Guide the field installation of electromagnetic flow meters

Abstract: The on-site installation information to guide the electromagnetic flow meter is provided by the excellent flow meter and flow meter production and quotation manufacturers. 1 Types and advantages and disadvantages of flow measuring instruments So far, there are as many as 60 types of flow instruments available for industrial selection. The reason why there are so many varieties is that there is still no one that can be used for any fluid type, any range, and any flow state. More flowmeter manufacturers choose models and price quotations. You are welcome to inquire. The following are the details of the article to guide the on-site installation of electromagnetic flowmeters. 1 Types and advantages and disadvantages of flow measuring instruments So far, there are as many as 60 types of flow instruments available for industrial selection. The reason for so many varieties is that a flow test instrument that can be applied to any fluid type, any range, any flow state and any use conditions has not yet been found. Among these flow meters, each product has its specific scope of application, as well as its limitations. According to the measurement principle, flow measuring instruments are divided into mechanical principle, thermal principle, acoustic principle, electrical principle, optical principle, atomic physics principle, etc. According to the most popular and extensive classification method at present, it can be divided into: differential pressure flowmeter, positive displacement flowmeter, float flowmeter, turbine flowmeter, electromagnetic flowmeter, fluid vibration flowmeter, ultrasonic flowmeter, mass flowmeter meters and open channel flow meters. The advantages and disadvantages and main application scope of various flowmeters are shown in Table 1 (due to the many types of mass flowmeters, the advantages, disadvantages and application scopes are different from each other, so they are not listed in the table): (The influence of viscosity is represented in fluid mechanics. The similarity quasi-number of , denoted as Re.Re=ρvL/μ,ρ,μis the density and viscosity of the fluid, v and L are the characteristic velocity and characteristic length of the flow field. The Reynolds number is small, which means that the viscous force between the particles is dominant when the fluid flows, and the particles of the fluid flow regularly parallel to the inner wall of the pipeline. Laminar flow state. The large Reynolds number means that the inertial force is dominant and the fluid is in a state of turbulent flow) 2 Measurement principle of electromagnetic flowmeter According to Faraday's law of electromagnetic induction, when a conductor moves in a magnetic field and cuts the magnetic field lines, induction will be generated at both ends of the conductor The direction of the electromotive force e is determined by the right-hand rule, and its magnitude is proportional to the magnetic induction intensity B of the magnetic field, the effective length L of the conductor in the magnetic field, and the velocity u of the conductor perpendicular to the magnetic field. If B, L, and u are perpendicular to each other, then: e=BLu Similar to this, if a non-magnetic pipe with an inner diameter of D is placed perpendicular to the direction of the magnetic field in a uniform magnetic field with a magnetic induction intensity of B, when the conductive liquid When moving at a flow velocity u in the pipe, the conductive liquid cuts the magnetic field lines, if a pair of electrodes are installed on both sides of the pipe section perpendicular to the diameter of the magnetic field (as shown in Figure 1). It can be proved that as long as the flow velocity distribution in the pipeline is symmetrical to the axis, an induced electromotive force will be generated between the two electrodes: e=kBDū where ū is the average flow velocity (m/s) on the pipe section; k is a constant coefficient, dimensionless ; D is the diameter of the measuring tube (m); B is the magnetic induction intensity (T). From this, the volume flow through the pipeline can be obtained: from the above formula, when the structure of the measuring tube is constant, the volume flow qv is proportional to the ratio e/B, and has nothing to do with the state and physical parameters of the fluid, and the ratio e/B can be measured Obtain the volume flow value qv. When the magnetic induction intensity B is a constant value, the volume flow qv is proportional to the induced electromotive force e. B is the magnetic induction intensity of a DC magnetic field or a sine wave AC magnetic field or other types of magnetic fields. It is provided by the excitation system of the electromagnetic flowmeter. The excitation system can provide various forms of magnetic field waveforms to the electromagnetic flow sensor. Different magnetic field waveforms directly determine the characteristics of the working magnetic field of the electromagnetic flow sensor, and basically determine the processing method of the flow signal of the electromagnetic flowmeter, which has a great influence on the working performance of the electromagnetic flowmeter. 3 Field application data and analysis of electromagnetic flowmeter The field test of electromagnetic flowmeter to measure the flow of clay cement slurry was carried out at the ground pre-grouting construction site of the gangue well in Zhujixi Coal Mine of Wanbei Coal and Electricity Group. During the test, water and three kinds of clay-cement slurries were tested respectively. The specific gravity of the clear water is 1.00g/cm3, and the specific gravity of the three kinds of clay cement slurries are 1.21g/cm3, 1.33g/cm3 and 1.39g/cm3 respectively. Since the technology of electromagnetic flowmeter to measure the flow of clean water is very mature, the flow rate of clean water measured by electromagnetic flowmeter is used as the standard data during the test, and the data when measuring clay cement slurry is compared with it to determine the accuracy of its measurement. . The pump volume of the grouting pump selected during the test is 99L/min; the grouting pipeline is open and pressureless during the test; the test time is 65min, and the sampling interval is 5min. The specific test data are shown in Table 2. The comparison curves of the four sets of data are shown in Figure 2. After analyzing the experimental data, the average instantaneous velocity of clean water is 1.327m/s, among which the average instantaneous velocity of the clay cement slurry with a specific gravity of 1.21g/cm3 is 1.31m/s; the average instantaneous velocity of the clay cement slurry with a specific gravity of 1.33g/cm3 is 1.324m /s; the average instantaneous velocity of clay cement slurry with a specific gravity of 1.39g/cm3 is 1.323m/s, and the error with the average instantaneous velocity of clean water is between -0.232% and -1.304%.
Owing to its customized level indicator and customized level indicator benefits, has become a buzzword in the customized level indicator market.
Guangdong Kaidi Energy Technology Co., Ltd. is a company that offers reliable products. For customization, customized level indicator and customized level indicator in different styles are also in the offer list. Click Kaidi level indicator for more details.
Guangdong Kaidi Energy Technology Co., Ltd. can assure you that we never compromise on our quality standards and are one of the best in the market at present.
give you an additional customized level indicator option for your customized level indicator, whether it being a customized level indicator, customized level indicator or customized level indicator. Go and get more info at Kaidi level indicator.