WO2011048385A2

WO2011048385A2 - Improvements in or relating to packaging

Info

Publication number: WO2011048385A2
Application number: PCT/GB2010/001963
Authority: WO
Inventors: Rickey Dean; Anthony John Lukasiewicz; Hendrik Stoltz; James Hugg; Jeffrey Steven Dean; Steven Troy Wineman
Original assignee: Elopak Systems Ag; Burrows, Anthony, Gregory
Priority date: 2009-10-22
Filing date: 2010-10-22
Publication date: 2011-04-28
Also published as: EP2490947A2; WO2011048385A3

Abstract

A segregated nitrogen flush system (10) segregates a nitrogen flow arrangement (12) for providing a nitrogen flush, a chemical flow arrangement (16) and a steam flow arrangement (14) for sterilization of the segregated nitrogen flush system. Electronics are segregated from a flow of sanitizing steam or chemical that would harm electronics and other controls. A filter (18) upstream from a nitrogen delivery path (28) provides a resilient transition from nitrogen flow to higher pressure flow of sanitizing steam. Nitrogen flow is commanded through the nitrogen delivery path (28) to a nitrogen flush assembly (22) having a forward nozzle and plenum member for providing nitrogen flush to partially closed cartons. Guide rails are configured to converge to close the cartons increasingly as they index forward. During a second operating mode, sanitizing steam flows through at least the filter. During a third operating mode, sanitizing chemical flows through the chemical flow arrangement (16) to the nitrogen flush assembly (22).

Description

IMPROVEMENTS IN OR RELATING TO PACKAGING

This present invention relates to a segregated gaseous medium flush system, such as for a carton filling machine.

WO-A-98/38092 discloses an interface between at least one aseptic or pasteurized product supply vessel, an aseptic or pasteurized product dispensing machine, and a cleaning liquid supply vessel, which interface comprises: at least one product inlet adapted for connection to at least one product supply vessel to receive at least one supply of the product; at least one product dispensing machine outlet adapted for connection to at least one product dispensing machine; at least one cleaning liquid inlet adapted for connection to at least one cleaning liquid supply vessel for cleaning the interface; first and second cleaning liquid supply valves arranged in series between the cleaning liquid inlet and the product dispensing machine outlet to define a cleaning liquid buffer zone therebetween; and first and second product supply valves arranged in series between the product inlet and the product dispensing machine outlet to define a product buffer zone therebetween, each zone being selectively coupled by valves to a source of sanitizing fluid to create a barrier respectively between the product dispensing machine outlet and the cleaning liquid inlet, and the product dispensing machine outlet and the product inlet. There is at least one drain coupled to the product buffer zone by a drain line, and first and second spaced drain valves in series in the drain line defining an isolation space therebetween. There is further a steam inlet and a steam outlet adapted for communicating with the isolation space for providing a steam buffer between the first and second spaced drain valves.

In a known type of packaging machine, typically used in dairy, juice, and the like liquid consumer product packaging forming and filling machines, a nitrogen or carbon dioxide flush system provides nitrogen or carbon dioxide gas (hereafter "nitrogen" or "carbon dioxide") flush of packaging cartons. Generally, a control unit selectively commands the flow of nitrogen or carbon dioxide through a series of conduits and filters to at least one nozzle in fluid communication with a carton containing end product. Typically, the cartons are flushed with the nitrogen or carbon dioxide above the product surface in the headspace of the carton to remove the air substantially from the carton and replace it with nitrogen or carbon dioxide directly prior to sealing the carton. Nozzles are used to introduce the nitrogen or carbon dioxide generally by penetrating the nozzle into the container and expelling the desired predetermined volume of nitrogen or carbon dioxide. The carton is then indexed to a sealing or capping station for closure of the carton. More than one in-line filter is used to filter out airborne particles and other contaminants from the flush system.

A common problem with such flush systems is that undesirable airborne particulates, microbiological contaminants, water, condensation, and other contaminants present in the flush system are not efficiently and effectively purged from the system during the sterilization processes. Such contaminants can come in contact with the end product within the carton, resulting in a poor end product shelf life for retailers and consumers. In order to sanitize the flush system, pressurized steam and/or chemicals have been used in the past for sanitization . The steam sanitization must be provided at a desirable temperature and pressure for a set time throughout the system. Steam pressures throughout the system are required to be maintained at a predetermined level to evacuate or purge the system of contaminants properly, e.g., 20 psi or greater in order to clear the system of residual water. Conventional flush systems are not segregated and provide only one of either steam sterilization or chemical sterilization or do not provide an efficient pressurized steam and chemical sterilization arrangement. The flush control systems sterilized in these systems are sensitive to chemicals and also steam, therefore it has been a problem to sterilize these components properly. Thus, it is desirable to provide a sterilization system that does not cause damage to electronics and other controls. Conventional systems result in inefficient, improper, and time-consuming sanitization and, thus, a lack of a proper sanitization procedure in the field. For example, some conventional systems only provide steam sterilization, which can be time- consuming as steam must be maintained for a set time. As yet another example, some conventional systems only provide chemical sterilization, which results in an increased amount of chemical requiring special handling, mixing, and recapturing .

A common problem with conventional flush systems is that they require more than one filter, e.g., more than one High Efficiency Particulate Air filter (hereafter "HEPA filters"), in association with a plurality of conduits leading to the nozzles for dispensing nitrogen or carbon dioxide to the cartons, resulting in an undesirable number of filters, sanitization complexity, maintenance, and replacement concerns. Another common problem is the lapse in time between the flush and carton closing and sealing which can allow air to be reintroduced into the carton, resulting in a decreased end product shelf life and lack of product freshness. Another common problem with typical flush systems is the relatively low speed or throughput of the cartons in receiving the flush, in particular the low throughput capacity of a flush system having space constraints .

Another common problem with conventional systems is that microbiological contaminants, airborne particles, chemicals, condensation, and the like contaminants can be left in the flush system, e.g., the nozzles and filters, after conventional sterilization processes such that the flush system does not receive proper evacuation purging. Accordingly, there exists a need for an improved flush system and process that forces out the left-behind liquids and condensation so that the flush system can be substantially purged and sanitized.

Accordingly, there exists a need for an improved sanitization arrangement for a flush system and process that includes a nitrogen or carbon dioxide flow arrangement for providing single indexing dual carton flush and a steam and chemical flow arrangement for sterilization.

According to one aspect of the present invention, there is provided a segregated gaseous medium flush system, comprising :

at least one flush assembly for selectively flushing at least one open container with a flow of gaseous medium to displace air from said at least one open container and replace said air with gaseous medium from said flow of gaseous medium;

a gaseous medium flow arrangement having at least one delivery path in fluid communication with said at least one flush assembly for controlling said flow of gaseous medium to said at least one flush assembly;

a control assembly coupled to said at least one delivery path for regulating volume and pressure of said flow of gaseous medium to said at least one flush assembly; a steam flow arrangement having a steam valve for controlling the flow of sanitizing steam through at least a filter, said filter being in fluid communication with said at least one nitrogen delivery path for filtering out contaminants, wherein said flow of sanitizing steam is selectively applied at a predetermined pressure and temperature for a predetermined period of time for sanitizing at least said filter; and

a chemical flow arrangement in fluid communication with said at least one nitrogen flush assembly controlling a flow of sanitizing chemical to said at least one flush assembly, wherein said chemical flow arrangement is segregated from at least one of (a) said control assembly, (b) said filter, (c) said steam flow arrangement and (d) said at least one delivery path.

According to another aspect of the present invention, there is provided a process for sanitizing a segregated gaseous medium flush system, comprising supplying a gaseous medium through a filter, a gaseous medium flow control assembly and at least one delivery path to at least one flush assembly whereby at least one open container has air displaced therefrom and replaced by said gaseous medium, supplying steam through a steam flow arrangement to said filter and thereby sanitizing said filter, supplying sanitizing chemical to said at least one flush assembly so that the sanitizing chemical bypasses at least one of (a) said control assembly, (b) said filter, (c) said steam flow arrangement and (d) said at least one delivery path.

According to a further aspect of the present invention, there is provided a gaseous medium flush assembly for a container filling machine, comprising:

at least two guide rails which converge gradually toward one another to close at least two open containers increasingly as said at least two open containers index through between said at least two guide rails;

a plenum member coupled to a first supply conduit for receiving a flow of gaseous medium, said plenum member having an internal chamber, a central nozzle, and a plurality of corner nozzles spaced apart from one another, wherein said plenum member selectively flushes one of said at least two open containers, which is partially closed, to displace air from a headspace of that one container and replace said air with gaseous medium from said flow of gaseous medium; and

a forward nozzle coupled to a second supply conduit for receiving another flow of gaseous medium, said forward nozzle having a dispensing end with a profile effective for forcing nitrogen into a headspace of another of said at least two open containers which is substantially closed, to displace air from that headspace and replace said air with gaseous medium from said other flow of gaseous medium. Owing to the present invention, it is possible to improve the degree of flushing of air from containers, and to improve the sanitizing of the flushing system without significant risk of damage to more susceptible parts of the system.

The gaseous medium may be, for example, nitrogen or carbon dioxide, whilst the containers may be, for example, liquid packaging cartons.

The preferred embodiments to be described with reference to the accompanying drawings comprise a segregated nitrogen flush system having a nitrogen flow arrangement for providing a nitrogen flush as well as a chemical flow arrangement and steam flow arrangement for sterilization of the segregated nitrogen flush system. The nitrogen flush control components are segregated from sterilization that would harm the control components. The nitrogen flow arrangement is in fluid communication with a filter, e.g., HEPA filter, to filter out contaminants, e.g., airborne particulates, from the nitrogen flow delivered to the cartons. The nitrogen flow arrangement selectively advances the flow of nitrogen through the nitrogen flow arrangement including through the filter and at least one nitrogen flush assembly which has nozzles for dispensing nitrogen into the cartons. The nitrogen flow arrangement has a control assembly for selectively controlling and maintaining the flow of nitrogen, e.g., regulating, sensing, and commanding the amount or volume and pressure of nitrogen flow to the nozzles. The electronics are segregated from the flows of sanitizing steam and chemicals, e.g., segregated by enclosure within a housing associated with the control assembly, to prevent damage of the electronic components contained therein, e.g., to prevent shorting-out and the like damage to any electrical control unit, controller, nitrogen flush control components, and the like.

When the segregated nitrogen flush system is in a first operating mode, nitrogen flows through the nitrogen flow arrangement, including through the filter, and exits through the nozzles of the nitrogen flush assembly to flush air, e.g., at least partly comprising oxygen, from at least one carton and substantially replace it with nitrogen. The nitrogen flush assembly includes a manifold portion having a forward nozzle and a plenum member with a plurality of nozzles to provide nitrogen flush to at least one carton. Cartons can be indexed in a single indexing dual carton configuration to increase throughput capacity of the nitrogen flush within a relatively limited amount of space. The improved nitrogen flush assembly of the segregated nitrogen flush system aids in performing nitrogen flush at a higher rate of speed, e.g., at least two partially closed cartons simultaneously, to prevent the influx of air back into the carton and to provide a desired predetermined pitch quantity or throughput of cartons prior to sealing. In addition, the lapse in time is minimized between the nitrogen flush and carton sealing to help to prevent the reintroduction of air within the carton.

When the system is in a second operating mode, the flow of nitrogen is cut off and a sanitizing steam is commanded to flow through the steam flow arrangement, including through the filter, and exit through a drain to an atmosphere. The sanitizing steam can alternatively be commanded to flow through the filter to downstream of the filter and expelled through the nozzles of the nitrogen flush assembly. The filter is in fluid communication with the steam flow arrangement to provide selectively a sanitizing pressurized steam flow through the filter to sanitize the filter. The filter provides a resilient transition from the pressure of the nitrogen flow to the high pressure flow of the sanitizing steam.

The chemical flow arrangement is in fluid communication with the nitrogen flush assembly to provide selectively a flow of sanitizing chemicals to the nitrogen flush assembly. When the system is in a third operating mode, the advancing flow of nitrogen and sanitizing steam is commanded to stop and the sanitizing chemical flows through the chemical flow arrangement, through the nitrogen flush assembly, and out through the nozzles. A water rinse is applied to the chemically sanitized components. Upon the stop of the advancing sanitizing steam and chemical flow, pressurized nitrogen is applied at a high enough pounds per square inch (psi) to evacuate the segregated nitrogen flush system of condensation, water, and chemicals to ensure proper evacuation purging.

In order that the invention may be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings, wherein:

Figure 1 is a diagram of fluidic circuitry of a segregated nitrogen flush system;

Figure 2 is a top perspective view of one embodiment of a nitrogen flush assembly of the segregated nitrogen flush system;

Figure 3 is a vertical sectional view taken along the line X-X of Fig. 2; Figure 4 is a top plan view of guide rails of the nitrogen flush assembly of the segregated nitrogen flush system and two partially closed cartons;

Figure 5a is a top plan view of a partially closed carton having an opening for receiving a flow of nitrogen;

Figure 5b is a top plan view of a partially closed carton having an opening for receiving a flow of nitrogen;

Figure 6 is a top perspective view of another embodiment of the nitrogen flush assembly;

Figure 7 is a vertical sectional view taken along the line X ' -X ' of Fig. 6;

Figure 8 is a top perspective view of yet another embodiment of the nitrogen flush assembly; and

Figure 9 is a top perspective environmental view of the nitrogen flush assembly of Figure 6 with the guide rails.

Referring to Figure 1, the segregated nitrogen flush system 10 has a nitrogen flow arrangement, indicated generally at 12, a steam flow arrangement, indicated generally at 14, and a chemical flow arrangement, indicated generally at 16. The system 10 includes a filter 18 in fluid communication with the nitrogen flow arrangement 12 and steam flow arrangement 14. The filter 18, e.g., a HEPA filter or the like, is operable for filtering out airborne particle contaminants and the like from the nitrogen flow arrangement 12 to help prevent contaminants from coming into contact with the end product in the cartons during nitrogen flush and so resulting in poor end product shelf life and product freshness. The filter 18 is also capable of withstanding applied pressurized steam at a desirable temperature and pressure for a set time for sanitization of the filter. The nitrogen flow arrangement 12 has a conduit path, indicated generally at 20, e.g., a plurality of pipes, tubes, and the like operably in fluid communication with one another, selectively to transport and deliver a nitrogen flow to at least one nitrogen flush assembly, indicated generally as 22, during a first operating mode. A plurality of components are in fluid communication with one another along the conduit path 20, including the filter 18, a nitrogen control valve 24 for controlling the on/off flow of nitrogen, an intermediate conduit path 27, a -control assembly, indicated generally at 30, and at least one nitrogen flush assembly 22. The nitrogen flush assemblies 22 have a plurality of nozzles, depicted generally as 32 in Figure 1, in operable association with openings of the cartons for selectively flushing the cartons with nitrogen. At least one nitrogen delivery path 28 is operably coupled to and between the intermediate conduit path 27 and each nitrogen flush assembly 22, so that the assembly 22 can receive nitrogen flow from the path 28. Preferably, a plurality of nitrogen delivery paths 28 and a plurality of nitrogen flush assemblies 22 are used, e.g., four paths 28 as illustrated in Figure 1 coupled to four assemblies 22 respectively. Each assembly 22 has at least two nozzles 32 for delivering nitrogen to partially closed cartons to displace the air substantially and replace it with nitrogen.

Each nitrogen delivery path 28 is connectible with the control assembly 30, and is formed of tubes, pipes, and the like conduits having an operably coupled nitrogen regulator 36, a sensor 38, and a nitrogen path valve 40 to control and maintain the flush of nitrogen to the assembly 22. The regulator 36, e.g., a proportional regulator, is operable for maintaining a predetermined volume and pressure, e.g., about 3 psi (pounds per square inch) of nitrogen flow to the plurality of nozzles 32 for a predetermined period of time during a first operating mode. The sensor 38 comprising a flow meter is operable for measuring and commanding the volume and pressure of the nitrogen flow, e.g., about 20-30 litres per minute, about 80-90 litres per minute, and the like. The nitrogen path valve 40 functions as an on/off valve for selectively controlling the flow of nitrogen from the nitrogen delivery path 28 into the nitrogen flush assembly 22, e.g., only allowing the flow of nitrogen to enter the assembly 22 during the first operating mode. An electrical assembly, e.g., a programmable controller, electronic control unit, nitrogen flush control components, and the like, is located in operable association with the control assembly 30 and is enclosed, e.g., within an enclosure, casing or housing, to provide a substantially clean aseptic electronics environment and to segregate the electronics from the sanitizing steam and chemical flows to help prevent the ingress of steam and chemicals.

The nitrogen control valve 24 and nitrogen path valve 40 are illustrated as pneumatic valves; however, it is understood that alternatively electric, hydraulic, or manual valves can be used. At least one additional filter 26, e.g., a sub-micron filter for filtering microbiological contaminants, 0.02 micron filter, 0.003 micron filter, and the like, can be used and is coupled to the nitrogen flow arrangement 12 and can be located upstream from the filter 18.

When the segregated nitrogen flush system 10 is in the first operating mode, any sanitizing steam flow and sanitizing chemical flow is commanded to stop and the nitrogen control valve 24 is actuated to command the flow of nitrogen through the conduit path 20. At least one intermediate conduit path 27 is in fluid communication with the filter 18 and at least one nitrogen delivery path 28. The nitrogen flow passes through the filter 18 and the path 27 and is selectively distributed amongst the paths 28. The configuration of the nitrogen flow arrangement 12 allows nitrogen flowing through the single filter 18 to enter each nitrogen delivery path 28, thereby eliminating the need for more than one filter 18, e.g., HEPA filter and the like in^¬ line filter. The nitrogen flow passing through each path 28 enters the respective nitrogen flush assembly 22 where it is dispensed by the plurality of nozzles 32 for forcing nitrogen into the headspaces of partially and substantially closed cartons to displace substantially the air and replace it with nitrogen, e.g., the air amount is decreased to about 5% by volume and nitrogen amount is increased to about 95% by volume. This aids in increasing end product shelf life and freshness.

The steam flow arrangement 14 of the segregated nitrogen flush system 10 has a steam conduit path, indicated generally at 42, to transport and deliver a sanitizing steam flow during a second operating mode. The path 42 can be a plurality of operably connected pipes, tubes, and the like in fluid communication with one another. A plurality of components are in fluid communication along the path -42, including the filter 18, a steam isolation valve 34, and a first steam control valve 44 for controlling the on/off flow of steam advanced through the steam flow arrangement 14. A steam regulator 46 is associated with the first steam control valve 44 and is used to command the pressure values of the sanitizing steam advanced through the steam flow arrangement 14. The sanitizing steam flows through the steam conduit path 42, including through the filter 18, e.g., HEPA filter, for sanitization of the filter 18. The steam isolation valve 34 can, as shown, be in operable association with the nitrogen flow arrangement 12 as well as the steam flow arrangement 14 and selectively controls the on/off flow of sanitizing steam allowed to advance from the filter 18 to either the intermediate conduit path 27 or a drain conduit path 49. A drain valve 50 coupled to the drain conduit path 49 can be used to selectively control the opening/closing of a drain 48 for evacuating and purging the sanitizing steam through the drain 48 to an atmosphere.

When the segregated nitrogen flush system 10 is in the second operating mode, the nitrogen control valve 24 stops the flow of nitrogen and the first steam control valve 44 is actuated to command the flow of sanitizing steam to advance through the steam conduit path 42. The steam regulator 46 maintains the predetermined pressure and temperature values of the steam for a predetermined period of time allowed by the valve 44. The steam flow passes through the filter 18, thereby sanitizing the filter 18, and is commanded, e.g., by the steam isolation valve 34, to flow through the drain conduit path 49 to the drain 48 where the sanitizing steam escapes into the atmosphere. The steam isolation valve 34 alternatively commands the flow of sanitizing steam coming through the filter 18 to flow through the intermediate conduit path 27 to the nitrogen delivery paths 28 and through the nitrogen flush assemblies 22 where it is expelled or purged out of the plurality of nozzles 32 for sanitization of the nitrogen flush assemblies 22.

At least one thermocouple 52 is operably coupled to the outside of the filter 18 to measure the temperature of the filter 18 and/or a tube and the like directly associated with the filter 18. The thermocouple 52 is connected to a programmable controller to confirm that the desired predetermined temperature has been maintained for the predetermined period of time for sanitization. If the temperature drops below the predetermined amount, a cycle complete will not be commanded and the steam sanitization process starts over again.

At least one thermocouple 52 can also be operably coupled to the outside of at least one of the plurality of nozzles 32 to measure the temperature of the nozzle (s) 32 and/or tubes and the like components directly associated with the nozzle (s) 32 when the steam isolation valve 34 commands the flow of sanitizing steam to, advance through the nitrogen delivery paths 28 to the nitrogen flush assemblies 22. The thermocouple 52 is connected to a programmable controller to confirm that the desired predetermined temperature has been maintained for the predetermined period of time. If the temperature drops below the predetermined amount, a cycle complete will not be commanded and the steam sanitization process starts over again.

When the filter 18 is used in accordance with one of the preferred embodiments of the invention, a predetermined value of steam pressure, e.g., about 20 psi or greater, and temperature, e.g., about 200° to 275° Fahrenheit can be applied for a sustained predetermined period of time, e.g., about 10 to 15 minutes, without damaging the filter 18, thereby allowing the sterilization of the filter 18 to help prevent contaminants from being introduced into the cartons during nitrogen flushing. The filter 18 provides a resilient transition from the pressure of the nitrogen flow during the first operating mode to the high pressure flow of the sanitizing steam during the second operating mode.

The first steam control valve 44, the drain valve 50, and the steam isolation valve 34 are illustrated as pneumatic valves; however, it is understood that alternatively electric, hydraulic, or manual valves can be used. It is further understood that the nitrogen flush assemblies 22 can be sanitized by the flow of sanitizing steam, flow of sanitizing chemicals, and combinations thereof .

The chemical flow arrangement 16 of the segregated nitrogen flush system 10 has a chemical conduit path, indicated generally at 54, to transport and deliver a sanitizing chemical flow during a third operating mode. The path 54 can be a plurality of operably connected pipes, tubes, and the like in fluid communication with one another to provide a flow of one or more chemicals to the nitrogen flush assemblies 22. A plurality of components are in fluid communication along the chemical conduit path 54, including a chemical control valve 56 for controlling the on/off flow of chemical advanced through the chemical flow arrangement 16, at least one second chemical control valve 57, and at least one check valve 58 for directing the flow of the sanitizing chemical toward the nitrogen flush assemblies 22 to prevent the back-flow of chemical or water or the application of other fluid flow on the chemical control valve 56 and any other upstream components. The configuration of the chemical flow arrangement 16 segregates it from various items, including from the filter 18, the steam isolation valve 34, the intermediate conduit path 27, and the control assembly 30, while allowing a flow of chemical to the nitrogen flush assemblies 22. Thus, generally speaking, the chemical conduit path 54 is arranged to bypass at least the control assembly 30 and provide a flow of chemical to the nitrogen flush assemblies 22. The sanitizing chemical flow advances through the path 54 to each nitrogen flush assembly 22 and flows out through the plurality of nozzles 32. The second chemical control valves 57 function as on/off valves for selectively controlling the flow of chemical through the check valves 58 into the nitrogen flush assemblies 22, e.g., only allowing the flow of chemicals to enter the nitrogen flush assemblies 22 during the third operating mode.

When the segregated nitrogen flush system 10 is in the third operating mode, any sanitizing steam flow and flow of nitrogen is commanded to stop and the chemical control valve 56 is actuated to command the flow of sanitizing chemical to advance through the chemical conduit path 54. The chemical flow does not pass through the filter 18, or the intermediate conduit path 27, and so bypasses the control assembly 30. The second chemical control valves 57 are also actuated to control the on/off flow of chemicals to advance through the nitrogen flush assemblies 22. The chemical flow is applied to each nitrogen flush assembly 22 and is discharged and purged from the plurality of nozzles 32. After a predetermined amount of sanitizing chemical has flowed for a predetermined time, the chemical control valve 56 commands the chemical flow to stop and heated water or steam can be applied to rinse the chemically sanitized components to help prevent chemical from being introduced into the cartons during nitrogen flushing.

The chemical control valve 56 is illustrated as a pneumatic valve; however, it is understood that alternatively an electric, hydraulic, or manual valve can be used. It is further understood that the chemical can be oxonia and the like effective for sanitization .

To help avoid water, condensation, and chemical from not being purged out of the segregated nitrogen flush system 10 after the second and third operating modes, a high pressured blow-off can be performed. Pressurized or compressed nitrogen is applied at a high enough psi to evacuate the segregated nitrogen flush system 10 of condensation, water, and chemical to ensure proper evacuation purging, e.g., about 55 psi or greater is applied for a predetermined time substantially to clear the system of residual water. The pressurized nitrogen is selectively applied after the sanitizing steam, sanitizing chemical, or the heated water rinse cycle has stopped. Pressurized nitrogen is generally applied for at least about one minute or greater at a predetermined pressure of at least about 60 psi or greater. The pressurized nitrogen is preferably applied at a range from about 60 psi to about 80 psi for about one minute or greater.

Referring generally to Figures 2 to 5b, the nitrogen flush assembly, indicated generally as 22 in Figures 2 and 3, provides nitrogen flush of cartons in a single indexing dual carton system having relatively significant space constraints. The nitrogen flush assembly 22 has a manifold portion, indicated generally as 102, formed of an air shield 104 and a housing 106 connected to a cover plate 108, e.g., by welding. The air shield 104 is connected to the housing 106 and has at least two opposing first and second vertical walls 110 and 112 configured to help prevent moving air surrounding the manifold portion 102 from blowing into a nitrogen flush region, indicated generally at 114, or otherwise impacting the nitrogen flush of the cartons. The vertical walls 110 and 112 generally converge gradually toward one another with respect to a longitudinal axis of the nitrogen flush assembly 22, indicated as line A in Figure 2. The distance between the vertical walls 110 and 112 is great enough to allow at least the upper parts of the cartons to pass therebetween.

A plenum member, indicated generally as 116, is connected to the top of the cover plate 108. The plenum member 116 has a plurality of corner nozzles 122 that are spaced apart, a central nozzle 124, and a casing 118 with an internal chamber 120, depicted in Fig. 3. A first supply conduit 129 is connected to the top of the plenum member 116, is in fluid communication with the internal chamber 120 and is in fluid communication with and coupled to the nitrogen delivery path 28, shown in Figure 1, for selectively providing a nitrogen flow to the internal chamber 120 for dispersing to the nozzles 122 and 124 during the first operating mode. Opposing guide rails 126 of the nitrogen flush assembly 22, shown in Figures 4 and 9, receive and guide the cartons in a single-file fashion as the cartons are moved forward, e.g., indexed by a carton conveyor and the like. The manifold portion 102 is spaced above the open top of the at least one carton contained by the guide rails 126, e.g., 3 mm from the top of the carton (s)^', to optimize nitrogen flushing. The guide rails 126 maintain at least one carton at a time for nitrogen flush. In an alternative embodiment, a dual arrangement of such guide rails 126 maintains at least two cartons at a time in a single indexing dual carton conveying arrangement for nitrogen flushing the at least two cartons simultaneously .

The corner nozzles 122 are in fluid communication with the internal chamber 120 of the plenum member 116 and are configured to extend from the outer vertical wall of the casing 118 and generally downward through the cover plate 108. The nozzles 122 are spaced from one another about the circumference of the plenum member 116, e.g., there are four spaced nozzles 122 as depicted in Figure 2, at least two spaced corner nozzles 122, a spider-like configuration, and the like. The corner nozzles 122 preferably are spaced to direct a flow of nitrogen generally to the four corners of the carton headspace. The central nozzle 124 is also in fluid communication with the internal chamber 120 and is configured to extend through the bottom of the casing 118 and cover plate 108 to direct a flow of nitrogen generally to the centre of the carton headspace. The cover plate 108 has a plurality of apertures through which each of the nozzles 122 and 124 extend respectively to deliver nitrogen to the nitrogen flush region 114.

The first supply conduit 129 is in fluid communication with the internal chamber 120 and is connected off-centre on the plenum member 116. The off-centre location helps prevent a direct path of travel for the nitrogen supplied by the first supply conduit 129. This configuration results in the nitrogen moving about for mixing in the internal chamber 120 of the plenum member 116 to create a backpressure such that the nitrogen will flow through the nozzles 122 and 124 to the nitrogen flush region 114 at substantially equal velocity .

The nozzles 122 and 124 of the plenum member 116 are fixed in location with respect to the plenum member 116 and cover plate 108. It is understood that alternatively the nozzles 122 and 124 can be adjustable and removable for maintenance and repair.

Referring to Figure 2, each nitrogen flush assembly 22 has a forward nozzle, indicated generally as 128, having a second supply conduit 130 and a dispensing end 132 for supplying nitrogen flush to the carton. The second supply conduit 130 is in fluid communication with the corresponding nitrogen delivery path 28 for providing a nitrogen flow through the forward nozzle 128 to an open carton during the first operating mode. The forward nozzle 128 is operably spaced above the path of the open top of the at least one carton, e.g., by 3 mm. The profile of the dispensing end 132 is effective for delivering nitrogen through an opening in a carton, e.g., the dispensing end 132 can be tapered, knife-like shaped, and the like. The forward nozzle 128 is configured to allow clearance for cartons to pass below it and can be coupled to fixed supports or slidably contact a guide, e.g., a sloped brace, web, and the like, for stability. It is understood that the forward nozzle 128 can alternatively extend through a forward aperture, e.g. a slot, through the cover plate 108 of the manifold portion 102, which can also be extended in length.

The location of the forward nozzle 128 can be fixed. In an alternative embodiment, the nozzle 128 is a reciprocating diving nozzle that is angled and configured, e.g., tapered, knife-like shaped, and the like, such that the forward nozzle 128 moves generally vertically and the dispensing end 132 penetrates through an opening of the carton into the headspace and expels nitrogen within the headspace of the carton, the headspace being the open space within the carton above the end product. It is understood that, in that alternative embodiment, any forward aperture in the cover plate 108 is sized to help guide the forward nozzle 128, e.g., sized small enough to allow generally axial movement while preventing undesirable radial movement or slop. The dispensing end 132 can be configured with at least one side aperture e.g., a slot, to dispense nitrogen generally sideways to help disperse air from the headspace of the container and replace it with nitrogen.

It is understood that the nozzles 122 and 124, and the first and second supply conduits 129 and 130 can be formed of tubes, pipes, removable connections, and the like. By way of non-limiting example, they can be formed of semirigid plastics, stainless steel, and the like capable of withstanding corrosion, chemicals, and a predetermined temperature for a predetermined time.

Each nitrogen flush assembly 22 has a second air shield 136 configured to help prevent, in conjunction with the air shield 104, moving air surrounding the manifold portion 102 from blowing into the nitrogen flush region 114 or otherwise impacting the nitrogen flush of the cartons. The second air shield 136 is generally vertical and transverse to the first and second vertical walls 110 and 112 of the air shield 104. The second air shield 136 is disposed to extend generally vertically to shield at least one side of the plenum member 116 and extend generally downward to be at least partly adjacent to one end of the housing 106 substantially transverse to the longitudinal axis A of the nitrogen flush assembly 22. The longitudinal dimension of the second air shield 136 extends to at least the outside width of the manifold portion 102. It is understood that the second air shield 136 can be connected to the manifold portion 102 or be a separate piece. The second air shield 136 is omitted from Figure 3 for clarity.

Referring to Figures 2 to 4 in general, a wider gap 138 is located between the opposing guide rails 126 to receive indexing cartons between the guide rails 126. The guide rails 126 gradually converge toward one another with respect to the longitudinal axis A of the nitrogen flush assembly 22 and are configured to receive at least one carton at a time in single file. Figure 4 depicts the guide rails 126 contacting opposing sides of first and second cartons 1 and 2 near the top of the first and second cartons 1 and 2 toward the upward facing carton opening, indicated generally as 3 in Figure 4. The end product within the cartons 1 and 2, e.g., a liquid end product, is omitted from Figure 4 for clarity. This configuration causes the first and second cartons 1 and 2 to become increasingly closed as they index forward between the guide rails 126 in the direction of convergence of the guide rails 126. A roof 101 of the manifold portion 102 is spaced, e.g., about 3 mm, above the carton openings 3 of at least one of the first and second cartons 1 and 2 contained by the guide rails 126 to optimize nitrogen flushing of the first and second cartons 1 and 2. The first and second cartons 1 and 2 exit to a carton top sealing station immediately after nitrogen flushing by sequentially indexing forward through a narrower gap 139 between the guide rails 126 located at the opposite end of the guide rails 126 from the wider gap 138. Guide rail mounting members 127, shown in Figure 9, are used to fixed the guide rails in place.

During the first operating mode, the nitrogen control valve 24 commands the flow of nitrogen through the nitrogen flow arrangement 12, so that the nitrogen is flooded or dispersed into the nitrogen flush region 114 and the region of the dispensing end 132 for nitrogen flushing of the cartons. The cartons are indexed forward, e.g., two at a time, in single file to enter the nitrogen flush assembly 22 through the wider gap 138 of the guide rails 126. As the first and second cartons 1 and 2 are indexed forward, the first carton 1 passes by the first manifold portion 102 for distribution of nitrogen, i.e., passes the plenum member 116, is increasingly closed by the converging guide rails 126, and stops under the forward nozzle 128 to receive nitrogen flush distributed by the (fixed) forward nozzle 128. The forward nozzle 128 can alternatively move generally downward so that the dispensing end 132 penetrates the carton opening 3 of the first carton 1 into the headspace of the carton to allow the nitrogen to be forced into the headspace of the partially closed first carton 1. As the first and second cartons 1 and 2 are indexed forward, the second carton 2 is partially closed by the converging guide rails 126 as it indexes forward and stops generally under the corner nozzles 122 and the central nozzle 124 of the plenum member 116. The nitrogen flush of the second carton 2 is distributed by the plenum member 116. The corner nozzles 122 target nitrogen flush generally to four outer corners, indicated generally as 140 in Figure 5b, of the carton opening to the headspace 4, while the central nozzle 124 targets nitrogen flush generally to the centre, indicated generally as 142 in Figure 5b, of the carton opening to the headspace 4 inside the second carton 2. The cartons 1 and 2 thereby receive substantially simultaneous nitrogen flush, substantially to displace air from the headspaces 4 of the cartons and replace it with nitrogen before indexing to a top sealing station for sealing of the cartons shut, substantially to retain the nitrogen in the headspaces of the cartons and to help prevent the reintroduction of air.

Referring to Figures 5a and 5b, these show non-limiting examples of partially closed first and second openings 144 and 146 respectively. As illustrated, the first carton 1 is more closed than the second carton 2, since it has traveled further forward within the guide rails 126. Referring to Figure 5a, the first opening 144 of the first carton 1 can receive a flow of nitrogen from the dispensing end 132 of the forward nozzle 128 for nitrogen flushing the first carton 1. The dispensing end 132 can have a profile that matches part of the first opening 144 such that the dispensing end 132 can penetrate through the first opening 144 and deliver nitrogen, e.g., delivered sideways through slots near the dispensing end 132, to the headspace 4. While Figure 5a depicts a partially or substantially closed first opening 144, it is understood that the dimensions of the first opening 144 and the extent to which it is closed can be any size and configuration effective to receive nitrogen from the forward nozzle 128. Referring to Figure 5b, the second opening 146 of the second carton 2 can receive nitrogen flush of its headspace 4 from the plenum member 116. The corner nozzles 122 generally target nitrogen flush to the four corners 140 and the central nozzle 124 generally targets nitrogen flush to the centre 142 of the carton opening to the headspace 4.

The manifold portion 102 of the nitrogen flush assembly 22 has mounting bracket 148 for removably mounting the manifold portion 102. The mounting bracket 148 has an elongated aperture 150 configured to receive a co-operating mounting element, e.g., a raised cylindrical member, a screw and nut arrangement, and the like. The mounting bracket 148 allows the manifold portion 102, and the components connected to the manifold portion 102, to be selectively removed as a unit for cleaning, e.g., cleansing with chemicals before reinstalling the manifold portion 102. Removal of the manifold portion 102 can be done by hand for example without the use of tools, or done relatively expeditiously with minor tool manipulation. In addition, first and second connections 152 and 154, e.g., removable sanitary connections, are coupled to the first supply conduit 129 and second supply conduit 130, respectively, to allow the first supply conduit 129 and second supply conduit 130 to be removed from respective nitrogen flow conduits to allow remote cleaning of the manifold portion 102 and connected components. The configuration of the manifold portion 102 facing toward the cartons, in particular the roof 101 and two vertical walls 110 and 112, is hygienically configured for cleanability, in particular substantially devoid of sharp corners and angles adverse to cleansing. Once the manifold portion 102 is mounted back in place after cleaning with chemicals, the sanitizing steam is applied to rinse the chemically cleansed components to further sanitize the nitrogen flush assembly 22 and to help prevent chemicals from being introduced into the cartons during nitrogen flushing .

The internal chamber 120 of the plenum member 116 is sized and configured, e.g., generally small and cylindrical, and the like, to allow the sanitizing steam to travel through the internal chamber 120 without condensing, thereby allowing the plurality of corner nozzles 122 and central nozzle 124 to reach and remain at the desired predetermined temperature for the predetermined time. Also, the plenum member 116 and the first and second supply conduits 129 and 130 are capable of self-draining, e.g., draining substantially by gravity through the central nozzle 124 and the dispensing end 132 respectively. Thermocouples 52 can, in effect, be coupled to the nitrogen flush assembly 22, e.g., to the outsides of the first and second supply conduits 129 and 130, to measure the temperature directly associated with the plurality of corner nozzles 122, the central nozzle 124, and the forward nozzle 128 when the steam isolation valve 34 allows the flow of sanitizing steam to advance through the nitrogen delivery path 28 to the nitrogen flush assembly 22. The thermocouples 52 are connected to a programmable controller to confirm that the desired predetermined temperature has been maintained for the predetermined period of time. If the temperature drops below the predetermined level, a cycle complete will not be commanded and the steam sanitization process starts over again .

Referring to Figures 4, 6, 7 and 9 generally, in another embodiment, a nitrogen flush assembly, indicated generally as 200, provides nitrogen flush of cartons in a single indexing dual carton system having relatively severs space constraints. This alternative embodiment provides a more permanently mountable manifold portion 202, and components connected thereto, when removal for cleaning, e.g., chemical cleansing, is not desired. Removal of the manifold portion 202 requires the use of tools for example. In addition, the nitrogen flush assembly 200 can generally be larger than the nitrogen flush assembly 22, which receives a sanitizing steam.

The nitrogen flush assembly 200 can be cleaned by the sanitizing chemical flow during the third operating mode. The nitrogen flush assembly 200 has a manifold portion, indicated generally as 202, formed of an air shield 204 connected to a cover plate 208, e.g., by welding. It is understood that the cover plate 208 and air shield 204 are alternatively formed as a single piece. It is further understood that additional air shields can be employed, e.g., such as the second air shield 236 of Figure 9 which can be configured to help prevent moving air surrounding the manifold portion 202 from blowing into the nitrogen flush region 214 or otherwise impacting the nitrogen flush of the cartons. The air shield 204 has at least two opposed vertical walls 210 and 212 configured to help prevent moving air surrounding the manifold portion 202 from blowing into the nitrogen flush region 214, or otherwise impacting the nitrogen flush of the cartons. The vertical walls 210 and 212 generally converge gradually toward one another with respect to a longitudinal axis of the nitrogen flush assembly 200, indicated generally as line B in Figure 6. A plenum member, indicated generally as 216, is connected to the cover plate 208 and is formed as a two- piece plenum having a casing 218 connected to a second cover plate 219, e.g., by bolts and the like. The second cover plate 219 can be removable to provide access for inspection. The plenum member 216 has a central nozzle 224, a plurality of corner nozzles 222 that are spaced apart, e.g., four corner nozzles 222, and an internal chamber 220, depicted in Fig. 7. A first supply conduit 226 is in fluid communication with a nitrogen delivery path 28 and is connected to the top of the plenum member 216 for selectively providing a nitrogen flow to the internal chamber 220 for dispersing to the corner nozzles 222 and central nozzle 224 during the first operating mode. Opposing guide rails 126, shown in Figure 4, of the nitrogen flush assembly 200 receive and guide the cartons in a single-file fashion as the cartons are indexed forward. A roof 201 of the manifold portion 202 is spaced, e.g., by 3 mm, above the open top of the at least one carton contained by the guide rails 126 to optimize nitrogen flushing.

The corner nozzles 222 are in fluid communication with the internal chamber 220 of the plenum member 216 and extend through the casing 218 and apertures in the cover plate 208 to the nitrogen flush region 214. The corner nozzles 222 are spaced from one another on the bottom of the plenum member 216, e.g., four spaced apart corner nozzles 222 extend from the bottom of the internal chamber 220. The central nozzle 224 is also in fluid communication with the internal chamber 220 and is configured to extend from the internal chamber 220 through the bottom of the casing 218 and an aperture in the cover plate 208. The first supply conduit 226 is in fluid communication with the internal chamber 220 and is connected off-centre on the plenum member 216. The off-centre location helps prevent a direct path of travel for the nitrogen supplied by the conduit 226. This configuration results in the nitrogen mixing or moving about in the internal chamber 220 of the plenum member 216 to create a backpressure such that the nitrogen will flow through all of the nozzles 222 and the central nozzle 224 to the nitrogen flush region 214 at substantially equal velocity.

A forward nozzle, indicated generally as 228, having a second supply conduit 230 and a dispensing end 232, supplies nitrogen flush to the carton. The conduit 230 is in fluid communication with a nitrogen delivery path 28 for selectively providing a nitrogen flow through the forward nozzle 228 to the region of the opening of the carton during the first operating mode. The forward nozzle 228 is spaced above the open top of the at least one carton, e.g., by 3 mm. The profile of the dispensing end 232 is effective to deliver nitrogen through an opening in a carton, e.g., the dispensing end 232 can be tapered, knife-like shaped, and the like. The forward nozzle 228 is configured to allow clearance for cartons to pass below it and can be coupled to fixed supports or slidably contact a guide, e.g., a sloped brace, web, and the like, for stability. It is understood that the forward nozzle 228 can alternatively extend through a forward aperture, e.g. a slot, of the manifold portion 202, which can also be extended in length. It is understood that any forward aperture is sized to help guide the forward nozzle 228, e.g., sized small enough to allow generally axial movement while preventing undesirable radial movement or slop.

The location of the forward nozzle 228 can be generally fixed. The forward nozzle 228 can alternatively be a reciprocating diving nozzle that is angled and configured, e.g., knife-like shaped, so that the forward nozzle 228 moves generally vertically and the dispensing end 232 penetrates through an opening of the carton and expels nitrogen to within the headspace 4 of the carton. The dispensing end 232 can be configured with at least one side aperture, e.g. slot, to dispense nitrogen generally sideways to help disperse air from the headspace 4 of the container and replace it with nitrogen.

The manifold portion 202 has at least two fixed mounting members 248 for mounting the manifold portion 202 in place. The mounting members 248 each have an elongate aperture 250 configured to receive a complementary mounting element, e.g., nut-and-bolt and the like. The mounting members 248 allow the manifold portion 202, and the components connected to the manifold portion 202, to be relatively permanently fixed in place such that tools and the like are required to remove the manifold portion 202. Two or more mounting members 248 are affixed to generally opposite sides of the nitrogen flush assembly 200. In addition, suitably configured leg extensions 252 can be used for mounting the nitrogen flush assembly 200 in a desired location and orientation. The configuration of the manifold portion 202 facing toward the cartons, e.g., the roof 201 and two vertical walls 210 and 212, is hygienically configured for cleanability, e.g., substantially devoid of sharp corners and angles adverse to cleansing. For sterilization, a sanitizing chemical is applied through the chemical flow arrangement 16 to the nitrogen flush assembly 200 where it is expelled from the nozzles 222, 224 and 228.

The dimensions and shape of the internal chamber 220 of the plenum member 216 are suitably sized, e.g., the chamber 220 has a larger diameter than the internal chamber 120, to allow the sanitizing chemical to flow through the internal chamber 220 and out of the plurality of corner nozzles 222 and center nozzle 224. The plenum member 216 can be generally square-shaped and the like. The plenum member 216, first supply conduit 226, and second supply conduit 230 are also capable of self-draining, e.g., draining substantially by gravity through the fixed central nozzle 224 and dispensing end 232 respectively. Water, e.g., heated water, can be applied to the nitrogen flush assembly 200 after chemical sanitization to rinse the chemically sanitized components and to help prevent introduction of chemicals to the cartons during the first operating mode.

During the first operating mode, nitrogen is commanded to advance through the nitrogen flow arrangement 12, so that the nitrogen is flooded or dispersed into the nitrogen flush region 214 and the region of the dispensing end 232 for nitrogen flushing of the cartons. The cartons are indexed forward, e.g., two at a time, in single file to enter the nitrogen flush assembly 200 through the wider gap 138 of the guide rails 126, shown in Figure 4. As the first and second cartons 1 and 2 are indexed forward, the first carton 1 passes by the first manifold portion 202 for distribution of nitrogen, i.e., passes the plenum member 216, and stops under the forward nozzle 228 for receiving a flow of nitrogen. The second carton 2 stops generally under the plurality of corner nozzles 222 and the central nozzle 224 of the plenum member 216. The forward nozzle 228 can move generally downward and at least partly through the carton opening 3 of the first carton 1 to allow the nitrogen to be forced into the headspace 4 of the partially closed first carton 1. The nitrogen flush of the second carton 2 is distributed by the plenum member 216. The corner nozzles 222 generally target nitrogen flush to the four outer corners 140, shown in Figure 5b, of the carton opening to the headspace 4 while the central nozzle 224 generally targets nitrogen flush to the centre 142, shown in Figure 5b, of the carton opening to the headspace 4. The first and second cartons 1 and 2 thereby receive substantially simultaneous nitrogen flush, substantially to displace air from the headspaces 4 of the cartons and replace it with nitrogen immediately before indexing to a top sealing station for sealing of the cartons to retain the nitrogen substantially in the headspaces of the cartons and to help prevent the reintroduction of air.

Referring to Figure 8, in another embodiment a nitrogen flush assembly, indicated generally as 300, for providing nitrogen flush of cartons is shown having a manifold portion, shown generally at 302, with an air shield 304 forming a nitrogen flush region 306, and a vertical slot 308 formed in the air shield 304 for guiding a forward nozzle, shown generally at 310, that is a diving nozzle. The forward nozzle 310 has a second supply conduit and a dispensing end 312 for supplying nitrogen flush to the carton. The profile of the dispensing end 312 is operable for delivering nitrogen through an opening in a carton, e.g., the dispensing end 312 can be tapered, knife-like shaped, and the like, and can reciprocate into the headspace through a substantially closed opening of the carton. The forward nozzle 310 at least partly slidably extends through the vertical slot 308 and is coupled to a first mounting member 314 that is actuated to move the forward nozzle 310 generally vertically. By way of non-limiting example, at least one elongate vertical aperture 316 can be formed in a fixed plate 318 to receive slidably at least one pin 320 of the first mounting member 314. The aperture 316 and vertical slot 308 are angled such that, when the at least one pin 320 is moved up and down by an actuator, the at least one pin 320 is translated vertically by engagement with the aperture (s) 316 and the forward nozzle 310 is translated vertically by its engagement with the vertical slot 308. At least one second nozzle, shown generally at 322, is coupled to a second mounting member 324 to deliver nitrogen flush to a second carton and can be fixed or movable generally vertically within an aperture, e.g., a slot, in the second mounting member 324 and manifold portion 302. It is understood that, alternatively, a plenum member like that depicted in Figure 2 or 6 can be used.

Claims

1. A segregated gaseous medium flush system, comprising: at least one flush assembly for selectively flushing at least one open container with a flow of gaseous medium to displace air from said at least one open container and replace said air with gaseous medium from said flow of gaseous medium;

2. A system according to claim 1, and further comprising a steam isolation valve coupled to said steam flow arrangement for selectively commanding said flow of sanitizing steam from said filter through at least one drain conduit path, or through at least one intermediate conduit path to introduce said flow of sanitizing steam to said at least one delivery path .

3. A system according to claim 1 or 2, wherein said control assembly comprises at least one sensor for determining a pressure level and volume of said flow of gaseous medium to said at least one flush assembly and comparing said pressure level and volume with a predetermined pressure level and volume.

4. A system according to any preceding claim, wherein said control assembly comprises at least one gaseous medium regulator operable for maintaining and controlling said flow of gaseous medium to said at least one flush assembly at a predetermined pressure level and volume.

5. A system according to any preceding claim and further comprising an electrical assembly in association with said control assembly, wherein said electrical assembly is segregated from said flow of sanitizing steam and said flow of sanitizing chemical and is housed within an enclosure to prevent the ingress of steam and said chemical.

6. A system according to claim 2 or any one of claims 3 to 5 as appended to claim 2, wherein said flow of sanitizing steam introduced to said at least one delivery path is expelled through a plurality of nozzles of said at least one flush assembly.

7. A system according to any preceding claim, wherein said gaseous medium flow arrangement further comprises a gaseous medium control valve for controlling on-and-off flow of gaseous medium.

8. A system according to any preceding claim, wherein said chemical flow arrangement further comprises a chemical control valve for controlling on-and-off flow of sanitizing chemical .

9. A system according to any preceding claim, wherein the or each flush assembly comprises a plenum member having a plurality of corner nozzles and a central nozzle to provide gaseous medium flush of a container.

10. A system according to claim 9, wherein the or each flush assembly comprises a forward nozzle which, in association with said plenum member, provides gaseous medium flush of two containers indexed in single file fashion.

11. A system according to claim 10, wherein said forward nozzle is a diving nozzle.

12. A system according to claim 10 or 11, wherein said forward nozzle has a dispensing end with a profile suitable for forcing said gaseous medium into a substantially closed container .

13. A system according to any one of claims 9 to 12, wherein said plenum member has an internal chamber which is sized to permit said flow of sanitizing steam to travel, without condensing, through said internal chamber and out through said corner nozzles and said central nozzle.

14. A system according to any preceding claim, wherein said at least one flush assembly comprises guide rails which converge gradually towards one another to close said at least one open container increasingly as said at least one open container advances through between said guide rails.

15. A system according to any preceding claim, wherein the or each flush assembly further comprises a manifold portion which is dismountable for cleaning.

16. A process for sanitizing a segregated gaseous medium flush system, comprising supplying a gaseous medium through a filter, a gaseous medium flow control assembly and at least one delivery path to at least one flush assembly whereby at least one open container has air displaced therefrom and replaced by said gaseous medium, supplying steam through a steam flow arrangement to said filter and thereby sanitizing said filter, supplying sanitizing chemical to said at least one flush assembly so that the sanitizing chemical bypasses at least one of (a) said control assembly, (b) said filter, (c) said steam flow arrangement and (d) said at least one delivery path.

17. A process according to claim 16 and further comprising, following ceasing of said supplying of said gaseous medium, selectively either commencing causing said steam to flow through said filter at a predetermined temperature and pressure for a predetermined period of time to sanitize said filter, or commencing causing said sanitizing chemical to flow through said at least one flush assembly to sanitize said at least one flush assembly.

18. A gaseous medium flush assembly for a container filling machine, comprising:

a forward nozzle coupled to a second supply conduit for receiving another flow of gaseous medium, said forward nozzle having a dispensing end with a profile effective for forcing nitrogen into a headspace of another of said at least two open containers which is substantially closed, to displace air from that headspace and replace said air with gaseous medium from said other flow of gaseous medium;

19. An assembly according to claim 18, wherein said forward nozzle is a diving nozzle and said dispensing end is effective for penetrating the opening of the substantially closed, other container and dispersing said gaseous medium into said headspace.

20. An assembly according to claim 18 or 19 and further comprising at least one mounting bracket and manifold portion dismountable for cleaning as a unit.

21. An assembly according to any one of claims 18 to 20, wherein said corner nozzles are four in number and serve generally to direct said gaseous medium to flow into four corners of an opening of said one container.

22. An assembly according to any one of claims 18 to 21, wherein said first supply conduit is coupled off-centre to said plenum member to create backpressure to promote flow of said gaseous medium through said corner nozzles and central nozzle substantially equally.

23. An assembly according to any one of claims 18 to 22, wherein said internal chamber is sized to permit a flow of sanitizing steam to travel, without condensing, through said internal chamber and out through said corner nozzles and said central nozzle.