Method and apparatus for treating liquid materials

A process for sterilizing a liquid food product in a pressure vessel at a predetermined temperature where said product can have and important property adversely affected by being excessively heated or excessively physically stressed, the improvement comprising the steps of:

• supplying said product to an apertured means of a film forming head positioned within said vessel at a uniform velocity throughout the length of the film forming head;
• discharging said product at a predetermined flow rate from said aperture means directly into said vessel without contacting any surface other than said aperture means to form a continuous substantially uniform thin isolated free falling film of said liquid product within said pressure vessel;
• directly heating said body of product as a continuous falling film to a predetermined sterilizing temperature in a predetermined time period by providing low velocity substantially saturated steam at a constant above atmospheric pressure to said pressure vessel in such a way as to maintain said film as a continuous, isolated free falling film of liquid product,
• causing said liquid body of product to pass directly from said aperture means to fall freely through said saturated steam without engaging any solid surface within said pressure vessel that is higher in temperature than said liquid product;
• providing a sufficient height of fall of said thin film in said low velocity steam to maintain said falling film as a continuous isolated free falling film during said time period t it is raised to the sterilization temperature of the liquid,
• cooling the interior surface of said vessel so as to provide a temperature that will not heat the fallen product;
• accumulating said liquid product of said falling film in said pressure vessel in contact with the cooled interior surface of said vessel, while maintaining said product in a liquid form in a continuous uninterrupted flow from falling as said continuous falling film to accumulating in said liquid form due to said predetermined discharge flow rate from said aperture means;
• and
• withdrawing said fallen liquid product from said vessel without subjecting it to splashing or other violent physical agitation.

An apparatus for heating a liquid product in a pressure vessel to a predetermined treatment temperature where said product can have an important property adversely affected by being excessively heated or excessively physically stressed, the improvement comprising:

• means for supplying said product to an aperture means of a film forming head positioned within said vessel at a uniform velocity throughout the length of said film forming head;
• said aperture means arranged for discharging said product at a predetermined flow rate from said aperture means directly into said vessel without contacting any surface other than said aperture means to form a continuous substantially uniform thin isolated free falling film of said liquid product within said pressure vessel;
• means for directly heating said body of product to bring it to said predetermined treatment temperature in a predetermined time period by providing low velocity substantially saturated steam at a constant above atmospheric pressure to said pressure vessel in such a way as to maintain said film as a continuous, isolated free falling film of liquid product;
• said aperture means arranged in said vessel to cause said body of liquid product to pass directly from said aperture means to fall freely through said saturated steam without engaging any surface within said pressure vessel that is higher in temperature than said liquid product;
• said aperture means located in said vessel to provide a sufficient height of fall of said thin film in said low velocity steam to maintain said falling film as a continuous isolated liquid film during said time period that it falls and is raised to said treatment temperature of the liquid;
• means for cooling the interior surface of said vessel so as to provide a temperature that will not heat the fallen product;
• said vessel arranged to accumulate said fallen product of said film in said pressure vessel in contact with the cooled interior surface of said vessel, while maintaining said product in liquid form in a continuous uninterrupted flow from falling as said continuous falling film to accumulating in said liquid form due to said predetermined discharge flow rate from said aperture means;
• and
• means for withdrawing said product from said vessel without subjecting it to splashing or other violent physical agitation.