GB417993A - Improvements in or relating to method and apparatus for pasteurizing deodorizing or similarly treating milk or like liquids - Google Patents

Abstract

417,993. Pasteurizing and deodorizing milk &c. STEVENS, A. H., 5, Quality Court, Chancery Lane, London.-(Pfaudler Co. ; 89, East Avenue, Rochester, New York, U.S.A.) Feb. 17, 1933, No. 4965. [Class 49.] Milk and like liquids are simultaneously pasteurized deodorized and deaerated by continuous and repeated circulation through a closed system under vacuum, the liquid being subjected to a partial vacuum while in a state of relatively fine subdivision within the system and being heated and maintained at pasteurizing temperature for the pasteurizing period whilst being circulated in the system. In one form, milk is withdrawn from a closed tank 16, Figs. 1, 2, by a pump 18 and passes through pipes 17, 19, a heater 9, a vacuum chamber 10 from which it is returned to the tank 16 by a pump 29 through pipes 28, 30, 31, 32. The heater 9 consists of inner tubes 11 through which the milk passes enclosed by tubes 12 through which the heating medium and if desired subsequently a cooling medium is passed, the ends of the tubes being connected by heads 13. The milk may be discharged into chamber 10 in a fine state of division, preferably by providing relatively small jet-like openings or relatively narrow slots 27 in the entry pipe 24 to facilitate removal of objectionable gases and vapours. The receptacle 10 is connected to vacuum through a pipe 36. To accelerate removal of the objectionable constituents, steam or air or other gas is supplied through a perforated pipe 38. The heating medium in heater 9 consists of water which is supplied through a pipe 41 and a valve 47 which is shut when the apparatus is full. The water is then circulated through pipes 41, 43, 12 and 45 by an injector 42 to which steam or other heated vapour or gas is supplied, for heating the water, through a pipe 48 having a valve 53 which is automatically controlled from a heat-responsive element 59 inserted in the milk discharging from the heater 9. The valve 53 has a byepass 50 with a valve 51 which can be opened to supply the steam &c. without the automatic control. A head of water is maintained while the ejector is operating by connecting pipe 43 with a pipe 46 by opening a three-way valve 44. The milk is circulated through the apparatus until the pasteurization and deodorization are completed, after which, whilst the circulation is being continued, cold water or other cooling liquid is passed through the apparatus 9 to cool the milk by opening valve 47 and by closing valve 44 to the injector, the cold water circulating through pipes 45, 12, valve 44 and discharging through pipe 46. In a modification (Fig. 3, not shown) the receptacle 10 is omitted and the removal of objectionable gases &c. is effected in the milk tank into which the milk coming from the heater is sprayed, the tank having a connection to vacuum, a perforated pipe through which steam is discharged and a propeller or other agitating means to assist in liberation of the gases &c. A second heat transfer unit is disposed above the unit 9 and is preferably used for cooling the treated milk when it is being discharged from the tank to the filling machine.