GB741678A - Improvements in or relating to a method of heat treating the contents of closed containers - Google Patents

Abstract

741,678. Sterilizing the contents of bottles &c. NISSEN, H. March 27, 1953 [March 29, 1952], No. 8493/53. Classes 49 and 81(1). In heat treating the contents of closed bottles or other containers in autoclaves by supplying steam under pressure to heat the bottles &c. to a desired temperature, maintaining the pressure and temperature for a period sufficient to accomplish the heat treatment and finally cooling the bottles &c. by exhausting the steam at a sufficiently slow rate to avoid breakage of or other damage to the bottles &c., the bottles stand in an open liquid bath, in order to enable, by evaporation of the liquid therefrom, the cooling period to be reduced. Further cooling by evaporation from the liquid bath after the exhausting of steam may be effected by causing pressure in the autoclave to drop below the pressure of the atmosphere by condensation of the remaining steam either by internal or external cooling of the autoclave or by connecting it to a jet or surface condenser. After attainment of atmospheric pressure within the autoclave, it may be connected with a pump for the production of a vacuum therein. As shewn, a bottle 7 whose contents are to be sterilized is placed in a bath 6 of distilled water in an autoclave 1, a test bottle 7 connected to a thermometer 8 being also provided, steam at 1“ atmospheres pressure is admitted through a valve 3, and, when the internal temperature of the bottles reaches 120‹C., the autoclave is left under a pressure of about 1 atmosphere for 20 minutes ; then the steam is exhausted via a valve 4 so that the water in the water bath evaporates evenly and quietly and the temperature drops in 15 min. to 100‹C., the temperature and pressure dropping at almost the same rate in the autoclave proper as in the bottles. Cooling is then continued by condensation of the steam by cooling of the autoclave and, if required, by a suction through the valve 4. The contents of the bottles are cooled to 65‹C. in “ to ¥ hour with high vacuum. Two or more water containers may be mounted above each other when a larger autoclave is used.