JPS59100381A - Nozzle for floating drying - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This invention applies to plastic films and paper after coating.

This hot air nozzle relates to a hot air nozzle that blows hot air onto a web such as aluminum foil, especially a thin web that requires low tension when passing through the drying chamber, and heats and dries the web while floating the web inside the drying chamber.

Fig. 1 shows an outline of a typical floating drying apparatus, in which a web 1 is sandwiched in a drying chamber A, and nozzles 2 are installed along the width direction of the web at different vertical pressures (in some cases, vertically opposing each other). A large number of nozzles 2 are arranged at regular intervals along the web feeding direction, and hot air ejected from these nozzles 2 is blown onto the web 1 to float the web 1 and dry it with hot air.

As this type of floating drying nozzle 2.

As illustrated in FIG. 9, the web 1 of the nozzle box 3
A pair of slits 27 along the width direction of the web are provided on the left and right sides of the surface facing the web 1, and hot air is blown out from the slits 27 toward the web 1, thereby connecting the web 1 and the upper wall 14 of the nozzle box 3 facing thereto. A known configuration is known in which a positive static pressure is generated in a central zone 28 surrounded by two jets of hot air from both slits 27 in between, thereby drying the web 1 while floating it.

For example, Japanese Patent Publication No. 44-11451, No. 45-36
No. 953, No. 53-551, No. 54-385
25, Japanese Patent Application Laid-Open No. 142473/1983, etc.

The present invention is directed to such a hot air nozzle.

In particular, the shape of the opening light of the hot air blowing slit 27 has been improved.

In other words, in this type of nozzle, in order to feed the web at high speed and increase processing efficiency, the distance between the nozzle and the web is extremely small, and in reality it is less than 10 mm, generally 5 mm.
It may be set to ~7 dragons.

However, for webs that are wide and require low tension.

Since the frictional resistance with the air is originally extremely small and the thickness is thin, the web tends to meander, especially buckling, even when subjected to a slight external force, and it is impossible to completely suppress this flaking. For example, if there is a structural defect in the nozzle (or if there is a slight imbalance in the tension in the width direction of sea urchins or sea urchins running at high speed, the web will become larger). This is because there are a variety of factors that make Webb uneasy.

The problem is how to eliminate the problem of the web coming into contact with the nozzle.

If the web comes into contact with a part of the nozzle, a mark will be placed on the web and the product will be rejected.1 In the worst case scenario, the web will be damaged, causing serious trouble.

In order to solve this important problem, once again considering the conventional nozzle structure, the static pressure zone 28 in FIG. 9 is extremely significant for maintaining the web 1 at a predetermined flying level. The hot air blown out from the pair of slits 27, 27 is mainly an air flow that flows away laterally outwardly of the dune 28 (in the direction of the arrow a in Fig. 9) while applying a positive static pressure to the dune 28. The web 1 is being dried. However, the flow of hot air in the direction of arrow a is
It is regulated by Webb 1, which has some vibrations and is running at high speed. Therefore, it has been found that when the web 1 has a flutter, the flow of the hot air is disturbed, and the flutter of the web 1 does not easily subside, and there is a tendency for the web 1 to become more fluttery. This flow of hot air in the direction of arrow a is caused by the fact that the distance between the opposing surfaces of the nozzle 2 and the web 1 is lQ.
Considering that it is less than mm, it can be said that it is preferable to restrict it with a fixed wall surface on the nozzle side.

This invention was proposed based on this knowledge, and basically, in a nozzle having the structure as described above, hot air ejected from a pair of slits 27 on the nozzle side is made to flow laterally outward, that is, in the direction of arrow a. The first purpose is to provide a fixed wall surface, suppress the fluttering that occurs in the web 1, and eliminate contact of the web with the nozzle.

Furthermore, in the conventional nozzle 2 shown in FIG. 9, each slit 27
An edge 20a stands at the upper end of the outer guide wall 20 constituting the outer guide wall 20, and if the web 1 touches this upper edge 20a, serious trouble such as tearing of the web 1 will occur.

Therefore, in this invention, the guide wall 20 has an edge 20a.
The purpose is also to prevent it from standing.
1□ Furthermore, each slit 27 is formed in series along the longitudinal direction of the nozzle box 3 with a constant gap.

If the spacing is uneven in the longitudinal direction, the amount of hot air emitted,
The jet pressure is inconsistent and the width of web 1 is reduced.
You will end up at 8' in the □ direction. However, the guides Fj, 19, 19 are attached to the lateral outer sides of the lateral walls 16, 16 connected to the top wall 14 of the nozzle box 3, and the guide walls 20 of each lateral side wall 16 and each guide plate 19 are used to prevent slips and holes. 27, when manufacturing the metal guide plate 19 itself and when attaching it to the nozzle hook 3, the upper edge portion of the guide wall 20 cannot be aligned in a straight line as it is. It was found that the fabrication precision of the opening light shape of the slit 27, which is extremely difficult and most important for controlling the hot air blowout, cannot be ensured.

It is also susceptible to thermal deformation during operation. Accordingly, another object of the present invention is to simultaneously eliminate such conventional problems at once by changing the shape of the upper end of the guide wall 20.

Next, the details will be explained based on the drawings. For convenience of explanation, FIGS. 2 to 7 illustrate the nozzle 2 arranged below the web 1, and the nozzle box 3 of this is arranged in the width direction of the web 1. It is formed in the shape of a long box with an open top along the top, and the middle part near the top of the long wall plates 4, 4 is inclined upward in a tapered shape, and the upper end sides of the long wall plates 4, 5 are parallel to each other and face each other in parallel. Horizontal flanges 6, 6 are integrally bent and connected outward from the upper ends of the contact wall plates 4, 4. Bottom plate of nozzle hook7.
In other words, it has supply ports 9, 9 connected to a hot air duct (not shown) at two locations in the front and back in the longitudinal direction on the opposite side to the surface facing the web 1, and above each supply port 9 in the nozzle box. A dynamic pressure suppression plate 11 with a large number of holes 10 formed on the entire surface is installed horizontally.

At the upper end opening of the nozzle box 3, a large number of rectifying plates 12 are fixed by welding or the like at regular intervals in the longitudinal direction between the fixed wall plates 4, and a hollow frame 13 is welded onto these rectifying plates 12. The hollow frame 13 has a flat rectangular cylindrical shape with parallel upper and lower walls 14 and 15 and horizontal side walls 16 and 16 running in the longitudinal direction, and the flat upper wall 14 is directly connected to the web 1. The lower wall 15 faces the nozzle box 3.
The upper surface of the opening is closed, and both ends in the longitudinal direction are opened into the drying chamber A, and a large number of through holes 17 are bored at predetermined intervals in the longitudinal direction at the center of the upper wall 14 in the web feeding direction. . The top wall 14 and both side walls 16 are formed by being bent in series.

Each lateral wall 16 has a vertical lower half 16a and connects to the upper wall 14, with a half 16b inclined at a constant inward inclination angle α and ζ
There is.

Guide plates 19, 19 are fixed to the lateral outer sides of the lateral side walls 16, 16 of the hollow frame 13, respectively. Each guide plate 1
Reference numeral 9 denotes a guide wall 20 that faces the inclined upper half portion 16b of each side wall 16 in parallel with a certain gap therebetween, and a lip 21 that is bent outward from the upper end of the guide wall 20 in a diagonally downward direction in the figure.

It is made of a metal plate and has a mounting wall 22 bent horizontally outward from the lower end of the guide wall 20 and fixed to the collar 6 of the nozzle box 3 via the mounting wall 22. That is, the bolt holes 23 are transparently provided in the collar 6 at appropriate intervals along the length, and the mounting wall 22 of the guide plate 19 is inserted into the bolt hole 25 through the elongated hole 24 provided in the collar 6.
is fastened with a nut 26 so that it can be slid laterally and laterally.

Thus, on both lateral outer sides of the hollow frame 13, the lateral side walls 1 of the hollow frame 13 are formed.
between 6 and 16 and guide walls 20 and 20.

A pair of hot air blowing slits 2 extending in the web width direction
7 is formed to be able to articulate at intervals. This slit 27
are continuous at regular intervals without interruption in the longitudinal direction.

Incidentally, the guide wall 20 of each guide plate 19 has the same inward inclination angle α1 as the inclined upper half portion 16b of each horizontal side wall 16 of the hollow frame 13.
In the diagram, it is tilted at approximately 70 degrees.

Each slit 27 is a constriction part 27 that communicates with the inside of the nozzle box.
Run-up portion 27b having a continuous interval above a and this
and has. The length of this run-up portion 27b is 5.3 to 21
．． 6n, preferably 1111, and the gap between the run-up portions 27b is set to 1.0 to 3.5fl, preferably about 1.81. Needless to say, the slit 27 may be formed in a shape that tapers upward.

In such a case, the hot air blown into the nozzle box 3 from the duct (not shown in Figure 1) through the supply port 9 is first suppressed by the dynamic pressure suppression plate 11, and is distributed over the entire area including the longitudinal direction inside the nozzle box. It is filled with uniform pressure, and is narrowed by the inclined parts 5 and 5 of the long wall plates 4 and 4 to become an even more uniform flow, and is finely partitioned in the longitudinal direction.
12 T:M'a 'a h-"'CM(7)')-
'J Knit 27. Each slit 27
The hot air that has reached the inside passes through the throttle part 27a and the run-up part 27b, and then blows out from the upper end of the slit 27 in a longitudinal direction toward the sea urchin knob 1 with a uniform wind speed distribution and direction. This is achieved in particular by a rectifying means consisting of a dynamic pressure suppressing plate 11 and a rectifying plate 12. The current plate 12 is for uniformly filling the entire area of the nozzle box 3 with the hot air from the supply port 9, and is in the form of a flat plate in which the hot air from the supply port 9 projects perpendicularly. Although it is desirable that there be one, the present invention is not limited to this, and the first part may be built in an oblique or mountain shape. And slit 2
Making the direction of the hot air from 7 uniform over the longitudinal direction of the slit is an important factor in preventing fluttering in the width direction of the web, and this point is particularly achieved by a large number of groups of rectifying plates 12.

Next, the results of actual measurement of the wind speed distribution and wind direction in the longitudinal direction of the slit 27 are shown in FIG. however.

This actual measurement result was obtained when there was no web in the nozzle, and when hot air was supplied into the nozzle box from Figure 8 (al: front and rear hot air supply I in the longitudinal direction). Figure (b) shows the case where the front supply port 9 is opened and the rear supply port 9 is closed, and Fig. 8 (tc) shows the case where the front supply port 9 is closed and the rear supply port 9 is opened. . A total of 60 rectifying plates 12 are placed below the slit 27 with a total length of 1250mm, each spaced at equal intervals, and the gap at the run-up portion 27b of the slit 27 is set to 1.8mm, so that the hot air velocity to the supply port 9 is was set at 25n□I/sec.

This measurement result also confirms that the wind speed distribution and wind direction in the longitudinal direction of the slit 27 are uniform.

Now, hot air is blown out from the pair of slits 27 toward the web 1 at a constant inward direction (1! oblique angle α), and between the upper wall 14 of the nozzle box 3 and the web, a jet of hot air is generated from both slits 27. Central zone 28 surrounded by
A stable positive static pressure is generated, which supports the web traveling at high speed at a predetermined floating level (5 to ?-i). The hot air blowing out from the slit 27 maintains the static pressure in the zone 28 constant, while a part of it flows into the hollow frame 13 through the through hole 17 provided in the center of the upper wall 14. The hot air is discharged from the open end in the longitudinal direction into the drying chamber A, and most of the hot air is directed laterally outward (in the direction of arrow a in Figure 5).
These two streams of hot air dry the web. Although it actually depends on the size of the through hole 17,
The flow of hot air in the direction of arrow a greatly contributes to the drying of the web 1.

Here, the flow of the hot air in the direction of arrow a, that is, in the lateral outward direction of the static pressure zone 28, is regulated by the surface of the web l in the close state and the wall surface 30 of the lip 21 on the nozzle side. If the web 1 were to fluctuate for some reason, the flow of hot air would be partially regulated by the web, so temporary turbulence would occur, but the flow would be rectified by the wall 30 and guided. Therefore, the flow of hot air is rectified as much as possible to quickly suppress the fluttering of the web and allow the web to run stably at a predetermined floating level. The hot air flows as a wall flow between the web 1 and the wall surface 30, and the presence of the wall surface 30 increases the contact area of the hot air with the web 1, which also contributes to improving the drying processing capacity of the web. . To this extent.

The inventors have fully anticipated that the wall surface 30 continuous to the upper end of the guide wall 20 will be formed horizontally parallel to the web 1. However, in this case, when the hot air escapes from the web at the extending end of the wall surface 30, negative static pressure is generated, and there is a fear that the web 1 may come into contact with the extending end of the wall surface 30. Therefore, in the example shown in FIG. 8, the wall surface 30 is inclined downwardly from the upper end of the guide wall 20 with respect to the virtual horizontal P along the web 1 at an inclination angle β of about 30 degrees. According to this, the web 1 is connected to the wall surface 3.
0, that is, there is no possibility of contact with the extending end of the lip 21.

In addition, a part of the hot air flowing into the first static pressure zone 28 flows into the hollow frame 13 through the through hole 17, so that this flow of hot air increases the drying efficiency of the web 1, and the sea urchin knobs in the static pressure zone 28. The coating liquid mist coming out from the coated surface hits the top wall 14.
Deposits are deposited on the top surface.

At the same time, this also prevents a situation in which the particles re-adhere to the web 1. For this reason, in one illustrated example, the upper wall 14 is formed as a flat surface facing parallel to the web, and the central zone 28
Although the upper wall 14 is intended to stabilize the static pressure in the zone 28, the upper wall 14 may be formed in a convex curved shape with a convex center or concavely curved shape, etc. In short, it is intended to stabilize the static pressure in the zone 28. , it is sufficient that there are no sharp parts that may come into contact with the web 1.

Further, the through holes 17 formed in the top wall 14 may be formed in two rows at the center of the top wall 14 in the web feeding direction, or if the holes 17 are spaced at regular intervals in the longitudinal direction, the shape and size of the holes 17 may be changed. If the shape and size are constant, the drilling interval may be changed between the center and both ends in the longitudinal direction.
It can be selected as appropriate depending on the purpose.

Finally, regarding the light from the opening of the slit 27, the upper end of the guide wall 20 is naturally rounded due to the bending process of the lip 21, and is flush with the upper surface of the upper wall 14 or slightly more. Also set the height low, and set the height of web 1
Make sure that the guide wall 20 does not come into contact with the upper end of the guide wall 20 and be damaged.

This is particularly problematic when the web is passed between the upper and lower nozzles 2 in the drying chamber A prior to drying.

Although the entire configuration of the illustrated nozzle is as described above, the present invention is not limited to this, and various design changes are possible.

For example, speaking of the first invention in this case.

The guide wall 20 and wall surface 30 constituting the slit 27 do not need to be formed by bending a metal plate as in the illustrated example, and the guide wall 2o and wall surface 30 may be box-shaped.

In addition, in the illustrated example, the dynamic pressure suppression plate 11 and the rectifying plate 12 are installed in the nozzle box as means for rectifying the hot air supplied from the duct into the nozzle box 3 through the supply port 9. are not essential to the implementation of the present invention, and even if implemented, the dynamic pressure suppression plate 11 and the rectifying plate 1
It is also possible to install only one of the two.

Furthermore, in the illustrated example 9, a hollow frame 13 is provided at the top of the nozzle box 3.
Although the hollow frame 13 is arranged and fixed, this hollow frame 13 is not necessarily necessary, and what is important here are the top wall 14 for forming the static pressure zone 28 and the horizontal side walls 16 for forming the pair of slits 27.

The lower wall 15 is not essential. It is not necessary that the two slits 27 have the same shape. Furthermore, when the hollow frame I3 is employed, the hot air flowing into the hollow frame I3 may be actively sucked in by a suction fan, and it is also possible to discharge the flowing hot air to the outside of the drying chamber A.

As explained above, the first invention of the present invention is a nozzle in which the web 1, which is traveling in a slump, is statically floated to a predetermined floating level by hot air jetted from a pair of slits 27 on the opposing surfaces of the nozzle box 3. An outward wall surface 30 is formed to extend horizontally or diagonally downward from the upper end of the guide wall 20 constituting the outer wall of each slit 27,
The hot air from each slit 27 is regulated to flow laterally outwardly by the wall surface 30 on the nozzle side without relying on the movable web 1. Therefore, even if the web flops, this flop can be quickly suppressed, the high-speed running of the web can be stabilized, and accidents in which the web comes into contact with the nozzle side can be effectively prevented.

Since there is no edge on the upper end of the guide wall 20, even if the web 1 comes into contact with the guide wall 20, there will be no serious trouble of damaging the web.

I did. The wall surface 30 actively promotes contact of the hot air to the opposing web surface, thereby increasing the web drying efficiency and contributing to preventing uneven drying.

In the second invention of the present case, the top wall 1 of the nozzle box 3
A guide plate 19 including guide walls 20, 20 that closely oppose the lateral side walls 16, 16 of 4 is bent horizontally or obliquely downward, and the inclined upper surface of this lip 21 becomes the wall surface 30. I took it as a thing. Therefore, this is in addition to the effects of the first invention.

When the guide plate 19 itself is manufactured, the upper end of the guide wall 20, which should form the important aperture light of the slit 27, is reinforced by the bending of the lip 21 and is finished in a straight line. As a result, when attaching and fixing the guide plate 19 to the nozzle hook 3.

'; l 'J, y) Gap (7) a? Is it easy?'
, 7. '), y) 27 (7) length
: A constant gap can be maintained in the hand direction, no thermal deformation occurs in the slit aperture shape even during drying operation, and uniformity of hot air velocity distribution and wind direction in the longitudinal direction of the slit 27 is ensured. .
1

[Brief explanation of drawings]

・FIG. 1 is a schematic front view showing an outline of a floating drying device to which the present invention is directed. 2 to 7 show a nozzle according to the present invention, with FIG. 2 being an external perspective view and FIG. 3 being a plan view. 4 is a sectional view taken along the line IV--IV in FIG. 3, FIG. 5 is an enlarged front view of essential parts, FIG. 6 is a side view, and FIG. 7 is a bottom view. Fig. 8 (al, '(bl, e) is a chart showing the measurement results of the wind speed distribution and wind direction from the slit by the nozzle according to the present invention. Fig. 9 is a longitudinal sectional front view of the conventional nozzle. 1... Web. 2... Nozzle. 3... Nozzle box. 4... Long wall plate of the nozzle box. 6... Tsuba. 7... Bottom plate of the nozzle box. 9... Hot air supply port. 11... Dynamic pressure suppression plate. 12... Rectifying plate. 13...・Hollow frame. 14...Top wall. 16...Horizontal wall connected to the top wall. 17...Through hole. 19. . . . . Guide plate. 20. . . . . Guide wall. 21... Lip. 22... Mounting wall. 27... Slit. 28... Static pressure zone. 30... Wall surface.

Claims (5)

[Claims] (1) The web 1 is placed on the upper surface side facing the web 1 of the long box-shaped nozzle box 3 along the width direction of the web I.
A pair of slits 27 extending in the width direction of the two nozzle boxes 3 are blown out from each slit 27 toward the web 1, and between the nozzle box 3 and the web 1, the hot air is blown out from the pair of slits 27 between the nozzle box 3 and the web 1. In a floating drying nozzle that generates static pressure in zone 2B surrounded by two jets of hot air to support the web l from the nozzle box 3 at a constant floating level and then dry it with hot air, the web 1 of the nozzle box 3 and Horizontal side walls 16, 16 connected to the opposing upper wall 14, and the horizontal 11'l wall 16
- The slit 27 is formed between the guide walls 20, which are fixed on the lateral and outer sides of the guide wall 16. A floating drying nozzle characterized in that a wall surface 30 continues outward from the upper end of each guide wall 20 and is formed horizontally or diagonally downward. (2) The long box-shaped nozzle box 3 along the width direction of the web 1 has a pair of slits 27 extending in the width direction of the sea urchin knob 1 on the upper surface side facing the web 1, and the nozzle box 3 has a pair of slits 27 extending in the width direction of the sea urchin knob 1. The supplied P1 air is blown out from each slit 27 toward the web 1, and static pressure is applied to the tube 28, which is surrounded by two jets of hot air from a pair of slints 27 between the nozzle box 3 and the web 1. In a floating drying nozzle that generates a web 1 and dries it with hot air while supporting the web 1 from the nozzle box 3 at a constant floating level, upper walls 14 are provided on both sides of the upper wall 14 of the nozzle box 3 facing the web 1 in the web feeding direction. It has horizontal side walls 16, 16 connected to the horizontal side walls 16, 16.
Guide plates 19, 19 including guide walls 20, 20 facing the lateral side walls X6, 16 at a predetermined interval on the lateral outer side thereof.
are fixed, the slots 27 are formed between each side wall 16 and the guide wall 20 of each guide plate 19 facing thereto, and the rib 21 is horizontally or outwardly directed from the upper end of each guide wall 20. A floating drying nozzle characterized by being bent diagonally downward. (3) The horizontal side wall 16 connected to the top wall 14 of the nozzle box 3 has a vertical lower half 16a and an inwardly inclined upper half 16b, and the guide wall 2 of each guide plate 19
3. The floating drying nozzle according to claim 2, wherein 0 faces the side wall 16 at an inward inclination angle α along the inclined upper half 16b of the side wall 16. (4) The top wall 14 of the nozzle box 3 is flat, and the top end of the guide wall 20 of each guide plate 19 is flush with the top wall 14 or positioned lower than the top wall 14. Floating drying nozzle according to item 2 or 3. (5) Each guide plate 19 has a horizontal mounting wall 22 connected to the lower end of the guide wall 20, and the mounting wall 22 of each guide plate 19 is attached to the horizontal collar 6 provided on the outside of the long wall plate 4 of the nozzle box 3. The floating drying nozzle according to claim 2, 3, or 4, which is fixed in a slide-adjustable manner.