Abstract: A wall means intended for apparatus for separation of a liquid-containing portion from a liquid-containing particle material which is fed through the apparatus in a predetermined direction (A). The wall means comprises a plurality of bar profiles defining continuous slots between them to allow through the liquid-containing portion. According to the invention each bar profile has on its inner side facing the liquid-containing particle material a ridge portion extending between the ends of the bar profile and being provided with two continuous guide surfaces which, as seen in a cross section of the rod profile, are inclined in relation to the drainage direction (B) of the liquid-containing portion through the adjacent slot. Furthermore, the inclined guide surfaces in their longitudinal direction are disposed to coincide with the predetermined direction of feed (A) of the liquid-containing particle material in order to influence the liquid-containing particle material to maintain this direction of feed (A).

Abstract: A gas capping liner system is described which encompasses a top channeled component and a bottom perforated layer component. The top channeled component has a plurality of alternating longitudinally extending channels. The channels are of two types, (1) structural for supporting the weight of overburden clay and topsoil above the liner and (2) gas-receiving, which permit the landfill gas to be collected. The perforated layer component is positioned such that the perforations are located above the gas-receiving channels.

Abstract: A skimmer/separator ladle comprises a handle of an elongated configuration and a bowl of a cup-shaped configuration defining an upper rim. The handle and the bowl are connected together and the handle extends upwardly from the bowl at the upper rim of the bowl. In order to render it possible to carry out any skimming/separation operation, the bowl has an outwardly protruding tongue arranged at a first rim section of the bowl, which tongue is located below the upper rim of the bowl, and further one or more through-going holes which are provided in the bowl and arranged at a second rim section of the bowl, which one or more through-going holes are located below the upper rim of the bowl and further located above the tongue.

Abstract: The screen cylinder includes a screening plate having contoured grooves along an inflow side and a backing cylinder having a plurality of openings therethrough and disposed on the outflow side of the screening cylinder. The contoured grooves are elongated in the axial direction and are closely circumferentially spaced one from the other about the screen cylinder. In one embodiment, circumferentially extending grooves are formed along the outflow side of the screening cylinder whereby pulp flows through the contoured grooves into the recesses and then through the openings of the backing cylinder. In another embodiment, the recesses are formed on the inflow side of the backing cylinder, the screening cylinder being provided with elongated slots along its outflow side in registry with the contoured slots. In this manner, increased flow capacity is provided. Additionally, the screening cylinder is removable when worn for replacement by a fresh screening cylinder which may then be secured to the backing cylinder.

Abstract: A filter apparatus for filtering a plurality of liquid or gas fluid samples containing particles to be filtered, such as bacteria or cells. The apparatus includes a filter; a device for simultaneously and independently filtering fluid samples on the filter; and apparatus for force filtering the samples. The device for simultaneously and independently filtering fluid samples includes at least one gasket including a plurality of through perforations held clamped in a sealed manner against one face of the filter by appropriate clamps. The clamps have perforations located for being brought into alignment with the perforations through the gasket and for cooperating therewith to put an upstream face of the gasket into communication, via the filter, with a plurality of independent inlets for samples of fluid to be filtered, and to put a downstream face of the gasket into communication with a plurality of likewise independent outlets for the fluid samples.

Abstract: A reusable filtration element for a coffee brewer has a microscopic arrangement of holes which permit coffee beverage to pass through while turbidity and sediment causing solids are effectively removed. The holes are preferably from 12 to 60 microns across and provide from 5 to 30 % open area in the filter element. In one preferred embodiment, the holes are circular, arranged in rows such that intersecting rows form an angle of 60.degree., and preferably taper from top to bottom. A preferred filtration element is preferably formed by photoetching stainless steel foil. The filtration element is preferably positioned over a foraminous support.

Abstract: Apparatus is disclosed for separation of liquid and solid waste materials from a mixture or other combination of such materials. A container is provided with a vertically disposed interior screen or perforated wall that is capable of retaining solid material while permitting liquid material to pass therethrough. The perforated wall divides the container into first and second portions. Waste material is provided to the first portion, and liquid material is removed from the second portion. Preferably disposed in the first portion is an onion bag or other porous, screening or filtering material for receiving the combination of liquid and solid material and retaining of the solid material. Liquid material can be removed from the second portion via a drain, or alternatively by a pump controlled by a liquid level sensor. The pump would be operated whenever the liquid level sensor sensed a sufficiently high predetermined level of liquid in the container.

Abstract: A filter plate for use in a press for separating cocoa butter from cocoa paste includes a plate body having an inlet surface facing the paste, and an outlet surface in which a spiral collection channel is formed. A plurality of holes extends through the body between the inlet and outlet surfaces. The holes communicate with, and are spaced along, the spiral collection channel.

Abstract: A filter apparatus (10) for filtering machine tool coolant is disclosed as including a filter assembly (12) including a foraminous non-reticulated metal screen (30) having minute openings and a smooth planar surface for providing improved scrape cleanability and preventing movement of machining chips, particulate and also elongate contaminants from one side of the filter (12) to the other side thereof.

Abstract: The present invention is a filter assembly for filtering contaminants from first and second fluid sources. The filter assembly includes front and rear portions having front and rear apertures, respectively, extending therethrough. The filter assembly also includes a web portion for spacing longitudinally the front and rear portions and having a filter orifice extending therethrough for allowing fluid flow between the front and rear apertures. The front and rear portions include means forming a filter disposed in each of the front and rear apertures for filtering contaminants from fluid flowing through the front and rear apertures.

Abstract: Filter apparatus for continuously filtering fluids containing large amounts of particles, including large amounts of ultrafine particles. The filter apparatus includes filter media and a backwash system which continuously removes deposited filtrate from an inlet side of the filter media. The filter apparatus also includes means for at least temporarily retaining filtered fluid in an outlet chamber of the apparatus at a location immediately proximate an outlet side of the filter media, such that backwashing of the filter means occurs continuously and instantaneously as filtered fluid passes through the filter means.

Abstract: A filter for cylindrical of flat filter equipment for the mechanical purification of liquids as described which is assembled of several filter elements (4) arranged one above the other which disclose always gap-shaped filter openings between them and which are fastened by rods led through them and locking flanges. The passage openings for the rods are formed as sleeves (7) to which distance holders (8) belong. The filter elements have trapezoidal cross-section, the outer longer base side (16a) of which, together with the height of a filter opening, make out the height of the sleeve (7).

Abstract: A filter segment disc of a segment filter comprises a support and drainage plate with slots radiating from the filter hub toward the filter edge. The slots are configured to provide a substantially uniform fluid flow over the filtering medium of the filter segment, reduce residence time of filtrate in the filter, eliminate dead spots in the flow, and facilitate cleaning of permanent filters.

Abstract: A filter nozzle equipped with annular filter discs which establish flow paths (26, 28), serving to conduct the filter liquid and which paths are radial (28) and also penetrate through (26) the filter discs (18). These passages (26) through the filter discs (18) are in themselves formed as passages (26) that become narrow in the flow direction of the filtered water, and are distributed uniformly over the disc (18). The discs (18) have projections which ensure that the passages (26) of two adjacent discs are not in alignment. With such a filter nozzle, the danger of blockage is much less than with known nozzles, assuring a steady operation and requiring less frequent cleaning.

Abstract: An apparatus for separation of ferromagnetic materials has a working chamber occupied by a ferromagnetic attachment in the form of plates with openings edged by shaped projections, a magnetizing system and means for consolidation of the plates made in the form of an additional magnetic field source, and inlet and outlet connections, respectively, for fluid medium. The spacing of the openings on the plate, their sizes and configuration, the sizes of the projections and the distance between the plates are selected to be variable throughout the volume of the working chamber depending on the magnetic properties and sizes (dispersity) of foreign particles in the fluid medium being purified, and viscosity of the fluid medium.

Abstract: The device described herein comprises a ladle type utensil having a handle attached to a substantially cylindrical cup having a bottom comprising either a flat or preferably a concave bottom in which a number of "domes" are set, which "domes" extend upward from the bottom of the said cup. Each dome has an opening at the crest thereof, which dome openings provide the only means for liquid to flow from beneath the cup into the interior of the cup. In the preferred modification there are seven of said domes, one being positioned in the center of the cup bottom and the others being arranged in a cricle around the central dome.

Abstract: A method and apparatus for treating a liquid mixture to separate a clarified fraction therefrom leaving a concentrated sludge fraction involve injecting a flocculent material into the liquid mixture; and inletting the liquid material and the flocculent maerial tangentially into a vertical tank having a perforated plate spaced from its upper end dividing the tank into an upper chamber and a lower chamber, a to produce a flow in the lower chamber having a rotational velocity in the horizontal direction adjacent the outer periphery of the lower chamber, and a lower rotational velocity in the horizontal direction adjacent the center of the lower chamber. The holes in the perforated plate define reduced-area passages from the lower chamber to the upper chamber producing a vertical flow of low velocity in the lower chamber and of higher velocity through the passage in the perforated plate.

Abstract: A self-cleaning vacuum head is disclosed which has the ability to discriminate between particles of different size, or the ability to separate fluids from particulate matter. The invention has two relatively moving surfaces which provide a changing locus of vacuum so that particles drawn against the surfaces are later separated therefrom. An oil spill clean-up system is also disclosed utilizing the self-cleaning vacuum head.

Abstract: A cylindrical screening basket for sorting and classifying fiber suspensions includes a wall which has an inner wall surface facing the fiber suspension and is provided with screen openings which lead into grooves arranged at the inner wall surface. The grooves extend essentially parallel to each other and transversely to the flow direction of the fiber suspension and are arched to define a downstream flank and an upstream flank, with the downstream flank having a sharper curvature than the upstream flank.

Abstract: Screen cylinders, and methods of making the same for use in removing contaminant particles from papermaking stock, have a seamless cylinder body and the openings or slots therethrough are formed by directing a focused laser beam at an outer surface while focusing the beam intermediate the outer an dinner surfaces to form an opening or slot with tapered walls. Wear bars may be applied to the inside surface as a bead of weld material. The seamless cylindrical body is formed by centrifugal casting or by cold roller extrusion.

Abstract: An improved filter of the type including closely spaced wedgewire windings defining a permanent filter media by allowing liquid flow through the gaps, in which the outer face of the wedgewire strands are ground away to eliminate the radiused corners on each strand, which corners create a small convergent region intermediate adjacent strands of wedgewire tending to trap solids and clog the filter when particles sizes are present in a range tending to wedge in those regions, particularly when gelatinous substances are also present.

Abstract: A scraper filter system, which comprises a screw-formed spiral impeller within a cylindrical filter element, and scraper means formed along the spiral end of the impeller for engagement with the internal surface of the filter element for scrapingly removing solid components deposited on the surface of the filter element.Further the present invention provides a filter system, which comprises a cylindrical filter element, a cylindrical casing allowing liquid components to flow from the inside to the outside through the filter element, a spiral impeller with the scraper means for engagement with the internal surface of the filter element for removing solid components, and further comprises a feed liquid inlet at one end of the cylindrical casing and filter cake discharge means including a cake discharge outlet at the outlet end of the casing.

Abstract: A cylindrical screen member of a centrifugal pulp screen used in paper manufacturing is disclosed. The pulp is agitated and impelled to pass through a plurality of parallel radial through-holes of the screen member by the centrifugal force imparted by a rotor. Each through-hole of the screen member has a cross-section elongated in a direction transverse to a horizontal line and inclined at an angle with respect to a vertical line. The pulp particles can linearly pass through the through-holes and flow out through the screen member smoothly. Therefore, the likelihood of blockage is reduced, and the power necessary to drive the rotor is economized.

Abstract: A filter element for filter systems, which comprises a plurality of plate members having a number of apertures therethrough and cutout grooves formed in the surface thereof, a plurality of wire members each having a retaining leg portion, which is inserted into one of the grooves of the plate member, whereby the top surfaces of the wire members are flashed in a definite plane for forming a plurality of slits for filtering a liquid.

Abstract: A device and method for detecting and quantifying a substance by filtration. The device includes a body having two parts (1 and 2) nested into each other. One of the parts (1) is used as a reservoir and the other part (2) is used as a filter-holder and as a receptacle. The device further includes a retention and reaction system including a strut (3), two multi-pierced or perforated plates (4 and 5) which encase a filtering member and a thin strut. A seal is further provided between the two parts. The reservoir and the receptacle are connected to an external circuit by means of conduits, mouthpieces and pipes. The interlocking of the two parts is achieved by means of jointed hooks.

Abstract: Apparatus for extracting liquid from a slurry containing fine solids and liquid comprising an endless screen formed of woven monofilaments of thermoplastic material so as to define a multiplicity of small openings extending between opposite sides thereof and a supporting structure for supporting the endless screen for movement through initial and intermediate operative run portions along an underside thereof in such a way as to present an upper operative side thereof for the accumulation of solids thereon by the passage of liquid through the openings thereof. The screen supporting structure comprises a multiplicity of fixed closely spaced parallel bars formed of material having favorable wear and coefficient of friction characteristics with respect to the thermoplastic material of the endless screen.

Abstract: A multiple-disc filter body for separating solid particles from a fluid flowing through the filter body from its inlet side to its outlet side, comprises a stack of filter discs in which the side faces of each pair of adjacent discs are formed with ribs of at least two different heights such as to define filtering passageways of a larger size on the inlet side of the filter stack and filtering passageways of a smaller size on the outlet side of the filter stack in series with the larger-size filtering passageways, whereby coarse particles are first separated by the fluid in the larger size filtering passageways, and then finer particles are separated from the fluid in the smaller size filtering passageways.

Abstract: A sanitary device for a sewerage channel with an openable grating includes a bottom plate and four side walls which together define a space therebetween for accommodating several filtering plates for filtering dirt or the like contained in the rain water which drains into the sewerage channel through the sanitary device. EAch of the four side walls has several apertures for passage of rain water to the sewerage channel. A first disinfecting container containing volatile disinfectant, such as mothballs, for cleaning the air inside the sewerage channel is attached to the side walls of the sanitary device. A hollow cylindrical tank is provided on an upper side of the bottom plate and extends upwards for receiving a second disinfecting container containing liquid disinfectant.

Abstract: A filter plate which is longitudinally partitioned between its inlet and outlet ends, and features liquid feed and collection troughs at the respective ends. Such plates may be associated in opposed, relatively inverted pairs to form enclosed flow channels characterized by fluid flow rates which are substantially uniform across the full transverse extent of the flow path and which facilitate the utilization of the full areal extent of the filter media employed therewith. Also described is a unitary filter element which may be usefully employed in the filter. The filter of the invention may be highly efficiently employed for dewatering of aqueous biomass suspensions, desalting of proteins, removal of secreted metabolites from cellular suspensions, and the like.

Abstract: A fluid filter element, filter, and process for its fabrication, wherein the filter element includes a flat base and a thin layer deposited thereupon having a pattern of channels through which a fluid may flow. In operation, the element is pressed against a flat surface, preferably the back side of another element in a stack of filter elements, whereupon the channels become closed conduits. The channels have a minimum dimension of the thickness of the layer, so that larger particles may not pass therethrough. Fabrication of the thin layer with the channels therein is preferably accomplished by masking a pattern corresponding to the channels and then vapor depositing the remainder of the thin layer, as masking and deposition permits accurate control of the height of the deposited layer, and, then, the minimum dimension of the channels.

Abstract: A filter employed for the extraction of beverages is formed of a piece of material having two planar surfaces and a plurality of uniformly distributed openings extending through the piece. A plurality of nipples, equal in number to the number of openings, project from and out of at least one of the planar surfaces and extend for a distance substantially equal to the thickness between the planar surfaces of the piece of material, each nipple being associated with one of the openings through the piece of material, and each opening extends through each nipple. The openings have a shape of a truncated cone, a truncated pyramid, or a truncated tetrahedron, and each opening at the end of each nipple, which is disposed away from the planar surface from which the nipple projects, forms a minor base of the opening shape and each opening at the other planar surface forms a major base of the opening shape.

Abstract: A back flushable filter which has a number of separable sections (2) which can be separately accessed and there can be provided a flow pattern so that one of the sections is being back flushed while the other sections are providing normal filtering. A valve configuration (11) providing for such access can be inched around to select each section in term. The filter preferably comprises a stack of separable segments which provide for inclined gaps between adjacent parts of each adjoining stack element with the convergents and gap size selected to encourage compaction of particles within the converging part of each gap but further selected such that on back flushing such compacted particles can be readily disgorged for total cleansing.

Abstract: A screen bowl centrifuge having slots which have successive portions which slope lengthwise toward a common axis, and additionally, slots which slope laterally toward the common axis. The screen bowl centrifuge may also have slots which conform to the predominant path of solids through the centrifuge by providing helically shaped screen bowl elements.

Abstract: A method and device for the separation of substantially solid bodies from a liquid are disclosed in which an obliquely arranged screen grid is provided with an upper region, a lower region, and two opposite edge regions and is suppllied with liquid at the upper region to separate the solid bodies from the liquid in the form of screenings which travel along an upwards facing surface of the screen grid. A cleaning device rests against the upwards facing surface of the screen grid and moves the screenings during movement of the cleaning device horizontally towards the edge regions to cause the screenings to pass onto transport surfaces situated adjacent to the edge regions. The transport surface extends along the length of the screen grid and is smooth.

Abstract: A process for forming a filter screen including the steps of forming a plurality of parallel linear grooves in a sheet of metal to a depth of about 0.5 to 1 mm, forming inclined openings in the grooves through the remainder of the sheet by means of a laser beam, the openings having a width of about 0.2 to 1 mm, the inclination of all the openings in a groove being the same direction, the inclination of openings in neighboring grooves being in the opposite direction to create zig-zag pattern, and compressing the sheet to flow metal from the sheet into the openings to make the openings more fine, in the range of 0.05-0.1 mm.

Abstract: A double screen or double-rack grate for use in the extra-fine screening of waste waters includes two rows of rods in laterally staggered arrangements with one row positioned behind the other in the direction of flow of waste water to be screened. Each rod of one row has a hydrodynamic cross section defined by a thickened head portion. Such row of rods is positioned downstream of a first row of rods including rods with substantially rotationally symmetrical cross sections.

Abstract: A plurality of blind openings (e.g. holes or slots) are formed through a first face of a steel plate and extend a predetermined distance short of the opposite face. Larger size openings are formed through the first face using the blind openings as pilot openings. The larger size openings extend into the plate short of the terminations of the blind openings. Metal is machined from the opposite face in parallel rows defining grooves and to a depth to uncover the terminations of the blind openings in the plate body thereby providing through-extending screen openings in the plate. The ridges (bars) between the grooves may be quadrate in cross-section, or a side face sloped (angled) by machining. A screen cylinder with bars of the invention has a maximum screen area (compared to prior art screens with bars).

Abstract: A filter segment disc of a segment filter comprises a support and drainage plate with slots radiating from the filter hub toward the filter edge. The slots are preferably of arcuate plan form and configured to provide a substantially uniform fluid flow over the filtering medium of the filter segment, reduce residence time of filtrate in the filter, eliminate dead spots in the flow, and facilitate cleaning of permanent filters. A filter support spacer may be provided adjacent the filtering surface to aid in support and positive spacing of the disc in a filter stack of which the disc may be an element.

Abstract: The coalescing plate is designed to separate immiscible components of differing densities mixed in a fluid. The plate includes bidirectional corrugations forming crests and valleys. Bleed holes are provided in the crests and valleys to allow the immiscible components to pass through. Plural plates are stacked and separated by spacers. The spacers are configured to provide multiple spacings between adjacent plates. The immiscible components less dense than the host fluid migrate upwardly and pass through the bleed holes in the crests. Solids and other components denser than the host fluid move downwardly and pass through the bleed holes in the valleys. The plates are readily cleaned in situ by passing a nozzle through the bleed holes nad introducing a pressurized fluid or gas to flush out the space between the plates.

Abstract: A porous filter element for filtering a liquid, the filter element having a plurality of seamless filter element units that are made of stainless steel or titanium powder wherein ranges of particle diameters, sintering densities, and nominal pore sizes define a final shape which is formed with undulations to provide bed surfaces for an auxiliary filtering agent.

Abstract: There are disclosed a chamber plate for use in cell fusion comprising a plate of single crystal silicon on which a plurality of chambers for holding at least a pair of unit cells are formed in array, said chamber having at the bottom a plate having slits which do not pass cells to be held; and a process for producing a chamber plate for use in cell fusion which comprises forming chambers for holding cells in a plate of single crystal silicon by anisotropic etching or isotropic etching by chemical etching.

Abstract: A filter panel comprises a plurality of substantially coplanar openings. It incorporates a two-dimensional array of parallel elongate passages. Each passage delimits a respective one of the openings. The array is substantially coplanar with the openings and the passages are substantially perpendicular to the array. Each opening is convergent from an interior profile both from the inlet and outlet side of the panel.

Abstract: A screen plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.

Abstract: A subterranean drainage and fluid filtration system includes an inlet conduit defined by fluid filtering fabric encasing a fluid pervious panel with raised lands and depressions to define passageways for the fluid. The fluid flows downwardly into a filtration system comprising the serpentine wrapped filter fabric in which core sheets and spacers are provided. These core sheets and spacers may be identical to one another and each includes raised lands so as to achieve flow of fluid downwardly and horizontally through the fluid filter.

Abstract: The sieve plate herein is formed of plate or sheet material into which relatively wide grooves, having a flat bottom 4 mm wide, are formed on one side to within 1 mm of the opposite side. Through this remaining membrane wall openings are formed having a width of about 1 mm. The small openings may either be spaced circular perforations or slots. The slots may be in zig-zag formation. Zig-zag formations are preferred because it maximizes the filtering area.

Abstract: A filter arrangement is suggested where the filter means (38) is placed between distance pieces (48, 50, 52). In order that the longitudinal edges (64, 66, 68) of the preferably zigzag-folded distance pieces cannot cause any damage to the filter means, they are provided with a substantially edgeless cap (90, 92, 94), of which the maximum width equals that of the distance pieces.

Abstract: The invention relates to a sieve for a paper pulp scrubber or similar equipment, and to a method for fabricating such a sieve. The sieve is produced by mechanical interfit of bars with support members, the bars carrying notches, the lips of which engage at least one V-shaped lateral groove formed in each support member, while the support members present, on their face receiving the bars, a first set of notches for positioning the bars. The cross-section of the support members at the level of the first notches has the same configuration and dimensions as the cross-section of the second notches and the cross-section of bars at the level of notches has the same configuration as the cross-section of notches formed in the support members. Assembling is made by bending a bar by an angle of about 20-25.degree. for widening a second notch and inserting a support member therein. The bar is then straightened back, so that the support member will be firmly clamped in the notch.

Abstract: A backwash strainer having a generally cylindrical filter element made up of a stack of spaced rings that are triangular in cross section, with the bases of said triangular rings disposed in a cylindrical surface. A hollow backwash arm has an open slot disposed on the inside of the cylindrical surface which operates at a predetermined distance from said element. The incoming water in said strainer flows from the inlet up through the straining element to the outlet. The backwash arm receives water from around the straining element, which flows through the element into the backwash slot and out with the debris accumulated on said strainer. Since the debris is supported on the flat interior of the rings, water flowing back into the arm into the slot in the hollow backwash arm forces trash and other debris from the rings down to the backwash water outlet. Water flowing through the clearance between the bars as used, helps flush the debris off the inside of the filter element.

Abstract: The microfilter foil is made of an inorganic substance such as metal with opened pores. Each pore is formed with a channel which increases in cross-section from the crest so as to obviate clogging. The foil is produced by exposure of a photosensitive layer of paint or lacquer with the use of an interference pattern produced by monochromatic and coherent light. A skin of inorganic material is produced on the photosensitive layer and portions of the skin are thereafter removed from the coated teeth in order to produce the pores in the subsequently formed foil.

Abstract: A screen plate and plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.