RU1820333C - Meter of flows rate of gas or liquid - Google Patents

Abstract

Usage: the invention relates to techniques for measuring the velocity of gas or liquid flows in both open and closed channels, in particular for measuring air velocity in ventilation ducts. SUMMARY OF THE INVENTION: the meter comprises a tubular body of rectangular cross section, a body in the form of a prism with a blade that is mounted on an axis, with cores included in the heels, the blade is made of steel tape, soldered to the axis and pressed into the body prisms, and body flow and plate form. 3 ill.

Description

The invention relates to techniques for measuring the velocity of gas or liquid flows, both in open and closed ducts, in particular for measuring air velocity in ventilation ducts, and can also be used to measure flow proportional to speed.

The aim of the invention is to expand the measuring range and increase sensitivity due to the direct influence of the flow on the oscillating - (- spruce).

Figure 1 presents the structural diagram of the meter; figure 2 - diagram of the registration of oscillations; and in Fig. 3, the basic aspect ratio of the meter.

The meter contains i tubular body 1 of rectangular (or circular) cross section, an oscillating body in the form of a light prism 2 with a blade 3. Prism 2 is provided with a hinge axis 4, for example, in the form of a steel axis with cores included in the heels 5, screwed into diametrically opposite walls of the tubular body 1. Thus, the prism 2 is balanced by the blade 3 and can swing like a clockwork. Following the oscillating body is placed around the body 6, for example, in the form of a plate of width d with a minimum clearance relative to the blade 3. Expansion of the housing

1 is provided by the beveled rear ends of the walls of the housing, where the blade 3 moves.

The registration oscillation circuit contains an inductor 7 with a core 8 included in the circuit of the electric oscillation generator 9. Next, a demodulator 10, an amplifier 11, a pulse shaper 12, and a frequency meter 13 follow.

The meter works as follows. Under the influence of turbulent vortices of the flow in front of body b and the oscillating body (prism

2 with a blade 3) leaves the resting position, I turn in one direction. There is an additional moment of pressure force flow acting on the front “wound of prism 2. Turn prism (L

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more strongly on the axis A. In this case, the blade 3 rigidly connected with it rotates in the opposite direction, opening the flow. The elastic flow reaction pushes the blade in the opposite direction. Due to the moment of inertia, the body is thrown in the opposite direction. Self-oscillations begin, the frequency of which is almost linearly dependent on speed.

A blade 3, which can be made of magnet material (or reinforced by it) crosses the field of the coil 7 above the core 8. In this case, losses occur in the circuit of the generator 9, leading to the amplitude and phase modulation of the frequency of the generator. The demodulator emits the arising pulses, which are amplified by the amplifier 11, fed to the driver 12 and then to the frequency meter 13.

An experimental verification of the meter in air at d 6-8 mm showed that the oscillations started at flow velocities of about 1.5-2.5 m / s and continued without interruption to speeds achieved at the laboratory setup of 60 m / s. The speed to frequency conversion ratio was 2.6-2.9 Hz / m / s. In the prototype layout, vibrations more resembling vibration started at a speed of 20 m / s and stopped at 50 m / s. which confirms the effectiveness of the proposed solution. Moreover, the meter works in

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Claims (2)

1. A gas or liquid flow velocity meter comprising an oscillating body located in a tubular body in the form of a trihedral prism mounted on a hinge axis located in the body of the prism along one of its side ribs perpendicular to the flow, and a flow body installed in the gap relative to the oscillating body A registrar, characterized in that. that, in order to expand the measurement range and increase sensitivity, the prism is equipped with a blade mounted cantilever on the side edge of the prism adjacent to the hinge axis, while the plane of installation of the blade is perpendicular to the opposite face of the prism directed against the direction of flow, and the flow around the body is fixed to the oscillating body, in the plane of the hinge axis perpendicular to the direction of flow, the width of the body flowing around is equal to the width of the face of the prism directed against the direction of flow, and the cross section of the tubular body and expanded in the area of the blade oscillation. 2. The meter according to claim 1. moreover, the blade is made in the form of a flat rectangular plate, the length of which in the direction of flow is L - (1.2-2.5) d, where d is the width of the face of the prism directed against the direction of flow. - / Figure 1 i j 8 fi g Fig 3