The correct selection of the vortex flowmeter can ensure the better use of the vortex flowmeter. What kind of vortex flowmeter should be selected according to the physical and chemical properties of the fluid medium to be measured? The diameter, flow range, lining material, electrode material and output current of the vortex flowmeter can all be adapted to the measured fluid. The nature and requirements of flow measurement.
1. Precise function inspection
Accuracy grade and function Select the instrument accuracy grade according to the measurement requirements and use occasions, so that it is economical and cost-effective. For example, for trade settlement, product handover and energy metering, you should choose a higher accuracy level, such as 1.0, 0.5, or higher; for process control, choose different accuracy levels according to the control requirements; some only It is to check the process flow and do not need to do precise control and measurement. You can choose a lower accuracy level, such as 1.5, 2.5, or even 4.0. At this time, you can choose a cheap plug-in vortex flowmeter.
2. Measurable medium
Measuring medium flow rate, instrument range and caliber When measuring general medium, the full-scale flow rate of the vortex flowmeter can be selected within the range of measuring medium flow rate 0.5-12m/s, and the range is relatively wide. The selected instrument specification (caliber) is not necessarily the same as that of the process pipeline. It should be determined whether the measurement flow range is within the flow rate range, that is, when the flow rate of the pipeline is low and cannot meet the requirements of the flow meter or when the measurement accuracy cannot be guaranteed at this flow rate, It is necessary to reduce the diameter of the meter to increase the flow rate in the tube and obtain satisfactory measurement results.
3. Selection of vortex flow transmitter
In the saturated steam measurement, the VA piezoelectric vortex flow transmitter is used. Due to the wide range of the vortex flowmeter, in practical applications, it is generally considered that the flow rate of the saturated steam should not be lower than that of the vortex flowmeter. The lower limit, which means that the fluid velocity must not be lower than 5m/s. Vortex flow transmitters of different calibers can be selected according to the amount of steam used, and the caliber of the transmitter cannot be selected based on the caliber of the existing process pipeline.
4. Selection of pressure compensation pressure transmitter
Because the saturated steam pipeline is long and the pressure fluctuates greatly, pressure compensation must be used. Considering the corresponding relationship between pressure, temperature and density, only pressure compensation can be used in the measurement. Since the saturated steam pressure of the pipeline is in the range of 0.3-0.7MPa, the pressure The range of the transmitter can be 1MPa.
5. Display instrument selection
Display instrument: Intelligent flow indicator, with functions of voltage stabilization compensation, instantaneous flow display and cumulative flow accumulation.