GB385588A - Improvements relating to centrifugal machines for drying pulpy material - Google Patents

Abstract

385,588. Centrifugal extractors. HEINZELMANN, H., 29, Giesserstrasse, Winterthur, Switzerland. March 24, 1931, No. 9004. Convention date, April 12, 1930. Void [Published under Sect. 91 of the Acts]. [Class 23.] A centrifugal machine for drying pulpy material has devices which exert a braking action against centrifugal force on the material during the first part of the drying process, and after part of the liquid has been expelled the remainder of the material is assisted through the drum by feeding devices. The outer drum 1 is carried by the shaft 5 while the inner drum 8 is secured to the shaft 12. The shafts are driven in the same direction at different speeds by means of the belt pulleys 6, 13. The drum 1 has a conical part 23 inclined to the axis at an angle greater than the angle of repose of the material for treatment, and a part 24 inclined at an angle less than the angle of repose. The part 23 has annular channels 35 covered by sieves 37 and having outlet openings 36. The part 24 consists of three sections I, II, III the inclination of each being opposite to that of the part as a whole. At the peripheries of the sections, openings covered by sieves 39 have outlets 40. The part 25 of the drum 8 has blades 27, 28, 29 shaped as shown in Fig. 2, and the part 26 carries pivoted plough blades 30 with balance weights 32 and adjustable setscrews 33. The interior of the drum 8 may be divided into two chambers by a transverse partition 34. The material to be dried is passed through the funnel 22 and shaft 5 to the space between the drums 1, 8 where it is moved outwards by centrifugal force. The shapes of the blades 27, 28, 29 retard its outward movement during the first part of the drying process and the expelled liquid passes through the sieves 37 to the casing. The material then passes to the section I of the drum 1 and separated liquid passes through the sieves 39, in a direction opposite to that in which the centrifugal force is acting, to the discharge outlets 40 ; with this arrangement the solids do not clog the sieve. With the assistance of the ploughs 30 the material passes on to sections II, III and the collector 51. A liquid for washing or otherwise treating the material can be passed through the pipe 21 to the interior of the drum 8 from whence it passes by openings 52 to section I. Another liquid may be passed through the pipe 19 to sections II, III. In a modification shown in Fig. 4, the drum part 23 has sieves 37 through which liquid flows into channels 35 and outlets 36. Metal flaps 54 over the sieves 37 form pockets which centrifugal force tends to close, but which the moving material tends to open, After passing the drum part 23, the material. in a partly dried state passes to the perforated drum 24 in which the drying is completed ; its passage through the drum 24 is assisted by blades 56 on the drum 8.