US3437422A - Sterilizer for containers - Google Patents

Description

April 8, 1969 e. A. GUCKEL 3,437,422

STERILIZER FOR CONTAINERS Filed April 19, 1965 Sheet of 4 INVENTOR.

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April 8, 1969 G. A. GUCKEL STERILIZER FOR CONTAINERS Sheet 3 M4 Filed April 19, 1965 R m w W L m U 5 w I H a 6 I 1 I I I I z I l 1 1 I 1 April 8, 1969 GUCKEL, 3,437,422

STERILIZER FOR CONTAINERS Filed April 19, 1965 FIG 4 INVENTOR. Gap/weer A. Gum :4

April 8, 1969 e. A. GUCKEL STERILIZER FOR CONTAINERS Sheet Filed April 19, 1965 INVENTOR. 652/4427- 14. Goa/(i4 irraeA/n United States Patent US. Cl. 21-80 17 Claims ABSTRACT OF THE DISCLOSURE A container sterilizer for aseptic canning has an enclosure housing about a tunnel structure through which containers are conveyed; the tunnel structure having a top closure wall and opposite side walls providing a heat confining passageway into which a sterilizing gas is introduced from an apertured conduit above the top closure wall. These tunnel structure walls are apertured for the flow of the gas into the tunnel structure, and the conveyer means is flat to provide a substantially closed bottom for the tunnel structure. The tunnel structure and enclosing housing hood are mounted for removal and replacement as a unit; and a plurality of sections of these units is provided. For conveying of the containers in a curved path the conveying means comprises a plurality of interconnected articulated plate sections. The aforementioned structure is mounted in an outer casing, the bottom closure of which includes resilient clamp members frictionally engaging the sides of the hood for providing a releasable connection.

This invention relates to the sterilization of containers and, more particularly, to an improved sterilizer for open mouth containers such as metal cans and the like. The improved sterilizer of this invention is especially useful in a sterile or aseptic packaging process in whcih containers and their covers are sterilized, the sterile containers filled with a sterile product, and the filled containers then covered and sealedall such operations being conducted under sterile or aseptic conditions.

As explained in Patent No. 2,771,645, entitled Apparatus for Sterilizing Food Containers, in an aseptic packaging process (which process usually involves rigid containers such as open mouth metal cans and is generally referred to as canning), steam or other gas is heated to an appropriate sterilizing temperature in excess of 212 F. and is then introduced into the packaging or canning apparatus to maintain sterile condition therein. Such apparatus need not be significantly pressurized, whereupon the sterile gaseous environment therein can approach atmospheric pressure, because the sterile gas introduced into the apparatus is itself effective to prevent the ingress of outside or ambient air and other gases thereinto because of it's permitted continuous escape (which is small because of the relatively low pressures) through any openings in the apparatus. The details of an aseptic canning process of the type being considered are set forth in the aforementioned patent as well as in Patent No. 2,685,520, among others.

As is well known, sterilization by heat is a function of time and temperature, and the relationship therebetween is generally logarithmic with temperature being dominant so that the time factor can be materially reduced as the temperature is elevated. Evidently, in commercial operations it is practicably necessary to have a high rate of production, and the attainment of this objective is apparently facilitated in an aseptic canning process by elevating the temperature of the sterilizing gas as much as possible since this should have the effect of reducing 'ice the time required to produce complete sterilization of the containers and covers therefor.

However, there are applicable temperature limitations due primarily to the characteristics of the containers employed (usually open mouth metal cans) which are comprised of materials that are sensitive to and deteriorate when heated to temperatures in the general order and in excess of 450 F. For example, in the canning of food products it is essential for product preservation that a hermetic seal be provided about the compartment in which the food product is contained. To facilitate this result, the seams and joints of the containers are usually equipped with a gasket material that is damaged by such temperatures. Also, it has been found that certain coating materials with which metal cans are covered (and the tin solder used for sealing the body seam thereof) are similarly afiected adversely by such high temperatures.

The seemingly incompatible factors of limitation on temperature and reduced residence time of the containers and their covers in the atmosphere of the sterilizing gas can be made compatible in a container sterilizer: if the sterilizing gas can be impinged directly into and about the containers, is then closely confined about the con tainers, and if turbulence can be created along the boundary layers of the container to increase the rate of heat transfer thereto. Accordingly, an object, among others, of the present invention is to provide an improved sterilizer for containers in which this result is attained.

Summarizing such improved sterilizer, it comprises a fiat-top conveyor adapted to seat containers thereon and transport the same through the sterilizer, a container-confining tunnel structure through which each container is transported and which in conjunction with such flat-top conveyor defines a restricted space about the containers for closely confining the sterilizing gaseous atmosphere in proximity therewith, and a distribution means for discharging the sterilizing gas into such tunnel for impingement into and against each container-the impingement of the sterilizing gas against the containers and the close confining of the gaseous atmosphere thereabout being effective to create turbulence in such atmosphere to facilitate the transfer of heat therefrom to the containers, and the moving flat-top conveyor effectively providing a bottom closure for the confined space through which the containers are transported.

An embodiment of the invention is illustrated in the accompanying drawings, in which:

FIGURE 1 is a diagrammatic top plan view of an aseptic food packaging or canning system embodying the invention;

FIGURE 2 is an enlarged, top plan view with the cover removed of one end portion of the container sterilizer;

FIGURE 3 is an enlarged, top plan view with the cover removed of the opposite end portion of the container sterilizer;

FIGURE 4 is a further enlarged, transverse sectional view taken along the line 44 of FIGURE 2;

FIGURE 5 is a transverse sectional view taken along the line 5-5 of FIGURE 7;

FIGURE 6 is a broken longitudinal sectional view taken along the line 6-6 of FIGURE 2;

FIGURE 7 is a broken longitudinal sectional view taken along the line 77 of FIGURE 2;

FIGURE 8 is a broken perspective view of a portion of the fiat-top conveyor; and

FIGURE 9 is a broken top plan view taken beneath the cover of the sterilizer as indicated by the line 99 in FIGURE 6.

The apparatus illustrated diagrammatically in FIGURE 1 constitutes an aseptic packaging or canning system in which containers (particularly open mouth metal cans) are sterilized, are then filled with a sterile product, and are thereafter closed with a sterile cover so that each container defines a hermetic enclosure about the sterile product. Such apparatus includes a container sterilizer having an infeed section 16 whereat empty containers are fed onto a conveyor for movement into and through the sterilizer 15. Sterilized containers are discharged from the sterilizer 15 through a housing 17 and into a filler 18 at which a sterile product (a food product, for example, such as milk) is introduced into the containers. A by-pass section 19 is arranged with the housing 17 and filler 18 so as to return to the infeed section 16 any excess containers or containers otherwise not admitted into the filler 18.

The filled containers are transported from the filler 18 through a sterile atmosphere defined by a covered conveyor 20 to closure apparatus 21 such as a can seamer. As each container is admitted into the closure apparatus 21, a sterile cover or lid is discharged in synchronism therewith from a cover sterilizer 22, each filled container and a cover therefor are then united in the closure apparatus 21 to hermetically seal the sterile product within the container, and the filled containers are then discharged through a conveyor section 23.

The entire apparatus including the container sterilizer 15, the cover sterilizer 22, the housing 17 and conveyor 20, the filler 18, and the closure apparatus 21 has a sterile atmosphere maintained throughout. In order to maintain such sterile atmosphere, a gaseous fluid such as steam, superheated to a temperature of about 500 F. at approximately atmospheric pressure, is continuously directed into the apparatus at appropriate locations. In the system illustrated, a heater unit 24 which, for example, may be of the gas burner type as indicated by the burne mechanism 25, has water delivered thereto through an infeed conduit 26. The water is converted into superheated steam within the heater unit 24 and is delivered to such locations along the apparatus by means of a discharge conduit 27.

In the apparatus shown, the sterile atmosphere within the filler 18 is provided by sterilizing air pumped through the heater 24 by a suitable blower or fan and conveyed to the filler by a manifold 28 (which is broken off in FIGURE 1 for purposes of simplifying the drawing and to permit a clear illustration of components of the system otherwise concealed by the manifold). With respect to the present invention, the container sterilizer 15, filler 18, closure apparatus 21, heater unit 24, and the respectively associated and intervening components all may be completely conventional.

The container sterilizer 15 includes an elongated, generally rectangular enclosure in the form of a casing or housing 29 having longitudinally extending side walls 30 and 31 and end walls 32 and 33 connected therewith. Such walls may be appropriately insulated, as illustrated best in FIGURES 4 and 6, and a removable cover or top wall 34 may cooperate with the side and end walls to define a substantially closed space or enclosure generally denoted 35. To effect such removability of the cover or top wall 34, the side and end walls may be provided with a plurality of upwardly extending studs 36 adapted to respectively pass through apertures provided therefor in the perimetric marginal edge portion 37 of such cover, and conventional nuts 38 threadedly engaging the studs may be used to tighten the cover in place.

The bottom of the enclosure is formed in part by a plurality of longitudinally disposed friction plates or spring clamps that extend generally intermediate the end walls 32 and 33 in transversely spaced parallel relation. Such elements are indicated most clearly in FIGURE 4, and those illustrated therein are respectively denoted with the numerals 39a, 39b and 39c. The elements 39 are substantially identical except that the element 39a, and its -counterpart (not shown) which will be disposed along the side wall 31, is essentially one-half the width of the elements 3% and 390 since it is required to cooperate with only one branch or leg of the conveyor system (de scribed in detail hereinafter) that transports containers through the sterilizer 15.

Each of the spring clamps 39 is provided with a generally flat bottom wall 40 riveted or otherwise fixedly secured in spaced locations therealong to a plurality of transversely extending and longitudinally spaced support channels 41. Formed integrally with the bottom wall 40 and extending upwardly therefrom are a pair of spring walls 42 and 43 (there being only one in the case of the element 39a) which are turned inwardly at their upper extremities and are adapted to frictionally engage the respective lower end portions 44 of an inverted, generally U-shaped hood 45 of generally rectangular cross-section, as shown in FIGURE 4. Such lower end portions 44 are turned upwardly upon themselves to reinforce and thereby strengthen the hood thereat.

It is evident from the drawings that a plurality of hoods and respectively associated conveyor legs are provided by the sterilizer 15 within the enclosure 35 and, for purposes of differentiation, such hoods are respectively designated 45a, 45b, 45c and 45d (there being four in the structure specifically illustrated).

The bottom of each hood 45 would be open except for the provision thereat of support blocks 46 and 47 which are fixedly secured to the respectively associated side walls of the hood by cap screws or other suitable means. The support blocks 46 are substantially coextensive in length with their associated hoods 45 and are adapted to respectively seat upon a pair of rails 48 and 49, formed by L-shaped channels, which define a track, the function of which will be described hereinafter. The rails 48 and 49 are supported at spaced intervals therealong by rigid brackets 50 and 51 that, in turn, are secured to and supported by an adjacent channel 41. Accordingly, the bottom wall of the enclosure 35 is also formed in part by the rails 48 and 49 as well as by the spring fasteners 39.

The bottom of the enclosure 35 is further formed by an endless, flat-topped conveyor generally designated with the numeral 52. As shown best in FIGURE 8, the conveyor 52 comprises a plurality of articulated, crescentshaped plates 53 which provide an upper carrying surface of substantially equal width whether the conveyor is moving in a straight line or in an 'arcuate or otherwise irregular path. Each plate 53 is riveted or otherwise fixedly secured to the upper component of a pair of chain links 54, such upper component of which is denoted 55 and the corresponding lower component of which is denoted 56.

The components 55 and 56 are spaced apart quite widely at their point of connection with the plate 53, and are provided thereat with a pin 57 that rotatably receives a roller 58 thereon which is interposed between the elements 55 and 56. The elements 55 and 56 converge from such wide spacing thereof toward a reduced spacing sufficient to receive a roller 58 therebetween which enables such end portions and roller 58 to be interposed between the more widely spaced end portions of another chain link 54 and to be pivotally mounted upon the pin 57 thereof. Thus, the conveyor 52 comprises a plurality of articulated sections, each of which includes a fiat plate 53, a chain link 54 having an upper component 55 to which the plate is fixedly secured and a lower component 56, a pin 57 extending between the components 55 and 56, and a roller 58.

The plates 53 of the conveyor are sufficiently wide to overlie the rails 48 and 49 which are effective to slidably support such plates thereupon. Thus, the conveyor itself, and in particular the articulated plates 53 thereof, forms a part of the lower wall component of the closure 35. It may be noted that the plates 53 provide a substantial surface area in slidable engagement with the tracks 48 and 49 and, as a result, a relatively good fluid flow restriction is defined therebetween. Further, the supports 46 and 47 are respectively provided along the inner end portions thereof with downwardly turned edges or lips 59 and 60 which substantially abut the upper surface of the plates 53. Therefore, although each hood 45 is not intended to be fluid tight, especially along the bottom thereof, the cooperative interrelation of the supports 46 and 47, the rails 48 and 49, and the plates 53 of the conveyor 52 is effective to significantly restrict the escape of sterilizing gas outwardly from each hood 45 through the bottom thereof.

Mounted within the interior of each hood 45 and extending longitudinally therealong is a distribution conduit oriented medially with respect to the hood and support in underlying relation with the top wall thereof by a plurality of longitudinally spaced, U-shaped hangers 61. A distribution conduit is disposed within each of the hoods 45 and, for purposes of identification, such distribution conduits are respectively denoted with the numerals 62a through 62d. Each conduit 62 is provided with a plurality of openings 63 along the underside thereof that permits the escape of sterilizing gas into the interior 64 of the associated hood 45. The conduits may be capped or otherwise closed at the ends thereof adjacent the wall 32 of the sterilizer, and they may be connected at one or more locations therealong to a supply conduit 65 which, as shown in FIGURE 1, is coupled to the main discharge conduit 27 through a branch conduit 66. In the sterilizer illustrated in FIGURE 2, the various distribution conduits 62 are respectively connected to the supply conduit 65 at two longitudinally spaced locations by manifold conduits 67 and 68.

It is evident in FIGURE 2 that each of the hoods 45 is transversely segmented and is thereby divided into a plurality of separate longitudinally extending hood sections. In the structure shown, the division between the successive sections of each hood occurs along the manifold conduits 67 and 68; and this arrangement permits ready access to the conveyor 52 because each or any one section of a hood 45 can be bodily lifted from the enclosure 35 simply by disconnecting the associated distribution conduit 62, whereupon the hood 45 and all of the components carried thereby are free to be lifted from the frictional grip of the resilient clamps 39 or spring walls 42 and 43 thereof.

By referring to FIGURE 7 in particular, it will be seen that each distribution conduit 62 is segmented to form sections approximately corresponding in length to the respectively associated hood sections. In order to facilitate quick and easy connection and release of such conduit sections, each of the manifold conduits 67 and 68 (and referring for description particularly to the conduit 67 as shown in FIGURE 7) communicates with a connector 69 which is swaged outwardly at the ends thereof, as shown at 70 and 71. The respectively adjacent ends of the distribution conduit sections are similarly swaged and are adapted to be wedged into sealing engagement (a gasket may be interposed therebetween) by a quick connector 72 in the form of a split collar that may be clamped together by fasteners 73, as shown in FIGURE 5. The connector 72 has a V-shaped channel therewithin which engages the end portions of the conduit section 62 and connector 69 to urge the same toward each other as the two sections of the connector are tightened thereabout.

Each of the sections of the respective hoods 45a through 45d is equipped adjacent the ends thereof with hookshaped hand-holds 74 which permit each such section to be conveniently grasped and elevated from the frictional grip of the spring walls 42 and 43 after the associated conduit section 62 has been released from the adjacent connector 69. Quite evidently, when a hood 45 is removed from the enclosure 35, the supports 46 and 47 are necessarily removed with the hood, whereupon the conveyor 52 and tracks 48 and 49 are completely exposed. Thus, should a jam-up or other malfunction occur along the conveyor, it can be quickly and easily cleared by removing the appropriate section of the hood 45 to provide access to the conveyor.

As shown most clearly in FIGURE 5, each hood section 45 is equipped at the ends thereof with a transverse wall 75 that provides partial end closures for the associated space 64. Each transverse end wall 75 has an opening 76 therein sufficiently large to enable containers 77 to be advanced thereth-rough by the conveyor 52. Corresponding generally to the configuration of the opening 76 is a tunnel continuation 78 extending between respectively adjacent hood sections; and since there are a plurality of such extensions, the sufiixes a through d are appropriately applied to the numeral 78 to differentiate between the various tunnel extensions and respectively associate the same with the hoods 45a through 45d. Accordingly, and considering the sections of the hood 45a, for example, there is a tunnel section 78a disposed beneath the connector 69 coupling the two distribution conduits 62a to the manifold 67 and, similarly, there is a tunnel continuation extending between the adjacent sections of the hoods 45a associated with the manifold conduit 68.

As seen in FIGURE 5, the tunnel continuation 78a has spaced apart, substantially parallel side walls 79 and 80 which are turned laterally adjacent their lower ends and then downwardly and are finally turned upwardly upon themselves as shown at 81 and 82 for respective engagement with the resilient walls 42 and 43 of the associated clamp elements 39. The laterally turned sections of the side walls 79 and 80 are respectively provided with spacers 83 and 84 along the undersides thereof which seat upon the rails 48 and 49 to support the tunnel continuation thereupon.

A longitudinally extending top wall or cover 85 seats upon the upper longitudinal edges of the side walls 79 and 80 and is provided with downwardly turned lips along the marginal edge portions thereof which extend along the upper edges of such side walls. The cover is readily removed to provide access to the interior of the tunnel continuation, and the entire tunnel continuation can be removed from the enclosure 35 by displacing the continuation upwardly to withdraw it from the frictional grip of the resilient walls 42 and 43, as in the manner of the various sections of the hoods 45. The particular manifold conduit 67 or 68, is readily removed to facilitate access to an underlying tunnel continuation by releasing the quick connectors 72 to separate the various connectors 69 from the respectively associated distribution conduits 62.

Mounted within the interior of each hood section is a tunnel 86 (letter sutnxes being added where appropriate to respectively associate the tunnels with the corresponding hoods 45). Each tunnel 86 has upwardly extending side walls 87 and 88 that are turned inwardly and then upwardly to provide a tunnel portion of reduced transverse dimension, as shown at 89, which closely approximates the outer diameter of the open mouth of a container 77. At the upper ends thereof, the side walls come together to form a cover or top closure wall 90. Adjacent their lower ends, the side walls 87 and 88 are respectively turned laterally to seat upon the aforementioned support blocks 46 and 47 to which they are riveted or otherwise fixedly secured.

The side walls 87 and 88 and top wall 90 of each tunnel are provided with a plurality of apertures 91 through which sterilizing fluid discharged from the distribution conduit 62 into the compartment 64 of the associated hood 45 enters the enclosures 92 defined within the tunnel to impinge upon the outer surface of each container 77 therewithin, and also to enter the interior of each such container through the open upper mouth thereof. Clearly, since the tunnel '86 is carried by the supports 46 and 47, it is necessarily removed with the associated 7 hood 45 whenever the hood is removed from the enclosure 35.

FIGURES 1 through 3 make it clear that the conveyor 52 is endless and travels completely through the sterilizer traversing a plurality of turns therewithin to define a plurality of substantially parallel legs or branches respectively corresponding to the hoods 45a through 45d. At its outermost extremity, the conveyor is entrained about a sprocket 93, and within the sterilizer the conveyor engages a plurality of sprockets respectively denoted, in the order of their progression through the sterilizer, with the numbers 94, 95, 96, 97 and 98. The conveyor in following the sprockets 93 through 96, inclusive, traverses in each instance an arcuate path of 180 to reverse its direction of movement. The sprockets 97 and 98 are used to displace the location of the conveyor to align the same with the sprocket 93 and entrance to the product filler 18.

At least one of the sprockets is rotatably driven so as to power the conveyor 52, and in the apparatus shown, the sprocket 96 is taken to be the drive element. In the usual manner, the drive sprocket 96 is provided with a plurality of teeth adapted to engage the various rollers 58 of the conveyor chain; and the sprocket is keyed or otherwise pinned to a shaft 99 which is supported for rotation in bearing structure 100 carried by a plate 101 bolted or otherwise rigidly secured to certain of the transverse channels 41. Below the plate 101 and bearing structure 100, the shaft 99 is equipped with an input sprocket 102 that is connected by a chain (not shown) to an appropriate prime mover as, for example, an electric motor. Such motor may run continuously whenever the apparatus is in operation, whereupon the conveyor 52 will serve to advance containers 77 from the container infeed section 16, completely through the sterilizer 15, through the housing 17, and into the product filler 18.

The containers 77 are fed to the conveyor 52 at the infeed section 16 in any convenient manner as, for example, by hand, by gravity along an infeed chute, or by a separate infeed conveyor. In any event, each container is positioned along the flat plates 53 of the conveyor, and suflicient friction exists between the upper surface of the plates 53 and the coextensive surface of the container bottom that each container is advanced without the provision of positive lugs, pusher fingers, or the like. Ordinarily, and assuming a condition in which containers are continuously fed onto the conveyor 52 with very little, if any, spacing between adjacent containers (the case illustrated in FIGURE 3, for example), the containers ultimately will be disposed in successive contiguous relation as they exit from the sterilizer 15 into the housing 17. This condition is also illustrated in FIGURE 3.

Disposed along the housing section 17 intermediate the discharge from the sterilizer 15 and entrance into the filler 18 is a container spacer apparatus, generally denoted with the numeral 103, operative to provide a fixed spacing between adjacent containers 77 appropriate for timing the movement thereof with the rate at which containers can be accepted by the filler apparatus 18. The spacer apparatus 103 may be conventional and, in the usual instance, takes the form of an interrupter or stopmeans to retard movement of the containers at its entrance (which causes the back-up and aforementioned successive juxtaposition of the containers, as shown in FIG- URE 3). The containers are then released and advanced in a manner to provide the requisite spacing therebetween and rate of movement thereon to satisfy the requirements of the filler 18, as indicated in FIGURE 3 by the containers in engagement with the star wheel 104 defining the entrance to the filler.

The sprocket wheels 94, 95 and 96 are respectively disposed at the end portions of successively adjacent pairs of hoods 45 and cause the conveyor 52 in each instance to traverse a 180 path to effect movement thereof in opposite directions through the successive hoods. For example, the sprocket 94 is disposed at the ends of the adjacent hoods 45d and 45c and causes the conveyor 52 to reverse its direction of movement which is right to left (as viewed in FIGURE 2) through the hood 45d and left to right through the hood 456. Accordingly, the containers 77 necessarily traverse a 180 arcuate path at such locations since they are carried by the conveyor 52 upon the top plates 53 thereof; and guide structure is provided along each such arcuate path to constrain the containers therewithin.

Referring to FIGURE 6 in particular, such guide structure includes a pair of supports 105 and 106 which may be integrally formed, as shown. The support 105 has an inverted U-shaped configuration and straddles the entire arcuate path established by the conveyor at the sprocket 96. This support is bolted or otherwise secured to the aforementioned plate 101. The support 106 has an L-shaped configuration with one leg thereof being formed integrally with the support 105 at the center thereof, and its other leg extending downwardly and being affixed at the terminal end thereof to the plate 101. Secured to the supports 105 and 106 are a pair of spaced apart guides 107 and 108-the first of which is an inner guide that is connected with the supports by one or more brackets 109; and the second of which is an outer guide that is connected with supports as by means of bolt and spacer units 110. The distance between the inner and outer guides 107 and 108 is just sufficient to enable containers 77 to be advanced therethrough; and the path defined between the guides 107 and 108 is arcuate and conforms to the 180 arc defined by the conveyor 52.

As shown best in FIGURE 9, the guides 107 and 108 terminate short of the end wall 75 of each adjacent hood 45, and the ends of the guides are restricted slightly in cross-section to form channels or recesses 111 and 112 thereat. Located within the respective recesses 111 and 112 are guide extensions 113 and 114 fixedly secured to the associated end wall 75 of the adjacent hood. This arrangement enables the length of the guides to be selectively varied since the guides 107 and 108 are freely movable with respect to the extensions 113 and 114 in both longitudinal and vertical directions. This arrangement is advantageous in that first, it facilitates removal of the hoods 45 without disturbing the guides 107 and 108 and second, it enables the sprocket to be shifted bodily to appropriately tension the conveyor 52. In this latter respect, it may be noted that the plate 101 effectively carries the sprockets 94 and 96 and it is divided centrally into two sections respectively associated with the sprockets 94 and 96. Each section, as shown in FIGURE '6, is supported on a plurality of the aforementioned channels 41 and can be adjustably located with respect thereto in the longitudinal direction within the dimensional limits defined by elongated slots 115 formed within each plate section and which respectively pass mounting bolts 116 therethrough which are used to fixedly anchor the plates in any position of adjustment thereof.

The sterilizer 15 is enclosed about and beneath the channels 41 by side covers 117 and by a bottom wall 118 (FIGURE 4). The bottom wall 118 may :be inclined, as shown, to enable any condensation that may form therealong to drain toward a sump through which such condensaltion can escape through one or more discharge openings 1 9.

In operation of the apparatus, empty containers (usually open mouth metal cans) are delivered to the sterilizer 15 at the infeed section 16 and are supported upon the conveyor 52 which transports the container through the sterilizer and finally delivers the sterile container at the infeed to the filler 18. The containers are randomly disposed along the conveyor 52, and since positive pusher elements are not required to assure advancement of the containers, there is no particular spacing or disposition enforced thereon. However, a positive spacing of predetermined amount is enforced on the containers after they leave the sterilizer 15 in order to time the advancement of the containers with the requirements of the filler 18.

The conveyor 52 comprises a plurality of articulated plates 53 which enable the conveyor to traverse rather confined arcuate paths with the result that the conveyor can make several continuous passes through the sterilizer 15, and in the structure illustrated, four such passes are provided. This substantially increases the capacity of the sterilizer without significantly increasing the overall dimensions thereof and, at the same time, permits a rather long-duration residence time for each container within the sterilizer. Such increased residence time assures thorough and complete sterilization of each container without causing the containers to approach temperatures which could damage the same.

The sterilizing gas, usually superheated steam, is distributed rather uniformly throughout the entire sterilizer within the various hoods 45 from which the sterilizing gas is accelerated toward the containers through the restricted openings or apertures 91 provided in the tunnel structures 86 respectively located within the hoods. The distribution of the apertures 91 causes the sterilizing gas to impinge onto and be directed toward key areas of the containers, and the tunnel components also confine the sterilizing gas closely about the containers. Accordingly, the configuration of each tunnel, which is somewhat bottle-shaped in cross-section, causes the containers to be rather accurately oriented in a transverse sense upon the conveyor 52 and, therefore, with respect to the apertures 91. The restriction of the tunnel that so guides the containers is adjacent the outwardly flared lip defining the open upper ends thereof which, therefore, restricts the amount of contact of each container with the tunnel and thereby minimizes the frictional resistance to movement developed therebetween.

The compartment or space 92 formed within each tunnel is a generally closed space in the sense that the flat top of the conveyor 52, as formed by the plates 53 thereof, extends across the bottom of the tunnel and is effective to close the same since the plates 53 along their underside slidably ride on the rails 48 and 49, and along the upper surface are in substantial abutment with the depending lips 59 and 60 provided by the support elements 46 and 47 upon which the tunnel structure is mounted. Evidently, then, the conveyor 52 is not only effective to transport each container through the sterilizer, but it also defines a bottom closure for each tunnel 86 and, as noted before, is of such character that multiple passes can be made through the sterilizer without significantly increasing the overall size thereof.

Access to the interior 35 of the sterilizer 15 is afforded simply by removing the cover or top wall 34 thereof, and access to any particular section of the conveyor is readily available simply by lifting any given hood section 45 upwardly after first disconnecting the distribution conduit 62 therewithin from the adjacent coupling 69 by means of the associated quick connector 72. Such removal of a hood section also removes the tunnel 86 mounted therewithin, whereupon the underlying conveyor 52 and rails 48 and 49 are completely exposed. Yet, when the hood section is in position, it is cooperatively engaged by the resilient walls 42 or 43 of the associated clamps 39 to substantially close off the bottom of the sterilizer enclosure 35.

As noted before, the fiat-topped conveyor also forms a part of the bottom closure for the apparatus; and in this respect, it materially contributes to the attainment of high speed operations (in excess of 400 containers per minute, for example) in that not only does it form a part of the bottom of the sterilizer enclosure 35, but it also directly forms a bottom closure for each tunnel 86 so that the sterilizing gas is closely confined about the containers 77 therewithin and thus speeds up the heat transfer operation from the sterilizing gas to the containers. Thus, the escape of sterilizing gas from the sterilizer is restricted, but the escape of a sufficient quantity is permitted, especially at the entrance and exit, to prevent the ingress of ambient air or other gases and thereby maintain an aseptic environment within the sterilizer.

While in the foregoing specification an embodiment of the invention has been illustrated and described in considerable detail for purposes of making a complete disclosure thereof, it will be apparent to those skilled in the art that numerous changes may be made in such details without departing from the spirit and principles of the invention.

What is claimed is:

1. In apparatus in 'which sterilized open mouth containers are filled with a sterile product under sterile conditions in a filling mechanism and sterile covers are thereafter applied to the product-filled containers, a container sterilizer comprising an enclosure housing having a curved path about which containers are to be conveyed, container conveying means within said housing for supporting container in upright position and including a plurality of interconnected plate sections for traversing such path with containers thereon, a tunnel structure Within said housing and extending along said path and having a top closure wall and opposite side walls providing a heat-confining passageway through which the containers are transported by said conveying means, said plate sections of said conveying means providing a bottom closure for said tunnel structure, and means for introducing a sterilizing gas into said housing, said tunnel structure being apertured to enable gas to flow into said heat-confining passageway.

2. The apparatus of claim 1 in which the sterilizing gas introducing means includes an apertured conduit within the housing and above said top closure wall, and certain of said apertures are provided in said top closure wall so that gas can flow into the interiors of such containers and other of said apertures are provided in said side walls so that gas can impinge against the outer sides of such containers.

3. The apparatu of claim 1 in which said side walls of the tunnel structure are offset inwardly toward each other adjacent the upper ends thereof to provide a spacing therebetween closely corresponding to the outer diameter of such open mouth containers so as to guide the same along such curved path at a relatively fixed transverse disposition with respect thereto.

4. In apparatus in which sterilized open mouth containers are filled with a sterile product under sterile conditions in a filling mechanism and sterile covers are thereafter applied to the product-filled containers, a container sterilizer comprising an enclosure housing having an entrance for the admission of containers thereinto and an exit for their discharge therefrom, a container conveying means within said housing for transporting containers in a substantially upright position between said entrance and exit, a tunnel structure within said housing and extending along said path and having a top closure wall and opposite side walls providing a heat-confining passageway through which the containers are transported by said conveying means, and means for introducing a sterilizing gas into said heat-confining passageway about said tunnel structure, said tunnel structure having apertures in its top and side walls for introduction of said sterilizing gas into said tunnel structure, and said conveying means including a flat-topped conveyor extending across said tunnel structure adjacent the bottom thereof and being located in close proximity to the lower edges thereof to provide a bottom closure wall for said heatconfining passageway.

5. The apparatus of claim 4 in which said side walls of the tunnel structure are offset inwardly toward each other adjacent the upper ends thereof to provide a spacing therebetween closely corresponding to the outer di- 11 ameter of such open mouth containers so as to guide the containers at a relatively fixed disposition with respect to said apertures.

6. In apparatus in which sterilized open mouth containers are filled with a sterile product under sterile conditions in a filling mechanism and sterile covers are thereafter applied to the product-filled containers, a container sterilizer comprising an enclosure housing having a curved path about which containers are to be conveyed, container conveying means within said housing for supporting containers in upright position and including a plurality of interconnecting articulated fiat sections for traversing such path with containers thereon, a tunnel structure within said housing and extending along said path and having top and opposite side walls providing a heat-confining passageway through which the containers are transported by said conveying means, and means for introducing a sterilizing gas into said heat-confining passageway about said tunnel structure, said tunnel structure having apertures in walls thereof for introduction of aid sterilizing gas into said tunnel structure, and said articulated sections extending across said tunnel structure adjacent the bottom thereof and being located in close proximity to the lower edges thereof to provide a bottom closure wall for said heat-confining passageway.

7. The apparatus of claim 6 in which certain of said apertures are provided in said top wall so that gas can flow into the interior of such containers and other of said apertures are provided in said side walls so that gas can impinge against the outer sides of such containers.

8. -The apparatus of claim 7 in which said side walls of the tunnel structure are offset inwardly toward each other adjacent the upper ends thereof to provide a spacing therebetween closely corresponding to the outer diameter of such open mouth containers so as to guide the containers at a relatively fixed disposition with respect to said apertures.

9. In a container sterilizer of an aseptic canning system, an outer casing, an enclosure housing within said casing having an entrance and an exit for containers, a tunnel structure within said housing between said entrance and exit and having a top closure wall and opposite side walls providing a heat confining passageway, a flat top conveyor for said containers extending across said tunnel structure adjacent the bottom thereof and providing a bottom closure for said tunnel structure, an apertured conduit within said housing and above said top closure wall of said tunnel structure for introducing a sterilizing gas into said housing, said tunnel structure having apertures in its top and side walls for flow of gas into said tunnel structure introduced into said housing.

10. The container sterilizer of claim 9 wherein said fiat top conveyor is slidably mounted in a track adjacent the bottom of each side wall of the tunnel structure.

11. The apparatus of claim 10 in which said tunnel structure side walls are in relatively close proximity with the sides of such containers to define a restricted space in adjacency therewith.

12. The apparatus of claim 10 in which said container conveying means traverses a curved path within said enclosure housing about which said containers are to be conveyed, the aforesaid container-carrying component of said conveyor including a plurality of interconnected articulated sections for traversing such curved path with containers thereon.

13. In a container sterilizer for an aseptic canning system, an outer casing, an enclosure housing within said casing having an entrance and an exit for containers, a tunnel structure within said enclosure housing between said entrance and exit and having a top closure wall and opposite side walls providing a heat confining passageway, fiat top conveying means for said containers extending across said tunnel structure adjacent the bottom thereof and providing a bottom closure for said tunnel structure, means for introducing a sterilizing gas into said enclosure housing, the tunnel structure having apertures therein for flow of gas into said tunnel structure introduced into said housing, said enclosure housing being removably mounted in said outer casing and providing a hood over and extending along said tunnel structure in overlying bridging relation therewith, and resilient clamp members forming a part of the bottom of said outer casing frictionally engaging the sides of said hood to define a releasable connection therewith, said tunnel structure being secured to said hood so as to be removable therewith.

14. The apparatus of claim 13 in which said hood and tunnel structure are each elongated and are coextensively segmented transversely into a plurality of hood sections and tunnel structure sections, each associated hood and tunnel structure section being removable from said enclosure independently of the others.

15. The apparatus of claim 14 in which each of said hood and tunnel structure sections is spaced from the others and each hood section is provided with an end wall having an opening therein aligned with the associated tunnel structure, and in which continuation tunnel structures are interposed between adjacent hood sections in alignment with the openings in the end walls thereof.

16. The apparatus of claim 15 wherein the means for introducing a sterilizing gas into said container housing hood includes a distribution conduit extending along said hood interiorly thereof and above the top wall of said tunnel structure, said distribution conduit being sectioned into lengths generally corresponding to said hood sections to permit removal of a conduit section therewith.

17. The apparatus of claim 15 in which said container conveying means traverses a curved path within said enclosure housing hood about which said containers are to be conveyed, and in which said conveying means includes a plurality of interconnected articulated sections for traversing such path with containers thereon.

References Cited UNITED STATES PATENTS 1,560,520 1*1/1925 Addison 99362 1,977,044 10/1934 Christie et al. 99-362 2,549,216 4/1951 Martin 21-80 XR 2,741,978 4/1956 Cheftel et al. 99-362 2,771,645 11/1956 Martin 21-80 2,835,003 5/1958 Abrams 21-80 XR 3,087,209 4/1963 Monk 2180 FOREIGN PATENTS 653,45 6 11/ 1937 Germany.

MORRIS O. WOLK, Primary Examiner.

J. ZATARGA, Assistant Examiner.

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