Filling machine comprising airflow system

Abstract

A paperboard container filling machine (10) comprising a sterile chamber (30, 40) having: an upper air distribution chamber (35, 45); a lower processing chamber (36, 46) housing a processing device (32, 42, 49) configured for interacting with the cardboard container passing through the processing chamber; a through-flow plate (37, 47) separating the distribution chamber (9) from the process chamber (36, 46); and a cardboard container transport subsystem (12) configured for transporting cardboard containers through the process chamber along a container transport path (14) from the inlet opening (31, 41) to the outlet opening (33, 43) of the process chamber. The through-flow plate has a predetermined thickness (T) and comprises a plurality of slits (38, 48) configured for directing air from the air distribution chamber to the process chamber, the slits having a predetermined length (L), a predetermined width (W), and a predetermined length / width ratio (L / W), where the thickness (T) is at least 1.5 times the predetermined width (W), and where the predetermined length / width ratio is greater than any of 4, 6, 8, 10, 15, and 20. A related method is also described.

Description

Technical Field

[0001] The present disclosure relates to a cardboard container filling machine, in particular to a filling machine for producing cardboard containers for pourable foods, which cardboard containers are also referred to as cartons. In particular, the present disclosure relates to the air flow system in such a machine, for example, to the air flow system in the aseptic chamber downstream of the disinfection chamber in the cardboard container filling machine. Background Art

[0002] When pourable foods are packaged in cardboard containers in a filling machine, the containers are typically disinfected in a disinfection chamber and then transported to an aseptic chamber where the containers are filled and then transported to the aseptic chamber where the containers are top-sealed. The first aseptic chamber, sometimes referred to as the filling chamber, typically includes one or more filling devices, each filling device including a filling nozzle and a filling valve, and the pourable food is dispensed from the filling nozzle into the container, and the filling valve controls the flow of the pourable food through the filling nozzle, usually metering the pourable food according to the size of the container being filled. The second aseptic chamber, sometimes referred to as the sealing chamber, typically includes one or more sealing jaws configured to seal the container.

[0003] In order to prevent any type of contamination and maintain the aseptic conditions of the containers established in the disinfection chamber, it is desirable to provide a sterile and uniform air flow in the aseptic chamber. However, due to the moving parts in the aseptic chamber, especially the processing equipment for performing the filling and sealing of the containers, it may be challenging to maintain a uniform air flow in the aseptic chamber. Moreover, the containers themselves being transported through the filling machine may disrupt the air flow in the aseptic chamber. In addition, since the containers are moved into and out of the aseptic chamber, it is difficult to maintain the airtightness of the aseptic chamber. The turbulence in the aseptic chamber combined with an aseptic chamber that is not airtight may result in impure air infiltrating into the aseptic chamber and contaminating the filling machine equipment and / or the containers.

[0004] An object of the present disclosure is to provide a cardboard filling machine having an improved air flow in the aseptic chamber. Another object of the present disclosure is to provide a uniform cleaning air flow through the aseptic chamber. Summary of the Invention

[0005] According to a first aspect, the present disclosure provides a cardboard container filling machine including an aseptic chamber, the aseptic chamber including:

[0006] An upper air distribution chamber;

[0007] A lower processing chamber accommodating processing equipment configured to interact with cardboard containers passing through the processing chamber;

[0008] A flow-through plate separating the air distribution chamber from the processing chamber; and

[0009] A cardboard container transport subsystem configured to transport cardboard containers through a processing chamber from an inlet opening to an outlet opening along a container transport path.

[0010] The flow-through plate has a predetermined thickness and includes a plurality of slits configured to direct air from an air distribution chamber to the processing chamber, the slits having a predetermined length, a predetermined width, and a predetermined length-to-width ratio, wherein the predetermined thickness is at least 1.5 times the predetermined width, and wherein the predetermined length-to-width ratio is greater than any of: 4, 6, 8, 10, 15, and 20.

[0011] The slits can be straight and / or arranged along a plurality of parallel lines.

[0012] The slits can occupy any of: 5% - 50% of the total area of the flow-through plate; and 10% - 30% of the total area of the flow-through plate.

[0013] The slits can be aligned with the container transport path.

[0014] The flow-through plate can be planar. The slits can be arranged parallel or substantially parallel to each other.

[0015] The slits can be aligned parallel or substantially parallel to the transport path.

[0016] The flow-through plate can include a substantially horizontal planar section and a first curved section and a second curved section, each curved section presenting a convex ruled surface facing the processing chamber, the ruled surface being defined by a plurality of rulings that are parallel and extend orthogonally or substantially orthogonally to the transport path.

[0017] According to a second aspect, the present disclosure provides a method for establishing an air flow in a sterile chamber of a cardboard container filling machine, the sterile chamber including:

[0018] An upper air distribution chamber configured to receive air from an air supply channel;

[0019] A lower processing chamber housing processing equipment configured to interact with cardboard containers passing through the processing chamber; and

[0020] A cardboard container transport subsystem configured to transport cardboard containers through the processing chamber from an inlet opening to an outlet opening along a container transport path,

[0021] The method includes the step of bringing air from the distribution chamber to the treatment chamber through a flow-through plate, the flow-through plate having a predetermined thickness and including a plurality of slits configured to direct air from the air distribution chamber to the treatment chamber, the slits having a predetermined length, a predetermined width, and a predetermined length / width ratio, wherein the predetermined thickness is at least 1.5 times the predetermined width, and wherein the predetermined length / width ratio is greater than any one of the following: 4, 6, 8, 10, 15, and 20.

[0022] According to another aspect, the present disclosure provides a carton container filling machine including a sterile chamber, the sterile chamber including:

[0023] an upper air distribution chamber;

[0024] a lower treatment chamber housing treatment equipment configured to interact with a carton container passing through the treatment chamber;

[0025] a flow-through plate separating the air distribution chamber from the treatment chamber, the flow-through plate including a plurality of through openings configured to direct air from the air distribution chamber to the treatment chamber; and

[0026] a carton container conveyance subsystem configured to convey a carton container along a container conveyance path through the treatment chamber from an inlet opening to an outlet opening of the treatment chamber.

[0027] The flow-through plate includes a substantially horizontal planar section and first and second curved sections, each curved section presenting a convex ruled surface facing the treatment chamber, the ruled surface being defined by a plurality of rulings that are parallel and extend orthogonally or substantially orthogonally to the conveyance path.

[0028] The through openings can be slits. The slits can be straight.

[0029] The slits can be arranged along a plurality of parallel lines.

[0030] The slits can be aligned with the container conveyance path.

[0031] The through openings can occupy any one of the following: 5% - 50% of the total area of the flow-through plate; and 10% - 30% of the total area of the flow-through plate.

[0032] The filling machine can include an elongated air distribution duct configured to receive air from an air supply passage, the air distribution duct including a plurality of through holes configured to distribute air in the air distribution chamber, and the air distribution duct presenting a semi-tubular convex surface facing the flow-through plate and having a straight duct axis extending orthogonally or substantially orthogonally to the container conveyance path.

[0033] According to another aspect, the present disclosure provides a method for establishing an air flow in a sterile chamber of a cardboard container filling machine, the sterile chamber comprising:

[0034] An upper air distribution chamber;

[0035] A lower processing chamber that houses processing equipment configured to interact with cardboard containers passing through the processing chamber; and

[0036] A cardboard container transport subsystem configured to transport cardboard containers along a container transport path through the processing chamber from an inlet opening to an outlet opening of the processing chamber.

[0037] According to another aspect, the present disclosure provides a cardboard container filling machine comprising a sterile chamber, the sterile chamber comprising:

[0038] An upper air distribution chamber;

[0039] A lower processing chamber that houses processing equipment configured to interact with cardboard containers passing through the processing chamber;

[0040] A flow-through plate that separates the air distribution chamber from the processing chamber;

[0041] A cardboard container transport subsystem configured to transport cardboard containers along a container transport path through the processing chamber from an inlet opening to an outlet opening of the processing chamber; and

[0042] An elongated air distribution duct configured to receive air from an air supply passage and comprising a plurality of flow-through holes configured to distribute air in the air distribution chamber.

[0043] The air distribution duct presents a semi-tubular convex surface facing the flow-through plate and has a straight duct axis that extends orthogonally or substantially orthogonally to the container transport path.

[0044] The flow-through holes can be circular.

[0045] According to another aspect, the present disclosure provides a method for establishing an air flow in a sterile chamber of a cardboard container filling machine, the sterile chamber comprising:

[0046] An upper air distribution chamber;

[0047] A lower processing chamber that houses processing equipment configured to interact with cardboard containers passing through the processing chamber;

[0048] A flow-through plate that separates the air distribution chamber from the processing chamber; and

[0049] A cardboard container transport subsystem configured to transport cardboard containers along a container transport path through the processing chamber from an inlet opening to an outlet opening of the processing chamber,

[0050] The method includes the step of distributing air in an air distribution chamber by bringing air from an air supply passage through an air distribution duct to the air distribution chamber, the air distribution duct including a plurality of flow holes configured to distribute air in the air distribution chamber, the air distribution duct presenting a semi-tubular convex surface facing a flow-through plate, and having a straight duct axis extending orthogonally or substantially orthogonally to the container transport path.

[0051] According to another aspect, the present disclosure provides an air flow system for a sterile chamber in a dumpable food container filling machine for blank feeding. The sterile chamber may include at least one inlet opening and at least one outlet opening for the passage of containers, and a container transport subsystem configured to transport containers from the inlet opening to the outlet opening through the sterile chamber along a container transport path. Typically, the containers will be transported through a disinfection chamber before reaching the sterile chamber. The transport subsystem may be a conveyor-based system or any other type of subsystem capable of transporting containers. The sterile chamber includes: an upper air distribution chamber configured to receive air from at least one air supply passage; a lower processing chamber housing processing equipment configured to interact with the containers; and a flow-through plate separating the distribution chamber from the processing chamber. Preferably, the flow-through plate extends above the entire interface between the upper air distribution chamber and the lower processing chamber. The flow-through plate includes a plurality of slits configured to direct air from the air distribution chamber to the lower processing chamber. The slits may be aligned parallel or substantially parallel to the transport path.

[0052] In one embodiment of the air flow system, the air distribution chamber includes at least one elongated air distribution duct that receives air from the air supply passage, wherein the at least one air distribution duct includes a plurality of flow holes configured to distribute air in the upper air distribution chamber.

[0053] In one embodiment of the air flow system, the air distribution duct is connected to the top wall of the air distribution chamber and presents a semi-tubular convex surface facing the flow-through plate.

[0054] In one embodiment of the air flow system, the air distribution duct has a straight duct axis extending orthogonally or substantially orthogonally to the container transport path.

[0055] In one embodiment of the air flow system, the flow-through plate is planar and disposed horizontally or substantially horizontally in the sterile chamber.

[0056] In one embodiment of the air flow system, the sterile chamber is a sterile filling chamber including a filling nozzle, and the flow-through plate is positioned at a height above the dispensing opening of the filling nozzle.

[0057] In one embodiment of the airflow system, the at least one flow-through plate includes a substantially horizontal planar section and a first curved section and a second curved section, each curved section presenting a convex ruled surface facing the lower processing chamber, the ruled surface being defined by a plurality of rulings that are parallel and extend orthogonally or substantially orthogonally to the transport path.

[0058] In one embodiment of the airflow system, the flow-through plate symmetrically encloses the at least one elongated distribution duct.

[0059] In one embodiment of the airflow system, the flow-through plate is positioned in a sterile sealed chamber.

[0060] In one embodiment of the airflow system, the system further includes a bottom wall having at least one exhaust outlet. Suction can be provided to the outlet.

[0061] In one embodiment of the airflow system, the slits are evenly spaced on the flow-through plate.

[0062] In one embodiment of the airflow system, the slits occupy 5% - 50% of the total area of the flow-through plate; more preferably 10% - 30% of the total area of the flow-through plate.

[0063] In one embodiment of the airflow system, the length-to-width ratio of the slits is greater than any of the following: 4, 6, 8, 10, 15, and 20.

[0064] In one embodiment of the airflow system, the angle of the slits relative to the transport path does not deviate from parallel by more than any of 2 degrees, 4 degrees, 6 degrees, 8 degrees, 10 degrees, 15 degrees, and 20 degrees.

[0065] Another aspect of the present disclosure relates to a method for establishing an airflow in a sterile chamber as described above, the method including the step of guiding air from an air distribution chamber to a processing chamber through the slits.

[0066] In one embodiment of the method, the method further includes the step of subjecting an upper air distribution chamber to a first pressure and subjecting a lower processing chamber to a second pressure, the second pressure being lower than the first pressure but higher than ambient pressure.

[0067] The multiple aspects and their features can be used in combination with each other.

[0068] The appended claims define the scope of protection claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] To facilitate understanding of the present disclosure, reference is made to the accompanying drawings. In the drawings, like reference numerals denote like features unless otherwise specified.

[0070] Figure 1Shows a container filling machine including a sterile filling chamber and a sterile sealing chamber.

[0071] Figure 2 More particularly shows the container filling machine according to Figure 1 wherein the side plate is removed.

[0072] Figure 3 Shows the container filling machine according to Figure 2 in a perspective view from below.

[0073] Figure 4 Shows the container filling machine according to Figure 1 in a perspective view from above.

[0074] Figure 5 Shows in perspective view the sterile filling chamber and the sterile sealing chamber according to Figure 1 of.

[0075] Figure 6 Shows the inlet opening and the outlet opening in the sterile filling chamber and the sterile sealing chamber according to Figure 1 of.

[0076] Figure 7 Shows an embodiment of a flow-through plate for the sterile filling chamber.

[0077] Figure 8 Shows a close-up view of the flow-through plate according to Figure 7 of.

[0078] Figure 9 Shows an embodiment of a flow-through plate for the sterile sealing chamber.

[0079] Figure 10 Shows an embodiment of an air distribution duct.

[0080] Figure 11 Shows the processing chambers of the filling chamber and the sealing chamber of an embodiment of the filling machine. Detailed Description

[0081] Embodiments of a blank-feeding cardboard container filling machine 10 according to the present disclosure will now be discussed in more detail with reference to the accompanying drawings.

[0082] The filling machine 10 includes a disinfection chamber 20 configured to disinfect a top-opening cardboard container (not shown) folded from a blank (not shown).

[0083] The filling machine 10 further includes a first sterile chamber 30 arranged downstream of the disinfection chamber and forming the filling chamber of the filling machine 10. The filling chamber 30 is configured to fill the disinfected top-opening cardboard container with a pourable food product. To this end, a filling nozzle 32 is arranged in the filling chamber 30. The food product is supplied from a food supply system 11 (seeFigure 1 It is supplied to the filling nozzle 32.

[0084] The filling machine 10 further includes a second aseptic chamber 40, which is arranged downstream of the filling chamber 30 and forms a sealed chamber of the filling machine 10. The sealed chamber 40 is configured to top-seal the cardboard container that has been filled in the filling chamber 30. For this purpose, a folding and sealing device 42 is arranged in the sealed chamber 40 (see Figure 2 ). In addition, the sealed chamber 40 may include a nitrogen flushing nozzle 49, which is arranged to fill the remaining space in the container with nitrogen before the container is sealed.

[0085] Therefore, after passing through the disinfection chamber 20, the container first passes through the filling chamber 30, in which the container is filled with pourable food. After passing through the filling chamber 30, the container passes through the sealed chamber 40, in which the container is sealed.

[0086] Both the filling chamber 30 and the sealed chamber 40 are aseptic chambers, which provide a sufficiently aseptic environment to give the filled container a predetermined shelf life. Therefore, the aseptic nature of the filling chamber 30 and the sealed chamber 40 inhibits contaminants that could otherwise reduce the shelf life of the filled container. Such contaminants can be, for example, bacteria, viruses, or other microorganisms. Both the filling chamber 30 and the sealed chamber 40 include cleaning nozzles 22, which allow the chambers 30, 40 to be dosed with a cleaning fluid during a cleaning cycle.

[0087] To maintain the aseptic conditions of the container and the food until the container is safely sealed, the filling machine 10 includes a first air flow system 34, configured to provide a controlled cleaning air flow through the filling chamber 30; and a second air flow system 44, configured to provide a controlled cleaning air flow through the sealed chamber 40. The cleaning air can be, for example, disinfected or near-disinfected air, sterile air, or HEPA air. HEPA air is generated by filtering air through a high-efficiency particulate air (HEPA) filter. As will be discussed in more detail below, the air flow systems 34, 44 are configured to provide an air flow of cleaning air that envelopes the container as the container is being processed by the processing equipment in the filling chamber and the sealed chamber.

[0088] The container transport subsystem 12 is configured to transport each container along a transport path 14 through the filling machine 10, including through the filling chamber 30 and the sealed chamber 40 (see Figure 4 ). The container transport subsystem 12 may include a conveyor or a linear actuator, which is configured to transport a carrier for the container through the filling machine 10. In the disclosed embodiment, the filling machine 10 includes three parallel container transport paths 14, and the container transport subsystem 12 includes a carrier 16, which is configured to carry three containers in parallel (see Figure 4—— The container transport subsystem 12 is disclosed as having no containers). In this embodiment, each container transport path 14 is straight. In other words, the container transport subsystem 12 is configured to transport containers through the filling machine along straight and parallel paths.

[0089] The filling chamber 30 is provided with an inlet opening 31 arranged to allow containers to be transported into the filling chamber 30 by the container transport subsystem (see Figure 6 ). The filling chamber 30 is also provided with an outlet opening 33 arranged to allow containers to be transported out of the filling chamber 30 by the container transport subsystem. Similarly, the sealing chamber 40 is provided with an inlet opening 41 arranged to allow containers to be transported into the sealing chamber 40 by the container transport subsystem and an outlet opening 43 arranged to allow containers to be transported out of the sealing chamber 40. The outlet opening 33 of the filling chamber 30 may form the inlet opening 41 of the sealing chamber 40, thus allowing containers to be directly transported from the filling chamber 30 to the sealing chamber 40.

[0090] In the filling chamber 30, the containers are transported from the inlet opening 31 to the outlet opening 33 along the parallel and straight container transport paths 14. Similarly, in the sealing chamber 40, the containers are transported from the inlet opening 41 to the outlet opening 43 along the parallel and straight container transport paths 14.

[0091] The filling chamber 30 includes an upper air distribution chamber 35 and a lower processing chamber 36 (see Figure 2 ). The filling chamber 30 also includes a flow-through plate 37 for separating the air distribution chamber 35 from the processing chamber 36 (also see Figure 3 ). The flow-through plate 37 may be integral, i.e., manufactured as a solid, uninterrupted workpiece. However, preferably, the flow-through plate 37 is composed of several partial plates 37a - 37d, which together separate the air distribution chamber 35 from the processing chamber 36, for example as Figure 7 shown.

[0092] The air distribution chamber 35 is configured to receive clean air from the air supply channel 18, and the flow-through plate 37 includes a plurality of slits 38 (for example, see Figure 8 ), which are configured to guide the clean air from the air distribution chamber 35 to the processing chamber 36. As previously mentioned, the clean air may be, for example, disinfected or near-disinfected air, sterile air, or HEPA air. In other words, the clean air is provided from the air supply channel 18, and the resulting air flow flows from the air distribution chamber 35 through the flow-through plate 37 to the processing chamber 36. In the processing chamber 36, the filling nozzle 32 is configured to distribute food into the containers.

[0093] In this embodiment, the air distribution chamber 35 is configured to receive clean air from four air supply channels 18 (for example, see Figure 3Receive clean air. However, in other embodiments, the air distribution chamber 35 may be configured to receive clean air from one, two, three, five or more air supply channels.

[0094] The flow-through plate 37 is preferably planar, and the slits 38 are preferably aligned parallel or substantially parallel to the container transport path 14. The purpose of this configuration is to enclose the container in a uniform clean air flow that flows from the flow-through plate 37 to the carrier 16. Preferably, the uniform air flow fills the entire processing chamber 36 without forming turbulent vortices or eddies, thereby preventing contaminated air from being drawn into the filling chamber from the outside of the processing chamber 36, particularly via an opening 60 formed in the bottom wall or floor 61 of the processing chamber 36, which opening 60 is configured to receive the container to be filled (see Figure 11 ). Preferably, in the processing chamber 36, the sterile area should extend all the way down from the flow-through plate 37 to the bottom wall 61, thereby preventing contaminated air from entering the open container that extends through the opening 60 (the top of which container is held above the bottom wall 61 by the carrier 16).

[0095] The flow-through plate 37 may be presented as a continuous surface that is interrupted only by the slits 38 and openings (e.g., the opening 26 for the filling nozzle and the opening 27 for the cleaning fluid conduit (see Figure 7 )) occupied by the necessary processing equipment that extends through the flow-through plate 37.

[0096] As Figure 8 shown, the slits 38 have a large aspect ratio, i.e., a large length / width ratio. Preferably, the aspect ratio of the slits 38 is greater than any of the following: 4, 6, 8, 10, 15, and 20. However, as long as the flow-through plate is structurally sound, the aspect ratio of the slits can even be greater. According to one embodiment, the aspect ratio of the slits 38 is in the range of 5 - 30, or more preferably in the range of 10 - 20. According to one embodiment, the length L of each slit 38 can be in the range of 10 mm - 40 mm, the width W in the range of 5 mm - 30 mm, or more preferably in the range of 10 mm - 20 mm. The flow-through plate 37 can be made of a stainless steel metal plate with a thickness T in the range of 1 mm - 5 mm. The slits 38 can occupy 5% - 50% of the total area of the flow-through plate 37, preferably 10% - 30% of the total area of the flow-through plate. Preferably, the slits 38 are arranged at evenly spaced intervals on the flow-through plate 38.

[0097] As described above, the slit 38 can be aligned parallel to the transport path 14 of the container. It has been found that such alignment causes relatively little turbulence in the processing chamber 36. Without wishing to be bound by theory, it is believed that this alignment of the slit 38 provides a stable parallel "air knife" that is relatively unaffected by the container as the container moves through the processing chamber 36 and thus causes limited or no turbulence in the cleaning air stream. As described above, it has been found that an elongated slit aligned parallel or substantially parallel to the transport path 14 of the container causes relatively little turbulence in the processing chamber 36. A small angle of the slit 38 relative to the transport path 14 will produce a similar but less favorable effect. It has been found that the angle of the slit 38 relative to the transport path 14 preferably should not deviate from parallel by more than any one of 2 degrees, 4 degrees, 6 degrees, 8 degrees, 10 degrees, 15 degrees, and 20 degrees.

[0098] Preferably, the slit 38 is provided with rounded ends, as Figure 8 shown. This may be advantageous for cleaning because materials with 90-degree angles are more difficult to keep clean.

[0099] In Figure 2 and Figure 3 the preferred embodiment shown, in addition to the flow-through plate 37, the first air flow system 34 further includes an elongated air distribution duct 50 configured to receive the cleaning air from the air supply passage 18 and distribute the cleaning air into the air distribution chamber 35. Each air distribution duct 50 includes a plurality of flow-through holes 51 (see Figure 10 ). In the air distribution chamber 35, each air distribution duct 50 may be connected to the top wall or roof plate 39 of the air distribution chamber (see Figure 2 ), for distributing the supplied air throughout the air distribution chamber 35. The purpose of the air distribution ducts 50 is to equalize the pressure gradient within the air distribution chamber 35 in order to provide a more uniform air flow through all portions of the flow-through plate 37.

[0100] In the preferred embodiment, each air distribution duct 50 is substantially semi-tubular and includes a convex surface 52 facing the flow-through plate 37 (see Figure 3 and Figure 10 ). Advantageously, the air distribution ducts 50 extend from one side of the air distribution chamber 35 to its opposite side. Preferably, each air distribution duct 50 has a straight duct axis A (see Figure 6 ), which extends substantially orthogonally to the container transport path 14 (see Figure 3 ). In addition, the size and / or distribution of the flow-through holes 51 can be adjusted according to the distance from the air supply passage 18 to obtain the same flow rate per unit area over the entire air distribution duct 50.

[0101] In Figure 2and Figure 3 In the preferred embodiment shown, the flow-through plate 37 is substantially planar and is horizontally positioned in the filling chamber 30 at a height directly above the lower part of the filling nozzle 32. To accommodate the filling nozzle 32 and the food supply system 11, the flow-through plate 37 can be cut or shaped as shown in Figure 7 shown. Preferably, the flow-through plate fits closely to the filling nozzle 32 and the food supply system 11 to avoid large openings that would cause uneven flow of the cleaning air from the air distribution chamber 35 to the processing chamber 36.

[0102] The sealing chamber 40, like the filling chamber 30, includes an upper air distribution chamber 45 and a lower processing chamber 46 (see Figure 2 ). The sealing chamber 40 also includes a flow-through plate 47 that separates the air distribution chamber 45 from the processing chamber 46 (also see Figure 3 ). The air distribution chamber 45 is configured to receive cleaning air from the air supply channel 19, and the flow-through plate 47 includes a plurality of slits 48 (e.g., see Figure 9 ), which are configured to direct the cleaning air from the air distribution chamber 45 to the processing chamber 46. As described above, the cleaning air can be, for example, disinfected or near-disinfected air, sterile air, or HEPA air.

[0103] In this embodiment, the air distribution chamber 45 is configured to receive cleaning air from three air supply channels 19 (e.g., see Figure 3 ). However, in other embodiments, the air distribution chamber 45 can be configured to receive cleaning air from one, two, four, five, or more air supply channels.

[0104] In the preferred embodiment, the flow-through plate 47 includes a planar section 55 and two curved sections 56 that adjoin the planar section 55 and are connected to the top wall or roof plate 57 of the sealing chamber 40 (e.g., see Figure 2 ). The planar section 55 is horizontally aligned so as to present a downward-facing planar surface facing the processing chamber 46. Each of the curved sections 56 presents a convex ruled surface facing the processing chamber 46, the ruled surface being defined by a plurality of rulings that are parallel and extend orthogonally or substantially orthogonally to the container transport path 14. Thus, the flow-through plate 47 presents a generally U-shaped cross-section. This configuration provides space in the processing chamber 46 for processing equipment (such as the folding and sealing device 42 and the nitrogen flushing nozzle 49) (see Figure 2 ). In the lateral direction of the sealing chamber 40, the flow-through plate 47 extends across the width of the sealing chamber 40 and abuts the side walls of the sealing chamber 40.

[0105] Similar to slit 38, slit 48 has a large aspect ratio. Preferably, the aspect ratio of slit 48 is greater than any one of the following: 4, 6, 8, 10, 15, and 20. According to one embodiment, the aspect ratio of slit 48 is in the range of 5 - 30, or more preferably in the range of 10 - 20. According to one embodiment, the length of each slit 48 can be in the range of 10 mm - 40 mm, and the width can be in the range of 5 mm - 30 mm, or more preferably in the range of 10 mm - 20 mm. The flow-through plate 47 can be made of a stainless steel sheet with a thickness in the range of 1 mm - 5 mm. The slit 48 can occupy 5% - 50% of the total area of the flow-through plate 47, preferably 10% - 30% of the total area of the flow-through plate 47. Preferably, the slits 48 are evenly spaced on the flow-through plate 48. The flow-through plate 47 can include rectangular and planar partial sections 47a - 47k, which are adjacent to form the flow-through plate 47, as Figure 9 shown.

[0106] The slit 48 is aligned with the container transport path 14. Thus, in the planar section 55, the slit 48 is arranged substantially parallel to the container transport path 14, while in the curved section 56, the slit 48 is arranged in parallel vertical planes. It has been found that this alignment causes limited turbulence in the processing chamber 46. The purpose of this configuration of the flow-through plate 47 is to enclose the top of the container in a uniform cleaning air flow that flows from the flow-through plate 47 to the bottom wall or floor 62 of the processing chamber 46 (see Figure 11 ). Preferably, the uniform air flow will fill the entire processing chamber 46 without forming turbulent vortices or eddies, thereby preventing contaminated air from being sucked in from the outside into the sealed chamber 40, especially via the opening formed at the bottom wall 62 of the filling chamber 30 (see Figure 11 ), such as the opening formed by the guiding groove 63 configured to fold the top of the container before the top of the container is sealed. Preferably, the guiding groove 63 is the only opening present in the bottom wall 62, thus contributing to the sterile area extending all the way down from the flow-through plate 47 to the bottom wall 62.

[0107] In Figure 2 and Figure 3 the preferred embodiment shown, in addition to the flow-through plate 47, the second air flow system 44 further includes an air distribution duct 53, which is configured to receive the cleaning air from the air supply channel 19 and distribute the cleaning air into the air distribution chamber 45. The air distribution duct 53 is preferably constructed in the same manner as the air distribution duct 51 in the filling chamber 30. Thus, the air distribution duct 53 preferably includes a plurality of flow-through holes 51 (see Figure 10 ), and the air distribution duct 53 is preferably connected to the top wall or roof 57 of the air distribution chamber 45 (see Figure 2 ) to distribute the supplied air throughout the air distribution chamber 45.

[0108] In a preferred embodiment, the air distribution duct 53 is substantially semi-tubular like the air distribution duct 50 and includes a convex surface 52 facing the flow-through plate 47 (see Figure 3 and Figure 10 ). Advantageously, the air distribution duct 53 extends from one side of the air distribution chamber 45 to its opposite side. Moreover, preferably, the air distribution duct 53 has a straight duct axis A (see Figure 6 ) extending substantially orthogonally to the container transport path 14 (see Figure 3 ). In addition, the size and / or distribution of the flow-through holes 51 can be adjusted according to the distance from the air supply passage 19 to obtain the same flow rate per unit area over the entire air distribution duct 53. Preferably, the flow-through plate 47 symmetrically encloses the distribution duct 53.

[0109] In the operation of the filling machine 10, all the clean air flowing from the air distribution chamber 35 into the processing chamber 36 in the filling chamber 30 preferably should pass through the slit 38 in the flow-through plate 37. Then the clean air can be discharged from the processing chamber 36 through the opening 60 in the bottom wall 61 (or more precisely, through the section of the opening 60 not occupied by the container, see Figure 11 ).

[0110] Similarly, in the operation of the filling machine 10, all the clean air flowing from the air distribution chamber 45 into the processing chamber 46 in the sealing chamber 40 preferably should pass through the slit 48 in the flow-through plate 47. Then the clean air can be discharged from the processing chamber 46 through the guiding groove 63 (see Figure 11 ).

[0111] The areas of the air outlets (such as the opening 60 and the guiding groove 63) can preferably be evenly distributed along the container filling transport path 14 to enclose the container in a uniform air flow. In some applications, this can enhance the flow of sterile air from the flow-through plates 37, 47 towards the bottom walls 61, 62. Additionally or alternatively, suction can be provided to the air outlets. However, if suction is provided, the suction should not be so strong that the pressure in a part of the corresponding processing chamber drops below the ambient pressure, because this may cause unclean air to enter the processing chambers 36, 46 through any gaps.

[0112] According to the present disclosure, a method for establishing an air flow of clean air in a sterile chamber of a filling machine (such as in a filling chamber or a sealing chamber) includes the step of guiding clean air from the air distribution chambers 35, 45 through the flow-through plates 37, 47 to the processing chambers 36, 46.

Claims

1. A cardboard container filling machine (10) including a sterile chamber (30, 40), said sterile chamber (30, 40) comprising: an upper air distribution chamber (35, 45); a lower processing chamber (36, 46) accommodating processing equipment (32, 42, 49), said processing equipment being configured to interact with cardboard containers passing through said processing chamber (36, 46); a flow-through plate (37, 47) separating said air distribution chamber (35, 45) from said processing chamber (36, 46); and a cardboard container conveying subsystem (12) configured to convey said cardboard containers along a container conveying path (14) through said processing chamber (36, 46) from an inlet opening (31, 41) of said processing chamber (36, 46) to an outlet opening (33, 43), characterized in that said flow-through plate (37, 47) has a predetermined thickness (T) and includes a plurality of slits (38, 48), said slits being configured to direct air from said air distribution chamber (35, 45) to said processing chamber (36, 46), said slits (38, 48) having a predetermined length (L), a predetermined width (W) and a predetermined length-to-width ratio (L / W), wherein said predetermined thickness (T) is at least 1.5 times said predetermined width (W), and wherein said predetermined length-to-width ratio (L / W) is greater than any one of: 4, 6, 8, 10, 15 and 20.

2. The filling machine (10) according to claim 1, wherein, said slits (38, 48) are straight.

3. The filling machine (10) according to any one of claims 1 and 2, wherein, said slits (38, 48) are arranged along a plurality of parallel lines.

4. The filling machine (10) according to any one of the preceding claims, wherein, said slits (38, 48) occupy any one of: 5% - 50% of the total area of said flow-through plate (14); and 10% - 30% of the total area of said flow-through plate (37, 47).

5. The filling machine (10) according to any one of the preceding claims, wherein, said slits (38, 48) are aligned with said container conveying path (14).

6. The filling machine (10) according to any one of the preceding claims, wherein, said flow-through plate (37, 47) is planar.

7. The filling machine (10) according to claim 6, wherein, said slits (38, 48) are arranged parallel or substantially parallel to each other.

8. The filling machine (10) according to claim 7, wherein, said slits (38, 48) are aligned parallel or substantially parallel to said conveying path (14).

9. The filling machine (10) according to any one of claims 1 to 5, wherein, The flow-through plates (37, 47) include a substantially horizontal planar section (55) and first and second curved sections (56), each curved section (56) presenting a convex ruled surface facing the processing chambers (36, 46), the ruled surface being defined by a plurality of rulings that are parallel and extend orthogonally or substantially orthogonally to the transport path.

10. A method of establishing an air flow in a sterile chamber (30, 40) of a carton container filling machine (10), the sterile chamber (30, 40) comprising: an upper air distribution chamber (35, 45) configured to receive air from an air supply passage (18, 19); a lower processing chamber (36, 46) housing processing equipment (32, 42, 49), the processing equipment being configured to interact with carton containers passing through the processing chamber (36, 46); and a carton container transport subsystem (12) configured to transport the carton containers along a container transport path (14) through the processing chamber (36, 46) from an inlet opening (31, 41) to an outlet opening (33, 43) of the processing chamber (36, 46), characterized in that the method includes the step of bringing air from the distribution chamber (38, 48) to the processing chamber (36, 46) through a flow-through plate (37, 47), the flow-through plate having a predetermined thickness (T) and including a plurality of slits (38, 48), the slits being configured to direct air from the air distribution chamber (35, 45) to the processing chamber (36, 46), the slits (38, 48) having a predetermined length (L), a predetermined width (W) and a predetermined length / width ratio (L / W), wherein the predetermined thickness (T) is at least 1.5 times the predetermined width (W), and wherein the predetermined length / width ratio (L / W) is greater than any one of: 4, 6, 8, 10, 15 and 20.

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