Bag Filter Maintenance

Maintenance notes of bag filters

The bag filter is a widely used industrial dust removal device, which can be used in cement manufacturing, metallurgy, gravel, chemical industry, mining, thermal power, and other industries.

Why Is Maintenance So Important

Compared with the electrostatic precipitator, another widely used dust collecting equipment, the bag filter may be slightly inferior in dust removal efficiency and performance, but it is favored in small-sized cement plants because of its simple structure, easy maintenance, and low cost.

A bag filter with excellent performance is expected by most users. However, no matter how good the performance is, if it is not properly operated and maintained, the performance will deteriorate in a short time.

Only when the operators have rich maintenance knowledge and correctly maintain the machine according to its design characteristics, can the performance of the original design be brought into full play.

Ash Cleaning of Filter Bags

In the routine maintenance of the bag filter, the most important work is to clean the accumulated ash in the filter bag of the filter. During the long-time operation of the bag filter, the dust particles will slowly gather on the surface of the filter bag to form a dust layer, which seriously reduces its working efficiency. If the filter bag is cleaned in time, the dust collector can basically maintain high dust removal efficiency for a long time.

filter bag ashes
Ashes accumulated in the filter bag

There are four common methods for cleaning the filter bag: pulse jet cleaning, back blowing cleaning, mechanical vibration cleaning, and acoustic cleaning.

Pulse Jet Cleaning

The ash cleaning principle of this method is to blow the high-speed jet airflow to the inside of the filter bag and form an airwave which makes the filter bag expand sharply and impact vibration from top to bottom, and shake off the dust attached to the filter bag. There are three main jet modes: forward jet, reverse jet, and opposite jet.

The pulse jet ash cleaning has a strong and good effect and can improve the filtering wind speed. It is one of the best ash cleaning methods at present.

Back Blowing Cleaning

Back blowing ash cleaning is to apply reverse pressure on the filter bag, so that the original cylindrical filter bag is compressed into a cake and then restored. This process can be repeated several times to achieve the purpose of ash cleaning. Generally, a metal ring shall be set on the filter bag at a certain distance to reduce the wear of the filter bag during the compression

Mechanical Vibration Cleaning

This ash cleaning method is to periodically vibrate each row of filter bags with the help of mechanical transmission devices to shake off the accumulated ash on the bags. Although this ash cleaning method is very efficient, it causes serious abrasion on the filter bag itself, so it is rarely used on bag filters produced in recent years.

Acoustic Ash Cleaning

With the help of the acoustic ash cleaner, the kinetic energy generated by pressure gas can be converted into acoustic wave energy and is easily transmitted to the filter bag, making the filter bag produce additional vibration and shake off the dust.

Acoustic ash cleaners that can be used on bag filter ash cleaning
Acoustic cleaners

This is currently the most advanced ash cleaning method, it does not consume a lot of power and causes little damage to the filter bags, but the cost for such a system is not cheap.

Find the Most Appropriate Cleaning Method

Bag filter has a wide range of applications. The specification, model, size, and performance of bag filter produced by different manufacturers are also very different. Therefore, there is no best ash cleaning method for all bag filters, only the most appropriate method for each one.

The specific ash cleaning method needs to be determined after considering the bag filter’s application occasion, the composition of the processed flue gas, the dust removal rate requirement, the flue gas treatment capacity, the budget funds and other aspects. If you are not sure which dust removal method is the best, please feel free to consult us through the form below.

Bag Filter Maintenance Notes

Bags of the bag type dust collecter
Bags in a bag filter
  • Before maintaining or repairing the bag filter, its power supply and air source must be cut off, and the airbag should be under normal pressure.
  • During the maintenance and repair of the bag filter, the dust inside shall be cleaned repeatedly to ensure that there is no dust inside. Open fire is strictly prohibited during lighting settings. Fire extinguishers shall be equipped on site to prevent dust explosion accidents.
  • Inflammables and explosives are strictly prohibited to be stacked around the dust collector, and good ventilation shall be ensured.
  • The status of the filter bags needs to be checked regularly. If the filter bag is found damaged, it shall be replaced in time. The standby filter bags shall be stored in a dry, ventilated, and dustproof environment.
  • The dust layer on the surface of the equipment and air duct shall be cleaned immediately.
  • The pulse controller and solenoid valve must be kept clean and free of dust and oil, and the control coil on the solenoid valve must be checked regularly.
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