GRANULATION COATING METHOD, BUFFLE DEVICE FOR GRANULATION COATING AND GRANULATION COATING APPARATUS

Abstract: The present invention relates to a granulation coating technique, and more particularly to a technique wherein granules are contained in a drum rotating about a substantially horizontal axis and the rotary drum is rotated for granulation of the granules and (or) coating. There is provided a rotary drum (1) for containing the granules (M) and rotating about the substantially horizontal axis, and also provided a buffle member (12) continuously or intermittently rotating or rocking in the granules (M) contained in this rotary drum (1). The buffle means is turned in the granules, so that the raw material of the granules can be prevented from adhering to the buffle member and the rotary drum or from dropping therefrom, thus obtaining products of uniform coating.

Description: FIELD OF THE INVENTION The present invention relates to a granulating and coating technique, and more particularly to a technique wherein powder and granules are contained in a drum rotating about a substantially horizontal axis and the rotary drum is rotated for granulation of the powder and granules and (or) coating thereof. BACKGROUND ART As this type of technique for granulating and coating described above, a technique for granulating and coating various powder and granules including medicines, foods, synthetic chemical products, etc. by supplying and discharging gas such as hot air blow into and from a rotary drum called coating pan while rotating the rotary drum around a horizontal axis, has been known. In the technique described above, there is raised a technical problem how to agitate and mix the powder and granules efficiently in the rotary drum in order to accomplish desired granulating or coating operation efficiently and homogeneously. To solve this problem, it has been proposed to provide a baffle device fixed in the rotary drum for functioning as an obstacle to the flow of the granules etc. (See Japanese Patent No. Sho 52-10665 Gazette). For the baffle device, there is proposed a baffle device of which position is movable along with an axis or between the inside and outside of the granular layer. In the former prior art described above, however, there is seen a phenomenon that the raw material of the powder and granules tends to adhere to the buffle device when processing of granulation and coating is carried out, then the material adhered is peeled off therefrom into the rotary drum, because the baffle device is installed on a fixed position. In such phenomenon, the adhered material detach from the baffle device, then it can be a cause to give the defects such as unevenness in the thickness of the coated layer, oversized products so-called double tablets and irregular-shaped products those which are resulted from the adhesion of the material peeled off to the granulated products. The later prior art described above provides an improved agitating operation accomplished by using the baffle device, however, the inventors herein found that it cannot solve all of the problems as described above and has defects due to the adhesion of powder and granules to the buffle device and the inner wall of the rotary drum and the their peeling off therefrom as well. EP-A-0 609 444 discloses a baffle apparatus comprising a baffle means 23 and baffle displacement means 24. Furthermore, the baffle displacement means 24 comprises a rotation shaft 25, an air cylinder 26, an air cylinder 27, a supporting arm 28 and an actuator 29 and mount bars 30. Both of the cylinders in connection with the supporting arm 28 and the mount bars 30 adjust the position of baffle plate 23 inside and outside of the powder and the granules or along the axis of rotation shaft 25. In view of the problems as described above, it is an object of the present invention to provide a granulating and coating technique capable of obtaining products of uniform granulating and coating. It is an another object of the present invention to provide a technique capable of eliminating the adhesion of the raw material of the powder and granules to the buffle device and their peeling off therefrom, and the problems associated thereto. It is a further object of the present invention to provide a technique for making excellent agitation of the powder and granules. It is a still further object of the present invention to provide a technique capable of improving the efficiency in the production of the granules or coated products. Aforementioned and other objects and the novel advantageous features of the present invention will be clarified in the description of this specification with referring to the drawings appended. DISCLOSURE OF THE INVENTION In the scope of the invention disclosed in the present patent application, the representative embodiment thereof can be outlined as follows. The granulating and coating method of the present invention is to achieve granulation and coating by using an apparatus for granulating and coating wherein material of powder and granules are contained in a rotary drum installed in said apparatus for granulating and coating, said rotary drum is rotated about a substantially horizontal axis therein, while rotating a baffle device at the inside of the layer of the powder and granules contained in the rotary drum, the baffle device being characterized by the features of claim 1. The baffle apparatus for granulating and coating of the present invention is one to be used for the granulating and coating apparatus which is installed with a rotary drum for containing the powder and granules and rotating about a substantially horizontal axis, and contains a baffle device according to any of claims 1 to 10. The granulating and coating apparatus of the present invention comprises said baffle apparatus installed thereto. In the granulating and coating technique specified in the present invention, the problems primarily caused by the peeling off of the adhered materials as described above, can be solved by continuously or intermittently rotating the baffle device at the inside of the layer of the powder and granules contained in the rotary drum to thereby prevent the adhesion of the raw materials of the powder and granules to the surface of the baffle device and the inner wall of the rotary drum. By turning this baffle device in the rotary drum, it becomes possible to provide products of uniform granulating and coating. In addition, the turning of the baffle device makes possible to perform thorough agitation of the raw materials of the powder and granules. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of one embodiment of the granulating and coating apparatus according to the present invention. Fig. 2 is a general view showing the concept of the apparatus thereof, Fig. 3(a) to (g) are diagrams explaining in order the variation in the position to turn the baffle device and the flow of the powder and granules, Fig. 4 is a front view showing one embodiment of the baffle device to be used in the present invention, and from Fig. 5 to Fig. 22 are diagrams showing the other embodiments of the baffle device according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Now the granulating and coating apparatus according to the present invention is described with referring to Figs. 1 and 2. A rotary drum 1 for containing and rotating powder and granules M like powder or tablets, which are the objectives to be granulated and/or coated, is supported on a rotary roller 4 so as to rotate about a horizontal axis by the actuation of a drive power 2 such as motor via a belt 3. The rotary drum 1 of this embodiment is formed in an octagonal sectional structure as an example of the polygonal structures, which allows to prevent from the slip of the powder and granules M in the rotary drum 1. In the fixed sites of each side of the octagonal rotary drum 1, there are provided a plurality of pores 5 made by means of punching, etc. The rotary drum 1 having the pores 5 can be constructed by firstly forming the pores 5 in a predetermined size of a plate, then connecting the plates each other in an octagonal shape by means of welding, or welding eight pieces of the plates having the pores 5 to a frame. On each sides of the octagonal rotary drum 1 having the pores 5, outer circumferential members 6, each of which can be separated and is a hermetic jacket being individually detachable, is formed respectively to secure easy and sure cleaning of the outer circumference of the drum having the pores 5. Each outer circumferential member 6 has a dimension corresponding to each side of the octagonal rotary drum 1, and it is allowed to be sealed to and peeled off from each side of the rotary drum 1 by holding it with a handle 9 in a manner to engage a first flange 7 fixed by welding to the outer side of the drum side and a second flange 8 fixed by welding to the inner side of the outer circumferential member 6. A space surrounded by the outer circumference of each side of the rotary drum 1, the inner side of the outer circumferential member 6 and the flanges 7 and 8, is formed to use as a space for exchanging gas 10. There are also provided two ducts (not shown) for supplying or discharging gas, such as hot air blow and cooled gas, to the inside of the rotary drum 1. As shown with solid line and broken line in Fig. 1, it is also possible to reverse the usage of the ducts from supply to the inside of the rotary drum 1 to discharge therefrom or vice versa. Additionally, a nozzle unit 11 for supplying coating solution or binder solution is inserted in a direction along with the axis (horizontal direction) into the rotary drum 1. In the rotary drum 1 of this embodiment according to the invention, there is provided a baffle member 12 (buffle means) being positioned in the layer of the powder and granules M. This baffle member 12 is to agitate the powder and granules M contained in the rotary drum 1 to thereby obtain products of uniform granulating and coating. The baffle member 12 of the invention is supported by an arm 13 (a member to be installed) which is installed on the one longitudinal side of the rotary drum 1, and it is capable of turning continuously or intermittently in the layer of the powder and granules M. For this purpose, the baffle member 12 is, for example, supported by the arm 13 via a rotary drive power 14 (drive means) such as air-operative rotary actuator, wherein a rotary shaft 15 is constituted so as to be turned (including be rotated and swung) by the rotary drive power 14. Therefore, the baffle device for granulating and coating specified in the present invention comprises the baffle member 12, the arm 13, the rotary drive means 14 and the rotary shaft 15 described above. The baffle member 12 is installed in a vertical direction with respect to the moving direction of the powder and granules M in the rotary drum 1. When the baffle member 12 is turned by the rotary drive power 14, it is swung at a constant speed and at an fixed range of angle, for example, in a range of more than 180 degrees if the rotary drive power 14 is a rotary actuator, while it is rotated at a constant speed and toward a certain direction if the rotary drive power 14 is a motor. The details of the operation for granulating and coating in this embodiment is now explained. Firstly, certain amount of raw material of the powder and granules is placed in the rotary drum 1, then a predetermined coating solution is supplied from the nozzle unit 11 into the rotary drum 1 while rotating the rotary drum 1 by actuating the drive power 2 via the belt 3, and the gas, such as hot air blow or cooled gas, is supplied form the rotary drum 1 or discharged thereto through the duct (not shown), if necessary. By continuing this procedure, the powder and granules M in the rotary drum 1 are tumbled, thereby the desired granulating and coating operation is allowed to carry out. In this embodiment, and in the process described above, the baffle member 12 capable of turning in the rotary drum 1 is installed in the rotary drum so that the powder and granules M being under the processing receive optimal agitation and mixing with it, which makes the granulating and coating operation efficient and uniform. In addition thereto, the baffle member 12 turns in the rotary drum 1, so that the defective production due to the adhesion of the powder and granules M to the surface of the baffle member 12 and the inner wall of the rotary drum 1 and the peeling off of the adhered materials therefrom can be prevented according to this embodiment. With referring to Fig. 3 (a) to (g), the positioning of the baffle member 12 during turning and the flow of the powder and granules M in this embodiment are now explained. In Fig. 3, the baffle member 12 is shown as a plate body of which one end be installed to the rotary shaft 15 to support itself, and the arrows in the figures represent the flow of the powder and granules M. Fig. 3(a) shows a state of the baffle member 12 which is taking position inclined 45 degrees anticlockwise with respect to the flow of the powder and granules. In this situation, the powder and granules M having moved toward the one side of the baffle member 12 flow from the rotary shaft 15 toward the free end of the baffle member 12 along with the incline thereof, while being agitated and mixed by the baffle member 12 (see Fig. 3(a)). Then, as shown in Fig. 3(b), when the baffle member 12 rotates about 45 degrees anticlockwise more, it takes right-angled position with respect to the direction of the flow of the powder and granules M. In this state, the flow of the powder and granules M is obstructed by the baffle member 12 and dispersed right and left along with the one side of the baffle member, thereby those powder and granules are agitated and mixed to the maximal extent by the baffle member 12 (see Fig. 3(b)). When the baffle member 12 is further turned 45 degrees anticlockwise, the powder and granules M are obstructed by said side of the baffle member 12 and agitated, however, those flow from the free end of the baffle member 12 toward the direction for the rotary shaft 15 in contrary to the case of Fig. 3(a) (see Fig. 3(c)). As shown in Fig. 3(d), when the baffle member 12 is still further turned 45 degrees anticlockwise, the direction of the baffle member 12 becomes substantially parallel to that of the flow of the powder and granules M. In this state, the flow of the powder and granules M is partly changed primarily at the site of the free end of the baffle member 12 and mostly flow along with the both side of the baffle member substantially in parallel or in contacting thereto (see Fig. 3(d)). As shown in Fig. 3(e), when the baffle member 12 is turned again 45 degrees anticlockwise, the flow of the powder and granules M is changed along with the reverse side of the baffle member 12 and they flow from the free end side toward the rotary shaft 15, thereby the powder and granules M are agitated and mixed (see Fig. 3(e)). When the baffle member 12 is further turned another 45 degrees anticlockwise, it faces the contrary side thereof to that of Fig. 3(b) toward the flow of the powder and granules M and takes right-angled position with respect to said flow. In this state, the flow of the powder and granules M is obstructed by the baffle member 12, thereby the powder and granules M are agitated and mixed (see Fig. 3(f)). As shown in Fig. 3(g), when the baffle member 12 is once more turned 45 degrees anticlockwise, it takes a position inclined 45 degrees clockwise with respect to the flow of the powder and granules M, then the powder and granules M flow from the rotary shaft 15 toward the free end of the baffle member along with the incline thereof, while being agitated and mixed (see Fig. 3(g)). Then, the baffle member 12 is turned clockwise to return from the position of Fig. 3(g) to that of Fig. 3(a), and it is swung between the position of Fig. 3(a) and that of Fig. 3(g) in the angle range of about 270 degrees. As described hereinabove, the powder and granules M are agitated and mixed while the baffle member 12 swings in repetition between the positions of Fig. 3(a) to (g), thus allowing to obtain products of uniform granulating and coating. In addition, because of the turning of the baffle member 12 in this embodiment, the contact of the powder and granules M to the surface of the baffle member 12 and the contacting direction thereof are always changing, the powder and granules M neither adhere to the sides of the baffle member 12 nor the inner wall of the rotary drum 1, which have been seen in the fixed-type buffle member, and therefore, it allows to prevent the production of defective products due to the dropping and the peeling off of such adhered materials. Now, hereinbelow, the modifications of the baffle member 12 according to the present invention are described with referring to Figs. 4 to 22. As partly shown in Figs. 1 and 2, Fig. 4 illustrates an example wherein the baffle member 12, one of which corner is formed in a circular shape, is fixed to the rotary shaft 15 in a manner only one end of the baffle member 12 is held by the rotary shaft 15. Fig. 5 is an example of the baffle member 12 wherein a slightly wide baffle member 12 is used and is fixed to the rotary shaft 15 of which position is somewhat inner side of the baffle member 12. Fig. 6 is an example of the baffle member 12 wherein it is in a rectangular shape. Fig. 7 is an example of the baffle member 12 wherein it is in a similar rectangular shape to that of Fig. 6 and is fixed to the rotary shaft 15 at the substantially central position of the longitudinal direction of the baffle member 12. Fig. 8 shows an example of the baffle member 12 wherein the shape of the underside thereof is circular, Fig. 9 does the same is elliptic, and Fig. 10 does the same is substantially triangular. By turning the baffle member 12 of Fig. 10 upside down to be reverse triangular shape, the upper layer of the powder and granules M can be agitated and mixed to a further extent, providing better performance in agitation and mixing thereof. In the example of Fig. 11, four pores 16 are formed through the baffle member 12 as an illustration to improve the agitation and the mixing of the powder and granules M by letting them passing through those pores 16. The baffle member 12 in Fig. 12 has a propeller structure. In an example as illustrated in Fig. 13, there is provided a structure wherein an electric motor is used as the rotary drive power 14 by which the rotary shaft 15 and the baffle member 12 are rotated toward a certain direction and at a constant speed continuously or intermittently via the belt 17. In Fig. 13, it is shown an example wherein three plates are situated as the baffle member 12 at an angle of substantially 120 degrees formed one another. In an example as illustrated in Fig. 14(a), the baffle device is composed of three baffle members 12 in a rectangular plate shape, which are shifted one another in a longitudinal direction of the rotary shaft 15 and are forming the angle of 120 degrees one another. The example illustrated in Fig. 14(b) is a baffle device composed of two rectangular baffle members 12 which are fixed side by side along the longitudinal axis of the rotary shaft 15 and intersect at right angles to each other. In these examples, the structures of the baffle device is constituted so as to agitate and mix the upper, middle and lower layers of the powder and granules M, or the upper and lower layers thereof, simultaneously. In the examples illustrated in Fig. 14(a) and (b), the upper baffle member 12 is made longer and the lower one is made shorter as shown with two-dotted chain lines. By using this type of the baffle device, it facilitates to the better agitation and mixing of the upper layer of the powder and granules M, thus allowing to provide improved products of granulating and coating. Figs. 15 to 19 are plan views of examples wherein non-plate structural bodies are employed as the baffle members 12. Fig. 15 shows a baffle member of which central portion is thicker than the other portion, Fig. 16 shows the one that the whole member is made thick, Fig. 17 shows the S-shaped one, Fig. 18 is the triangular one in the view from plane direction, and Fig. 19 is the square one in the same view. Fig. 20 is an example of the baffle device wherein the buffle member 12 is constituted with a plate being bent in a V-shape and is fixed to a slider 18 opposite to the arm 13. Fig. 21 is an example of the baffle device wherein two rectangular plates are fixed to the rotary shaft 15 as the buffle members 12 in a state that they oppose each other while each one end are closed and the other ends are apart, thereby said baffle members 12 are movable respectively via the slider 18 along with the arm 13 to close and separate each other. In this example, therefore, the baffle members 12 are rotatable around the rotary shaft 15 and movable along with the arm 13 via slider 18, thereby allowing to adjust the position of the baffle members 12 for the agitation and mixing of the powder and granules M in a wide range. The example illustrated in Fig. 22 shows the baffle device wherein the rotary shaft 15 is installed in an inclined state, which is also included in the embodiment of the baffle device according to the present invention. The present invention is described in detail based on the examples described hereinabove, however, the present invention should not be limited to the description in those examples and it will be apparent to those skilled in the art that various modifications and variations of the method and apparatus of the present invention which fall within the scope of the present invention can be made. For example, the shape and size of the baffle member 12 and the structure of the arm 13 for installing the baffle member 12 are not limited to the ones described in the aforementioned examples. And the sectional structure of the rotary drum 1 may be other polygonal shape than octagonal one, or even round shape. Further, the structure and manner for the attachment and detachment of the rotary drum 1 and the manner of the installation of the plate having pores 5 are not limited to the ones described in the aforementioned examples. Further, it is also optional to replace the rotary drive power 14 from the air-operative type to oil-hydraulic type or motor-operative type as well as a piping system. The baffle members 12 may be coated with fluorine resin or silicone resin, or may be made of engineering plastics. The position of the baffle members 12 may be changed between the inside and outside of the layer of the powder and granules M contained in the rotary drum 1. It is also possible to insert only the part of the baffle member 12 vertically into the layer of the powder and granules M. In the above description, the present invention is explained in connection with its use for the granulation and/or coating of medicines, foods and synthetic chemicals, however, it should not be limited to such use, and it can be widely utilized in the granulation and/or coating of other granules and the processing of granules, such as drying, mixing, etc. INDUSTRIAL APPLICABILITY The followings are the summarized advantageous effects obtainable by the representative embodiments of the present invention. (1) By turning the baffle means at the inside of the layer of the powder and granules, the adhesion of the raw materials of the powder and granules to the buffle means and the inner wall of the rotary drum can be prevented, thereby the defects in coating due to the peeling off of the adhered materials can be prevented. (2) Because of the advantageous effect mentioned in (1), the occurrence of oversized and irregular or abnormal-shaped products those which are caused by the peeling off of the adhered materials can be prevented. (3) The turning of the baffle members allows to provides homogeneous and ideal agitation of the powder and granules. (4) Because of the advantageous effect mentioned in (3), the extensibility of the coating solution is improved, thereby the homogeneous coating can be readily made. (5) Because of the advantageous effects mentioned in (3) and (4), the unevenness in the thickness of the coated layer can be eliminated, thereby coating products with uniform quality can be manufactured steadily. (6) Because of the advantageous effects mentioned from (1) to (5), uniform products having no contamination of impurities can be obtained, therefore, it is very useful and significant in view of Good Manufacturing Practice (GMP), when it is applied for the manufacturing of medicines.

Claims: A baffle device for granulating and coating to be used in a granulating and coating apparatus which contains powder and granules and is provided with a rotary drum 1 rotating about a substantially horizontal axis, characterized in that it contains a baffle means 12, supported by an installable arm 13 via a rotary drive means 14, wherein a rotary shaft 15 connected to said rotary drive means 14 and to said baffle means 12, respectively, is constituted so as to be turned by said rotary drive means so that said baffle means 12 is continuously or intermittently rotated or turned inside of the layer of the powder and granules contained in said rotary drum 1. The baffle device according to claim 1, characterized in that the baffle means 12 is swung at a constant speed and at the angle range of at least 180 degrees. The baffle device according to claim 1, characterized in that the baffle means 12 is a plate. the baffle device according to claim 3, characterized in that the plate contains pores therein. The baffle device according to claim 1, characterized in that the baffle means 12 is a non-plate member. The baffle device according to claim 1, characterized in that a plurality of baffle means 12 are installed therein. The baffle device according to claim 6, characterized in that a plurality of baffle means 12 are installed side by side and shifted one another in the longitudinal direction of an arm 13 to be installed. The baffle device according to claim 7, characterized in that a plurality of baffle means 12 are installed therein and that the upper baffle member is constituted longer than the lower baffle member. The baffle device according to claim 1, characterized in that the position for installing the baffle means 12 can be changed in the longitudinal direction of the axis of said arm 13 to be installed. The baffle device according to claim 9, characterized in that a plurality of baffle means 12 are installed therein and the position for installing each baffle means 12 can be changed in the longitudinal direction of the axis of said arm 13 to be installed. A method for granulating and coating using a granulating and coating apparatus which contains powder and granules and is provided with a rotary drum 1 rotating about a substantially horizontal axis, characterized in that the granulating and coating is carried out by continuously or intermittently rotating or turning a baffle device according to any one of claims 1 to 10 inside of the layer of the powder and granules contained in said rotary drum 1. A granulating and coating apparatus containing powder and granules and is provided with a rotary drum 1 which rotates about a substantially horizontal axis, characterized in that it contains a baffle device according to any one of claims 1 to 10. The granulating and coating apparatus according to claim 12, characterized in that the baffle means 12 are vertically installed with respect to the moving direction of the powder and granules.

Inventors: MORO SHOICHI, NAKAZAWA SHINZO, OGAWA MASANORI, YAMADA SHURI, MORO, SHOICHI, NAKAZAWA, SHINZO, OGAWA, MASANORI, YAMADA, SHURI, MORO, SHOICHI, C/O TOKYO TANABE COMPANY LIMITED, NAKAZAWA, SHINZO, C/O TOKYO TANABE COMPANY LIMITED, OGAWA, MASANORI, C/O FREUND INDUSTRIAL COMPANY LTD, YAMADA, SHURI, C/O FREUND INDUSTRIAL COMPANY LTD.
Applicants: FREUNT IND CO LTD, TOKYO TANABE CO, FREUND INDUSTRIAL CO., LTD., TOKYO TANABE COMPANY LIMITED
Application year: 1992
Main classification: B01J2
IPC codes: B01J2