Hello Friends,
I have to design a bag filter to control particulate emission from a coal pulverizer. The data sets are as follows:
Inlet gas flow rate: 2100 Nm3/hr
Inlet particulate concentration: 1000 - 1500 mg/Nm3
Desired efficiency: 99%
Temperature of Inlet flue gas: 50 - 100 C
My queries are:
1. How to decide which type of fabric should be use?
2. How many compartments and bags are need to achieve desired efficiency?
3. What will be the pressure drop due to the bag house?
Thanks in advance.
1. The type of fabric to be used depends on lot of factors amongst which are the physical and chemical nature of the gas and dust being handled, temperature and most importantly the particle size. Best is to get in touch with Bag Manufacturer.
2. You need to find/select the A/C ratio or filtering velocity. If it is an unknown application you can then calculate based on some empirical data. Now if you divide the total flow by the filter velocity then you get the area. You then need to select the bag dimensions and length. Find out the area of one bag. Divide total area by one bag area and you will find the total no of Bags. In one row maximum no of Bags that can be accommodated per pulse valve (if it is Pulse Jet Filter) varies between 12 to 18 nos. Arrange the Bags accordingly as per the aspect ratio and you have plan area. Pitch between Bag to Bag shall be at least 200 mm for a bag diameter of 150 mm.
3. Pressure drop depends on the A/C ratio what you have chosen and generally in the range of 150 - 200 mm WC.
Dear Pradip Sir,
Thanks for clearing my doubt. I still have a query. We have calculated no of bags depending upon particle size and air to cloth ratio. But, we have not considered inlet concentration for the calculation. And, how can be sure about efficiency of the design?
Thanks in advance.
Check Chapter 6 of the following book. You can find straight forward method for designing of a fabric filter:
Air Pollution Control: A Design Approach
by C. David Cooper
F. C. Alley
What are the particle size analysis? Is the dust dry or contain moisture? From where you need to suck the dust - Conveyors or directly from the Pulverizer?
These basic questions to be answered before you can select the type of Fabric Filter.
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioecology
- Systems Ecology
- Landscape Ecology
- Connectivity