Type of filter bag breakage
The main performance is the non-woven layer of filter material wear, fall off, this phenomenon is due to the uneven airflow distribution, dust in the high filtration wind speed on the surface of the filter bag caused by erosion; Or the filter bags are damaged due to friction between them due to improper installation; Or the installation of the spray pipe is not vertical, resulting in holes in the 30-40 cm range of the mouth, and loss of filtration performance.
The results are as follows: the mouth of the filter bag is damaged, the body of the filter bag is damaged, the lower part of the filter bag is damaged, and the bottom of the filter bag is damaged.
Dust filter bag mouth part
Most of the damaged parts of the bag mouth are within 30-40 cm below the bag mouth, and the bottom layer of the filter material is blown out and falls off. Most of them are caused by high compressed air, askew of spray pipe and deformation of flowerboard. Attention should be paid to the quality of installation in the installation process.
Filter bag body position
The contact part of the filter bag and the skeleton was worn out due to pulse spraying for a long time, which showed obvious wear marks in the direction of transverse and vertical bars. Attention should be paid to the size of filter bag and skeleton, dust removal skeleton surface smoothness.
The bottom of the filter bag is broken
Wear at the bottom of the bag is quite common. Maybe because the bottom of the bag cage is too small or the bag is too long, the bag cage can only support the bottom of the bag. The inner side of the filter bag is worn due to the excessive cleaning and filtration of the filter bag. Or dust accumulation is too high to form eddy current wear filter bag.
The most obvious manifestation of chemical corrosion is the sharp decline in the strength of dust-removing cloth bags, which is specifically manifested in acid corrosion, alkali corrosion, oxidation corrosion and hydrolysis corrosion, etc., leading to the loss of filtration load that can be borne by filter bags and thus the loss of filtration performance. This phenomenon is mainly due to the problems in the selection of filter bags or the operating environment beyond the bearing range of the fiber, leading to the loss of filter bag performance and failure.
High temperature filter material generally exists acid corrosion, mainly sulfur oxide. Especially in the flue gas dust removal of coal-fired boilers and power plants, high-sulfur coal is adopted, and the sulfur oxide content in flue gas is high in the power-bag combination project, which can reach 5000mg/Nm3. Under the high temperature environment, the sulfur oxide forms the sulfite, the sulfuric acid, causes the acid corrosion to the filter material to be ineffective. If the flue gas contains HF, glass fiber filter material cannot be used, easy to acid corrosion caused by filter material failure.
Generally control the flue gas operating temperature above the acid dew point, such as below the acid dew point temperature must shut down the dust collector system, to avoid corrosion filter bag. Acid liquid still has hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid to wait.
It often appears in sodium salt and ammonia chemical production process dust removal, such as sodium chloride, ammonia water, sodium carbonate and other conditions. For power plants, cement plants, waste incineration plants, steel plants and other areas of smoke dust less.
Oxidation corrosion refers to the damage to filter material caused by the presence of a certain amount of oxidizing substances, mainly the oxidation corrosion of PPS filter material, which can cause oxidation damage to PPS filter material, including nitrogen oxide, oxygen, ozone, concentrated sulfuric acid, etc. The appearance is intact, but the strength drops sharply. It is only about 200N, which is close to the end of the service life of the filter material, and the filtering effect is lost.