Apologies for vagueness. A compressed air motor does work, in this case 1KW worth. A nozzle just sits there and restricts the gas flow, with no apparent work being done. The energy removed from the system is the same in both the case of the nozzle and the motor. So where did the available energy...
Assume a compressed air motor, whose input power 1 cubic metre/minute at 200 psi. The motor exhaust is say, 20 psi at the appropriate volume say 10 - 11 cubic metre/minute. The motor produces 1KW due to its inefficiencies.
Suppose the motor is replaced with a nozzle whose flow rate is the...
hi experts
This ought to be obvious but it sounds wrong.
If I have a pipe carrying butane at a constant flow rate at room temperature fed from a liquid gas bottle without a restrictor so that the gas is almost condensing, then have a constriction in the pipe to accelerate the gas, will...
Hi pixel01
Thanks for your reply. Could you just clear up a few points for me.
Is n the number of moles of gas in 1 m3 ?
Is E the answer in Watts ?
Presumably I need to work out the amount of energy for the incoming gas and subtract the amount of energy left in the exhaust gas taking...
Hi All
I'm trying to work out a method to determine the efficiency of a compressed air motor.
Obviously I can measure the input pressure and flow rate of the compressed air, and I can measure the output power of the motor with a dynomometer.
What I want to know is how much energy is...
Hi
I'm really interested in the liquid properties. I can do the gas stuff (mostly, when I get the sums right :-0 ).
I'm interested in the change of density between 353k (448.9psi) and 293k(124.6 psi).
I thought as it was a liquid it was incompressable thus the pressure didn't matter...
The question is not as trivial as it might at first seem. It could be by volume (tricky for gases with changing pressures), by mass, by atoms as I suggested earlier. As any of these will yield different results it seems a pretty arbitrary thing.
Bitman
"A Copper test is performed much as you would test for chlorine residue. A level of copper in the range of 0.15 through 0.20 ppM"
The above is an extract from a page on swimming pool ionisers. The ionisers produce copper ions for water cleaning purposes.
0.2ppM (parts per Million) - I...
I think that gas expansion of the injected vapour will cause the overall temperature to fall.
I also think that heat of condensation will cause the temperature to rise.
So that if the heat lost in expasion of the added vapour is greater than the heat gained by condensation the temperature will...
Hi
Thinking about it that makes sense. OK Now for the tricky question.
If the vapour that was to be added to the vessel was at a higher pressure, using an expansion nozzle the vapour would expand and absorb heat energy.
Is this true ?
If so how can I derive (Anyone derive ?) a...
Hi Helios
Wiki says
"enthalpy changes of condensation are always negative (heat is released by the substance)."
but finding out by how much is not easy as the energy released varies with pressure and temperature (looking at the wiki page)
I think I'm going to have to do a great deal...
So just to confirm. If I add vapour to the vessel some of the vapour will condense (to maintain the vapour pressure) and the temperature will fall.
This seems counter intuitive as when we have a barbeque the gas being used by the barbeque cause a drop in temperature of the cylinder. But in...
Hi
I have a fixed volume container which holds gas under pressure in a part liquid/part vapour form at normal temperatures.
If I add additional vapour to the container it should condense to increase the liquid level, however the vapour pressure should remain the same.
Would this cause...