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  1. Roberttt

    Adiabatic expansion in cilinder

    Hi, I am working on an adiabatic expansion problem. The problem is that air got compressed and after it is compressed it expands and cools to a certain temperature what causes icing on instruments in the process. I tried to calculate it with the following formula: p11-gamma * T1gamma =...
  2. Roberttt

    Unsteady state heat transfer in an aerosol can

    @LittleInch Can't I calculate the hc factor by calculating the Nusselt number (with Prandtl number and Grashof Number), and then h=(Nu*k)/L ? When I do that I find a h value from 312 W/m2K. And I am a bit stuck of what the exact meaning is of the characteristic time. I need this value to...
  3. Roberttt

    Unsteady state heat transfer in an aerosol can

    @EdStainless The cans are not being shaken. I have looked at that already but the Fourier Number is too low to use the Heisler Chart. I got a heat transfer book that says that there is another way to calculate it, so that is what I did and I found a time of around 35 seconds to heat up the LPG...
  4. Roberttt

    Unsteady state heat transfer in an aerosol can

    @LittleInch I already did it that way and got an end temperature of 55 C, but because I want to get to know more about unsteady state heat transfer I'd prefer to calculate it on the theoretical way as well.
  5. Roberttt

    Unsteady state heat transfer in an aerosol can

    The thickness of the can wall is 0.20mm (0.00787 inch).
  6. Roberttt

    Unsteady state heat transfer in an aerosol can

    @chicopee: Are these cans filled with the propellant LPG and the substance that is labeled on the tank for the buying customer are tested in the water bath? Yes, the cans are filled with LPG, those cans are tested in a waterbath. Is the water temperature staying the same while the cans travel...
  7. Roberttt

    Unsteady state heat transfer in an aerosol can

    Hi, Since I'm working in an aerosol packing manufacturer, I've been looking to a heat transfer problem. Here is a description of the case: The filled aerosol cans with propellant LPG need to be tested to make sure that they do not fail when heating the can up. As you can see on aerosol cans...
  8. Roberttt

    Mixing problems

    May I ask you what you mean with mechanical mixing?
  9. Roberttt

    Mixing problems

    Here some information: Htank = 2.5m Dtank = 1.8m Vtank = 5.828 m3 Himpeller from bottom = 0.5m Hsecond impeller from bottom = 1.5m Dimpeller = 0.6m D/T = 0.34 (looks correct to me!) I do not have more data yet about the mixer. Will do some research tomorrow. I did also some other research...
  10. Roberttt

    Mixing problems

    Hi, So I am optimising a mixing tank to mix a few compounds with each other. We only got some problems during the mixing; For some reason the propeller only mixes the centre of the tank and not the sides of the tank as well as at the base of the tank what leads to a heterogeneous mixture. A...
  11. Roberttt

    LPG blend in a closed vessel

    Thanks @rense! Just a quick question; If I want to calculate the number of moles in the headspace with n = pV/RT, is p the vapour pressure from the pure component, or (like in this case with propane) the fraction 0.18886 times the vapour pressure of the pure component? And is the volume the...
  12. Roberttt

    LPG blend in a closed vessel

    @rens The link from the old paper does not work for me. Is there another way how I can see it?
  13. Roberttt

    LPG blend in a closed vessel

    Hmm. A simple model is enough in this case so via Excel should be enough. So in a mass balance way it should go: Accumulation = STREAM IN - STREAM OUT STREAM IN is in this case 0 and STREAM OUT should be the flow that the pump produces. This is an overall mass balance over the whole vessel...
  14. Roberttt

    LPG blend in a closed vessel

    Hmm, allrighty. Is there maybe a way then how to calculate the number of moles that evapourates? I used the pV=nRT for that to calculate n/V (the concentration) and than multiply that answer by the volume above the liquid (in case of 52.8m3 it will be 7.2m3 (60-52.8) to get the number of moles...
  15. Roberttt

    LPG blend in a closed vessel

    Hi all! First of all, sorry if my English isn't that good. I'm a Dutch Chemical Engineering trainee so still learning things. After a day of 2 doing some research to the problem described below, I don't know what to do next. I hope someone here can help me to find a solution for this problem...

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