Abstract: The invention relates to a thermal servomotor which includes two operating elements which act oppositely on an actuating bridge. The operating elements are thermally insulated from each other and each has a temperature-dependent filling and a separate heating element for differently thermally influencing the two fillings.

Abstract: Effective separation of unwanted particles, such as tramp material, is effected from a paper pulp suspension (typically a medium consistency suspension, e.g. having a consistency between 5-15 percent). A generally annular opening is defined by a disc connected to a rotating shaft, and a ring stationarily mounted to a housing. The housing includes a pulp inlet, a pulp outlet, an inlet chamber, and an outlet chamber, with a separated-out particles outlet communicating with the inlet chamber, preferably extending downwardly from it. A rotating element having a plurality of generally radially extending projections, is also mounted on the shaft, adjacent the disc, and the projections cover the annular opening (radially spanning it) at spaced locations along its circumference. The projections may be teeth-like structures, or pegs, and preferably have their leading edges, viewed in the direction of rotation, sloping with respect to the radial direction.

Abstract: A method for the treatment of a suspension, such as pulp, with one or more treatment liquids in a manner that maximizes treatment efficiency and minimizes heat loss. The pulp flows in a flow path confined to a given web thickness, and has first and second opposite sides. Treatment liquid is added to the first side of the flow path at spaced predetermined points along its length. Liquid displaced by the treatment liquid is withdrawn from the second side of the flow path at substantially the predetermined points. The displaced liquid at the first predetermined point along the flow path consists essentially of original suspension liquid, while the liquid fraction of the pulp past the last predetermined point of the flow path is composed mainly of treatment liquid added at the last predetermined point. Treatment can be accomplished at super-atmospheric pressure and at a temperature above 100.degree. C. The web thickness is between about 50-500 mm.

Abstract: An apparatus and method are provided for treating flowing suspensions, extracting liquid from the suspensions and, if desired, introducing a treatment liquid into the flowing suspensions. Suspension flows in an elongated container from an inlet to an outlet in a first direction, and a screen surface is mounted within the container for screening a portion of the liquid from the suspension. The screen body is elongated in the direction of elongation of the container and defines a screen cavity volume within it, the volume tapering inwardly in the first direction. A baffle is disposed within the screen cavity volume. During movement of the screen in a second direction, opposite the first direction, at a higher speed, backflushing of the screen takes place, substantially evenly over the whole of the screen surface.

Abstract: The invention relates to a thermal servomotor which includes two operating elements particularly bellows boxes, which act oppositely on a valve actuating bridge. Each operating element has a temperature-dependent filling. Each operating element is connected to a relatively small container having a volume on the order of 0.2 cm.sup.3 by a capillary passage which has the effect of partially thermally insulating each operating element from the associated container. Each container contains the medium of the filling that determines the pressure and separate heating apparatus is associated with each of the two containers.

Abstract: An apparatus and method for mixing a fluid, such as chlorine or oxygen gas, into a suspension, such as comminuted cellulosic material. A circular cross-section conduit defines a flow path for a suspension, and a circular smooth-faced disc is mounted in the conduit for rotation, covering substantially the entire interior of the conduit. A relatively small opening extends through the disc, and that disc is rotated in the conduit with small portions of suspension flowing in the conduit progressively passing through the opening and being fluidized when passing through the opening. The fluid is introduced into the suspension as the suspension flows through the opening, and in this way an even distribution of fluid in the suspension, with minimum power consumption, is provided.

Abstract: An apparatus and method are provided for treating flowing suspensions, extracting liquid from the suspensions and, if desired, introducing a treatment liquid into the flowing suspensions. Suspension flows in an elongated container from an inlet to an outlet in a first direction, and a screen surface is mounted within the container for screening a portion of the liquid from the suspension. The screen body is elongated in the direction of elongation of the container and defines a screen cavity volume within it, the volume tapering inwardly in the first direction. A baffle is disposed within the screen cavity volume. During movement of the screen in a second direction, opposite the first direction, at a higher speed, backflushing of the screen takes place, substantially evenly over the whole of the screen surface.

Abstract: An apparatus and method for removing dense impurities, such as sand, from a fluid, such as liquids use in the production of cellulosic pulp. A vertically upstanding tank substantially circular in cross-section is provided including a top wall, bottom wall, and side wall. The fluid with dense impurities is introduced into the tank with a whirling motion. Vertical stagnation of the dense impurities against the side wall interior (which can result in damage to the tank wall) without dampening the whirling motion imparted to the fluid is prevented by mounting a perforated funnel in the tank at the area of the tank where the vertical stagnation is likely to occur.

Abstract: A method and apparatus for the thickening of a suspension of comminuted fiber material and liquid. A reciprocal screen assembly having a variable volume interior chamber is mounted for movement along the axis of a container through which suspension to be dewatered flows. Mechanical apparatus, such as a hydraulic cylinder actuated rod, moves the screen assembly in either the direction of flow of suspension in the container, or in the direction opposite thereto, and the screen assembly is relatively rotatable with respect to the container. During movement of the screen assembly in the direction of flow of the suspension (at about the same velocity as the suspension flow), liquid passes through the screen assembly into the interior chamber, and is expelled from the container. The screen assembly is moved more quickly in the direction opposite to the direction of suspension flow, and the variable volume of the interior chamber thereof decreases quickly so that backflushing of the screen assembly is effected.

Abstract: A method and apparatus for dewatering a suspension of comminuted fiber material and liquid. A suspension is passed in a given direction in a container of generally circular cross-section having a hydraulic piston mounted generally concentrically therein. There are no movable components extending between the piston and the walls of the container in which it is disposed, therefore leakage from the container is minimized. The piston has screens for separating liquid from the suspension associated therewith, and is movable in the same direction as the suspension flow during removal of some liquid from the suspension, and is movable in a direction opposite to the direction of fluid flow to facilitate cleaning of the screens and to return the piston to a position wherein it can move in the direction of flow again.