Shanghai Yichuan Electromagnetic Flow MeterIt is an instrument made according to Faraday's law of electromagnetic induction, used to measure the volumetric flow rate of conductive liquids. At present, electromagnetic flowmeters have been widely used for flow measurement of various conductive liquids in industrial processes, such as corrosive media such as acids, alkalis, salts, etc; Various application fields for slurry flow measurement.
Range confirmation: For general industrial electromagnetic flow meters, it is advisable to measure a medium flow rate of 2-4m/s. In special cases, the low flow rate should not be less than 0.2m/s, and the maximum should not be greater than 8m/s. If the medium contains solid particles, the commonly used flow rate should be less than 3m/s to prevent excessive friction between the lining and the electrode; For viscous fluids, the flow velocity can be chosen to be greater than 2m/s. A higher flow velocity helps to automatically eliminate the effect of viscous substances attached to the electrode, which is beneficial for improving measurement accuracy.
The main advantages of electromagnetic flowmeter are as follows:
1) The sensor structure of an electromagnetic flowmeter is simple, with no movable parts inside the measuring tube and no throttling components that hinder fluid flow. So when the fluid passes through the flowmeter, it will not cause any additional pressure loss, making it one of the flow meters with low operating energy consumption.
2) It can measure the flow rate of contaminated media, corrosive media, and suspended liquid-solid two-phase flow. This is because the internal flow components of the instrument measuring tube only come into contact with the inner lining and electrodes of the measuring tube, and their materials can be selected according to the properties of the measured fluid. For example, using polytetrafluoroethylene or polytetrafluoroethylene as lining can measure various corrosive media such as acids, alkalis, salts, etc; The use of wear-resistant rubber as an inner lining is particularly suitable for measuring liquid-solid two-phase flows such as slurry and cement slurry with solid particles and high wear, as well as various suspended liquids such as fibrous liquids and pulp.
3) Electromagnetic flowmeter is a volumetric flow measurement instrument that is not affected by the temperature, viscosity, density, or conductivity (within a certain range) of the measured medium during the measurement process. Therefore, after being calibrated with water, electromagnetic flow meters can be used to measure the flow rate of other conductive liquids.
4) The output of an electromagnetic flowmeter is only proportional to the average flow velocity of the measured medium, and is independent of the flow state under symmetric distribution (laminar or turbulent). So the range of electromagnetic flow meters is extremely wide, with a measurement range of up to 100:1, and some even have an operational flow range of up to 1000:1.
5) Electromagnetic flowmeter has no mechanical inertia, sensitive response, can measure instantaneous pulsating flow, and can also measure flow in both positive and negative directions.
6) The diameter range of industrial electromagnetic flow meters is extremely wide, ranging from a few millimeters to several meters, and there are already real flow calibration equipment with a diameter of up to 3m in China, laying the foundation for the application and development of electromagnetic flow meters.
The main shortcomings of electromagnetic flow meters currently still exist as follows:
1) Cannot be used to measure gases, vapors, and liquids containing large amounts of gas.
2) It cannot be used to measure liquid media with very low conductivity, such as petroleum products or organic solvents. Currently, electromagnetic flow meters are powerless.
In summary, electromagnetic flow meters have obvious advantages, but they also have limitations. Electromagnetic flow meters are undoubtedly advanced, but they are not omnipotent. Proper use of electromagnetic flow meters and leveraging their advantages can provide greater services for our production and daily life.