Refrigerated air dryer question
Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 20 of 26
  1. #1
    Join Date
    Aug 2007
    Location
    Florida
    Posts
    147
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4

    Default Refrigerated air dryer question

    I found an old refrigerated air dryer that I want to use but don't really know anything about them. Do these units need to be part of a system of air tanks, ect.. to actually work or can I essentially just hook it inline with my compressor hose and get it to work? It's a really small 110v 10cfm unit and I want to add it in-between my plasma cutter and compressor. Does it take a little bit for these refrigerated units to start working? I would assume It would need to run by itself a few minutes before I could rely on it to condense the water in the line?

  2. #2
    Join Date
    Apr 2004
    Location
    Modesto, CA USA
    Posts
    8,727
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1693

    Default

    Saw one about like that on clist so I looked it up. Best to run 10-15 minutes before air flow so condensor chills down. Probably best to chill as soon as possible so tank stays dry. I would have it run full time so it stays cold regardless of airflow. Not really big enough for constant spraying etc so it has to be before the tank to allow storage of dry air for intermittent use.
    10cfm is around 3 HP.
    Bill D

  3. #3
    Join Date
    Apr 2007
    Country
    UNITED STATES
    State/Province
    West Virginia
    Posts
    1,443
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    639

    Default

    I have one on my air system. It’s a 25cfm or so unit. I have mine between the 25 cfm compressor and my air system. It works. My air system is well designed to drain well but I still used to get water everywhere in the system. Since I put the dryer in I never find any water in the system. I do think it would be better to turn it on 15min or so ahead but I don’t do that. I generally turn the main air valve, compressor, and dryer off at the end of each day and turn them all on at the same time in the morning. I also drain the tank in the morning and at the end of each day.

  4. #4
    Join Date
    Jul 2019
    Country
    UNITED STATES
    State/Province
    Connecticut
    Posts
    30
    Post Thanks / Like
    Likes (Given)
    54
    Likes (Received)
    10

    Default

    We shut the compressor off at the end of every day and leave the dryer running. it actually failed on us for the first time the other week after over 6 years of unmaintained use. we also have an automatic drain valve on the compressor so water build up is never an issue.

  5. #5
    Join Date
    Aug 2007
    Country
    UNITED STATES
    State/Province
    Idaho
    Posts
    2,562
    Post Thanks / Like
    Likes (Given)
    1105
    Likes (Received)
    1403

    Default

    I have one like that I put between the pump and tank so I have dry air in the tank, it works well.

  6. #6
    Join Date
    Nov 2019
    Country
    CANADA
    State/Province
    Ontario
    Posts
    677
    Post Thanks / Like
    Likes (Given)
    1085
    Likes (Received)
    163

    Default

    leave it running, it will turn on and off when needed.
    also dont have it too close to the compressor, about 10ft is sufficent, helps with pulling the heat down which gets drier air output. being right before the plasma input will work fine also but 10scfm seems a little small for a plasma.

  7. #7
    Join Date
    Apr 2004
    Location
    Modesto, CA USA
    Posts
    8,727
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1693

    Default

    Good idea to run multiple feet of metal pipe before the dryer and tank. That will help cool the air before it hits the dryer.
    Bill D

  8. Likes BT Fabrication liked this post
  9. #8
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    8,969
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4339

    Default

    Quote Originally Posted by Bill D View Post
    Good idea to run multiple feet of metal pipe before the dryer and tank. That will help cool the air before it hits the dryer.
    Which is the opposite of what you want but other than that, a wonderful idea ....

  10. #9
    Join Date
    Apr 2007
    Country
    UNITED STATES
    State/Province
    West Virginia
    Posts
    1,443
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    639

    Default

    In a typical system a refrigerated dryer should be after the receiver (tank). The receiver generally is the first step in drying since the air slows down and cools some there. What would be a good addition is to add an air cooler, like a high pressure high flow radiator with a fan between the pump and receiver.

    I don’t leave my dryer on all the time. It’s control is just a thermal switch on the coil. It is insulated but not very well and still will cycle on and off when not in use.

  11. #10
    Join Date
    Aug 2014
    Location
    Wisconsin Rapids WI
    Posts
    492
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    118

    Default

    The OP didn't say what type of dryer he had. If you are not using a tank to cool and take some of the water out of the air, the dryer must be able to handle both the higher moisture content and the higher inlet temperature of that air. The type and capacity of the dryer tell you if you can run it without a tank. Dave

  12. Likes BT Fabrication liked this post
  13. #11
    Join Date
    Feb 2017
    Country
    UNITED STATES
    State/Province
    California
    Posts
    912
    Post Thanks / Like
    Likes (Given)
    9
    Likes (Received)
    376

    Default

    Generally, the dryer is set after the tank/compressor to allow for clean/dry air to be supplied throughout your shop. The goal of the dryer is to provide high quality air for the shop. I turn my compressor and my air dryer off each evening when locking up the shop. If you are concerned about water collecting in your tank, you should install an automatic purge on the bottom of the tank.

  14. #12
    Join Date
    Apr 2004
    Location
    Modesto, CA USA
    Posts
    8,727
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1693

    Default

    Quote Originally Posted by EmanuelGoldstein View Post
    Which is the opposite of what you want but other than that, a wonderful idea ....
    Why would you want to cool overheated air? The goal is for the air leaving the chiller to be below the dew point. If it is too hot going in that small chiller will not be able to cool it down low enough at high flow rates. Yes it will remove more heat at a higher inlet temp but the important thing is the outlet temp after the chiller. Are you saying I have it backwards and dew point or below is not needed for condensation to occur?
    Bill D

  15. #13
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    8,817
    Post Thanks / Like
    Likes (Given)
    2322
    Likes (Received)
    3229

    Default

    My Kaeser "Air Center", self contained 10HP factory built screw with refrigerated dryer and tank. Has the dryer connected immediately after the pump .
    Dryer delivers air to the tank, the tank supplies the shop.....

    Dryer kicks on a minute or so before the pump fires off....System works great.
    Solved the moisture in our air...allows the soda blaster to run without clogging issues.....

    Cheers Ross

  16. #14
    Join Date
    Sep 2002
    Location
    People's Republic
    Posts
    6,440
    Post Thanks / Like
    Likes (Given)
    757
    Likes (Received)
    3825

    Default

    I have had driers after the tank and before the tank

    Right now I have an IR compressor unit with remote tank, drier between

    4 years, not a drop of water in the tank. Or anywhere.

    Ever

    I think I will take the dry tank

    Old setup 5hp vertical with HF drier, water in the tank, but dry lines

  17. Likes kustomizer liked this post
  18. #15
    Join Date
    Apr 2007
    Country
    UNITED STATES
    State/Province
    West Virginia
    Posts
    1,443
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    639

    Default

    Quote Originally Posted by AlfaGTA View Post
    My Kaeser "Air Center", self contained 10HP factory built screw with refrigerated dryer and tank. Has the dryer connected immediately after the pump .
    Dryer delivers air to the tank, the tank supplies the shop.....

    Dryer kicks on a minute or so before the pump fires off....System works great.
    Solved the moisture in our air...allows the soda blaster to run without clogging issues.....

    Cheers Ross
    Of course i don't know anything about this compressor but similar compressors I've seen in the past will use an aftercooler stage, built into the box, before the dryer, then the receiver.

    Air comes off the compressor very hot it makes absolutely no sense from an energy efficiency perspective to have a refrigerated dryer as your first drying step. Much more efficient to use some means of air cooling first.

    Where I used to work we had a very large compressed air system with 5 200hp atlas copco screw compressors. These systems had the drier before the receiver. In this case they were desiccant dryers and would dry the air to a very low dew point. These compressors had various air coolers internally with automatic drains on the coolers to condense as much water out before the dessicant dryer.

  19. #16
    Join Date
    Aug 2007
    Country
    UNITED STATES
    State/Province
    Idaho
    Posts
    2,562
    Post Thanks / Like
    Likes (Given)
    1105
    Likes (Received)
    1403

    Default

    I have 4 - 3hp quincy pumps taking turns, then 18 feet of ziz zag pipe into a 10 cfm refr dryer into a 120 gal tank, never a drop of water in it. Dry air everywhere, I like it. I can run 5 cnc Haas machines on one 3 hp quincy at any one time which is harder than I tend to want to work.

  20. #17
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    8,969
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4339

    Default

    Quote Originally Posted by Bill D View Post
    Why would you want to cool overheated air? The goal is for the air leaving the chiller to be below the dew point.
    Wull, this is not going to be popular but ...

    Temps in Kunshan in summer run high nineties, low hundreds. But the worst part is, relative humidity must be 90% ? You can drink a gallon of water a day and not pee, but the sweat pouring off just soaks your clothes. It's not an easy situation for getting dry air.

    Originally it was set up as some people suggest (there's two differing views on this out there, not just me being contrarian). Air from compressor (30 hp Sullair in this case) into a receiver with auto-drains then to a smaller refrigerator then out to the system. (It was a big loop in our case, had proper drops and all that.)

    It didn't work for doodly. I'm not so sure this dew point thing is the magic people believe. For one, the air is highly compressed, which changes the dew point drastically. For another, does all the water fall out instantly at the dew point, or does a lot get carried along in the flow of air, which can be pretty speedy if you are feeding several air-gobbling machines ? Maybe you really want to go considerably below the dew point, to extract as much as possible ? And then pull the air for your machines from the driest possible place, rather than off a refrigerator which has air flowing through it at high speed ?

    I swapped the reefer to right after the compressor, went for the max temp drop and to hell with the dew point, then stored the driest air we could get in the receiver. I can't see that storing wet air is a good idea. Kept the auto-drains (don't think they actually work that well, did it manually on a schedule as well) and we got way less water out of the receiver (as you'd expect) this way.

    It made a large improvement. This runs counter to one of the popular air-drying theories but worked way better for us, in a nasty environment.

  21. #18
    Join Date
    Apr 2007
    Country
    UNITED STATES
    State/Province
    West Virginia
    Posts
    1,443
    Post Thanks / Like
    Likes (Given)
    886
    Likes (Received)
    639

    Default

    Quote Originally Posted by EmanuelGoldstein View Post
    Wull, this is not going to be popular but ...

    Temps in Kunshan in summer run high nineties, low hundreds. But the worst part is, relative humidity must be 90% ? You can drink a gallon of water a day and not pee, but the sweat pouring off just soaks your clothes. It's not an easy situation for getting dry air.

    Originally it was set up as some people suggest (there's two differing views on this out there, not just me being contrarian). Air from compressor (30 hp Sullair in this case) into a receiver with auto-drains then to a smaller refrigerator then out to the system. (It was a big loop in our case, had proper drops and all that.)

    It didn't work for doodly. I'm not so sure this dew point thing is the magic people believe. For one, the air is highly compressed, which changes the dew point drastically. For another, does all the water fall out instantly at the dew point, or does a lot get carried along in the flow of air, which can be pretty speedy if you are feeding several air-gobbling machines ? Maybe you really want to go considerably below the dew point, to extract as much as possible ? And then pull the air for your machines from the driest possible place, rather than off a refrigerator which has air flowing through it at high speed ?

    I swapped the reefer to right after the compressor, went for the max temp drop and to hell with the dew point, then stored the driest air we could get in the receiver. I can't see that storing wet air is a good idea. Kept the auto-drains (don't think they actually work that well, did it manually on a schedule as well) and we got way less water out of the receiver (as you'd expect) this way.

    It made a large improvement. This runs counter to one of the popular air-drying theories but worked way better for us, in a nasty environment.
    It does make good sense to get rid of as much water out of the air prior to the receiver as possible. It doesn't make sense to use a refrigerated dryer as the first step. This would be like using a refrigerated cooler to cool your car engine. Sure you could do it by why not use the ambient air which is relatively much cooler as a first step.

    Akg C-1835BG $255.83 Air Cooled Aftercooler, Max HP 10, 35 CFM | Zoro.com

    The reason the receiver is generally used as the first step to drop the water out in smaller systems is that this is the cheapest option and is very effective.

    I have a little book from ingersoll rand on compressed air system design and all the trade-offs. It has lots of great info on the subject. It's a shame companies don't seem to publish things like this anymore.

  22. Likes BT Fabrication liked this post
  23. #19
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    8,817
    Post Thanks / Like
    Likes (Given)
    2322
    Likes (Received)
    3229

    Default

    Quote Originally Posted by Pete Deal View Post
    Of course i don't know anything about this compressor but similar compressors I've seen in the past will use an aftercooler stage, built into the box, before the dryer, then the receiver.

    .

    Pete:
    You are correct...i did not mention the aftercooler in my description and indeed there is one air/air cooler with a directed forced air setup...
    Thanks for pointing to this important component and its position in the air steam.
    Cheers Ross

  24. #20
    Join Date
    Apr 2018
    Country
    UNITED STATES MINOR OUTLYING ISLANDS
    Posts
    8,969
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4339

    Default

    Quote Originally Posted by Pete Deal View Post
    The reason the receiver is generally used as the first step to drop the water out in smaller systems is that this is the cheapest option and is very effective.
    But then you are rotting out your receiver and also I am convinced by seeing it in practice that in a hot environment, the water in the receiver goes back into the air, then you have to remove it again. Basically a receiver is a little ocean and sky in a closed environment. We know how that works.

    In practice, in a hostile environment, the other way worked much better for us. (And it's not just me, there are other places as experienced as Ingersoll who recommend the same thing. I'm not smart enough to invent this, just smart enough to try it.)

  25. Likes AlfaGTA liked this post

Tags for this Thread

Bookmarks

Posting Permissions

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