Views:0 Author:Site Editor Publish Time: 2021-10-29 Origin:Site
In the market ,there are four main types of water flow meter:mechanical water flow meters,ultrasonic flow meters, vortex volumetric flow meters, or magnetic flow meters.We can choose different water flow meter from the points of cost ,practical application ,maintenance.Today we will intoduce thes four major flow meter from the points of working principle ,highlights and disadvantages.
Mechnical water flow meter
This type water flow meter adpots shunt,propeller, or paddle wheel technology and measure the water fluid through turbine rotation.When water flows through the pipeline, the turbine of the mechanical water flow meter will rotate.The volumetric flow rate of water is proportional to the rotation speed of the blades.
Advantages of mechanical water flow meter
The most economical type .
Disadvantages of mechanical water flow meter
If there are large particals in the measured water ,it is easy to casue mechanical water flow meter to block and can’t work well.Thus it will increase the maintenance cost.Besides,mecahnical water flow meter can’t perform well in the low flow situation.
Vortex flow meter
The vortex flowmeter uses the principle of fluid oscillation to measure flow. When the fluid passes through the vortex flow transmitter in the pipeline, two rows of vortices proportional to the flow velocity are alternately generated up and down after the vortex generator of the triangular column. The release frequency of the vortex is proportional to the flow rate.
Advantages of vortex flow meter
It is characterized by small pressure loss, large measuring range, and high accuracy. It is hardly affected by fluid density, pressure, temperature, viscosity and other parameters when measuring volume flow under working conditions. There are no movable mechanical parts, so the reliability is high and the maintenance is small. Instrument parameters can be stable for a long time.
Disadvantages of vortex flow meter
The price of this type flow meter is relatively high and it is mainly used to measure gas ,steam type medium .
The ultrasonic open channel flowmeter is a non-contact instrument, which uses the principle of acoustic reflection to detect the liquid level in the weir trough, and obtains the water flow through the weir trough through conversion.
Advantages of ultrasonic flow meter
The application range of liquid ultrasonic flowmeter is very wide (the outer diameter of the tube is from 12mm to 5m, or even larger), and the pipe diameter is from DN80 to DN1000. The selected instrument adopts acoustic waveguide technology, which can withstand various extreme process conditions (temperature range: -200~600℃; Pressure resistance range: can be at the same level as the process flange) .
Disadvantages of vortex flow meter
Due to the inherent weaknesses of ultrasonic and electronic measuring instruments, such as being easily affected by temperature and radiation, improper installation and use will seriously affect their measurement accuracy and service life.
The electromagnetic flowmeter is a flowmeter that performs flow measurement according to Faraday's law of electromagnetic induction.When the conductive fluid flows through the magnetic field perpendicular to the direction of flow, the conductive fluid induces an induced voltage E proportional to the average flow velocity. The induced voltage is detected by two electrodes directly in contact with the fluid, and then amplified, filtered and shaped by the converter. Send to transmitter to complete the display and output control of instantaneous flow and cumulative flow.
Advantages of electromagnetic flow meter
Compared with other flow meters, there are no obstructing flow parts in the measuring tube of the electromagnetic flowmeter, it is not easy to be blocked, and the maintenance cost is low. The requirements for the front straight pipe section are relatively low.
The structure of the sensor of the electromagnetic flowmeter is simple, and there is no or any throttling part that hinders the flow of the fluid in the measuring tube. Therefore, when the fluid passes through the flow meter, it will not cause any additional pressure loss. It is one of the flow meters with low energy consumption in the flow meter.
Electromagnetic flowmeter has no mechanical inertia and has a more sensitive response. It can measure instantaneous pulsating flow, and also can measure flow in both positive and negative directions.
Wide application.Choose different electrodes and linings to measure the flow medium of dirty, corrosive and suspended liquid-solid two-phase flow.
The electromagnetic flowmeter is a volume flow measuring instrument. During the measurement process, it is not affected by the temperature, viscosity, and density of the measured medium, and the measurement accuracy is high.
Disadvantages of electromagnetic flow meter
Magnetic flow meter Cannot measure media with low conductivity, such as pure water
Above on,electromagnetic flow meter is the most appropriate type flow meter for water fluid measurement.