In our HDPE plant for flow measurement of slurry (hexane and polymer) to decanter centrifuge, we are using purge type venturi tube. We are facing problems of frequent choking of this venturi. Can anyone suggest a suitable flow measurement technique?

 

You can use Wedge element with Remote seal type
DP transmitter.

Jari

 

Hi

You can try a wedge meter with DP or Multi Variable Transmitter.

Regards

PP Muthu
Rezayat Trading Company
Kuwait

 

If your process fliud is conductive, I would go with a MagFlow.

If its not conductive, then depending on its thermal characteristics and flow rate, something like a Heated RTD type meter works well too.
Both are very unrestrictive to flow.

Other possible solutions are a Coriolis Flowmeter, a Vortex Shedding Meter or if you can suffer the pressure drop, an orifice plate & DP cell with some sort of suitable seal fluid in the impulse legs.

Hope this is of some use.

 

In my opinion magnetic flow meter (magflow) will be the best option.

 

Use a strap on Doppler Flowmeter if the pipe size is larger than .5 inches, and flow velocity is greater than 1 foot per second. Try it with a portable before purchasing one. Usually the reps have demo units. I have rentals if you would like to try one. My rental fee is alot less than the rental companies. I can be contacted at [email protected]

 

Mr. Ramkrishna,

While not exactly state of the art technology, and If you can live with reduced accuracy, but good linearity and repeatability you might consider a Doppler type flow monitor. If the slurry stays relatively consistent with respect to suspended solids, a one time calibration can be done to improve accuracy. If cost is a concern, this might be a viable alternative to the technologies suggested.

Wayne Shimanis
Vortex Technologies, Inc.

 

Perhaps the problem is with the changing quality of the sluury. If so then monitoring the slurry concentration and taking steps to ensure it always remains within limits that do not promote blocking, would be more appropriate.
If so then i would recomend looking for an online sensor such as a density or viscosity transmitter. This may also be of value in conjunction with your flow rate measurement to provide nett mass calculations etc.

 

Might I suggest using a coriolis mass flow meter. It will serve you two purposes in your application. The mass measurement for the rate and total of your slurry and the second would be a concentration measurement using the density measurement of the mass meter. Here you can control the quality make up of the liquid. Coriolis will be a little more expensive then traditional volumetric measuring devices,but the cost of ownership is far less. You will be satisfied with the use of the coriolis mass flow technology.

Steve Stone
Direct Flow Measurement
The Foxboro Company