JP3071137B2 - Method and apparatus for controlling supply of additive liquid 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 supply of an additive 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 (eg, water, or an appropriate coagulant or heavy metal fixed thereto). Is added, and is lifted by centrifugal force accompanying the rotation of the granulation dish, granulates by falling down due to its own weight, and grows into granules of a predetermined size, and then overflows. It is designed to be discharged. At this time, the supply of the powder is generally supplied in a fixed amount by a screw conveyor, and the supply of the additive liquid is carried out by means of visually judging the rolling state of the granulated granules, humidity, etc., and means for artificially adjusting the supply. However, there is a problem that the amount of the supplied liquid often becomes excessive or insufficient to make granulation impossible.

For this reason, the powder supply amount is continuously measured,
In order to control and maintain the ratio between the supplied powder and the additive liquid at a preset ratio, a method has been proposed in which the amount of the additive liquid to be added is regulated based on the above measured value (Japanese Patent Application No. Hei. No. 75464).

However, according to this 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. 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. Moreover, means for blowing slaked lime into the waste gas is used for the treatment of toxic gas, for example HCl, in the waste gas. The blowing amount of slaked lime is performed according to the concentration of HCl. Is constantly fluctuating. Therefore, at the time of granulation, it is necessary to adjust the amount of the supply liquid according to the component of the treated ash, but there is a problem that the operation of adjusting the amount of the supply liquid is extremely troublesome.

For this reason, the applicant of the present invention measures the water content on the surface of the granules to be granulated first, thereby accurately adjusting the amount of the supplied liquid, and enables automatic continuous operation of the bread granulator. A method and an apparatus for controlling the supply of an additive liquid of a tumbling granulator that makes it possible have been proposed (Japanese Patent Application No. 6-192842). The outline is shown in FIG.

In FIG. 1, a pan-shaped granulator 1 has the above-mentioned 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 on the mounting table 5 at an angle.
At the other end, a lifting screw rod 8 is attached to adjust and hold the granulating dish 3 at an arbitrary angle. 10 is a hopper for storing processed powder,
Reference numeral 11 denotes a screw conveyor, 12 denotes a drive motor of the conveyor, and 13 denotes a discharge pipe. The powder in the hopper is supplied to an appropriate place of the granulating dish 3 at a substantially constant speed.

Reference numeral 20 denotes an additive liquid supply control circuit, and a supply liquid control valve provided on an injection nozzle 21 provided to face the granulation dish 3 and an additive liquid supply pipe 22 connecting the nozzle and the pump P. 23, a moisture measuring device 24 for the granules to be granulated, and an arithmetic circuit 25 for adjusting the amount of water jetted from the nozzle 21 in accordance with the detected moisture content of the granules. The moisture meter 24 uses, for example, an imager. Imager 2 in this case
Reference numeral 4 denotes a camera (hereinafter referred to as a CCD camera 24) equipped with a CCD type solid-state image pickup device (pixel) that detects a change in contrast (usually a change between black and white) in accordance with the water content of the granules, that is, easily processes image information. Is used. The contrast of the color of the particles imaged by the camera is detected, and the area of a white portion or a black portion is measured.
Reference numeral 26 denotes a color color contrast (black and white area ratio) calculation unit.

Originally, in the above-mentioned rolling granulator, as shown in FIGS. 3 and 4, the powder W supplied to the granulating dish 3 moves upward by rotating the granulating dish as indicated by an arrow. The spray water sprayed from the spray nozzle 21 adheres to the surface with each powder element a as a nucleus to form a water film b, and constitutes a single coarse particle 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 form the granules p4, which are grown into granules pn of a predetermined size, and then discharged from one side of the granulation dish 2 by the action of centrifugal force.

In this case, in the tumbling granulation method, the ratio between the granular powder and the liquid is constant if the powder has a constant component, but the allowable range is small. Therefore, when the supply water is excessive,
Excess moisture remains in the granulation dish without adhering to the granules,
By repeating this, the inside of the granulation dish eventually becomes a muddy fluid state, and granulation becomes impossible, so that the operation is stopped and this must be scraped out.

In addition, when the supply liquid amount is insufficient, the initially discharged rolling granules absorb the required water and grow to a predetermined diameter and are discharged. May be deficient in water sequentially, and may eventually be discharged without being granulated to a predetermined diameter.

For this reason, by measuring the water content on the surface of the granules to be granulated, it is possible to determine whether the supply liquid amount is excessive or insufficient, and to control the excess or deficiency of the supply water. At this time, the moisture is preferably measured by measuring the moisture on the surface of the granules during tumbling granulation in the granulating dish 3.

FIG. 3 shows a plan view of the granulating 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, it is preferable that the moisture measuring section h measures the moisture near the boundary between the granulation process sections f and e.

[0013] In this case, when the supply of water is insufficient, the area of the white portion of the granules is larger than that in the case of the standard moisture content. The area of this white part is calculated by the area calculation unit 2
The calculation circuit 25 operates the supply liquid control valve 23 to control ON / OFF of the liquid discharged from the nozzle 21. In this case, it is also possible to control the rotation of the drive motor 12 of the powder feeding conveyor 11 to control the powder feeding amount.

Further, in a state where the supplied water is excessive, the area of the white portion of the powder becomes smaller as compared with the case of the standard water content. The area of the white part is calculated by the area calculation part 26, and the arithmetic circuit 25 operates the supply liquid control valve 23,
The ON / OFF control of the liquid ejected from the nozzle 21 is performed, the rotation of the drive motor 12 of the conveyor 11 is accelerated, the amount of powder delivered is increased, the ratio of the powder to the liquid is controlled, and Adjust the water content.

[0015]

However, even with the above-mentioned method, as described above, the allowable range of the supply amount of the processing liquid based on the components of the powder is small, and there is a possibility that the formation of particles may be disrupted during continuous operation. . In this regard, the above measurement controls the amount of liquid supplied by measuring the water content of the granules, but as a result of various studies, there is a problem in the presence or absence of nuclei forming before the granules, that is, the center of the granules. It turned out that there is. That is, in long-term operation, only the above-mentioned method based on the measurement of the water content of the powder does not sufficiently form core particles serving as a basis for the granulation process, and as a result, does not grow into a powder having a desired diameter. There is.

In view of the foregoing, an object of the present invention is to prevent the above-mentioned drawbacks by periodically re-forming nuclei.

[0017]

Means for Solving the Problems To achieve the above object, a method for controlling the supply of an additive liquid of a rolling granulator according to the first invention is provided.
The powder and the additive liquid are respectively supplied to the inclined pan-shaped granulation dish, and the surface moisture of the granules to be granulated is measured in a granulator for rotating and granulating the granulation dish, and the addition liquid is measured. Controlling the supply, regulating the supply of each of the powder and the additive liquid from the normal operation at preset time intervals, and shifting to a nuclear particle forming operation for forming a core particle having a predetermined diameter. .

In the above method, the supply of the powder for forming the nucleus particles and the supply of the additive liquid are controlled at predetermined intervals to form the nucleus particles which are the basis of the granulation process. And granulation work can be performed reliably.

The second invention also relates to another method for forming core particles, in which the powder and the additive liquid are supplied to an inclined pan-shaped granulating dish, and the granulating dish is rotated by rotating the granulating dish. In the granulator to measure the surface moisture of the granules to be granulated, while controlling the supply of the additive liquid, measuring the particle diameter formed,
When the core particle diameter falls below a predetermined value, the supply of the powder and the additive liquid is regulated from the normal operation, and the process shifts to a core particle forming operation for forming core particles of a predetermined diameter. I do.

According to the above method, the particle diameter to be granulated is measured, and when the diameter falls below a predetermined value, the process shifts to a core particle forming operation, and when the diameter reaches the predetermined value, the granulation is started. Judge that the operation will be performed smoothly, and switch to normal operation.

In the first and second aspects of the invention, the water content can be measured by using an imager and measuring the color contrast depending on the water content of the particles.

Thus, it is possible to easily measure a change in color contrast.

Further, the third invention relates to an apparatus for implementing the first invention, wherein the powder and the additive liquid are supplied to an inclined pan-shaped granulating dish, and the granulating dish is rotated to granulate. The granulator includes an imager for photographing the granules to be granulated, an arithmetic circuit for determining the supply of the additive liquid to the powder, and a supply liquid control valve, and detects a change in color contrast due to the water content of the granules. Detected by the imager, and controls the supply of the additive liquid in accordance with the change in the contrast, and regulates the supply of the powder and the additive liquid from the normal operation every predetermined time,
A core particle forming circuit for shifting to a core particle forming operation for forming core particles of a predetermined diameter.

In the case of the above-mentioned apparatus, a core particle forming circuit is provided to control the supply of the powder and the supply of the additive liquid at predetermined time intervals so that the core particles forming the basis of the granulation process can be formed. By forming, granulation work can be performed reliably.

Further, the fourth invention relates to an apparatus for carrying out the second invention, wherein the powder and the additive liquid are supplied to an inclined pan-shaped granulation dish, and the granulation is performed by rotating the granulation dish. The granulator includes an imager for photographing the granules to be granulated, an arithmetic circuit for determining the supply of the additive liquid to the powder, and a supply liquid control valve, and detects a change in color contrast due to the water content of the granules. Detecting by the imager, controlling the supply of the additive liquid according to the change in the contrast, determining the particle diameter formed in a certain range by the imager, and determining the particle diameter to fall below a preset value. In this case, there is provided a core particle forming circuit which regulates the supply of the powder and the additive liquid from the normal operation and shifts to a core particle forming operation for forming a core particle having a predetermined diameter.

In the case of using the above-mentioned apparatus, a nuclear particle forming circuit is provided to measure a particle diameter formed within a certain range by an image pickup device. If the particle diameter falls below a preset value, the normal operation is started. By regulating the supply of the powder and the additive liquid to form core particles that are the basis of the granulation process, the granulation operation can be performed reliably.

[0027]

FIG. 1 shows an embodiment of the present invention. The bread-type granulator 1 and the additive liquid supply control circuit 20 have the same structure as that shown in FIG. 2, and the same components are denoted by the same reference numerals and description thereof will be omitted. The supply of the powder and the additive liquid is always controlled by the additive liquid supply control device 20. The additive liquid supply control device A of the present invention periodically and forcibly forms core particles serving as seeds of particles for reliably performing granulation in the granulator 1 having the additive liquid supply control circuit 20. And a nuclear particle shaping circuit 30 for performing the process.

The nuclear particle forming circuit 30 includes an arithmetic circuit 31
And a timer 32 for issuing a time command to the arithmetic circuit 31
And a command circuit 33 for controlling the drive of the drive motor 12 for rotating and driving the powder supply screw conveyor 11 and providing the supply liquid control signal to the supply liquid control valve 23 for the injection nozzle 21. The arithmetic circuit 31 responds to a command signal given at a predetermined time interval from the timer 32 or the conventional CCD camera 24 by the CCD camera 24.
The measured particle diameter is measured separately and in parallel with the measured value of the granular moisture, and the supply of the powder and the additive liquid is regulated according to a command signal given when the particle diameter falls below the set particle diameter. In this case, a command is issued to the command circuit 33 to shift to the nuclear particle forming operation.

The operation procedure will be described. An operation method for measuring the water content on the powder surface and controlling the supply of the powder and the additive liquid is the same as the conventional method, and the description thereof will be omitted. However, the particles to be measured at this time are particles P2 to P4 in FIG. 4 (hereinafter referred to as core particles PA), and the measurement position h in the granulation process part f is a position at which the core particles are measured. The particles at that time are formed into particles Pn of a predetermined size (hereinafter, referred to as particles having a predetermined diameter) by a subsequent granulation action when the particles are formed to a predetermined size, but are not powdered for a long time operation. With only the above-mentioned method based on the measurement of the moisture content of the body, the core particles serving as the basis of the granulation process are not sufficiently formed, and as a result, the powder is discharged in the form of a powder until the powder having a desired diameter is not grown and granulated.

Normally, these states are detected and corrected by the arithmetic circuit 25. However, as described above, the allowable range of water is extremely small, and it is difficult to correct the water once it breaks down. As a result, in the regulation by the arithmetic circuit 25, for example, it may be difficult to form the predetermined diameter particles Pn in about three hours. The core particle shaping circuit 30 temporarily suspends the granulation operation by the additive liquid supply control circuit 20 during the granulation, and shifts to the core particle shaping operation. For example, a method of operating the arithmetic circuit 31 every 30 minutes and issuing a command to the command circuit 33 to shift to the nuclear particle shaping operation is the second method. Let the diameter of the particles be measured in parallel with the measurement of the moisture in the particles,
It is determined whether or not the particle diameter is at a predetermined size. As a result, when the particle diameter falls below a set value, a command is issued to a command circuit 33 to shift to a nuclear particle forming operation.

At this time, the measurement of the particle size is performed by using a CCD camera 2
In addition to the method of directly measuring the particle diameter in step 4, the number of particles in a certain area is counted by the CCD camera 24, and when the number reaches a certain number or more (that is, when the particle diameter falls below the predetermined diameter), the nucleus is counted. The process may shift to the particle forming operation. In this case, the arithmetic circuit 31 is provided with a particle number measuring device, and measures whether or not the black-and-white ratio by the area calculator 26 is at a predetermined ratio and the number of white spots having a predetermined diameter at that time.

The core particle forming procedure is, for example, when the supply of the liquid is excessive, the supply of the liquid is stopped and only the powder is supplied. When the shortage of the liquid is detected by the powder, the supply of the liquid is started, only the powder is supplied, and the roll is formed to check the quality of the formation of the core particles from the color contrast (ratio of the amount of black and white). .

The measuring procedure is as follows: judging the suitability of the supply liquid from the color contrast, and when it is judged that the supply liquid is in an appropriate amount, the supply of the powder and the liquid is temporarily stopped, and the core particles having a predetermined diameter are determined. Is continued until the number reaches a predetermined number. When the number reaches the predetermined number, the core particle forming operation is terminated, and the operation returns to the normal operation.

[0034]

As described above, according to the present invention, since the core particle shaping operation is performed at regular intervals during the granulation operation, the supply of the additive liquid during the conventional rolling granulation is automatically controlled. When regulating, an error often occurs in the supply of additive liquid due to changes in the amount of powder, changes in the content, etc.
It is possible to prevent the correction of this from becoming difficult and the granulation from becoming impossible. Further, at this time, in the above-mentioned nuclear particle forming operation, the state of the particles is determined based on the color contrast of the image pickup device, so that the determination can be made easily. When the particle size is determined based on the number of granulated core particles within a certain range of the particles, the determination can be easily performed.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of an additive liquid supply control method of a tumbling granulator of the present invention.

FIG. 2 is an explanatory view of a conventional additive liquid supply control method of a rolling granulator.

FIG. 3 shows a plan view of a granulating dish.

FIG. 4 is an explanatory diagram of a granulation procedure.

[Explanation of symbols]

 A Additive liquid supply control device 1 Rolling granulator 3 Granulating dish 20 Additive liquid supply control circuit 30 Nuclear particle forming circuit

Claims (5)

(57) [Claims] 1. A granulator that supplies a powder and an additive liquid to an inclined pan-shaped granulating dish and rotates the granulating dish to measure the surface moisture of the granulated granules. Then, while controlling the supply of the additive liquid, the supply of the powder and the additive liquid is regulated from the normal operation every predetermined time, and the operation shifts to a core particle forming operation for forming core particles of a predetermined diameter. A method for controlling the amount of liquid added to a tumbling granulator, characterized in that: 2. A granulator for supplying a powder and an additive liquid to an inclined pan-shaped granulating dish and rotating the granulating dish to measure the surface moisture of the granulated granules. Then, while controlling the supply of the additive liquid, the particle diameter formed is measured, and when the core particle diameter falls below a preset value, the supply of the powder and the additive liquid is regulated from the normal operation. A method for controlling the amount of liquid added to a tumbling granulator, wherein the method shifts to a core particle forming operation for forming core particles having a predetermined diameter. 3. The method for controlling the supply of an additive in a tumbling granulator according to claim 1, wherein the water content is measured by using an imager to measure the color contrast depending on the water content of the particles. 4. A granulator for supplying a powder and an additive liquid to an inclined pan-shaped granulating dish and rotating the granulating dish to granulate,
An imager for photographing the granules to be granulated, an arithmetic circuit for determining the supply of the additive liquid to the powder and a supply liquid control valve are provided, and a change in color contrast due to the water content of the granules is detected by the imager. Then, the supply of the additive liquid is controlled in accordance with the change in the contrast, and the supply of the powder and the additive liquid is regulated from the normal operation every predetermined time, so that the core particles having a predetermined diameter are formed. An additive liquid supply control device for a tumbling granulator, comprising a core particle forming circuit for shifting to a core particle forming operation. 5. A granulator for supplying a powder and an additive liquid to an inclined pan-shaped granulating dish and rotating the granulating dish to granulate,
An imaging device for photographing granules to be granulated, an arithmetic circuit for determining the supply of the additive liquid to the powder, and a supply liquid control valve are provided, and a change in color contrast due to the water content of the granules is detected by the imaging device. Then, while controlling the supply of the additive liquid according to the change in the contrast, determine the particle size formed in a certain range by the imager, when the particle size is less than a predetermined value, usually The addition of a tumbling granulator characterized by comprising a core particle forming circuit for regulating the supply of the powder and the additive liquid from the operation and shifting to a core particle forming operation for forming a core particle having a predetermined diameter. Liquid supply control device.