Apparatus and method for coating or encapsulating an article

Abstract

The present invention provides an apparatus for coating or encapsulating articles, comprising a drum with a perforated wall rotatably mounted within a drum chamber, the drum being suitable for containing and agitating a batch of articles to be coated during rotation of the drum; a dispenser group having one or more nozzles for spraying a coating product onto the articles contained in the drum; at least one gas inlet of the chamber on one side of the drum for directing clean drying gas toward the perforated wall of the drum; and at least one gas outlet of the chamber on the other side of the drum for extracting dirty drying gas from the chamber after passing through the drum. The apparatus also includes an adjustable closure system interposed between the drum and the gas outlet of the chamber, which can define an actual flow path for the dirty drying gas that is smaller than the flow path provided by the gas outlet of the chamber, and further displace or concentrate the flow path to match the area of ​​the drum wall actually covered by the batch of articles. Automatic adjustment of the closure system, which in some cases takes into account the position of the nozzle within the drum, is envisioned.

Description

Technical Field

[0001] The present invention relates to an apparatus for coating or encapsulating articles, of the type comprising a rotating drum for agitating a batch of articles to be coated with a particular product, and through which the product is sprayed through at least one nozzle disposed inside the drum. These apparatuses are used, for example, for coating particulate articles such as in the form of tablets or pills, which are common in pharmaceutical and confectionery products.

Background Art

[0002] Apparatuses for coating or encapsulating are widely used in the pharmaceutical field for applying an outer layer of one or more products to particulate articles such as in the form of tablets or pills.

[0003] These apparatuses essentially comprise a container within which a drum containing a production batch of articles to be coated rotates. The apparatus generally comprises one or more spray nozzles for the product used to coat the articles. This spraying operation is carried out while the drum is rotating and agitating the batch of articles to ensure a uniform coating of all the articles. Also conventionally, the drum is perforated and the coating apparatus comprises a circuit for forced gas, generally air, passing through the drum, which helps to dry the sprayed product after it has been applied to the articles to be coated.

[0004] The aim of these apparatuses is to apply a coating of a predetermined thickness to a batch of specific articles, and the coating is generally measured in terms of weight gain in the most efficient possible way, consuming an appropriate amount of coating product with a minimum operating time.

[0005] It has been found that the distance between the nozzle and the free surface of the articles to be coated is an important factor in ensuring an accurate and efficient coating. However, this distance is not the only parameter involved when seeking an optimal coating. Other factors such as the injection direction of the sprayed product also play an important role, and it is particularly important to direct the injection in a direction essentially perpendicular to the free surface of the batch of articles to be coated.

[0006] Devices with fixed nozzles cannot meet these requirements and can only operate efficiently for very specific batches of articles.

[0007] In fact, the smaller the batch of articles to be coated, the greater the distance between the free surface of the articles agitated inside the drum and the spray nozzle, and a device with fixed nozzles, which is particularly suitable for large batches, cannot be used for small batches, and vice versa.

[0008] Similarly, for example, when the characteristics of the product used to coat the articles change, different distances may be required between the free surface of the articles and the nozzles for the same batch of articles.

[0009] For the purpose of providing a more versatile device, a coating device with a movable spray nozzle is disclosed, which can take different spatial positions and, in some cases, can also be oriented to adapt to the batch of articles and / or the product used for its coating.

[0010] Japanese Patent Application Laid-Open No. 2003-062500 describes a coating device equipped with a positioning group of a series of nozzles. This positioning group has only one degree of freedom and can only move the nozzles vertically to approach or move away from the bottom of the drum.

[0011] European Patent No. 1200197 describes an alternative to the aforementioned device, which further enables the nozzles to approach or move away from the wall of the drum. It should be noted that the nozzle positioning mechanism is controlled by a sensor that detects in real time the distance between the measurement point and the free surface of the batch of articles agitated inside the drum.

[0012] European Patent No. 3597048 describes an improved coating apparatus provided with a movable spray nozzle, which is based on a mechanism that simultaneously approaches or moves away from the free surface of a batch of articles inside the drum and changes the angular position to maintain the nozzle essentially perpendicular to the free surface. The apparatus can be equipped with an ultrasonic type sensor, which can measure the instantaneous distance between the measurement point inside the drum and the free surface of the batch of articles, automatically correct the distance between the nozzle and the batch of articles, and adjust it to the target value.

[0013] Of course, if the nozzle can be arranged at an optimal distance from the batch of articles inside the drum, it helps to improve the efficiency of the operation of the apparatus compared to an apparatus with a fixed spray nozzle when the apparatus operates with different batch sizes. Depending on the batch size and the properties of both the articles to be coated and the product used for coating, there are optimal recipe parameters, which can include, in addition to the batch size and the operating time, the rotational speed of the drum, the flow rate and / or pressure of the product to be sprayed, and further the selected position of the spray nozzle inside the drum.

[0014] However, despite the above, in practice, the efficiency has not improved as much as expected.

Prior Art Documents

Patent Documents

[0015]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0016] Accordingly, an object of the present invention is to further improve the efficiency of the coating operation, and in particular, to improve the efficiency of an apparatus having means for arranging a spray nozzle at a selected position inside a drum according to recipe parameters, an apparatus and a method for coating or encapsulating an article.

Means for Solving the Problem

[0017] In order to encourage the product sprayed in the direction of the batch of articles inside the drum to be properly applied to the articles, the gas passing through the drum follows a preferred direction. Specifically, measures are known to ensure that the gas passes through the batch of articles contained in the drum.

[0018] For this purpose, the drum is rotatably mounted and arranged within a cylindrical chamber, which chamber has one gas inlet of the chamber on a first side of the drum for directing clean dry gas towards the perforated wall of the drum and at least one gas outlet of the chamber on the other side of the drum for extracting the dirty dry gas that has passed through the drum from the chamber. During rotation of the drum, the batch of articles accumulates at the bottom of the drum but is slightly displaced towards one side of the drum. In order to ensure that the gas follows the preferred direction, the gas outlet of the chamber is arranged to coincide with the area of the drum where the batch of articles accumulates, allowing the gas to pass through the batch of articles.

[0019] Even when the device presents movable nozzles and these nozzles can approach the batch of articles to find the best spraying state and minimize product loss when the device operates with small batches, the batch of articles may be arranged on the perforated wall of the drum in a different behavior, especially when compared to a large batch of articles, the articles may be distributed so as to cover a smaller surface of the perforated wall of the drum.

[0020] As a result, the gas flow escapes from the drum through the perforated wall to areas not actually covered by the articles. This effect is also experienced even when the spray nozzles are arranged in the best position relative to the free surface of the articles inside the drum.

[0021] This gas flow transports the coating product without attaching the coating product to the article. The gas flow is sprayed onto the perforated wall of the drum and not onto the article itself. The gas flow causes loss of useful product. The gas flow causes fouling in the gas piping duct downstream of the barrel winding chamber. The gas flow degrades the cleaning filters conventionally used for gas cleaning. Clearly, all of these are disadvantageous for the efficiency of the coating operation.

[0022] The present invention proposes, according to all claims 1, an apparatus comprising an adjustable closing system interposed between the drum and the gas outlet of the barrel winding chamber. The closing system can define the actual flow path of the dirty dry gas to be smaller than the flow path provided by the gas outlet of the chamber and can be further displaced or concentrated to coincide with the area of the drum wall that is actually covered by the batch of articles.

[0023] In a variant, the apparatus comprises a controller for operating the closing system, which controller is for adjusting at least automatically the state of the closing system or for issuing a recommendation signal when the state of the closing system or the state of coincidence with the area of the drum wall that is actually covered by the batch of articles is not optimal. By this measure, the adjustment of the closing system or the corresponding warning for informing the operator that the actual gas outlet is not optimal according to the size of the batch of articles is automated.

[0024] In a variant, the apparatus utilizes the further advantage of the known relationship between the size of the batch finally determining the area of the drum wall covered by the batch of articles and the position of the spray nozzles to automatically adjust the state of the closing system or generate a recommendation signal according to the position of the spray nozzles of the apparatus with movable nozzles. All of this is advantageous for the overall efficiency of the coating operation.

[0025] In the context of the present invention, the position of the nozzle is understood both as the spatial position and the orientation of the nozzle, or as a combination of both parameters. The spatial position may be defined, for example, based on a virtual reference or coordinate axis, based on other parts of the device such as the distance from the drum wall, or based on external elements such as the distance from the free surface of a batch of articles inside the drum.

[0026] In the device to which the present invention is applied, a dispenser group, and more particularly the associated mechanism that enables the nozzle to be placed at a selected position inside the drum according to recipe parameters, is operable manually or electrically. In both cases, the position of the nozzle inside the drum for the coating operation is used to adjust a closed-loop system or to issue a recommendation signal, i.e., a recommendation for the adjustment of the closed-loop system.

[0027] The present invention contemplates that the operator may manually position the nozzle at the selected position according to the recipe parameters by operating the associated mechanism. The associated mechanism may of course be a mechanism controlled from outside the drum or an electric mechanism. The operator knows, for example based on an experimental table, which is the optimal position of the nozzle according to the recipe parameters for the type and size of the batch of articles.

[0028] The present invention further contemplates that the device has means for assisting or automating the selection of the position of the nozzle.

[0029] Thus, in another variant of the present invention, the device comprises a sensor for measuring the distance (di) between a measurement point and the free surface of a batch of articles contained in the drum, and the mechanism of the dispenser group is an electric mechanism controlled based on the measurement value of the said sensor. Thus, the dispenser group has the ability to automatically position the nozzle at a position with a target distance (d0) relative to the free surface of the batch of articles inside the drum, and then, the same automatic adjustment of the state of the closed-loop system is caused by the controller.

[0030] The automatic adjustment of the closed system can be further performed separately or without the involvement of the nozzle position, thereby enabling the implementation of the present invention even in an apparatus equipped with a fixed nozzle.

[0031] In this sense, in another variant of the present invention, the apparatus comprises a sensor for measuring the distance (di) between the measurement point and the free surface of the batch of articles contained in the drum, and the size of the area of the drum wall actually covered by the batch of articles is estimated based on the measurement value of the said sensor without considering the position of the nozzle.

[0032] As far as the closed system is concerned, this can comprise a set of gates including a single movable gate or a plurality of movable gates, and the single movable gate or the plurality of movable gates can be actuated by respective actuators controllable by a controller.

[0033] The gas outlet is arranged on one side of the drum and covers a part of the perforated wall extending to the bottom or near the bottom of the said drum.

[0034] In an embodiment, the apparatus comprises a drying gas suction group downstream of the chamber surrounding the drum, the drying gas suction group bringing a vacuum state in the chamber, whereby the flow of the contaminated drying gas can be urged in one outlet direction (L) of the chamber. The closure system has a plurality of gates arranged across the gas flow path from the gas outlet of the chamber, these gates being configured in the form of blades such as slat shutters, which are overlapped and rotatably mounted about respective rotation axes essentially perpendicular to the direction (L), and two or more gates are operable by a controller between at least one open position (A) in which the blades are arranged essentially parallel to the direction (L) and a closed position (B) in which the blades are essentially perpendicular to the direction (L), and the movement of these gates from the open position (A) to the closed position (B) starts from the gate at the highest position and continues to the gate immediately below, by the operation of the gates in a cascade arrangement such that the gas flow path gradually becomes smaller and converges towards the lower position of the perforated wall of the drum.

[0035] In the open position (A), it is advantageous if the lower edge of the blade of the movable gate fits snugly against the perforated wall of the drum.

[0036] In the closed position (B), it is advantageous if the upper and lower edges of the blade of the operable gate fit snugly against their respective adjacent frames or gates, essentially airtight.

[0037] However, the object of the present invention is also a method for coating or encapsulating an article, comprising passing a gas flow through a chamber and a rotating drum having a perforated wall surrounded by the chamber, the rotating drum accommodating and stirring a batch of articles to be coated while a coating product is being discharged onto the articles from the inside of the drum by at least one nozzle, and the method further comprising the operation of concentrating the actual flow path of the outlet gas flow from the chamber so as to coincide with the area of the wall of the drum actually covered by the batch of articles.

[0038] In a variant of the method, the drum is surrounded by a barrel winding chamber, the chamber having at least one gas inlet of the chamber on a first side of the drum for directing clean dry gas towards the perforated wall of the drum and at least one gas outlet of the chamber on the other side of the drum adjacent to the perforated wall for extracting the dirty dry gas that has passed through the drum from the chamber, and the method further includes automatically operating an adjustable closure system interposed between the drum and the gas outlet of the chamber, the closure system being able to define the actual flow path of the dirty dry gas to be smaller than the flow path provided by the gas outlet of the chamber and being further displaced or concentrated to coincide with the area of the wall of the drum actually covered by a batch of articles.

[0039] The size of the area of the wall of the drum actually covered by a batch of articles can be estimated based on a measurement of the distance between a measurement point and the free surface of the batch of articles contained in the drum, or, when the nozzle is a movable nozzle, based on the position of the nozzle inside the drum. In the latter case, the position of the nozzle is manually selected according to recipe parameters including at least the size of the batch of articles, or using a measurement of the distance between a measurement point and the free surface of the batch of articles contained in the drum.

Brief Description of the Drawings

[0040]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0041] Figures 1 and 2 schematically show a type of device 100' known for manufacturing tablets, and more particularly for coating granular pharmaceutical articles 2 with a coating product 8. The device 100' comprises a drum 3 having a perforated wall 4 rotatably mounted in a barrel-shaped chamber 5, and the drum 3 is suitable for accommodating and stirring a batch of articles 2 to be coated during rotation of the drum. For this purpose, a series of blades, flaps, or the like (not shown) are provided in the drum 3 in a known manner, and these blades collect and lift a part of the batch of articles during rotation of the drum 3 in the direction indicated by the arrow C in the example, and when the blades reach a specific arrangement, the batch of articles is dropped.

[0042] The device 100' comprises a dispenser group 6 having a plurality of nozzles 7 for spraying the coating product 8 onto the articles accommodated in the drum 3 according to recipe parameters.

[0043] The chamber 5 has a gas inlet 10 of the chamber 5 on the first side of the drum 3 for directing a clean dry gas 12a towards the perforated wall 4 of the drum, and a gas outlet 11 on the other side of the drum adjacent to the perforated wall 4 of the drum 3 for extracting the dirty dry gas 12b that has passed through the drum 3 from the chamber 5.

[0044] Figures 1 and 2 show how batches of different sizes of the article 2 to be coated are distributed in different behaviors within the drum 3. More specifically, FIG. 1 shows that when the apparatus 100’ operates at maximum capacity, the arrangement and configuration of the gas outlet 11 of the chamber 5 ensure that substantially all of the dirty dry gas 12b withdrawn from the chamber 5 passes through the batch of the article 2. However, when the same apparatus 100’ operates with a very small batch of the article 2 (see FIG. 2), the area 4a of the perforated wall 4 of the drum 3 actually covered by the article 2 becomes smaller and is slightly displaced towards the bottom side of the drum 3, leaving an uncovered area 4b of the perforated wall 4 facing the gas flow path provided by the gas outlet 11. Through this uncovered area 4b of the perforated wall 4, the dirty gas 12b may drag the product 8 not attached to the batch of the article 2 and exit the drum 3. This flow of the dirty gas 12b exiting the drum 3 without passing through the batch of the article 2 gradually reduces the efficiency of the coating operation. This is because, as described above, the gas 12b is sprayed onto the perforated wall 4 of the drum 3, thereby causing loss of useful product, dirt in the gas duct downstream of the barrel chamber 5, and deterioration of the cleaning filter conventionally used in the outlet gas treatment unit.

[0045] FIG. 3 shows a facility using the apparatus 100 for coating or encapsulating the article 2 according to the present invention. This facility includes the apparatus 100, a gas supply unit 110 for supplying gases such as air blown into the apparatus 100, a gas treatment unit 120 for the gas exiting the apparatus 100, and a product supply unit 130 for the product used to coat the article.

[0046] The supply unit 130, which is shown enlarged within the frame in Fig. 3, corresponds to a supply unit equipped with blockage detection means, as described in Spanish Utility Model No. 1232314. For this purpose, the supply unit 130 comprises drive means 130a for the product 8 and a conduit 130b, which establishes a fluid connection between the drive means of the product and the injection nozzle 7 (disposed inside the drum). The supply unit 130 has the feature that each conduit 130b has a portion consisting of a flexible sleeve clamped from the outside by a detector 130c, and this detector 130c uses a load cell installed on the sleeve to convert the increase in pressure that the sleeve can exert on the load cell due to the expansion of the sleeve when a blockage occurs in the associated conduit or nozzle that can gradually reduce the efficiency of the device into a measurable electrical signal. Naturally, other supply units different from those exemplified here may be used.

[0047] Fig. 4 schematically shows and illustrates a variant form of the device 100. The device 100 according to the present invention shares some features with the conventional device 100', and the same reference numerals are used to indicate these common features of both devices.

[0048] As a feature of the device 100, the device 100 comprises an adjustable closing system 30 interposed between the drum 3 and the gas outlet 11 of the chamber 5. This closing system 30 can not only define an actual flow path for the dirty dry gas 12b that is smaller than the flow path provided by the gas outlet 11 of the chamber 5, but in addition, in the closing system 30, the restricted flow path can be concentrated to coincide with the region of the perforated wall 4 of the drum 3 covered by the batch of articles 2 in any case.

[0049] Although not shown, the device 100 in Fig. 4 comprises a dry gas suction group downstream of the chamber 5, and this dry gas suction group can bring a vacuum state into the chamber 5, thereby promoting the flow of the dirty dry gas 12 in the direction of the outlet (L) of the chamber 5.

[0050] As shown in FIG. 4, the closed system 30 of the apparatus 100 comprises a set of three movable gates 31, 32, 33. The gates 31, 32, 33 are arranged across the gas flow path, overlapped, and configured in the form of blades as a slat shutter, rotatably mounted about their respective axis of rotation 31b, 32b, 33b which is essentially perpendicular to the direction (L). Each gate 31, 32, 33 is movable between two end positions, namely, an open position (A) in which the blades are arranged essentially parallel to the direction (L), taking a substantially horizontal orientation in the example of FIG. 4, and a closed position (B) in which the blades are arranged essentially perpendicular to the direction (L), taking a substantially vertical orientation in the example of FIG. 4.

[0051] In this example, the upper gate 31 and the intermediate gate 32 are further operable by respective actuators 31a, 32a controllable by the controller 1 and have the goal of automatically adjusting the gas flow path through the gas outlet 11, as will be described below. The lower gate 33 is arranged in a stationary orientation in the open position (A).

[0052] In device 100, the mechanical solution adopted consists in each movable gate being provided with two end fingers or bolts, which are rotatably inserted into respective holes provided in the side of the gas outlet duct, specifically in the region of the gas outlet 11 of chamber 5. At least one of these fingers, or an integral part thereof, extends outside chamber 5 and is firmly attached to the transmission lever outside chamber 5. The transmission lever is actuated, in the case of the upper gate 31 and the intermediate gate 32, here by respective actuators 31a, 32a as a piston group. The transmission lever is hinged to the piston and is adapted to ensure the rotation of the transmission lever and the rotation of the associated gate in the next first or opposite direction by the movement of the piston in one direction or the opposite direction. Referring to Figure 4 showing the gates 31, 32, 33 in the open position (A), as the piston groups of the actuators 31a, 32a retract, the respective transmission levers rotate reliably clockwise, and then the associated upper gate 31 and intermediate gate 32 also rotate clockwise to the closed position (B).

[0053] Note that the operation of the upper gate 31 and the intermediate gate 32 from the open position (A) to the closed position (B), starting from the gate at the highest position and continuing to the gate immediately below, by the operation of the cascade array of gates, gradually reduces the gas flow path and gradually concentrates it towards the lower region of the perforated wall 4 of the drum 3. Thus, in the case of an operation where the size of the batch of articles continuously decreases, the gas flow path to the region of the perforated wall 4 that is not covered is closed.

[0054] Due to the presence of a device with a movable spray nozzle, the operator can add the position of the nozzle inside the drum as a recipe parameter. The optimal position of the nozzle is known depending on the nature of the article to be coated and, in particular, the size of the batch of articles to be coated. This position can be known, for example, based on an experimental table.

[0055] According to the features provided by the device, the nozzle can be positioned manually or automatically, and there are a plurality of known mechanisms for moving the nozzle, including mechanisms that enable linear movement, combinations of movements, and further mechanisms that can not only place the nozzle at a desired position but also change its orientation.

[0056] In any case, the position of the nozzle as a recipe parameter is directly related to the size of the batch of articles, and the size of the batch of articles determines how much smaller or more displaced the area of the perforated wall actually covered by the batch of articles is towards the bottom of the drum during the rotation of the drum.

[0057] The device 100 exemplifying the present invention utilizes this finding, and the controller 1 can operate the closed system 30 to automatically adjust the state of the closed system 30 according to the position of the nozzle 7. Alternatively, in a simple version of the device 100, the controller 1 may be equipped to issue a recommendation signal 16 when the state of the closed system 30 is not optimal according to the position of the nozzle 7, and the operator may manually adjust the state of the closed system 30.

[0058] In the device 100 of FIG. 4, a dispenser group 6 with a plurality of spray nozzles 7 has an associated mechanism 9 that assists in placing the nozzles 7 at selected positions inside the drum. Specifically, the mechanism 9 is electrically driven and is controlled by a sensor 14 that detects in real time the distance (di) between the measurement point and the free surface 2a of the batch of articles 2 housed in the drum 3. Thereby, the dispenser group 6 has the ability to automatically place or correct the placement of the nozzles 7 at a position at a target distance (d0) from the free surface 2a of the batch of articles 2 inside the drum 3. The sensor 14 can be placed at a fixed point, or the sensor 14 can move with the nozzle 7. This type of dispenser group is described, for example, in European Patent No. 3597048.

[0059] Examples of known sensors are probe or remote sensing types, such as laser type mechanical transducers, but radar / soner type sensors are particularly preferred. One example of a sensor suitable for the implementation of this variant of the present invention is the industrial radar sensor VEGAPULS64 commercially available from VEGA.

[0060] Figures 5 to 7 serve to show the operation of this version of apparatus 100 in the respective situations of maximum feed rate, medium feed rate, and minimum feed rate. In each case, one recipe parameter is the distance from nozzle 7 to the free surface 2a of the batch of article 2, and these distances may be equal or different in each case. - Figure 5 shows the situation of maximum feed rate. The measured value of sensor 14 is used in a method known per se to automatically position nozzle 7 at a position at a target distance (d0) from the free surface 2a of the batch of article 2. The controller 1 (not shown) is programmed in the situation of maximum feed rate to relate the position taken by nozzle 7 close to the center of the drum and to take this target distance (d0) into account with respect to the free surface 2a of the batch of article 2. In this situation of maximum feed rate, the region 4a of the perforated wall 4 of drum 3 actually covered by the batch of article 2 is such that it is not necessary to restrict the outlet 11 of the dirty drying gas 12b. The controller 1 accordingly operates the closed system 30 so that both the upper gate 31 and the intermediate gate 32 take their respective open positions (A). - Figure 6 shows the situation of medium input quantity. Using the measured value of sensor 14 in the above method, the nozzle 7 is automatically positioned at a position of a target distance (d0) from the free surface 2a of the batch of article 2. It should be noted that the position of the nozzle 7 is different from the position taken in the situation of maximum input quantity. The controller 1 (not shown) associates this position of the nozzle 7 with the situation of medium input quantity where the area 4a of the perforated wall 4 of the drum 3 actually covered by the batch of article 2 is smaller than before, and the uncovered area 4b of the perforated wall 4 of the drum 3 facing the area affected by the upper gate 31 remains. In this case, it is desirable to restrict the outlet 11 of the contaminated dry gas 12b and define a smaller actual flow path 11a (the enlarged area within the frame in the figure) to encourage the contaminated dry gas 12b to pass through the batch of article 2. The controller 1 correspondingly operates the closed system 30 so that the upper gate 31 takes the closed position (B) and the intermediate gate 32 takes the open position (A). - Figure 7 shows the situation of minimum input quantity. Again, using the measured value of sensor 14, the nozzle 7 is automatically positioned at a position of a target distance (d0) from the free surface 2a of the batch of article 2. The position of the nozzle 7 is different from the positions taken in the situations of maximum and medium input quantities. The controller 1 (not shown) associates this position of the nozzle 7 with the situation of minimum input quantity where the area 4a of the perforated wall 4 of the drum 3 actually covered by the batch of article 2 is even smaller than before, and the uncovered area 4b of the perforated wall 4 of the drum 3 facing the areas affected by the upper gate 31 and even the intermediate gate 32 remains. In this case, it is desirable to further restrict the outlet 11 of the contaminated dry gas 12b and define an even smaller actual flow path 11a (the enlarged area within the frame in the figure) to encourage the outlet of the contaminated dry gas 12b to preferably pass only through the batch of article 2. The controller 1 correspondingly operates the closed system 30 so that the upper gate 31 and the intermediate gate 32 take the closed position (B).

[0061] In the apparatus 100 of this example, so that the gas flow path is actually restricted and concentrated in the target area, the dimensions of the upper gate 31, the intermediate gate 32, and the lower gate 33 are selected such that, in the open position (A), the lower edges 31d, 32d, 33d of the blades constituting the gates fit exactly to the perforated wall 4 of the drum 3. In this example, the selected length of the blade measured from the axis of rotation is greater than the distance from the axis of rotation of the drum 3, and there is a defined angular position that can vary slightly from blade to blade, at which position this adjustment is made. This is intended to prevent the gas flow path in the gap that may exist between the blade and the drum 3 when the gate takes the open position (A).

[0062] Sealing elements can be provided at the lower edges 31d, 32d, 33d of the gates using dynamic gaskets, but these sealing elements can be omitted. In fact, at a distance of about 5 mm, it has been confirmed that it does not change the accurate operation of the apparatus 100 and does not significantly affect the redirection of the gas flow through the flow path enabled by the gate arranged in the open position (A).

[0063] To close the gas flow path airtight or essentially airtight, in the closed position (B), the upper edges 31c, 32c and the lower edges 31d, 32d of the blades of the operable upper gate 31 and intermediate gate 32 fit essentially airtight to their respective adjacent frames or gates. In this example, the lower edges 31d, 32d of the blades of the upper gate 31 and the intermediate gate 32 overlap the blades in the immediately lower position.

[0064] In a conventional apparatus, even if it has a movable nozzle, it has been found that the average loss of the coating product 8 floating in the gas is 30% - 20%, which means that the loss is greater in a specific recipe. By implementing the apparatus 100, the average loss of the coating product 8 floating in the gas is only 10%.

[0065] Those skilled in the art should recognize that other versions of the closed system 30 are possible, and in particular, that the number of operable gates can be increased or decreased without affecting the essence of the present invention.

[0066] As can be understood, the closed system 30 illustrated by FIGS. 4 to 7 gives the device 100 the ability to individually adjust the gas flow path through the outlet 11 as far as the concentration towards the lower region of the drum 3 is concerned. In practice, the closed system 30 based on a plurality of gates is intended to operate such that the operable gates take either the open position (A) or the closed position (B) at the ends and do not take an intermediate position. Thus, in this example, three concentration levels of the gas flow path are always obtained, which are directed towards the lower region of the perforated wall 4 of the drum 3.

[0067] However, other options are possible.

[0068] The device 101 in FIG. 8 illustrates an alternative variant of the present invention having the ability to continuously adjust the gas flow path.

[0069] As a feature of the device 101, the device 101 comprises an adjustable closed system 30 having a single movable gate 34 interposed between the drum 3 and the gas outlet 11 of the chamber 5. This movable gate 34 is, for example, of the guillotine type which can move downwards to further seal the gas outlet 11 of the chamber 5. The single gate 34 preferably has a circumferential arch shape and is arranged coaxially with the drum 3. The single gate 34 preferably has a sealing element such as a dynamic seal gasket 34a attached thereto to obstruct the gas flow path in the gap defined between the single gate 34 and the perforated wall 4 of the drum 3.

[0070] For the operation and guided movement of the single gate 34, a rack and pinion unit, gears, bearings, guides, etc. may be required.

[0071] This single-gate solution may not be suitable for the coating of pharmaceutical products, but the process and machinery must meet the industry requirements regarding specific rules for strict compliance in pharmaceutical manufacturing, such as FDA / BGA rules, as well as the reliability, accuracy, hygiene, and quality requirements necessary in the pharmaceutical industry. Variations of the device 101 in FIG. 8 may be important for other industrial applications that require fewer procedural requirements. [Appendix] [Configuration 1] An apparatus (100) for coating or encapsulating an article (2), comprising: A drum (3) having a perforated wall (4) rotatably mounted within a barrel winding chamber (5), the drum (3) being adapted to receive and agitate a batch of articles (2) to be coated during rotation of the drum (3); A dispenser group (6) having at least one nozzle (7) for spraying a coating product (8) onto the articles contained in the drum (3); At least one gas inlet (10) of the barrel winding chamber (5) on a first side of the drum (3) for directing a clean dry gas (12a) towards the perforated wall (4) of the drum (3); At least one gas outlet (11) of the barrel winding chamber (5) on the other side of the drum (3) adjacent to the perforated wall (4) of the drum (3) for extracting the dirty dry gas (12b) passing through the drum (3) from the barrel winding chamber (5); Comprising: The apparatus comprises an adjustable closing system (30) interposed between the drum (3) and the gas outlet (11) of the barrel winding chamber (5), the closing system (30) being capable of defining the actual flow path (11a) of the dirty dry gas (12b) to be smaller than the flow path provided by the gas outlet (11) of the barrel winding chamber (5), and further being displaceable or concentratable to coincide with the region (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of articles (2). Apparatus (100) characterized thereby. [Configuration 2] The apparatus (100) according to the above [Configuration 1], comprising a controller (1) for operating the closing system (30), the controller (1) being adapted to at least automatically adjust the state of the closing system (30) or issue a recommendation signal (16) when the state of the closing system (30) is not optimal or does not coincide with the region (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of articles (2). Apparatus (100) characterized thereby. [Configuration 3] The apparatus (100) according to [Configuration 2] above, wherein the dispenser group (6) has an associated mechanism (9), and the associated mechanism (9) is capable of moving the nozzle (7) and placing it at a selected position inside the drum (3), and the size of the region (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of articles (2) is estimated based on the instantaneous position of the nozzle (7) inside the drum (3). Apparatus (100). [Configuration 4] The apparatus (100) according to [Configuration 3] above, comprising a sensor (14) for measuring the distance (di) between a measurement point and the free surface (2a) of the batch of articles (2) contained in the drum (3). The associated mechanism (9) of the dispenser group (6) is an electric mechanism controlled based on the measurement value of the sensor (14). Therefore, the dispenser group (6) has the ability to automatically position the nozzle (7) at a position of a target distance (d0) with respect to the free surface (2a) of the batch of articles (2) inside the drum (3). Next, the controller (1) causes an automatic adjustment of the state of the closed system (30). Apparatus (100) characterized by this. [Configuration 5] The apparatus (100) according to [Configuration 2] above, comprising a sensor (14) for measuring the distance (di) between a measurement point and the free surface (2a) of the batch of articles (2) contained in the drum (3), and the size of the region (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of articles (2) is estimated based on the measurement value by the sensor (14). Apparatus (100) characterized by this. [Configuration 6] The apparatus (100) according to any one of [Configuration 2] to [Configuration 5] above, wherein the closed system (30) comprises a single movable gate (34) or a set of gates (31, 32, 33) including a plurality of movable gates, and the single movable gate (34) or some of the plurality of movable gates (31, 32) can be actuated by respective actuators (34a, 31a, 32a) controllable by the controller (1). Apparatus (100) characterized by this. [Configuration 7] The apparatus (100) according to the above [Configuration 6], comprising a drying gas suction group downstream of the barrel winding chamber (5), the drying gas suction group bringing a vacuum state into the barrel winding chamber (5), whereby the flow of the contaminated drying gas (12b) can be urged in one outlet direction (L) of the barrel winding chamber (5), The closed system (30) has a plurality of gates (31, 32, 33) arranged across the gas flow path, the plurality of gates (31, 32, 33) being overlapped and configured in the form of blades such as a slat shutter rotatably mounted about respective rotation axes (31b, 32b, 33b) essentially perpendicular to the outlet direction (L), two or more of the plurality of gates (31, 32) being operable by the controller (1) between at least one open position (A) in which the blades are arranged essentially parallel to the outlet direction (L) and a closed position (B) in which the blades are essentially perpendicular to the outlet direction (L), the operation of the plurality of gates (31, 32, 33) from the open position (A) to the closed position (B) starting from the gate at the highest position and continuing to the gate immediately below, so that the gas flow path gradually becomes smaller and converges towards a lower position of the perforated wall (4) of the drum (3). The apparatus (100) is characterized by this. [Configuration 8] The apparatus (100) according to the above [Configuration 7], characterized in that in the open position (A), the lower edges (31d, 32d, 33d) of the blades of the plurality of gates (31, 32, 33) fit exactly against the perforated wall (4) of the drum (3). [Configuration 9] The apparatus (100) according to the above [Configuration 7] or the above [Configuration 8], characterized in that in the closed position (B), the upper edges (31c, 32c) and the lower edges (31d, 32d) of the blades of the two or more operable gates (31, 32) fit essentially airtight against their respective adjacent frames or gates. [Configuration 10] A method for coating or encapsulating an article (2), Including passing a gas stream through a chamber (5) and a rotating drum (3) having a perforated wall (4) surrounded by the chamber (5), the rotating drum (3) containing and agitating a batch of articles (2) to be coated while a coating product (8) is discharged onto the articles from the inside of the rotating drum (3) by at least one spray nozzle (7). The method is characterized by including an operation of concentrating an actual flow path (11a) of an outlet gas stream from the chamber (5) so as to coincide with an area (4a) of the perforated wall (4) of the rotating drum (3) that is actually covered by the batch of articles (2). [Configuration 11] The method according to the above [Configuration 10], wherein the chamber (5) is a barrel-shaped chamber, the chamber (5) having at least one gas inlet (10) on a first side of the rotating drum (3) for directing a clean dry gas (12a) towards the perforated wall (4) of the rotating drum (3), and at least one gas outlet (11) of the chamber (5) on the other side of the rotating drum (3) adjacent to the perforated wall (4) of the rotating drum (3) for extracting a dirty dry gas (12b) that has passed through the rotating drum (3) from the chamber (5). The method includes automatically operating an adjustable closing system (30) interposed between the rotating drum (3) and the gas outlet (11) of the chamber (5), the closing system (30) being capable of defining an actual flow path (11a) of the dirty dry gas (12b) to be smaller than a flow path provided by the gas outlet (11) of the chamber, and being displaced or concentrated so as to coincide with the area (4a) of the perforated wall (4) of the rotating drum (3) that is actually covered by the batch of articles (2). [Configuration 12] The method according to the above [Configuration 11], wherein the size of the area (4a) of the perforated wall (4) of the rotating drum (3) that is actually covered by the batch of articles (2) can be estimated based on a measured value of a distance (di) between a measurement point and a free surface (2a) of the batch of articles (2) contained in the rotating drum (3), or based on the position of the spray nozzle (7) inside the rotating drum (3).

Claims

Claim 1 An apparatus (100) for coating or encapsulating an article (2), comprising: a drum (3) having a perforated wall (4), rotatably mounted within a jacket chamber (5), the drum (3) being configured to accommodate and agitate a batch of articles (2) to be coated during rotation of the drum (3); a dispenser group (6) having at least one nozzle (7) for spraying a coating product (8) onto the articles accommodated in the drum (3); at least one gas inlet (10) of the jacket chamber (5) on a first side of the drum (3) for directing a clean dry gas (12a) towards the perforated wall (4) of the drum (3); at least one gas outlet (11) of the jacket chamber (5) on the other side of the drum (3) adjacent to the perforated wall (4) of the drum (3) for extracting the dirty dry gas (12b) that has passed through the drum (3) from the jacket chamber (5); wherein the apparatus comprises an adjustable closure system (30) interposed between the drum (3) and the gas outlet (11) of the jacket chamber (5), the closure system (30) being capable of defining an actual flow path (11a) of the dirty dry gas (12b) to be smaller than the flow path provided by the gas outlet (11) of the jacket chamber (5), and further capable of being displaced or concentrated to coincide with an area (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of articles (2); the apparatus comprises a dry gas suction group downstream of the jacket chamber (5), the dry gas suction group being capable of creating a vacuum within the jacket chamber (5), thereby promoting the flow of the dirty dry gas (12b) in an outlet direction (L) of the jacket chamber (5); The adjustable closing system (30) has a plurality of gates (31, 32, 33) arranged across the gas flow path, and the plurality of gates (31, 32, 33) are overlapped and are configured in the form of blades such as a slat shutter, rotatably mounted about respective rotation axes (31b, 32b, 33b) that are essentially perpendicular to the outlet direction (L). Two or more of the plurality of gates (31, 32) are operable between at least one open position (A) where the blades are arranged essentially parallel to the outlet direction (L) and a closed position (B) where the blades are essentially perpendicular to the outlet direction (L). The movement of the two or more gates (31, 32) from the open position (A) to the closed position (B) starts from the gate at the highest position and continues to the gate immediately below, and due to the operation of the two or more gates (31, 32) in a cascade arrangement, the gas flow path gradually becomes smaller and is concentrated towards the lower position of the perforated wall (4) of the drum (3). The apparatus (100) is characterized in this regard.

2. The apparatus (100) according to claim 1, comprising a controller (1) for operating the closing system (30), and the controller (1) is for at least automatically adjusting the state of the closing system (30) or issuing a recommendation signal (16) when the state of the closing system (30) does not match the region (4a) actually covered by the batch of the articles (2) on the perforated wall (4) of the drum (3). The apparatus (100) is characterized in this regard.

3. The apparatus (100) according to claim 2, wherein the dispenser group (6) has an associated mechanism (9), and the associated mechanism (9) is for moving the nozzle (7) so that it can be arranged at a selected position inside the drum (3), and the size of the region (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of the articles (2) is estimated based on the instantaneous position of the nozzle (7) inside the drum (3). The apparatus (100) is characterized in this regard.

4. The apparatus (100) according to claim 3, comprising a sensor (14) for measuring the distance (di) between the measurement point and the free surface (2a) of the batch of the articles (2) accommodated in the drum (3). The associated mechanism (9) of the dispenser group (6) is an electric mechanism controlled based on the measured value of the sensor (14), and thus the dispenser group (6) has the ability to automatically position the nozzle (7) at a position of a target distance (d0) with respect to the free surface (2a) of the batch of the articles (2) inside the drum (3). Next, the controller (1) causes an automatic adjustment of the state of the closing system (30) as well. A device (100) characterized by this.

5. The device (100) according to claim 2, comprising a sensor (14) for measuring the distance (di) between the measurement point and the free surface (2a) of the batch of the articles (2) accommodated in the drum (3), and the size of the region (4a) of the perforated wall (4) of the drum (3) actually covered by the batch of the articles (2) is estimated based on the measured value by the sensor (14). A device (100) characterized by this.

6. The device (100) according to any one of claims 2 to 5, characterized in that the plurality of gates (31, 32, 33) can be actuated by respective actuators (34a, 31a, 32a) controllable by the controller (1). A device (100) characterized by this.

7. The device (100) according to claim 6, characterized in that the two or more gates (31, 32) are operable between the open position (A) and the closed position (B) by the controller (1). A device (100) characterized by this.

8. The device (100) according to claim 7, characterized in that in the open position (A), the lower edges (31d, 32d, 33d) of the blades of the plurality of gates (31, 32, 33) fit exactly to the perforated wall (4) of the drum (3). A device (100) characterized by this.

9. The device (100) according to claim 7 or 8, characterized in that in the closed position (B), the upper edges (31c, 32c) and the lower edges (31d, 32d) of the blades of the two or more operable gates (31, 32) fit exactly to their respective adjacent frames or gates, essentially airtight. A device (100) characterized by this.

10. A method for coating or encapsulating an article (2), comprising Passing a gas flow through a chamber (5) and a rotating drum (3) having a perforated wall (4) surrounded by the chamber (5), wherein the chamber (5) has at least one gas inlet (10) on a first side of the rotating drum (3) for directing a clean dry gas (12a) towards the perforated wall (4) of the rotating drum (3), and at least one gas outlet (11) on the other side of the rotating drum (3) adjacent to the perforated wall (4) of the rotating drum (3) for extracting a dirty dry gas (12b) that has passed through the rotating drum (3) from the chamber (5), and the rotating drum (3) allows a gas flow to pass through and contain and agitate a batch of articles (2) to be coated while a coating product (8) is being discharged onto the articles (2) from the inside of the rotating drum (3) by at least one spray nozzle (7). Operating an adjustable closure system (30) that is interposed between the rotating drum (3) and the gas outlet (11) of the chamber (5) and is operable to define the actual flow path (11a) of the dirty dry gas (12b) to be smaller than the flow path provided by the gas outlet (11) of the chamber, so as to concentrate the actual flow path (11a) of the outlet gas flow from the chamber (5) to coincide with the area (4a) of the perforated wall (4) of the rotating drum (3) that is actually covered by the batch of articles (2). Including The closure system (30) has a plurality of gates (31, 32, 33) arranged across the gas outlet (11), and the plurality of gates (31, 32, 33) are overlapped and rotatably mounted about respective rotation axes (31b, 32b, 33b) that are essentially perpendicular to the direction (L) that the outlet gas flow follows when passing through the gas outlet (11), and are configured in the form of blades such as a slat shutter. Two or more of the plurality of gates (31, 32) are operable between at least one open position (A) where the blades are arranged essentially parallel to the direction (L) and a closed position (B) where the blades are essentially perpendicular to the direction (L). Concentrating the actual flow path (11a) of the outlet gas stream is achieved by the operation of the two or more gates (31, 32) from the open position (A) to the closed position (B) starting from the gate at the highest position and continuing to the gate immediately below, such that the flow path (11a) of the gas gradually becomes smaller and converges towards the lower position of the perforated wall (4) of the rotary drum (3). A method characterized by this.

11. The method according to claim 10, characterized in that the size of the region (4a) of the perforated wall (4) of the rotary drum (3) actually covered by the batch of the articles (2) can be estimated based on the measured value of the distance (di) between the measurement point and the free surface (2a) of the batch of the articles (2) accommodated in the rotary drum (3), or based on the position of the spray nozzle (7) inside the rotary drum (3).

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