System and method for inspecting containers

Abstract

Inspecting system (10) for inspecting containers, comprising: a connection head (24) suitable for being attached to a mouth (52) of a container (50) to be inspected; blowing means (20) connected, via a first duct (22), to the connection head (24) and configured to introduce gas into the container (50), so as to create inside the container (50) an overpressure with respect to the pressure of the environment in which the container (50) is located; a pressure detector (26); and a contaminant sensor (30). The pressure detector (26) is configured to detect a pressure decrease over a given period of time inside the container (50), after said overpressure has been created therein, to determine whether the container is leaking. The inspecting system (10) is configured in such a way that, when the detection of pressure decrease inside the container 50 is finished, the contaminant sensor (30) is connected to said connection head (24), so that the overpressure created inside the container (50) results in a flow of gas from the container (50) to the contaminant sensor (30); the contaminant sensor (30) is configured to detect the presence of contaminants in said flow of gas from the container (50), so as to determine whether the container (50) is contaminated.

Description

[0001] “System and method for inspecting containers ”

[0002] DESCRIPTION

[0003] Technical Field

[0004] The present invention relates to an inspecting system for containers, in particular used reusable containers, for example, water cooler bottles made of PET.

[0005] More particularly, the invention relates to an inspecting system for detecting leaks in containers as well as of contaminants inside such containers.

[0006] The invention further relates to an inspecting method carried out by means of such system.

[0007] Background Art

[0008] For empty containers that can be reused, such as, for example, water cooler bottles made of PET, it is known that a series of checks must be carried out before the containers are refilled, in order to discard containers that are unsuitable for reuse. Unsuitable containers are, for example, those with leaks, due, for example, to holes and cracks created by repeated use of the container, orthose that contain contaminants because they are used to hold substances other than water and potentially dangerous, such as solvents, fuels, poisons, etc.

[0009] Leak detection inspecting systems include systems configured to apply pressures other than atmospheric pressure to the inside of containers, by gas-suction or gasblowing, and to verify the maintenance of the applied pressure, which is the basis for distinguishing between containers with leaks and containers without leaks. A system of the above-mentioned type is described, for example, in document US5591899A.

[0010] Instead, for the detection of contaminants, systems are known that are configured to suck air present in containers and analyse it by using appropriate sensors. Since contaminants are usually deposited on the inner walls of containers, such systems typically comprise a probe that can be inserted into the container to be analysed, by means of which probe suction is performed as close to these walls as possible. A system of the above-mentioned type is disclosed, for example, in US5571978A.

[0011] The above-mentioned known systems are not able to perform both leak and contaminant detection.

[0012] An object of the present invention is to overcome the limitations of prior art by providing an inspecting system capable of detecting both leaks in containers and contaminants present therein. Another object of the present invention is to provide an inspecting system that makes it possible to detect the presence of both leaks and contaminants in a short time.

[0013] These and other objects are achieved with the inspecting system as claimed in the appended claims.

[0014] Summary of Invention

[0015] The inspecting system for containers according to the invention comprises: a connection head suitable for being attached, in a sealed manner if necessary, to a mouth of a container to be inspected; blowing means connected, via a first duct, to the connection head and configured to introduce gas, via the first duct and the connection head, into the container, so as to create inside the container an overpressure with respect to the pressure of the environment in which the container is placed; a pressure detector, associated with the connection head.

[0016] The pressure detector is configured to detect a pressure variation over a given period of time inside the container, specifically a pressure decrease inside the container after said overpressure has been created inside said container, and to compare the detected pressure variation with a threshold value of pressure variation, above which the detected pressure decrease is considered to be due to a leak in the container.

[0017] The inspecting system further comprises a contaminant sensor.

[0018] The inspecting system is configured in such a way that, when the said detection of pressure decrease inside the container is finished, said contaminant sensor is connected to said connection head, so that the overpressure created inside the container results in a flow of gas from the container to the contaminant sensor. Said contaminant sensor is configured to detect the presence of specific contaminants in said flow of gas from the container, so as to determine whether the container is contaminated.

[0019] The inspecting system further comprises, preferably, a first valve, arranged between the first duct and the connection head. Said first valve is configured to be in an open configuration, thereby bringing the first duct into communication with the connection head, when the blowing means are operating to create the overpressure in the container, and to be in a closed configuration, thereby interrupting such communication, after the overpressure has been created, during said detection of pressure decrease inside the container. Furthermore, said first valve is configured to return to the open configuration when said detection of pressure decrease inside the container is finished.

[0020] The contaminant sensor is, for example, an electrochemical sensor or an optical sensor.

[0021] The connection head is preferably moveable in the vertical direction by means of suitable handling means, for example, a piston, so that it can be attached to the mouth of the container to be inspected.

[0022] Preferably, the contaminant sensor has an inlet connected to a second duct which in turn is branched from the first duct via a branch valve that is arranged along said first duct, between a first portion of the first duct, located upstream of the branch valve and oriented toward the blowing means, and a second portion of the first duct, located downstream of the branch valve and oriented toward the connection head.

[0023] When the blowing means are operating to create the overpressure in the container, the branch valve is configured to be in a first configuration where communication between the first portion of the first duct and the second portion of the first duct is allowed and communication from the first duct to the contaminant sensor is prevented.

[0024] When said detection of pressure decrease inside the container is finished, the branch valve is configured to be in a second configuration where communication between the second portion of the first duct and the contaminant sensor is allowed and communication to the first portion of the first duct is prevented, so that the overpressure created inside the container results in a flow of gas from the container to the contaminant sensor, passing through the connection head, the first valve, the first duct portion, the branch valve and the second duct.

[0025] The inspecting system further comprises, preferably, an escape valve arranged along the second duct, between the branch valve and the contaminant sensor.

[0026] The escape valve is provided with a port to the outside environment, configured to open when the pressure of said flow of gas from the container under overpressure is greater than a certain threshold value, in order to prevent the contaminant sensor from being hit by a flow of gas with an excessive pressure, which could damage it. Therefore, thanks to the escape valve, the pressure of the flow of gas coming from the container and reaching the contaminant sensor is limited and controlled.

[0027] The inspecting system further comprises, preferably, suction means connected to an outlet of the contaminant sensor. The suction means are configured to suck gas from the contaminant sensor, so as to clean the contaminant sensor from any contaminants remaining after a previous inspection. By sucking gas out of the contaminant sensor, in fact, clean air coming from the outside environment is conveyed into said contaminant sensor, which clean air reaches the inlet of the sensor through the port of the escape valve and the second duct.

[0028] According to an embodiment variant, the inspecting system comprises an outlet duct branched from the first duct via the branch valve and provides for arranging the contaminant sensor along the second portion of the first duct. When the blowing means are operating to create the overpressure in the container, the branch valve is configured to be in a first configuration where communication between the first portion of the first duct and the second portion of the first duct is allowed and communication from the first duct to the outlet duct is prevented. When said detection of pressure decrease inside the container is finished, the branch valve is configured to be in a second configuration where communication between the second portion of the first duct and the outlet duct is allowed, so that the overpressure created inside the container results in a flow of gas from the container to the outlet duct, passing through the contaminant sensor.

[0029] The inspecting method for inspecting containers according to the invention comprises the steps of

[0030] - detecting the possible presence of leaks in a container by the steps of

[0031] - bringing the container into communication, in a sealed manner, with blowing means,

[0032] - creating inside the container an overpressure with respect to the pressure of the environment in which the container is placed,

[0033] - detecting a pressure variation over a given period of time inside the container with respect to said overpressure created inside it, and

[0034] - comparing the detected pressure variation with a predetermined threshold value of pressure variation, above which the detected pressure variation is considered to be due to a leak in the container (50), and

[0035] - detecting the possible presence of contaminants inside the container by the steps of

[0036] - opening a passage from the container under overpressure to a contaminant sensor, so that a pressurized flow of gas flows naturally from the container to the contaminant sensor, because of the pressure difference between the inside of the container, which is under overpressure, and the outside environment, which is typically at atmospheric pressure, and

[0037] - detecting, by means of the contaminant sensor, the presence of any contaminants in the flow of gas, thus allowing determining whether the container is contaminated.

[0038] The inspecting method further comprises, preferably, the step of creating a continuous flow of air through the contaminant sensor in order to keep it clean.

[0039] The inspecting method further comprises, preferably, the step of allowing a part of the flow of gas coming from the container under overpressure to escape to the outside environment before said flow of gas reaches the contaminant sensor, so as to limit the pressure of the flow of gas reaching the contaminant sensor and prevent the contaminant sensor from being hit by a flow of gas with an excessive pressure, which could damage it.

[0040] Advantageously, thanks to the inspecting system and the inspecting method according to the invention, it is possible to carry out the inspection of containers to detect both leaks and contaminants.

[0041] In addition, thanks to the introduction of gas into the container to be inspected during the step of creating an overpressure, a mixing advantageously takes place inside the container, which mixing allows displacing any contaminants that may be present, which would typically adhere to the inner walls of the container, thereby facilitating transit thereof toward the contaminant sensor. This makes it unnecessary to use a probe to be inserted into the container through the mouth of the container to obtain a gas sample as close as possible to the inner walls of the container. For this reason, preferably, the connection head of the inspecting system according to the invention does not comprise a probe of the above-mentioned type.

[0042] Furthermore, by exploiting the overpressure created inside the container, the inspecting system does not require any suction means to suck gas from the inside of the container to detect the presence of contaminants. For this reason, preferably, the inspecting system according to the invention does not comprise any means for sucking gas from the inside of the container to be inspected.

[0043] Brief Description of Drawings These and other features and advantages of the present invention will become clear from the following description of preferred embodiments, given by way of nonlimiting example with reference to the annexed figures, in which elements indicated by the same or similar reference numbers denote elements having the same or similar functionality and construction, and wherein:

[0044] Fig. 1 shows a schematic view of a system for inspecting containers according to a first embodiment of the invention;

[0045] Figs. 2a-2b schematically show steps of a method for inspecting containers according to a first embodiment of the invention, in which the flows of gas in the system are indicated by dashed lines and arrows;

[0046] Fig. 3 shows a schematic view of a system for inspecting containers according to a second embodiment of the invention;

[0047] Fig. 4a-4b schematically show steps of a method for inspecting containers according to a second embodiment of the invention, where the flows of gas in the system are indicated by dashed lines and arrows;

[0048] Fig. 5 shows a schematic view of a system for inspecting containers according to a third embodiment of the invention;

[0049] Fig. 6a-6b schematically show steps of a method for inspecting containers according to a third embodiment of the invention, where the flows of gas in the system are indicated by dashed lines and arrows.

[0050] Description of Embodiments

[0051] An inspecting system 10 for inspecting containers 50, for example, water cooler bottles made of PET, according to a first embodiment of the present invention is shown in Figure 1.

[0052] The inspecting system 10 comprises blowing means 20 connected, via a first duct 22, to a connection head 24 suitable for being attached, in a sealed manner if necessary, to the mouth 52 of a container 50 to be inspected. The connection head 24 is preferably moveable in the vertical direction by means of appropriate handling means 25, for example, a piston, so that it can be attached to the mouth 52 of the container 50.

[0053] The blowing means 20, for example, a compressor, are configured to introduce gas, via the first duct 22 and the connection head 24, into the container 50. In particular, the blowing means 20 allow creating, inside the container 50, a higher pressure (overpressure) with respect to the pressure of the environment in which the container is placed.

[0054] The inspecting system 10 further comprises a pressure detector 26, associated with the connection head 24, and a first valve 27, preferably arranged between the first duct 22 and the connection head 24.

[0055] The pressure detector 26 is configured to detect a pressure variation inside the container 50 over a given period of time, specifically a pressure decrease inside the container 50 after said overpressure has been created inside the container 50. The pressure detector 26 is further configured to compare the detected pressure variation with an appropriately selected threshold value of pressure variation, above which the detected pressure decrease is considered to be due to a leak in the container 50. In other words, the pressure detector 26 monitors the pressure trend in the container 50 and verifies the maintenance of the applied pressure over a sufficient time. If this is not the case, it is concluded that the inspected container 50 is leaking.

[0056] The first valve 27 is configured to be in an open configuration, thereby bringing the first duct 22 into communication with the connection head 24, when the blowing means 20 are operating to create the overpressure in the container 50, and to be in a closed configuration, thereby interrupting such communication, after the overpressure has been created, during said detection of pressure decrease inside the container 50.

[0057] The inspecting system 10 further comprises a contaminant sensor 30 having an inlet 30a connected to a second duct 32 which in turn is branched from the first duct 22 via a second valve 34. Said second valve 34 is a branch valve of the 3-way type, arranged along said first duct 22, between a first portion 22' of the first duct 22, located upstream of the branch valve 34 and oriented toward the blowing means 20, and a second portion 22" of the first duct 22, located downstream of the branch valve 34 and oriented toward the connection head 24.

[0058] The second valve 34 is suitable for switching between a first configuration and a second configuration. In the first configuration, the second valve 34 allows communication between the first portion 22' of the first duct 22 and the second portion 22" of the first duct 22 and prevents communication from the first duct 22 to the contaminant sensor 30. In the second configuration, the second valve 34 allows communication of the second portion 22" of the first duct 22 with the contaminant sensor 30 and prevents communication with the first portion 22' of the first duct 22. The second valve 34 is configured to be in the first configuration when the blowing means 20 are operating to create the overpressure in the container 50.

[0059] The first valve 27 is configured to return to the open configuration, and the second valve 34 is configured to switch to the second configuration, when the said detection of pressure decrease inside the container 50 is finished. In this way, the overpressure created inside the container 50 results in a flow of gas from the container 50 to the contaminant sensor 30, passing through the connection head 24, the first valve 27, the first duct portion 22' of the first duct 22, the second valve 34 and the second duct 32.

[0060] The contaminant sensor 30 is therefore configured to detect the presence of specific contaminants in said flow of gas coming from the sensor 50, so as to determine whether the container 50 is contaminated. The contaminant sensor 30 is, for example, an electrochemical sensor or an optical sensor.

[0061] Preferably, the blowing means 20 introduce dry air into the container 50. This makes both leak and contaminant detection more accurate. In fact, when damp air is present inside the container under overpressure, the pressure decrease due to leaks in the container is smaller than when the container is filled with dry air, whereby leak detection is less accurate.

[0062] The inspecting system 10 may advantageously be a so-called 'inline' inspecting system, i.e. arranged along the path of a conveyor belt (not shown). This makes it possible to effect inspection of the containers along a transport line, without having to pick them up therefrom.

[0063] According to further embodiments (not shown), the inspecting system comprises a plurality of connection heads, each associated with a respective first duct, first valve, second valve, second duct and contaminant sensor. Each connection head can be associated with respective blowing means, or it is possible to provide for common blowing means connected in parallel to the first portions of the various first ducts.

[0064] Referring to Figures 2a-b, the steps of a first embodiment of the inspecting method, carried out by means of the inspecting system 10, are illustrated below.

[0065] The connection head 24 is initially attached, preferably in a sealed manner, to the mouth 52 of the container 50.

[0066] The blowing means 20 are then activated to create an overpressure inside the container 50. At this step, shown in Figure 2a, the first valve 27 is in the open configuration and the second valve 34 is in the first configuration. After creating said overpressure, the blowing means 20 are deactivated and the first valve 27 is brought to the closed configuration, thereby keeping the connection head 24 attached in a sealed manner to the mouth 52 of the container 50. The pressure detector 26 then detects the pressure variation inside the container 50, particularly any pressure decrease due to leaks in the container 50. Such pressure decrease that may have occurred is then compared with an appropriately selected threshold value of pressure variation, above which the detected pressure decrease is considered to be due to a leak in the container 50.

[0067] When the detection of pressure decrease inside the container 50 is finished, the first valve 27 is brought to the open configuration and the second valve 34 is brought to the second configuration, whereby a flow of pressurized gas flows naturally from the container 50 to the contaminant sensor 30 (as shown in Figure 2b), due to the pressure difference between the inside of the container 50, which is under overpressure, and the outside environment, which is typically at atmospheric pressure. The contaminant sensor 30 then detects the presence of contaminants that may be present in the flow of gas, thereby allowing determining whether the container 50 is contaminated.

[0068] Referring to Figure 3, an inspecting system 110 for inspecting containers 50 according to a second embodiment of the invention is described below.

[0069] As with the first embodiment, the inspecting system 110 comprises blowing means 20 connected, via a first duct 22, to a connection head 24 suitable for being attached, in a sealed manner if necessary, to the mouth 52 of a container 50 to be inspected. The connection head 24 is preferably moveable in the vertical direction by means of appropriate handling means 25, for example, a piston, so that it can be attached to the mouth 52 of the container 50.

[0070] The blowing means 20 are configured to introduce gas, via the first duct 22 and the connection head 24, into the container 50. In particular, the blowing means 20 allow creating, inside the container 50, a higher pressure (overpressure) with respect to the pressure of the environment in which the container 50 is located.

[0071] As with the first embodiment, the inspecting system 110 comprises a pressure detector 26, associated with the connection head 24, and a first valve 27, preferably arranged between the first duct 22 and the connection head 24.

[0072] The inspecting system 110 further comprises a contaminant sensor 30, having an inlet 30a connected to a second duct 32 which in turn is branched from the first duct 22 via a second valve 34. Said second valve 34 is a branch valve of the 3-way type, arranged along said first duct 22, between a first portion 22' of the first duct 22, located upstream of the second valve 34 and oriented toward the blowing means 20, and a second portion 22" of the first duct 22, located downstream of the second valve 34 and oriented toward the connection head 24.

[0073] As with the first embodiment, the second valve 34 is suitable for switching between a first configuration and a second configuration. In the first configuration, the second valve 34 allows communication between the first portion 22' of the first duct 22 and the second portion 22" of the first duct 22 and prevents communication from the first duct 22 to the contaminant sensor 30. In the second configuration, the second valve 34 allows communication of the second portion 22" of the first duct 22 with the contaminant sensor 30 and prevents communication with the first portion 22' of the first duct 22.

[0074] According to the present embodiment, an escape valve 36, for example of the 'T'- type or 'Y'-type, is arranged along the second duct 32, between the second valve 34 and the contaminant sensor 30.

[0075] The inspecting system 110 according to the present embodiment further comprises suction means 40 connected to an outlet 30b of the contaminant sensor 30.

[0076] As with the first embodiment, the second valve 34 is configured to be in the first configuration when the blowing means 20 are operating to create the overpressure in the container 50. The first valve 27 is configured to return to the open configuration, and the second valve 34 is configured to switch to the second configuration, when said detection of pressure decrease inside the container 50 is finished. In this way, the overpressure created inside the container 50 results in a flow of gas from the container 50 to the contaminant sensor 30, passing through the connection head 24, the first valve 27, the first duct portion 22' of the first duct 22, the second valve 34 and the second duct 32.

[0077] The escape valve 36 has a port 36a toward the outside environment, said port being configured to open when the pressure of the flow of gas coming from the container under overpressure exceeds a certain threshold value, in order to prevent the contaminant sensor 30 from being hit by a flow of gas with an excessive pressure, which could damage it. Therefore, thanks to the escape valve 36, the pressure of the flow of gas coming from the container 50 and reaching the contaminant sensor 30 is limited and controlled.

[0078] The contaminant sensor 30 is therefore configured to detect the presence of specific contaminants in said flow of gas coming from the sensor 50, so as to determine whether the container 50 is contaminated. The contaminant sensor 30 is, for example, an electrochemical sensor or an optical sensor.

[0079] The suction means 40 are configured to suck gas from the contaminant sensor 30, so as to clean this sensor from any contaminants remaining after a previous inspection. By sucking gas out of the contaminant sensor 30, in fact, clean air coming from the outside environment is conveyed into said contaminant sensor, which clean air reaches the inlet 30a of the sensor 30 through the port 36a of the escape valve 36 and a portion of the second duct 32.

[0080] The inspecting system 110 may advantageously be a so-called 'inline' inspecting system, i.e. arranged along the path of a conveyor belt (not shown). This makes it possible to effect inspection of the containers along a transport line, without having to pick them up therefrom.

[0081] In this case, too, according to further embodiments (not shown), the inspecting system may comprise a plurality of connection heads, each associated with a respective first duct, first valve, second valve, second duct and contaminant sensor. Each connection head can be associated with respective blowing means, or it is possible to provide for common blowing means connected in parallel to the first portions of the various first ducts.

[0082] Referring to Figures 4a-b, the steps of a second embodiment of the inspecting method, carried out by means of the inspecting system 110, are illustrated below.

[0083] The connection head 24 is initially attached, preferably in a sealed manner, to the mouth 52 of the container 50.

[0084] The blowing means 20 are then activated to create an overpressure inside the container 50. At this step, shown in Figure 4a, the first valve 27 is in the open configuration and the second valve 34 is in the first configuration.

[0085] After creating the above-mentioned overpressure, the blowing means 20 are deactivated and the first valve 27 is brought to the closed configuration, thereby keeping the connection head 24 attached in a sealed manner to the mouth 52 of the container 50. The pressure detector 26 then detects the pressure variation inside the container 50, particularly any pressure decrease due to leaks in the container 50. Such pressure decrease that may have occurred is then compared with an appropriately selected threshold value of pressure variation, above which the detected pressure decrease is considered to be due to a leak in the container 50.

[0086] During said steps, the suction means 40 are operating, creating a continuous flow of air through the contaminant sensor 30 in order to keep it clean, as described above and shown in Figure 4a.

[0087] When the detection of pressure decrease inside the container 50 is finished, the first valve 27 is brought to the open configuration and the second valve 34 is brought to the second configuration, whereby a flow of pressurized gas flows naturally from the container 50 to the contaminant sensor 30 (as shown in Figure 4b), due to the pressure difference between the inside of the container 50, which is under overpressure, and the outside environment, which is typically at atmospheric pressure. At this step, if the pressure of the flow of gas coming from the container 50 is excessive, it is limited by means of the escape valve 36, as shown in Figure 4b.

[0088] The contaminant sensor 30 then detects the presence of contaminants that may be present in the flow of gas coming from the container 50, thereby allowing determining whether the container 50 is contaminated.

[0089] Referring to Figure 5, an inspecting system 210 for containers 50 according to a third embodiment of the present invention is described below.

[0090] As with the first embodiment, the inspecting system 210 comprises blowing means 20 connected, via a first duct 22, to a connection head 24 suitable for being attached, in a sealed manner if necessary, to the mouth 52 of a container 50 to be inspected. The connection head 24 is preferably moveable in the vertical direction by means of appropriate handling means 25, for example, a piston, so that it can be attached to the mouth 52 of the container 50.

[0091] The blowing means 20 are configured to introduce gas, via the first duct 22 and the connection head 24, into the container 50. In particular, the blowing means 20 allow creating, inside the container 50, a higher pressure (overpressure) with respect to the pressure of the environment in which the container is placed.

[0092] As with the first embodiment, the inspecting system 210 further comprises a pressure detector 26, associated with the connection head 24, and a first valve 27, preferably arranged between the first duct 22 and the connection head 24. The inspecting system 210 further comprises a second valve 34, in particular a branch valve of the 3 -way type, arranged along the first duct 22, between a first portion 22' of the first duct 22, located upstream of the branch valve 34 and oriented toward the blowing means 20, and a second portion 22" of the first duct 22, located downstream of the branch valve 34 and oriented toward the connection head 24. Furthermore, an outlet duct 232 is branched from the first duct 22 via the second valve 34 and is open toward the outside environment.

[0093] The inspecting system further comprises a contaminant sensor 30 arranged along the second portion 22" of the first duct 22 and having an inlet 30a oriented toward the connection head 24 and an outlet 30b oriented toward the second valve 34.

[0094] The second valve 34 is suitable for switching between a first configuration and a second configuration. In the first configuration, the second valve 34 allows communication between the first portion 22' of the first duct 22 and the second portion 22" of the first duct 22. In the second configuration, the second valve 34 allows communication of the second portion 22" of the first duct 22 with the contaminant sensor 30 and prevents communication with the first portion 22' of the first duct 22.

[0095] As with the first embodiment, the second valve 34 is configured to be in the first configuration when the blowing means 20 are operating to create the overpressure in the container 50. The first valve 27 is configured to return to the open configuration, and the second valve 34 is configured to switch to the second configuration, when the above-mentioned detection of pressure decrease inside the container 50 is finished. In this way, the overpressure created inside the container 50 results in a flow of gas from the container 50 to the outlet duct 232, passing through the connection head 24, the first valve 27 and the contaminant sensor 30.

[0096] The contaminant sensor 30 is therefore configured to detect the presence of specific contaminants in said flow of gas coming from the container 30, so as to determine whether the container 50 is contaminated. The contaminant sensor 30 is, for example, an electrochemical sensor or an optical sensor.

[0097] The inspecting system 210 may advantageously be a so-called 'inline' inspecting system, i.e. arranged along the path of a conveyor belt (not shown). This makes it possible to effect inspection of the containers along a transport line, without having to pick them up therefrom.

[0098] In this case, too, according to further embodiments (not shown), the inspecting system may comprise a plurality of connection heads, each associated with a respective first duct, first valve, second valve, second duct and contaminant sensor. Each connection head can be associated with respective blowing means, or it is possible to provide for common blowing means connected in parallel to the first portions of the various first ducts.

[0099] Referring to Figures 6a-b, the steps of a third embodiment of the inspecting method, carried out by means of the inspecting system 210, are illustrated below.

[0100] The connection head 24 is initially attached, preferably in a sealed manner, to the mouth 52 of the container 50.

[0101] The blowing means 20 are then activated to create an overpressure inside the container 50. At this step, shown in Figure 6a, the first valve 27 is in the open configuration and the second valve 34 is in the first configuration.

[0102] After creating the above-mentioned overpressure, the blowing means 20 are deactivated and the first valve 27 is brought to the closed configuration, thereby keeping the connection head 24 attached in a sealed manner to the mouth 52 of the container 50. The pressure detector 26 then detects the pressure variation inside the container 50, particularly any pressure decrease due to leaks in the container 50. Such pressure decrease that may have occurred is then compared with an appropriately selected threshold value of pressure variation, above which the detected pressure decrease is considered to be due to a leak in the container 50.

[0103] When the detection of pressure decrease inside the container 50 is finished, the first valve 27 is brought to the open configuration and the second valve 34 is brought to the second configuration, whereby a flow of pressurized gas flows naturally from the container 50 to the contaminant sensor 30 (as shown in Figure 6b), due to the pressure difference between the inside of the container 50, which is under overpressure, and the outside environment, which is typically at atmospheric pressure. The contaminant sensor 30 then detects the presence of contaminants that may be present in the flow of gas, thereby allowing determining whether the container 50 is contaminated.

[0104] Advantageously, thanks to the inspecting systems 10, 110 and 210 and the inspecting methods illustrated above, it is possible to carry out the inspection of containers 50 to detect both leaks and contaminants.

[0105] Furthermore, thanks to the introduction of gas into the container 50 to be inspected during the step of creating the overpressure, a mixing advantageously takes place inside the container, which mixing allows displacing any contaminants that may be present, which would typically adhere to the inner walls of the container, thereby facilitating transit thereof toward the contaminant sensor 30. This makes it unnecessary to use a probe to be inserted into the container 50 through the mouth 52 thereof to obtain a gas sample as close as possible to the inner walls of the container 50. For this reason, preferably, the connection head 24 of the inspecting systems 10, 110, 210 described above does not comprise a probe of the above-mentioned type.

[0106] Furthermore, by exploiting the overpressure created inside the container 50, the described inspecting systems 10, 110, 210 do not require any suction means to suck gas from the inside of the container 50 to detect the presence of contaminants. For this reason, preferably, the inspecting systems 10, 110, 210 do not comprise means for sucking gas from the inside of the container 50 to be inspected.

Claims

CLAIMS1. Inspecting system (10; 110; 210) for inspecting containers, comprising:- a connection head (24) suitable for being attached to a mouth (52) of a container (50) to be inspected;- blowing means (20) connected, via a first duct (22), to the connection head (24) and configured to introduce gas, via the first duct (22) and the connection head (24), into the container (50), so as to create inside the container (50) an overpressure with respect to the pressure of the environment in which the container (50) is located;- a pressure detector (26), associated with the connection head (24); and- a contaminant sensor (30), wherein said pressure detector (26) is configured to detect a pressure variation over a given period of time inside the container (50), specifically a pressure decrease inside the container (50) after said overpressure has been created inside said container, and to compare the detected pressure variation with a threshold value of pressure variation, above which the detected pressure decrease is considered to be due to a leak in the container (50), said inspecting system (10; 110; 210) being characterized by being configured in such a way that, when the aforementioned detection of pressure decrease inside the container (50) is finished, said contaminant sensor (30) is connected to said connection head (24), so that the overpressure created inside the container (50) results in a flow of gas from the container (50) to the contaminant sensor (30), said contaminant sensor being configured to detect the presence of specific contaminants in said flow of gas from the container (50), so as to determine whether the container (50) is contaminated.

2. Inspecting system (10; 110; 210) according to claim 1, further comprising a first valve (27), arranged between the first duct (22) and the connection head (24), said first valve (27) being configured to be in an open configuration, thereby bringing the first duct (22) into communication with the connection head (24), when the blowing means (20) are operating to create the overpressure in the container (50), and to be in a closed configuration, thereby interrupting such communication, after the overpressure has been created, during said detection of pressure decrease inside the container (50).

3. Inspecting system (10; 110; 210) according to claim 2, wherein said first valve (27) is configured to return to the open configuration when said detection of pressure decrease inside the container (50) is finished.

4. Inspecting system (10; 110; 210) according to any of the preceding claims, wherein the contaminant sensor (30) is an electrochemical sensor or an optical sensor.

5. Inspecting system (10; 110; 210) according to any of the preceding claims, wherein the connection head (24) is moveable in the vertical direction by suitable handling means (25).

6. Inspecting system (10; 110) according to any one of the preceding claims, wherein the contaminant sensor (30) has an inlet (30a) connected to a second duct (32) which in turn is branched from the first duct (22) via a branch valve (34) that is arranged along said first duct (22), between a first portion (22') of the first duct (22), located upstream of the branch valve (34) and oriented toward the blowing means (20), and a second portion (22") of the first duct (22), located downstream of the branch valve (34) and oriented toward the connection head (24), wherein, when the blowing means (20) are operating to create the overpressure in the container (50), the branch valve (34) is configured to be in a first configuration where communication between the first portion (22') of the first duct (22) and the second portion (22") of the first duct (22) is allowed and communication from the first duct (22) to the contaminant sensor (30) is prevented, and wherein, when said detection of pressure decrease inside the container (50) is finished, the branch valve (34) is configured to be in a second configuration where communication between the second portion (22") of the first duct (22) and the contaminant sensor (30) is allowed, so that the overpressure created inside the container (50) results in a flow of gas from the container (50) to the contaminant sensor (30).

7. Inspecting system (110) according to any of the preceding claims, further comprising:- an escape valve (36) arranged along the second duct (32), between the branch valve (34) and the contaminant sensor (30), said escape valve (36) being provided with a port (36a) to the outside environment, configured to open when the pressure of said flow of gas from the container under overpressure is greater than a certain threshold value.

8. Inspecting system (110) according to any of the preceding claims, further comprising:- suction means (40) connected to an outlet (30b) of the contaminant sensor (30), said suction means (40) being configured to suck gas from the contaminant sensor (30), so as to clean the contaminant sensor (30) from any contaminants remaining after a previous inspection.

9. Inspecting system (210) according to any one of claims 1 to 5, further comprising a branch valve (34) arranged along said first duct (22), between a first portion (22') of the first duct (22), located upstream of the branch valve (34) and oriented toward the blowing means (20), and a second portion (22”) of the first duct (22), located downstream of the branch valve (34) and oriented toward the connection head (24), and an outlet duct (232) branched from the first duct (22) via said branch valve (34), wherein the contaminant sensor (30) is arranged along said second portion (22") of said first duct (22), wherein, when the blowing means (20) are operating to create the overpressure in the container (50), the branch valve (34) is configured to be in a first configuration where communication between the first portion (22') of the first duct (22) and the second portion (22") of the first duct (22) is allowed and communication from the first duct (22) to the outlet duct (232) is prevented, and wherein, when said detection of pressure decrease inside the container (50) is finished, the branch valve (34) is configured to be in a second configuration where communication between the second portion (22") of the first duct (22) and the outlet duct (232) is allowed, so that the overpressure created inside the container (50) results in a flow of gas from the container (50) to the outlet duct (232) passing through the contaminant sensor (30).

10. Inspecting method for inspecting containers (50) comprising the steps of:- detecting the possible presence of leaks in a container (50) by the steps of:- bringing the container (50) into communication, in a sealed manner, with blowing means (20),- creating an overpressure inside the container (50) with respect to the pressure of the environment in which the container (50) is placed,- detecting a pressure variation over a given period of time inside the container(50) with respect to said overpressure created inside it, and- comparing the detected pressure variation with a predetermined threshold value of variation, above which the detected pressure variation is considered to be due to a leak in the container (50), and- detecting the possible presence of contaminants inside the container (50) by the steps of:- opening a passage from the container (50) under overpressure to a contaminant sensor (30), so that a pressurized flow of gas flows naturally from the container (50) to the contaminant sensor (30),- detecting, by means of the contaminant sensor, the presence of any contaminants in the flow of gas, thus allowing determining whether the container is contaminated.

11. Inspecting method according to claim 10, further comprising the step of creating a continuous flow of air through the contaminant sensor (30) in order to keep it clean.

12. Inspecting method according to claim 10 or 11, further comprising the step of allowing a part of the flow of gas coming from the container (50) under overpressure to escape to the outside environment before said flow of gas reaches the contaminant sensor (30), so as to limit the pressure of the flow of gas reaching the contaminant sensor (30).

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