Device and method for covering or sealing item

Abstract

To make it possible for an air flow to surely go through a batch of items in a drum.SOLUTION: An apparatus 100 includes a chamber 5 having a gas outlet 11, and a drum 3 that is rotatably mounted within the chamber 5 and has a perforated wall 4. Batches of items 2 to be coated, housed in the drum 3, are agitated by the rotation of the drum 3. A nozzle 7 for spraying the coating product 8 onto the items inside the drum 3 is arranged. The apparatus 100 includes a sealing system 30 between the gas outlet 11 of the chamber 5 and the drum 3, and the sealing system 30 can define an actual flow path through which gas passes after passing through the batch of items 2 to be smaller than the gas outlet 11. The nozzle 7 is moved within the drum 3 by a related mechanism 9, and based on the position of the nozzle 7, the size of a region 4a of the perforated wall 4 that is covered by the batch of items 2 is estimated.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an apparatus for coating or encapsulating articles, which comprises a rotating drum for agitating a batch of articles to be coated with a particular product, the product being sprayed through at least one nozzle located inside the drum. These apparatus are used, for example, to coat granular articles, such as those in the form of tablets or pills, which are common in pharmaceutical and confectionery products. [Background technology]

[0002] Coating or encapsulating devices are widely used in the pharmaceutical field to apply one or more outer layers of a product to granular articles, for example in the form of tablets or pills.

[0003] These devices essentially comprise a container in which a drum containing the manufactured batch of articles to be coated rotates. The device is generally equipped with one or more spray nozzles for the product used to coat the articles. This spraying action occurs while the drum rotates to agitate the batch of articles, ensuring uniform coating of all articles. Additionally, the drum is conventionally perforated, and the coating device includes a forced gas circuit, typically air, that passes through the drum to help dry the sprayed product after it has been applied to the articles to be coated.

[0004] The purpose of these machines is to apply a predetermined thickness of coating to a particular batch of articles, typically measured in terms of weight gain, in the most efficient manner possible, consuming the correct amount of coating product in the minimum amount of operating time.

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

[0006] Machines with fixed nozzles cannot meet these requirements and can therefore only operate effectively on very specific batches of articles.

[0007] In practice, the smaller the batch of articles to be coated, the greater the distance between the free surface of said articles agitated inside the drum and the spray nozzle, and devices with fixed nozzles that are particularly suitable for large batches cannot be used for small batches, and vice versa.

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

[0009] In order to provide a more versatile device, a coating device is disclosed that has movable spray nozzles that can be positioned in different spaces and, in some cases, can be oriented differently to suit the batch of articles and / or the product being used to coat them.

[0010] JP 2003-062500 describes a coating device fitted with a series of nozzle positioning groups which have only one degree of freedom, allowing the nozzles to be moved only vertically towards or away from the bottom of the drum.

[0011] EP 1200197 describes an alternative to the aforementioned device, which also makes it possible to move the nozzle closer to or further 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 being stirred in the drum.

[0012] EP 3597048 describes an improved coating device comprising a movable spray nozzle which moves the nozzle towards or away from the free surface of a batch of articles inside the drum simultaneously by means of a mechanism which changes its angular position to maintain the nozzle essentially perpendicular to said free surface. The device may comprise an ultrasonic type sensor which measures the instantaneous distance between a measuring point inside the drum and the free surface of the batch of articles, and which is able to automatically correct and adjust the distance between the nozzle and the batch of articles to a target value.

[0013] Naturally, being able to position the nozzles inside the drum at an optimal distance from the batch of articles helps improve the efficiency of operation of the apparatus relative to apparatuses with fixed spray nozzles when the apparatus operates with different batch sizes. Depending on the batch size and the properties of both the articles being coated and the product used for coating, there will be optimal recipe parameters, which may include the rotational speed of the drum, the flow rate and / or pressure of the product being sprayed, as well as the selected position of the spray nozzle inside the drum, in addition to the batch size and operating time.

[0014] However, despite the above, in practice the efficiency improvement has not been as great as expected. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-062500 [Patent Document 2] European Patent No. 1200197 [Patent Document 3] European Patent No. 3597048 Summary of the Invention [Problem to be solved by the invention]

[0016] An object of the present invention is therefore an apparatus and method for coating or encapsulating articles that further improves the efficiency of coating operations, and in particular improves the efficiency of an apparatus having means for positioning spray nozzles at selected positions inside a drum according to recipe parameters. [Means for solving the problem]

[0017] To encourage proper application of a product sprayed towards a batch of articles inside the drum to said articles, measures are known to ensure that the gas passing through the drum follows a preferred direction, in particular that the gas passes through the batch of articles contained in the drum.

[0018] To this end, the drum is rotatably mounted and positioned within a drum wrapping chamber, the chamber having one gas inlet on a first side of the drum for directing clean, dry gas against the perforated wall of the drum and at least one gas outlet on the other side of the drum for extracting dirty, dry gas that has passed through the drum. During drum rotation, batches of articles accumulate at the bottom of the drum but are slightly displaced to one side of the drum. To ensure that the gas follows a preferred direction, the gas outlet of the chamber is positioned to coincide with the area of ​​the drum where the batches of articles accumulate, allowing the gas to pass through the batches of articles.

[0019] Even if the device exhibits movable nozzles and the device operates with small batches, and these nozzles can approach the batch of articles to find the best spray conditions and minimize product loss, the batch of articles may be placed on the perforated wall of the drum in a different manner, in particular the articles may be distributed so as to cover a smaller surface of the perforated wall of the drum compared to larger batches of articles.

[0020] This allows the gas flow to escape from the drum through the perforated wall into areas not actually covered by the article, even when the spray nozzle is optimally positioned inside the drum relative to the free surface of the article.

[0021] This gas flow carries the coated product without adhering it to the article. The gas flow is sprayed onto the perforated wall of the drum, not onto the article itself. The gas flow causes loss of useful product. The gas flow causes fouling in the gas piping ducts downstream of the wrapping chamber. The gas flow deteriorates the scrubbing filters traditionally used for gas scrubbing. Clearly, all of these are detrimental to the efficiency of the coating operation.

[0022] The invention proposes a device comprising an adjustable closure system interposed between the drum and the gas outlet of the drum-wrapping chamber, all according to claim 1. The closure system 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 can be further displaced or concentrated to match the area of ​​the drum wall that is actually covered by the batch of articles.

[0023] In a variant, the device comprises a controller for operating the closure system, the controller being at least adapted to automatically adjust the state of the closure system or to issue a recommendation signal if the state of the closure system or the state of the correspondence of the drum wall with the area actually covered by the batch of goods is not optimal, whereby the adjustment of the closure system or a corresponding warning is automated to inform the operator that the actual gas outlet is not optimal according to the size of the batch of goods.

[0024] In a variant, the device takes further advantage of the known relationship between the size of the batch and the position of the spray nozzles, which ultimately determines the area of ​​the drum wall covered by the batch of articles, and automatically adjusts the state of the closing system or generates a recommendation signal depending on the position of the spray nozzles of devices with movable nozzles, all of which is advantageous for the overall efficiency of the coating operation.

[0025] Within the context of the present invention, the position of the nozzle is understood as both 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 imaginary references or coordinate axes, based on other parts of the device, such as the distance to the wall of the drum, or based on external factors, such as the distance to the free surface of the batch of articles inside the drum.

[0026] In the apparatus to which the present invention is applied, the dispenser group, and more particularly the associated mechanism that enables the nozzles to be positioned at selected positions inside the drum according to recipe parameters, can be operated manually or electrically, and in both cases the position of the nozzles within the drum for the coating operation is used to adjust the closure system or to generate a recommendation signal, i.e., a recommendation to adjust the closure system.

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

[0028] The present invention further contemplates that the apparatus have means for assisting or automating the selection of the nozzle location.

[0029] Therefore, in another variant of the invention, the device 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 mechanism of the dispenser group is an electric mechanism controlled based on the measurement value of said sensor, so that the dispenser group is capable of automatically positioning the nozzle inside the drum at a target distance (d0) relative to the free surface of the batch of articles, which then causes an equally automatic adjustment of the state of the closed system by the controller.

[0030] The automatic adjustment of the closure system can furthermore be carried out separately or without involvement of the nozzle position, which makes it possible to implement the invention also in devices with fixed nozzles.

[0031] In this sense, in another variant of the invention, the device comprises a sensor that measures 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 that is actually covered by the batch of articles is estimated based on the measurements of said sensor, without taking into account the position of the nozzle.

[0032] As far as the closure system is concerned, it may comprise a single movable gate or a set of gates including multiple movable gates, which may be actuated by respective actuators controllable by a controller.

[0033] The gas outlet is located on one side of the drum and covers a portion of the perforated wall that extends to or near the bottom of said drum.

[0034] In one embodiment, the apparatus includes a dry gas suction group downstream of the chamber surrounding the drum, which creates a vacuum in the chamber, thereby urging the flow of dirty dry gas in one outlet direction (L) of the chamber. The closure system includes a plurality of gates arranged across the gas flow path from the gas outlet of the chamber, the gates being configured in the form of slat-shutter-like blades that are superimposed and rotatable about their respective rotation axes that are essentially perpendicular to the direction (L). 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). The movement of the gates from the open position (A) to the closed position (B) is such that the gas flow path becomes smaller and converges toward a lower position on the perforated wall of the drum by the operation of the cascade gates, starting with the highest gate and continuing to the gates immediately below.

[0035] Advantageously, in the open position (A), the lower edge of the blade of the movable gate fits flush against the perforated wall of the drum.

[0036] Advantageously, in the closed position (B), the upper and lower edges of the blades of the actuatable gate fit essentially airtightly against the respective adjacent frames or gates.

[0037] However, an object of the present invention is also a method for coating or encapsulating articles, comprising passing a gas stream through a chamber and a rotating drum having a perforated wall surrounded by said chamber, the rotating drum containing and agitating a batch of articles to be coated while a coating product is ejected by at least one nozzle from inside the drum onto said articles, the method further comprising the operation of concentrating the actual flow path of the exit gas stream from the chamber to coincide with the area of ​​the drum wall actually covered by the batch of articles.

[0038] In a variation of the method, the drum is surrounded by a drum-wrapping chamber, the chamber having at least one gas inlet on a first side of the drum for directing clean dry gas against a perforated wall of the drum, and at least one gas outlet on the other side of the drum adjacent the perforated wall for extracting dirty dry gas that has passed through the drum from the chamber, the method further comprising automatically operating an adjustable closure system interposed between the drum and the gas outlet of the chamber, the closure system being capable of defining an actual flow path for the dirty dry gas that is smaller than the flow path provided by the gas outlet of the chamber and being further displaced or concentrated to match the area of ​​the drum wall actually covered by the batch of articles.

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

[0040] [Figure 1] 1A-1C are schematic diagrams showing two operating situations of the same conventional apparatus for coating or encapsulating articles, operating with different sized batches of articles to be coated. [Figure 2] 1A-1C are schematic diagrams showing two operating situations of the same conventional apparatus for coating or encapsulating articles, operating with different sized batches of articles to be coated. [Figure 3] 1 is a general exterior view of a typical installation using an apparatus for coating or encapsulating articles according to the present invention; [Figure 4] 1 is a schematic diagram of an apparatus according to the present invention; [Figure 5]1A-1C are schematic diagrams showing three operating situations of the same apparatus according to the invention operating with different sized batches of articles to be coated. [Figure 6] 1A-1C are schematic diagrams showing three operating situations of the same apparatus according to the invention operating with different sized batches of articles to be coated. [Figure 7] 1A-1C are schematic diagrams showing three operating situations of the same apparatus according to the invention operating with different sized batches of articles to be coated. [Figure 8] FIG. 2 is a schematic diagram of another apparatus according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] 1 and 2 show diagrammatically an apparatus 100' of a known type for producing tablets, and in particular for coating granular pharmaceutical articles 2 with a coating product 8. The apparatus 100' comprises a drum 3 having a perforated wall 4 rotatably mounted in a winding chamber 5, the drum 3 being suitable for receiving and agitating a batch of articles 2 to be coated during rotation of the drum. To this end, the drum 3 is provided in a known manner with a series of blades, flaps or the like (not shown) which, during rotation of the drum 3 in the direction shown by arrow C in the example, collect and lift portions of the batch of articles and drop the batch of articles when the blades reach a specific position.

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

[0043] The chamber 5 has a gas inlet 10 on a first side of the drum 3 for directing 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 the perforated wall 4 of the drum for withdrawing dirty dry gas 12b that has passed through the drum 3 from the chamber 5.

[0044] 1 and 2 illustrate how different sized batches of articles 2 to be coated behave differently within the drum 3. More specifically, FIG. 1 illustrates that when the apparatus 100′ is operating at maximum capacity, the arrangement and configuration of the gas outlet 11 in the chamber 5 ensures that substantially all of the dirty drying gas 12b extracted from the chamber 5 passes through the batch of articles 2. However, when the same apparatus 100′ is operated with a much smaller batch of articles 2 (see FIG. 2), the area 4a of the perforated wall 4 of the drum 3 that is actually covered by the articles 2 becomes smaller and shifts slightly toward the bottom 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. It is through this uncovered area 4b of the perforated wall 4 that the dirty gas 12b can exit the drum 3, dragging along any product 8 that is not attached to the batch of articles 2. This flow of dirty gas 12b exiting the drum 3 without passing through the batch of articles 2 gradually reduces the efficiency of the coating operation. This is because, as mentioned above, the gas 12b is sprayed onto the perforated wall 4 of the drum 3, thereby causing loss of useful product, fouling the gas piping ducts downstream of the wrapping chamber 5 and deteriorating the cleaning filters conventionally used in the outlet gas treatment units.

[0045] 3 shows an installation using the device 100 for coating or encapsulating an article 2 according to the invention. The installation comprises the device 100, a supply unit 110 for a gas such as air to be blown into the device 100, a treatment unit 120 for the gas leaving the device 100, and a supply unit 130 for the product used to coat the article.

[0046] The supply unit 130, shown enlarged in the box in Figure 3, corresponds to a supply unit equipped with a blockage detection means, as described in Spanish Utility Model No. 1232314. To this end, it comprises a drive means 130a for the product 8 and a conduit 130b, which establishes a fluid connection between the drive means for the product and the injection nozzle 7 (located inside the drum). The supply unit 130 has the particular feature that each conduit 130b comprises a flexible sleeve clamped from the outside by a detector 130c, which, by means of a load cell mounted on the sleeve, converts into a measurable electrical signal the increase in pressure that the sleeve, due to its expansion, may exert on the load cell in the event of a blockage in the relevant conduit or nozzle, which may gradually reduce the efficiency of the device. Naturally, other supply units different from those illustrated here may also be used.

[0047] 4 shows a schematic illustration of a variation of the device 100. The device 100 according to the 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] A feature of the device 100 is that it comprises an adjustable closure system 30 interposed between the drum 3 and the gas outlet 11 of the chamber 5, which closure system 30 is not only able to define an actual flow path for the dirty drying gas 12b that is smaller than the flow path provided by the gas outlet 11 of the chamber 5, but in addition, in the closure system 30, said restricted flow path can be concentrated in each case to coincide with the area of ​​the perforated wall 4 of the drum 3 that is covered by the batch of articles 2.

[0049] Although not shown, the apparatus 100 of FIG. 4 includes a dry gas suction group downstream of the chamber 5, which creates a vacuum in the chamber 5, thereby urging 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 closure system 30 of the device 100 comprises a set of three movable gates 31, 32, 33. The gates 31, 32, 33 are arranged across the gas flow path, superimposed, and configured in the form of blades as slat shutters rotatably mounted about respective rotation axes 31b, 32b, 33b essentially perpendicular to the direction (L), and each gate 31, 32, 33 is movable between two extreme positions, i.e., an open position (A) in which the blade is arranged essentially parallel to the direction (L) and oriented substantially horizontally in the example of Fig. 4, and a closed position (B) in which the blade is arranged essentially perpendicular to the direction (L) and oriented substantially vertically in the example of Fig. 4.

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

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

[0053] It should be noted that the movement of the upper gate 31 and intermediate gate 32 from the open position (A) to the closed position (B) results in a cascading of gates, starting with the highest gate and continuing to the gate immediately below, which progressively reduces the gas flow path and concentrates it towards the lower regions of the perforated wall 4 of the drum 3, thus closing off the gas flow path to the uncovered areas of the perforated wall 4 in the case of operations with successively smaller batch sizes of articles.

[0054] The presence of a device with a movable spray nozzle allows the operator to add the position of the nozzle inside the drum as a recipe parameter. The nature of the articles to be coated and in particular the size of the batch of articles to be coated determines the optimum position of the nozzle. This position can be determined, for example, based on experimental tables.

[0055] Depending on the features provided by the device, the nozzle can be positioned manually or automatically, and there are several known mechanisms for moving the nozzle, including linear movement, mechanisms that allow a combination of movements, and even mechanisms that not only place the nozzle in the desired position but also allow its orientation to be changed.

[0056] In either case, the nozzle position as a recipe parameter is directly related to the size of the batch of articles, which determines how small or how far the area of ​​the perforated wall actually covered by the batch of articles displaces toward the bottom of the drum during drum rotation.

[0057] The device 100 exemplifying the present invention makes use of this finding, with the controller 1 being able to operate the closure system 30 to automatically adjust the state of the closure system 30 according to the position of the nozzle 7. Alternatively, in a simpler version of the device 100, the controller 1 may be equipped to issue a recommendation signal 16 if the state of the closure system 30 is not optimal according to the position of the nozzle 7, so that an operator can manually adjust the state of the closure system 30.

[0058] In the device 100 of FIG. 4 , a dispenser group 6 equipped with a plurality of spray nozzles 7 has an associated mechanism 9 that helps position the nozzles 7 at selected positions inside the drum 3. In particular, the mechanism 9 is motorized and controlled by a sensor 14 that detects in real time the distance (di) between a measurement point and the free surface 2 a of the batch of articles 2 contained in the drum 3, thereby giving the dispenser group 6 the ability to automatically position or correct the positioning of the nozzles 7 at a target distance (d0) from the free surface 2 a of the batch of articles 2 inside the drum 3. The sensor 14 can be located at a fixed point or can move together with the nozzles 7. A dispenser group of this type is described, for example, in EP 3597048.

[0059] Examples of known sensors are mechanical transducers of the probe or telemetry sensor type, for example laser type, but sensors of the radar / sonar type are particularly preferred. One example of a sensor suitable for implementing this variant of the invention is the industrial radar sensor VEGAPULS64 marketed by the company VEGA.

[0060] 5-7 serve to illustrate the operation of this version of the apparatus 100 in maximum, medium, and minimum load situations. In each case, one recipe parameter is the distance from the nozzle 7 to the free surface 2a of the batch of articles 2, which distances may be equal in value or may differ in each case. 5 shows the maximum loading situation. The measurements of the sensor 14 are used, in a manner known per se, to automatically position the nozzle 7 at a target distance (d0) from the free surface 2a of the batch of articles 2. The controller 1 (not shown) is programmed to relate the position of the nozzle 7 to be close to the center of the drum in the maximum loading situation and to take into account this target distance (d0) from the free surface 2a of the batch of articles 2. In this maximum loading situation, the area 4a of the perforated wall 4 of the drum 3 that is actually covered by the batch of articles 2 does not have to restrict the outlet 11 of the dirty drying gas 12b. The controller 1 operates the closing system 30 accordingly, so that both the upper gate 31 and the intermediate gate 32 are in their open positions (A). FIG. 6 shows the medium-load situation. Using the measurements of the sensor 14 in the manner described above, the nozzle 7 is automatically positioned at a target distance (d0) from the free surface 2a of the batch of articles 2. Note that the position of the nozzle 7 is different from that in the maximum-load situation. The controller 1 (not shown) associates this position of the nozzle 7 with the medium-load situation, in which the area 4a of the perforated wall 4 of the drum 3 that is actually covered by the batch of articles 2 is smaller than in the previous case, leaving an uncovered area 4b of the perforated wall 4 of the drum 3 facing the area affected by the upper gate 31. In this case, it is desirable to restrict the outlet 11 for the dirty drying gas 12b and define a smaller actual flow path 11a (enlarged area within the frame in the figure) to encourage the dirty drying gas 12b to exit through the batch of articles 2. The controller 1 accordingly operates the closing system 30, causing the upper gate 31 to assume the closed position (B) and the intermediate gate 32 to assume the open position (A). 7 shows the minimum loading situation. Here too, the measurements of the sensor 14 are used to automatically position the nozzle 7 at a target distance (d0) from the free surface 2a of the batch of articles 2. The position of the nozzle 7 differs from that in the maximum loading and medium loading situations. The controller 1 (not shown) associates this position of the nozzle 7 with the minimum loading situation, in which the area 4a of the perforated wall 4 of the drum 3 that is actually covered by the batch of articles 2 is even smaller than in the previous case, leaving an uncovered area 4b of the perforated wall 4 of the drum 3 facing the area influenced by the upper gate 31 and also the intermediate gate 32. In this case, it is desirable to further restrict the outlet 11 of the dirty drying gas 12b and to define an even smaller actual flow path 11a (enlarged area within the frame in the figure), thereby facilitating the exit of the dirty drying gas 12b preferably only through the batch of articles 2. The controller 1 operates the closing system 30 accordingly, causing the upper gate 31 and the intermediate gate 32 to assume the closed position (B).

[0061] To ensure that the gas flow path is actually restricted and concentrated in the desired area, in this example device 100, the dimensions of the upper gate 31, intermediate gate 32, and lower gate 33 are selected so that in the open position (A), the lower edges 31d, 32d, 33d of the blades that make up said gates fit flush against the perforated wall 4 of the drum 3. In this example, the selected length of the blades, measured from the axis of rotation, is greater than the distance away from said axis of rotation of the drum 3, and there are defined angular positions, which may vary slightly from blade to blade, at which this adjustment is made. This is intended to prevent the flow of gas in any gap that may exist between the blades and the drum 3 when the gates are in the open position (A).

[0062] The lower edges 31d, 32d, 33d of the gates may be provided with sealing elements using dynamic gaskets, but these sealing elements may also be omitted. In practice, it has been determined that a distance of about 5 mm does not alter the correct operation of the device 100, nor does it significantly affect the redirection of gas flow through the flow passages made possible by the gates in the open position (A).

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

[0064] In conventional devices, even with movable nozzles, the average loss of coated product 8 suspended in the gas is observed to be 30% to 20%, which means that the loss will be greater for certain recipes. By implementing device 100, the average loss of coated product 8 suspended in the gas is only 10%.

[0065] Those skilled in the art will recognize that other versions of the closure system 30 are possible, particularly those having more or fewer operable gates, without affecting the essence of the invention.

[0066] As can be seen, the closure system 30 illustrated by Figures 4 to 7 provides the device 100 with the ability to individually adjust the flow path of gas through the outlet 11 as far as concentration towards the lower region of the drum 3. In practice, the closure system 30 based on multiple gates is intended to operate such that the actuatable gates are either in an end open position (A) or in a closed position (B), with no intermediate positions. This results in three levels of concentration of the flow path of gas, always towards the lower region of the perforated wall 4 of the drum 3, in this example.

[0067] However, other options are possible.

[0068] Device 101 of Figure 8 illustrates an alternative variation of the present invention having the ability to continuously adjust the gas flow path.

[0069] The device 101 is characterized in that it comprises an adjustable closure system 30 having a single movable gate 34 interposed between the drum 3 and the gas outlet 11 of the chamber 5, the movable gate 34 being, for example, of a guillotine type that can be moved 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 is preferably fitted with a sealing element, such as a dynamic sealing gasket 34a, to prevent the passage of gas in a gap determined between the single gate 34 and the perforated wall 4 of the drum 3.

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

[0071] While this single gate solution may not be suitable for coating pharmaceutical articles, where the process and machinery must comply with certain regulations of strict compliance in drug manufacturing, e.g., industry requirements regarding FDA / BGA regulations, as well as the reliability, precision, hygiene, and quality demands necessary in the pharmaceutical industry, variations of apparatus 101 of FIG. 8 may be important for other industrial applications with less procedural demands.

[0072] [Note] [Configuration 1] An apparatus (100) for covering or encapsulating an article (2), comprising: a drum (3) having a perforated wall (4) rotatably mounted within a winding chamber (5), the drum (3) being suitable for containing and agitating 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) in the wrapping chamber (5) on a first side of the drum (3) for directing clean, dry gas (12a) toward the perforated wall (4) of the drum (3); at least one gas outlet (11) in the drum (3) on the other side of the drum (3) adjacent to the perforated wall (4) of the drum (3) for extracting the contaminated dry gas (12b) that has passed through the drum (3) from the drum (5); Equipped with The apparatus (100) comprises an adjustable closure system (30) interposed between the drum (3) and the gas outlet (11) of the wrapping chamber (5), the closure system (30) being capable of defining an actual flow path (11a) of the dirty drying gas (12b) that is smaller than the flow path provided by the gas outlet (11) of the wrapping chamber (5) and of displacing or concentrating the perforated wall (4) of the drum (3) to coincide with the area (4a) of the perforated wall (4) that is actually covered by the batch of articles (2). [Configuration 2] The device (100) according to the above [Configuration 1], further 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 to issue a recommendation signal (16) if the state of the closing system (30) is not optimal or does not correspond to the area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2). [Configuration 3] The apparatus (100) according to the above [Configuration 2], wherein the dispenser group (6) has an associated mechanism (9) that moves the nozzles (7) and positions them at selected positions inside the drum (3), and the size of the area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2) is estimated based on the instantaneous position of the nozzles (7) inside the drum (3). [Configuration 4] The device (100) according to the above [Configuration 3] is provided with 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), 1. An apparatus (100) characterized in that the associated mechanism (9) of the dispenser group (6) is an electric mechanism controlled based on the measurements of the sensor (14), so that the dispenser group (6) is capable of automatically positioning the nozzles (7) at a target distance (d0) relative to the free surface (2a) of the batch of articles (2) inside the drum (3), which then triggers, by the controller (1), an equally automatic adjustment of the state of the closing system (30). [Configuration 5] The device (100) according to the above [Configuration 2], further 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 area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2) is estimated based on the measurement value by the sensor (14). [Configuration 6] The apparatus (100) according to any one of the above [Configuration 2] to [Configuration 5], characterized in that the closing system (30) comprises a set of gates (31, 32, 33) including a single movable gate (34) or 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). [Configuration 7] The device (100) according to the above [Configuration 6] further comprises a dry gas suction group downstream of the wrapping chamber (5), the dry gas suction group creating a vacuum in the wrapping chamber (5) and thereby urging the flow of the contaminated dry gas (12b) in one outlet direction (L) of the wrapping chamber (5); The closure system (30) has a plurality of gates (31, 32, 33) arranged across the gas flow path, the plurality of gates (31, 32, 33) being configured in the form of blades, such as slat shutters, superimposed on one another and rotatably mounted about respective rotation axes (31b, 32b, 33b) essentially perpendicular to the outlet direction (L), and two or more gates (31, 32) of the plurality of gates (31, 32, 33) are controlled by the controller (1) to rotate the blades so that they are essentially parallel to the outlet direction (L). and a closed position (B) in which the blades are essentially perpendicular to the outlet direction (L), and the movement of the gates (31, 32, 33) from the open position (A) to the closed position (B) is such that the movement of the gates (31, 32, 33) from the open position (A) to the closed position (B) begins with the highest gate and continues to the gate immediately below, such that the gas flow path becomes smaller and smaller and converges towards a lower position of the perforated wall (4) of the drum (3). [Configuration 8] The device (100) according to [Configuration 7] above, 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 snugly against the perforated wall (4) of the drum (3). [Configuration 9] The device (100) according to [Configuration 7] or [Configuration 8] above, characterized in that in the closed position (B), the upper edges (31c, 32c) and lower edges (31d, 32d) of the blades of the two or more operable gates (31, 32) fit snugly against their respective adjacent frames or gates in an essentially airtight manner. [Configuration 10] A method for coating or encapsulating an article (2), comprising the steps of: the method comprises passing a gas stream through a chamber (5) and a rotating drum (3) surrounded by the chamber (5) and having a perforated wall (4), the rotating drum (3) containing and agitating a batch of articles (2) to be coated while a coating product (8) is ejected onto the articles from inside the rotating drum (3) by at least one spray nozzle (7); 10. The method according to claim 9, further comprising the step of converging the actual flow path (11a) of the outlet gas stream 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). [Configuration 11] The method according to the above [Configuration 10], wherein the chamber (5) is a drum chamber and has at least one gas inlet (10) on a first side of the rotating drum (3) for directing clean dry gas (12a) toward 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 dirty dry gas (12b) that has passed through the rotating drum (3) from the chamber (5); The method comprises 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 drying gas (12b) that is smaller than the flow path provided by the gas outlet (11) of the chamber, and displacing or concentrating the perforated wall (4) of the rotating drum (3) to coincide with the area (4a) of the perforated wall (4) that is actually covered by the batch of articles (2). [Configuration 12] The method according to [Configuration 11] above, characterized in that 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 measurement of the distance (di) between a measurement point and the 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

1. An apparatus (100) for covering or encapsulating an article (2), comprising: a drum (3) having a perforated wall (4) rotatably mounted within a winding chamber (5), the drum (3) being adapted to contain 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) in the wrapping chamber (5) on a first side of the drum (3) for directing clean, dry gas (12a) towards the perforated wall (4) of the drum (3); at least one gas outlet (11) in the drum (5) on the other side of the drum (3) adjacent to the perforated wall (4) of the drum (3) for extracting the contaminated dry gas (12b) that has passed through the drum (3) from the drum (5); Equipped with the device (100) comprises an adjustable closure system (30) interposed between the drum (3) and the gas outlet (11) of the wrapping chamber (5), the closure system (30) being capable of defining an actual flow path (11a) of the dirty drying gas (12b) that is smaller than the flow path provided by the gas outlet (11) of the wrapping chamber (5) and being capable of being displaced or concentrated to coincide with the area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2); the device (100) comprises 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 to issue a recommendation signal (16) when the state of the closing system (30) does not correspond to the area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2); 1. An apparatus (100) according to claim 1, wherein the dispenser group (6) has an associated mechanism (9) for moving the nozzles (7) and positioning them at selected positions inside the drum (3), and wherein the size of the area (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 nozzles (7) inside the drum (3).

2. 2. The device (100) according to claim 1, comprising a sensor (14) for measuring the distance (di) between a measurement point and a free surface (2a) of the batch of articles (2) contained in the drum (3), 10. The device (100) according to claim 1, wherein the associated mechanism (9) of the dispenser group (6) is an electric mechanism controlled based on the measurements of the sensor (14), so that the dispenser group (6) is capable of automatically positioning the nozzles (7) at a target distance (d0) relative to the free surface (2a) of the batch of articles (2) inside the drum (3), which then triggers, by the controller (1), an equally automatic adjustment of the state of the closing system (30).

3. 3. The device (100) according to claim 1 or 2, further 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 area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2) is estimated based on the measurement by the sensor (14).

4. An apparatus (100) for covering or encapsulating an article (2), comprising: a drum (3) having a perforated wall (4) rotatably mounted within a winding chamber (5), the drum (3) being adapted to contain 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) in the wrapping chamber (5) on a first side of the drum (3) for directing clean, dry gas (12a) towards the perforated wall (4) of the drum (3); at least one gas outlet (11) in the drum (5) on the other side of the drum (3) adjacent to the perforated wall (4) of the drum (3) for extracting the contaminated dry gas (12b) that has passed through the drum (3) from the drum (5); Equipped with the device (100) comprises an adjustable closure system (30) interposed between the drum (3) and the gas outlet (11) of the wrapping chamber (5), the closure system (30) being capable of defining an actual flow path (11a) of the dirty drying gas (12b) that is smaller than the flow path provided by the gas outlet (11) of the wrapping chamber (5) and being capable of being displaced or concentrated to coincide with the area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2); the device (100) comprises 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 to issue a recommendation signal (16) when the state of the closing system (30) does not correspond to the area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2); The device (100) comprises 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 area (4a) of the perforated wall (4) of the drum (3) that is actually covered by the batch of articles (2) is estimated based on the measurement by the sensor (14).

5. 5. The device (100) according to any one of claims 1 to 4, characterized in that the closure system (30) comprises a set of gates (31, 32, 33) including a single movable gate (34) or a plurality of movable gates, the single movable gate (34) or some of the plurality of movable gates (31, 32) being operable by respective actuators (34a, 31a, 32a) controllable by the controller (1).

6. 6. The device (100) according to claim 5, further comprising a dry gas suction group downstream of the wrapping chamber (5), which creates a vacuum in the wrapping chamber (5) and thereby urges the flow of the dirty dry gas (12b) in one outlet direction (L) of the wrapping chamber (5), The closure system (30) has a plurality of gates (31, 32, 33) arranged across the gas flow path, the plurality of gates (31, 32, 33) being configured in the form of blades, such as slat shutters, superimposed and rotatably mounted about respective rotation axes (31b, 32b, 33b) essentially perpendicular to the outlet direction (L), and two or more gates (31, 32) of the plurality of gates (31, 32, 33) are controlled by the controller (1) to rotate the blades so that they are essentially parallel to the outlet direction (L). and a closed position (B) in which the blades are essentially perpendicular to the outlet direction (L), and the movement of the gates (31, 32, 33) from the open position (A) to the closed position (B) is such that the movement of the gates (31, 32, 33) from the open position (A) to the closed position (B) begins with the highest gate and continues to the gate immediately below, so that the flow path of the gas becomes gradually smaller and converges towards a lower position of the perforated wall (4) of the drum (3).

7. 7. The device (100) according to claim 6, wherein in the open position (A), the lower edges (31d, 32d, 33d) of the blades of the gates (31, 32, 33) fit flush against the perforated wall (4) of the drum (3).

8. 8. The device (100) according to claim 6 or 7, characterized in that in the closed position (B), the upper edges (31c, 32c) and lower edges (31d, 32d) of the blades of the two or more operable gates (31, 32) fit flush against their respective adjacent frames or gates in an essentially airtight manner.

9. A method for coating or encapsulating an article (2), comprising the steps of: the method comprises passing a gas stream through a chamber (5) and a rotating drum (3) surrounded by said chamber (5) and having a perforated wall (4), said rotating drum (3) containing and agitating a batch of said articles (2) to be coated while a coating product (8) is ejected onto said articles from inside said rotating drum (3) by at least one spray nozzle (7); the method comprising the operation of converging the actual flow path (11 a) of the outlet gas stream from the chamber (5) to coincide with the area (4 a) of the perforated wall (4) of the rotating drum (3) that is actually covered by the batch of articles (2), the chamber (5) is a drum chamber and has at least one gas inlet (10) on a first side of the rotating drum (3) for directing 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 dirty dry gas (12b) that has passed through the rotating drum (3) from the chamber (5); the method comprising 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 drying gas (12b) smaller than the flow path provided by the gas outlet (11) of the chamber, displacing or concentrating the perforated wall (4) of the rotating drum (3) to coincide with the area (4a) actually covered by the batch of articles (2), 1. A method for estimating 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) based on the measurement of the distance (di) between the measuring point and the 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).

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