This is a rotary sterilizer that is ideal for sterilizing all kinds of containers (including jars), using hydrogen peroxide (H2 O2) in its liquid state in order to increase the shelf-life of products such as fruit juices, milk and derivatives. In order to achieve this objective, it is, in fact, essential to exercise great caution during the decontamination of the containers and regarding the hygiene of the bottles. To this end, there is an initial phase during which the container is preheated with hot air (or steam) in the infeed star wheel of the machine, where the injection of hydrogen peroxide, at a concentration of 30%, also takes place.
The oxygenated water is injected (together with the hot air) through special “atomizer” nozzles in the form of spray, so as to totally cover the internal wall of the container with a thin film, considerably reducing the quantity required for each container (0.2-1ml.). These small quantities of hydrogen peroxide are injected extremely quickly, in a few tenths of a second, time intervals that are extremely difficult to control with mechanically operated spraying valves.
For this reason, the injection times of the various cycles are entirely controlled by an electronic system; each “atomizer” nozzle is supplied by two solenoid valves (one for hot air and the other for peroxide), activated, in turn, by the PLC, which controls all the phases of the machine. In this way, maximum flexibility of the entire system is guaranteed together with optimization of consumption. Once the first phase in the infeed star wheel has been completed, the containers enter the rotating carousel where the peroxide activation phase is initiated using hot air at temperatures of 110-120°C (or steam at 121°C). Also, during this phase, control of the hot air (or steam) injection times is of fundamental importance; this is carried out by solenoid valves, operated by the PLC.
The machine is equipped with safety devices that control the efficacy both of the “atomizer” nozzles and of the blowing nozzles; if a nozzle were to malfunction, this would, in fact, result in the failure to sterilize the corresponding container. In the event of a nozzle malfunction, the machine stops in a preset position so as to allow the operator to remove the unsterilized bottle (an automatic ejection system of the bottle also exists, as an optional).
The machine is also equipped with a hot air (or steam) temperature control system consisting of probes positioned on the ends of the blowing nozzles; if the temperature is too low, the machine stops in order to avoid the risk of the peroxide not being activated and the containers not being sterilized.
In order to reduce possible traces of peroxide, reaching residual concentrations of less than 0.5 p.p.m., it is possible to add a third rinsing phase of the bottles with sterile water, if steam is used as the fluid used for activating the peroxide.
If, on the other hand, hot air is used (patented technology), this guarantees high levels of decontamination of the containers (log 5) even with short treatment times, leaving the said containers completely dry.
In order to guarantee the perfect cleaning and decontamination of the containers, the machine may be equipped with a filtered air laminar flow cabinet using HEPA filters; in this way, the area in which sterilization takes place is kept in a state of slight overpressure, allowing the air to flow towards the outside, thereby avoiding possible sources of contamination. The containers reach a high level of decontamination and arrive at the filling phase in the required conditions of hygiene and sterility.
