Positive displacement pumps for continuous

[drmiller100]

Hi.
Continuous requires a steady controllable supply of wash. I think for a few reasons it needs to be a positive displacement pump and it needs to pump the cloudy stuff in a cheap recipe.
I need 20 to 25 gph at 1 to 4 psi.
Would this combined withna 12 volt dc controller work?

https://www.northerntool.com/products/s ... 236-342811

[Yummyrum]

Can’t see why not , although you’ll need to bypass the pressure switch .

EDIT: I pulled one of those apart a few years back and I recall there not being a huge area in and around diaphragm and valves . So maybe it might not be suitable for a lumpy beer . Should be right with Sugar wash though .

I think it was Pope that looked at air operated diaphragm pumps on his continuous stripper.

[drmiller100]

Can’t see why not , although you’ll need to bypass the pressure switch .

EDIT: I pulled one of those apart a few years back and I recall there not being a huge area in and around diaphragm and valves . So maybe it might not be suitable for a lumpy beer . Should be right with Sugar wash though .

I think it was Pope that looked at air operated diaphragm pumps on his continuous stripper.

As I understand the pressure switch shuts off over 60 psi. Should not be a worry.

So assuming 5 psi or less will a dc controller hurt the pump motor if I run out it at half speed

[Salt Must Flow]

I did a quick search and SHURflo DC pumps have brushless motors. Apparently you can use an electronic speed controller (ESC) specifically designed for brushless DC permanent magnet motors.

[drmiller100]

I did a quick search and SHURflo DC pumps have brushless motors. Apparently you can use an electronic speed controller (ESC) specifically designed for brushless DC permanent magnet motors.

Thank you.

So like pulse width modulation?

[Salt Must Flow]

I did a quick search and SHURflo DC pumps have brushless motors. Apparently you can use an electronic speed controller (ESC) specifically designed for brushless DC permanent magnet motors.

Thank you.

So like pulse width modulation?

I wish I could help you there. I do not know much about using speed controllers with DC brushless motors. The only controllers I've every made were for heating elements. If you Google asking if SHURflow pump motors have DC brushless motors, the results I saw said they do. Also if you Google if you can use an electronic speed controller for DC brushless motors, the results say you can.

[Yummyrum]

Yes it would be PWM
You can buy controllers for those pumps .They use them in RVs to run lower rate and save battery draw . They are PWM . But probably any generic PWM 12v motor controller should work .
Some PWM controllers have adjustable Frequency that you can tweak to suit a particular motor . Particularly at low speed where the Frequency of Mark/space can have an effect on torque .

Oh and sorry about the need to bypass pressure switch …. Silly me

Heres one example

[drmiller100]

Crap. Dup

[drmiller100]

Yes it would be PWM
You can buy controllers for those pumps .They use them in RVs to run lower rate and save battery draw . They are PWM . But probably any generic PWM 12v motor controller should work .
Some PWM controllers have adjustable Frequency that you can tweak to suit a particular motor . Particularly at low speed where the Frequency of Mark/space can have an effect on torque .

Oh and sorry about the need to bypass pressure switch …. Silly me

Heres one example

Thank you to you and salty..

It seems to me speed controllers at the fringes could be flaky but I'm looking at 30 to 40 percent. The other thing which you already know is when a continuous gets going and it is good the beer injected starts boiling in the lines. Which is good.
But pressure changes because of this. I wonder how this affects a speed conteoller.

Theory is all great. Time to get busy.

[NZChris]

It should work until a particle gets stuck.

I use a very cheap 12V 23g/hr pump from Fleabay to pump murky wash from a fermenter to containers, then from the containers to a preheater. Whatever pump you choose, there will be a maximum particle size that won't cause a problem, but sellers don't always tell you what that is. I have had a few problems, but I'm not trying to run a continuous still so it isn't a big deal. For continuous applications, I would install two pumps so that one could be isolated for cleaning, or use a much more expensive lobe pump that could handle any expected solids.

[shadylane]

A diaphragm pump isn't a positive displacement pump.
Mabe something like this and a pwm to drive it.

[shadylane]

Or something like this and power it with a "wallwort"

[bluc]

A diaphragm pump isn't a positive displacement pump.
Mabe something like this and a pwm to drive it.

Thats what i went for fingers crossed

[drmiller100]

A diaphragm pump isn't a positive displacement pump.
Mabe something like this and a pwm to drive it.

I'd need 3 of them. Will they hold up to continuous duty?

[Yummyrum]

I’m going down the Peristaltic pump road for my continuous stripper myself Shady .
Drmiller said in OP he needs to pump 20-25 USgal
/hour
Thats around 1.25 - 1.6 litres per min .
Big Peristaltic pumps are expensive and hard to find much above 1l/min

Been doing some playing with peristaltic pumps myself .
Got this supposed 2l/min pump , but it seems that its a far stretch . Sure , it can but it is only meant to be run that hard for short bursts . I would take peristaltic pump ratings and half them for continuous operation … unless you expect to replace them very periodically .

[shadylane]

I’m going down the Peristaltic pump road for my continuous stripper myself Shady .
Drmiller said in OP he needs to pump 20-25 USgal
/hour
Thats around 1.25 - 1.6 litres per min .
Big Peristaltic pumps are expensive and hard to find much above 1l/min

I had a brain fart, I got the L/m and Gal/m crossed.

[Salt Must Flow]

Or something like this and power it with a "wallwort"

Diaphragm pumps are positive displacement pumps. Diaphragm pumps similar to what the OP listed are often used by manufacturers for bottling in conjunction with precise timers. They are relatively consistent, have a repeatable flow rate and are reliable.

[Salt Must Flow]

It should work until a particle gets stuck.

I use a very cheap 12V 23g/hr pump from Fleabay to pump murky wash from a fermenter to containers, then from the containers to a preheater. Whatever pump you choose, there will be a maximum particle size that won't cause a problem, but sellers don't always tell you what that is. I have had a few problems, but I'm not trying to run a continuous still so it isn't a big deal. For continuous applications, I would install two pumps so that one could be isolated for cleaning, or use a much more expensive lobe pump that could handle any expected solids.

Another option would be to use inline filters/screens to guard against fouling the pump.

Instead of multiple pumps, another option would be to have a redundant filter/filters. Occasionally switching over from one filter to the other. That allows you to clean a filter while the other is in use.

[LWTCS]

I do know of a commercially successful operator that runs his centrifugal pump full blast and governs his feed rate with a by-pass valve upstream from his injector into the column. The by-pass sends the extra beer back to his beerwell to be recirculated back to the beer column.

Centrifugal pumps can otherwise be a pain in the ass to manually run without employing a PID loop.

Evidently he can dial it in nicely.

[shadylane]

Diaphragm pumps are positive displacement pumps. Diaphragm pumps similar to what the OP listed are often used by manufacturers for bottling in conjunction with precise timers. They are relatively consistent, have a repeatable flow rate and are reliable.

I had to look it up. Your right.
I thought it wouldn't be positive displacement due to the flexibility of the diaphragm.

[drmiller100]

I do know of a commercially successful operator that runs his centrifugal pump full blast and governs his feed rate with a by-pass valve upstream from his injector into the column. The by-pass sends the extra beer back to his beerwell to be recirculated back to the beer column.

Centrifugal pumps can otherwise be a pain in the ass to manually run without employing a PID loop.

Evidently he can dial it in nicely.

Most of the pumps I've looked at are vane pumps at the flow rates I'm talking about. I us d a vane automotive fuel and it worked for a while but was rough to regulate.

A centrifigal is very back pressure sensitive for flow rate and I don't want to work that hard at it.

I'm thinking about that diaphragm pump with a bypass.

Thank you all for ideas

[shadylane]

Maybe use gravity, have an elevated tank and gravity feed it into the column.
Then the type of pump or pressure regulation wouldn't mater.

[drmiller100]

Maybe use gravity, have an elevated tank and gravity feed it into the column.
Then the type of pump or pressure regulation wouldn't mater.

My still is 9 feet tall. It needs to push wash to the top to run the condenser.

When the thing gets rolling it starts boiling the wash in the lines feeding the column like a coffee percolator.
It really needs a positive displacement pump

[GrumbleStill]

In my experience, the best type of pump for an application like this would be a Mono pump. They are a positive displacement pump that use a helical screw rotor. They are used heavily in process industries where pumping mixtures and slurries at a constant feed rate under varying conditions is essential.

The down side is that they are bloody expensive, and probably beyond the reach of the typical hobbyist, but if you can pick one up on the cheap, it wouldn’t let you down.

[tommysb]

the Mono pumps look really interesting Gramble! Thanks for bringing those to our attention! Smallest ones run about 500 USD/EUR/GBP so not easy for hobby scale operation, but not out of reach either.

[LWTCS]

Yeah thanks.
At first I thought you were referring to an auger type screw pump. Which by the way also does a nice job of pushing solids.

I need to look at that design more.

[LWTCS]

Ah, here is a good summary of the differences:

"A screw pump typically refers to a 3 rotor or 2 rotor screw pumps. These differ from a progressive cavity pump in that they are typically used for pumping lubricating fluids. Screw pumps are all metal pumps and are typically used for nonabrasive fluids. They also can pump at much higher discharge pressures that a progressive cavity pump. Screw pumps typically run at direct motor speeds."

[bluc]

Any insights on perstaltic pumps for this application? are they a good choice @lwtcs?

[bluc]

Maybe use gravity, have an elevated tank and gravity feed it into the column.
Then the type of pump or pressure regulation wouldn't mater.

My still is 9 feet tall. It needs to push wash to the top to run the condenser.

When the thing gets rolling it starts boiling the wash in the lines feeding the column like a coffee percolator.
It really needs a positive displacement pump

What type pump you running?

[drmiller100]

Maybe use gravity, have an elevated tank and gravity feed it into the column.
Then the type of pump or pressure regulation wouldn't mater.

My still is 9 feet tall. It needs to push wash to the top to run the condenser.

When the thing gets rolling it starts boiling the wash in the lines feeding the column like a coffee percolator.
It really needs a positive displacement pump

What type pump you running?

Read this thread. I don't have a great answer yet but am going to try some of the ideas mentioned