Are there any data for the flow meter selection? Where are the ultrasonic flowmeters, float meters and vortex flow meters located? What's the biggest difference?
Float meters are used for small tube diameters and low flow rates. Commonly used instrument caliber 40-50mm below, minimum caliber to achieve 1.5-4mm. Suitable for measuring low velocity small flow in liquid, for example, diameter 10mm below the glass tube rotameter full flow nominal diameter, velocity between 0.2-0.6m/s, even lower than 0.1m/s; metal tube rotameter and diameter greater than 15mm glass tube rotameter is slightly higher, the velocity is between 0.5-1.5m/s.
The float flowmeter is a volumetric flow meter, also called a rotor flowmeter, in which the float moves up and down with the flow rate in the vertical cone tube and changes the flow area between them.
Vortex flowmeter is mainly used to measure the flow of medium fluid in industrial pipeline, such as gas, liquid, steam and so on. It is characterized by small pressure loss, large measuring range and high accuracy. It is almost unaffected by parameters such as fluid density, pressure, temperature and viscosity when measuring volume of flow. Therefore, the utility model has the advantages of high reliability and little maintenance. The instrument parameters can be stable for a long time.
The float flowmeter can be used to lower Reynolds number, the viscosity is not sensitive to the shape of the float, circulation gap Reynolds number as long as more than 40 or 500, the Reynolds number of flow coefficient changes is constant, i.e. the change of fluid viscosity does not affect the flow coefficient. This value is much lower than the requirement of minimum Reynolds number 104-105 for a standard orifice plate, such as a differential pressure instrument.
