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

Can someone help me figure out how much torque I need

  1. Feb 13, 2015 #1
    Hello Im new to site and need some help building a big mixer similar to picture the problem i have run into is i need to know what size motor and gear reducer box i need for this application i need to find out how much torque it takes to spin the paddle wheel when fully loaded the the weight of my material is 10,500 lbs my paddle is 5 ft in diameter 14 feet long and I need this to spin at 15-20 rpm can anyone help me with equation for this thanks. http://www.robinrents.com/stow-paddles.jpg [Broken]
     
    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Feb 13, 2015 #2

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    Is there anything similar you can compare it with? Such as a concrete mixer? Otherwise I suspect you might have to make a series of smaller prototypes to scale, measure the torque and power required and extrapolate.
     
  4. Feb 13, 2015 #3

    billy_joule

    User Avatar
    Science Advisor

    With mixing being such a key process in industry I'd guess there's been considerable research done, have you checked unit operation text books?
     
  5. Feb 13, 2015 #4

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    There must be a lot of variables.. viscosity, size and shape of the paddle, clearance between paddle and container..

    http://en.wikipedia.org/wiki/Mixing_(process_engineering [Broken])

    It goes on to reference the "North American Mixing Forum sponsored Handbook of Industrial Mixing".
     
    Last edited by a moderator: May 7, 2017
  6. Feb 13, 2015 #5
    And 2.5ft instead of the 7ft i wrote
     

    Attached Files:

  7. Feb 14, 2015 #6
    Yes your picture is exactly what im trying to build.
     
  8. Feb 14, 2015 #7
    yes i have the problem is no one make a mixer in the size Im making its either much smaller or much bigger.
     
  9. Feb 14, 2015 #8
    I am a complete newbie who makes tons of mistakes. someone check my work!

    at a 1:1 gear ratio you need a motor with a1137 watt output or 50,000ft*lbs
    at a 1:2 ratio you need 567 watts or 25000ft*lbs
    I don't know how to incorporate the rpm in this formula.
     

    Attached Files:

    Last edited: Feb 14, 2015
  10. Feb 14, 2015 #9
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Can someone help me figure out how much torque I need
Loading...