JP2951849B2 - Method and apparatus for controlling additive liquid supply amount in tumbling granulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling the amount of an additive supplied to a tumbling granulator, particularly a bread granulator.

[0002]

2. Description of the Related Art The above-mentioned tumbling granulator supports a pan-shaped granulating dish at an angle, and a powder (eg dust) and an additive liquid (usually water, or an appropriate coagulant or binder). Is added, and is lifted by the centrifugal force associated with the rotation of the granulation dish, granulates by its own weight, falls down, grows into granules of a predetermined size, and is discharged by overflow. It is like that. At this time, the supply of the powder is generally continuously supplied in a constant amount by a screw conveyor, and the supply of the additive liquid is performed by means of visually judging the humidity and the like of the granulated granules and artificially adjusting them. I have.

However, the supplied powder is not always constant, and the supply amount per unit time generally fluctuates. For this reason, it is necessary for an operator to constantly monitor this and adjust the liquid amount. However, there is a drawback that the amount of the supplied liquid often becomes excessive or insufficient to make granulation impossible.

[0004] For this reason, the powder supply amount is continuously measured beforehand, and the additive liquid to be added based on the above measured value is used to control and maintain the ratio between the supplied powder and the additive liquid at a preset ratio. (Japanese Patent Application No. 4-75464) has been proposed. FIG. 8 shows the outline of this method. The powder W is supplied to the screw conveyor 51 from the hopper 50 storing the powder W. 52 is a screw conveyor drive motor, and 53 is a discharge port of the conveyor. Further, the bonding liquid supply means 54 includes a spray nozzle 55 provided opposite the pump P and the pan-shaped granulation dish 3 of the granulator 1, a bonding liquid supply pipe 56 connecting the spray nozzle 55 and the pump P, and The pump drive motor M is a variable speed motor, and the pumping pressure of the pump P, that is, the rotation speed of the pump P is appropriately selected.

The powder W discharged from the screw conveyor 51 is supplied to a granulating dish 3 attached at a predetermined angle as measured by a powder supply amount measuring means 60, for example, an impact flow sensor. You. Reference numeral 61 denotes a weight converter. The numerical value is input to the ratio setting device 62. At the same time, the hydraulic pressure of the supply pipe 56 is detected by the pressure sensor 63,
The output is input to the ratio setting device 62. Ratio setting device 6
2 compares the ratio of the two with a preset numerical value, determines the amount of liquid supplied to the supplied powder, that is, determines the pressure of the supply pipe 56 with a flow control valve, and instructs the hydraulic pressure regulator 64 of the required hydraulic pressure. Alternatively, the rotation speed of the pump drive motor M may be controlled via a rotation speed controller (inverter) 65. The liquid pressure at this time was detected by a pressure sensor and fed back, and an attempt was made to automatically operate the apparatus so as to maintain a predetermined supply liquid amount.

[0006]

According to the above method, there is no problem when the components of the powder are constant, but when the components of the powder fluctuate, it is necessary to change the ratio of the powder: supply liquid. There is. For example, when granulating ash generated from an incinerator for municipal garbage, the ash component discharged is not constant due to the components of the burning material, and therefore differs each time. In addition, means for injecting slaked lime into the waste gas is used for treating toxic gas such as HCl in the waste gas. This blowing is performed in accordance with the concentration of HCl, and thus the composition of the treated ash is constantly changing. Therefore, when granulating, it is necessary to adjust the amount of the supplied liquid in accordance with the granulation, but this operation of controlling the amount of the supplied liquid in accordance with the components has problems such as extremely troublesome operations.

In view of the above problems, the present invention indirectly measures the water content of granules during granulation, easily adjusts the amount of water supplied to the granules, and provides The purpose is to enable automatic continuous operation of the machine.

[0008]

Means for Solving the Problems To achieve the above object, the first invention relates to a method for indirectly measuring the water content of granules in the above granulator and controlling the supply amount of additive liquid.
The powder and the additive liquid are continuously supplied to the inclined pan-shaped granulating dish, respectively, and in a granulator that granulates by rotating the granulating dish, the granules to be granulated are photographed by an imager, The gist of the present invention is to detect a change in color contrast due to the water content of the granules and control the supply amount of the additive liquid.

Further, the second invention is characterized in that the imaging device according to the first invention captures an image of granules being granulated in a granulation dish.

The third aspect of the present invention relates to an apparatus for carrying out the first aspect of the present invention, wherein the powder and the additive liquid are continuously supplied to an inclined pan-shaped granulating dish, and the granulating dish is rotated to form the granulated dish. A granulator for granulating, comprising an imager for photographing granules to be granulated, an arithmetic circuit for determining the supply amount of the additive liquid to the powder, and a supply liquid amount adjusting valve, and a color according to the water content of the granules. The change in contrast is detected by an image pickup device, and the supply amount of the additive liquid is controlled in accordance with the change in contrast.

[0011]

The amount of water contained in the granules is measured on the surface of the granules, and the supply amount of the additive liquid is controlled based on the measured amount. Therefore, even if the powder supply amount and its components fluctuate, the supply liquid amount is automatically adjusted accordingly. At this time, the measurement of the moisture content of the granules is performed by indirect measurement for measuring a change in the color contrast of the granule surface due to the moisture content.

[0012]

1 to 4 relate to a reference example, and 1 indicates a bread granulator. The pan-shaped granulator 1 has the pan-shaped granulating dish 3 attached to one end of a drive shaft 2, and is rotated at a predetermined speed by a drive motor 4. The drive shaft 2 is mounted obliquely on a mounting table 5, and the mounting table 5 is supported at one end by a base 6.
A lifting screw 8 is attached to the other end, and the granulating dish 3 is adjusted and held at an arbitrary angle.

Reference numeral 10 denotes a hopper for storing processed powder, 11 denotes a screw conveyor, 12 denotes a drive motor of the conveyor, 13
Denotes a discharge pipe, which supplies the powder in the hopper to an appropriate place of the granulating dish 3 at a substantially constant speed.

Reference numeral 20 denotes an additive liquid supply amount control device, which is an injection nozzle 21 provided to face the granulating dish 3 and an additive liquid supply pipe 22 provided in an additive liquid supply pipe 22 connecting the nozzle and the pump P. Adjusting valve 23 and moisture measuring device 2 for granules to be granulated
And an arithmetic circuit 25 for adjusting the amount of water jetted from the nozzle 21 in accordance with the water content of the granules to be detected. The moisture meter 24 uses, for example, an infrared moisture meter. In this method, the presence or absence of moisture and the amount of moisture are detected by irradiating infrared rays and reflected light from the surface of the granules, and utilizes the fact that light of a specific wavelength reacts due to the presence of moisture. 2
Reference numeral 6 denotes a moisture converter.

Next, the principle of measurement of the amount of water required for tumbling granulation according to this reference example will be described. Originally, as shown in FIG. 3, the above-mentioned tumbling granulator moves the powder w supplied to the granulating dish 3 upward by rotating the granulating dish 3
The spray water ejected from the surface adheres to the surface with each powder element a as a nucleus to form a water film b, thereby constituting the coarse-grained body p1. The coarse particles p1 move upward with the rotation of the granulation dish and fall under their own weight, whereby the coarse particles p1 are combined with each other, that is, tumbled and granulated, to become large particles p2. In the same manner, the particles are recombined, the powder adheres to the surface by the tumbling granulation action, and grows in a snowball manner to form large grains p3. Hereinafter, this is repeated to obtain the granules p4, and the granules p having a predetermined size
After growing to n, it is released from one side of the granulation dish 2 by the action of centrifugal force.

At this time, due to the centrifugal force due to the above-mentioned rolling and the compaction due to the drop, the liquid film c having a constant thickness necessary for forming the bonding film is pressed between the cores of the granules as shown in FIG. The excess water is pushed out to form an external liquid film d. Although the powder adheres to the external liquid film and is further granulated, the size of the granulated granules depends on the initial operation conditions such as the diameter, inclination angle, rotation speed, and depth of the granulation dish, or the size of the granules. It is determined by body weight, powder components and the like. Therefore, the water content of the discharged granules is limited, and when the supply water is excessive, the excess water remains in the granulation dish without adhering to the granules, and by repeating this process, the There is a problem that the inside of the grain dish becomes muddy, the granulation becomes impossible, the operation is stopped, and the operation has to be scraped out, and such work is extremely troublesome.

The reason is that, in a general kneading operation, the ratio between the supplied powder and the liquid can be set arbitrarily, and the ratio between the powder and the liquid of the discharged kneaded material is the ratio at the time of supply. And sent out as it is. Therefore, automation is possible.
However, in tumbling granulation, the granules are subjected to centrifugal force and compaction due to falling by rolling, and the thickness of the liquid film between the powders is inevitably reduced. That is, in order to granulate to a predetermined diameter, the water content inside the granules is constant irrespective of the ratio between the supplied powder and the liquid. Therefore, the fluctuation of the liquid content of the granules is caused by the external liquid film d.
And the permissible value is small. Therefore, by measuring the thickness of the external liquid film, it is possible to measure the water content of the granules.

Further, when the amount of the supply liquid is insufficient, the tumbling granules to be discharged at first absorb the required water and grow to a predetermined diameter and are discharged. May become insufficient in water sequentially and may not be granulated to a predetermined diameter and may be discharged.

Therefore, by measuring the moisture on the surface of the granules to be granulated, it is possible to detect a slight change in the thickness of the external liquid film d and determine whether the supply liquid amount is excessive or insufficient. At this time, as shown in FIG. 1, the moisture meter 24 a may be provided to face the granules having a predetermined diameter discharged from the granulation dish 3 as shown in FIG. The moisture on the surface of the granules during tumbling granulation is measured. For example, when the diameter of the granulation dish 3 is 3 m, it takes about 30 minutes from supply of powder to discharge as granules. Therefore, in the measurement of the moisture content of the granules after the completion of the granulation, the response treatment may be delayed, and it is preferable to measure the surface moisture of the granules in the granulation dish 3 during the granulation for the prompt treatment.

FIG. 2 shows a plan view of the granulation dish 3. B and C indicate the supply positions of the powder and the additive liquid, respectively. When the granulation dish is rotated in the direction of arrow A, the powder and the water supplied in the manner described above are initially mixed and granulated sequentially. , F part is a granulation process part which has been granulated into small particles, and g part is a particle group gathering part with a substantially completed diameter. Granulation by a pan-type granulating tray has these classification effects. Therefore, the moisture measurement is performed in the granulation process section f
Is preferably measured.

The numerical value measured by the moisture measuring device 24 is converted into a moisture amount by a moisture converter 26, and the arithmetic circuit 2
Numeral 5 calculates the excess or deficiency of the water content, and operates the supply liquid amount adjustment valve 23 for the injection nozzle 21 to adjust the discharge amount from the nozzle 21.

Next, FIG. 5 shows an embodiment of an additive liquid amount control device for implementing the additive liquid supply amount control method of the tumbling granulator of the present invention. Although the additive liquid amount control device 20 of the reference example described above measures the surface moisture of the granules with the moisture meter 24, the present embodiment illustrates an example of indirectly measuring the moisture content of the granules. .

That is, the added liquid amount control device 3 of this embodiment
Numeral 0 includes a particle-containing moisture measuring device 31 together with the injection nozzle 21. This indirect moisture measuring device 31 performs indirect measurement of moisture by measuring the change in the contrast by measuring the change in the contrast by using the fact that the contrast of the color changes due to the moisture contained in the granules. The moisture content measuring device 31 is constituted by an imager, and is provided so as to take an image of granules in the granulating dish 3 during granulation.

In this case, the image pickup device 31 detects a change in contrast (usually a change between black and white) in accordance with the water content of the particles, that is, a solid-state image pickup device (pixel) of a CCD system in which image information processing is easy. ) (Hereinafter referred to as a CCD camera). FIG. 6 shows an example in which the contrast of the color of a particle imaged by this camera is detected and the area of a white portion or a black portion is measured.

FIGS. 6A and 6B are photographs showing the particle structure of the granulated granules. FIG. 6A shows a photographed image (original image) taken by a normal camera, and FIG. 6B shows an original image of FIG. To black and white 2
An image represented by a value is shown. In this case, the granules are white in a dry state and become black (gray) as they contain moisture.
Changes to It is assumed that the granules in FIG. 6A contain the optimum moisture. In this state, the black / white ratio of the granules, that is, the water content cannot be measured.
5B, the area of the white portion is calculated in the area calculation section 32 shown in FIG. 5, stored in the arithmetic circuit 33 as a reference value, and the measured value is compared with the reference value in the arithmetic circuit 33. 23, or the number of rotations of the drive motor 12 of the conveyor 11 is controlled, and the other structure of the additive liquid amount control device 30 is the same as that of the previous example. Omitted.

The color of the granular material changes due to the change in the water content. FIG. 7 shows this change in an image (schematic diagram) expressing the original image in black and white binary. In FIG. 7, (a)
Is a granule with a standard moisture content, (b) is a granule with insufficient moisture,
(C) shows granules having excessive moisture.

In the state where the supply water is insufficient in FIG. 7B, the area of the white portion of the granules is larger than that in the case of the standard water content in FIG. The area of this white part is calculated by the area calculation unit 3
In this state, the arithmetic circuit 33 operates the supply liquid amount adjusting valve 23 to adjust the amount of liquid discharged from the nozzle 21. In this case, the conveyor 11 for feeding powder is used.
The rotation of the drive motor 12 is controlled to control the amount of powder to be sent out. In addition, in the state in which the supply water is excessive as shown in FIG. 7C, the area of the white portion of the granules is smaller than that in the case of the standard moisture content in FIG. The area of the white portion is calculated by the area calculation unit 32. In this state, the arithmetic circuit 3
3 operates the supply liquid amount adjusting valve 23 to adjust the amount of liquid blown out from the nozzle 21, accelerate the rotation of the drive motor 12 of the conveyor 11, increase the amount of powder delivered, and increase the amount of powder and liquid. And the moisture content of the granules is adjusted.

When the image is taken by the CCD camera of this embodiment, there is an advantage that the particles in the granulating dish can be measured from a remote distance as compared with the moisture meter using infrared rays in the previous example. That is, in the infrared moisture meter, it is necessary to install the apparatus at a position close to the granules (for example, a distance of 20 to 30 cm). Cm or more). Therefore, there is an advantage that it can be installed in a place where the atmosphere in the granulation dish is poor.

[0029]

As described above, the present invention is intended to calculate the excess or deficiency of the liquid supply amount by measuring the surface moisture amount of the granulated granules by rotating the granulation dish, and to control the liquid supply amount. Therefore, it is easy to control the water content of the granules, and an appropriate amount of the additive liquid is always supplied to the powder so that the granulation can be performed satisfactorily. However, the required additive liquid is not supplied and the excess and deficiency does not occur, so that the granulation failure due to the excess and deficiency can be prevented, and the operation can be automated. In this case, the camera that measures the contrast by measuring indirectly measuring the water content of the granules from the change in color contrast due to the water content of the powder during granulation, allows the granules to be measured to be measured. On the other hand, it can be measured from a long distance, and has an advantage that it is not affected by the atmosphere in which the powder in the granulation dish is scattered.

[Brief description of the drawings]

FIG. 1 is an overall explanatory view showing a reference example of an apparatus for implementing an additive liquid supply amount control method of a tumbling granulator.

FIG. 2 shows a plan view of a granulating dish.

FIG. 3 is an explanatory diagram of a granulation procedure.

FIG. 4 is a partially enlarged explanatory view of granulated granules.

FIG. 5 is an overall explanatory view showing one embodiment of an apparatus for implementing a method for controlling the supply amount of an additive liquid in a tumbling granulator of the present invention.

FIG. 6 is a photograph showing the particle structure of the granulated granules,
(A) is an image taken by a normal camera (original image)
(B) shows an image in which the original image of (a) is represented by binary values of black and white.

FIGS. 7A and 7B are schematic diagrams showing changes in FIG. 6B depending on the moisture content of the granules, wherein FIG. 7A shows granules having a standard moisture content, FIG. 7B shows granules having a low moisture content, and FIG. Granules with excess moisture are shown respectively.

FIG. 8 is an explanatory view of a conventional method for controlling the supply amount of an additive liquid in a tumbling granulator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 granulator 3 granulating dish 20 additive liquid supply amount control device 21 injection nozzle 23 supply liquid amount adjustment valve 24 moisture measuring device 25 arithmetic circuit 30 additive liquid supply amount control device 31 imaging device

Claims (3)

(57) [Claims] 1. A granulator for continuously supplying a powder and an additive liquid to an inclined pan-shaped granulating dish and rotating the granulating dish to granulate the granulated material. A method for controlling the supply amount of an additive liquid in a tumbling granulator, which comprises photographing with a granulator, detecting a change in color contrast due to the water content of the granules, and controlling the supply amount of the additive liquid. Wherein the imaging device is added liquid supply amount control method of a rolling granulator according to claim 1, wherein the shooting granules granulation in the granulation pan. 3. A granulator that continuously supplies powder and an additive liquid to an inclined pan-shaped granulating dish and rotates the granulating dish to granulate the granulated material. An imager, an arithmetic circuit for determining the supply amount of the additive liquid to the powder and a supply liquid amount adjustment valve are provided, and a change in color contrast due to the water content of the granules is detected by the imager, and the change in the contrast is detected. An additive liquid supply amount control device for a tumbling granulator, wherein the additive liquid supply amount is controlled in accordance with the supply amount.