NSI Equipment Pvt. Ltd. sugar Evaporator consists essentially of a tubular calandria serving as a heat exchanger the heating medium is normally exhaust steam. The juice flows through the tubes, while the steam moves in the space outside the tubes. The steam comes in contact with the Tube surface.A series of vessels, in which excess water from the juice is evaporated to forma more concentrated liquid, now called syrup. The vessels work in series under increasing vacuum conditions, to reduce the boiling temperature gradually as the concentration increases step-wise. This prevents over heating of juice and loss of sucrose. The vessels together form a triple-, quadruple- or quintuple-effect evaporator.
In a multiple-effect evaporator, juice is boiled in a sequence of vessels, each held at a lower pressure than the last. Because the boiling temperature of juice decreases as pressure decreases, the vapor boiled off in one vessel can be used to heat the next, and only the first vessel (at the highest pressure) requires an external source of heat. The exhaust steam supply to the first evaporator is controlled to give the total evaporation required to maintain the product syrup at the set range of 65 to 70 refractometer solids.Multiple effect evaporation commonly uses sensible heat in the condensate to preheat juice to be flashed. In practice the design liquid flow paths can be somewhat complicated in order to extract the most recoverable heat and to obtain the highest evaporation rates from the equipment.
Advantages / Design feature :
Less tube height less vapour pressure
Multi down take for bigger diameter of Calandria for large capacity
Better condensate removal