GB481257A - Improvements in centrifugal machines for cleaning sand or similar granular materials - Google Patents

Abstract

481,257. Centrifugal machines. CIMENT MANUFACTURE SOC. ANON. July 27, 1937, No. 20819. Convention date, July 28, 1936. [Class 23] Sand and other granular materials are successively washed, dewatered and screened in a centrifugal machine 2 the lateral wall of which is composed of superposed rings 14 which can be moved relatively to one another to form slots of desired width for the discharge of the washing water and grains of material of predetermined size. Compression springs 15 are interposed between the rings which have a cover 12 and a base 6 supported by ball bearings on the stationary hollow shaft 3 by means of a fixed collar 8. The base 6 has a bevel gear wheel 9 meshing with a pinion 10 on the driving shaft 11. The nut 16 is first screwed down to close the gaps between the rings 14 and sand or other material is put into the vessel 2 through the manhole 18. The vessel is rotated and washing water is passed from the pipe 5 to the hollow shaft 3 so that jets are discharged from the apertures 13. The sand and water are thoroughly mixed by an impeller 17 on the shaft and the nut 16 is rotated so that fine slots are made by the springs 15 forcing the rings 14 apart. This permits the washing water to discharge to the trough 20 but retains the sand. Further water is added to rinse the washed sand and the water supply is then stopped. The speed of rotation is then increased to dry the sand, and if desired compressed air may be supplied through the shaft 3. The nut 16 is then loosened to widen the slots between the rings to permit the sand to be discharged. By adjusting the size of the slots, sand grains of progressively increasing size may be discharged. The rings have inclined faces 22 to guide the sand to the slots 15, and an external shield 21 deflects it to the trough 20.