Page 1 of 2 12 LastLast
Results 1 to 13 of 17

Thread: Cvhf

  1. #1
    Join Date
    Jul 2006
    Location
    Cape Cod
    Posts
    157

    Cvhf

    Gents I posed a ? about recovering R123. Several responses mentioned they ran the recovery machine over night. I would be concerned about freezing up. Even if the Barrels were Dry. Or am I just a worrier??

  2. #2
    Join Date
    Jun 2004
    Posts
    246
    Dont run it overnight.

  3. #3
    Join Date
    Oct 2006
    Location
    Central Texas
    Posts
    632
    I've been in involved w/ that, as long as you have your pumps (evap&condenser) running freeze up will not occur. The only time I've done this ,or seen this done, was during vapor recovery, all the liquid had been removed. It's always good to be concerned about what's going on, I think you should be worried if you didn't ask anyone. Hope this helps.
    Sic Semper Tyrannis.

  4. #4
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,334
    Quote Originally Posted by txhvac View Post
    I've been in involved w/ that, as long as you have your pumps (evap&condenser) running freeze up will not occur. The only time I've done this ,or seen this done, was during vapor recovery, all the liquid had been removed. It's always good to be concerned about what's going on, I think you should be worried if you didn't ask anyone. Hope this helps.
    yep. run your pumps to get out the liquid, then finish up recovering vapor overnight. never froze up an evaporator before. if you can run your pumps overnight without overheating the loop, it wouldn't hurt.
    "Mother" is the name for God on the lips and hearts of children....The Crow

  5. #5
    Join Date
    Jan 2005
    Posts
    604
    I'm with Nun.
    Never run your equipment unattended.
    Yes, the possibility for freeze-up exists, especially if you are unable to run pumps. Which is generally the case around here.
    I usually try to finish my day with recovering vapour down to 18" hg vac. ( r-11) and let system stand overnight and then finish recovering vapour the next morning. Any time you might actually save by doing it all in one go, can be lost by having only one freeze-up in 10 years.
    I work for a company that pushes for the bottom line on jobs, but would rather not have any problems and call backs, so it's do it right the first time.
    A quote from, where I'm not sure, comes to mind, " why is it that we can't find the time to the job right the first time, but can always find time to do it over again" or something like that. I'm gettin' older and forget how it actually went, but I've never forgoten what it meant.

  6. #6
    Join Date
    Jun 2006
    Location
    Midwest
    Posts
    284
    Have to stir the pot here! Don't need no stinking flow for R123 recovery.
    It's All Good!!!

  7. #7
    Join Date
    Jul 2001
    Location
    maryland
    Posts
    1,355
    I'm with the guy with two first names (JimBob), you guys would piss me off trying to recover gas from a chiller like that. Just drain the barrels. You're gonna push-pull all the liquid out anyway. Have a sightglass in-line with your hoses going to your recovery cylinder. When no more liquid shows in the glass switch to vapor recovery, set the relief on the cylinder and go home.


    -JB

  8. #8
    Join Date
    Jan 2004
    Posts
    1,174
    I wouldn't run the pumps either, or drain the barrels and I always run the reclaim overnight on vapour mode.You should know if you have all of the liquid out of the evaporator and if it is trapped in the economizer or anywhere elso for that matter, it won't freeze up the tubes.

  9. #9
    Join Date
    Jun 2006
    Location
    Midwest
    Posts
    284

    Thumbs up

    Quote Originally Posted by acjourneyman View Post
    I wouldn't run the pumps either, or drain the barrels and I always run the reclaim overnight on vapour mode.You should know if you have all of the liquid out of the evaporator and if it is trapped in the economizer or anywhere elso for that matter, it won't freeze up the tubes.


    Exactly!
    It's All Good!!!

  10. #10
    Join Date
    Apr 2005
    Location
    Boulder,CO.
    Posts
    552
    Typically we use a portable purge on our recovery Tanks also.

  11. #11
    Join Date
    Mar 2004
    Location
    ottawa canada
    Posts
    2,041

    Cvhf

    R123 Recovery. 9yr Trane tech lots of 123 experience .Recover the liquid first using push-pull method into storage tanks. Switch to vapor for overnight no pumps no circulation needed . how can you freeze the tube if theres no liquid to boil off ???????? We use the Trane Evacupac and 650lb Storage tanks. liquid recovery should be about 2/3 hrs for 1000lbs assuming chiller is tight and bundles are at room temp . babysitting the process is only needed if theres air in chiller or lack of storage tanks to allow for possible non- condensables Fill one tank at a time dont daisy chain them together,less chance of leaks on quick connect fittings.Save last tank for vapour process .The colder the water for the condensor on your recovery unit the better .dont put the water through the condensor at full flow it decreases the heat transfer rate .

  12. #12
    Join Date
    Nov 2004
    Location
    North Florida/South Georgia
    Posts
    988

    Why roll the dice?

    Re - tubing a chiller or even part of the tubes is very costly & could be embarrasing if you are the one responsible for it.

    Not trying to stir the pot but I would like to spell out some facts as I know them.

    I think we all agree that we can remove the liquid through push/pull or with a liquid pump or both.
    In my opinion, push pull works fine with large hoses, the truth is, the liquid transfer shouldn't take long anyway.

    You can speed up the vapor recovery with three methods:
    1) modify your recovery unit for large hoses.
    2) modify it to use more than one hose.
    3) circulate chilled water through the condenser instead of munincipal water.

    Now lets talk about when to transfer to vapor.
    It has been stated that a sight glass will reveal if all of the liquid is gone.
    I say this with all due respect, but I completely disagree.

    I would urge everyone, especially if you have a machine with a sub cooler or a water cooled oil circuit to consider the following methods or procedures.

    When you "think" you are done with the liquid, go ahead & switch to vapor recovery.

    Make sure your chilled water pump is on. (cheap insurance)

    Check your temp/pressure conversion chart, when the pressure of the refrigerant you are recovering equals 35*, STOP! Valve off the recovery unit & check that pressure again in 30 minutes, if it rises, there is still some liquid trapped in the chiller somewhere.

    Start recovering again, when you reach 35*, stop, valva off & wait another 30 minutes.
    When the pressure no longer rises, then & only then is it safe to proceed past the point of freezing.

    You should still have your pump on.

    And under no circomstances should you leave it unattended over night.

    While your at lunch or going to get parts & as long as you are close by, its okay to let it run unattended, but only after you have gone below freezing.

    The problems I have with leaving it unattended are many, but just to cover a few; What if someone comes in at night & turns the recovery equip off or what if they change your valves around or somthing like that?

    What if the recovery equipment fails?

    In my mind, leaving it unattended is never a good idea.

    Its up to you to make it idiot proof.

    I'm sure some will think this is overkill, but I would rather error on the side of caution.
    All my leon freaked out!

  13. #13
    Join Date
    Jul 2001
    Location
    maryland
    Posts
    1,355
    Now lets talk about when to transfer to vapor.
    It has been stated that a sight glass will reveal if all of the liquid is gone.
    I say this with all due respect, but I completely disagree.
    You can disagree if you like, disrespectfully even, but I think you're going way overboard. The sightglass WILL show you if there is no liquid in the evap. You can then do a separate liquid recovery on the economizer if you wish, but there are no tubes in the economizer so who cares if there is some liquid trapped there.

    Secondly, if some butt-head bothers your recovery set-up while you're away then they just bought the job. Period.

    I guess we're gonna have to agree to disagree.

    -JB

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event