Desulfurization brine flow meter is one of the instruments often used in flow measurement. Desulfurization brine flowmeter according to the principle of work there are many kinds of, selection needs to be based on the actual working conditions to choose the right flowmeter.
Project Overview
Let's talk about some of the flow meters commonly used in demineralized water flow measurement.
一、Magnetic inudctive flowmeter
Magnetic inductive flowmeter is a flow measurement instrument that works based on the principle of electromagnetic induction. It consists of a sensor and a transmitter.
1.Working Principle
Magnetic inductive flowmeter basic principle is: in general non-conductive materials made of pipes outside, installed a pair of magnetic poles N and S, to generate a magnetic field. When the conductive liquid flows through the pipe, because the fluid cuts the magnetic lines of force and produced a magnetic susceptibility to electromotive force, this induced potential by the perpendicular direction of the magnetic poles and the two electrodes lead, when the strength of the magnetic field is unchanged, the diameter of the pipeline a certain amount of this induced potential size is only related to the flow rate, the size of the induced potential is transmitted to the display instrumentation, it can be read out the flow rate.
2.Vantage
- 1)No moving parts or resisting fluids in the measuring conduit, resulting in low pressure loss, no mechanical inertia, and therefore a sensitive response.
- 2)Wide measurable range: range ratio is generally 10:1, up to 100:1, the flow rate range is generally 1-6m/s, can be extended to 0.5-10m/s; flow rate range from 90mL/h to more than 100,000m3/h; pipe diameter range from 2mm to 2400mm or 3000mm.
- 3)Can measure the volume flow of liquids containing solid particles, suspensions or acids, alkalis, salt solutions, etc. with a certain conductivity, can also measure the pulsating flow, and can be bi-directional measurement.
- 4)Flow signal and fluid volume flow between the linear relationship, so the instrument has a uniform scale; and the volume of fluid flow with the physical properties of the medium, flow state has nothing to do, so the electromagnetic flowmeter can be used to measure the volume of other conductive liquids after calibration with water only without correction.
- 5)The front straight section requirement is low compared to most other flow meters.
3.Drawbacks
- 1)The operating temperature and pressure must not be too high.
- 2)Limited range of application and cannot be used to measure the flow of non-conductive fluids such as gases, steam and petroleum products, and fluids containing a high number of large air bubbles.
- 3)When the flow rate and velocity distribution do not meet the set conditions, large measurement errors will occur.
- 4)When the flow rate is too low, to amplify and measure with the interference signal to the order of magnitude of the induced potential is more difficult, and the instrument is also prone to zero drift; 5) Electromagnetic flowmeter signals are relatively weak, the outside world slightly interfere with the accuracy of the measurement can be affected.
二、Ultrasonic flowmeter
Ultrasonic flow meter is through the detection of fluid flow on the ultrasonic beam (or ultrasonic pulse) to measure the volume flow meter.
1.Principle of operation: sound waves propagate in the fluid, the downstream direction of the sound wave propagation speed will increase, against the direction of the flow is reduced, the same propagation distance has a different propagation time. Propagation time method is the use of propagation speed difference and the relationship between the measured liquid flow rate to obtain the flow rate, and combined with the diameter of the pipe to obtain the flow rate.
2.Vantage
- 1)Ultrasonic flowmeter can be used for non-contact measurement, clamp-on transducer ultrasonic flowmeter can be installed without stopping the flow of the carrier pipe, as long as the pipeline to be measured outside the installation of the transducer can be, i.e., can not be disconnected or can not be punched on the existing pipeline with ultrasonic flowmeter to measure the flow rate.
- 2)Ultrasonic flowmeter for flow resistance measurement without additional pressure loss.
- 3)Instrumentation coefficients of the measuring meter can be calculated from the geometry of the actual measuring pipe and acoustic channel, etc., which can be calibrated by the dry method, and generally do not need to be calibrated for real flow except for the type with a measuring pipe section.
- 4)Ultrasonic flowmeter for large round and rectangular pipelines, and the principle of the pipe diameter is not limited to its cost is basically independent of the pipe diameter.
- 5)Doppler ultrasonic flow meters can measure liquids with a high solid phase content or containing air bubbles.
3.Drawbacks
- 1)Propagation time method in the ultrasonic flowmeter can only be used for clean liquids and gases, can not measure the suspended particles and bubbles over a certain range of liquids; on the contrary, the Doppler method of LSF can only be used to measure the liquids containing a certain amount of heterogeneous phase.
- 2)External clamped transducer ultrasonic flowmeter can not be used for lining or scaling of the pipe is very thick, and can not be used for the lining (or rust) and the inner pipe peeling (if the sandwich gas will seriously attenuate the ultrasonic signal) or corrosion is serious (change the ultrasonic path) of the pipeline.
- 3)The Doppler method of ultrasonic flowmeter in most cases does not have a high number of measurements.
- 4)Cannot be used for pipe diameter less than DN25mm.