Abstract: Gas is separated from fluent material, particularly a liquid or a cellulose fiber suspension having a consistency of about 8-18%, utilizing a closed separation apparatus having a spiral housing with a central axis, a fluent material inlet channel, a fluent material outlet, and a gas outlet. A pressure differential is maintained between the inlet channel and the spiral housing, and the pressure differential is converted to kinetic energy of the fluent material by causing the fluent material to flow through one or more spiral flow paths through the inlet channel toward the spiral housing. In the spiral housing a rotor is rotated to impart a strong centrifugal force to the fluent material to cause gas to separate and collect adjacent the central axis of the spiral housing, from which the gas is removed. The strong centrifugal force caused by the rotating rotor discharges the fluent material through the outlet. The spiral flow paths rotate with the rotor in the spiral housing.

Abstract: The present invention relates to a mixing of gas into a medium. The method and apparatus in accordance with the present invention are especially applicable in the bleaching plants of the wood processing industry for mixing gaseous bleaching chemicals into pulp and to bleaching process of pulp, in which the mixing method and apparatus in accordance with the present invention are applied. An excellent application is mixing ozone-containing gas into a fiber suspension flowing in a pipe line and an ozone bleaching process. The previously known methods and apparatuses have not been able to mix satisfactorily large volumes of gas, about 50% of the total volume of the flow, into the medium flow.

Abstract: Gas is separated from fluent material, particularly a liquid or a cellulose fiber suspension having a consistency of about 8-18%, utilizing a closed separation apparatus having a spiral housing with a central axis, a fluent material inlet channel, a fluent material outlet, and a gas outlet. A pressure differential is maintained between the inlet channel and the spiral housing, and the pressure differential is converted to kinetic energy of the fluent material by causing the fluent material to flow through one or more spiral flow paths through the inlet channel toward the spiral housing. In the spiral housing a rotor is rotated to impart a strong centrifugal force to the fluent material to cause gas to separate and collect adjacent the central axis of the spiral housing, from which the gas is removed. The strong centrifugal force caused by the rotating rotor discharges the fluent material through the outlet. The spiral flow paths may be stationary or may rotate with the rotor in the spiral housing.

Abstract: A method and apparatus for controlling the flow of a fiber suspension having a direction of flow and a consistency from 5-25% including a treatment chamber having an axis extending in the direction of flow of the fiber suspension, a suspension inlet and a suspension outlet opposite the suspension inlet, the suspension inlet and outlet having the same diameter and an axis in alignment with the axis of said treatment chamber;a fluidizing rotor within the chamber for fluidizing the fiber suspension, the fluidizing rotor having an axis of rotation transverse to the axis of the treatment chamber; anda throttling arrangement disposed between the rotor and the suspension outlet for throttling the suspension flow.

Abstract: The present invention relates to a method of and an apparatus for treating pulp. The apparatus according to the present invention is especially suitable for carrying out bleaching processes of the wood processing industry and for separation of residual gases remaining in the suspension in the processes. The method of the present invention is characterized in that pulp at the consistency range of 8 to 20% is subjected to at least the following treatment steps in a closed pressurized process: feeding pulp with a pump to a chemical mixer; mixing chemicals with the pulp; introducing the pulp flow by means of the pressure of the pump to a process vessel; treating the pulp with chemicals in the process vessel; removing gases from the pulp in connection with the process vessel or after it in a closed pressurized separator; in the gas separation, preventing fibers from exiting with the gas; and guiding the pulp via a closed path to a following process step.

Abstract: A method and mixer are provided for mixing chemical (such as a gas like chlorine or oxygen) with a slurry (such as paper pulp having a consistency of about 1-16%) in such a way that separation of gas from the slurry at the discharge from the mixer is avoided. Where the mixer housing has a radial discharge, the leading and trailing walls of the discharge (in the direction of circular and tangential movement of slurry within the main body housing of the mixer) present curved configurations to transition the slurry from circular/tangential movement to radial movement. The curvature of the configurations (which may be provided by inserts) does not exceed an angle of about 10 degrees at any point along them until radial flow is established.

Abstract: A method and an apparatus for dividing the flow of fiber suspensions of the pulp and paper industry in which the fiber suspension is caused to flow into a space uniting the inlet and the outlet flows and in which space a vortex flow is created to prevent the suspension from forming a strong fiber network and from causing blockage of the system. The pressure of the suspension further is increased so that the suspension flowing into the apparatus need not be pressurized. The apparatus includes a vortex chamber provided with one inlet and several outlets, at least one of the outlets is preferably provided with a device for regulating the flow through the outlet. The apparatus further includes a rotor for moving the suspension through the several outlets towards further processing devices.

Abstract: In the inventive method and apparatus for the continuous discharge of water and fine particles from a suspension, particularly fibrous pulp, the pulp or suspension is thickened without forcing the removal of water through a relatively thick, uncontrollably gathered fiber mat. In the method, the suspension to be thickened is fed into a filtering chamber, the suspension is continuously mixed for equalizing consistency differences, the liquid is continuously removed from the suspension through a filter and the thickness of a fiber mat which forms on the filter surface is controlled by subjecting the mat to shear stresses. In a thickening apparatus for practicing this method, at least one of co-operating surfaces--i.e. the filtering surface (8) and its counter-surface (10)--is provided with loosening members (12) for non-mechanically limiting the thickness of a fiber mat forming on the filtering surface and thereby preventing the uncontrolled formation of such a mat on the filtering surface (8).

Abstract: An arrangement for discharging medium consistency pulp in connection with diffeent pulp treatment devices or apparatuses, the arrangement having a mass chamber, which is arranged between a screw discharging pulp from a pulp treating apparatus and a centrifugal pump transferring the pulp further so that both the screw and the pump are substantially at the same horizontal level with the pulp treatment apparatus. Thus, the presence of a drop leg having a height of several meters is prevented, whereby the centrifugal pump has no need to pump the pulp upwards back to the height of the pulp treatment apparatus.

Abstract: A method for keeping a screen surface or a filter surface clean, wherein a pressure fluid is introduced from a conduit to a secondary side of a screen/filter drum, which fluid flows, during an underpressurized stage caused by blades of a rotor rotating on a primary side of the screen/filter drum, through the screen/filter drum from the secondary side to the primary side thereby rinsing the openings of the drum and making them clear.

Abstract: An apparatus for treating high-consistency fiber suspension is especially suitable for short distance conveyances of thick fiber suspensions (consistency more than 15%) in pulp and paper industry, for example for discharge of mass towers either with or without any actual pump. The treatment of fiber suspension with a consistency more than 15% is not possible with the known technique without a displacement type of pump, which is expensive and easy to break. Additionally, in discharging of the mass tower, drop leg, etc., fiber suspension causes trouble by arching in the container in such a way that it forms an open chamber around the pump located at the bottom of the container which chamber is slowly filled by fiber suspension. The problems are solved or minimized by arranging a feed apparatus in the pump chamber, which feed fiber suspension to a fluidizing rotor, for fluidizing the fiber suspension, whereafter the suspension flows onwards.

Abstract: The present invention relates to a method and apparatus for the continuous discharge of water from suspension, especially from fibrous pulp, whereby pulp is caused to thicken without having the water to be removed through a thick uncontrollably gathered fiber mat.In accordance with the invention the suspension to be thickened is fed into a filtering chamber, the suspension is formed as a layer that is continuously being mixed for equalizing the consistency differences, the liquid is continuously removed from the suspension and the thickness of the fiber mat being formed on the filter surface is controlled by subjecting said mat to shear stresses.The above described method is realized by an apparatus, in which at least one of the co-operating surfaces, the filtering surface (8) and its counter surface (10), is provided with means (12) for non-mechanically limiting the thickness of a fiber mat on the filtering surface, whereby a uncontrolled formation of a fiber mat on the filtering surface (8) is prevented.

Abstract: A method and an apparatus for dividing and uniting flows of high-consistency fibre suspensions. To prevent clogging of the distributor the fibre suspension is caused to flow into a space unitting the inlet and the outlet flows, where a turbulent flow extending to the valves regulating the discharge flow is created. The distributor includes a vortex chamber provided with an inlet and outlets and with regulating valves connected to the outlets and disposed at a short distance from the outlets. According to a preferred embodiment of the the invention, a rotor provided with vanes is disposed in the vortex chamber.

Abstract: A centrifugal pump and a method of separating gas from a gas containing liquid-solids suspension. The method and apparatus of the invention is especially suitable for pumping of fiber suspensions in the pump and paper industry. The pump includes a suspension chamber having a suspension inlet and a suspension outlet, a gas chamber in fluid communication with the suspension chamber and a perforated surface located between the suspension chamber and the gas chamber for substantially preventing the solids from passing into the gas chamber.

Abstract: A method and an apparatus for treating high-consistency fiber suspension are especially suitable for short distance conveyances of thick fiber suspensions (consistency more than 15%) in pulp and paper industry, for example for discharge of mass towers either with or without any actual pump. The treatment of fiber suspension with a consistency more than 15% is not possible with the known technique without a displacement type of pump, which is expensive and easy to break. Additionally, in discharging of the mass tower, drop leg, etc., fiber suspension causes trouble by arching in the container in such a way that it forms an open chamber around the pump located at the bottom of the container which chamber is slowly filled by fiber suspension. The problems are solved or minimized by arranging a feed apparatus (31) in the pump chamber, which feeds fiber suspension to a fluidizing rotor (21), for fluidizing the fiber suspension, whereafter the suspension flows onwards.

Abstract: The invention relates to an apparatus for mixing chemicals in fibre suspensions. The apparatus comprises a rotor (8) provided with blades and mounted to rotate in a casing (1) having an inlet (3) and an outlet (5) for the fibre suspension; and an inlet or inlets (6) for chemicals. The rotor (8) comprises a fluidizing and gas separating section (9), a pumping section (10) and a section (12) for mixing chemicals. An inlet (25) for chemicals leads to a space (24) between the pumping section (10) and the mixing section (12). The blades of the mixing section preferably cooperate with the casing wall (17) provided with ribs (18).

Abstract: A centrifugal pump for liquids containing solid material, the impeller of which has two or several vanes. In a bottom projection the leading edge (3) of the impeller (1) vane (2) is curved backwards in relation to the rotating direction of the impeller. The angle between the leading edge (3) and the outer edge (5) is obtuse in a meridian and a bottom projection. The outer end (10) of the leading edge of the vane is positioned behind a shoulder (9) provided with grooves (11), which cooperates with the vanes of the impeller. The form of the leading edge causes the fibres and the sticks to be conveyed towards the point of the vane where they are crushed by the combined effect of the groove and the vanes.

Abstract: A method and apparatus allow the simple and effective attachment or detachment of a centrifugal pump to a tank while the tank is filled with a liquid or suspension. The pump rotor is axially movable from a first position where a portion of the rotor is inside the tank, to a second position where no portion of the rotor is inside the tank. With the rotor in the second position, a closing member mounted interiorly of the tank is actuated by an actuator exterior of the tank to effect movement of the closing member to close off a liquid or suspension discharge opening in the tank. The pump housing can then be flushed out, and detached from the tank. During reattachment, the pump housing is filled with fluid under pressure to substantially equalize the pressure on opposite sides of the closing member before the closing member is moved to uncover the tank discharge opening.

Abstract: The operation of a centrifugal pump which pumps a liquid or suspension (e.g. 8-12 percent consistency) containing gas is controlled to minimize pump power consumption, or to vary the pump flow rate. The suspension is rotated within the pump so that a gas bubble is created at a central part of the pump, and gas is discharged from the gas bubble, at a gas discharge pressure. The differential pressure between the suspension inlet and the gas discharge is determined, and the head and/or discharge flow rate of the pump are controlled by controlling the differential pressure so determined. The discharge flow rate may be maintained constant utilizing a control valve and flow meter in the pump discharge line, in which case controlling the discharge of gas from the gas bubble controls the head, and minimizes power consumption for a given flow rate. Alternatively the flow rate is controlled by controlling the gas discharge, with no control valve in the pump discharge line being provided.

Abstract: The disclosure describes a method and a device for pumping fiber suspensions of high consistency. Shear forces disrupting fiber flocs are induced near the front edge of the vanes of the impeller in a centrifugal pump which fluidize the fiber suspension hereby converting it into an easily pumpable state. This is effected by an inlet part having recesses and/or lobes in its inner surface in front of the impeller which cooperate with a rotor having an outer surface in which there are recesses and/or lobes disposed into the inlet part.