JPS6155714A - Liquid level controller of tank - Google Patents

Abstract

PURPOSE:To attain liquid level control in a tank by providing a vibrating tube whose low end is led directly or indirectly in the liquid in the tank, a vibrator supporting the vibrating pipe and vibrating it virtually and a valve equivalent means. CONSTITUTION:When the vibrator 4 is energized, a vibrating rod 6 is moved vertically and the vibrating tube 3 is also moved vertically. When the pipe 3 is moved downward, a valve plate 8 cannot follow it, a slight clearance is obtained at the upper end 7 of the pipe 3, and the air in the pipe 3 is discharged upward. When the pipe 3 comes to the lower limit, the valve 8 catches up with and a valve sheet 7 is closed. When the pipe 3 rises while the valve inlet of the valve 8 is closed, the air in the pipe is expanded, the pressure in the tank 1 and the pipe 3 is lowered to rise the liquid level in the pipe. The pressure fluctuation is delivered in the gas in the pipe 3, a standing wave of the pressure in the gas or liquid is generated, the fluctuated pressure is large in the part of the valve plate 8 and less at the lower part of the pipe 3. Thus, the gas is discharged upward between the valve plate 8 and the valve sheet 7. The liquid in the pipe 3 is risen by repeating this state.

Description

[Detailed description of the invention] [Purpose of the invention] "Industrial application field" This invention relates to a device for controlling the liquid level in a container.

``Prior art'' A related invention to this BAL is a vibrating column pump (Japanese Patent Application No. 71.6, 1986-0/1989), which the applicant has already applied for.
There is a patent application No. 1983-0-tart). In a vibrating column pump, the efficiency of the pump action can be improved by adjusting the excitation frequency and excitation acceleration. And the excitation frequency vjL
If the number and excitation speed are not appropriate, the pump will not discharge the liquid and the liquid will rise only halfway up the suction pipe. Therefore, it is extremely inconvenient as a pump.

The present invention was made by paying attention to this phenomenon of vibrating column pumps, and aims to control the liquid level in a container by a simple means.

[Structure of the invention]

This IAF! A is a vibrating tube whose lower end communicates directly with the liquid in the container or indirectly through a stationary tube, an excitation device that supports the vibrating tube and vibrates the vibrating tube in the vertical direction, and a vibrating device that applies pressure to the fluid in the vibrating tube. This is a liquid level control device for a container equipped with means equivalent to a valve that causes fluctuations.

"Example" FIG. 1 is a longitudinal sectional view. A liquid is contained in the container/, and the lower end of the vibrating tube J is submerged in water so that it is below the liquid level. The vibration excitation device DA is attached to a frame 5 fixed to the container 1 so that vibrations are not transmitted to the frame 5. frame! may be fixed to other objects instead of being fixed to the container l.

The vibrating tube 3 is fixedly supported by a vibrating rod 6 at the output section of the vibrating device. The upper end of the vibrating tube 3 is a valve seat 7, which is in contact with the valve plate 5, and a spring de is compressed and inserted between the valve plate and the frame 5 to press the valve plate t against the valve seat 7. The vibration device used is one that can change the vibration frequency and vibration acceleration. For example, the control device 10 changes the speed of the electric motor provided in the vibration device to change the vibration frequency at which the internal imbalance 2i occurs. In a vibrating device that generates vibrations due to rotationally uneven weight, if the excitation acceleration is also changed, the amount of eccentricity of the uneven weight can also be adjusted. The vibrating device is not limited to one that causes reciprocating motion of a solenoid.

When the vibration device DA is energized, the vibration rod 6 moves up and down, and the vibration tube 3
move up and down.

The effects are as follows.

When the valve plate t is vibrated so as to move without following the vibrating tube 3 (Figs. 7 to 6) ■ When the vibrating tube 3 moves downward in Fig. does not follow this, but moves downward with a delay, and at the upper end, a slight gap is created between the vibrating tube J and the valve plate t. At this time, the air inside the vibrating tube 3 escapes to the top.

@ When the vibrating tube J reaches the lower limit, the valve plate t catches up and closes the valve seat as shown in Fig. 3 ◇θ When the vibrating tube 3 rises with the valve opening closed by the valve plate t, the inside of the vibrating tube 3 The air expands, the pressure inside both tubes decreases, and the liquid level inside the tubes rises (Figure 6).

Furthermore, when the vibrating tube J descends, the liquid in the vibrating tube 3 does not fall much due to the inertia of the liquid.

Therefore, at this time as well, gas is discharged to the upper part, the pressure inside the vibrating tube 3 decreases, and the liquid rises.

Due to this action, the vibration tube J is contained in the gas inside the vibration tube 3.
Alternatively, pressure fluctuations due to the valve plate ξ are transmitted and a standing wave of pressure is generated in the gas or liquid, but the pressure standing wave has a large fluctuating pressure at the portion of the valve plate t and decreases at the lower part of the vibrating tube 3. Therefore, gas escapes from between the valve plate t and the valve seat 7 to the upper part. Similarly, by repeating the state from Φ to θ, the liquid rises in the vibrating tube J.

In addition, the valve plate t is made to move following the vibrating tube 3,
When the vibrating tube 3 is moved up and down, the liquid level inside the tube also moves up and down as the pressure of the air column inside the tube changes. This vertical movement of the liquid level is accompanied by the vibration phenomenon of a type of spring JX quantity system consisting of the elasticity of the air column and the mass of the liquid column, and therefore the damping due to friction etc. is small, so the vibration of the vertical movement of the vibrating tube 3 If the number is set to the natural frequency of the air-liquid column system inside the pipe, the air pressure inside the pipe will become extremely high. Therefore, if the valve is opened above a certain set pressure, the valve will open when the air column pressure in the pipe exceeds the valve's set pressure, and the upper limit of the air column pressure will be maintained at the valve set pressure, which will cause vibration. - The average value of the air column pressure per cycle is below atmospheric pressure, and the liquid column rises in proportion to the pressure wave. This happens continuously and the liquid level rises. When the movement of the valve plate t follows the movement of the vibrating tube 3, the upper limit of the rise of the liquid in the vibrating tube J is large, so the vibrating tube 3 can be made longer, so that the range of liquid level control can be widened.

The limit of the rise in the liquid level within the tube due to such vibration of the vibrating tube J can be adjusted by adjusting the excitation frequency and excitation speed of the vibrating tube 3. Due to changes in the liquid level in the vibrating tube 3, the open liquid level in the container l rises and falls.

Depending on the excitation frequency and excitation acceleration of the vibrating tube 3, the liquid level in the tube can be pushed down below the open liquid level of the container.

Therefore, the range in which the open liquid level can be adjusted is ΔH, the range in which the liquid level in the tube of the vibrating tube 3 can be changed is ΔH, the range in which the liquid level in the tube of the vibrating tube 3 can be changed is Y1, and the cross-sectional area inside the vibrating tube 3 is al, and the vibrating tube If the outer cross-sectional area of 3 is a2, then (A a2) ΔH== aI Y. The negative sign means that as Y increases, the water depth H of the container / decreases, and as Y decreases, the water depth (2) increases.

FIG. 2 is a longitudinal sectional view of another embodiment of the invention. In this embodiment, the valve plate is fixed to the output part/da of a vibrating device l/ which vibrates at the same frequency as the vibrating device fixed to the frame 3. Vibration device ≠, // is controller / vibration r
The number of IJs and the phase of vibration between the vibration devices tt and ii are adjusted. In this embodiment, the excitation device R'l, /
By changing the phase difference of the vibrations of /, the suction force of the vibrating tube J changes, so the liquid level in the vibrating tube 3 changes, and the liquid fighting surface of the container l changes -
can change the water level. By adjusting the phase and the excitation frequency together, the liquid level in the vibrating tube 3 can be changed significantly, so the water level adjustment range of the open liquid level λ can be widened.

FIG. 3 shows a stationary tube lλ placed and fixed below the vibrating tube J in FIG.
The effect is the same.

〔Effect of the invention〕

This invention comprises a vibrating tube whose lower end communicates directly with the liquid in the container or indirectly through a stationary tube, an excitation device that supports the vibrating tube and vibrates the vibrating tube in the vertical direction, and a valve phase roaring means. Therefore, the liquid level in the container can be adjusted. Some vibration devices can be digitally controlled, making them suitable for liquid level control during process control.

[Brief explanation of drawings]

1 to 3 are longitudinal sectional views of embodiments of the present invention, and FIGS. 7 to 6 are longitudinal sectional views showing the operation of FIG. 1. l...Container -1.Liquid level 3.Vibration tube...Excitation device...Frame 6.Φexcitation rod 7.Valve seat T...
Valve plate De...Spring 10...Control device //...Excitation device /λ...Stationary tube /J...Flexible joint /lI...Output section/j--Fist controller. Patent Applicant Ebara Corporation Representative Arai - Department Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A vibrating tube whose lower end communicates directly with the liquid in the container or indirectly through a stationary tube, an excitation device that supports the vibrating tube and vibrates the vibrating tube in the vertical direction, and a vibrating device that applies pressure to the fluid in the vibrating tube. A liquid level control device for a container equipped with means equivalent to a valve that causes fluctuations.