Apparatus and method including a hydrocyclone separator in combination with a tubular filter

A separator for separating solid particles from a liquid comprising a tapered tube having a wide and a narrow end, a tangential inlet at the wide end of the tube for feeding the liquid and particle mixture tangentially into the tube at sufficiently high velocity to cause the mixture to rotate and thereby form a vortex, an outlet at the narrow end of the tube for the removal of at least some of the solid particles, an outlet at the wide end of the tube for the removal of the liquid and the remaining solid particles, a housing having a tubular filter located therein, a first exit and a second exit, the filter being mounted coaxially with the tube at the wide end thereof, the outlet at the wide end of the tube comprising a cylindrical vortex finder provided coaxially with the tube for guiding liquid and the remaining solid particles from the tapered tube to the tubular filter, the first exit positioned to allow liquid which has passed through and been filtered by the filter to pass out of the housing, wherein the housing second exit includes a further outlet for causing some liquid and remaining solid particles to pass axially and rotationally across the surface of the filter to detach trapped solid matter and then out of the housing through said second exit.