Cement Dust Filter Bags

How to choose dust filter bag for cement plant?

Because the long-term operating temperature of polyester filter bags under air drying conditions should be less than 120℃, and in flue gas with higher moisture, its long-term working temperature can only be reduced to 60~100℃; Aramid filter bags are temperature-resistant and chemical-resistant The performance is better. Under high moisture flue gas conditions, its temperature resistance will be reduced from 240℃ to 150℃. P84 type polyvinyl chloride has excellent high temperature resistance, acid and alkali resistance, and is suitable for coal-fired flue gas dust removal, but P84 filter bags can make up for its shortcomings and cannot have good hydrolytic stability. As the king of filter materials, PTFE filter bags have good chemical resistance, but they are expensive.

Different dust-containing gas, dust-containing gas can be divided into three forms: the relative humidity is less than 30% is dry gas; the relative humidity is less than 30% to 80% is the general state; the relative humidity is greater than 80% is the high-humidity gas. For dusty gases with high humidity and high temperature, especially for gases containing SO3, condensation will occur in cold air. This will not only cause scale and blockage on the surface of the filter bag, but also corrode the filter bag. So pay special attention.

Dust is generated in almost all parts of the cement production process, and the removal of dust from the cloth bag covers almost the entire cement production process. It is particularly important to choose a bag filter and a dust bag for the corresponding dust bag. According to different working conditions, crushers, dryers, coal mills, raw material mills, kiln heads, kiln glue, vertical mills, cement grinding conditions (such as temperature, humidity) to determine the filter material is reasonable to achieve efficient dust removal and reduce dust removal costs .

1. Sprinkle limestone and auxiliary materials on the crusher to produce more dust and a lot of dust. The moisture content in the dust is high, and the generated dust is small. Cement factory filter bags can work at room temperature, so dust bags are usually used as economical and effective polyester dust bags, or waterproof polyester bags can be used when the humidity is high.

2. Divide the raw material into several parts, and then measure the powder in the raw material mill (also called the raw material mill). The humidification tower obtains heat from the preheater, so that hot and humid air enters the abrasive, thereby reducing dust and dust concentration. In addition to dust removal in the raw filter, sometimes the room temperature polyester dust bag is not selected for the humidification tower, and the dust collection of the humidification tower needs to use a polyester waterproof filter bag.

3. The next step is to calcine the raw materials at a high temperature, that is, to remove dust from the rotary kiln of the cement plant. The dust discharged from the head of the cement kiln has a higher temperature and a higher concentration. But Flume requires the filter in the dust collector to have a lower wind speed and a cheaper price. The furnace dust removal temperature is also very high, accompanied by strong corrosive gases (such as sulfuric acid and nitric acid), generally use Polyester dust filter bag or channel dust bag. In addition, due to the high temperature and high steam, the cement vertical furnace is also made of woven glass fiber filter bag mixed with glass fiber powder.

4. After the raw materials are calcined, use a clinker cooler to cool to semi-finished products. Some are collected in the coal mill and sent back to the rotary kiln and calciner. The grinder is prone to dust explosion, so the polyester film is made of polyester antistatic powder bag. After sintering the other part of the sintering machine, the dust is removed, and finally it becomes a cement product. The dust in this area must be collected continuously, and polyester filter bags can be selected at room temperature.

5. The fabric and design of dust-removing filter bags should pursue high-efficiency filtration, convenient dust removal, and durability. The selection of dust-removing bags is very important. It has a direct impact on the dust removal effect. The choice of dust filter bag can be selected from factors such as gas temperature, humidity and chemistry, particle size, dust concentration, filtration wind speed, and dust removal method.