Abstract: A separator comprises a cyclone for removing more dense particles e.g. sand and a filter for removing less dense particles e.g. organic material from a liquid e.g. water. The arrangement is such that the filter experiences a shearing/scouring force which assists in preventing blockage.

Abstract: A separator for separating a mixture of liquids into a more dense component and a less dense component. It comprises a tube (52, 53, 54) of decreasing cross-section, at least one tangential inlet (59, 60), and outlet (57, 58) for the less dense component on the tube axis, and an outlet for the more dense component on the tube wall in the form of a spiral groove (61), preferably with a plurality of outlet ports (62) at the groove base. The separator may for example be used for separating a small volume of oil from water or, with suitable adjustment, a small volume of water from oil.

Abstract: A separator for separating a relatively small volume e.g. up to 20% of a less dense liquid from a larger volume of a denser liquid, for example for separating small volumes of crude oil from produced water from an oil-well, in the form of an elongated tube of reducing cross-sectional area. The separator has at least one tangentially-disposed inlet (5, 105) for the mixture of liquids, adjacent the wide end of the separator, an outlet (10, 121) for the denser compartment at the narrow end, and an axially disposed outlet (11, 122) for the less dense component. A further outlet (6, 113) for the denser component may be provided intermediate the two ends. The two outlets (10, 121 or 6, 113) for the denser component are provided with pressure control means (85, 93) for controlling the pressure of the denser component.