GB1374023A - Centrifuge - Google Patents

Abstract

1374023 Centrifugal separators PENNWALT CORP 2 Feb 1972 [26 Feb 1971] 4979/72 Heading B2P A sludge centrifuge, Figs. 1 and 2, comprises a rotatable bowl 14, with an annular, inwardly extending liquid-overflow lip 34 at one end of the bowl, feed outlet means 21 disposed near the opposite end of the bowl and radially inwardly fromthe overflow lip for discharging feed radially toward the peripheral wall 32 of the bowl, means 26 and/or 42 for removing accumulated sludge from the wall, and a plurality of radially extending accelerator vanes 54 angularly. spaced from 4‹ to 30‹ apart from one another. The inner edge of each vane being disposed radially, as seen in plan view, anywhere between the feed outlet means 21 and a point located one-half inch outwardly from the overflow lip 34, the outer edge of each vane being disposed radially outwardly from the overflow lip a distance equal to at least one-third the total distance a from the overflow lip 34 to the peripheral wall 32, and each vane being wholly disposed in the end portion of the bowl opposite the overflow lip, the axial dimension e of the end portion being not more than one-third of the total axial length c of the bowl. This arrangement of accelerator vanes is stated to improve flow orientation, reduce turbulence and greatly increase the effectiveness of the separation process. Feed slurry is introduced into the bowl 14 through a stationary tube 16 provided with a solenoid valve 18 and opening into a core 20 from which the slurry exits via the outlet means 21. Alternatively, the slurry may be fed through a single pipe or via a feed receiving cup having one or more conduits extending to the bottom of the bowl. Accumulated sludge may be removed by means of a skimmer 24 which is reciprocable by a pair of pneumatic piston-cylinder assemblies. Subsequent to the skimmer 24, or instead of it, a knife blade 42, mounted by means of arms 41 on a shaft 40 rotatable by a motor 38, is used to remove the sludge, the latter in this case being discharged through openings 44, 46 in the bowl and housing respectively. The knife blade has a notch 56 which cooperates with the vanes 54 to allow the blade to be moved radially outwardly towards the wall 32. In a modification, Figs. 3 and 4 (not shown) only the skimmer (24a) is used and the accelerator vanes (54a) have no inner and outer rims and extend to the bottom of the bowl. In a further modification, Fig. 7B (not shown), the accelerator vanes (54c) do not extend completely to the wall (32c) of the bowl. In Fig. 7A, the vanes 54b are used in conjunction with a knife blade 42b and extend completely to the bowl bottom 33b which is inclined to minimize sludge accumulation. Other dimensions are given.