Patent GB-1514850-A (GB)
Title: Sterilizer for culture media and laboratory ware
IPC: A61L2/24
Filed: 1976-07-26
Abstract: 1514850 Automatic sterilizers NEW BRUNSWICK SCIENTIFIC CO INC 26 July 1976 31071/76 Heading A5G Sterilizer for taking a solid or fluid especially culture media and laboratory ware through a timed temperature cycle without bringing the solid or fluid into direct contact with steam comprises (a) a vessel 11 for receiving in use the solid or fluid and having top and bottom portions; (b) a closely fitting jacket 12 surrounding the vessel and defining with the vessel a narrow jacket space 37 therebetween the jacket having top and bottom portions; (c) a boiler 32 including a heater 33, 34 for boiling water to form steam and for transferring a mixture of boiling water and steam generated in the boiler from the boiler to the jacket by the expansion of water in forming steam; (d) a supply conduit 42 joining the boiler to the jacket proximate the top thereof for carrying boiling water and steam from the boiler to the jacket near the top thereof and into the jacket space for heating the vessel and any contents therein; (e) guiding means 13 for leading the water through the jacket space to the bottom of the jacket in a path such that the water makes contact with a portion of the exterior of the vessel great enough for effective heating of the vessel and contents thereof, (f) a return conduit 39 joining the jacket proximate the bottom thereof to the boiler for returning the water from proximate the bottom of the jacket to the boiler; (g) a first pipe 56 and valve for introducing cooling water into the jacket near the top thereof; (h) a second pipe and valve for draining water from the jacket: (i) a temperature sensor 48 in the vessel adapted for transmitting a signal corresponding to the temperature of the vessel; and (j) a programmable controller constructed and arranged for receiving signals from the sensor for controlling heat output by the heater and flow of cooling water in response to the signal and an imposed timed-temperature program. A solid or fluid is taken through a timed temperature cycle by the above apparatus by boiling water at a first high rate in the boiler, transferring the boiling water at the first high rate through the supply conduit into the jacket, through the jacket and back to the boiler through the return conduit, the first high rate transfer of the boiling water being continued until the vessel reaches a first selected elevated temperature; transferring boiling water at a second average medium rate under the control of the sensor in the vessel and the programmer and the controller to hold the vessel at the first selected elevated temperature for a preselected period of time; transferring boiling water at a third low rate and cooling water through the jacket to lower the temperature of the vessel to second elevated temperature; and continuing to pass boiling water at the third low rate through the jacket and passing cooling water through the jacket as necessary in order to hold the vessel at the second elevated temperature, all of the steps being carried out automatically under the control of the programmer and controller.