Patent ID: 7972445

Claim:
A continuous pan crystallization apparatus comprising: a cylindrical housing having a vertical axis in which plurality of vacuum chambers are stacked one above the other on a common axis; each said chamber substantially having a W-shaped bottom with space below being surrounded by the passive steam of the chamber below; each said chamber having associated therewith a fixed set point control for condition of massecuite and discharge volume per hour and that the per hour discharge volume of a given operation chamber is greater than the per hour discharge volume of the immediately preceding operation chamber; a heat supply means comprising vertical tube fixed annular calandria supplied by active heating steam from a common supply external to the cylindrical housing; a central downtake in which an axial flow impeller or a mechanical circulator is located; at least one mechanism operable to control a) heating steam pressure, b) vapour pressure, c) massecuite condition, d) feed syrup supply proportion and flow rate, e) ratio of feed syrup to seed supply, f) massecuite level, and g) transfer of massecuite from the upper to the lower pan using transferring means which include gravity discharge means; a massecuite discharge pipe in the bottom of every chamber equipped with a control valve regulated by a level sensor of the same chamber and connected to the massecuite supply pipe of the next lower chamber; an inlet for introduction of feed syrup in each chamber connected to a common syrup feed header through a control valve regulated by a brix sensor; a means for continuously introducing seed crystals into the first operation chamber; an outlet for continuously withdrawing sugar syrup and product crystals from the last operation vacuum chamber; means for exhausting vapour and non-condensables through a common vapour line connected to a condenser/vapour recompressor and also equipped with means for entrainment separation; means for removal of condensate; means for bypassing a particular operation chamber by arrangement of appropriate pipes; means for cleaning comprising valve-controlled steam supply line, hot and cold water supply lines with a wash out drain line connected to the massecuite discharge duct in the floor of the chamber and regulated by a control valve, outflowing into a common wash out drain pipe; each chamber having, a bottom mounted mechanical circulator, all but the lowermost of said mechanical circulators being housed in an insulated pocket in a vapour space segment of a succeeding chamber therebelow.