GB1354810A - Centrifugal separator discharge control system - Google Patents

Abstract

1354810 Centrifugal separators SIGNAL OIL & GAS CO 21 Aug 1972 [30 Aug 1971] 38822/72 Heading B2P A centrifugal separator for separating a mixture of two fluids of different densities comprises means to sense the fluid pressure in the outlet 38 for the centrifugally separated lighter fluid, means to sense the fluid pressure in the separator inlet 44, and a valve 54 in the lighter fluid outlet 38 and operably connected to both sensing means to discharge separated lighter fluid from the separator when the sensed pressure of the lighter fluid exceeds a preselected value above the sensed inlet fluid pressure. The separator may be used for separating an oil-water mixture and comprises a perforateinner drum 12 within an imperforate outer drum 14 and spaced therefrom by radial septa 24 which divide the annular space between the drums into sectors 28. The interior of the inner drum 12 is likewise divided into sectors 32 by radial septa 30. Vanes 36 and 42 are provided between the ends of the inner and outer drums. The whole assembly is rotatably mounted in bearings 46, 50 and driven by a belt 52. The valve 54 is of the diaphragm type and is connected in the outlet 38 by a bearing and seal housing 53. A coil spring may be incorporated in the valve to bias it towards the open position. In operation, the oil water mixture fed through the inlet 44 is forced outwardly into the annular space between the drums 12 and 14 by the vanes 36. Water separated outwardly by centrifugal force in the annular space is directed by the vanes 42 out through the heavier fluid outlet 48. The oil flows inwardly through openings 16 in the iner drum 12 to form a cylinder of pure oil at the centre thereof and is directed to the lighter fluid outlet 38. The septa 24, 30 keep the fluid rotating at the same speed as the integral unit. As shown, one side of the diaphragm tending to open the valve 54 is subject to the pressure in the lighter fluid outlet and the other side tending to close the valve is subject to the pressure in inlet 44. The valve 54 will remain closed until there is sufficient accumulation of oil within the drum 12 to create a pressure greater than the pressure in inlet 44. In another embodiment, Figs. 4 and 5 (not shown), the lighter and heavier fluid outlets are at opposite ends of the separator which has a central, perforated hollow drive shaft through which the lighter fluid is discharged towards its outlet. The interior of both the inner and outer drums are divided by weir-type partitions so that separation occurs by stages in the annular space between the drums.