News

What is a bag filter?
A bag filter is a type of dust removal equipment whose purpose is to remove dust contained in exhaust gases from industrial processes. It is suitable for various applications with different temperatures and gas types by selecting the filter media accordingly.
The advantage of a bag filter over a cyclone is that it can collect submicron particles.

Structure:
Bag filters separate the dust from the exhaust gas by collecting them with filter media. Dust accumulates on the surface of the filter media. The filter media is cleaned by a reverse air flow called backwash (pulse jet).
Bag filters are available in a variety of filter media. Filters are made of materials ranging from polyester, heat-resistant nylon to fiberglass. Select according to conditions such as the characteristics of gas or dust.
Filter media are consumables. When damaged or worn, dust may leak outdoors.
Triboelectric dust monitors are now installed downstream of the baghouse in order to detect dust leaks and prevent air pollution.

Advantages and disadvantages：

The main designs are vibrating baghouses, reverse air filter baghouses and pulse jet baghouses. The main difference between the designs is how the bag is cleaned.

A vibrating baghouse is a mechanical system. As the name suggests, the vibrating screen system works by vibrating the accumulated dust cake from the filter bag. Bags are suspended from the top of the unit and attached to tube sheets at the bottom of the baghouse. There, dirty air enters, and when it's pulled up, the filter collects dust and particles inside the bag, and clean air exits through the top.

Its main advantages are low initial investment cost, basic design and simple operation. Since these units are often divided into sections, it is not necessary to shut down the entire system for cleaning. Nonetheless, these units take up space, are less suitable for high-temperature contaminants, and are more energy-intensive and time-consuming than other cleaning methods. Furthermore, even with a small amount of positive pressure in the bag, the collection efficiency is reduced.

With a reverse air filter baghouse design, airflow is reversed through the filter bags by an exhaust fan that rotates on the bag module. In reverse air systems, dust and particulates will collect outside the bag, and dust cakes will accumulate outside the bag. The cleaning process requires reverse air to be blown through the bag to release particles and dust.

A reverse air baghouse system is a cost-effective method that produces less pressure than a pulse jet baghouse system that uses compressed air. Because they consist of multiple compartments, parts can be cleaned without shutting down the entire system. The gentle cleaning cycle is ideal for high temperature collections and extends the life of the bag. On the downside, cleaning must be done frequently, and there is no effective way to remove residual dust, which requires more maintenance than other types of baghouse systems.

Pulse jet baghouse systems utilize bursts of compressed air that are directed through the clean side of the filter bag to remove dust cake from the surface of the filter media. The bags hang from tube sheets and are supported by metal cages during cleaning - air pulses are pushed through the bags to remove solids, which are then collected in a hopper below.

The obvious advantage of a pulse jet system is that the baghouse will clean while the system continues to be online. It also cleans better than a shaker or reverse airbag system, saves space and therefore requires fewer bags. The main disadvantage is that it uses dry compressed air, which increases energy costs. It also requires special types of fabrics to filter out high-temperature pollutants. Finally, pulse jets cannot tolerate high moisture levels or are used where humidity is created by high moisture gases or levels.

Overall, baghouse systems are versatile and efficient. Capable of capturing small-micron particle dust with a removal efficiency of over 99%. The system can manage from millions of cubic meters to hundreds of thousands of cubic meters per hour. The basic design structure is simple, stable and reliable, and the investment is less than other air pollution control devices. However, some system designs may require higher power consumption. These systems are easy to maintain, but they do require ongoing maintenance to operate at peak efficiency. Finally, baghouse systems are best suited to operate in relatively dry environments, although there are exceptions based on filter media design. They are not recommended for collecting sticky dusty contaminants or gases.

Process for ordering Sinft filter bags：

Contact a Sinft filter bag expert
At Sinft Filters, we offer a range of industrial dust filter bags for production and manufacturing facilities. For filter bags in any construction, please contact us today.