According to the type of filter cloth damage:
mechanical damage
Its main performance is the wear and tear of the non-woven layer of the filter medium, which is caused by uneven airflow distribution and dust erosion on the surface of the filter cloth under high filtration wind speed; or because the filter cloth is not installed in place, the friction between the filter cloth and the damage , or the installation of the injection tube is not vertical, resulting in holes in the range of 30 to 40 cm of the mouth, resulting in loss of filtration performance. The polypropylene filter cloth is close to zero emission and can meet the strictest environmental protection standards; it has good ash cleaning performance, can provide higher ventilation, or can reduce the pressure difference. Environmental filter cloth is a filter medium woven from natural fibers or synthetic fibers. Include wire mesh or strainer.
Specifically, at the mouth of the damaged cloth, the cloth bag is damaged, the lower part of the broken filter cloth, and the bottom of the filter cloth is damaged.
filter bag mouth
The damage to the bag mouth of the filter cloth is mostly in the range of 30-40cm downward from the bag mouth, which is mainly manifested in the blowing off of the bottom layer of the filter material. Most of them are caused by high compressed air, skewed blowpipe, and deformation of the faceplate. During the installation process, attention should be paid to the installation quality.
Filter bag body position
Due to the long-time pulse injection, the contact part of the filter cloth and the skeleton is worn, and obvious wear marks appear in the horizontal and vertical rib directions. Attention should be paid to the size of the filter cloth and the skeleton, the surface finish of the dust removal skeleton, etc.
The bottom of the filter cloth is damaged
A worn bottom of the filter cloth is more common, possibly because the bottom of the bag cage is too small or the filter cloth is so long that the bag cage can only support the bottom of the bag. When the action is too large and the inner side of the filter cloth is worn, the filter cloth is cleaned and filtered. Or excessive dust accumulation forms eddy current wear filter cloth.
For chemical corrosion filter cloth:
Chemical etching is the most obvious manifestation of strength in acid etching, alkaline etching, oxidation and corrosion of discarded dust bags, especially as a result of corrosion of the filter cloth hydrolysis loss, can withstand the load, thereby losing filter performance. This phenomenon is mainly due to the selection problem with the cloth or the use of environmental conditions exceeding the range of the fiber, resulting in filter cloth performance and failure loss.
Acid corrosion of filter cloth
High temperature filter materials generally have acid corrosion, mainly sulfur oxides. Especially in the flue gas desulfurization of coal-fired boilers, high-sulfur coal is used, and the content of sulfur oxides in the flue gas is high, reaching 50000 mg/nM3. In high temperature environments, sulfurous acid and sulfuric acid are formed from sulfur oxides, causing corrosion and failure of filter materials. If the flue gas contains HF, the glass fiber filter material cannot be used, which is easily corroded by acid, resulting in the failure of the filter material.
The operating temperature of the control flue gas is generally above the acid dew point. If the temperature is lower than the acid dew point, the filter system must be closed to avoid corrosion of the filter cloth. Acidic liquids include hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid.
Alkali corrosion of filter cloth
Most of them appear in the production process of sodium salt and ammonia chemical industry, such as sodium chloride, ammonia water, sodium carbonate and other working conditions. There are few areas of flue gas dust removal such as power plants, cement plants, waste incineration plants, and steel plants.
Oxidation and corrosion of filter cloth
Oxidative corrosion damage refers to a certain amount of oxidant, due to oxidative corrosion mainly used in PPS-based filter media filters, will cause the oxide-based filter material PPS nitrogen oxides, oxygen, ozone damage, concentrated sulfuric acid.
