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: 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 rotary drum filter of the pipe machine type has a stationary vacuum breaker valve-discharge elbow assembly at the discharge end of the drum which defines a streamlined, smoothly curving, and substantially unobstructed discharge flow passage with gradually changing flow cross sectional areas. The valve member includes a valve closure segment at its inlet end that is structurally connected to the annular outlet end flange and sealing rim by an extension segment which forms a continuation of the valve segment. The cross sectional shapes and areas of the flow passage at the valve outlet and discharge elbow inlet are the same, but the area gradually increases in a direction toward the outlet of the elbow, and the shape gradually changes from a segmented circle to a full circle in the same direction.

Abstract: A center valve rotary drum filter includes radially disposed baffles or vanes which extend in the center valve opening from axial surface channels to a central drainage conduit. The baffles provide channels in the center valve opening which collect, direct, and accelerate filtrate flow toward the drainage conduit thereby improving the overall operating efficiency of the filter. The center valve rotary drum filter further includes a curved flow passage between the flow-confining walls. This flow passage is curved toward the central axis of the drainage conduit for directing filtrate flow to the drainage conduit. In a preferred case, the curved flow passage comprises a concavely curved, cone-like member having a broad proximal base and a narrow distal end. The base end is directed toward the one of the radial flow-confining walls opposite the entrance to the drainage conduit, the distal end being directed toward the central axis of the drainage conduit.

Abstract: A shower pipe for a rotary drum filter has a square cross-sectional shape defined by top, bottom and side walls. The sidewalls and a pair of lengthwise-extending continuous diffusion flanges depending from the bottom wall of the pipe stiffen the pipe against sag for placement at a 12 o'clock position spanning the filter drum. The pipe is formed of fiberglass reinforced plastic in two longitudinally-divided hollow sections in a pair of mirror image, trough-like molds. Each section has a pair of interconnection flanges for mating the sections together. The interconnection flanges extend normally to the sidewalls to stiffen the pipe when the bottom wall of the pipe is vertically-oriented for placing the pipe at a 9 o'clock position along one side of the filter durm. Glass rods are secured in the interior corners of the pipe to provide diagonal rigidity, for placing the pipe at, e.g., 10-11 o'clock position between the top and side of the filter drum.

Abstract: A cell head for an electrolytic cell includes a generally tubular protective insert concentrically positioned within the head to shield the inner side walls thereof from the scouring action of corrosive gas bubbles produced during electrolysis within the cell. The insert includes a lower connecting flange which fits between the mating connecting flanges of the cell head and its underlying electrolyte tank to block off access of gas bubbles rising through the electrolytic within the tank to the inner side walls of the cell head. The insert is readily replaceable without replacing the entire cell head.

Abstract: A vacuum breaker valve-discharge elbow assembly for a rotary drum filter of the pipe machine type is adjustably mounted to the drive gear housing for the filter via a separate mounting plate. A valve flange is secured to the mounting plate. The mounting plate is in turn transversely and axially adjusted on the gear housing via adjusting bolts to accurately seat the valve within its valve housing in the drum. The discharge elbow is then secured to the mounting plate independently of the valve. The valve can be rotationally adjusted on the mounting plate without disturbing the prior axial and transverse adjustment of the plate and valve by providing slotted fastener access holes on the valve flange and close-tolerance valve flange guide shoulders on the mounting plate. Cooperative calibration plates on adjacent valve flange and mounting plate surfaces facilitate precise angular adjustment of the valve.

Abstract: A vacuum breaker valve-discharge elbow assembly for a rotary drum filter of the pipe machine type is adjustably mounted to the drive gear housing for the filter via a separate mounting plate. A valve flange comprising a separate clamping ring clamps the valve to the mounting plate. The mounting plate is in turn transversely and axially adjusted on the gear housing via adjusting bolts to accurately seat the valve within its valve housing in the drum. The discharge elbow is then secured to the mounting plate independently of the valve. The valve can be rotationally adjusted without limitation on the mounting plate without disturbing the prior axial and transverse adjustment of the plate and valve by loosening the clamping ring to enable rotation of the valve along close-tolerance guide surfaces of the mounting plate. Cooperative calibration plate and pointer on adjacent surfaces of the valve body and packing collar facilitate precise angular adjustment of the valve.

Abstract: A butterfly valve for use with corrosive fluids is constructed of fiberglass-reinforced plastic (FRP). The valve blade is mounted in the valve body on a shaft comprising a continuous strand fiberglass-reinforced plastic rod secured in a sleeve. Exposed end portions of the rod are coated with plastic resin and machined for journaling in the valve body. An FRP sealing layer coats the sleeve and adjacent portion. A pressurizeable O-ring seal surrounds the passageway of the valve body for sealing against the periphery of the blade. The periphery of the blade is rounded and sized so that the O-ring cups the periphery of the blade when closed. The valve body is formed in two tubular sections which are connected together during assembly of the valve. The end faces of the two sections are oppositely beveled to jointly form an inverted V-shaped channel for the O-ring seal. The beveled end faces provide acutely angled edges tangentially contacting the sides of the O-ring along the inner surface of the valve body.

Abstract: A substantially entirely plastic rotary drum filter is made by applying a layer of plastic to the interior surface of a cylindrical mold, removing the mold, and applying at least one additional layer of plastic to the exposed exterior surface of the shell formed by the first layer. A plastic annular axial valve housing with plural valve chambers and a central valve receiving space is mounted to a head assembly at the head end of the shell. A tail assembly closes the opposite end of the shell to form the drum. Circumferentially spaced interior plastic bucket sections are positioned midway between the head and tail assemblies. Upon the periodic application of a vacuum to the valve chambers, filtrate is delivered from the exterior of the drum through an associated bucket and plastic drainage conduit to an associated valve chamber. Plastic reinforcing rings strengthen the drum along its length and in the region of the bucket section.

Abstract: A substantially entirely plastic rotary drum filter is made by applying a layer of plastic to the interior surface of a cylindrical mold, removing the mold, and applying at least one additional layer of plastic to the exposed exterior surface of the shell formed by the first layer. A plastic annular axial valve housing with plural valve chambers and a central valve receiving space is mounted to a head assembly at the head end of the shell. A tail assembly closes the opposite end of the shell to form the drum. Circumferentially spaced interior plastic bucket sections are positioned midway between the head and tail assemblies. Upon the periodic application of a vacuum to the valve chambers, filtrate is delivered from the exterior of the drum through an associated bucket and plastic drainage conduit to an associated valve chamber. Plastic reinforcing rings strengthen the drum along its length and in the region of the bucket section.

Abstract: A deck structure is described for a filtering apparatus having a rotatably mounted, generally cylindrical drum with filtering and vacuum drainage capability. The deck structure includes the following components: (1) a plurality of circumferentially spaced, axially extending, imperforate channel members affixed to the outer peripheral surface of the drum, the channel members each including a first peripherally extending surface which is radially spaced from the peripheral surface of the drum, the first surfaces defining filtrate slots which are at least about as wide in a circumferential direction as the first surfaces; (2) a plurality of axially extending, evenly circumferentially spaced dams mounted adjacent the outer periphery of at least some of the channel members, the dams defining filtrate compartments therebetween which lead to the vacuum drainage apparatus; and (3) a perforate support for supporting a filter above the filtrate compartments.

Abstract: A rotary drum filter used to form and wash a pulp mat in the paper making process has a cylindrical filter drum with trunnions at its opposite ends mounting the drum for rotation about a central axis. One of the trunnions is hollow and is rotatably connected to an open end of a stationary vacuum pipe for draining filtrate from the drum during its rotation. Packing material provides a fluid seal at the rotatable connection between the vacuum pipe and the hollow trunnion. The hollow trunnion has an inner wall lined with a fiberglass-reinforced plastic material. An outer end portion of the inner wall is recessed to provide a seat for a packing sleeve insert made of an abrasion-resistant material. The inner surface of the packing sleeve insert provides a continuation of the lined inner surface of the hollow trunnion. An outer flange collar of the insert is threadedly fastened to an outer end surface of the hollow trunnion to hold the insert in place.

Abstract: A rotary drum filter of the center valve type has replaceable valve seats in the form of pairs of opposed arcuate valve seat segments which are threadedly connected to channel sidewall portions of the drum in the region of the annular channel which receives the relatively stationary arcuate valve member. Each valve seat segment has a corner indentation between radially and axially outer faces thereof for seating the valve member.