BY VEDANT PATHAKBag filter, cyclone, scrubber or ESP: choosing the right APCD
Short answer: There is no 'best' air pollution control device, only the best one for your dust, temperature and emission norms.
In 5+ years of consulting on Air Pollution Control Devices, the most expensive mistake I've seen is choosing the equipment before understanding the application.
Start with five questions
- What is the dust (type, particle size, abrasiveness, stickiness)?
- What is the gas temperature and moisture?
- What is the airflow, and does it vary?
- What emission limit must you meet?
- Is the dust explosive or combustible?
A quick guide
- Cyclone: coarse dust (above 10 µm), low cost, often a pre-cleaner
- Bag filter: fine dust, very high efficiency, temperature-limited by media
- Wet scrubber: sticky, hot or explosive dust and gases, but you then need to handle water
- ESP: very high volumes at high temperature, as in power and cement; high capital cost
The right APCD is the cheapest one that meets the norm reliably for ten years, not the cheapest one on the quotation.
Often the answer is a combination: a cyclone in front to protect a bag filter, with the right fan behind it.