Thread: Heat Exchanger coil for compressed air line

In the MWF we were discussing ways of removing moisture from compressed air and I posted a picture of a finned copper heat exchanger one of my BILs gave to me some years ago. I was looking for ways of adapting this to my reticulated compressed air system. The two main problems were, no room inside the shed to mount the pipes, and where to put the drains. QCInspector suggested I stretch the coils into Z'eds and mount it sideways outside the shed with a single drain on the lowest part of the copper.

Here is the original heat exchanger
Cufinmedpipe3.jpg

First thing I needed to check on was the pressure rating. I contacted the Solar Engineer BIL who gave me this heat exchanger a few years ago and he said when new this finned copper tubing was rated at 25 bar so I figured running at 8 bar might be OK.
I plugged one end up and connected it to the compressed at 8 bar and turned the air pressure on remotely - no bang, and pressure stayed good for 5 days.

Then I had to see if the 180º rounded corners would bend back apart to create angled horizontal runs - no problem (see below) I could bend them by hand more than enough.

Then I needed to bend the short section marked with the red arrow through 90º so it was no longer bent.
There was no way this could be bent easily so I heated the corner with a propane torch and then stuck a 300 mm long steel bar partially down inside tube and it bent easily enough.

Mounting on the outside wall of the shed was tricky because "side on" the heat exchanger was quite floppy, so I made up some temporary brackets/spacers to hold everything at the right angles. I had found these beaut little pipe wall offsets in my stash that were made for 19mm pipe (the 1/2" pipe plus fins makes the ID of the heat exchanger pipe 23mm) but there was enough meat in the green plastic material to allow for a 23 mm opening to be drilled.

Red arrow in this one shows where compressed air line enters shed and a second drain is located.
CUpipe1.jpg

View the other way. You can just see the compressor enclosure and the red arrow in this one points to a temporary manual tap/drain for the exchanger pipes.
CUpipe2.jpg
I will replace the tap with some sort of a solenoid that I can activate inside the shed although it might be easier to allow any water to drain back into the compressor tank as this already has an automated solenoid on it.

Think I might need something different though.

Haven't had time to test it - did some chainsaw work for youngest bro this morning and I'm stuffed.