Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. EricKvaalen

    Thermocompressor design

    I used to have a spreadsheet for that, but I would have to search old disks for it. You can contact me through my site Eric_Kvaalen.com
  2. EricKvaalen

    critical phase behaviour of hydrocarbon and water mixtures

    If the water stays essentially in its own phase, then the hydrocarbon phases will act pretty much as though the water weren't there. So if the temperature is sufficiently high, the hydrocarbon phases will combine into one supercritical phase. (The minimum temperature for this to occur depends on...
  3. EricKvaalen

    Multiple RO's in series

    First a comment to sshep--adiabatic does not mean constant enthalpy. If the gas does some work or accelerates, then its enthalpy decreases even if no heat is transferred out of the gas. (I think this is what hacksaw was saying.) Now some comments on the calculation of a series of orifices. When...
  4. EricKvaalen

    Multiple RO's in series

    I agree that for adiabatic flow you get critical flow easily, without a long, narrow pipe. But achieving the isothermal case would be tricky. If you simply add the required heat before the orifice, then the temperature will increase in the part where you add the heat, but then as the gas goes...
  5. EricKvaalen

    Multiple RO's in series

    I think you're talking about a situation in which the heat transfer between the gas and the environment is very high so that the temperature stays the same even as the gas accelerates to a high speed. This would require some combination of very narrow tubing and a slow decrease in diameter to...
  6. EricKvaalen

    Multiple RO's in series

    CatBoy, you haven't told us how you made out with your analysis of this problem. Just wondering. http://Eric.Kvaalen.com
  7. EricKvaalen

    Multiple RO's in series

    I agree that the temperature will go down a bit (perhaps even a lot in this case--I haven't done the calculation). In fact that's what I said in my post of March 27th. The speed of sound is of course a function of the temperature. But what matters for my argument is not the speed of sound in...
  8. EricKvaalen

    Multiple RO's in series

    P.S. The fact that the temperature goes down somewhat as the velocity increases after each orifice does not change the validity of the argument. The speed of the gas if it gets to Mach 1 in an orifice is determined by the stagnation temperature, not by the actual temperature. And the stagnation...
  9. EricKvaalen

    Multiple RO's in series

    It's true that I simplified a little. The truth is that if the gas has a high velocity in the pipe (I'm not talking about in the orifices), its temperature will be lowered a bit, and so the temperature at the end (where the velocity is highest) will be a bit lower than at the beginning. I...
  10. EricKvaalen

    Multiple RO's in series

    You will not have choked flow in all three orifices. If any is choked, it will only be the last one (as EGT01 guessed would be the case). The temperature in the pipe will be constant (except in the vicinity of each orifice). This means that the speed of sound is the same for each section--in...
  11. EricKvaalen

    Multiple RO's in series

    For any flow rate, you can calculate the pressure upstream from the third orifice, and then the pressure upstream from the second, and finally the pressure upstream from the first. (This is possible because for each orifice there is a relation between flow rate, downstream pressure, and upstream...

Part and Inventory Search

Back
Top