EP3227492A1 - Discharge of material from a batch digester - Google Patents

Discharge of material from a batch digester

Info

Publication number
EP3227492A1
EP3227492A1 EP15820554.2A EP15820554A EP3227492A1 EP 3227492 A1 EP3227492 A1 EP 3227492A1 EP 15820554 A EP15820554 A EP 15820554A EP 3227492 A1 EP3227492 A1 EP 3227492A1
Authority
EP
European Patent Office
Prior art keywords
digester
cone
outlet opening
nozzles
base
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.)
Withdrawn
Application number
EP15820554.2A
Other languages
German (de)
French (fr)
Inventor
Lasse Hernesniemi
Henri KESSELI
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.)
Andritz Oy
Original Assignee
Andritz Oy
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
Application filed by Andritz Oy filed Critical Andritz Oy
Publication of EP3227492A1 publication Critical patent/EP3227492A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C7/00—Digesters
    • D21C7/08—Discharge devices

Definitions

  • the present invention provides systems for improving the flow of a discharge stage of a batch digester used in chemical pulping.
  • a digester reactor vessel is filled with wood chips and steam is added to pressurize and heat the chips. Warm black liquor is fed in to the digester. The black liquor impregnates the chips. After impregnation, black liquor is removed from the digester reactor vessel and returned to an accumulator vessel. Thereafter, the digester reactor vessel is filled with hot black and white liquors to be used to cook the chips. The chips in the digester are cooked for a predetermined time and temperature to form pulp. After cooking, filtrate liquid is pumped into the digester reactor vessel to displace the hot liquor which is removed from the vessel. The pulp and filtrate form a slurry which is discharged from the digester reactor vessel and pumped under pressure to a blow tank.
  • a novel solution has been developed for equalizing the discharge flow from a batch digester.
  • a purpose of the invention is to provide as wide and versatile a solution as possible for the problems limiting this aim. The purpose is achieved such that the apparatus defined in the preamble of the independent claims is implemented as defined in the characterizing part of the claims. Preferred embodiments of the invention may correspond to the dependent claims.
  • a batch digester for treating comminuted lignocellulosic fibrous material comprises an inlet for introducing comminuted lignocellulosic fibrous material, a circular cylindrical wall portion, an outlet opening for discharging treated comminuted lignocellulosic fibrous material, and a hemispherical bottom wall portion between said circular cylindrical wall portion and the outlet opening.
  • a stationary flow diverter having a form of a double cone and being supported by supporting legs is arranged above the outlet opening of the digester for preventing direct vertical pulp flow to the outlet.
  • the double cone diverter comprises a first cone having a base and extending upwardly from the base, and a second cone having said base common with said first cone, and extending downwardly.
  • the diverter is supported to the bottom of the digester by means of supporting legs for preventing the generation of turbulence.
  • the supporting legs are arranged to function as vortex-breakers.
  • the cone base has a diameter, which is longer than the outlet opening diameter.
  • the apexes of the cones are located on the vertical central axis of the digester.
  • the vertex angle of the first cone is 70 degrees or less, typically 50-70 degrees.
  • the vertex angle of the second cone is 80-120 degrees, typically 90-1 10 degrees.
  • a plurality of upper dilution nozzles are arranged in the periphery of the digester wall at an elevational level between the apex of the first cone and the upper ends of the supporting legs in the vertical direction.
  • the feeding of dilution liquid is directed essentially to the vicinity of the walls of the digester so that the upper nozzles are directed to feed dilution liquid downwards to the fibrous material in the bottom portion.
  • a plurality of lower dilution nozzles is arranged at a level below the cone base and above the digester outlet in the vertical direction.
  • the lower nozzles are directed to feed dilution liquid towards the outlet.
  • the upper and lower nozzles are typically evenly spaced about the periphery of the digester wall.
  • the upper ends of the supporting legs are typically connected to an upper part of the second cone of the diverter.
  • the lower ends of the supporting legs engage on the inside of the bottom wall of the digester, and the legs have a height so that the upper ends of the legs are located higher than the lower dilution nozzles, but lower than the upper dilution nozzles.
  • the modification moves the central pulp flow into the dilution area, improves pulp movement on the side of the digester wall and forces dilution liquid to meet pulp in the bottom of digester.
  • Fig. 1 is a schematic side view of a bottom section of a batch digester illustrating one embodiment of the present invention. Detailed description of the invention
  • Fig. 1 shows the basic diagram of a bottom section of a batch digester 10 with dilution nozzles and a double cone with supporting legs.
  • the digester 10 has a circular cylindrical wall portion 12 and a hemispherical bottom 1 1 .
  • the bottom has an outlet opening 13 for discharging fibrous material, such as pulp, from the digester.
  • the outlet opening has a diameter L1 .
  • a vertical central axis 23 of the digester typically passes through the center of the outlet opening 13.
  • the hemispherical bottom section is provided with a stationary flow diverter 14, which has a form of a double cone 15.
  • the diverter is arranged above the outlet opening 13 for preventing a direct vertical pulp flow downward to the outlet.
  • the double cone 15 comprises a first cone 16 having a base 18 and extending upwardly from the base, and a second cone 17 having said base common with said first cone, and extending downwardly.
  • Apex 21 is at the upper end of the first cone 16, and the cone expands out to meet the expanded portion of the lower cone 17, referred to as second cone, thus the double cone has apexes at opposite ends.
  • the double cone can be manufactured in one piece or the two cones can be attached, e.g. by welding, together.
  • the diameter of the diverter is at its largest.
  • the largest diameter L2 of the double cone 15, i.e. the diameter of the cone base 18, is longer than the outlet diameter L1 so that the direct vertical pulp flow downward to the outlet opening is prevented.
  • the diameter of the diverter shall not be too long so that there is enough space for the flow between the diverter and the bottom wall.
  • the double cone diverter 14 is supported to the bottom of the digester by means of supporting legs 19.
  • the supporting legs are arranged to function as vortex-breakers for preventing the generation of turbulence.
  • the upper ends of the supporting legs are typically attached to an upper part of the second cone 17 of the diverter.
  • the apexes 21 and 20 of the essentially right cones 16 and 17 are located on the vertical central axis 23 of the digester.
  • the cones 16, 17 have a central axis coinciding with the central axis 23 of the digester.
  • the vertex angle Z of the first cone 16 is 70 degrees or less, typically 50-70 degrees.
  • the vertex angle D of the second cone 17 which is inverted with respect to the first cone is 80-120 degrees, typically 90-1 10 degrees.
  • the first cone 16 is higher than the second cone 17.
  • a plurality of upper dilution nozzles 25 is arranged in the periphery of the digester wall at an elevational level between the apex 21 of the first cone 16 and the upper ends of the supporting legs 19 in the vertical direction.
  • upper nozzles are disposed in the cylindrical wall portion at a level 22 or above, which is located above the point where the hemispherical bottom area starts. Then a problem is that dilution liquid tends to flow upward and pulp is thickening in the bottom, which prevents uniform material flow through the outlet 13.
  • the upper nozzles 25 according to the new arrangement are disposed at a lower level than in known batch digesters in which the upper nozzles are located at the level 22 or above.
  • the upper nozzles 25 are directed so that dilution liquid flows mainly downward in the vicinity of the digester wall to the fibrous material in the bottom. Thus the dilution liquid meets the pulp in the bottom of the digester and does not flow upward.
  • a plurality of lower dilution nozzles 24 is arranged at a level below the cone base 18 and above the outlet opening 13 in the vertical direction.
  • the lower nozzles 24 are directed to feed dilution liquid towards the outlet opening.
  • the lower dilution nozzles must be pointed to the outlet flange of the digester to avoid turbulence above the bottom outlet and liquor flow upward.
  • each supporting leg 19 is typically attached to an upper part of the second cone 17 of the diverter.
  • the attachment may be direct or by means of a spacer ring.
  • the supporting legs have a height y (26) extending from the lowest point to the uppermost point thereof. The height of the legs is such that the upper ends of the legs are located higher than the lower dilution nozzles 24, but lower than the upper dilution nozzles 25.
  • the supporting legs have to be designed so that they are sufficiently strong to bear the weight of the material column in the digester.
  • pulp With the properly located upper nozzles and the double cone, pulp will be forced into the bottom dilution zone of the digester. These modifications are ensuring that dilution liquid and pulp flow meet before the digester outlet connection. More homogenous pulp consistency (and temperature) decreases pump out time of the digester, reduces dilution volume and reduces mass of "dry pulp cakes" during an emptying sequence of the digestion process. It also improves the production capacity of the digester plant.
  • a modeled discharge process of the batch digester showed that the upper dilution liquid flows almost totally downstream towards the digester outlet. Thus it is reducing the area of the thickened pulp in the hemispherical bottom. It was also discovered that the digester flow field is a very straightforward through-flow. Flow paths of fibers do not show any weighting (bias) by cross-section and the flow field higher in the digester (above the diverter) almost resembles plug flow.
  • a modeled discharge process in a prior art digester in which the upper nozzles are located at the level 22 and the bottom has no double cone, shows that the upper dilution liquid flows upward. Then pulp is thickening in the spherical bottom, which prevents uniform outflow.
  • Diluted pulp-liquor mixture tends to find the shortest route towards the bottom outlet along the centerline, right in the beginning of the discharging sequence, leaving the outer walls of the digester bottom filled with continuously thickening pulp. This "doughnut" of thick pulp must then be removed using excessive amount of dilution liquor in the end of the discharging sequence. Formation of a thick pulp layer on bottom walls is specific for the round-bottomed digesters.
  • the above mentioned problems are thus solved in connection with discharge from a batch digester. In this arrangement the even discharge consistency has been obtained without the use of moving, such as rotating, mechanical discharge means.

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  • Paper (AREA)

Abstract

The present invention relates to a batch digester for treating comminuted lignocellulosic fibrous material. The digester comprises an inlet for introducing comminuted lignocellulosic fibrous material, a circular cylindrical wall portion, an outlet opening for discharging treated comminuted lignocellulosic fibrous material, a hemispherical bottom wall portion between said circular cylindrical wall portion and the outlet. The digester comprises also a stationary diverter disposed in the bottom portion above the outlet opening. The diverter comprises a first cone having a base and extending upwardly from the base, and a second cone having said base common with said first cone, and extending downwardly, wherein said diverter is supported by supporting legs, which engage on the inside of the bottom wall and are arranged around the outlet. A plurality of upper dilution nozzles are arranged in the periphery of the digester wall at an elevational level between the apex of the first cone and the supporting legs, and a plurality of lower dilution nozzles are arranged in the periphery of the digester wall vertically below the upper nozzles.

Description

Discharge of material from a batch digester Field of the invention The present invention provides systems for improving the flow of a discharge stage of a batch digester used in chemical pulping.
Prior art In a typical conventional operating cycle for a batch cooking process, a digester reactor vessel is filled with wood chips and steam is added to pressurize and heat the chips. Warm black liquor is fed in to the digester. The black liquor impregnates the chips. After impregnation, black liquor is removed from the digester reactor vessel and returned to an accumulator vessel. Thereafter, the digester reactor vessel is filled with hot black and white liquors to be used to cook the chips. The chips in the digester are cooked for a predetermined time and temperature to form pulp. After cooking, filtrate liquid is pumped into the digester reactor vessel to displace the hot liquor which is removed from the vessel. The pulp and filtrate form a slurry which is discharged from the digester reactor vessel and pumped under pressure to a blow tank.
In batch digesters, the whole amount of pulp inside the digester is produced essentially simultaneously and the pressurized digester is discharged after a batch cook into a storage tank with atmospheric pressure. Mixers or scrapers have typically not been used at the bottom of the batch digester. When the pulp is allowed to flow freely to the discharge opening of the digester, it is nevertheless not possible to make the pulp exit with homogeneous quality in the initial and final stages of the discharge. The most dilute material is first passed to the center of the digester, and thus to the discharge opening. In the vicinity of the digester wall the consistency of the pulp is increased, since the liquid flows more easily via the center part, diluting the pulp therein. In the vicinity of the wall, the discharge from the digester of pulp at higher consistency is thus more difficult and slower. Thus, also the consistency of the pulp in digesters and tanks is often fluctuating with respect to time and location. Thickening of the pulp in the vicinity of the digester wall has been prohibited by spraying dilution liquid to the edge zones of the digester, as described e.g. in US Patent 51 16475, in which the digester has a conical bottom. A digester having a hemispherical bottom is described in Papermaking Science and Technology, Chemical Pulping, Book 6A, 1999, pages 501 -506. However, the supply of dilution liquid has not always yielded the desired result, especially in batch digesters having a hemispherical bottom head. Thus, there exists a need to control the discharge flow better and maintain the overall vertical flow velocity homogeneous and thus the pulp quality also homogeneous. Said problem is present especially in digesters having a hemispherical bottom. Generally a stream of pulp together with liquor is discharged from a batch digester to an atmospheric blow tank. Typically, pulp in the central part of the digester is flowing faster than the pulp and liquor on the side of the digester wall. This flow is characterized by gross variation in downward velocity between the inner surface of the digester wall and the center of the digester. The use of dilution nozzles has not solved this problem sufficiently. Due to the shape of the digester bottom and the positions of dilution nozzles, especially upper dilution nozzles, dilution liquor is typically not meeting pulp stream in the center of the digester in an efficient way.
This will cause consistency variations, additional dilution liquid charge, "dry pulp cakes", and extended emptying time.
The purpose and solution of the invention
A novel solution has been developed for equalizing the discharge flow from a batch digester. A purpose of the invention is to provide as wide and versatile a solution as possible for the problems limiting this aim. The purpose is achieved such that the apparatus defined in the preamble of the independent claims is implemented as defined in the characterizing part of the claims. Preferred embodiments of the invention may correspond to the dependent claims. A batch digester for treating comminuted lignocellulosic fibrous material comprises an inlet for introducing comminuted lignocellulosic fibrous material, a circular cylindrical wall portion, an outlet opening for discharging treated comminuted lignocellulosic fibrous material, and a hemispherical bottom wall portion between said circular cylindrical wall portion and the outlet opening.
In accordance with the present invention, a stationary flow diverter having a form of a double cone and being supported by supporting legs is arranged above the outlet opening of the digester for preventing direct vertical pulp flow to the outlet. The double cone diverter comprises a first cone having a base and extending upwardly from the base, and a second cone having said base common with said first cone, and extending downwardly. The diverter is supported to the bottom of the digester by means of supporting legs for preventing the generation of turbulence. Thus the supporting legs are arranged to function as vortex-breakers. The cone base has a diameter, which is longer than the outlet opening diameter.
Typically the apexes of the cones are located on the vertical central axis of the digester. The vertex angle of the first cone is 70 degrees or less, typically 50-70 degrees. The vertex angle of the second cone is 80-120 degrees, typically 90-1 10 degrees. A plurality of upper dilution nozzles are arranged in the periphery of the digester wall at an elevational level between the apex of the first cone and the upper ends of the supporting legs in the vertical direction. Preferably, the feeding of dilution liquid is directed essentially to the vicinity of the walls of the digester so that the upper nozzles are directed to feed dilution liquid downwards to the fibrous material in the bottom portion. In addition, a plurality of lower dilution nozzles is arranged at a level below the cone base and above the digester outlet in the vertical direction. Preferably, the lower nozzles are directed to feed dilution liquid towards the outlet. The upper and lower nozzles are typically evenly spaced about the periphery of the digester wall. The upper ends of the supporting legs are typically connected to an upper part of the second cone of the diverter. The lower ends of the supporting legs engage on the inside of the bottom wall of the digester, and the legs have a height so that the upper ends of the legs are located higher than the lower dilution nozzles, but lower than the upper dilution nozzles.
Advantages of the invention include e.g. the following: The modification moves the central pulp flow into the dilution area, improves pulp movement on the side of the digester wall and forces dilution liquid to meet pulp in the bottom of digester. In the following the invention is described in more detail by reference to the accompanying drawing wherein
Fig. 1 is a schematic side view of a bottom section of a batch digester illustrating one embodiment of the present invention. Detailed description of the invention
Fig. 1 shows the basic diagram of a bottom section of a batch digester 10 with dilution nozzles and a double cone with supporting legs.
The digester 10 has a circular cylindrical wall portion 12 and a hemispherical bottom 1 1 . The bottom has an outlet opening 13 for discharging fibrous material, such as pulp, from the digester. The outlet opening has a diameter L1 . A vertical central axis 23 of the digester typically passes through the center of the outlet opening 13.
The hemispherical bottom section is provided with a stationary flow diverter 14, which has a form of a double cone 15. The diverter is arranged above the outlet opening 13 for preventing a direct vertical pulp flow downward to the outlet. The double cone 15 comprises a first cone 16 having a base 18 and extending upwardly from the base, and a second cone 17 having said base common with said first cone, and extending downwardly. Apex 21 is at the upper end of the first cone 16, and the cone expands out to meet the expanded portion of the lower cone 17, referred to as second cone, thus the double cone has apexes at opposite ends.
The double cone can be manufactured in one piece or the two cones can be attached, e.g. by welding, together.
At the point of contact between said first and second cones, i.e. at the base, the diameter of the diverter is at its largest. The largest diameter L2 of the double cone 15, i.e. the diameter of the cone base 18, is longer than the outlet diameter L1 so that the direct vertical pulp flow downward to the outlet opening is prevented. On the other hand, the diameter of the diverter shall not be too long so that there is enough space for the flow between the diverter and the bottom wall.
The double cone diverter 14 is supported to the bottom of the digester by means of supporting legs 19. Thus the supporting legs are arranged to function as vortex-breakers for preventing the generation of turbulence. The upper ends of the supporting legs are typically attached to an upper part of the second cone 17 of the diverter.
Typically the apexes 21 and 20 of the essentially right cones 16 and 17 are located on the vertical central axis 23 of the digester. In other words, the cones 16, 17 have a central axis coinciding with the central axis 23 of the digester. The vertex angle Z of the first cone 16 is 70 degrees or less, typically 50-70 degrees. The vertex angle D of the second cone 17 which is inverted with respect to the first cone is 80-120 degrees, typically 90-1 10 degrees. Thus generally, the first cone 16 is higher than the second cone 17.
A plurality of upper dilution nozzles 25 is arranged in the periphery of the digester wall at an elevational level between the apex 21 of the first cone 16 and the upper ends of the supporting legs 19 in the vertical direction. In a known digester arrangement upper nozzles are disposed in the cylindrical wall portion at a level 22 or above, which is located above the point where the hemispherical bottom area starts. Then a problem is that dilution liquid tends to flow upward and pulp is thickening in the bottom, which prevents uniform material flow through the outlet 13. In Fig. 1 the upper nozzles 25 according to the new arrangement are disposed at a lower level than in known batch digesters in which the upper nozzles are located at the level 22 or above. In the new arrangement the upper nozzles 25 are directed so that dilution liquid flows mainly downward in the vicinity of the digester wall to the fibrous material in the bottom. Thus the dilution liquid meets the pulp in the bottom of the digester and does not flow upward.
A plurality of lower dilution nozzles 24 is arranged at a level below the cone base 18 and above the outlet opening 13 in the vertical direction. Preferably, the lower nozzles 24 are directed to feed dilution liquid towards the outlet opening. The lower dilution nozzles must be pointed to the outlet flange of the digester to avoid turbulence above the bottom outlet and liquor flow upward.
The upper end of each supporting leg 19 is typically attached to an upper part of the second cone 17 of the diverter. The attachment may be direct or by means of a spacer ring. The supporting legs have a height y (26) extending from the lowest point to the uppermost point thereof. The height of the legs is such that the upper ends of the legs are located higher than the lower dilution nozzles 24, but lower than the upper dilution nozzles 25. The supporting legs have to be designed so that they are sufficiently strong to bear the weight of the material column in the digester.
With the properly located upper nozzles and the double cone, pulp will be forced into the bottom dilution zone of the digester. These modifications are ensuring that dilution liquid and pulp flow meet before the digester outlet connection. More homogenous pulp consistency (and temperature) decreases pump out time of the digester, reduces dilution volume and reduces mass of "dry pulp cakes" during an emptying sequence of the digestion process. It also improves the production capacity of the digester plant.
A modeled discharge process of the batch digester showed that the upper dilution liquid flows almost totally downstream towards the digester outlet. Thus it is reducing the area of the thickened pulp in the hemispherical bottom. It was also discovered that the digester flow field is a very straightforward through-flow. Flow paths of fibers do not show any weighting (bias) by cross-section and the flow field higher in the digester (above the diverter) almost resembles plug flow. A modeled discharge process in a prior art digester, in which the upper nozzles are located at the level 22 and the bottom has no double cone, shows that the upper dilution liquid flows upward. Then pulp is thickening in the spherical bottom, which prevents uniform outflow.
Diluted pulp-liquor mixture tends to find the shortest route towards the bottom outlet along the centerline, right in the beginning of the discharging sequence, leaving the outer walls of the digester bottom filled with continuously thickening pulp. This "doughnut" of thick pulp must then be removed using excessive amount of dilution liquor in the end of the discharging sequence. Formation of a thick pulp layer on bottom walls is specific for the round-bottomed digesters. In accordance with this invention, the above mentioned problems are thus solved in connection with discharge from a batch digester. In this arrangement the even discharge consistency has been obtained without the use of moving, such as rotating, mechanical discharge means.

Claims

Batch digester for treating comminuted lignocellulosic fibrous material, the digester comprising
an inlet for introducing comminuted lignocellulosic fibrous material,
a circular cylindrical wall portion (12),
an outlet opening (13) for discharging treated comminuted lignocellulosic fibrous material,
a hemispherical bottom wall portion (1 1 )between said circular cylindrical wall portion (12) and the outlet opening (13), characterized in that it further comprises a stationary diverter (14) disposed in the bottom portion above the outlet opening, said diverter comprising a first cone (16) having a base (18) and extending upwardly from the base, and a second cone (17) having said base common with said first cone, and extending downwardly, wherein said diverter (14) is supported by supporting legs (19), each leg having an upper end and a lower end and the lower ends being engaged on the inside of the bottom wall and arranged around the outlet opening (13), and
a plurality of upper dilution nozzles (25) which are arranged in the periphery of the digester wall at an elevational level between the apex (21 ) of the first cone (16) and the upper ends of the supporting legs, and a plurality of lower dilution nozzles (24) which are arranged in the periphery of the digester wall vertically below the upper nozzles (25).
Batch digester according to claim 1 , characterized in that an upper end of each supporting leg (19) is attached to the second cone (17).
Batch digester according to claim 1 or 2, characterized in that the lower nozzles
(24) are arranged at a level below the cone base (18) in the vertical direction and are directed to introduce dilution liquid towards the outlet opening.
Batch digester according to claim 1 , 2 or 3, characterized in that the upper nozzles
(25) are directed to introduce dilution liquid downwards to the fibrous material in the bottom portion.
Batch digester according to any of the preceding claims, characterized in that the vertex angle of the first cone (16) is 70 degrees or less, typically 50-70 degrees. Batch digester according to any of the preceding claims, characterized in that the vertex angle of the second cone (17) is 90 degrees or more, typically 90-1 10 degrees.
Batch digester according to any of the preceding claims, characterized in that the outlet opening (13) has a diameter (L1 ), and the cone base (18) has a diameter (L2), which is longer than the outlet opening diameter.
Batch digester according to any of the preceding claims, characterized in that the supporting legs (19) are arranged to function as vortex-breakers.
Batch digester according to any of the preceding claims, characterized in that the apexes (21 , 20) of the cones (16, 17) are located on the vertical central axis (23) of the digester.
EP15820554.2A 2014-12-05 2015-12-02 Discharge of material from a batch digester Withdrawn EP3227492A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20146070A FI20146070A (en) 2014-12-05 2014-12-05 Removal of material from a batch cooker
PCT/FI2015/050845 WO2016087717A1 (en) 2014-12-05 2015-12-02 Discharge of material from a batch digester

Publications (1)

Publication Number Publication Date
EP3227492A1 true EP3227492A1 (en) 2017-10-11

Family

ID=55071051

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15820554.2A Withdrawn EP3227492A1 (en) 2014-12-05 2015-12-02 Discharge of material from a batch digester

Country Status (3)

Country Link
EP (1) EP3227492A1 (en)
FI (1) FI20146070A (en)
WO (1) WO2016087717A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE545646C2 (en) * 2021-05-28 2023-11-21 Valmet Oy Treatment vessel having reduced outlet end diameter

Family Cites Families (6)

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Publication number Priority date Publication date Assignee Title
SE8903417L (en) 1989-10-17 1991-04-18 Sunds Defibrator Ind Ab SATISFY BREAKING COOKER
US5372679A (en) * 1992-06-08 1994-12-13 Air Products And Chemicals, Inc. Reactor system for treating cellulosic pulp at a constant upward flow velocity
US6280575B1 (en) * 1998-05-29 2001-08-28 Andritz-Ahlstrom Inc. Frusto-conical outlet for a cellulose material treatment vessel
US20030145962A1 (en) * 2001-08-02 2003-08-07 Glens Falls Group, Llc. System and for improving the movement and discharge of material from vessels
FI20030209A7 (en) * 2003-02-12 2004-08-13 Sulzer Pumpen Ag Arrangement and method for processing pulp and method for modernizing a pulp tower
US8647473B2 (en) * 2011-01-25 2014-02-11 Metso Paper Sweden Ab Continuous digester with a bottom scraper equipped with draining apertures

Non-Patent Citations (2)

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Title
None *
See also references of WO2016087717A1 *

Also Published As

Publication number Publication date
FI20146070A7 (en) 2016-06-06
FI20146070A (en) 2016-06-06
WO2016087717A1 (en) 2016-06-09

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