Patent GB-1457750-A (GB)
Title: Centrifugal separator for three phase mixture
IPC: B01D17/02
Filed: 1973-12-31
Abstract: 1457750 Centrifugal separators SIGNAL OIL & GAS CO 31 Dec 1973 [16 Jan 1973] 60225/73 Heading B2P A centrifugal separator for separating a fluid mixture consisting of a higher density liquid a lower density liquid and a gas comprises a rotatable drum 10, Figs. 1 and 2, inlet means 46 for feeding the fluid mixture into the drum near the axis of rotation at one end of the drum, a separation chamber 32 adjacent the inlet means for receiving the gas and some of the liquids of the mixture and for separating the gas from the liquids, an impeller 44 within the drum proximate the inlet means for directing degassed higher density liquid and lower density liquid outwardly into the drum and where the highest density liquid separates from the lower density liquid and means 31, 70 for recovering the separated liquids from the drum. The centrifugal separator may be used for treating all oil-water-gas mixture. A perforated barrel 18 is fixed in the drum by radially ex tending septa 20 which divide the annular space between the drum and the barrel into 'sectors and which extend partly within the barrel thereby also dividing its interior into sectors. Weirs 22, 24, 26 ad 28 are arranged in the annular space to facilitate the oil-water separation. The gas separation chamber 32 is isolated from the interior of the barrel 18 by a plate 34 and has a face plate 36 provided with inlet and outlet ports 38, 40 and with a gas discharge nozzle 29 communicating with a discharge pipe 30 surrounded by the mixture inlet annclus 46. The impeller 44 consists of curvilinear vanes extending from the inlet annulus 46 to the wall of the drum. A discharge turbine 48 is provided at the outlet end of the separator. In operation, the oil-water-gas mixture is pumped through the inlet annulus 46 and is directed outwardly by the impeller 44 whereby the gas is released and enters the separation chamber 32 through the ports 38 and the oilwater mixture passes into the annular space between the drum 10 and the barrel 18. Any oil and water entrained with the gas into the chamber 32 is separated therein by centrifugal force and discharged through the ports 40 back into the impeller area 42. The gas is removed centrally through the nozzle 29 and the pipe 30. A pressure regulator (not shown) is provided on the pipe 30 for controlling the gas-liquid interface level within the chamber 32. In the annular space the water and oil are centrifugally separated. The oil passes through the perforations into the interior of the barrel and is discharged through a tube 31. The water passes over the weir 28, through the turbine 48, which recovers the energy imparted to the mixture entering the separator, and through the exit annulus 70. In a modification, Fig. 4 (not shown) the face plate (52) of the gas separator chamber has only inlet ports (50), the peripheral wall of the chamber being provided with longitudinal slots (54) for the discharge of entrained water and oil. In a further modification, Fig. 5, solids present in the oil-water mixture are separated by centrifugal force and collect near the first weir 24 where they are periodically removed through a valved opening 62. Clean out plugs are provided at 64.