Improvements in and relating to vacuum pans for boiling sugar and like purposes

摘要

PICT:0458882/III/1 A vacuum pan 1 for boiling sugar and the like has a vertical tubular shaft 5 extending into the pan and carrying spaced heating and agitating elements 3, 4. Part of the shaft is double-walled to form an annular passage 10 round a central bore 12 serving as a heating fluid conduit to at least one element 3, and the passage 10 communicates with a compartment 11 formed by partitioning another part 6 of the shaft and conducting heating fluid to at least one other element 3. The pan has a calandria 2 between the steam-heated elements 3, 4 which may each comprise a multi-tubular structure or a set of radial field tubes on a rotary sectional shaft. Steam admitted by pipes 13, 33 to the conduits 10, 12 passes therefrom by ports 29, 30 to outlet pipes 23, 26.