摘要:
The invention relates to a former-press section (100, 110) of a paper machine and to a method of transferring a web from a former to a press section. Between the former section (100) and the press section (110) there is a pre-press zone (PP) which removes water from the web (W) and through which the web (W) is passed as a closed draw from the former section (100) to the press section (110). The upper wet wire (10) or the equivalent transfer wire (10A) of the former section (100) is passed through the pre-press zone (PP), the web (W) being passed on the lower face of said wire into and through the pre-press zone (PP). Inside the loop of the upper wet wire (10) or of the equivalent transfer wire (10A) and/or inside the loop of the lower wet wire (20) there are transfer devices (15, 15a, 16, 26) based on the use of a pressure difference. The transfer devices (15, 15a, 16, 26) are arranged to operate in connection with threading or an operational malfunction such that the web (W) is separated from the upper wet wire (10) or the equivalent transfer wire.
摘要:
An arrangement and method for improving runnability, and dryer section length, by using a vertical impingement dryer before a first dryer cylinder of a group of dryer cylinders. After a pressing section, the web is dried with a pre-impingement dryer, closely followed by a vertical impingement dryer, which is closely following by the first dryer cylinder. The pre-impingement dryer and vertical impingement dryer of the first dryer cylinder to have a drying temperature of approximately 80° C. with no undesirable sticking to the dryer cylinder. The pre-impingement dryer can be arranged to dry a first side of the web, and a vertical impingement dryer after the first dryer cylinder is arranged to dry a second side of the web. The impingement drying takes place directly against the web without an intervening fabric.
摘要:
The invention relates to a method for operating a calender, comprising a cylindrical heated roll and a flexible belt surrounding a stationary support beam which supports at least one actuator which may urge a concave load shoe against the heated roll by the flexible belt to form an extended and heated nip through which a fiber web passes to be calendered and a separating mechanism for having at least one of the rolls movable into and away from the nip characterized in that the flexible belt is a flexible tubular jacket which forms a part of an enclosed shoe roll such that the ends of the jacket have end walls mounted thereto, which end walls are rotatably mounted in relation to the support beam, and in that at least one of the end walls is driven by a drive arrangement which drive arrangement may be activated to drive the end walls and thereby also the jacket independently of its position in relation to the fiber web or the heated roll.
摘要:
In a press section in a paper or board machine, the transfer of a web (W) is accomplished as a closed draw through the press section. The press section has at least three separate press nips (N1, N2, N3). In the first nip dewatering takes place on two sides. The closed draw of the web (W) through the press section is accomplished as a substantially straight run. The press nips each have their own fabric loops (20, 21; 30; 40, 41). The nips (N2, N3) following after the first nip (N1) have one water-receiving fabric (30, 40), which is placed in the nip (N2, N3) on the opposite side of the web (W) with respect to the other nip in the running direction of the web in the machine.
摘要:
The invention relates to an apparatus for calendering a fiber web, wherein the fiber web passes through an extended and heated nip, said nip being formed on one side by a cylindrical heated roll and on the other side by a flexible tubular jacket which is pressed against the heated roll by means of a concave load shoe, said tubular jacket surrounding a stationary support beam which supports at least one actuator which may urge said load shoe and said flexible tubular jacket against said heated roll, and wherein the extension of the load shoe in the axial extension is less than the axial extension of the jacket and the heated roll such that when the load shoe is urged against the heated roll there will be formed tapered sections at each side end of the jacket within the nip wherein said tapered section are substantially covered by said fiber web such that a small strips of the fiber web at each edge is not calendered in said extended nip.
摘要:
An arrangement and method for improving runnability, and dryer section length, by using a vertical impingement dryer before a first dryer cylinder of a group of dryer cylinders. After a pressing section, the web is dried with a pre-impingement dryer, closely followed by a vertical impingement dryer, which is closely following by the first dryer cylinder. The pre-impingement dryer and vertical impingement dryer of the first dryer cylinder to have a drying temperature of approximately 80° C. with no undesirable sticking to the dryer cylinder. The pre-impingement dryer can be arranged to dry a first side of the web, and a vertical impingement dryer after the first dryer cylinder is arranged to dry a second side of the web. The impingement drying takes place directly against the web without an intervening fabric.
摘要:
A web (W) passes through a press section having two separate press nips (N1, N2). At least the first press nip (N1) has two water-receiving press felts (31, 41). After the first nip (N1), the web (W) is separated from one press felt (31/41) and transferred on support of the opposite press felt (41/31) through the second press nip (N2). One roll of the first nip (N1) is a press suction roll (11, 110) and the web (W) is transferred to follow the press felt (31, 41) on the side of said press suction roll (11, 110) by means of an underpressure in a suction zone (11a, 110a) of said press suction roll (11, 110). The press felt (31, 41) on the side of the press suction roll (11, 110) is also passed through the second nip (N2) of the press section.
摘要:
A press roll belt is arranged to be used in connection with a roll (10) forming a press nip. The belt (12) of the press roll (10) is provided with a groove pattern formed of intersecting grooves (11A, 11B). A press concept has at least one press nip formed between two rolls (30, 32) to remove water from a web. At least one press nip (NA) of the press concept is formed such that the cover (22) or the belt (12) of at least one roll (30A, 32A) forming the press nip is provided with groove patterning formed of intersecting grooves (11A, 11B; 21A, 21B).
摘要:
The invention relates to a method for operating a calender, comprising a cylindrical heated roll and a flexible belt surrounding a stationary support beam which supports at least one actuator which may urge a concave load shoe against the heated roll by means of said flexible belt to form an extended and heated nip through which a fiber web passes to be calendered and a separating mechanism for having at least one of the rolls movable into and away from the nip characterized in that said flexible belt is a flexible tubular jacket which forms a part of an enclosed shoe roll such that the ends of said jacket have end walls mounted thereto, which end walls are rotatably mounted in relation to said support beam, and in that at least one of said end walls is driven by means of a drive arrangement which drive arrangement may be activated to drive the end walls and thereby also the jacket independently of its position in relation to the fiber web or the heated roll.
摘要:
The invention relates to a method and an apparatus calendering a fiber web, wherein the fiber web passes through an extended and heated nip, said nip being formed on one side by a cylindrical heated roll and on the other side by a flexible tubular jacket which is pressed against the heated roll by means of a concave load shoe, said tubular jacket surrounding a stationary support beam which supports at least one actuator which may urge said load shoe and said flexible tubular jacket against said heated roll, and wherein the extension of the load shoe in the axial extension is less than the axial extension of the jacket and the heated roll such that when the load shoe is urged against the heated roll there will be formed tapered sections at each side end of the jacket within the nip characterised in that said tapered section are substantially covered by said fiber web such that a small strips of the fiber web at each edge is not calendered in said extended nip.