Fluid Mechanics Help Please

[smilinggilroy]

test 002 has sneeked through the firewall

Yeah.. can somebody piss this idiot off -QUICKLY!!

 

[MHB]

I agree with the first part of your comments speedie, Copper is many times better a conductor of heat than is stainless steel. Both have their advantages and disadvantages but Copper is undeniably better at transferring heat (Link Thermal Conductivity), you can use much thinner Stainless as its stronger but its much harder to work and the list goes on...Its a personal call, tho I will say every commercial brewery made limits the use of copper to decoration and keeps it the hell away from the beer.

A little copper can catalyse protein condensation in the kettle, if it is still in the beer after the kettle it accelerates Permanent Haze formation in packaged beer. Generally its strongly recommended to not allow any copper into contact with beer. That said there are probably some very minor requirements for copper in trace amounts as there are for Molybdenum, Phosphorous and Zinc, for mash enzymes, that doesnt translate into chunks of metallic copper being good for beer.

 

[Acasta]

A little copper can catalyse protein condensation in the kettle, if it is still in the beer after the kettle it accelerates Permanent Haze formation in packaged beer. Generally its strongly recommended to not allow any copper into contact with beer. That said there are probably some very minor requirements for copper in trace amounts as there are for Molybdenum, Phosphorous and Zinc, for mash enzymes, that doesnt translate into chunks of metallic copper being good for beer.[/size][/font]

PERMANENT HAZE you say? Now I'm throwing out my copper chiller Haha. Do you think a copper coil in the boil for 15min and then cooling for 30min could have negative effects?

 

[bonj]

If you use polyclar/gelatin or any equivalent post fermentation clarifying aid, the copper's catalysis (didn't know that was a word, but I tried it out and firefox speller says yes! ) probably won't do much harm. I'd say that on the average homebrewer's scale and consumption rate, it will probably go unnoticed.

Copper is also avoided in commercial breweries because it corrodes with hot caustic, which the commercial brewers love for various reasons. Aluminium doesn't fare too well with caustic either, even though it is also a far better heat conductor than stainless steel.

 

[MHB]

I used a copper chiller for years, am about to move to a stainless counterflow. It isn't one of those things that's going to make a huge change to your beer, nor would I be in a hurry to change it if I had a copper chiller.

donburke has made a choice, like we all do, on balance I think it's a good choice. Copper in an acidic environment like a wort has its downsides, one of them is that it can decrease the stability of your beer. As Bonj said acting to reduce the Haze Forming potential of the wort will reduce the effects, as will reducing the amount of copper in/downstream of the kettle, I can't see gelatine having any effect, PVPP defiantly will.

For me it one of those incremental changes, brewing involves hundreds of small steps, each of them has an effect on the finished beer, individually they might make little or no apparent difference, cumulatively it can make a huge difference. If I can keep making choices that favour better brewing well I should be making better more consistent beer, and for me that's what it's all about.

MHB

 

[manticle]

MHB - any likelihood copper will affect beer pre-boil (eg copper manifold, brass fittings etc) or is it just post-kettle you are referring to?

 

[bonj]

MHB - any likelihood copper will affect beer pre-boil (eg copper manifold, brass fittings etc) or is it just post-kettle you are referring to?

possibly. but any protein it brings out will likely get coagulated in the boil.... so it may even be a benefit. It has been shown to darken your wort though, which is why no-one uses copper boilers anymore (they just clad the outside in copper to make it look pretty.

 

[michael_aussie]

my 2 coils arrived today, as soon as i got home i made a bodgie join of the two coils in series,

and another bodgie coupling to the garden hose, all consisting of some gaffa tape

well it leaked, and i got squirted a fair bit,

even with these leaks i managed a flow rate of 4 litres a minute through 32 metres of 6mm id coil

now the next question is, will it improve flow rate if i connect the coils in parallel ?

all things being equal (roughly the same inlet set up, roughly the same outlet set up, same inlet pressure, no limit in the source flow) two identical paths in parallel will always give more flow than the same two paths in series.

 

[Tony]

Fluid and electricity are much the same.

for a given quantity (voltage or pressure) the amount that gets through (Current or Flow/volume) is dependant on resistance in the line.

2 x 1 ohm resisters in series will give you 2 ohms
2 x 1 ohm resisters in parallel will give you 0.5 ohms.

So i recon you will get roughly 4 times the flow with them in parallel

let us know

 

[donburke]

Fluid and electricity are much the same.

for a given quantity (voltage or pressure) the amount that gets through (Current or Flow/volume) is dependant on resistance in the line.

2 x 1 ohm resisters in series will give you 2 ohms
2 x 1 ohm resisters in parallel will give you 0.5 ohms.

So i recon you will get roughly 4 times the flow with them in parallel

let us know

well i wont get to find out,

ends up being that the only practical configuration i can get is to use approx 20 to 25 metres of the stuff, in series, stretched slightly to allow flow between the coils,

might use the balance as a pre-chiller

still in progress and will post some pics/results when i have them

 

[donburke]

Why am I thinking I need some Gucci gear
GB

bling attracts bling, the gucci was drawn to the shiny stainless steel coil

 

[donburke]

i installed the coil in the kettle today, ended up using 24 metres of 8mm OD 6mm ID stainless pipe

the flow of tap water exiting the coil was 4 litres per minute

the flow of water (will be wort) being pumped from vessel to vessel through the coil using the march pump was just under 1 litre per minute

i will soon find out how functional it will be as a cooling coil / herms coil

 

[donburke]

i'm resurrecting an old thread, sorry, but its mine

ok, so all this talk of botulism has got me wanting to start chilling my beer again,

i have been no chilling when brewing during warmer weather, as it takes forever to get the beer down those last 10 degrees, works well in winter when temps are cooler, but no good in summer

so i have this glycol chiller sitting in my cellar, making my font look all pretty, with 2 product coils sitting in it that arent being used, so i'm going to try running the cooling water through the product lines en route to the immersion chiller

i can use tap water to get me down to say 40 or 50 deg, then use chilled water, or alternatively, i can use the chilled water from word go

i have a question ...

will 3 degree cooling water chill my wort down much quicker than say 22 degree water during the first half of chilling (say 100 down to 50) ? or is the difference only going to be apparent as i approach the cooler temps ?

 

[mark0]

i have a question ...

will 3 degree cooling water chill my wort down much quicker than say 22 degree water during the first half of chilling (say 100 down to 50) ? or is the difference only going to be apparent as i approach the cooler temps ?

At 100degC, should make a 24% increase in cooling rate
100-22=78
100-3=97
(97-78)/78=0.2436=24%

At 50degC, should make a 67% increase in cooling rate
50-22=28
50-3=47
(47-28)/28=0.6786=67%

At 30degC, should make a 237% increase in cooling rate
30-22=8
30-3=27
(27-8)/8=2.375=237%

This in not a linear increase, as the wort temp drops the benefit increases. An average of 67% across the 100 to 30degC range.

 

[Robbo2234]

I have been thinking the same thing, my plan is to go from the tap into a immerision chiller in a esky with ice and then into a counterflow to do the wort chilling. I dont know how effective it will be but i suppose there is only one way to find out!

 

[cdbrown]

I have been thinking the same thing, my plan is to go from the tap into a immerision chiller in a esky with ice and then into a counterflow to do the wort chilling. I dont know how effective it will be but i suppose there is only one way to find out!

Now you got me thinking that I could use the miracle box I have (got 3 of them) to pre-chill the tap water before being run through the immersion chiller. The current water temps out of the tap means I only get down to 30c and then it's up to the fridge to help that last bit. Having the pre-chilled water will be similar to winter temps and help get the temp down further (and slightly faster).

Good thinking don and robbo

 

[Robbo2234]

I dont know what salt would do to your coils but if you add some salt in your esky you can drop the water even colder, salt water freezes at a lower temp

 

[Robbo2234]

or even if your game stick some glysol in your freezer a few days before!
but I think that poisonous so i wouldnt do that!

typing before thinking!

 

[sim]

I pre-chill water in my fermenting fridge, but always start with tap water. If it doesnt put a strain on the glycol machine then using it from the start would be awesome!

 

[donburke]

At 100degC, should make a 24% increase in cooling rate
100-22=78
100-3=97
(97-78)/78=0.2436=24%

At 50degC, should make a 67% increase in cooling rate
50-22=28
50-3=47
(47-28)/28=0.6786=67%

At 30degC, should make a 237% increase in cooling rate
30-22=8
30-3=27
(27-8)/8=2.375=237%

This in not a linear increase, as the wort temp drops the benefit increases. An average of 67% across the 100 to 30degC range.

excellent mark, clear and concise calcs, thank you

looks like i will benefit where i need it most, i.e. last 10 / 20 deg


i bought the fittings this afternoon, and hooked it all up,


i am using both coils in parallel (hopefully to decrease resistance if it works the same as electricity)


i have approx 8 metres of garden hose from tap to glycol chiller and approx another 8 metres from glycol chiller to immersion chiller

turned it on for a test run, flow rate was good, water was coming out very cold, glycol tank temp increased from - 3 to about 6 deg for the few minutes with the tap fully open


looks like it will involve a bit of trial and error with tap flow rate so as not exhaust the cooling capacity of the glycol chiller (its rated to chill 50 litres per hour from ambient to 3 degrees or something along those lines)