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Steam Ejector Design Resources

  1. Aug 17, 2007 #1

    I was just wondering if anyone had any advice on sources of steam ejector design principles. I've seen one textbook on the topic of steam ejectors that is now out-of-print, and haven't been able to find any suitable online resources (generally, they're very basic and don't quantify much. They're more along the lines of "make sure the ejector isn't choked with steam"). I would like to go from my design parameters, such as desired suction pressure and steam temperature and pressure to determine nozzle diameter, etc.

    I realize there are some existing ejector ratios that require only a throat diameter, with all other proportions of the ejector being determined from this value, such as the Langhaar ejector. I suppose I am curious about how to determine a suitable throat diameter in these situations, for instance.

    I really wanted to get ahold of a paper by DeFrate and Hoerl ... I can't remember the title ... that seemed to go into greater depth than other papers about theory.

    Anyway, if anyone can suggest any leads or give any advice, it would be greatly appreciated.
  2. jcsd
  3. Aug 20, 2007 #2


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    For what process is one designing a steam ejector.

    See - http://www.croll.com/_website/pr/vetheory.asp [Broken]

    This might be of interest - http://www.graham-mfg.com/downloads/218.pdf [Broken]

    I found a couple of papers which reference "L.A. Defrate, A.E. Hoerl, Optimum design of ejector using digital . . . . (1959)", but that is buried in the bibliography of the articles, which must be purchased.

    Analysis of a vapour ejector refrigeration system with environment friendly refrigerants
    Last edited by a moderator: May 3, 2017
  4. Jun 16, 2008 #3
    steam ejector / thermocompressor design

    "investigation of an injector heat pump" http://www.ornl.gov/sci/engineering_science_technology/eere_research_reports/electrically_driven_heat_pumps/advanced_cycle_development/other_publications/ornl_con_144/ornl_con_144.pdf" [Broken]
    Last edited by a moderator: May 3, 2017
  5. Jun 16, 2008 #4


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  6. Jun 17, 2008 #5
    Have you tried the manufacturer's - I remember getting useful info from reading a catalog from (?) Foster Wheeler.
  7. Jul 24, 2008 #6
    A one-dimension model can be created using compressible flow equations with conservation of mass and momentum. Compressible flow equations are avaible in a undergraduate level fluid mechanics text. These equations will give you the relationship between initial (stagnation) pressure of a fluid and throat diameter and exit diameter and minimum exit pressure ~ refrigerant pressure and pre-post shock pressures and etc...

    As for mixing efficiency and how close the ejector actually comes to the ideal "turbine-compressor" cycle, htat's more art than science from what I have read...
  8. Jun 14, 2010 #7
    I have read perry's book, jet world, etc.. But they do not clearly explain (may be reason is that my English skill is not good to understand those book) .

    My question is :

    1) If system needs to suck 1000 kg/hr DAE, does it need to have 1000 kg/hr DAE motive fluid?
    2) If ejectors motive fluid is water like venturi scrubber at above system, does it need to have 1 m3/hr motive water (because of density or S.G.)?
    3) It is easy to get motive nozzle diameter by critical flow ratio in compressible fluid equation (At dry air, ratio is under 0.53 ). Therefore does ejector venturis throat have diameter which is calculated by critical flow ratio (At dry air, ratio is over 0.53) ?
    4) At mixing tank which makes fume, how can I have fumes flow rate? I have calculate it by both liquids reaction heat by temperature and water with reactant flow rate to tank. is it correct solution?
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