Abstract:
A cleaner receives input pulp stock in an inverted conical chamber (26), which acts as a hydrocyclone to direct heavyweight reject flows outwardly, lightweight reject flows into a discharging vortex chamber and accept flows in between to a vortex finder for removal. The cleaner body has an inverted hydrocyclone chamber (34) formed beneath the inverted cone and a ceramic splitter (36) below which skims off the heavyweight reject flow from the accept flow, and diverts it into the inverted hydrocyclone chamber (34). A portion of the diverted heavyweight reject flow is removed through a toroidal heavyweight rejects relief outlet (47), but the larger fraction of the heavyweight reject flow is recirculated within the inverted hydrocyclone chamber. Because the chamber narrows as it extends upwardly, the flow increases in speed and angular velocity to such an extent that the flow within the inverted hydrocyclone chamber matches the flow passing by the chamber, thereby preventing turbulent mixing.
Abstract:
A rigid metal housing is positioned downstream of a coating applicator. The housing supports a plurality of positionable contact elements formed of a low friction, high wear-resistant material, which extend inwardly from the housing to engage a slow speed rotating rod. At least one of the contact elements is adjustable to support the rod for stable rotation, and to retain an effective seal between the contact elements and the rod to thereby prevent leakage of clearing/lubricating fluid into the applied coating. The contact elements may be advanced inwardly as the elements and thr rod wear, thereby extending the effective life of the rod holder apparatus. Screws may bear against a rear contact element through segmented backing plates allowing refinement of the coat weight along the width of the substrate. Furthermore, an air tube may be positioned between the housing and a rear fixture to adjust overall coating thickness.
Abstract:
A high temperature pressing roll (22) has a cast or formed steel roll (38) which is coated with a molybdenum-containing alloy. The preferred alloy has 14 to 16 percent molybdenum, 28 to 30 percent nickel, 30 to 34 percent chrome, 1.2 to 1.8 percent silicon, 4 to 4.5 percent boron, a maximum of 0.2 percent carbon and copper between 3 and 3.8 percent with the balance being iron. The roll is first coated with a bonding coating consisting of nickel and chromium. This bonding layer is then flame sprayed or plasma sprayed with a molybdenum alloy. The coating once applied is ground to a 30 RA or smoother surface. The mobilybdenum alloy is sprayed on to achieve a surface depth of approximately forty thousandths of an inch.
Abstract:
A papermaking machine has a stock manifold or headbox which is tapered in the machine direction. Paper stock flows through a bank of tubes (18) from the stock manifold to a slice for injecting stock onto a forming wire (12). Each tube in the tube bank (18) extends in a plane which is substantially parallel to the direction of motion of the paper web being formed. The tubes are connected to the interior of the headbox manifold along a stock supply wall. A plurality of supply conduits (36) are connected to the supply wall and discharge emollients such as chemicals and fillers into the manifold where they are immediately drawn, together with the stock, into adjacent tube ends which feed the stock and added chemicals to the slice for forming a paper web.
Abstract:
The dryer of this invention employs a vacuum chamber interposed below and between first and second heated dryer rolls (26, 28). The vacuum chamber has two sides and a top which overlies two grooved reversing rolls (110, 114). The vacuum chamber controls all flow of air in the gap between and below the dryer rolls. The dryer-fabric-backed paper web passes from the first dryer roll around the reversing rolls and up to the second dryer roll. The dryer fabric seals the vacuum chamber, and air is drawn therefrom. The two rolls within the chamber permit a greater fraction of the dryer roll surfaces to be maintained in contact with the web, and the chamber permits a vacuum to be drawn on two rolls, and three sections of web which are not engaged by rolls, by a single vacuum source for significant cost savings.
Abstract:
High powered lasers are used to score the bark (28) on logs (26) before they are mechanically debarked. Typical of the lasers employed are multi-kilowatt CO2 industrial lasers. A high powered laser beam (20) is brought to a focus just above the surface of the bark (28) on the log (26). A jet of compressed air is blown co-axially with the beam and facilitates the beam's formation of a narrow slot in the surface of the bark. Logs are advanced and rotated by a plurality of parallel augers (42) extending across the base of a trough (40). The lasers are positioned in a gap beneath and in between sets of augers. The beam's focus may be adjustable with respect to the bark's surface. The motion of the log with respect to a laser head produces a spiral cut along the surface of the log which slices the long fibers in the bark.
Abstract:
A doctor (10) is disclosed for creping tissue (T) from a surface (S) of a Yankee dryer (12). The doctor (10) includes a frame (14) and a support (16) which extends from the frame (14). A swing arm (18) is pivotally secured to the support (16) about a pivotal bearing (20). The swing arm (18) defines a further bearing (22). A pivot (24) extends through the further bearing (22) for rotatable movement relative to the swing arm (18) such that the pivot (24) is rotatably supported by the swing arm (18). A doctor (26) is rigidly secured to the pivot (24) for doctoring the tissue (T) from the surface (S) of the dryer (12). A blade (28) is removably secured to the doctor (26), the blade (28) defining an operative edge (30) which cooperates with the surface (S) of the Yankee dryer (12) for creping the tissue (T) from the surface (S) of the dryer (12). A loader (32) is operatively connected to the pivot (24) for rotating the pivot (24) within the further bearing (22) for loading the operative edge (30) against the surface (S) of the dryer (12). A blade angle changer (34) is operatively connected to the swing arm (18) for pivoting the swing arm (18) relative to the support (16), the arrangement being such that movement of the angle changer (34) selectively changes an angle ( alpha ) defined between the blade (28) and the surface (S) of the dryer (12). The operative edge (30) is disposed substantially along an axis of rotation (36) of the pivotal bearing (20), the arrangement is such that when the blade (28) wears due to contact with the operative edge (30) with the surface (S) of the dryer (12), the angle ( alpha ) is changed to optimize the creping without significantly altering the disposition of the operative edge (30) relative to the surface (S) of the dryer (12).
Abstract:
An extended nip press has a heated backing roll (22), on the surface of which a paper web (28) is preheated before it passes through the extended nip. The paper web is restrained on the surface of the backing roll (22) to achieve post-pressing drying. During a portion of the post-pressing drying, the extended nip press may be arranged so that the paper web is not backed by the pressing/drying felt, thus allowing free venting from the web to occur. In some cases, this zone will be augmented by a vacuum assist unit to draw steam away. This high temperature press is capable of outgoing dryness in the range of sixty-five percent versus fifty percent for conventional technology. This combination of high temperature pressing and drying can be expected to improve the maximum strength of the web by approximately 20 percent or more over conventional pressing methods. Two high temperature press dryers of this invention may be combined to achieve outgoing dryness of approximately seventy percent.
Abstract:
A method and apparatus for winding a continuous web (W) of material into a winding roll (12) wound on a starting core (15) including a winding drum (11) with a pinch roller (10) for laying the web onto the winding drum (11) with the drum having perforations (32, 33), and a knife (16) which moves radially outwardly form within the drum intermediate a suction zone (34) beneath the perforations. The apparatus operates by applying suction to the perforations, cutting the web on the surface of the drum, and releasing the lead cut end (18, 37) of the web to start onto a core with an adhesive (39) causing the lead end to wind onto the core and the trailing cut end (19, 38) finishing onto a wound roll (12).
Abstract:
In a paper-making machine a roll (22) is composed of two parts: a metallic base shell (38), which is constructed of conventional spun-cast steel alloy; and a thin outer shell (40) constructed of a material of high thermal diffusivity. The outer shell (40) is one to a few tenths of an inch thick and is in intimate contact with the surface of the steel alloy base shell (38). Typical materials of high thermal diffusivity for uses in the outer shell (40) are copper and aluminum. The roll (22) may be formed by flame spraying a layer of copper approximately two-tenths of an inch thick on the surface of a steel alloy base shell (38). The roll (22) is employed where improved heat transfer to a paper web is desired for example in an impulse paper dryer, or in a calendar.