The decontamination process involves a classic autoclaving/sterilization cycle, involving the following steps:
- Pre-vacuuming: Air is extracted using a vacuum pump. Air is easily evacuated from the shredded waste, letting the steam penetrating the waste better and ensuring a uniform temperature throughout the dwell time. During this stage, condensates are blocked in the decontamination chamber. The extracted air is considered as potentially contaminated and is hence filtered through a 0.2 µm filter before being released from the chamber.
- Heating: The steam produced by the integrated steam generator is injected to heat the chamber as well as the solid and liquid waste. The steam is injected at the bottom of the chamber and the temperature control sensor is located at the top of the chamber. This ensures the steam is distributed evenly and heats both solid and liquid waste.
- Decontamination (sterilization) at 135 °C/275 °F, treatment time/dwell time: 10 or 20 min: (The sterilization dwell time can be adapted according to local requirements). During this stage, the temperature is uniform throughout the treatment chamber to ensure decontamination of the solid waste (at the top of the chamber). Liquid is stored in a cavity at the bottom of the chamber until the end of the decontamination stage and is also thermally treated. Liquid is only discharged into the drain once the cycle has finished.
- Cooling and return to atmospheric pressure: The steam is released from the machine as atmospheric pressure is reached. The steam is condensed, cooled and discharged through the drain piping in the sewer. Decontaminated liquids are also cooled and discharged in the sewer.