Peristaltic pumps

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

silverbrewer

Well-Known Member
Joined
Apr 19, 2009
Messages
167
Reaction score
1
Location
Birmingham UK
This is my first post, so a tiny bit of off topic history to set the scene....

I am about to re-commence brewing after "loosing my way". I went into my local pub in Birmingham UK and had to pay £3.05 ($4.46) for a pint of Fullers ESB, so now I have re-seen the light, and it is my vowed intent to make a Fullers ESB clone, if it kills me! I was using two 22 gallon stainless vessels, and intend using them again, plus a "keggle". Anyway, back to topic...

It seems to me, that given a bit of ingenuity, perastaltic pumps are easy to rig up without going to the great expense of a shop bought one, so this is hopefully the start of a peristaltic pump thread that should put these sanitary and powerful pumps within the grasp of everyone. I will post pictures as things progress. Constructive comments for and against would be welcome....

The reason I fancy building one is that the motor I have fitted on my grain mill is fully speed controlled and very powerful, so I can rotate at any speed from zero to 180 rpm, and it is sitting idle except for when the grain mill is doing it's duty...

All a peristaltic pump consists of is a length of decent silicone tube much like most of us use anyway, and some sort of device that lets 2 or 3 rollers gently squeeze the tube against an outer circular "fence" as the rollers get driven around by almost any motor with a suitable speed, or even better a motor with a speed controller. (Some pumps don't even bother with the outer fence, but as a consequence flex the tube rather alarmingly)The bigger you make the diameter of the surface the tube is squeezed against, the larger the flow rate is for a given tube size and motor RPM, assuming your motor speed is fixed.

I even built a very very tiny peristaltic pump to water cool the brush deck motor of my "Roomba" floor robot, and that has worked faultlessly for a couple of years now, but the water it is pumping is not boiling hot, just very warm!

My main question to the forum is, has anyone running a perastaltic pump had any failures of the tube due to the mechanical flexing of the tube at our elevated brewing temperatures? I doubt anyone has if they have chosen the proper silicone tube, and I reckon that looking at all it's other benefits it should appear more often in our breweries.

Pro's.
Self priming to several feet.
Very very exact flow control via control of RPM, by pulse width modulation or even a stepper motor. If you wanted to pump 1.003 gallons from one place to another, this will do it.
If the pump is turned off, it stops the flow as if it was a tube clamp.
Nothing but silicone tube in contact with our wort.
No violent turbulence imparted to the wort.
Cheap to own if you construct it yourself.
One motor can drive more than one pump

Cons.
If the tube fails you are snookered.
If the pump is turned off, it stops the flow as if it was a tube clamp.
The pump is capable of developing pressure, and suction, so a rims stuck mash could get sucked clean through the mesh bottom:mad:
If the motor fails, all your pumps are out, and so is the grain mill.

As an aside, (and a bit electronic) nowadays, almost any motor can be speed controlled, or any RC servo can be remotely driven to open valves etc. via extremely cheap "Picaxe" chips and a couple of relays (PIC means programmable interface controller) The ones I like to use are only a few $ and are designed to be programmed for free, on your own PC and by kids at school. Do not assume though that just cos kids use them at school that it will be easy to get your head round the programming bit though, even though the programming required is as simple as it gets! When you are as old as me, its all double dutch! It must be said that modern chips are very clever and give us the ability to fully automate at a fraction of the cost of industrial controllers.
 
The peristaltic pumps that I have looked at have all been too slow for my needs. I suppose you could build one of any size desired, but I don't see the need. My mag drive pump does the job without problems and can move liquids fast when needed.

I'd like to know more about the the Picaxe or PIC chips. That sounds like it might be a useful as a speed control on a DIY stir plate. The price is right where it needs to be.
 
This sounds like a great idea to get your sparge volumes in synch...I'll be checking in to see how your progress is going!
 
This sounds like a great idea to get your sparge volumes in synch...I'll be checking in to see how your progress is going!

Exactly what I was thinking...

I am also very interested in these chips you are talking about. Do you have any links to an interwebs supplier?

Great first post and welcome to the forum! :mug:
 
I have always wanted to build a perisaltic pump especially if someone could figure out how to build one semi reliable with basic handtools and it doesnt cost as much as a march pump or similiar!!

I mean really they are so simple and easy to clean its just stupid.. and probably the most steril way to transferr anything
 
I too would be a bit concerned about too slow a flow. Of course the way around this is just to build it bigger with larger diameter tubing.
 
I too would be a bit concerned about too slow a flow. Of course the way around this is just to build it bigger with larger diameter tubing.

As painfully slow as I run my sparge I'm sure these would be perfect!
 
off-topic, but always good to see other brewer's checking out the equipment forum at 9:25 in the morning...writing a thesis is way overrated
 
...so there I was, writing away in a feeble attempt to graduate when I suddenly became deeply interested in peristaltic pumps...McMaster-Carr has an amazing variety of tubing with temp ratings, food and beverage use, and in a variety of durameters (hardness). Not sure if you've bought your tubing yet, but they seem to have a slight edge over the corner hardware store when it comes to options. Let us know what materials you ended up using
 
I too would be a bit concerned about too slow a flow. Of course the way around this is just to build it bigger with larger diameter tubing.


Yes, those I have seen are way too slow. You would also need one with dual heads to make a balanced sparge system. I don't have any trouble eyeballing the sparge rate manually, but I do have to stay nearby to keep an eye on it.

I've always thought that a diaphram pump might be a better way to go. I've never seen an economical one with a high enough temperature rating. The main problem seems to be that no one has designed a pump with home brewing specifically in mind. Most of us adapt a March or similar pump. These do work OK, but a properly designed paristaltic or diaphram pump might possibly work a lot better. The self priming feature alone for these pumps would be a big improvement. Too bad we are such a small market that it's probably not lucrative enough for someone to design a pump specifically for home brewing use.
 
I've always thought a peristaltic pump would be great for homebrewing. I'm glad we have a discussion on how building one might work. If you are worried about flow just use a larger diameter tube for the actual pump part, then have it connected to your normal size tubing at the inlet and outlet.

Also it won't pull too much suction since silicone tubing will collapse, granted my thick walled 1/2" stuff can have a lot more suction on it than the thin walled 3/8" I had before.
 
Finding the right gear motor to drive a peristaltic pump will be the biggest challenge IMO.

How big would the pump tube need to be in order to pump 4 gpm? I think it would have to be much larger than you realize.
 
I use a peristaltic pump with my aquarium setup. I've replaced the tubing, and it does get crushed after a while. Granted, I'm only running room temp water through it.

The tubing is Tygon, I picked it up from US Plastics. I have the 3/16" od, 1/16" ID stuff. It lasts about 6-8 months before I need to swap it out. (running 1 minute every 29)

That all being said, making a switchover plumbing system that could start the pump/flow with the peri pump, then go with either syphon or gravity would be killer.

B
 
How big would the pump tube need to be in order to pump 4 gpm? I think it would have to be much larger than you realize.

We can go with a small diameter tube, but the pump housing must be very large to accomdate the long tube.

If we use a displacement of .o5 gl/Rev., 4 gl/min or 240 gl/hr
we need a motor RPM = 80. HP < .5 for small tubing (guessing)


Cheers,
ClaudiusB
 
Thanks for the interest guys...

The tube I have bought is all singing and dancing flexy soft silicone, and cost a whopping £40 for 5 metres, but it is suitable for hi temps and peristaltic pumps. As suggested on this forum, I will check out American ebay seller ngs2009 (Nora Stark) when I want more tube.

The PIC chips I am rattling on about are a sub species of the standard PIC chips and are available from PICAXE. The big thing about these chips over the standard PIC chips is they have an enbedded program that means they can be programmed on your home PC and all you have to do is download the free manuals from the help section of the site, download the free programmer software and engage your brain, so only I hard bit there! The chips cost a few cents more than the standard PIC.

So far I have used these chips to control an engine coolant pre heater system on my car, which each morning, moves all the climate control motors to where they need to be and then fires up a coolant pump and then the heating element. I also made an engine coolant alarm system for my camper, which is just a circuit that checks a pair of digital temp sensors, one on each cylinder bank. I am just learning, so no fancy stuff yet, but I did write the programmes and design the circuits, so I went straight out and had a beer to celebrate.

A friend of mine on the Honda Insight car forum has used these chips to make a massively complex battery management system for his hybrid cars new lithium batteries, and it now does an easy 150 MPG (Mine only averages 107 !! It sends info to a digital display and all sorts of clever stuff, so with the application of the aformentioned brain, there is no reason why any home made brewery set-up cannot have the sort of control that the newest Brew-magics have got. Hopefully some of the boffins amongst you will check picaxe's out and verify how much use they could be to the automation brigade on this forum, as I am only a few points away from "Dumb" as far as how these thing truly work....but programmers amongst you will see the potential I am sure. They seem to be very popular in Australia for some weird reason.

I am intending to keep the construction of the pump as simple as I can. I'm thinking skateboard wheels for the rollers and making it so the rotating arm diameter is either easily variable, or easily changeable to vary the flow rate in a 1/2" tube so it sticks to approximately the standard tube size and can give a varied flow rate.

I need empirical flow rates from you guys, but I am collecting a stainless keg on Friday, so in a while, and after lots of grinding and welding noises from the shed I will be able to find out for myself!

More later...
 
I am going to knock up a pump that uses 1 metre of the 1/2" tube. By my calculations, that will pump out about 10 litres a min at 100rpm which is 2.6US gallons. For all I know, my motor may not be up to it, or the pipe will explode, but only time will tell.

It won't be pretty, and will use skateboard wheels to squeeze the pipe. If it proves the concept I will make a propper one.
 
What would you use for the fence? I was thinking of rolling flat stock (steel) in a half round and use 3 rollers. The half round would be solidly mounted on a back plate and the rollers would be mounted on a round disc on the end of the driven shaft. The pulley ratio (motor to shaft) would be 10 to 15 to 1 using pulleys or tooth driven pulleys so that a 1725 motor would rotate at 172.5 or 115 rpm to near zero using a speed control. That's 2.875 or 1.92 rounds per second. Double tubes could be used for synchronous displacement of 2 fluid transfers such as a sparge operation.

What are your thoughts on this?
 
By the looks of this one, a fence might not necessary: Greylor Company | Model 200 | Pump manufacture and Distributor It looks like the hose is simply wound tightly around the rollers. If it is wound tightly enough, then the rollers act as the pinch point, but it might not work as well for thicker walled tubing. I don't think construction tolerances would be as much of an issue with this design (much easier for DIY)
 
What would you use for the fence? I was thinking of rolling flat stock (steel) in a half round and use 3 rollers. The half round would be solidly mounted on a back plate and the rollers would be mounted on a round disc on the end of the driven shaft. The pulley ratio (motor to shaft) would be 10 to 15 to 1 using pulleys or tooth driven pulleys so that a 1725 motor would rotate at 172.5 or 115 rpm to near zero using a speed control. That's 2.875 or 1.92 rounds per second. Double tubes could be used for synchronous displacement of 2 fluid transfers such as a sparge operation.

What are your thoughts on this?

That's a pretty good idea. I was thinking of taking a a block of wood, cut a circle into it. Then take and cut half of the circle away. Cut a hole in the center of the circle and place a windshield wiper motor behind it. Then cut 2 discs of derlin or even hardwood with 3 even spaced holes on it's edge and sandwich small wheels between the layers.

The inside of the circle would need to be sanded really well to keep from damaging the tubing. But for a prototype I think it would work great. Then a bigger stronger model could be made later out of better materials.
 
This is what i'm thinking for a base. It could be cut out of a piece of 2x12.

PumpBase.jpg
 
The tubing and roller diameter will dictate the force needed to compress the tubing. The ends of the half round will need a lead radius at entry and exit of the half round so you don't cut the hose. As a second thought I was thinking of 2024 aluminum for my pump and half inch ID hose.
A gearmotor would be very easy to use for this but are somewhat expensive. I could anodize the aluminum once the design was finalized.
 
Yeah I rounded out the entries and exits to keep the tubing safe. I think I am going to give this a whirl, it may be a cheaper and more effective solution than another march pump for my setup.
 
Hey, with half a dozen peeps all doing research work then this peristaltic thing may fly!

All these ideas seem OK to me. As long as a second roller gets onto the wall before the earlier one leaves, then pumping should flow nicely. Running two or more pipes on the same wall is fine as the pipe can run dry so if a pipe is unused then no problems. I am going the wood route with skateboard wheels to prove the concept, but one of you lot might just beat me to it at this rate.

I don't like the look of having no wall at all, as the tube has to bend a whole lot more, but given that some production units work this way, then it must be a reliable method.

I am making my wall with side walls to help retain the tube under the rollers. This may not be needed.

It is the surface speed of the rollers and the internal diameter of the tube that gives the flow rate, so the bigger the circumference that the rollers are on , the slower the motor needs to rotate, so within reason you can choose a size that suits the revs of your motor. I am thinking that if the wall is more of a full circle then the side loads on the drive shaft may be lessened a fair bit. Three rollers on a half circle wall will put a side load on the shaft, but if the circle is increased to nearer a full circle and there are more than 4 rollers, then the forces caused by the tube will cancel out and the shaft will not see sideways forces as a roller traverses fresh air, but more rollers makes it more complex, and pummels the tube more often .....Does this make sense or am I talkin drivel again.

Geared windshield wiper motors should be up to the job, and are everywhere, and free if you search around!

Smaller versions of geared motors like the windshield wiper motors can be found in cars that have powered steering wheel placement systems. I am thinking of using one of these nice small motors to power an Archemedes screw system to slowly deliver grain to my grain mill rollers. Not actually needed, but much more elegant than dumping it in a hopper and having the grain fighting to find space between the rollers! (Someone at work then suggested I go the whole hog, and feed the grain mill one grain at a time using tweezers, but I ignored him!)
 
Update....

I am looking at using the inside surface of an alloy wheel as the wall that the tube goes on! The advantage of this is it already has an accurate concentric ring in the center of the wheel that can be used to mount some sort of home made bearing carrier for the motor shaft, or bearings for a shaft that then connects via a drive coupling to your motor. I have a feeling in my brewery water that this is going to work !

I have a spare 14" Mazda Miata wheel that should do fine for initial experiments, and access to much bigger Jaguar ones if I need to go bigger. The 14" wheel gives two different sized surfaces that can be used that are about what I think I need to get over the 2 GPM target flow rate.

For those experimenting with a wood or MDF wall, a smooth final surface can be made by fitting thin metal shim onto the surface.
 
I love the idea of a peristaltic pump and instantly thought of brewing applications the second I laid eyes on one. You can count me in as an experimenter. I'll make sure to post back with any failures or successes.
 
Update....

I am looking at using the inside surface of an alloy wheel as the wall that the tube goes on! The advantage of this is it already has an accurate concentric ring in the center of the wheel that can be used to mount some sort of home made bearing carrier for the motor shaft, or bearings for a shaft that then connects via a drive coupling to your motor. I have a feeling in my brewery water that this is going to work !

I have a spare 14" Mazda Miata wheel that should do fine for initial experiments, and access to much bigger Jaguar ones if I need to go bigger. The 14" wheel gives two different sized surfaces that can be used that are about what I think I need to get over the 2 GPM target flow rate.

For those experimenting with a wood or MDF wall, a smooth final surface can be made by fitting thin metal shim onto the surface.

Will you be using a gasoline engine to run this thing? It seems to be getting kinda large.
 
I saw the brewmation pump before and it looks great. But $199 and it doesn't even come with the motor and control? That is crazy. And it doesn't even look like the internal hose is user serviceable.

Skateboard wheels look like they would be great to prototype with, but I'm not too familiar with using them. Can you just mount them with just a bolt?
 
Gasoline engine........ err no! But feel free to send me over a nice V8 of some description I will stick it in my Miata....I'm not an expert on big engines, but I think an LS1 is about what I will be wanting.. :D

The pump has to have quite a large diameter to give a decent flow rate without the motor having to thrash round too fast. I am aiming for 100 RPM with 1/2" tube to give a couple of gallons per minute which should be enough to cope with my requirements. From smaller pumps I have built for some farm work, they take quite a bit of power to turn the rollers over the tube etc etc so it is always guesswork as to how powerful to make the motor unless you are one of those clever bastards who can calculate it out using a slide rule....The farm one is turned by the river, so it was a right game making bigger and bigger paddle wheels for it untill we got it right, but now my mate has spring water pumped up to his sheep and pigs 24/7, and all for free.
If we are really lucky, a standard windshield motor may be up to the job, but I'm not holding my breath. I have a mate truing up the inside of an alloy wheel on the massive lathe he has in his garage, Then I will be ready for some real live testing....I will test it out using my large geared motor first, but if the thing works with a windshield motor, then unfortunately, the guys working at March pumps may be out of a job:(
 
Things are progressing with the home made peristaltic pump. I have bought a cheap skateboard and removed the wheels. As it was a cheap one, the wheels are a bit skinny, so I stuck them in the lathe and gave them a bit if a trim to get the part that will contact the tube a bit wider (27 mm).

The goal here is to get a flow rate of 2 gallons a minute at about 100 RPM, but it has dawned on me that as the sparging operation will need two pumps, then if the flow rate is a bit lower than the target I can just run both pumps at once to get the high flow rate that the post boil cooling operation will require. If the flow target is met by one pump then they can be made smaller. For this experimental MK1 version, I am going to go the MDF semi circle route, with little side walls to contain the tube, with three wheels on the rotating "spider". I will use oilite bearings a bit like the monster mill uses as that is what I have used on my homebuilt mill, and I have some spares..
 
Mash Pump
I came across this one the other day.


Wow! And it will pump a whopping 0.19 GPM. That's gonna make for a mighty long brew day and it will be nearly worthless for the purpose of recirculation not to mention a very slow rate if you try to pump wort through a chiller.

What a bargain at $4,200 for the automated system! I wonder if they have actually sold any of these rigs. I think I'll pass on this for the time being.
 
Hey guys,
Here are a few basic drawings of my pump. Measurements may have slightly altered. (can't remember)
I cut and drilled mine on a 1500 x 1500 CNC router I have, but i'm sure it would be possible with hand tools.
I have only tested it with a variable speed drill once and it worked great. It will be attached to a geared motor eventually. I don't
have any flow rates as yet. The main problems with building these pumps is finding a geared motor with the appropriate RPM and torque, they need a lot.

The Pumps main components consist of.
* 2 x Rotor case - 20mm black Nylon
* 2 x Cover - 10mm perspex
* 2 x rotor - 3mm steel
* 3 x rotor wheels - 20 x 20 nylon
* 2 x 25mm bearings 10mm shafts


These are the CAD files..

peristaltic.jpg


Cheers.
 
Thanks Jonathon,

Are you planning on using this on your newest setup? What RPM and flow rate are you anticipating? And finally, what kind of tubing (material) is in there and initially does it look like a good choice?
 
Back
Top