PARTANEN, Hannu (Alvettulanmutka 15, Jyväskylä, FI-40520, FI)
CLAIMS
1. A method for adjusting the distance of a suction box (21) used in a web-forming machine from an outer surface of a shell (11) of a counter roll (10), which suction box (21) comprises a curved cover (23) and a bottom (25) opposite in relation to the cover (23) and which suction box (21) is supported from its ends to bearing cups (13a, 13b) of the counter roll (10) by means of slot pieces (41a, 41b), characterised in that the suction box (21) is supported from its bottom (25) to a support structure (31) by means of pressure hoses (51a, 52b, 51b, 52b), whereby a section between the slot pieces (41a, 41b) of the suction box (21) is movable in the radial direction of the counter roll (10) by means of a pressure medium prevailing in pressure hoses (51a, 52b, 51b, 52b, 510a, 510b, 520a, 520b).
2. A method according to claim 1, characterised by the following steps: - fastening at a first edge of the bottom (25) of the suction box (21) a first support rail (22a, 220a),
- fastening at a second edge of the suction box (21) a second support rail (22b, 220b),
- fastening to the support structure (31) a first counter support rail (32a, 320a), - fastening to the support structure (31) a second counter support rail (32b,
320b),
- arranging a joint of the first support rail (22a, 220a) and the first counter support rail (32a, 320a) so that it comprises a first space in which a first pressure hose (51a, 510a) is located and a second space in which a second pressure hose (52a, 520a) is located,
- arranging a joint of the second support rail (22b, 220b) and the second counter support rail (32b, 320b) so that it comprises a third space in which a third pressure hose (51b, 510b) is located and a fourth space in which a fourth pressure hose (52b, 520b) is located, - whereby the first support rail (22a, 220a) and the first counter support rail (32a, 320a) and the second support rail (22b, 220b) and the second counter support rail (32b, 320b) are movable in relation to each other by means of a pressure medium prevailing in said pressure hoses (51a, 52a, 51b, 52b, 510a, 520a, 510b, 520b).
3. A method according to claim 2, characterised by the following steps:
- locating into a rectangular shaped space formed between inner surfaces of horizontal arms of the first support rail (22a) in the shape of a letter L and the first counter support rail (32a) in the shape of a letter L a first pressure hose (51a), - locating into a rectangular shaped space formed between an outer surface of the horizontal arm of the first support rail (22a) and an upper surface of the support structure (31) a second pressure hose (52a),
- locating into a space formed between inner surfaces of horizontal arms of the second support rail (22b) in the shape of a letter L and the second counter sup- port rail (32b) in the shape of a letter L a third pressure hose (5 Ib),
- locating into a rectangular shaped space formed between an outer surface of a horizontal arm of the second support rail (22b) and the upper surface of the support structure (31) a fourth pressure hose (52a).
4. A method according to claim 2, characterised by the following stages:
- locating into a rectangular shaped space formed between a lower surface of an upper horizontal arm of the first support rail (220a), comprising a vertical arm and two horizontal arms at a distance from each other, and an upper surface of a horizontal arm of the first counter support rail (320a) in the shape of a letter L a first pressure hose (51 Oa),
- locating into a rectangular shaped space between an upper surface of the lower horizontal arm of the first support rail (220a) and a lower surface of the horizontal arm of the first counter support rail (320a) a second pressure hose (520a), - locating into a rectangular shaped space formed between a lower surface of an upper horizontal arm of the second support rail (220b), comprising a vertical arm and two horizontal arms at a distance from each other, and an upper surface of a horizontal arm of the second counter support rail (320b) in the shape of a letter L a third pressure hose (51 Ob),
- locating into a rectangular shaped space between an upper surface of the lower horizontal arm of the second support rail (220b) and a lower surface of the horizontal arm of the second counter support rail (320b) a fourth pressure hose (520a).
5. An arrangement for adjusting the distance of a suction box (21) used in a web- forming machine from an outer surface of a shell (11) of a counter roll (10), which suction box (21) comprises a curved cover (23) and a bottom (25) opposite in relation to the cover (23) and which suction box (21) is supported from its ends to bearing cups (13a, 13b) of the counter roll (10) by means of slot pieces (41a, 41b), characterised in that the suction box (21) is supported from its bottom (25) to a support structure (31) by means of pressure hoses (51a, 52b, 51b, 52b), whereby a section between the slot pieces (41a, 41b) of the suction box (21) is movable in the radial direction of the counter roll (11) by means of a pressure medium prevailing in pressure hoses (51a, 52b, 51b, 52b, 510a, 510b, 520a, 520b).
6. An arrangement according to claim 5, characterised in that the fastening between the suction box (21) and the support structure (31) comprises:
- a first support rail (22a, 220a) fastened to a first edge of the bottom (25) of the suction box (21),
- a second support rail (22b, 220b) fastened to a second edge of the suction box (21),
- a first counter support rail (32a, 320a) fastened to the support structure (31),
- a second counter support rail (32b, 320b) fastened to the support structure (31),
- a joint between the first support rail (22a, 220a) and the first counter support rail (32a, 320a) which joint comprises a first space in which a first pressure hose (51a, 510a) is located and a second space in which a second pressure hose
(52a, 520a) is located, - a joint between the second support rail (22b, 220b) and the second counter support rail (32b, 320b) which joint comprises a third space in which a third pressure hose (51b, 510b) is located and a fourth space in which a fourth pressure hose (52b, 520b) is located, - whereby the first support rail (22a, 220a) and the first counter support rail (32a, 320a) and the second support rail (22b, 220b) and the second counter support rail (32b, 320b) are movable in relation to each other by means of a pressure medium prevailing in said pressure hoses (51a, 52a, 51b, 52b, 510a, 520a, 510b, 520b).
7. An arrangement according to claim 6, characterised in that the fastening between the suction box (21) and the support structure (31) comprises:
- a first pressure hose (51a) located in a rectangular shaped space formed between inner surfaces of horizontal arms of the first support rail (22a) in the shape of a letter L and the first counter support rail (32a) in the shape of a letter
L,
- a third pressure hose (52a) located in a rectangular shaped space formed between a lower surface of a horizontal arm of the first support rail (22a) and the upper surface of the support structure (31), - a third pressure hose (51b) located in a rectangular shaped space formed between an inner surfaces of horizontal arms of the second support rail (22b) in the shape of a letter L and the second counter support rail (32b) in the shape of a letter L,
- a fourth pressure hose (52a) located in a rectangular shaped space formed be- tween a lower surface of the horizontal arm of the second support rail (22b) and the upper surface of the support structure (31).
8. An arrangement according to claim 6, characterised in that the fastening between the suction box (21) and the support structure (31) comprises: - a first pressure hose (510a) located in a rectangular shaped space formed between a lower surface of an upper horizontal arm of the first support rail (220a), comprising a vertical arm and two horizontal arms at a distance from each other, and an upper surface of a horizontal arm of the first counter support rail (320a) in the shape of a letter L,
- a second pressure hose (520a) located in a rectangular shaped space between an upper surface of a lower horizontal arm of the first support rail (220a) and a lower surface of a horizontal arm of the first counter support rail (320a),
- a third pressure hose (510b) located in a rectangular shaped space formed between the lower surface of an upper horizontal arm of the second support rail (220b), comprising a vertical arm and two horizontal arms at a distance from each other, and an upper surface of a horizontal arm of the second counter support rail (320b) in the shape of a letter L,
- a fourth pressure hose (520a) located in a rectangular shaped space between an upper surface of a lower horizontal arm of the second support rail (220b) and a lower surface of the horizontal arm of the second counter support rail (320b). |
Adjusting the distance of a suction box from a counter roll
FIELD OF THE INVENTION
The invention relates to a method according to the preamble of claim 1.
The invention also relates to an arrangement according to the preamble of claim 5.
PRIOR ART
In paper and board machines, suction boxes are used in many locations for removing water from the web and/or for transferring the web from one fabric to another.
EP patent specification 912798 describes a suction box used in a paper or board machine. In the suction box, there are moving strips, which form a curved surface at least in the use situation of the suction box. The strips are located into U- formed holders in which there are load elements by means of which the strips can be loaded against the wire.
FI patent specification 943909 describes a method and a device in a strip former in which the load forces of load strips are provided by means of uncompressed liquid pressure medium. For moving the load strips hydraulic hoses are used, whereby the pressure load of the load strips is obtained substantially rigid.
Suction boxes according to prior art, being curved and functioning against a counter roll, are usually supported to the bearing cups of the roll by means of slot pieces. The slot pieces are dimensioned so that the distance of the cover of the suction box from the outer surface of the shell of the counter roll becomes as desired. The section of the suction box between the slot pieces is usually unsup- ported. The negative pressure of the suction box and the tension of the fabrics travelling on the surface of the roll contribute to form forces acting on the suction
roll, which tend to pull the suction box towards the counter roll. When only the ends of the suction box are supported with the slot pieces to the bearing cups of the counter roll, the suction box can due to the above-mentioned forces deflect to a curve from the middle. The centre part of the suction box is then closer to the outer surface of the shell of the counter roll than the end parts of the suction box. This can again cause problems for the moisture profile of the web.
SUMMARY OF THE INVENTION
With the arrangement according to the invention, the distance of the cover of the suction box from the outer surface of the shell of the counter roll can be kept as desired over the whole length of the suction box.
The principal characteristic features of a method according to the invention are presented in the characterising part of claim 1.
The principal characteristic features of an apparatus according to the invention are presented in the characterising part of claim 5.
The other characteristic features of the invention are presented in the dependent claims.
In the arrangement according to the invention, the suction box is supported from its bottom to the support structure by means of pressure hoses, whereby the posi- tion of the suction box in relation to the counter roll can be adjusted.
The suction box according to the invention is applicable to be used in a web- forming machine. In this specification, a web-forming machine refers to a paper, board, tissue or pulp-drying machine.
BRIEF DESCRIPTION OF THE FIGURES
Fig. 1 shows a schematic cutaway diagram in the cross direction of the machine of a suction box and a counter roll related to it.
Fig. 2 shows a schematic section A-A of Fig. 1 in the longitudinal direction of the machine.
Fig. 3 shows an enlargement of point Bl of Fig. 2.
Fig. 4 shows an enlargement of point B2 of Fig. 2.
Fig. 5 shows an alternative to fastening a first edge of the suction box to the support structure shown in Fig. 3.
Fig. 6 shows an alternative to fastening a second edge of the suction box to the support structure shown in Fig. 4.
DESCRIPTION OF ADVANTAGEOUS EMBODIMENTS
Fig. 1 shows a schematic cutaway diagram in the cross direction of the machine of a suction box 21 and a counter roll 10. The counter roll 10 comprises a shell 11 to the ends of which are fastened shaft journals 12a, 12b. The shaft journals 12a, 12b, for their part, are rotatably supported to bearings in bearing cups 13a, 13b and the bearing cups 13a, 13b are supported to the frame structures of the ma- chine.
The suction box 21 is supported from its ends by slot pieces 41a, 41b to the bearing cups 13 a, 13b of the counter roll 11. The suction box 21, on the other hand, is supported from its opposite side in relation to the slot pieces 41a, 41b i.e. from the bottom 25 to a support structure 31 which in turn is supported to the frame structures of the machine.
Fig. 2 shows a schematic section A-A in the cross direction of the machine of the roll 10 and the suction box 21 shown in Fig. 1. The suction box 21 comprises a cover 23 of curved shape in which there are openings 24 via which negative pres- sure in the suction box 21 is conveyed to a space between the cover 23 of the suction box 21 and the roll 10. A web 63 travels on the outer surface of the shell 11 of the roll 10 between two fabrics 61, 62. At a first edge of the bottom 25 of the suction box 21, there is a first support rail 22a in the shape of letter L and at a second edge of the bottom 25 of the suction box 21 there is a second support rail 22b in the shape of letter L. In the support structure 31, there are in a corresponding manner a first counter support rail 32a in the shape of letter L and a second counter support rail 32b in the shape of letter L. Into a first rectangular shaped space between the upper surface of the horizontal arm of the letter L of the first support rail 22a and the lower surface of the horizontal arm of the letter L of the first counter support rail 32a is located a first pressure hose 51a. Into a second rectangular shaped space between the lower surface of the horizontal arm of the letter L of the first support rail 22a and the upper surface of the support structure 31 is located a second pressure hose 52a. Into a third rectangular shaped space between the upper surface of the horizontal arm of the letter L of the second sup- port rail 22b and the lower surface of the horizontal arm of the letter L of the second counter support rail 32b is located a third pressure hose 51b. Into a fourth rectangular shaped space between the lower surface of the horizontal arm of the letter L of the second support rail 22b and the upper surface of the support structure 31 is located a fourth pressure hose 52b.
The first pressure hose 51a and the third pressure hose 51b constitute a first pair of pressure hoses. The second pressure hose 52a and the fourth pressure hose 52b constitute a second pair of pressure hoses.
Fig. 2 also shows a laser 71 by means of which one can measure the distance of the cover 23 of the suction box 21 from the outer surface of the shell 11 of the roll
10 and/or the straightness of the cover 23 of the suction box 21 in the cross- machine direction.
Fig. 3 shows an enlargement of point Bl of Fig. 2 showing the fastening of the first edge of the suction box 21 to the support structure 31. At the bottom of the suction box 21, there is the first support rail 22a in the shape of letter L and in the support structure 31 there is in a corresponding manner the first counter support rail 32a in the shape of letter L. Into the first rectangular shaped space between the inner surfaces of the horizontal arm of the letter L of the first support rail 22a and the first counter support rail 32a is located the first pressure hose 51a. Into the second rectangular shaped space between the outer surface of the horizontal arm of the letter L of the first support rail 22a and the upper surface of the support structure 31 is located the second pressure hose 52a.
Fig. 4 shows an enlargement of point B2 of Fig. 2 showing the fastening of the second edge of the suction box 21 to the support structure 31. At the bottom of the suction box 21, there is the second support rail 22b in the shape of letter L and in the support structure 31 there is in a corresponding manner the second counter support rail 32b in the shape of letter L. Into the third rectangular shaped space between the inner surfaces of the horizontal arm of the letter L of the second support rail 22b and the second counter support rail 32b is located the third pressure hose 51b. Into the fourth rectangular shaped space between the outer surface of the horizontal arm of the letter L of the second support rail 22b and the upper surface of the support structure 31 is located the fourth pressure hose 52b.
Fig. 5 shows an alternative to fastening a first edge of the suction box 21 to the support structure 31 shown in Fig. 3. A first support rail 220a at the bottom 25 of the suction box 21 is constituted of a vertical arm and two horizontal arms at a distance from each other. A first counter support rail 320a fastened to the support structure 31 is in L shape, the horizontal arm of which positions itself in a space between the horizontal arms of the first support rail 220a. Into a first rectangular
shaped space between the lower surface of the upper horizontal arm of the letter L of the first support rail 220a and upper surface of the horizontal arm of the first counter support rail 320a is installed a first pressure hose 510a. Into a second rectangular shaped space between the upper surface of the lower horizontal arm of the first support rail 220a and the lower surface of the horizontal arm of the first counter support rail 320a is installed a second pressure hose 520a.
Fig. 6 shows an alternative to fastening a second edge of the suction box 21 to the support structure 31 shown in Fig. 4. A second support rail 220b at the bottom 25 of the suction box 21 is constituted of a vertical arm and two horizontal arms at a distance from each other. A second counter support rail 320b fastened to the support structure 31 is in L shape, the horizontal arm of which positions itself in a space between the horizontal arms of the second support rail 220b. Into a third rectangular shaped space between the inner surface of the upper horizontal arm of the second support rail 220b and the upper surface of the horizontal arm of the first counter support rail 320b is located a third pressure hose 510b. Into a fourth rectangular shaped space between the upper surface of the lower horizontal arm of the second support rail 220b and the lower surface of the horizontal arm of the second counter support rail 320b is installed a fourth pressure hose 520a.
The distance of the cover 23 of the suction box 21 from the outer surface of the shell 11 of the counter roll 10 can thus be adjusted by the pressure hoses 51a, 51b, 510a, 510b constituting the first pair and the pressure hoses 52a, 52b, 520a, 520b constituting the second pair. By increasing the pressure in the pressure hoses 51a, 51b, 510a, 510b constituting the first pair and by decreasing the pressure correspondingly in the pressure hoses 52a, 52b, 520a, 520b constituting the second pair, the cover 23 of the suction box 21 transfers farther from the outer surface of the shell 11 of the counter roll. By increasing the pressure in the pressure hoses 52a, 52b, 520a, 520b constituting the second pair and by decreasing the pressure correspondingly in the pressure hoses 51a, 51b, 510a, 510b constituting the first pair, the cover 23 of the suction box 21 transfers closer to the outer surface of the
shell 11 of the counter roll 10. The suction box 21 is supported from its ends rigidly to the bearing cups 13a, 13b by means of the slot pieces 41a, 41b, whereby by adjusting the pressure of the pressure hoses 51a, 51b, 510a, 510b constituting said first pair and the pressure hoses 52a, 52b, 520a, 520b constituting said second pair the section between the support pieces 41a, 41b of the suction box 21 is affected. In this way, the curved cover 23 of the suction box 21 can be kept all the time for the whole width of the machine straight and at a standard distance from the outer surface of the shell 11 of the roll 10.
In the fastening between the suction box 21 and the support structure 31, the use of the pressure hoses 51a, 51b, 52a, 52b, 510a, 510b, 520a, 520b in adjusting the distance between the suction box 21 and the outer surface of the shell 11 of the counter roll 10 is substantial.
Each pressure hose 51a, 52a, 51b, 52b, 510a, 510b, 520a, 520b can be constituted of an integrated pressure hose extending over the whole length of the suction box 21. Each pressure hose, on the other hand, can be constituted of several separate parts, whereby pressure medium prevailing in each part is separately adjustable. By means of pressure hoses constituted of separate parts, the zone adjustment of the suction box 21 can be implemented.
In the embodiments shown in the figures, the suction box 21 is supported to the support structure 31 by two pressure hoses 51a, 52a, 51b, 52b, 510a, 520a, 510b, 520b constituting a pair. In this way, the section of the suction box 21 between the suppoit pieces 41a, 41b can be deflected both towards the roll 10 and away from the roll 10. However, the invention can also be implemented so that the lower pressure hoses 52a, 52b, 520a, 520b are omitted, whereby the section of the suction box 21 between the support pieces 41a, 41b can be deflected with the upper pressure hoses 51a, 51b, 510a, 510b only away from the roll 10. Then, the suction box 21 can be supported from below from its ends e.g. by means of bellows via the support pieces 41a, 41b against the bearing cups 13a, 13b. Furthermore, the
invention can also be implemented so that the upper pressure hoses 51a, 51b, 510a, 510b are omitted, whereby the section suction box 21 between the support pieces 41a, 41b can be deflected with the lower pressure hoses 52a, 52b, 520a, 520b only towards the roll 10.
Above were described only some advantageous embodiments of the invention and it is evident for those skilled in the art that several modifications can be made to them within the scope of the enclosed claims.
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