A vertical separator for the treatment of slurry comprising a liquid part and solid particles; said vertical separator comprising: - a tubular screen device , with a substantially vertical axis (Z), provided with a perforated filtering wall ; - a feeding device to feed the slurry to said tubular screen device ; said feeding device comprising pumping means ; - a first discharge device to discharge the liquid part after the liquid part has been separated from at least one portion of the solid particles by the perforated filtering wall ; and - a second discharge device to discharge said at least one portion of the solid particles; wherein said tubular screen device houses counter-pressing means , which are designed to generate a reaction, which partially counters the pushing action exerted by said pumping means upon the slurry; and wherein said counter-pressing means comprise screw means ; wherein the screw means are wound around said vertical axis (Z) and are rotated in a direction of rotation so as to generate a head that is opposite to and less than the one generated by said pumping means ; said vertical separator being characterized in that: the first discharge device comprises a lower collecting tank to collect the liquid part exiting from said tubular screen device ; and the second discharge device comprises an upper chamber to collect the solid material separated from the slurry, and a discharge chute to discharge the solid material from the upper chamber to removing means. said vertical separator comprising: - a tubular screen device , with a substantially vertical axis (Z), provided with a perforated filtering wall ; - a feeding device to feed the slurry to said tubular screen device ; said feeding device comprising pumping means ; - a first discharge device to discharge the liquid part after the liquid part has been separated from at least one portion of the solid particles by the perforated filtering wall ; and - a second discharge device to discharge said at least one portion of the solid particles; - a tubular screen device , with a substantially vertical axis (Z), provided with a perforated filtering wall ; - a feeding device to feed the slurry to said tubular screen device ; said feeding device comprising pumping means ; - a first discharge device to discharge the liquid part after the liquid part has been separated from at least one portion of the solid particles by the perforated filtering wall ; and - a second discharge device to discharge said at least one portion of the solid particles; wherein said tubular screen device houses counter-pressing means , which are designed to generate a reaction, which partially counters the pushing action exerted by said pumping means upon the slurry; and wherein said counter-pressing means comprise screw means ; wherein the screw means are wound around said vertical axis (Z) and are rotated in a direction of rotation so as to generate a head that is opposite to and less than the one generated by said pumping means ; said vertical separator being characterized in that: the first discharge device comprises a lower collecting tank to collect the liquid part exiting from said tubular screen device ; and the second discharge device comprises an upper chamber to collect the solid material separated from the slurry, and a discharge chute to discharge the solid material from the upper chamber to removing means. the first discharge device comprises a lower collecting tank to collect the liquid part exiting from said tubular screen device ; and the second discharge device comprises an upper chamber to collect the solid material separated from the slurry, and a discharge chute to discharge the solid material from the upper chamber to removing means. <EOS>