Hello, I'm a student who's new to the brewing industry and I'm having a little trouble with how I would design a whirlpool. I'm amazed at some of the knowledge pouring out of these message boards so thought this would be a good place to post my problem!
I hope you can help me with some tips on how to design a whirlpool for large scale operations. I'm talking about a wort inlet flow of about 100'000 kg/day!
This is for a little project I'm doing with my friends so we already know the basic mass balances but designing the equipment to meet these balances is more difficult. Any help would be much appreciated!
All of the following quoted from various sources:
Whirlpool preferred height/width ratio of 0.8/1. Hot wort is injected tangentially, at about 30 degrees to the tangent to the vessel wall, often at a rate of about 3.5 m/s.
Larger vessels often have slightly convex bottoms (trub pile sits up on the hump) with wort outlets placed at 2/3 full volume , 1/3 full volume and at the side/bottom of the vessel. Sometimes a trub dam or stand pipe will be required depending on vessel design/effectiveness. You may also consider a screen filter prior to the heat exchanger further downstream.
Pumps used to drive the wort from the copper to the whirlpool should exert minimal shear and not disrupt the trub. Care should be taken not to over circulate the wort as this will disrupt the trub.
In large volume vessels, coriolis forces may cause eddies in the whirl. Direction of whirl should be considered ( ie. are you north or south of the equator)
Hope this gives you some food for thought.
Cheers for the reply Liam! I found the angle and rate of injection particularly useful. Would you or anybody else happen to know the working volume of a whirlpool? Say would you stop the injection when you reach 80% of the tanks capacity?
Also economically speaking would it be best for a brewery to use two whirlpools? So when one whirlpool is being emptied/cleaned, the other one can be filled.
For whirlpool vessels, typically there is little (10% or less) head space. Most I've seen typically fill to lowermost level of sprayball/jet assembly.
The number of whirlpools necessary for any given operation will depend on the number of vessels in brewhouse. ie. are there more than one of each of:
1/ Mash mixer
2/ Lauter tun/wort separation
It also depends on mashing schedule etc. Also depends on required productivity of facility. A hot wort holding tank can sometimes come in handy if available fermentation space is ever delayed. Not recommended to leave it in the whirlpool for too long.
Usually, one whirlpool is sufficient in a four vessel brewhouse. With multiple systems, come multiple whirpools.
Cheers! you seem to know your stuff! I'm guessing you work in a brewery, which one?
My project is probably best as a single system! From my whirlpool volume (5 m3), the duty required per hour (38 bbl US), the injection time (15 mins) and the velocity of the wort (3.5 m/s) which I'm going to locate 2/3 of the way up the tank.
Does anyone know what would be a decent schedule for this whirlpool? I'm guessing about an hour for each 'batch' of wort..
15 minutes filling, 20 minutes settling, then the rest emptying and cleaning so it's ready for the next load. (This is for Ale)
There seems to be alot of variations in this procedure. I guess it depends on lots of variables like the type of beer, amount of hopping, dimensions of the tank, particles sizes etc.
You name it, I've probably worked there.
Generally speaking, all whirlpool procedures are very similar. Regardless of the size.
You're on the right track it seems.
In terms of brewhouse scheduling, I would suggest you take a look at Malting and Brewing Science Vol. 2 and/or The Practical Brewer to begin to understand resource scheduling and manipulation in a busy brewhouse. It's not difficult, but it can be very dynamic and changeable. You need to design flexibility into your brewhouse schedule for many reasons.
Type of beer is largely irrelevant. However, on the 'out' side, you should size your heat exchanger/cooling system to be able to 'cool in' in (ideally) less than 45 minutes. Whatever the batch size.
Cheers for all the info Liam, it did help me get off on the right track! (Well at least I hope so) I've been spending so much time on this project over the last few days that I haven't had enough time to go to the beer festival in town I'm handing this section in on Monday so life will get back on track shortly
I couldn't find the books you recommended anywhere but I found these ones quite useful...
The Biotechnology of Malting and Brewing - J.S. Hough
Handbook of Brewing - William A. Hardwick
PS Do you have any idea how much these vessels cost? I can't find any quotes anywhere!
Last edited by Cougar; 04-22-2007 at 02:54 PM.
What size of vessel are you talking about. I could probably give you a reasonable estimate. You mentioned the figure of 100 000 kg of wort per day. this figure is vor how many brews? 4, 6 , 8 , or more?
That's ok it's only a very rough estimate at this stage & I'm handing this in pretty soon so I'm going to calculate it by its cost/kg of stainless steel. Anyway it's a 6m3 vessel made from stainless steel with a wall thickness is 5mm. By number of brews do you mean number of fermentations?
A 60 hl total capacity vessel - lets assume that you are putting in 50 hl wort (5m3) then this means 20 brews / day to achieve 1000 hl / day. I think you have a mismatch in your figures - are you sure you mean 100,000 kg / day ? At 10,000 kg / day, this is sensible for a smallish setup, you would fill and empty with 2 brews / day. If this is a start-up, I suspect even this is ambitious. You are talking about producing approx 10,000 litres of beer a day - again, are you sure you have the scaling correct ?
My gut feel is that 5mm thick stainless steel is overkill - but the construction guys such as JVNW (I think I've got their name right) would be better able to specify materials
Hiya thanks for your concern you are right that there was a slight problem with my sizing. The size of a whirlpool needed for a 1000hl batch would just be too big. It could handle that demand in a day but it would be holding up the fermentation stage. If I understand correctly this is not good for the quality of the wort.
Originally Posted by dick murton
I'm doing this as part of a big design project I've been assigned at university. Since I was only in the preliminary stages of design I had time to turn my attention towards designing a hydrocyclone. They can handle a big brew (1000hl/hr) and they take up a much smaller space.
I just got a bit confused with the brewhouse scheduling!
Now it is reasonably late on Sunday night after a couple of beers, but I am even more confused. What batch size are you trying to deal with ? How many hectolitres ber brew, how many brews per day ? Residence time in a whirlpool - try a max of 20 minutes transfer into WP, absolute max of 30 minute stand, and then 45 minute transfer to FV time. + trub emptying / flushing time - say 2 hour turn round time.