Results 1 to 5 of 5
  1. #1
    Join Date
    Feb 2015
    Location
    UAE
    Age
    26
    Posts
    12
    Rep Power
    0

    Pumped overfeed cooler as dx



    Hi Everyone,

    Can I use a pumped overfeed cooler as DX(direct expansion)
    The scenario is like this, I have a pumped overfeed cooler but I only have some high pressure liquid connection available at the area. Can I connect it to the high pressure liquid line through a hand expansion valve? or a thermostatic expansion valve?. Do I need a distributer..? the available cooler is bottom feed and its 23kW. If anyone have similar experience please help..

    Thanks



  2. #2
    Join Date
    May 2007
    Location
    Auckland
    Age
    67
    Posts
    3,362
    Rep Power
    31

    Re: Pumped overfeed cooler as dx

    Hello Rockie.
    generally liquid over feed evaps are purpose designed for each application. All to do with circuit lenghts and internal pressure increases and flow rates.
    Yes hand expansion valve or electronic pulse expansion valve, by HP liquid do you mean from the existing pump supply?. You should check existing pumping capacity as by adding additional coils you could effect whole system performance, get an engineer to do system re-design calculations first before changing anything.

  3. #3
    Join Date
    Feb 2015
    Location
    UAE
    Age
    26
    Posts
    12
    Rep Power
    0

    Re: Pumped overfeed cooler as dx

    Thanks Magoo.
    By HP liquid I mean supply from the high pressure receiver. I already have 2 DX coolers in the same area with thermostatic expansion valve. Now we are going to add 2 more coolers(we have 2 pumped overfeed cooler with the same capacity in our service stock) but without TX valve. Instead we will use normal hand expansion valve. Is there any problem with this

  4. #4
    Join Date
    Dec 2007
    Location
    australia
    Posts
    2,460
    Rep Power
    27

    Re: Pumped overfeed cooler as dx

    Quote Originally Posted by ROCKY123 View Post
    Thanks Magoo.
    By HP liquid I mean supply from the high pressure receiver. I already have 2 DX coolers in the same area with thermostatic expansion valve. Now we are going to add 2 more coolers(we have 2 pumped overfeed cooler with the same capacity in our service stock) but without TX valve. Instead we will use normal hand expansion valve. Is there any problem with this
    Without modification it would be very crude & capacity not guaranteed unless distributor, as well as circuiting modified.
    Also possibility of high levels in pumped over feed vessel, as any liquid returning from these units could affect levels if plant on low loads.

  5. #5
    Join Date
    May 2007
    Location
    Auckland
    Age
    67
    Posts
    3,362
    Rep Power
    31

    Re: Pumped overfeed cooler as dx

    Hi Rockie.
    With the spare coils in stock , do they have surge/ accumulator vessels attached to them ?
    What refrigerant are you using? What temperatures are required in chiller area ?
    Some photos of stock coils would good.
    magoo

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •