The present invention relates to a screen for accepting waste material, the waste material comprising fines and oversize material, wherein the screen comprises: a trough with a top opening, a base opening for discharging the fines material and an oversize material outlet for discharging the oversize material; driven elongate rotating members for causing movement of the waste material, wherein each rotating member comprises a shaft and a plurality of mutually parallel blades, wherein each blade independently has a plurality of radial protrusions which act on the material during the movement thereof, wherein for one or more blades on each shaft independently, at least one of the radial protrusions on the or each blade is an extended radial protrusion, wherein the material to be screened is introduced at one end of the shafts and expelled at the other end, characterised in that each elongate rotating member independently is held and rotatably mounted at both ends, wherein the driven elongate rotating members comprise a first plurality of driven elongate rotating members disposed in a first arc along one side and along at least a portion of the base of the trough for causing circular or helical flow of the waste material and a second plurality of driven elongate rotating members disposed in a second arc along the other side of the trough and along at least a portion of the base of the trough for causing circular or helical flow of the waste material, wherein, for each plurality of driven elongate rotating members, at least one elongate rotating member runs at a different speed to the other elongate rotating members, and wherein the speed of the elongate rotating members does not decrease towards the top opening of the trough.

Provided is a method for producing a polyacrylic acid (salt)-based water absorbent resin in which the physical properties (especially liquid permeability) are improved and maintained even in large scale production. The method for producing a polyacrylic acid (salt)-based water absorbent resin, which sequentially includes a polymerization step, in which a monomer aqueous solution having acrylic acid (salt) as a main component is polymerized, a drying step, in which a water-containing gel-like crosslinked polymer obtained in the polymerization step is dried, and a classification step, in which a polymer obtained in the drying step is classified, wherein a rocking-type sieve classification apparatus is used in the classification step, and the rocking-type sieve classification apparatus has a sieve net having a trajectory and a rotation speed in the following ranges; radial gradient R: from 5 to 40 mm, tangential gradient T: from 0.1 to 25 mm, eccentric gradient E: from 40 to 80 mm, and rotation speed F: from 60 to 600 rpm.

A self-cleaning screen is formed via additive printing. The dimensions of the self-cleaning screen are modified. Supports are printed via additive printing. The supports are formed over a plurality of wires. Side seals may be additively printed along major sides of the plurality of wires. Wear of the screens is monitored.

A self-cleaning screen is formed via additive printing. The dimensions of the self-cleaning screen are modified. Supports are printed via additive printing. The supports are formed over a plurality of wires. Side seals may be additively printed along major sides of the plurality of wires. Wear of the screens is monitored.

In a method for cleaning blinding particles in crushers, material to be crushed is fed via a feed stream (1) to a crushing tool, and from there is separated by a screen (7) into a conveyor stream (8) that passes through the screen (7) and a return stream (10) that is held back by the screen (7) and returned to the feed stream (1), thereby forming a conveyance circuit (9). The method makes an efficient, continuous crusher operation possible, wherein idle times for cleaning blinding particles can be avoided. The particle size distribution and/or the material volume are measured at specified intervals in parts of the conveyance circuit (9) and/or conveyor stream (8), and if the particle size distribution and/or material volume deviate above a predefined limit value, the particle size created by the crushing tool is increased for a predefined time period.

A collection device for vibration sifter according to the present invention is a collection device for vibration sifter for collecting on-sifter powder remaining on an upper surface of a sifter of a vibration sifter device. The collection device for vibration sifter includes a hollow shaft in a hollow shape that is disposed above the sifter located within a surface along a horizontal plane as an axis in a direction along a vertical direction, a nozzle that is attached to an lower end of the hollow shaft, elongates in a radial direction from the hollow shaft, includes a first suction port on a bottom surface and a second suction port on a side surface at an end of elongation in the radial direction, and includes a cavity communicating with the hollow space of the hollow shaft, a suction unit that sucks air inside the cavity of the nozzle and inside the hollow space of the hollow shaft, and a suction controller that controls the suction unit to suck the air when the sifter of the vibration sifter device is vibrating.

A collection device for vibration sifter according to the present invention is a collection device for vibration sifter for collecting on-sifter powder remaining on an upper surface of a sifter of a vibration sifter device. The collection device for vibration sifter includes a hollow shaft in a hollow shape that is disposed above the sifter located within a surface along a horizontal plane as an axis in a direction along a vertical direction, a nozzle that is attached to an lower end of the hollow shaft, elongates in a radial direction from the hollow shaft, includes a first suction port on a bottom surface and a second suction port on a side surface at an end of elongation in the radial direction, and includes a cavity communicating with the hollow space of the hollow shaft, a suction unit that sucks air inside the cavity of the nozzle and inside the hollow space of the hollow shaft, and a suction controller that controls the suction unit to suck the air when the sifter of the vibration sifter device is vibrating.

The present invention discloses a staggered and inter-impinging self-cleaning screening device, comprising a plurality of staggered and inter-impinging rotating screening mechanisms arranged in a tilted downward conveying direction, movement generating mechanisms, and pulse warning automatic cleaning mechanisms; the staggered and inter-impinging rotating screening mechanisms are adjacently arranged or arranged every other shaft; the self-cleaning screen devices are equidistantly coupled and installed on the outer surface of the rotating shaft; the rotating shaft is constructed into a hollow structure, and provided with spray-holes; the self-cleaning screen devices of the rotating shaft are equidistantly staggered with each other in the coaxial direction; the pulse warning automatic cleaning mechanism comprises an overload detector, and a controller; the overload detector is installed at one end of the rotating shaft; the movement generating mechanism includes planar cams installed at both ends of the rotating shaft assembly.