CA2831861A1 - A sealing arrangement for sealing between a first drum and an end casing member - Google Patents
A sealing arrangement for sealing between a first drum and an end casing member Download PDFInfo
- Publication number
- CA2831861A1 CA2831861A1 CA2831861A CA2831861A CA2831861A1 CA 2831861 A1 CA2831861 A1 CA 2831861A1 CA 2831861 A CA2831861 A CA 2831861A CA 2831861 A CA2831861 A CA 2831861A CA 2831861 A1 CA2831861 A1 CA 2831861A1
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- CA
- Canada
- Prior art keywords
- sealing
- drum
- 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.)
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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
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- 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
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- 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
Abstract
A sealing arrangement (500) for sealing between a first drum (102) and an end casing member (210) included in an apparatus for processing pulp, the first drum being rotatable about an axis of rotation (107) in relation to the end casing member and the sealing arrangement, and the first drum being provided with a permeable outer surface (106) which axially extends between a first end (503) and a second end of the first drum, and at least at the first end the first drum is provided with an end surface (506), the sealing arrangement comprising a sealing member (510); first pressure means (516) for forcing the sealing member in a direction towards the first drum to bear against a portion of the end surface; a circumferentially extending sealing element (508) held by a holder (512); and second pressure means (522) for forcing at least a first portion (524) 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 pressure means, and a terminal second portion (528) of the sealing element is in proximity to the sealing member, wherein the sealing arrangement comprises means (545) 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, and wherein the means for forcing the second portion (528) of the sealing element (508) in a direction towards the first drum are separate from the second pressure means (522). An apparatus for processing pulp having such a sealing arrangement (500).
Description
A SEALING ARRANGEMENT FOR SEALING BETWEEN A FIRST DRUM AND
AN END CASING MEMBER
Technical Field 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 proc-essing 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 ar-rangement. 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. Further, the present invention relates to an apparatus for proc-essing pulp comprising a sealing arrangement of the above-mentioned sort.
Background of the Invention 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 liq-uors after the bleaching steps. There is a plurality of different types of washing equipment operating according to different principles.
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 liq-uid is pressed out of the pulp. The roll press may also include one or more wash-ing zones prior to the press nip. One example of such a roll press is disclosed in US 3,980,518, where the axes of rotation of the press rolls are lying in substan-tially the same horizontal plane. The pulp is fed in the direction of rotation of the press rolls through the press nip and the pulp passes the press nip between the press rolls from below upwards. Another example of a roll press is disclosed in W02009/075642.
Another known washing equipment is the drum washer, where the cellu-lose-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. A further development of the original drum washer is the pressurized dis-placement washer, where the filtrate, under overpressure, is forced to pass through the permeable outer surface.
In general, around at least a portion of the circumference of the permeable outer surface of the drum or press roll, 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. By means of the sealed-off gap, the dewatering of the pulp is enhanced. Sealing arrange-ments including a plurality of components are generally required to seal off such a gap. W02010/036193 discloses sealing arrangements for sealing between a mov-able 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 ar-rangements for sealing between each end of a rotatable press roll and the end casing member may also be required. In the detailed description below, 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. 10-11. Further, a drum washer may also be equipped with a corre-sponding sealing arrangement for sealing between an end of the rotatable single filter drum and an end casing member.
AN END CASING MEMBER
Technical Field 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 proc-essing 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 ar-rangement. 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. Further, the present invention relates to an apparatus for proc-essing pulp comprising a sealing arrangement of the above-mentioned sort.
Background of the Invention 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 liq-uors after the bleaching steps. There is a plurality of different types of washing equipment operating according to different principles.
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 liq-uid is pressed out of the pulp. The roll press may also include one or more wash-ing zones prior to the press nip. One example of such a roll press is disclosed in US 3,980,518, where the axes of rotation of the press rolls are lying in substan-tially the same horizontal plane. The pulp is fed in the direction of rotation of the press rolls through the press nip and the pulp passes the press nip between the press rolls from below upwards. Another example of a roll press is disclosed in W02009/075642.
Another known washing equipment is the drum washer, where the cellu-lose-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. A further development of the original drum washer is the pressurized dis-placement washer, where the filtrate, under overpressure, is forced to pass through the permeable outer surface.
In general, around at least a portion of the circumference of the permeable outer surface of the drum or press roll, 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. By means of the sealed-off gap, the dewatering of the pulp is enhanced. Sealing arrange-ments including a plurality of components are generally required to seal off such a gap. W02010/036193 discloses sealing arrangements for sealing between a mov-able 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 ar-rangements for sealing between each end of a rotatable press roll and the end casing member may also be required. In the detailed description below, 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. 10-11. Further, a drum washer may also be equipped with a corre-sponding sealing arrangement for sealing between an end of the rotatable single filter drum and an end casing member.
The Object of the Invention 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 dis-closed in more detail in connection with Figs. 10-11. 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.
Summary of the Invention The above-mentioned objects of the present invention are attained by providing a sealing arrangement for sealing between a first drum and an end cas-ing 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 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 sur-face, 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 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, wherein the sealing arrangement comprises means for forc-ing 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, and wherein the means for forcing the second portion of the sealing element in a direction to-wards the first drum are separate from the second pressure means.
By means of the sealing arrangement according to the present invention, 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. Thus, by means of the present invention, an improved seal-ing between a rotatable drum and a stationary end casing member of an appara-tus 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 pres-sure 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 5 movement of the second portion and the sealing element in the circumferential direction, to avoid a dislocation of the sealing element in the circumferential direc-tion. 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 ele-ment may be located circumferentially outside of the groove of the holder.
According to an advantageous embodiment of the sealing arrangement according to the present invention, 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. By means of this embodiment, the sealing between a rotatable drum and a stationary end casing member is further improved.
According to a further advantageous embodiment of the sealing arrange-ment according to the present invention, 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 sur-face. This is an efficient manner to force the second portion of the sealing element towards the end surface, and the sealing between a rotatable drum and a station-ary end casing member is yet further improved.
According to another advantageous embodiment of the sealing arrange-ment according to the present invention, 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.
Alternatively, 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.
According to yet another advantageous embodiment of the sealing arrangement according to the present invention, the means for forcing the second portion of the sealing element in a direction towards the first drum comprise the first pressure means. This is an efficient manner to force the second portion of the sealing element towards the end surface, as the first pressure means already pre-sent to force the sealing member are used, and thus, no additional pressure means are required. Thus, the sealing between a rotatable drum and a stationary end casing member is further improved. Alternatively, 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 pres-sure means, and may be separate from the first pressure means.
According to still another advantageous embodiment of the sealing arrangement according to the present invention, the sealing member and the sec-ond portion of the sealing element comprise complementary guiding means en-gaging one another, and the guiding means are arranged to guide the second por-tion 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.
According to an advantageous embodiment of the sealing arrangement according to the present invention, 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. However, other guiding means are possible, e.g. two projections in engagement with one another.
According to a further advantageous embodiment of the sealing arrange-ment according to the present invention, the sealing member is provided with the recess, and the second portion of the sealing element is provided with the projec-tion. This is an efficient way to force the second portion of the sealing element to-wards the end surface, and the sealing between a rotatable drum and a stationary end casing member is still further improved. Alternatively, the sealing member is provided with the projection, and the second portion of the sealing element is pro-vided with the recess.
According to another advantageous embodiment of the sealing arrange-ment according to the present invention, 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 ar-ranged to force the first portion of the sealing element in an axial direction towards the first drum, and 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 direc-tion towards the first drum. By means of this embodiment, the sealing between a rotatable drum and a stationary end casing member is further improved.
According to yet another advantageous embodiment of the sealing arrangement according to the present invention, 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. By means of this embodiment, the sealing between a rotatable drum and a stationary end cas-ing member is yet further improved. Alternatively, the end surface may be sub-stantially 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, and 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.
According to still another advantageous embodiment of the sealing arrangement according to the present invention, 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.
Further, the above-mentioned objects of the present invention are attained by providing 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 be-tween 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 11, or the features of any of the above-mentioned embodiments of the sealing arrangement. By means of the apparatus according to the present invention, an improved sealing between the rotatable drum and the stationary end casing member of the apparatus is pro-vided, and the processing of pulp in the dewatering apparatus is improved.
Further positive effects resulting from the apparatus according to the present invention and its embodiments correspond to the effects mentioned in connection with the vari-ous embodiments of the sealing arrangement according to the present invention.
A
sealing arrangement according to the present invention may be provided for each end of the first drum.
According to an advantageous embodiment of the apparatus according to the present invention, at least at the first end 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.
According to a further advantageous embodiment of the apparatus accord-ing to the present invention, 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 ar-rangement is particularly advantageous for an apparatus having two counter-ro-tating 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. Thus, in a roll press with two drums, 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.
According to another advantageous embodiment of the apparatus accord-ing to the present invention, at least one of the end casing members holds a sec-ond 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 11, or the features of any of the above-men-tioned embodiments of the sealing arrangement.
The above-mentioned features and embodiments of the sealing arrange-ment and the apparatus, respectively, may be combined in various possible ways providing further advantageous embodiments.
Further advantageous embodiments of the sealing arrangement and the apparatus, respectively, according to the present invention and further advantages with the present invention emerge from the detailed description of embodiments.
Brief Description of the Drawings The present invention will now be described, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, in which:
Fig. 1 is a schematic side view of an apparatus provided with an em-bodiment 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 mem-ber of the apparatus of Fig. 1 provided with sealing means ac-cording 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 arrange-ment 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 arrange-ment of Fig. 4; and 5 Figs. 1 0-1 1 are schematic partial perspective views of a sealing arrange-ment according to prior art.
Detailed Description of Preferred Embodiments Fig. 1 shows an embodiment of the apparatus for dewatering cellulose-containing pulp provided with an embodiment of the sealing arrangement accord-10 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 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, and the second drum 104 is rotatable about a second axis of rotation 109. The drums 102, 104 may comprise a plurality of fil-trate channels 110 radially inwards of the outer surface 106, 108 to lead evacu-ated filtrate away. The two drums 102, 104 define a press nip 112 between them, in which press nip the pulp is pressed, and are arranged to rotate in opposite di-rections, as indicated by arrows R1 and R2. The apparatus may be arranged to feed the pulp through the press nip 112 in a substantially vertical direction from be-low upwards, however, the pulp can be fed through the press nip 112 in other di-rections.
The apparatus may comprise a casing which includes a vat 114, 116, 118, in which the drums 102, 104 are installed, the vat 114, 116, 118 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 114, 116, 118 and the outer surface 106, 108 of the respective drum 102, 104. The vat 114, 116, 118 may be built up of a first side vat segment 114 which partly encloses the outer surface 106 of the first drum 102, a second side vat segment 116 which partly en-closes the outer surface 108 of the second drum 104, and a central vat segment 118 partly enclosing the outer surface 106, 108 of the drums 102, 104 between the press nip 112 and the side vat segments 114, 116. The central vat segment 118 may be movable in a substantially vertical direction for providing additional acces-sibility to the region in proximity to the press nip 112. In Fig. 1, on the left side of the apparatus, the central vat segment 118 is shown in an inoperative opened po-sition, whereas on the right side of the apparatus, the central vat segment 118 is shown in an operative closed position.
As mentioned above, a gap 124, 125 may be formed between the vat 114, 116, 118 and the outer surface 106, 108 of the drums 102, 104. In Fig. 1, only the right side of the apparatus illustrated the apparatus in a closed and operating posi-tion, and thus, only the gap 124 with regard to the second drum 104 and the vat 116, 118 is shown, whereas the gap 125 with regard to the first drum 102 and the vat 114, 118 is not present in Fig. 1. However, a corresponding gap 125 with re-gard to the first drum 102 is illustrated by a broken line in Fig. 1. When the left side of the apparatus is in a corresponding closed and operating position, the gap is provided between the first drum 102 and the vat 114, 118.
Said casing may comprise a first side casing member 115 which extends between the ends of the first drum 102 and to which the first side vat segment is mounted, and a second side casing member 117 which extends between the ends of the second drum 104 and to which the second side vat segment 116 is mounted. The side casing members 115, 117, together with their side vat seg-ments 114, 116, 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. In Fig. 1, on the left side of the apparatus, the first side casing member 115 is in the opened position, whereby access to the drum 102 is pro-vided, whereas on the right side of the apparatus, the second side casing member 117 is in the closed position. Alternatively, only one of 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.
Further, 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 ga-ble, and a stationary second end casing member 212 in the form of a second ga-ble (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 mem-ber 140 may be mounted to the end casing members 210, 212. Each side casing member 115, 117 may be pivotally attached to the central casing member 140, and each side casing member 115, 117 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 115, 117. The central vat seg-ment 118 may be mounted to the central casing member 140.
Sealing means 404 (see Fig. 3) may be provided between each movable side casing member 115, 117 and the central casing member 140, and between each movable side casing member 115, 117 and the end casing members 210, 212. Further, axial sealing units 180, 182 may be mounted to each side casing member 115, 117, each axial sealing unit 180, 182 extending along to the longitu-dinal 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 115, 117 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. the at-mosphere, at the position where the pulp is distributed to the gap 124, 125.
Each axial sealing unit 180, 182 may be in the form of a scraper. Thus, by way of the above-mentioned sealing means and axial sealing units 180, 182, 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 distrib-uting pulp on the first drum 102 and a second pulp distribution device 128 for dis-tributing pulp on the second drum 104. Pulp to the distribution devices 126, 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 sur-face 106, 108 of the drum 102, 104 may form a mat on the drums 102, 104. From the pulp distribution devices 126, 128 to the press nip 112, the pulp is fed in the gap 124, 125 in the direction of rotation R1, R2 of the drums 102, 104 while being dewatered , or dewatered and washed.
Fig. 2 shows the central vat segment 118 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). In Fig. 2, the end cas-ing 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 112 is conveyed.
The pulp transport screw 152 may extend in an axial direction and may be ar-ranged 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 115 of Fig. 1 pro-vided with the sealing means 404 mentioned above. The surfaces 406, 408, 410, 412, 414 of the first side casing member 115 to be sealed against opposite sur-faces are peripheral surfaces of the first side casing member 115, 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 sur-faces 406, 408, 410, 412, 414 provided on the first side casing member 115 and surfaces opposite said surfaces 406, 408, 410, 412, 414 of the first side casing member 115. 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. How-ever, a pulp dewatering apparatus provided with the sealing arrangement accord-ing to the present invention may have a casing without movable side casing mem-bers.
With reference to Figs. 4 to 9, aspects of the sealing arrangement 500 ac-cording to the present invention are schematically illustrated. 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 em-bodiment 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. In Fig. 5, 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. At the first end 503, 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 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 arrange-ment 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 112, or past the press nip to a region after the press nip 112. Thus, the sealing element 508 may be elongated in the circumferential direction C. The sealing ar-rangement 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. However, other pressure means are possible as previously mentioned above.
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 5 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 ro-tation R1 of the first drum 102. With reference to Fig. 9, the holder 512 holds sec-ond pressure means 522 for forcing, e.g. by pushing, at least a first portion 524 of 10 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. In Fig.
9, the sealing element 508 has been removed for illustrative purposes to show the sec-ond 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 15 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 be-tween the sealing element 508 and a bottom surface of the groove 514.
The sealing member 510 is arranged to withstand greater forces com-pared to the sealing element 508. These greater forces may be caused by pulp, which after the press nip 112 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. Further, 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 115 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 115 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.
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.
Summary of the Invention The above-mentioned objects of the present invention are attained by providing a sealing arrangement for sealing between a first drum and an end cas-ing 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 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 sur-face, 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 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, wherein the sealing arrangement comprises means for forc-ing 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, and wherein the means for forcing the second portion of the sealing element in a direction to-wards the first drum are separate from the second pressure means.
By means of the sealing arrangement according to the present invention, 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. Thus, by means of the present invention, an improved seal-ing between a rotatable drum and a stationary end casing member of an appara-tus 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 pres-sure 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 5 movement of the second portion and the sealing element in the circumferential direction, to avoid a dislocation of the sealing element in the circumferential direc-tion. 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 ele-ment may be located circumferentially outside of the groove of the holder.
According to an advantageous embodiment of the sealing arrangement according to the present invention, 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. By means of this embodiment, the sealing between a rotatable drum and a stationary end casing member is further improved.
According to a further advantageous embodiment of the sealing arrange-ment according to the present invention, 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 sur-face. This is an efficient manner to force the second portion of the sealing element towards the end surface, and the sealing between a rotatable drum and a station-ary end casing member is yet further improved.
According to another advantageous embodiment of the sealing arrange-ment according to the present invention, 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.
Alternatively, 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.
According to yet another advantageous embodiment of the sealing arrangement according to the present invention, the means for forcing the second portion of the sealing element in a direction towards the first drum comprise the first pressure means. This is an efficient manner to force the second portion of the sealing element towards the end surface, as the first pressure means already pre-sent to force the sealing member are used, and thus, no additional pressure means are required. Thus, the sealing between a rotatable drum and a stationary end casing member is further improved. Alternatively, 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 pres-sure means, and may be separate from the first pressure means.
According to still another advantageous embodiment of the sealing arrangement according to the present invention, the sealing member and the sec-ond portion of the sealing element comprise complementary guiding means en-gaging one another, and the guiding means are arranged to guide the second por-tion 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.
According to an advantageous embodiment of the sealing arrangement according to the present invention, 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. However, other guiding means are possible, e.g. two projections in engagement with one another.
According to a further advantageous embodiment of the sealing arrange-ment according to the present invention, the sealing member is provided with the recess, and the second portion of the sealing element is provided with the projec-tion. This is an efficient way to force the second portion of the sealing element to-wards the end surface, and the sealing between a rotatable drum and a stationary end casing member is still further improved. Alternatively, the sealing member is provided with the projection, and the second portion of the sealing element is pro-vided with the recess.
According to another advantageous embodiment of the sealing arrange-ment according to the present invention, 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 ar-ranged to force the first portion of the sealing element in an axial direction towards the first drum, and 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 direc-tion towards the first drum. By means of this embodiment, the sealing between a rotatable drum and a stationary end casing member is further improved.
According to yet another advantageous embodiment of the sealing arrangement according to the present invention, 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. By means of this embodiment, the sealing between a rotatable drum and a stationary end cas-ing member is yet further improved. Alternatively, the end surface may be sub-stantially 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, and 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.
According to still another advantageous embodiment of the sealing arrangement according to the present invention, 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.
Further, the above-mentioned objects of the present invention are attained by providing 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 be-tween 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 11, or the features of any of the above-mentioned embodiments of the sealing arrangement. By means of the apparatus according to the present invention, an improved sealing between the rotatable drum and the stationary end casing member of the apparatus is pro-vided, and the processing of pulp in the dewatering apparatus is improved.
Further positive effects resulting from the apparatus according to the present invention and its embodiments correspond to the effects mentioned in connection with the vari-ous embodiments of the sealing arrangement according to the present invention.
A
sealing arrangement according to the present invention may be provided for each end of the first drum.
According to an advantageous embodiment of the apparatus according to the present invention, at least at the first end 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.
According to a further advantageous embodiment of the apparatus accord-ing to the present invention, 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 ar-rangement is particularly advantageous for an apparatus having two counter-ro-tating 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. Thus, in a roll press with two drums, 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.
According to another advantageous embodiment of the apparatus accord-ing to the present invention, at least one of the end casing members holds a sec-ond 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 11, or the features of any of the above-men-tioned embodiments of the sealing arrangement.
The above-mentioned features and embodiments of the sealing arrange-ment and the apparatus, respectively, may be combined in various possible ways providing further advantageous embodiments.
Further advantageous embodiments of the sealing arrangement and the apparatus, respectively, according to the present invention and further advantages with the present invention emerge from the detailed description of embodiments.
Brief Description of the Drawings The present invention will now be described, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, in which:
Fig. 1 is a schematic side view of an apparatus provided with an em-bodiment 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 mem-ber of the apparatus of Fig. 1 provided with sealing means ac-cording 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 arrange-ment 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 arrange-ment of Fig. 4; and 5 Figs. 1 0-1 1 are schematic partial perspective views of a sealing arrange-ment according to prior art.
Detailed Description of Preferred Embodiments Fig. 1 shows an embodiment of the apparatus for dewatering cellulose-containing pulp provided with an embodiment of the sealing arrangement accord-10 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 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, and the second drum 104 is rotatable about a second axis of rotation 109. The drums 102, 104 may comprise a plurality of fil-trate channels 110 radially inwards of the outer surface 106, 108 to lead evacu-ated filtrate away. The two drums 102, 104 define a press nip 112 between them, in which press nip the pulp is pressed, and are arranged to rotate in opposite di-rections, as indicated by arrows R1 and R2. The apparatus may be arranged to feed the pulp through the press nip 112 in a substantially vertical direction from be-low upwards, however, the pulp can be fed through the press nip 112 in other di-rections.
The apparatus may comprise a casing which includes a vat 114, 116, 118, in which the drums 102, 104 are installed, the vat 114, 116, 118 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 114, 116, 118 and the outer surface 106, 108 of the respective drum 102, 104. The vat 114, 116, 118 may be built up of a first side vat segment 114 which partly encloses the outer surface 106 of the first drum 102, a second side vat segment 116 which partly en-closes the outer surface 108 of the second drum 104, and a central vat segment 118 partly enclosing the outer surface 106, 108 of the drums 102, 104 between the press nip 112 and the side vat segments 114, 116. The central vat segment 118 may be movable in a substantially vertical direction for providing additional acces-sibility to the region in proximity to the press nip 112. In Fig. 1, on the left side of the apparatus, the central vat segment 118 is shown in an inoperative opened po-sition, whereas on the right side of the apparatus, the central vat segment 118 is shown in an operative closed position.
As mentioned above, a gap 124, 125 may be formed between the vat 114, 116, 118 and the outer surface 106, 108 of the drums 102, 104. In Fig. 1, only the right side of the apparatus illustrated the apparatus in a closed and operating posi-tion, and thus, only the gap 124 with regard to the second drum 104 and the vat 116, 118 is shown, whereas the gap 125 with regard to the first drum 102 and the vat 114, 118 is not present in Fig. 1. However, a corresponding gap 125 with re-gard to the first drum 102 is illustrated by a broken line in Fig. 1. When the left side of the apparatus is in a corresponding closed and operating position, the gap is provided between the first drum 102 and the vat 114, 118.
Said casing may comprise a first side casing member 115 which extends between the ends of the first drum 102 and to which the first side vat segment is mounted, and a second side casing member 117 which extends between the ends of the second drum 104 and to which the second side vat segment 116 is mounted. The side casing members 115, 117, together with their side vat seg-ments 114, 116, 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. In Fig. 1, on the left side of the apparatus, the first side casing member 115 is in the opened position, whereby access to the drum 102 is pro-vided, whereas on the right side of the apparatus, the second side casing member 117 is in the closed position. Alternatively, only one of 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.
Further, 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 ga-ble, and a stationary second end casing member 212 in the form of a second ga-ble (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 mem-ber 140 may be mounted to the end casing members 210, 212. Each side casing member 115, 117 may be pivotally attached to the central casing member 140, and each side casing member 115, 117 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 115, 117. The central vat seg-ment 118 may be mounted to the central casing member 140.
Sealing means 404 (see Fig. 3) may be provided between each movable side casing member 115, 117 and the central casing member 140, and between each movable side casing member 115, 117 and the end casing members 210, 212. Further, axial sealing units 180, 182 may be mounted to each side casing member 115, 117, each axial sealing unit 180, 182 extending along to the longitu-dinal 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 115, 117 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. the at-mosphere, at the position where the pulp is distributed to the gap 124, 125.
Each axial sealing unit 180, 182 may be in the form of a scraper. Thus, by way of the above-mentioned sealing means and axial sealing units 180, 182, 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 distrib-uting pulp on the first drum 102 and a second pulp distribution device 128 for dis-tributing pulp on the second drum 104. Pulp to the distribution devices 126, 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 sur-face 106, 108 of the drum 102, 104 may form a mat on the drums 102, 104. From the pulp distribution devices 126, 128 to the press nip 112, the pulp is fed in the gap 124, 125 in the direction of rotation R1, R2 of the drums 102, 104 while being dewatered , or dewatered and washed.
Fig. 2 shows the central vat segment 118 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). In Fig. 2, the end cas-ing 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 112 is conveyed.
The pulp transport screw 152 may extend in an axial direction and may be ar-ranged 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 115 of Fig. 1 pro-vided with the sealing means 404 mentioned above. The surfaces 406, 408, 410, 412, 414 of the first side casing member 115 to be sealed against opposite sur-faces are peripheral surfaces of the first side casing member 115, 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 sur-faces 406, 408, 410, 412, 414 provided on the first side casing member 115 and surfaces opposite said surfaces 406, 408, 410, 412, 414 of the first side casing member 115. 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. How-ever, a pulp dewatering apparatus provided with the sealing arrangement accord-ing to the present invention may have a casing without movable side casing mem-bers.
With reference to Figs. 4 to 9, aspects of the sealing arrangement 500 ac-cording to the present invention are schematically illustrated. 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 em-bodiment 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. In Fig. 5, 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. At the first end 503, 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 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 arrange-ment 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 112, or past the press nip to a region after the press nip 112. Thus, the sealing element 508 may be elongated in the circumferential direction C. The sealing ar-rangement 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. However, other pressure means are possible as previously mentioned above.
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 5 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 ro-tation R1 of the first drum 102. With reference to Fig. 9, the holder 512 holds sec-ond pressure means 522 for forcing, e.g. by pushing, at least a first portion 524 of 10 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. In Fig.
9, the sealing element 508 has been removed for illustrative purposes to show the sec-ond 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 15 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 be-tween the sealing element 508 and a bottom surface of the groove 514.
The sealing member 510 is arranged to withstand greater forces com-pared to the sealing element 508. These greater forces may be caused by pulp, which after the press nip 112 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. Further, 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 115 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 115 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 ar-rangement 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 en-gaging one another, e.g. a recess 532 and a projection 534 engaging the recess 532. 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 ele-ment 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 ax-ial 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 sec-ond 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.
When the end surface 506 is in the form of an annular surface 506 sur-rounding the first axis of rotation 107, as illustrated in Fig. 5, or in the form of an annular surface portion surrounding the first axis of rotation 107, 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.
In 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 cor-responding 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.
To further illustrate the drawbacks overcome by the sealing arrangement 500 according to the present invention, 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. 10-11. 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. However, in the prior art sealing arrangement 700, 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. As a result of this, 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 leak-age 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. Leakage of pulp suspension and/or filtrate and wear on the seals and on the drum impair the processing of pulp in the dewatering apparatus. 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.
By the sealing arrangement 500 according to the present invention, 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 seal-ing 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 sur-face 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. Thus, 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.
The invention shall not be considered limited to the embodiments illus-trated, but can be modified and altered in many ways by one skilled in the art, without departing from the scope of the appended claims.
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 ele-ment 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 ax-ial 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 sec-ond 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.
When the end surface 506 is in the form of an annular surface 506 sur-rounding the first axis of rotation 107, as illustrated in Fig. 5, or in the form of an annular surface portion surrounding the first axis of rotation 107, 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.
In 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 cor-responding 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.
To further illustrate the drawbacks overcome by the sealing arrangement 500 according to the present invention, 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. 10-11. 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. However, in the prior art sealing arrangement 700, 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. As a result of this, 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 leak-age 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. Leakage of pulp suspension and/or filtrate and wear on the seals and on the drum impair the processing of pulp in the dewatering apparatus. 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.
By the sealing arrangement 500 according to the present invention, 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 seal-ing 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 sur-face 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. Thus, 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.
The invention shall not be considered limited to the embodiments illus-trated, but can be modified and altered in many ways by one skilled in the art, without departing from the scope of the appended claims.
Claims (14)
1. A sealing arrangement (500) for sealing between a first drum (102) and an end casing member (210) included in an apparatus for processing pulp, the first drum being rotatable about an axis of rotation (107) in relation to the end casing member and the sealing arrangement, and the first drum being provided with a permeable outer surface (106) which axially extends between a first end (503) and a second end of the first drum, and at least at the first end the first drum is pro-vided with an end surface (506), the sealing arrangement comprising a sealing member (510), first pressure means (516) 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 (508) held by a holder (512), and second pressure means (522) for forcing at least a first portion (524) 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 pressure means, and a terminal second portion (528) of the sealing element is in proximity to the sealing member, characterized in that the sealing arrangement comprises means (545) 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, and in that the means (545) for forcing the second portion (528) of the sealing element (508) in a direction towards the first drum (102) are separate from the second pressure means (522).
2. A sealing arrangement according to claim 1, characterized in that the means (545) for forcing the second portion (528) of the sealing element (508) in a direction towards the first drum (102) are arranged to push the second portion of the sealing element in the direction towards the first drum.
3. A sealing arrangement according to claims 1 or 2, characterized in that the means (545) for forcing the second portion (528) of the sealing element (508) in a direction towards the first drum (102) comprise biasing means for biasing the second portion of the sealing element towards the end surface (506).
4. A sealing arrangement according to claim 3, characterized in that the biasing means comprise at least one compression spring (518).
5. A sealing arrangement according to any of the claims 1 to 4, character-ized in that the means (545) for forcing the second portion (528) of the sealing element (508) in a direction towards the first drum (102) comprise the first pres-sure means (516).
6. A sealing arrangement according to claim 5, characterized in that the sealing member (510) and the second portion (528) of the sealing element (508) comprise complementary guiding means (536) engaging one another, and in that the guiding means are arranged to guide the second portion of the sealing element in a direction towards the first drum (102).
7. A sealing arrangement according to claim 6, characterized in that the guiding means (536) comprise a recess (538) and a projection (540) engaging the recess.
8. A sealing arrangement according to claim 7, characterized in that the sealing member (510) is provided with the recess (538), and in that the second portion (528) of the sealing element (508) is provided with the projection (540).
9. A sealing arrangement according to any of the claims 1 to 8, character-ized in that the end surface (506) forms an angle with the axis of rotation (107), in that the first pressure means (516) are arranged to force the sealing member (510) in an axial direction (A) towards the first drum (102), in that the second pressure means (522) are arranged to force the first portion (524) of the sealing element (508) in an axial direction towards the first drum, and in that the means (545) for forcing the second portion (528) of the sealing element are arranged to force the second portion of the sealing element in an axial direction (A) towards the first drum.
10. A sealing arrangement according to claim 9, characterized in that each of the sealing member (510) and the sealing element (508) is arranged to bear against a portion of an end surface (506) which is substantially perpendicular to the axis of rotation (107) of the first drum (102).
11. A sealing arrangement according to any of the claims 1 to 10, characterized in that each of the sealing member (510) and the sealing ele-ment (508) is arranged to bear against a portion of an end surface (506) which is in the form of an annular surface (506) surrounding the axis of rotation (107) or in the form of an annular surface portion surrounding the axis of rotation.
12. An apparatus for processing pulp, comprising at least one first drum (102) rotatable about an axis of rotation (107) and provided with an outer surface (106) permeable to liquid, the outer surface axially extending between a first end (503) 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 dewatering the pulp, the first drum being rotatably mounted to two end casing members (210, 212), at least at the first end (503) the first drum being provided with an end surface (506), and at least one of the end casing members holds a sealing arrangement (500) for sealing between the first drum and the re-spective end casing member, the first drum being rotatable in relation to the seal-ing arrangement, characterized in that the sealing arrangement (500) com-prises the features mentioned in any of the claims 1 to 11.
13. An apparatus according to claim 12, characterized in that the appara-tus comprises a second drum (104) rotatable about an axis of rotation (109) and provided with an outer surface (108) permeable to liquid, the first and second drums (102, 104) defining a press nip (112) between them, in which press nip the pulp is pressed, and in that the apparatus is arranged to feed the pulp through the press nip in the direction of rotation (R1, R2) of the press rolls.
14. An apparatus according to claim 13, characterized in that at least one of the end casing members (210, 212) holds a second sealing arrangement (500) for sealing between the second drum (104) and the respective end casing mem-ber, the second drum being rotatable in relation to the second sealing arrange-ment, and in that the second sealing arrangement (500) comprises the features mentioned in any of the claims 1 to 11.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE1150290A SE535742C2 (en) | 2011-04-01 | 2011-04-01 | Sealing device for sealing between a first drum and an end casing element included in a pulp processing apparatus |
| SE1150290-3 | 2011-04-01 | ||
| PCT/SE2012/050311 WO2012134373A1 (en) | 2011-04-01 | 2012-03-21 | A sealing arrangement for sealing between a first drum and an end casing member |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2831861A1 true CA2831861A1 (en) | 2012-10-04 |
Family
ID=46931736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2831861A Abandoned CA2831861A1 (en) | 2011-04-01 | 2012-03-21 | A sealing arrangement for sealing between a first drum and an end casing member |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP2694726A4 (en) |
| CN (1) | CN103547732B (en) |
| CA (1) | CA2831861A1 (en) |
| SE (1) | SE535742C2 (en) |
| WO (1) | WO2012134373A1 (en) |
Families Citing this family (1)
| 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 |
Family Cites Families (7)
| 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 |
| FI20001603A (en) * | 2000-07-04 | 2002-01-05 | Andritz Ahlstrom Oy | Tiivistejõrjestely |
| SE0102811L (en) * | 2001-08-23 | 2003-04-24 | Metso Paper Inc | Seal on press rolls |
| SE517932C2 (en) * | 2001-09-19 | 2002-08-06 | Kvaerner Pulping Tech | Sealing arrangement for drum filters or filter presses as well as cuff and holding elements for one |
| SE528728C2 (en) * | 2005-06-03 | 2007-02-06 | Metso Paper Inc | Device for treating cellulose pulp |
| SE531687C2 (en) * | 2007-11-09 | 2009-07-07 | Metso Paper Inc | Method and unit for sealing adjustment in a washing device and washing device comprising sealing adjustment unit |
| SE531845E (en) * | 2007-12-13 | 2012-03-06 | Metso Paper Inc | Apparatus for washing and dewatering of pulp |
-
2011
- 2011-04-01 SE SE1150290A patent/SE535742C2/en not_active IP Right Cessation
-
2012
- 2012-03-21 WO PCT/SE2012/050311 patent/WO2012134373A1/en active Application Filing
- 2012-03-21 CN CN201280010207.6A patent/CN103547732B/en not_active Expired - Fee Related
- 2012-03-21 EP EP12765460.6A patent/EP2694726A4/en not_active Withdrawn
- 2012-03-21 CA CA2831861A patent/CA2831861A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| SE535742C2 (en) | 2012-12-04 |
| EP2694726A1 (en) | 2014-02-12 |
| SE1150290A1 (en) | 2012-10-02 |
| EP2694726A4 (en) | 2014-08-27 |
| CN103547732A (en) | 2014-01-29 |
| WO2012134373A1 (en) | 2012-10-04 |
| CN103547732B (en) | 2016-06-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request |
Effective date: 20161025 |
|
| FZDE | Dead |
Effective date: 20190321 |