Abstract: An improved conveyor system for machine tool cleaning applications comprises a sump internal to a machine tool, a recirculating system in fluid communication with the sump, a hinge belt conveyor, portions of which are interposed between the sump and the recirculating system for removing coarse solids from the fluid, and a fine filter interposed between the sump and the recirculating system for removing fine solids from the fluid.

Abstract: Rotary filter including a perforated, rotatable drum and at least one blowback valve located in close proximity to the interior surface of the drum. In a preferred embodiment, the blowback valve includes an opening adjacent the drum for the discharge of a gas and the opening includes at least one radial position adjusting device alignable with a hole in the perforated drum, whereby the radial position of the blowback valve in relation to the interior of the drum is adjustable externally through perforations in the drum. The external adjustment permits drums longer than possible with prior art rotary filters.

Abstract: A drum filter is characterized in that its filtrate compartments (20) comprise a bottom part (28,30) and a side surface (32), which is provided with a lip or curved portion (34) extending towards the inside of the compartment (20) from the edge of the side surface opposite the bottom part. The lip (34) prevents the filtrate from escaping from the compartment (20) back through the wire surface, when the drum filter (20) is rotated.

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: A drum filter for thickening lime sludge in which the lime sludge is thickened on a filter layer (precoat) formed by the lime sludge on the filter periphery. The filter is provided with high pressure liquid nozzles continuously reciprocating in the longitudinal direction of the drum in such a way that, during each rotation of the drum, part of the filtering layer is continuously detached and drops into a vat containing the lime sludge.

Abstract: A method and apparatus for doctoring (cutting) the solids off a precoat filter. A stationary doctor blade continuously doctors mud (from a mud bath) from the surface of a rotating porous surface vacuum drum. A traveling doctor blade, located upstream of the stationary doctor blade, moves back and forth along the drum. The stationary blade extends the width of the rotating vacuum drum while the traveling blade is shorter and is also located nearer to the drum surface.

Abstract: A liquid filter comprises a cloth filter media in the form of a drum. Contaminated liquid flows into the interior of the drum thence radially outwardly through the cloth filter media as the filter rotates. Sludge is constantly backwashed from the filter media by pressurized liquid in the reverse direction of filtration. Flexibility of the cloth filter media materially enhances backwashing efficiency. Sludge is collected by a collector internally of the drum.

Abstract: An automatic drum filter comprises a tank having a drum therein with a continuous filter media wrapped around substantially the entire periphery thereof. A supply roll of said media is supported externally of the tank for rotation about an axis substantially parallel to the axis of the drum. Filter media is advanced about the drum of the filter by means of an assembly which engages, advances, and then disengages the media.

Abstract: A slurry filter apparatus in which a pump mechanism having a valve and a valve seat, each of which is made of a wear-resisting metal material, is capable of moving a slurry of high density and containing hard particles, under pressure, the flow of slurry being injected so as to strike the face of the filter at an a predetermined, non-tangential angle. Coarse particles contained in the slurry are uniformly dispersed by the shearing forces due to cavitation generated through the high pressure injection of the slurry and abrupt speed changes of the flow of slurry. A caked layer of particular material is thereby prevented from forming on the surface of the filter.

Abstract: A filter apparatus has a drum rotatable about an axis and having a foraminous outer wall with an inner surface, a support screen lying directly on the inner surface, a filter mesh lying directly on the support screen, and a protective screen lying on the filter mesh and holding same against the support screen. The support screen and mesh are held in place by a retaining seal having at least two lips defining at least one recess snugly receiving the edges of the support screen and mesh with one the lips between the support screen and the drum inner surface. The protective screen lies on the other lip of the seal and presses the seal against the surface of the drum while clamping the edges in the recess.

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: This invention increases the efficiency and flow rate of rotary drum filtration and makes possible the use of such filtration for volatile and high temperature materials. According to the invention a rotary drum filter unit operates continuously in a pressure vessel and solids are intermittently discharged from the vessel. The filtered solids are scraped from the drum periphery and dropped into a trough in the vessel communicating with a discharge passageway. When the passageway is filled with solids, a shroud, driven by a reciprocating ejector traps the solids in the passageway. The ejector compacts the trapped solids forming plugs which are sequentially discharged from the pressure vessel.

Abstract: In apparatus for thickening a suspension of pulp material which includes an endless foraminous belt wrapping two spaced horizontally supported rolls, a special doctor mechanism is provided for transferring thickened pulp from the bare surface of the second roll into a trough mounted in the space bounded by the two rolls and the upper and lower runs of the belt. More specifically, the doctor mechanism includes a rigid doctor blade mounted with its working edge in close but spaced relation with the bare surface of the roll to remove pulp therefrom without contact with the roll surface. Provision is also made for periodically oscillating the blade about a horizontal axis to move its working edge away from and back to its closely spaced working relation with the roll.

Abstract: In a drum washer for washing the pulp for making paper to remove pulping liquors, the method and apparatus for providing the filtrate liquid being drained from the drum and pulp mat during a portion of the rotation cut-off which liquid can be continuously sampled and analyzed to give a more positive indication of washing efficiency.

Abstract: Apparatus is provided for dewatering an aqueous clay suspension by a process which includes preparing a partly dewatered filter cake and concurrently compressing the partly dewatered filter cake on a filtration drum while applying vacuum suction to it from inside the drum, and then removing the dewatered cake from the filter. The process also purifies the filter cake. An apparatus suitable for carrying out the process comprises a rotary vacuum filter, means for compressing the clay filter cake on the filter medium and means for applying vacuum filtration to the same portion of the cake being compressed. The compression means may comprise a rotatable roll mounted for rolling compressive contact with the filter cake. The rotatable roll may have a non-stick bearing surface to which solids of the filter cake are substantially non-adherent. The rotatable roll may be a pneumatic roll designed to conform to the filter drum and increase the size of the contact zone between the filter drum and the compression roll.

Abstract: An apparatus for dewatering and squeezing a water containing material comprises a drum with a sieve mantle defining two co-operating drum sections, each comprising a feed screw extending therein. The first section of the drum in the feed direction is formed for dewatering of the material mainly by self-drainage. The first drum section is rotatable and is provided with means for cleaning the sieve mantle holes. The second section is formed for increased compression of the material, and has a thread height for the feed screw smaller at the outlet of the second section than at the inlet to this section.

Abstract: Method and drum filter for thickening of slurry and for treatment of the slurry with liquid. The slurry to be thickened is passed onto the filter face of a drum (3) revolving in a basin (3), and the treatment liquid is passed through the pulp web formed on the drum. The consistency of the pulp web is increased by pressing a compression plate (10) against the pulp web. The compression force of the compression plate (10) is produced by means of the pressure of a liquid and/or gas passed to the convex side of the plate. The compression force can be adjusted by adjusting the pressure prevailing in the gas space outside the drum (3).

Abstract: A filtering apparatus for filtering cutting oil containing metal chips so that the filtered cutting oil can be recycled includes a reservoir, a filtering drum journalled within the reservoir and having a filtering screen support and a filtering screen extending about the periphery of the drum and secured to the drum by the filtering screen support, a chip discharge device including a belt entrained around guide rollers for carrying separated metal chips out of the reservoir, a discharged chip receiving bin disposed outside the reservoir adjacent to the discharge end of the chip discharge device and a filtered oil receiving bin disposed outside of the reservoir adjacent to a filtered oil discharge area of the reservoir. The drum is rotated by a motor located atop the reservoir and connected to the drum. An air spray device extends within the drum for spraying air at the filtering screen to dislodge any metal chips clinging to the screen.

Abstract: It is desirable to be able to treat medium consistency (e.g. about 8-12% by weight) paper pulp suspensions with treatment liquid (e.g. a wash liquid), and to thicken the pulp to about 30-50% consistency at the same time. A moving (e.g. rotating) channel is defined by a root wall and upstanding side walls--some or all of which are perforated--and treatment liquid is introduced by an arcuately elongated distributor with perforated side walls into the center of the pulp within the channel, filtrate flowing out through the perforated walls. A pivoted wall portion of the stationary housing of the treatment device restricts outflow of the thickened pulp cake from the device, the cake flowing between a doctor blade and the pivoted wall portion.

Abstract: A sieve bend has been described incorporating a headbox 40, throat mechanism 46, nip flap 90 and sieve surface area 52 supported by frame 96 which may have portions thereof rotated or positioned behind headbox 40 temporarily until its use is desired. The invention overcomes the problem of requiring frequent end for end reversal of the sieve surface area and of debris jamming the throat mechanism. Further, the invention permits in process variation of the sieve surface area 52 in response to downstream conditions.

Abstract: A drum filter is disclosed in which a filter media layer is applied over a section of a drum member disposed in a tank which receives a liquid to be filtered, the filter media layer constructed of a thin metal with a pattern of holes formed by chemical etching, with the diameters thereof increasing in the direction of flow. The diverging hole shape reduces the tendency for plugging of the hole. One or more scraper blades are urged against the filter media layer which is rotated past the scraper blade causing a flexing of each section of the filter media layer to unplug any holes which do become clogged.

Abstract: A method for application in conjunction primarily with so-called rotating filters of the kind which include a substantially cylindrical filter tube (1) which is provided with a permeable wall and which is sealingly journalled at preferably two axially spaced locations, preferably at the ends of the tube, and which is arranged for rotation about its longitudinal axis in a filter jacket (2), wherewith material to be filtered, the so-called feed, is supplied to a space or chamber (11) located between the filter jacket and the filter tube, and the filtered substance, the filtrate, being tapped-off from the interior of the filter tube.The method is particularly characterized by sealing and journalling the filter tube (1) in a manner adapted to substantial changes in temperature in the filter tube and that facilities are provided for sterilizing the filter.

Abstract: A process is disclosed for recovering a cellulose ether from a cellulose ether suspension in which the cellulose ether is recovered as a filter cake from a pressure filtration, particularly using a rotary pressure filter. Clogging of the separation or filtration device is avoided, providing for a long useful life. A multi-layer wire mesh filter medium is employed, formed of mesh layers of different wire thicknesses and/or mesh size. After removal of the filter cake, the filter medium is cleaned with steam, compressed air or pressurized water.

Abstract: An apparatus for treating, e.g., washing or filtering, fiber suspensions having a consistency of 8-20%, the apparatus including at least on rotatable filtering surface, an arrangement for feeding the suspension to a treatment region of the apparatus, and an arrangement for discharging the suspension from the treatment region, the feeding arrangement including at least one pressure chamber for fluidizing the suspension, at least one inlet duct for introducing the suspension to the chamber, and at least one feed duct for transferring the suspension from the pressure chamber to the treatment region.

Abstract: In a causticizing process for separating at least white liquor and lime sludge out of the process, filters in the form of discs or drums are arranged. The filtrations take place under positive pressure and the filters are arranged in a closed system. Such a pressure filter can also be arranged for the separation of sludge.

Abstract: An interceptor for the continuous removal of solid matter from a mixture of solids and liquids includes a screening drum rotating while in operation in a given direction of rotation. The mixture is fed to the outer surface of the jacket of the drum, whereby the liquid enters the drum and solid matter remains on the outer surface of the drum jacket. A solids discharge device is provided adjacent the outer surface of the drum to remove deposited solid matter. At least the lower half of the screening drum is surrounded by a tank to which a mixture inlet is connected. A liquid outlet is connected to the interior of the screening drum. The level of the mixture in the tank is controlled in such a way that it is above the level of the cleansed liquid inside the screening drum. The mixture introduced into a flow chamber surrounding the drum jacket flows substantially in the same direction as the direction of rotation of the drum.

Abstract: A filtering apparatus filters cutting oil containing metal chips so that the filtered cutting oil can be recycled. The filtering apparatus includes a reservoir, a filtering drum journalled within the reservoir and having a filtering screen extending about the periphery of the drum, chip discharge device for carrying separated metal chips of the reservoir, a discharged chip receiving bin disposed outside of the reservoir adjacent to the discharge end of the chip discharge device and a filtered oil receiving bin disposed outside of the reservoir adjacent to a filtered oil discharge area of the reservoir. A permanent magnet is disposed outside the reservoir so as to attract metal chips to the bottom of the reservoir from where the chips are discharged by the chip discharge device.

Abstract: A method and apparatus for forming on the outside of a permeable, rotatable drum by feeding a pulp slurry through a mat forming and pressing zone, followed by a mat washing zone. In the mat washing zone, the mat is washed with liquid from the first source and then washed with liquid from a second source.A Washing baffle has a first portion extending from its upstream end partially along the outside surface of the drum and slightly spaced from the outside surface of the drum. This first portion is followed by a second portion extending partially along the outside surface of the drum and spaced further from the outside surface of the drum than the first portion. A valve is provided for controlling the velocity of liquid through a slot into a circumferential space separating the washing baffle from the drum.

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 solid-liquid separating apparatus for obtaining a liquid component, for example, from a used solid-liquid mixture for reuse of the same, which includes a filtering member having a hollow cylindrical shape made of a hard porous material such as porous ceramics, sintered metal, layered metal net, sintered resin, unwoven cloth, and the like. The hard porous material is provided with continuous air holes and a device is provided for reducing the pressure in the inner hollow space of the filtering member during the rotation thereof. A scraper is provided for scraping a solid component remaining on the filtering surface of the filtering member after the liquid component is sucked into the inner space of the filtering member. The separating apparatus further includes a cutter for effectively removing the solid component and a device which allows reuse of the mixture with solid particles evenly distributed therein.

Abstract: An apparatus for continuously separating intermixed solids and liquids from industrial waste. The device includes an elongated conduit having an inlet and outlet and where the interior of the conduit forms a mixing chamber. The industrial waste is pumped into the inlet of the mixing chamber and a polyelectrolyte compound is introduced into the mixing chamber at at least two spaced locations along the conduit. The outlet of the conduit is then passed across both a stationary screen and then into a rotating drum separator, which, together, remove the water from the waste material.

Abstract: An automatic drum filter comprises a perforated drum having a continuous filter media wrapped around substantially the entire periphery thereof. A supply roll of the media and a reroll drum are supported for rotation about an axis substantially parallel to the axis of the drum. A variable speed motor drives only the reroll drum. A pair of endless chains extend around each end of the drum so as to preclude axial displacement of the media on the drum.

Abstract: The seal has particular use as a seal in vats having a rotatable drum. The seal prevents material from getting between the ends of the drum and adjacent vat inside surface.

Abstract: The improved rotary vacuum filter discharge flow assembly provides a discharge filtrate stream having a substantially increased filtrate flow velocity, a reduced vacuum loss, a reduced level of turbulence and air entrainment to means defining an axially-extending valve-receiving space in communication with a remote filtrate collection area. The subject assembly, which is located at one end of a rotary vacuum filter, includes a plurality of radially-disposed, inlet conduit means connected to and in communication with the rotary vacuum filter discharge flow assembly and comprises a plurality of radially-disposed discharge conduit means for transporting the discharge filtrate stream from the inlet conduit means to the valve-receiving space means. Each of the discharge conduit means are connected at one end to one end of the inlet conduit means, and are joined at the other end to respective adjacent discharge conduit means for defining the valve-receiving space means.

Abstract: A pulp mat is formed on the outside of a permeable, rotatable drum by feeding a pulp slurry through a mat forming and pressing zone, followed by a mat washing zone. In the mat washing zone, the mat is washed with liquid from a first source and then washed with liquid from a second source.A washing baffle has a first portion extending from its upstream end partially along the outside surface of the drum and slightly spaced from the outside surface of the drum. This first portion is followed by a second portion extending partially along the outside surface of the drum and spaced further from the outside surface of the drum than the first portion.

Abstract: A shower pipe for a rotary drum filter includes first and second parallel rows of spray holes which extend along the length of the pipe. The holes in one row are staggered with respect to the holes in the other row, with both rows being positioned circumferentially in the same quadrant of the pipe. Each spray hole has its own separate fan-shaped diffusion flange extending in a generally parabolic curve from the adjacent hole. Each spray hole may be formed by a premolded plastic sleeve-like insert which is inserted through and seated within prebored holes in a section of the pipe. Each insert defines a spray hole or nozzle for discharging liquid under pressure from the pipe onto its associated diffusion flange. Each diffusion flange member may be premolded to include a female threaded upper portion which threads onto a male threaded projectng portion of the insert extending from the outer wall of the pipe.

Abstract: The novel sealing means of this invention generally comprises a replaceable, annular-shaped sealing device having a substantially L-shaped radial cross-sectional configuration for effecting the indirect fluid-tight sealing of an entry passageway formed at the entrance to either of the channel means. The L-shaped radial cross section of the sealing device comprises an axially-extending base section capable of extending within and effectively sealing off, in a fluid-tight manner, either of the entry passageways. The sealing device also includes a radially-extending leg section capable of facilitating the effective sealing of either of the entry passageways and for maintaining the sealing device in a substantially fixed position within the entry passageway means by the securing engagement of the inner radial surface of the leg section with the outer end of either of the respective trunnion and the inner vat insert element.

Abstract: Filter chambers composed of two adjacent filter disks are attached to a drum-like filtrate collection chamber and are adapted to rotate therewith. The filtrate penetrates the filter disks and enters the collection chamber and thereafter exits the collection chamber through a collection space. The collection space is sealed from the trough by means of a rotating seal. The suspension inlet is provided on a sidewall of the trough and the suspension outlet is provided on the opposite wall of the trough. The disk concentrator serves to remove filtrate from aqueous suspensions containing fibrous components.

Abstract: Apparatus has a rotary drum provided with a heating jacket therearound. The drum is mounted on a base pivotally supported on a pedestal. The base can be caused to take different orientations so as to enable the drum to take different attitudes. While the drum is in a vertical position, a mixture of fine particles and a liquid is supplied into the drum through a supply passage formed axially in a rotary shaft which extends into the drum rotatably and axially slidably relative to the drum. The mixture is filtered through a filter disposed in the drum. Filter liquid is discharged to the outside. The particles are prevented from passing through the filter and remain in the drum. Thereafter, the particles are heated and dried by a heating jacket on the drum while the drum is caused to assume a horizontal position and being rotated. The drum is then inclined such that the initially upwardly directed end thereof is directed obliquely downward.

Abstract: A backwashable filter comprises (a) an outer case, (b) a rotatable, permeable filter drum, (c) a fibrous filter element supported on the surface of the drum, (d) one or more stationary backwash arms, (e) a feed inlet leading to one side of the filter drum and (f) a filter outlet emerging from the other side of the drum. The backwash arms are in close contact with the filter element. The tendency of the feedstock to bypass the filter and enter the backwash arms is thereby reduced.

Abstract: An apparatus for treating a fiber suspension, comprises a drum rotatably journalled to a stand and having an envelope surface to support a fiber web formed from the fiber suspension. A curved wall plate which is concave in the direction to the envelope surface of the drum is spaced from the envelope surface (and generally parallel thereto) to define a material space therebetween for said fiber web. The space includes an axial inlet gap and an axial outlet gap. The wall is continuous and encloses a major portion of the envelope surface of the drum and is arranged to move freely in the circumferential direction of the drum to compensate for radial alterations during adjustment of the distance of the wall from the envelope surface at one or more positions between the inlet gap and outlet gap. Adjustment devices cooperate with the wall for adjusting the distance of the wall from the envelope surface of the drum.

Abstract: Drill cuttings, and similar slurries or mixtures oily solid particles, are treated by a dryer apparatus which vaporizes the liquid and discharges relatively large solid particles for disposal. Vapor and entrained solid fines are conveyed from the dryer to a condenser and then to a rotary drum vacuum filter having a precoated filter media disposed thereon. The solid fines are filtered by the filter media comprising diatomaceous earth or perlite and the clarified condensed liquid is conveyed to separator means for separating oil, water and any other liquids present. The filter media stripped from the filter and contaminated with entrapped solid fines is conveyed through the dryer means and disposed with the solids particles being discharged from the dryer.

Abstract: A rotary drum vacuum filter suitable for processing pulp slurries is provided with a vacuum expression belt. The invention provides a method and apparatus for tracking and controlling the belt during operation. The belt is positioned by a moveable frame for expressing filtrate from the pulp web and in operation a control unit monitors lateral movement of the belt with respect to the drum. When drifting occurs the belt is adjusted horizontally during operation to counter drift. The adjustment can be repeated as necessary. If continued drift cannot be corrected then the belt is moved vertically to an inoperative position.

Abstract: An arrangement for scraping the filtered solids build-up from the surface of a drum filter is disclosed, in which a scraper is mounted with an edge against the surface so that rotation of the drum will accomplish scraping of the surface. Clutching engagement with a rotary drive member is produced by a predetermined extent of axial shifting of the drum against the resistance of a spring bias force. The drum is also arranged to be subjected to an axial pressure force developed by flow through the filter so that clutching engagement is automatically produced upon build-up of solids to a predetermined extent to cause a level of pressure force to be developed to produce a consequent axial shifting sufficient to produce clutching engagement and rotation of the drum. A drag out conveyor moving through the tank engages a rotary sprocket which comprises the rotary drive member, and the scraper edge and drum are positioned to directly deposit the scraped solids on the conveyer to be removed from the tank.

Abstract: The device according to the present invention comprises a unidirectionally circulating endless filter cloth with a napped filter layer on the surface, a solid-liquid mixture supply device installed on the front side of filter cloth, a depressurizing suction device installed on the backside of the filter cloth, a non-filterable content withdrawing device installed downstream of the solid-liquid mixture supply device and the depressurizing suction device, and a filter cloth wash device installed downstream of the non-filterable content withdrawing device in the running direction of the filter cloth and located between the non-filterable content withdrawing device and the solid-liquid mixture supply device or the depressurizing suction device. The depressurizing suction device is equipped with a depressurized suction port splaying in the running direction of said filter cloth.

Abstract: The present invention provides a rotary drum filter wherein one or preferably two rotary drum filters are submerged in a tank of liquid to be filtered. Each rotary drum filter is comprised of a generally cylindrical tank having a perforated outer wall plate over which is applied a cloth type filter media. A suction pipe is included inside the rotary drum filter so that filtered liquid can be drawn into the rotary drum filter through the pressure differential established by the suction pipe. Clean filtered liquid exits the suction pipe to the industrial apparatus with which the filter apparatus is used. A backwash vacuum box extending generally the length of the rotary drum filter media is in contact with a portion of the rotary drum filter media. A partial vacuum is established in the vacuum box such that filtered liquid can be drawn outwardly from the rotary drum filter such that solids accumulated on the filter media are drawn off from the filter media thereby cleaning that section of the filter media.

Abstract: A shower pipe for a rotary drum filter includes a fiberglass pipe body of rectangular cross section with two rows of spray holes and with the holes of one row being staggered with respect to the holes of the other row. The upper row includes a separate diffusion flange for each hole. The lower row includes a continuous diffusion flange which is reinforced and rigid to resist deflection and serve as a striker to limit the thickness of pulp stock passing upwardly by the flange. The lower flange includes a flexible flange extension which extends to the pulp mat on the drum to limit heat loss from the spray of washer fluid. Different diffusion flanges on the same pipe define different spray trajectories to prevent overconcentration of spray impinging the mat.

Abstract: A separator with a magnetic drum which rotates through a well-defined liquid flow path to separate magnetic particles from liquid delivered to the flow path by way of a trough. A weir extends between the trough and the drum to define a gap at the entry end of the flow path. The weir is hinged to swing downwardly and upwardly to automatically increase and decrease the width of the gap when the incoming flow rate increases and decreases, respectively, the weir thus acting to maintain the liquid level in the trough substantially constant at various incoming flow rates. The trough is shaped to spread the incoming liquid across the length of the drum in a streamlined manner. The housing of the separator is of a fabricated construction enabling easy removal and replacement of an arcuate apron which coacts with the drum and the housing to define the flow path.

Abstract: Pulp sheet take-off apparatus which allows removal of drum valve parts from existing high vacuum rotary drum filters and significantly increases the production capability of existing and newly designed high vacuum rotary drum filters includes an enclosed take-off chamber that is mounted immediately adjacent and parallel to the face of the filter drum on the descending side thereof, the chamber being connected by piping to the filter drum barometric leg or other subatmospheric pressure source as a means of maintaining subatmospheric pressure in the chamber equal to or less than the internal pressure of the filter drum.

Abstract: A filter of the type including a filter drum mounted within a settling tank containing a liquid to be filtered, with filtering flow drawn through a filter media on the outer surface of the drum, in which a fluid connection to the liquid circulation system is established by interfitting of tube sections as the filter drum is lowered into the tank at installation. Guiding members are included to properly position the drum as it is lowered to insure the tube sections move together as the filter drum is lowered. A valving arrangement is disclosed in one embodiment for isolating the particular drum filter from the circulation system upon removal. In another embodiment, an arrangement is utilized for producing intermittent rotation of the drum by engagement with the flights of a drag-out conveyor.