FLOW-OPTIMIZED EDGE TREATMENT

Abstract

A flow body for a format control unit of a Fourdrinier wire machine for producing a web of fibrous material, includes: a flow dividing device which is configured for separating an edge strip from a fibrous stock suspension stream, in a region of a flow division the flow dividing device including a rounded edge with a curvature radius greater than 2 mm.

Claims

1. A flow body for a format control unit of a Fourdrinier wire machine for producing a web of fibrous material, the flow body comprising: a flow dividing device which is configured for separating an edge strip from a fibrous stock suspension stream, in a region of a flow division the flow dividing device including a rounded edge with a curvature radius greater than 2 mm.

2. The flow body according to claim 1, wherein the web of fibrous material is a paper web or a cardboard web, the curvature radius being greater than 3 mm to 18 mm.

3. The flow body according to claim 1, wherein the rounded edge of the flow dividing device includes a rounding (a) a rounding having the curvature radius in a semi-circular cross section, or (b) at least a rounding which—in a cross section of the rounding—includes a circular segment of greater than 90°.

4. The flow body according to claim 1, wherein the rounded edge of flow dividing device has a rounding or a curvature that is elliptical or circle-like in a cross-section, a dividing axis of the rounding including twice a length of the curvature radius.

5. The flow body according to claim 1, wherein the flow body includes a lower edge which is arranged at an angle α relative to the flow dividing device, wherein the angle α is within a range of 10° to 60°.

6. The flow body according to claim 5, wherein the angle α is within a range of 10° to 45°.

7. The flow body according to claim 1, wherein the flow body includes a lower edge which is arranged at an angle α relative to the flow dividing device, the flow body being configured such that the flow dividing device is arranged above the fibrous stock suspension stream, such that the angle α is in a range of 120° to 170°.

8. The flow body according to claim 1, wherein the flow body includes a first side, a second side, and a curved diverter element, the flow dividing device being connected with the curved diverter element which is configured for diverting a wave subsequent to the flow division from the first side to the second side of the flow body.

9. The flow body according to claim 8, wherein the flow body includes a collecting device arranged in a region of the flow body above the flow dividing device or the curved diverter element such that a plurality of drops that develop from the fibrous stock suspension stream and the edge strip in the region of the flow division are collected by the collecting device, wherein the collecting device is geometrically shaped such that the plurality of drops which are collected by the collecting device are diverted away from the fibrous stock suspension stream and the web of fibrous material.

10. The flow body according to claim 1, wherein the flow body includes at least one flushing device configured for discharging a flushing water through a supply line and a plurality of corresponding outlet openings on at least one side of the flow body.

11. A format control unit of a Fourdrinier wire machine for producing a web of fibrous material, the format control unit comprising: a flow body configured for being immersed in a fibrous stock suspension stream, the flow body including: a flow dividing device which is configured for separating an edge strip from the fibrous stock suspension stream, in a region of a flow division the flow dividing device including a rounded edge with a curvature radius greater than 2 mm.

12. The format control unit according to claim 11, wherein the flow body is configured for being easily replaced in a case of wear, and, based upon a corresponding form-fit geometry of the flow body, the flow body is configured for guiding a flow of the fibrous stock suspension stream without a plurality of disturbances to a wire point of impact, wherein the web of fibrous material is a paper web, a cardboard web, or a packaging paper web.

13. The format control unit of claim 12, wherein the flow body is mounted by way of a screw-connection or a clamp-connection in the format control unit, and, based upon the corresponding form-fit geometry of the flow body, the flow body is configured for guiding the flow of the fibrous stock suspension stream without the plurality of disturbances due to a plurality of larger edges or gaps to the wire point of impact

14. A method of using a format control unit of a Fourdrinier wire machine for producing a web of fibrous material, the method comprising the steps of: providing that the Fourdrinier machine is configured for producing the web of fibrous material from at least one fibrous stock suspension and that the format control unit includes a flow body, which includes a flow dividing device which is configured for separating an edge strip from a fibrous stock suspension stream, in a region of a flow division the flow dividing device including a rounded edge with a curvature radius greater than 2 mm; revolving at least a Fourdrinier wire—which is continuous—in a circumferential direction; applying, by way of a headbox nozzle of a headbox, the at least one fibrous suspension formed as the fibrous stock suspension stream over a width of the Fourdrinier wire to form the web of fibrous material; and mounting two of the format control unit on two opposite sides parallel relative to web center of the Fourdrinier wire, the two of the format control unit being configured for separating the edge strip from the fibrous stock suspension stream in a region of the fibrous stock suspension stream and from an edge of the Fourdrinier wire, the flow dividing device of the flow body being arranged at an angle (α′) in a range from 10° to 45° relative to a plane of the Fourdrinier wire machine (x-y axis).

15. The method of using the format control unit according to claim 14, wherein the format control unit is configured for being mechanically adjustable, and wherein an adjustment of the format control unit is such that the flow dividing device is configured for being adjusted in a defined manner in a range of 10° to 45° with respect to the plane of the Fourdrinier wire machine (x-y axis), wherein the web of fibrous material is a paper web, a cardboard web, or a packaging paper web.

16. The method of using the format control unit according to claim 14, wherein the format control unit is configured for being pivoted away from the web of fibrous material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawing, wherein:

[0039] FIG. 1 shows a schematic perspective partial representation of a first embodiment of a format control unit with a flow body and a flow dividing device;

[0040] FIG. 2 shows a schematic perspective partial representation of an additional embodiment of a flow body and shows a possible section A of the embodiment shown in FIG. 1;

[0041] FIG. 3 is a schematic cross-sectional depiction of three embodiments for a flow body and a flow dividing device; and

[0042] FIG. 4 shows a schematic perspective partial representation of an additional embodiment of a format control unit with a flow body and a dividing device.

[0043] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

[0044] FIG. 1 shows a schematic perspective partial representation of a first optional embodiment of format control unit 7 with flow body 1 and flow dividing device 2. The fibrous stock suspension stream is shown via schematic flow lines 5, 5′, wherein 5′ represents the edge strip separated from the fibrous stock suspension stream. Fibrous stock suspension stream 5 impinges the Fourdrinier wire in the region of stream impingement point 6, which is not shown in detail, and the paper web is formed. The web center and direction of travel being shown as 9. To clarify the perspective view, a coordinate system with x-, y- and z-axis is shown, wherein the web plane of the Fourdrinier is formed by the x- and y-axis. Schematically shown area A is illustrated in the following figures in various embodiments. The flow of fibrous stock suspension stream 5 is in the x-z plane until the flow impinges on the wire. From then on the fibrous web is moved with the wire in the x-y plane.

[0045] FIG. 2 shows a schematic perspective partial representation of an additional optional embodiment of flow body 1 and shows a possible section A of the embodiment shown in FIG. 1. Flow dividing device 2 is shown and connects positively to diverter element 3. In addition, a collecting device 4 is shown above the diverter element, which is suitable for collecting drops arising from fibrous stock suspension stream 5 and from the area of edge strip 5′ and for discharging them with format control unit 7. The region marked B shows a sectional plane for the embodiments shown cross-sectionally in FIG. 3.

[0046] FIG. 3 is a schematic cross-sectional depiction of three optional embodiments for flow body 1 and flow dividing device 2. Flow-dividing device 2 is shown with a semicircular cross section 10, a cross section 11 of 90° to 180° and an elliptical or circle-like cross section 12. The embodiment with a cross section of 90° to 180° has an edge on the side facing away from web center 9, which causes a flow break. On the side facing web center 9, the circular element of the flow dividing device is positively connected with the flow body and also with format control unit 7. The embodiment with the elliptical or circle-like cross-section is also designed in such a way that a positive transition to the side of the flow body is provided, in particular on the side facing web center 9. All three optional embodiments also show a schematic optional flushing device 14 in various advantageous positions. Said flushing device has a supply line and outlet openings on at least one side of the flow body or below the lower edge of flow body 15. The flushing device can also be designed as a separate pipeline which is not shown and has a coupling valve which is not shown, connected to a flushing water supply not shown.

[0047] FIG. 4 shows a schematic perspective partial representation of an additional optional embodiment of format control unit 7 with flow body 1 and dividing device 2. The fibrous stock suspension stream is illustrated via schematic flow lines 5, 5′, wherein 5′ represents the edge strip separated from the fibrous stock suspension stream. Fibrous stock suspension stream 5 impacts the Fourdrinier—which is not shown in detail—in the region of stream impingement point 6, and the paper web is formed, wherein the web center and direction of web travel is identified by number 9. For clarification of the perspective view, a coordinate system is shown with x-, y- and z-axis, wherein the plane of the paper web and the Fourdrinier is formed by the x- and y-axis. Compared to FIG. 1, flow dividing device 2 is merely reversed, meaning that, relative to the paper web, flow dividing device 2 is located above fibrous stock suspension stream 5.

COMPONENT IDENTIFICATION LISTING

[0048] 1 Flow body [0049] 2 flow dividing device [0050] 3 diverter element [0051] 4 collecting device [0052] 5 fibrous stock suspension stream [0053] 5′ edge strip [0054] 6 stream impingement point [0055] 7 format control unit [0056] 8 radius [0057] 9 web center and direction of travel [0058] 10 semi-circle cross section [0059] 11 cross section with circle segment greater than 90° to 180° [0060] 12 cross section with elliptical or circle-like shape [0061] 13 dividing axis [0062] 14 flushing device [0063] 15 lower edge of flow body

[0064] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.