SU564531A1 - Electromagnetic flow gauge - Google Patents

Description

(54) ELECTROMAGNETIC FLOW METER

one

The invention relates to the field of measuring the flow rate of a liquid by the electromagnetic method.

Flowmeter sensors {1, which contain a magnetic system and create a magnetic field in a pipeline, perpendicular to the longitudinal axis and electrodes on opposite walls, with a line connecting electrodes, perpendicular to the induction field, are known. When using flow sensors in pressure pipelines, point electrodes are used, however the Sherkliff weighting function for point-like electrodes is non-uniform, which leads to a significant error at non-asymmetric velocity diagram.

Flow meters f23 / are known in which, when using a rectangular cross section channel and electrodes - conductive walls, the weighting function is homogeneous. However, due to the limitation of the length of the device along the flow, a three-dimensional potential distribution takes place, and not a two-dimensional one. The effect of the terminal effects associated with the three-dimensional potential distribution decreases with increasing instrument length. Increasing the length of the electrodes brings the total weight function closer to the ideal (at constant

the width of the zone of the curved weight function at the ends of the electrodes increases the homogeneous middle section), however, the magnetic system should also increase accordingly. Due to the presence of a magnetic field gradient at the ends of the magnet, circulating currents arise in the liquid in a plane perpendicular to the magnetic field. This reduces the resulting potential difference across the electrodes. Therefore, the size of the magnetic system must exceed the size of the electrodes, which must be placed in the zone of the most uniform, magnetic field. Thus, while striving to bring the sensor closer to the ideal size, its dimensions and energy consumed by the magnetic system are here.

Claims (2)

The purpose of the invention is to reduce energy consumption by providing a uniform weight function between the electrodes at their final length. A composite electrode is used for this: three spaced plates. The central electrode is a measuring lm, and the same potential is maintained at the side electrodes as at the measuring one. The field in the interelectrode zone is the same as in the case of solid electrodes, the plane-parallel in the central part and blunt along the edges, since an artificially equipotential surface is created composite electrode. Therefore, the weighting function for the central measuring electrode is strictly uniform. Due to the use of narrow electrodes, the entire sensor has small dimensions along the length of the channel. A uniform magnetic field must be created only in the zone of the middle electrode, since the edge areas of the magnetic field are guard electrodes, while the size of the magnetic system relative to the electrodes is reduced. The drawing shows the flow meter. Electromagnetic flow meter contains a pipe body 1 and a non-conductive non-magnetic material, electrode 2, measuring electrode 3 connected to Earth, guard electrodes 4 and 5, and magnetic system 6. Potential removed from the electrode through the extruder repeater 7 is fed to electrodes 4 and 5. , 4 and 5 are the same, and there is no distortion of the floor at the boundaries between electro electrodes. The field covering the electrode 3 is odious, and the marginal areas occur in the zones of the guard electrodes 4 and 5, the output resistance of the electrical repeater is small, and the voltage generated on the electrodes 4 and 5 when the fluid moves does not affect the output signal. The voltage from the output of the repeater is fed to the measuring circuit. The magnetic system is located in such a way that the uniform field is located in the zone of the electrode 3, and the edge areas in the zone of the electrodes 4 and 5. Circulating currents do not affect the external potential of these electrodes. When fluid flows through a filled rectangular pipeline 1, it intersects the magnetic field created by the magnet system b and induces a potential on electrode 3 (relative to electrode 2}, | proportional to the average velocity. The potential of electrode 3 is fed to an earttern trailer, the output of which is connected to the receiver device and electrodes 4 and 5. Due to the presence at the electrode boundaries of the 3 potentigshov from electrodes 4 and 5, the weight function lines at the electrode 3 are parallel, the weight function distribution is two-dimensional throughout the whole measuring volume, Although the electrode 3 has finite dimensions. The non-axisymmetry of the flow and any other disturbances in the velocity diagram will not introduce errors into the measurement. The electrodes are much narrower than the width of the channels, the magnetic system has a relatively small dimensions in the direction of fluid flow and to create the required field in the measuring volume. 1 | 5 energy is reduced - the airgrom of the flow meter is reduced. - ....,;. Described; the flow meter significantly improves the metrological parameters of electromagnetic flow meters, increases energy consumption, eliminates the imost in the restful portion that allows the flow meter mounted EA .ventilem, knee, etc. elements, FIXING the distortion in the plot of speeds. Electromagnetic Flowmeter, which contains a non-magnetic non-conductive section of a rectangular pipeline, a magnetic system and measuring electrodes on the side walls, which, with a whole reduction in energy consumption, are installed on one of the side walls on either side of the measuring electrode two guard electrodes, potentials on a second, are equal, to the potential of the central electrode. Sources of information, schchn those in attention when. Expert: 1. Corsuky L; M ,. Electromagnetic Hydraulic Instruments, 1964, p. 17. 2. Korsunsky LM Electromagnetic Flow Meters with a Rectangular Dimension Journal I 10, 1960, p. equipment rSr