Sand screw dryer

Abstract

An apparatus and process for separating drilling fluid from drill cuttings are disclosed. The separations are performed in a drying auger unit, including: an inclined housing having side walls joined by a bottom and having an inlet end and an outlet end; at least one inlet for feeding a cuttings slurry to the inlet end; a helical auger located in the housing for transporting drill cuttings from the inlet end of the housing to the outlet end of the housing, and a drive for rotating the auger, an elevated pan disposed in and extending the length of the housing and having an arcuate cross section with a radius greater than a radius of the helical auger, wherein the pan is disposed proximate at least a lower quadrant of the helical auger; the housing further comprising a liquid recovery zone adjacent to the pan for transporting drilling fluids, separated from the drill cuttings during transport along the pan by the helical auger, to a liquid collection zone disposed adjacent to the inlet; an outlet for recovering drilling fluids from the liquid collection zone; and at least one fluid inlet nozzle for injecting a fluid into the liquid recovery zone to facilitate transport of any solids in the liquid recovery zone to the liquid collection zone; and at least one outlet for recovering drill cuttings having a reduced content of drilling fluids.