Air elimination demo

hot_rod · February 20

I built this demo, 1" copper tube running 8.8 gpm, room temperature.

30- 35% glycol.

I pump 1/2 tube of air from the hand air pump. Run until the fluid turns clear.

The Discal cleared the fluid 100% within 20 minutes.

I switched to the ramp purger, wit 18" upstream piping for best performance. I ran it for an hour and 15 minutes and the fluid is still cloudy, foam.

Switched back to the Discal and same 20 minute result to clear the air microbubbles out.

I'd guess maybe 20% of ramp purgers are properly installed with 18" straight piping upstream, making performance even worse.

I'll try the demo tomorrow with plain tap water for comparison.

Screenshot 2025-02-20 at 3.27.32 PM.png

Screenshot 2025-02-20 at 3.27.21 PM.png

ethicalpaul · February 20

You know I love this! time lapse video of the 20 minute one requested please!!

Edit: I like it so much I'm going to paste the images inline so people don't have to download them. The forum software here for some reason doesn't always make the images inline…I think maybe if you import them with the button they don't get inlined. Not great!

mattmia2 · February 20

I think my parents had that bike pump except it got thrown out when it broke instead of those numerous repairs.

hot_rod · February 20

https://forum.heatinghelp.com/discussion/comment/1843906#Comment_1843906

This one has a piece of Heatway Entran tube on it! It made a great air hose.

hot_rod · February 20

https://forum.heatinghelp.com/discussion/comment/1843902#Comment_1843902

I'll film it tomorrow and send it to Ray for a Boiler Room Detective post.

How do I make it a time lapse? Using my I-phone for the video.

ethicalpaul · February 20

Cool thanks! This document describes how, toward the bottom in the Time Lapse section:

https://support.apple.com/en-my/guide/iphone/iph61f49e4bb/ios

RascalOrnery · February 20

Neat, I love stuff like this. Do the micro bubbles cause boiler and components to rust or is that more large quantities of air?

hot_rod · February 20

https://forum.heatinghelp.com/discussion/comment/1843920#Comment_1843920

within the air bubble is some oxygen. The o2 contacts ferrous metals and oxidizes or rusts the metal. So the more you eliminate on start up the lesser the oxidation potential

Ideally within a short period of time the 02 in a sealed system becomes consumed and corrosion stops. You have what is called “dead” water. Water that is starved of oxygen.

However Mother Nature hates imbalance, so 02 will try and continue to migrate into closed oxygen starved systems. It does this through Pex tube, yes even with oxygen barriers. Around seals and packings, valve stems, pump seals, butyl diaphragms in expansion tanks. The hotter the fluid, the higher the rate of O2 ingress.

So you want an efficient, working air separator working all the time. Because rust never sleeps.

Some hydronic installers are going all non ferrous. Stainless boiler, stainless expansion tanks, stainless or composite circulators, copper or plastic piping.

The other option is to use a hydronic conditioner that has oxygen scavengers in the blend. As these get consumed, additional inhibitor is added occasionally

Open type Outdoor wood boilers, the plain steel type, are a classic example of a system needing constant scavenger maintenance.

Additionally the air bubbles or pockets reduce the ability of the fluid to transfer the energy from the boiler and heat emitters

IMG_9737.png

EBEBRATT-Ed · February 21

Glycol will always foam especially when pushing the velocity. The air will probably leave the water much quicker.

PC7060 · February 21

https://forum.heatinghelp.com/discussion/comment/1843902#Comment_1843902

I’ve often pondered why some folks attach pictures versus posting in page using the picture icon. Ford versus Chevy thing?

mo8414 · February 26

Thats pretty cool. Reminds me of a spirovent but looks like it might work even better.

hot_rod · February 26

I believe Spirotherm was the originator of the microbubble resorber type of air separator. Many have followed.

The Caleffi Discal has a large chamber, the low velocity zone. The bigger the chamber the more you slow the fluid to grab the air. Larger composite media inside. Very easy to disassemble and clean or replace top cap. You can see the needle valve and remove dirt/ rust or teflon tape particles, the two main reasons a vent dribbles.

I can actually hand tighten these pieces together with the fine thread o-ring seals it holds pressure.

Not much technology inside the scoop or ramp type "camelback" air purgers. A low velocity zone with some deflectors to move bubbles up and out.

mattmia2 · February 26

not much inside of either. i assume you're mostly paying for the brass

Air elimination demo

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