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  1. #1
    Join Date
    May 2004
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    Under The Milky Way
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    York YT never seen one like this

    A chiller we have been working on this week....It had problems. We were told by the technicians on site that it was "losing oil" as there was no puddle on the floor we deduced that it was in the evaporator and logged. The high approach and slightly lower back pressure suggested this. Discharge superheat looked OK at 22degrees F. There was no charge of refrigerant in the machine, oil was at the bottom glass on the sump. We evacuated the machine and left it standingwith a Torr gage on there. Then we were instructed to run the machine. I know that the charge removed was short (by at least 100kg). Others had leak tested the machine and so we put in new refrigerant (R123). Got the oil halfway up the second glass and thought we would run the machine up to full load and get the oil back, then adjust the levels etc until all came back to normal. Machine started up, and then after a while pumped the oil from the sump. We had all sorts of problems getting any oil back. Initially we did seem to be having a little bit of luck at full load, but that was short lived. The refrigerant in the cooler was very flat with foaming and not really any of the usual effervescence, so I know we have a heat exchange problem and then only a 4 degree C TD on the chilled water confirms this. Then we noticed the refrigerant had turned a muddy brown color and noticed rust in it, so the inside of the shell must be rusting. It turns out that the chiller had been left opened up after a rebuild a while back. The oil pick up isn't getting oil back either. I am actually concerned that this may be a bearing fault as well, so we shut the machine down. The evap is a flooded one so how is this ever going to get cleaned up, and this rust "powder" is probably in the condenser as well, which might explain the high head pressure.... I've never seen one like this, and can't decide what to do with it..
    A problem shared is a problem halved

  2. #2
    Join Date
    Sep 2007
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    What vintage machine are we talking about , the rust internal on that machine as you said could have been from being open for awhile but I would think that there were other causes for the rust , you could install a clean up kit on the evaporator to clean up the chiller refrigerant. Sounds like you need to spend some time with this Chiller.
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  3. #3
    Join Date
    May 2004
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    Quote Originally Posted by york56 View Post
    What vintage machine are we talking about , the rust internal on that machine as you said could have been from being open for awhile but I would think that there were other causes for the rust , you could install a clean up kit on the evaporator to clean up the chiller refrigerant. Sounds like you need to spend some time with this Chiller.
    The refrigerant looked like dirty water, with a reddish tint. I haven't had the problem before, but as well as that the thing that concerns me is that the oil isn't coming back to the sump. Apprently the techs on site have kept adding oil, but I can't get it back. They maintain that when the refrigerant was removed the oil was seperated, but my worry is that either there is a bearing problem, or something else. On a 20+ year old machine, there comes a time to think about knocking it on the head. It used to be a R11 machine and was retrofitted.
    A problem shared is a problem halved

  4. #4
    Join Date
    May 2001
    Location
    Western Wa
    Posts
    1,864
    The first order of business is to check the oil return eductor for debris plugging the gas line.
    If there's any doubt on the oil return drier, change it.

    Start with the ABCs and go from there.

    Get the flows within spec. Do an oil analysis to see what's going on.
    Get the unit tight if it isn't.

    With that much oil logging you may have to distill the refrigerant.
    God Bless our Veterans

    God Bless the USA

  5. #5
    Join Date
    Dec 2008
    Location
    Dixiana, AL
    Posts
    2,611
    Your purge foul gas line check valve is defective, more than likely. No need to explain, if you know the YT then you can envision the scenario with the fill and drain timing, and then suddenly you lose the oil in about 2-3 minutes. Powdered rust in the oil is an abrasive and will cause lots of problems with lots of things, including this. The other thing that can cause this is a balance piston seal that is either missing or so worn it might as well not be there. Could be something in the bearings, but normally that won't manifest itself in a time cycle loss - once the oil pump comes on, you lose the oil.

    Even on a retro'ed machine, if you had any load at all on the thing, 22* sounds a little high on the discharge SH (not if it was unloaded). What's your evap approach? It sounds like these issues are playing off of each other. Has anyone opened the evap by removing the suction 90 and checked the condition of the mist eliminators? A machine that sat open and developed acid (of which fine, powdered rust is a sign) will eat the eliminators out of the screens and deposit the leftover material under the distributor plate to act as a restriction to refgt flow, causing high disch SH and high evap approach.

    A standard molded core desiccant filter will not remove powdered rust if used in a cleanup kit because the micron rating is not small enough. You can put a standard configured cleanup kit on and modify the filter shell to accept a 1 micron wound yarn filter and that will take the rust out of that stream of liquid, but you'll never get the rust out of the shells without "pickling" the barrels, and that generally means it's less expensive to make a doorstop out of it and get another one.

  6. #6
    Join Date
    Nov 2006
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    US
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    112
    I like the door stop idea. CYA

  7. #7
    Join Date
    May 2004
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    Quote Originally Posted by klove View Post
    Your purge foul gas line check valve is defective, more than likely. No need to explain, if you know the YT then you can envision the scenario with the fill and drain timing, and then suddenly you lose the oil in about 2-3 minutes. Powdered rust in the oil is an abrasive and will cause lots of problems with lots of things, including this. The other thing that can cause this is a balance piston seal that is either missing or so worn it might as well not be there. Could be something in the bearings, but normally that won't manifest itself in a time cycle loss - once the oil pump comes on, you lose the oil.

    Even on a retro'ed machine, if you had any load at all on the thing, 22* sounds a little high on the discharge SH (not if it was unloaded). What's your evap approach? It sounds like these issues are playing off of each other. Has anyone opened the evap by removing the suction 90 and checked the condition of the mist eliminators? A machine that sat open and developed acid (of which fine, powdered rust is a sign) will eat the eliminators out of the screens and deposit the leftover material under the distributor plate to act as a restriction to refgt flow, causing high disch SH and high evap approach.

    A standard molded core desiccant filter will not remove powdered rust if used in a cleanup kit because the micron rating is not small enough. You can put a standard configured cleanup kit on and modify the filter shell to accept a 1 micron wound yarn filter and that will take the rust out of that stream of liquid, but you'll never get the rust out of the shells without "pickling" the barrels, and that generally means it's less expensive to make a doorstop out of it and get another one.
    I did have a suggestion of semtex. From what I know, the problem has been going on for 3-4 months. Last year it had a re-build. Normally I would think this to eliminate the bearings, but I am concerned with this rust, which looks like a powder as some was removed and shown to me. The eductor (apparently) was blown out with nitrogen. Personally I would have removed and checked more thoroughly. Hadn't considered the purge foul gas line though...I am at the point where I don't want to take the risk trying to fix this and coming out of it with no result.
    A problem shared is a problem halved

  8. #8
    Join Date
    Jan 2008
    Location
    windy city
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    machine will rot from the inside out. have a 19C that is dying a slow death. pull about (2) 5 gal. buckets of rust out of it annually

  9. #9
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    May 2004
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    Quote Originally Posted by heavymetaldad View Post
    machine will rot from the inside out. have a 19C that is dying a slow death. pull about (2) 5 gal. buckets of rust out of it annually
    I agree with you. Any fix that we might do to this York is going to be a temporary thing. It might last 2 years, 2 months, 2 weeks. The only real long term fix is a replacement. To get the rust out I think you would end up using industrial vinegar or similar and as someone earlier said (I think Randy S) "pickling". I might do an oil analysis, if I can find any of it to analyze and go from there. I hate to charge money for something that looks hopeless.

    Klove, Discharge superheat at 85% 14.3 degrees C, at 97% 12.2 degrees C. Approach is too high 3.5 degrees C (flooded cooler).......Apparently the eliminators were checked, but again I am going on what I have been told.

    Forgot to mention that after it's re-build I was told it was started up and then the motor blew up, so there would most probably be a big acid clean up on as well.
    A problem shared is a problem halved

  10. #10
    Join Date
    Oct 2003
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    tidewater, va
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    2,147
    motor blew up...that should be an open drive, bungle. if it is, acid wouldnt have come from there, right?


    r404a

  11. #11
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    Dec 2008
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    Dixiana, AL
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    Quote Originally Posted by bunglebear View Post
    I agree with you. Any fix that we might do to this York is going to be a temporary thing. It might last 2 years, 2 months, 2 weeks. The only real long term fix is a replacement. To get the rust out I think you would end up using industrial vinegar or similar and as someone earlier said (I think Randy S) "pickling". I might do an oil analysis, if I can find any of it to analyze and go from there. I hate to charge money for something that looks hopeless.

    Klove, Discharge superheat at 85% 14.3 degrees C, at 97% 12.2 degrees C. Approach is too high 3.5 degrees C (flooded cooler).......Apparently the eliminators were checked, but again I am going on what I have been told.

    Forgot to mention that after it's re-build I was told it was started up and then the motor blew up, so there would most probably be a big acid clean up on as well.
    You gotta look at where I'm from, bear. I ain't smart enough to convert C to F in my head What 404 said is rite. No acid from the motor, but I don't think you need any more from what you've explained here. Powdered rust is a surefire sign of copious amounts of acid. Pickling is circulating citric acid thru the shells to clean them, you're correct. And it's a long and laborious job. Wait 'til nobody's lookin' and throw a handful of broken glass up into the motor intake fan. Motor won't last much longer and it'll give 'em an excuse to get rid of the thing.

  12. #12
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    Jan 2008
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    windy city
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    heard of pickling, don't know how it's done, but crunchy vlasics are tasty

  13. #13
    Join Date
    May 2004
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    Acid is from the rust, not the motor.....

    I think 12 degree C discharge superheat is about 22 degree F and 3.5 degrees C appraoch would be 6-8 degreees F.

    Either way, it's going to be too expensive to repair properly.

    There used to be a pickles place in Waco called Big Georges.....very good fried pickles
    A problem shared is a problem halved

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