JPH04100532A - Fluidizing compression granulator - Google Patents

Abstract

PURPOSE:To increase bonding strength to a large extent by compaction and to form a compacted granule while holding a spherical shape by providing the blower connected to the lower part of a granulation tank through the first valve, the suction apparatus connected to the lower part of a granulation bed through the second valve and the exhaust port formed to the upper part of the granulation tank. CONSTITUTION:When the first valve 4 is opened in such a state that the second valve 7 is closed, air flows as shown by an arrow A. The powder raw material 8 in the tank 1 is fluidized by said air and flocculated by the adhesion of the raw material itself and the adhesion imparted by the slight humidity or org. solvent vapor due to a temp. and humidity control apparatus 3. When the first valve 4 is closed and the second valve 7 is opened, air flows as shown by an arrow B. That is, the air in a granulation tank 1 is sucked in a tank 10 and compression granulation is carried out by this sucked air. By this method, the flocculated raw material is compacted to obtain a granule. In this granulation apparatus, the granulation tank 1 is held to positive pressure at the time of fluidization and the tank 10 is evacuated by a vacuum pump 11 and the granulation tank 1 is held to negative pressure at the time of compression.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a granulation device for carrying out a novel granulation method capable of granulating spherical particles with a minute particle size.

[Prior Art] Conventionally, several granulation methods for obtaining spherical particles are known.

One method is to place raw material powder onto a rotating perforated plate, add a binder, and then roll the powder into granules. According to this granulation method, spherical granules can be obtained, but the particle size is several millimeters to several tens of millimeters, and it is difficult to obtain particles with a particle diameter of several millimeters or less, and it is difficult to control the particle size. Another problem is that the particle size varies. Also, controlling moisture is troublesome.

A spray granulation method is known as another granulation method that produces spherical granules. In this granulation method, raw material powder is dissolved into a liquid, a binder is added thereto, and then the mixture is sprayed. By blowing hot air through this, the liquid in the sprayed material is instantaneously evaporated, and the powder left behind by the evaporation of the sprayed liquid is obtained as spherical granules.

According to this granulation method, spherical particles from several tens of microns to several hundred microns are obtained, but most of them are hollow. In addition, the slurry needs to be adjusted and the equipment is large, making it unsuitable for small-lot, high-mix production.

In addition to the above, various granulation methods such as fluidized bed granulation and agitation granulation are known, but it is difficult to obtain spherical particles.

Further, as a method for forming spherical granules, spherical particles can also be obtained by forming cylindrical granules using an extrusion granulator and subjecting the cylindrical granules to a spherical granulator. However, it has the same problems as transfer granulation, such as the inability to obtain granules with minute particle sizes.

As described above, in all conventional granulation methods, spherical granules with particle diameters in the range of 0.1 mm to 1 mm cannot be obtained. Moreover, there are many variations in particle size, making it relatively difficult to granulate particles with a nearly constant size. Therefore, when trying to obtain particles with uniform particle sizes, problems such as low yields occur. had.

The inventor of the present invention has discovered that it is possible to granulate particles with a wide range of spherical shapes and particle diameters ranging from 0.1 mm to 1 mm, which could not be obtained by any conventional granulation method. We have developed a granulation method with less variation in diameter.

The granulation method applies cohesive energy to the raw material powder by applying pressure to form aggregates with strong adhesive strength, and uses, for example, the fluidized bed method, agitated flow method, or oscillating flow method to produce spherical and minute particles. It is designed to form granules. That is, it is a granulation method that adds a compression granulation method to the basics of conventional granulation methods such as a fluidized bed granulation method, and can be called a fluidized compression granulation method.

In this granulation method, granulation is possible in a dry state; for example, if the raw material has adhesive strength, compression is performed in a dry state to form an aggregate,
Spherical and highly compacted granules can be formed by a fluidized bed method or the like. Furthermore, when using raw materials with weak or non-adhesive strength, granules can be similarly formed in the presence of a slight amount of moisture or organic solvent vapor (for example, alcohol vapor).

This granulation method involves, for example, forming aggregates in a fluidized bed device by increasing the gas pressure in the device and applying pressure to the raw material to compress it, and then fluidizing it by reversing the direction of the air flow after a predetermined period of time. This method simultaneously forms spherical granules in the same device. This method is also convenient when the formation of aggregates by compression and granulation by flow are repeated. That is, in the present invention, it is possible to combine the formation of aggregates by compression and granulation by flow using separate devices, or by changing the direction of air flow in the same device. The former has the advantage of performing the compression action more effectively, while the latter has the advantage of sharing equipment and shortening the time. is particularly effective.

The gas used in this granulation method is preferably air or an inert gas such as nitrogen.

Furthermore, the principle of this method will be explained theoretically.

In the self-sufficient granulation process, granules are formed by repeating agglomeration and dispersion to a particle size with a balance between cohesive energy and dispersion energy.

Here, using Lumbu's equation, it can be expressed as follows.

O=(]-ε)/π ・K ・Had2 In this formula, a
is the tensile stress of a powder bed randomly packed with equal spherical particles, ε
is the porosity, K is the coordination number, H is the average adhesion force at seven points of contact, and d is the particle size of the raw material. If the dispersion energy is 0 or more, the aggregation will be broken, and if the dispersion energy is 0 or less, the aggregation will continue.

Now, if raw material powder is put into a container and fluidizing air is supplied from the bottom, a fluidized bed will be formed as is well known. At this time, if a suitable fluidized state is maintained, granulation is carried out in the case of powder with strong adhesive force due to the fluid rolling action. The granules (agglomerates) remain separated from the powder even after the fluidization state is stopped, and the yield is poor because no adhesive force is exerted, and the strength of the granules is weak and easily crumbles.

By applying a counter pressure here, the flow state is stopped and pressure is applied to the agglomerates, thereby consolidating the agglomerates. This also causes the powder to adhere to the aggregates and homogenize them.

In other words, dispersion energy and spheroidization energy are imparted by the flow of the powder raw material, and spherical aggregates are formed by the adhesive force of the raw material itself or, in the case of raw materials without adhesive force, by the adhesive force due to the application of a slight amount of moisture or organic solvent vapor. By applying further pressure, cohesive energy is added and a compacted powder is obtained. Moreover, it is characterized in that granules having a wide range of particle sizes, including particle sizes from 1 mm to 1 mm, which cannot be obtained by conventional granulation methods, can be obtained at a high yield.

Generally, in a fluidized bed granulation method, etc., a binder is used, and aggregates are formed by adhering the powder to the binder on the particle surface. Therefore, the powder does not adhere uniformly in a spherical shape, and therefore only a fluid with an amorphous shape and a low bulk density is obtained.

In this method, as described above, the aggregates are formed in a dry state or in an atmosphere containing a small amount of moisture or organic solvent vapor, so that the resulting aggregates are approximately spherical. However, since the formed aggregates are mostly attached by the adhesive force of the raw material powder itself, they are easily destroyed if left as is.As mentioned above, applying pressure to the aggregates consolidates them, greatly increasing the adhesive strength. It is made to form compacted particles while maintaining its spherical shape.

[Problems to be Solved by the Invention] The present invention provides a device for realizing the fluidized compression granulation method as described above, which has a simple structure and can fully demonstrate its characteristics. be.

1. Means for Solving the Problem] The fluidized compression granulation device of the present invention includes a blower connected to the lower part of the granulation tank via a first valve, and a blower connected to the lower part of the granulation layer via a second valve. It is equipped with a suction device and an exhaust port provided above the granulation tank, and when the first valve is opened and the second valve is closed, the air from the blower is used to fluidize the granulation tank. By closing the tank and opening the second valve, suction is applied to the powder and granules in the tank to granulate them.

Moreover, instead of the suction device, a blower connected to the top of the tank via a second valve is installed, and in addition to suction from the bottom, air is blown from the top to apply pressure to the powder and granules, resulting in fluidization and formation by pressurization. There are other variations, such as using grains.

[Example] Next, examples of the dry fluidized compression granulation apparatus of the present invention will be shown.

FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention, where l is a granulation tank, 2 is a blower, 3 is a temperature and humidity control device, 4 is a first valve, 5 is a tank, and 6 is a A vacuum pump, 7 a second valve, and 8 a raw material fed onto a net 9.

With this configuration, air flows in the direction of arrow A by opening the first valve while keeping the second valve 7 closed. As a result, the powder raw material 7 in the tank is fluidized, and as mentioned above, aggregates are formed by the adhesive force of the raw material itself or by the adhesion of a slight amount of moisture or organic diaphragm vapor provided by the temperature control device. First, when the first valve 4 is closed and the second valve 7 is opened, the fluid flows as shown by arrow B. That is, the gas in the granulation tank 1 is sucked into the tank 10, thereby performing the compression granulation described above. This compacts the agglomerates and yields granules. Also, this operation may be repeated.

In the granulating apparatus of this embodiment, the inside of the granulating tank 1 is maintained at a positive pressure during fluidization, and the inside of the tank 10 is made vacuum by the vacuum pump 11, and the inside of the granulating tank 1 is under negative pressure during compression.

In this embodiment, the flow path indicated by the broken line may be closed and N, gas, etc. may be used.

FIG. 2 is a diagram showing the second embodiment, in which the granulation tank l, the air blower e
! 2, temperature control temperature control device 3, first valve 4゜10, second valve 7
．． It is composed of 11. In this embodiment, the inside of the granulation tank 1 is always under positive pressure.

In this embodiment, the first valve 4. By opening lO,
The gas flows in the direction of arrow A, and the powder raw material in the granulation tank 1 is fluidized to form aggregates in the same manner as in Example 1. Then the first
When the second valve 4.10 is closed and the second valve 7.11 is opened, the gas flows in the direction of arrow B and compression granulation is performed. This embodiment can also be made closed by connecting the channels as shown by broken lines.

FIG. 3 is a diagram showing a third embodiment. This example is
The inside of the granulation tank 1 is always under negative pressure, and when the first valve 4.10 is opened, the gas flows as shown by arrow A, and the powder raw material in the granulation tank 1 is fluidized and aggregates are formed. The first valve 4.10 is closed and the second valve 7.11 is opened to allow gas to flow in the direction of arrow B, thereby performing compression granulation.

This embodiment can also be closed by connecting the channels as shown by broken lines in the drawings.

The fourth section shows a fourth embodiment of the granulation device of the present invention, and is an embodiment in which the configuration is extremely simple.

In this Figure 4, ■ is a granulation tank, 3 is a temperature and humidity control device,
12 is an exhaust fan, 14 is a compressor 15, which is a relatively large capacity tank, and 16 is a switching valve.

In such a device, when the valve 16 is closed and the exhaust fan 12 is operated, the air inside the granulation tank 1 is discharged to the outside of the tank by the exhaust fan 12, and the pressure inside the tank becomes negative, thereby controlling the temperature of the atmosphere. After passing through the heating device M3 and adjusting the desired temperature and humidity, it is sent into the tank from the lower part of the tank 1. The raw material powder 8 put into the tank is fluidized by this air.

When the multiple fluidization valve 16 is opened for a fixed period of time, for example, several seconds, the air in the tank 15 is sent into the tank. tank 15 here
Since the tank 1 has a relatively large capacity, a large volume of air is sent in at once, so that the pressure inside the tank 1 becomes positive and becomes a constant high pressure, and pressure is applied to the raw material 7.

Fluidization and compression are performed in this manner, and the aforementioned fluidized compression granulation is performed. By repeating the above-mentioned operation as many times as necessary, fluidization and compression are repeated to obtain a desired granulated product.

Here, the capacity of the tank 15 needs to be relatively large in order to apply a constant pressure, and is determined by the size of the granulation tank 1, the amount of raw material to be input, etc. Although a bag filter 17 is shown in FIG. 4, the bag filter may not be used.

In particular, if the height of the granulation layer is increased, there is no problem even without using a bag filter, and a cyclone may be used instead of a bag filter.In this way, when a bag filter is not used, Compression efficiency is improved because air is added directly to the raw material.

FIG. 5 is a diagram showing a fifth embodiment of the present invention. In this Figure 5, ■ is a granulation tank, 18 is a blower, 3 is a temperature and humidity control device, 4 is a first valve, 14 is a compressor, 15 is a large capacity tank, and 16 is a second valve. be. Also, 19 is a valve,
20 is a vibrator/lid whose vibrator is arranged as shown in FIG. 6 when viewed from above. 21 is a cyclone.

In this embodiment, air from the floor 18 passes through a temperature and humidity control device and is supplied to a pipe grid 20 from which it is sent downward. The air from the pipe grid 20 flows downward, is reflected by the curved bottom 1a of the tank 1, and flows upward. The raw material powder 8 being introduced is fluidized by these flows and forms an aggregate. Also the first
When the second valve 4 is closed and the second valve 16 is opened, a large amount of air is sent into the tank from the tank 15, the pressure inside the tank is increased, and compression granulation is performed.

This fifth embodiment does not use the net 9 as in the other embodiments (and because it is not necessary to feed or suction air from the bottom of the pattern l, the bottom la has an extremely simple shape). Therefore, the strength of the sole 1a can be increased.

Therefore, greater pressure can be applied to the raw material. Therefore, it becomes possible to granulate raw materials with extremely weak self-adsorption power. Since it is possible to increase the pressure in this way, it is desirable that the tank 5 has a larger capacity.

In addition, since the pipe grid is placed in a place where it will be located inside the pipe grid when the raw material is introduced, it is preferable to have a structure that does not interfere with the fluidization and pressurization of the raw material.
In addition, it is preferable to have a structure that facilitates fluidization in conjunction with the shape of the bottom of the tank.

In each of the embodiments described above, it is also possible to further provide a crushing blade in the granulation tank as shown in FIG. As a result, when large lumps are produced during fluidized compression granulation, it becomes possible to crush them into single-size granules with a desired diameter.

Furthermore, by adding a vibrating device as shown in FIG. 8, it becomes possible to add fluidization and other effects due to vibration.

[Effect of the invention 1] The device of the present invention can perform fluidization and compression with an extremely simple configuration, thereby realizing a novel granulation method as explained in the specification, and making it possible to produce spherical and fine particles. It is possible to form granules with a particle size.

[Brief explanation of the drawing]

1 to 5 are diagrams showing the configurations of the first to fifth embodiments of the present invention, respectively, and FIGS. A cross-sectional view of the tube, FIG. 7 is a schematic diagram showing a configuration in which the device of the present invention is provided with crushing blades, and Section 8 is a schematic diagram of a configuration in which a vibration device is added to the device of the present invention. Tank, 2...-Blower, 3.
...Temperature control device, 4. ■ 0...First valve 5...Tank, 6...Vacuum pump, 1...Second valve. 8...Raw materials

Claims (9)

[Claims] (1) A granulation tank, an exhaust port provided at the top of the granulation tank, a temperature and humidity control device, a blower connected to the bottom of the granulation tank via a first valve, and a temperature and humidity control device. an exhaust port through a second valve that branches between the first valves, and a vacuum pump and tank connected to the lower part of the granulation tank through a second valve different from the second valve; By opening the first valve, air is introduced from the bottom of the granulation tank by a blower to fluidize the raw material, and by closing the first valve and opening the two second valves, air is sucked into the tank. This is a fluidized compression granulation device that pressurizes the raw material through reverse flow from the top. (2) A granulation tank, an exhaust port provided through a first valve connected to the upper part of the granulation tank, and connected to the lower part of the granulation tank through a temperature and humidity control device and another first valve. a flow path connecting the blower and the upper part of the granulation tank via a second valve;
The granulation tank is equipped with an exhaust port that exhausts air from the bottom of the granulation tank via another second valve, and by opening the two first valves, the air from the blower is sent to the granulation tank to fluidize the raw material. A fluid compression granulation device in which the air from the blower flows back through the flow path from the upper part of the granulation tank to pressurize the raw material by closing a first valve and opening two second valves. (3) A granulation tank, an exhaust fan that exhausts air from the top of the granulation tank through a first valve, an inlet that lets air flow in from the bottom of the granulation tank through another first valve, a bottom part of the granulation tank and the It is equipped with a flow path that connects to the exhaust fan through a second valve, and an inlet that connects to the upper part of the granulation tank through another second valve. The raw material is evacuated by a wind fan and air is introduced from the bottom of the granulation tank to fluidize the raw material.The first valve is closed, the two second valves are opened, and the exhaust fan is used to suck air from the bottom of the granulation tank through the flow path. A fluidized compression granulation device that compresses raw materials by flowing air backwards from the top. (4) A granulation tank, an inlet for introducing air through a temperature and humidity control device connected to the bottom of the granulation tank, an exhaust fan connected to the top of the granulation tank, and a valve connected to the top of the granulation tank. The raw material is fluidized by the air passing through the temperature and humidity control device by suctioning the exhaust air by the exhaust fan, and then the valve is opened to A fluidized compression granulation device characterized by applying pressure to the raw material by backflowing air from a large capacity tank to a granulation tank. (5) The fluid compression granulation apparatus according to claim (1), wherein the blower, the vacuum pump, and the first and second inlets are connected by a flow path to form a closed system. (6) The fluid compression granulation apparatus according to claim (2), wherein the blower, the first and second exhaust ports, and the inlet are connected to form a closed system. (7) The fluidized compression granulation apparatus according to claim (3), wherein the exhaust fan is connected to the inflow port and the exhaust port to form a closed system. (8) A granulation tank, a pipe grid inserted from the side wall of the granulation tank, a blower connected to the pipe grid via a first valve, and a second valve connected to the top of the granulation tank. The first valve is equipped with a compressor and a large-capacity tank connected to the pipe grid, and when the first valve is opened, the air from the blower flows out from the pipe grid, thereby fluidizing the raw material.
A fluidized compression granulation device in which a first valve is closed and a second valve is opened to send air from a tank into a granulation tank to compress raw materials. (9) Claims (1), (2), (3) comprising a vibration device for applying vibration to the powder and granular material in the granulation tank,
(4), (5), (6), (7) or (8) fluid compression granulation device.