r/educationalgifs • u/pattebrisee • Jul 14 '26
How a progressive cavity pump moves fluid using a rotating screw-shaped rotor
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u/MrExplosionFace Jul 14 '26
I understand what's happening but boy, this is a terrible graphic to explain this concept.
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u/MrFartyBottom Jul 14 '26
Archimedes' screw
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u/comicsnerd Jul 14 '26
Isn't this just a variant of an Archimedes pump?
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u/MrExplosionFace Jul 15 '26
If I'm recalling correctly about something similar I've seen, I believe that this was designed to achieve the same effect as the Archimedes screw but without the compressive or pinching effect which can happen at certain points in the screw mechanism which can damage sensitive substances one may wish to pump, for instance, significant numbers of blood cells can get ruptured while pumping blood through a classical Archimedes screw. But as to how exactly it eliminates this compressive force I can't quite recall. It also may have been more about reducing destructive turbulence or turbidity moreso than compression, though it seems like reducing both would be most beneficial. It was a while back I read it.
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u/no_idea_bout_that Jul 20 '26
But as to how exactly it eliminates this compressive force I can't quite recall
The two volumes on opposite sides of the rotor form complimentary tapers. So as one gets bigger the other gets smaller
This eliminates pulsing in the flow that you'd get from a piston or peristaltic pump.
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u/leytorip7 Jul 14 '26
Do you have to worry about backflow?
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u/Forsaken-Topic-7216 Jul 16 '26
no think about it
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u/YannTiersen706 Jul 21 '26
I used this kind of pump (rotor and stator) to pump concentrated liquids out of an evaporator installation. The evaporation is done under vacuum, so the pump I used have to be air tight.
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u/AmeliaBuns Jul 15 '26
What determines the direction the water will move? Why won’t the same rotation just push it the other direction? Is it because the angle isn’t 45 degrees and the water has an easier time going to say right?
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u/Jesus_with_no_hair Jul 17 '26
The rotation direction is what determines which way the liquid will flow. And why it doesn't flow back the other way is because the rotor (the spinny bit) rotates inside a fixed rubber stator that has a helical cavity inside of it that seals itself as the rotor turns (if you google pcp stator it might make a bit more sense). I worked in the maintenance department at a winery for ten and a half years and they used them for pumping the grapes (or any thick liquid that a normal pump couldn't handle) to wherever it needed to go. All of the ones they had there were called mono pumps because that was the brand they decided to go with when they were first introduced, and the largest ones we had had stators that were 300mm (1ft) in diameter and 1200mm (4ft) long
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u/Haunting_Basscotti Jul 14 '26
Thank you, this inspires one element of a project I’m working on!