Pasteurising system control methodology

The present invention relates to a control method for tunnel pasteurising systems in which, at the end of the treatment, each product must have remained above a predetermined temperature for at least a predetermined time, and accumulated at least a predetermined quantity of pasteurisation units. In tunnel systems, the products, like bottles or other containers, to be pasteurised are fed by a conveyor along a path which is usually divided into three main zones: a heating zone in which the product temperature is gradually raised; a heat treatment zone in which the product temperature is brought to and kept at the pasteurising temperature; and a cooling zone in which the product temperature is gradually lowered. The heat treatment zone is, in turn, divided into a plurality of sub-zones which operate independently. The product is heat treated by applying a flow of hot fluid at the required temperature on the product. Usually the fluid is a liquid, such as hot water, which is injected or sprayed or applied in an equivalent or similar manner on the product; other fluids are contemplatable, like gases, such hot air, which are injected on the product. In the following, the terms "injection", "inject", "injected" will be used to refer to any known manner for applying a flow of hot fluid on products in tunnel pasteurising systems.