The 21st century has witnessed tremendous levels of emissions. An increasing awareness of the harmful effects of air pollution has led to stricter norms by the Pollution Board to curb emissions. More and more industries must comply with these strict guidelines to limit air contamination.
When it comes to controlling industrial pollution, there has been a lot of discussion and confusion about the best option: a bag filter or a wet scrubber.
Does your business face the same dilemma? With years of expertise in Air Pollution Control our team of experts has identified the major factors that must be considered when choosing the right product between Bag Filter and Scrubber.
What is a Bag Filter?
A Bag Filter is a pollution control device that separates particulate matter from air of a manufacturing/processing facility.
RIECO supplied process Baghouse for 11,00,000 m3/hr gas flow
Some of the Important Parameters to be considered while Selecting/Designing a Bag Filter:
- Volume Flow Rate (m3/hr)
- Dust load at Bag Filter Inlet (g/m3)
- Outlet emission required (mg/Nm3)
- Particle Size distribution (microns)
- Operating/Surge Temperature (Deg C)
- Nature of Dust (Acidic/Hygroscopic/Abrasive/Explosive)
- Bulk Density of the dust (kg/ m3)
What are Wet Scrubbers?
One of RIECO’s supplied Scrubber for handling corrosive gases
In a wet scrubber, the dirty gas stream is brought into contact with a scrubbing liquid via a spraying mechanism. The scrubbing liquid reacts with the polluted particles to neutralize their harmful effect.
- Wet scrubbers can handle high temperatures and moisture.
- In wet scrubbers, flue gases are cooled hence, smaller overall equipment size.
- They can remove both particles & gases.
- They can neutralize corrosive gases.
The following table states the relative Advantages & Disadvantages of Wet Scrubbers compared to other control devices
| Advantages | Disadvantages |
|---|---|
| Small space requirements: Scrubbers reduce the temperature and volume of the unsaturated exhaust stream thereby reducing the vessel sizes compared to other control devices. | Corrosion problems: Water along with dissolved pollutants can form acid solutions which are highly corrosive. Wet-dry interface areas can also result in corrosion. |
| No secondary dust sources: The particles once collected cannot escape from hoppers or during transportation. | High power requirements: High operating costs since high collection efficiencies for particles can be achieved only at high pressure drops. |
| Handles high-temperature, high-humidity gas streams: Condensation or Temperature limit problems cannot occur as in case of ESPs & bag houses. | Water-disposal problems: To meet waste-water regulations, settling ponds or sludge clarifiers may be needed. |
| Minimal fire and explosion hazards: Various dry dusts are flammable. Using water eliminates the possibility of explosion. | Difficult product recovery: Dewatering and drying of scrubber sludge lead to recovery of dust for reuse difficult and very expensive. |
| Ability to collect both gases and particles | Meteorological problems: Saturated exhaust gases produce steam plume resulting in precipitation & fog which may cause local meteorological problems. |
So, to conclude our discussion, we would like to provide the following guidelines to help you select the correct solution for your air pollution control problem:
| Parameter | Bag Filter | Scrubber |
|---|---|---|
| Dust characteristics: | Dry and Free flowing | Hygroscopic and Sticky |
| Particle size: | Fine | Large |
| Temperature to be handled: | < 250 Deg. C | > 250 Deg. C |
| Contaminants involved: | Does not contain Sulphur Dioxide, Ammonia etc. | Sulphur Dioxide, Ammonia etc. |
Did you know?
With an experience of 46+ years, RIECO’s Clean Air Solutions have catered to various industry pollution control requirements with more than 3000+ happy customers across the globe in 10+ industries.
Connect with our experts rvp@rieco.com, harshwardhan@rieco.com, rahul.pandagale@rieco.com to learn more about our Clean Air Solutions and kindly visit our website www.rieco.com to know more about our various offerings and solutions.
Thank You for Reading !