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Just wondering

Posted: Thu Jun 18, 2009 8:25 pm
by Knotz
Me and my friend stumbled upon this crazy idea because he has a fish tank air pump battery powered compressor and when you take it out it works like a gem suck in air form the back then pumps is forcefully through an exit tube do you think this is a good idea to install on the back of a rifle so the air pressure will constanly refill

Posted: Thu Jun 18, 2009 9:01 pm
by mark.f
Uh,

What do you think?

Posted: Thu Jun 18, 2009 9:02 pm
by thedeathofall
I doubt it would get much pressure. Does it have a pressure rating on it, saying how much and how hard it pumps?

Posted: Thu Jun 18, 2009 10:02 pm
by TurboSuper
No, it would be good for clearing crumbs off your keyboard though.

Posted: Thu Jun 18, 2009 10:07 pm
by Knotz
TurboSuper wrote:No, it would be good for clearing crumbs off your keyboard though.
it says on the box its pumps 15 gallons/1.5 secs

Posted: Thu Jun 18, 2009 10:11 pm
by jmadden91
Thats not a measure of how much pressure its good for mate

Posted: Thu Jun 18, 2009 10:25 pm
by Hotwired
Pumping air down through a dozen or so inches of water doesn't score too highly in my book :P

Still, if you want to be certain, seal off the end with a pressure gauge and let it go for a bit.

Posted: Thu Jun 18, 2009 10:39 pm
by spencetron
That would totally never pump to ANY useable pressure.

Posted: Thu Jun 18, 2009 10:41 pm
by noob of noobs
Small electrical pumps that are meant to dish out high pressures into tires usually fail; they burn out under the heavy volume of air spudding requires.
I doubt the fish pump will be able to do much better.

Posted: Thu Jun 18, 2009 11:47 pm
by THUNDERLORD
Dang thread got me thinking of using a fridge compressor to airate a huge fish tank now. :P
Problem is I have no space for one, or any fish.

Hmmm...maybe I could run water through one and build a fountain outside(???)

I suggest looking around for an old refridgerator, freezer, air-conditioner etc. and read in how-to section Poland_Spud's post.

I found one on a fridge (working) and one on a spring water dispenser (like new) same week.
Be careful, they put out more than PVC stuff can handle if filled to high. 8)
C'Mon 1000th post! :lol:

Oh BTW, welcome to SF's, soon you'll know the difference between a "wanker" and a "poofer"...[/joke] :P

Posted: Fri Jun 19, 2009 12:39 am
by awkward poop
its not really worth it mate, unless you use the air pumps that people with large fish breeding set ups have which run to multiples of 8+ tanks. those get pricey so you would get a better price and performance from a fridge compressor.

Posted: Fri Jun 19, 2009 1:09 am
by THUNDERLORD
awkward poop wrote:its not really worth it mate, unless you use the air pumps that people with large fish breeding set ups have which run to multiples of 8+ tanks. those get pricey so you would get a better price and performance from a fridge compressor.
It would probably take a compressor from a large air-conditioner for 8 tanks.
Might be a problem keeping it lubricated too since it would exhaust into the tank also. Or maybe a little of the tanks water (?)

I am curious about running water through one, since the refrigerant enters as a gas and gets compressed into liquid anyway.

IIRC HVAC/science is that it changes from liquid to gas (at indoor radiator).
The heat moves towards it leaving the air cold(since the heat moved).
It transfers the heat with it (to the outside radiator).
And gets mashed (compressed) into liquid again...repeat...
(there's a metering device on the indoor radiator for liquid flow regulation). edit: and heat pump reverses the flow.

Was thinking about the theory today for an expansion chamber to prevent freezing issues with CO2...YMBASI.

Yeah, maybe I could use one for a small garden waterfall or fountain bird bath size thing (And No not a cherub pissing)... :P
Or a small pressure washer(?)

I'll be careful with the wiring, I was anxious to see if it worked and almost shocked myself on open wires once already. :shock: 8)

Posted: Fri Jun 19, 2009 1:13 am
by Technician1002
THUNDERLORD wrote:
awkward poop wrote:its not really worth it mate, unless you use the air pumps that people with large fish breeding set ups have which run to multiples of 8+ tanks. those get pricey so you would get a better price and performance from a fridge compressor.
It would probably take a compressor from a large air-conditioner for 8 tanks.
Might be a problem keeping it lubricated too since it would exhaust into the tank also. Or maybe a little of the tanks water (?)

I am curious about running water through one, since the refrigerant enters as a gas and gets compressed into liquid anyway.

IIRC HVAC/science is that it changes from liquid to gas (at indoor radiator),
the heat moves towards it leaving the air cold(since the heat moved), it transfers the heat with it (to the outside radiator), gets mashed (compressed) into liquid again...repeat...
(there's a metering device on the indoor radiator for liquid flow regulation).

Was thinking about the theory today for an expansion chamber to prevent freezing issues with CO2...YMBASI.

Yeah, maybe I could use one for a small garden waterfall or fountain bird bath size thing (And No not a cherub pissing)... :P
Or a small pressure washer(?)

I'll be careful with the wiring, I was anxious to see if it worked and almost shocked myself on open wires once already. :shock: 8)
FYI, It doesn't turn into a liquid in the compressor. Compression heating raises the temperature above condensation. This then goes to the condenser where it is cooled to the condensation temperature and it gives up lots of heat and turns back to liquid. (the hot coil)

Posted: Fri Jun 19, 2009 1:37 am
by THUNDERLORD
Technician1002 wrote: FYI, It doesn't turn into a liquid in the compressor. Compression heating raises the temperature above condensation. This then goes to the condenser where it is cooled to the condensation temperature and it gives up lots of heat and turns back to liquid. (the hot coil)
(I was editing to add some "."'s instead of commas and spaces)
It's too late to get my books out now.
I was wondering about fluid inside the compressor because IIRC that's bad for it(?) But IIRC, they burn up from leaks ,running dry.

I thought the compressor increases the pressure so right as the gas is exiting (maybe end of push(?)) it has the pressure needed to become liquid despite it's temperature???

Thanks Tech, this helps me visualize it better.
I'll check it out more tommorrow.
I have some capillary size copper and a copper (expansion chamber?) looking part on it. Was thinking of connecting bike filler to test temperature change today. 8)

EDIT: Remember heat moves to cold.
when you touch something cold, your hand feels cold because the heat is leaving, so I prefer my explanation that the heat of inside air moves to the coil making the room feel cold and the heat is released outside.
Or opposite for heat pump.

Posted: Fri Jun 19, 2009 3:29 am
by inonickname
Don't even consider it. The only pressure it's made for is to pump past a small depth of water, and they are often so small that flow is insignificant.