FI118350B - Dilution Outlet Box - Google Patents

Description

'I.fi, · * 118350

FIELD OF THE INVENTION The invention relates to a dilution headbox for a paper machine, board machine or the like.

Dilution headbox solutions are known in the art in which dilution water, preferably water derived from a wire section, is introduced into the pulp barrel to control the basis weight of the web from the web width. The dilution water is led to the dilution water manifold and further through valves to different positions along the headbox width. If it is desired to adjust the basis weight of the web by the width of the web, the adjustment is made by controlling the dilution valves and thus the dilution flows.

15 The prior art dilution headbox structure of the applicant is known in the art where the dilution water is led to a so-called. a mixing chamber filled with dilution water. Said mixing is conducted in a column supply lines for which the distances from the ends of the tubes is the output side. Thus, there is a flow gap between the inlet tubes and the outlet tubes, from which the dilution water flows to the mass. The flow gap is thus annular.

The mixing chambers are several adjacent to the headbox width and are separated by partitions. Each mixing chamber is supplied with at least one unit, preferably two units, of dilution water from above. The connections open to the top of the mixing chamber. Preferably at least 2 · · · 2 inlet lines are provided in each mixing chamber, preferably there can also be more than 2 lines in the inlet lines. These inlet pipe rows is at the distance • ·: from aligned with the ends of the output side of the pipe lines. The combined flow of Li + L2 of the pulp Li * and the dilution water L2 is thus led in the outlet tubes 30 to, for example, the intermediate chamber and the turbulence generator. However, the application is not intended to be limited solely to the embodiment comprising the intermediate chamber.

A problem in the above distribution of dilution water to the pulp funnel has been shown by the inhomogeneity of the Z direction. Dilution water easily enters more into the lower tubes than the upper tubes, especially at high dilution ratios. This further affects the Z-weight basis weight distribution of the web, which should be homogeneous, i.e., uniform in that height direction.

In order to solve the above problem, this application discloses that the flow gap between the inlet pipe and the outlet pipe is formed differently in height. In order to have the same flow to all columns of the column, the dilution flow for certain pipes must be more restrictive than for other pipes of the given pipeline. Therefore, in order to solve the above-mentioned problem, this application discloses a structure in which the ends of the inlet pipe are at a different distance from the outlet pipes at their respective ends, at their inlet ends. The application also discloses another embodiment. It is possible that each putkiri-VISSA the inlet side tubes, or sleeves different diameters. In this case, the so-called. the feed gap is different in height and thus the dilution flow L2 can be adjusted as desired in relation to the flow L1 of the pulp stock Mi. Preferably, the solution according to the invention is used in solutions where the dilution water is supplied from one feed point to at least two adjacent columns of piping. toon. Problems have been found in such geometries when the flow gap remains constant in height. It is also possible to supply e.g. • · «·· ♦ is added to the dilution chamber. · · ·. water through two together.

The dilution headbox according to the invention is characterized by what is stated in the claims.

2 3 118350

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

Fig. 1A shows a prior art dilution headbox as a principal and illustrative representation.

Figure 1B shows a headbox structure according to the invention.

Figure 1C shows area Xi of Figure IB.

Fig. 1D is a section I-1 in Fig. 1C.

Figure IE shows the so-called. a basic situation in which the inlet pipes of the column line are 15 of the same diameter and the same length.

Figure 2A shows a solution according to the invention and the flow gap formed Dj, shown DING, so that the inlet side of the tube end within the tube changing the output side 'Come tube lined up in the vertical direction. The distance H] is at its minimum.

• · · 20 I · I • ·! Figure 2B shows another embodiment in which the distance Hi is at its maximum * 1 i * 'V.

• · · • · · ·· 1 • · · • • • 1

Figure 3A illustrates an embodiment of the invention wherein the pulp inlet tube, i. The outer diameter of the 25 inlets in each vertical row of inlet pipes differs in height ·· ♦ between the tubes in the row of tubes. In the embodiment of Figure 3A. \ The outside diameter of the inlet tube, or inlet sleeve, decreases as it goes from top to bottom.

• · · 1 · · * ·· • · • 30

Figure 3B is a sectional view II-II in Figure 3A.

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Figure 3C illustrates an embodiment of the invention in which the diameter of the inlet tube, or sleeve, behaves in contrast to the previous embodiment, i.e., the outer diameter increases from the top to the bottom.

Figure 3D is a sectional view III-III in Figure 3C.

Figure 3E is a sectional view IV-IV of Figure 3C.

Figure 1A shows a prior art dilution headbox 100 10 in a schematic and illustrative view. The pulp column Mi is led from the mas-Sanj ako logs Jj to the 11 tubes of the pulpit. The dilution water is led from the dilution manifold J2 to the dilution water and the dilution water flow L2 is adjusted by the valves V1, V2 ... 11, and further to the intermediate chamber E and further to the turbulence generator G and the lip cone K and to the forming wire Hi, the dilution water is preferably tap water supplied from the wire section one through b and further from the wire well 300 transported by the pump Pi to the dilution manifold J2. By adjusting the dilution water flow L2, the net weight ·, · * 20 HÖ of the web is adjusted over the web width.

Figure 1B shows a dilution headbox 100 according to the invention. water from above is fed through the unit (s) 12ai, 12a2 ... to the mixing chamber 13ai, 13a2 ... and wherein in the mixing chamber 13ai, 13a2 ... the pulp Mi,,,, 25 is directed to the inlet pipe 14au, 14ai.2; 14a2.i, 14a2.2 ·. · Through the mixing chamber 13ai, * · * *. ···, I3a2 · .., whereby the dilution water combined with the outlet pipe 15au, 15a2.i, 15a3 i ... • M *. ·, Den and mass flow rate Li + L2 are passed. The dilution water L2 flows through the ring gap, i.e. the flow gap Dj, through the pulp Mi 1 • · · ·! in the mixing chamber 13ai, 13a2 ...

«·: '·· 30 • * 118350 5

Fig. 1C shows the area X 1 in Fig. 1B and Fig. 1D is a section I -1 in Fig. 1C. As shown in the figure, mixing chambers 13 consist of structures separated by spacers 16ai, 16a2 ... comprising at least two adjacent tube rows 14an, 14aj, 2 ... 14a2.i, 14a2,2 ... 14a3i, 14a3. 2 ...

There are one or more dilution water inlets, such as inlet pipes 12ai, 12a2 ..., for each mixing chamber 13a (, 13a2, 13a3 ...). Preferably, dilution water is led from each mixing chamber to two or three adjacent tubes. ..14a2, i, 14a2.2 ... 15an, 15ai.2 ... 15a2, i, 15a2.2 ··· The tubes may be in the same plane or zig-zag as in the embodiment of the figure.

Figure IE shows the so-called. the basic situation where all the inlets for fresh pulp, or so-called. the sleeves are the same diameter and the same length. The difficulty in the above structure is precisely the uniform distribution of the dilution water in the Z or altitude.

Figure 2A embodiment, a flow distribution to the United pulp stock M and of the dilution water flow, Li + L2, the Z-direction of each * * outlet pipe as homogeneous as possible by forming the inlet side of the tube • · · • «· · '20, and between the exit end of the tube away Hi such that the diluting L2 • · * I · * comes to the same extent Q for all columns 15ai.i, 15ai.2, 15ai.3; 15a2.i, • * »·· * / 15a2.2, 15a2.3 · .. Therefore, the flow gap Di is formed such that the flow resistance of * * ·“ f is at its highest at the top tube rows and decreases downward as the ** * here. This flow resistance may have been formed such that the distance Hi is. 25 at its lowest point at the top pipes and increases as it goes down. This preferably influences the flow distribution in the Z direction, whereby all the columns of the column 4a *, 15a, 2; 15a2.i, 15a2.2 ··· gives the same amount of Q (1 / min) for each • · · * “* row of dilution flow L2. In the embodiment, the flow gap Di between the upper pipe • ♦ '·; · * and the inlet pipe is smaller than the lower one, i.e. the flow gap Di • t • * ·· 30 increases from the top to the bottom. The sum flow L1 + * · '** L2 is then influenced so that the flow rate remains as constant as possible in the Z direction. Preferably, the cross sectional area of the mixing chamber remains constant in the Z direction, thereby optimizing its manufacturing cost.

Figure 2B is an embodiment of the invention, wherein the distance between the inlet side of the tube, and outputting Hi five downside to the pipe in the mixing chamber 13 is greatest at the top and decreases in the downward direction.

Figure 3A illustrates an embodiment of the invention wherein the inlet tube 14ai.i, 14ai.2; 14a2.i, 14a2.2 ... i.e., the outer diameter of the inlet sleeve decreases from the top 10 downwards, whereby the feed gap Di widens from the top down. Here, the effect is the same as in the embodiment of Figure 2A. From the flow Li to the pulp pulp Mi we obtain as much as possible in each column. In this way, the structure of the paper in the Z direction is as homogeneous as possible.

Figure 3B is a sectional view II-II in Figure 3A.

Figure 3C illustrates an embodiment of the invention in which the diameter of the sleeve behaves the opposite, i.e., the outer diameter of the inlet sleeve, or inlet pipe, increases when going upwards, so-called. the feed gap Di decreases from top to bottom as: * * 20.

Fig. 3D shows section III-III in Fig. 3C, Fig. 3E, Fig. 3E. Fig. 3C is a sectional view taken along the line IV-IV showing the mixing device. A chamber 13aj, into which dilution water L2 is introduced through I2ai. Mixing Chamber- * ♦ # • · · !!! the amount of dilution water L2 supplied to the mouth 13ai is controlled by the valve V1 (not shown). From the mixing chamber 13ai, the dilution water is led to the tubes 15aii ... l5a2.i ... l5a3, i of at least two rows of adjacent tubes. Hereby, a single valve '·; · * can be used to conduct dilution water preferably in the width direction of the headbox to a minimum of ** ** 30 mm 100 mm. The mixing chamber 13ai, 13a2 ... comprises at least two inlet pipes 14ai.i, 14ai, 2 ..., 14a2.i, 14a2.2 ... and the outlet pipes 11a, 15ai, 2 ..., 118350 7 15a2.i , 15a2,2 ... adjacent columns for supplying dilution water in mixing chamber 13ai, 13a2 ... to at least two columns tubes 15ai.i, 15a] .2 ..., 15a2.i, 15a2,2 ...

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Claims (6)

A dilution inlet carriage (100) for a paper machine, cardboard machine or the like, which dilution inlet carriage (100) comprises channels (12ai, 12a2 · ..) for supply of dilution water and inlet pipes (14ai.i, 14ai.2,14a1.3). 14a2.i, 14a2.2—) for conducting stock (Mi) to a mixing chamber (13), wherein inlet chamber (13) is provided with inlet tubes (14ai.1,14ai.2; 14a2.i, 14a2. 2 ···) for the stock and opposite them and at a distance (Hi) from these outlet pipes 10 (15ai.i, 15ai.2; 15a2.i, 15a2.2 ...) j where the inlet pipes (14au, 14ai.2 ...) opens into the mixing chamber (13ai, 13a2 ...) and a flow gap (Di) intersects between the respective inlet pipes and the outlet pipe opposite, characterized in that the flow slots (Di) between the inlet pipes and outlet pipes are designed differently. in relation to each other in the Z-direction, so that the flow is of the same amount to all pipes in a vertical row, the restriction of the dilution flow at certain pipes being drier than at the other pipes in the respective row of pipes, wherein the flow gap (D 1) is designed in such a way that the distance (Hi) between the inlet pipe and the outlet pipe varies in the Z direction or that the flow peaks (D 1) are formed differently between the pipes in Z the direction using inlet pipes (14ai, i, 14ai.2, 14ai.3; 14a2.i, 14a2.2 · ..) for the stock * ·: *. · (Mi) of different diameters. »* · • t · • · •« • · · · '·· ϊ The dilution inlet carriage (100) according to Claim 1, characterized in that the · · * * · ··· ′ flow gap (Hi) grows in the Z direction on the road from the top down, whereby the distance • · ** · * (Hi) between the inlet pipe and the outlet pipe is larger at the lower pipes than at the upper pipes. • * • ·· ··· • m The dilution inlet carriage (100) according to claim 1, characterized in that the flow gap (Hi) decreases in such a way in the Z-direction that the distance (Hi) between the inlet pipe and the opposite the outlet pipe is greatest at the upper inlet pipes for the stock and decreases along the road downwards. • · • · t • ·· • · 118350 The dilution inlet carriage (100) according to claim 1, characterized in that the flow gap (Di) is formed in such a way between the inlet pipe and the opposite pipe on the outlet side, that the pipe diameter on the inlet side is greatest at the top pipes and decreases on the top pipes. wherein the feed gap (D 1) for the so-called dilution flow is at least at the Upper tubes and grows down the road downstream. The dilution inlet carriage (100) according to claim 1, characterized in that the flow gap (D1) is formed in such a way between the inlet pipe and the outlet pipe that the diameter of the inlet pipe is at least at the upper pipes and grows in the way downwards, Di) decreases down the road and is greatest at the Upper pipes. The dilution inlet carriage (100) according to claim 1, characterized in that the mixing chamber (13ai, 13a2 ...) comprises at least two adjacent vertical rows of inlet pipes (14ai.i, 14ai.2 ..., 14a2). i, 14a2.2 ...) and outlet pipes (15ai i, 15ai, 2 ..., 15a2, i, 15a2.2 ...) for feeding dilution water into the mixing chamber (13ai, 13a2 ...) to the pipes ( 15ai.i, 15ai.2 ..., 15a2.i, 15a2.2 ...) in at least two vertical rows. a · f \ *! 20 ·· a * a · • »« a • · • a «I ·» • aa · • • ft aaaa aaa aaa aaaa aaa aa aaa aa aaa aaaa aaa aaa aaa aaa aaa aaaa aaa aaa aaa aaa aaa aaa a aa aa