阅读说明：本技术 在片材成形系统中减少边缘波的方法和片材成形系统 (Method for reducing edge waves in a sheet forming system and sheet forming system ) 是由 W.鲁夫 M.罗思 于 2019-07-05 设计创作，主要内容包括：在用于在长网造纸机或者长网造纸板机的片材成形系统中在将由流浆箱提供的纸浆悬浮液射流施加至环绕的筛网的区域中减少边缘波的方法中,在两个筛网侧上分别针对所形成的片材使用射流边缘定界装置,所述射流边缘定界装置的轮廓能够通过一个或者多个能变化地调节的弯折部位进行调节,在所述弯折部位的区域中,射流边缘定界装置的轮廓基本上分别能够横向于筛网运行方向偏转,其中,相应的能变化地调节的弯折部位能够在其沿横向的位置方面和/或在其弯折半径方面和/或在其沿筛网运行方向的位置方面变化地调节。还给出了适用于执行所述方法的片材成形系统。(In a method for reducing edge waves in a sheet-forming system of a fourdrinier or fourdrinier machine in the region of the application of a pulp suspension jet provided by a headbox to a surrounding screen, jet edge delimiting means are used on both screen sides for the formed sheet, the profile of which can be adjusted by means of one or more variably adjustable bending points in the region of which the profile of the jet edge delimiting means can be deflected essentially transversely to the screen running direction, wherein the respective variably adjustable bending point can be variably adjusted with respect to its position in the transverse direction and/or with respect to its bending radius and/or with respect to its position in the screen running direction. A sheet forming system suitable for performing the method is also presented.)

1. Method for reducing edge waves (R) in a sheet forming system (10) of a fourdrinier or fourdrinier machine in the area of the application of a pulp suspension jet provided by a headbox (12) to a surrounding screen (3), in which method jet edge delimiting means (14) are used on both screen sides in each case for the sheet formed, the profile of which can be adjusted by means of one or more variably adjustable bending points (16), in the area of which bending points the profile of the jet edge delimiting means (14) can be deflected essentially in each case transversely to the screen running direction (MD), wherein the respective variably adjustable bending point (16) can be deflected in terms of its position in the transverse direction (CD) and/or in terms of its bending radius (R)_i) Variably adjustable in respect of and/or in respect of its position in the direction of travel (MD) of the screen.

2. Method according to claim 1, characterized in that during operation of the relevant paper machine the respective variably adjustable bending point (16) can also be adjusted with respect to its position in the Cross Direction (CD) and/or with respect to its bending radius (R)_i) Variably adjustable in respect of and/or in respect of its position in the direction of travel (MD) of the screen.

3. Method according to at least one of the preceding claims, characterized in that the respective variably adjustable bending point (16) can be stepless or stepped in its position in the Cross Direction (CD) and/or in its bending radius (R)_i) In and/or in the direction of travel (MD) of the screenVariably adjustable in position.

4. A sheet forming system (10) of a fourdrinier paper or board machine, in particular for carrying out a method according to one of the preceding claims, the sheet forming system has a headbox (12), a surrounding screen (3) and respective jet edge delimiting means (14) on both screen sides, onto which screen (3) a pulp suspension jet provided by the headbox (12) is applied, the contour of the jet edge delimiting means can be adjusted by means of one or more variably adjustable bending points (16), in the region of the bend, the contours of the jet edge delimiting means (14) can each be deflected essentially transversely to the screen running direction (MD), wherein the respective variably adjustable bending point (16) can be adjusted with respect to its position in the Cross Direction (CD) and/or with respect to its bending radius (R)._i) Variably adjustable in respect of and/or in respect of its position in the direction of travel (MD) of the screen.

5. Sheet forming system according to claim 4, characterized in that the respective variably adjustable bending location (16) can also be adjusted with respect to its position in the Cross Direction (CD) and/or with respect to its bending radius (R) during operation of the relevant paper machine_i) Variably adjustable in respect of and/or in respect of its position in the direction of travel (MD) of the screen.

6. Container according to one of the preceding claims 4 to 5, wherein the respective variably adjustable bending point (16) can be infinitely or hierarchically related in terms of its position in the transverse direction (CD) and/or in terms of its bending radius (R)_i) Variably adjustable in respect of and/or in respect of its position in the direction of travel (MD) of the screen.

7. Sheet forming system according to one of the preceding claims 4 to 6, characterized in that a respective jet edge delimiting device (14) is fixed on the headbox (12) and is preferably deflectable.

8. Sheet forming system according to one of claims 4 to 6, characterized in that the respective jet edge delimiting means (14) is fixed to the wire section of the relevant paper machine.

9. Sheet forming system according to at least one of the preceding claims 4 to 8, characterized in that the respective jet edge delimiting means (14) starts, viewed in the screen running direction (MD), at a preset or presettable distance (B) from the headbox (12).

10. Sheet forming system according to at least one of the preceding claims 4 to 9, characterized in that the respective jet edge delimiting means (14) is adjustable in the z-direction in order to variably set the gap between the surrounding screen (3) and the jet edge delimiting means (14).

11. Sheet forming system according to at least one of the preceding claims 4 to 10, characterized in that the contour of the respective jet edge delimiting means (14) can be adapted to the respective jet incident geometry by means of at least one variably adjustable bending point (16).

12. Sheet forming system according to at least one of the preceding claims 4 to 11, characterized in that the distance between the two lateral jet edge delimitations is greater than the outflow width of the headbox (12).

13. Sheet forming system according to at least one of the preceding claims 4 to 12, characterized in that at least one further variably adjustable bending point (16) of the respective edge jet boundary (14) following the variably adjustable first bending point (16) in the screen running direction (MD) is arranged in conjunction with the at least substantially straight section of the edge jet boundary profile.

14. Sheet forming system according to at least one of the preceding claims 4 to 13, characterized in that the respective jet edge delimiting means (14) is cut off over its entire length or in sections by a plurality of cuts (20) extending substantially in the z direction in each case, and in that the bending radius of the respective variably arranged bending point (16) can be set variably by reinforcing a defined region of the edge jet boundary (14) by means of clamping pieces (KS1, KS2) of different lengths (L1, L2) in the transverse direction (CD) and/or in the screen running direction (MD) and/or variably by the length of the non-reinforced region of the edge jet boundary (14).

15. Sheet forming system according to at least one of the preceding claims 4 to 14, characterised in that the position of the variably adjustable bending point (16) arranged in the area of incidence of the pulp suspension jet (2) on the surrounding screen (3) seen in the screen running direction (MD) is located at most 50mm behind the jet incidence point within the pressure field which occurs in the pulp suspension jet (2) in front of and on the wire section of the relevant paper machine in the screen running direction (MD) by deflection of the pulp suspension jet on the jet incidence point (4) on the surrounding screen (3).