GB810521A - Method and apparatus for removing entrained moisture from oil - Google Patents

Abstract

Water which is occluded in a substantially water-immiscible liquid, e.g. a virgin fuel or lubricating oil, is removed by forming an intimate mixture of the liquid and an inert gas, such as air, whereby a fine dispersion of the gas <PICT:0810521/III/1> <PICT:0810521/III/2> <PICT:0810521/III/3> in the liquid is obtained, subjecting the dispersion to circulation and repeated compression and expansion thereby causing a foam of gas and water to separate from the liquid, and finally passing the mixture to a quiescent zone where the moisture-laden gas is liberated leaving the required water-free liquid product. Hydrocarbon oils may be dehazed at a temperature of 90-170 DEG F., preferably 100-118 DEG F., to obtain bright, clear products. The oil is first separated from free water in tank 6 (Fig. 1), and then flows through conduit 10 into the bottom of tank 15. An electric motor 24 is mounted on supports above the open top of tank 15; the driving shaft 25 depends into the tank, and a rotor 26 is attached to the shaft. The rotor has upper and lower spiders 28, 29 (Figs. 2 and 3); and spaced-apart staves 34 extend between the rims 30, 32 of the spiders. Coaxial with the rotor is a stator 35 which also comprises a plurality of vertical staves 39, these being mounted between rings 37, 38 so as to be parallel to staves 34. A chamber 40 is positioned between ring 37 and the plate 17 which supports the motor; and atmospheric air is accessible to the rotor through opening 18, chamber 40 and the openings 31 in spider 28. The oil, discharged from conduit 10, moves upwardly through the openings 33 in spider 29 into the rotor where it is vigorously agitated; and air is simultaneously drawn into the rotor so that fine bubbles of air are dispersed in the oil. The dispersion moves outwardly through the openings between the staves of the rotor and of the stator and, in the course of this movement, it is compressed and subsequently expanded; and there is a circulation of the dispersion in the tank during which moisture is separated from the oil and is absorbed by the air in the form of foam. The foam rises and flows, together with oil, down spillway 42 into tank 43, where the foam breaks. The oil, now in a clear and bright condition, is withdrawn via conduit 44. The treatment of vegetable oils is also referred to.