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  1. #1
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    Dec 2001
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    Cleaning the water side of a DX chiller evaporator

    I have a customer with a York W1LC420 chiller. The evaporator bundle is plugged. There is a new flow switch. It will not close. This is a glycol chiller, chills glycol for their process equipment. They have lost one compressor already and we found that the oil pressure switch was bypassed and the old flow switch was corroded/stuck and also bypassed. Chiller requires 55 GPM, the pump is good for 110 GPM, the impeller and piping are clean/clear.

    So how successful can we expect to be with chemicals to clean the water side of the bundle? Not the refrigerant side. No punching tubes. This system is using a 50/50 mix of propylene glycol. The reservoir in the plant had no cover for many years and they had sludge/dirt in the bottom of the reservoir. No strainers going to the chiller so now the evap is plugged.

    The chiller is from 1999 so 20 years old, one bad compressor and a plugged bundle. Maybe time to look at a new chiller? I hate to throw in the towel but also don't want to waste the customer's money. If anyone has experience with cleaning this please let me know what I can expect. 5 PSI going in, ZERO PSI coming out. Close the discharge valve and we do see the 5 PSI on the outlet. There is some flow but not enough to close the flow switch.
    R2B4BTU

  2. #2
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    Nov 2011
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    Interesting, I never knew they made that condenser frame into a liquid cooler. Those units as condensers were always a pain.

    first you have to figure out what's in it, then get with a treatment specialist to figure out the best chemical for the job. we use safety scale 888 for scale, but that prolly isn't scale buildup. you could attempt an acid cleaning.

    those shells prolly have baffling of some kind to direct the water through the barrel, and if the crap is impacted into the baffling, I doubt you'll have much luck.

    How large is the piping inlet? at 55 GPM, prolly very small. you could try puling the piping, and look inside, might get lucky and be able spray, or mechanically remove the blockage.


    If it were me, and it was my customer, I would give several options.


    1: we can attempt to clean the barrel, but cannot promise A: how long it will take, or what it will cost, and B: the attempt may be unsuccessful.


    2: we can attempt to source a replacement heat exchanger. Plate and frame heat exchangers are very affordable, and could easily be installed on that unit. However, if the system is still dirty, the possibility of plugging a plate and frame is VERY high. so the replacement may fail sooner than later.


    3: stop sinking money into a 20 year old unit. It's reaching the end of its' life expectancy, and at 40 tons, a replacement will likely be cheaper than what it might cost keep the old girl ticking.


    personally, I would push for option 3.

  3. #3
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    Apr 2003
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    Did you take a pressure drop across the bundle, look in the bundle from piping end, how nasty is the water - is it black, muddy or skinks. If the bundle is blocked the system has to be nasty also. Get with a local chemical treatment company to get some right cleaner circulate and flush. This job can be a lot of hours if it's any size.

  4. #4
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    Try strong rydlyme solution with a utility pump and a garden hose fitting adapted to a 5 gallon bucket, recirculate the rydlyme and keep adding more as ph increases.
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  5. #5
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    Quote Originally Posted by valdelocc View Post
    Try strong rydlyme solution with a utility pump and a garden hose fitting adapted to a 5 gallon bucket, recirculate the rydlyme and keep adding more as ph increases.
    Why not use the system pump?

  6. #6
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    Quote Originally Posted by jimp View Post
    Why not use the system pump?
    The point is to isolate the HX and clean just that part of the loop containing the chemical exposure to where is needed, also it would take a lot more chemicals to fill the whole loop and circulate it using the system pump, I prefer to keep a visual on the return to the bucket, see how much crap is coming back, that's the way I always done it !
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  7. #7
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    rydlyme chemical is a descaler we don't know what typ e of blockage this is has. If its dirt it won't touch it.

  8. #8
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    Quote Originally Posted by servicefitter View Post
    rydlyme chemical is a descaler we don't know what typ e of blockage this is has. If its dirt it won't touch it.
    Rydlylime works fine dissolving mud and dirt, I have used it to clean dirt from open loops and it got the job done! http://www.apexengineeringproducts.c...ons_7Jun16.pdf
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  9. #9
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    Quote Originally Posted by valdelocc View Post
    The point is to isolate the HX and clean just that part of the loop containing the chemical exposure to where is needed, also it would take a lot more chemicals to fill the whole loop and circulate it using the system pump, I prefer to keep a visual on the return to the bucket, see how much crap is coming back, that's the way I always done it !
    Normally the open systems I clean have shut off valves to the process with a bypass. That way I can run the Citranox or rydlyme and all the unwanted crap ends up in the tank.

    Another thing to think about is, if the chiller h/x is plugged, I wonder how plugged the process h/x's are.

  10. #10
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    Quote Originally Posted by jimp View Post
    Normally the open systems I clean have shut off valves to the process,........
    I service some systems that don't even have barrel isolation valves, there isn't such "normally" around here
    There is not better place for the working men than the union! 100% UA the only HVAC union!

  11. #11
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    Install a pot feeder this one of many brands
    https://www.coolingtowerchemicals.co...r-p/cw-nep.htm

  12. #12
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    Quote Originally Posted by valdelocc View Post
    Rydlylime works fine dissolving mud and dirt, I have used it to clean dirt from open loops and it got the job done! http://www.apexengineeringproducts.c...ons_7Jun16.pdf
    What i read about the product didn't go far enought looks like a decent product.

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