Help me push a lot of air down a long tube

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Help me push a lot of air down a long tube

goodnight mooned: Aug 2, 2007

ANIME AKBAR posted:

Pressure regulators are a new thing to me, can they efficiently drop a compressor output (>50psi) to a very low pressure (<3psi)? Also I don't think I'll be able think I'll be able to put the regulator near the output, so it would be compressor>regulator>long haul tubing>manifold>short haul tubing>heatsinks.

The heatsink fins won't provide too much resistance to the air (they're only about 4" long and 0.5" deep), so I need very little pressure to get a lot of airflow at the final output (I think?).

My basic problem is I don't know the theory behind compressed air and the various devices. My expertise is in electronics, but it seems that compressed gas systems are described in very different terms from electrical circuits.

So let's say I want my total output to be have pressure Pout at some volumetric flow rate Vout. What should my compressor be rated, and how can I account for losses in the tubing/regulator?

The pressure drop is proportional to flow rate and inversely proportional to your tube diameter.

e: I think using an air compressor and pressure regulators could work fine.

goodnight mooned fucked around with this message at 08:27 on Mar 31, 2017

# ¿ Mar 31, 2017 08:23

Adbot: ADBOT LOVES YOU

# ¿ May 3, 2024 10:18

goodnight mooned: Aug 2, 2007

ANIME AKBAR posted:

Now this sounds useful, especially since it addresses another major concern I have, which is that the air from a compressor will probably be fairly warm. Mixing it with ambient air will help.

So combining this compressor with this booster should give me plenty of output, right?

Also with that compressor, will I need to remove moisture from the output even if I'm using a booster?

Yeah but the way these components are specified is really obtuse, especially when they don't distinguish psig from psia, which matters since the pressure at my regulator/booster output is going to be pretty low.

Air pressure at your output is going to be lower than at the input?
Outputs of air compressors are usually defined at 0 bar.

ANIME AKBAR posted:

I'm used to dealing with electrical components, which always come with their own datasheet with curves detailing what to expect under various operating conditions, but for this compressed air stuff they just throw a few numbers at you. I don't know what to expect in specific conditions, aside from conservation of mass and energy, of course.

You should be able to get performance curves for compressors and regulators from the manufacturer, and you can estimate the friction losses through a pipe.

ANIME AKBAR posted:

For the booster above, it says it gives 155-250cfm of output flow with 90psi of input pressure. But isn't that dependent on the pressure at the output port? And my compressor can only deliver 3cfm at 90psi, and the booster has a 12:1 ratio, so I can only expect up to 36cfm at the output. So does that mean this booster is a bad match for this compressor?

That is an air compressor with high pressure but low flow (look at the size of the tank). You don't need 90psi to move air 25 feet.

Are you limited in the size tubing you can run? Because if you can run ducting you could use a centrifugal fan (they can move a lot of air) and avoid using a compressor.

# ¿ Mar 31, 2017 19:48

goodnight mooned: Aug 2, 2007

ANIME AKBAR posted:

I mean at the output near my heatsinks, after whatever booster/regulator I use.
I guess that's one disadvantage of McMaster then. Never seen such documentation from them.
Right, I just need a few psig, I think. But the only thing I could find to directly generate that was the $500 blower in my first post.
I can use maybe 2" for most of the run, but few feet will need to be 1" or less.
Unfortunately there are a lot of bends in the air's path, and this is something that will not be installed permanently. I will have to be able to set it up and tear it down in minutes, so flexible hose/tubing is going to be necessary.

Seems to me you're overthinking this then if you're just aiming for something cheap and temporary.

Go back and read babyeatingpsychopath's solution because he nailed it.

# ¿ Apr 1, 2017 03:16

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Help me push a lot of air down a long tube