What is the cause of filter cloth damage?

According to the type of filter cloth damage:

Mechanical damage

Its main performance is that the non-woven fabric layer of the filter medium is worn and detached, which is caused by uneven airflow distribution and dust scouring on the filter cloth surface at high filtering wind speed; or because the filter cloth is not installed in place, the friction between the filter cloth and the damage, or the injection tube is not installed vertically, resulting in holes within the range of 30 to 40 cm from the mouth, resulting in loss of filtering performance. Polypropylene filter cloth is close to zero-emission and can meet stringent environmental protection standards; it has good cleanability and can provide higher ventilation volume or reduce pressure difference. Environmentally friendly filter cloth is a filter medium woven from natural or synthetic fibers. Including metal mesh or filter screen.

Specifically, at the mouth of the damaged cloth, the cloth bag is damaged, the lower part of the filter cloth is broken, and the bottom of the filter cloth is damaged.

Filter cloth bag mouth

The damage to the filter cloth bag mouth is ly within 30-40 cm below the bag mouth, mainly manifested as the bottom layer of the filter material is blown off. Most of them are caused by reasons such as too high compressed air, skewed blowpipe, and deformed flower disc. Attention should be paid to the installation quality during installation.

Filter cloth bag body position

Due to long-term 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.

Damage to the bottom of the filter cloth

The bottom of the filter cloth is more common, which may be because the bottom of the bag cage is too small or the filter cloth is too long, and the bag cage can only support the bottom of the bag. When the action is too large to cause the inner side of the filter cloth to wear, the filter cloth is cleaned and filtered. Or excessive dust accumulates to form eddy currents to wear the filter cloth.

Chemical corrosion filter cloth:

Chemical etching is obvious manifestation of strength in acid etching, alkaline etching, oxidation and corrosion of discarded dust bags, especially as a result of corrosion of the hydrolysis loss of the filter cloth, which can withstand the load and thus lose the filtering performance. This phenomenon is mainly due to the selection problem with the cloth or the use environment conditions exceeding the range of the fiber, resulting in the loss of filter cloth performance and failure.

Acid corrosion of filter cloth

High-temperature filter materials are generally subject to acid corrosion, mainly sulfur oxides. Especially in the flue gas desulfurization of coal-fired boilers, high-sulfur coal is used, and the sulfur oxide content in the flue gas is high, reaching 5000 0mg/nM3. Under high temperature conditions, sulfurous acid and sulfuric acid are formed from sulfur oxides, causing corrosion and failure of the filter material. If the flue gas contains HF, glass fiber filter material cannot be used, which is easily corroded by acid, resulting in filter material failure.

The operating temperature of the flue gas is generally controlled above the acid dew point. If it is lower than the acid dew point temperature, the filter system must be shut down to avoid corrosion of the filter cloth. Acidic liquids include hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, etc.

Alkali corrosion of filter cloth

Most of them occur in the production process of sodium salts and ammonia chemicals, such as sodium chloride, ammonia water, sodium carbonate and other working conditions. There are fewer flue gas dust removal fields such as power plants, cement plants, waste incineration plants, and steel plants.

Oxidative corrosion of filter cloth

Oxidative corrosion damage refers to a certain amount of oxidants, which will cause the oxide-based filter material PPS to be destroyed by nitrogen oxides, oxygen, ozone, and concentrated sulfuric acid.