water combiner

[charland]

I'm looking for a combiner to proportionally mix water with two other aqueous solutions. looking at flowrates of about 15 gpm and pressures of about 150 psi with a mix ratio of 16% of A, 16% of B and 68% water. The flow rate of the water will not be consistent in the application so a solution that works proportionally within a flow range would be ideal. I would also like the pumped water to do all the work (ie. drive the pump that injects the liquids). Initially I was looking at using a gear pump flow divider in reverse but am getting steered away from the idea by our supplier who is concerned about the low pressures and use of water (not enough lubrication). I'm not entirely convinced that the idea is bad yet as we could use nylon gears with some clearance gaps seeing as our pressures are low and leakages would be internal and tolerated.

Does anyone have any experience mixing solutions in an application like this?

Thanks
Charlie

 

[griffengm]

Charland,
There is such an animal with adjustable proportion control but to the best of my knowledge, it is not set to mix three components. However, I can see it set to run two mixers in parallel and then mix the two mixtures. I believe it uses a venturi (Bernoulli?) principle so the are no moving parts.
I can see it but for the life of me cannot recollect its' name. Some one else want to take it from here?

Griffy

 

[IceStationZebra]

You didn't mention where the output will go - i.e. backpressure. Assuming no back pressure you only have 1.3hp to play with at full flow. (hp = gpm*psi/1714) Thats not a lot to turn two other pumps considering friction, efficiency and internal leakage will probably drop that the 1.0hp or less.

I doubt that you will find your flow divider off the shelf. The cheapest way would be to tie the shafts from 3 appropriately sized pumps together. 1:1:4.25

I have reservations about using a venturi device. The fact that the water flow varies will result in an erratic suction level and therefore probably an erratic mix ratio.

ISZ

 

[waterexpert]

I think what you need is a static mixer-

see

http://www.chemineer.com/kenics_products.php

for example.

Regards

Sean

http://www.expertise-limited.co.uk

 

[IceStationZebra]

waterexpert - I don't see how those perform the metering function he's looking for? ISZ

 

[charland]

Thanks guys,

I think that the best solution going forward is a venturi device and we would need to stipulate an inlet pressure. That said, our customer has decided that they will solve this themselves as they have some employees doing nothing at this particular time so I'm off the case.

Thanks again
Charlie