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OscarJ.1-Visitor
1-Visitor
December 19, 2011
Question

sizing the air receiver using EOS

  • December 19, 2011
  • 6 replies
  • 4059 views

Good morning,

This model shows how to size an air receiver according to the consumption demand and the pressure band.  The EOS used is Soave, Redlich an Kwogn (SRK) using the basic van der Waal mixing rules as shown in Prausnitz, The Properties of Gases and Liquids, 5th Ed., McGraw-Hill (2001). The example below has two components (air) but it can be used for other gas mixtures. 

This Mathcad model was written by Oscar Delgado.  You may modify and use the model for your own calculations.  If you use the model "as is", then please cite me as well as the other sources mentioned above.

Regards,

Oscar J.

    6 replies

    V
    ValeryOchkov24-Ruby IV
    24-Ruby IV
    December 19, 2011

    Sorry, but real air is not a mixture of O2 and N2 - real air is a humid air.

    See for example this calculation:

    http://twt.mpei.ru//MCS/Worksheets/rbtpp/eng/tab26.xmcd

    O
    OscarJ.1-VisitorAuthor
    1-Visitor
    December 19, 2011

    Good morning,

    The air receiver is usually located AFTER the drying units in the CPIs. That’s why the water content in the mixture is really lower than humid air -to avoid condensate problems in the instruments-. I think that you can use that Model for sizing the receiver, but it could be a great idea to make the calculation of water content to achieve the dew point requirements and then analyze if the error is or not negligible. I will work on this sujet!.

    Thank you for your comments,

    Regards,

    Oscar J.


    H
    HarveyHensley12-Amethyst
    12-Amethyst
    December 20, 2011

    Welcome to the Chemical Engineering space.  I see that you were able to follow my brief directions for submitting documents and worksheets.

    This is a very well designed worksheet.  I must admit that I don't understand exactly what it does, but that is not the point.  For those that do understand and want a good example how to do it.  you've provided one.  I'm sure that some of my submissions will also assume that the reader is knowledgeable in the subject.  Unless our objective is to teach a subject, then extensive explanations should not be required...only enough for the practitioner to know how to use the program.

    Thanks for your contribution.  I see it is in Prime.  I'll have to re-look at Prime' in the next version.  So far, I'm still using MC15.  However, since I have Prime 1.0 installed I was able to read your worksheet.

    A
    aibelman1-Visitor
    1-Visitor
    December 20, 2011

    Any chance of saving it under MC12 or MC14?

    Regards,

    Danny

    O
    OscarJ.1-VisitorAuthor
    1-Visitor
    December 20, 2011

    Good morning,

    Mr. Hensley: thank you for your directions and comments. I hope to write a new model including the comments of Mr. Ochkov and maybe more explanations. 

    Mr Magee: I’m sorry. I write the model in MPrime and I don’t know how you do the change (there is a converter but it works from M15 to MPrime). If you want, I could send you a PDF of the model.

    Regards,

    Oscar J.


    O
    OscarJ.1-VisitorAuthor
    1-Visitor
    January 2, 2012

    Good morning,

    Air receiver2: same model with the Antoine Eq for the water content.

    Regards,

    Oscar J.

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