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 (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:
The invention concerns an equipment and a method in the transfer of a paper/board web in a paper or board machine. In an embodiment of the invention, the dryer section comprises at least one group of drying cylinders in which, instead of a conventional wire draw, a transfer belt (H100) is employed, to which the web (W) is affixed by effect of adhesion and which transfer belt is passed over drying cylinders (K1, K2, . . . ) and reversing rolls (E1, E2, . . . ) and further in said group (RI) of drying cylinders in the dryer section. The invention also concerns a method in the transfer of the web (W) in the dryer section (K) of a paper/board machine. In an embodiment of the invention, the web (W) is passed, while meandering in loop shape and while adhering to the face of the transfer belt (H100), from a drying cylinder (K1) in the group (RI) of drying cylinders in the dryer section (K) onto a reversing roll (E1) and further from the reversing roll onto the next drying cylinder (K2) and further in the group (RI) of drying cylinders.
摘要:
In the manufacture of a paper or board web (W), the web is slit or cut, the rising/lowering (H) of the edges of a slit/cut gap (C) formed at the slitting/cutting point or the width (L) of the gap is measured by means of a measurement device (21A; 21B; 21C), and the curl of the paper or board web (W) is regulated based on the result of measurement. A paper or board machine line has means for regulating curl in the web (W); means for slitting or cutting the paper or board web and for measuring the rising/lowering (H) of the edges of a slit/cut gap (C) formed at the slitting/cutting point or the width (L) of the slit/cut gap (C) in connection with the manufacture of the web (W) in order to regulate the curl of the web (W) based on the result of measurement.
摘要:
A high speed dryer section has single-wire draw drying groups (R1, RN). A paper or board web (W) is supported by a wire (F) as it meanders over drying cylinders (20) in an upper row and reversing cylinders/rolls (21) in a lower row. A first cylinder drying group (R1) has at least five drying cylinders. In the first cylinder drying group (R1) a runnability component (30) is placed in a pocket space defined by every two successive drying cylinders (20) and the reversing roll (21) between them and by the drying wire (F) for applying a high under-pressure of 1000-8000 Pa to an area (50Y) in which the web (W) separates from the drying cylinder (20), and by which runnability component (30) a lower under-pressure of 100-500 Pa is produced in at least part of the rest of the pocket space (T).
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 sealing arrangement (7) against a moving fabric (4b) in a paper machine or the like. The sealing arrangement includes a stiff sealing element (9) placed on the fabric's (4b) side on the entire width in connection with a paper sheet (4a) supported by the fabric (4b). The sealing element has been arranged on a support so that the location of the sealing element with respect to the fabric (4b) can be adjusted nearer to or, correspondingly, further from the fabric. As a sealing element there is at least a single-chambered labyrinth sealing (19).
摘要:
A paper web (w) is passed from the press section (10) to the drying section in a paper machine. The drying section has at least one transfer suction roll (16) for passing the web in a closed draw from the transport belt (12) of the press section to the drying wire (F) of the first cylinder drying group (14). The cylinder drying group has at least one vacuum box (30) stabilising the travel of the web. A high negative pressure is maintained in the transfer suction roll, this pressure being between −35 kPa and −80 kPa in order to attach the web to the drying wire.
摘要:
A fiber-web machine dryer section has a drying group with single-wire draw so the drying wire (F) presses the web (W) against heated cylinder surfaces with the web (W) at the side of the outside curve of reversing cylinders (11) situated between drying cylinders (10, 12). A pocket space (T) is formed between two adjacent drying cylinders (10) and a reversing cylinder (11) situated between them, and the drying wire (F). A negative pressure component (20) placed in the pocket space (T) creates a pressure difference over the drying wire (F) and the web (W) for attaching the web (W) to the drying wire (F) so the cross-direction shrinkage of the web (W) is controllable. The wire tension (F) is maintained at a level help control cross-direction shrinkage of the web. The pocket space (T) is sealed by sealing members (25, 26) to maintain negative pressure in the pocket space.
摘要:
A fiber-web machine dryer section has a drying group with single-wire draw so the drying wire (F) presses the web (W) against heated cylinder surfaces with the web (W) at the side of the outside curve of reversing cylinders (11) situated between drying cylinders (10, 12). A pocket space (T) is formed between two adjacent drying cylinders (10) and a reversing cylinder (11) situated between them, and the drying wire (F). A negative pressure component (20) placed in the pocket space (T) creates a pressure difference over the drying wire (F) and the web (W) for attaching the web (W) to the drying wire (F) so the cross-direction shrinkage of the web (W) is controllable. The wire tension (F) is maintained at a level help control cross-direction shrinkage of the web. The pocket space (T) is sealed by sealing members (25, 26) to maintain negative pressure in the pocket space.