EP1128851A1

EP1128851A1 - Device and method for sterilising screwcaps

Info

Publication number: EP1128851A1
Application number: EP99948902A
Authority: EP
Inventors: Gerhard Gruber
Original assignee: Tetra Laval Holdings and Finance SA
Current assignee: Tetra Laval Holdings and Finance SA
Priority date: 1998-11-10
Filing date: 1999-09-29
Publication date: 2001-09-05
Also published as: WO2000027440A1; AU6198299A; DE19851654A1; TW419383B

Abstract

The invention relates to a method and a device for sterilising screwcaps which are treated with atomised hydrogen peroxide, then dried and conveyed to a sanitation chamber for further treatment. The inventive device comprises means (2, 63) for conveying the caps, means (3, 44) for applying the hydrogen peroxide and an outlet pipe (5). According to the inventive method, the caps are transported by vertical conveyor channels (2) in order to use their weight, exposed to a gaseous mixture of 25 % hydrogen peroxide and hot sterilised air for approximately 1 second, then dried with hot sterilised air for longer than 6 seconds and collected in the outlet pipe (5) before being guided away, into the sanitation chamber. This ensures that the sterilisation process is reliably carried out in a shorter space of time and that the device is compact and technically simple and does not occupy too much space.

Description

DEVICE AND METHOD FOR STERILIZING SCREW CAPS

The invention relates to a method and a device for the sterilization of screw caps, wherein the screw caps are sprayed with atomized hydrogen peroxide after the process, then dried and fed to a hygiene room for further processing. According to the device, means are used for supplying the caps, for applying the hydrogen peroxide, and a discharge pipe is connected to the hygiene room of a packaging machine.

It is known to pack food in packaging under aseptic conditions, various types of packaging being closed with screw caps, which are then also fed to a hygiene room in the packaging machine under aseptic conditions and screwed onto the packaging there. The invention relates to the sterilization upstream of the packaging process, because the packs must already be sterilized in the hygiene room.

It is known to sterilize parts of packaging, the entire packaging, and in particular screw caps, by wetting the surfaces of the screw caps with hydrogen peroxide, which is dried before the caps are screwed onto the packaging, so that the caps are then dry and sterile Hygiene room can be fed. This sterilization of screw caps of known devices requires a considerable drying time because the peroxide layer cannot be dried quickly enough. In order to reduce the drying times, the process has already started to atomize liquid hydrogen peroxide and apply it to screw caps as a spray. This resulted in drying times that you thought you could not go below.

In addition, sterilization units used in practice are space-consuming and are often provided with operating lines which have at least a considerable horizontal component. As a result, several drives are required, by means of which the screw caps frequently come into contact with aggregate elements with all the disadvantages associated with them, such as friction and the risk of recontamination. This can also result in undesirable congestion effects. The cleaning of the sterilization units also proved to be particularly complex because external cleaning components first had to be connected and then removed before the sterilization operation was in progress. The invention is therefore based on the object of further developing the method for sterilizing characterized at the beginning and also the sterilizing device so that the sterilization can be carried out reliably in a shorter time with regard to the method; and with regard to the device, it has a compact, technically simple and little space-consuming structure and can also be integrated into the packaging machine in such a way that the sterilization device can be cleaned together with the packaging machine at the place (cleaning in place).

With regard to the method, this object is achieved according to the invention in that the caps are conveyed on feed paths with vertical components to utilize their weight, are gassed for more than 0.5 seconds with a mixture of about 25% hydrogen peroxide and hot sterile air, then longer than Dried for 6 seconds with hot sterile air and stowed in a buffer section before being discharged into the hygiene room. By conveying the caps on more or less vertical feed paths, for example in pipelines, etc., product columns (caps arranged one above the other in the pipelines) can be built up, so that the caps are pressed down with a conveying force due to their own weight so that the Funding takes place automatically without the intervention of additional drive elements. This eliminates many contacts with machine components. This also significantly reduces the risk of recontamination.

The shorter sterilization time is surprisingly given the special gassing according to the invention, in which the caps are gassed for only 0.5 seconds (or of course longer) with the marked mixture, in contrast to the still relatively large droplets when atomizing the Known H ₂ 0 ₂ mixture, in which one works practically with a liquid phase, smaller droplets are achieved according to the invention by mixing in sterile air, so that one better speaks of nebulizing. According to the invention, fine gas condensation is carried out on the surfaces of the caps to be sterilized in the course of the so-called gassing with such small liquid droplets that the drying time can be greatly reduced and nevertheless the bacteria and spores are sufficiently killed in the desired manner. The mixture is preferably prepared by first atomizing the 25% H ₂ 0 ₂ according to the invention at about room temperature, mixing it with sterile air at room temperature and then heating it together before it hits the cap surfaces, particularly preferably to a temperature between 80 ° C and 140 ° C, a temperature of 120 ° C of the mixture shortly before hitting the surfaces of the caps to be sterilized has proven to be favorable and sufficient.

The gassing times for adequate sterilization can be surprisingly reduced in this way. In some screw caps for closing packaging for liquid foods, relatively sensitive plastics are used which are to be bought on the market and sterilized according to the invention. It must then be ensured that such caps are not deformed and destroyed by excessive heating, because otherwise they no longer fulfill their function, for example the screwing and closing torques are no longer guaranteed. In the case of a cap of this type of plastic currently on the market, it has been found that its heating should not exceed 150 ° C. In temperature ranges below, however, the cap can be sterilized with the method according to the invention without further considerations.

It has further proved to be favorable if according to the invention the caps ₂ 0 ₂ mixture are gassed longer than 0.9 seconds, and preferably longer than 1, 2 seconds with the above-mentioned H. The caps treated in this way by fumigation are then properly sterilized if the applied H ₂ 0 mixture is subjected to hot sterile air for 0.6 seconds or longer in the specified time and is thus dried. It is expedient according to the invention if the caps are dried with hot sterile air for longer than 6 to 9 seconds, preferably longer than 7 to 8 seconds and particularly preferably 7.5 seconds. The temperature can be 90 ° C, for example.

For the method, in particular if, according to the invention, the caps on a web are subjected to the sterile air during their continuous transport, the desired times can be minimized by having an intended, for example, the sterile air drying at a constant temperature and the same air flow cap empirically determined amount of moisture so that the sterilization results are satisfactory. If, for example, an adequate amount of moisture has been found during empirical determination and a fumigation time has been determined, you can constantly accept the fumigation conditions in the course of the minimization process and try to reduce the drying time. Finally, the minimum time to sterilize the caps is ultimately determined by the time it takes to dry. In this respect, the teaching according to the invention according to the above features allows the entire sterilization process to be optimized quickly.

It has also proven advantageous for the method if, according to the invention, the caps are stopped in a fumigation room of an evaporator during the fumigation. The drying of the H ₂ 0 ₂ mixtures required for germ killing is preferably carried out while the caps are being transported continuously, on the other hand the gassing of the caps is carried out very cheaply and precisely when the caps are at a standstill. In order to carry out such a process cheaply, the task mentioned at the outset was developed to develop a compact, technically simple, little space-consuming device, which can preferably even be integrated into the downstream packaging machine in such a way that it can be cleaned together with it ( CIP).

According to the invention, this object is achieved for the device in that an evaporator with a cap brake device and with means for mixing hydrogen peroxide and sterile air, connected to it a drying device and under this the discharge pipe for the caps and provided with closable insertion openings for cleaning agents under a supply pipe and that the drying device has a star wheel rotatably driven in a drying housing next to an annular tube with a ring of receiving pockets for the caps. Due to the arrangement of the individual components of the new device with a high proportion from "top to bottom", the dead weight of the caps to be conveyed can be used to bring them through the evaporator, the drying device and then into the discharge pipe without the need for special drives . A relatively weak but precisely controllable motor is provided only for the control of the star wheel, in order to precisely control the dwell times of the caps in the individual units and also to control them variably in the course of operation.

The cap brake device allows the caps to be stopped in the evaporator and further conveyed to the dryer at the desired times (or "run" by their own weight). After the caps have been vapor-coated with the mixture of hydrogen peroxide and sterile air, each cap passes through the drying device. A precisely calculated number of caps per unit of time is held in the drying device for a predetermined time in precisely predefined receiving pockets on the circumference of the star wheel and is thus treated in the desired manner. The then sterile cap can be dispensed into the discharge tube.

If, according to the teaching of the invention, insertion openings for cleaning agents are provided at several points, which can be opened and closed, the unit with its individual equipment can be automatically cleaned with solvents and then rinsed with water. This cleaning on site is referred to in technology as Clean In Place (CIP). It is also expedient according to the invention if the cap brake device of the evaporator has two brake forks which are arranged at a distance from one another and can be moved into an approximately tubular vaporization chamber and if the means for mixing hydrogen peroxide and sterile air is provided with a nozzle which blows into a gasifier chamber and downstream heating channels. which open into the steaming room. The caps can be guided from vertical tubes into a vaporization space, which may also run vertically, and can be removed from this downward. In the steaming room, the controlled movable ones take care Brake forks for stopping one or more caps so that they stand still against the fumigants.

The fumigants have a gasification chamber with heating channels, which is preferably arranged on the side of the vaporization chamber opposite the cap braking devices. The heating channels are located between the steaming chamber and the gasification chamber. Thus, for example, a 25% hydrogen peroxide solution can first be atomized into the gasification chamber and mixed with hot sterile air (70 ° to 100 ° C) in it - all at about 10 to 30 ° C. This mixture, which is still too cold for gassing, then flows through the heating channels mentioned, which are horizontal, e.g. run perpendicular to the tubular evaporation chamber. At its inner end next to the vaporization chamber, the mixture reaches the required temperature of, for example, 120 ° C., which is, so to speak, a gas mixture that condenses on the cooler caps (30 to 60 ° C., preferably 40 to 50 ° C.) . When such a condensate dries, all germs, bacteria and spores are killed off perfectly, resulting in satisfactory sterilization.

In an advantageous further development of the invention, the star wheel provided with spokes is mounted on one side in the disk-shaped, rear floor of the drying housing and carries on its periphery open, approximately quarter to semicircular receiving pockets, next to which a circular guide rod attached to the star wheel extends over 360 ° . The spokes of the star wheel carry an annular holder radially on the outside, next to which the mentioned guide rod is fastened so that it partially covers the receiving pockets in the lateral projection. Screw caps inserted into the receiving pockets are then held by the arcuate base of the receiving pocket and the adjacent part of the guide rod mounted on the side and can be guided in this way over the arc of 300 ° from the entry into the drying housing to its exit. The caps are on the outside against the cylinder-shaped inner surface of the drying housing. Due to this construction of the drying device, depending on the speed of the star wheel, the caps can be subjected to the treatment, namely the drying of the H ₂ 0 ₂ mixture, for more or less. By blowing hot sterile air into the drying housing, it is kept sterile, and there is an overpressure that propagates through the piping throughout the unit. This reduces the risk of recontamination. The overpressure is of the order of 0.1 bar to 0.4 bar, preferably between 0.15 and 0.3 bar.

The weight of the caps arranged above it, which deliberately and desirably line up in a first upper storage section of a length of about 600 mm, is used to fill the receiving pockets. The weight of the screw caps from this storage section is sufficient to push out, for example, the bottom two steamed or fumigated caps as far as the starwheel when the tubular vaporization chamber is opened by pulling back the brake forks. hen. If, for example, two caps are always intermittently gassed and then released to the star wheel, two caps are initially in contact with the circumference of the star wheel in such a way that the circumference of the lower front cap lies in the arcuate base of the receiving pocket and the next cap arranged above it on the circumference of the first cap. By turning the star wheel further, the lower cap is rotated further while the next empty receiving pocket runs up and then picks up the next cap. In this way, all of the pockets can be filled with caps.

In principle, the drying device has the hollow cylindrical drying housing, the ring-shaped wall of which defines the height of the housing and runs outside at a distance along the circumference of the star wheel. On one side of this ring-shaped wall is the disk-shaped, rear-side base in which the star wheel is mounted, and on the opposite side, in a preferred embodiment, a likewise disk-shaped, front-side cover is hinged, which can be opened and closed. This can even be provided with a disk-shaped viewing window, preferably made of borosilicate glass. The lid is expediently placed with the help of silicone on the circular ring edge of the annular wall and fastened there so that an overpressure atmosphere can be maintained in the drying housing. It is ensured that the aggregate has as few gaps or capillary openings as possible so that no bacteria accumulate and can be dragged into the hygiene room.

In addition to the aforementioned circular guide rod, there are also guide rods attached to the housing to ensure the position of the caps as they are dragged around the circular arc of 300 ° by the rotating star wheel. These guide rods are attached with a range of expansion to ensure that the material compensates for movement in the event of temperature fluctuations.

Advantageously, the invention is further characterized in that the ring tube running alongside the ring of the receiving pockets is closed at both ends via a circular arc of approximately 300 °, the ends are in the area of the supply and the removal of the caps, outflow nozzle holes evenly on the star wheel facing side are provided and on the side opposite the ends of the ring tube a supply connection for hot sterile air is attached. The latter is, so to speak, between the ends and ensures a central supply of sterile hot air which, in a preferred embodiment, at a temperature of 90 ° C. with a volume flow of 25 m ³ per hour and with the generation of the excess pressure of between 0.15 and 0. 3 bar is blown. The caps are preferably arranged in the receiving pockets in such a way that their cavity faces the aforementioned outflow nozzle holes. The nozzles are designed in such a way that an approximately conical gas flow emerges from each nozzle hole. The drying hot air flows into the bottom of the len cap and around it. It has been found that when the active oxygen is released, the bacterial shells are broken when drying, and the actual sterilization process takes place in this drying device, killing the bacteria and spores.

According to the invention, it is also advantageous if on the side of the star wheel opposite the ring tube at the bottom of the drying housing an annular cleaning tube is attached by means of a connecting flange for the introduction of cleaning agent and has outlet openings for the cleaning agent. In this way, conveniently arranged means are provided in order to be able to automatically clean and rinse all of the furnishings in the drying housing with solvent and then with water.

In a favorable embodiment, an electrical safety switch is also attached to the drying housing, which measures the vacuum state in the drying housing, so that it is ensured before operation that the housing and the line connections are vacuum-tight. A transmission can also be attached between the motor and the drive shaft and, in a particularly expedient embodiment, it can be provided with a positioning safety coupling. In this way, the star wheel is always locked in position, so that the tubular supply line for caps on the drying housing is always opposite a receiving cap. This is then referred to as the zero position of the star wheel in relation to the incoming caps. It is then ensured that there is always a receiving pocket facing a cap and not the sharp boundary between two receiving pockets.

On the lower delivery side there is a drain pipe for the sterilized caps next to the drying housing. This has monitoring devices arranged at a distance from one another on the outside, which can either have glass panes for observation or electrical or optical sensors. In this discharge pipe there is then a second lower buffer section as a storage section of overlapping caps. Depending on the height of the accumulation section, the speed of rotation of the star wheel can be increased or decreased. A measuring and control circuit is preferably provided, which controls the motor as a function of the height of this storage section and regulates the speed of rotation of the star wheel accordingly.

Before the continuous, normal sterilization operation, in which the star wheel in a preferred embodiment rotates at an average speed of 6.7 revolutions per minute (this results in a speed for the screw caps of 133 mm per second), the automatic cleaning with subsequent water rinsing takes place (Clean In Place = CIP). For this purpose, the cleaning system is connected to the cap inlet and outlet and to the flange of the drying housing provided for this purpose. The outlet-side end of the discharge pipe can also be connected to the packaging machine instead of the separate cleaning system, so that the automatic cleaning can be done together with the cleaning cycle of the packaging machine. When the cleaning medium is available, appropriate valves are opened, and the cleaning media rect blown at the connection points in the Sterilisierungsvom ^', for example via the outlet openings in the circular ring extending cleaning tube into the drying enclosure. In the meantime, sterile warm air is continuously blown into the device so that the cleaning medium cannot accumulate in a ring pipe or other parts. After switching off the cleaning media, for example cleaning solutions and water (for the rinsing process), care is taken to remove these media and dry them with sterile air.

Between this cleaning and the normal sterilization operation, it is expedient to sterilize the device. For this purpose, sterile air is blown in, a peroxide nozzle is switched on for a while in order to blow in H ₂ 0 ₂ . This peroxide is also dried off again with hot sterile air at a temperature in the range between 80 and 120 °. Then the entire device is also sterilized after cleaning. Hot sterile air is then introduced to generate the above-mentioned overpressure in order to keep the entire inner surfaces sterile and to avoid recontamination.

Further features, advantages and possible uses of the present invention result from the following description of a preferred exemplary embodiment in conjunction with the attached drawings. These show:

Figure 1 perspective the essential parts of the sterilization device, in which the

Lid of the drying housing is shown open and on the right a heating block with star-shaped projecting connection elements of each heating element is shown,

FIG. 2 shows a schematic cross-sectional view of the carburetor,

FIG. 3 shows the perspective view of the carburetor of FIG. 1 from a different viewing direction,

FIG. 4 shows a cross-sectional view through the carburetor of FIG. 3 when viewed along the line IV-IV of FIG. 5,

5 shows a central cross-sectional view through the carburetor with the aluminum block (heating block) on one side and the brake cylinders on the other side of the tubular vapor deposition chamber,

FIG. 6 shows a cross-sectional view along the line VI-VI of FIG. 5,

FIG. 7 shows a perspective and schematic of the essential parts of the drying housing with an internal star wheel,

Figure 8 shows the drying housing of Figure 7, but which extends over 300 °

The ring tube is pulled out in the axial direction,

FIG. 9 shows the top view of the star wheel, Figure 10 is a cross-sectional view of the star wheel obliquely from above and

Figure 11 is a view of the star wheel of Figure 9 when you look at it from top to bottom.

The sterilization device essentially assembled in FIG. 1 has, as a means for supplying the screw caps 1 shown in FIGS. 7 and 8, a vertically extending supply pipe 2 at the top left, including as a means for applying hydrogen peroxide a vaporizer, generally designated 3, followed by this at the bottom right a drying device, generally designated 4, and connected to its outlet at the bottom left, a discharge pipe 5, which can be connected at the bottom to a hygiene room, not shown, of a packaging machine. At the points marked 6 there are closable insertion openings for cleaning agents, but these are not shown completely, because these are only connections for the automatic cleaning before the start of operation.

Drying equipment

The drying device 4 has a cylindrical casing-shaped drying housing 7 with a circular disk-shaped base 8, an annular wall 9 fastened to its periphery and a lid 10 which is hinged to the annular wall 8 and a borosilicate glass window 12 and stem handles 13 for closing Has. A star wheel 14, which is drawn out in FIGS. 9 to 11, is rotatably mounted in the base 8 of the cylinder-shaped drying housing 7. In FIG. 10 you can see its drive shaft 15. This is seated via a bearing 16 in the bottom 8 of the drying housing 7 and ends in one piece in a flange 17 on which a cover 19 sealed by silicone is placed by means of a cap nut 18. The actual circular element of the star wheel 14 is fastened between the flange 17 and the cover 19, i.e. the ring 21 with the cross-shaped spokes 23 carrying the multiplicity of part-arc-shaped receiving pockets 20. The ring 21 of the receiving pockets 20 and the spokes 23 are produced from a 5 mm thick sheet steel element. In the extension of the spokes 23 radially outward, there are four fastening brackets 24 on the rim 21 for holding an annular guide rod 25. In addition to the rim 21 of the receiving pockets 20 there is an annular tube 26. This begins in the area of the feed opening 27 for the screw caps 1 and runs then as shown in FIGS. 7 and 8 over a partial circular arc of 300 ° in a clockwise direction to the outlet-side opening 28 of the drying housing 7 and ends there. Both ends 29 and 29 'of the ring tube 26 are closed. The ring tube 26 is open on the side opposite the ends 29, 29 ', on which a supply connection 30 for hot sterile air is attached.

1, the hot sterile air is supplied via a pipeline 31 from a heating block 32, in which heating blocks (not shown) are arranged, which are supplied with heating energy via the connection elements 33. In normal operation, the sterile air enters at the top the cone according to arrow 34 to get into the ring tube 26 after sufficient heating. At the start of operation, a small carburetor chamber 35 is attached, into which a 25% H ₂ 0 ₂ solution is introduced to support the sterilization. This feed is closed during operation.

The hot sterile air passes through the supply connection 30 into the ring tube 26 and leaves it through outflow nozzle holes, not shown, which are provided uniformly on the side of the ring tube 26 facing the star wheel 14. The position of these outflow nozzle holes can be seen indirectly according to FIG. 8 in that on the side facing the ring of caps 1, i.e. small cones 36 are shown to the viewer of FIG. 8 facing away from the ring tube 26, which represent escaping gas mixture, namely hot sterile air. The caps 1 are arranged so that their open side face the gas cones.

A ring-shaped cleaning tube 37 can also be seen from FIG. 8 and in particular FIG. 7, which rotates concentrically around the shaft 15 of the starwheel 14 with a smaller diameter than the ring tube 26 for sterile air. This circular cleaning pipe

37 is supplied at an eccentric point 6 detergent, where you have a connecting flange

38 recognizes at the bottom 8 of the drying housing 7. The circular cleaning tube 37 also has outlet openings for the cleaning agent, but these are not particularly marked.

Evaporator

To apply hydrogen peroxide to the screw caps 1 to be sterilized, the evaporator 3 has a tubular gassing space 40 which extends in connection with the two connecting flanges 41 (FIG. 3). Longitudinally to the gassing space 40 arranged vertically in the installation position of FIG. 1 are cap guide strips 42, by means of which it is ensured that the caps 1 fed vertically from the top downwards through the stainless steel feed tube 2 remain in the correct position even during the gassing and above all get no flat contact with the inner flat surfaces of the fumigation space 40. The cavity of the vaporization chamber 40 is shown partially broken off in FIG. 3 and is located in a block 43 made of stainless steel.

On this block 43, on one side, which can be seen at the top in FIGS. 3 and 4 and on the left in FIG. 5, is the cap brake device, generally designated 44. An upper brake cylinder 47 and a lower brake cylinder 48, the front piston rod of which is designed as a brake fork 49, are held via a central web 46 held on a carrier 45.

In Figure 2, the same states are shown schematically larger for clarity. The brake fork 49 of the upper brake cylinder 47 is shown there in the retracted position, while the lower brake fork 49 is extended and holds the stack of caps 1 extending further to the right in FIG. 2 on the outside. Gravity acts on the caps 1 in accordance with the direction of travel 50 of the arrows in FIG. 2, which are pushed downward in the direction of 50 by their weight. In Figure 5, this transport direction 50 of the caps 1 is shown vertically from top to bottom. The cap brake device 44 thus ensures that the correct number of caps is stopped in the gassing space 40 or that they are released for further transport into the drying device 4.

On the side of the gassing chamber 40 opposite the cap braking device 44, a nozzle 51, clearly shown in FIG. 2, is shown as a means for mixing H ₂ O ₂ and sterile air, which is supplied with a 25% hydrogen peroxide solution according to arrow 53. Atomized peroxide solution and sterile air are distributed to a fine mist in a gasification chamber 54. This nozzle is not shown in FIGS. 3 to 6, but the receiving plate 55 at the outer end of a heating block 56 made of aluminum, through which heating channels 57 running parallel at a distance pass. Heating elements 58 ensure a high temperature in the heating channels, so that the gas mixture entering the vaporization chamber 40 through these channels 57 is brought to the desired temperature. The heating elements 58 can be fastened with the clamping plates 59, and connecting cables 60 supply the heating elements 58 with energy. A temperature sensor 61 allows the temperature in the carburetor chamber 54 to be measured with its connection 62.

The manifold 63 connected downstream of the carburetor 3 in FIG. 1 allows the screw caps 1 to be fed through the feed opening 27 of the drying housing 7 into the star wheel 14. Analogously, a further manifold 64 is flanged to this opening 28 for removal from the discharge opening 28 for the screw caps 1 , to which the discharge pipe 5 connects. The lower second buffer section of already sterilized screw caps can form in this, and the glass panes 65a and 65b permit visual observation or electronic interrogation for the existence of caps at this height in the discharge pipe 5.

The drying device 4 can be attached to the packaging machine or a building wall via the frame 66. The motor 67 takes care of the drive of the star wheel, the positioning safety circuit (not shown) and possibly a transmission being located behind the drying device 4. An electrical safety switch 68 is shown attached to the drying housing 7 at the bottom right in FIG. 1, with which it can be queried whether the housing 7 is more or less vacuum-tight, for example by tightening the star handles 13 and pressing the swivel cover 10 against the silicone seal 69. The operation

The cleaning system is first connected to the locations designated by 6, so that the cleaning medium supplied to the sterilization device cannot escape. Then the swing door 10 is closed, and after checking for leaks, the cleaning cycle of the packaging machine and thus also for the sterilization device can be carried out. If the cleaning agent is available, corresponding valves are opened and the cleaning media are blown in via the openings, for example the cleaning pipe 37. Sterile hot air is blown in permanently during the cleaning process via the heating block 56, the heating block 32 and cone 34 and the pipeline 31. This prevents the cleaning media from accumulating undesirably on surfaces. After the cleaning medium has been blown in, hot air is blown in to dry the entire interior of the sterilization device.

Then the interior of the sterilization device itself must be sterilized. Sterile air is mixed with atomized peroxide solution and blown into the openings discussed. After the peroxide has dried, it can be assumed that the sterilization process has been completed. Thereafter, hot sterile air is continuously introduced in the temperature range specified above with a slight excess pressure of 0.15 to 0.3 bar so that the system remains sterile.

In normal operation, screw caps are inserted into the feed pipe 2 at 6 and accumulate above the upper brake fork 49 to form a first upper storage section. If the lower brake fork 49 is extended while the upper brake fork 49 is retracted, then the caps 1 are jammed on the lower brake fork. The upper brake fork can then be extended without changing anything. The desired number of caps 1, for example two of these screw caps, is then available in the gassing space 40 for the gassing. Fumigation takes place through the described H ₂ 0 ₂ sterile air mixture, this gas condensing on the surfaces of the caps. These are very small droplets, which of course cannot be recognized on the caps without aids.

It has been shown that after a residence time of 1.2 seconds in the gassing space 40, the sterilization can be carried out without any problems. Therefore, the lower brake fork 49 is retracted after this time, while the stack of caps 1 is still held above the upper brake fork 49. The respective two caps 1 fall down over the elbow 63 and the feed opening 27 into the receiving pocket 20 of the star wheel 14 opposite the opening 27. The foremost cap lies exactly on the arcuate bottom of the pocket 20, while the rear cap rests first on the front . In the preferred embodiment described here, the star wheel 14 rotates at 6.67 revolutions per minute, so that the second receiving pocket 20 is opposite the feed opening 27 in a predetermined time, so that the second cap can fall into the second pocket. In the course of operation, all of the receiving pockets 20 are filled, so that an image is obtained approximately as in FIGS. 7 and 8.

In the form of the gas cone 36, hot sterile air flows at a temperature of 90 ° and the volume flow of 25 m ³ per hour into the drying housing 7, so that each cap is dried for about 8 seconds.

If you start from plastic screw caps with an elastomer. based on polyethylene in a preferred example, these caps having a diameter of about 40 mm, then the sterilizing device can sterilize at an average speed of the star wheel of 6.67 revolutions per minute about 12,000 caps per hour.

Each cap remains in the evaporator for about 1.2 seconds and is brought to a temperature of about 45 ° C. The hydrogen peroxide consumption of the peroxide solution is 540 grams per hour in this particular example.

The distance between the brake forks is equal to the distance between two screw caps 1. Two caps always fall on the lower brake arm. The upper one is then immediately moved out again or closed. After the gassing in the evaporator, the caps are "in a jam" in front of the drying device 7. The entire vertical pipeline can form a storage section.

The star wheel 14, which is driven by the geared motor 67, begins to rotate and drags the caps at the wrap angle of 300 ° from the first position opposite the feed opening 27 to the second position opposite the discharge opening 28, the caps 1 under the outlet openings of the ring tube 26 or pass under the gas jets 36.

The drying time and the spray time in the evaporator 3 are determined by the speed of rotation of the star wheel 14.

After leaving the drying housing 7, the caps pass through the lower elbow 64 into the discharge pipe 5 and are again "in a jam" in the vertical pipe 5, which guides the caps to the hygiene chamber (not shown).

Connections for the cleaning media are denoted by 6 and are located at the top of the feed pipe 2, at the inlet opening 27 of the drying housing 4, in the drying housing 4 above the flange 38 and at the outlet opening 28 of the drying housing 4. Reference list

1 screw cap

2 feed pipe

3 evaporators

4 drying device

5 discharge pipe

6 openings for detergents

7 drying housing

8 Circular disk-shaped bottom of the drying case

9 Drying cabinet wall

10 lids

11 hinge

12 borosilicate windows

13 star knobs

14 star wheel

15 drive shaft

16 bearings

17 flange

18 cap nut

19 Lids 0 pockets 1 rim 3 spokes 4 mounting brackets 5 guide rod 6 ring pipe 7 feed opening for screw caps 8 opening of the drying housing 9, 29 'ends of the ring pipe 0 supply connection for sterile air 1 pipeline 2 heating block 3 connection elements for heating energy 4 cones - entry of sterile air 5 carburetor chamber 6 Cone - escaping sterile air 7 cleaning pipe 8 connection flange 0 fumigation space 1 connection flange 2 cap guide strips 3 stainless steel block 4 cap brake device 5 support 6 center bar 7 upper brake cylinder 8 lower brake cylinder 9 brake fork 0 arrows (transport direction of the caps) 1 nozzle 2 blow-out nozzle 3 arrow 4 carburetor chamber 5 mounting plate 6 heating block 7 Heating channels 8 heating elements 9 clamping plates Connecting cable

Temperature sensor

Connection of the temperature sensor

Manifold

Manifold a, b panes of glass

frame

engine

Safety switch

Silicone gasket

Claims

Patent claims

1. A method for sterilizing screw caps (1) which are sprayed with atomized hydrogen peroxide, then dried and fed to a hygiene room for further processing, characterized in that the caps (1) are conveyed to vertical paths by means of their weight on feed paths (2) are gassed for longer than 0.5 seconds with a mixture of about 25% hydrogen peroxide and hot sterile air, then dried for longer than 6 seconds with hot sterile air and stored in a buffer zone (in the discharge pipe 5) before being discharged into the hygiene room.

2. The method according to claim 1, characterized in that the caps (1) are gassed for longer than 0.9 seconds and preferably longer than 1, 2 seconds with the hydrogen peroxide mixture.

3. The method according to claim 1, characterized in that the caps (1) are dried for longer than 6 to 9 seconds, preferably longer than 7 to 8 seconds and particularly preferably 7.5 seconds with hot sterile air.

4. The method according to claim 1 or 3, characterized in that the caps (1) are acted on a web during their continuous transport with the sterile air (36).

5. The method according to claim 1 or 2, characterized in that the caps (1) in a fumigation space (40) of an evaporator (3) are stopped during the fumigation.

6. Device for the sterilization of screw caps (1) with means (2, 63) for supplying the caps (1), means (3, 44, 51) for applying hydrogen peroxide and with a discharge pipe (5) which is connected to the hygiene room Packaging machine is connected, characterized in that under a feed pipe (2) an evaporator (3) with a cap brake device (44) and with means (3, 51, 54, 44) for mixing hydrogen peroxide and sterile air, thereon a drying device (4) and underneath this the discharge pipe (5) for the caps (1) is connected and provided with closable insertion openings (6) for cleaning agents and that the drying device (4) has a star wheel (4) which is rotatably driven in a drying housing (7) next to an annular pipe (26). 14) with a ring of receiving pockets (20) for the caps (1).

7. The device according to claim 6, characterized in that the cap brake device (44) of the evaporator (3) has two mutually spaced, in an approximately tubular evaporation space (40) movable brake forks (49) and that the means (52, 51, 44) for mixing hydrogen peroxide and sterile air is provided with a nozzle (52) blowing out into a gasification chamber (54) and downstream heating channels (57) which open into the vaporization chamber (40).

8. Apparatus according to claim 6 or 7, characterized in that the star wheel provided with spokes (23) (14) is mounted on one side in the disk-shaped, rear bottom (8) of the drying housing (7) and approximately open at its periphery to the outside quarter to semicircular receiving pockets (20) carries, next to which an annular guide rod (25) attached to the star wheel (14) extends over 360 °.

9. Device according to one of claims 6 to 8, characterized in that in addition to the ring (21) of the receiving pockets (20) over a circular arc of about 300 ° ring tube (26) is closed at both ends (29, 29 ') , the ends (29, 29 ') are located in the area of the feed (27) and the discharge (28) of the caps (1), outflow nozzle holes are provided uniformly on the side facing the star wheel (14) and on the ends (29 , 29 ') of the ring tube (26) opposite side a supply connection (30) for hot sterile air is attached.

10. Device according to one of claims 6 to 9, characterized in that on the ring tube (26) opposite side of the star wheel (14) at the bottom (8) of the drying housing (7) has an annular cleaning tube (37) by means of a connecting flange ( 38) is fixed for the introduction of cleaning agent and has outlet openings for the cleaning agent.