High flow rate for recirculation

[RPh_Guy]

Anyone have tips for increasing flow rate?

I'm using a RIMS on a 10gal round cooler with MKII pump and a bazooka tube. My tubing and connections are all 1/2" ID.

I know crush plays a large role, so I'm working on dialing in my crush (3-roller mill) and I also condition my grain. I'm not currently using rice hulls.

Would a false bottom allow a higher flow rate vs my bazooka tube?

Any tips for preventing the grain bed from compacting/causing stuck flow?

Thanks guys.

 

[Dland]

Not sure how it would work in a cooler, but I have good recirc flow, I use a simple false bottom, I think from Brew Hardware. My mash tun is inverted keggel, with tap port now acting as a sump,. I don't use rice hulls except with substantial rye %, never had a stuck mash, pretty good efficiency with fairly fine grain crush, but not as fine as the BIAB brewers I suspect.

I also tend to mash in a little wet (maybe 1/2 gallon over beersmith calc., eg 7 gallons instead of 6.5) so there is always a little wort above the grain.

 

[Jag75]

I would think a false bottom would definitely help with your flow rate. I have a small filter on my Grainfather. I added a false bottom and it's been much better .

 

[Vale71]

Would a false bottom allow a higher flow rate vs my bazooka tube?

That's a definite YES.

Any tips for preventing the grain bed from compacting/causing stuck flow?

Ehm... don't drive the pump too fast? Probably not what you wanted to hear but until you improve your setup there's really not much else you could do.

For long term improvement:

- get a false bottom (see above)
- condtion malt before crushing
- get a 15 gal vessel to reduce the grain bed's thickness (assuming the larger vessel has a proportionally larger diameter)

 

[RPh_Guy]

I guess there's a false bottom in my future!

Do you use something to prevent it from collapsing?

 

[day_trippr]

Hard to believe the difference in lautering capacity between a braid and a full FB is a revelation...

Cheers!

 

[jcav]

Try some rice hulls in your next batch. I bet it will make a difference with the flow rate and you will be a believer!

John

 

[day_trippr]

Rice hulls with a bazooka is still never going to be in the same area code as a full FB wrt lautering capacity.
Fluid physics shall not be denied. "Surface Area Matters"...

Cheers!

 

[jcav]

Sure with the false bottom combo that would be the best bet, but use the rice hulls! Another benefit of rice hulls in the mash tun is that it also helps to maintain a more even temperature throughout the whole tun, so give um a try.......


John

 

[day_trippr]

In general I try to avoid using rice hulls as the deer hate them in the spent grain, and 20+ pounds is too much to dump on the neighbor's dozen hens in one shot. I run a Blichmann FB which is a uniquely awesome design but not infallible, so when the wheat content hits 25% or more I use around a half pound of hulls to dodge the likely locked-up mash. Learned that lesson long ago

Cheers!

 

[RPh_Guy]

Rice hulls with a bazooka is still never going to be in the same area code as a full FB wrt lautering capacity.
Fluid physics shall not be denied. "Surface Area Matters"...

It sounds like you aren't realizing how much open surface area a bazooka tube has. Let's do some geometry.

Just eyeballing it, the wire is maybe 25% of the width of the holes. So... A 1x12" bazooka tube has 3.14*12*0.75^2 = 21 square inches of open surface area.

The open surface area of the false bottom is a little harder to eyeball. Let's say the distance between circles is 80% of the circle diameter. A 12" diameter false bottom has about 30 square inches of open surface area (I'll spare you the math but you're welcome to check).

Definitely larger but I'd call that the same "area code". It's NOT crazy to think a bazooka tube could work. For comparison the cross sectional area of 1/2" ID tubing is 0.2 square inches.

@jcav I have used rice hulls quite a bit, but I stopped when I started conditioning since conditioning made such a huge difference for lautering. Recirculating is a whole different animal though, so I probably should give them another try... at least until I get some of these other things changed.

 

[day_trippr]

I'm not sure "open area" alone is the whole story (one grain husk will cover more open area on the bazooka than an FB, yes?) and not all FBs are made of an array of simple holes, but whatever, I think you'll appreciate the superior performance of a good FB...

Cheers!

 

[AF1HomeBrew]

this.https://www.homebrewtalk.com/forum/threads/norcal-sparge-diffusion-plate.673611/

 

[RPh_Guy]

I'm not sure "open area" alone is the whole story

That's why I'm asking the question... and you were acting like I was being absurd for asking it.

Just hoping to get a feel for how just products compare in practice before I make a purchase.

"Surface Area Matters"...

The Blichmann FB has little slits and so it probably has less open surface area than my bazooka tube.

this.https://www.homebrewtalk.com/forum/threads/norcal-sparge-diffusion-plate.673611/

Does this somehow help increase flow rate during recirculation?

Do you guys have recommendations for a good 12" false bottom? I would be using a high flow pickup like the one from brewhardware.com.
I'm not quite ready to increase the size of my mash tun right now.

 

[Jag75]

I guess there's a false bottom in my future!

Do you use something to prevent it from collapsing?

I got an idea from someone here in the Grainfather thread to use stainless bolts and nuts as legs. It keeps it at the right height.

 

[day_trippr]

That's why I'm asking the question... and you were acting like I was being absurd for asking it.

That's a bit more than I intended to convey, so, sorry 'bout that.

Anyway, I still think there's no comparison between the two solutions, and tbh don't recall reading of many folks even trying to recirculate through a bazooka tube. Wrt the Blichmann FB design in particular, compared to the perforated FB I used on my 10g cooler it is profoundly superior in performance. Has to have something to do with their design, there's something about that works better than a grid of open holes.

I think it should be clear you need to get away from reducing lautering solutions to their "open space". It should be obvious there's more to it than that...

Cheers!

 

[AF1HomeBrew]

Does this somehow help increase flow rate during recirculation?

yes, if you use a RIMS and recirculate during mashing. It helps return the liquid on top of the grain at or just under the liquid level without disturbing the grain bed or compacting the grain bed, which happens when you have a tube floating inside your mashtun for the return.

 

[AF1HomeBrew]

I use a BCS controller to control my RIMs, pump, and 2 induction plates that my HLT and mashtun sit on. Until I started to use this diffusion plate the temp probes in my mashtun & RIMS would be several (5-10) degrees apart, because of rate of return wasn’t fast enough. We figured out that having a tube floating on the side in the mashtun was causing the grain bed to compact due to the circular motion of the liquid being returned. Now the flow rate is much faster and the temp difference between the RIMS & Mashtun temp probes might be 1-2 degrees apart for a short period.

 

[RPh_Guy]

yes, if you use a RIMS and recirculate during mashing. It helps return the liquid on top of the grain at or just under the liquid level without disturbing the grain bed or compacting the grain bed, which happens when you have a tube floating inside your mashtun for the return.

Ah, gotcha. I am already using a return that diffuses the flow in the top of the mash tun, so I should already be good from that standpoint.

profoundly superior in performance.

Thanks, it might be possible that the Blichmann FB for the 7.5 gal kettle could fit a cooler. It may be a bit too large.

 

[AF1HomeBrew]

If you need a false bottom for your cooler, you need this: https://www.morebeer.com/products/false-bottom-stainless-steel-domed-12-diameter.html

doesn’t matter if you have an orange,yellow or blue cooler.

 

[day_trippr]

Well that is the usual prescription
I'll add, however, you really want this upgrade when using with a cooler...

https://www.homebrewtalk.com/forum/threads/fb-gasket-for-10g-rubbermader-mlt.381111/

Note the original images were borked with the forum runner change of aught-14 but I reposted them in post #21...

Cheers!

 

[Vale71]

It sounds like you aren't realizing how much open surface area a bazooka tube has. Let's do some geometry.

More important than the surface area is the distance the wort has to travel through the grain bed. The longer the distance traversed the higher the flow resistance. With a bazooka some wort will have to traverse diagonally and this increases the distance quite a bit. With a false bottom wort will traverse nearly vertically (at least for small sized tuns like ours, with big equipment it's a bit more complicated) and then flow to the outlet through the empty area beneath the FB where there are no grains and resistance is nearly zero. This results in a lower overall flow resistance and reduced tendency to compacting/channeling in the grain bed. If this is not enough than a larger tun will further reduce the grain bed height and the distance traversed.

 

[RPh_Guy]

Thank you. That makes perfect sense!

 

[ba-brewer]

I have the morebeer 12in domed false bottom. I used it primarily in a 8gal kettle in a RIMS setup to do 5gal batches. It have had good luck with batches of beer with like 40% wheat malt without compacting the grain bed with a decent flow and no rice hulls.

I recently did some upgrades and started using the false bottom with a 11gal bayou classic kettle. For 5gal batches it still seems to work the same(have not done any wheat beers) but for the 10gal batches I have been doing lately it does seem much more prone to compacting and sensitive to the flow rate. I have increased the gap on my mill to .042, condition my grain and it is still sensitive.

Also with the pickup below the height of the port on the kettle, the speed of the sparge must be fairly slow or the vacuum can be lost and wort get trapped in the mash. When I had a bazooka tube in a cooler that was never a issue and I could tip the cooler to allow it continue draining while the wort heated.

edit: the 11gal bayou classic is tall and skinny like a cooler mash tun.

 

[jcav]

@jcav I have used rice hulls quite a bit, but I stopped when I started conditioning since conditioning made such a huge difference for lautering. Recirculating is a whole different animal though, so I probably should give them another try... at least until I get some of these other things changed.[/QUOTE]

RPH Guy I totally understand with conditioning the grain. I use rice hulls in my 3 vessel e-herms and with the rice hulls it doesn't matter if I use a lot of wheat, flaked maize, oats or other gummy stuff, I can recirculate wide open. Try the rice hulls in your next batch and see if you can recirculate with no issues. It made a huge difference with my system. I also have a full false bottom in my keggle mash tun and I am a fan of false bottoms. Hopefully you can find a solution that works for you and your system. Good Luck!


John

 

[RPh_Guy]

I'm on the fence between:

Standard holes .... https://www.brewhardware.com/product_p/fb12d.htm
- and -
Slotted holes .... https://www.homebrewing.org/12-Stainless-Steel-Domed-False-Bottom_p_1058.html

Thoughts?
Do you guys think either design is preferable? The guys at AIH claim theirs reduces channeling.

The one from brewhardware comes with the high-flow elbow (which I definitely want).. and I noticed there's also a support available:
https://www.brewhardware.com/product_p/fbstand.htm

 

[wilserbrewer]

By my eye the FB with the holes looks to provide more “open area” for wort to flow.

“Reduces channeling” ? By being more restrictive idk [emoji52]q

The included high flow elbow is a plus imo...eliminates potential clogging nightmares...

 

[RPh_Guy]

The Blichmann and Spike false bottoms are also slotted and have lower open area. I don't know if they just look prettier or if there's actually something to it.

 

[ba-brewer]

The AIH says it has brass parts but you get a ball lock in the deal.

I think I would go with brewhardware and get the support thing. There is a comment toward the bottom about needing support if you are using a pump. I believe that is my problem with 10gal batches. I had the drain very close to the bottom to reduce dead space and lost wort when batch sparging but I think the additional 10lb of grains is enough to flatten the doom and lower the drain port restricting flow.

 

[RPh_Guy]

The AIH says it has brass parts but you get a ball lock in the deal.

I'm just looking at the false bottom; I wouldn't use their connections.