Abstract:
An apparatus for sterilizing, filling and sealing containers has a sterilization chamber, a cooling chamber, and a filling and sealing chamber, through which the containers are conveyed by means of an endless conveyor device. For presterilizing the chambers before the apparatus is put into operation, these chambers are acted upon by a gaseous sterilizing agent flowing through them, which is fed through an inlet or an outlet for the containers. In order that regions less affected by the flowing sterilizing agent as it flows, because they are in the lee, will also be disinfected well, the flow direction of the sterilizing agent is changed multiple times. A blower with a reversible flow direction is used for this purpose.

Description:
BACKGROUND OF THE INVENTION 
     The invention is based on an apparatus for sterilizing, filling and sealing containers. Before being put into operation each time, the individual chambers as well as the filling and sealing devices built into them in such apparatus are sterilized by having a sterilizing agent in gaseous or vapor form, such as a mixture of hydrogen peroxide and air, flow through them and act on them for a predetermined period of time. To that end, the device for feeding the sterilizing agent into and through the chambers is designed so as to have the sterilizing agent flow in one direction through the chambers in succession. It sometimes happens that in corners reached only poorly by the sterilizing agent, germs will serve and will get into containers and into the product to be placed in them. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The apparatus according to the invention has the advantage over the prior art that by reversing the flow direction of the sterilizing agent in the sterilization chamber and in the filling and sealing chamber, places in the lee of one flow direction are reached in the opposite flow direction, thus substantially increasing the reliability of the sterilization. Another advantage is that with increased sterilization reliability, the length of time needed to presterilize the apparatus is shortened, thus reducing the consumption of a sterilizing agent. 
     The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1-4 show an apparatus for sterilizing, filling and sealing containers in various indexing positions during presterilization and during operation. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In a boxlike housing  10 , a sterilization chamber  12 , a cooling chamber  13  and a filling and sealing chamber  14  are disposed side by side, separated by a heat-insulating partition  11  and communicating with one another through openings  15 ,  16 . The sterilization chamber  12  has an inlet opening  17  and the filling and sealing chamber  14  has an outlet  18 , each oriented coaxially with the openings  15 ,  16 , and each preceded and following by a respective sluice  21 ,  22 . The two sluices  21 ,  22  can be closed by means of flaps  23 ,  24 . From the inlet opening  17  to the outlet opening  18 , a linear conveyor device extends through the chambers  12 ,  13 ,  14 , such as an endless conveyor chain  25 , which carries the containers that are to be sterilized, filled and sealed, such as bottles, vials or similar heat-stressable packaging containers, through the chambers. A heating device  26  for heating the containers to the sterilization temperature is built into the sterilization chamber  12 , and a filling device  27  and a sealing device  28  are built into the filling and sealing chamber  14 . The top of the cooling chamber  13  and filling and sealing chamber  14  is formed by a superfine filter  29 , which above itself defines an air distribution chamber  30 . 
     To assure a high-quality sterility of the liquid products to be packed and packaged in the containers, such as vaccines, medicines, of foods, it is important that the containers be disinfected, filled and sealed in a completely sterile atmosphere in the apparatus. The apparatus is therefore equipped with a device that before the apparatus is put into operation presterilizes the chambers  12 ,  13 ,  14 , through which the containers are carried, and the filling and sealing devices with a gaseous sterilizing agent, such as a mixture of hydrogen peroxide and air, and during operation keeps them at a slight overpressure in a sterile air atmosphere. 
     To that end, the chambers  12 ,  13 ,  14  can be made to communicate with sterilizing agent generator  31  and a sterile air source  32 . A line  35  leads from the sterile air source  32  via a valve  36 , a blower  37  whose feeding direction is reversible, and a second valve  38  in the air distribution chamber  30 . A second line  42 , which begins at the sterilizing agent generator  31  and can be blocked off by a valve  41 , leads to a distributor  43  in the line  35  between the blower  37  and the valve  36  near the sterile air source  32 . A line  45  also leads from the distributor  43  via a valve  46  into the sluice  22  at the outlet opening  18 , and a line  47  leads via a valve  48  to the bottom of the cooling chamber  13  and filling and sealing chamber  14 , where this line branches off and discharges with multiple branches  51 ,  52 ,  53 ,  54  into these chambers  13 ,  14 . A line  56  with a valve  57  also connects the sluice  21  at the inlet opening  17  to the line  35  between the blower  37  and the air distribution chamber  30 . 
     The apparatus described above is prepared for operation as follows: 
     First, the lines and the superfine filter  29  in the cooling chamber  13  and the filling and sealing chamber  14  are disinfected with a mixture of hydrogen peroxide and air (FIG.  1 ). To that end, the valves  46 ,  57  are connected to the sluices  21 ,  22 , which are closed with the flaps  23 ,  24 , and the valve  36  is connected to the sterile air source  32 , and the other valves  41 ,  48 ,  38  are opened. The blower  37  is turned on, so that the blower feeds from the air distribution chamber  30  to the branch  43 . After the valve  41  is opened, gaseous sterilizing agent flows from the sterilizing agent generator  31  through the lines  42  and  47  and the branches  51 - 54  through the cooling chamber  13  and the filling and sealing chamber  14  from below, sweeps past the fixtures built into them, penetrates the pores in the superfine filter  29 , and via the air distribution chamber  30  reaches the blower  37 , which feeds it in circulatory fashion into the line  47  via the distributor  43 . Additional sterilizing agent is also delivered from the sterilizing agent generator  31  at overpressure. 
     After an about five-minute treatment of the lines and the superfine filter  29 , the valves  38  and  48  are now closed, and the valves  46  and  47  to the sluices  21 ,  22  are opened (FIG.  2 ), so that the sterilizing agent dispensed by the sterilizing agent generator  31  flows from the distributor  43  through the line  45  into the sluice, and from there through the outlet  18  into the filling and sealing chamber  14  and the cooling chamber  13 . Through the opening, it reaches the sterilization chamber  12 , and from there it flows through the inlet  17  into the sluice and through the line  56  to reach the blower  37 . With the addition of more sterilizing agent delivered at overpressure, the circulating sterilizing agent is kept flowing in this direction of revolution for a few minutes. On flowing through the chambers  14 ,  13 ,  12 , the sterilizing agent sweeps along its walls and the surfaces of the built-in fixtures, such as filling and sealing devices  27 ,  28 . 
     Since in the flow around potruding parts, regions in the lee are acted upon by the sterilizing agent to a lesser extent, the direction of the flow is reversed after a certain duration of treatment. To that end, the blower  37  is reversed, so that it now feeds the sterilizing agent through the line  56  into the sluice  21  and through the inlet opening  17  first into the sterilizing agent  12  and from there through the opening  15  into the cooling chamber  13  and the filling and sealing chamber  14 , through the outlet opening  18  and back to the blower  37  again through the closed sluice  22  and the line  45 . The blower  37  keeps up this circulation of the sterilizing agent for a certain length of time, and an additional sterilizing agent is added continuously by the sterilizing agent generator  31 . 
     The direction of the flow through the chambers  12 ,  13 ,  14  that are to be sterilized is perferably changed multiple times, so that finally even regions of the chambers  12 ,  13 ,  14  and their built-in fixtures that remain in the lee are disinfected to a high degree. 
     After presterilization lasting about 20 minutes, the chambers  12 ,  13  and  14  and their devices are flushed with sterile air (FIG.  4 ). Once the supply of sterilizing agent has been stopped, which is done by closing the valve  41 , the valves are connected to the sluices  21 ,  22 , and the valves  36  and  38  in the line  35  and the valve  48  in the line  47  are all opened. By switching the blower  37  to the feeding direction in which feeding is from the sterile air source  32  in the air distribution chamber  30 , air flows through the sterile air source  32  through the valves  36 ,  38  into the air distribution chamber  30  and from there through the superfine filter  29 , which is preferably an LF filter (laminar flow filter), in a laminar flow into and through the cooling chamber  13  and the filling and sealing chamber  14 . The superfine filter  20  traps germs and dust particles, so that in the chambers  13  and  14 , a sterile atmosphere at a slight ovepressure is built up and maintained. Air drawn off at the bottom through the branches  51 ,  52 ,  53 ,  54  and aspirated through the line  47  by the blower  37  via the distributor  43  is recirculated. 
     To begin the filling operation, after flushing has been done for a certain length of time, the flaps  23 ,  24  of the sluices  21 ,  22  are opened (FIG.  4 ). The containers to be filled are places on the conveyor chain  25  and are then first carried through the sterilization chamber  12 . There, they are heated to a high sterilization temperature, at which germ adhering to them die off. After cooling down in the cooling chamber  13 , the containers are then filled and sealed in the filling and sealing chamber  14 , and they then pass out of the apparatus through the sluices  22 . The air emerging through the opened sluices  21 ,  22  is replaced by aspirating fresh air through the sterile air source  32 . 
     The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.