RU2808444C1 - Liquid level gauge operating over wide range of pressures, temperatures and volumes - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: devices for measuring liquid level. The device contains a reservoir (1), on which a non-magnetic body (2) is fixed, as well as a non-magnetic tube (3). One end of the tube (3) is plugged, and the other is hermetically fixed to the body (2) and connects the internal volume of the tube with the atmosphere and the optical output of the laser rangefinder (4). The tube (3) is fitted with a freely moving washer (5) made of magnetic stainless steel. Along the outer perimeter of the washer (5), floats (6) with an open bottom, made of non-magnetic material, are evenly distributed. Inside the tube (3) there is a permanent magnet (9) freely moving in it, on which a reflector (8) of the laser beam generated by the laser rangefinder (4) is fixed.

EFFECT: increase of the accuracy of measurements and an expansion of functionality.

2 cl, 1 dwg

Description

Field of technology to which the invention relates

The invention relates to high-precision level gauges with a continuous measurement scale, designed to measure the level of liquid, including aggressive liquid, in vessels with a volume from a fraction of a liter to thousands of liters under high pressure and at high temperature.

State of the art

A known level gauge according to A.S. No. 732677, G01F 23/05 from 05/05/80.

The disadvantage of this level gauge is that its ideology and design are adapted for bypass level indicators that record the upper and lower values of the liquid level, which are absolutely unsuitable for working with viscous liquids such as oil, which have a large surface tension force, leading to the float sticking to the tank body, especially in extreme positions. Deposition of heavy components, such as bitumen and coke, on the surface of the float leads to loss of buoyancy and the need for periodic washing of the level gauge structural elements, which requires periodic disassembly and reassembly with replacement of sealing elements and leak testing of the device operating under high pressure. The main disadvantage of a bypass float level gauge is its large volume, due to the need to ensure the buoyancy of the float due to its size, which is unacceptable for high-pressure separators, the volume of which usually does not exceed 1 liter.

There is also a patent for invention number 2625262 dated July 12, 2017. A level gauge for a continuous automatic transfer system for viscous liquid under high pressure. The disadvantage of this level gauge is its specialty, that is, it is designed to solve a specific problem and is not intended for widespread use.

Disclosure of the Invention

The purpose of the present invention is to create a universal level gauge characterized by:

- high measurement accuracy over a wide range of measured volumes;

- a wide range of liquids whose level needs to be measured;

- a wide range of pressure in the vessels on which the level gauge is installed;

- wide range of temperatures of vessels in which the level gauge is installed.

This goal is achieved by the fact that the level gauge consists of a float and a non-magnetic tube, one of the ends of which is plugged, and the second is hermetically sealed to the body and connects the internal volume of the tube with the atmosphere, on which there is a washer made of magnetic stainless steel that moves freely along it along the outer perimeter of which evenly several floats made of non-magnetic inert material are distributed and fixed, and inside the tube there is a permanent magnet freely moving in it with a reflector of a laser beam mounted on it, formed by a laser range finder, mounted on the body opposite the end of the tube connected to the atmosphere, at the plugged end of which is coaxial with it secures a non-magnetic ring, the outer diameter of which is greater than the inner diameter of the magnetic stainless steel washer.

Description of drawings

In fig. 1 Shown is a liquid level gauge operating over a wide range of pressures, temperatures and volumes.

Carrying out the invention

The device consists of a non-magnetic level gauge housing 2 attached to the tank 1, on which the unplugged end of the non-magnetic tube 3 is hermetically sealed, connecting its internal volume with the atmosphere and the optical output of the laser range finder 4, the beam of which is located coaxially inside the tube 3. The tube 3 is fitted with a washer 5 made of magnetic stainless steel, freely movable along the tube 3 by non-magnetic floats 6 with an open bottom, fixed along the outer perimeter of the washer 3. At the plugged end of the tube 3, a non-magnetic ring 7 is fixed coaxially with it, the outer diameter of which is greater than the inner diameter of the washer 5, which prevents unauthorized removal of the washer 5 from tube 3. Inside tube 3 there is a reflector 8 of the laser beam of the rangefinder 4 made in the form of a coil, which prevents it from warping and jamming when moving inside tube 3. Inside the coil there is a permanent magnet 9 that interacts through a magnetic field with washer 5. The length of tube 3 is selected in such a way that when the reflector coil 8 touches the bottom of the tube 3, the magnet 9 is located opposite the washer 5 and when the washer 5 moves upward together with the pop-up floats 6, it moves together with it and the reflector 8 in accordance with the change in the liquid level in the tank 1.

The device works as follows

The beam of the rangefinder 4 passes inside the tube 3, reaches the reflector 8 and, reflecting from it, returns to the rangefinder 4, measuring the distance from the rangefinder to the reflector 8 with an accuracy of fractions of a millimeter. When the liquid level in the reservoir 1 changes, the floats 6 begin to move, moving along the tube 3 washer 5, which interacts with it through the magnetic field of the permanent magnet 4, moving it together with the reflector 8 inside the tube 3.

The change in the position of the reflector 8 will be recorded by the range finder 4, the signal of which is inversely proportional to the height of the position of the reflector 8 and corresponds to the liquid level in tank 1.

In the initial state, the tank 1 is empty and the floats 6 rest with their open part on the bottom of the tank 1, and the permanent magnet 4 is located opposite the washer 5 and interacts with it through a magnetic field. The operation of the level gauge begins with calibration, which includes weighing a measuring container with liquid that will be in the tank. The liquid from the measuring container is slowly poured into tank 1 until the floats 6 begin to float, i.e. the laser rangefinder 4 will record the movement of the magnet 9 and the reflector 8. At this moment, the overflow of liquid stops, and the remaining liquid in the measuring container is weighed, i.e. The dead volume not measured by the level gauge is determined, which must be added to all further readings of the level gauge. The second stage is the calibration of the rangefinder in ml/mm, for which the remaining liquid from the measuring container is poured into reservoir 1, the readings of the rangefinder 4 are recorded and the ratio of the change in volume to the rangefinder readings is calculated.

If tank 1 has a complex geometric shape, then it is necessary to calibrate the entire scale of the level gauge.

The proposed level gauge has no restrictions on application and can be used:

- for level measurement in the volume range from ml to m3;

- at any pressure in the tank;

- over a wide range of liquid temperatures;

- for measuring the level of aggressive liquids;

- for measuring with high accuracy determined by the accuracy of the range finder.

Claims (2)

1. A level gauge consisting of a float with an open bottom and a non-magnetic tube, one of the ends of which is plugged, and the second is hermetically fixed to the body and connects the internal volume of the tube to the atmosphere, characterized in that a freely moving magnetic stainless steel washer is put on the tube , along the outer perimeter of which several floats with an open bottom, made of non-magnetic inert material, are evenly distributed and fixed, and inside the tube there is a permanent magnet freely moving in it with a reflector of a laser beam attached to it, formed by a laser range finder, mounted on the body opposite the one connected to the atmosphere end of the tube. 2. A level gauge according to claim 1, characterized in that at the plugged end of a tube made of non-magnetic material, a non-magnetic ring is fixed coaxially with the tube, the outer diameter of which is larger than the inner diameter of the magnetic stainless steel washer.

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