Granulation apparatus and granulation method

Abstract

To provide a granulation apparatus and granulation method that can appropriately form granulated powder while reducing the amount of solvent used. [Solution] The granulation apparatus of the embodiment comprises a first processing layer, a liquid injection nozzle, a first gas injection nozzle, a second processing layer, and a second gas injection nozzle. The liquid injection nozzle injects binder liquid into the first processing layer to form aggregates, and the first gas injection nozzle injects gas vertically upward between the liquid injection nozzle and the outlet in the first processing layer. The aggregates that reach the outlet against the flow of gas from the first gas injection nozzle are introduced from the first processing layer to the second processing layer, and the second gas injection nozzle injects gas into the second processing layer at a higher temperature than the gas injected from the first gas injection nozzle.

Description

Technical Field

[0001] Embodiments of the present invention relate to a granulating apparatus and a granulating method.

Background Art

[0002] In the manufacturing process of ceramics, foods, etc., granulation may be performed from a powder state to a granular state. For example, in spray granulation, a slurry is prepared by dissolving raw material powder in a powder state together with a binder in a solvent. Then, by spraying the prepared slurry onto a treatment layer using a liquid injection nozzle or the like, aggregates in which particles contained in the raw material powder are bound by a binder or the like are sprayed onto the treatment layer. Then, by spraying a relatively high-temperature gas onto the treatment layer, the solvent of the slurry evaporates in the aggregates. As a result, granulated powder in a granular state is formed.

[0003] Here, in granulation, it is required to reduce the amount of solvent used. Also, it is required that granulated powder is appropriately formed by granulation. For example, it is required to appropriately reduce the ratio of fine particles having a small particle size and hollow granules or the like formed as granulated powder.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a granulating apparatus and a granulating method capable of appropriately forming granulated powder while reducing the amount of solvent used.

Means for Solving the Problems

[0006] According to the embodiment, the granulation apparatus comprises a first processing layer, a liquid injection nozzle, a first gas injection nozzle, a second processing layer, and a second gas injection nozzle. Raw material powder is fed into the first processing layer, and the first processing layer has an outlet at its vertically downward end. The liquid injection nozzle injects a binder solution, in which a binder is dissolved in a solvent, into the first processing layer, thereby forming aggregates in which particles contained in the raw material powder are bound together. The first gas injection nozzle injects gas vertically upward between the liquid injection nozzle and the outlet in the first processing layer. The second processing layer communicates with the first processing layer through the outlet, and aggregates that have reached the outlet against the flow of gas from the first gas injection nozzle are introduced from the first processing layer to the second processing layer. The second gas injection nozzle injects gas into the second processing layer at a higher temperature than the gas injected from the first gas injection nozzle, thereby evaporating the solvent of the binder solution in the aggregates introduced into the second processing layer. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing an example of the configuration of a system in which a granulation apparatus is used in the embodiment, etc. [Figure 2] Figure 2 is a schematic diagram showing the calculation results obtained by simulation in a second verification related to the embodiment, etc. [Modes for carrying out the invention]

[0008] The embodiments will be described below with reference to the drawings.

[0009] Figure 1 is a schematic diagram showing an example of the configuration of a system 1 in which a granulator 10 is used in an embodiment. In the example shown in Figure 1, the system 1 includes a grinding device 2 in addition to the granulator 10. An introduction pipe 3 is connected to the grinding device 2, and the grinding device 2 is connected to the granulator 10 via a relay pipe 5. Raw material powder is introduced into the grinding device 2 through the introduction pipe 3 (arrow A1).

[0010] The pulverizer 2 is a dry pulverizer. In the example shown in Figure 1, the pulverizer 2 pulverizes the particles contained in the raw material powder using a jet mill. Specifically, the pulverizer 2 generates a high-speed airflow inside by injecting gas at high speed (arrow A2). The particles are then pulverized by collisions caused by the high-speed airflow. At this time, the particles are pulverized to a size approximately that of primary particles. Note that particle pulverization in the pulverizer 2 may be performed by methods other than a jet mill. In one example, the particles contained in the raw material powder are pulverized to a size approximately that of primary particles using either a bead mill or a ball mill. The pulverized raw material powder is discharged from the pulverizer 2 (arrow A3) and supplied to the granulator 10 through the inside of the relay pipe 5.

[0011] The granulation apparatus 10 includes a housing 11 that forms the outer casing. Inside the housing 11, a first processing layer 12 and a second processing layer 13 are formed as processing spaces. In the example shown in Figure 1, the second processing layer 13 is positioned adjacent to the first processing layer 12, vertically below it (towards arrow Z1). Inside the housing 11, a partition wall 15 separates the first processing layer 12 and the second processing layer 13. Therefore, inside the housing 11, the first processing layer 12 is formed vertically above the partition wall 15 (towards arrow Z2), and the second processing layer 13 is formed vertically below the partition wall 15. In the following description, the first processing layer 12 will also be referred to as the "upper layer" or "upper processing layer," and the second processing layer 13 will also be referred to as the "lower layer" or "lower processing layer."

[0012] An outlet 16 for the first processing layer 12 is formed in the partition wall 15 of the housing 11. The outlet 16 is located at the vertically lower end of the first processing layer 12. The first processing layer 12 opens vertically downward at the outlet 16. The second processing layer 13 communicates with the first processing layer 12 through the outlet 16. The communication portion connecting the first processing layer 12 and the second processing layer 13 includes the outlet 16, and communication between the first processing layer 12 and the second processing layer 13 is not possible without passing through the outlet 16.

[0013] Furthermore, in the example shown in Figure 1, as mentioned above, the second processing layer 13 is adjacent to the first processing layer 12 on the vertically lower side, so the first processing layer 12 opens to the second processing layer 13 at the outlet 16. The second processing layer 13 communicates directly with the first processing layer 12 at the outlet 16, and the outlet 16 also functions as the inlet for the second processing layer 13. Due to this configuration, in the example shown in Figure 1, the outlet 16 is located at the vertically upper end of the second processing layer 13. The second processing layer 13 opens vertically upward at the outlet 16 of the first processing layer 12 (the inlet for the second processing layer 13), and opens to the first processing layer 12.

[0014] Furthermore, an outlet 17 for the second processing layer 13 is formed in the housing 11. The second processing layer 13 opens to the outside of the housing 11 at the outlet 17 and to the outside of the granulation apparatus 10. In the example shown in Figure 1, the outlet 17 is located at the vertically lower end of the second processing layer 13 and is formed at the vertically lower bottom of the housing 11. The second processing layer 13 opens vertically downward at the outlet 17.

[0015] The granulation apparatus 10 includes a control unit 18. The granulation apparatus 10 performs granulation from a powder state to a granular state. The control unit 18 controls the operation of the granulation apparatus 10 during granulation. In this process, the operation of components described later, including the powder input head 21, liquid injection nozzle 23, first gas injection nozzle 26, and second gas injection nozzle 28, is controlled by the control unit 18.

[0016] The control unit 18 includes a processor or integrated circuit (control circuit) including a CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), or FPGA (Field Programmable Gate Array), and a storage medium such as memory. The control unit 18 may have only one integrated circuit or may have multiple integrated circuits. The control unit 18 performs processing by executing programs stored in the storage medium, and controls the operation of the granulation apparatus 10 in granulation. The processing by the control unit 18 may be performed by an integrated circuit of a single computer, or by integrated circuits of multiple computers working together. Alternatively, the processing by the control unit 18 may be performed by a server in a cloud environment. In this case, the processing by the control unit 18 is performed by a virtual processor on the cloud server.

[0017] The granulation apparatus 10 is equipped with a powder input head 21, which is located in the first processing layer 12. In the first processing layer 12, the powder input head 21 is located at the vertically upper end. Raw material powder, which has been pulverized to the size of primary particles, is supplied to the powder input head 21 from the pulverization apparatus 2. The powder input head 21 then introduces the supplied raw material powder into the first processing layer 12 by spraying it or other means.

[0018] The granulation apparatus 10 also includes a liquid supply pipe 22 and a liquid injection nozzle 23. In the granulation apparatus 10, the binder liquid is supplied to the liquid injection nozzle 23 through the inside of the liquid supply pipe 22 (arrow A4). In the binder liquid, the binder is dissolved in the solvent at an appropriate concentration. The liquid injection nozzle 23 is located in the first processing layer 12, and in the first processing layer 12, the liquid injection nozzle 23 is located at the vertically upper end. The liquid injection nozzle 23 sprays (sprays) the supplied binder liquid into the first processing layer 12 (arrow A5).

[0019] In the first processing layer 12, the binder liquid is sprayed onto the raw material powder introduced by the powder input head 21. As a result, in the first processing layer 12, the particles contained in the raw material powder are bound together by the binder in the binder liquid. This forms aggregates B1, which are aggregates of multiple particles of the raw material powder. Each aggregate B1 contains multiple particles of the raw material powder, as well as the binder and solvent of the binder liquid.

[0020] The granulation apparatus 10 includes a first gas supply pipe 25 and a first gas injection nozzle 26. In the granulation apparatus 10, gas is supplied to the first gas injection nozzle 26 through the inside of the first gas supply pipe 25 (arrow A6). The gas is supplied to the first gas injection nozzle 26 at a temperature at which the solvent of the binder liquid contained in the aggregate B1 does not evaporate. In one example, the gas is supplied to the first gas injection nozzle 26 at a temperature within the room temperature range. According to the Japanese Pharmacopoeia of the Ministry of Health, Labour and Welfare, room temperature corresponds to a temperature range of 15°C or higher and 25°C or lower.

[0021] The first gas injection nozzle 26 is positioned in the first processing layer 12 between the liquid injection nozzle 23 and the outlet 16, and between the powder input head 21 and the outlet 16. Therefore, in the first processing layer 12, the first gas injection nozzle 26 is positioned vertically below the powder input head 21 and the liquid injection nozzle 23. And in the first processing layer 12, the first gas injection nozzle 26 is positioned vertically above the outlet 16.

[0022] In this embodiment, the first gas injection nozzle 26 injects gas supplied through the first gas supply pipe 25 into the first processing layer 12 (arrow A7). In the first processing layer 12, the gas injection position from the first gas injection nozzle 26 is located vertically below the raw material powder input position and the binder liquid injection position. The first gas injection nozzle 26 also injects gas vertically upward. Therefore, in the region of the first processing layer 12 where aggregates B1 are formed by the injection of binder liquid onto the raw material powder, a gas flow directed vertically upward is formed by the gas from the first gas injection nozzle 26.

[0023] Due to the configuration as described above, by passing through the first processing layer 12 against the gas flow from the first gas injection nozzle 26, the aggregate B1 reaches the outlet 16. For this reason, the particles contained in the raw material powder aggregate to a size that allows the aggregate B1 to pass through the region where the upward vertical gas flow is formed by the first gas injection nozzle 26, so that the aggregate B1 can reach the outlet 16. That is, the relatively small aggregate B1 cannot pass through the region where the upward vertical gas flow is formed and cannot reach the outlet 16. Only the aggregate B1 in which the particles have aggregated to a certain size can pass through the region where the upward vertical gas flow is formed and can reach the outlet 16.

[0024] In the granulation device 10, the aggregate B1 is introduced from the first processing layer 12 to the second processing layer 13 only through the outlet 16. From the first processing layer 12 to the second processing layer 13, the aggregate B1 that has reached the outlet 16 against the gas flow from the first gas injection nozzle 26 is introduced from the first processing layer 12 to the second processing layer 13. Only the aggregate B1 in which the particles have aggregated to a certain size is introduced to the second processing layer 13 through the outlet 16. In an example of FIG. 1, as described above, since the second processing layer 13 is adjacent to the first processing layer 12 on the vertically lower side, the aggregate B1 is introduced into the second processing layer 13 from the vertically upper side through the outlet 16.

[0025] The granulation apparatus 10 includes a second gas supply pipe 27 and a second gas injection nozzle 28. In the granulation apparatus 10, gas is supplied to the second gas injection nozzle 28 through the inside of the second gas supply pipe 27 (arrow A8). The gas supplied to the second gas injection nozzle 28 is at the temperature at which the solvent of the binder liquid contained in the aggregate B1 evaporates. Therefore, the gas supplied to the second gas injection nozzle 28 is at a higher temperature than the gas supplied to the first gas injection nozzle 26. The temperature of the gas supplied to the second gas injection nozzle 28 is an appropriate temperature corresponding to the type of solvent in the binder liquid, for example, a temperature corresponding to the boiling point of the solvent in the binder liquid. In one example, the temperature of the gas supplied to the second gas injection nozzle 28 is any temperature of 50°C or higher.

[0026] The second gas injection nozzle 28 is positioned in the second processing layer 13 between the outlet 16 and the discharge port 17 of the first processing layer 12. In the example shown in Figure 1, in the second processing layer 13, the second gas injection nozzle 28 is positioned vertically below the outlet 16 and vertically above the discharge port 17. The second gas injection nozzle 28 injects gas supplied through the second gas supply pipe 27 into the second processing layer 13. In the second processing layer 13, gas is injected from the second gas injection nozzle 28 towards the aggregate B1 introduced from the first processing layer 12. The second gas injection nozzle 28 injects gas at a temperature at which the solvent in the binder liquid contained in the aggregate B1 evaporates. Therefore, the second gas injection nozzle 28 injects gas in the second processing layer 13 at a higher temperature than the gas injected from the first gas injection nozzle 26.

[0027] The gas from the second gas injection nozzle 28 causes the solvent in the binder liquid to evaporate in the aggregate B1, forming granulated powder B2 in a granular state. In the second processing layer 13, the granulated powder B2 moves toward the discharge port 17 (arrow A9). The granulated powder B2 is then discharged from the discharge port 17 to the outside of the housing 11. In this way, the granulated powder B2 formed by granulation is obtained. In the manufacturing process of ceramics and food products, the formed granulated powder is used for press molding and other processes.

[0028] In the example shown in Figure 1, the first processing layer 12 is provided with one powder input head 21 and one liquid injection nozzle 23, and two first gas injection nozzles 26. However, the number of each of the powder input head 21, liquid injection nozzle 23, and first gas injection nozzles 26 is not particularly limited, as long as there is one or more. For example, there may be multiple powder input heads 21 and multiple liquid injection nozzles 23. Also, there may be only one first gas injection nozzle 26 or three or more.

[0029] Furthermore, in the example shown in Figure 1, raw material powder is ejected vertically downward from the powder input head 21, and binder liquid is ejected from the liquid injection nozzle 23 with the ejection direction aligned with a virtual horizontal plane. However, the ejection direction (input direction) of the raw material powder and the ejection direction of the binder liquid in the first processing layer 12 are not particularly limited. For example, raw material powder may be ejected in the first processing layer 12 with the ejection direction aligned with a horizontal plane, or raw material powder may be ejected in the first processing layer 12 with the ejection direction inclined with respect to the vertical direction and the horizontal plane. Also, binder liquid may be ejected vertically downward in the first processing layer 12, or binder liquid may be ejected in the first processing layer 12 with the ejection direction inclined with respect to the vertical direction and the horizontal plane.

[0030] However, in all embodiments, each of the one or more first gas injection nozzles 26 in the first processing layer 12 is positioned vertically below each of the one or more powder input heads 21 and the one or more liquid injection nozzles 23. In the first processing layer 12, each of the one or more first gas injection nozzles 26 is positioned vertically above the outlet 16. In the first processing layer 12, each of the first gas injection nozzles 26 injects gas vertically upward between the liquid injection nozzle 23 and the outlet 16. Each of the first gas injection nozzles 26 injects gas into the first processing layer 12 at a temperature at which the solvent of the binder liquid contained in the aggregate B1 does not evaporate.

[0031] Furthermore, in the example shown in Figure 1, only one second gas injection nozzle 28 is provided in the second processing layer 13, and gas is injected from the second gas injection nozzle 28 with the injection direction aligned with a virtual horizontal plane. However, the number of second gas injection nozzles 28 is not particularly limited as long as there is one or more; for example, multiple second gas injection nozzles 28 may be provided. Also, the injection direction of the relatively high-temperature gas in the second processing layer 13 is not particularly limited. For example, the gas may be injected in the second processing layer 13 toward the vertical downward side, or the gas may be injected in the second processing layer 13 with the injection direction inclined with respect to the vertical direction and the horizontal plane.

[0032] However, in all embodiments, in any configuration, in the second processing layer 13, each of the one or more second gas injection nozzles 28 injects gas at a higher temperature than the gas injected from the first gas injection nozzle 26. Each of the second gas injection nozzles 28 injects gas into the second processing layer 13 at a temperature at which the solvent of the binder liquid contained in the aggregate B1 evaporates.

[0033] In the embodiments described above, the liquid injection nozzle 23 injects the binder solution, which is the binder dissolved in the solvent, into the first processing layer 12, thereby forming aggregates B1 in which particles contained in the raw material powder are bound together. Therefore, in these embodiments, it is not necessary to dissolve the raw material powder together with the binder in the solvent, and thus the need to prepare a slurry is eliminated. Consequently, the amount of solvent used for granulation can be reduced. In addition, since the need to prepare a slurry is eliminated, the time required for granulation can be shortened.

[0034] Furthermore, in the embodiment, the first gas injection nozzle 26 injects gas vertically upward between the liquid injection nozzle 23 and the outlet 16 in the first processing layer 12. As a result, in the first processing layer 12, only aggregates B1 in which particles have aggregated to a size that can pass through the region where a vertically upward gas flow is formed by the first gas injection nozzle 26 can reach the outlet 16. Then, only the aggregates B1 that reach the outlet 16 against the gas flow from the first gas injection nozzle 26 are introduced from the first processing layer 12 to the second processing layer 13. As a result, evaporation of the solvent using a relatively high-temperature gas is performed in the second processing layer 13 only on aggregates B1 in which particles have aggregated to a certain size. Consequently, the formation of fine particles as granulated powder is effectively suppressed, and the proportion of fine particles formed as granulated powder is appropriately reduced.

[0035] Furthermore, in the embodiments, aggregates B1 are formed in the first processing layer 12 by spraying binder liquid toward the raw material powder. In this case, the amount of solvent contained in aggregates B1 is reduced compared to aggregates formed by spraying a slurry in which the raw material powder and binder are dissolved. By reducing the amount of solvent in aggregates B1, the force that causes the solvent to spread outward from aggregates B1 is reduced when the solvent contained in aggregates B1 is evaporated in the second processing layer 13. As a result, the formation of hollow granules as granulated powder is effectively suppressed, and the proportion of hollow granules formed as granulated powder is appropriately reduced.

[0036] Furthermore, in the embodiments, only aggregates B1, in which particles have aggregated to a certain size, are introduced into the second processing layer 13. Therefore, after a certain amount of time has elapsed since the binder was attached to the raw material powder particles in the first processing layer 12, the solvent contained in the aggregates B1 is evaporated in the second processing layer 13. In other words, in aggregates B1, the time it takes for the solvent to evaporate is delayed compared to the time it takes for the particles to bond together with the binder. Therefore, in aggregates B1, the solvent is evaporated when the bonding between the particles is relatively stable. Consequently, granulated powder is formed more appropriately.

[0037] As described above, in the embodiments, the amount of solvent used is reduced, and the time required for granulation can be shortened. Furthermore, the proportion of fine particles with small particle sizes and hollow granules formed as granulated powder is appropriately reduced, resulting in the proper formation of granulated powder.

[0038] Furthermore, in one example shown in Figure 1 of the embodiments, the second treatment layer 13 is positioned adjacent to the first treatment layer 12, vertically below it, and aggregates are introduced into the second treatment layer 13 from vertically above through the outlet 16. This configuration makes it possible to shorten the path length of the connecting portion between the first treatment layer 12 and the second treatment layer 13. By shortening the path length of the connecting portion between the first treatment layer 12 and the second treatment layer 13, the adhesion of aggregates B1 and binders to pipes, etc., at the connecting portion is effectively prevented.

[0039] In the example shown in Figure 1, the second processing layer 13 is positioned adjacent to the first processing layer 12, vertically below it. However, in the embodiments, the configuration is not limited to one in which the first processing layer 12 and the second processing layer 13 are aligned vertically. Even in configurations where the first processing layer 12 and the second processing layer 13 are not aligned vertically, in the first processing layer 12, each of the one or more first gas injection nozzles 26 injects gas vertically upward between the liquid injection nozzle 23 and the outlet 16. In the second processing layer 13, each of the one or more second gas injection nozzles 28 injects gas at a higher temperature than the gas injected from the first gas injection nozzles 26.

[0040] Here, as a verification related to the embodiment, the following first verification was performed. In the first verification, a binder liquid was sprayed onto the raw material powder in one processing layer formed inside the housing. The weight of the raw material powder in the processing layer was set to approximately 400g, and the binder liquid was sprayed in the processing layer from the vertically upper side to the vertically lower side. The binder concentration in the binder liquid was set to approximately 3.5%, and the amount of binder liquid sprayed was set to approximately 10mL / min. In addition, in the first verification, gas was sprayed into the processing layer at room temperature in parallel with the spraying of the binder liquid. In the processing layer, the gas was sprayed from the vertically lower side to the vertically upper side.

[0041] In the first verification, the aforementioned binder liquid and gas were continuously injected for about 20 minutes to induce aggregation of particles contained in the raw material powder. After 20 minutes of aggregation, the formed aggregates were observed using an electron microscope. The observation results showed that the aggregation in the first verification appropriately formed aggregates of a certain size, for example, aggregates with a particle size of 50 μm or larger. Therefore, it was demonstrated that by injecting a gas at room temperature in parallel with injecting the binder liquid towards the raw material powder in a single treatment layer, the particles of the raw material powder appropriately bind together and aggregates are appropriately formed.

[0042] Furthermore, a second verification related to the embodiments, etc., was also performed as described below. The second verification was performed by simulation. In the second verification, the simulation conditions were set to introduce the same number of particles with a particle size of 10 μm and particles with a particle size of 100 μm into a single processing layer. In this case, it was assumed that each particle was introduced into the processing layer from the vertically upward side. In addition, it was set that an outlet was formed at the vertically downward end of the processing layer, and that gas was injected from a gas injection nozzle vertically upward between the particle introduction position and the outlet. Therefore, the simulation was performed in an environment in which a gas flow directed vertically upward was formed in the processing layer due to the gas injection.

[0043] In the simulation for the second verification, the time change in the number of 10 μm particles reaching the outlet and the time change in the number of 100 μm particles reaching the outlet were calculated under the aforementioned environment. Figure 2 is a schematic diagram showing the calculation results from the simulation in the second verification related to the embodiment, etc. In Figure 2, the horizontal axis represents time relative to the time when particles were introduced into the processing layer, and the vertical axis represents the number of particles that reached the outlet. In Figure 2, the time change in the number of 10 μm particles is shown by a dashed line, and the time change in the number of 100 μm particles is shown by a solid line.

[0044] As shown in Figure 2, the simulation results showed that most of the 100 μm particles reached the outlet after a certain amount of time had elapsed since they were introduced into the treatment layer. On the other hand, most of the 10 μm particles did not reach the outlet even after a certain amount of time had elapsed since they were introduced into the treatment layer. Therefore, it was demonstrated that by forming a gas flow vertically upward in the treatment layer, relatively small aggregates become unable to reach the outlet, and only aggregates of a certain size are able to reach the outlet.

[0045] According to at least one embodiment or example, a liquid injection nozzle injects a binder liquid into a first processing layer to form aggregates, and a first gas injection nozzle injects gas vertically upward between the liquid injection nozzle and the outlet in the first processing layer. The aggregates that reach the outlet against the flow of gas from the first gas injection nozzle are then introduced from the first processing layer to the second processing layer, and a second gas injection nozzle injects gas into the second processing layer at a higher temperature than the gas injected from the first gas injection nozzle. This makes it possible to provide a granulation apparatus and granulation method that can appropriately form granulated powder while reducing the amount of solvent used.

[0046] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0047] 1...System, 10...Granulator, 11...Housing, 12...First processing layer, 13...Second processing layer, 16...Outlet, 21...Powder input head, 23...Liquid injection nozzle, 26...First gas injection nozzle, 28...Second gas injection nozzle, B1...Agglutinator, B2...Granulated powder.

Claims

1. As the raw material powder is introduced, a first processing layer having an outlet at its vertically downward end, A liquid injection nozzle that sprays a binder solution, in which the binder is dissolved in a solvent, onto the first processing layer to form aggregates in which particles contained in the raw material powder are bound together, In the first processing layer, between the liquid injection nozzle and the outlet, a first gas injection nozzle is provided that injects gas vertically upward, The aggregates, which are connected to the first processing layer through the outlet and reach the outlet against the flow of gas from the first gas injection nozzle, are introduced into the second processing layer from the first processing layer. The second gas injection nozzle injects gas at a higher temperature than the gas injected from the first gas injection nozzle into the second processing layer, thereby evaporating the solvent of the binder liquid in the aggregate introduced into the second processing layer. A granulation apparatus equipped with the following:

2. The second processing layer is arranged adjacent to the first processing layer on the vertically downward side, The aggregate is introduced into the second processing layer from the vertically upper side through the outlet. A granulation apparatus according to claim 1.

3. The raw material powder is introduced into the first processing layer, which has an outlet at its vertically lower end. By spraying the binder solution, which is a binder dissolved in a solvent, onto the first processing layer from a liquid spray nozzle, aggregates are formed in which the particles contained in the raw material powder are bound together. In the first processing layer, gas is injected from the first gas injection nozzle vertically upward between the liquid injection nozzle and the outlet, The aggregates that have reached the outlet against the flow of gas from the first gas injection nozzle are introduced from the first processing layer into the second processing layer, which is in communication with the first processing layer through the outlet, By injecting gas from the second gas injection nozzle in the second processing layer at a higher temperature than the gas injected from the first gas injection nozzle, the solvent of the binder liquid is evaporated in the aggregate introduced into the second processing layer. A granulation method comprising the following:

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