Dust Removal Equipment in Fertilizer Production
During the fertilizer production process, a large amount of dust is generated, which not only affects the working environment and the health of workers but also may cause potential safety hazards. Therefore, dust removal equipment is of crucial importance. The following are several common types of dust removal equipment used in fertilizer production:
1. Cyclone Dust Collector
Working Principle
The cyclone dust collector separates dust from gas by utilizing centrifugal force. When the dust-laden gas enters the cyclone dust collector at a relatively high speed, the gas rotates downward in a spiral along the cylinder wall. During the rotation, the dust particles are thrown towards the cylinder wall due to the effect of centrifugal force and then fall into the dust hopper along the cylinder wall under the action of gravity, while the purified gas is discharged upward from the center of the cyclone dust collector.
Characteristics and Application Scenarios
The cyclone dust collector has a simple structure, is easy to operate, and has a relatively low cost. It can also handle a large flow of dust-laden gas. It has a good separation effect on larger dust particles (generally larger than 5 – 10 μm). In fertilizer production, it is often used for the preliminary separation of coarse dust generated during processes such as raw material crushing and screening. For example, it is used to handle the dust generated during the crushing of phosphate rock in phosphate fertilizer production.
2. Baghouse Dust Collector
Working Principle
The baghouse dust collector mainly relies on the filtration principle for dust removal. After the dust-laden gas enters the dust collector, it passes through the filter bags, and the dust particles are trapped on the surface of the filter bags, while the gas permeates through the filter bags and is discharged from the air outlet. As the filtration process continues, the dust layer on the surface of the filter bags will gradually thicken, which will lead to an increase in resistance. When the resistance reaches a certain level, the filter bags need to be cleaned. There are various ways of cleaning, such as mechanical vibration cleaning and pulse jet cleaning. After cleaning, the filter bags can continue to work.
Characteristics and Application Scenarios
The baghouse dust collector has a high dust removal efficiency and can achieve a good collection effect on fine dust with a particle size between 0.1 and 1 μm. Generally, the dust removal efficiency can reach over 99%. It has strong adaptability and can handle various types of dust with different properties. In fertilizer production, it is often used in processes such as granulation and drying in compound fertilizer production. The dust generated in these processes has a relatively small particle size and certain adhesiveness, and the baghouse dust collector can effectively remove the dust to ensure a clean production environment.
3. Wet Dust Collector
Working Principle
The wet dust collector captures dust by making the dust-laden gas fully contact with a liquid (usually water). Common types include spray towers and Venturi dust collectors. Taking the spray tower as an example, the dust-laden gas enters from the bottom of the tower, and the liquid is sprayed down from the top of the tower. Inside the tower, the gas and the liquid flow in opposite directions. The dust particles collide and agglomerate with the droplets, forming larger particles and then flowing into the water tank at the bottom together with the liquid under the action of gravity. The purified gas is discharged from the top of the tower.
Characteristics and Application Scenarios
The wet dust collector has a good adaptability to high-temperature and high-humidity dust-laden gas and can also remove some harmful gases in the gas simultaneously, such as ammonia gas generated during the fertilizer production process. However, it also has some disadvantages. For example, it will generate wastewater that requires subsequent treatment, and the equipment may be corroded. In fertilizer production, it is often used to handle the dust-laden gas generated during processes such as fertilizer reaction and evaporation. The gas generated in these processes has a relatively high temperature and humidity, and the wet dust collector can effectively reduce the dust concentration.