GB971234A - A process for operating continuous sugar centrifuges and sugar centrifuges for use in such proces - Google Patents

Abstract

971,234. Centrifuges. BRAUNSCHWEIGISCHE MASCHINENBAUANSTALT. Sept. 28, 1962 |Nov. 24, 1961], No. 36858/62. Heading BID. In the operation of continuous sugar centrifuges with substantially conical centrifuge cages, over the screening surface of which the layer of material being centrifuged is transported, the said layer of material is heated over its entire height, thereby increasing the output of the centrifuge. The layer of material being centrifuged may be heated, at least in the region of the top edge of the centrifuge cage, to the limit of the solution temperature range used in the production, thereby regulating the centrifuge to optimum output. Preferably said layer of material is heated as uniformly as possible over its entire height, suitably to 52-80 ‹C. and especially 65-75 ‹C., and air circulation, and currents of air between the inside of the cage, the molasses compartment, and/or the sugar compartment, particularly those passing through the layer of material on the centrifuge, are prevented. Heating may be effected frictionally, or by external means, e.g. by admitting steam or hot air into the molasses compartment, or by dielectric heating. Heating media, e.g. steam or hot air, are preferably admitted to said compartment in the region of the narrowest cross-section of the centrifuge cage. Control instruments may be used to measure the temperature of the layer of material as close as possible to the top edge of the centrifuge cage, e.g. placed suitably in the molasses compartment, and thereby effect regulation of either the layer thickness, i.e. input rate if frictional heating is used, or of the energy input, if external heating is used. Apparatus as shown comprises a substantially conical screening surface and centrifuge cage 2 arranged inside a housing, surrounded by the molasses compartment 4 and communicating over the top edge with the sugar compartment 5, the casing being enclosed by top and bottom covers 12, 13 and a baffle, suitably an extended sugar crystal deflector ring 14, being inserted in the region of the gap between the sugar compartment and the centrifuge cage, the baffle extending into the cage to a position in which it makes sealing contact with the layer of material being centrifuged. The material feeder 11 may also be fitted with a baffle 15. In the apparatus of Fig. 1, heating is effected by friction. That of Fig. 2 includes an inlet pipe 17 connected to a mixing valve 21 and control valve 22, and a source of steam or hot air at 22a and cold air at 22b, the control valve being regulated by a temperaturesensing device 19 in the molasses compartment to maintain a constant temperature therein. In Fig. 3, the centrifuge cage or its screen surface constitutes an electrode for dielectric heating and a counter-electrode 18 is mounted inside the centrifuge cage, 20 being a temperature-sensing device.