Pumping solutions for chocolate syrup 2

[Vexxis]

Hi all,

I am researching ways to pump small doses (~10-40grams) of chocolate syrup with an accuracy constraint of +/- 10%. One thing I noticed with the syrup is that the viscosity can vary greatly with temperature, 10000-25000 centipoises. The environment this will be used in does not have a constant temperature so either the pump will need to be able to deal with the range of viscosity or the temperature could have some level of control internally.

Some of the options of I have been exploring:

Piston Pumps
Diaphragm Pumps
Bellows Pumps
Impeller Pumps
Lobe Pumps
Positive Displacement Pumps (Using stepper motors and a pressing plate to squeeze bags of syrup or similar)
Some sort of auger design (fondue machine?)

One thing I have noticed is that certain pump designs such as impeller pumps are very difficult to clean. It would be nice to have fairly easy access to cleaning the pump head or a disposable pump head. My favorite options so far are positive displacement options that inherently make it so no syrup touches the mechanical parts.

If anyone has any experience with something similar I would love to hear from you! Thanks

 

[1gibson]

You probably want a peristaltic pump.

 

[TenPenny]

You don't mention a flow rate, but depending on what you are doing, there are some companies such as Zenith, that make accurate metering pumps used for vitamin addition and similar very accurate small flow applications.

Or a peristaltic, if your tolerance is 10% might be fine.

 

[IRstuff]

First time I've ever looked up the density of chocolate syrup ;-)

So, your weights, coupled with the density, say that the volumes you're trying to deposit are with the range of a syringe-type system, so flow can be controlled by volume, somewhat independent of viscosity. Something like:

https://www.thingiverse.com/thing:482873

possibly.

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[Vexxis]

The flow rate would be about 10mL/s. Also it would not be for continuous flow but instead for single shots at inconsistent timings. I have also looked into peristaltic and I was mainly worried about the frequency of replacing the tubing. The metering pumps may be a bit out of my price range - I also forgot to mention that a low cost, less than say $200 would be ideal (not including the electronic controls)/chasis etc. The hard cap on price for the pump itself would be around $300.

Thanks for the ideas

 

[Vexxis]

IRstuff - that is a nice idea. My concern with this one would be that it would need to be filled often. I am pumping from a large bag or container of chocolate syrup (5-10Litres)

 

[MFJewell]

I'd probably find a bunch of Oompa Loompas. They did the job just fine at Wonka's factory.

 

[EdStainless]

For things like this if you used a peristaltic you would replace tube with every bag of syrup.
That would help keep the tube in shape and keep the system clean.
A small diaphragm pump would fit the application, if you could allow a fairly slow cycle then viscosity would not have much impact.

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P.E. Metallurgy, Plymouth Tube

 

[IRstuff]

What's your volume per day requirements?

speaking of bags, have you considered a Juicero? They're probably pretty cheap now ;-)

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[MJCronin]

The real pros use a ladle and chute arrangement ....

MJCronin
Sr. Process Engineer

 

[Vexxis]

IRstuff - Volume per day would be around 5 Litres. What type of pumping did the Juicero use?

EdStainless - very good point about changing the tubes w/ bag at same time. The chocolate syrup pump will be used in an under the counter pumping setup, not unlike under the counter dairy dispensing units. So the cycle time of a diaphragm pump could be a problem if there was a quick need for chocolate syrup, I would need to examine how quickly a diaphragm pump could go through a cycle for a viscous fluid. Definitely worth looking into! Thank you.

 

[LittleInch]

How about

http://server-products.com/equipment/pumps/food-container-pumps/82000.htm

Nice, neat, simple, cheap, user controlled

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Vexxis]

Thanks for the suggestion LittleInch,

We currently use a similar product but we want to design something that we can integrate into our system. I have actually considered making a sort of automated hand pump within the system where a linear actuator would do the pumping action at the press of a button. The largest obstacle to overcome with this design is that we have several dispense sizes ranging from 7.5mL to 30mL. With a single handpump this would require multiple pumps from the user. Perhaps I could create a hand pump similar to that with 3 nozzles that have preset sizes for each pump.

 

[CH5OH]

I would go with the little inch solution and either control the number of strokes or strokelength (pneumatic actuator,4 2 control valve,lineair position electric feedback,cheap PLC)

 

[LittleInch]

Sorry, I was being a bit flippant, but my point was that this operation isn't really a pumping issue, but a delivery of fixed volume issue and hence I don't think a pump based solution is the best, especially at this sort of viscosity.

Sometimes you see the fluid sitting in a pressurised vessel and then the dispensing is done by rapidly opening and closing solenoid valves with the either a set amount for each "pulse" or a set time for the different amounts you want.

The peristaltic pump if driven by saw a worm gear DC motor with a good turn down and then timed could give you good repeatability.

As I'm sure you've discovered, the drink dispensing industry does this a lot.

Search for syrup BIB (Bag in box) dispensing systems.

you find sites like this

http://www.sodadispenserdepot.com/syruppumps.html

Just give them a call





Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[EdStainless]

Two options come to mind.
Automate a simple plunger pump (aka ServerProducts style) with an air cylinder and position sensors. Very similar dosage metering pumps are common in dispensing pigments and additives for both paints and personal care products.
Another option is someone like KNF who makes diaphragm metering pumps.


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P.E. Metallurgy, Plymouth Tube