FI119775B - Apparatus for distributing steam - Google Patents

Description

Apparatus for distributing steam

The invention relates to a device for applying steam to a moving web of material, e.g. to a paper web to be dried and passing through a press section of a papermaking machine. Such a device primarily comprises a steam blasting box. Reference is made to DE 41 25 062 A1.

10 Such a steam blasting box is mainly used in papermaking. Its purpose is to increase the temperature of the material web by increasing the drying efficiency of the press section by applying steam to the material web. The steam blasting plate then offers the possibility of influencing the moisture-transverse profile of the material web by the use of different steam imports.

In the known structure, the steam exiting the compartment chambers (or 1-zone chambers ") is controlled by valves 20 located inside the steam blasting box. Each repair zone is provided with a separate valve, usually a pneumatic control.

The exclusion of the control valve means that the corresponding zone can no longer be repaired, resulting in a degradation of the paper quality. Replacing defective valve • · ·:. requires expensive downtime. Until then, a steady state of operation is achieved, it is often necessary to have a long period of time (I disassembly, installation and • · · *; ”130 heating time).

• · ·

It is an object of the invention to provide a device of the type described above, which satisfies as many of the following requirements as ί.ϊ:. ••• .35 1. It must be possible to select the width of the zone chambers • · ***. minimized and number of zone chambers • ·. correspondingly as large as possible (steam blast slab: 1 '· 1 at a certain length of the barbell).

2. The control valves must be capable of simple repair or replacement without the need to temporarily stop the machine for this purpose.

2 5 3. The distance between the steam blast box and the passing web (which is mostly supported by the roll) must be adjustable. In normal operation, the distance should be relatively short, but relatively high for start-up or maintenance purposes.

10

The features of claim 1 are decisive for the set task.

While prior art size control valves 15 determine the minimum width of the zone chambers, according to the invention, the zone chambers can be dimensioned to be extremely small, since the control valves are located in principle outside the steam blast box and sideways adjacent to the machine.

20 This also gives the advantage that the control valves are also accessible when operating the machine so that, if necessary, the control valve or other control valves • · ·: *. · Can be repaired or replaced without the need for expensive • · Σ.ί.ϊ 25 shutdown necessary.

It is indeed necessary in the construction method according to the invention. Each zone chamber is connected by its own ("compartment") steam line to the control valve. In addition, the difficulty is that due to the required displaceability of the steam blast box, each section steam line must be made to be movable. thus steam • «· '· [' the part attached to the blasting box (with the inlet end outside the steam blasting box) and the movable ....: 35 which is connected (directly or indirectly) * to the said control valve and connected to said inlet head In this connection, the essential part of the invention is based on the fact that the distance between the adjacent inlet ends (wire sections attached to the steam blasting box) is substantially greater than that of the adjacent compartment steaming inside the blasting box. distance between htts.

In other words: the parts attached to the steam blasting box of the sectional steam lines are fan-spread against the flow direction outside the blasting box. Only this makes it possible to provide an unusually large number of sectional steam conduits (and thus a very large number of relatively narrow zone chambers) with relatively small cross-sectional dimensions of the steam blasting box, yet sufficient space is available at the inlet end for switchable movable conduit connections.

In a preferred embodiment of the invention, the following is provided: Steam is supplied from the main steam line to a steam dispenser mounted outside the paper machine, preferably adjacent to the paper machine, e.g., on the drive side or e.g. in the basement; This steam distribution device is equipped with individual control elements (control valves). Each individual zone chamber in the steam room: .1 hall is connected by means of a separate compartment steam line to the corresponding control valve. The parts attached to the steam blast chamber of the compartment steam line end (against the flow direction) outside the steam blower: on a plate, eg an installation plate, which is · · · fixed to the steam blower box. Installation The flexible wires between the plate and the control valves receive the shaking movements and compensate for the possible heat expansion of the · · · ΓΙΙ box. The valve drive • · · * ·] 'is controlled by an electric motor.

The invention will now be described by a preferred embodiment '. with the accompanying drawings: Figure 1 overall view; 4

Fig. 2 is a cross-sectional view of a steam blasting box;

Fig. 3 a zone chamber having a perforated plate insert; Fig. 4/5 Connection of flexible wires with steam blast box wires, Fig. 4: open, Fig. 5: closed

Fig. 6 installation example in press section; 10

FIGS. 7/8 is an exemplary embodiment different from FIGS. 2 and 3.

The steam blasting box 48 consists of a self-supporting stainless steel structure; it extends across the paper machine transverse to the web travel direction from the treatment side FS to the drive side TS (Fig. 8). In Figure 1, only the use of the steam blow box-side end is shown. The lower support frame 1, 1 'is welded with strips 43 having bores 10 and 11. The lower support frame 1, 1' and the upper support frame 2 are interconnected by side walls 8 and 9. This design provides optimum transverse stability. The support frames 1, 1 'and 2 and the side walls 8 and 9 define the central chamber ... 15. Through this extends a bundle of tubes consisting of • · • · * steam lines 4, each of which opens into the zone chamber 3 • · ·' • *. for feeding vapor I "to the passing paper web P.

The lower chamber 12 opens up a steam passage 13. As shown in Figure 1, the preheating steam ("steam II") flowing into this passes through the bores 10 and 14 into the chamber 15 which surrounds the bundle of pipe-30. through this steam II finally arrives. . ·. in a different embodiment, the inlet steam II is first passed through the chamber 12 from the service side to the treatment side and passes through the bores in the connection zone 45 to the chamber 15 ** '"35 (Figures 7 and 8) This steam II, which has a higher temperature ....: than steam I inside the compartment steam line 4, ensures that, even when the valves are closed, the compartment steam lines 4 and • · individual zone chambers 3 This does not cool, which results in the fact that there is no or little condensation of steam in the conduits and zone chambers, otherwise strict separation between steam I and steam II is ensured.

5

The individual zone chambers 3 are disposed on the lower support frame 1, 1 '. They are secured by the side plates 19 and 17. A separate steam line 4 always opens into the zone chambers. Each zone chamber includes a perforated plate insert 20 having 10 perforated plates 34 whose free cross-sectional area increases towards the vapor removal. These perforated plates 34 effect that the vapor I contained in the individual zones is uniformly distributed over the width of the zone. The individual perforated sheet bags 20 may be withdrawn for service (Fig. 3).

15

The individual zone chambers 3 are limited by a common vapor discharge plate 22 (Fig. 1). This is screwed onto the plate members 19 and 1, or secured by guide strips 44 so that it can be disassembled without any problem for cleaning. It has a plurality of rows of blowing openings 32 arranged in succession 20 longitudinally. The direction of the vapor removal may be perpendicular to the direction of travel of the paper or as shown in Figure 2 at an angle so that the vapor I flows against the incoming web. Everywhere • · * where steam condensation could take place are: .V 25 outlets 11, 18 with associated gutters 24, 25,! · ': 26, 27.

• "· Vapor blow box 48 of the drive-side end of which rests • 1 · j · Figure *: *. Accordingly, the mounting plate 28, which may be e.g. an extension of the lower bracket frame 1, 1 '(Fig. 2), is movable over the bracket 51. Steam lines 4 are extended against the flow direction of the steam • · · "I over the drive end of the steam blasting box; their inflow ends are secured e.g.

IM

ί.,. ί si on the mounting plate 28. In total, the adjustment marked with R ·; · *: 35 elements are located laterally outside the paper machine and comprise a control valve for each zone chamber 3. The inlet 35, which is operated by the stepper motor M. The connection of the control valves • · · * * '35 to the mounting plate 28 is provided by the wires 29, 6, which are at least partially formed as flexible wires. The outflow ends 29 'of the flexible conduits are attached to a so-called service plate 30. This service plate 30 is connected to the mounting plate 28 by means of the quick-release fasteners 31. These quick-release fasteners allow rapid disassembly when disassembling the steam blasting box. The control valves 35 are made such that they can be assembled in a plurality of side-by-side positions in the steam distribution duct 36. Each of the steam distribution channels 36 is supplied with steam from the main steam line H.

Advantages of the described construction of the actuator R: 1. The placement outside the steam blast box allows a very large number of zone chambers 3 and proper maintenance of the valves 35 while the machine is running.

2. No limitation of the steam temperature is required as the control valves do not have wear parts such as diaphragms (no steam cooling).

20 3. Fine steam metering is possible due to the use of a stepper motor.

·· · • «: · * 4. Easy and inexpensive switching from manual to automatic: .V 25 is possible.

• · * · · · · · · · ·! 5. Compressed air supply is not necessary (I / P converter: exclusion).

• · · • ··:: 30 6. Direct reading of valve position is possible.

• · · • · ·. * !! A known method can be used to ensure that the valve • · · • · · *. the amount of steam coming out of the bar is almost independent of the resistors, ie. despite the differing lengths of the individual pipelines *: · *: φ <* #. with the same valve setting each zone becomes ... almost the same amount of steam.

• · · • · • · 7

From the cross-sections of Figures 2 and 7, it can be seen that within the steam blasting box 48 or 48 ', the compartment steam lines 4 are superimposed on one another and adjacent to each other (free distance a). However, the same vapor lines are fan-shaped outside the steam blast box so that their inlet end 4 'has a relatively large free distance b, whereby (for example) b can be 10-50 times that of a (Fig. 4). This allows the number of zone chambers 3 to be made very large (their width B very small); at the same time, all the connections 29 'connecting the flexible conductors 29 to the inflow ends 4' can be placed in one and the same plane on the mounting plate 28.

In the extreme case, the width of the individual zone chambers may be reduced to a dimension which is only slightly larger than the outer diameter of the individual steam conduit 4.

Fig. 6 schematically illustrates a press section in which a pre-press point is formed between two press rolls 45 and 46 through which the paper web to be dried passes together with 2 felts. Behind the pre-press point, the lower felt passes through the felt guide roller 49, while the paper web together with the upper felt 1 • · 1 passes through the press roll 46 (most often a suction roll roll) up to the press point formed by the rollers. between. The press roll 47 is non-felt, i.e.. this comes in direct contact with the paper web. To continuously clean this roll, one or two stencils 50 are provided. In the very tight space between the rollers 49, 46 and 47, on the one hand, and the stencils 50, on the other, the steam blowing box 48, already explained above, is located. however, it is horizontally moveable to temporarily move it away from the Telas • · · * ... 46.

*: ··: 35 • · · · · 1 · • ·

Claims (9)

Device for spreading meadow ("meadow I") on a movable web (P), e.g. on a paper web to be dried and running through the press portion of a papermaking machine, having the following characteristics: a) an elongated meadow blowing carriage (48) extends transversely to the running direction of the web over the entire width of the web; B) in the meadow blowing slide (48) there is a plurality of the width of the web in a row of adjacent zone chambers (3); c) each zone chamber (3) is connected to a control valve (35) in a meadow source (H) via its own compartment angel conduit (4, 29); d) the meadow blower (48) is slidably positioned so that the distance between the meadow blower and the path of the web can be adjusted, characterized by the following additional characteristics: e) each control valve (35) is laterally plate-shaped : cut at a distance from the meadow blower, e.g. laterally outside the paper machine, and • ·: 25 via a movable part (29) of the sectional angular joint • · · · the joint joined to one in the meadow blower • · · Attached inflow end (4 ') of part (4) of the • · · (F) the areas of the sectional angular line (4) located inside the muffler (48) are located so that the free distance (a) between each other lying wires (4), seen in the cross-section of the meadow fan (pictures 2 or • 3), are only a fraction of the free spacing. Which is (b), which is between one another being and on the outside of the meadow blower (4), Fig. 4 or 5), g) at least one mounting plate 5 (28) is located at one end of the meadow blower (48). , which extends to an area outside the longitudinal range of the meadow blower (e.g., laterally to the area outside the paper machine), and of the section (4) of the sectional angular cord, each inflow end (4 ') is fixed in mounting plate (28). 2. Apparatus according to claim 1, characterized in that, for preheating or heating of the meadow blowing carriage (48), meadow ("meadow II") can be measured into the meadow blowing carriage independently of the meadow ("meadow II") to be measured on the material web. (P). 3. Device according to claim 1 or 2, characterized in that, by means of a service plate (30), at least one group of the elastic lines (29) can be connected to the mounting plate (28). • · · • · · • · \ m, m Device according to any of the preceding claims, characterized in that each control valve can be controlled with a stepper motor (M). Device according to any of the preceding claims, characterized in that the width (B) of a single zone chamber (3) is approximately the same as the diame -ter (D) of the angel conduit opening therein (4) 6. Apparatus according to any of the preceding claims, ** characterized in that in the upper area of the meadow-blowing carriage, a sanctity is provided: (33), in which can be inserted transversely in relation to the running direction of the track, providing support for dismantling the meadow blower from the paper machine (Fig. 2). Use of a device according to any of the preceding claims in a press section comprising at least three press rolls (45 - 47), characterized in that: a) the paper web runs together with a blanket over an intermediate press roll (eg a suction press roll) 46) in the pressing point formed by the suction press roll and a feltless press roll (a so-called central roll 47); b) the meadow blower (48) extends the paper web as it runs over the suction roll (46) and is relocatable relative to this, so that the distance to the suction roll can be adjusted; C) is placed in the feltless press roll of the non-web cicell part, a rake (50). Use of a device according to claim 7, characterized in that in the feltless press roll (47), two consecutive rails (50) have been placed. Use of a device according to claim 7 or 8, characterized in that the paper web before said pressing point together with the felt and a second felt runs through a pre-pressing point and that the • · · • · 1 second blanket runs from the pre-press point to a hinge: .i .: roller (49). · · · · · · · · · · · · · · · · · · · · · · · · ·