Sterilization apparatus, packaging machine having a sterilization apparatus and a method for sterilizing

A sterilization apparatus for sterilizing a web of packaging material advancing along a web advancement path-comprises an irradiation device for sterilizing the advancing packaging material web, a main shielding chamber housing the irradiation device and comprising an advancement channel having an inlet opening and an outlet opening and through which, in use, the packaging material web advances along the sterilization portion, an auxiliary shielding chamber upstream of the advancement channel along the web advancement path, the auxiliary shielding chamber having an inner space in fluid connection with the advancement channel and comprising an extraction opening allowing gas extraction from the auxiliary shielding chamber. An aspiration device generates a first flow of gas within the advancement channel from the outlet opening to the inlet opening and a second flow of gas from the inlet opening to the extraction opening.

TECHNICAL FIELD

The present invention relates to a sterilization apparatus for sterilizing a web of packaging material, in particular a web of packaging material for the production of sealed packages of a pourable product, in particular a pourable food product.

The present invention also relates to a packaging machine for producing sealed packages of a pourable product, in particular a pourable food product, having a sterilization apparatus.

The present invention also relates to a method for sterilizing a web of packaging material, in particular a web of packaging material for the production of sealed packages of a pourable product, in particular a pourable food product.

BACKGROUND ART

As is known, many liquid or pourable food products, such as fruit juice, UHT (ultra-high-temperature treated) milk, wine, tomato sauce, etc., are sold in packages made of sterilized packaging material.

A typical example is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by sealing and folding laminated strip packaging material. The packaging material has a multilayer structure comprising a base layer, e.g. of paper, covered on both sides with layers of heat-seal plastic material, e.g. polyethylene. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a layer of oxygen-barrier material (an oxygen-barrier layer), e.g. an aluminum foil, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.

Packages of this sort are normally produced on fully automatic packaging machines, which advance a web of packaging material from a magazine unit through a sterilization apparatus for sterilizing the web of packaging material and to an isolation chamber (a closed and sterile environment) in which the sterilized web of packaging material is maintained and advanced. During advancement of the web of packaging material through the isolation chamber, the web of packaging material is folded and sealed longitudinally to form a tube having a longitudinal seam portion, which is further fed along a vertical advancing direction.

In order to complete the forming operations, the tube is filled with a sterilized or sterile-processed pourable product, in particular a pourable food product, and is transversally sealed and subsequently cut along equally spaced transversal cross sections within a package forming unit of the packaging machine during advancement along the vertical advancing direction.

Pillow packages are so obtained within the packaging machine, each pillow package having a longitudinal sealing band, a top transversal sealing band and a bottom transversal sealing band.

In the recent years, sterilization apparatuses have become available, which are configured to sterilize the web of packaging material by means of the application of physical irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation.

A typical sterilization apparatus of this kind comprises an irradiation device typically having a pair of electron beam emitters spaced apart from one another. An advancement channel, through which, in use, the web of packaging material advances, is interposed between the electron beam emitters. Each one of the electron beam emitters is adapted to direct the respective electron beam onto one respective face of the web of packaging material advancing through the advancement channel.

Furthermore, such a kind of sterilization apparatus must provide for means that guarantee to safely discharge ozone and other undesired components, which may form during the application of the sterilizing irradiation.

For this reason, a typical sterilization apparatus sterilizing by means of a sterilizing irradiation comprises a main shielding chamber housing the irradiation device, a first auxiliary shielding chamber connected to the main shielding chamber and arranged upstream of the main shielding chamber and a second auxiliary shielding chamber connected to the main shielding chamber and being arranged downstream of the main shielding chamber. In use, the un-sterilized web of packaging material enters the first auxiliary shielding chamber, is sterilized within the main shielding chamber and the sterilized web of packaging material enters the second auxiliary shielding chamber from where it advances into the isolation chamber.

Furthermore, the sterilization apparatus also comprises an isolation housing, which houses in its inner space the main shielding chamber, the first auxiliary shielding chamber and the second auxiliary shielding chamber and from which any undesired components are extracted.

Thus, such a sterilization apparatus comes along with a rather complex design, in particular requiring the presence of the isolation housing.

Even though this kind of sterilization apparatus and, accordingly, also the packaging machine provides for good results, a desire is felt to simplify the design of these kinds of sterilization apparatus sterilizing by means of the application of sterilizing irradiation.

DISCLOSURE OF INVENTION

It is therefore an object of the present invention to provide a sterilization apparatus to overcome, in a straightforward and low-cost manner, at least one of the aforementioned drawbacks.

In particular, it is an object of the present invention to provide a sterilization apparatus, which comes along with a simplified design.

It is a further object of the present invention to provide a packaging machine to overcome, in a straightforward and low-cost manner, at least one of the aforementioned drawbacks.

In particular, it is an object of the present invention to provide a packaging machine, which comes along with a simplified design.

It is a further object of the present invention to provide a method for sterilizing to overcome, in a straightforward and low-cost manner, at least one of the aforementioned drawbacks.

According to the present invention, there is provided a sterilization apparatus as claimed in claim1.

According to the present invention, there is also provided a packaging machine according to claim8.

According to the present invention, there is also provided a method for sterilizing according to claim10.

Preferred embodiments are claimed in the dependent claims.

BEST MODES FOR CARRYING OUT THE INVENTION

Number1indicates as a whole a packaging machine for producing sealed packages2of a pourable product, in particular a pourable food product such as pasteurized milk, fruit juice, wine, tomato sauce, etc., from a tube3of a web4of packaging material. In particular, in use, tube3extends along a longitudinal axis, in particular having a vertical orientation.

Web4at least comprises a layer of fibrous material, in particular paper, covered on both sides with respective layers of heat-seal plastic material, e.g. polyethylene.

Preferably, web4also comprises a layer of gas- and light-barrier material, e.g. aluminum foil or ethylene vinyl alcohol (EVOH) film, and at least a first layer and a second layer of heat-seal plastic material. The layer of gas- and light-barrier material is superimposed on the first layer of heat-seal plastic material, and is in turn covered with the second layer of heat-seal plastic material. The second layer of heat-seal plastic material forms the inner face of package2eventually contacting the filled pourable food product.

More specifically, web4comprises a first face5and a second face6, in particular first face5being the face of web4forming the inner face of the formed package2eventually contacting the filled pourable food product.

A typical package2obtained by packaging machine1comprises a longitudinal seam portion and a pair of transversal sealing bands, in particular a transversal top sealing band and a transversal bottom sealing band.

With particular reference toFIG. 1, packaging machine1is configured to advance web4along a web advancement path P, to sterilize web4during advancement along path P, to form tube3from web4and to fill tube3and to form single packages2from the filled tube3.

Preferentially, packaging machine1comprises:a magazine unit7adapted to provide for web4at a host station8;a sterilization apparatus9configured to sterilize at least first face5, preferentially also second face6, of web4at a sterilization station10, arranged downstream of host station8along path P;an isolation chamber14connected to sterilization apparatus9and separating an inner environment15, in particular an inner sterile environment, from an outer environment16and being configured to receive the sterilized web4from sterilization apparatus9;a tube forming device17extending along a longitudinal axis, in particular having a vertical orientation, and being arranged, in particular at a tube forming station18, at least partially, preferably fully, within isolation chamber14and being adapted to form tube3from the, in use, advancing and sterilized web4;a sealing device19at least partially arranged within isolation chamber14and being adapted to longitudinally seal tube3formed by tube forming device17so as to form a longitudinal seam portion of tube3;filling means20for filling tube3with the pourable product, in particular the pourable food product;a package forming unit21adapted to at least form and transversally seal tube3, in particular the, in use, advancing tube3, for forming packages2; andconveying means22for advancing in a known manner web4along path P from host station8to tube forming station18and to advance tube3along a tube advancement path Q towards and at least partially through package forming unit21.

Preferentially, packaging machine1also comprises pressure control means configured to control the pressure within at least isolation chamber14and within at least portions of sterilization apparatus9.

In particular, sterilization station10is arranged upstream of tube forming station17. In other words, sterilization apparatus9is arranged upstream of isolation chamber14along path P.

In particular, package forming unit21is arranged downstream of isolation chamber14and tube forming device17along path Q.

Preferentially, conveying means22are adapted to advance tube3and any intermediate of tube3in a manner known as such along path Q, in particular from tube forming station18towards and at least partially through package forming unit21. In particular, with intermediates of tube3any configuration of web4is meant prior to obtaining the tube structure and after folding of web4by tube forming device16has started. In other words, the intermediates of tube3are a result of the gradual folding of web4so as to obtain tube3, in particular by overlapping opposite lateral edges of web4with one another.

With particular reference toFIG. 1, sterilization apparatus9comprises:an irradiation device26arranged in the area of sterilization station10and being adapted to sterilize at least first face5, preferentially also second face6, by directing a sterilizing irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation, onto at least first face5, preferentially also onto second face6, while, in use, web4advances along a sterilization portion P1of path P;a main shielding chamber27housing the irradiation device and comprising an advancement channel28, in particular extending along a longitudinal axis, having an inlet opening29and an outlet opening30arranged downstream of inlet opening29along path P, and through which, in use, web4advances along sterilization portion P1;a first auxiliary shielding chamber31being arranged upstream of advancement channel28along path P and having a respective first inner space32being in fluid connection with advancement channel28.

Preferentially, sterilization apparatus9also comprises a second auxiliary shielding chamber33being arranged downstream of advancement channel28along path P and having a second inner space34being fluidically connected to advancement channel28and inner environment15.

In particular, advancement channel28is interposed between the first inner space32and the second inner space34.

Preferentially, each one of inlet opening29and outlet opening30extends along a respective extension axis, the respective extension axes being parallel to one another.

It should be noted that main shielding chamber27, in particular also first auxiliary shielding chamber31, even more particular also second auxiliary shielding chamber33are configured to shield the sterilizing irradiation, in particular the electromagnetic irradiation, even more particular the electron beam irradiation. The shielding allows to avoid that any sterilizing irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation, penetrates out of sterilization apparatus9.

With particular reference toFIGS. 1 and 2, irradiation device26comprises:at least a first irradiation emitter, in particular a first electron beam emitter35, configured to direct the sterilizing irradiation, in particular the electromagnetic irradiation, even more particular the electron beam irradiation, in use, on first face5; andpreferentially also a second irradiation emitter, in particular a second electron beam emitter36, configured to direct the sterilizing irradiation, in particular the electromagnetic irradiation, even more particular the electron beam irradiation, in use, on second face6.

Preferably, first electron beam emitter35and second electron beam emitter36are arranged side-by-side and distanced from one another so that at least a portion of advancement channel28is interposed between first electron beam emitter35and second electron beam emitter36.

In particular, first electron beam emitter35is placed such to face, in use, first face5and second electron beam emitter36is placed such to face, in use, second face6.

In even further detail, first electron beam emitter35is arranged within a first portion37of main shielding chamber27and second electron beam emitter36is arranged within a second portion38of main shielding chamber27. Preferentially, the advancement channel28is interposed between the first portion37and the second portion38.

With particular reference toFIG. 2, main shielding chamber27comprises two inner walls42at least partially delimiting advancement channel28. In particular, inner walls42are parallel to one another and distanced from one another so that the space between inner walls42defines advancement channel28.

Preferentially, one inner wall42delimits first portion37and the other inner wall42delimits second portion38.

More specifically, each inner wall42comprises a respective exit window43configured to allow the transmission of electron beam irradiation. In particular, in use, first electron beam emitter35and second electron beam emitter36transmit the electron beam irradiation onto respective first face5and second face6through the respective exit window43.

In further detail, main shielding chamber27comprises a first principal wall44comprising inlet opening29and a second principal wall45comprising outlet opening30, first principal wall44and second principal wall45being parallel to and distanced from one another. Main shielding chamber27is arranged such that, in use, second principal wall45is arranged downstream of second principal wall44along path P.

Preferentially, inner walls42are transversally, in particular perpendicularly, mounted to and are interposed between first principal wall44and second principal wall45.

Preferably, main shielding chamber27also comprises outer lateral walls46being parallel to inner walls42and being interposed between and connected to first principal wall44and second principal wall45.

With particular reference toFIGS. 2 and 3, first auxiliary shielding chamber31comprises an access opening47and a discharge opening48for web4, in particular through which, in use, web4respectively enters into and exits from first auxiliary shielding chamber31.

Preferentially, access opening47and inlet opening29are non-coaxially arranged with respect to one another. In other words, access opening47is arranged with respect to inlet opening29such that an imaginary line extending from access opening47to inlet opening29is inclined with respect to an imaginary line extending from inlet opening29to outlet opening30of advancement channel28. In even other words, a projection of inlet opening29and a projection of access opening47onto a projection surface are transversally displaced from one another. In this way, a shielding effect of the sterilizing irradiation is guaranteed in the prolongation of advancement channel28.

Preferentially, first auxiliary shielding chamber31is connected to, in particular mounted to, main shielding chamber27. In particular, first auxiliary shielding chamber31is positioned such that, in use, first auxiliary shielding chamber31is arranged upstream of main shielding chamber27along path P.

In more detail, first auxiliary shielding chamber31comprises a principal plate49, in particular parallel to first principal wall44and second principal wall45, and outer lateral plates50connected to, in particular mounted to, principal plate49and laterally delimiting first auxiliary shielding chamber31. In particular, lateral plates50are transversally, in particular perpendicularly, mounted to main shielding chamber27, in particular to first principal wall44.

Preferentially, principal plate49comprises access opening47. Even more preferentially, principal plate49also carries a sealing member51for sealing access opening47for allowing feeding in of web4and limiting entrance of gas into first inner space32through access opening47.

In the preferred embodiment shown, first auxiliary shielding chamber31, in particular first inner space32, is further delimited by first principal wall44.

In an alternative embodiment not shown, first auxiliary shielding chamber31could comprise a further principal plate parallel to and distanced from principal plate49and comprising discharge opening48. In such an alternative embodiment, outer lateral plates50would be also mounted to the further principal plate and the latter would be mounted to first principal wall44.

In a preferred embodiment, first auxiliary shielding chamber31also comprises an extraction opening52, in particular distinct from the access opening47, configured to allow to extract gas from first inner space32of first auxiliary shielding chamber31.

In particular, extraction opening52is arranged in one of outer lateral plates50.

In the preferred embodiment shown, sterilization apparatus9also comprises a first deviation device, in particular a plurality of rollers53, arranged within first auxiliary shielding chamber31and configured to direct, in use, web4along a deviation portion P2of path P from access opening47to inlet opening29. In particular, in the preferred embodiment, this is necessary as access opening47and inlet opening29are non-coaxially arranged.

With particular reference toFIGS. 2 and 4, second auxiliary shielding chamber33comprises an access mouth55and a discharge mouth56for web4, in particular through which, in use, web4respectively enters into and exits from second auxiliary shielding chamber33.

Preferentially, sterilization apparatus9and isolation chamber14are connected to one another through second auxiliary shielding chamber33. In other words, in use, web4advances through discharge mouth56into isolation chamber14.

Preferentially, second auxiliary shielding chamber33comprises a principal plate57, in particular distanced from and parallel to first principal wall44and second principal wall45, and outer lateral plates58connected to, in particular transversally mounted to, principal plate57and laterally delimiting second auxiliary shielding chamber33. In particular, lateral plates58are mounted to main shielding chamber27, in particular second principal wall45.

In the preferred embodiment shown, second auxiliary shielding chamber33is further delimited by second principal wall45.

In an alternative embodiment not shown, second auxiliary shielding chamber33could comprise a further principal plate parallel to and distanced from principal plate57and comprising access mouth55. In such an alternative embodiment, outer lateral plates58would be also mounted to the further principal plate and the latter would be mounted to second principal wall45.

In the preferred embodiment shown, sterilization apparatus9also comprises a second deviation device, in particular at least one roller59, arranged within second auxiliary shielding chamber33and configured to direct, in use, web4along a deviation portion P3of path P from outlet opening30to discharge mouth56.

In a preferred embodiment, sterilization apparatus9comprises an aspiration device configured to generate at least:a first flow of gas within advancement channel28from outlet opening30to inlet opening29(i.e. the first flow of gas is opposite to the advancement direction of web4); anda second flow of gas from inlet opening29to extraction opening52and, in particular, out of first inner space32.

By providing for the first flow of gas from outlet opening30to inlet opening29it is guaranteed that web4, in particular first face5, even more particular also second face6, remain sterile after the sterilization as any contaminants are directed away from the sterile web4, in particular the sterile first face5, even more particular also the sterile second face6.

By providing for the second flow of gas from inlet opening29to extraction opening52contaminants and other undesired components such as ozone are removed from sterilization apparatus9, in particular first inner space32, in a controlled manner.

Preferentially, the aspiration device is also configured to generate a third flow of gas from second inner space34to advancement channel28, in particular from discharge mouth56to outlet opening30.

Preferably, the aspiration device is also configured to generate a fourth flow of gas from inner environment15, in particular through discharge mouth56, into second inner space34.

In a preferred embodiment, the aspiration device comprises a suction conduct61arranged within first inner space32and being configured to at least partially guide the second flow of gas, in particular at least to extraction opening52. Suction conduct61has an intake mouth62(through which, in use, the gas of the second flow of gas enters) and being arranged in the proximity of inlet opening29.

In more detail, suction conduct61comprises a first conduct portion63extending parallel to inlet opening29and comprising intake mouth62and a second conduct portion64being fluidically and, in particular also mechanically, connected to first conduct portion63and extraction opening52.

Preferentially, first conduct portion63also comprises a web passage65being arranged opposite to intake mouth62and being configured to allow, in use, entrance of web4into first conduct portion63. In particular, intake mouth62is also configured to allow for the exit of web4from first conduct portion63. In other words, in use, web passage65is positioned upstream of intake mouth62, which again is positioned upstream of inlet opening39along path P.

In even further detail, first conduct portion63comprises a first structured sheet66and a second structured sheet67defining in collaboration intake mouth62and, in particular also web passage65. Preferentially, first structured sheet66is connected to, in particular fixed to, second conduct portion64, and second structured sheet67is connected to and protrudes from first principal wall44into first inner space32.

Preferentially, the aspiration device also comprises at least one suction device configured to generate the suction force and being fluidically connected to second inner space34through a(n) (outer) tubing68(only partially shown) connected to first auxiliary shielding chamber31in the area of extraction opening52. Even more preferentially, the aspiration device is configured to direct the gas extracted from first auxiliary shielding chamber31, in particular first inner space32, to a regeneration circuit of packaging machine1.

In a most preferred embodiment, packaging machine1comprises pressure control means configured to maintain a first pressure within first auxiliary shielding chamber31, a second pressure within second auxiliary shielding chamber33and a third pressure within isolation chamber14.

Preferentially, pressure control means are configured to control the first pressure, the second pressure and the third pressure such that the second pressure is higher than the first pressure and the third pressure is higher than the second pressure. In other words, pressure control means are configured to control the first pressure, the second pressure and the third pressure such that the first pressure is lower than the second pressure and the second pressure is lower than the third pressure.

These pressure distributions allow to further guarantee to avoid contaminating the sterile environments within packaging machine1.

Preferentially, pressure control means are configured to control:the first pressure to be substantially constant, in particular to be substantially identical to the atmospheric pressure;the second pressure to range between 10 to 60 Pa above ambient pressure, in particular between 20 to 40 Pa above ambient pressure; andthe third pressure to range between 100 to 600 Pa above ambient pressure, in particular between 200 to 400 Pa above ambient pressure.

In a preferred embodiment, pressure control means comprise a portion of sterilization apparatus9, in particular a valve72coupled to first auxiliary shielding chamber31and configured to selectively open or close so as to respectively allow or prevent a gas to enter into first auxiliary shielding chamber31, in particular first inner space32, for controlling the first pressure.

Preferentially, pressure control means comprise the aspiration device.

Pressure control means also comprise a sterile gas circuit, in particular a closed sterile gas circuit, configured to introduce sterile gas, in particular sterile air, into isolation chamber14.

With particular reference toFIG. 4, pressure control means also comprises a restriction group73configured to control the pressure drop from isolation chamber14to second auxiliary shielding chamber33.

Preferentially, restriction group73comprises two restriction sheets74configured to restrict the cross-sectional size of discharge mouth56.

Even more preferentially, restriction sheets74are moveable for allowing to adjust the pressure drop.

In the specific example shown, restriction sheets74are manually moveable so as to adjust the relative positions. In an alternative embodiment not shown, pressure control means could comprise an actuator configured to adjust the relative positions of restriction sheets74.

In use, packaging machine1forms packages2filled with the pourable product.

Preferentially, the method of forming packages2also comprises a step of controlling the pressure during which the pressure within at least sterilization apparatus9and isolation chamber14is controlled.

In more detail, during the main step of advancing web4, conveying means22advance web4from magazine unit7along advancement path P through sterilization apparatus9and to tube forming device17.

More specifically, the main step of advancing web4comprises:a first sub-step of advancing, during which web4advances along deviation portion P2;a second sub-step of advancing, during which web4advances along sterilization portion P1; andpreferentially, a third sub-step of advancing, during which web4advances along deviation portion P3.

Even more specifically, during the first sub-step of advancing, web4advances through first inner space32from access opening47to inlet opening29.

Preferentially, during the third sub-step of advancing, web4advances through second inner space34from access mouth55to discharge mouth56.

During the main step of forming tube3, tube forming device17gradually overlaps the opposite lateral edges of web4with one another so as to form a longitudinal seam portion.

During the main step of longitudinally sealing tube3, sealing device19seals the longitudinal seam portion.

During the main step of advancing tube3, conveying means22advance tube3(and any intermediates of tube3) along path Q to package forming unit21.

During the main step of filling tube3, filling means20fill the pourable product into the longitudinally sealed tube3.

During the main step of obtaining single packages2, package forming unit21forms and transversally seals tube3between successive packages2and, preferentially, also transversally cuts tube3between successive packages2.

In more detail, during the main step of sterilizing web4, at least a step of directing a sterilizing irradiation, in particular electromagnetic irradiation, even more particular electron beam irradiation, at least onto first face5, preferentially also onto second face6is executed.

Preferentially, during the main step of sterilizing web4, the first sub-step of advancing and the second sub-step of advancing, even more preferentially also the third sub-step of advancing, are executed.

Preferentially, during the step of directing a sterilization irradiation, irradiation device26directs the sterilizing irradiation, in particular the electromagnetic irradiation, even more particular the electron beam irradiation, at least onto first face5, preferentially also onto second face6for sterilizing first face5and, preferentially also second face6.

In even more detail, during the step of directing a sterilization irradiation, first electron beam emitter35directs the electron beam irradiation onto first face5, and preferentially second electron beam emitter36directs the electron beam irradiation onto second face6while web4is advanced through advancement channel28along sterilization portion P1.

Preferentially, the step of directing a sterilization irradiation is executed during the second sub-step of advancing.

Advantageously, during the step of sterilizing also the step of generating a first flow of gas within advancement channel28from outlet opening30to inlet opening29and a second flow of gas from inlet opening29to extraction opening52are generated and, in particular gas is extracted from first inner space32.

In more detail, during the step of generating, the second flow of gas flows at least partially through suction conduct61. Preferentially, the second flow of gas enters suction conduct61through intake mouth62and flows to extraction opening52. Even more preferentially, after entering the suction conduct61, the second flow of gas flows through first conduct portion63and then through second conduct portion64. Then, the second flow of gas is removed from first inner space32through extraction opening52.

In even further detail, during the step of generating, the suction device generates the suction force for generating the first flow of gas and the second flow of gas. Preferentially, the gas is extracted from first inner space32through extraction opening52and into tubing68. Even more preferentially, the gas extracted from first inner space32is directed into the regeneration circuit.

In more detail, during the step of controlling the pressure, the pressure control means control the first pressure, the second pressure and the third pressure such that the first pressure is lower than the second pressure and the second pressure is lower than the third pressure.

Preferentially, the pressure control means control the pressures such that:the first pressure is substantially constant, in particular substantially identical to the atmospheric pressure;the second pressure ranges between 10 to 60 Pa above ambient pressure, in particular between 20 to 40 Pa above ambient pressure; andthe third pressure ranges between 100 to 600 Pa above ambient pressure, in particular between 200 to 400 Pa above ambient pressure.

More specifically, the first pressure is controlled through valve72. Valve72opens to guide a gas into first auxiliary chamber31if the first pressure falls below a predetermined pressure value, in particular below atmospheric pressure. The latter case may occur in these cases in which the suction force applied by the suction device would extract gas from first inner space32in an amount being larger than the gas entering into first inner space32through inlet opening29.

Preferentially, pressure control means control the third pressure through the sterile gas circuit introducing sterile gas into isolation chamber14.

Preferentially, the pressure drop between isolation chamber14and second auxiliary shielding chamber33is controlled by restriction group73and the first flow of gas within advancement channel28generating a third flow of gas from second inner space34towards advancement channel28, in particular from discharge mouth56to outlet opening30.

The advantages of sterilization apparatus9according to the present invention will be clear from the foregoing description.

In particular, sterilization apparatus9comes along with a simplified structure with respect to the ones known in the art.

Even more particular, sterilization apparatus9allows to remove contaminations and other undesired compositions such as ozone from the sterilization apparatus9without the need of an additional isolation housing.

Clearly, changes may be made to sterilization apparatus9as described herein without, however, departing from the scope of protection as defined in the accompanying claims.