GB1091556A - Liquid purifying - Google Patents

Abstract

<PICT:1091556/C4-C5/1> <PICT:1091556/C4-C5/2> <PICT:1091556/C4-C5/3> An apparatus for purifying oil containing water e.g. turbine lubricating oil is shown in Fig. 1 as modified by Fig. 2 and comprises a centrifuge disc-type bowl 1 in a chamber 2 which is surrounded by a collector housing defining another chamber 3 closed by a hood 7 and surrounded by an annular heating chamber 4 provided with electrical heating rods or steam heating coils. A window is provided at 60. A pipe 9 connected to a vacuum pump serves to put the chamber 3 under vacuum. In use, the water-laden oil is fed at 5 into the chamber 4 and passes via a pipe 6, a channel 7a in the hood, a pipe 8, and an inlet 12 into the bowl 1 where the free water is separated. The partially purified oil discharges from the bowl via an annular outlet 13 and holes 30 in a disc 29 secured to the bowl, into the chamber 3 where, due to the existing vacuum, water dissolved in the oil is evaporated and is sucked through the pipe 9, entrainment of foam through the pipe 9 being prevented by a thin plate 62. The purified oil is extracted at 10. In the event of failure of the purified oil extraction pump and consequent rise of the oil level in the chamber 3 a float switch 61 automatically shuts down the centrifuge. To permit continuous discharge of the separated free water from the centrifuge bowl during centrifugation, a rubbing-collar type seal 20, 26 (see Division F2) is provided between the rotating wall of the oil outlet 13 and the stationary cover 14 of the chamber 2, whereby the space 27 defined by the cover 14 is pressure-isolated from the collector housing. The free water is discharged from the bowl, via an annular outlet (not shown) into the space 27 and is removed therefrom to atmosphere via a pipe 28. In a modification, instead of a rubbing-collar type seal being provided, the cover for the chamber 2 carries two, spaced-apart lip-type seals having their lips urged into contact with the wall of the oil outlet 13 by the combined action of a garter spring and of partially cleaned oil, which passes, through an aperture in the outlet wall, into the space between the seals. In a further modification, Fig. 4, a liquid seal is provided between the interior of the housing and the chamber 2. Partially purified oil passes through a bleed hole 51 in the outer wall of the discharge outlet 13 and accumulates in a chamber 42 to form the liquid seal barrier. Excess oil in the chamber is removed through a paring tube 41 which opens into the chamber 3. The free water is discharged through a passage 52 in the bowl 46 and passes through an annular gap 53 and through a port 54 into the chamber 2. In a modified form of Fig. 4, the paring tube 41 is omitted and the flange 40 at the lower end of the member 37 has attached thereto a number of radially extended guide members which direct excess sealing oil to the inlets of axial passages formed in the member 37. A further construction includes a vacuum tank separate from the centrifuge proper, the oil being pumped, after having been subjected to centrifuging to remove free water, into that tank where the dissolved moisture is evaporated.