JPS5814219A - Controller for small amount of slurry liquid - Google Patents

Abstract

PURPOSE:To perform level control for a tank including slurry even for a small amount of flow continuously, by transmitting an output signal of a regulator to an oscillation circuit. CONSTITUTION:The liquid in a tank 1 is discharged via a regulating valve 2. On the other hand, the tank 1 is equipped with a level detector 3 detecting the level of the liquid in the tank 1 and an output of the level detector 3 controls the switching of a regulating valve 5 via a regulator 4, a signal oscillating circuit 5 and an electropneumatic converter 6. The circuit 5 can be built in the regulator 4 or a mu-CPU can realize the regulator 4 and the circuit 5, and the circuit 5 gives an oscillation to the output signal of the regulator 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a level control device for a container containing slurry, and particularly to a control device suitable for minute flow rate control.

Conventionally, in level control of a container containing slurry, when the flow rate is small, the particle size of the slurry cannot be ignored compared to the cross section of the control valve, and the pulp becomes clogged with slurry, making continuous control impossible. It was possible. For this reason, on/off control, etc., has been performed, but since the fluctuations that affect the process after this control loop are large, the processing capacity of the equipment must be increased, which is uneconomical.

An object of the present invention is to provide a minute slurry liquid control device that can continuously control the level of a container containing slurry even at a minute flow rate without adversely affecting the process of the control loop.

In order to achieve such an object, the present invention provides a container with a control valve, wherein the control valve detects the level of liquid in the container and adjusts opening/closing based on an output signal thereof. It is equipped with means for applying vibration to the signal.

Hereinafter, the present invention will be explained in detail using Examples.

FIG. 1 is a schematic configuration diagram of an embodiment of a micro-slurry liquid control device according to the present invention. There is a container 1, and this container l
The liquid inside is discharged via a control valve 2. On the other hand, the container 1 is equipped with a level detector 3 that detects the level of the liquid in the container 1, and the output of the level detector 3 is transmitted via a controller 4, a signal vibration circuit 5, and an electro-pneumatic converter 6. The degree of opening and closing of the control valve 5 is controlled.

The signal oscillation circuit 5 includes a controller 4 as shown in FIG.
an adder 7 to which the output from the adder 7 is input;
The adder 7 includes a subtracter 8 to which the output from the adder 7 is input.
A signal from a relay circuit 9 is input to each of the subtracters 8 and 8. The relay circuit 9 generates an on/off signal X (see FIG. 3(d)) based on the signal generator v (see FIG. 3(e)) from the signal generator IO,
The results input to the adder 7 and the subtracter 8, respectively, the output signal I from the controller 4 (see FIG. 3(a)), are passed through the adder 7 to the output signal I shown in FIG. 3(b). Signal ■,
This signal is converted into the signal ! shown in FIG. 3(C) via the subtracter 8. , and is input to the electro-pneumatic converter 6.

The electro-pneumatic converter 6 is an electric signal converter shown in FIG. 3(C).

1 into a compressed air signal, and this air signal is input to the control valve 5.

As shown in detail in FIG. 4, the control valve 5 includes an actuator section that receives a compressed air signal from the electro-pneumatic converter 6 and generates the operating force necessary to obtain the corresponding valve opening degree. Diaphragm plate 14, diaphragm stem 15, plum slam 16, balance spring 18
, a valve body 19 that directly controls the flow rate by the movement of the actuator, and a plug 17 that is integrally formed with the actuator. It is composed of seat rings 20 and 21. In such a configuration, the compressed air signal that activates the valve is supplied to socket 1
It enters the diaphragm case 12 through a conduit connected to 1, and applies a force to the left in the figure to the diaphragm plate 14 via a diaphragm 13 made by Merchant Rubber.

The diaphragm stem 15 and the υ plug stem 16 push the plug 17 to the left in the figure. A balance spring 1.8 is set on the left side of the diaphragm plate 14 in the figure, and a force directed to the left in the figure from an axis obtained by multiplying the pressure of compressed air by the effective area of the diaphragm,
It comes to rest at a position where the reaction force exerted by the spring 18 in the right direction in the figure is balanced. That is, the pneumatic pressure signal and the positions of the stems 15 and 16 maintain a proportional relationship. The controlled fluid is regulated by being throttled between the plug 17 and the seat ring 20.degree. 21 while passing through the body 19.

By passing the controller's output signal through a vibration circuit in this way, the ideal control signal is given vibration with a predetermined amplitude and period, and the opening degree of the control valve is constantly changing, reducing the flow rate. It is also controlled by vibrating. In this case, if the level is controlled within a certain range, small fluctuations will not adversely affect subsequent processes. Therefore, since the valve opening always changes, the positions between the slurry particles change, so the slurry does not clog the inlet side, and continuous control of the slurry liquid at a minute flow rate becomes possible.

In this embodiment, a signal oscillation circuit is provided after the controller, but the signal oscillation circuit may be built into the controller, or the controller and signal oscillation circuit may be realized by the μm CPU. And yes, it goes without saying.

As is clear from the above, the micro-slurry liquid control device according to the present invention can continuously control the level of a container containing slurry even at a micro-flow rate without adversely affecting the control loop process. Become in control.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of a micro-slurry liquid control device according to the present invention, and FIG. 2 is a circuit diagram showing an embodiment of a signal oscillation circuit used in the micro-slurry liquid control device according to the present invention. FIG. 3 is a time chart showing the operation of the signal oscillation circuit, and FIG. 4 is a sectional view showing one embodiment of the control valve used in the micro-slurry liquid control device according to the present invention.

Claims (1)

[Claims] 1. A control valve is provided in the container, and the control valve detects the level of liquid in the container and adjusts opening and closing based on its output signal, and is provided with means for applying vibration to the output signal. Features a micro-slurry liquid control device.