Can I fit a controller to my pump to adjust the flow rate?

[DuncB]

Currently I use an all in one brew system similar to Brewzilla, Anvil etc. It has a built in pump which can be used to recirculate during the mash, whirlpool and pump out the kettle.
The only way to control the flow is to throttle the output with an inline valve. I'm wondering is there a way to adjust the pump speed and hence the flow with a Rheostat / dimmer type
control or other eletronics?
The temperature and steps of the mash and boil are controlled by a SmartPID which does turn the pump on and off at various stages, there are some spare relays on the SmartPID if needed but
it is turned on and off by a 12V relay at the moment.

 

[tracer bullet]

It basically works but I wouldn't do it.

Pump speed is controlled by frequency. A dimmer just squelches the voltage level. In the end the pump may spin more slowly, not because it's actually slower, but because it's weaker. At some point it might overheat trying.

 

[DuncB]

Thanks for that @tracer bullet
How do they control pump flow on units such as the brewtools systems?
They have a slider on the control panel screen for flow from 0 to 100 percent.
Do they just have an electronically controlled valve or use a different type of pump that is adjustable?

 

[tracer bullet]

Yeah, good question. Maybe a DC pump? Although I'm not sure how that's controlled. I don't think a normal dimmer switch works with DC.

This is the point where someone who knows more will hopefully have a better or more thorough answer.

 

[DuncB]

The pump on my unit is an AC pump just switched via the 12 V relay. I do remember using dimmer switches on DC circuits with light bulbs that I played around with as a child, think it was signified by a sawtooth line with an arrow through it. Expect someone will correct me.

 

[Climb]

There are many ways to control motor speed. Different motor types (AC induction, permanent magnet, DC, etc.) require different methods. But more importantly than all of those details, is the type of pump on your motor. (For clarification, the motor turns the pump and the pump moves the fluid.) Most home brew pumps are magnetically coupled to the motor. This allows slippage between the motor shaft and the pump and provides several advantages for the home brew application. In my mind, the primary advantage is low cost. With a magnetically coupled pump, motor speed control is not needed to control flow rate. With a magnetically coupled pump, flow rate is adjusted by a valve on the output of the pump. A mechanical valve is much less expensive that a speed controller for an AC induction motor. Also, in brewing we are directly concerned about flow rate, not motor speed.

One advantage that I see in using a AC induction motor with a speed controller for brewing, is that most speed controllers let you run the motor in both directions. Running the motor in reverse could be useful in dealing with a stuck sparge.

If you have a motor with speed control, a magnetically coupled pump doesn’t have much of an advantage compared to a mechanically coupled pump, as long as you are using the motor speed and not a mechanical valve on the output to control the flow rate.

I am not familiar with all-in-one brewing systems or the type of motor an pump they use, but for cost reasons, I would expect that they would use an AC induction motor with a magnetically coupled pump.

 

[doug293cz]

...

If you have a motor with speed control, a magnetically coupled pump doesn’t have much of an advantage compared to a mechanically coupled pump, as long as you are using the motor speed and not a mechanical valve on the output to control the flow rate.

...

One huge advantage to a magnetically coupled pump for brewing, or any food application, is that there are no shaft seals to leak or let in contaminants (including air.) IMO this is the main reason for using mag coupled pumps.

Brew on

 

[ITV]

Without knowing what type of pump motor that you have, the motors with a fan in the back are designed to run at full rated speed to allow adaquate airflow across the motor to keep it from overheating.

 

[DuncB]

Thank you @Climb and @doug293cz

Think I won't worry anymore about it, touch wood it works fine it can recirculate via the top tube and also whirlpool side branch at the same time so it's powerful enough and doesn't seem to suffer from blockages so I'll just use the mechanical valve as needed. Let's hope the pump doesn't fail!

 

[DuncB]

@ITV
It doesn't have a fan in it just seems to be a sealed motor and pump I think of the magnetic type mentioned above.

 

[Nummisoft]

I connected 40 € vdf to 65 W magnetically coupled induction pump and it seems to work ok. Long term experience is yet to come.

 

[Mad Mann]

Jumping on this thread for a controlled chilling method. New chilling setup, and looking to control wort output via a PID controller. Has anyone attempted this? Is there an electronically controlled valve out there that will work for this application or is it better to control the flow via the pump? The issue I have not solved for on the valve is they seem to be open or closed and therefore unable to adjust flow based on temperature. Any thoughts?

 

[DuncB]

@Mad Mann
You are fitting a temp sensor to the cooling circuit wort outflow. Then planning on using the output that would go to turn a fridge on and off but attaching that to a valve which would get tightened to slow wort flow thru the chiller and hence you get cooler wort.
I can't answer whether there is a small adjustable valve but I have seen these
https://www.brewshop.co.nz/duotight-solenoid-valve.html
This could handle the pressure not sure about temperature and the tube is pretty weedy but you could control the rate of flow by just turning this valve off and on again at a fast speed.
Or turn a screw attached to a pipe clamp tighten would slow flow loosen increase , you could use a small electric drill / screwdriver for this.

 

[mabrungard]

Using an outlet valve to throttle flow is a very good way to adjust flow. Without a motor designed to be speed-controlled, it's not very good for the motor to be electronically 'throttled'. Our hobby level pump motors are not suited.

Another consideration with valve throttling is that when you throttle a centrifugal pump, the load on the motor actually goes DOWN. The motor is working harder when the valve and flowrate are at their max.

 

[Mad Mann]

Using an outlet valve to throttle flow is a very good way to adjust flow. Without a motor designed to be speed-controlled, it's not very good for the motor to be electronically 'throttled'. Our hobby level pump motors are not suited.

Another consideration with valve throttling is that when you throttle a centrifugal pump, the load on the motor actually goes DOWN. The motor is working harder when the valve and flowrate are at their max.

Thanks for the response! Trying to chill wort in one pass and goes straight to the fermenter without having to hand throttle. Finding a specific valve has been challenging as I think there needs to be some flow so the PID can sense temp change. Sounds like I will have to stick with the manual option.

 

[Nummisoft]

Proportional motor valve would make it possible to adjust flow with voltage. For example Motorized Valves – BruControl

 

[DuncB]

@mabrungard
Thank you for your info, looks like my magnetic motor on the pump with the valve is the best option. That keeps things easy.
@Nummisoft I will file your Bru control valve away in case needed in the future. Some great stuff on that site thanks.

 

[Scout]

One advantage that I see in using a AC induction motor with a speed controller for brewing, is that most speed controllers let you run the motor in both directions. Running the motor in reverse could be useful in dealing with a stuck sparge.

Except, it would have to be a reversible motor or three phase. Many plain jane single phase motors will run the same direction no matter the polarity.

 

[mabrungard]

One advantage that I see in using a AC induction motor with a speed controller for brewing, is that most speed controllers let you run the motor in both directions. Running the motor in reverse could be useful in dealing with a stuck sparge.

Most pumps used in brewery settings are centrifugal pumps. Reversing the motor direction will not produce a flow reversal in those pumps.

 

[augiedoggy]

I used to use DC pumps like the tan food grade 12 and 24v models and the brewpi 24v TD5 with pwm speed controllers when I homebrewed for years. now
I still use multiple TD5s this way with pwm speed controllers at my Brewpub. We have larger ac pumps as well all the way up to .75 hp. when it comes to the stainless td5 pumps, topsflo the manufacturer actually makes a model designed for speed control and brewery use but ironically its not the model 95% of brewery supply reseller offer... I purchased mine from the brewpi store. most of the ones you find are designed for solar use and have mppt boosters in them which actually fight the pwm controller effect making them work poorly this way.

Funny Fact, many will say those little 12v tan dc pumps are too weak for brewing but I had a pump malfunction about a year ago and had to use one to pump 3bbl (95gallons) of beer from a conical fermenter into the bottom of a brite to transfer and it actually worked ok. I was surprised it could handle the headspace and backpressure of 90+ gallons of beer. I dont like to use our larger pumps for this purpose as they are bad for the beer once fermented.

 

[Tropicpine]

I had the same situation, installed a rheostat, had the over heating issue and installed an auxiliary 120v ac fan powered by the same circuit that powers the pump. Note: power for the fan is taken from the circuit before the rheostat so the fan runs at full speed whenever the pump circuit is powered.
Now my pump runs cooler than it did when I ran it at full speed.