FI83342C - TURBULENSGENERATOR I INLOPPSLAODAN AV EN PAPPERSMASKIN. - Google Patents

Description

The invention relates to a turbulence generator for a paper machine headbox. The invention relates to a turbulence generator for a paper machine headbox.

Solutions are known from the prior art in which the total flow is equalized at the discharge end of the tubes of the turbulence generator of the headbox of a paper machine by using separate tubes with stepped diameters. However, known .jq solutions have not been able to satisfactorily solve flow problems. The flow has not been sufficiently uniform and thus the above-mentioned issue has a detrimental effect on the quality of the paper to be formed.

The object of the invention is a completely new type of turbulence generator, in which the problems of flow unevenness are avoided, especially in the direction of the wire and web width. The invention has realized the use of separate flow control sections located at the discharge end of the turbulence generator, by means of which the flow is deflected when it comes from a straight tube of the tur-2Q bulge generator substantially horizontally, i.e. in the direction of the dashboard. According to the invention, guide parts are used which are fitted between adjacent tubes of the turbulence generator. The guide parts comprise surfaces inclined with respect to the machine direction longitudinal axis X of the paper machine. By means of said inclined wedge-shaped surface 22, the flow is guided along the surface of the guide part on both sides of the guide part and in such a way that the flows cross and mix efficiently. The angle of the plane of the flow-guiding surface with respect to the resultant direction of the flow and the machine direction X is less than 12 ".

The turbulence generator according to the invention is mainly characterized in that the turbulence generator comprises, at the discharge end, flow control sections deflecting the mass flow laterally, arranged at the discharge end wherein the flow control portion has flow deflecting surfaces substantially at the same angle to the central axis of the control portion, the flow control surfaces extending substantially towards each other at the discharge end of the control portion, wherein said surfaces direct lateral flow flow substantially in the direction of the wire width of the paper machine.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figure 1 schematically shows the headbox of a paper machine 15

Figure 2 shows an axonometric and partially schematic diagram of a prior art paper machine headbox turbulence generator.

Figure 3 shows a paper machine headbox comprising a turbulence generator according to the invention with flow control parts according to the invention.

Turbulence generator according to the invention shown in Figure 4 mainly in the direction of arrow K d of Figure 3 as seen in an axonometric view of 25.

Figure 5 illustrates the operation of the flow control part according to the invention. Shown are two adjacent control sections seen from above.

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Figure 6A shows a mounting part used to install the flow control part according to the invention, which is located between two adjacent turbulence generator tubes.

Figure 6B shows an axonometric view of a flow control section according to the invention.

3 83342 1 shown in Figure 6C of the flow control according to the invention Figure 6B, the direction of the arrow ^.

Figure 7A is a front view of a preferred embodiment of a turbulence generator according to the invention.

Fig. 7H shows a section T-Γ from Fig. 7A.

Figure 1 is a schematic side view of a paper machine headbox. The headbox of the paper machine comprises the manifold shown schematically in Figure 1, an associated manifold, a leveling chamber and an intermediate chamber, a turbulence generator associated with the leveling chamber, and further a lip cone or lip channel.

Fig. 2 shows an axonometric turbulence generator object and a headbox of the invention, partly in section. The longitudinal axis of the paper machine in the machine direction is denoted by X and the transverse axis perpendicular to it is denoted by Y. The object of the invention is to improve the uniformity of the flow precisely in the direction Y, i.e. from the wire width.

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Figure 3 shows in more detail a headbox according to the invention. The turbulence generator 10 directs the flow from the generator tubes 11a, 11b ... to the lip cone and further to the wire.

In Figure 4, 25 of the turbulence generator according to the invention the direction of arrow D of Figure 3 is shown as seen from the direction ^ and presentation is axonometric. The turbulence generator 10 comprises a plurality of tubes 11a, 11b from which the pulp flow is further directed to the lip cone. According to the invention, separate flow control parts 12 are provided in the discharge end E with respect to the flow of the turbulence generator, which comprise flow control surfaces 13a and 13b. The flow control sections are always arranged in two adjacent turbulence generator tubes 1 1a, 1 lb; 1 le, 1 Id. . . between. At the same time, the central axis of the guide member 12 is the axis of symmetry of the guide member 12, and the surfaces 13a and 13b are at respective angles oC to the central axis. The angle oC is preferably in the range 5-12 °. The angle o <of the flow control surfaces 13a and 13b. shall not exceed 12 °. If the angle is greater than 12 °, the flow is detached from the above-mentioned guide surfaces ^ 83342 1 13a, 13b. Surfaces 13a and 13b run in the flow direction towards each other.

In the embodiment of Figure 4, the flow section is sharp with respect to the flow from the discharge end.

Surfaces I3a and 13b are preferably planar.

Thus, as shown in Fig. 4, the turbulence generator 10 according to the invention comprises a plurality of flow control sections 12 at the discharge end E of the turbulence generator.

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Figure 5 schematically shows the operation of the flow control part according to the invention. Figure 5 shows two adjacent flow control sections; flow control sections 12a and 12b. The angle oC of the surface 13a and 13b of the flow control section 12 with respect to the central and symmetry axis 15 Xj of the control section 12 is less than 12 °. The flows of the pipes on both sides of the flow control section cross and mix efficiently. The flow at the edges of the tube consists, as shown in the figure, of the machine direction component V1 of the paper machine, the direction of which is at the same time the direction of the main flow and the transverse (direction Y) component V. Component V ^ 20 is considerably larger than component V. In addition, the directions of the components V 1 at the end of the control section are opposite, so that the summed vector of the above-mentioned vectors is a zero vector, so that the direction of the total flow is maintained in the direction X.

Fig. 6A shows a fastening part 14 used for fastening the flow control part according to the invention. The fastening part 14 is arranged between two adjacent tubes of a turbulence generator, e.g. tubes 11a and 11b. The fastening part 14 comprises a hole 16 into which the counter-fastening means 15 of the guide part 12 can be inserted. Thus, by using the fastening part 14, the guide parts 12 can be changed as desired. Depending on the flow and in order to obtain the desired result, it is possible to replace in the headbox control parts 12 whose flow deflection angle is. is the most advantageous for the respective flow and mass quality.

Fig. 6B shows the control part 12 in an axonometric view. The guide part 12 is symmetrical with respect to its central axis Xj. In the embodiment of the figure, the guide part 12 comprises flow-deflecting planar surfaces 5 83342 11a and 13b, which are located at substantially the same angle oC to the central axis X1 of the part. By means of the flow deflecting surfaces 13a and 13b of the control part 12, the flow is directed laterally (direction Y) and the flow 5 from the straight tubes of the turbulence generator is smoothed so that the flow from the headbox is as even as possible. The parts 12 are used to adjust the mass flow specifically in the direction of the wire width (direction Y).

The flow control part 12 to be placed at the end of the turbo-10 lens tubes 11a, 11b according to the invention shown in Fig. 6B comprises a fastening means 15, preferably a fastening spindle, which can be inserted into the The cross-sectional shape of the mandrel 15 is 15 yrapry and the mandrel is located on its central axis on the central axis X 1 of the flow control section 12.

In Figure 6C is shown in Figure 6B, according to a flow control 12 of Figure 6B, viewed in the direction of arrow D. The flow control surfaces 13a and 20 13b are straight and are at an angle oC to the central axis Xj. When the flow control section 12 is positioned between the tubes 11a and 11b of two adjacent turbulence generators 10, the flow control section 12 is located on its central axis Xj so that the direction of the axis X1 is parallel to the machine direction longitudinal axis X of the paper machine. The guide part 12 shown in the figure is blunt with respect to the flow at the discharge end.

Fig. 7A shows an arrangement of control parts according to the invention in a turbocharger generator 10. It can be seen from the figure that the pipes and guide parts are located in rows and 30 so that the guide parts do not hit the same row when viewed from above. Flow mixing is thus most efficient.

Fig. 7B is a section T-I of Fig. 7A. The figure shows the overlap of the guide parts 12, which effectively equalizes the flow in each row of pipes Α ^, Α2, Α ^ ....

Claims (9)

A paper machine headbox turbulence generator (10), the turbulence generator (10) comprising flow control sections (12) deflecting the mass flow in the lateral (Y) direction at the discharge end (E), arranged in straight turbulence generator tubes (11a, 11b ...) to the discharge end (E) such that the flow control part (12) is located between two adjacent tubes (11a, 11b; 11b, 11c; ...) of the turbulence generator, characterized in that the turbulence generator (10) comprises such flow control parts (12), wherein the flow control portion (12) has flow deflecting surfaces (13a and 13b) substantially at the same angle (o) to the central axis (X 1) of the control portion (12), the flow control surfaces (13a, 13b) extending substantially to each other at the discharge end of the control portion with the above-mentioned surfaces directing the flow laterally and from adjacent turbulence generator tubes (11a, 11b; ...) to and thus equalizing the flow substantially in the direction of the wire width (Y) of the paper machine. 1 Claims Turbulence generator according to claim 1, characterized in that the flow deflecting surfaces (13a, 13b) of the flow control part are located at substantially the same angle (α) to the longitudinal and symmetry axes (X 1) of the part (12), which axis of symmetry ( X 1) is located substantially parallel to the machine direction longitudinal axis (X) of the paper machine. Turbulence generator according to Claim 1 or 2, characterized in that the turbulence generator comprises tubes (11a, 11b ...) which are substantially straight at the discharge end, flow control parts (12) being arranged at the discharge end (A) of said pipes. Turbulence generator according to one of the preceding claims, characterized in that the flow control part (12) of the turbulence generator is sharp at its discharge end 35 relative to the direction of flow. 7 83342 Paper machine turbulence generator according to one of the preceding claims 1 to 3, characterized in that the flow control part (12) is blunt from the discharge end with respect to the flow direction. Turbulence generator according to one of the preceding claims, characterized in that the angle (α) of the flow deflecting surface (13a, 13b) of the flow guide section (12) with respect to the central axis (X 1) of the guide section (12) and the machine direction longitudinal axis (X) is in the range of 5-12 °. 10 6 83342 Turbulence generator according to one of the preceding claims, characterized in that the length (L) of the flow-deflecting surfaces (13a, 13b) of the flow control section (12) of the turbulence generator is in the range from 20 to 30 mm. 15 Turbulence generator according to one of the preceding claims, characterized in that the flow guide part (12) comprises fastening means (15) by means of which the guide part (12) can be fastened between the adjacent tubes (11a, 11b) 20 of the turbulence generator (10). ) to counter-attachments (16). Turbulence generator according to the preceding claim, characterized in that the fastening means (15) of the flow control part (12) consist of a fastening spindle which can be inserted into the hole (16) of the counter-fastening means of the fastening part (14), the guide part (12) being replaceable. 30 35 8 83342