maximizing shirron efficiency

[dooksh]

brewed using the shirron plate chiller three times with little success.
my last two brew using the shirron went not so good .took me about 40 minutes recirculating to get the wort to 74f. the first time i brewed using the shirron i tried to do one pass and ended up with a 100f wort.

i am using a march pump and an a aquarium pump. filling my 7 gallon bucket using the aqurium pump with water. it takes about 7 buckets full of water + about 22 pounds of ice to get to 74F.

i tested my water and wort flow and came out with this:
march pump - 6 quarts per minute
aquarium pump - 6 quarts per minute
my tap water temp is about 78F
any tips for maximizing my chilling efficiency

 

[samc]

Are you flowing the wort & cooling water in opposite direction? I've had some issues with my plate chiller as well, but the direction of flow is a key part of the process.


edit - don't know if your coolant flow is enough per minute. never did it that slow.

 

[dooksh]

how do i know if my sticker on my shirron (wort in ect..) is taped on the opposite side?
maybe thats my problem

 

[samc]

wort in and water out would be on one end. just make sure you are not putting wort in/water in on the same end.

 

[Bentpirate]

Since you are using a March pump (I have a simular set up); instal a ball valve at the 'wort in' either at the chiller or off the pump and close it part way. Another handy tool is an in-line thermometer. This allows you to adjust the hot wort flow by the temperature on the out side.
It takes me about 15 minutes go from 200 deg. to 72 deg, directly into the carboy waiting for the air pump and pitch.... just a thought

 

[dooksh]

is there any equation that could help me?

 

[Bentpirate]

Not that I am aware of. I keep everything close and in easy reach and throtle back or open up as needed watching the temperature of the wort entering the carboy. Since the pump is magnetic driven it will keep spinning full or wort with out damage. I usually start with opening the ball valve about 1/4 and open / close as needed.

 

[shadowmage36]

Yes, there are equations for counter-current heat exchangers:

Q = U*a*ΔT(log-mean)

Where Q is the heat load across your heat exchanger between the process fluid and the product fluid (water and wort, respectively), U is your heat transfer coefficient (depends on your exchanger's material), and a is your heat transfer area. ΔT(log-mean) is the log-mean temperature differential across your heat exchanger, which you usually want at about 10*C. I've shown the equation for that below:

ΔT(log-mean) = {(T2[feed] - T1) - (T2 - T1[feed])} / ln((T2[feed] - T1)/(T2 - T1[feed]))

T1 and T2 are the temperatures of your product and process fluid, respectively, at the outlet, while T1[feed] and T2[feed] are the temperatures at the inlets. By setting everything you can figure out what your heat flow is in Watts/time, which is the Q value. However, if you want to use a different method, you can also use this equation:

Q = ρ1*q1*C1*(T1 - T1[feed])

Where rho is your wort density, q1 is your wort flowrate, and C1 is your wort heat capacity. For all intents and purposes, C1 can be set at 4.184J/g/K, or 1 BTU/lb/F, depending on what units you like. From these equations and a bit of algebra, you can figure out what temperature cooling fluid you need to go from boiling to pitching temperature in a reasonable amount of time. Please feel free to either keep posting in this thread or PM me with any other questions. I'm a chemical engineer by profession and quite good at these sorts of engineering things.

EDIT: Note that the first heat capacity (constant pressure!) that I listed for water is joules per GRAM per degree Kelvin/Celsius, NOT per gallon!!

 

[dooksh]

thanks shadowmage36 . i am not a very smart man so i cant even try to understand those equations . but i did make a test today and found out that
i need to keep the water flow twice faster than the wort flow.
thanks anyway . will let know how it worked for me

 

[shadowmage36]

If you can get me the following bits of information, I can make you a lovely little excel spreadsheet which will tell you everything you need to know. I can make it with fill-in boxes so all you have to do is input your wort and water temperatures, flow rates, and desired cooling time, and it can tell you what limits you'll have (tell it flow rates and temperatures and it'll tell you how long to cool, tell it temperatures and desired cooling time and it'll tell you flow rates, etc.). All I need from you is the following:

Wort temperature going in
Water temperature going in
Wort temperature going out
Water temperature going out
Water flow rate
Wort flow rate
Material of construction (specifically what the plates are made of. Don't necessarily need this but it'll mean more detail in the final answer)
Heat exchanger area (if you know what that is)

If you can get me that information (except those last two, if you don't know them, they're not exactly needed) then I can make you an excellent sheet that'll give you plenty of information.

This offer goes out to anyone who wants it, btw. I won't guarantee anything, since I'm not a certified professional engineer , but I will say that you should get pretty damn good results from it!

 

[passedpawn]

First, absolutely maximize your water flow. What is the flow rate of your aquarium pump? Those things slow down dramatically with much head pressure, so eliminate any kinks in hoses, etc.

Slow down your wort flow. Usually you can slow that down enough to get one-pass cooling. It might be pretty slow.

If you are only cooling to 70's, you shouldn't even need ice.

 

[shadowmage36]

I'm currently working on a document to explain the four main types of heat exchangers used by homebrewers and how to maximize your efficiency with all of them. With any luck I'll be able to post it later today. I'll hopefully have explained it in a bit more detail than I did here...Sorry about that, by the way. I gave an engineer's answer to the question asked, when I probably should have given the pragmatist's answer (higher water flow rate + lower wort flow rate = faster chilling). With any luck what I'm going to post later will provide enough explanation that the algebra will make more sense!

 

[passedpawn]

gave an engineer's answer to the question asked

I believe this forum is about 50% engineers, so your answer likely satisfied more than you think.

 

[shadowmage36]

I believe this forum is about 50% engineers, so your answer likely satisfied more than you think.

Eh, 50% might be a bit high, but you're right that it's a decent number. And most of them probably have more experience than I do (being only 2 years out of school myself at this point). But I at least try to be helpful!

 

[dooksh]

thanks again shadowmage36. here are some details:
Wort temperature going in - 212
Water temperature going in - about 59 (with a bucket of ice)
Wort temperature going out - about 65
Water temperature going out - didnt check
Water flow rate - 2 quarts per minute
Wort flow rate - 1 quart per minute
the shirron is : 12.5" long, 3" deep, and 2" thick
made of 10 stainless steel plates with copper sheets between each plate.

didnt have much time when i made the test run . so i could be wrong a (degree + quart) or two. thanks again
maybe someone else could write up more exact rates

 

[shadowmage36]

All right, here we go...

Given the information you provided, the water coming out of your heat exchanger should have been around 140*F, giving an average temperature difference (delta-T[log-mean]) across your heat exchanger of about 26.6*F. If you'll recall the equations I posted above, this one:

Q = U * a * Delta-T[log-mean]

shows how much energy you're removing per unit time (minutes, in this case). You're getting about 85.2 kilojoules out per minute, or a rate of roughly 1.42 kW. Not too shabby. That means your U*a value (unique to your exchanger) is about 5.795 kJ per minute per degree Celsius of temperature difference. This works out to about 96.6 W/*C, or 53.7 W/*F. So, for every extra *F of average temperature difference, your heat transfer rate increases by almost 54 watts.

Using those numbers you gave me, as long as you had 40 quarts of water at that starting temperature, for a 5 gallon batch going from boiling to pitching temp, you could do it in twenty minutes. If you wanted to double both flow rates, you probably could, allowing you to chill your whole batch in 10 minutes. I'll be posting more information in another thread at some point later today, and I'll be sure to link to it, so that you can use them as you need to.

Also, dooksh, I'm working up that sheet for you real quick. Would you prefer it to be in *F or *C?

EDIT: Okay, some of those numbers are wrong...Suffice to say, more flow on the cooling side means lower outlet temperature on the wort side. I've fixed the temperature differential now, so all data are accurate.

 

[dooksh]

i Would prefer *C

 

[shadowmage36]

All right then. I'll put the rest of it in metric as well, if you don't mind. Makes my life a hell of a lot easier. All temperatures in *C, all flows in liters/minute, all energy in kJ, all weight in kg. Excellent. Should have it for you in a bit.

 

[Tom]

brewed using the shirron plate chiller three times with little success.
my last two brew using the shirron went not so good .took me about 40 minutes recirculating to get the wort to 74f. the first time i brewed using the shirron i tried to do one pass and ended up with a 100f wort.

i am using a march pump and an a aquarium pump. filling my 7 gallon bucket using the aqurium pump with water. it takes about 7 buckets full of water + about 22 pounds of ice to get to 74F.

i tested my water and wort flow and came out with this:
march pump - 6 quarts per minute
aquarium pump - 6 quarts per minute
my tap water temp is about 78F
any tips for maximizing my chilling efficiency

I would recommend hooking up the water hose to the Shirron first until the wort gets down to the 80s, then start pumping the ice water.