collect smoke Coal ash and dust in gas. Used in metallurgy to collect oxides of tin, zinc, lead, aluminum, etc. In addition, the highest electrostatic filtering capacity of the electrostatic precipitator is 0.02um, and the temperature is 400-500 ℃. These two points are always out of reach of the bag and the filter.