APPARATUS AND METHOD FOR PREPARING A MIXTURE OF A LESS DENSE LIQUID AND A MORE DENSE LIQUID

摘要

1. An apparatus for separating a mixture of a less dense liquid component and a more dense liquid component comprises a vessel (1) having a vertical axis, an annular inlet (5) for the mixture in the bottom of the vessel and opening upwardly, the inlet being provided with means (4) for causing the mixture to swirl about the vertical axis as it leaves the inlet, a first outlet (8) at the centre of the annular inlet for the discharge of primarily the less dense liquid component which has been drawn down inside a vortex created by the swirling liquid, and a second outlet (10) towards the bottom of the vessel and spaced from the first inlet for the discharge primarily of the more dense liquid component which has been forced away from the vertical axis of the vessel by the centrifugal forces of the swirling liquid. 2. An apparatus according to claim 1, wherein control valves are provided on the two outlets, the valves being controlled in accordance with the quantities of the less dense liquid and the more dense liquid within the vessel to retain the levels of the two liquid components within predetermined ranges. 3. An apparatus according to claim 1 or claim 2, wherein level detectors (13, 14) are provided to detect the level of the free surface of less dense liquid component and the level of the interface between the two liquid components. 4. An apparatus according to any one of claims 1-3, wherein the vessel (1) is a high pressure vessel and a gas outlet (11) is provided at the top of the vessel. 5. An apparatus according to claim 4, wherein a demisting device is associated with the gas outlet (11) to dry the gas as it leaves the vessel (1) and return the liquid separated from the gas back to the main body of liquid in the vessel. 6. An apparatus according to any one of claims 1-5, wherein the swirl is caused by the annular inlet being provided with a tangential or involute feed (4). 7. An apparatus according to claim 6, wherein two tangential or involute feed inlets (4) are provided diametrically opposed to one another. 8. An apparatus according to any one of claims 1-7, wherein a hollow cylindrical shield (6A, 6B) is provided at the bottom of the vessel surrounding the annular inlet (5). 9. A method of separating a mixture of a less dense liquid component and a more dense liquid component comprises the steps of introducing the mixture under pressure into a vessel (1) through an annular inlet (5) in the bottom of the vessel and which is opened upwardly such that it swirls the mixture about a vertical axis and generates a vortex in which the less dense liquid component forms as a layer on top of the more dense liquid component and is also drawn down into the centre of the vortex; removing primarily the less dense liquid component through a first outlet (8) at the centre of the annular inlet; and removing primarily the more dense liquid component through a second outlet (10) from a region below the layer of the less dense liquid component. 10. A method according to claim 9, further comprising the steps of monitoring the quantities of the more dense and less dense liquid component in the vessel and controlling the outlet flow through the first and second (8, 10) outlets in order to maintain the levels of the two liquid components in the vessel at predetermined levels. 11. A method according to claim 10, wherein the step of detecting the amounts of liquid components in the vessel comprises detecting the level of the free liquid surface and the level of the interface between the two liquid components.