4o8 



CHAPTER XX 



claimed in Howard's classic patent (3754, 1813). This method passed into, 

 and still remains, a part of standard refinery practice in certain houses. 



Development of the Centrifugal. — The earliest reference to the centrifugal 

 as a mechanical power is contained in Penzoldt's French patent (8941, 1837), 

 as applied to drying wool. Hardman's British patent (9998, 1843) claimed 

 the application of centrifugal force as a new principle for removing liquids 

 from solids and was developed as being especially applicable to the sugar 

 industry. The machine illustrated by Hardman was a basket carried on a 

 vertical shaft, overhead belt-driven, and rotating in rigid bearings. He 

 stated that the revolutions should be 800-1,000 per minute, and called his 

 machine a molasses " disperser." The patent also claimed the liquoring 

 of the sugar in the machine with high-grade syrup. 



Fig. 254 



Very shortly after this a second patent was taken out by AUiott (10070, 

 1844), with reference to the drying of textiles. The upper bearing of his 

 machine was supported at the end of an arm of a crane-shaped frame, a 

 feature which still remains in use in certain machines. Another application 

 of centrifugal force is due -to Seyrig (French patent 3947, 1848), in whose 

 design the upper bearing of the spindle was carried in an inverted U-frame 

 or arcade, supported on the curb or outer casing of the perforated basket. 

 The machine was driven by friction cones or by buff wheels through belt 

 gearing. This type of machine was extensively used, and some still remain 

 in operation in cane sugar factories, especially in Brazil and Mauritius. 

 A modernized form of this design appears in Fig. 254. 



A patent granted to Brooman, as agent (12742, 1849), fixed another 

 standard type of machine, namely, that supported on top of the vertical 

 spindle, combined with under-drive, as indicated in a modern form in Fig 255. 

 Rotch, as agent, in a patent (13023, 1850), introduced a hemispherical 



