Cleaning machine for cleaning empty containers suitable for being filled with pourable products and associated method

Abstract

A cleaning machine (1) for cleaning empty containers (2), the cleaning machine (1) comprising: a conveyor (4) comprising seats for respective containers (2) and configured to convey a plurality of containers (2) in respective seats of the plurality of containers (2) along a cleaning path (P); and at least one treatment station (C1) comprising a tank (7) for containing a cleaning medium for cleaning the containers (2), a cleaning path (P) extending through the tank (7), and at least one sonotrode (11) arranged adjacent to the cleaning path (P); a sensor unit (12) configured to sequentially inspect each seat to detect the presence of a container (2) in the seat downstream of the entry station (I) and to generate a signal relating to the absence of a container (2) in the inspected seat; and a control unit (14) configured to receive the signal and to control the ultrasound generator (11) based on the received signal to modulate the level of ultrasound generation.

Description

Technical Field

[0001] The present application relates to a washing machine for washing (and cleaning) empty containers suitable for being filled with pourable products, preferably pourable foodstuffs.

[0002] The present application also relates to a method for treating an empty container suitable for being filled with a pourable product, preferably a pourable food product. Background Art

[0003] Washing machines are known which are configured to wash and clean containers adapted to be filled with pourable products (typically containers after use which have been emptied of the pourable product which they are adapted to contain).

[0004] An example of a cleaning machine is known for example from EP-A-2727660 in the name of the same applicant.

[0005] In detail, a typical cleaning machine is part of a processing assembly for processing containers, which also includes filling machines, labeling machines, sealing machines, etc., which are distributed sequentially along a processing line or path.

[0006] Typically, the cleaning machine is located upstream of the filling machine along the processing line.

[0007] Typical cleaning machines of the above types basically include:

[0008] - cleaning channel;

[0009] - an endless chain conveyor that propels the containers along a closed cleaning path that extends inside the cleaning tunnel from the entry station to the exit station;

[0010] a feeding system for feeding the containers to be processed to the chain conveyor; and

[0011] - A plurality of successive treatment zones or stations are arranged between the inlet station and the outlet station, intersecting the cleaning path, and a chain conveyor advances the containers through the plurality of successive treatment zones.

[0012] In detail, the feeding system comprises an endless conveyor and a sequencing device inserted between the endless conveyor and an inlet station of the chain conveyor.

[0013] The endless conveyor defines a mobile platform on which corresponding rows of containers to be cleaned are gradually formed, the containers being fed to the platform in a known manner. Such rows advance towards an inlet station.

[0014] The sequencing device withdraws the containers from the corresponding rows and feeds them to the chain conveyor in a given ratio.

[0015] The chain conveyor is supplied with such corresponding rows of containers to be cleaned by a supply system at an inlet station and discharges the cleaned items at an outlet station.

[0016] In detail, the chain conveyor comprises a plurality of beams to which a feeding system feeds corresponding rows of containers at an inlet station.

[0017] In more detail, each beam comprises a plurality of aligned pockets organized into respective rows, each pocket being configured to receive one container to be processed at a time, to convey such container from an entry station through a cleaning channel, along a cleaning path and through all processing zones to an exit station, and to deliver a respective cleaned container at the exit station.

[0018] More precisely, each beam discharges a respective cleaned container at an exit station and then returns along a return path to an entry station where it receives a new empty container to be cleaned.

[0019] According to the advancing direction of the container along the cleaning path and in the cleaning channel, the processing zone comprises in sequence: a pre-cleaning zone, at least a first cleaning zone and a second cleaning zone, and a plurality of consecutive rinsing zones.

[0020] The pre-cleaning zone, the first cleaning zone and the second cleaning zone include respective cleaning baths defined by respective tanks filled with cleaning chemicals and through which the containers are advanced.

[0021] Each rinsing zone comprises several rinsing baths filled with rinsing liquid and / or spraying devices for directing a spray of rinsing liquid to a container.

[0022] Typically, the container needs to be processed through the cleaning zone for a relatively long time and at a relatively high temperature to effectively strip away most of the encrusted dirt piles, especially the heavily settled dirt piles at the bottom of the container itself.

[0023] This can result in higher energy consumption or longer cleaning times.

[0024] In order to reduce energy consumption and / or cleaning time, it has been proposed, for example in WO-A-2020119958 in the name of the same applicant, to use ultrasound to assist the cleaning process.

[0025] In short, ultrasonic waves propagate in water, and more generally, propagate in a medium in a relatively periodic motion relative to the medium itself, causing local micro-regions within the medium to periodically transition from a decompressed state to a pressurized state.

[0026] During decompression conditions, the air dissolved in the medium tends to form numerous microbubbles, which burst when the pressure increases, thereby releasing energy.

[0027] This energy can be used to deagglomerate the aforementioned encrusted dirt piles, making cleaning the container significantly easier, requiring less energy and / or less time.

[0028] Despite good performance and effective functionality, the Applicant has observed that the cleaning machine and the related method are still capable of further improvements, in particular in terms of energy consumption, better dimensioning of the cleaning machine and better management of the so-called "overspeed" operating condition.

[0029] More specifically, the need for operation of a cleaning machine in so-called "overspeed" conditions is known in the art. More precisely, the filling machine is fed with a preset nominal ratio of containers to be filled. If, for a certain period of time, the filling machine is fed with a ratio lower than the nominal ratio, the cleaning machine must compensate for the lower ratio by operating the chain conveyor at a higher speed, i.e. by operating in overspeed conditions.

[0030] However, higher speed chain conveyors result in less bath time, which may result in improper cleaning of the container.

[0031] The proposed solution is to increase the temperature of the cleaning bath. However, the size of typical cleaning machines is such that the transient time to reach the new higher temperature is too long to compensate for the overspeed condition, resulting in some containers not being properly cleaned. Summary of the invention

[0032] It is therefore an object of the present application to provide a washing machine for washing containers and a related method for treating containers designed to overcome at least one of the above-mentioned drawbacks in a straightforward and low-cost manner.

[0033] This object is achieved by a washing machine and an associated method as claimed in the appended independent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Non-limiting embodiments of the present application will be described below by way of example with reference to the accompanying drawings, in which:

[0035] Figure 1 is a schematic side view, partially cut away, of a cleaning machine according to the present application, wherein a number of components are removed for clarity;

[0036] Figure 2 According to the implementation mode of the present application, including Figure 1 A schematic block diagram of a processing component of a cleaning machine; and

[0037] Figure 3 According to an alternative embodiment of the present application, comprising Figure 1 A schematic block diagram of the processing components of a cleaning machine. DETAILED DESCRIPTION

[0038] refer to Figure 1 , number 1 indicates a washing machine as a whole, which is used to wash empty containers 2 suitable for filling with pourable products, preferably pourable food products, such as beer, wine, water, juice, soft drinks, milk or the like.

[0039] In particular, the container 2 is defined by a corresponding empty bottle (for example a returnable glass bottle) intended to be filled with a pourable product.

[0040] According to one embodiment, the washing machine 1 is part of a processing assembly 100 for processing the container 2. For example, the processing assembly 100 can be defined by a packaging assembly for packaging the pourable product with the container 2, i.e. an assembly 100 for washing the container 2, for filling the container 2 by means of the filling machine 101, for labeling the container 2 and for closing the container 2.

[0041] The cleaning machine 1 comprises:

[0042] a cleaning channel 3 into which the empty containers 2 are fed and are cleaned accordingly; and

[0043] A conveying device 4 comprising seats (not shown) for receiving respective containers 2 and configured to convey cyclically a plurality of containers 2 located in their respective seats along the cleaning path P in a forward direction.

[0044] Preferably, the conveying device includes a chain conveyor 4, which is used to make the container 2 advance along a closed loop cleaning path P in the cleaning channel 3 so as to convey the container 2 from one end of the channel 3 along a general direction D to the other end, preferably along a horizontal direction relative to gravity.

[0045] In detail, the chain conveyor 4 is of the type described in WO-A-2020119958 and comprises:

[0046] - a pair of chains (not shown), elongated parallel to the cleaning path P and parallel to each other; and

[0047] a plurality of continuous conveyor beams (known per se and not shown) extending between the chains transversely to the chains and to the cleaning path P and, more in detail, orthogonally thereto.

[0048] In particular, each beam comprises a row of pockets (known per se and not shown) aligned orthogonally to the cleaning path P and configured to receive a respective container 2 .

[0049] In more detail, the pocket of each beam defines the aforementioned seat.

[0050] In this way, the containers 2 carried by the respective beams are aligned orthogonally to the path P and are respectively housed in the respective pockets.

[0051] The cleaning machine 1 also comprises a supply system 5 of known type (only Figure 1 ), the supply system 5 is used to supply a series of empty containers 2 along the direction D and at the inlet station I of the washing channel 3. Conveniently, the containers 2 are supplied by the supply system 5 along the direction D, and the containers 2 supplied along the direction D are appropriately arranged in rows orthogonal to the path P.

[0052] In other words, the supply system 5 is configured to supply, at the inlet station 1, respective rows of containers 2, each formed by a respective plurality of empty containers, to the conveyor 4.

[0053] In use, and sequentially, the frontmost container 2 of each row of containers 2 is transferred by the supply system 5 to the corresponding pocket of the beam travelling at the inlet station I.

[0054] In practice, each beam is configured to receive a corresponding row of containers 2 at the entry station I.

[0055] The washing machine 1 further comprises an output conveyor 6 which receives the rows of cleaned and rinsed containers 2 from the chain conveyor 4 at the outlet station O of the washing tunnel 3 .

[0056] Thus, the conveyor 4 is configured to convey the containers 2 from the inlet station I to the outlet station O via the beams and the pockets of the beams.

[0057] In view of the above, the cleaning path P includes:

[0058] a washing branch Q extending from the inlet station I to the outlet station O and along which the containers 2 are advanced by means of a chain conveyor 4; and

[0059] - A return branch R extending from the outlet station O to the inlet station I and defining a return zone through which the beam returns towards the inlet station I after having discharged the container 2, ie after having emptied the corresponding bag of the beam therein.

[0060] According to the above-mentioned advancing direction of the container 2 along the path P, the cleaning machine 1 comprises a plurality of treatment stations or treatment zones in sequence along the cleaning branch Q, namely:

[0061] - Pre-cleaning zone P1;

[0062] - First clean zone C1;

[0063] - preferably, a second cleaning zone C2; ​​and

[0064] - Final rinse zone H1.

[0065] In the present disclosure, for the sake of clarity, terms like “upstream” and “downstream” are intended to refer to the direction of advancement of the container 2 along the path P throughout the specification and claims.

[0066] The operation of the cleaning machine 1 in the pre-cleaning zone P1 , the second cleaning zone C2 and the final rinsing zone H1 is well known, for example from WO-A-2020119958, and will therefore not be described in detail here.

[0067] Reference will be made below to the first cleaning zone C1.

[0068] The first cleaning zone C1 comprises respective tanks 7 for holding respective cleaning media or agents for cleaning the container 2 .

[0069] In detail, the tank 7 is filled with a cleaning agent, the temperature of which is made higher in use than in the pre-cleaning zone P1, for example between 65° C. and 80° C., so that dirt on the containers 2 advancing therein is completely removed.

[0070] In more detail, the path P, and in particular the portion of the washing branch Q, extends through and along the canister 7 .

[0071] The tank 7 thus defines a cleaning (hot) bath of the washing machine 1 for cleaning and rinsing the containers 2 .

[0072] Preferably, the pre-cleaning zone P1 and the second cleaning zone C2 comprise respective tanks 8 , 10 filled with cleaning agents at different respective temperatures (according to a known manner and not described herein), thereby defining respective further cleaning baths (and treatment stations) of the cleaning machine 1 .

[0073] Conveniently, the cleaning agent filling each canister 7, 8, 10 comprises a respective alkaline aqueous solution, in particular the alkaline aqueous solution comprises sodium hydroxide.

[0074] The first cleaning zone C1 further comprises at least one ultrasonic generator 11 which is arranged adjacent to the path P to define an ultrasonic treatment section U of the path P.

[0075] In detail, the ultrasonic generator 11 is coupled to the can 7 and is configured to propagate ultrasonic waves through the cleaning medium so that the container 2 undergoes ultrasonic cleaning treatment during its passage through the can 7 and advancement along the ultrasonic treatment section U.

[0076] In more detail, the ultrasonic generator 11 is of the type described in WO-A-2020119958 and comprises a plurality of ultrasonic transducers or transmitters (known in the art), which are conveniently in plate form, configured to convert electricity into ultrasound and are arranged sequentially adjacent to each other and in parallel along the path P.

[0077] Preferably, the cleaning machine 1 comprises a generator (not shown) for providing electrical energy to the generator 11 .

[0078] Preferably, the ultrasonic generator 11 comprises:

[0079] a first generator member 11 a arranged adjacent to the pot 7 and defining a first extension of the ultrasonic treatment section U; and

[0080] - A second generator member 11 b arranged adjacent to the can 7 and operatively downstream of the first generator member 11 a.

[0081] According to the preferred and non-limiting embodiment shown, the cleaning machine 1 comprises a hollow channel 13 extending through the canister 7 and being fluidically isolated therefrom.

[0082] Specifically, the path P, in particular the cleaning branch Q, has an inlet section Q1 inside the tank 7 for advancing the container 2 in the tank 7 and an outlet section Q2 for removing the container 2 from the tank 7 .

[0083] Conveniently, the hollow passage 13 extends through the canister 7 in such a way as to be interposed between the inlet section Q1 and the outlet section Q2 .

[0084] Conveniently, the hollow passage 13 defines a passage (eg an inspection and / or maintenance passage) accessible by a maintenance operator from outside the cleaning machine 1 .

[0085] More specifically, the size of the hollow passage 13 enables an operator, ie, a person of normal size, to fit within the hollow passage 13 and perform inspection and / or maintenance operations.

[0086] Due to the presence of the hollow passage 13 , inspection and / or maintenance of components located at and near the canister 7 is facilitated and improved.

[0087] According to the preferred embodiment shown, the hollow channel 13 is blind, ie its inlet corresponds to its outlet.

[0088] Therefore, the inspection and / or maintenance passage defined by the hollow passage 13 is a blind passage or a blind hole, and not a through passage or a through hole.

[0089] Alternatively, the hollow passage 13 is defined by a through hole, ie the hollow passage extends through the pot-like member 7 from one side to the other side.

[0090] Conveniently, the first generator member 11a is arranged along the inlet section Q1 and the second generator member 11b is arranged along the outlet section Q2.

[0091] The Applicant has observed that such a configuration results in an improved cleaning effect on the container 2 .

[0092] According to one aspect of the present application, a cleaning machine 1 comprises:

[0093] - a sensor unit 12 configured to sequentially check each seat (i.e. each pocket of each beam) in order to detect the presence of a container 2 in the seat downstream of the inlet station 1 and to generate a signal associated with the absence of a container 2 in the seat checked (i.e. the absence of any container 2 in the seat); and

[0094] - A control unit 14 configured to receive the signal and to control the generator 11 based on the received signal to modulate the level of ultrasonic generation when the inspected seat is conveyed along the ultrasonic treatment section U or when a preset number of seats operably downstream of the inspected seat are conveyed along the ultrasonic treatment section U.

[0095] It is stipulated that the aforementioned statement "a preset number of seats operably downstream of the inspected seat" means seats continuous with respect to the inspected seat, i.e., seats passing through the beam of the sensor unit 12 after the inspected seat, for example, seats positioned along the return branch R when the above-mentioned inspected seat is inspected by the sensor unit 12.

[0096] In detail, according to one aspect of the present application, the sensor unit 12 is configured to sequentially check each beam to detect the presence of a container 2 on each beam, and to generate a first signal associated with the inspected beam being completely empty, i.e., a first signal associated with the absence of a container 2 in all the pockets / seats of the beam.

[0097] Therefore, the control unit 14 is configured to receive said first signal and, based on said first signal and when a completely empty beam is conveyed along the ultrasonic treatment section U, to control the deactivation of the generator 11 .

[0098] Conveniently, the control unit 14 is implemented with the advancement speed of the conveyor 4 (ie is always aware of the advancement speed of the conveyor 4 during operation) so that the control unit 14 can track the position of each beam along the cleaning path P.

[0099] Therefore, the control unit 14 is configured to deactivate the generator 11 precisely when a completely empty beam is detected to be conveyed along the sonication section U.

[0100] In this way, when the beam is conveyed along the ultrasonic treatment section U completely without containers 2 , the generator 11 is deactivated, saving electrical energy and reducing production and environmental costs.

[0101] Advantageously, the ultrasound transmitters are distributed along portions of the path P and can be selectively activated independently of each other to define an ultrasound treatment section U.

[0102] According to another aspect of the present application, the sensor unit 12 is configured to sequentially check each beam to detect the percentage of full seats (or bags) relative to empty seats for each beam, and to generate a second signal related to the detected percentage, wherein a full seat (or bag) is a seat occupied by a container 2.

[0103] Therefore, the control unit 14 is configured to receive the second signal and to control the generator 11 based on the second signal to increase the level of the above-mentioned ultrasonic generation when the detected percentage is below a preset threshold for a predetermined number of preferably consecutive inspected beams.

[0104] It is provided that the above-mentioned number of checked beams cannot also be defined by consecutive beams, i.e., cannot be defined by beams that are adjacent to each other. In other words, the number of checked beams may include beams that are not directly adjacent to each other, and beams that are relatively close to each other with respect to the path P but are not adjacent. For example, the predetermined number of checked beams may include a group of beams that are close to each other but not necessarily adjacent, thereby defining an area of ​​grouped beams for which a seat is not completely occupied by a container 2, and for which a percentage detected is below a preset threshold.

[0105] More specifically, the control unit 14 is configured to control the generator 11 based on the second signal to increase the number of activated ultrasonic transmitters when the detected percentage is below said preset threshold for said predetermined number of consecutive inspected beams.

[0106] Even more specifically, the control unit 14 is configured to increase the number of enabled ultrasonic transmitters when the detected percentage is below the preset threshold for the predetermined number of consecutive inspected beams and when a preset number of beams operably downstream of the consecutive inspected beams are conveyed along the ultrasonic treatment section, thereby increasing the level of ultrasonic generation for the containers 2 carried on such preset number of beams.

[0107] Due to the fact that the ultrasonic transmitters are distributed along the path P, and according to the present application, the control unit 14 is configured to control the generator 11 based on the second signal to increase the extension of the ultrasonic treatment section U along the cleaning path P when the detected percentage is lower than the preset threshold for a predetermined number of consecutive inspected beams, thereby modulating the level of ultrasonic generation.

[0108] Due to the above configuration, the management of the above-mentioned overspeed operating condition is greatly improved.

[0109] More precisely, when a certain number of beams are filled with containers 2 at a percentage below said predetermined threshold, a rate of containers 2 to be filled less than the nominal rate will be fed to the filling machine 101. The washing machine 1 will therefore have to operate in said overspeed condition to compensate for the rate less than the nominal rate.

[0110] Thanks to the configuration according to the present application, the modulation of the ultrasonic generation, in particular the increase of the ultrasonic generation, compensates for the above-mentioned shorter bath time during overspeed conditions, allowing correct cleaning of the container 2 without increasing the temperature of the cleaning bath.

[0111] Advantageously, the sensor unit 12 is arranged with respect to the cleaning path P downstream of the inlet station I and upstream of the pre-cleaning zone P1 .

[0112] The Applicant has observed that this positioning of the sensor unit 12 is the optimal positioning with respect to the cleaning path P.

[0113] Alternatively, the sensor unit 12 may be arranged at a loading movement platform of the supply system 5 , which is known per se and is not described in detail.

[0114] According to a preferred embodiment, the sensor unit 12 comprises:

[0115] - at least one first sensor (not shown) configured to detect the presence of a first container 2 in each beam; and

[0116] - At least one second sensor or set of sensors (not shown) configured to detect the presence of other containers 2 in each beam.

[0117] In one embodiment, the control unit 14 is configured to control the generator 11 to modulate the generation of ultrasound waves by increasing the power supplied to the generator 11 itself, wherein the power is electrical power.

[0118] according to Figure 2 In the first preferred embodiment shown in FIG. 1 , the processing assembly 100 comprises:

[0119] - cleaning machine 1;

[0120] - a filling machine 101 operatively arranged downstream of the cleaning machine 1 ; and

[0121] A buffer device 102 operatively interposed between the cleaning machine 1 and the filling machine 101 and configured to temporarily store a plurality of cleaned containers 2 to be filled.

[0122] According to an aspect of the application, the processing assembly 100 comprises a further sensor unit 112 which is located at the buffer device 102 and is configured to detect the storage percentage of the containers 2 in the buffer device 102 itself, ie the filling level of the buffer device 102 .

[0123] Therefore, the control unit 14 is further configured to control the generator 11 to increase the level of the ultrasonic wave generation when and at the same time as the detected storage percentage is lower than a preset threshold.

[0124] Due to the above arrangement, the management of overspeed conditions is further improved.

[0125] More specifically, if the storage percentage of the buffer device 102 is below a preset threshold, the filling machine 101 will receive fewer containers 2 in a given period of time, i.e., the rate will be less than the nominal rate. Therefore, the cleaning machine 1 will have to operate in the overspeed condition to compensate for the less than nominal rate.

[0126] Thanks to the configuration according to the present application, the modulation of the ultrasonic generation, in particular the increase of the ultrasonic generation, compensates for the above-mentioned shorter bath time during overspeed conditions, allowing correct cleaning of the container 2 without increasing the temperature of the cleaning bath.

[0127] according to Figure 3 In the second preferred embodiment shown in , the processing assembly 100 comprises an inspector device 103 which is operably inserted between the cleaning machine 1 and the filling machine 101 and is configured to inspect the cleaned containers 2 upstream of the filling machine 101 and to discard the containers 2 based on said inspection.

[0128] According to one aspect of the present application, the processing component 100 includes an additional sensor unit 122, which is located at the inspector device 103 and is configured to detect the discard percentage of containers 2 discarded by the inspector device 103, that is, to detect the percentage of containers 2 discarded by the inspector device 103 relative to the total number of containers 2 supplied to the filling machine 101.

[0129] Therefore, the control unit 14 is further configured to control the generator 11 to increase the level of the ultrasonic wave generation when the detected rejection percentage is higher than a preset threshold.

[0130] Due to the above arrangement, the management of overspeed conditions is further improved.

[0131] More specifically, if the discard percentage of the buffer device 103 is above a preset threshold, the filling machine 101 will receive fewer containers 2 in a given period of time, i.e., the rate will be less than the nominal rate. Therefore, the cleaning machine 1 will have to operate in the overspeed condition to compensate for the less than nominal rate.

[0132] Thanks to the configuration according to the present application, the modulation of the ultrasonic generation, in particular the increase of the ultrasonic generation, compensates for the above-mentioned shorter bath time during overspeed conditions, allowing correct cleaning of the container 2 without increasing the temperature of the cleaning bath.

[0133] The operation of the cleaning machine 1 will now be briefly described.

[0134] The feed system 5 advances the rows of containers 2 to be cleaned in a manner parallel to the direction D towards the cleaning channel 3 .

[0135] Suitably positioned containers 2 are arranged with their respective longitudinal axes orthogonal to path P.

[0136] The beam of the chain conveyor 4 retracts (or is supplied with) the corresponding row of containers 2 at the entrance station I, pushes the containers 2 along the cleaning branch Q in the cleaning channel 3, discharges the rows of cleaned containers 2 onto the output conveyor 6 at the exit station O, and returns along the return branch R without containers 2.

[0137] In detail, the containers 2 of each row are first carried by the corresponding bags through the pre-cleaning zone P1 , then through the first cleaning zone C1 , then through the second cleaning zone C2 , and then through the rinsing zone H1 .

[0138] During operation, the control unit 14 controls the generator 11 for modulated ultrasonic generation based on the first signal and / or the second signal and / or in dependence on a detection of the sensor unit 112 and / or the sensor unit 122 .

[0139] From the above it is clear how the washing machine 1 and the treatment assembly 100 allow the implementation of a method for treating empty containers suitable for being filled with a pourable product, the method comprising the following steps:

[0140] a) supplying a plurality of empty containers to be cleaned into corresponding seats;

[0141] b) cyclically advancing the seats along a cleaning path from an entry station, at which the containers to be cleaned are fed into the seats, to an exit station, at which the cleaned containers leave the respective seats;

[0142] c) the conveying seat passes a cleaning medium for cleaning the container;

[0143] d) activating an ultrasonic generator to propagate ultrasonic waves through the cleaning medium;

[0144] e) conveying the holder through an ultrasonic treatment section of the cleaning path to expose the container to ultrasonic waves;

[0145] f) sequentially checking each seat to detect the presence in the seat of a container downstream of the inlet station;

[0146] g) generating a signal associated with the absence of a container in the inspected seat; and

[0147] h) controlling an ultrasonic generator based on the signal to modulate a level of ultrasonic generation as the inspected seat is conveyed along the ultrasonic treatment section or as a preset number of seats operatively downstream of the inspected seat are conveyed along the ultrasonic treatment section.

[0148] From the foregoing description, the advantages of the washing machine 1 and the associated method for treating empty containers 2 according to the present application will be clear.

[0149] In particular, due to the above configuration, the management of the above-mentioned overspeed operating condition is greatly improved.

[0150] More precisely, when a certain number of beams are filled with containers 2 at a percentage below said predetermined threshold, the filling machine 101 will be fed with a rate of filled containers 2 less than the nominal rate. Therefore, the cleaning machine 1 will have to operate in said overspeed condition to compensate for the rate less than the nominal rate.

[0151] Thanks to the configuration according to the present application, the modulation of the ultrasonic generation, in particular the increase of the ultrasonic generation, compensates for the above-mentioned shorter bath time during overspeed conditions, allowing correct cleaning of the container 2 without increasing the temperature of the cleaning bath.

[0152] Additionally, the need for oversizing of the cleaning machine 1 is eliminated, since overspeed conditions can be easily compensated for by effective control and modulation of the ultrasonic generation, without the need for a larger tank 7.

[0153] Thus, the cleaning machine 1 may be less bulky, thereby allowing for greater usable space within the processing assembly 100 .

[0154] However, it is obvious that changes may be made to the cleaning machine 1 and the related method as described herein without departing from the scope of protection as defined in the appended claims.

Claims

1. A cleaning machine (1) for cleaning empty containers (2) suitable for being filled with a pourable product, the cleaning machine (1) comprising: a conveyor (4) comprising seats for receiving respective containers (2) and configured to cyclically convey a plurality of containers (2) in respective seats of the plurality of containers (2) along a cleaning path (P) extending from an entry station (I) at which, in use, each seat is supplied with a respective container (2) to be cleaned, to an exit station (O) at which, in use, the conveyor (4) discharges the cleaned containers (2); and - at least one treatment station (C1), comprising at least one tank (7) and at least one ultrasonic generator (11), the at least one tank (7) being used to contain a cleaning medium for cleaning the container (2), the cleaning path (P) extending through the tank (7), the at least one ultrasonic generator (11) being arranged adjacent to the cleaning path (P) to define an ultrasonic treatment section (U) of the cleaning path (P), and being configured to propagate ultrasonic waves through the cleaning medium, so that the container (2) is subjected to ultrasonic cleaning treatment while the container (2) passes through the tank (7) and advances along the ultrasonic treatment section (U); Wherein, the cleaning machine (1) further comprises: - a sensor unit (12) configured to sequentially check each seat in order to detect the presence of a container (2) in said seat downstream of said inlet station (I) and to generate a signal associated with the absence of a container (2) in the checked seat; and - A control unit (14) configured to receive the signal and to control the ultrasonic generator (11) based on the received signal so as to modulate the level of ultrasonic generation when the inspected seat is conveyed along the ultrasonic treatment section (U) or when a preset number of seats operably downstream of the inspected seat are conveyed along the ultrasonic treatment section (U).

2. The cleaning machine according to claim 1, further comprising: a supply system (5) for supplying, at the inlet station (I), respective rows of containers (2), each formed by a respective plurality of empty containers (2), to the conveyor (4); wherein the conveyor (4) comprises a plurality of continuous beams, each beam having a plurality of said seats, each beam being configured to receive a corresponding row of containers (2) at said inlet station (I); and in: - the sensor unit (12) is configured to sequentially check each beam to detect the presence of a container (2) on said beam and to generate a first signal associated with the checked beam being completely empty; - the control unit (14) is configured to receive the first signal and, based on the first signal and when a completely empty beam is detected to be transported along the sonication section (U), to control the deactivation of the sonotrode (11).

3. The cleaning machine according to claim 1 or 2, further comprising a supply system (5) for supplying, at the inlet station (I), respective rows of containers (2) each formed by a respective plurality of empty containers (2) to the conveyor (4); in, The conveyor (4) comprises a plurality of continuous beams, each beam having a plurality of said seats, each beam being configured to receive a corresponding row of containers (2) at the inlet station (I); and in: - the sensor unit (12) is configured to sequentially check each beam to detect, for each beam, the percentage of full seats relative to empty seats and to generate a second signal related to the detected percentage; The control unit (14) is configured to receive the second signal and to control the ultrasonic generator (11) based on the second signal to increase the level of ultrasonic generation when the detected percentage is below a preset threshold for a predetermined number of inspected beams.

4. The cleaning machine according to claim 3, wherein: The ultrasonic generator (11) comprises a plurality of ultrasonic transmitters which are distributed along a portion of the cleaning path (P) and can be selectively activated independently of each other to define the ultrasonic treatment section (U); as well as Wherein the control unit (14) is configured to control the ultrasonic generator (11) based on the second signal to increase the number of activated ultrasonic transmitters when the detected percentage is lower than the preset threshold value for the predetermined number of inspected beams.

5. The cleaning machine according to claim 4, wherein: The control unit (14) is configured to increase the number of enabled ultrasonic transmitters when the detected percentage is below the preset threshold value for the predetermined number of inspected beams and when a preset number of beams operably downstream of the inspected beams are conveyed along the ultrasonic treatment section (U), thereby increasing the level of ultrasonic generation for the containers (2) carried on such preset number of beams.

6. The cleaning machine according to claim 4 or 5, wherein: The control unit (14) is configured to control the ultrasonic generator (11) based on the second signal to increase the extension of the ultrasonic treatment section (U) along the cleaning path (P) when the detected percentage is lower than the preset threshold value for the predetermined number of inspected beams, thereby modulating the level of ultrasonic generation.

7. A cleaning machine according to any one of the preceding claims, comprising a pre-cleaning station (P1) comprising a tank (8) for containing a cleaning medium for pre-cleaning the container (2) and arranged upstream of the treatment station (C1) with respect to the cleaning path (P); and in, The sensor unit (12) is arranged downstream of the inlet station (I) and upstream of the pre-cleaning station (P1) with respect to the cleaning path (P).

8. A processing assembly (100) for processing a container (2) suitable for being filled with a pourable product, the assembly (100) comprising: - A cleaning machine (1) according to any one of the preceding claims; - a filling machine (101) operatively arranged downstream of said cleaning machine (1) for filling the cleaned containers (2) with said pourable product; as well as - a buffer device (102) operatively inserted between the cleaning machine (1) and the filling machine (101) and configured to temporarily store a plurality of cleaned containers (2) to be filled; wherein the processing assembly (100) comprises a further sensor unit (112), the further sensor unit (112) being located at the buffer device (102) and being configured to detect a storage percentage of the container (2) in the buffer device (102); and The control unit (14) is further configured to control the ultrasonic generator (11) to increase the level of ultrasonic generation when and at the same time when the detected storage percentage is lower than a preset threshold.

9. A processing assembly (100) for processing a container (2) suitable for being filled with a pourable product, the assembly (100) comprising: - A cleaning machine (1) according to any one of claims 1 to 7; - a filling machine (101) operatively arranged downstream of said cleaning machine (1) for filling the cleaned containers (2) with said pourable product; as well as - an inspector device (103) operatively inserted between the washing machine (1) and the filling machine (101) and configured to inspect the washed containers (2) upstream of the filling machine (101) and to discard the containers (2) based on the inspection; wherein the processing assembly (100) comprises a further sensor unit (122), the further sensor unit (122) being located at the inspector device (103) and being configured to detect a discard percentage of containers (2) discarded by the inspector device (103); and The control unit (14) is further configured to control the ultrasonic generator (11) to increase the level of the ultrasonic wave when the detected discard percentage is higher than a preset threshold.

10. A method for treating an empty container (2) suitable for being filled with a pourable product, the method comprising the steps of: a) supplying a plurality of empty containers (2) to be cleaned into corresponding seats; b) cyclically advancing the seats along a cleaning path (P) from an entry station (I) at which the containers (2) to be cleaned are fed into the seats to an exit station (O) at which the cleaned containers (2) leave the respective seats; c) conveying the seat through a cleaning medium for cleaning the container; d) activating an ultrasonic generator (11) to propagate ultrasonic waves through the cleaning medium; e) conveying the holder through the ultrasonic treatment section (U) of the cleaning path (P) so that the container (2) is exposed to the ultrasonic waves; f) sequentially checking each seat to detect the presence in said seat of a container (I) downstream of said inlet station; g) generating a signal associated with the absence of a container (2) in the seat under inspection; as well as h) controlling the ultrasonic generator (11) based on the signal to modulate the level of ultrasonic generation when the inspected seat is conveyed along the ultrasonic treatment section (U) or when a preset number of seats operably downstream of the inspected seat are conveyed along the ultrasonic treatment section (U).

11. The method according to claim 10, wherein: The step a) of supplying comprises: supplying respective rows of containers (2), each formed by a respective plurality of empty containers (2), to a plurality of consecutive beams, each beam having a plurality of said seats and being adapted to receive said rows one at a time; wherein the step f) of inspecting comprises sequentially inspecting each beam to detect the presence of a container (2) on said beam; wherein the step g) of generating comprises generating a first signal associated with the checked beam being completely empty; and Therein, step h) of controlling comprises controlling the deactivation of the ultrasonic generator (11) based on the first signal and when a completely empty beam is detected to be transported along the ultrasonic treatment section (U).

12. The method according to claim 10 or 11, wherein: The step a) of supplying comprises: supplying respective rows of containers (2), each formed by a respective plurality of empty containers (2), to a plurality of consecutive beams, each beam having a plurality of said seats and being adapted to receive said rows one at a time; wherein the step f) of inspecting comprises sequentially inspecting each beam to detect, for each beam, the percentage of full seats relative to empty seats; wherein the step of generating g) comprises generating a second signal related to the detected percentage; and Therein, the step of controlling h) comprises controlling the ultrasonic generator (11) based on the second signal to increase the level of ultrasonic generation when the detected percentage is below a preset threshold for a predetermined number of inspected beams.

13. The method according to claim 12, wherein: The step d) of enabling includes: enabling the ultrasound transmitter; and Therein, step h) of controlling comprises: increasing the number of activated ultrasonic transmitters when the detected percentage is below said preset threshold for a predetermined number of detected beams.

14. The method according to claim 13, wherein: The step of controlling h) further comprises increasing the number of enabled ultrasonic transmitters when a preset number of beams operably downstream of the inspected beam are conveyed along the ultrasonic treatment section (U), thereby increasing the level of ultrasonic generation for the containers (2) carried on such preset number of beams.

15. The method according to any one of claims 10 to 14, further comprising the following steps: i) filling said container (2) with said pourable product after cleaning said container (2); l) temporarily storing the cleaned containers (2) by means of a buffer device (102) at a position operatively downstream of the outlet station (O) and, before step i) of filling, at a position operatively upstream; m) detecting the storage percentage of the container (2) in the buffer device (102); as well as The control step h) further comprises: controlling the ultrasonic generator (11) to increase the level of the ultrasonic wave when and at the same time when the detected storage percentage is lower than a preset threshold.

16. The method according to any one of claims 10 to 14, further comprising the steps of: i) filling said container (2) with said pourable product after cleaning said container (2); o) inspecting the cleaned containers (2) by means of an inspector device (103), in a position operatively downstream of said outlet station and in a position operatively upstream before said step i) of filling; p) upon said checking step o) discarding the container (2); q) detecting a discard percentage of containers (2) discarded by said inspector device (103); and The control step h) further comprises: controlling the ultrasonic generator (11) to increase the level of the ultrasonic wave when the detected discard percentage is higher than a preset threshold.

Images