why do i suck at Whirlpool?

so i got the More Beer 5/10 split with a recirculation/whirlpooling arm. Like This and This

My BK has a stainless scrubbie on the end of the pick up tube, then to a 1/2" ball valve, to some camlock fittings, to my pump, and onto the recirc arm.

i've tried it with the IC and just the recirc arm, and i don't seem to be getting enough of a whirlpool. the water barely seems to be moving. hardly a "whirlpool" effect.

can anybody tell me what i'm doing wrong? are my camlocks restricting flow too much? could it be my hoses are too long? wtf?

try moving the recirculating arm up more towards the top

Is the scrubbie getting clogged up with hops//trub and causing a restriction at the pick up tube?

Could be that the inside diameter of your hoses and/or fittings is too small and possibly causing excessive restriction. What size hoses are you using? It's best to keep the hoses as short as possible for best performance.

Might be a combination of any of the above, ie hoses too small and clogged scrubbie partially inhibiting the flow.

You can get a feel for how much restriction your hoses and fittings are causing by pumping into a bucket and timing how long it takes to pump five gallons of water. Check that against the pump specs. Assuming you are using a March 809 it has a max flow rate of 6 gpm at zero head, so I would think that you should be able to easily get 3-4 gpm out of it taking into account some losses for restrictions and head.

i've tried the recirc arm at the top, middle and bottom of the kettle.

as for hose, it's 1/2" hose, but each half is probably 6 feet long. this test was with water, so i don't believe the scrubbie is cloggged. i will try pumping into a bucket and see what my flow rate is.

slakwhere said:

i've tried the recirc arm at the top, middle and bottom of the kettle.

as for hose, it's 1/2" hose, but each half is probably 6 feet long. this test was with water, so i don't believe the scrubbie is cloggged. i will try pumping into a bucket and see what my flow rate is.

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The problem with using 1/2" hose is that the ID of the barbed fittings is usually substantially smaller and causes a lot of undesirable resistance. The hoses are on the long side too, which is also a contributing factor. IME, restrictions on the suction side are considerably more detrimental than on the output side, but I'm not exactly clear on why that is the case.

The bucket test will tell the tale and leave no doubt. You could repeat the bucket test with the shortest and largest diameter hoses you have on hand to demonstrate the performance difference. It should be a dramatic difference.

yeah i saw the bobby_m video on the camlocks and his modifications (of course after i bought all my camlock stuff), so i was thinking it could be the restriction of the camlocks themselves...

i may just remove the recirc arm and give it a go that way, it's not very large diameter... then play with the hose, maybe shorten some things and see what gains i can make.

when i do the bucket fill test, should it be 5 gallons in the kettle until it goes into the bucket? or should i fill the kettle? will head pressure adjust this measurement?

What is the size of your pickup tube? Is 1/2" like the rest of the system? Because a restriction here would have a big effect like Catt said. Also if the whirlpool arm is a smaller diameter (let's say 3/8") than the rest of the system I believe this would improve the speed of the whirlpool. Based on http://en.wikipedia.org/wiki/Bernoulli's_principle This is how I have mine set up and it works great.

the pick up tube and the rest of the gear came from bargain fittings... looks like he only sells 1/2" side pick up tubes. i am beginning to wonder if the scrubbie is affecting things on the pick up side. i'll give it a test today to whirlpool with the existing setup but not scrubbie (and do the bucket test both ways).

slakwhere said:

yeah i saw the bobby_m video on the camlocks and his modifications (of course after i bought all my camlock stuff), so i was thinking it could be the restriction of the camlocks themselves...

i may just remove the recirc arm and give it a go that way, it's not very large diameter... then play with the hose, maybe shorten some things and see what gains i can make.

when i do the bucket fill test, should it be 5 gallons in the kettle until it goes into the bucket? or should i fill the kettle? will head pressure adjust this measurement?

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The head pressure in the kettle and elsewhere above the pump will affect the flow rate, but it will be relatively minor and will decrease as the water level falls. IOW, yes, but not a great deal and not worth worrying about for your approximate flow rate testing.

I'd fill the kettle completely and stop the pump when the bucket reaches the 5 gallon level or whatever other level you choose. If the hose is submerged in the receiving bucket, the flow will slow slightly as the water level rises in the bucket, but this will also be very minor and can be ignored for the approximate testing just like the water level in the kettle. You only want to get a general idea of what's going on and how much resistance the pump is working against. No need to go for extreme precision unless you want to, of course.

k i will find a ballpark value and let you know

once primed i seem to get about 2gpm from the bk to the HLT. then the GFCI in my switchbox started tripping and it was cold so i stopped for the night. that seems like pretty slow flow. anyone know what's reasonable?

Just curious but are you trying to just keep the wort moving around the immersion chiller for better chilling efficiency (which I don't generally think of as 'whirlpooling') or are you actually trying to get a sufficient whirlpool so you can let it settle and then drain?

If you're just trying to keep it moving for better chilling it shouldn't need to move all that much for decent chilling efficiency but if you are actually trying to whirlpool-then-let-settle (so you can drain it through a valve) then I'm not sure that rig is going to get you there (and I don't think it was designed to but I'm just guessing).

I'm very inexperienced when it comes to whirlpooling, I only do it for the rare 10 gal batch I do. And in that case I use a stainless steel wire whisk (after the wort is fully chilled) and crank like mad until it's climbing up the walls of the kettle. Using something like a whisk (instead of something solid like the big metal spatula I first tried) allows me to get a major whirlpool (and some aeration as a side benefit). I don't even have a pick-up tube, just the hole for the valve but all the wort comes out (with some tipping).

i'm hoping for both. whirlpooling to remove junk to a cone, and improved cooling.

slakwhere said:

i'm hoping for both. whirlpooling to remove junk to a cone, and improved cooling.

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The 2 gpm seems very low to me. I will run a similar test with mine so that you will at least have some kind of a benchmark for comparison. I've never actually measured my pumping rate, so I'm interested too.

FWIW and IMO, the main purpose of doing the whirl pool when pumping in a loop back to the BK is to keep the wort moving and mixing as it passes over the chiller coils (IC) or through a CFC (what I use). The objective is fast cooling and particularly to get the wort to about 140F or below asap in order to help preserve the volatile hop flavor and aroma essences. I think it also helps reduce DMS precursors. We all know what happens if you just put an IC in the kettle without somehow stirring the wort. That would be the other extreme.

The second reason for "whirlpooling" would be to form the elusive trub/debris cone in the center of the kettle prior to draining it. The typical procedure is to give the wort a good stir to get it spinning, then stop and wait 10-20 minutes for the debris to drop out. You don't need a pump for this and you don't need to go hog wild trying to generate a deep vortex or anything like that. Just giving it a good stir for 30-60 seconds is plenty. I've found that the waiting part is more important than the spinning part of this method, but YMMV, blah...blah...blah.

Stand by for my pumping test results. I will be using the dreaded 5/8" ID braided PVC tubing.

i left water in the HLT and the BK, i was gonna try and pump the other way today when i have some time. still wondering if it's the scrubbie in the BK causing my issues.

Time is your friend on producing a decent compact cone. I generally cool my wort past my target, remove the immersion chiller and give it a good stir, then let it sit about 30 minutes.

When whirlpooling I find that the middle third of the vessel is a good place to return the wort when pumping. Too low or too high does not seem to swirl the wort in my experience.

With the 1/2" OD stainless tubing and a march pump, you should have plenty of return volume to swirl the wort.

I'm not sure how much obstruction the scrubby will cause though.

OK, I just ran a test using my Little Giant 3-MD-MT-HC pump. It's has a 1/25th hp motor and it's rated at 500 GPH @ 1 ft head. That would be 8.33 gpm. I think this pump is very similar to the common March 809's seen everywhere.

I was able to pump 5 gallons of cold water in 42 seconds. Using my keen 3rd grade math skills I calculate that to be about 7.14 gpm or about 429 gph. That translates to about a 14% efficiency loss due to restrictions, frictional loss etc. I was expecting much worse performance.

So Slakwhere, you are encountering big time losses somewhere in the system it seems. I would expect you should be able to easily exceed 4 gpm.

are you pumping to a bucket below the level of the vessel? or to another vessel on the same level? pump underneath?

Yes, the kettle I'm pumping out of is about a foot below the receiving bucket. I could easily run the test again with a different configuration if you'd like, but I would expect only a very minor difference in the results. Matter of fact, I will go do it right now. I will raise the receiving bucket to the same level as the kettle. brb.

OK, ran the test a second time with the receiving bucket raised up to the same level as the kettle. The results were nearly identical with the second test taking about 43 or 44 seconds to pump the 5 gallons, although part of that difference may have been due to my slow response hitting the stop watch. Negligible difference really. I'm pumping up over the top of the receiving bucket, so the pump is working against a slight pressure head, but it can't be much at all.

i ran a test in the HLT and it took ~1m to move 1 gallon. i removed the dip tube, cut the tip at an angle and then ran another test. over 2x performance! 5 gal in almost 2.5 minutes.

wondering if my dip tubes were simply too close to the end of the hlt/bk. going to trim them up a bit more and do some more tests.

anybody have a recommended gap from kettle bottom to dip tube?

slakwhere said:

i ran a test in the HLT and it took ~1m to move 1 gallon. i removed the dip tube, cut the tip at an angle and then ran another test. over 2x performance! 5 gal in almost 2.5 minutes.

wondering if my dip tubes were simply too close to the end of the hlt/bk. going to trim them up a bit more and do some more tests.

anybody have a recommended gap from kettle bottom to dip tube?

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A gap of about 1/2" between the end of the dip tube and the kettle bottom should be plenty. That's about what I have in my kettle.

I thought you had pumped at 2 gpm in the first test, not 1 gpm. Did I miss something? It's still at 2 gpm if you pumped only 5 gallons in 2.5 minutes. Try the test with both the dip tube and the tube on the return removed entirely and see what happens. That should reveal a lot.

sorry, the first numbers from the other day were pump. numbers from today were just hose on the end of the hlt. after modifying the pickup tube to no longer touch the bottom of the kettle, i'm getting about 5 gal in 1:30. definite improvement!

opening the ball valve on the BK has the water at a trickle compared to the HLT. going to drain it, cut the pick up tube, and retest it. i bet it's just that i haven't left enough room around the end of the pick up tube for water to flow.

slakwhere said:

sorry, the first numbers from the other day were pump. numbers from today were just hose on the end of the hlt. after modifying the pickup tube to no longer touch the bottom of the kettle, i'm getting about 5 gal in 1:30. definite improvement!

opening the ball valve on the BK has the water at a trickle compared to the HLT. going to drain it, cut the pick up tube, and retest it. i bet it's just that i haven't left enough room around the end of the pick up tube for water to flow.

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That's much better! The 5 gallons in 1.5 minutes would be about 3.33 gpm. I still think you could improve on that considerably and probably well exceed 4 gpm.

just dropped the pump off the brew stand. bounced off the ground and busted the head. end of my experiments till January

slakwhere said:

just dropped the pump off the brew stand. bounced off the ground and busted the head. end of my experiments till January

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Aww man! Sorry to hear about that. Fortunately the replacement heads aren't too expensive, but it's still a bummer no matter how you look at it.

slakwhere said:

just dropped the pump off the brew stand. bounced off the ground and busted the head. end of my experiments till January

Click to expand...

This a 809 March?
Look into a SS Chugger head they were on ebay at $39.95 a direct swap.
Add a March 315 HF impeller (pt# 0809-0107-0200, list $24) a $19 upgrade at March distributors, 12.1' head pump becomes 18.6' head. This is a nice cheap plus a cheap increase.

Catt, your up late, Storage Wars on TV what a hoot.
Wife and I went to a few to check them out years ago.

Hey Carl. Yeah, up late watching this big winter storm blow in. About to fire up the snow blower and get a jump on it. I've got a bourbon barrel aged RIS sitting in the fridge. Might have to break that out as a winter warmer before I venture out. How's the weather out in the bay area? I've been doing a lot of California dreaming here lately. Sure do wish I was out there and not back here in this ****.

My friends in Va. and Ct. are being hammered by snow and cold also.
In my area last week we hit low 70's now the high 50's days low 40's nights.
We'll be into heavy rain later this week and weekend. Nothing new the island's still above sea level. Just have to figure out wifey presents to make up for the fermenter purchase. I was shocked she gave the green light on the purchase, she gave in over the many months looking at what is available.
Stay warm and take care plus beware of this months heating bill. Carl.

yeah i found the chugger SS replacement head on ebay. i had heard they existed, and with the ease in which this one broke i figure SS was the way to go.

what exactly is "head" for a pump? the amount of lift it can pump a liquid? i shouldn't ever have to pump 18' above my pump, but i assume that it means more pressure when i'm pumping at lower head?

slakwhere said:

what exactly is "head" for a pump? the amount of lift it can pump a liquid? i shouldn't ever have to pump 18' above my pump, but i assume that it means more pressure when i'm pumping at lower head?

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Static head is simply the height of the water column (when nothing is moving). This can be easily converted to psi (1 vertical ft = 0.433 psi). Dynamic head includes the frictional losses in the pipes, hoses, fittings etc. The max head with pump in regard to pump specs (performance curves) is the shut off head or max height the pump is capable of, but even though the fluid will reach this height, the flow will be zero. At anything less than the max head, there will be flow and the flow will increase as the head decreases. The rate of change is not linear and that's why the performance curve is necessary. There is also the head on the suction side of a pump to consider which will offset the pressure head on the output side. I may not have this exactly right, but it should be a reasonably close explanation.

that makes perfect sense.

To improve the whirlpool could you put a 1/2" to 1/4" reducer at the end of your whirlpool arm to create a jet?

i may try that as well once the new head gets here

I may sound over the top on pump performance I use two times the flow you think you need. Elevation changes (head) input / output, length of lines plus every fitting especially direction changes like 90 degree fittings restrict flow.
Best part with magnetic pumps you can throttle them down, underpowered
pumps your just flat screwed. A complete system all in 1/2" ID lines and fittings without restrictive quick disconnects will flow properly.