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Reverse Air Baghouse Dust Collector: Design, Operation, Models, and FAQs

Application

Reverse air baghouse dust collector cleaning is most effective for handling coarse and medium dust with minimal stickiness.
The equipment efficiently manages contaminants that easily detach from the filter material. It is particularly suitable for dust generated in industries such as:

Cement production
Metallurgy
Gypsum and lime production
Woodworking
Mining

However, they may face challenges with sticky or fine dust, which requires more intensive purification (e.g., pulse-jet).

Backflow filtration setups are also used in cases such as:

When contaminant concentrations are relatively low, frequent bag cleaning is not necessary.
When the filter material cannot withstand the high mechanical stresses typical of pulse-jet or shaker systems, alternative methods may be necessary. The backflow method is gentler and helps extend the lifespan of the elements.
By operating at lower pressures, you can save on the energy-intensive equipment typically needed to produce high-pressure pulses.
It is effective in conditions where complications arise due to cold temperatures. Moisture can freeze inside compressors or in areas where condensation accumulates, causing malfunctions. The backward sectional collector does not require high-pressure compressed air, eliminating freezing issues and reducing the need for gas drying.
It is used in large configurations where pulse-jet cleaning is physically challenging due to the size of the equipment and economically impractical.

Commentary by Filtration Expert Michael Klepik

Design and Working Principle

The reverse air baghouse design consists of the following key components:

Housing – A metal or corrosion-resistant casing that contains the bags. The housing is divided into chambers (or sections), allowing one part of the sleeves to be cleaned while the others continue to operate.
Filter bags – Long cylindrical elements made of specialized materials (fabric, felt, fiberglass). These are installed vertically and secured at the top of the housing.
Valve system – It controls the airstream supply to different chambers of the collector. During backflow purification, one or more valves close to isolate the section being cleaned, then reopen to allow normal flow.
The reverse air fan baghouse includes a specialized fan that supplies airflow in the opposite direction through the sleeves to clean them.
Plenum chamber – The space above the sleeves where clean stream collects before being discharged outside or supplied for the backward flow.
Hopper – Located at the bottom of the housing, this hopper collects the dust shaken off the bags.

How does a reverse air baghouse work?

During reverse air baghouse operation, the setup is divided into two sections, with the airflow alternating between filtration and cleaning. The reverse air baghouse working principle involves switching between two modes.

While a section is in filtration mode, gas enters the sleeves from below, and particulate matter settles on the inner surface, gradually increasing the section's aerodynamic resistance.
When the aerodynamic resistance reaches its limit, the section switches to regeneration mode. The clean stream outlet valve closes, and the reverse air baghouse begins working by opening the inlet valve.
The backflow passes through the bags, breaking up the layer of pollutants accumulated on the inner surface. The dust is then dropped into the hopper and removed using a screw conveyor or another discharge mechanism. The used backflow is directed into the dirty gas duct.
After purification, the section returns to its filtration cycle, and the next section switches to cleaning. Each section is regenerated in sequence, ensuring continuous operation of the equipment.

A – filtration mode, B – self-cleaning mode

The reverse air flow rate of a reverse air baghouse typically ranges from 3.5 to 7 feet per second (ft/s). In some cases, it can reach up to 10 ft/s. This rate must be sufficient for the proper purification of accumulated pollutants from the elements. To determine the optimal backward gas flow rate, it is crucial to consider the type of dust, filter size, airflow volume, and other specific parameters of the system.

Comparison of Pulse-Jet and Reverse Air Baghouse Filter

Our company specializes in manufacturing high-quality filters that can be adapted to meet the specific requirements of your production. If necessary, any model can be modified into a reverse air system to suit particular operating conditions.

Explore our products below to find the optimal solution for your production needs.

Blizzard Bag Filter RS (round bags)

Performance: 2 300 — 35 300 cfm

Blizzard Bag Filter FS (flat bags)

Performance: 2 300 — 14 000 cfm

Blizzard Bag Filter NEW

Performance: 600 — 235 000 cfm

Blizzard Bag Filter 50

Performance: 14700 — 235000 cfm

Blizzard Bag Filter BIG

Performance: 9000 — 235 000 cfm

Blizzard Bag Filter 30

Performance: 14700 — 235000 cfm

Improving Regeneration Efficiency

To enhance regeneration efficiency, the shaking of the purification elements can be performed simultaneously with the backflush process. After regeneration, not only does resistance decrease, but dust collection efficiency also improves as the layer of contaminants on the fabric surface is removed. Subsequently, the efficiency is restored. To achieve a quick restoration, it is important not to remove dust that has penetrated into the fabric and settled in the pores during regeneration. Therefore, backward sectional purification should be performed at reduced speeds, similar to the filtration speed.

Table of Recommended Filtration Speeds in ft³/(ft²·s):

This comparison highlights that the choice between pulse-jet and reverse air cleaning baghouse dust collectors depends on the specifics of the application, operational requirements, and budget considerations.

How to Choose a Baghouse?

Frequently Asked Questions (FAQ)

1. What are the advantages of backward sectional purification compared to the pulse-jet method?
Backward sectional purification offers several benefits: it is more cost-effective to operate, uses less energy, extends filter lifespan due to its gentler process, and performs better in cold temperatures since it does not need high-pressure compressed air.
2. What type of dust load is best suited?
The backward flow device is most effective for minimal to medium contaminant loads. It helps maintain a long lifespan for the sleeves and reduces operational costs when pollutants do not require frequent and intense cleaning
3. What control systems are used for backflow purification device?
It is managed by an air valve system that controls the airflow and isolates sections for purification. A fan provides the necessary stream for particulate removal.
4. Can reverse baghouse be used in low temperatures?
Yes, they are well-suited for cold temperatures.
5. How often does a backwash collector need maintenance?
Regular maintenance includes checking filters, the valve control system, and the fan, but the frequency depends on contaminant levels and operational conditions
6. How do you choose between pulse-jet and backward flow technology?
The choice depends on specific operating conditions. A backflush device is ideal for configurations with minimal to moderate pollutant loads, cold temperatures, and cost considerations. Pulse-jet equipment is better for high loads where frequent and intense sleeves cleaning is needed.
7. Can a reverse air baghouse in cement plant be used effectively?
Yes, but it is generally more effective when combined with shaking or other purification methods. Due to the large volumes of emissions and the high stickiness of particles in cement production, it is necessary to add a vibration cleaning unit.

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