View Full Version : Whirlpool direction?

02-22-2005, 01:20 AM
Does it matter? (i.e. - clockwise or counter-clockwise). I'm working on the design of the kettle/whirlpool here in Vietnam, still north of the equator (I think 18 degrees north) - the reason I ask is I know water flows down the drain in the opposite direction south of the equator.
My guess is that it doesn't matter, it's being pumped around and the trub pile will form whichever direction one pumps. Or?

Ted Briggs
02-22-2005, 05:34 AM
It seems to me that following the natural course would be best. North of the equater cyclonic, and south anti-cyclonic. Fighting mother nature never works well. Anyone heard of any studies on this?

02-22-2005, 06:54 AM
Direction won't matter. A trub pile is a trub pile. The Coriolis effect is only applicable to macrosystems like the Atlantic Jet Stream. I don't think it will have any effect on your brew kettle.

Luck to ya'

02-22-2005, 02:59 PM
The force is very, very, small.

Check out this web site. Very interesting and quite thorough.


Also was cited in a USA Today article so I will have to trust that he is a real professor and a citable source.


In case you can't take the time my favorite debunking is that the direction dogs turn before lying down has been claimed to be be dependent upon the hemisphere in which they live.

02-25-2005, 07:01 AM
Anyone heard of any studies on this?
Yes, Experiments with a Whirlpool Tank. By G. Van Gheluwe and M. Dadic Molson Breweries published in The Brewers Digest, September 1972

In the study, many factors were studied. Their research showed an increase in sedimentation of 6.2 % by running counter clockwise vs. clockwise.


Ted Briggs
02-28-2005, 06:03 AM
What was thier conclusion for this result??
More fuel for the fire...Which hemisphere was the study conducted in?? Maybe someone should repeate it in the other. Assuming it was in the north maybe one of our Aussie Brewers???

02-28-2005, 11:34 AM
Thanks for posting this question. I've wondered about it since working with a whirlpool that had anti-cyclonic rotation. It had the worst trub piles I've ever experienced also.

I work with a well engineered system now, with cyclonic/clockwise flow. The system is in the Northern Hemisphere. Trub piles are great. Even with dark brews where trub tends to fall apart readily. The diameter is about twice the height dimension. The bottom slope is gentle, towards the outlet, at about 2-3 degrees. The outlet is attached to a "box" which is attached to the floor of the whirlpool. Its dimensions are about 2-3 times the diameter of the outlet pipe.

I remember some research that concluded the inlet velocity is the most important factor, and then the dimensions. Although I can't cite the paper. I can transfer ~20BBLs in about 12 minutes through 3" piping which narrows to 1.5" about 1 foot before the tangential inlet.

I also remember some advice that you can get more yield from the whirlpool by slowing the pump speed near the end, as the trub pile stays together more, or falls apart less quickly thereby giving up more wort with less trub in it. Can anyone verify that in practice?

Good luck with the design, and if anyone has links to a whirlpool design paper, please post.

I'd go with the Clockwise-Cyclonic design!


02-28-2005, 05:36 PM
Which hemisphere was the study conducted in??

The experiments were conducted at the Molson Brewery in Montreal.


Perhaps your brewhouse design is a more significant factor. Excessive velocities will break up trub particles and reduce the quality of your trub pile. Such factors include pumps and piping. Bad design and poor operation (running the pump too long etc.) will be far more detrimental to trub pile formation than which way you pump the wort and the Correolis effect.

Basic Stokes law V=d^2 (S-S1)g / 18m


V is settling velocity

d^2 is the particle diameter squared

S-S1 is density difference of the particle and the liquid

g is the gravitational constant

m is viscosity if the liquid

With this equation you can see the importance of maintaining the trub particle size.

If you shred your trub particles, they will not settle well.

Brauwelt has a nice article about maximum wort velocites in the January 1996 issue.