The difference between turbine flowmeter and vortex flowmeter

　　There are various types of instruments and equipment used for industrial flow measurement. In the use of industrial instruments, choosing different instruments and equipment due to different usage environments can be said to be a form of instrument selection today. For various similar but different instruments, users will inevitably make wrong choices during use. This article introduces the comparison between vortex street meter and turbine flowmeter to facilitate our later selection.

　　Vortex flowmeter:

　　The vortex flowmeter is designed and manufactured based on the Karman vortex principle. The fluid oscillation principle is used to measure the flow rate. When the fluid passes through the vortex flow transmitter in the pipeline, two rows of vortices proportional to the flow velocity are generated alternately up and down behind the vortex generator of the triangular column. The release frequency of the vortex is related to the average velocity of the fluid flowing through the vortex generator and the characteristics of the vortex generator.

　　Vortex flowmeter: mainly used for flow measurement of industrial pipeline medium fluid, such as gas, liquid, steam and other media. Its characteristics are small pressure loss, large range, high accuracy, and almost unaffected by fluid density, pressure, temperature, viscosity and other parameters when measuring working volume flow. There are no moving mechanical parts, so it has high reliability and low maintenance. The instrument parameters can be stable for a long time.

　　The vortex flowmeter is designed and manufactured based on the Karman vortex principle. The fluid oscillation principle is used to measure the flow rate. When the fluid passes through the vortex flow transmitter in the pipeline, two rows of vortices proportional to the flow velocity are generated alternately up and down behind the vortex generator of the triangular column. The release frequency of the vortex is related to the average velocity of the fluid flowing through the vortex generator and the characteristics of the vortex generator.

　　The lower limit flow rate of the vortex flowmeter depends on the working density and kinematic viscosity of the medium, and its upper limit flow rate is generally not affected by the pressure and temperature of the medium. Therefore, to determine the flow range, it is only necessary to determine the actual available lower limit flow rate. After calculating the lower limit flow rate, the corresponding caliber can be determined by looking up the flow range table.

　　Turbine flowmeter:

　　Turbine flowmeter is the main type of velocity flowmeter. Its principle is that when the measured fluid flows through the turbine flowmeter sensor, the impeller is forced to rotate under the action of the fluid, and its speed is proportional to the average flow velocity of the pipeline. At the same time, the blades periodically cut the magnetic lines of force generated by the electromagnet, changing the magnetic flux of the coil. According to the principle of electromagnetic induction, a pulsating potential signal, that is, an electric pulse signal, will be induced in the coil. The frequency of this electric pulse signal is proportional to the flow rate of the measured fluid. Simply put, it is similar to a household water meter. Once the medium flows, it pushes a wheel to rotate, so that the flow rate can be calculated based on the rotation.

　　The turbine flowmeter is an instrument that uses a multi-blade rotor (turbine) to sense the average flow velocity of the fluid and derive the flow rate or total amount. The turbine outputs a signal by cutting the magnetic flux lines through the rotation of the impeller, and then obtains the flow measurement through signal processing and output. The vortex street obtains the flow measurement by detecting the Karman vortex and then processing the output signal.

　　Turbine flowmeters are widely used in the following measurement objects: petroleum, organic liquids, inorganic liquids, liquefied gas, natural gas, coal gas and cryogenic fluids, etc. They have simple structure, few processed parts, light weight, easy maintenance, large flow capacity (large flow rate for the same caliber) and can adapt to high parameters (high temperature, high pressure and low temperature).