FI69140B - MASSINLOPPSLAODA FOER EN PAPPERSMASKIN EL DYL - Google Patents

Description

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(11) UTLÄGGNINGSSKRIFT 0 ^ 140 C (45) Ptr.tti zy 11 :: .. 1 ·.!: Y 10 12 1935 (51) Kv.lk. «/ Lnt.CI. * D 21 F 1/02 ( 21) Patent application - Patentansikning 2203/70 (22) Filing date - Ansökningidag 11 .08.70 iFh '' (23) Starting date - Giltighetsdag 1 1.08.70 (41) Made public - Blivit offentllg 15 * 02.71

National Board of Patents and Registration (44) Date of publication and date of publication. -, n nfi Qc

Patent- och registerstyrelsen 'Ansökan utlagd och utl.skriften publicerad 3 b · Oo .05 (32) (33) (31) Privilege requested — Begärd priority 14.08.69, 22.10.69 Federal Republic of Germany-Förbundsrepubl iken Tyskland (DE) P 1941424.5 , 1953086.0 (71) Escher Wyss GmbH., Ravensburg, Federal Republic of Germany-Förbundsrepubliken Tyfekland (DE) (72) Hans Dahl, Ravensburg, Anton Kurz, Langenargen, Federal Republic of Germany-Förbundsrepublen Tyskland (DE) (74) Oy Koister Ab (54) ) Feeder for paper machine or similar - Massainloppslada för en pappersmaskin el.dy1

The invention relates to a feeder for a paper machine or the like, having a perforated plate extending over the entire width of the web to be formed, having a plurality of parallel channels expanded after the initial part in the flow direction of the pulp slurry for conveying the pulp slurry.

German patent application 1,220,247 discloses a pulp feeder in which a pulp distributor is connected between a pulp supply line and a pulp feed box. The function of this is to slow down the flow from the speed prevailing in the supply line to the speed prevailing in the pulp supply box and it is made to expand stepwise so that its opening angle can be larger than that of a normal diffuser.

The pulp feeder disclosed in German patent application 853 256 has a pipe bundle connected between a pulp filling chamber filled with a pulp manifold and a pulp feed box, which extends over the entire width of the track to be formed and has 2,69140 multiple, parallel pipes. The forced, laminar flow through the pipes must also remain valid in the pulp feed box.

German public document 1 461 071 discloses another type of pulp feeder with very long tubes in a pipe bundle. Although a long bundle of pipes leads directly to the feeder, a device must be connected in front of it to create uniform pressure conditions.

The official description of the short description of French patent application 1,558,396 discloses long, tubular channels with a conically expanding initial part. However, a grid must be connected behind these channels in order for the flow to be uniform in the drain nozzle.

In modern pulp feeders, long tube bundles have been replaced by short perforated plates. However, in such a mass feeding device, disclosed in German Offenlegungsschrift 1,290,797, longer diffusers must be connected to the perforated plates. In the pulp feeder according to German patent specification 1,236,922, perforated plate plates spaced apart from the perforated plate are to be connected, and it is proposed to connect to the last perforated plate stability surfaces running parallel to the direction of travel of the wire.

The described pulp feeders with a bundle require a large construction length and a complex distribution or pressure equalizer. The described pulp feeders with a perforated plate are expensive due to the parts to be connected to them and also require a rather large construction length.

The basic object of the invention is to make possible a simple, inexpensive and compact pulp feeding device.

In the pulp supply device according to the invention, this object is solved in that said expansion of the channels of the perforated plate is stepped so that at least two steps follow the initial part and that the junction between two successive channel parts is made with an opening angle ά of at least 100 °.

In this case, it is particularly important that the diameter of the channels on their inlet side is 8-22 mm, whereby the combined cross-sectional areas of the channels form 5-20% of the total cross-sectional area of the perforated plate. In addition, the length of the initial part must be 5-10 times the diameter of the channels on their inlet side. Finally, the diameter of the channels must be 25-40 mm on the outlet side, whereby the common cross-sectional area of the channels forms 40-85% of the total cross-sectional area of the perforated plate.

Especially favorable results are obtained if the channel diameter of the inlet side of 10-15 mm, the channels common cross-sectional surface forms a 8-15% orifice plate over the entire cross-sectional surface, and if the initial portion of a length of 6-8 times as large as the channel inlet side of the diameter, and if the channel diameter on their outlet side 25-40 mm, whereby the common cross-sectional area of the channels forms 50-75% of the total cross-sectional area of the perforated plate.

A fairly simple manufacture of a perforated plate can be achieved by arranging the channels in separate rows and one or more stages of one channel and the corresponding stages of adjacent channels in the same row merging in the row direction, the walls of the merging steps running at least substantially in the row direction.

It is particularly advantageous if all the steps following the beginning of the channels in one row converge in the row direction and the walls of the steps run exactly in the row direction. In this way, drilling of stairs can be avoided. Stairs can be formed by interconnected strips running the entire length of the row.

Compared to known pulp feeders, the pulp feeder according to the invention has substantial advantages. Preferably the flow accelerating orifice plate channels at the input side is created by a powerful choking, ensuring furnish all of the channels good distribution all the way down. Due to the stepped design of the expansion of the channels in the perforated plate, the deceleration following said acceleration of the flow in the perforated plate can take place without unstable separations and harmful deposits in a short way. In this case, the flow velocity at the end of the channels can only be slightly higher than the velocity of the part following the perforated plate of the mass feed, in which case the perforated plates to be connected behind the perforated plate, which form deposits, can be omitted.

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The drawing shows the embodiments of the invention in a simplified manner, and other embodiments of the invention are also described in connection therewith.

In the drawing: Figure 1 shows a vaakaleikkauskuvantoa direction of the channels perforated plate sectors, Figure 2 shows a view of a perforated plate of the arrow Z direction in Figure 1, Figure 3 shows a vaakaleikkauskuvantoa perforated plate and the pulp slurry outbound,

Fig. 4 shows a cross-sectional view taken along line IV-IV of Fig. 3

a, Figure 5 shows a pattern of four corresponding sectional view of a second embodiment, and Figure 6 shows the Figure 4 a similar sectional view of still another form of embodiment, Figure 7 shows a sectional view of the direction of the channels in the perforated plate sectors, Figure 8 shows a view of a perforated plate of the arrow in Figure 7 in the Y direction, Figure 9 shows a vaakaleikkauskuvantoa perforated plate, and of its pulp slurry inlet channel, Fig. 10 shows a sectional view along the line XX in Fig. 9, and Fig. 11 shows a sectional view corresponding to Fig. 7 of a different embodiment.

As shown in Figures 1 and 2, the paper machine t.m.s. the drawing of the perforated plate 1 for the supply of pulp shows only a sector extending over the entire width of the track to be formed and has several, parallel channels 2 for the pulp slurry. As a.o. four arrows indicate, the pulp slurry enters the channels 2 of the perforated plate 1 on the left inlet side 3 of the drawing and exits them on their outlet side 4.

The channels 2 of the perforated plate 1 are - in the flow direction of the pulp slurry - expanded stepwise after the initial part 5. The three steps following the initial part 5 are marked with the numbers 6, 7 and 8.

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On the inlet side 3 of the channels 2, their diameter, i.e. the diameter of the initial part 5 is 8-20 mm, preferably 10-15 mm, the cross-sectional surfaces of the channels 2 making up a total of 5-20%, preferably 8-15%, of the total cross-sectional area of the perforated plate 1. The length of the initial part 5 is 5-10 times, preferably 6-8 times, as large as the diameter of the channels 2 on their inlet side, i. than the diameter of the initial part 5. On the outlet side 4 of the channels 2, their diameter, i.e. the diameter of the step 8 is 25-40 mm, the cross-sectional surfaces of the channels 2 making up a total of 40-85%, preferably 50-75%, of the total cross-sectional area of the perforated plate 1.

The diameter of the stages 6, 7, 8 of the channels 2 is 1.2-1.5 times as large as the diameter of the respective channel part 5 or 6 or 7. The length of the different steps 6, 7,8 is 30-60 mm, preferably 40-50 mm.

The inlet edges of the ducts 2 are rounded with a radius of 25-35% on the inlet side of the ducts. i.e. initial part 5, diameter. Instead, the inlet edges of the channels 2 can be shaped with a bevel of 15-25% of the diameter of the initial part 5. The outlet edges of the channels 2 are rounded to a radius of 2-3 mm.

It is preferable to make the channels with a circular cross-section, as in the embodiment. If the channels are given a second cross-sectional shape, for example a hexagonal cross-section, then the diameter is considered to be the hydraulic diameter of the cross-section. .

The junction area between successive channel sections is made in the shape of a cone jacket and expands in the flow direction of the pulp slurry, with an opening angle λ of 100-150 °. However, the joint can also be formed on a surface running vertically to the axis of the channel, whereby it is advantageous to round the angle in the recess of the step.

The initial part 5 and the following steps 6, 7, 8 are made cylindrical. However, these channel sectors can be molded so that they expand in the flow direction of the pulp slurry by an opening angle of up to 3 °. However, it is preferable to select only an opening angle of 1-2 °.

The channels 2 with a cross-section of the circle are placed as close as possible. They all have the same distance a, where the distance b of adjacent rows is a / 2 · V3. This arrangement, resembling a cell structure, is indicated in Figure 2 by a cross-line of equilateral triangles drawn in thin lines.

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In the embodiment according to Fig. 3, the perforated plate 1 is shown in its entire dimension above the width of the track to be formed.

It is mounted in the pulp pit 9. The pulp slurry is introduced into the perforated plate 1 through an inlet channel 10 which runs transversely to its flow direction. The feed cross-section 11 of the inlet duct 10 is dimensioned so that the flow rate in this feed cross-section is 45-85% of the speed at which the flow takes place in the initial part 5 of the channels 2 of the perforated plate 1.

In addition, the cross section of the inlet channel 10 narrows substantially with respect to the width of the perforated plate 1.

For the backflow of the pulp slurry, the inlet channel 10 has an outlet cross section 12 which is 8-15% of the feed cross section 11.

The embodiment according to Figures 3 and 4 shows the advantages of the invention particularly clearly. The perforated plate 1 can be connected immediately in front of a simple inlet duct 10 supplying the pulp slurry obliquely, and the outlet nozzle 13 of the pulp pit 9 can be connected immediately behind the pulp pit 9.

As shown in Fig. 5, instead of the outlet nozzle 13 at the height of the lower edge of the perforated plate, an outlet nozzle 14 located at the height of the center of the perforated plate 1 can also be used.

Also in the form shown in Fig. 6, in which the pulp is removed by means of a compressed air cushion 15, the perforated plate 1 made according to the invention offers substantial advantages. The short perforated plate 1 can be connected immediately in front of the pulp pit and again a simple inlet channel 10 is sufficient for pulp distribution.

In the perforated plate shown in Figures 7 and 8, the four steps following the initial part 5 are marked with the numbers 6, 7, 8 and 9.

The channels 2 are arranged in separate rows 20, 21 and 22 and the steps 6, 7, 8, and 9 following the beginning 5 of the channels 2 of the rows 20, 21, 22 merge. in the direction of the line. The walls of the interlocking stairs 6, 7, 8, 9 run e.g. in the direction of the line.

On the inlet side 3 of the channels 2, their diameter, i.e. the diameter of the initial part 5 is 8-20 mm, preferably 10-15 mm, the cross-sectional surfaces of the channels 2 making up a total of 5-20%, preferably 8-15%, of the total cross-sectional area of the perforated plate 1. The length of the initial part 4 is 5-10 times, preferably 6-8 times, as large as the diameter of the channels 2 on their inlet side 3, i. than the diameter of the initial part 5.

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According to the above-mentioned cross-sectional area percentages (%), the holes of the initial parts 5 are close to each other. The width d of the step 6 immediately following the initial part is the same as the distance c of the holes of the initial parts 5.

In this case, the cross-sectional area serving the mass flow in the stage 6 is 1.3-2.3 times as large as the sum of the cross-sectional surfaces of the holes in the initial parts 5. In addition, the cross-sectional area of the stage 7 or 8 or 9 is 1.3-2.3 times as large as the cross-sectional area of the immediately preceding stage 6 or 7 or 8. The length of the different stages 6, 7, 8, 9 is 30-60 mm, preferably 40-50 mm.

The inlet edge of the ducts 2 is rounded with a radius of 25-35% of the diameter of the ducts on their inlet side, i. of the initial 5 diameters. Instead, the inlet edges of the channels 2 can be formed with a bevel of 15-25% of the diameter of the initial part 5.

The partitions between the last steps 19 of two adjacent rows 20, 21 and 22, 21 must be very thin. Out-flow side of the wheels of the four edges of the preferred partitions can also make the outlet side 4 towards the thinning continuously.

The junction area between two successive channel sections 5, 6 or 6, 7 and 7, 8 and 8, 9 can be made in the same way as described in connection with Figures 1 and 2. The channel parts also do not have to have a k.o. the cross-sectional areas remain the same along the entire length of the channel section, but the walls of the channels can have an opening angle of 1-2 ° (maximum 3 °) which expands the cross-section of the flow-through.

In the embodiment according to Figures 9 and 10, the hole plate is shown in its entire dimension over the entire width of the track to be formed. It is mounted in the pulp pit 9. The pulp slurry is fed to the perforated plate 1 through an inlet channel 10 which runs transversely to its flow direction. The feed cross-section 11 of the inlet duct 10 is dimensioned so that the flow velocity in this feed cross-section is 45-85% of the speed at which the flow takes place in the initial part 5 of the channels 2 of the perforated plate 1. For the backflow of the pulp slurry, the inlet channel 10 has an outlet cross section 12 which is 8-15% of the feed cross section.

The rows of channels in the perforated plate 1 extend over the width of the track to be formed, i.e. in Fig. 9 parallel to the drawing plane.

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However, the rows of channels can also run, for example, vertically with respect to the width of the track to be formed.

The perforated plate 1 shown in Fig. 11 is assembled from separate parts, namely a perforated strip 23 with holes in the initial part 5 and strips 24, 25, 26, 27 glued to the perforated strip 23 and to each other.

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Claims (8)

9,691 40 A feeding device for a paper machine or the like, having a perforated plate (1) extending over the entire width of the web to be formed, having a plurality of parallel channels (2) expanded in the flow direction of the pulp slurry for conveying the pulp slurry, characterized in that said perforated plate ( 1) the extension of the channels (2) is stepped so that at least two steps (6,7) follow after the initial part (5) and that the junction area between two successive channel parts (5,6,7,8) is made at an opening angle {?), which is at least 100 °. Feeding device according to Claim 1, characterized in that the junction area between the two successive duct sections (5,6,7,8) is formed by an opening angle (oC) of 180 °. Feeding device according to claim 1, characterized in that the diameter of the channels (2) on the inlet side is 8-22 mm, the sum of the cross-sectional areas of the channels (2) on their inlet side being 5-20% of the total cross-sectional area of the perforated plate (1). ) is 5-10 times the diameter of the channels (2) on their inlet side (3) and that the diameter of the channels (2) on their outlet side (4) is 25-40 mm, whereby the sum of the cross-sectional areas of the channels (2) is 40-85% of the perforated plate (1 ) over the entire cross-sectional area. Feeding device according to Claim 1, characterized in that the diameter of each stage (6,7,8) of the channels (2) is 1.2 to 1.5 times the diameter of the corresponding channel part (5,6,7) above. Feeding device according to Claim 1, characterized in that the channels (2) are arranged in separate rows (20, 21, 22) and in that one or more stages (16, 17, 18, 19) of one channel (2) and the corresponding steps (16,17,18,19) of the adjacent channels (2) of the same row (20,21,22) coincide in the direction of the row, the walls of the interlocking steps (16,17,18,19) being located at least substantially in the direction of the row (20); , 21, 22). Feeding device according to Claim 6, characterized in that all subsequent steps (16, 17, 18, 19) of the beginning of the channels (2) of one row (20, 21, 22) coincide in the row direction and that the steps the walls are located in the direction of the row. 10,691 40 Feeding device according to Claim 6, characterized in that the cross-sectional area of the channel part (16, 17, 18, 19) available for the flow of mass is 1.3 to 2.3 times in each case of the previous channel part (5, 16, 17, 18). ) cross-sectional area. Pulp feed device according to Claim 1, characterized in that the length of the individual steps (16, 17, 18) is 30 to 60 mm. Il 11 Patentkrav 69140