GB893633A - Improvements in and relating to process and apparatus for inspissating liquids - Google Patents

Abstract

<PICT:0893633/III/1> <PICT:0893633/III/2> In an evaporator of the type in which the liquid to be inspissated is caused to flow downwardly in the form of a thin boiling film, along with the vapours produced, through a nest of steam-heated tubes 3 (Fig. 1), improved distribution of the liquid to, and improved wetting of, the tubes is achieved by causing the heated or superheated liquid as it enters the expansion chamber 4, at 5, to impinge on one or more baffles 6, 7 whereby the liquid is separated from the vapour produced, the so-separated liquid being collected on a peripherally flanged apertured plate 8 where it builds up and is urged through the apertures therein, by static pressure only, on to a second apertured plate 11, and is then urged, along with previously separated vapour, through the apertures in this lower plate to the heating tubes 3, the vapour being fed to the space between the two apertured plates through the annular passage 9 without loss of pressure. The apertures in the plates 8 and 11 are preferably the same in number as, and positioned directly above, the tubes 3. The top apertured plate is preferably provided with a cover 12 and apertured eddy-preventers 13. In the construction of Fig. 2, the passage 9 for transferring the vapour to the space between the apertured plates constitutes a central tubular skirting to the upper plate 8. In a modification, the top plate in which the tops of the heating tubes are embedded constitutes the lower apertured plate, the tops of the tubes accordingly being provided with restricted orifices.