Baghouse Versus Cyclone

Advice on choosing a chip and dust removal system, based on the shop's situation. June 15, 2014

Question (WOODWEB Member) :
I am trying to make the right decision with an upgrade to our new shopís dust collection system. So far Iíve made it by with a used cyclone thatís probably rated for around 2500 cfm and some after filters that we have drop into 55 gallon drums. With our new location, the layout that the piping must follow and the added equipment we are looking at 8000 cfm possibly a bit more. A few others in our area are running Donaldson-Torit cyclones and are happy with them but a few are saying to go with a baghouse.

I understand how they both work, one in detail the other in concept, but would really appreciate real life experience from those who use both. We are a custom cabinet shop that works mostly with plywood, hardwoods and very little MDF. The majority of fines are produced by the widebelt. We are looking at a CNC in the very near future. We don't do much heavy milling as we do not currently own a molder but that could change. What can anyone tell me? Stick with the cyclone? Or what about a baghouse? I don't want to go with both.

Forum Responses
(Dust Collection and Safety Equipment Forum)
From contributor B:
This is a very common series of questions. Has anyone calculated the total requirement of the system? This is accomplished by adding up all of the ports that will be connected to the system and leaving some room for growth. I assume if you are at 8,000 plus CFM this will be an outdoor installation. Will you be returning air to the building? This will require an abort gate. How do you want to dispose of the material - barrels, dumpster, roll-off, etc.?

It sounds like youíre mainly panel processing. If you were heavy to chip (moulder/planer) I would stay with the cyclone/afterfilter. It sounds like a baghouse is the better solution. Because of the fines from the sander, I would recommend keeping the air-to-cloth ratio around 6-7:1. So if you need 8,000 cfm, make sure the bag house has at least 1,300 square feet of cloth. Used units are everywhere right now. It pays to buy more cloth than you need. You can always purchase a collector with say a 20 HP motor today that can be upgraded later if the demand is there. Again the trick is to make sure you have enough cloth in the beginning. When looking at a baghouse you have basically three choices - shaker, pulse and reverse air to get the cake off of the bags. For your application, all would work well.

From the original questioner:
I have been looking a bit more into baghouses of late after talking with a few others here who use them. The only calculations on the cfm have been done by the dealers that I have been talking to, with simple line drawings showing runs and port sizes. Some of the bigger machine requirements I am guessing at as my boss is planning on buying them down the road, but we still need to size for them. We would be doing a lot of panel processing as we are a custom cab shop, but there would be a bit of milling as well. No heavy molder yet. I need to dump the refuse into a three yard dumpster as I am tired of unclamping barrels and manually dumping them.