Abstract:
A screening deck (10) for a wood chip screening apparatus including a plurality of parallel bars (60a, 60b, 60c, 60d; 80a, 80b, 80c, 80d) mounted in grids (13, 14), with the bars of at least one grid having top surfaces disposed in at least two planes.
Abstract:
A self-loading, controlled deflection roll (10) for forming a pressure nip (N) with another roll (34) has at least one support shoe (24, 26), and preferably two opposed support shoes, mounted in a stationary support shaft (16) for controlling the deflection of the roll shell (18) in the direction of the nip (N). At either end of the controlled deflection roll (10), a pair of opposed guide shoes (44, 82) are pivotally disposed on the stationary support shaft (16) to apply pressure against the roll shell (18) to stabilize the position of the roll shell (18) relative to the stationary shaft (16). At least one guide shoe (44, 82) at either end of the roll (10) is equipped with a compensating piston to permit its face surface to move radially outwardly relative to the guide shoe support on the stationary shaft (16). Also, at least one of the guide shoes (44, 82) at either end of the roll (10) is pivotally supported on the stationary shaft (16) to allow rotational movement of its guide shoe about an axis in a plane substantially parallel with a nip plane (NP) through the nip (N) and the longitudinal axis of the roll. The guide shoes (44, 82) provide equal stabilization forces at substantially right angles to the plane of the nip regardless of the relative translational position of the roll shell (18) disposed about the stationary shaft (16).
Abstract:
An extended nip press (10) with an improved press shoe (22) and pressure applying apparatus. The press (10) includes a backing roll (14), a shoe (22), a belt (58), one or more felts (54) for passing between the shoe (22) and the backing roll (14) with the web (W), and a pressure applying apparatus for selectively forcing the shoe (22) toward the backing roll (14), such that the belt (58), the one or more felts (54) and the web (W) are urged against the backing roll (14) to establish a pressure zone (P) between the shoe (22) and the backing roll (14). The pressure applying apparatus is operable to vary the pressure profile of the pressure zone (P). The pressure applying apparatus engages the shoe (22) at three or more points on the shoe (22), spaced in the machine direction. The pressure applying apparatus includes three hydraulic pressure applying devices (34a, 34b and 34c) which are independently operable to vary the pressure profile. The press shoe (22) has a stiffness value in the range of approximately five million to fifty million mm /meter width, and the pressure profile can be varied by flexing the press shoe (22).
Abstract:
A papermaking machine (10) uses a low pressure water jet (63) mounted on a pneumatic actuator (65) for movement at least as fast in the cross machine direction as the paper web (12) moves in the machine direction for a distance of 2 to 12 inches. The jet rapidly cuts a tail with a blunt end of 2 to 12 inches wide from the web. The actuator (65) is mounted on a screw or belt driven carriage (60) to traverse the web (12) and expand the tail after it has been threaded through the dryer section (18) until the tail encompasses the entire web and thus completes the threading process. A controller (81) coordinates an air jet (53) positioned beneath a doctor blade (52) and a vacuum suction roll (82) which engages the last press roll (36). The air jet (53) and vacuum suction roll (82) are actuated when the blunt end of the tail engages the doctor blade (52). In this way, a tail with little or not streamer is formed and blown onto a dryer fabric supported.
Abstract:
An apparatus and method for protecting a wood chip destructuring device (10) from damage due to tramp material (4). The destructuring device includes a pair of destructuring rolls (50, 60) operating a pre-established distance from each other and an infeed chute (3) for delivering a stream of wood chips (1) to pass through a region between the destructuring rolls (50, 60). Said protection system includes a sensing unit (20) and a control unit (24) to detect tramp material (4) present in the chip stream. If tramp material (4) is detected in the wood chip (1) flow, the protection system operates to further separate the destructuring rolls so that the surfaces of the destructuring rolls (50, 60) will not be damaged by the tramp material (4) as the flow of material passes between the destructuring rolls.
Abstract:
An air density separator (20) has a vertical air separation chamber (24) that opens downwardly to allow rejected material (54) to fall out from the chamber (24) through the open bottom. The air density separator (20) is configured to recirculate the air and entrained fines, and so minimizes emissions and costly air treatment processes. The air separation chamber (20) is connected by a first duct (26) to a cyclone (28). A fan (30) is positioned adjacent the lower end (34) to the air separation chamber (24), and draws air through a second duct (27) out of the cyclone (28) for reintroduction into the air chamber (24). The fan (30) by way of the cyclone (28) draws air through the first duct (26) from the air separation chamber (24). The fan (30) exhausts into the vertical air separation chamber (24) below the material infeed (61) through a plenum (31). An oscillating screen (36) composed of bars (38) extends into the separation chamber (24) of the air density separator (20) and is used to disperse material into the separation chamber (24). The bars (38) are spaced apart to allow air to be drawn up through the bars (38) to separate the light component (56) in the feed material (44) from heavier materials (54). A tray (61) to which the bars (38) are mounted is caused to oscillate by an eccentric weight (50) which is mounted to the bars (38) and driven to oscillate in a horizontal plane. The tray (61) is suspended by four universal linkages (47) to a support frame (46), the linkages (47) allowing the tray (61) and attached bars (38) to oscillate.
Abstract:
The Extended Nip3 press apparatus of this invention has an endless loop nip blanket (32) which is clamped at each end head by a circular array of twelve clamp segments (70) which are positioned radially by the hydraulic actuation of an axially positionable circumferential clamp ring (60). The blanket is separately sealed by an air tube seal (62) which extends between the clamp ring (60) and the interior of the blanket (32). Because the clamping arrangement is independent of the seal, inadvertent loss of air pressure will not cause the blanket to become unclamped.
Abstract:
For distributing stock evenly across the face of a tube bank (30) in a papermaking machine, the stock supply header (14) has an increasing change in cross-sectional area per unit width traveling from the inlet end (16) to the recirculation end (18) of the header (14). The header top wall (22) converges toward the bottom wall (24), while the rear wall (26), converges toward the front wall (28). The change in a cross-sectional area down the header (14) from the inlet end (16) to the recirculation end (18) is thus closely matched to an ideally parabolic shape.
Abstract:
A new dryer section (20) of an existing dryer section of the two tier double-felted type has air caps (42) disposed over the upper dryer rolls (28) to simultaneously dry both sides of the web (26) to increase drying rates. The heated pressurized air is blown through multiple air impingement holes (48) in the air cap nozzle plates (46) to impinge the web (26) at a temperature of 500-900 degrees Fahrenheit and air speeds of 20,000-40,000 feet per minute. The dryer fabric (30) employed is foraminous with a permeability of between 400-1,200 cubic feet per minute per square foot and is designed to withstand peak temperatures of between 500-600 degrees Fahrenheit. The design of the air caps (42) utilizes recirculation of the blowing air to control drying rates.
Abstract:
The invention pertains to a load roll arrangement for loading a winding arrangement with one or several wound rolls on the same axis, during the winding of a web-like material, particularly paper, onto winding cores in a multiple-drum winder wherein support drums form a winding bed, in which the winding arrangement, rotating about its axis, is supported, with a support beam (60), vertically movable dependent upon the wound roll diameter, with a multipart load roll, consisting of a number of load rollers (42), which, individually with respect to the support beam (60), are vertically movable on a mounting arrangement and can be maintained in contact with the wound roll along a nip, with means for the fluid-like, particularly hydraulic, pressing of the load rollers (42) against the winding arrangement, and with an additional adjustment device, by means of which the mounting arrangements (50) of the individual load rollers (42) can be moved to different heights, independently of each other with respect to the support beam (60) according to the specifications of the resulting differences in diameter of the winding cores. In order to apply the rolls in the presence of varying wound roll diameters, due to the additional adjustment arrangement (70) of the invention, it has become possible to bring the load rolls hanging on the support beam at more greatly varying heights, and in this way to adapt the load rolls to a "diameter profile" that results along the winding bed from winding cores that differ from each other.