Abstract: Disclosed is a hub ring for a filter wherein a supporting member having a plurality of supporting portions is interposed between a pair of keep plates, a supporting plate for a filter wherein a plurality of wave portions extending substantially in the circumferential direction are arranged in the radial direction, and methods for manufacturing these members. The hub ring has a great opening ratio to achieve a low pressure loss property and causes substantially no residence of polymer, and the hub ring can be manufactured at a low cost. The supporting plate has high pressure resistance, low-pressure loss property, good directivity of polymer flow and excellent polymer mixing effect, and it is suitable for use as a retainer disposed inside of a filter.

Abstract: A monolithic ceramic filter having a portion of the partition wall of a honeycomb structure exposed with its end face on an outer wall surface of the structure and increased in thickness as compared to the remaining portion of the partition wall to form a flow resistance relaxing portion is disclosed. The monolithic ceramic filter may also have a groove-shaped recess which is separated via a partition from a liquid supply passage of a honeycomb structure and is in communication with the outside of the structure. The flow resistance of the filtrate within the partition walls may be diminished to enable efficient filtration. The filter is produced simply by extrusion molding. There is no necessity of forming holes for discharging the filtrate in some cases.

Abstract: Disclosed is a hub ring for a filter wherein a supporting member having a plurality of supporting portions is interposed between a pair of keep plates, a supporting plate for a filter wherein a plurality of wave portions extending substantially in the circumferential direction are arranged in the radial direction, and methods for manufacturing these members. The hub ring has a great opening ratio to achieve a low pressure loss property and causes substantially no residence of polymer, and the hub ring can be manufactured at a low cost. The supporting plate has high pressure resistance, low-pressure loss property, good directivity of polymer flow and excellent polymer mixing effect, and it is suitable for use as a retainer disposed inside of a filter.

Abstract: Filter apparatus for filtering contaminants from a fluid, such as machine tool coolant, are disclosed. One filter apparatus includes a filter drum unit having a generally cylindrical open perforated support sheet with a cylindrical screen element mounted thereabout. Circumference varying mechanisms, such as turnbuckles, are connected relative to the support plate to vary the circumference of the support plate and the tautness of the screen element. A disc filter assembly having a mandrel and fluidly attached annular disc filter elements is also described. Each annular disc filter element has an inner structure with concentric ribs forming concentric grooves therebetween which are connected to radially extending grooves. A screen element is supported by the ribs so that the microscreen will not tear while allowing filtering of fluid into the grooves which are in fluid communication with the mandrel.

Abstract: A filter device for separating solid material from a liquid includes a filter housing with vertically extending removable sidewalls wherein at the location of the removable sidewalls connections are provided to receive two vertically extending sidewalls in spaced parallel relationship whereby a fluid impermeable sidewall may be inserted into the circumferential section of the housing when the liquid permeable section is removed for cleaning without interfering with the continual operation of the filter device. Moreover, the filter device of the present invention may be a first filter or pre-filter in a multi-stage filter system wherein a second filtering device is received within the first filter, the second filtering device includes a plurality of first tubular filters having an open bottom end and a closed top end and a second tubular filter centrally disposed of the first tubular filters in flow communication therewith.

Abstract: A method for manufacturing a supporting plate provided inside of a disc-type filter having filter media at surface portions thereof including the steps of: forming an annular plate having opposed surfaces; andforming a plurality of wave portions on the annular plate that alternately extend beyond the opposed surfaces in opposite directions by pressing, each of the plurality of wave portions extending substantially in a circumferential direction of the annular plate and the plurality of wave portions being arranged substantially adjacent to each other in a radial direction of the annular plate.The supporting plate has high pressure resistance, low-pressure loss property, good directivity of polymer flow and excellent polymer mixing effect, and it is suitable for use as retainer disposed inside of a filter.

Abstract: To provide a filter for highly viscous fluid permitting a foreign matter in a supporting layer to be easily removed and its final layer to be directly washed, a method for efficiently producing a refined polymer by using said filter and a method for producing moldings by molding said refined polymer.

Abstract: The present invention pertains to rotary disc filters and in particular to sectors for such filters. Drainage channels are formed in broad, planar surfaces of the filter media support member of the sector, with the drainage channels being parallel and aligned toward elongate side channels at radial sides of the sector. The sectors have elongate side channels at radial sides of the sector. The side channels can be connected to the central shaft of the rotary disc filter apparatus so that fluid flows directly from the side channels to fluid handling means in the central shaft of the filter apparatus. The present invention further discloses planar drainage members made of elongate slats that are aligned side-by-side slats so that adjacent slats are interengaged fashion.

Abstract: A suction strainer for straining water from the emergency suppression pool of a boiling water reactor includes a plurality of stacked, perforated disks having an internal core with a minimum internal radius r(x) that decreases with increased distance from the intake of the strainer, so that the core has a tapered profile. Internal radius r(x) may vary linearly or exponentially or a combination of both. The stacked, perforated disks each include a first surface that faces in the direction of the intake and a second surface, that faces away from the intake. A circumferential band may connect the first and second surfaces together.

Abstract: A filter device for separating solid material from a liquid includes a filter housing with vertically extending removable sidewalls wherein at the location of the removable sidewalls connections are provided to receive two vertically extending sidewalls in spaced parallel relationship whereby a fluid impermeable sidewall may be inserted into the circumferential section of the housing when a liquid permeable section is removed for cleaning without interfering with the continual operation of the filter device.

Abstract: A filter sleeve (26) surrounds a rod-shaped, flexible drain core with flow paths for removing a pressed-out liquid from the pressing chamber of a press. For mounting one or both ends of the filter sleeve (26) and the drain core on the press, a rubber or elastically deformable shaped element (29) with a ring-like bead (22) is firmly connected with the filter sleeve (26) at its end. The shaped element (29) inseparably penetrates the fabric of the filter sleeve (26) because of an elastomer coating, and the bead (22) is automatically positioned in a groove (24) of a support body (23) because of its previous stretching.

Abstract: An in-tank fuel filter includes a body comprising layers of spun bonded and melt blown filtration media and a fitting for mounting the filter to an in-tank fuel pump inlet. An outer layer of the body is preferably spun bonded material which exhibits good abrasion resistance. One or more inner layers of melt blown filtration media define smaller pore sizes and thus exhibit smaller particle filtration capability. The mounting fitting is made of a fuel compatible material and may either be a multiple part device or be in-situ molded on the filter body. A separator may be disposed in the interior of the filter to prevent its collapse and improve fuel withdrawal through the mounting fitting.

Abstract: A selectively removable sludge filtration system that provides for retrofit into a container and separation of the sludge solids from the sludge liquids therein. A pair of spaced vertically oriented filter assemblies each define a filtrate cavity therein and are connected by separator plates. The filter assemblies permit the flow of sludge liquids into the filtrate cavity, but not sludge solids. A set of fasteners hold the filter assemblies in the container and bias the filter assemblies against the container bottom. The fasteners may be released to provide for removal of the sludge filtration system from the container. A fluid communication passageway directs filtrate from the filtrate cavity to a position exterior of the container. Functionally applying this sludge filtration system provides a method of retrofitting a container with a sludge filtration system and removing filtrate from a sludge in the container.

Abstract: A filter for cross-flow filtration of a fluid containing suspended or emulsified substance is constructed of equally dimensioned plates. Between the plates there are passages for retentate and permeate flow. The plates have in- and outlet openings to form collection channels, through which unfiltered fluid is led to and retentate and permeate is led away from the passages. There are plates (1) (membrane plates) comprising a membrane of material which is chemically and physically inert to the fluid, which membrane has a pore size of 0.1-50 .mu.m through which membrane the permeate passes. There are also plates (2) which are impervious to the fluid. Retentate (6) and permeate (8) passages are formed between the plates (1, 2), which all have three openings (3, 4, 5). The retentate passages (6) are connected to the channel for unfiltered fluid and to the channel for retentate and sealed against the channel for permeate.

Abstract: A thin film membrane formed to a predetermined shape is produced by bending the membrane to create a loop and softening the membrane that makes up the loop with either thermal energy or a swelling solvent. The softened loop is then drawn between plates or about a mandrel to form a membrane with a predetermined fold radius. The fold region produced by the method of the instant invention does not require an adhesive sealant to prevent unfiltered liquid from diffusing through the membrane. The method is especially well suited for preparing membranes for use in the production of spiral wound filters.

Abstract: An in-tank fuel filter for securement to an in-tank fuel pump assembly includes a retaining or mounting ring which is utilized to secure the filter to the fuel pump assembly inlet. The mounting ring includes a collar which is received about the outlet stack of the fuel filter assembly and assists retention of the fuel filter assembly on the fuel pump inlet and maintains a fluid tight seal notwithstanding dimensional changes of the outlet stack occasioned by long term contact with fuel. The fuel pump assembly also includes a depending lug parallel to but offset from the inlet fitting. The mounting ring also includes complementary means to receive and grip the lug, namely, a plurality of resilient fingers arranged in a non-circular, i.e., elongate pattern such as an oval which compensates for inlet fitting to lug spacing variations and retains the fuel filter on the fuel pump assembly during subsequent manufacturing and assembly steps.

Abstract: A filter element for use in a rotating vacuum filter assembly is provided. It has frame having an inner end, an outer end and intermediate sides which define the perimeter of opposed substantially parallel filter regions and a central filter chamber, wherein the inner end is adapted for mounting the frame to a hollow central hub and wherein the inner end defines a central passage which cooperates with a corresponding passage in the hub for communication between the filter chamber and the interior of the hub.

Abstract: A disc filter used in the pulp and paper industry meets modern requirements by axially dividing the tank and shaft (with the flow channels) into at least two separate and distinct portions, so that the treatment of pulp in several different stages using the same disc filter is possible.

Abstract: In a fuel filter disposed in a fuel tank for automobiles, a filter cloth is prevented from being damaged or broken so as to maintain the filtering property stably for a long period of time. The fuel filter disposed in a fuel tank for automobiles has a frame body for swelling the filter cloth wherein outer surfaces of the frame body arc gently at the portion where the frame body contacts the filter cloth, whereby the filter cloth is prevented from being damaged or broken even if the filter cloth repeatedly contacts the frame body.

Abstract: A support element is provided for a tubular filter device having an oversized filter sock. The support element provides relief portions within which excess filter media of the filter sock enters, during use of the tubular filter device, to eliminate detrimental wrinkling and compaction of the filter media.

Abstract: Frames holding separate sections of a filter medium, each covering a section of the perforated sidewall of an annual disc of a device for filtering liquids are held in sealing arrangement with the sidewall by a circumferential holding system containing a circumferential groove engaging the frame, which in a preferred embodiment can be slidingly inserted and removed.

Abstract: The invention disclosed is a stacked, permeable membrane assembly, comprising two clamping plates with spaced, permeable membrane assemblies between them on a simplified frame. Each membrane assembly includes a membrane support means, conveniently a rigid screen, covered by a pair of membranes. The frame is designed to retain the membrane-covered support in internal grooves. Additional membrane support plates and sealing collars are not required.

Abstract: A filter is provided which combines a woven wire mesh over a supporting body. The supporting body is typically a metal perforated tube which provides fluid communication between the well bore and the production equipment string. The woven wire mesh acts as a filter to prevent the influx of sand particles, provides openings oriented at various angles relative to its surface, so that some area is available for fluid entry even when particulate matter is lodged on the surface above an opening, provides interior channels that allow fluid to travel from one location on the mesh surface to another location over an opening into the supporting body, and does not provide "straight-through" openings, thus forcing the fluid to make multiple turns to pass through the mesh, thereby dissipating the fluid's energy and increases the mesh's erosion resistance. When particulate matter accumulates on the mesh's surface, the resulting particle cake remains porous, heightening the filter's resistance to plugging.

Abstract: A disc filter (and disc filter constructed from a number of sectors) includes a filter member and a supporting structure. The supporting structure is formed by two opposed perforated plates which each have at least about 70% flat supporting portions which separate recess portions (which typically extend radially). The recess portions of each plate are welded to either supporting portions or recess portions of the other plate.

Abstract: Disclosed is a hub ring for a filter wherein a supporting member having a plurality of supporting portions is interposed between a pair of keep plates, a supporting plate for a filter wherein a plurality of wave portions extending substantially in the circumferential direction are arranged in the radial direction, and methods for manufacturing these members. The hub ring has a great opening ratio to achieve a low pressure loss property and causes substantially no residence of polymer, and the hub ring can be manufactured at a low cost. The supporting plate has high pressure resistance, low-pressure loss property, good directivity of polymer flow and excellent polymer mixing effect, and it is suitable for use as a retainer disposed inside of a filter.

Abstract: A filter for an in-tank type fuel pump. The filter comprises a frame, a bag type screen adapted to be kept in an expanded condition by the frame, and a flat protector to be interposed between the screen and a bottom surface of the fuel tank. The protector is attached to the screen substantially at the central portion of the protector in the longitudinal direction thereof, so that it may be pressed against the tank bottom surface by a small deflecting force of the screen. This construction is effective to cause less transmission of noise of the pump to the tank.

Abstract: An adsorbent filter for removing caffeine from liquids. The filter is composed of a matrix of fibrous material; and adsorbent particulate material integrated within the matrix of fibrous material, so that passage of a liquid having a caffeine concentration ranging from about 20 to about 100 mg per 100 mL of liquid through the matrix for a contact time of less than about 2 minutes results in at least a 40 percent reduction in the caffeine concentration of the liquid. The matrix of fibrous material may be selected from woven fabrics, knit fabrics and nonwoven fabrics. The adsorbent material may be clay minerals such as, for example, smectite clay minerals. Examples of smectite clay minerals include, bentonite clays and montmorillonite clays. Generally speaking, the filter can be adapted to provide at least a 40 percent reduction in the caffeine concentration for about 1 cup to about 40 cups of a liquid.

Abstract: A water purification device comprises a compartment for holding a supply of impure water; a purified water collection zone; and a dense hydrophilic membrane between the compartment and the purified water collection zone. The membrane is capable of functioning by membrane distillation. A water vapour condensing surface is provided in the purified water collection zone. The condensing surface is spaced from the membrane.

Abstract: A filter unit for a septic tank including a cylindrical filter housing having two chambers therein, a first chamber having a plurality of stacked disc-dam filter units and a second chamber. Each disc-dam filtering unit is provided with an upstream side and a downstream side and the cylindrical housing has an opening in the bottom thereof in flow communication with the upstream side of the disc-dam filtering units. A vertically extending partition is provided to separate the first chamber from the second chamber and the partition includes flow-through openings therethrough of preselected size for controlling the rate of flow from the downstream side of the disc-dam units into the second chamber.

Abstract: Filter for continuous filtration of liquids containing solids in a closed cylindrical vessel with a pressure difference between the liquid to be filtered and the filtrate, with disks which are formed by hollow filter sectors and supported at a distance from one another on a driven horizontal hollow shaft normal to the shaft, with filter beds on both sides of every filter sector and a hollow space located between the latter allowing the filtrate to flow out through the hollow shaft, and with devices which are movably pressed against on both sides of every filter disk for removing and discharging solids from the filter beds forming the outer sides of the filter disks and for cleaning these filter beds, wherein every device for removing and discharging solids from and cleaning the filter beds is formed by a closed hollow box unit which is completely surrounded by the liquid to be filtered and has a plurality of chambers which are separated from one another, wherein every chamber has at least one inlet gap compre

Abstract: A filter device for separating solid material from a liquid includes a filter housing with vertically extending removable sidewalls wherein at the location of the removable sidewalls E-shaped connections are provided to receive two vertically extending sidewalls in spaced parallel relationship whereby a fluid impermeable sidewall may be inserted into the circumferential section of the housing when the liquid permeable section is removed for cleaning without interfering with the continual operation of the filter device. A pump or other apparatus are provided within the housing for removing filtered waste water therefrom.

Abstract: A filter is provided for use with an in-tank fuel pump for an internal combustion engine. The filter is disposed within a fuel tank and includes a main filtration chamber connected to an inlet of the fuel pump and a return fuel chamber connected to the engine for introducing thereto return fuel from the engine. The main filtration chamber has an upper side peripheral wall formed from a meshed filter medium. The return fuel chamber is connected to the main filtration chamber in such a manner that the upper side peripheral wall of the main filtration chamber serves as a partition wall between the main filtration chamber and the return fuel chamber. In one embodiment, the return fuel chamber has a peripheral wall formed from sheet or plate impermeable to fluid.

Abstract: A fuel tank filter assembly for a vehicle is disclosed which includes a suction pipe and a filter connected through the pipe to an inlet port of a bottom plate for a fuel suction pump, and which is characterized in that the bottom plate is formed of resin material so as to be integral with the suction pipe. Also disclosed is a shape retaining frame of a box-like shape made of a resin and having downwardly extending protrusions.

Abstract: There is disclosed a filtration unit for the selective separation of substances from fluids by membrane adsorbers, comprising a plurality of filtration chambers arranged in parallel and using membrane adsorber packs having a variable number of porous laminar sections, and wherein at each membrane adsorber pack, the same pressure drop is maintained between feed and permeate.

Abstract: The invention concerns an inorganic filtration unit for a liquid medium (2) with a view to recovering a filtrate, the unit comprising at least one inorganic, rigid, porous structure (A), presenting first (a.sub.1) and second (a.sub.2) principal faces opposite each other, at least one cavity (4) being arranged in the structure at a distance from the two faces, defining bearings (6), the cavity or the principal faces being coated with at least one separating layer (3). According to the invention, the porous structure (A) comprises at least one channel (8) with tight walls opening out on the two faces (a.sub.1 and a.sub.2) and arranged to traverse a bearing (6), with a view to constituting a first circulation network (R.sub.1) tight with respect to the cavity (4).

Abstract: The apparatus (1) comprises a first chamber (3) having an inlet (2) and a second chamber (23) having an outlet (24), with flow spaces disposed between the two chambers. The flow spaces are divided by a longitudinally running filter fabric (17) into an intake space (13) and a discharge space (14). The cross-section of the intake space continuously diminishes from the intake end to the discharge end, whereas the cross-section of the discharge space is smallest at the intake end and increases to a maximum toward the discharge end. Several filtering planes may be stacked about a hollow cylinder (4) forming the first chamber and run radially outward. The result is a filter apparatus in which the medium to be filtered is kept in continuous flow, and the filter fabric is optimally utilized.

Abstract: A filter for sterile filtration of suspensions, comprising a pressure vessel, at least one candle filter element arranged in the pressure vessel, the at least one filter element having a hollow member with a lower portion which is formed as a filtering medium and an upper portion which is formed as a closed tube with an unwrapped self-supporting filtering medium, and a tube for carrying off a filtrate, the tube being formed as a central tube which is arranged in the hollow member and the filtering medium and is removable so as to permit inspection and cleaning of the filter element without opening the pressure vessel.

Abstract: The present invention relates to a filter apparatus for separating solids from a liquid, said apparatus comprising an outer shell (1), a pipe (2) attached thereto for liquid infeed, a filter cartridge (3) formed by ring-shaped elements placed inside said outer shell, the rings being spaced at a distance from each other so as to provide horizontally outward flaring slits (4) between the rings, through which slits the liquid is adapted to flow, a discharge pipe (5) for the removal of the liquid from the space between the outer shell and the filter cartridge, and a second discharge pipe (6) for the removal of solids from inside the filter cartridge. Conventional filter equipment have a complicated construction and require the use of separate cleaning equipment.

Abstract: A method and apparatus for processing sludge, which utilizes filter plates and flow regulating means to form condensed sludge of higher concentration, have been developed. The filter plates are disposed within a sludge tank and noncondensed sludge is added to the sludge tank to completely cover the filter plates. Filtrate is then removed from the sludge tank by the filtrate extraction means via the permeable walls of the filter plates. As the filtrate passes through the permeable walls a first condensed sludge forms on the filter plates. After first condensed sludge is formed on the filter plates, a flow regulating means is operated to form second condensed sludge, an even higher concentrations of condensed sludge.

Abstract: An improved filter assembly for filtering liquid, in particular milk. The improved assembly comprises a retainer for connecting the filter assembly to a liquid supply tube, a filter sock, having a predetermined diameter and length, for filtering the liquid, and an internal support coil, having coils of varying pitch, located within and supporting the filter sock, also having a predetermined diameter and length. The internal support coil extends substantially the entire length of the filter sock. The diameter of the filter sock is slightly greater than the diameter of the internal support coil so that the filter sock fits snugly over the internal support coil. The predetermined length of the filter sock is longer than the predetermined length of the internal support coil so that a flexible tab is provided at the open end of the filter sock.

Abstract: A filter component having a substantially rigid support core and a filter element. The core includes a projecting first anchoring rib and the filter element (which is substantially flat in a repose position) has first and second spaced end panels. At least the first end panel of the element is attached to the anchoring rib when the element is mounted on the component. Element-component attachment is, in one aspect, by panel-mounted hook-like devices which attach to the rib. Attachment devices may also be embodied as clip mechanisms or rivet-like fasteners. A retaining tab on the component platform fits into a tab notch on the filter element when the element is mounted on the component.

Abstract: A filter for an in-tank pump of an automobile fuel tank includes a flat bag-shaped filter body, a connector body and a suction nozzle. The filter body has a closed front end and a rear end wall and includes a mesh member and a filter frame having a plurality of longitudinal and lateral ribs formed on the upper and lower portions thereof. The connector body includes a cylindrical attachment for attaching the filter body to a suction port of an in-tank pump and an end plate joined to an outer surface of the rear end wall of the filter body. The suction nozzle is attached to the end plate of the connector body so that it communicates with the cylindrical attachment and thrusts into the filter body. The suction nozzle is made of a deformable material and formed into a mesh cylinder having a closed forward end disposed within the filter body at a position of the closed front end of the filter body.

Abstract: A recyclable, flexible filter element comprising a tubular, outer braided jacket supported by a helical spring. The bottom of the tube of the jacket is turned inside the helical spring and is sealed by a removable fastening device which is inserted into the bottom of the helical spring to engage the spring through the thickness of the braided jacket. The top of the outer braided jacket is fastened and sealed to a flange and washer assembly which also contains the top of the internal support spring.

Abstract: A liquid purifying porous filter and a filter assembly employing the same can significantly improve filtering performance for impurities in the drinking water, liquors, liquidous seasoning or pool water and can perform back washing while purifying operation is maintained. The filter assembly is small in size, compact and easy to handle, and achieves high performance both in senses of quality and quantity, and is capable of performing back washing while maintaining operation, is compact and is easily installed.

Abstract: A method and materials for separating oil from water, using stacked disks to coalesce the oil, is disclosed. The method of coalescence allows configuration of systems which are compact, efficient, adaptable to modular configuration, and have a very high flow rate.

Abstract: A filter apparatus for filtering machine tool coolant is disclosed as including a drum filter or a disc filter assembly including a hollow rotatable mandrel mounting a drum filter assembly or plurality of removable hollow disc filter elements each element having a foraminous non-reticulated metal screen 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 to the other side thereof.

Abstract: Embodiments of this invention include pressure differential barrier members for separating selected substances from fluid, gaseous and/or liquid, and methods of making same. They include separation material which, with respect to the fluid to be treated, is pervious and exhibits desired separation capabilities. They may also, at least in part, include material which is substantially impervious to the fluid. They include bridges spanning flow paths to form lateral flow paths, and they may also include flow paths that are unbridged. All flow paths through such embodiments are either through structural elements which themselves have desired separation capabilities or are occupied by separation material that is pervious to the fluid being treated and is of such desired characteristics.

Abstract: A pressure filter includes a pressure vessel having a pressure chamber and a circumferential edge; a turntable rotatably mounted within the pressure vessel about a horizontal axis; a plurality of filters non-rotatably mounted to the turntable and spaced apart from each other at the circumferential edge of the pressure vessel and rotatable around the horizontal axis through a center of the pressure vessel such that the plurality of the filters continuously dip into and out of a solid solution in a bottom of the pressure chamber. A blow-off station is positioned above the solid suspension in the pressure chamber for freeing filter cake that has dried on the plurality of filters. A filter cake conveyor conveys the blown-off filter cake through a pressure lock in the pressure vessel.

Abstract: A modular table filter for a circular horizontal rotating table filter includes a number of sections which may be assembled on the support frame thereof. The sections are annular-sector-shaped and, when assembled, form an annulus on the table filter. Each section, in turn, may be broken down into an outer subsection and an inner subsection. Filtration fabric, or textile, may be placed on top of the outer subsection, and secured therein by the inner subsection, which is designed to lock thereinto. Alternatively, each section may be an integral annular-sector-shaped frame having a peripheral groove or channel. Filtration textile may be placed on top of the frame, and over the groove or channel, and wedges driven thereinto to hold the fabric tautly across the frame.

Abstract: A filter sector for a filter disk of a rotating filter having a plurality of such filter sectors includes two spaced plate-shaped elements formed from a relatively thin material and defining main planes. Protrusions outwardly extend from the main planes and are shaped out of the material of the plate-shaped elements. The protrusions are adapted to keep a filter cloth at a distance from the main plane. Interior bulbs shaped out of the material of the plate-shaped elements extend from the interior sides of the plate-shaped elements. The protrusions and the interior bulbs have a material thickness substantially corresponding to the material thickness of the main plane. The interior bulbs are adjoined at engaging contact surfaces to provide strength and torsional rigidity to the sector.