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What heat capacity is needed to evaporate water in oil

  1. Nov 14, 2016 #1
    1. The problem statement, all variables and given/known data
    In an industrial fryer is f.e. 400 kW. Heating capacity installed. The fryer may contain as much as 1.450 ltr of oil. I can fry 2.000 kg of chicken nuggets per hour in that. These products loose 7% of moisture/water in this process. That water can only escape from oil in gas form i.e. steam.
    My question is, how much of my 400 kW is spend on the undesired steam forming of the 140 liter of water coming from the product. Can anybody give an indication?
    In another thread I read that it takes as much as 8 kW to evaporate 1 liter of water. This would be more than the installed power in my fryer so cannot be true in this case. The frying process seems to be a much more efficient way to create steam but is not very efficient because we do not need steam.

    2. Relevant equations
    To evaporate 1 liter of water at room temperature requires ca. 8 kW I read in another post

    3. The attempt at a solution

    [ Mod Note: member indicates he is working with this industrial fryer and he is not a student ]
    Last edited by a moderator: Nov 14, 2016
  2. jcsd
  3. Nov 15, 2016 #2
    The problem was you had the wrong figure to evaporate , it's not 8Kwhrs/liter

    2260000J to to turn 1liter water (@100C) to steam divide by 3600 = 627 Whrs = 0.627 Kw hrs ....x 140 = 87.888 Kw hrs

    This is a lot of energy if some way could be found to capture this steam , put it through a heat exchanger to heat water for coffee and tea , washing dishes, you would have a million $ invention
  4. Nov 15, 2016 #3


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    Staff: Mentor

    @Adrianus & @oz93666 Just to make sure it is clear, it looks to me like the two of you are using different conventions for decimals; comma versus period. So that's 1450 L of oil and 2000 kg of chicken. Unless that is lunchtime on an aircraft carrier with a single galley, that's not a kitchen, that's a processing plant.

    But yeah, I certainly hope the place already has some sort of energy and water recovery system on its exhaust...

    88 kW (88 kWh per hour) is real money.
  5. Nov 15, 2016 #4
    Hi Russ, you are right, in Europe we use periods to separate 1.000 and comma b4 decimals but we have a good understanding. It is by the way for processing plants where such industrial fryers play an important role. I believe that I got a very good answer now from oz. 88 kW is a very realistic figure to work with. Thank you mr. Oz93666
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