Abstract: A dewatering arrangement in the press section of a web-forming machine having a press suction roll (10) and a press fabric (13) arranged to run via the press suction roll (10). The dewatering arrangement has a saveall (15), which is installed in conjunction with the press suction roll (10), and drainage facilities (18) for removing the collected water from the saveall (15). The saveall (15) has a concave guide surface (19) which in the cross direction is located on a partial distance of the circumference of the press suction roll (10) and at a distance from the surface of the press suction roll (10) in order to accomplish a vacuum effect and to hence remove water from the press suction roll (10).

Abstract: Backwater cycle of and process for circulating water in a paper machine having a wet zone. The backwater cycle includes at least one application device arranged to apply a composition containing at least one of pigment and filler onto a fiber web in the wet zone, a first backwater cycle that supplies a stock inlet with backwater removed from the production process upstream, relative to a web travel direction, of the at least one application device, and a second backwater cycle that accepts a remainder of the backwater. The process includes extracting backwater from the fiber web, and feeding backwater, which is not charged with the at least one of pigments and fillers, to a stock inlet.

Abstract: The invention relates to a process and an apparatus for recycling backwater in a papermaking machine. According to the invention backwater draining through a forming fabric is collected into several collecting means (51, 52, 53, 54) and pumped by separate pumps (20) in at least two and preferably numerous separate flows (81 to 85) directly as substantially air free separate flows to the fibre process (12, 30, 40) of the short circulation in order to implement a fast, air free and split recycling of backwater from said forming fabric to said fibre process.

Abstract: An anti rewet deck is provided for press rolls used to increase consistency of fibrous pulp slurry from approximately 4 percent up to about 30 to 50 percent. This is accomplished by biasing the location of the drainage holes in the roll shell to the forward edge of the drainage compartments within the roll shell. To avoid the necessity for handing of the rolls, a mechanism is provided for accomplishing the purposes of minimizing rewet at practical production rates by providing baffle plates which effectively orient the draining pattern in the desired direction. Such baffles can be permanently or removably installed once the desired handing of the rolls is determined.

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 removable baffle insert for positioning in a filtrate compartment of a rotary drum vacuum filter comprising an elongated C-shaped member positioned between a pair of compartment walls and having one arm thereof providing the ceiling of the compartment to prevent filtrate run-back during the filtration cycle.

Abstract: A double cylinder press for the formation of fibrous layers is capable of extracting fibers from fiber-containing liquid, causing the fibers to be adsorbed on the surfaces of wire gauzes 41 of cage cylinders 40 disposed in a stationary butt 10 and a swing butt 12, allowing masses of fibers produced in the course of the formation of fibrous layers to spontaneously drop down from above a region in which the cage cylinders are brought into pressure contact with each other to be collected, and allowing waste liquid resulting from compression and dehydration of the fibers to be dropped and discharged out of the double cylinder press with high efficiency.

Abstract: A rotary filter drum in which the drum is a single cell having a perforated cylindrical wall and solid end walls. A hollow central shaft extends through the drum and its opposite ends extend axially from the end walls. The drum contains a plurality of relatively narrow elongated open-top pans that are equally spaced radially from and angularly about the central shaft. Each pan is defined by a bottom, spaced apart inner and outer sidewalls which extend the full length of the drum and the drum end walls. The pan walls are secured to the ends of the drum. The pans are located so the open tops face the direction of drum rotation and the entire leading edge of the outer sidewall of the pan is secured to the perforated cylindrical wall. A closed conduit connects the bottom portion of each pan to the central shaft which in turn connects to the vacuum source so the filtrate is removed from and vacuum applied to the interior of the drum solely through the central shaft but via the pans and connecting conduits.

Abstract: A rotary vacuum filter having a barometric or drop leg for generating vacuum in the filtration cycle of the filter wherein the end of the leg immersed in the seal pit is formed to a frustro-conical configuration for both reducing turbulence in the seal pit as the air-liquid mixture exits therefrom and for recovering a portion of the energy in the velocity head of the air-liquid mixture flow.

Abstract: A thickener apparatus includes a shaftless cylinder mold having a perforated cylindrical shell supported by two end members one of which is an open frame structure having radially extending support beams interconnecting a short rotational shaft aligned with the axial center of rotation of the cylinder, and a peripheral ring member which supports the shell of the cylinder mold. The shell is sufficiently rigid to be self supporting and has a backing cloth overly covering the perforated portion of the cylinder, and a face cloth covering the backing cloth, both of which act as a screen to permit the white water to collect in the central hollow portion of the cylinder mold to be subsequently discharged therefrom.

Abstract: A web-forming method and apparatus particularly suited for cellulose pulp. The web is initially formed on a rotary wire cylinder which has a horizontal axis and a crest situated at the highest part of the cylinder over the horizontal axis, the cylinder during rotation thus having an upwardly travelling side which turns upwardly toward the crest and a downwardly travelling side which turns downwardly from the crest. At the upwardly travelling side of the cylinder is a headbox having its slice situated adjacent the crest for projecting onto the rotating cylinder a pulp slurry jet at a speed greater than the peripheral speed of the cylinder, so that the deposited pulp slurry will start to form a web while turning with the cylinder up to and then downwardly from the crest thereof. An outer wire has a portion wrapped partially around the cylinder, through an angle of at least 180.degree.