Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Thermo dry ice question

  1. Mar 27, 2006 #1
    I need a kick start for the following question. We're studying open/closed systems at the moment.

    "450kg of ice at -18 degrees C is to be removed from a freezer using a jet of steam. How much dry steam at 100 degrees C is required if the final temp of the effluent is 5 degrees C?"

    This is what I've sussed out so far.. because mass is being added to the system (the mass of the steam) I assume this is an open system problem. I haven't been given any information regarding enthalpy of either the ice or the steam so I'm assuming it's a simple matter of working out how much energy I need to bring the ice up to 5 degrees and introducing that energy into the freezer in the form of steam that will be giving up energy as it cools down to 5 degrees.

    Can anyone point me in the right direction?

    Last edited: Mar 27, 2006
  2. jcsd
  3. Mar 29, 2006 #2

    Andrew Mason

    User Avatar
    Science Advisor
    Homework Helper

    It should be a simple matter of algebra. Just set up the expression for heat h needed to raise the temperature of 450 kg of ice to 5 degrees and the heat lost by a mass m of stream. Equate the two and solve for m.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook