Vortex flowmeters are mainly used for flow measurement of medium fluids in industrial pipelines, such as gas, liquid, steam and other media. The vortex flowmeter is characterized by small pressure loss, large measuring range and high precision. When measuring the volume flow of the working condition, the vortex flowmeter is hardly affected by parameters such as fluid density, pressure, temperature and viscosity. There are no moving mechanical parts, so the vortex flowmeter has high reliability and low maintenance. Instrument parameters can be stable for a long time. The vortex flowmeter adopts piezoelectric stress sensor, which has high reliability and can work in the working temperature range of -20℃～+250℃. Vortex flowmeter has analog standard signal and digital pulse signal output. It is easy to be used with digital systems such as computers. It is a relatively advanced and ideal flow meter. But also need to pay attention to some problems.
1. The minimum flow problem of the vortex flowmeter
The amplitude of the signal of the vortex flowmeter is proportional to the square of the flow velocity and the density of the measured medium. That is to say, when the detection sensitivity of the vortex flowmeter is constant, the working pressure of the fluid increases, the density increases, and the measured flow rate can be reduced. As the density increases, the signal amplitude of the vortex flowmeter also increases, and the detection sensitivity of the vortex flowmeter can be lowered. For normal pressure gas, the lower limit flow rate of the vortex flowmeter can reach 4~5m/s. For pressurized gases, such as compressed air, the lower limit flow rate will decrease due to the increase in density. Therefore, when selecting the model, the actual flow rate should be considered.
2. Influence of vibrating vortex flowmeter
Compressed air is produced by air compressors or high-pressure fans. When these devices are running, there are different degrees of vibration, and sometimes the vibration is relatively strong, and this vibration will be transmitted through the connecting pipeline. In the selection and location of vortex flowmeters, this influencing factor should be fully considered. In various detection methods, due to different detection elements, the anti-vibration performance of vortex flowmeters is also different. For the vortex street of the detection element, the vibration resistance can reach 0.5~1G. When determining the installation location of the vortex flowmeter, it should be as far away as possible from power equipment such as air compressors and fans.
3. Influence of pulsating flow on vortex flowmeter
Most of the gases output by fans and compressors contain pulsation of certain components. For the vortex flowmeter, the pulsation frequency and amplitude of the gas output by the Roots fan are related to the rotational speed of the waist wheel and the volume of the fixed displacement, usually the pulsation frequency is 100~200HZ; while the frequency of the output gas of the reciprocating compressor low, generally only a few Hz. In addition, some air-using equipment, if the air hammer, pneumatic tools, etc., will also cause the pulsation of the air flow, and the frequency and amplitude of this pulsation are random.
So far, Q&T has developed a vortex flowmeter that can be used in a vibration environment, which will definitely be favored by customers.