Spent grain in my HLT

[MikeRoy]

Yeah, I was a bit surprised too.

Its a Bohemian Brewing (mid 90s) 10 bbl Monobloc with stacked HLT and mash tun. Opened the HLT for inspection and saw a decent amount of grain in the tank. The process pipe is all connected using one pump. The HLT overflow is connected to the mash tun drain pipe ( as in the HLT overflow tees into the drain for the mash tun). The mash tun will at times clog and I'm forced to spray water up it to unclog it, but obviously grain is backing into the HLT.

Has anyone ever experienced this with a Bohemian or similar set up?

My intention is to order some screen gaskets and install them on all the HLT valves in hopes of keeping grain out.

Beyond that anyone have any insight on how to prevent this from happening again?

[Scott M]

Not sure about access, but re-plumbing the HLT overflow so that it has no connection with the Mash Tun would be the route I would look into. Screens tend to get plugged up.

[MikeRoy]

Scott,
That's one potential solution, though my thought is that once the HLT overflows (which it does at the end of knockout then it will push any grain build up off the screen and down the drain.

Thanks.

[GlacierBrewing]

I don't see how the grain could "climb" the overflow pipe inside the HLT. I'm thinking a more likely culprit is due to your mash recirc. If you are using your brew kettle as a grant, the path out of the brew kettle through the pump on the way back to the mash tun will take the wort and grain pieces past the HLT top valve. It would be closed but there is a short section of pipe, about three to four inches, that exist directly after the junction where the pipe splits to the mash tun and this top HLT valve. I believe it is this short section that gets grain "packed" into it and waits there until it can get access into the HLT. Hope this helps.

Prost!
Dave

[MikeRoy]

Dave,
I agree with you about that short section of pipe being a culprit for grain( nice design flaw).

Assuming this is the only culprit for the grain in the HLT I would think the only thing to do is to do frequent checks of the HLT and rinse out grain.

Do you really not think that grain couldn't back its way up the HLT overflow pipe when I'm spraying water up the "shared" drain pipe?

Just curious since I know you've brewed on these systems and know a lot more about them then I do.

Thanks.

[GlacierBrewing]

Dave,
I agree with you about that short section of pipe being a culprit for grain( nice design flaw).

Assuming this is the only culprit for the grain in the HLT I would think the only thing to do is to do frequent checks of the HLT and rinse out grain.

Do you really not think that grain couldn't back its way up the HLT overflow pipe when I'm spraying water up the "shared" drain pipe?

Just curious since I know you've brewed on these systems and know a lot more about them then I do.

Thanks.

Hiya Mike,
If you are spraying up the mash tun drain/HLT overflow then, yea, the first and easiest route for your spray water would be to enter the HLT via the overflow valve. Maybe to test this, do a brew and DON'T spray up that drain piping. If you refill your HLT to full (read: overflowing) then that will rinse and stray grain from that drain piping and there should not be a need to spray up that pipping.

Prost!
Dave

[BadgerC]

Hi Mike.
It's been a few years but I used to brew on a 15bbl Bohemian monobloc. My least favorite system ever. Had the same problem. I believe the problem is two-fold. One being the overflow pipe. If I recall correctly, it seems to me that things used to "burp" up through it on occasion. The second being a short length of pipe that supplies the water to the HLT. If I recall, it's tied into the main line like everything else. Great design flaw. I think it was their attempt at using one pump that led to this as well.
Anyway,if you try to recirculate your HLT at anytime after wort has flowed through the pump that small section of pipe will harbor debris. The only solution I found was to make sure that "main line" get's completely drained before "spinning" or topping up the HLT. Seemed to work for us but don't hold me to this it's been several years and my recollections of that system are fading (or being suppressed).
Be Well.
Badger