JPH0829268B2 - Centrifugal dehydrator chemical injection rate controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical injection rate control device for a centrifugal dehydrator for solid-liquid separation of sludge to produce a separated liquid and a dehydrated cake.

[0002]

2. Description of the Related Art As is well known, a chemical injection rate control device for a centrifugal dehydrator is constructed as shown in FIG. In the figure, a centrifugal dehydrator 1 for solid-liquid separating sludge to produce a separated liquid and a dehydrated cake is composed of an outer case 2 and an inner case 3, and one inclined side end 2a of the outer case 2 is dehydrated. A cake discharge port 4 is provided, and a separated liquid discharge port 5 is provided at the other large-diameter end 2b.

Further, an inner pipe 3 is provided with an inflow pipe 6 for supplying a liquid to be treated such as sludge, and a screw 7 and an inflow hole 8 for supplying a treatment liquid which is a chemical are provided on a peripheral surface thereof. .

Further, the centrifugal dehydrator 1 is provided with a densitometer 9 for measuring the concentration of the separated liquid produced by solid-liquid separation,
The amount of chemicals added is adjusted based on the concentration measured by the densitometer 9.

Further, a drive pulley 11 interlocked with the main motor 10 is provided on one shaft of the outer case 2, and a gear mechanism 13 composed of a planetary gear or the like is connected to the inner case 3 on the other shaft. Has been done. The outer body 2 is a main motor 10
And the rotation is transmitted to the inner case 3 via the gear mechanism 13.

The inner case 3 and the outer case 2 rotate in the same direction with a slight rotational difference. The differential speed motor 14 has a detector 15 for detecting the current value thereof, and a detection value from the detector 15 is compared with a preset value in a preset range, and the differential speed motor is approximated to the preset value. A control unit 17 including a controller 16 that controls the motor 14 is provided.

As shown in FIG. 6, the relationship between the amount of chemicals added to the centrifugal dehydrator 1 and the concentration of the separated liquid becomes clear as the amount of the added chemicals increases at the beginning, as shown in FIG.
Next, when the amount of chemicals added is too large, the concentration of the separated liquid becomes cloudy.

[0008]

As shown in FIG. 6, the separation liquid concentration of the conventional centrifugal dehydrator and the chemical addition amount become clear as the chemical addition amount increases, but the chemical addition amount increases. If the amount is too large, on the contrary, the concentration of the separation liquid deteriorates. Therefore, the concentration of the separation liquid becomes the same for X when it is excessively added and Y when it is excessively added. There is a problem that it is not possible to determine whether there is an excess or excess, and therefore it is not possible to adjust the optimum chemical addition amount for the liquid to be treated by automatic control.

The present invention has been made to solve the above problems, and it is possible to automatically adjust the amount of chemical addition to the liquid to be treated by making it possible to judge whether the amount of chemical addition is too small or excessive. An object is to provide a chemical injection rate control device for a centrifugal dehydrator.

[0010]

A chemical injection rate control device for a centrifugal dehydrator according to the present invention measures the concentration of a separated liquid produced from a centrifugal dehydrator for solid-liquid separation of a liquid to be treated with a densitometer, The color of bubbles of the separation liquid is measured by an optical color sensor, and is processed by a determination means from the concentration measurement value measured by the densitometer and the color measurement value of the bubbles of the separation liquid measured by the optical color sensor. This is a large judgment as to the amount of chemicals added to the liquid.

[0011]

The chemical injection rate control device of the centrifugal dehydrator according to the present invention uses an optical color sensor to measure the color of bubbles of the separated liquid generated by the centrifugal dehydrator and also to measure the concentration of the separated liquid.
Based on the color measurement value and the concentration measurement value of the bubbles of the separated liquid, it is determined by the determination means whether the amount of the chemical added to the centrifugal dehydrator is excessive or excessive.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment according to the present invention. In FIG. 1, the same or equivalent components as in FIG. In the figure,
Reference numeral 18 is an optical color sensor that determines whether the amount of chemical added to the liquid to be treated is large or small. The optical color sensor 18 measures the color of bubbles generated on the upper portion of the separation liquid. Reference numeral 19 is a control unit as a judgment unit for automatically adjusting the chemical addition amount by judging the amount of the chemical addition to the liquid to be treated from the measured value of the separated liquid measured by the optical color sensor 18 and the measured value of the concentration meter 9. is there.

Next, the operation will be described. When the optical color sensor 18 indicates the degrees of white, black, and intermediate colors thereof by the amount of light reflection, the optical color sensor 18 can measure the result as shown in FIG. In addition, bubbles are generated in the separated liquid of the centrifugal dehydrator 1, and the color of the bubbles tends to become white as the amount of chemicals added increases. Therefore, the relationship between the added amount of chemicals and the color degree of bubbles of the separated liquid is shown in a characteristic curve in FIG.

The optical color sensor 18 measures the bubbles of the separated liquid discharged from the centrifugal dehydrator 1 and stored in a storage tank (not shown) by the optical color sensor 18, and also determines the concentration of the separated liquid. It is measured by a total of 9. Then, based on the measured value of the color of the foam measured by the optical color sensor 18 and the densitometer 9 and the concentration of the separated liquid, it is judged by the control unit 19 whether the chemical added to the centrifugal dehydrator 1 is excessive or insufficient, and the chemical addition is performed. The amount is automatically adjusted.

That is, it is determined whether the amount of chemical added to the centrifugal dehydrator 1 is excessive or insufficient based on the foam color measurement value and the concentration measurement value measured by the optical color sensor 18 and the densitometer 9, The controller 19 automatically adjusts the amount of chemicals added to the liquid to be treated so that the characteristic curve shown in FIG.

From the above, the concentration meter 9 for the separation liquid and the optical color sensor 18 are used together, and the concentration of the separation liquid and the output voltage of the optical color sensor 18 exist within the appropriate range of the characteristic curve shown in FIG. By controlling the chemical addition amount by the control unit 19 as described above, automatic control for suppressing the chemical addition amount to the liquid to be treated within an appropriate range can be performed.

Thus, the optical color sensor 18 and the densitometer 9 are
It was possible to prevent the excessive addition of chemicals by using, and to measure the state of the separated liquid at an appropriate amount of chemical, and it became possible to automatically control the centrifugal dehydrator 1 using the concentration of the separated liquid as an index.

[0018]

As described above, according to the present invention, the concentration of the separated liquid produced from the centrifugal dehydrator for solid-liquid separation of the liquid to be treated is measured by a densitometer, and the color of bubbles in the separated liquid is optically measured. It is measured by a static color sensor, and it is possible to judge the amount of chemicals added to the liquid to be treated from the concentration measurement value measured by the above densitometer and the color measurement value of the bubbles of the separation liquid measured by the optical color sensor. Since it is configured, there is an effect that it is possible to automatically adjust the chemical addition amount to the liquid to be treated by judging whether the chemical addition amount is too small or excessive.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a chemical injection rate control device for a centrifugal dehydrator according to an embodiment of the present invention.

FIG. 2 is a characteristic curve diagram showing an output voltage characteristic of an optical color sensor.

FIG. 3 is a characteristic curve diagram showing the relationship between the amount of chemicals added and the chromaticity of bubbles in the separated liquid.

FIG. 4 is a characteristic curve diagram showing the concentration of a separated liquid and the amount of chemicals added to an optical color sensor.

FIG. 5 is a schematic configuration diagram showing an example of a conventional chemical injection rate control device for a centrifugal dehydrator.

FIG. 6 is a characteristic curve diagram showing the relationship between the concentration of separated liquid and the amount of chemicals added.

[Explanation of symbols]

 1 Centrifugal dehydrator 9 Densitometer 18 Optical color sensor 19 Control unit (determination means)

Claims (1)

[Claims] 1. A chemical injection rate control device for a centrifugal dehydrator for injecting a chemical into a centrifugal dehydrator to perform solid-liquid separation of a liquid to be treated to produce a separated liquid and a dehydrated cake. A densitometer that measures the concentration of the generated separation liquid, an optical color sensor that measures the color of the bubbles in the separation liquid, and a concentration measurement value measured by the densitometer and the separation liquid measured by the optical color sensor. A chemical injection rate control device for a centrifugal dehydrator, comprising a determination means for determining the amount of a chemical added to a liquid to be treated based on the color measurement value of bubbles.