Bypassing a Cyclone Collector

Cyclone collectors require a sealed vacuum to function. But you can build a larger sealed room if you need a greater bulk capacity. April 19, 2011

I have a small 2hp Grizzly cyclone in my shop in the corner. The collection barrel it came with is just too small. I'm having to empty it at least once a day when I'm busy. Is there any way I can run a pipe from the bottom of the cyclone and out the wall and just shoot the dust into a big pile? I took the collection barrel off, started the machine, and it seems to suck air into the cyclone instead of push it out. I'm thinking that it has to be a sealed chamber to get its suction. How can I get around this? Here's a picture of my cyclone when I first installed it.

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Forum Responses
(Dust Collection Forum)
From contributor G:
The cyclone's vacuum integrity must be maintained. What you want to do needs a motorized rotary air lock - a device under the cyclone that catches the dust and every so often rotates and dumps a load below without breaking the vacuum seal on the cyclone. You can then use an auger or blower to blow outside into a dumpster, or whatever. The problem is that the rotary air lock will cost you several times what your Grizzly cyclone cost, let alone the auger/blower, etc.

Do you want to return the air to the shop? If not, then just sell the collector and get a blower to connect to the system. I did not think much of them, but I have seen a couple of systems where the owner built a vacuum tight box instead of the barrel and had a door and used a shovel to remove the dust... You could have that door inside or outside.

From contributor D:
When I had a one bag collector and emptied it twice a day, I added up my time for doing so, and soon realized I had already spent the money for a real central system, but I didn't have it. I bought one the next day (or started the process), and things improved greatly.

I built an airtight room as described above that would hold 160 c/ft of shavings, and had an airtight door to the outside for my neighbor that would come and haul it for her horses.

I went from 2 hours a week or more to zero time spent on the shavings. The shop air was filtered and returned to the shop. The shop was cleaner by far, and cool in the summer, heated in the winter. Go the extra mile and put the fan and cyclone above the dust bin, isolated from the shavings and shop, and you lose all the noise also. Use a wireless controller, and it is heaven on Earth.

From the original questioner:
Good ideas. I hadn't thought of the airtight room. Guess it helps knowing how these systems actually work. It would be nice to get rid of that loud noise too, so maybe setting the whole thing outside would be best, and building a large box underneath. Is there a limit to the size of box depending on your hp or cfm? Thanks.

From contributor D:
No limits beyond keeping it airtight. If it is not airtight, the dust will bypass the system and end up in your filter bags. Look at Oneida's website for some info on sequence of things. Just don't buy their idea of a barrel for shavings - think room.

In my current shop we have a rotary air lock at the bottom of the cyclone and it is great. Duct, fan, cyclone, filters is the sequence. The system remains at high pressure, and all air is returned to the building after filtration. You may think of the Grizzly unit as part of the learning curve. Their specs for HP and CFM are often suspect.