Flow is a dynamic quantity, so flow measurement is a complex technology, from the measured flow body, including gas, liquid and mixed fluid of three different physical properties of the fluid;From the measurement conditions, but also a variety of, in the metallurgical industry as an example, the production of liquid – water measurement, because of the different production system, is divided into clean ring water, turbidized ring water, steel rolling wastewater, smelting wastewater, domestic wastewater and other different media.
The selection and application of flow meter are also different according to different sewage quality.In use, different discharged sewage can be used in different flow meters.
Ultrasonic flow meters
Ultrasonic flow meter adopts advanced multi-pulse technology, signal digital processing technology and error correction technology, so that the flow meter can adapt to the environment of the industrial site, the measurement is more convenient, economic and accurate.The products reach the advanced level at home and abroad, can be widely used in petroleum, chemical, metallurgy, electric power, water supply and drainage fields.It is also measured by flow speed to reflect the size of the flow.
Although the ultrasonic flow meter appeared in the 1970s, it is very popular because it can be made into a non-contact type, and can be linked with the ultrasonic water level meter to measure the open flow, and does not produce disturbance and resistance to the fluid.Ultrasonic flow meter can be divided into time difference type and Doppler type according to the measuring principle.
In addition, the ultrasonic Doppler flow meter made of Doppler effect is mostly used to measure the medium with certain suspended particles or bubble medium, which has certain limitations, but it solves the problem that the time difference ultrasonic flow meter can only measure a single clear fluid, and is also considered as an ideal instrument for non-contact measurement of bi-directional flow.
Electromagnetic flow meter
Electromagnetic flow meter is a new flow meter developed rapidly with the development of electronic technology in the 1950s and 1960s.Electromagnetic flow meter is a kind of instrument which uses electromagnetic induction principle and measures the flow of conductive fluid according to the electromotive force caused by the conductive fluid through external magnetic field.It has a series of excellent characteristics, which can solve the problems that other flow meters are not easy to use, such as dirty flow, corrosion flow measurement.
The measuring channel is a smooth straight pipe, which will not be blocked. It is suitable for measuring liquid solid two-phase fluids containing solid particles, such as paper pulp, mud, sewage, etc.
Comparison of ultrasonic and electromagnetic flow meters
Electromagnetic flow meter and ultrasonic flow meter, because the meter flow channel does not set any obstruction, are no obstruction flow meter, is suitable for solving the flow measurement difficult problem of a class of flow meter, especially in the big mouth flow measurement has more outstanding advantages, it is one of the rapid development of a class of flow meter.
Finally, for sewage flow meter selection, each flow meter has its own advantages and disadvantages, in the process of sewage treatment, should be selected according to the actual needs.The cost of ultrasonic flow meter is low, the measurement accuracy is high, the operation is stable, the installation and maintenance is convenient, the price will not be higher and higher with the increase of pipe diameter, but it will be more and more expensive because of the increase of sound path.The electromagnetic flow meter has stable measurement, wide application range and can measure a variety of media, but it is easy to be interfered by electromagnetic waves.As the diameter of the pipe increases, the price becomes more and more expensive.
Post time: Oct-15-2021