摘要:
The invention comprises a method and an arrangement in a paper machine or the like close to a moving web (29) usually supported against a wire (1), and a paper machine including such an arrangement, and a sealing device having several such arrangements (100). According to the invention, a movable sealing (5) is arranged in the drying section of a paper machine, between two regions (3, 4) with different pressures. Certain air amounts (V1, V2) are supplied to and/or discharged from each side of the sealing (5) in order to create certain pressures in said regions. Air can move between said regions only through certain paths. In normal operating situations the seal (5) according to the invention is automatically adjusted to the desired position in relation to the web.
摘要:
A device for transferring a material web, particularly a web made of paper, board, tissue, or other pulp. In order to transfer the material web and, preferably, a supporting belt from a first supporting surface to a subsequent supporting surface, a pick-up zone to lift the material web off the first supporting surface and a stabilizing zone to stabilize the material web are arranged before the subsequent supporting surface, where vacuum can be applied to the pick-up zone and the stabilizing zone from one vacuum source each. Here, the pick-up zone is sub-divided into at least two pick-up sub-zones across the material web running direction, where the vacuum can be switched on separately in at least one pick-up sub-zone. This invention also relates to a process for transferring a material web performed with the device according to the invention.
摘要:
A device for transferring a material web includes a transfer zone to which vacuum can be applied and at least one sealing mechanism with sealing lips. The sealing mechanism limits or divides the transfer zone, where suction can be applied to a space between the sealing lips.
摘要:
A machine for producing and/or treating a material web, in particular of paper or board, in which the material web can be guided along a material web guide path by means of at least one material web guide device from a material web production section or material web input section, in order to pass at least one material web treatment device, having an apparatus for forming a transfer strip of the material web and transferring the transfer strip through the machine, it being possible for the material web to be transferred along the material web guide path in that, by means of the apparatus for forming and transferring the transfer strip, a leading transfer strip of the material web is formed and guided through the machine, and the width of the transfer strip is increased to the full material web width (what is known as “tail widening”), and having an apparatus for detecting a break in the material web. The apparatus for detecting a break in the material web is provided and designed for the purpose of responding to a break in the transfer strip or the material web during the transfer of the material web, in particular during the increase in the width of the transfer strip.
摘要:
A drying section of a machine for the manufacture of a material web, in particular of a paper or of a board web, comprises a smoothing nip which is extended in the web running direction and is formed between two pressing areas lying opposite one another of which at least one is formed by a shoe roll, with at least 70%, and preferably at least 90%, of the outer shoe roll diameter lying above the machine base. In a method for the combined drying and smoothing of a material web, in particular of a paper web or of a board web, in a drying section, the following steps are provided: the material web is first dried to a pre-settable drying content >60%, in particular >65%, and preferably >70%; the material web having this pre-settable drying content is guided through a smoothing nip which is extended in the web running direction and is formed between two pressing surfaces lying opposite one another of which at least one is formed by a rotating belt and of which at least one is heated; the pressing time resulting in the extended smoothing nip is selected >0.8 ms; and the material web is further dried after the smoothing nip.
摘要:
A web (16) running from an opening nip (K1) between a cylinder (10) and a supporting fabric (18) toward a roll (14), is supported by a negative pressure created by a blow box (30). In an intensified negative pressure region (34′), i.e. close to the disengaging point (40) between the supporting fabric and the cylinder, the pressure is greater than at a distance from this disengaging point. The negative pressure is controlled according to parameters which act on the runability of the web and which can be varied, such as web velocity, web solid contents, pulp composition, paper or paper board quality, web grammage, a characteristic of the web, such as porosity, traction acting in the web, or web tension, cylinder temperature, and/or the running situation, such as a web break, a threading situation, or a normal run, so the desired runability is maintained between the cylinder and the roll.
摘要:
An apparatus and method for conditioning a moving porous web on a papermaking machine is disclosed. The web has a first and a second surface and a high temperature gaseous boundary layer adjacent at least the second surface. The apparatus contains means for conveying the first surface of the porous web adjacent a support surface in a direction of travel, means for applying a cooling gas against the second surface of the web in a direction substantially normal to the second surface of the web to exert a gas pressure adjacent the second surface, means for stripping at least a portion of the boundary layer away from the second surface of the web prior to contacting the web with the cooling gas, and means for exerting a vacuum force adjacent the first surface of the web associated with the support means and substantially opposite the location at which the pressure force is exerted adjacent the second surface of the web in order to promote, by a combination of the pressure and vacuum forces, a flow of gas through the web from the second surface to the first surface. The apparatus may also include means for moisturizing the web subsequent to cooling the web. The apparatus and method provide a novel combination of stripping and gas pressure/vacuum force effects for more rapid and efficient removal of the boundary layer at the speeds of modern papermaking machines to improve the condition of the web for further on-line treatments, such as calendaring.
摘要:
A blow box (18) for supporting the web run in a paper machine or the like, which blow box comprises members for maintaining a negative pressure at least in one negative pressure region (24) between the wire (20) and the blow box. The members comprise a blocking member (30, 32), which is arranged, regarding the wire's running direction, at the beginning and/or at the end of said negative pressure region, which extends across the wire and projects towards the wire, and which is movable in relation to the blow box, and blowing members (34, 36), with which air is ejected with blows between said blocking member and the wire from said negative pressure region and/or with which air is prevented from entering this negative pressure region. The blocking member is connected to the blow box by a hinge member (40, 42), which allows the blocking member to rotate around the articulation point of the hinge member due to the pressure difference between the pressure acting on the blocking member's blocking surface (30′, 32′) directed towards the wire and the pressure acting on the blocking member's back surface (50, 50′) directed away from the wire.
摘要:
The invention relates to an arrangement in a multi-cylinder dryer of a paper machine, which arrangement includes at least one drying cylinder (10) and at least one roll (11,12) located at a different height to the cylinder and at a distance to it in the machine direction, the paper web (14) travelling from the drying cylinder (10) to this roll (11, 12). Dry air is brought to the dryer through a beam (13) located in front of the paper web (14) in the machine direction, in which dryer the air is directed by means of nozzles (33) arranged in the beam into a throat (21) between the drying cylinder (10) and the paper web (14) mainly to intensify the drying effect. A doctor (27) is arranged in, or in connection with the said beam (13) to keep the surface of the drying cylinder clean. The beam (13) is arranged to form with the roll (12) a smooth, high channel (25), at least on the side of the roll (12), for the passage of the web during a disturbance.
摘要:
Device and method for handling a material web, in which the material web is guided by at least one smooth support surface and is then guided together with a porous support belt to a deflection roll includes a suction box. The suction box has a wall opposite from the porous support belt, and creates a vacuum that draws the material web from the support surface to the porous support belt. The device also includes at least one sealing element positioned near a front end, in the web travel direction, the sealing element cooperating with the porous support belt, and a vacuum zone in which the vacuum is provided. The vacuum zone adjoins a side of the porous support belt not contacting the material web and is defined between the porous support belt, the at least one sealing element, the wall of the suction box, and at its rear end, the deflection roll. The device also includes a slot-shaped first suction opening provided in the suction box wall near the rear end of the vacuum zone adjacent to the deflection roll so that air can be aspirated from the vacuum through the first suction opening; and at least one additional suction opening communicating with the vacuum. The at least one additional suction opening is provided in the suction box wall.