Baghouse Particulate Conglomeration Issue
Baghouse Particulate Conglomeration Issue
(OP)
Greetings,
I have a customer who has a 20 year old baghouse. He does not have the money to replace it at this time, but they have ongoing issues that nobody seems to know the solution to. Our in-house engineers have made suggestions, but I wanted to reach out and see if we are on the same page. We hope to replace their equipment in the future, but for now, we are just trying to figure out a temporary solution.
The problem is they are getting material (PVC Dust) conglomerating in different locations inside the baghouse. It commonly occurs at the top, near the cell plate, on the bags, and even near the access door. They had several professionals/engineers come and look at it, but have only been advised to change bag styles, add ground wires to bags, ground the baghouse, and numerous other ideas that have not remedied the problem. After a brief phone conference with our engineer and their plant manager, we determined the air inlet was coming in below the bags (at hopper) and not allowing the particles to fall with gravity. The particles are then building up at various locations and sticking together, developing a honeycomb effect. We came up with three solutions.
1. Lower airflow with the damper and decrease airflow into the baghouse until the material can utilize gravity to fall.
2. Shut off the baghouse once a day and then pulse the bags to ensure no build-up.
3. Move the inlet closer (higher) to the cell plate (also adding a baffle so direct air doesn't damage bags).
Baghouse Information:
100 Poly Filters Bags (1257 Area)
4:1 Air to Cloth Ratio
5028 CFM
Dimensions (84" W 130" L)
Moisture Content: 0.03lb
Temperature Avg: 95F
Location: Outdoors
No Static
No Moisture
Good airflow at all times
Any other suggestions on this would be appreciated, or if I am missing something, please advise. Thank you in advance.
I have a customer who has a 20 year old baghouse. He does not have the money to replace it at this time, but they have ongoing issues that nobody seems to know the solution to. Our in-house engineers have made suggestions, but I wanted to reach out and see if we are on the same page. We hope to replace their equipment in the future, but for now, we are just trying to figure out a temporary solution.
The problem is they are getting material (PVC Dust) conglomerating in different locations inside the baghouse. It commonly occurs at the top, near the cell plate, on the bags, and even near the access door. They had several professionals/engineers come and look at it, but have only been advised to change bag styles, add ground wires to bags, ground the baghouse, and numerous other ideas that have not remedied the problem. After a brief phone conference with our engineer and their plant manager, we determined the air inlet was coming in below the bags (at hopper) and not allowing the particles to fall with gravity. The particles are then building up at various locations and sticking together, developing a honeycomb effect. We came up with three solutions.
1. Lower airflow with the damper and decrease airflow into the baghouse until the material can utilize gravity to fall.
2. Shut off the baghouse once a day and then pulse the bags to ensure no build-up.
3. Move the inlet closer (higher) to the cell plate (also adding a baffle so direct air doesn't damage bags).
Baghouse Information:
100 Poly Filters Bags (1257 Area)
4:1 Air to Cloth Ratio
5028 CFM
Dimensions (84" W 130" L)
Moisture Content: 0.03lb
Temperature Avg: 95F
Location: Outdoors
No Static
No Moisture
Good airflow at all times
Any other suggestions on this would be appreciated, or if I am missing something, please advise. Thank you in advance.
Michael Iverson
Equipment Manager
U.S. Air Filtration, Inc.
951-417-1745
mike@usairfiltration.com





RE: Baghouse Particulate Conglomeration Issue
Are you sure that the compressed air for pulsing the bags is dry? Water in compressed air is a very common problem.
You might consider lowering your pulse rate. This will allow a thicker and denser filter cake to develop before each pulse, which is more likely to fall into the hopper.
RE: Baghouse Particulate Conglomeration Issue
Thanks again!
Michael Iverson
Equipment Manager
U.S. Air Filtration, Inc.
951-417-1745
mike@usairfiltration.com
RE: Baghouse Particulate Conglomeration Issue
Magnehelic control also implies that all of the bags are pulsed at once, which is not desirable. This results in all airflow through the baghouse coming to a momentary stop. The rush of air back though the bags after the pulse is done will tend to reattach the powder to the filter bag rather than allowing it drop. Zoned pulsing might help.
RE: Baghouse Particulate Conglomeration Issue
I asked him about the pulse rate on the bags. He stated at one point, they were on a timer and each diaphragm valve would pulse for .01 seconds, in order, not all at one time. He understood filter cake and why it is important to have it. He said they moved to a Magnehelic control as one of their options over the timer board. He stated the valves are integral and use a control board that ensures they fire in zones, and not all at once. When we design our multi-channel boards, unless the customer requests it, pulse at intervals, and not all at one time.
You are very knowledgeable in this field, and I appreciate your feedback and assistance. I hope re-routing the inlet solves their problem, but if not, we may need to explore possible pulsing issues.
Michael Iverson
Equipment Manager
U.S. Air Filtration, Inc.
951-417-1745
mike@usairfiltration.com
RE: Baghouse Particulate Conglomeration Issue