Flow Rates, Pump Size, Chiller's Ability to Cool...

[dfreese]

So I've read far too much at this point.

We have 5x10BBL fermenters, and it seems that the rule of 5-10GPM flow rate per jacket would give us a max flow rate of 50GPM.

However, as I understand it, if the pump were running at 50GPM, you'd need a chiller capable of 90,000 BTUs or something massive like that. I'm trying to figure out now, if I have a unit that would give me 27,000 BTUs with a 1HP pump, would this suffice? It seems to me that by everything I've read that it would, but then I wonder if the system could handle it.

We'd only be crashing one tank at a time, maybe holding one at 34, and the others would be at 68.

How am I misunderstanding the flow rate of this? Thanks!

[jimvgjr]

One quick method to calculate a BTU Load is:
Flow Rate X Temperature Drop X 500.

For example if you have 50 GPM flow from your chiller system, leaving at 25 F and returning at 27 F, the Heat Load can be calculated as:

50 GPM X 2 F TD (27 F - 25 F) X 500 = 50,000 BTU/HR

In regards to Glycol Flow you need to remember it will be rare that all of your vessels will be "calling" for cooling simultaneously, although the 50 GPM is possible and is your Maximum Flow- it's probably more realistic your Design Flow will be about 50% of the Maximum Flow.

I ran your load data and came up with a Brewery Cooling load of less than 15,000 BTU/HR- I think a system rated at 27,000 BTU/HR @ 28 F Glycol and 90 F Ambient would service this load without problem.

Hope this helps, Good Luck.

Jim


Jim VanderGiessen Jr.
CEO, Pro Refrigeration, Inc
253-735-9466 Ext 203
Mobile 253-732-9402
www.prochiller.com
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[dfreese]

Ok. And the chiller I'm looking at has a nominal flowrate of about 8 gpm. Is that too low?

Edit:

http://www.legacychillers.com/cms_da...d_MCS23456.pdf

That is the pump data that I have for the unit I am looking at. Will the 1ms pump (1HP) suffice?

[jimvgjr]

Ok. And the chiller I'm looking at has a nominal flowrate of about 8 gpm. Is that too low?

Edit:

http://www.legacychillers.com/cms_da...d_MCS23456.pdf

That is the pump data that I have for the unit I am looking at. Will the 1ms pump (1HP) suffice?

I'd contact Legacy and ask to speak with someone in their applications department.

Good Luck,
Jim

[v2comp]

I have (6) 3 bbl plastic conical tanks, each with a 120' 1/2" stainless coil suspended from the top and hanging down approximately 8" from the bottom of the cone.
the tanks are insulated with 1 1/4" black closed cell foam insulation basically glued to the tank surface.
can you give me some guidance as to the hp and btu's I might need in a system like this?

[jimvgjr]

I have (6) 3 bbl plastic conical tanks, each with a 120' 1/2" stainless coil suspended from the top and hanging down approximately 8" from the bottom of the cone.
the tanks are insulated with 1 1/4" black closed cell foam insulation basically glued to the tank surface.
can you give me some guidance as to the hp and btu's I might need in a system like this?

For a free load estimate, the best place to start is to fill out our brewery survey sheet. This not only covers the brewery load, but includes additional loads you might consider servicing with your chiller system. The Survey Sheet can be downloaded in either MS Excel or PDf format here: http://www.prochiller.com/reSalesLit.html

I ran a load estimate based on the following:

2 Ea 3 Bbl Active Fermentation at 68 F
2 Ea 3 Bbl Crash Cooling from 68 F to 34 F in 24 hrs
2 Ea 3 Bbl Conditioning/Holding at 34F

Estimated Cooling Load is apprx 3,200 BTU/HR. I added some extra safety factor for unknowns due to coil and insulation properties- but think this is a safe number.

As far as HP, this is maybe 1/2 or 3/4HP. Unfortunately our systems only go as small as 2 HP (rated at 15,000 BTU/HR @ 28 F Glycol and 90 F Ambient), which is probably hard to justify for this application.

Hope this helps and Good Luck,

Jim

[v2comp]

thank you sir, I really appreciate the guidance.