A. Ahlstrom Corporation

Andritz Oy

Enso-gutzeit Oy

Ahlstrom Machinery Oy

Enso-gutzeit Osakeyhtio

Enso-gutzeit Osakeytio

Enzo-gutzeit Oy

Raimo O Kohonen

Pasi H Immonen

Jukka Heino

Kaj Henricson

Pentti A Vikio

Erkki E Savolainen

Kari Peltonen

Holger Engdahl

Jorma Elonen

Raimo Pitkanen

Tuomo Lintunen

Matti Lankinen

Heikki Manninen

Ari Pelkio

Harry Erlund

Riitta Rahkonen

Tapani Niiranen

Pekka Karppinen

Erikki Savolainen

Ari Pelki&ouml;

Jukka Niskanen

Markku Kosonen

Pasi H&auml;rk&ouml;nen

Kader Rahkonen

An arrangement and a rotor for screening of pulp is disclosed that is suitable for the screening of chemical and mechanical pulps, i.e. fiber suspensions of the wood processing industry. A feature of the arrangement and rotor is that inside the rotor ( ) there is arranged at least one dilution liquid chamber (24&prime;, 24&Prime;, 24&prime;&Prime;) restricted by a surface of the rotor ( ), which surface is provided with means for connecting said at least one chamber (24&prime;, 24&Prime;, 24&prime;&Prime;) with the screening space defined between the rotor and the screen drum in such a way that dilution liquid from said at least one chamber (24&prime;, 24&Prime;, 24&prime;&Prime;) is brought into the screening space at a distance of at least 20 mm from the inner surface of the screen drum ( ).

Arrangement and rotor for screening of pulp

Multistage disc filter

Method and apparatus for treating a gas containing aqueous fiber suspension in a fiber line process of a pulp mill including at least one of pulp screening, washing and bleaching includes (a) transferring the gas containing fiber suspension at a consistency to a treatment station; (b) treating said fiber suspension at the same level by removing a portion of the water from the fiber suspension so as to generate aqueous filtrate and treated fiber suspension having a relatively higher consistency; (c) simultaneously pumping and degassing the filtrate at the same level; and (d) pumping the treated fiber suspension having the relatively higher consistency away from the treatment station at the same level by imparting to the treated fiber suspension sufficient shear force so as to render the fiber suspension pumpable.

Method and apparatus for treating a gas containing aqueous fiber

Method and apparatus for treating a fiber suspension

A method of separating an aqueous solids containing suspension includes (a) subjecting a first solids containing suspension to centrifugal forces so as to separate the suspension into a first gas containing flow, a second gas-free flow and a third flow; (b) feeding the third flow into a flotation cell having a bottom; (c) introducing air at the bottom of the flotation cell into the third flow for separating from the third flow a fourth partial flow; (d) withdrawing the air containing third flow after the separation of the fourth partial flow from the flotation cell; and (e) subjecting the third flow to the centrifugal forces of step (a). An apparatus for the separation of gas and lightweight material from a gas and lightweight material containing aqueous solids suspension is also described and includes a centrifugal pump for separating the gas and lightweight material from the solids suspension with a suspension inlet and an outlet for the lightweight material; a flotation cell for separating the lightweight material from a solids suspension; and a circulation loop connecting the outlet of the centrifugal pump, the flotation cell and the suspension inlet of the pump.

Method and apparatus for improving flotation separation

A method of removing liquid from a thickener, a filter, a washer or the like water-separating device obviates the need for the conventional use of a long drop leg and large filtrate tank. On an upstream face of a liquid-pervious member, a layer of liquid-containing substance is formed. At a downstream face of the liquid-pervious member, a negative pressure (e.g. partial vacuum) is generated to induce the flow of a liquid or a liquid-and-gas filtrate from the liquid-containing layer through the liquid-pervious member. The filtrate is conducted from the vicinity of the downstream face of the liquid-pervious to an inlet of a filtrate pump; such conducting of filtrate is carried out through an enclosed flow passage whereby the filtrate pump generates at least a portion of the negative pressure at the downstream face of the liquid-pervious member. An apparatus for likewise removing filtrate from a thickener, a filter, a washer or the like industrial filtering device is also disclosed.

Apparatus for removing liquid from the thickeners, filters, and washers

Filter cylinder with drainage surface

An apparatus for treating pulp includes a pressure-proof outer casing for a suspension to be treated. A shaft is rotatably arranged in the outer casing and a number of disks are arranged substantially radially on the shaft within the casing. The disks are formed by a number of sectors each having two opposite filter surfaces for allowing liquid from the suspension to be drained therethrough and a liquid compartment between the filter surfaces for the drained liquid or filtrate, so that a substantially annular filter surface is formed. The liquid compartment is in communication with a liquid discharge member. The apparatus further includes members for dividing the annular filter surfaces into two or more portions. The members are stationary relative to the casing, so that the members are used for separating different treatment stages of fiber suspension from one another.

Apparatus for treating fiber suspension

The present invention relates to a method and apparatus for discharging a disc filter. The method and apparatus are excellent for handling fiber suspensions in the pulp and paper industry. In earlier known means, the filter cake thickened on the filter surfaces of the disc filter is detached by means of water or compressed-air jets and the cake allowed to freely fall to an axial chute disposed below the shaft level of the filter, wherefrom the pulp most usually is transferred by means of a screw conveyor. The pulp, however, easily clogs the inlet opening of the chute, whereby pulp material accumulates in the space between the discs with harmful consequences. The above-mentioned problem is solved by arranging a conveying means (9), preferably a belt conveyor, between and/or adjacent the filter discs (6), onto which conveying means the cakes are allowed to fall freely and wherefrom the belt (9) quickly and in a forced or positive manner transfers the cakes further to a discharge chute (4) disposed on the side of the filter, thus preventing the pulp material from accumulating between the discs.

Method and apparatus of discharging a disc filter

In a procedure for filtering lime sludge meant to be regenerated to lime. Lime sludge is produced in the causticizing process in a sulphate cellulose mill, where it can be reused after regeneration to lime. In the procedure, lime sludge suspension is filtered on a filter drum in continuous rotation by depositing lime sludge on the drum and detaching part of the superficial layer of the lime sludge on the drum with a scraper so that the deeper lime sludge layer on the drum, which by-passes the scraper, serves as filtering medium for the superficial layer that is detached (as a so-called pre-coat). The purpose is to arrange the control of the filtering process so that the dry matter content of the lime sludge detached from the drum is substantially constant, and its essential feature is that the dry matter content of the lime sludge detached from the drum is followed so that when the dry matter content tends to decrease, the speed of rotation of the drum is first raised within a given control range and, after the control range has been used up, the scraper is moved closer to the surface of the drum so that at least part of the deeper lime sludge layer on the drum, serving as filtering medium, is detached and, if the scraper is returned to its earlier position, is replaced with a new lime sludge layer, whereupon the control is again continued with the aid of the drum's speed of rotation.

Procedure for filtering lime sludge meant to be regenerated to lime

A method for improving the operation of a disc filter used for the filtering of fluids containing solid matter such as fibers. Known filtering methods have the drawback that the rate of water exhaustion is limited, because a vacuum tends to be created inside the sectors when the filtered fluid is drained by suction from the central channel of the disc filter. This drawback is an obstacle to increasing the speed of rotation and therefore to increasing the capacity of the disc filter. With the method of the present invention, this problem is solved by providing the disc filter with a means of admitting ambient air into the disc sectors and the central shaft channel and/or with equipment for blowing air into the sectors and the channel to remove the filtered fluid from them.

Disc filter

Filter press for separating the liquid from the silt of sludge by using running filter strips guided by rollers journalled in bearings in the girder frame of the filter press. One side section of the frame is equipped with removable frame sections for the purpose of exchanging the filter strips and the opposite side section of the frame has been equipped with pull rods, supporting the frame during the exchange of the filter strips. The lower ends of the pull rods are secured to the ends of telescopic support extensions, extentable sideways from the lower part of the frame and the upper pull rod ends are attached to the upper section of the frame.

Filter press

Procedure and apparatus for the washing of cellulose in the form of a continuous web. The continuous web produced in a concentrating zone is washed in a washing zone comprising between 2 and 6 washing steps, so that into the web pressurized washing liquid is introduced according to the counter-current principle to the purpose of displacing the suspension liquid contained in the web, using one pumping operation for transporting the washing liquid through a plurality of washing steps.

Procedure and apparatus for cellulose washing

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Savonlinna, Finland

Raimo O Kohonen