×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

small refrigeration/evaporation device

small refrigeration/evaporation device

small refrigeration/evaporation device

(OP)
I need a way to cool water flowing through a 1.5mm ID tygon tube.  It needs to be something pocket-sized, and I am having trouble coming up with anything like this.  Any suggestions?  Thanks.

RE: small refrigeration/evaporation device

Thermoelectric chiller?  A chemical "ice pack?

To beter give you an answer we need:  1 How much water, 2 how quickly, 3 How big a pocket, and 4 any restriction on what it can have in it (nuclear power devices, batteries, fuels...)

RE: small refrigeration/evaporation device

(OP)
1. the amount of water is small, enough to be pumped quickly through 12 ft or 1.5mmID tubing.
2. needs to cool it at a fast rate, but the deltaT is only 5 degrees F
3. I am hoping to find something 3"x3"x.75"
4. restrictions are that it should be safe to carry on your person.  So, nuclear power, acidic, heavy batteries, etc. I cannot use.
Once again, thanks for the help.

RE: small refrigeration/evaporation device

aquarium chiller?
peltier cooler?

RE: small refrigeration/evaporation device

Quote:

1. the amount of water is small, enough to be pumped quickly through 12 ft or 1.5mmID tubing.
means what picoliters?

Quote:

2. needs to cool it at a fast rate, but the deltaT is only 5 degrees F
  means what?  nanoseconds? femtoseconds?
TE cooler is one choice.  Another would be Freon, CO2, or N2, or Ar.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

RE: small refrigeration/evaporation device

Well, that leaves us only moderately more enlightened, Dawn6 - throw us a freakin' bone, will ya?  Put some numbers to the how much and how fast figures, even if they are order-of-magnitude guesses.

Thermoelectric coolers - see melcor.com, or better do a google search for that term, or peltier coolers like mac says.

Ice packs are pretty common - look in your local drug store or athletic supply store.  Commonest reaction is mixing ammonium nitrate with water.  If the water coming out of your tube need not be pure, consider mixing the nitrate directly.  Um, caution: buying large amounts of nitrate may get you questioned by authorities.

RE: small refrigeration/evaporation device

(OP)
Okay, I just did a little experimental test and I have a flow rate of 35mL/min through my tubing.  However, I can put it in a reservoir in line with the tubing to slow it down.  Sorry I can't provide many details as I am just trying out ideas at this stage and only need ideas of possible mechanisms that would work.  

RE: small refrigeration/evaporation device

a can of 1,1,1,2 tetrafluoroethane would do the trick, just make sure you get the pure stuff that isn't diluted like the home "freeze sprays" use. the dilution agent doesn't evaporate like the tetrafluoroethane. (it has a boiling point below -40deg)

something like this
http://www.techspray.com/newinfo/1672.pdf

Luck is a difficult thing to verify and therefore should be tested often. - Me

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources