FI102774B - Blowing box used in paper machine drying section and method in paper machine drying section - Google Patents

Description

102774

Blowing Box and Method Used in the Drying Part of a Paper Machine Bläsningsläda för användning vid et torkningsparti av en pappersmaskin och förfarande vid et torkningsparti S av en pappersmaskin

The invention relates to a blow box 10 for use in a dryer section of a papermaking machine, comprising at least one chamber space and a nozzle arranged therewith through which a blow is arranged to be provided or roller and dryer wire, for example, to limit the pocket space to provide a vacuum effect on the wire runs, particularly the closing inlet nip.

The invention also relates to a method in a dryer section of a papermaking machine, wherein the method of providing an ejection effect utilizes a blow box located in a drying group employing normal single wire threading of the papermaking dryer for two adjacent drying cylinders

25

The dryer section of the paper machine is known to use single or double wire export. Single-wire delivery refers to an export in which the web passes from one drying cylinder to another, supported by one and the same drying wire, at intervals within the cylinder row. In a twin-wire feeder with top and bottom wire running, the web has free unsupported spaces as it passes from one cylinder row to another.

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The present invention relates mainly to single wire export. In prior art single-wire multi-cylinder dryers 35, the drawback has been the tendency of the web to separate from the surface of the drying wire in the cylinders where the drying web is forced out, which is further reinforced by the induction of excess silicon in the drying wire and cylinder surfaces. Said detachment even causes breaks, or at least bagging and wrinkling of the web.

As paper machine speeds increase, paper machine runnability 5 is further emphasized. In the prior art, various blowing boxes or so-called runner components have been used to enhance the runnability of a paper machine. One such is disclosed in Applicant's FI Patent Publication 80491, which discloses a blowing simulator for use in a multi-cylinder dryer for a papermaking machine to support the dryer wire when first leaving the dryer cylinder and the web to be dried by ejection blowing or blowing. . Puhallusimu-compartment provides a drying wire and the web inlet side of the ejection-15 blow the wire and the web travel in the direction opposite to the direction of ejecting a blowing said vacuum field and the turning cylinder, the blades adjoining the gap space vacuum field from said blow-suction boxes of the drying wire and 20 flow parallel to the ejection blowing is obtained at the output side the blow level of the wall or the like in connection against the dryer .

It is an object of the invention to further develop this known solution so as to further enhance the vacuum effect during driving.

It is a further object of the invention to provide a blowing box which can control the airspace of the pocket space also during threading of the web.

It is an important object of the invention to provide a blow box that achieves a vacuum as close as possible to it. past a movable body of a papermaking machine, such as a wire, and available during both normal driving and threading.

Reference may also be made to the F1 patent publication 82098, which discloses a nozzle arrangement for a paper machine blow box 3 102774, comprising one or more nozzles in connection with a blow box or tube through which a movable paper machine member, such as a wire, , * blasting of a drying cylinder, guide roll, felt or the like. The blow box and its nozzles have a certain functional safety clearance from the movable member. A nozzle flap hinged about a transverse hinge axis is hinged to the nozzle or nozzle slot. The nozzle flap controls air blasting to the intended target and possibly maintains the required differential pressure of 10. The nozzle flap is thus hinged so that, in its operative position, its outer edge has only the required operational safety distance much shorter than the moving machine member, and the nozzle flap can rotate to the required safety distance when a paper lump or other obstacle passes. The disadvantage of this known arrangement is that said nozzle flap can only control the discharge air from the nozzle one-sided, i.e. it cannot prevent the discharge air from the nozzle from expanding and consequently the maintenance of the differential pressure remains poor. Another disadvantage is that the blowing cannot be directed against the downstream direction of the nozzle flap. Nor does it take into account the different situations that occur during head-dressing.

It is also an object of the invention to provide an arrangement which provides sufficient safety distances for passing a stack of paper or other obstruction 25 along a wire past a blow box.

To achieve the above and later objects, the paper machine blow box collector of the invention is characterized in that the blow box comprises at least one movable nozzle such that the nozzle is close to the wire in normal driving conditions and has a nozzle and / or farther from the wire.

The process of the invention in the drying section of the papermaking machine, in turn, is essentially characterized in that the method blows at least one nozzle of the blister 102774 so that blowing is achieved as close as possible to the wire during normal driving and farther away from blowing.

5

According to the invention, the vacuum effect provided by the blower box can be enhanced by bringing the vacuum nozzles as close as possible to the wire and the web traveling with it.

The blowing box according to the invention is preferably a two-piece so-called pocket box, which, taking into account the safety clearance, essentially fills in the entire pocket space between the drying cylinders and the pivoting cylinder below them intermittently.

15

The box according to the invention preferably utilizes flexible nozzles which, when in contact with the paper stack or other similar barrier, avoid the nozzle so that it cannot break or otherwise damage the wire or pu-mold box.

The device according to the invention, while driving, enhances the vacuum effect and the deaeration and, in turn, provides a very effective deaeration during the head extension.

25

When using the device according to the invention in normal single wire delivery, the air volume of the lower pivoting suction cylinder can also be reduced since the blow box according to the invention can enhance the vacuum effect in the pocket, wire runs and closing inlet nip.

According to one embodiment of the invention, the blow box is divided into two parts, a basic box and a separate box. According to a preferred embodiment of the blowing box according to the invention, the second part 35 of the box is movable and is moved depending on the operating phase of the paper machine, i.e. its position in the driving / tapping position is different. This achieves the advantage that since each of these situations requires different venting arrangements, the box will achieve optimum venting for each step.

5 The base box is preferably fixed and is provided with a lower nozzle. The lower nozzle of the base box and the upper nozzle, if any, may be functionally insulated with separate blowing chambers.

A fixed pivoting box 10 is attached to the fixed base box, the pivoting of which is controlled by an actuator e.g.

The top nozzles of both boxes preferably employ flexible nozzle arrangements to prevent damage to the nozzles when any solid material passing through the wire strikes the nozzle.

15 The flexibility of the separate box top nozzle is very advantageous, the top box top nozzle can be replaced, if desired, with a seal which is close to the wire surface without touching it.

The principle in the operation of the box is that bringing the nozzle closer 20 can effectively influence the vacuum level generated by the box.

Thus, in the blow box according to the invention, the operation is enhanced by a rotatable separate box section, in which the flexible nozzle closer to the wire surface further raises the required vacuum level.

25 In addition to reaching the vacuum level, the effective venting of the nozzles is important in the case of head tapping. For this reason, the box is designed to operate in such a way that, in the event of a head-on, the air is exhausted as efficiently as possible through both the lower and upper nozzles 30. Upon successful completion of the head extension, the control box is rotated counterclockwise by the guide cylinder to obtain the most effective underpressure effect. If the separate box is swiveled to the base box, the air inlet of the base box lower nozzle will be cut off. Turning the box into a head-up situation can be done with a paper machine breaker 35.

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If desired, the proposed solution can also be implemented with both boxes rotatable, whereby the distance of both top nozzles from the wire surface can be adjusted to obtain the required vacuum effect.

5

In addition, the invention also improves the efficiency of the so-called pocket blowing box for single-wire export by optimizing the geometry of both top nozzles and by dividing the box into two parts by venting the nozzle.

10

The invention raises the bleed through the single-wire dryer section by improving the efficiency of the blower box. Efficiency is thus based on optimizing the mouth geometry of the blower box and central blowing in the optimum range.

15

The box can be made more efficient by reducing the angle between the nozzle and the wire. In this case, blowing will more effectively prevent the boundary layer air that comes with the wire from entering the box space.

20 the inlet side of the nozzle box will be a key operation, for which reason the amount of air coming from the nozzle has to be large enough to prevent the incoming boundary layer of air along the influence of the wire. The operation of the outlet nozzle is facilitated by a wire surface which expels air from the pocket space, which, like the nozzle, acts as a deaerating active part.

Other advantages include easier installation of the box into narrow drying geometries due to the two-part construction. In addition, the total amount of air to be blown in the system shown may be kept constant.

In the following, the invention will be described in more detail with reference to the figures in the accompanying drawings, in which details the invention is not intended to be narrowly limited.

35 102774 7

Fig. 1 schematically shows a blow box in the running position with the nozzles in close proximity to provide a high vacuum.

Fig. 2 schematically illustrates the blow-in position of the blow box-5to in which the actuator has moved the nozzles farther away, whereby the flow through the open wire is increased.

Figure 3 is a schematic illustration of a blow box application with a separate passage in the running position with the nozzle close to 10 wires and the auxiliary nozzle closed.

Figure 4 is a schematic illustration of a blow box application with a separate passage and box in the head-up position with the nozzle at a distance and the auxiliary nozzle open.

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Fig. 5 is a schematic illustration of a blower box application with fixed box components in the running position. In the position 2 shown in the figure, the passage between the boxes is closed and the flexible nozzle is located close to the cylinder, and in position 1 the fixed halves of the box are in the 20 threading position with the passage open and blowing on.

In the embodiments shown in Figures 1-6, two adjacent steam-heated drying cylinders 10 in the upper row RY are shown in the drying group applying the conventional single-wire method. The drying fabric 17, with its outer pin 25, passes through the drying group of the paper web W and presses it against the heated surfaces of the cylinders 10 to achieve an evaporative drying effect. Below the drying cylinders 10 are non-heated turning cylinders 14 or the like. The direction of rotation of the drying cylinders 10 and pivoting cylinders / rolls 14 is indicated in the figures by reference arrows S. -. Before / after the drying group, the drying section has one or more single-wire export groups or other types of drying groups as shown in the figures.

The arrangements shown in Figures 1-6 are particularly suited to situations where, for some reason, rotary roller 14 is unable to maintain / achieve normal suction power or requires even higher vacuum levels 102774 8 in rolls, or when it is desired to partially or fully

As shown in Figures 1-6, combined blowing boxes 20, fitted into the slots of the cylinders 10 are used. which cover the turning cylinders 14, etc. overhead free sectors as perfectly as the security clearances allow. The blowing boxes 20 comprise walls, on the inside of which are formed at least one chamber space 22, from which air is blown through the nozzle (s) 30,37,38,39 to achieve the desired effect. The bottom of the blow box 20 may, if necessary, be provided with end sealing strips 21 against the outer surface of the roll 14.

The blowing boxes 20 shown schematically in Figures 1-6 are so-called pocket boxes 15 which substantially fill the two adjacent drying cylinders 10 and the pocket space T, which is partially limited by the pivoting roll 14 and the wire 17 interlaced with them.

1-6, the nozzle 30 is a resilient nozzle formed by a stationary blow box body 33 and a pivotally movable nozzle member 32 having a nozzle opening 40. The movable nozzle member 32 comprises an air chamber 43, nozzle port 40. The body member 33 is provided with a pivot space in which a pivot part 35 made at a point opposite to the nozzle opening of the movable nozzle member 32 is disposed movably in this pivot space 34. In the normal driving position, the spring 31 secured to the body member 33 is open and holds the movable nozzle member 32 in the driving position, i.e. the nozzle opening 40 as close as possible to the wire 17 passing through it or the like. When the paper stack, memory or the like is located near the nozzle, the movable nozzle member 32 moves out of the way to prevent the nozzle member 30 or the wire 17 from being broken or damaged. Under the influence of the paper body or the like, the spring 31 is compressed and thus pulls the movable nozzle body towards the body part 33, leaving a larger space between the nozzle part 32 and its adjacent wire 17 or the like, allowing the paper body to pass.

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Fig. 1 schematically illustrates a blowing box 20 in a running position with the nozzles 30 close to the cylinder 10 and the wire 17, which results in a high vacuum because the nozzles 30 are moved by actuator 50 as close as possible to the cylinder 10 and wire 17. decreases. The pivot portions 34,35 of the nozzles 30 are connected via the shaft 51 to the actuator 50, whereby the actuator actuates the movable nozzle portion 32 of the nozzle 30 via the pivot part 34,35.

10

Fig. 2 shows the blow box 20 of Fig. 1 in the head-tapping position, whereby the nozzles 30, i.e. their movable nozzle parts 32, are moved away from the cylinder 10 by an actuator 50, whereby the flow through the open wire 17 is increased. After the head-up 15 situation, the actuator 50, via the shaft 51 and the pivot portion 34.35, returns the nozzle 30 to the driving position.

The invention raises the venting by a single-wire dryer section based on optimizing the mouth geometry of the blow box 20, i.e., bringing the nozzle 30 as close to the wire as possible.

In Figures 3-5, the blow box 20 is divided into two parts.

Other advantages of the embodiments shown in Figures 3-5 include easier installation of the system-25 min in narrow drying geometries due to the two-part structure. In addition, in the configuration shown, the total amount of air to be blown remains constant.

In the embodiment shown in Figures 3 and 4, the blow box 20 is formed of two parts, consisting of a movable separate part 61 and a fixed part 62. The movable member 61 is pivotally secured to the fixed box member 62 by a securing member 64, which is flexible if necessary. The position of the pivoting box 61 is rotated through the actuator 63 as shown by the arrows S63. There is a passage Z between the box portions 61.62 35. The movable portion 61 is disposed on the inlet side, whereby its nozzle orifice 38 is blown ejection blast against the running direction of web W 102774 10 to enhance the vacuum effect. The nozzle of the movable member 61 may also be a flexible nozzle 30.

Figure 3 shows the blow box 20 in the running position with the nozzle 5 38 close to the cylinder 10 and the auxiliary nozzle 37 closed and the blow box 20 with a separate passage Z.

Figure 4 shows the blow box of Figure 3 with a separate passage Z in the head-up position, with nozzle 38 distant from cylinder 10 and auxiliary nozzle 37 open.

In the embodiment of Figures 3 and 4, the larger base box 62 is fixed and provided with a lower nozzle 37. The lower nozzle 37 and optional upper nozzle 30 of the base box 62 are preferably functionally insulated with separate blowing chambers (not shown). Attached to the fixed base box 62 is a pivotable disc box 61, the pivoting of which is controlled by the actuator 63, e.g., a control cylinder. The principle of operation of the box 20 is that bringing the nozzle 38 closer can effectively influence the vacuum 20 of the box 20.

In addition to reaching the vacuum level, the effective venting of the nozzles is important in the case of head tapping. For this reason, the box 20 is designed to operate in such a way that, in a head-up situation, the air 25 is exhausted as effectively as possible by means of both the lower and the upper nozzles 30,37; When the head insertion is successful, the individual box 61 is rotated counterclockwise by the control cylinder 63 to obtain the most effective vacuum effect possible. If the stand-alone box 61 is pivoted to the base box 62, the air supply to the lower nozzle 37 30 of the base box 62 is cut off.

If desired, the solution shown may also be implemented so that both boxes 61.62 are pivotable, whereby the distance of both top nozzles from 38.30 to the wire surface can be adjusted to obtain the required vacuum 35 effect.

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Figure 5 schematically illustrates a blow box 20 with fixed box members 71.72 in running position 2 with groove Z closed and flexible nozzle 30 close to cylinder, and in position 1 the fixed halves 71,72 are in threading position with groove Z open and pu-5 hallus 39 is on. Sole Z can be closed / unlocked by actuator 72 and vent port 39 can be opened and closed by actuator 74.

In the solution shown, the upper nozzles 30 10 of both box portions 71.72 employ flexible nozzle arrangements to prevent damage to the nozzles 30 and the wire 17 as any solids carried by the wire 17 pass by the nozzle. The flexibility of the upper nozzle 30 of the left separate box 71 is necessary, the upper nozzle 30 of the basic box 72 may be replaced by a seal close to the wire surface 17 without touching it, since the wire 17 carries air out of the pocket space.

Fig. 6 shows a simple embodiment of the invention, in which the blow box 20 is provided with flexible nozzles 30 on both the inlet and outlet sides. Unlike the above application examples, this box does not have a separate option for head-up and normal driving situations.

The invention has been described above only with reference to one preferred embodiment thereof, the details of which, however, are not intended to be narrowly limited. Many modifications and variations are possible within the scope of the inventive idea defined in the following claims.

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Claims (12)

A blower for use in a drying portion of a paper machine, said blower comprising at least one carnal space (22) and a nozzle (30,37, 38,39) arranged therewith, a blower being arranged to be provided therethrough; said blower (20) being located in a dryer group which applies normal single wire routing in the drying portion of the paper machine in a pocket (T) to a portion limited by two adjacent drying cylinders (10) and a lower break cylinder or roller (10) located therebetween ) and a drying wire (17) for providing the suppressive action at the viral race, in particular in the sealing entrance nip, can be characterized in that the blower (20) comprises at least one sliding nozzle (30,38) in such a manner that the nozzle (30) , 38) in a normal driving situation is located near the wire 15 (17) and the nozzle (30,38) is displaced or moves further away from the wire (17) for end guide and / or bypass sizing of a paper lump or equivalent. Blower according to claim 1, characterized in that the displaceable nozzle (30) of the blower (20) is formed by a stationary body part (33), which is pivotally attached to a movable nozzle part (32), which movable nozzle portion (32) is displaceable by mediating a functional device (50) to the proximity of the wire (17) for the time of normal driving and away from the wire (17) for the time of an end position. 3. A blowing carriage according to claim 1, characterized in that the blowing carriage (20) is formed of two parts and that at least one of the parts (61) is slidable by means of a functional device 30 (63) in such a way that a the nozzle opening (38) formed in the part (61) is located as close to the wire (17) as possible during normal driving and the nozzle (38) is displaced by oscillation of the leather part (61) further away from the wire (17) for the time of an end position. 35 102774 16 Blower as claimed in claim 3, characterized in that a lower nozzle (37) is arranged on the second statonary part (62) of the blower (20), which is arranged to be closed when pivoting the sliding part (61) into normal driving position. and which lower nozzle 5 (37) is arranged to be open during an end-to-end situation for achieving the largest possible outlet. Bladder carriage according to claim 1, characterized in that the blower carriage is formed of two parts, between which is a passport (Z), which can be opened and closed either by displacement of one part (61) of the carriage (20) or by mediation of a functional organ (73). A blower as claimed in claim 5, characterized in that in the end of the passageway (Z) facing the breaking cylinder (14) there is arranged a blow opening (39) which can be opened and closed by means of a functional means (74) in such a manner. , that the blow aperture (39) is open during an end closure situation. Blower according to any of the preceding claims, characterized in that the blower (20) has at least one resilient nozzle (30) comprising a stationary body part (33) and a movable nozzle part (32), which are joined to each other by the mediation of a spring (31) and a hinge (34,35) in such a manner that when a paper lump or the corresponding hits against the moving part (32), the spring (31) is arranged to be pressed assembled in such a manner that the lump of paper or the like may pass past the nozzle (30) to displace the movable nozzle portion (32). A method in a drying portion of a paper machine, wherein the method is used to effect the ejection action of a blower (20) located in a drying group applying normal single-wire feeding in the drying portion of the paper machine in a pocket (T) space. a portion limited by two adjacent drying cylinders (10) and a lower breaking cylinder or roller (14) located therebetween, and a drying wire (17), characterized in that in the process at least one nozzle (30,38) of the blower ( 20) is displaced in such a way that during normal driving, the blow is achieved as close to the wire (17) as possible and the blow is further farther away from the wire (17) during the ending and / or bypassing of a paper lump or equivalent. 5 9. A method according to claim 8, characterized in that in the method a nozzle (30) is displaced, the movable nozzle part (32) of a stationary body part (33) which is pivotally fastened by means of a functional device (50) being moved to the vicinity of the wire (17). ) for the time of normal driving and away from the wire (17) for the time of an ending situation. Method according to claim 8, characterized in that in the method a part (61) of the blower (20) is displaced by means of a functional device (63) in such a way that a nozzle opening (38) formed in the displaceable part (61) ) is located as close to the wire (17) as possible during normal driving and that the nozzle (38) is displaced by oscillation of the slidable part (61) further away from the wire (17) for the time of an end position. 20 11. A method according to any of claims 8 to 10, characterized in that the method uses an additional nozzle (37) for providing the largest possible outlet during an end-loading situation. 25 Method according to any of claims 8-11, characterized in that the method uses at least one resilient nozzle (30) comprising a stationary body part (33) and a movable nozzle part (32) which are joined together by means of mediation. of a spring (31) and a hinge (34,35) in such a manner that when a lump of paper 30 or similar hits against the moving part (32), the spring (31) is pressed together to displace the moving part and the nozzle part (32) means that the paper lump or equivalent can pass past the nozzle (30). 35