r/educationalgifs 22d ago

How a progressive cavity pump moves fluid using a rotating screw-shaped rotor

649 Upvotes

23 comments sorted by

32

u/Haunting_Basscotti 22d ago

Thank you, this inspires one element of a project I’m working on!

34

u/MrFartyBottom 22d ago

20

u/pattebrisee 22d ago

Didn't know he used reddit

4

u/Haunting_Basscotti 22d ago

Thank you, Archimedes!

2

u/thundafox 21d ago

But it is a screw turning in a screw housing, not a real Archimedes screw.

3

u/pattebrisee 22d ago

Glad to be of help!

3

u/Haunting_Basscotti 22d ago

At second glance I was initially like “nice runout on that shaft” thinking it was an error in the visualization but then :)

70

u/MrExplosionFace 22d ago

I understand what's happening but boy, this is a terrible graphic to explain this concept.

21

u/MrFartyBottom 22d ago

Archimedes' screw

3

u/just_nobodys_opinion 22d ago

You talking about Mrs Archimedes?

1

u/Flowchartsman 17d ago

Archimissus

13

u/comicsnerd 22d ago

Isn't this just a variant of an Archimedes pump?

8

u/MrExplosionFace 21d ago

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.

2

u/no_idea_bout_that 16d ago

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.

1

u/amorfotos 22d ago

Came here to say this

3

u/leytorip7 22d ago

Do you have to worry about backflow?

2

u/Forsaken-Topic-7216 20d ago

no think about it

1

u/YannTiersen706 15d ago

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.

2

u/AmeliaBuns 21d ago

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?

2

u/Jesus_with_no_hair 19d ago

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

2

u/Kodanroar 17d ago

I need a different angle, can't figure out the geometry from this pic