JP7237360B2 - coating equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating apparatus for coating, mixing, drying, and the like of powders such as pharmaceuticals, foodstuffs, and agricultural chemicals, and more particularly to a coating apparatus provided with a rotating drum that is rotationally driven around its axis.

Equipped with a rotating drum to apply film coating, sugar coating, etc. to tablets, soft capsules, pellets, granules, and the like of pharmaceuticals, foods, agricultural chemicals, etc. (hereinafter collectively referred to as granules). coating equipment is used (see, for example, Patent Documents 1 to 3).

A coating apparatus of this type usually comprises a rotary drum in which powder or granular material is housed, which is driven to rotate about its axis, and whose one end in the axial direction is constituted by an annular mouth ring; and a spray nozzle unit having a spray nozzle for spraying a spray liquid toward the granular material layer formed inside the rotating drum.

JP-A-2006-26592 JP 2014-4556 A JP 2014-147923 A

In this type of coating apparatus, the spray liquid is sprayed onto the powder layer in the rotating drum, the powder layer is agitated as the rotary drum rotates, and the spray liquid spreads on the surface of each powder particle. A coating film of the spray liquid component is formed on the particle surface through a series of processes of drying and solidifying the spray liquid on the particle surface by blowing air into the rotating drum. In the process of this coating process, the mist of the spray liquid, its solidified powder, powder particles, abrasion powder of the coating film, etc. may adhere to the spray nozzle and the spray arm that supports the spray nozzle, resulting in deposits. be. This deposit can clog the spray nozzle. In addition, these deposits gradually grow as the coating process progresses, and when they reach a certain size, some of the deposits fall into the powder layer and become a factor in lowering the coating quality. , may be mixed in the product.

In addition, the rotation of the rotating drum may cause powder to be placed on the spray arm. ) will occur. In addition, in a process in which the spray liquid is not sprayed, if dripping occurs from the spray nozzle, the spray liquid mixes with the powder layer in that process, resulting in a defective product.

In this type of coating apparatus, a plurality of spray nozzles are generally arranged along the central axis of the rotating drum. Therefore, among the problems described above, the problem relating to the spray nozzles becomes more serious as the number of spray nozzles increases.

In view of the above circumstances, it is a technical object of the present invention to make it possible to reduce the number of spray nozzles arranged in a coating apparatus.

A coating apparatus according to the present invention, which has been devised to solve the above-mentioned problems, accommodates a granular material therein, is driven to rotate about its axis, and has an annular mouth ring portion at one end in the axial direction. and a spray nozzle unit having a spray nozzle for spraying a spray liquid toward the granular material layer of the granular material formed inside the rotary drum, The spray nozzle unit has a support portion capable of supporting the spray nozzle, and a region of the granular material layer where the spray liquid is sprayed moves from one end side to the other end side in the axial direction, or moves in the axial direction. and a swing drive unit for swinging the spray nozzle so as to move from the other end side to the one end side of the spray nozzle.

According to this configuration, in the granular material layer, the region where the spray liquid is sprayed moves from one end side to the other end side in the axial direction of the rotary drum, or from the other end side to the one end side in the axial direction of the rotary drum. The spray nozzle can be rocked as it moves. Therefore, even if the number of spray nozzles is small, it is possible to spray the spray liquid to the area from one end side to the other end side of the rotating drum in the axial direction of the granular material layer. That is, according to the coating apparatus of the present invention, it is possible to reduce the number of installed spray nozzles.

In the above configuration, the rotating drum is connected to a peripheral wall portion along the axial direction and one end of the peripheral wall portion in the axial direction, the diameter of which gradually decreases toward the one end side in the axial direction, and the mouth. and an end wall portion connected to the other end of the ring portion in the axial direction, and the support portion intersects a boundary surface passing through the boundary between the peripheral wall portion and the end wall portion, or the The spray nozzle may be supported so that the spray nozzle is positioned closer to one end in the axial direction than the boundary surface.

According to this configuration, the entire spray nozzle is not located in the inner space of the peripheral wall of the rotating drum where most of the granular material layer exists, and the spray nozzle crosses the boundary between the peripheral wall and the end wall. It intersects the boundary surface through which it passes, or is located on one end side of the rotary drum in the axial direction of the boundary surface. Therefore, it is possible to suppress the formation of deposits on the spray nozzle and its supporting portion. In addition, it is possible to suppress the particles from being placed on the support portion of the spray nozzle. Moreover, even if dripping occurs from the spray nozzle in a process in which the spray liquid is not sprayed, it is possible to prevent the spray liquid from being mixed into the granular material layer.

On the other hand, since the spray nozzle intersects the boundary surface passing through the boundary between the peripheral wall portion and the end wall portion, or is positioned on the one end side of the axial direction of the rotating drum from the boundary surface, the spray nozzle is more difficult to use than the conventional one. away from the granular layer. On the other hand, in the granular material layer, the spray nozzle is arranged so that the region where the spray liquid is sprayed moves from one end side to the other end side in the axial direction, or moves from the other end side to the one end side in the axial direction. Since it is oscillated, it is possible to prevent the coating process from being hindered due to the spray nozzle moving away from the granular material layer.

Said structure WHEREIN: The said rocking drive part may change the rocking speed of the said spray nozzle.

With this configuration, by changing the swing speed of the spray nozzle, it is possible to adjust the liquid amount of the spray liquid per unit area that is sprayed on the granular material layer per unit time.

In the above configuration, when viewed from one end in the axial direction, the axis that is the center of the swing of the spray nozzle is on the side opposite to the rotation direction of the rotating drum during the coating process with respect to the vertical line. may be inclined to

With this configuration, it becomes easy to spray the spray liquid from the spray nozzle onto the powder layer that is inclined by the rotation of the rotary drum during the coating process.

Said structure WHEREIN: The said spray nozzle unit may have a vertical movement drive part which vertically moves the said support part.

With this configuration, it is possible to move the position of the spray nozzle up and down according to the amount of the granular material layer, the conditions of the coating process, and the like.

According to the present invention, it is possible to reduce the number of spray nozzles arranged in the coating apparatus.

1 is a schematic front view showing a coating apparatus according to an embodiment of the invention; FIG. 2 is a schematic partial cross-sectional view seen from the right side of FIG. 1 showing a coating apparatus according to an embodiment of the present invention; FIG. 2 is a schematic partial cross-sectional view seen from the upper side of FIG. 1 showing a coating apparatus according to an embodiment of the present invention; FIG. FIG. 3 is a view in the direction of arrow A in FIG. 2; FIG. 4 is a schematic cross-sectional view of the rotary drum during coating, viewed from the front side; 6 is a schematic partial cross-sectional view from the right side of FIG. 5 showing the rotating drum and nozzles during the coating process; FIG.

FIG. 1 is a schematic front view showing a coating apparatus according to an embodiment of the invention. FIG. 2 is a schematic partial sectional view seen from the right side of FIG. 1 showing a coating apparatus according to an embodiment of the present invention. FIG. 3 is a schematic partial cross-sectional view seen from the upper side of FIG. 1 showing a coating apparatus according to an embodiment of the present invention. This coating apparatus 1 is a tablet coating apparatus that performs sugar coating (sugar coating) on tablets (granules). Of course, the present invention is not limited to this, and the coating device 1 may be a tablet coating device that performs film coating processing on tablets, or a coating device that performs other coating processing on other powders and granules. may

A coating apparatus 1 comprises a rotating drum 2 , a casing 3 housing the rotating drum 2 , and a spray nozzle unit 4 .

The rotating drum 2 accommodates the granular material therein and is rotationally driven around an axis X extending in the horizontal direction. The rotary drum 2 includes a peripheral wall portion 2a having a polygonal (dodecagonal in the illustrated example) cross section in the radial direction, an end wall portion 2b connected to the front end (one end in the direction of the axis X) of the peripheral wall portion 2a, and a rear wall portion 2b connected to the peripheral wall portion 2a. and an end wall portion 2c connected to the end (the other end in the direction of the axis X). The peripheral wall portion 2a extends along the axis X direction. Each side surface of the peripheral wall portion 2a is provided with a ventilation portion formed of a porous portion. The end wall portion 2b gradually decreases in diameter toward one end side in the axis X direction. Also, the diameter of the end wall portion 2c gradually decreases toward the other end side in the axis X direction. The front end of the end wall portion 2b is connected to the rear end of an annular mouth ring portion 2d, and a front end opening 2e is provided at the front end of the mouth ring portion 2d. The inner peripheral surface of the mouth ring portion 2d has a shape that gradually expands in diameter toward the front. A portion of the rotating drum 2 behind the rear end of the end wall portion 2c is omitted from the drawing.

A front end portion of the casing 3 constitutes a chamber 3a, and a door portion 3b is provided on the front surface of the chamber 3a. A part of the spray nozzle unit 4 is accommodated in the chamber 3a. In addition, a discharge port 3c for the treated granular material is provided in the lower part of the chamber 3a.

The spray nozzle unit 4 includes a spray nozzle 5, a support portion 6 for supporting the spray nozzle 5, a swing driving portion 7 for swinging the spray nozzle 5, and a vertical motion driving portion for vertically moving the support portion 6. part 8;

The spray nozzle 5 is for spraying a spray liquid such as a film agent liquid toward the granular material layer formed inside the rotating drum 2 . A spray liquid supply pipe (not shown) is connected to the spray nozzle 5 . In this embodiment, the spray nozzle 5 is a one-fluid nozzle that sprays the spray liquid only with the spray liquid, but the present invention is not limited to this, and for example, the spray liquid is sprayed using compressed air or the like. It may be a two-fluid nozzle or the like.

As shown in FIG. 4, the spray nozzle 5 has a spray port 5a at one end in the central axis L direction. The spray nozzle 5 is fixed to the support shaft 6a. The driving force of the swing driving portion 7 is transmitted to the support shaft 6a, and the support shaft 6a rotates (turns) around its central axis C, thereby swinging (turning) the spray nozzle 5. As shown in FIG. That is, the center axis C of the support shaft 6a is the center of the swing of the spray nozzle 5 (hereinafter referred to as swing axis C). In this embodiment, the swing axis C is orthogonal to the central axis L of the spray nozzle 5, but the intersection angle between the swing axis C and the central axis L may not be right, and the swing axis C and the center The axis line L does not have to intersect. Further, the swing axis C is arranged on a plane perpendicular to the axis X of the rotary drum 2 .

As shown in FIG. 5, during the coating process, the rotary drum 2 rotates clockwise when viewed from the front (see the white arrow). The swing axis C of the spray nozzle 5 is inclined in the direction opposite to the rotation direction of the rotary drum 2 with respect to the vertical line. The inclination angle α is, for example, 30° to 60°. The granular material layer S is inclined forward in the direction of rotation of the rotary drum 2 with an upward slope. Therefore, when viewed from the front side, the center axis of the spray nozzle 5 is at an angle close to a right angle with respect to the powder layer S even during the swinging motion, and the spray nozzle 5 efficiently sprays the powder layer. S can be sprayed. During the coating process, a processing gas such as hot air or cold air is supplied into the rotary drum 2 from a portion of the peripheral wall 2a of the drum 2 that is not blocked by the powder layer S. Then, the processing gas passes through the granular material layer S in the rotating drum 2 and is exhausted from the ventilation section of the peripheral wall portion 2a of the rotating drum 2 (on the diagonally lower left side in FIG. 5).

In this embodiment, the support portion 6 supports the spray nozzle 5 so that the spray nozzle 5 is located on the one end side in the direction of the axis X from the boundary surface passing through the boundary B between the peripheral wall portion 2a and the end wall portion 2b. . However, the present invention is not limited to this, and the support portion 6 supports the spray nozzle 5 so that the spray nozzle 5 intersects the boundary surface passing through the boundary B between the peripheral wall portion 2a and the end wall portion 2b. good too. 1 to 5 show the arrangement of the spray nozzles 5 when the spraying is stopped when the coating apparatus 1 is not performing the coating process. In this state, the entire spray nozzle 5 is located on the inner peripheral side of the mouth ring portion 2d.

The support portion 6 includes a support shaft 6a fixed to the spray nozzle 5, a shaft support portion 6b that swingably supports the support shaft 6a, and a driving force for swinging the spray nozzle 5 with respect to the support shaft 6a. and a driving force transmission support portion in which a mechanism for transmitting is incorporated. The driving force transmission support portion includes a first arm portion 6c extending forward from the shaft support portion 6b, a second arm portion 6d extending leftward (as viewed from the front side) from the front end of the first arm portion 6c, It has a third arm portion 6e extending upward from the left end (when viewed from the front side) of the second arm portion 6d.

The swing drive unit 7 is installed above the chamber 3a. A cover portion 7a that covers the outer periphery of the third arm portion 6e is provided on the lower side of the swing driving portion 7. As shown in FIG. Although not shown, the swing drive unit 7 includes a drive source such as a motor that generates a drive force for swinging the spray nozzle 5, and the drive force generated by the drive source in the third arm portion 6e. and a driving force transmission mechanism for transmitting power to the driving force transmission mechanism. A sensor for detecting the position of the spray nozzle 5 in the swinging direction is also built in, and the swinging operation of the spray nozzle 5 is controlled based on the detection result of this sensor.

A vertical motion drive unit 8 is also installed above the chamber 3a. The vertical motion driving section 8 is installed on the left side of the rocking driving section 7 (when viewed from the front side). The vertical motion driving section 8 has a lifting arm section 8a extending downward from the inside thereof. The lower end of the lifting arm portion 8a is connected to the left end (when viewed from the front side) of the second arm portion 6d. Although illustration is omitted, the vertical motion driving unit 8 includes a driving source such as a motor that generates driving force for vertically moving the lifting arm portion 8a, and a driving force generated by the driving source is transmitted to the lifting arm portion 8a. and a driving force transmission mechanism for moving up and down.

When the elevating arm portion 8a moves up and down, the support portion 6 (third arm portion 6e) moves up and down with respect to the swing drive portion 7 (cover portion 7a). Thereby, the vertical position of the support portion 6 is adjusted. The driving force transmission mechanism in the vertical movement driving portion 8 or the support portion 6 is configured so that the driving force for swinging the spray nozzle 5 can be transmitted even during the vertical movement of the support portion 6 .

As shown in FIG. 6, the spray nozzle 5 is swung during the coating process. During the oscillating motion of the spray nozzle 5, the center of spray of the spray nozzle 5 (central axis L) reciprocates between the two lines shown. Due to the swinging motion of the spray nozzle 5, the spray region R where the spray liquid is sprayed by the spray nozzle 5 on the surface layer of the granular material layer S moves from the position P1 on the front side (one end side in the direction of the axis X) to the rear side. (the other end side in the direction of the axis X) to position P2.

In this embodiment, the spray nozzle 5 is located on the one end side in the direction of the axis X with respect to the boundary surface passing through the boundary B between the peripheral wall portion 2a and the end wall portion 2b during the swinging motion of the spray nozzle 5 . However, the present invention is not limited to this, and the spray nozzle 5 intersects the boundary surface passing through the boundary B between the peripheral wall portion 2a and the end wall portion 2b during the oscillating motion of the spray nozzle 5. good too.

In this embodiment, the speed (swing speed) of the swing operation of the spray nozzle 5 can be changed (by control of the swing drive section 7). For example, between the posture of the spray nozzle 5 that sprays the spray region R at the front side position P1 and the posture of the spray nozzle 5 that sprays the spray region R at the rear side position P2, the swing speed may continuously increase and decrease. Alternatively, the swinging speed may be changed to increase or decrease in stages, or a state (stop state) in which the swinging speed becomes 0 may be provided a plurality of times so that the swinging motion is stopped. You may make it intermittent.

The spray area R at the rear position P2 is farther from the spray nozzle 5 than the spray area R at the front position P1. Further, the angle of the central axis L of the spray nozzle 5 with respect to the surface layer of the granular material layer S is smaller in the spray area R at the rear position P2 than in the spray area R at the front position P1. Therefore, when the spray speed of the spray liquid from the spray nozzle 5 is constant, the amount of the spray liquid sprayed per unit area per unit time is greater than the spray area R at the front position P1 at the rear position P2. , the spray area R is smaller. Therefore, in order to make the amount of the spray liquid sprayed per unit area per unit time in the spray region R as constant as possible regardless of the position of the spray region R, the spray nozzle 5 is oscillated. As a specific example of the spraying operation, there are the following two patterns A and B, for example. The spray speed of the spray nozzle 5 is constant in any pattern. In either case, the same operation is repeated multiple times during one coating process.

In pattern A, first, the spray nozzle 5 sprays the spray region R at the front position P1 for a predetermined time, and then, while continuing spraying, the spray nozzle 5 is swung to cover the spray region R at the rear position P2. After taking the position for spraying, the spray area R at the rear side position P2 is sprayed for a predetermined time. After that, the spraying is stopped, and the spray nozzle 5 is swung while the spraying is stopped, and the spray region R at the front side position P1 is returned to the sprayable posture. In this case, the spray time for the spray area R at the rear position P2 is set longer than the spray time for the spray area R at the front position P1. Further, the swing speed of the spray nozzle 5 is constant from the posture of spraying the spray region R at the front side position P1 to the posture of spraying the spray region R at the rear side position P2.

In pattern B, immediately after the spray nozzle 5 first sprays the spray area R at the front side position P1, the spray nozzle 5 is swung while continuing spraying to take the attitude of spraying the spray area R at the rear side position P2. Then, the spraying is stopped immediately after the spray nozzle 5 assumes the attitude of spraying the spraying region R at the rear side position P2. Then, the spray nozzle 5 is swung while spraying is stopped, and the spray region R at the front side position P1 is returned to a sprayable posture. In this case, the oscillating speed of the spray nozzle 5 is set so as to gradually decrease from the posture of spraying the spray region R at the front side position P1 to the posture of spraying the spray region R at the rear side position P2. It is

The coating apparatus 1 configured as described above can enjoy the following effects.

The spray nozzle 5 can be oscillated so that the spray area R moves from the front position P1 to the rear position P2 in the granular material layer S. Therefore, even if the number of spray nozzles 5 to be provided is small, the spray liquid can be sprayed onto the area of the granular material layer S from the front position P1 to the rear position P2. That is, according to the coating apparatus 1 according to this embodiment, it is possible to reduce the number of spray nozzles 5 to be arranged.

The entire spray nozzle 5 is not positioned within the inner space of the peripheral wall portion 2a of the rotating drum 2 where most of the granular material layer S exists, and the spray nozzle 5 is located at the boundary between the peripheral wall portion 2a and the end wall portion 2b. It intersects with the boundary surface passing through B, or is located on the one end side of the axis X direction from the boundary surface. Therefore, it is possible to suppress the formation of deposits on the spray nozzle 5 and its support portion 6 . In addition, it is possible to suppress the particles from being placed on the support portion of the spray nozzle. In addition, even if dripping occurs from the spray nozzle in a process in which the spray liquid is not sprayed, mixing of the spray liquid into the granular material layer S can be suppressed.

On the other hand, since the spray nozzle 5 is positioned on the one end side in the direction of the axis X from the boundary surface passing through the boundary B between the peripheral wall portion 2a and the end wall portion 2b, the spray nozzle 5 is further away from the granular material layer S than conventionally. It will be. On the other hand, since the spray nozzle 5 is oscillated so that the spray area R moves from the front position P1 to the rear position P2 in the powder layer S, the spray nozzle 5 can be moved to the powder layer S in the conventional manner. It is possible to prevent the coating process from being disturbed due to the distance from the

The present invention is not limited to the above-described embodiments, and various modifications are possible within the technical scope of the present invention. For example, in the above embodiment, one spray nozzle 5 is provided, but two or more may be provided as necessary.

Further, in the above-described embodiment, the spray nozzle 5 is oscillated so that the spray region R moves from the front position P1 to the rear position P2 in the powder layer S. The spray nozzle 5 may be oscillated so that the spray area R moves from the rear position P2 to the front position P1.

In the above-described embodiment, the radial cross-sectional shape of the peripheral wall portion 2a of the rotary drum 2 is polygonal, but it may be circular, and the shape of the peripheral wall portion 2a may be conical, polygonal conical, or the like. may be Further, in the above-described embodiment, the coating apparatus 1 includes the rotating drum 2 that is rotationally driven around the axis X extending in the horizontal direction. It may be a coating device with a drum.

Reference Signs List 1 Coating device 2 Rotating drum 2a Peripheral wall 2b End wall 2d Mouth ring 4 Spray nozzle unit 5 Spray nozzle 6 Support 7 Swing drive 8 Vertical motion drive B Boundary between peripheral wall and end wall C Spray nozzle Swing axis R Spray area S Granule layer X Axis of rotating drum

Claims (5)

a rotating drum in which powdery material is accommodated and driven to rotate about its axis, and one end in the axial direction of which is constituted by an annular mouth ring; A coating apparatus comprising a spray nozzle unit having a spray nozzle for spraying a spray liquid toward a granular material layer,
The spray nozzle unit is
a support capable of supporting the spray nozzle;
In the granular material layer, the spray nozzle is arranged such that a region where the spray liquid is sprayed moves from one end side to the other end side in the axial direction, or moves from the other end side to the one end side in the axial direction. and a rocking driving part for rocking the coating apparatus. The rotary drum is connected to a peripheral wall portion along the axial direction and one end of the peripheral wall portion in the axial direction. and an end wall portion connected to the other end of the direction,
The support portion is arranged so that the spray nozzle intersects a boundary surface passing through the boundary between the peripheral wall portion and the end wall portion, or the spray nozzle is located on one end side of the boundary surface in the axial direction. , supporting said spray nozzle. 3. The coating apparatus according to claim 1, wherein the swing drive section can change the swing speed of the spray nozzle. When viewed from one end side in the axial direction, the axis that is the center of the swing of the spray nozzle is inclined with respect to the vertical line in the opposite direction to the rotating direction of the rotating drum during coating. The coating apparatus according to any one of claims 1 to 3, characterized in that: 5. The coating apparatus according to any one of claims 1 to 4, wherein the spray nozzle unit has a vertical movement driving section for vertically moving the support section.

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