Cheap(ish) Peristaltic Pump Idea

[NoHawk]

I've been looking at adding a pump to my brewing setup, and for some reason (sanitation and self-priming, mostly), I keep coming back to peristaltic pumps in my head. The problem is, the peristaltic pumps I've found for purchase are either absurdly expensive, or have a flow rate too low to be of any use. After some good amount of googling, I found these two hand pumps(They're basically the same thing, just different color...):

http://www.acehardware.com/product/index.jsp?productId=1272832
http://www.amazon.com/dp/B004L0O3F8/?tag=skimlinks_replacement-20

Here's my thinking: It looks like a peristaltic pump, but without seeing the inside, I cant tell for sure... The description on the Ace one says "Moving parts do not come in contact with liquid" which sounds like it is.

Assuming it is, if I could open it up, replace the tubing with silicone (or something else high-heat and food safe), modify the hand crank to hook up to a drill, I'd be in business.

I'm pretty confident that this would work, but before I drop the money on one of these pumps, I figured I'd throw this idea out to y'all to see what you think.

 

[Stealthcruiser]

Hose looks pretty small dia. on the Ace hardware one, so not sure if a 1/2 inch or so, (the norm), would fit in the housing.



Edit: Have you searched the D I Y forum, as there were a couple made in there, that looked to be up to the task.

 

[NoHawk]

Yeah, I've seen the DIY ones. I might try to make one of those, but I think the idea of an off-the-shelf option (with limited modification) might appeal to more people.

 

[Stealthcruiser]

Rock on, Brother, and keep us posted!

 

[thekraken]

Any updates, NoHawk?

 

[NoHawk]

Yeah! I got the pump in the mail a few days ago (bought the Ace one) and I've been playing with it a bit. I'm gonna do a full write-up once I get some free time to mod it. But here's the basics so far.

I took it apart. It IS a peristaltic pump. It only pumps in one direction. If you turn the pump backwards, it has a mechanism that retracts the rollers slightly (ideal for siphoning/storage).

Some specs: 60 revoultions pumped 1.5 quarts. This means you need something driving the pump at least 160 RPMs for pump one GPM.
Using a jurry-rigged a drive shaft using an allen wrench and some other assorted hardware, I managed to pump just over a gallon in 60 seconds, but there was a few seconds where I had to stop a few times to keep hoses from flying around, and I wasn't taking it that fast. With a better drive shaft (one that's properly aligned) and hoses secured on both ends, I think 2-3 GPM would not be unreasonable.

The mods I want to do: I want to replace all the parts that come into contact with liquid with stuff that will handle high heat and are foodsafe. I have no idea if they are now, but I suspect not. I also want to rig up a drive shaft so I can run it with a cordless drill. That's it, really. I'm gonna tackle that this weekend or next.

 

[aangel]

Hey here's a big question: can your peristaltic pump create a positive air pressure "head"? IE, if you were pumping from one pot into another, would the peristaltic pump be able to do a "full drain" transfer? With regular brew pumps, the piping or tubing between the pump outlet and output vessel is essentially "dead space" once the pump inlet runs dry.

My other question is "can this peristaltic pump create negative pressure, aka suction, thus self-priming?" if that's the case, you could draw fluid up to a higher level with it.

 

[johngaltsmotor]

For a high quality peristaltic both answers are yes. When it squeezes the tubing together it completely seals the inside so as it rotates the tubing naturally flexing back open creates a negative pressure to self-prime. You can also blow bubbles into a tank with a quality peristaltic as it pumps air.
However, most are not intended to compress the tubing well enough to generate vacuum - the tighter of a seal you want the more you have to squeeze the tube at the edges where it bends fatigues sooner when under higher pressure.

 

[aangel]

That makes sense. I certainly hope it'll prove possible to have a foodsafe, $<100 pump that can create suction / head of air pressure and have a good 0.5-2G/minute flow rate. I likes the idea of a self-priming, sanitary, clean-in-place pump I does

 

[NoHawk]

Hey, posted a build log over at a new thread here.

 

[aangel]

In my idle wanderings, I found a few possible candidates for that "ideal" homebrew pump:

http://www.princessauto.com/en/detail/metal-drill-pump/A-p5770250e
https://www.hopshopuk.com/mashing-equipment/drill-pump-stainless-steel-p-1912.html
http://www.rolling-beers.fr/stainless-steel-drill-pump-novaxdrill-20mm-p-892.html?language=en

The bottom two are listed specifically for hot wort applications. Could be the solution for sanitary pumping with no priming required.

 

[MaltedBayerl]

Is it really cheaper for you to order from Europe than from the U.S. or so you just like the stuff better? It says you're in Toronto. Just curious

 

[augiedoggy]

lol the first pump you linked States "NOT SAFE FOR AQUARIUM USE"... I'm gonna take a wild guess and assume its not foodsafe either..

http://www.princessauto.com/en/detail/metal-drill-pump/A-p5770250e


why not just uses these foodsafe pumps? I have been using them for over a year with good results.. they are made by topsflo and actually designed for food applications like drinking fountains and safe for boiling temps unlike the repurposed black ones all over this site..

http://www.ebay.com/itm/Solar-12V-2...0&var=&hash=item4869c1fd4c&afsrc=1&rmvSB=true