Question for the engineers

[MrNate]

I'm working on my new lauter tun design and I was wondering if it would be feasible to pump spent grain from the tun. Would a sewage or effluent pump work? The new brewery will be in the basement, so ideally I'd like to pump it up and out to the compost pile. Watering down the grain to move it is no problem, I'm mainly worried about the ability of a pump to move a slurry like that.

Any thoughts?

[corkybstewart]

What I saw in Belgium was an auger system that had a 4" auger in a tube that carried the grain from the basement mash tun to trucks outside. I think spent grain will be too heavy and coarse for a pump. My FIL has a similar system for getting grain from the truck to the loft for storage. You might look at agri supply stores for ideas.

[M.K. Jeeves]

A macerator style pump may work but it would still be a headache given the nature of whats being pumped.
The auger pump sounds like the ticket, as the spent grain is being lifted by a screw instead of the suction created by an impeller.
I've had experience with with sewage/ macerator pumps (not in brewing) and if the grain is in a slurry as you mentioned it may work. A clogged pump is a pain, but I would much rather take apart a pump packed with spent mash rather than what is usually found in one of those. Its amazing what people think will flush.:)

[danno]

don't want to dissuade you from your goal here, but wouldn't engineering in the capability to tip over your mash tun be easier than pumping it out? our club big brew system has that capability, we just tip the tun 90º (and more) to dump the spent grain. I'd really like to do that with mine, too, but I haven't gone past merely speculative redesigns yet...

[corkybstewart]

But then he still has to tote all that spent grain up out of the basement, that's what he's trying to avoid. I jsut put my mash tun keg in the wheelbarrow and haul it to someplace in the yard. It can get pretty damn heavy, think about 42 pounds of grain, saturated with water and maybe a few gallons left in after sparging. But all I have to do is slide mine off and let it fall into the wheelbarrow. Mr. Nate has stairs to deal with.

[danno]

lol, see what happens when I try and multitask? completely missed the part about the basement...

[MrNate]

Yeah... I mean, there's always the backup plan of multiple 5-gal buckets, but I was hoping that something like a trash pump might make quick work of a dirty job.

The tippy-dump method was the original plan, but keeping it stationary solved so many other problems that I figured I'd look into this method. The archimedian screw method would likely be more reliable, but might be out of range price and scale-wise.

I'm taking a look at macerator pumps now. I think that has a shot of working if the mash is thinned enough.

[Quin]

I specified one of these for a 20% solids sludge cake at a wastewater treatment plant. It mentions spent grain in their advertisement.

I'd hate to have to pay for one myself.

http://www.moyno.com/website/products/2000hs/hs_system.php

[MrNate]

Originally posted by Quin
I specified one of these for a 20% solids sludge cake at a wastewater treatment plant. It mentions spent grain in their advertisement.

I'd hate to have to pay for one myself.

http://www.moyno.com/website/products/2000hs/hs_system.php

The more I dig into this, the more what you describe seems to be the case. I can find pumps that can handle up to 70% solids, but I can't find 'em cheap. Not on eBay, anyway.

My next idea is to try building my own peristaltic pump out of 2" or 3" tubing. What thinks you? They use these to move concrete slurries, so the theory seems to be sound. The mechanicals don't seem too complex either... Uh oh, famous last words!

[Quin]

Seems like more trouble than its worth. I use a 30 qt cooler with wheels for 5 gallon batches. I plan on using a 60 qt with wheels for 10 gallon batches. Shouldn't be that much of a problem to drag/wheel up the stairs.

[corkybstewart]

Maybe some sort of pulley system like a dumbwaiter might be easier and cheaper, although 2 plastic buckets should be able to tote any amount of grain. Make multiple trips, burn calories, get fit while you brew.

[MrNate]

Nope, I've made my decision... It's medical experiments for the lot of you!

[Otis_The_Drunk]

Originally posted by MrNate
Nope, I've made my decision... It's medical experiments for the lot of you!

Will there be psychotropic drugs involved? :D

[MrNate]

Are "roller pumps" the same thing as peristaltic pumps/hose pumps? Because if so, it seems like there are plenty to be had for reasonable amounts of money. Apparently, they're like candy for agribusiness.

I'm finding tons of pumps to be had cheaper than the DIY route, up to 1.5" inlet size. I'm betting that could handle a thinned out mash.

PS: Only for you, Otis. Only for you.

[SirVeza]

MrNate...

Have you considered buying a pig? They love spent grains and can make you methane gas to power your brew burners.

I'm sure they'd be happy to help you drink the beer too, so maybe a pig is not a good idea.

LOL

Greenly yours,

Dan Carol
Homebrewing In The Philippines (http://homebrewinghobby.blogspot.com/)

[MrNate]

Not a bad idea, except that pigs are amazingly commited to illustrating the theory of "conservation of matter."

Meaning if I have a pig in the basement, I'm still going to have to pump something out. :D