Ing. A.Rossi

Pasteurization and sterilization

Tube in tube pasteurizers


Once the production chain is completed, the elements responsible for product degradation must be inhibited in order to save the product preservation. Ing. A. Rossi uses a tubular pasteurizer with which the product to be packaged is brought to the pasteurization temperature. This type of processing is suitable for concentrated, semi-concentrated, fruit juice or fresh products, previously transformed to a direct packaging in glass, plastic, tinplate or brick.
The exchanger is composed of 4 concentric pipes in order to heat the product on two cylindrical surfaces and guaranteeing a uniform temperature inside. The thermo vector fluid is water heated by a direct steam injection.

Tube in tube and scraped surface sterilizers


In order to extend the preservation of treated products aseptic packaging, which consists in filling polifilm pre-sterilized bags with sterilized product at room temperature, is used. The product sterilization and cooling is obtained with tube in tube exchangers.
Composed of 4 or 2 concentric tubes, the exchangers include:

  • A product heating section with water overheated by a direct steam injection;
  • Up to the sterilization temperature, depending on the nature, pH, free water and previous treatments of the product;
  • A maintenance section at sterilization temperature and two cooling sections, the first generally cooled by tower water, and the second by refrigerated water or always by tower water.

Equipped with a washing and sterilization system with cooling constant pressure and with barriers in the dwelling and cooling sections (in order to prevent and avoid environmental contaminations), the Ing.A.Rossi sterilizers guarantee the right aseptic degree of the treated product and its preservation and stability in the warehouse.


The presence of scraped surface exchangers allows the containing of circulation pressures , in periods when the high production of high-viscosity products and concentration that might affect at high temperatures the product texture (Bostwick and Blotter).
To avoid this, Ing.A.Rossi offers tube in tube heat exchangers for heating and temperature maintenance stages and scraped surface exchangers for cooling stages. This solution well suits tougher products in which concentration and viscosity are essential characteristics.
Completely scraped surface solutions may be developed for particular products with suspension ingredients or with particular viscosity such as ready sauces and purees, as well as in systems in which the great possibility of variations in the capacities would not be applicable to the pipe system.

Sterilization and aseptic cooling


Ideal for high capacity systems and constant production, the Flash Cooler has been designed for sterilization and aseptic cooling of high viscosity concentrates, in which the preservation of the natural characteristics of the product and power and energy consumption are the priorities.

Concentrated products are heated up to sterilization temperatures by a direct steam injection and kept to temperature for the necessary time inside a holding tank. Here-hence they are sent to the under vacuum chamber where, by means of the flash effect, the product undergoes an immediate cooling at a temperature which can be adjusted between 15° and 38°C. This technology requires operating pressures which do not affect the organoleptic characteristics of the product.
The automatic control of the entire process allows a continuous monitoring and regulation of the production parameters, minimizing labour costs and improving the total capacity of the line.