EP2694726A1 - Dispositif d'étanchéité pour un scellement étanche entre un premier tambour et un élément de boîtier d'extrémité - Google Patents

Dispositif d'étanchéité pour un scellement étanche entre un premier tambour et un élément de boîtier d'extrémité

Info

Publication number
EP2694726A1
EP2694726A1 EP12765460.6A EP12765460A EP2694726A1 EP 2694726 A1 EP2694726 A1 EP 2694726A1 EP 12765460 A EP12765460 A EP 12765460A EP 2694726 A1 EP2694726 A1 EP 2694726A1
Authority
EP
European Patent Office
Prior art keywords
drum
sealing
sealing element
pulp
sealing arrangement
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Withdrawn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
EP12765460.6A
Other languages
German (de)
English (en)
Other versions
EP2694726A4 (fr
Inventor
Magnus Danielsson
Tobias LÖÖF
Hans LÖVGREN
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.)
Valmet AB
Original Assignee
Metso Paper Sweden AB
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 Metso Paper Sweden AB filed Critical Metso Paper Sweden AB
Publication of EP2694726A1 publication Critical patent/EP2694726A1/fr
Publication of EP2694726A4 publication Critical patent/EP2694726A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/06—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums
    • B01D33/067—Construction of the filtering drums, e.g. mounting or sealing arrangements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/06—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums
    • B01D33/073—Filters with filtering elements which move during the filtering operation with rotary cylindrical filtering surfaces, e.g. hollow drums arranged for inward flow filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/35—Filters with filtering elements which move during the filtering operation with multiple filtering elements characterised by their mutual disposition
    • B01D33/37—Filters with filtering elements which move during the filtering operation with multiple filtering elements characterised by their mutual disposition in parallel connection
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/44—Regenerating the filter material in the filter
    • B01D33/46—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element
    • B01D33/466—Regenerating the filter material in the filter by scrapers, brushes nozzles or the like acting on the cake-side of the filtering element scrapers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D33/00—Filters with filtering elements which move during the filtering operation
    • B01D33/58—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element
    • B01D33/62—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for drying
    • B01D33/64—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for drying by compression
    • B01D33/646—Handling the filter cake in the filter for purposes other than for regenerating the filter cake remaining on the filtering element for drying by compression by pressure rollers
    • 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
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
    • D21C9/06—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents in filters ; Washing of concentrated pulp, e.g. pulp mats, on filtering surfaces
    • 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
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/18—De-watering; Elimination of cooking or pulp-treating liquors from the pulp

Definitions

  • the present invention relates to a sealing arrangement for sealing be- tween a first drum and an end casing member included in an apparatus for processing pulp, especially cellulose-containing pulp, the first drum being rotatable about an axis of rotation in relation to the end casing member and the sealing arrangement.
  • the first drum is provided with a permeable outer surface which axially extends between a first end and a second end of the first drum, and at least at the first end the first drum is provided with an end surface.
  • the sealing arrangement comprises a sealing member, first pressure means for forcing the sealing member in a direction towards the first drum to make the sealing member bear against a portion of the end surface, a circumferentially extending sealing element held by a holder, and second pressure means for forcing at least a first portion of the sealing element in a direction towards the first drum to make the first portion bear against a portion of the end surface.
  • the holder is arranged to hold the second pressure means, and a terminal second portion of the sealing element is in proximity to the sealing member.
  • the present invention relates to an apparatus for processing pulp comprising a sealing arrangement of the above-mentioned sort.
  • Fibre lines producing cellulose-based products may comprise some type of washing equipment for separating the liquor of the cooking from the pulp. Later on in the process, washing equipment is also provided to separate bleaching liquors after the bleaching steps. There is a plurality of different types of washing equipment operating according to different principles.
  • the roll press When producing cellulose-based products, a roll press is frequently used for washing and/or dewatering the cellulose-based pulp.
  • the roll press comprises two co-operating and counter-rotating press rolls, each having a permeable outer surface, a so called mantle surface, whereby the outer surface is permeable to liq- uid pressed out of the pulp.
  • the pulp is deposited on the permeable outer surface and pressed in the roll nip, or the press nip, between the press rolls, whereby liquid is pressed out of the pulp.
  • the roll press may also include one or more washing zones prior to the press nip.
  • washing equipment is the drum washer, where the cellulose-containing pulp is deposited and dewatered on a single rotating filter drum, which has a permeable outer surface, after the addition of washing liquid, which displaces the liquor remaining on the pulp web after the preceding process step, for example a cooking step or bleaching step.
  • the static pressure causes the contaminated liquid, called filtrate, to pass through the outer surface permeable to liquid.
  • the pressurized displacement washer where the filtrate, under overpressure, is forced to pass through the permeable outer surface.
  • an axially extending and circumferential gap or space may be provided which is sealed off from the atmosphere to produce an overpressure in order to force the filtrate from the pulp, which is located on the outer surface in said gap, to pass through the permeable outer surface.
  • the sealed-off gap By means of the sealed-off gap, the dewatering of the pulp is enhanced. Sealing arrangements including a plurality of components are generally required to seal off such a gap.
  • WO2010/036193 discloses sealing arrangements for sealing between a movable side casing member and the outer surface of a rotatable press roll, between the movable side casing member and an end casing member, and between the movable side casing member and a central casing member. Further, sealing arrangements for sealing between each end of a rotatable press roll and the end casing member may also be required.
  • a prior art sealing arrangement for sealing between an end of a rotatable drum, or roll, and a stationary end casing member is illustrated and disclosed in more detail with refer- ence to Figs. 10-1 1 .
  • a drum washer may also be equipped with a corresponding sealing arrangement for sealing between an end of the rotatable single filter drum and an end casing member.
  • the inventors of the present invention have identified drawbacks in prior art sealing arrangements for sealing between a rotatable drum and a stationary end casing member in an apparatus for dewatering pulp, especially cellulose- containing pulp.
  • One drawback identified by the inventors is that pulp may get jammed between the rotatable drum and the sealing arrangement for reasons disclosed in more detail in connection with Figs. 10-1 1 .
  • the jammed pulp may result in leakage of pulp suspension and/or filtrate and may result in increased wear on the rotatable drum and on the sealing arrangement. Further, if the sealing function is impaired, the pressure within the sealed-off gap or space may not be maintained which impairs/deteriorates the dewatering efficiency.
  • the object of the present invention is thus to provide an improved sealing arrangement for sealing between a rotatable drum and a stationary end casing member of an apparatus for dewatering pulp.
  • a further object is to provide an improved sealing arrangement for sealing between a rotatable drum and a stationary end casing member of an apparatus for dewatering pulp, where the above-mentioned problems in prior art are overcome.
  • the above-mentioned objects of the present invention are attained by providing a sealing arrangement for sealing between a first drum and an end casing member included in an apparatus for processing pulp, especially cellulose- containing pulp, the first drum being rotatable about an axis of rotation in relation to the end casing member and the sealing arrangement, and the first drum being provided with a permeable outer surface which axially extends between a first end and a second end of the first drum, and at least at the first end the first drum is provided with an end surface, the sealing arrangement comprising
  • first pressure means for forcing the sealing member in a direction towards the first drum to make the sealing member bear against a portion of the end sur- face
  • sealing element held by a holder, and second pressure means for forcing at least a first portion of the sealing element in a direction towards the first drum to make the first portion bear against a portion of the end surface
  • the holder being arranged to hold the second pres- sure means, and a terminal second portion of the sealing element is in proximity to the sealing member
  • the sealing arrangement comprises means for forcing the second portion of the sealing element in a direction towards the first drum to make the second portion bear against a portion of the end surface
  • the means for forcing the second portion of the sealing element in a direction towards the first drum are separate from the second pressure means.
  • the terminal second portion of the sealing element is efficiently and sufficiently pressed against the end surface, thus preventing pulp from getting jammed be- tween the sealing element and the end surface, and also preventing pulp from getting jammed between the sealing member and the end surface. Consequently, the wear on the end surface, on the rotatable drum and on the sealing element is efficiently decreased. Further, leakage of pulp suspension and/or filtrate is avoided, since the sealing function is not compromised by jammed pulp forcing the terminal second portion of the sealing element and/or the sealing member away from the end surface.
  • an improved sealing between a rotatable drum and a stationary end casing member of an apparatus for dewatering pulp is provided, and the processing of pulp in the dewatering apparatus is improved.
  • Each pressure means may be in the form of a pressure member, a pressure unit or pressure equipment.
  • the first pressure means may comprise basing means, e.g. a compression spring, a leaf spring, a torsion spring or bar, a volute spring etc, or may comprise other pressure means, e.g. pressure means actuated by a pressurized fluid, such as gas or liquid, etc, or other suitable pressure means.
  • the sealing member may be rigid, and may, for example, be made of a polymer material.
  • the sealing element may be made of a polymer material.
  • the second pressure means may comprise an inflatable tube of a flexible material, e.g. a polymer material.
  • the holder may be in the form of a circumferentially extending holder, and may e.g. comprise a circumferentially extending groove which may hold the second pressure means and the sealing element.
  • the sealing element may be elongated in the circumferential direction.
  • the end surface may be formed by a solid circular plate, or by an end ring, or any other structure of the first drum.
  • the end surface may be in the form of an annular surface surrounding the axis of rotation or an annular surface portion surrounding the axis of rotation.
  • the annular surface or surface portion may be formed by an end ring.
  • the sealing arrangement may comprise locking means for circumferen- tially, or tangentially, locking the second portion of the sealing element to prevent a movement of the second portion and the sealing element in the circumferential direction, to avoid a dislocation of the sealing element in the circumferential direction.
  • the sealing arrangement may comprise a guide unit for guiding the sealing member.
  • the locking means may be arranged to lock the second portion of the sealing element to the guide unit, to the holder or to the sealing member, for ex- ample, or combinations thereof may also be possible.
  • the sealing arrangement may be defined as an end seal arrangement.
  • the second portion of the sealing element may be located outside of the holder, or more specifically, the second portion of the sealing element may be located circumferentially outside of the holder.
  • the second portion of the sealing element may be located outside of the groove of the holder, or more specifically, the second portion of the sealing element may be located circumferentially outside of the groove of the holder.
  • the means for forcing the second portion of the sealing element in a direction towards the first drum are arranged to push the sec- ond portion of the sealing element in the direction towards the first drum.
  • the means for forcing the second portion of the sealing element in a direction towards the first drum comprise biasing means for biasing the second portion of the sealing element towards the end surface.
  • the biasing means comprise at least one compression spring. This is an efficient way to force the second portion of the sealing element towards the end surface, and the sealing between a rotatable drum and a stationary end casing member is still further improved.
  • the biasing means may comprise other springs, e.g. a leaf spring, a torsion spring or bar, a volute spring etc, or may comprise other pressure means, e.g. pressure means actuated by a pressurized fluid, such as gas or liquid, etc.
  • the means for forcing the second portion of the sealing element in a direction towards the first drum comprise the first pressure means.
  • the sealing between a rotatable drum and a stationary end casing member is further improved.
  • the means for forcing the second portion of the sealing element in a direction towards the first drum are separate from the first pressure means.
  • the means for forcing the second portion of the sealing element in a direction towards the first drum may comprise third pressure means acting on the second portion of the sealing element.
  • the third pressure means may e.g. be structured in a corresponding way as the first pressure means, and may be separate from the first pressure means.
  • the sealing member and the sec- ond portion of the sealing element comprise complementary guiding means engaging one another, and the guiding means are arranged to guide the second portion of the sealing element in a direction towards the first drum. This is an efficient way to force the second portion of the sealing element towards the end surface, and the sealing between a rotatable drum and a stationary end casing member is still further improved.
  • the guiding means comprise a recess and a projection engaging the recess. This is an efficient way to force the second portion of the sealing element towards the end surface, and the sealing between a ro- tatable drum and a stationary end casing member is further improved.
  • other guiding means are possible, e.g. two projections in engagement with one another.
  • the sealing member is provided with the recess, and the second portion of the sealing element is provided with the projection. This is an efficient way to force the second portion of the sealing element towards the end surface, and the sealing between a rotatable drum and a stationary end casing member is still further improved.
  • the sealing member is provided with the projection, and the second portion of the sealing element is provided with the recess.
  • the end surface forms an angle with the axis of rotation
  • the first pressure means are arranged to force the sealing member in an axial direction towards the first drum
  • the second pressure means are arranged to force the first portion of the sealing element in an axial direction towards the first drum
  • the means for forcing the second portion of the sealing element are arranged to force the second portion of the sealing element in an axial direction towards the first drum.
  • each of the sealing member and the sealing element is arranged to bear against a portion of an end surface which is substantially perpendicular to the axis of rotation of the first drum.
  • the end surface may be substantially parallel to the axis of rotation
  • the first pressure means may be arranged to force the sealing member in a radial direction towards the first drum
  • the second pressure means may be arranged to force the first portion of the sealing element in a radial direction towards the first drum
  • the means for forcing the second portion of the sealing element may be arranged to force the second portion of the sealing element in a radial direction towards the first drum.
  • each of the sealing member and the sealing element is arranged to bear against a portion of an end surface which is in the form of an annular surface surrounding the axis of rotation or in the form of an annular surface portion surrounding the axis of rotation.
  • an apparatus for processing pulp comprising at least one first drum rotatable about an axis of rotation and provided with an outer surface permeable to liquid, the outer surface axially extending between a first end and a second end of the first drum, the apparatus is adapted to receive the pulp on the outer surface of the first drum and to process the pulp situated on the outer surface while rotating the first drum, and the apparatus is adapted to process the pulp by at least dewa- tering the pulp, the first drum being rotatably mounted to two end casing members, at least at the first end the first drum being provided with an end surface, and at least one of the end casing members holds a sealing arrangement for sealing between the first drum and the respective end casing member, the first drum being rotatable in relation to the sealing arrangement, wherein the sealing arrangement comprises the features mentioned in any of the claims 1 to 1 1 , or the features of any of the above-mentioned embodiments of the sealing arrangement.
  • a sealing arrangement according to the present invention may be provided for each end of the first drum.
  • the first drum is provided with an end surface which is in the form of an annular surface surrounding the axis of rotation or in the form of an annular surface portion surrounding the axis of rotation.
  • the apparatus comprises a second drum rotatable about an axis of rotation and provided with an outer surface permeable to liquid, the first and second drums defining a press nip between them, in which press nip the pulp is pressed, and the apparatus is arranged to feed the pulp through the press nip in the direction of rotation of the press rolls.
  • the innovative sealing arrangement is particularly advantageous for an apparatus having two counter-rotating press rolls forming a press nip.
  • the sealing element may circumferentially extend, in the direction of rotation of the first drum, from the sealing member to the press nip, or past the press nip to a region after the press nip.
  • a sealing arrange- ment according to the present invention may be provided for each end of the first drum and the second drum, respectively.
  • four sealing arrangements may be provided, where two sealing arrangements may be held by the first end casing member and two sealing arrangements may be held by the second end casing member.
  • At least one of the end casing members holds a second sealing arrangement for sealing between the second drum and the respective end casing member, the second drum being rotatable in relation to the second sealing arrangement, and the second sealing arrangement comprises the features mentioned in any of the claims 1 to 1 1 , or the features of any of the above-mentioned embodiments of the sealing arrangement.
  • Fig is a schematic side view of an apparatus provided with an embodiment of the sealing arrangement according to the present invention.
  • Fig 2 is a schematic top view of the of the vat segments of Fig. 1 ;
  • Fig 3 is a schematic perspective view of the first side casing member of the apparatus of Fig. 1 provided with sealing means according to prior art;
  • Fig 4 is a schematic partial view of the first end casing member of
  • Fig. 2 provided with an embodiment of the sealing arrangement according to the present invention
  • Fig 5 is a schematic view of the first end of the first drum of Fig. 1 ;
  • Fig. 6 is a schematic partial top view of the sealing arrangement of Fig. 4 bearing against the first end of the first drum;
  • Figs. 7-9 are schematic partial perspective views of the sealing arrangement of Fig. 4.
  • Figs. 10-1 1 are schematic partial perspective views of a sealing arrangement according to prior art.
  • Fig. 1 shows an embodiment of the apparatus for dewatering cellulose- containing pulp provided with an embodiment of the sealing arrangement accord- ing to the present invention.
  • the apparatus may also be arranged to wash the pulp.
  • the apparatus may have a substantially symmetric configuration with regard to a symmetry plane 101 , and in Fig. 1 , the left side of the apparatus, i.e. to the left of the symmetry plane 101 , illustrates the apparatus in an opened position, whereas the right side of the apparatus, i.e. to the right of the symmetry plane 101 , illustrates the apparatus in a closed and operating position.
  • the apparatus may comprise a first rotatable drum 102 or press roll and a second rotatable drum 104 or press roll, each drum 102, 104 having a permeable outer surface 106, 108. Each permeable outer surface 106, 108 extends axially between a first end 503 and a second end of the respective drum 102, 104.
  • the first drum 102 is rotatable about a first axis of rotation 107
  • the second drum 104 is rotatable about a second axis of rotation 109.
  • the drums 102, 104 may comprise a plurality of filtrate channels 1 10 radially inwards of the outer surface 106, 108 to lead evacuated filtrate away.
  • the two drums 102, 104 define a press nip 1 12 between them, in which press nip the pulp is pressed, and are arranged to rotate in opposite di- rections, as indicated by arrows Ri and R 2 .
  • the apparatus may be arranged to feed the pulp through the press nip 1 12 in a substantially vertical direction from below upwards, however, the pulp can be fed through the press nip 1 12 in other directions.
  • the apparatus may comprise a casing which includes a vat 1 14, 1 16, 1 18, in which the drums 102, 104 are installed, the vat 1 14, 1 16, 1 18 partly enclosing the outer surface 106, 108 of each drum 102, 104, whereby a space or gap 124, 125 for each drum 102, 104 is defined, limited by the vat 1 14, 1 16, 1 18 and the outer surface 106, 108 of the respective drum 102, 104.
  • the vat 1 14, 1 16, 1 18 may be built up of a first side vat segment 1 14 which partly encloses the outer surface 106 of the first drum 102, a second side vat segment 1 16 which partly encloses the outer surface 108 of the second drum 104, and a central vat segment 1 18 partly enclosing the outer surface 106, 108 of the drums 102, 104 between the press nip 1 12 and the side vat segments 1 14, 1 16.
  • the central vat segment 1 18 may be movable in a substantially vertical direction for providing additional accessibility to the region in proximity to the press nip 1 12. In Fig. 1 , on the left side of the apparatus, the central vat segment 1 18 is shown in an inoperative opened position, whereas on the right side of the apparatus, the central vat segment 1 18 is shown in an operative closed position.
  • a gap 124, 125 may be formed between the vat 1 14,
  • FIG. 1 only the right side of the apparatus illustrated the apparatus in a closed and operating position, and thus, only the gap 124 with regard to the second drum 104 and the vat 1 16, 1 18 is shown, whereas the gap 125 with regard to the first drum 102 and the vat 1 14, 1 18 is not present in Fig. 1 .
  • a corresponding gap 125 with regard to the first drum 102 is illustrated by a broken line in Fig. 1 .
  • the gap 125 is provided between the first drum 102 and the vat 1 14, 1 18.
  • Said casing may comprise a first side casing member 1 15 which extends between the ends of the first drum 102 and to which the first side vat segment 1 14 is mounted, and a second side casing member 1 17 which extends between the ends of the second drum 104 and to which the second side vat segment 1 16 is mounted.
  • the side casing members 1 15, 1 17, together with their side vat segments 1 14, 1 16, may be pivotable about a pivot axis 121 , 123, and movable be- tween a closed position and an opened position for providing access to the drums 102, 104.
  • the first side casing member 1 15 is in the opened position, whereby access to the drum 102 is provided, whereas on the right side of the apparatus, the second side casing member 1 17 is in the closed position.
  • the side casing members could be movable, whereas the other could be stationary, or both side casing members could be stationary.
  • the movable side casing member could also be movable in other ways than by pivoting about the respective pivot axis 121 , 123.
  • the casing may include a central casing member 140, in the form of a stationary base unit 140 positioned substantially below the first and second drums 102, 104, a stationary first end casing member 210 in the form of a first gable, and a stationary second end casing member 212 in the form of a second gable (the end casing members 210, 212 being shown in Fig. 2).
  • the drums 102, 104 may be pivotally mounted to the end casing members 210, 212, and thus be rotatable in relation to the end casing members 210, 212.
  • the central casing member 140 may be mounted to the end casing members 210, 212.
  • Each side casing member 1 15, 1 17 may be pivotally attached to the central casing member 140, and each side casing member 1 15, 1 17 may also be connected to the central casing member 140 via a respective hydraulic cylinder 178, 179 for controlling the movement of the respective side casing member 1 15, 1 17.
  • the central vat segment 1 18 may be mounted to the central casing member 140.
  • Sealing means 404 may be provided between each movable side casing member 1 15, 1 17 and the central casing member 140, and between each movable side casing member 1 15, 1 17 and the end casing members 210, 212. Further, axial sealing units 180, 182 may be mounted to each side casing member 1 15, 1 17, each axial sealing unit 180, 182 extending along to the longitudinal extension of the respective drum 102, 104 and is adapted to abut the outer surface 106, 108 of the drum 102, 104 when the side casing member 1 15, 1 17 is in its closed position. The sealing means and the axial sealing units 180, 182 are adapted to seal off the gap 124, 125 from the external surroundings, i.e.
  • Each axial sealing unit 180, 182 may be in the form of a scraper.
  • the gap 124, 125 and the surfaces defining the gap 124, 125 are sealed off from the atmos- phere.
  • the apparatus may comprise a first pulp distribution device 126 for distributing pulp on the first drum 102 and a second pulp distribution device 128 for distributing pulp on the second drum 104.
  • Pulp to the distribution devices 126, 128 may be supplied in various ways known to the skilled person.
  • the pulp distribution devices 126, 128 may be arranged to distribute pulp to the gap 124, 125 along the whole axial length of each drum 102, 104.
  • the pulp distributed on the outer surface 106, 108 of the drum 102, 104 may form a mat on the drums 102, 104.
  • the pulp is fed in the gap 124, 125 in the direction of rotation Ri , R 2 of the drums 102, 104 while being dewatered , or dewatered and washed.
  • Fig. 2 shows the central vat segment 1 18 in the apparatus as viewed from above with the drums excluded.
  • the apparatus may rest on the ground via four legs 186, 187, 188, 189 (only two legs are shown in Fig. 1 ).
  • the end casing members 210, 212 of the casing are schematically shown.
  • the apparatus may also includes a pulp transport screw 152, which for example can be in the form of a pulp disintegrating screw or a shredder screw, towards which the pulp which has been pressed in the press nip 1 12 is conveyed.
  • the pulp transport screw 152 may extend in an axial direction and may be arranged to disintegrate the pulp and transport the pulp axially away from the press for further processing.
  • Each drum 102, 104 may be provided with a respective doctor bar 154, 156, and each doctor bar 154, 156 may be provided at the bottom thereof with a respective doctor blade 158, 160 for scraping the outer surface 106, 108 of the respective drum 102, 104.
  • Fig. 3 schematically shows the first side casing member 1 15 of Fig. 1 provided with the sealing means 404 mentioned above.
  • the surfaces 406, 408, 410, 412, 414 of the first side casing member 1 15 to be sealed against opposite surfaces are peripheral surfaces of the first side casing member 1 15, and the sealing means 404 may extend along the entire extension of the peripheral surfaces 406, 408, 410, 412, 414.
  • the sealing means 404 may be adapted to seal between surfaces 406, 408, 410, 412, 414 provided on the first side casing member 1 15 and surfaces opposite said surfaces 406, 408, 410, 412, 414 of the first side casing member 1 15.
  • the surfaces 406 and 414 are adapted to be sealed against oppo- site surfaces provided on the end casing members 210, 212 of the apparatus, and the surfaces 408, 410 and 412 are adapted to be sealed against opposite surfaces provided on the central casing member 140 of the apparatus.
  • the second side casing member may be provided with corresponding sealing means 404.
  • a pulp dewatering apparatus provided with the sealing arrangement accord- ing to the present invention may have a casing without movable side casing members.
  • FIG. 4 schematically shows a part of the inside of the first end casing member 210 as viewed from the first drum 102, where the first end casing member 210 is provided with an embodiment of the sealing arrangement 500 according to the present invention.
  • the first drum 102 may be mounted to the first end casing member 210 by means of bearings 502 and the first drum 102 is rotatable in relation to the sealing arrange- ment 500.
  • a first end 503 of the first drum 102 is schematically shown, which may be provided with an end member 505 arranged to be journalled in the bearings 502.
  • the first drum 102 may be provided with an end ring 504 which defines an end surface 506.
  • the end surface 506 may be in the form of an annular surface 506 surrounding the first axis of rotation 107, or an an- nular surface portion surrounding the first axis of rotation 107.
  • the end surface 506 may extend along the entire circumference of the first drum 102.
  • the first drum 102 may also be provided with the end surface 506 without the end ring 504.
  • the end surface 506 may be substantially perpendicular to the axis of rotation 107 of the first drum 102.
  • the sealing arrangement 500 is arranged to seal between the end surface 506 and the first end casing member 210.
  • the sealing arrangement 500 comprises a circumferentially extending sealing element 508 and a sealing member 510.
  • the sealing member 510 is provided in the region where pulp is deposited onto the outer surface 106 of the first drum 102 by the first pulp distribution device 126.
  • the sealing element 508 may extend along the circumfer- ential extension of the end surface 506 from the sealing member 510, along the circumferential extension of the gap 125 for the first drum 102 and to the press nip 1 12, or past the press nip to a region after the press nip 1 12.
  • the sealing element 508 may be elongated in the circumferential direction C.
  • the sealing arrangement 500 may comprise a circumferentially extending holder 512 arranged to hold the sealing element 508, and the holder 512 may comprise a circumferentially extending groove 514 which is at least partially engaged by the sealing element 508.
  • the holder 512 may comprise at least two circumferentially extending walls 515, 517 defining the groove 514 (see Fig. 4). Each circumferentially extending wall 515, 517 could be divided into a plurality of units circumferentially spaced apart.
  • First pressure means 516 e.g. biasing means, are provided for forcing, e.g. by pushing or biasing, the sealing member 510 in an axial direction A towards the first drum 102 to make the sealing member 510 bear against a portion of the end surface 506.
  • the first pressure means 516 may comprise a compression spring 518.
  • the sealing member 510 may be in the form of a block and may be made of a rigid material, e.g. a polymer material.
  • the sealing member 510 may be in the shape of a parallelepiped, e.g. a substantially rectangular parallelepiped or cuboid, or even a cube.
  • the sealing element 508 may also be made of a polymer material, or any other suitable material.
  • the sealing arrangement 500 may comprise a guide unit 520 arranged to hold and guide the sealing member 510.
  • the guide unit 520 is arranged to prevent a dislocation of the sealing member 510 in the direction of rotation Ri of the first drum 102.
  • the holder 512 holds second pressure means 522 for forcing, e.g. by pushing, at least a first portion 524 of the sealing element 508 in an axial direction A towards the first drum 102 to make the first portion 524 bear against a portion of the end surface 506.
  • the sealing element 508 has been removed for illustrative purposes to show the second pressure means 522.
  • the first portion 524 may form the major portion of the sealing element 508.
  • the second pressure means 522 may comprise a tube 526 adapted to be pressurized and inflatable by a fluid, e.g. gas, and may extend along the longitudinal extension of the sealing element 508 and may be positioned between the sealing element 508 and a bottom surface of the groove 514.
  • the sealing member 510 is arranged to withstand greater forces compared to the sealing element 508. These greater forces may be caused by pulp, which after the press nip 1 12 and after the scraping of the doctor blade 158, still remains on the drum 102 and in the region of the end ring 504 of the drum 102, and thus re-enters the gap 125. These greater forces may also be caused by pulp moving in an axial direction A toward the end ring 504 after being deposited on the outer surface 106 of the first drum 102. Further, one end of the axial sealing unit 180 may also be arranged to partially bear and seal against the sealing member 510, which also apply an axial force on the sealing member 510.
  • the sealing member 510 is located in a region where the axial sealing unit 180, the sealing means 404 of the first side casing member 1 15 and the circumferential sealing element 508 meet, which makes the region complex with regard to sealing.
  • the sealing means 404 of the first side casing member 1 15 may bear against an outward-curving surface 525 of the holder 512 and against a first side wall 527 of the guide unit 520.
  • the axial sealing unit 180 may axially bear against a second wall 529 of the guide unit 520 and axially against the sealing member 510.
  • a terminal second portion 528 of the sealing element 508 is in proximity to the sealing member 510 for sealing against the sealing member 510.
  • the second portion 528 of the sealing element 508 may be located circumferentially outside of the holder 512.
  • the second portion 528 of the sealing element 508 may be located circumferentially outside of the groove 514 of the holder 512.
  • the sealing arrangement 500 may comprise locking means 530 for circumferentially, or tangen- tially, locking the second portion 528 of the sealing element 508 to prevent a movement or dislocation of the sealing element 508 and its second portion 528 in the circumferential direction C.
  • the locking means 530 may be arranged to circumferentially lock the second portion 528 of the sealing element 508 to the guide unit 520.
  • the locking means 530 may comprise complementary means engaging one another, e.g.
  • the guide unit 520 may be provided with the projection 534, and the second portion 528 of the sealing element 508 may be provided with the recess 532. How- ever, other locking means for preventing the dislocation of the sealing element 508 and its second portion 528 in the circumferential direction C are possible.
  • the sealing member 510 and the second portion 528 of the sealing element 508 comprise complementary guiding means 536 engaging one another.
  • the guiding means 536 may comprise a recess 538 and a projection 540 engag- ing the recess 538.
  • the recess 538 may have at least one wall 542 which forms an angle with the axis of rotation 107 of the first drum 102.
  • the projection 540 may have at least one wall 544 which forms an angle with the axis of rotation 107 of the first drum 102.
  • the sealing member 510 may be provided with the recess 538, and the second portion 528 of the sealing element 508 may be provided with the pro- jection 540, or vice versa. Other designs of the complementary guiding means may also be possible.
  • the sealing arrangement 500 comprises means 545 for forcing the second portion 528 of the sealing element 508 in a direction towards the first drum 102 to make the second portion 528 bear against a portion of the end surface 506 (see Fig. 8).
  • the means 545 for forcing the second portion 528 of the sealing element 508 in a direction towards the first drum 102 may comprise the first pressure means 516.
  • the first pressure means 516 are arranged to force, by pushing, e.g. biasing, the second portion 528 of the sealing element 508 in an axial direction A towards the first drum 102 to make the second portion 528 bear against a portion of the end surface 506.
  • the guiding means 536 are arranged to guide the second portion 528 of the sealing element 508 in the axial direction A towards the first drum 102.
  • the means 545 for forcing the second portion 528 of the sealing element 508 in a direction towards the first drum 102 to make the second portion bear against a portion of the end surface 506 may be located outside the groove 514 of the holder 512, and may be separate from the second pressure means 522.
  • each of the seal- ing member 510 and the sealing element 508 is consequently arranged to bear against a portion of the annular surface 506 surrounding the axis of rotation 107 or a portion of the annular surface portion surrounding the axis of rotation.
  • Figs. 4 and 6 only half of the end casing member 210 is illustrated. It is to be understood that the other half of the end casing member 210, which is lo- cated on the other side of the symmetry plane 101 , may be provided with a corresponding sealing arrangement 500 for the first end of the second drum 104. It is to be understood that the apparatus shown in Fig. 1 may be provided with one sealing arrangement 500 for each end of the respective drum 102, 104. Thus, the apparatus may be provided with four sealing arrangements 500, each end casing member 210, 212 holding two sealing arrangements 500.
  • a prior art sealing arrangement 700 for sealing between an end of a rotatable drum, or roll, and a stationary end casing member is now illustrated with reference to Figs. 10-1 1 .
  • the prior art sealing ar- rangement 700 shown comprises a guide unit 720, first pressure means 716, a holder 712, second pressure means 722, locking means 730 and a first portion 724 of a sealing element 708 which may correspond to the corresponding features shown in Figs. 4-9.
  • the terminal second portion 728 of the sealing element 708, which is in proximity to the sealing member 710, is not supported by any means for forcing the second portion 728 of the sealing element 708 to make the second portion 728 bear against a portion of the end surface 506.
  • the pressurized tube 726 of the second pressure means 722 which is held by the groove 714 the holder 712 has a sealed end adjacent to the second portion 728 of the sealing element 708, and the sealed end cannot be in- flated. Consequently, the pressurized tube 726 cannot apply a sufficient axial force on the second portion 728 of the sealing element 708 in the direction toward the first drum, and the second portion 728 of the sealing element 708 does not bear, or does not sufficiently bear, against the end surface.
  • pulp lo- cated in the region of the sealing member 710 and the sealing element 708 may easily force the second portion 728 of the sealing element 708 away from the end surface 506 and may be wedged or jammed between the sealing element 708 and the end surface 506 when the drum rotates.
  • the jammed pulp may result in leakage of pulp suspension and/or filtrate, as media may pass between the sealing element 708 and the end surface 506.
  • the jammed pulp may also dislocate the sealing member 710, which also may result in leakage of pulp suspension and/or filtrate.
  • the jammed pulp may also result in increased wear on the rotatable drum, e.g. the end ring of the drum, and on the sealing member 710 and sealing element 708.
  • the second portion 528 of the sealing element 508 is sufficiently forced in an axial di- rection A toward the end surface 506 to make the second portion 528 of the sealing element 508 sufficiently bear against the end surface 506. Consequently, no pulp, or only a reduced amount of pulp, is allowed to enter between the end surface and the second portion 528 of the sealing element 508 and no pulp is jammed therebetween, or the amount of jammed pulp is radically reduced.
  • leakage of pulp suspension and/or filtrate and wear on the rotatable drum 102 and on the sealing element 508 and sealing member 510 are efficiently avoided by means of the sealing arrangement 500 according to the present invention.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

L'invention concerne un dispositif d'étanchéité (500) pour assurer un scellement étanche entre un premier tambour (102) et un élément de boîtier d'extrémité (210) compris dans un appareil de traitement de pâte, le premier tambour étant apte à tourner autour d'un axe de rotation (107) en relation avec l'élément de boîtier d'extrémité et le dispositif d'étanchéité, et le premier tambour comportant une surface externe perméable (106) qui s'étend axialement entre une première extrémité (503) et une seconde extrémité du premier tambour, et au moins à la première extrémité, le premier tambour comporte une surface d'extrémité (506), le dispositif d'étanchéité comprenant un élément d'étanchéité (510) ; des premiers moyens de pression (516) pour forcer l'élément d'étanchéité dans une direction vers le premier tambour à porter contre une partie de la surface d'extrémité ; un élément d'étanchéité (508) s'étendant de façon préiphérique maintenu par un dispositif de maintien (512) ; et des seconds moyens de pression (522) pour forcer au moins une première partie (524) de l'élément d'étanchéité dans une direction vers le premier tambour à amener la première partie à porter contre une partie de la surface d'extrémité, le dispositif de maintien étant disposé pour maintenir les seconds moyens de pression, et une seconde partie terminale (528) de l'élément d'étanchéité est à proximité de l'élément d'étanchéité, l'élément d'étanchéité comprenant des moyens (545) pour forcer la seconde partie de l'élément d'étanchéité dans une direction vers le premier tambour à amener la seconde partie à porter contre une partie de la surface d'extrémité, et les moyens pour forcer la seconde partie (528) de l'élément d'étanchéité (508) dans une direction vers le premier tambour sont séparés des seconds moyens de pression (522). L'invention concerne également un appareil de traitement de pâte ayant un tel dispositif d'étanchéité (500).
EP12765460.6A 2011-04-01 2012-03-21 Dispositif d'étanchéité pour un scellement étanche entre un premier tambour et un élément de boîtier d'extrémité Withdrawn EP2694726A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1150290A SE535742C2 (sv) 2011-04-01 2011-04-01 Tätningsanordning för tätning mellan en första trumma och ett ändhöljeselement inkluderade i en apparat för bearbetning av massa
PCT/SE2012/050311 WO2012134373A1 (fr) 2011-04-01 2012-03-21 Dispositif d'étanchéité pour un scellement étanche entre un premier tambour et un élément de boîtier d'extrémité

Publications (2)

Publication Number Publication Date
EP2694726A1 true EP2694726A1 (fr) 2014-02-12
EP2694726A4 EP2694726A4 (fr) 2014-08-27

Family

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Application Number Title Priority Date Filing Date
EP12765460.6A Withdrawn EP2694726A4 (fr) 2011-04-01 2012-03-21 Dispositif d'étanchéité pour un scellement étanche entre un premier tambour et un élément de boîtier d'extrémité

Country Status (5)

Country Link
EP (1) EP2694726A4 (fr)
CN (1) CN103547732B (fr)
CA (1) CA2831861A1 (fr)
SE (1) SE535742C2 (fr)
WO (1) WO2012134373A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE540211C2 (en) * 2016-11-11 2018-05-02 Valmet Oy A pressure device for a sealing arrangement, a sealing arrangement and an apparatus for processing pulp

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3007518A (en) * 1958-06-06 1961-11-07 Forming Machine Company Of Ame Means for preventing leakage of fluid
WO2003018907A1 (fr) * 2001-08-23 2003-03-06 Metso Paper, Inc. Joints pour rouleaux presseurs

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI20001603A (fi) * 2000-07-04 2002-01-05 Andritz Ahlstrom Oy Tiivistejõrjestely
SE517932C2 (sv) * 2001-09-19 2002-08-06 Kvaerner Pulping Tech Tätningsordning för trumfilter eller filterpressar samt manschett och hållarelement till en sådan
SE528728C2 (sv) * 2005-06-03 2007-02-06 Metso Paper Inc Anordning för behandling av cellulosamassa
SE531687C2 (sv) * 2007-11-09 2009-07-07 Metso Paper Inc Metod och enhet för tätningsjustering i en tvättanordning samt tvättanordning innefattande enhet för tätningsjustering
SE531845E (sv) * 2007-12-13 2012-06-19 Metso Paper Inc Apparat för tvättning och avvattning av massa

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3007518A (en) * 1958-06-06 1961-11-07 Forming Machine Company Of Ame Means for preventing leakage of fluid
WO2003018907A1 (fr) * 2001-08-23 2003-03-06 Metso Paper, Inc. Joints pour rouleaux presseurs

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2012134373A1 *

Also Published As

Publication number Publication date
CN103547732B (zh) 2016-06-08
SE535742C2 (sv) 2012-12-04
WO2012134373A1 (fr) 2012-10-04
CN103547732A (zh) 2014-01-29
CA2831861A1 (fr) 2012-10-04
SE1150290A1 (sv) 2012-10-02
EP2694726A4 (fr) 2014-08-27

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