A. Ahlstrom Corporation

A. Ahlstrom Osakeyhtio

Kamyr, Inc.

Kamyr Ab

Ahlstrom Machinery, Inc.

Toivo J Niskanen

Kaj Henricson

Vesa J Vikman

Kari Peltonen

Mika P Makela

Olavi E Pikka

Voitto Reponen

Johan E Gullichsen

Jukka Timperi

Brian F Greenwood

Reijo Vesala

Frey Viking Sundman

Jorma A Tuomaala

Stephen J Dunn

Raimo Fellman

Esko Harkonen

Jaakko Kujala

Voitto O Reponen

Jaakko P Kujala

Esko J Harkonen

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.

Method and apparatus for separating gas from a gaseous material

Method and apparatus for mixing a first medium to a second medium and a

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;

Method and apparatus for improving the control and treatment of fiber

Method of an apparatus for treating pulp

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. Alternatively, the discharge may allow the tangential movement of the pulp in the main housing to continue by cutting off the original radial pulp discharge outlet, and welding or otherwise attaching a retrofit new discharge outlet to the main housing body similar to a pump volute with a gradually increasing cross-section.

Minimizing gas separation in a mixer outlet

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.

Method and apparatus for dividing flow of high-consistency fiber

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).

Method and apparatus for thickening a fiber suspension and removing fine

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.

Arrangement for discharging pulp from a pulp treatment apparatus

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.

Method for keeping a screen or filter surface clear

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. The feeder apparatus raises the pressure of the fiber suspension sufficiently for the fluidization, not too high, in which case the operational members would be stressed redundantly. Fiber suspension is fed excessively to the rotor, whereby the feeding pressure of fiber suspension is controlled by throttling devices arranged separate from the feed apparatus in the back-circulation or passage.

Apparatus for pumping high consistency fiber suspension

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.

Method and apparatus for thickening fiber suspension

Method and apparatus for dividing and uniting the flows of

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.

Pump and a method of separating gas by such from a fluid to be pumped

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. The feeder apparatus raises the pressure of the fiber suspension sufficiently for the fluidization, not too high, in which case the operational members would be stressed redundantly. Fiber suspension is fed excessively to the rotor (21), whereby the feeding pressure of fiber suspension is controlled by throttling devices (34) arranged separate from the feeder apparatus in the back-circulation or passage.

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Hamina, Finland

Toivo J Niskanen