Abstract: The invention relates to a method and a biogas plant for producing biogas, preferably from rice straw, wherein a substrate is fermented in two reactors (1, 2) in a circulating manner, so that a methane production from cellulose-and/or lignocellulose-containing substrate can be improved.

Abstract: The invention relates to a method and a biogas plant for producing biogas, preferably from rice straw, wherein a substrate is fermented in two reactors (1, 2) in a circulating manner, so that a methane production from cellulose-and/or lignocellulose-containing substrate can be improved.

Abstract: A bar screen with a screen cleaner has a vertically movable carriage with a rake pivotally connected thereto by pivot arms. A foldable lever assembly is pivotally connected to the carriage and to the pivot arms and assures a fully extended position and a folded position which correspond to a position of engagement of the rake with the screen and a position of disengagement of the rake with the screen, respectively. A lower stop engages the foldable lever assembly and moves it from a folded position to an intermediate folded position at the end of downward movement of the carriage and before the lever assembly reaches fully extended position so that the rake remains in a position of disengagement with the screen during downward movement of the carriage and is held in this position until the lever assembly is moved to fully extended position in response to upward movement of the carriage.

Abstract: A pump for conveying waste water and the like embodying a substantially vertically arranged drivable screw mounted for rotation within a fixed pipe having an inlet at the lower end thereof and an outlet at the upper end thereof. At least one upstanding baffle is mounted below the screw and in the vicinity of the inlet with at least the upper portion of the baffle extending in the direction of conveyance.