Can Tempature Formula

[JGUTE69]

Hello, I am working on developing a new can warming system for my company and I need some help or direction to figure the water temperature needed to raise the overall can and product temp.

We have a can at 32-34 degree F that will enter an enclosed insulated tunnel. The can will have 1-2 minutes of time inside the tunnel and we need to raise the temperature to around 68-70 degree F with-in that time frame. The can will be filled with Beer and the lid applied to it. We will be using spray nozzles over head to shower the cans with hot water. So I basically am looking for a formula or a way to figure out what that temp should be. The cans are 2.6" diameter and are 6.75" tall.

Any help would be super appreciated.

Thank you, IV

 

[MintJulep]

I would start by calculating the total heat required per can. Just assuming magical convection within the beer.

Then I'd check if the necessary convection coefficient on the outside of the can is within the limits of possible.

 

[Latexman]

Falling film heat transfer outside will be pretty good. Natural convection inside will be poor and limit the process.

Good Luck,
Latexman

 

[IRstuff]

There, solved; you just have to figure out how to get 400+ W into the can, continuously

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[LittleInch]

Your OP can be read two ways.

Is this just the can being warmed up before you put the beer in or is the can already full of beer with the lid on?

The higher the water temp the higher the heat transfer. Do you recycle the hot water left at the bottom (you should).

The difficulty if the can is full of liquid is the internal convection inside the can and where the will be any degradation of the bed if it gets warned to much at the edge.

A little more information please.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JGUTE69]

The cans will be filled at this point with the lid applied. We will have approx. 4GPM of water flowing over the cans by use of a Bex nozzle to form a cone spray.

I have done something similar in the past with steam. Would this be the same or would the parameters change? With steam I was heating a cabinet up to 148F degrees and the cans would take a minute and half to raise roughly 30F-34F in that time. I am thinking if I have direct water contact on the cans then the temp of the water could be a bit lower or am I backwards on this.

IV

 

[LittleInch]

I think you could use a lower temp but I would lower them into a bath of water with a counter flow it you're going to do that or maybe roll the cans to increase the circulation within the can.

Steam is remarkably good at doing something like this. Using a hot water spray isn't going to be as good as the heat into the can isn't as good as when it is surrounded by steam and condensate at near 100C.

Or maybe lower in a batch of cans into a water bath with a circulation pump to even out any temperature hot spots.

Absolute minimum additional temperature the water needs to be is about 15F / 8 C higher than your final required temperature. Then it's just a matter of varying the time in the spray / water bath to get to your desired temp.





Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JGUTE69]

LittleInch,
Thank you for the feedback, it is really appreciated. So if I were to pump 120F-140F water over the cans at a higher flow rate, say 16GPM, would that add to the heat dispersion.

Also a continuous flow of hot water should generate a bit of steam as the cabinet is enclosed and insulated so I am hoping this will aid in the heat removal also.

Would Newton's law of Cooling/Heating be the correct formula to use in this instance? Sorry I am completely ignorant when it comes to formulas, as I am really just a mechanical designer. I prefer test methodology as from what I have experienced in the past is you cannot rely on most formulas in real world applications. This is a pretty abstract application.

I a going to throw some cans in my fridge and then spray them with 120F water from my faucet that flows at 1.5GPM in an open air environment to see what temps I get a different intervals. I may have some Styrofoam around I could use to make an enclosure of some sorts.

 

[LittleInch]

Adding more flow increases overall heat input if your water outlet temperature is the same plus it increases the heat input into each can and therefore reduces the time taken to heat it up.

It's more a matter of simple heat transfer and heat capacity calculation. If I was you I would start with a water volume say 15 to 20 times bigger than your can volume. Lower the can into the volume which you have at different temperatures which you insulate to stop too much heat escaping, then measure the temperature of the liquid in the can. To do that I would create a hole in the centre in which I could insert a thermometer and immerse the can almost to the top. Also create some sort of swirl or flow around the can in the water bath to simulate the spray effect.

From that measure temp vs time for different water temperatures.

That will give you some reasonable idea about heat transfer rates from the water into the can at different water temperatures

A water spray at a certain temperature should be pretty close to a water bath immersion provided the can is sprayed from all sides.

Might be a bit better, but I suspect a bit worse than a water bath, so initially add 25% to the time taken from the water bath and you should be good.

I would be surprised if your water temp would be much lass than 80-90 C to heat a can in 90 seconds based on your previous results.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JGUTE69]

LittleInch,
Good afternoon, so I decided to do the worst real world application for my testing. I put 12 cans in my fridge at home. I measured the out of fridge temp at 46F degrees spot on it 4 can that I checked. My faucet has around 35PSI pressure and flows at 1.5GPM and on the hottest is set at 120F degrees almost steady. I simply put 6 of the can direct under the water on a spray setting sitting on the bottom of the sink roughly 6" above the can with no insulation or heat retention and blasted them full pressure for 2 minutes and the average temp rise was 30.2 degrees. I then took the last 2 cans and ran them under 50% of the flow so roughly .75GPM and the average temp raise was 25.25F degrees.

I think with the water at 4GPM coming out of the nozzles, I should be aiming for a higher water temp like 140F, that is about the highest I can run it do to my superiors placing a non metal restriction on the conveyor chain and sprockets. That plus the insulated cabinet should help create a warm atmosphere to bring it up another few degrees. I need about 35 to 38 degrees of overall temp raise so I think I am on the right path.

IV

 

[chicopee]

Sealed cans filled with effervescent beer. The effervescence from carbon dioxide. So what could possibly go wrong when you heat up a gas such as carbon dioxide in a sealed container.

 

[pierreick]

Hi,
Consider this resource to support your work:

https://nzifst.org.nz/resources/unitoperations/httrapps.htm

Good luck
Pierre