GB648767A - Improvements in and relating to evaporating and concentrating apparatus - Google Patents

Abstract

An evaporator comprises three steam-heated calandria sections interconnected in such a way that their tubes are traversed in series by the liquor under treatment, and means for controlling the heating of the three sections separately and independently of one another. The three sections may be embodied in a common shell or they may be separate. The apparatus is suitable for sterilizing and con <PICT:0648767/III/1> <PICT:0648767/III/2> <PICT:0648767/III/3> centrating milk. The shell 1 (Figs. 1 and 2), contains tubes 4 secured between end-plates 3 and arranged to form a preheater B, divided into six sections 8 to 13, and an evaporator A steam-heated by means of inlet 6 and condensate-outlet 6a. The feed first flows through sections 13 to 9 of the preheater which are all heated by thermo-compressed vapour from the system supplied through inlet 7; the condensate being discharged through outlet 7a. In the treatment of milk, section 8 is used as a sterilizer which is steam-heated to a temperature of 220 DEG F. by means of inlet 7b and outlet 7c; the milk having been first preheated to 157 DEG F. at a pressure of 40 lbs. per square inch in sections 13 to 9. The sterilized milk passes from section 8 through valve 15 into evaporator A where flashing takes place; the vapour and milk being conveyed by tangential conduit 16 into separator 17 from the bottom of which concentrated milk is withdrawn. Fig. 3 shows an apparatus for treating large quantities of milk wherein the preheater 20, sterilizer 21, and evaporator 28 are separate; the two latter sections being connected through a flash-chamber 23. Valves 25 and 26 are provided so that part of the preheated milk may be returned, if desired, to the storage tank 18. In this embodiment, the evaporator 28 is heated by thermo-compressed vapour from the separator 30. Specifications 384,741, 387,598 and 640,946 are referred to.