In considering baghouse filter advantages and disadvantages, it is important to understand what a baghouse system is, exactly what baghouse filters remove, and how the system works. For those who may be in the market for a baghouse filtration, keep in mind that baghouse applications range from small household workplaces to large industrial facilities. The systems are versatile and can be designed for almost any dust-producing application but are most effective in collecting contaminants in relatively dry environments.
What is a Baghouse System?
A baghouse dust collector is a large, industrial-scale fabric filtration system engineered to collect, capture, and separate harmful particulates, dust, and gasses from the air at processing, production, and manufacturing plants. On a basic level, the systems act as air pollution control devices or apparatus. The filtration system is designed to remove and process dirty air detrimental to human health and the environment and replace it with clean air.
A baghouse dust collector is composed of five basic parts. There is a cylindrical tube-like filter baghouse compartment and a supporting frame structure. Next, there is a fan to push or pull air through the baghouse. Thirdly, there is the baghouse cleaner that collects the accumulated dust cakes. Fourth is the collection hopper, where the accumulated dust cakes are stored until removal. Finally, a discharge unit automatically or manually removes the dust cakes from the hopper.
What Do Baghouse Filters Remove?
Baghouse dust collectors are regarded as highly effective systems that are capable of achieving up to 99.9% efficiency. Depending on the design and fabric filter, baghouse filters remove and can withstand or capture abrasive particles, acid gasses, filter explosive dust, mists, fumes, and fine powders. They can collect difficult-to-capture air pollutants and airborne toxic materials found in dust and welding fumes, and particulate residue.
Given the high efficiency, the systems are well regarded and widely used across many different industrial sectors—food processing and agricultural plants, asphalt and cement plants, coal processing plants, quarries, steel and iron foundries, chemical and paint manufacturing plants, utilities, power generation, and energy plants, and so on.
Advantages and Disadvantages of the Principal Baghouse Designs
That said, baghouse designs do differ. Three principal designs are the shaker baghouse, the reverse air filter baghouse, and the pulse jet baghouse. The primary difference between the designs is how the bags are cleaned.
A shaker baghouse is a mechanical system. As the name suggests, shaker systems work by shaking accumulated dust cakes from the filter bag. The bags are hung from the top of the unit and are attached to a tube sheet at the bottom of the baghouse. There, the dirty air enters, and, as it is pulled up, the filter collects dust and particulates inside the bag, and clean air exits through the top.
Its primary advantage is its low initial investment costs, fundamental design, and simple operation. As the units are generally compartmentalized into sections, the entire system does not have to be shut down when cleaned. Nonetheless, the units take up space, are not well-suited for high-temperature contaminants, and are more energy and time-intensive than other cleaning methods. Also, collection efficiency can be reduced when even small amounts of positive pressure are inside the bag.
With reverse air filter baghouse designs, airflow is reversed through the filter bags via an exhaust fan rotating over the bag module. In reverse air systems, dust and particulates collect outside the bags, where dust cakes accumulate. The cleaning process requires reverse air blown through the bag to release the particulates and dust.
A reverse air baghouse system is a cost-effective method that generates lower pressure than the pulse jet baghouse system, which utilizes compressed air. Because they consist of multi-compartment, sections can be cleaned without shutting the whole system down. The gentle cleaning cycle is ideal for high-temperature collection and allows for a longer bag life. On the downside, cleaning must be done often, there are no effective means to remove residual dust buildup, 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 a filter bag to remove the dust cakes from the surface of the filter media. The bags are hung from the tube sheet and supported by metal cages during cleaning—pulses of air push through the bag to dislodge solids where they are collected in a hopper below.
The clear advantage of a pulse jet system is the baghouses are to be cleaned as the system continues online. It also cleans better than shaker or reverse air baghouse systems, is space-efficient and, as a result, requires fewer bags. The main disadvantages are its use of dry compressed air, which adds to energy costs. It also requires special types of fabrics to filter higher temperature contaminants. Finally, pulse jets cannot tolerate high moisture levels or be used where humidity is generated from high moisture gasses or content.
Overall, baghouse systems are versatile and efficient. Capable of capturing small micron particle dust with a removal efficiency of over 99%. Systems can manage from millions of cubic meters per hour to hundreds of thousands of cubic meters. The basic design structure is simple, stable, reliable, and less of an investment than other air pollution control units. However, some system designs can require large power consumption. Those systems are easily maintained, but they do require ongoing maintenance to function at peak efficiency. Finally, though there are exceptions depending on the filter media design, baghouse systems are best suited for operation in relatively dry environments. They are not recommended for collecting sticky dust-like contaminants or gasses.
Contact the Experts at CPE Filters
At CPE Filters, we offer a range of industrial dust collection systems for production and manufacturing facilities. To inquire about baghouse filters or any other dust collector equipment, please contact us at CPE Filters today.