GB692574A - Improvements in and relating to methods of and apparatus for dewatering materials - Google Patents

Abstract

692,574. Filters. BRUCKENBAU FLENDER GES. June 16, 1950 [Aug. 5, 1949], No. 15123/50. Class 46 [Also in Group XXX] An apparatus for dewatering solid-liquid mixtures such as a slurry of fine coal, consisting of a static dewatering tower having preferably parallel sides and an inlet for the material to be dewatered adjacent to its upper end and a water outlet adjacent the lower end is characterized in that the tower is erected in an inclined position and is provided with a screen arranged over its lower inclined bottom wall and preferably extending over the entire surface. Slurry is supplied to a tower 1 from an inlet 2 and comes to rest against a wall 3 and hinged plate 3<SP>1</SP>. Water drains away through screens 6 to an outlet 8 connected to a collecting receptacle 18 communicating with a discharge tank 21 by a pipe 20. Dewatering may be assisted by suction provided by a vacuum pump 19, the pipe 20 in this case acting as an atmospheric seal. Compressed air may be introduced for agitating the tower contents or for cleaning the screens, a cock 22 being closed at this stage. In Fig. 2 the tower 1 is subdivided into zones 13 ... 16 by the provision of spaced draining pippes 9 ... 12, the zones being operable independently. The screen 6 may be arranged in step-like form, Fig. 3 (not shown). As in Fig. 1 an upper screen 7 may be provided and the tower may be closed or provided with a cover as shown. With independent operation of the zones the uppermost of them effects a preliminary dewatering of the mixture as it slides down the inclined bottom 5. For this purpose the suction pipe 24 of the uppermost zone is closed and the valve 26 in the by-pass pipe 25 opened, after which thewater may drain freely from the tank 21. Further dewatering by suction takes place in the various zones in succession as soon. as the material has sealed the screen of the particular zone from the outside air. When the tower is full the uppermost zone is again connected to the vacuum pump, whereupon final dewatering of the remaining zones is effected simultaneously.