Abstract:
An apparatus for sterilizing cap-like closures for closing bottles includes a conveying system to move the cap-like closures through a treatment zone in which the cap-like closures are exposed to ultraviolet radiation for sterilization, the treatment zone having ultraviolet radiation sources for emitting ultraviolet light. Within the treatment zone, the conveying system includes a rotor that can be driven to rotate about a vertical rotor axis, and closure holders formed on a periphery of the rotor. Each closure holder is oriented with a longitudinal extension thereof in a direction of the rotor axis. The closure holders are configured for moving the cap-like closures vertically from top to bottom through the treatment zone on a treatment section between a closure supply and a closure discharge.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is the national phase under 35 USC 371 of international application no. PCT/EP2011/004595, filed Sep. 13, 2011, which claims the benefit of the priority date of German application no. 10 2010 052 207.4, filed Nov. 24, 2010. The contents of the aforementioned applications are incorporated herein in their entirety. 
     FIELD OF DISCLOSURE 
     The invention relates to a device for disinfecting or sterilising closures. 
     BACKGROUND 
     For example in plants in the drinks industry, it is common and known to sterilise or disinfect the closures used to close filled bottles or other containers, in particular cap-like closures such as screw closures, flat caps, crown corks etc., before use i.e. before their application to the respective container. 
     For this sterilisation, amongst others UV radiation, in particular UV-C radiation, is suitable, to which the closures are exposed on their outer and inner face for a sufficient treatment duration, for example for a treatment time of around 120 seconds. 
     UV radiation sources in the sense of the invention are in particular all known UV radiation sources or UV lamps, amongst others mercury-doped high-pressure and low-pressure lamps or high-pressure and low-pressure gas discharge lamps, but also quartz lamps, deuterium lamps etc. emitting UV radiation. Preferably the UV radiation sources in the sense of the invention are low-pressure gas discharge lamps emitting UV light and preferably rod-shaped, low-pressure, gas discharge lamps emitting UV light. 
     The term “substantially” in the sense of the invention means deviations from the precise value by +/−10%, preferably +/−5% and/or deviations in form of changes irrelevant to function. 
     SUMMARY 
     The object of the invention is to provide a device which, with a high sterilisation quality or disinfection rate, also allows a reproducible high performance (number of sterilised or disinfected closures per time unit). 
     Particular advantages of the device according to the invention lie for example in that despite this high performance, this can be made very compact with little construction space or volume, that constant i.e. reproducibly high disinfection rates are achieved in sterilisation, and that the disinfection or sterilisation takes place without the use of chemicals and at low operating costs, which result amongst others from the reduced power consumption above all for the operation of the UV radiation sources and from the long service life of these radiation sources. The device according to the invention is suitable for closures of widely varying types, in particular also for cap-like closures such as screw closures, flat caps, crown corks etc. 
     Preferably in the device according to the invention, the at least one treatment chamber is subjected to a slight positive pressure of a sterile gaseous and/or vaporous medium, for example sterile air, so that penetration of ambient air and the germs this carries into the treatment chamber or treatment zone is effectively prevented, above all also in the region of the closure inlets and outlets. The ozone generated by the UV radiation in the treatment chamber also has a sterilising or disinfecting effect on the closures and thus supports the sterilising and/or disinfecting effect of the UV radiation. 
     Refinements, advantages and possible applications of the invention arise from the description below of embodiment examples and the figures. All features described and/or shown in the figures, alone or in any combination, are in principle the object of the invention irrespective of their summary in the claims or back reference. The content of the claims is declared a constituent part of the description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention is explained below with reference to one embodiment example shown in the figures. These show: 
         FIG. 1  in perspective view a device according to the invention for sterilising closures which are intended to close bottles or similar containers; 
         FIG. 2  a top view of the device in  FIG. 1 ; 
         FIGS. 3 and 4  in perspective part view, the device in  FIG. 1  in a view from above; 
         FIG. 5  the device in  FIG. 1  in perspective view and in cross section; 
         FIG. 6  an enlarged part depiction of  FIG. 5 ; 
         FIG. 7  the device in  FIG. 1  in side view and in the region of a lower closure discharge or closure transport section; 
         FIG. 8  in simplified part view and in side view, two closure holders formed on a rotor of the device. 
     
    
    
     DETAILED DESCRIPTION 
     The device described generally with numeral  1  in the figures serves to sterilise or disinfect closures  2 , for example closures in the form of caps, screw caps, sport caps, flat caps or crown corks etc. which are used to close containers not shown e.g. in the form of bottles. For this the device  1  preferably forms an apparatus connected before a closing machine to close the containers, from which apparatus the sterilised closures  2  are supplied to the closing machine under sterile or germ-free conditions. 
     The device comprises amongst others a device housing  3  which, in the embodiment shown, in top view has a polygonal shape, i.e. is formed hexagonal, surrounding a vertical machine or rotor axis MA. The interior  4  of the housing  3 —with the exception of the inlets and outlets for the closures  2 —is tightly sealed against the environment, namely by a peripheral wall  5  surrounding the machine axis MA, an upper housing wall  6  hexagonal in the present embodiment, and a lower housing wall  7  also hexagonal. In the peripheral wall  5  are provided inspection windows  8  which are preferably designed impermeable to UV light or at least greatly damping the UV light transmission, for example made of a correspondingly equipped transparent plastic or glass, and/or which can be closed by flaps not shown. On the top of the housing  3  or in the region of the housing wall  6  there is provided a housing part  9  protruding over the top of this housing wall, via which part amongst others the interior  4  can be accessed for repair and/or maintenance purposes. 
     In the interior  4  of the housing  3  is held a rotor  10  which can be driven circulating about the vertical machine axis MA. In the embodiment shown, the rotor  10  is formed as a circular cylindrical, hollow drum surrounding the machine axis MA concentrically with a drum casing with cage-like structure, which is formed by a multiplicity of closure holders  11  each holding a multiplicity of closures  2 . The closure holders  11 , which are each oriented with their longitudinal extension parallel or substantially parallel to machine axis MA and at their upper end are open for the introduction of closures  2  and at their lower end are open for the discharge of closures  2 , as a whole form the cage- or mesh-like structure or the cage-like, inherently stable casing of the rotor  10  and for this are provided distributed on the periphery of the rotor  10  at equal angular and pitch spacings about the machine axis MA. Ring-like holders  12  concentrically surrounding the machine axis MA and offset to each other in the direction of this axis connect the closure holders  11  together into the grid-like structure of the rotor  10 . In the region of their lower ends, the closure holders  11  are attached to a circular disc-shaped carrier element  13  arranged coaxial with the machine axis MA, such that the closure holders  11  each protrude over the periphery of the carrier element  13  and the lower open ends of the closure holders  11  are not covered by the carrier element  13 , rather they are exposed in the region of the carrier element  13  or below this carrier element. 
     The closure holders  11  are also formed mesh-like and each consist of several rod- or bar-like closure guide rails  14  spaced apart from each other and oriented parallel to machine axis MA, which between them form a holding chamber to hold a multiplicity of closures  2  such that the closures  2  in each closure holder  11  form a one-track row or group of closures extending in the axial direction parallel to machine axis MA and are largely exposed as far as possible in the respective closure holder  11  i.e. are covered by the closure guide rails  14  only on a small part of their surface. Furthermore the closure holders  11  in the embodiment shown are designed such that the closures  2  in the closure holders  11  have a predefined orientation in relation to machine axis MA such that they are oriented with their closure or cap axis radial to machine axis MA and for example with their open cap side radially towards the outside. 
     With the carrier element  13 , the rotor  10  is mounted in a bearing  15  on the underside of the housing  3  or on the lower housing wall  7  there, rotatable about the machine axis MA, and can be driven by means of a drive  16  (electric motor with gear) circulating in pulses or steps about the machine axis MA corresponding to arrow A. 
     UV light sources are provided distributed in the interior  4  of the housing  3  i.e. in the treatment chamber of the device  1  and not circulating with the rotor  10 , namely in the embodiment example shown in the form of rod-like UV lamps  17  and  18  which are each held suspended from the upper housing wall  6  or lamp holders  19  there and oriented with their axes parallel to machine axis MA. The outer UV lamps  17  in relation to machine axis MA are arranged radially outside the movement track of the closure holders  11  and the inner UV lamps  18  in relation to machine axis MA are arranged radially inside the movement track of closure holders  11  or the cage-like structure formed by the closure holders  11 , namely in the embodiment shown offset to gaps such that in relation to machine axis MA, each inner UV lamp  18  lies radially opposite a gap between two outer UV lamps  17 . The number of inner UV lamps  18  is for example the same or approximately the same as the number of closure holders  11  on rotor  10 . Preferably however the number of outer UV lamps  17  and inner UV lamps  18  in each case is smaller than the number of closure holders  11 . By the arrangement of UV lamps  17  and  18 , in particular by the offset arrangement of these lamps, it is guaranteed that the closures held in the closure holders  11  are moved through as even a UV radiation field as possible on the UV treatment section formed by the angular region of the rotary movement of the rotor  10  between the closure supply  20  and the closure discharge  22 . The dome-like housing part  9  contains amongst others the electrical function elements which are necessary for controlling the UV lamps  17 ,  18  and with which UV lamps  17 ,  18  or their lamp holders  19  are connected via electric lines. 
     The UV lamps  17  and  18 , which are preferably formed identical or substantially identical, each extend with their lower free end up to near the level of the top of the disc-like carrier element  13  and are there spaced slightly from the top or the level of the top of the carrier element. In principle it is possible to form the outer UV lamps  17  with a slightly greater length such that these lamps with their lower free end protrude downwards beyond the plane of the carrier element  13  and extend into a channel-like segment  26  which is formed from the lower housing wall  7  in the outer region of the interior  4  and surrounds the machine axis MA in a circular ring-like manner. This arrangement and formation of the outer UV lamps  17  guarantees particularly reliably that also the bottom closures  2  in the closure holders  11 , but also the regions coming into contact with these closures  2 , in particular also the surface  25 , are intensively treated with or exposed to UV light. 
     In the upper region of the interior  4  or the treatment chamber formed by this, above the movement track of the closure holders  11  is provided a closure supply  20  which is formed by the lower end of an outer closure transport section  21  and to which the closures to be sterilised are supplied via this closure transport section  21 . In the closure transport section  21 , the closures already have their orientation corresponding to their orientation in the closure holders  11 . In the region of the underside of the housing  3 , below the movement track of the closure holders  11 , a closure discharge  22  is provided which is substantially formed by the inlet or by an upper open end of the closure transport section  23  which extends through the lower housing wall  7  into the interior  4  and is arranged with its open end below the movement track of the closure holders  11  of the rotor  10  and there forms the closure discharge  22 . Via the closure transport section  23 , the sterilised closures  2  are supplied germ-free to the closing machine not shown. In addition to the closure discharge  22  and the closure transport section  23 , a closure discharge formed by a closure guide  24  is provided below the movement track of the closure holders  11 , via which discharge rapid emptying of the device  1  or rotor  10  is possible i.e. accelerated removal of closures  2  from the closure holders  11 , for example on faults in the device  1 , in a plant comprising the device  1 , on a format change i.e. on conversion from one closure type to another closure type etc. 
     The closure guide  24  guided out of the housing  3  ends in the interior  4  below the movement track of the closure holders  11 . By corresponding control means not shown, the outlet there formed by the closure guide  24  can be controlled such that closures  2  do not enter the closure guide  24  in normal operation of the device  1  but only on accelerated emptying of the device  1  and/or rotor  10 . 
     In the embodiment shown, the closure transport sections  21  and  23  and the closure guide  24  are each formed by several guide rails holding and guiding the closures  2  between them. Furthermore in the embodiment shown the closure transport sections  21  and  23  and the closure guide  24 , at least in the vicinity of the device  1 , each have a vertical course so that the closures  2  in the closure transport sections  21  and  23  and in the closure guide  24  are transported or moved solely because of gravity. In order however to prevent re-infection of the sterilised closures  2  on the closure transport section  23 , this is contained in a casing or housing not shown which is preferably subjected to positive pressure of a sterile gaseous and/or vaporous medium, for example sterile air under positive pressure. 
     The closure supply  20  and closure discharge  22  in relation to machine axis MA are arranged at an angle spacing which corresponds to a multiple of the pitch spacing of the closure holders  11  on the rotor  10 , i.e. so that whenever a closure holder  11  with its open upper end stands at the closure supply  20  in the stoppage phase of the rotary movement of rotor  10 , another closure holder  11  with its lower open end stands at the closure discharge  22 . Furthermore the closure discharge  22  in relation to the rotation direction A of rotor  10  is spaced by as large an angular amount as possible, i.e. for example by an angular amount of slightly less than 360°, e.g. by an angular amount of 330° or around 330°, from the closure supply  20  in order to achieve as long a treatment section as possible and hence, even at high performance of the device  1  i.e. a high number of closures  2  sterilised per time unit with this device  1  or a correspondingly high rotation speed of the rotor  10 , as long a treatment duration as possible for disinfection or sterilising of the closures  2 , notably with the reduced diameter of rotor  10  and the compact form of device  1  as a whole. 
     With the drive  17  the rotor  10  is driven in pulses about the machine axis MA such that the rotor  10  in each movement phase of the pulsed rotary movement executes a rotation step corresponding to the pitch spacing of two closure holders  11 , and in each stoppage phase of the pulsed rotary movement an empty closure holder  11  stands below the closure supply  20 , via which the closure holder  11  is then filled completely with closures from the closure transport section  21 . With the pulsed rotary movement of the rotor  10 , the closure holders  11  each filled with closures  2  are moved along the UV lamps of the treatment section formed by the UV lamps  17  and  18  and extending over the angular region between the closure supply  20  and the closure discharge  22  and thus are disinfected by the UV light or UV radiation from the activated UV lamps  17  and  18 . 
     As shown in  FIG. 8 , on UV treatment, because of the rotary motion of rotor  10  indicated by arrow A, the bottom closure arranged in respective closure holder  11  rolls with its peripheral surface in the manner of a friction wheel on the closure contact surface  25  formed by the lower housing wall  7  and not moving with the rotor  10 , whereby according to arrows B for each of the lowest closures  2  a rotary or rolling motion is generated which is transferred from closure to closure, to all closures  2  arranged in the respective closure holders  11  and lying on each other with their peripheral surfaces, so that finally all closures  2  in each closure holder  11  rotate in opposing directions according to arrows B and are thus exposed to UV radiation over their entire surface and optimally disinfected or sterilised. 
     Every time a closure holder  11  of the rotor  10  reaches the closure supply  22 , all sterilised closures  2  of this closure holder fall onto the closure transport section  23  via which the disinfected or sterilised closures are then supplied for further use. 
     UV lamps  17  and  18  are activated constantly for example during operation of the device  1 . Taking into account the diameter of the rotor  10 , the speed of the pulsed rotary movement of the rotor  10  is selected such that the duration which the closure holders  11  require for movement from the closure supply point  20  to the closure discharge  22  corresponds to the treatment time necessary for the desired sterilisation level, for example a treatment time of 120 seconds. 
     In principle however it is also possible to design the control of the UV lamps  17  and  18  such that these can be switched on and off in particular to control the UV radiation power, i.e. can be operated in cycles or pulses. 
     To prevent the penetration of germs into the interior  4  of the housing  3 , this interior is exposed to a positive pressure, for example a positive pressure of sterile air. The disinfection or sterilisation of the closures  2  takes place firstly directly by the UV radiation (UV-C radiation) but also supported by the ozone generated by this UV radiation which collects in the interior  4 . 
     The particular advantages of the device  1  are that chemical-free sterilisation or disinfection of the closures  2  takes place, that the device  1  can be produced compactly with low construction volume, that high disinfection rates are possible wherein the disinfection power in particular can be set also by the speed of the pulsed rotary movement of the rotor  10  and/or by the UV power emitted by the UV lamps  17  and  18 , and that by the own rotation of closures  2  (arrow B) in the closure holders  11 , a constant reproducible quality of sterilisation or disinfection is achieved. A further essential advantage lies in the reduced operating costs of the device  1  which are due in particular to the relatively low energy consumption for the UV lamps  17  and  18  and the relatively long service life of these lamps (up to 15,000 operating hours). 
     In addition to the function elements described above, the device  1  for example also has devices for cleaning, in particular for foam cleaning, of the device, devices for extraction of ozone, measurement and monitoring devices or equipment, in particular also for function monitoring of the UV lamps  17  and  18 , and nozzles for transport of closures  2  by conveyor air etc. 
     The invention has been described above with reference to one embodiment example. It is evident that numerous modifications and derivations are possible without leaving the inventive concept fundamental to the invention. 
     It has been assumed above that the sterilisation or disinfection of closures  2  takes place in a single rotor  10  or the closure holders  11  fitted there. In principle however it is possible to structure to device in the mariner of a cascade or modular, namely for example with at least two rotors  10  which are then arranged with their rotor axes e.g. coaxial, namely such that the closures  2  treated in a first rotor  10  at the closure discharge from this rotor do not enter the closure transport section  23  but via a closure supply enter a closure holder  11  of the further rotor  10 , with which the closures  2  are then moved through a further treatment zone or section, for example a further UV treatment zone. In principle in particular with such a cascade-like or modular structure, there is also the possibility of providing at least two treatment zones with different treatment media. 
     LIST OF REFERENCE NUMERALS 
       1  Device 
       2  Closure 
       3  Device housing 
       4  Interior 
       5  Peripheral wall 
       6  Upper housing wall 
       7  Lower housing wall 
       8  Dome-like segment of upper housing wall 
       9  Housing part 
       10  Rotor 
       11  Closure holder 
       12  Holder 
       13  Carrier element 
       14  Closure guide element 
       15  Bearing 
       16  Drive 
       17 ,  18  UV lamps 
       19  Lamp holder 
       20  Closure supply 
       21  Closure transport section 
       22  Closure discharge 
       23  Closure transport section 
       24  Closure guide 
       25  Surface 
       26  Recess 
     A Direction of rotation of rotor  10   
     B Direction of rotation of closures  2   
     MA Machine axis