Selection of measuring instruments
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The condenser section of our distillation tower is equipped with a flow meter for intermittent operation. The process requires measurement of three fluids: acid water, xylene, and crude anhydride. Due to space constraints, only one instrument can be installed. A metal tube float flow meter was chosen for this purpose, but its measurement accuracy is poor. Moreover, crude anhydride tends to solidify easily, which often leads to clogging of the meter and causes difficulties in the operational process. I’d like to ask everyone for some advice.
I forgot to mention that the three media pass through the pipeline in sequence according to the processing steps. I’m sorry.
Acidic water? What kind of acid? What is the concentration? Both xylene and acetic anhydride are non-conductive; a vortex flow meter should be considered. What is the traffic range? What about the work traffic? The minimum flow rate for vortex flowmeters is generally 0.8 cubic meters per hour; therefore, they present certain issues in applications with low flow rates. Moreover, xylene is flammable and explosive, so an explosion-proof flowmeter is necessary. As for what is known as acid water, an electromagnetic flowmeter is a good choice, but the electrodes must be made of corrosion-resistant alloys; otherwise, they will fail after a short time. Thus, taking into account factors such as material, range, and conductivity, it’s really difficult to find a flowmeter that can measure three different media simultaneously. A more ideal option would be a Cryo mass flowmeter, which offers good accuracy and a long service life, but its corrosion-resistant alloy casing means the cost is likely to be around 100,000 yuan or more. Therefore, it is recommended to use an electromagnetic flowmeter for measuring acid water, and a vortex flowmeter for measuring xylene and acetic anhydride (provided the flow rate isn’t too low)
Since the required measurement accuracy is not high, an ultrasonic measurement approach is used; the density only needs to be adjusted when the medium is changed. For now, it’s cheap and practical; I’ll replace it when there are better products available. Thank you for following.
I think I’ll go with an elliptical gear flow meter!