Crude terephthalic acid (CTA) Slurry flow Measurement

Dear all,
We are in a bit of a bind here. We need to measure the flow of Crude terephthalic acid (CTA) which is going into our vertical decanters. Temperature is around 200 degC. At present, we are measuring the flow by looking at the vibrations on the decanters and current generated by the drive motor. We used to have an ultrasonic flowmeter, but it didn't work. Then we tried for different vendors such as Emerson, yokigawa to install Mag flow, but they regretted due to line size if 6 inch. Finally we found Flexim. But during testing stage we found that we won't get continuous flow and there will be some sirt if signal fail. So not reliable.
Please suggest some solutions so that we can move forward
 
If you have exhausted all the major instrument suppliers,,,but they usually have something.
Just thinking out of the box. here ...If you can you measure the mass of the vertical decanter ..
There is a system used in the food/others industry that measures the rate of change of weight ...google volumetric and gravimetric flow. Some careful maths is required for reading the mass...this can be surprisingly tricky to get the correct rate of change on the mass.

Not sure if that helps ....not being familiar with your process.
Good Luck!
 
If you have exhausted all the major instrument suppliers,,,but they usually have something.
Just thinking out of the box. here ...If you can you measure the mass of the vertical decanter ..
There is a system used in the food/others industry that measures the rate of change of weight ...google volumetric and gravimetric flow. Some careful maths is required for reading the mass...this can be surprisingly tricky to get the correct rate of change on the mass.

Not sure if that helps ....not being familiar with your process.
Good Luck!
Dear Carl,
Thanks for the reply. Let me explain our process concern.
1. Fluid operating temperature is 200 deg celcius. Design is 230
2. No straight line available.
3. Fluid is Acetic acid slurry with a very high concentration of acetic acid.
Due to these reasons, no vendor is ready to provide any transmitter. Hope you can provide some more inputs
 
Hello Salman
Like I said can you measure the mass of the vessel that it is dispensed to? If so then you could have a solution...never mind all the vibration on theload cells ...that can be dealt with either mechanically or by other means.
 
Hello Salman
Like I said can you measure the mass of the vessel that it is dispensed to? If so then you could have a solution...never mind all the vibration on theload cells ...that can be dealt with either mechanically or by other means.
One more thing I forgot to add. Our process is somewhat like this. Feed is given to the vessel. There are three capacitive type level sensor to measure the level. When all the three level sensors read 100 %, then discharge valve opens and empty the vessel. Feed is constant. Total time taken to complete one cycle is 15 sec.
So my query is will the load cell be able to work under these circumstance
 
Yes it sounds ok...15 seconds is plenty...is it a centrifugal decanter ? do you have a P&ID
...if your concern is to read the mass change in 15 seconds....the load cell and conditioning instrument can do this.....but you have to filter the signal correctly otherwise you will get an inaccurate reading ....like I said the weighing of something can be surprisingly tricky.
but you know the specific weight of your product ...you know the volume of your container...therefore you should be able to calculate the relative height of the product in your container/vessel. I assume you have a plc resolving the logic/maths
 
Hello Dave,
Thanks for the reply. But it would be a big risk to use elbow considering that the fluid is Acetic acid at 200 degree Celsius. Don't you think?
 
the transmitter elevation as suggested under the presumption that you would not experience solids buildup. Liquid services normally require filled lines with XMTR below the line
 
Thanks dave for the reply. I suggested my management to go for a trial with this. But they did not agree with this. Instead of this, we are going with Flexim make ultrasonic flowmeter. This flowmeter uses Noise tracking as well as time of flight mode. Using both the mode, we were able to get the desired result.
Thanks for all the suggestions guys
 
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