A. Ahlstrom Corporation

Ahlstrom Corporation

Jukka Timperi

Reijo Vesala

Vesa J Vikman

Jorma Elonen

Toivo J Niskanen

Kaj Henricson

Olavi E Pikka

Voitto Reponen

Seppo Hokkanen

Kari Anttonen

Vesa Wikman

Pumping of medium consistency cellulose pulp is effected from stand pipes or like small sized pulp vessels to which pulp is normally discharged from storage towers, treatment towers, washers, filters, presses, thickeners, or the like, particularly pumping of high temperature pulps from said stand pipes. A pump inlet is attached to a discharge opening of a stand pipe, pressurizing cellulose pulp in said stand pipe by closing the stand pipe off from the atmosphere, maintaining a superatmospheric pressure in the stand pipe, allowing the cellulose pulp to flow into the pump through the pump inlet, and pumping the cellulose pulp further using the pump.

Method and apparatus for pumping cellulose pulp

A multi-stage centrifugal pump has a shorter shaft length compared to conventional multi-stage pump with the same number of impellers on the drive shaft (e.g. about 17-28% shorter length). The shorter length is obtained by utilizing first and second annular slide bearings. Adjacent at least one end (and preferably both) of a rotatable elongated shaft of the pump (which mounts the impellers) within a casing the first slide bearing is mounted to a stationary end structure while the second slide bearing is mounted to the shaft for rotation with it. A plurality of O-rings may be provided to mount the second slide bearing to the shaft. A sleeve with shoulder engaging opposite ends of the second slide bearing may be provided, and the slide bearings may have a clearance of about 0.04-0.1 mm between them, with a lubricant in the clearance. A labyrinth seal is typically provided in the most remote shoulder. The slide bearings are of silicon carbide or a similar material, and have a length (in the dimension of elongation of the shaft) of about 10 cm or less. The impellers may be mounted to the shaft without keys by providing polygonal protrusions concentric with the shaft formed on the impellers and cooperating with similarly shaped polygonal recesses in an adjacent impeller.

Centrifugal pump

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

A pump for pumping an air containing medium includes rear vanes (11) on the propeller back plate of the pump and a back ball arranged so that a radially widening space is created between the impeller back plate and the rear wall for guiding the flow of the medium, generated by the combined effect of forces with different directions and different intensities directed at the medium in the spaces between the rear vanes, past gas discharge opening (12) in the rear wall of the pump or for retarding the flow thereby preventing the flow from entering the gas discharge opening (12).

Apparatus for separating gas with a pump from a medium being pumped

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 and apparatus for pumping a liquid-fiber suspension, and specifically for pumping high consistency fiber suspensions in the pump and paper industry. The method of pumping a liquid-fiber suspension includes the moving of the suspension into a pump, separating a portion of the liquid part of the suspension from the liquid-fiber suspension during the pumping operation and directing the separated liquid to the suspension at a point somewhere between a situs in advance of the pump inlet and the pump outlet. This method is enabled by an apparatus, in which at least part of the surfaces of the pump (1) is provided with filter surfaces (6, 7, 8, 9, 10), through which the liquid separated from the suspension is returned either into the pump, directly in front of the suction opening (11) of the pump (1) or to some other suitable place in the vessel containing the suspension.

Method and apparatus for pumping high consistency pulp

The method and apparatus include that the rear vanes (11) of the pump or the members operating therewith are arranged so that they either direct the flow of the medium, generated by the combined effect of forces with different directions and different intensities directed at the medium in the space behind the impeller in the vane gaps of said rear vanes, past gas discharge opening (12) in the rear wall of the pump or they slow down said flow so that its extension to said gas discharge opening (12) is prevented.

Method and apparatus for separating gas with a pump from a medium being

A centrifugal pump for separating an entrained gas from a working fluid in which the pump housing has a hollow chamber therein, an axially extending inlet into the chamber, an outlet leading out of the chamber, and a gas vent for the chamber; a rotatable shaft mounted in the housing in axial alignment with the inlet; an impeller is disposed in the chamber and mounted on the shaft for rotation therewith, the impeller includes a plate for dividing the chamber into a first chamber portion communicating with the inlet and outlet and a second chamber portion communicating with the vent. The plate has an aperture extending therethrough for allowing the passing of working fluid and gas therethrough; and is further provided with at least one pumping vane disposed in the chamber portion for pumping the working fluid into the first chamber portion through the inlet and out of the first chamber portion through the outlet. The second chamber portion is partitioned into a plurality of spaces by a plurality of back vanes secured to the plate and a liquid rotatable within the second chamber portion upon the impeller rotating whereby to create pressure differences in the spaces for removing gas in the second chamber portion through the vent.

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

A method of pumping high consistency pulp in form of a plurality of lumps in a pulp and gas containing space with a centrifugal pump having a suction opening communicating with said pulp containing space and a rotor extending through the suction opening into the pulp space including fluidizing the high consistency pulp by the rotating action of the pump rotor; and thereby forming a continuous fluidized pulp containing zone in form of a liquid lock in front of and around the suction opening of the pulp so as to substantially limit the suction action of the pump to the fluidized pulp containing zone and to prevent the gas from flowing in between and past the pulp lumps toward the suction opening. The centrifugal pump for attachment to the wall of the pump containing vessel includes a housing having a suction opening for connection to the wall of the pulp containing vessel and a discharge opening; and an impeller mounted for rotation with the housing, the impeller including a rear plate, at least one pumping vane attached to the rear plate, and a rotor projecting from the impeller toward the suction opening of the pump, the rotor includes at least one blade extending from the impeller through the suction opening beyond the wall of the pulp containing vessel and into the pulp containing vessel by a distance at least equal to the diameter of the suction opening.

Method and apparatus for pumping high consistency medium

A fluidizing centrifugal pump for medium to high consistency fiber suspension includes a housing having an inlet channel and an outlet and an impeller operatively rotatable about the pump axis. The impeller has a working vane and at least a blade extending substantially axially from the working vane and disposed in the inlet channel for fluidizing suspension which is received in the pump inlet. A feeding vane, preferably in the form of a spiral thread, is disposed in the inlet channel, radially-outwardly from the fluidizing blade and extending along at least a portion of the axial extension of the blade. The feeding vane, which may be operatively rotatable with the impeller or stationarily fixed to the pump housing, provides axially-directed feeding of suspension through the inlet channel toward the working vanes, concurrent with fluidizing of suspension in the channel by the impeller blade, thereby effectively preventing reverse flow of suspension in the inlet channel and correspondingly increasing the operating efficiency of the centrifugal pump.

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Kotka, Finland

Jukka Timperi