JP3036599B2 - Fluid granulation coating equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid granulation coating apparatus for granules, and more particularly, to a fluid granulation coating apparatus capable of performing stable coating of granules.

[Prior Art] In a technique in which a spray nozzle generally used in a fluidized-granulation coating apparatus is installed above a space inside a processing vessel or on an upper vessel wall of a processing vessel and sprayed downward or obliquely downward, fluidized granular material or In some cases, the spray liquid adheres to the spray nozzle to change the spray pattern, or the spray liquid is dried by the fluidizing air and scattered before being attached to and coated on the granular material.
Further, in the above technique, there is a problem that the spray droplets are scattered and dissipated because the probability of contact between the spray droplets and the granular material is small. Further, the above-mentioned technique is that, when the coating target is spherical granules, due to the weight of the spherical granules themselves, unlike the case of powders and granules, sufficient flow cannot be performed in the processing container, and the lower portion than the middle of the processing container. There is a problem that the fluidized granules are concentrated around the position (1), and this portion becomes dense. In order to prevent this, it is conceivable to increase the inflowing air pressure and the amount of air.However, when the inflowing air pressure and the amount of air are increased, the coating liquid is scattered as described above, and the spray pattern is reduced. Distortion will not result in a stable coating. As described above, when the spherical granules are coated by a technique in which the nozzle (spray nozzle) is provided above the processing container, the distance between the nozzle and the spherical granules is too large, and the spray liquid is not adhered to the spherical granules. There is also a disadvantage that the powder is dried to be a fine powder and dissipated. In addition, since spherical granules have a predetermined surface area, unlike granular materials, if there is not sufficient fluidization, problems such as partial coating or inability to perform stable coating will occur. .

Also, in the technique of installing a spray nozzle at the bottom of the processing vessel and spraying upward, the temperature of the fluidizing air flow is high due to the coating, so that the drying and dissipation of the spray liquid is promoted, and the spray air is sprayed. A blow-through phenomenon occurs due to the flow, and drying and dissipation of the spray liquid occurs. Also for this,
The control range of the amount of sprayed air becomes small, and the agglomeration and agglomeration of the powder and granules easily occur. Further, even when the position of the spray nozzle is at the bottom, there is an inconvenience that, as in the case of the above-described technique, the powdery particles adhere to the spray nozzle, the spray pattern changes, and stable coating cannot be performed.

In order to solve such inconvenience, the present applicant has proposed a fluidized-granulation coating apparatus using a lateral spray method (Japanese Patent Application No. 60-41597).

In the apparatus according to this proposal, the mounting position of the spray nozzle is a lower part of a truncated conical shape tapering downward below the interface of the granular material flowing in the processing container.

According to such a configuration, the spray nozzle is cleaned by the powder and granules circulating in the processing container, the spray liquid can be prevented from adhering, the spray pattern does not change, and stable granulation coating can be performed. In addition, since it is not affected by the inflowing air pressure, the amount of air, the temperature, etc., even if the air pressure, the amount of air, and the temperature are increased, the inflowing air pressure, the amount of air, and the temperature can be further increased without dispersing the spray liquid by drying. Aggregation and agglomeration in the grain coating can be suppressed. And in order to spray a binder and a coating liquid near the high density of the powder or spherical granules,
Granulation or coating can be performed in a short time. In addition, since it is not provided on the bottom, it has various effects such as no adhesion to the spray nozzle. In addition, as a secondary effect of the spray air of the spray nozzle, agglomeration and agglomeration of powders and granules are appropriately destroyed, the particle size can be adjusted arbitrarily, and it is not necessary to sort particles after granulation, Further, by controlling the amount of sprayed air, the air pressure, and the like of the compressed air jet nozzle, various effects such as the prevention of aggregation and agglomeration of the granular material can be obtained.

[Problems to be Solved by the Invention] However, in the case of the coating of spherical granules, the fluidized granulation coating device proposed above dissipates compared to the granules because the spherical granules have their own weight compared to the granules. However, in the case of a powdery or granular material, there is a problem that the above-mentioned coating by side spraying is still not sufficient.

For example, when coating a granular material using a coating solution having a relatively high water content, it is difficult to dry the powder, which causes agglomeration and agglomeration of the granular material, or causes the granular material to form a fluidized bed. May escape away from airflow. In addition, there are cases where it is not sufficient even when a uniform coating or the like is performed on the granular material.

Therefore, an object of the present invention is to provide a fluidized-granulation coating apparatus capable of performing more stable coating of a granular material than a conventional apparatus.

Another object of the present invention is to provide a fluidized-granulation coating apparatus which does not cause agglomeration or agglomeration of powders and granules even when a coating solution and a binder having low volatility are used.

Means for Solving the Problems In the fluidized-granulation coating apparatus according to the present invention, at least one spray nozzle, at least an intake duct and an exhaust duct, and a frustoconical lower part tapered downward. A fluidized-granulation coating device provided below the interface of the granular material flowing through the spray nozzle and at the position of the truncated cone, the periphery of the spray nozzle. And air blowing means for blowing dry air, and means for arbitrarily controlling the air flow.

[Operation] Accordingly, the powder and granules scattered around the fluidized bed airflow are returned to the fluidized bed airflow by the dry air blown out from the air blowing means provided around the spray nozzle. The instantaneous speed when the body comes in contact with the spray liquid such as the coating liquid blown out from the spray nozzle is increased, and it is dispersed in the fluidized bed air flow,
Therefore, it is possible to perform more stable coating of the granules than the conventional apparatus, and to use a fluidized granulation coating apparatus that does not agglomerate or agglomerate the granules even when using a less volatile coating solution or binder. It can achieve the task of being able to provide.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

FIG. 1 is a sectional view showing the configuration of one embodiment of the present invention.

The fluidized-granulation coating apparatus S of this embodiment includes a fluidized-granulation vessel 1 as a processing vessel, a two-fluid nozzle 4 as a spray nozzle, an intake duct 6, an exhaust duct 7, and the like. The fluidized-granulator container 1 has a frustoconical lower part 2, a back filter 3, and a two-fluid nozzle 4 for spraying.
An air duct 6 is provided at the bottom of the fluidized-granulator container 1, and an exhaust duct 7 is provided at the upper portion of the fluidized-granulator container 1. I have.

The distal end of the above-described intake duct 6 is open to the atmosphere, and a filter (not shown) for filtering and cleaning air from the upstream side (the distal end side) in the middle thereof, and dehumidifying moisture in the air. And a flowing air heater 9 for warming the air.

On the other hand, the distal end of the exhaust duct 7 is connected to an exhaust fan (not shown), and an exhaust damper 11 for opening and closing the joint is provided at a connection port between the exhaust duct 7 and the chamber 10. I have. Note that a dust collector (not shown) is connected to an exhaust port of an exhaust fan (not shown).

Further, an airflow rectifying plate 12 composed of an outer hole plate is disposed between the fluidized-granulator container 1 and the above-described intake duct 6,
The air flow straightening plate 12 defines the intake duct 6 and the granulation coating chamber 13. Further, a back filter 3 is provided above the inside of the fluidized-granulator container 1, and the back filter 3 separates the above-mentioned granulation coating chamber 13 and the chamber 10 to which the exhaust duct 7 is connected. It is defined.

In the above-mentioned granulation coating chamber 13, a plurality of two-fluid nozzles 4 for spraying are provided at appropriate positions in the circumferential direction at the position of the above-mentioned truncated conical lower part 2 (in FIG. 1). Only one is shown).

The two-fluid nozzle 4 may be either a flat-blowing nozzle or a round-blowing nozzle, and is not particularly limited to a particular type of nozzle. The two-fluid nozzle 4 is connected to a first conduit 15 having one end connected to the supply pump 14 and a second conduit 17 having one end connected to the first compressed air heater 16a. ing. Then, a spray liquid such as a binder or a coating liquid blown out from the supply pump 14 via the first conduit 15 is supplied to the two-fluid nozzle 4.

On the other hand, the second pipe line 17 is connected to a first compressed air dehumidifier 18a and a first compressor 19a in addition to the above-described first compressed air heater 16a. In the compressed air, the first compressed air dehumidifier 1
The water contained in the compressed air is removed by cooling through the compressed air 8a, and thereafter, the compressed air is heated through the first compressed air heating 16a to be dried compressed air to form the two-fluid nozzle 4
It is to be sent to.

The portion of the second conduit 17 (preferably a portion which is not affected by the temperature of the fluidized-granulator container 1 itself and is closest to the fluidized-granulator container 1) is provided with, for example, an electric first temperature measuring element 20a.
Are arranged. The first temperature measuring element 20a generates an electric signal corresponding to the detected temperature of the element 20a.
Is connected to the temperature signal generator 21a. The signal generated by the first signal generator 21a is connected to a temperature detection controller 22 connected to the output side of the first temperature signal generator 21a.
The output signal is further input to a fluidized-granulation-coating-machine control device 23 which controls the operation of the entire apparatus. The fluidized-granulation-coating-machine controller 23 is connected to the input side of the fluidized-air humidity controller 8 and the fluidized-air heater 9 based on the input signal from the first temperature detection controller 20a. Valve 9a, supply pump 14, first compressed air heater 16a, first compressed air dehumidifier 18a, first compressor 19a, second compressed air heater 16b described later, second compressed air dehumidifier 18b and 2nd
Of the compressor 19b.

Further, an air blowing means is formed around the two-fluid nozzle 4. That is, the air blow-out part 5 is provided so as to surround the two-fluid nozzle 4, and the air blow-out part 5 is connected to a third conduit 24 having one end connected to the second compressor 19b. In the middle of the pipe 24, the second compressed air dehumidifier 1 is sequentially arranged from the second compressor 19b side.
8b, a second compressed air heater 16b is provided so that the dry compressed air is sent into the air blowing section 5.

FIG. 2 shows a specific configuration example of the air blowing section 5, and the configuration will be described below with reference to FIG.

The air blowing portion 5 includes a main body 25 formed in a ring shape and having a bottom around a tip portion (a portion represented in a substantially spherical shape in FIG. 2) of the two-fluid nozzle 4, and And a cover 26 provided so as to cover the opening surface. The third pipe 24 described above is connected to the bottom of the main body 25, and the dry compressed air is introduced into the chamber 27 defined between the main body 25 and the lid 26 as described above. It has become. Specifically, the size of the main body 25 is selected to be, for example, about 5 to 15 cm in terms of outer diameter. The lid 26 is a metal filter having a mesh formed by a metal member. For example, a sintered filter or the like is used. In FIG. 2, the two-fluid nozzle 4 shows only its external shape for the sake of simplicity (the same applies to FIGS. 3 and 4).

The portion of the third pipe 24 connected to the air blowing section 5 (preferably, a portion which is not influenced by the temperature of the fluidized-granulator container 1 itself and is closest to the fluidized-granulator container 1) Second
Temperature measuring element 20b is disposed. In addition, a third temperature measuring element 20c is provided at a location in the granulation coating chamber 13 where the granular material is fluidized. And these second
And the third temperature measuring element 20b, 20c are connected to the second and third temperature signal generators 21b, 21c, respectively, and the output signal thereof is supplied through the above-mentioned temperature detection controller 22 to the flow granulation coating. Input to the machine controller 23,
For the operation control of the present apparatus as described above.

The operation of the present apparatus having the above-described configuration will be described below with reference to the case of coating a granular material as an example.

First, a granular material is put as a material into the fluidized-granulator container 1 from a material supply port (not shown) of the fluidized-granulator container 1, and the material-supplied port is closed.

Next, when an exhaust fan (not shown) is operated, air flows from the upstream side of the intake duct 6 toward the airflow rectifying plate 12 as indicated by a dashed line arrow in FIG.
Is set to the open state in advance). The air that has flowed into the airflow straightening plate 12 is further airflow straightened.
After passing through 12, it flows into the granulation coating chamber 13. Therefore, a fluidized bed airflow is formed in the granulation coating chamber 13 as shown by a solid line arrow in the figure, and the granular material is fluidized by the fluidized bed airflow. At the same time, the air blowing section 5
Then, air is blown obliquely upward from the fluidized bed airflow as indicated by the two-dot chain line arrow in FIG. As a result, the upper part of the fluidized bed air flow is shifted downward (the air flow straightening plate 12 side).
In a part of the flow toward the bottom, there is formed a flow that is returned to the rising portion of the fluidized bed airflow again during the descent as shown by the dotted line arrow.

In such a state, a spray liquid such as a binder or a coating liquid is supplied from the two-fluid nozzle 4 to the granulation coating chamber.
It is designed to spray toward the powder and granules flowing inside 13.

In this way, after the predetermined time has elapsed and the granulated and coated powder and granules have been generated, the exhaust port damper 11
Is closed, the granulated and coated powders fall onto the airflow rectifying plate 12 and are deposited.

Here, the flow velocity of the compressed air blown out to the fluid nozzle 4 through the second conduit 17 is generally 50 to 500 m / s from the viewpoint of controlling the generation of agglomerates of the granular material. In the range, the value is set to a substantially constant value according to the type of the granular material. Therefore, the velocity of the fluidized bed airflow cannot be arbitrarily adjusted. That is, in general, if the velocity of the fluidized bed air flow is increased beyond a predetermined value, the fluidized bed will be distorted. Therefore, it is not possible to increase the flow velocity to prevent the dissipation of the powder and the like.

On the other hand, the flow velocity of the compressed air blown out from the air blowing part 5 is set to a value necessary and sufficient to increase the instantaneous velocity of the powder when contacting the binder or the coating liquid without disturbing the fluidized bed air flow. For example, in this example, 0.5
It is set in a range of about 20 m / sec. Of course, it is not limited to the range shown in this example.

Because uniform granulation and coating can be performed in this way,
In sustained-release preparations represented by fine particles, particles, and pills, the coating layer can be controlled, and the quality characteristics can be stabilized.

Next, a second embodiment of the air blowing section 5 will be described below with reference to FIG. In this embodiment, the same members and the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the lid 26 has a plurality of slits 28 arranged around a central portion thereof, for example, on two or three concentric circles. The slit 28 is, for example,
It has a rectangular opening surface and a tongue piece 29 provided to protrude into the chamber 27 of the air blowing section 5. The tongue piece 29 has a flat portion 29a substantially parallel to the lid 26. The compressed air in the chamber 27 between the flat portion 29a of the tongue piece 29 and the lid 26 is indicated by a two-dot chain line in FIG. As shown by, a deflection action is applied so as to be blown obliquely from the opening surface.

Incidentally, as the size of the opening surface of the slit 28, for example,
In terms of the length of the opening surface in the short axis direction, it is preferably about 0.5 to 1 mm. Also, as the total area of the opening surfaces of all the slits 28,
About 10 cm ² is preferable.

With such a configuration, compressed air is blown out from the slit 28 to increase the instantaneous speed of the granular material as in the first embodiment, and in particular, the fluidized-granulator container 1 with the two-fluid nozzle 4 interposed therebetween.
The compressed air blown out from the slit 28 provided on the side opposite to the bottom portion of the fluidized bed forms an air flow as indicated by the dotted arrow in FIG. Is the same as in the first embodiment.

Next, a third embodiment of the air blowing section 5 will be described below with reference to FIG. 4, but the same members and configurations will be denoted by the same reference numerals, and description thereof will be omitted. The description will focus on differences from the example.

In this embodiment, as shown in FIG. 4, a plurality of slits 28 'are formed in the lid 26 at an angle to the thickness direction of the lid 26. The plurality of slits 28 'are formed around the two-fluid nozzle 4 in the same manner as in the second embodiment.
Are arranged on concentric circles. The shape of the opening surface of the slit 28 'may be square or circular, and is not particularly limited to a specific shape.

Incidentally, the width of the slit 28 'is set to 0.
It is set to 5-1mm.

With such a configuration, compressed air is blown obliquely to the lid 26, and each slit 2 is slightly away from the lid 26.
The two-fluid nozzle 4
(See FIG. 4). The airflow increases the instantaneous velocity of the granules in contact with the spray liquid blown out from the two-fluid nozzle 4 in the same manner as in the first embodiment, and appropriately disperses the granules. Become.

[Effects of the Invention] As described above, in the present invention, the powder and granules scattered around the fluidized bed airflow are returned to the fluidized bed airflow by the air blowing means for blowing dry air. As a result, the probability of contact between the droplets and the spray droplets is improved.
Coating of particles, pills, etc. can be performed effectively and efficiently.

In addition, the speed at which the particles and the like come into contact with the coating liquid and the like is increased by the air blown out from the air blowing means and the particles and the like are dispersed, so that a uniform coating is obtained and the quality characteristics are stable. Can be achieved. In addition, it has various remarkable effects that it is easy to handle because of its simple configuration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a fluidized-granulation coating apparatus according to the present invention, FIG. 2 is an enlarged cross-sectional view showing a first embodiment of an air blowing section of the apparatus, and FIG. FIG. 4 is an enlarged sectional view showing a second embodiment of the air blowing section, and FIG. 4 is an enlarged sectional view showing a third embodiment of the air blowing section. DESCRIPTION OF SYMBOLS 1 ... Processing container (fluid granulator container), 2 ... Truncated cone-shaped lower part, 4 ... Spray nozzle (two-fluid nozzle), 5 ... Air blowing part, 25 ... Body part, 26 ... Lid Body, 28, 28 '... slit, 29 ... tongue piece, 29a ... flat part, S ... fluidized granulation coating equipment.

Claims (1)

(57) [Claims] At least one spray two-fluid nozzle connected to a supply pump and a first line, and a compressor and a second line, respectively, and at least an intake duct and an exhaust duct downward. A fluidized-bed granulator having a cylindrical processing container having a tapered cylindrical trapezoidal lower portion, and provided below the interface of the granular material flowing through the two-fluid nozzle for spraying and at the truncated cone position A fluidized-granulation coating apparatus comprising: a coating apparatus; and an air blowing means for blowing dry air around the two-fluid nozzle for spraying, and a means for arbitrarily controlling the air flow.