1668Re: [diy_3d_printing_and_fabrication] Re: Greetings, and extrusion
- Feb 1, 2011A peristaltic pump is a simple and therefore dependable device.
What you would need to figure out is how to make the flow continuous and not pulsed though.
I'll be looking forward for what you come up with!
On Tue, 2011-02-01 at 09:16 +0000, ttelmah wrote:
--- In firstname.lastname@example.org, Jack Coats <jack@...> wrote:
> The concrete industry regularly pumps 'hard to pump' fluids, and the
> plastics injection molding industry uses a screw pump that works in
> stages (all on one axis) to get the pressure higher as it flows
> through the heating chamber.
> I did not find 'monnow' pump (Seems to be a "C'mon now" music/dance
> with racy lyrics going around in some circles) ... any reference would
> be a appreciated.
> http://www.plasticstech.info/equipment/injection-molding-machine/ has
> a schematic images, but the details of the compression screw isn't
> show very well.
> Monolithic.com uses a peristaltic pump for pumping concrete to shoot
> onto the inside of their domes. That concrete is very viscous since
> it needs to be quite 'dry' to stick overhead without forms. This is
> also what is used in hospitals (on a different scale) for pumping
> blood so the blood doesn't come in contact with the pump directly.
> Monolithic uses replaceable flexible lines inside their pump due to
> the erosion of the fluids.
> I am pretty sure this is similar to what other companies use too.
> is one from Make: Magazine ... Ok for pumping some things, but shows
> the principle anyway!
Yes, peristaltic makes a lot of sense, in view of what I said, since you can treat the pipe as a 'disposable' item.
Thanks for the archive link.
I'm sure the name was something like monnow. It was two spiral helixes running inter-twinned with each other, and could pump things like sewage, cement etc., without stones hurting the pump. I think it was patented probably in the early 20th century, and the patent expired a few years ago. The name was I think the company that held the patent, and certainly forty years ago, you could still buy them with this name, but on the web, can't see anything resembling the name. I'll dig out some of my old Victorian engineering encyclopediae, and see if I can get the name right.
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