Attention Engineers... Help please!

[camaronat]

If you can scrounge up a thermo or fluids book from where you work, you should be set.

I imagine if I would die if I knew what gases you were using, then there must be some engineering books around [img]tongue.gif[/img]

[Linxs]

0.28 liter/minute = 0.0098881 cubic foot/minute
Equals
0.0098881 cubic foot/minute = 14.238864 cubic foot/day
About 10 days.. This is just a quick calculation.

I was bored here at work. [img]smile.gif[/img]

[camaronat]

Oh ok. then you have 2 constants.

[camaronat]

The only thing I can come up with is the Bernoulli equation, but I do not remember how to get time into the equation.

[camaronat]

I guess that works, but it doesn't make sense to me. Oh well

[JusFlyinBy]

Originally posted by Linxs:
0.28 liter/minute = 0.0098881 cubic foot/minute
Equals
0.0098881 cubic foot/minute = 14.238864 cubic foot/day
About 10 days.. This is just a quick calculation.

I was bored here at work. [img]smile.gif[/img]

That wont work linxs, because you are assuming the volume is going to decrease. The volume of the gas in the cylinder isnt going to change as you pump the crap out. The pressure will decrease, but not the volume.

And yea camaronat, theres thermo books around here, I was just hopin someone could help me out so I dont have to go to someone else here, look like a fool (even though I am [img]tongue.gif[/img] ), and ask for there book/help.

[Linxs]

Originally posted by JusFlyinBy:
</font><blockquote>quote:</font><hr />Originally posted by Linxs:
0.28 liter/minute = 0.0098881 cubic foot/minute
Equals
0.0098881 cubic foot/minute = 14.238864 cubic foot/day
About 10 days.. This is just a quick calculation.

I was bored here at work. [img]smile.gif[/img]

That wont work linxs, because you are assuming the volume is going to decrease. The volume of the gas in the cylinder isnt going to change as you pump the crap out. The pressure will decrease, but not the volume.

And yea camaronat, theres thermo books around here, I was just hopin someone could help me out so I dont have to go to someone else here, look like a fool (even though I am [img]tongue.gif[/img] ), and ask for there book/help. </font>[/QUOTE]If you are controling the flow at a constant .28 SLM then what's wrong with the calculation?

[JusFlyinBy]

Think about it. You are saying that I have 142 cubic feet of this stuff, and that I am depleting it at .00988 cubic feet per minute. So after one minute, I should only have 142 - .00988 cubic feet of stuff left right? No...

After 10 minutes, I will sill have 142 cubic feet of that gas, just at a lower pressure, correct?

I dont have 142 SCF of this gas, its in a 142 SCF container, is that how I confused you?

[Linxs]

Originally posted by JusFlyinBy:

Check it out. Im using a bottle of mixed gas at 1200 PSI in a bottle with a volume of 142 SCF. I will be using that gas at a flow of 0.28 SLM. So the question is, how long will it take for that bottle to deplete at that flow rate?

(I am just going on logic here, but I do not always approach things with the correct logic)
Accoding to your question:

.28 SLM is your flow rate which is constant. I assume it's self adjusting (electronically)

142 SCM is your space avalable in your bottle.

If you say these are constant and will not change then all you have to do is convert .28 SLM/ per min into SCM/per min. and solve for 142 SCM. Logically this is how I would approach it with constants in the equation.

[JusFlyinBy]

Use what equation?

[Linxs]

Originally posted by JusFlyinBy:
Think about it. You are saying that I have 142 cubic feet of this stuff, and that I am depleting it at .00988 cubic feet per minute. So after one minute, I should only have 142 - .00988 cubic feet of stuff left right? No...

After 10 minutes, I will sill have 142 cubic feet of that gas, just at a lower pressure, correct?

I dont have 142 SCF of this gas, its in a 142 SCF container, is that how I confused you?

But like you said you are controling the flow rate. If you control the flow rate, PSI would not matter in the bottle (untill you were are very low amounts in which case you could not sustain a .28 SLM flow rate). I simply gave an equation based on your constants.
At a constant flow of .28SLM you will deplet your 142 SCF bottle in about 10 days.

[ August 25, 2004, 02:04 PM: Message edited by: Linxs ]

[Linxs]

Originally posted by JusFlyinBy:
Use what equation?

This equation:
At 0.28 liter/minute (flow rate) you will use 0.0098881 cubic foot/minute (just converting Liters per min in cubic feet per min)

still at a constant .28 SLM you'll be using 0.0098881 cubic foot/minute which will be 14.238864 cubic foot/day Converting cubic feet per min into cubic feet per day)

With the above constants you'll depleat your bottle in about 10 days..

[JusFlyinBy]

I definitley understand your logic, but that just, it doesnt seem like that would work, I dunno, im pretty confused right now. I actually have time to get to the bottom of this now, so Ill solve it and let you know if your logic is correct.

[Linxs]

Originally posted by JusFlyinBy:
I definitley understand your logic, but that just, it doesnt seem like that would work, I dunno, im pretty confused right now. I actually have time to get to the bottom of this now, so Ill solve it and let you know if your logic is correct.

Please, I am curious now....

[lastbird]

I work for a flow controll company.
I was just wondering the brand you are useing (stec, units, brooks, etc.)