Application Research of Electromagnetic Flow Meter in Pharmaceutical Production

The electromagnetic flow meter is an instrument that uses the Faraday electromagnetic induction to measure the volume flow of conductive liquid. The electromagnetic digital water flow meter is often used in conductive liquid volume flow measurements, such as acids, alkalis, salt, and chemical solutions. Although the reliability and stability of electromagnetic flow sensors are much better than other kinds of flowmeter, some problems will occur in the actual application.

In biopharmaceutical companies, water meters, turbine flow meters, vortex flow meters, electromagnetic flow sensors, and ultrasonic flow meters are commonly used in the measurement of water, steam, wastewater, and organic solvents. Combined with sewage discharge flow measurement, macrolide sulfate, and amikacin sulfate resin extraction, as well as cleaning positions on the column liquid metering and control of the magnetic flow transmitter experience, summarizes the electromagnetic digital water flow meter in the measurement and control of flow should pay attention to matters.

In the pharmaceutical production process of amikacin sulfate, the charcoal stripping operation involves adding BB-K8 concentrate to the charcoal stripping tank, adjusting the pH with dilute sulfuric acid, and then adding activated carbon to decolorize the solution, which is pumped and filtered through 0.45-micron filtration into the crystallization tank for crystallization. During the crystallization process, the pH value of the crystallization solution is the key parameter, which has a very great influence on the pH value of the finished product, organic residues, and related substances, so it is necessary to control the amount of dilute sulfuric acid added and the rate of addition. As the feeding amount is determined, the amount of acid added is also fixed according to the principle of acid-base neutralization, together with many years of process mapping, the production process requires the use of metering means to control the amount of dilute sulfuric acid added (570L). The control scheme we choose is to use the metering pump to pump dilute sulfuric acid into the charcoal stripping tank through the pipeline, the pipeline is installed with a flow meter, and when the accumulated flow reaches 570L, the flow meter outputs a switch signal to control the power supply of the metering pump and stops the addition of acid, to achieve the purpose of control.

Due to the strong corrosiveness of dilute sulfuric acid and the uneven flow rate of acid addition in the process, and the process requires low control accuracy, so during the selection period, the company's metrologists determined the use of tantalum electrode, tetrafluoro-lined, electromagnetic digital water flow meter with switching output as metrological instrumentation. Although the electromagnetic flow transmitter measuring the volume flow of conductive fluids is a very mature instrument, if we usually do not pay attention to maintenance and repair, it will affect the normal use of the electromagnetic flow transmitter. Next, we combined with pharmaceutical companies over the years of selection, maintenance, and usage, summarize the electromagnetic flow meter in the flow measurement and control process.

The electromagnetic flow sensor can only measure the flow of conductive liquids whose conductivity shall not be less than 5 μs/cm. After the magnetic flow transmitter operation was normal, the company's calibration personnel in the shutdown maintenance period of water as a measuring medium for the electromagnetic flow sensor to verify the accuracy of the measurement process, once again the phenomenon of flow did not show. After checking, the reason is that the pharmaceutical process water conductivity is less than 3μs/cm, and the conductivity is too low to cause the meter to work properly. Through this matter, we fully realize that the electromagnetic flow sensor can only measure the conductivity ≥ 5μs/cm of acid, alkali, salt solutions, water, sewage, corrosive liquids, and mud, slurry, pulp, pulp, and other fluid flow, but can not measure the gas, steam, and pure water flow.

The reliability of the electromagnetic digital water flow meter is good, but because its measurement medium is mostly suspended solids or dirt, the sensor electrode surface is more susceptible to contamination. If the electromagnetic digital water flow meter is not cleaned and maintained for a long time, it will not work.

As a flow measurement instrument for sewage discharge, you can choose a large-diameter electromagnetic flow sensor for measurement. Whether installation, use, maintenance, and repair costs are very low, measurement accuracy and reliability to meet the use of measurement requirements. The company daunomycin on the column liquid measurement with small and medium diameter electromagnetic digital water flow meter, because the measured medium is solid-liquid two-phase difficult to measure the fluid. The electromagnetic flow transmitter measurement is a more correct choice, but in the use of nearly two years after the emergence of flow display sometimes phenomenon. The inspection found that the reason is that the upper column of liquid in the measurement of the pipe wall precipitation, scaling, staining the electrodes, the formation of passivation film or oxide layer, and the electrode surface is insulated and disconnected from the measurement circuit.

In summary, the electromagnetic flow transmitter plays a big role in flow measurement. The electromagnetic flow sensor can measure corrosive liquids, but as the instrument selection personnel, must understand and correctly provide the properties of the measured medium, the use of the electromagnetic flow meter premise is the measured fluid must be electrically conductive, and the conductivity can not be lower than the threshold (i.e., the lower limit value of 5μs/cm).

All instruments require maintenance, and electromagnetic flow meters are no exception. Generally, customers need to disassemble the electromagnetic flow meter and clean the electrodes once in one to one and a half years to ensure the measurement accuracy of the electromagnetic flow meter.