The invention discloses a portable sterilizer for use when filling containers for transporting goods under aseptic conditions, which provides increased transport capacity, more flexible formats and connections for the containers, while facilitating handling of the goods, and which comprises a portable boiler, systems for pre-washing using chemicals and other means necessary for sanitizing all the parts thereof. For washing, it uses chemicals, circulation waters and the hot water (or any other liquid poured into said boiler) produced from the liquid phase inside said portable boiler. The device may include a pump for pressure washing with other types of cleaners, cold water, chemicals, etc.； For sterilizing, it uses the vapour phase of water or other liquids in said portable boiler, ultraviolet rays and/or another means of sterilization, and it is connected between the outlet of the pasteurization system of a production plant and the return lines of said pasteurizer. Said system is connected by means of flexible hoses. The system washes and sterilizes the filling and return lines of receptacles or containers, as well as the valve of said receptacles or containers. The system may also wash and sterilize the filling and return lines of the producer in a partial manner.
