GB413460A - Method of and apparatus for pasteurising lacteal liquids - Google Patents

Abstract

413,460. Pasteurizing and deodorizing cream &c. MURRAY DEODORISERS, Ltd., Room 23, G.P.O. Building, Auckland, New Zealand.-(Assignees of Murray, H. L. ; 15, King Edward Avenue, Epsom, Auckland, New Zealand.) April 24, 1933, Nos. 11930, 11931, and 11933. Convention dates, May 26, 1932, July 20, 1932, and Sept. 22, 1932. [Class 49.] Lacteal liquids such as cream are pasteurized by gently diffusing or mingling together steam and a substantially thin or dispersed body of the liquid while passing through a container to cause a substantially instantaneous raising of the liquid to pasteurization temperature. The process may be effected under ordinary pressure, and creation of vacuum in the pasteurizing chamber may be prevented by provision of air vent means. Alternatively, the pasteurization may be carried out under vacuum, e.g. by drawing the liquid through the pasteurizer by the pull of the vacuum. In one, form, the liquid is fed from an inlet 2, Fig. 1, through a diffuser tube 1 to an outlet 3, the tube 1 having small orifices 18 through which steam diffuses from a jacket 12 to which it is supplied through a regulating valve 13 and which it leaves through outlet 17. Within tube 1 is disposed a core 8 having blades 10 which contact with the tube and which, on rotating the tube by means of a hand-wheel 11, effect removal of deposit formed by the liquid in the orifices 18. The blades 10 may be in sections and staggered to allow the streams of liquid to intermingle during the heating step. In a modification, Fig. 2, a series of spaced rings 20 replace the perforated tube 1, the rings having central supporting bosses 22 from which extend spokes which are preferably of spiral form to prevent the liquid flowing straight through. The bosses 22 fit on a central spindle 24 on which they are secured by a nut 29 which clamps them against a shoulder 30. Knife blades connected together by bridge members 33 and removably secured in position by nuts 35 extend between the rings 20 which can be rotated by a hand-wheel 11 so as to clean out the spaces between the rings. Circular blades which can rotate on a shaft and which are removable may also be employed. In a further form, the liquid is passed in diffused or rain form through the steam, the liquid being supplied through a pipe 45, Fig. 5, having a strainer 46 to a float tank 44 which may be of the kind described in Specification 220,627, [Class 49]. The liquid passes from tank 44 through pipe 2 to a hollow spray ring 42 disposed in the pasteurizing chamber 37, and meets steam at a pressure only slightly above atmospheric supplied through a valve 13, the steam expanding and losing its superheat on entering the chamber 37. The chamber has a relief valve which is set to relieve any vacuum created by condensation of the steam or any pressure above the low pressure desired. The treated liquid leaves through a pipe 39 which acts as a seal. In a modification (Fig. 6 not shown), the chamber 37 is of inverted conical form and the liquid is supplied in a spray from a chamber which has at the bottom a removable spray plate with orifices in ring form thereon. The steam is supplied to an expansion chamber at the top of the pasteurizing chamber into which it passes through a conical-shaped perforated plate. To complete pasteurization the liquid may be passed from the pasteurizer to a holding vessel 57, Fig. 4, which is substantially closed at the top by a plate 58 having a downwardly projecting cylindrical portion 59. An outlet 60 and a drain 61 are provided. With the pasteurizer of Figs. 1, 2 the outlet 3 is connected tangentially to the vessel 57, the pasteurizer being mounted at a lower level than this connection to ensure sealing thereof. With the pasteurizer of Fig. 5, the bottom pipe of the pasteurizer 47 is straight and projects down into the liquid in the vessel 57 to form the seal and the cover plate 58 is omitted. The Specification as open to inspection under Sect. 91 comprises also the use of the pasteurizer with a deodorizer constructed as described in Specification 404,729 the vacuum maintained in the deodorizer drawing the liquid through the pasteurizer and thence into the deodorizer. Means are included for automatically varying the ratio between the vacuum in the pasteurizer and the deodorizer consisting of a cylinder having large and small portions 72, 73, Fig. 10 (Cancelled) with large and small pistons 75, 76 respectively connected to one piston rod 77 which actuates a butterfly valve 84, in the pipe 71 connecting the pasteurizer with the deodorizer, through a connecting rod 82 and a lever 83. The upper end of the cylinder has a cover 78 from which a pipe 79 extends to a suitable point on the pasteurizer. The space 74 between the pistons is connected by a pipe 80 to the deodorizer. The rod 82 has a shoulder 85 to receive removable weights 86. The areas of the pistons correspond to the degress of vacuum in the pasteurizer and deodorizer respectively, the larger piston 75 corresponding to the lower degree of vacuum in the pasteurizer, and so long as the balance is maintained the valve 84 will remain open. If the vacuum in the pasteurizer increases, the piston 75 will be moved upwards causing closing of the valve 84 and restoration of the required ratio of vacuum. This ratio may be varied by altering the weights 86. To prevent rapid movement of the valve 84 dash pot means may be fitted to the rod 87, the rod 82 or the lever 83. This subject-matter does not appear in the Specification as accepted.