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View Full Version : Have to have a mill room?



woohokie
02-19-2013, 11:21 AM
Hey all, as we are finalizing the layout of our space one of the things I hadn't fully thought through was the milling part of the process. We are planning on a 7bbl setup for draft/growler fills only at a location with only 2900 sq ft.

I have considered Jimboney's mill with a cabinet and realizing that milling and mashing in will take more time and labor than if we were to use an auger and hydrator, but as space is at a premium, a malt mill on a rollable cabinet seems appealing. So, is it completely naive of me to think we could do it that way without the need for a separate milling room with ventilation, and would any city or other governing agency even allow such a simple setup? Any input is always appreciated.

YSBrewer
02-19-2013, 11:41 AM
As has been said here before, use the term "grain crushing" when speaking with officials. Milling brings to mind flour and fine dust. If you are milling inside the brewery you will always have dust on everything.

We use a very simple grain room that is maybe an 8X8 room. I use a 14 gal wet/dry vac with a bag in it to suck the grain dust as it comes from the mill. There is zero dust in the room and the "drywall" bag for wet/dry vacs keeps the fine dust contained. It works beautifully for us!

woohokie
02-20-2013, 06:12 AM
^^ thanks for the advice. I've heard the term grain crushing on here before and will be sure to follow suit. I'm thinking the cabinet + shop vac and crushing by the 50lb sack hopefully will work.

TGTimm
02-28-2013, 02:23 PM
Please Google "dust explosion", and check out this website: http://www.dustexplosion.info/

It's amazing how much really fine dust is generated in dry-milling grain. This is probably why local authorities get a bit nervous when you mention it.

Using a shop vac to minimize dust may sound like a good idea, but I'll stick with an explosion-proof dust collection system--like those used for woodworking. We used to use a shop vac to clean the milling room, until one of our employees got (quite literally) knocked on her butt by a static electric discharge from the grain passing through the plastic hose. Now every bit of plastic the grain passes through (drop tubes, dust collection hoses) in our mill house has a grounding wire inside, even if the run is only a foot or less.

The brewery where I work originally had the mill in the shop. That was over ten years ago, and there's still dust caked in odd places.

yap
02-28-2013, 02:30 PM
If a municipality is going to be anal about explosion proof mill room, they probably will not accept a shop vac for dust removal. One of the key things needed for explosion is a spark and a shop vac would be a very good source for one...

YSBrewer
03-07-2013, 11:31 AM
Just curious, how many stories are out there about grain rooms exploding at breweries?

On a side note google "shop vac dust collection" and you'll see there are numerous ways to use a shop vac appropriately.

Bierkoenig
03-07-2013, 01:23 PM
If a municipality is going to be anal about explosion proof mill room, they probably will not accept a shop vac for dust removal. One of the key things needed for explosion is a spark and a shop vac would be a very good source for one...

A dust collector is light years better than a shop vac. They have a lot more power which means collection scoops can be bigger and farther from the actual dust leakage source. The one Harbor Freight sells is usually $190 on sale and has served me well in my shop at home and at the brewery. I also recommend caulking leaky joints in the sheet metal on your mill, hopper, unloader, case, or anywhere else with silicone--it's easy to remove if need be, but keeps a LOT of dust from leaking out of the system in the first place.

YSBrewer
03-08-2013, 05:09 AM
I would say that a dust collector sounds good other than the harbor freight only filters to 5 micron. A shopvac bag goes to .4 micron so you are sure to contain more dust. Either way, whatever works for you. There are plenty of cheap ways to skin this cat - or blow one up! :)

Bierkoenig
03-08-2013, 09:15 AM
I would say that a dust collector sounds good other than the harbor freight only filters to 5 micron. A shopvac bag goes to .4 micron so you are sure to contain more dust. Either way, whatever works for you. There are plenty of cheap ways to skin this cat - or blow one up! :)

The stock bag on the HF dust collector has been adequate for me, but I keep my system pretty well sealed. I've heard from others that it is too loose of a mesh. The good news is that it is identical to the name brand collectors of the same design on the market (look at them closely and you'll be convinced that they come out of the same factory), so using a tighter aftermarket bag of your choosing is no problem.

edthebrewer
03-08-2013, 09:30 AM
I know a 7 bbl brewery in Oregon, they ran into technicalities about a grain room.

So they roll the mill out, and crush under an awning outside

liammckenna
03-13-2013, 12:15 PM
I know a 7 bbl brewery in Oregon, they ran into technicalities about a grain room.

So they roll the mill out, and crush under an awning outside

If you don't contain the dust, it will almost certainly lead to problems later. Malt dust is alive with beasties that will take up residence anywhere they encounter a little moisture. It can also be very fine and remain airborne for surprisingly long times. Inhaling this dust on a long term basis (even in small quantities) can lead to lung issues. It contains a lot of amorphous silica in addition to the aforementioned beasties and it's tendency to absorb moisture from your lungs.

I like the idea of doing it outside (mill on wheels). Otherwise, contain it and properly ventilate it.

Don't tempt fate by thinking that grain mill explosions are rare. The code exists for a reason.

Google grain mill explosions.

Pax.

liam

Rocco
08-07-2013, 09:39 AM
As per NFPA 70/NEC the “equipment” in this case is a Portable Vacuum Cleaner. It should be certified by a NRTL for Division 1, Class II, Group F and G.

This means that the level of protection (EPL) provided by the equipment in this case, is for Division 1.

There is also available in North America, equipment certified for Division 2, Class II for combustible dust (except metal dust).

In either Division 1 or Division 2, the inner parts of the “cleaner” such as: collection bag, main filter, safety filter assembled upstream, must all be conductive and static dissipative. This also includes the construction of the “cleaner” itself. This is a must!

Please note: The NRTL Certification, either for Division 1 or Division 2, only certifies the possibility to use the equipment in the presence of combustible dusts, in this case, and not the collection or recovery of these dusts.

It is the manufacturer’s responsibility to make sure that the inner parts of the “cleaner” is properly built and provide the right protection level (EPL).

This is called good manufacturing practices.

mashpaddled
08-07-2013, 12:53 PM
Generally speaking, when you are looking at designing your grain mill you need to keep your local health inspectors happy but also make sure you are OSHA-compliant (or if you operate in a state with a state level OSHA program that you are compliant with the state program) for both structure and employee safety.

OneMoreBrewer
08-07-2013, 05:23 PM
The stock bag on the HF dust collector has been adequate for me, but I keep my system pretty well sealed. I've heard from others that it is too loose of a mesh. The good news is that it is identical to the name brand collectors of the same design on the market (look at them closely and you'll be convinced that they come out of the same factory), so using a tighter aftermarket bag of your choosing is no problem.

They make HEPA dust collectors too. This is what you should use. It will reduce the dust and provide safe to breath air. We used these in the seed and grain industries before I was a brewer. Ideally you locate the motor outside the dusty areas and pipe in the suction ducting to prevent sparks.

Anyone who doesn't think dust explosions are a risk is a fool. New Belgium? Come on man. The real guys know its a real risk. Coors and the like use completely sealed rooms for grain elevation and transfers, and they have a lot less dust than any of us small guys.

Wake up people, our work environments are dangerous places. Dust explosions (new belgium), people falling in and dying in tanks (coors), kegs exploding and killing someone (redhook) Don't put employees at unnecessary risk. It's just not worth it. Employees - pay attention and follow rules, it's worth it.