RU2340878C1 - Fluid level monitoring sensor - Google Patents

Abstract

FIELD: physics; measurements.

SUBSTANCE: present invention pertains to measuring techniques and can be used for monitoring the level of different fluids in devices, containers and tanks of stationary and moving equipment. The sensor for measuring the level of a fluid has a hermetic case (1), in form of section of a pipe made from non-magnetic material, upper and lower flanges (2), at the butt ends of the case and joined together by three stud-bolts with nuts, spherical displacer (3), made from non-magnetic material, ring shaped permanent magnet (4), put inside the spherical displacer. The case 5, of the detector element (reed switch) is fixed on the outer surface of the case of the sensor by screws. Reed switch 6, is outside the case of the sensor. The inlet and outlet pipes (12, 13), welded to the flanges of the sensor when the sensor is mounted on user products, hermetically join the sensor to the pipes.

EFFECT: increased efficiency and accuracy of monitoring fluid level.

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Description

The invention relates to devices for controlling the level of a liquid and can be used to control the level of various liquids in apparatuses, containers and vessels of stationary and mobile installations.

A device [1] is known for indicating the liquid level, consisting of a hollow body with holes, inside of which there are reed switches, a grid and a float with a built-in permanent magnet, while the float is placed coaxially with the body.

Closest to the proposed technical essence is a device for indicating the liquid level [2], comprising a hollow body with holes made of non-magnetic material and consisting of three parts coaxially connected to each other by means of threaded connections, inside the body there is a grid, a cylindrical float made of non-magnetic material with a permanent magnet mounted on it, made in the form of a disk, a reed switch is placed in the upper part of the housing.

The disadvantages of the known devices for indicating the liquid level are the lack of reliability and measurement accuracy with a long service life, because when using cylindrical floats in these devices, it is possible to jam (seize) inside the housing due to the large friction force arising between the cylindrical surfaces of the housing and the float due to the appearance of a plaque layer on these surfaces from the effects of controlled fluid products during long-term operation of the sensor.

The proposed design of the sensor will significantly improve the reliability and accuracy of measuring the liquid level.

This goal is achieved by the fact that in the sensor for monitoring the liquid level, containing a hollow body with holes made of non-magnetic material, a float with a built-in permanent magnet, a reed switch, the body is made in the form of a pipe segment, the ends of which are hermetically connected to the ends of the drain tubes of the liquid tank , and is equipped with stops to limit the stroke of the float, made in the form of a hollow ball, inside of which is located below the center at a distance of 0.3-0.4 of the radius of the ball is a permanent magnet, which is made in the form of a ring, and g Rkoni disposed outside the sensor housing, wherein its longitudinal axis is perpendicular to the plane of the permanent magnet, the reed switch contacts displayed on the terminal block disposed in the housing the sensor element.

Figure 1 presents the sensor for measuring the liquid level, which contains: 1 - sealed housing, made in the form of a pipe segment of non-magnetic material; 2 - upper and lower flanges located on the ends of the housing and interconnected by three studs with nuts; 3 - a ball-shaped float made of non-magnetic material in the form of two hemispheres and interconnected by a weld; 4 - a permanent magnet made in the form of a ring and located inside a spherical float; 5 - housing of the sensing element (reed switch), mounted on the outer surface of the sensor housing with screws; 6 - reed switch located outside the sensor housing; 7 - three studs with nuts; 8, 9 - sealing gaskets; 10, 11 - restrictive stops of non-magnetic material; 12, 13 - inlet and outlet tubes welded to the sensor flanges when mounting the sensor on consumer products.

Figure 2 shows the connection diagram of the sensor to the tank. The housing of the sensor 1 with a hollow spherical float 3 is connected to the reservoir 14 by the method of communicating vessels using a supply pipe 12 with valve 15 and a discharge pipe 13 with valve 16.

The sensor for monitoring the liquid level works as follows. When filling a reservoir or vessel 14 with liquid under pressure through a pipe 19, the liquid simultaneously enters the internal cavity of the sensor housing 1 through an open valve 15 and raises the float 3 with a permanent magnet placed in it to the liquid level X controlled by the sensor (the upper point of the sensor operation zone level).

The magnetic field of a permanent ring-shaped magnet located inside the ball-shaped float 3 acts on the reed switch (not shown in FIG. 2), placed in the housing 5 of the sensing element (reed switch), and the magnetically controlled contacts of the reed switch are closed. Information on finding the contacts of the reed switch of the sensing element in the closed position via the cable communication line 17 enters the amplifier-converting unit 18, in which an output signal is generated which is detected by ignition using the control unit 19, the power supply unit 20, the electronic key 21 and the actuating device 22 indicator light "Exit" and entering the registrar. When the tank is further filled with liquid above level X, the contacts of the reed switch remain in the closed position, and the float 3 rises up to touch the surface of the upper limit stop 10 of the sensor.

When the liquid level drops below the X level by a certain value ΔX, corresponding to the lower point of operation, the contacts of the reed switch open and remain in the open state with a further decrease in the liquid level until the next cycle of operation.

Information on finding the contacts of the reed switch in the "open" position on the cable line through the amplifier-converting unit 18 is sent to the recorder, and the indicator frame "Output" goes out.

Improving the reliability and accuracy of the proposed liquid level sensor is achieved by:

1) ensuring the tightness of the housing by connecting the upper and lower flanges to the ends of the sensor housing through rubber gaskets using three studs with nuts and a welded connection of the flanges to the outlet pipes;

2) reducing the friction force between the inner cylindrical surface of the cylindrical body of the sensor and the float, because the float is made in the form of a hollow ball and its contact with the cylindrical surface of the sensor housing can occur only along one diametrical line of the ball, which eliminates jamming of the float;

3) increasing the sensitivity of the reed switch to the magnetic field of an annular magnet, which is magnetized in the direction coinciding with its axis, perpendicular to the plane of the permanent magnet, as a result of which the magnetic force increases, ensuring the operation of magnetically controlled contacts of the reed switch and eliminating the presence of false operations of the reed switch;

4) a stable orientation of the float in the sensor housing filled with liquid, due to the fact that the permanent magnet is made in the form of a ring and is located inside the float below the center of the hollow ball at a distance (0.3-0.4) of the length of the radius of the ball.

Thus, the use of the proposed liquid level sensor will improve the reliability and accuracy of control.

Information sources

1. USSR author's certificate No. 859615 A, E21B 47/04, publ. bull. No. 31, 1981.

2. Patent for the invention of the Russian Federation No. 2175387, E21B 47/04, G01F 23/30, publ. bull. No. 30, 2001.

Claims (1)

A sensor for monitoring the liquid level, comprising a hollow body with holes made of non-magnetic material, a float with a built-in permanent magnet, a reed switch, characterized in that the body is made in the form of a pipe segment, the ends of which are hermetically connected to the ends of the drain tubes of the liquid tank, and is equipped stops to limit the stroke of the float, made in the form of a hollow ball, inside of which, below the center at a distance of 0.3-0.4 of the radius of the ball, is a permanent magnet, which is made in the form of a ring, and the reed switch is located outside the sensor housing, and its longitudinal axis is perpendicular to the plane of the permanent magnet, the contacts of the reed switch are output to the terminal block located in the housing of the sensing element.

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