JP3477581B2 - Granulation method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granulation method capable of granulating particles having a high bulk density.

[0002]

2. Description of the Related Art As a conventional granulation method, a fluidized bed granulation method is known in which a raw material is fluidized and granulated by supplying air from below while spraying a binder liquid in a granulation tank. There is. The granulated product obtained by such a granulating method is generally indefinite and has a low bulk density.

Recently, in a granulating apparatus similar to the fluidized bed granulating apparatus, a rotary porous plate is arranged in a granulating tank, raw materials are put on the rotary porous plate, and a binder is sprayed from the upper side or from the lower side. There is a method of blowing air to perform rolling granulation.

According to this granulation method, a relatively spherical granulation product can be obtained, and a granulation product having a bulk density higher than that of the granulation product obtained by the fluidized bed granulation method can be obtained. However, a product having a predetermined particle size and a sufficiently large bulk density cannot be obtained.

Stirring granulation is a granulation method that can obtain a relatively high bulk density. However, the agitation granulation has adhesion and cannot be provided with a drying means. Therefore, a desired particle size cannot be obtained with a high yield.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a granulation method capable of efficiently obtaining a spherical granulated product having an extremely high bulk density.

[0007]

In the granulation method of the present invention, a raw material powder is put on a rotating porous plate arranged in a granulation tank, a binder liquid is sprayed from the upper part, and flowed by an air flow from the lower part. The granulation in the liquefied state and the rolling granulation by suppressing the air flow are alternately repeated, and a granulated product having a spherical shape and a high bulk density can be efficiently obtained.

The granulation method of the present invention comprises the granulation in the fluidized state as described above and the rolling granulation by rotation in the state in which the amount of air from below is reduced on the surface of the rotating porous plate. The following method and the like are effective in order to specifically realize this operation, and particularly to realize a repeated operation at a relatively short time interval.

The first is to suppress fluidization by instantly raising the pressure by adding air from a pressure tank or the like to the upper side of the rotary perforated plate in a state of being fluidized by the air flow from the lower side of the rotary perforated plate. Rolling granulation is performed with the amount of air from below being reduced. By repeating this operation, granulation in a fluidized state and rolling granulation can be repeated.

The second method is to make the fluidized state by the air flow from the lower side of the rotary porous plate, and then to suppress the exhaust from the upper side of the rotary porous plate to raise the pressure in the tank to lower the pressure. Rolling granulation is performed in a state in which the amount of air is reduced. By repeating this operation alternately, granulation in a fluidized state and rolling granulation can be repeated.

In the above-mentioned first or second method of the present invention, the bed height is measured by an appropriate bed height measuring means, and the bed height at the time of flow is controlled by controlling the air flow from below or at the time of rolling granulation. The bed height is controlled to a desired value by controlling the pressure in the tank and the amount of air blown from below.

In the granulating method of the present invention, the moisture content of a moisture meter is measured, and when the moisture content reaches a desired set value, the amount of binder liquid sprayed, the amount of air supplied, the temperature of air, etc. are controlled. Granulation can be carried out while maintaining the set water content to obtain a granulated product having a desired constant value, a spherical shape, and a higher bulk density.

Even in the method of the present invention in which the water content is controlled, better granulation becomes possible by adding the layer height control.

[0014]

EXAMPLE An example of the method of the present invention will now be described based on the illustrated apparatus.

FIG. 1 is a diagram showing a first embodiment based on the method of the present invention, in which a rotary porous plate 2 is arranged in a granulating tank 1 and a stirring blade 3 is arranged above the granulating tank 1, and a blower port 4 is provided. Rotating perforated plate 2
Sends air below. A spray gun 5 for spraying a binder liquid such as water is provided above the rotary porous plate 2, and an air supply port 7 for pressurization is further provided via a pressurizing tank 6. Further, 10 is a layer height measuring device applying an ultrasonic range finder, 2
0 is a heat exchanger, 21 is a flow meter, and 22 is a blower.

Granulation by the granulating method of the present invention using the granulating apparatus having such a structure is performed by the following operations.

First, the raw material powder is charged into the rotary porous plate 2 through the raw material charging port 11, the binder liquid is sprayed by the spray gun 5, and the flowable air is sent through the blower port 4 to supply the rotary porous plate 2. Granulation is carried out by rotating.
That is, the raw material powder is fluidized by the air flow from below in the state where the binder liquid is applied, and granulation is performed in the fluidized state while the rotary porous plate 2 is rotating. The movement of the raw material at this time is shown in FIG. Here, if the valve 7a between the air supply port 7 and the tank 6 is opened, the air from the pressure tank 6 is supplied, the pressure in the granulation tank 1 is increased, and fluidization is suppressed. In this way, the pressure in the granulation tank increases, and as a result, the amount of air from the blower port 4 decreases, so that the air flow swirls around the upper surface of the rotating perforated plate 2 with the reduced air flow. Rolling granulation is performed by rolling the raw material by the flow. This state is shown in FIG.

Subsequently, the pressurized air in the tank is discharged from the exhaust port 8 and is decompressed, so that the amount of air from the blower port 4 is increased and the fluidized bed is again formed as shown in FIG. 2 (A). During this time, the air in the pressure tank 6 reaches a certain volume.

By opening the valve 7a of the pressurized air supply port 7 again, the rolling granulation shown in FIG. 2B is started as described above.

By repeating the above operation alternately,
Granulation in the fluidized state shown in FIG. 2 (A) and FIG. 2 (B)
The rolling granulation shown in is alternately repeated.

In this manner, both granulation operations of fluidized bed granulation to form irregularly shaped particles having a small bulk density and a relatively large diameter and rolling granulation to form spherical particles having a large bulk density are carried out. By repeating the steps alternately, spherical particles having a large bulk density can be efficiently obtained.

In the first embodiment, the flow rate from the blower port 4 may be the flow rate at which the raw material can be fluidized as described above, but it is the most desirable air amount in the granulating method of the present invention, and It is desirable to carry out the granulation operation while keeping the flow rate constant.

If the pressure of the air in the pressure tank 6 is too large, the pressure in the tank will be too high, and the air will pass through the small holes of the rotary porous plate 2 from the top to the bottom. Therefore, the desired rolling motion cannot be obtained. If the amount of air or the pressure is too small, fluidization cannot be suppressed and effective rolling operation cannot be obtained.

In order to obtain the above-mentioned desired fluidization and to obtain a preferable tank pressure for rolling operation, in the above embodiment, a bed height measuring device utilizing ultrasonic waves is installed. By using this bed height measuring device to bring the bed height to a desired value, it is possible to obtain a desired fluidization and rolling operation. That is, in order to obtain the desired fluidization, the bed height in the fluidized state is measured, and if it deviates from the desired value, the amount of air blown from the air blowing port 4 is controlled according to the difference. This makes it possible to maintain a desired layer height. Further, by adjusting the pressure in the pressure tank 6 on the basis of the difference between the measured layer height during the rolling operation and the desired layer height, the pressure in the tank when pressurized is desired. It should be a value. Such measurement of the layer height is not limited to the layer height measuring device to which the ultrasonic distance meter is applied as in the present embodiment, and the layer height may be measured by another device or means.

Next, there is a certain correlation between the water content and the particle size, and the average particle size of the particles during granulation can be determined by calculating the water content. Therefore, if granulation is performed while keeping the water content constant, the average particle diameter can be kept constant. Further, by continuing the granulation while keeping the average particle diameter constant, it is possible to increase the bulk density while keeping the average particle diameter constant. Even in granulation while controlling the water content, it is effective to add the above-mentioned control of the layer height.

In the granulating apparatus for realizing the method of the embodiment of the present invention, a moisture meter 9 is installed as shown in FIG.
Although not shown in the figure, the following granulation is possible by controlling the granulation conditions by controlling the spray liquid amount by the spray gun 5 based on the measured value of the moisture meter. That is, based on the measurement of the water content by the water content meter 9, if the water content is controlled to be constant when the particle diameter reaches a desired value, the particle diameter can be kept constant for the reason described above. .

By alternately repeating both of the above-mentioned granulation operations while keeping the particle size constant by controlling the water content, the particle size is constant, the bulk density is high and the sphericity is high. Granules can be obtained very efficiently.

FIG. 3 is a diagram showing an apparatus for realizing a second embodiment in which the method of the present invention is performed by another means.
In this figure, 1 is a granulation tank, 2 is a rotary perforated plate, 3 is a stirring plate, 4 is a blowing port, 5 is a spray gun, 9 is a moisture meter, 1
0 is a bed height measuring device, 11 is a raw material inlet, and these are shown in FIG.
It is substantially the same as the granulating apparatus of. Reference numeral 12 is a blower connected to the exhaust port, and 13 is an open damper connected between the exhaust port and the exhaust blower.

In this apparatus, first, a raw material is fed through the inlet 11, air is blown through the air blower 4, and the binder liquid is sprayed through the spray gun 5 to form a fluidized bed as shown in FIG. . Then, the open damper 13 is opened to reduce the exhaust capacity, thereby increasing the pressure in the tank and rolling granulation as shown in FIG. 2 (B).

That is, since the air sent from the blower port 4 is suppressed and the flow rate is decreased due to the increase in the pressure in the tank, the raw material is not fluidized and fluidization is suppressed. Thereby, a small amount of air flowing through the small holes of the rotary porous plate 2 is included, and the raw material is rolled by the swirling flow caused by the rotation of the rotary porous plate 2 to perform rolling granulation.

When the open damper 13 is closed again to increase the efficiency of exhaust, the pressure in the tank is decreased, the air flow from the blower port 4 is increased, and the original state is restored, so that the raw material is fluidized. .

As described above, also in the method of the second embodiment, by controlling the granulation and the exhaust in the fluidized state as shown in FIG. Switching to rolling granulation can be performed by increasing the internal pressure and decreasing the air flow from the blower port 4.

Here, since the size of suppressing the exhaust amount can be changed depending on the intake amount of the air from the exhaust damper 13 which is opened, the intake amount from the exhaust damper 13 is shown in FIG.
The pressure in the tank may be adjusted so as to obtain the rolling state as shown in (B).

According to the first and second embodiments described above, for example, both operations are repeated every 1 second or every several seconds, and (A) in FIG.
The above state can be repeated for 1 second, and the state of (B) can be repeated at intervals of 2 seconds or the like to granulate. In order to realize this, the air supply time interval of the pressure tank in the first embodiment and the opening time interval of the open damper in the second embodiment may be set appropriately.

Also in the method of the second embodiment, the granulating apparatus is provided with a moisture meter and a system for controlling the granulating conditions based on the measured values, so that the average particle diameter is kept constant. It is possible to efficiently obtain a granulated product having a constant average particle diameter and a large bulk density by performing the granulation by alternately repeating both granulations.

Also in the second embodiment, the method of the present invention can be effectively realized by using the layer height measuring device. That is, a preferable fluidized state can be obtained by controlling the amount of air blown from the air blowing port 4 based on the value of the bed height measured by the bed height measuring device during fluidization. Further, in the rolling operation, it is preferable to adjust the pressure in the tank by controlling the opening amount from the opening damper 13 or by opening the opening damper and controlling the blowing amount from the blowing port 4 based on the measured value of the bed height. It is possible to obtain various rolling motions. Also in the case of granulation based on the water content control according to the second embodiment, good granulation can be performed even if the layer height is controlled.

In the embodiment described above, the rotary perforated plate 2 having a large number of small holes is used as the rotary plate. However, instead of the rotary porous plate, a rotary plate in which small holes are not formed may be used. In this case, it can be fluidized by the air flow rising from the gap between the granulation tank and the rotary plate. Also, in the case of rolling operation, good rolling operation can be performed by a slight air flow from the above-mentioned gap. However, it is more desirable to use the rotating porous plate as in the embodiment.

In the apparatus shown in FIG. 1 and the like, numeral 15 is a compressed air tank, and by opening the valve 14 , a large amount of air can be sent from the blower port 4 at one time. This is for opening a large amount of air at a time by opening the valve 14 so as to fluidize it when it is not fluidized immediately when switching from rolling granulation to fluidization. In addition, 16 is a backwash pressure tank and a bag filter 1
The purpose of this is to drop the powder or granules adhering to No. 7, but it is also possible to utilize this tank 16 and design it so that it also serves as the pressure tank in the first embodiment.

Next, an experimental example using the method of the first embodiment of the present invention will be shown. In Experimental Example 1, acetaminophen, lactose, and microcrystalline cellulose were mixed at 5: 3.5: 1.5, and 5% of hydroxypropylcellulose was used as a raw material. In Experimental Example 2, etenzamid, lactose, and microcrystalline cellulose were used. 5:
3.5: 1.5, hydroxypropyl cellulose 5%,
In Experiment 3, lactose and corn starch were 7: 3, and 5% hydroxypropyl cellulose was used as a sample.
The rotation speed of the rotating perforated plate is 300 rpm and the wind speed is 1.0 m.
Granulation was performed with purified water under the operating condition of / s. A backwashing pressure tank 16 was used as a pressure tank, and fluidization was repeated for 1 second and rolling was repeated for 2 seconds.

The particles obtained by the above experiment are shown in the following table. For comparison, the table shows the same sample granulated by the conventional method under the same operating conditions.

[0041] Table Experimental conventional methods mean particle size method of Example 1 present invention 189μm 193μm loosen apparent density 751kg / m ³ 499kg / m ³ firm apparent density 920kg / m ³ 680kg / m ³ length ratio (minor axis / major axis ) 0.94 0.81 mETHOD conventional methods mean particle diameter of example 2 invention 163μm 159μm loosen apparent density 720kg / m ³ 483kg / m ³ firm apparent density 893kg / m ³ 593kg / m ³ length ratio (minor axis / major axis) 0.96 0.78 mETHOD conventional methods mean particle size of example 3 invention 194μm 201μm loosen apparent density 655kg / m ³ 503kg / m ³ firm apparent density 722kg / m ³ 593kg / m ³ length ratio (Short axis / Long axis) 0.92 0.73 As is apparent from this table, the density is the same as that obtained by the method of the present invention. A larger than with the method, granulation of heavy obtain.

Since both the method of the present invention and the conventional method are experiments in which the water content is controlled, a heavy granule having substantially the same particle size distribution and a larger bulk density than the conventional example is obtained. I can do things. Further, as is apparent from the experimental examples, the method according to the present invention has a long / short ratio close to 1, and has a greater sphericity than the conventional method.

[0043]

According to the method of the present invention, by alternately repeating granulation by fluidization and granulation by rolling, it is possible to obtain heavy particles having high sphericity which cannot be obtained by the conventional method. . Further, if layer height control and water content control are added to this method, heavy particles and the like with a desired particle size can be obtained.

[Brief description of drawings]

FIG. 1 shows an apparatus for implementing the method of the first embodiment of the present invention.

FIG. 2 is a diagram showing the state of particles in the method of the present invention.

FIG. 3 shows an apparatus for implementing the method of the second embodiment of the present invention.

[Explanation of symbols]

1 granulation tank 2 rotating perforated plates 3 stirring plates 4 Blower 5 spray guns 6 pressurized tank 8 exhaust port 9 Moisture meter 10-layer height measurement sensor 12 blower 13 Open damper

Front Page Continuation (72) Inventor Kazuo Nishii 3-10-18 Kitamachi, Nerima-ku, Tokyo Fuji Paudal Co., Ltd. Co., Ltd. (72) Inventor Tetsuro Kamata 3-10-18 Kitamachi, Nerima-ku, Tokyo Fuji Paudal Co., Ltd. Within the corporation (56) Reference JP 62-258734 (JP, A) JP 4-100532 (JP, A) JP 62-234537 (JP, A) JP 62-227439 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01J 2/00

Claims (5)

(57) [Claims] 1. In granulation in which a raw material powder is put on a rotating plate arranged in a granulating tank and a binder liquid is sprayed from above the rotating plate and air is blown from below, by an air flow from below. A granulation method in which granulation in a fluidized state and rolling granulation while giving an air flow on a rotating rotary plate with a small amount of air blown from below are repeated at regular time intervals. 2. The air from the pressure tank is added to the upper side of the rotary plate at regular time intervals so that when the air is supplied from above, the rolling granulation is performed while the air flow is being given and the air in the rotary plate is The granulating method according to claim 1, wherein the granulation is performed in a fluidized state by reducing the air pressure of the rotary plate due to the exhaust. 3. When the granulation is performed in a fluidized state by blowing a predetermined amount of air from the lower side of the rotating plate, the exhaust gas is suppressed to raise the pressure in the granulating tank to increase the pressure from the lower side. 2. The granulation method according to claim 1, wherein rolling granulation is performed repeatedly while suppressing air flow and applying an air flow in the form of a rotary plate. 4. The above granulation operation is repeated while measuring the water content of the raw material by a water content meter, and after reaching the desired set water content, both granulation operations are repeated while maintaining the set water content. The granulating method according to claim 1, 2, or 3. 5. The bed height in a fluidized state and a rolling state is measured, and the bed height in each state is controlled by adjusting the amount of air blown from below based on the measured values. 4 granulation method.