JPH045520A - Level sensor - Google Patents

Abstract

PURPOSE:To measure a level with high accuracy even in high-temperature, high-noise environment or special environment wherein poisonous gas is present by detecting the border surface between different phases from variation in the viscous resistance in the border surface by using a rotator, and measuring the liquid level. CONSTITUTION:A torque sensor 21 when detecting torque variation of a motor 13 exceeding a specific quantity judges this point as the border surface between two phases and sends a data read instruction signal to a movement quantity sensor 22, which records the movement distance from an initial position in the up-down direction of the rotator or the movement distance of the whole rod. Consequently, the distance from the initial position to the border surface is measured and the level is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a level sensor. In particular, the level sensor of the present invention relates to a level sensor that detects a liquid level under special environments such as high-temperature melting furnaces, toxic atmospheres, and high-noise environments.

[Prior Art and Problems] The basis of level measurement is to detect the position of the interface between two different phases using various methods and to measure how far that position is from a reference point. Therefore, level measurement is performed by first detecting the boundary surface based on the difference in physical properties of the two phases forming the boundary surface, and combining this with distance measurement.

The primitive methods of detecting the interface include visually confirming the interface between the gas and liquid phases, floating a float on the liquid phase, and reflecting or refracting ultrasound or electromagnetic waves at the interface. There are also methods that utilize various physical quantities, such as the difference in beam absorption between two phases.

However, these conventional level sensors have sufficient accuracy under special environments such as high temperature and high noise.
Stable measurements cannot be made. For example, under extremely harsh conditions such as in a glass melting furnace, a level sensor using a float will be damaged due to expansion of the gas inside the float, making measurement impossible. Furthermore, with a level sensor that detects the interface between two phases using electromagnetic waves, measurement accuracy cannot be expected due to interference due to noise from the high-voltage power supply or diffuse reflection of the electromagnetic waves. In addition, in optical level sensors, particularly those using infrared rays, the presence of high concentration soot and high temperature turbulence inside causes diffuse reflection, reducing measurement accuracy. Furthermore, when sound waves are used, accuracy decreases due to acoustic reflection, noise from the drive unit, and the like. In addition, both elements have a short lifespan in a high-temperature environment.

An object of the present invention is to provide a level sensor that can stably perform highly accurate level measurements over a long period of time even under high temperatures of 1700° C. or higher, high noise environments, or special environments containing poisonous gases. It is in.

[Means for Solving the Problems] The present invention is a level sensor comprising a detection section and a data processing section, the detection section comprising: a vertically movable rotating shaft; a rotor attached to the rotating shaft; The data processing unit includes a rotation motor that drives the rotation shaft, and the data processing unit includes a motion change sensor that detects a change in motion of the rotation motor due to a change in the viscosity of the subject, and a motion change sensor that measures the amount of vertical movement of the rotor. The level sensor comprises a movement amount sensor, and the movement change sensor determines that a change in movement of the rotation motor by a predetermined amount or more has reached a two-phase interface, and reads position data of the movement amount sensor. This is what we provide.

[A working rotator is used to detect the interface between different phases based on the change in viscous resistance at the interface, and measure the liquid level.

"Example" Next, the present invention will be explained in more detail with reference to Examples.

FIG. 1 is a schematic sectional view showing a specific example of the device of the present invention.

In FIG. 1, an apparatus 100 of the present invention includes a detection section and a data processing section 20.

The detection unit has a rotating shaft 11 provided vertically, a disk rotor 12 attached to the tip of the rotating shaft 11, and a rotation motor 13 that drives the rotating shaft 11. Also, around the rotating shaft 11, there is a rod 14 that rotatably supports the rotating shaft 11, and a moving motor 15 that moves the rod 14 up and down.
is provided.

On the other hand, the data processing unit 20 includes a torque sensor 21 that detects a torque change amount, which is a change in motion of the rotation motor 13 due to a change in viscosity, and a movement amount sensor 22 that measures a movement distance of the rod 14.

When the torque sensor 21 detects a change in the torque of the rotation motor 13 by a predetermined amount or more, it determines this point as a two-phase boundary and sends a command signal to the movement amount sensor 22 to read data. , the movement amount sensor 22 records the movement distance of the rotor in the vertical direction or of the entire rod from the initial position. As a result, the distance of the boundary surface from the initial position is measured, and level measurement is performed.

Note that, depending on the viscosity of the liquid to be measured, if the liquid rises as the rotor rises due to the Weissenberg effect, data correction is performed as necessary taking into account the viscosity of the subject.

The shape and size of the rotor are appropriately selected depending on the viscosity of the liquid whose interface is to be detected, in addition to the disk shape. In addition, when used in an extremely high temperature environment such as a glass spinning furnace, it is preferable to use a heat-resistant metal such as molybdenum or niobium for the rotor, rod, and rotating shaft.

Therefore, in order to measure the liquid level using the device of the present invention, the rod is moved up and down without rotating the rotor 12 as shown in FIG. , rotational speed) is detected, and the liquid level 25 is detected and measured based on the amount of movement of the rod from the reference point 24 to that point.

In measuring the level, the type of physical quantity directly obtained from the rotor and the rod to detect the boundary surface of each phase is not particularly limited. That is, the change in motion of the rotor may be the amount of change in torque when the rotation speed is constant, or the amount of change in rotation speed when the torque is constant. Further, the means for measuring the amount of movement of the rod and the change in motion of the rotor may be electrical, optical, or mechanical.

[Effects of the Invention] By using the level sensor of the present invention, highly accurate level measurements can be stably performed over a long period of time even under special environments such as high temperatures, high noise, and toxic atmospheres.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view showing an example of the integrated device of the present invention;
The figure is an explanatory diagram showing a method of level measurement. The main symbols in the figure are as follows. ll: rotating shaft, 12: rotor, 14: rod, 20: data processing unit, 21: torque sensor, 22: movement amount sensor.

Claims (1)

[Claims] A level sensor comprising a detection section and a data processing section, the detection section comprising: a rotation shaft that is movable up and down, a rotor attached to the rotation shaft, and a rotor that drives the rotation shaft. The data processing unit includes a motion change sensor that detects a change in motion of the rotation motor due to a change in the viscosity of the subject, and a movement sensor that measures the amount of vertical movement of the rotor. A level sensor characterized in that the motion change sensor reads position data of the movement amount sensor, determining that a motion change of the rotation motor of more than a predetermined amount has reached a two-phase interface.