A sifter includes a screen including a cylindrical portion. A helix is positioned within the cylindrical portion and extends between a first end of the helix and a second end of the helix. The helix defines a volume, such as an annular gap extending between the first end of the helix and a second end of the helix and extending inwardly from an inner surface of the helix by at least 25 percent of an inner diameter of the inner surface of the helix, the volume being available to receive particles sifted by the sifter. The helix may be a metal coil secured at ends thereof to a shaft driven by a motor. The screen and/or endcaps secured to the screen includes an opening through which particles that do not pass through the screen are urged by the helix.

[Object] To provide a building material manufacturing apparatus that is suitable for suppressing clogging of a screen that screens a building raw material. [Solution] A building material manufacturing apparatus X1 includes at least a screen part 10 and a cleaning mechanism part 40. The screen part 10 includes at least one screen sheet 12 that has an inclination and that has a screen mesh. The cleaning mechanism part 40 includes a scraping part 40a. When the apparatus operates in a building material manufacturing mode in which a building raw material M is supplied to the screen sheet 12 and the screen sheet 12 is performing a wave motion, the scraping part 40a is separated from the screen sheet 12, and, when the apparatus operates in a cleaning mode in which the building raw material M is not supplied to the screen sheet 12 and the screen sheet 12 is not performing a wave motion, the scraping part 40a rotates in contact with the screen sheet 12.

A sifter includes a screen including a cylindrical portion. A helix is positioned within the cylindrical portion and extends between a first end of the helix and a second end of the helix. The helix defines a volume, such as an annular gap extending between the first end of the helix and a second end of the helix and extending inwardly from an inner surface of the helix by at least 25 percent of an inner diameter of the inner surface of the helix, the volume being available to receive particles sifted by the sifter. The helix may be a metal coil secured at ends thereof to a shaft driven by a motor. The screen and/or endcaps secured to the screen includes an opening through which particles that do not pass through the screen are urged by the helix.

A combine harvester includes a housing having a rear hood and defining an interior, a blower for generating an air stream in a substantially rearward direction, and a cleaning system separating residue from a crop material such that the residue is transported via the air stream rearwardly to be discharged from the housing. A chopper rotor assembly is disposed within the interior below the rear hood and includes a chopper rotor having a plurality of blades for chopping the residue as it is received via the air stream. A chopper housing is disposed within the interior and defines an inlet of the chopper rotor for receiving the residue and an outlet spaced rearward from the chopper rotor for discharge of the chopped residue from the interior of the housing. An air gap through which the air stream may exit the interior is defined between the rear hood and chopper rotor.

The present disclosure is directed to rotors for pressure screens with cylinders for screening solid contaminants from a solid slurry. The rotor includes a cylindrical hub, a plurality of foils spaced radially outward from the hub, and a plurality of struts coupling the plurality of foils to the hub. The struts include a forward edge having a forward-swept shape that creates streamlines that move contaminants and fibers from the general local flow field and those dislodged from the inner surface of the pressure screen cylinder radially inboard towards the hub. The streamlines produced by the forward-swept struts can reduce or prevent deposition of solid contaminants on the forward edge of the strut and on the leading edge of the foil. The struts can also include a release region proximate the inboard end of the strut.

The present disclosure is directed to rotors for pressure screens with cylinders for screening solid contaminants from a solid slurry. The rotor comprising a cylindrical hub, at least one foil spaced radially outward from the cylindrical hub, and at least one strut coupling the at least one foil to the cylindrical hub, wherein the at least one strut is a forward-swept strut having a forward edge. Additionally disclosed are methods of using the rotor.