Peristaltic Pump

Discussion in 'The Projects Forum' started by Jona Ranola, Jun 28, 2015.

  1. Jona Ranola

    Thread Starter New Member

    Jun 15, 2015
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    I just want to ask if peristaltic pump like http://www.adafruit.com/products/1150 can pump sticky or pasty liquids? Like a texture of cerelac or catsup? We are thinking if it is possible. We will not pump a large amount so we really do want something small like this for our project.
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Catsup and cooked grains are very difficult because they are non-Newtonian. They thin (decrease viscosity) when subjected to shear (pressure). That means, the volume in your perastaltic pump is thin but you are pumping into a hose that is much more viscous.

    I think another type of pump is needed.
     
  3. #12

    Expert

    Nov 30, 2010
    16,248
    6,745
    The site which sells that pump has all sorts of information, forums, videos, FAQs, contact information. Why not ask the people who sell it?
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,087
    3,027
    That's true for a thixotropic liquid, like paint. You want paint to be thin when you brush or spray it but very viscous once applied, so it doesn't run or sag.

    What I think you meant is the opposite, a dilatant fluid, like starch or wet sand, that sets up hard when sheared but flows easily when "relaxed".

    I personally don't think ketchup (or even catsup!) or dilute ceralac would be a problem for a good peristaltic pump. A high-solids suspension could be a problem.

    Not all peristaltic pumps are created equally. The kind I'm most familiar with are like these from Masterflex. The itty-bitty toy from Adafruit is not the same.

    Pumping of very difficult fluids is often accomplished with progressive cavity pumps, such as those from Moyno. They work great with starch or suspended ground grain.
     
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Catsup/ketchup is sheer thinning.
    http://www.firstscience.com/SITE/ARTICLES/ketchup.asp
     
  6. RichardO

    Well-Known Member

    May 4, 2013
    1,228
    382
    I always called it "thinsitropic". :rolleyes:

    Shaking a bottle of ketchup makes it thinner and easier to pour. Just remember to have the lid on before doing the shaking. :eek:
     
    GopherT likes this.
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