Two Liquids phases flow: Phases ratio?

[Gottburg]

As a result acidulations process, we get a two liquid phase flow: an oily phase and brine (water and sodium sulfate).
Liquid phases ratio is critical to a later centrifuge operation.
So far a uncomplicated sampling procedure is used to visually evaluate the phases ration, but we want to go with an on line system.

Does anyone know a instrument to evaluate on line the two phases ratio?

Any comments on this would be appreciated.

 

[jmw]

An interesting problem. One assumes the phases are distinct and flowing in horizontal pipework?
Just thinking aloud, but perhaps one of the gamma ray absorption density meters might do the trick if transmitting through the stream top to bottom i.e. through both phases. It would probably need some in situ-calibration and assumes the interface doesn't give too many problems.



JMW

http://www.ViscoAnalyser.com

 

[Gottburg]

JMW, thanks for the thoughts

Some extra info:
Both phases are:
Oily: SG 0.95
Aqueous: SG varies between 1.08 to 1.18. Basically is sodium sulfate in water. And no control on it.
Temp= 100 C

We have all kind of piping orientation: vertical and horizontal. Also we have a static mixer in the line. Therefore both phases should be well mixed. But is not an emulsion, this is a fact.

Also we have a coriolis mass flow meter, but since SG varies the SG given by the flow meter does not helps out.

Some other ideas?

 

[jmw]

This sounds more complex since the variation in the aqueous phase sg means you cnanot use the density measurement to determine the ratio. This would also aply to the gamma ray device.
On the plus side the fact that this is a well homogenised fluid flow and isn't really two phase i.e. the components are not separated into discrete phases,rather the opposite given the static mixer, means that any form of density meter will return a true density for the homogenised fluid.
The problem therefore is to determine the s.g. of the aqueous phase i.e. the sodium sulphate solution.
Is there a point in the system where the sodium sulphate solution is seperate from the combined flow?
If so then a density meter can be used to determine the density of the sodium sulphate solution and use this as a live input to a density meter in the combined flow stream.
The main stream density meter software will then use the base density of the oily component and the live input of sodium sulphate density with the measured base density of the combined flow stream to determine the ratio of oily to aqueous.

Absent a seperate sodium sulphate fluid flow, things get complex as it is important to pin down an sg value for this component by some other means.

Perhaps a conductivity measurement or pH will reveal the sodium sulphate content of the combined stream but whether this would reveal anything about its composition in the aqueous phase is moot.

That is, will a conductivity measurement relate to the concentration of the sulphate in water or in the combined flow stream? If the latter we are struggling, if the former then we can develop a relationship with the SG of the aqueous stream and thus use this as an input to our density meter software for the determination of the ratio. (can't comment on if your mass meter has suitable software or if it measures density with sufficient accuracy in which case a separate dedicated density meter will be required).

JMW

http://www.ViscoAnalyser.com

 

[jmw]

PS
If the sg of the aqueous solution varies only infrequently or slowly, then sampling to determine the s.g. would be a way out since this value can be determined by periodic sampling and updated in the density meter software as and when necessary.
this would be OK if the ratio varies more frequently and more significantly than the aqueous solution s.g. and if the two variations are unrelated.

Another thought; if the current method involves visual estimation, perhaps a colour meter/refractometer would work or some other optical method. This would be ok if the optical properties are unafected by the s.g. of the aqueous solution.

JMW

http://www.ViscoAnalyser.com