SU1765698A1 - Mass vibrational flowmeter - Google Patents

Abstract

SUMMARY OF THE INVENTION: A flow meter comprises a housing with tubes, a tube excitation assembly, and readout assemblies. The tubes are connected to the body by plates that are perpendicular to the plane of oscillation. The plates are located at the points of attachment of the removal and excitation assemblies. 4 il.

Description

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yes ° The invention relates to the field of instrumentation, and more specifically to a device for; The third mass flow rate of the compressed gas WG, as well as the quantity JE4 A SftiWt KWt th -v-, and

these media in units / masses, and foioll6ef to be used in the automation of technological processes and implementations of the system. calculations at tempering | 1bSyu1 сТ5е 4 in the oil, gas, chemical industry and other industries & LH

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 There is a known mass vibratory flow rate, rTs%, with a VSH | Yy yz flow sensor, which is connected to (5Ga1Dr ssD) with supply and discharge channels of 5k dy STRGili gas and fixed ffaWu with U6 piping, signal pickup nodes containing solenoids, - a pipeline, and magnets, sealed with a tube no. in a pipeline, and an excitation of oscillations, consisting of a sol, sMpirtneiHdro on one pipe of the Hi-Fi, and a magnet placed on the second pipeline, and an electronic unit, connected Wi &

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the solenoid with the inputs and outputs of the pickup nodes

The disadvantages and other devices are, firstly, the discrepancy between the center of mass of oscillating pipelines and the point at which the amplitude of oscillations of the pipelines is maximum, and secondly, the final rigidity of the pipelines in the direction perpendicular to the direction of oscillations excited by the oscillation excitation unit. Both deficiencies result in

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a sharp increase in the measurement error of the flow rate when an external vibration is applied to the device, especially in the case of coincidence (or proximity) of the vibration frequency to the natural vibration frequency of the pipelines.

The closest to this invention to the technical essence and the achieved result is a mass vibratory flow meter, consisting of a flow sensor containing a base with channels for supplying and discharging liquid and fixed on it with the possibility of oscillations by pipelines, signal pickup units

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consisting of magnets mounted on the base of the solenoids and mounted on the pipelines, and an oscillation excitation unit consisting of solenoids mounted on the serially connected solenoids and magnets located on the pipelines, and an electronic unit connected to the outputs of the signal pickup nodes and the inputs of the oscillating node.

The disadvantage of this device is also an increased error in measuring the mass flow under the influence of external vibration due to the always remaining residual imbalance of the oscillating pipelines and the technological spread of their stiffness, including in the direction of oscillations excited by the oscillation excitation unit. Because of this, the effect of vibration on the pipelines different and causes an increase in flow measurement error.

The purpose of the invention is to improve the accuracy of flow measurement and reduce the influence of external vibration on the readings of the device.

This goal is achieved by the fact that in a mass vibratory flow meter consisting of a flow sensor containing a base with supply and discharge channels and connected to it with the possibility of oscillations relative to the base and each other with pipelines, the excitation oscillations and pickup signals consisting each of the pipelines, which are mounted on the basis of solenoids and placed on the pipelines of magnets, and an electronic unit connected to the outputs of the signal pickup units and the inputs of the oscillation excitation unit Warping flow sensor elastic elements, you are a complements, for example in the form of plates arranged in a plane perpendicular to the direction of oscillation pipelines excited oscillation drive unit.

In order to increase the natural frequency of vibrations of pipelines while maintaining the rigidity of pipelines in the direction of Coriolis forces, elastic elements can be connected to the pipelines in a place as far as possible along the axis of the pipelines from the points of fixing the pipelines at the base of the flow sensor.

In order to minimize the influence of external vibration on the instrument readings, the elastic elements can be connected to the piping at the place where the pickup stations are installed, and their stiffness in the direction of oscillations excited by the excitation unit is chosen to be as small as possible.

The invention is illustrated by the drawings, which depict the structural schemes of the flow sensor with the arrangement of elastic elements in the form of plates connected to the pipelines at a location as far as possible along the axis of the pipelines from their attachment points at the base of the device (Fig. 1), and at the installation site at the pipelines nodes pickup signal (figure 2).

The flow sensor (Fig. 1) consists of a base 1 with inlet channels 2 and a drain 3 of liquid and attached to it with the possibility of oscillations relative to the base 1 and relative to each other pipelines 4 and 5. Signal removal units consist of 6- located on the basis of solenoids 9 and fixed on the pipelines 4 and 5 of the magnets 10-13. The oscillation excitation unit consists of solenoids 14 and 15 installed on the base 1 and magnets 16 and 17 mounted on pipelines 4 and 5. Pipelines 4 and 5 are connected to base 1 by elastic elements made in the form of plates installed in a plane perpendicular to the direction of oscillation of pipelines 4 and 5, excited by the vibration excitation unit.

The difference in the flow sensor shown in FIG. 2 is that the elastic elements — plates 20–23 — are connected to pipelines 4 and 5 in the place where the magnets 10–13 of the signal pickup nodes are attached to them.

The device works as follows.

An electronic unit (not shown), perceiving an output sinusoidal signal from one of the signal pickup units, for example from series-connected solenoids 6 and 8, produces a pulse signal of the same frequency with amplitude depending on the amplitude of the input signal, which is fed to solenoids 14 and 15 vibration excitation unit. In this way, pipelines 4 and 5 are oscillated in opposite phase at natural frequency and the amplitude of these oscillations is stabilized.

At the same time, the signal from the output of this pickup unit is compared in the electronic unit with a sinusoidal signal from the second pickup unit (from the output of series-connected solenoids 7 and 9). In this case, a unified signal is formed at the output of the electronic unit, which is proportional to the time shift between said sinusoidal signals, which, in turn, is proportional to the mass flow rate of liquid or compressed gas through the device.

The plates have rigidity in the direction of oscillations excited by the oscillation excitation unit, equal to about 2-3 pipe stiffnesses in the same AVAILABLE, due to this, it provides 5 seconds not only protection of the considered oscillatory system from external vibration, x.w w .

but also increases sensitivity to

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change in mass flow through pipelines. This is due to the fact that 10 of the projection of the square of the total (its own and elastic elements) stiffness increases the frequency of natural oscillations of the pipelines in the SCALES of excitement caused by the excitation of the vibrations, and accordingly vibrating pipelines Coriolis force. In proportion to the Coriolis sludge, the de- piping increases at the installation site of 20 signal pickup nodes.

- In the flow sensor (FIG. 2), due to the fact that the elastic elements — plates 20–23 — are connected to pipelines 4 and 5 in the place where the magnets 10–13 are attached to them 25, maximum protection of the signal pick-up points from external air vibrations is achieved. reducing the sensitivity to changes in mass flow through the device; the rigidity of the plates 20-23 in the 30 direction of oscillations excited by the oscillation excitation unit is performed

It is negligibly small compared with the rigidity of pipelines 4 and 5 in the same direction.

Claims (2)

1. A mass vibratory flow meter consisting of a flow sensor containing a base with fluid inlet and outlet channels and fixed in it with the possibility of oscillations relative to the base and each other with pipes, oscillation excitation units and signal pickup units consisting of installed on the basis of solenoids and on the pipelines of the magnets, and the electronic unit connected to the outputs of the signal pickup units and the inputs of the oscillation excitation unit, characterized in that, in order to improve the accuracy of flow measurement by reducing the influence of external vibration on the flow meter readings; each of the pipelines is connected to the base of the flow sensor by elastic elements made in the form of plates placed in a plane perpendicular to the direction of vibration of the pipelines. 2. Flow meter pop 1, characterized in that the elastic elements are connected to the piping at the place of installation of the signal pickup and drive unit on them and are made with low rigidity in the direction of the excited vibrations l ( 1 / I -a y / hl 20 / U Ш 7 №21 5-5 7h and rsh / Ukh / utuul 227 I7 figs Type B C Have ten -Y: AL / ff 20 Lshg4 Sh