[go: up one dir, main page]

GB1589134A - Method and apparatus for pumping fibre suspension - Google Patents

Method and apparatus for pumping fibre suspension Download PDF

Info

Publication number
GB1589134A
GB1589134A GB18175/78A GB1817578A GB1589134A GB 1589134 A GB1589134 A GB 1589134A GB 18175/78 A GB18175/78 A GB 18175/78A GB 1817578 A GB1817578 A GB 1817578A GB 1589134 A GB1589134 A GB 1589134A
Authority
GB
United Kingdom
Prior art keywords
impeller
pump
fibre
inlet part
fibre suspension
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB18175/78A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ahlstrom Corp
Original Assignee
Ahlstrom Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FI771541A external-priority patent/FI62871B/en
Application filed by Ahlstrom Corp filed Critical Ahlstrom Corp
Publication of GB1589134A publication Critical patent/GB1589134A/en
Expired legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D7/00Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts
    • F04D7/02Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type
    • F04D7/04Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being viscous or non-homogenous
    • F04D7/045Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being viscous or non-homogenous with means for comminuting, mixing stirring or otherwise treating
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2210/00Working fluid
    • F05B2210/10Kind or type
    • F05B2210/13Kind or type mixed, e.g. two-phase fluid
    • F05B2210/132Pumps with means for separating and evacuating the gaseous phase

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Paper (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
  • Preliminary Treatment Of Fibers (AREA)

Description

(54) METHOD AND APPARATUS FOR PUMPING FIBRE SUSPENSION (71) We, A. AHLSTRÖM OSAKEYHTIÖ of 29600 Noormarkku, Finland; a Finnish body corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a method and an apparatus for pumping fibre suspensions and utilizing a centrifugal pump and is for pumping fibre suspensions or pulps of high consistency.
Centrifugal pumps can successfully be used in the paper and cellulose industry for pumping fibre suspensions or pulps having consistencies less than 6% on condition that the pump has been correctly designed and that its input pressure is adequately high. A centrifugal pump is not, however, suitable for high consistency suspensions or pulps as, owing to flocculation of the pulp, the pump will be clogged. Expensive pumps based on the positive displacement principle must therefore be used for pumping high-consistency suspensions or pulps.
It is an object of the invention to provide a method and an apparatus which makes it possible to use centrifugal pumps for pumping suspensions or pulps of considerably higher consistencies than until now.
According to the present invention there is provided a method for pumping a high consistency fibre suspension with a centrifugal pump, characterized in that shear forces disrupting fibre-to-fibre bondings are generated in front of the impeller and/or at the front edges of the impeller vanes whereby the fibre suspension is fluidized and becomes capable of being pumped.
Also according to the present invention there is provided a centrifugal pump apparatus for pumping high consistency fibre suspension including means provided and adapted to fluidize the fibre suspension to facilitate pumping by generating shear forces disrupting fibre-to-fibre bondings in front of the impeller and/or at the front edges of the impeller vanes. Preferably the fluidizing means includes an inlet part having recesses and/or projections in its inner surface in front of an impeller and/or at the front edges of the impeller vanes, which co-operate with the impeller vanes, and/or a rotor having an outer surface in which there are recesses and/or projections disposed in the inlet part to generate shear forces which disrupt fibreto-fibre bondings and fluidize the fibre suspension.
The shear forces which are generated in the pump in front of the impeller and/or at the front edges of the impeller vanes, disrupt fibre agglomerations or flocks formed in the fibre suspension. The invention is based on the fact that the fibre suspension, when being subjected to forces disrupting fibre-to-fibre bondings, becomes fluidized, i.e. is converted into an easily pumpable state. Compared to a conventional centrifugal pump, a pump according to the invention operates at a lower inlet pressure.
An apparatus according to the invention can e.g. be used for discharging suspensions or pulps of consistencies from 5 to 25% from suspension or pulp vessels. According to known methods, pulp is discharged from a vessel by mechanical devices such as transport screws or rotating scrapers. Discharge of high-consistency pulps requires much energy and robust constructions. Vibrating devices e.g. based on ultra sonic waves have been suggested to be used for discharging pulps from vessels but in practice these have been proved ineffective. When high-consistency pulps are discharged from large vessels the pulp is usually diluted in front of the outlet in order to make it flow out.
In an embodiment according to the invention the pump is disposed in the outlet of the pulp vessel whereby a rotor running through the inlet part of the pump and the outlet of the pulp vessel fluidizes the pulp so that it can flow into the pump underneath due to gravitational forces.
The invention will be described in more detail below, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a vertical sectional view of one embodiment of an apparatus according to the invention, Fig. 2 shows a section along line A-A in -Fig. 1, Fig. 3 shows another embodiment of the invention, Fig. 4 shows a section along line B-B in Fig. 3, Fig. 5 shows an alternative of the embodi -meat in Fig. 3, Fig. 6 shows a section along line C-C in Fig. 3, Fig. 7 shows yet another embodiment of the invention, Fig. 8 shows a vertical sectional view of an embodiment of the invention and Fig. 9 shows a section along line D-D in Fig. 8.
In figures 1 and 2 the numeral 1 refers to a pump housing which includes an inlet part 2. In the housing there is an impeller 3 rotably journalled and having vanes 4 and a back wall 5. One side of the impeller is open and the inner surface 6 of the pump housing having the form of the vane edge guides the flow. By the front edges of the vanes there are recesses 7 in the inner surface of the housing.
In the pulp or fibre suspension these bring about flow components (iri Fig. 1 marked with x) alternating in direction and deviating from the main flow direction (marked with y) and shear forces disrupting the fibre-to fibre bondings as the width of the flow passage in the impeller between the pump housing and the back wall of the impeller alternately increases and decreases when the impeller rotates. Owing to this, the fibre suspension becomes fluidized at the front edges of the vanes and its flow resistance de creases.
Figures 3 and 4 show another embodiment, where the numerals 2 and 3 refer to the same parts as in figure 1. The outline 8 of the cross section of the inlet part 2 is here non-round.
The fibre suspension flows thus to the impel ler 3 through a pipe the cross section of which is composed of deeper parts 9 further away from the center and of shallower parts 10 closer to the center. While the impeller rotates, the fibre suspension in the inlet part is also brought into rotating motion and, because of the non-round cross section, subjected to shear forces as the cross section in the direction of the Rotation: alternately increases and decreases. Hereby the fibre suspension becomes fluidized just in front of the impeller and flows unhindered to the vane passages of the impeller.
Figures 5 and 6 show an alternative where a non-round rotor 11, has been disposed into the inlet part 2 of the pump the cross section outline 8 of which is non-round, to enhance the rotating motion of the fibre suspension and the fluidization in the inlet part.
Figure 7 shows yet another embodiment where a vibrator 12 has been disposed in the pump inlet part 2 to vibrate the fibre suspension in the inlet part so that it becomes fluidized.
Figures 8 and 9 show an embodiment of the invention where the inlet part 2 of the pump is connected to the outlet 14 of the pulp vessel 13 in order to remove pulp from the vessel.
A rotor 15 running through the inlet part of the pump and the outlet of the pulp vessel has been mounted on the same shaft 19 as the impeller 5. The rotor has been furnished with rib-shaped lobes 16 and the inlet part of the pump and the outlet of the pulp vessel with rib-shaped lobes 17, 18 the main direction of which is axial.
If necessary the pulp vessel may be provided with several outlets each of which is connected to a pump.
The invention is illustrated by the following examples.
Example 1 A rotor 11 according to Figs. 5 and 6 in the inlet part in front of the impeller had the following dimensions: Max. diameter 85 mm Min. diameter 75 mm The corresponding dimensions of the inlet part were 150 mm and 130 mm.
Number of revolutions 1500 1/mien Flow rate 3000--7500 1/mien Example 2 Recesses 7 according to Figs. 1 and 2 at the front edges of the impeller vanes were made with a cylindrical cutter the diameter of which was 120 mm.
Max. depth 3 mm Number 8 Diameter of inlet part 150 mm Number of revolutions 1500 1/mien Flow rate 3000-7500 1/mien Tests have prooved that a pump according to the invention is well adapted for pumping various pulps used in the paper and cellulose industry having consistencies from 8 to 12%.
It is possible to pump pulps of even higher consistencies. When the consistency is less than 6% the pump operates at an inlet pressure which is 2 to 3 metres (water head) lower than a conventional pulp pump.
The invention is not limited to the embodiments presented here but several modifications can be made of it without departing from the principle of the invention. E.g. the rotor in front of the impeller can rotate at a different angular speed than the impeller 4: WHAT WE CLAIM IS: 1 A method for pumping a high consistency fibre suspension with a centrifugal pump, characterized in that shear forces disrupting fibre-to-fibre bondings are generated in front of the impeller and/or at the front edges of the inpeller vanes whereby the fibre suspension is fluidized and becomes capable of being pumped.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (12)

  1. **WARNING** start of CLMS field may overlap end of DESC **.
    Fig. 2 shows a section along line A-A in -Fig. 1, Fig. 3 shows another embodiment of the invention, Fig. 4 shows a section along line B-B in Fig. 3, Fig. 5 shows an alternative of the embodi -meat in Fig. 3, Fig. 6 shows a section along line C-C in Fig. 3, Fig. 7 shows yet another embodiment of the invention, Fig. 8 shows a vertical sectional view of an embodiment of the invention and Fig. 9 shows a section along line D-D in Fig. 8.
    In figures 1 and 2 the numeral 1 refers to a pump housing which includes an inlet part
    2. In the housing there is an impeller 3 rotably journalled and having vanes 4 and a back wall 5. One side of the impeller is open and the inner surface 6 of the pump housing having the form of the vane edge guides the flow. By the front edges of the vanes there are recesses 7 in the inner surface of the housing.
    In the pulp or fibre suspension these bring about flow components (iri Fig. 1 marked with x) alternating in direction and deviating from the main flow direction (marked with y) and shear forces disrupting the fibre-to fibre bondings as the width of the flow passage in the impeller between the pump housing and the back wall of the impeller alternately increases and decreases when the impeller rotates. Owing to this, the fibre suspension becomes fluidized at the front edges of the vanes and its flow resistance de creases.
    Figures 3 and 4 show another embodiment, where the numerals 2 and 3 refer to the same parts as in figure 1. The outline 8 of the cross section of the inlet part 2 is here non-round.
    The fibre suspension flows thus to the impel ler 3 through a pipe the cross section of which is composed of deeper parts 9 further away from the center and of shallower parts 10 closer to the center. While the impeller rotates, the fibre suspension in the inlet part is also brought into rotating motion and, because of the non-round cross section, subjected to shear forces as the cross section in the direction of the Rotation: alternately increases and decreases. Hereby the fibre suspension becomes fluidized just in front of the impeller and flows unhindered to the vane passages of the impeller.
    Figures 5 and 6 show an alternative where a non-round rotor 11, has been disposed into the inlet part 2 of the pump the cross section outline 8 of which is non-round, to enhance the rotating motion of the fibre suspension and the fluidization in the inlet part.
    Figure 7 shows yet another embodiment where a vibrator 12 has been disposed in the pump inlet part 2 to vibrate the fibre suspension in the inlet part so that it becomes fluidized.
    Figures 8 and 9 show an embodiment of the invention where the inlet part 2 of the pump is connected to the outlet 14 of the pulp vessel 13 in order to remove pulp from the vessel.
    A rotor 15 running through the inlet part of the pump and the outlet of the pulp vessel has been mounted on the same shaft 19 as the impeller 5. The rotor has been furnished with rib-shaped lobes 16 and the inlet part of the pump and the outlet of the pulp vessel with rib-shaped lobes 17, 18 the main direction of which is axial.
    If necessary the pulp vessel may be provided with several outlets each of which is connected to a pump.
    The invention is illustrated by the following examples.
    Example 1 A rotor 11 according to Figs. 5 and 6 in the inlet part in front of the impeller had the following dimensions: Max. diameter 85 mm Min. diameter 75 mm The corresponding dimensions of the inlet part were 150 mm and 130 mm.
    Number of revolutions 1500 1/mien Flow rate 3000--7500 1/mien Example 2 Recesses 7 according to Figs. 1 and 2 at the front edges of the impeller vanes were made with a cylindrical cutter the diameter of which was 120 mm.
    Max. depth 3 mm Number 8 Diameter of inlet part 150 mm Number of revolutions 1500 1/mien Flow rate 3000-7500 1/mien Tests have prooved that a pump according to the invention is well adapted for pumping various pulps used in the paper and cellulose industry having consistencies from 8 to 12%.
    It is possible to pump pulps of even higher consistencies. When the consistency is less than 6% the pump operates at an inlet pressure which is 2 to 3 metres (water head) lower than a conventional pulp pump.
    The invention is not limited to the embodiments presented here but several modifications can be made of it without departing from the principle of the invention. E.g. the rotor in front of the impeller can rotate at a different angular speed than the impeller 4: WHAT WE CLAIM IS: 1 A method for pumping a high consistency fibre suspension with a centrifugal pump, characterized in that shear forces disrupting fibre-to-fibre bondings are generated in front of the impeller and/or at the front edges of the inpeller vanes whereby the fibre suspension is fluidized and becomes capable of being pumped.
  2. 2. A method according to claim 1, char
    acterized in that the fibre suspension is vibrated.
  3. 3. A method according to claim 1, characterized in that the fibre suspension flowing to the impeller is brought into rotating motion having alternate flow components towards and away from its rotation axis.
  4. 4. A method according to claim 1, characterized in that flow components alternating in direction and deviating from the main direction of the flow of the fibre suspension are generated in the fibre suspension flowing in the impeller.
  5. 5. A centrifugal pump apparatus for pumping high consistency fibre suspension, including means provided and adapted to fluidize the fibre suspension to facilitate pumping by generating shear forces disrupting fibre-to-fibre bondings in front of the impeller and/or at the front edges of the impeller vanes.
  6. 6. Apparatus as claimed in claim 5, characterized in that it includes an inlet part having recesses and/or projections in its inner surface in front of an impeller and/or at the front edges of the impeller vanes, which cooperate with the impeller vanes, and/or a rotor having an outer surface in which there are recesses and/or projections disposed in the inlet port to generate shear forces which disrupt fibre-to-fibre bondings and fluidize the fibre suspension.
  7. 7. A pump apparatus according to claim 6, characterized in that the rotor disposed in the inlet port of the pump is coupled with the impeller.
  8. 8. A pump apparatus according to claim 6, characterized in that the rotor disposed in the inlet part of the pump rotates at a different angular speed than the impeller.
  9. 9. A pump apparatus according to claim 7 or 8, characterized in that the rotor runs through the outlet of a pulp vessel connected to the pump.
  10. 10. An apparatus according to claim 9, characterized in that there are recesses and/or projections in the inner surface of the outlet of the pulp vessel.
  11. 11. A centrifugal pump apparatus constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.
  12. 12. A method of pumping a high consistency fibre suspension with a centrifugal pump substantially as herein described and illustrated with reference to the accompanying drawings
GB18175/78A 1977-05-16 1978-05-08 Method and apparatus for pumping fibre suspension Expired GB1589134A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI771541A FI62871B (en) 1977-05-16 1977-05-16 FOERFARANDE FOER PUMPNING AV EN FIBERSUSPENSION
FI781071A FI82728C (en) 1977-05-16 1978-04-10 Device for pumping a fiber suspension

Publications (1)

Publication Number Publication Date
GB1589134A true GB1589134A (en) 1981-05-07

Family

ID=26156874

Family Applications (1)

Application Number Title Priority Date Filing Date
GB18175/78A Expired GB1589134A (en) 1977-05-16 1978-05-08 Method and apparatus for pumping fibre suspension

Country Status (16)

Country Link
JP (1) JPS5416702A (en)
AT (1) AT357043B (en)
AU (1) AU514833B2 (en)
BR (1) BR7803004A (en)
CA (1) CA1128368A (en)
CS (1) CS223822B2 (en)
DE (1) DE2818540C3 (en)
ES (1) ES469724A1 (en)
FI (1) FI82728C (en)
FR (1) FR2391378A1 (en)
GB (1) GB1589134A (en)
IN (1) IN150144B (en)
IT (1) IT1108104B (en)
NO (1) NO150574C (en)
NZ (1) NZ187259A (en)
SE (1) SE438714B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5413460A (en) 1993-06-17 1995-05-09 Goulds Pumps, Incorporated Centrifugal pump for pumping fiber suspensions
RU2152540C1 (en) * 1997-11-26 2000-07-10 Муниципальное предприятие "РЕМСТРОЙБЛАГОУСТРОЙСТВО" Centrifugal pump to transfer and milling of construction materials

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI62871B (en) * 1977-05-16 1982-11-30 Ahlstroem Oy FOERFARANDE FOER PUMPNING AV EN FIBERSUSPENSION
FI69683C (en) * 1982-02-08 1986-03-10 Ahlstroem Oy CENTRIFUGALPUMP FOER VAETSKOR INNEHAOLLANDE FASTA AEMNEN
FI67580C (en) * 1983-07-12 1985-04-10 Ahlstroem Oy FOERFARANDE OCH ANORDNING FOER FIBRERING SILNING OCH PUMPNING AV CELLULOSAMASSA OCH RETURPAPPER
JPS61198593U (en) * 1985-05-31 1986-12-11
US4776758A (en) * 1987-07-06 1988-10-11 Kamyr Ab Combined fluidizing and vacuum pump
FI85751B (en) * 1988-06-17 1992-02-14 Ahlstroem Oy FOERFARANDE OCH ANORDNING FOER PUMPNING AV TJOCKT MEDIUM.
SE464318B (en) * 1990-02-28 1991-04-08 Flygt Ab SHAFT CONSTRUCTION FOR A PUMP WHEEL ROTARY RUBBER
JP2636966B2 (en) * 1990-12-20 1997-08-06 株式会社三興ポンプ製作所 Submersible pump for drain with cutter

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE564826C (en) * 1932-11-23 Siemens Schuckertwerke Akt Ges Device for conveying gases or liquids with a helical gear in the inlet channel of a centrifugal motor and a diffuser connected between the helical and centrifugal motor and flowed through from the inside to the outside
DE704138C (en) * 1938-11-18 1941-03-24 Masch Fabriken Wagner Doerries Face plate holder with horizontal shaft
DE836435C (en) * 1941-11-20 1952-04-15 Clyde Paper Company Ltd Method and device for defibrating paper pulp
US2371681A (en) * 1943-01-18 1945-03-20 Jr Augustus C Durdin Centrifugal cutting pump
DE1000677B (en) * 1952-12-20 1957-01-10 Doerries A G Vorm Maschinenfab Refiner
US3128051A (en) * 1960-11-07 1964-04-07 Dag Mfg Co Pump
CH411584A (en) * 1964-07-10 1966-04-15 Kolb Eugen Ag Centrifugal pump for pumping contaminated liquids
CH459510A (en) * 1966-07-08 1968-07-15 Sulzer Ag Prefabricated installation element for air conditioning systems
BE724376A (en) * 1967-12-15 1969-05-22
DE1703075A1 (en) * 1968-03-28 1972-01-13 Moertl Karl Clearance for pump suction pipes
IE34587B1 (en) * 1969-05-19 1975-06-25 Warman Equip Centrifugal froth pump
DE2411043A1 (en) * 1974-03-08 1975-09-18 Abs Pumps Ltd Submerged sewage pump with disintegrator - exerts disintegrating forces in radial direction by radial rounded teeth on discs
US3961758A (en) * 1974-08-23 1976-06-08 Peabody Barnes, Inc. Centrifugal pump with integral grinder
CH582788A5 (en) * 1974-09-23 1976-12-15 Escher Wyss Gmbh
GB1568388A (en) * 1975-11-29 1980-05-29 Blum A Pump with comminuating means at the inlet

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5413460A (en) 1993-06-17 1995-05-09 Goulds Pumps, Incorporated Centrifugal pump for pumping fiber suspensions
RU2152540C1 (en) * 1997-11-26 2000-07-10 Муниципальное предприятие "РЕМСТРОЙБЛАГОУСТРОЙСТВО" Centrifugal pump to transfer and milling of construction materials

Also Published As

Publication number Publication date
SE7805509L (en) 1978-11-17
NZ187259A (en) 1981-05-01
FI82728C (en) 1991-04-10
JPS5416702A (en) 1979-02-07
DE2818540B2 (en) 1979-04-12
SE438714B (en) 1985-04-29
CS223822B2 (en) 1983-11-25
IT7868105A0 (en) 1978-05-15
CA1128368A (en) 1982-07-27
DE2818540A1 (en) 1978-11-30
FI82728B (en) 1990-12-31
FI781071A7 (en) 1979-10-11
AU3575878A (en) 1979-11-08
BR7803004A (en) 1979-05-29
DE2818540C3 (en) 1984-08-30
AT357043B (en) 1980-06-10
NO150574B (en) 1984-07-30
FR2391378A1 (en) 1978-12-15
AU514833B2 (en) 1981-02-26
JPS6246713B2 (en) 1987-10-03
IN150144B (en) 1982-07-31
FR2391378B1 (en) 1982-04-23
NO150574C (en) 1984-11-07
ES469724A1 (en) 1979-09-16
IT1108104B (en) 1985-12-02
NO781627L (en) 1978-11-17

Similar Documents

Publication Publication Date Title
US4855038A (en) High consistency pressure screen and method of separating accepts and rejects
US3726401A (en) Screening machine
US6551054B1 (en) Method and apparatus for pumping a material and a rotor for use in connection therewith
GB1589134A (en) Method and apparatus for pumping fibre suspension
JPH0242193A (en) A device for separating gas from a medium by means of a pump
JP3355578B2 (en) Equipment for processing fiber suspensions
US4435122A (en) Method and apparatus for pumping fiber suspensions
US4396502A (en) Screening apparatus for a papermaking machine
US4780053A (en) Method and apparatus for pumping fiber suspensions
US4744722A (en) Method and apparatus for the mixing of liquid or gas into pulp stock
EP0478228A1 (en) Method and apparatus for the discharge of gas from a liquid solids mixture
US8950584B2 (en) Apparatus for screening fibrous suspensions
FI77481C (en) Strainer.
US4971519A (en) Method and apparatus for pumping high consistency medium
US4981583A (en) High consistency pressure screen and method of separating accepts and rejects
US5110456A (en) High consistency pressure screen and method of separating accepts and rejects
US20050045529A1 (en) Vortex inducing rotor for screening apparatus for papermaking pulp
US5341936A (en) Screening device for a fiber slurry, and a backwash means therefor
RU2386471C1 (en) Reciprocation pump impeller
EP0475669A2 (en) A mass tower and apparatus for the discharge thereof
FI85750B (en) Method for pumping highly concentrated fibre suspension using centrifugal pump
FI66037B (en) ANORDNING FOER SIKTNING AV FIBROES SLAM

Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PE20 Patent expired after termination of 20 years

Effective date: 19980507