When choosing a vortex flowmeter and an electromagnetic flowmeter, you need to consider multiple factors to ensure that the selected flowmeter can accurately and reliably meet the measurement needs. The following is a detailed comparison and selection recommendations for the two:
Measurement principle and scope of application
Vortex flowmeter: Based on the "Karman vortex" principle, it is suitable for liquids or gases, but has certain requirements for the temperature, pressure, and viscosity of the medium. It is not suitable for measuring liquids with high viscosity, granular solid media, and liquids containing foam and bubbles. In addition, the vortex flowmeter has poor seismic resistance and is not easy to install under vibrating conditions.
Electromagnetic flowmeter: Based on Faraday's law of electromagnetic induction, it is only suitable for conductive liquids and has high requirements for the purity of the medium. It cannot measure non-conductive media.
Accuracy and stability
Vortex flowmeter: The accuracy and stability are relatively low, generally between 1% and 2%.
Electromagnetic flowmeter: The accuracy and stability are high, and can reach 0.5% accuracy, so it is more suitable for occasions where high-precision measurement is required.
Range and pressure loss
Vortex flowmeter: The range ratio can reach 1:10, the measurement range is wide, and the pressure loss is small, which helps to reduce operating costs.
Electromagnetic flowmeter: The range is extremely wide, and the measurement range can reach 100:1 or even higher. Similarly, the electromagnetic flowmeter will not generate additional pressure loss during the measurement process.
Structure and maintenance
Vortex flowmeter: The structure is simple and firm, there are no moving parts, and it is very reliable for long-term operation. It is easy to maintain, and the sensor does not directly contact the medium.
Electromagnetic flowmeter: The sensor structure is also simple and firm, there are no moving parts, it is not easy to have mechanical failures, and it has a long service life. And the sensor is easy to clean and disinfect, suitable for industries with high hygiene requirements. However, the installation and commissioning requirements of electromagnetic flowmeters are strict and need to be carried out in accordance with specifications.
Price and application
Vortex flowmeter: Although the scope of application is narrow, the price is relatively cheap, and it is widely used in many industries such as thermal power, petroleum, and chemical industry.
Electromagnetic flowmeter: The scope of application is wide, but the price is relatively high. It is particularly suitable for occasions with high requirements for flow accuracy, small pipelines, or flow control, such as liquid mixing, water treatment and other industries.
Special considerations
Vortex flowmeter: cannot measure fluid media with a temperature of ≥300℃, and has low high temperature resistance. It has high requirements for straight pipe sections, and usually needs to ensure a straight pipe section length of 40D in front and 20D in the back to meet the measurement requirements. It is not suitable for pipes with a diameter greater than DN300mm.
Electromagnetic flowmeter: Limited by the insulation lining material of the measuring tube, it is currently unable to measure high-temperature and high-pressure fluids. In order to ensure the measurement accuracy, the fluid needs to maintain a stable flow in the pipeline, and a certain length of front and rear straight pipe sections is required before and after the electromagnetic flowmeter. It is easily affected by the surrounding electromagnetic field, and may affect the accuracy of the measurement in an environment with large electromagnetic interference.
In summary, the choice of vortex flowmeter or electromagnetic flowmeter depends mainly on the specific application scenario and requirements. If you need to measure gas or steam flow, are more sensitive to price, and have a small vibration in the working environment, the vortex flowmeter may be more suitable. If you need to measure the flow of conductive liquids, have high accuracy requirements, or have strict requirements on hygiene in the working environment, the electromagnetic flowmeter is a better choice.