KR100775225B1 - Air knife in continuous galvanizing line - Google Patents

Abstract

An air knife used in a continuous galvanizing line is provided to exhaust air uniformly in a width direction of a steel plate corresponding to an air exhaust profile by forming a multi-step uniform pressure space between a chamber and a rib. An air knife comprises a chamber(10), a rib support(30), an upper rib(50) and a lower rib(70). The chamber forms a multi-step uniform pressure space. The rib support is connected at a front side of the chamber and has a supporter for maintaining strength of the air knife. The upper and lower ribs are installed at a front side of the rib support and cooperate with each other to form a gap serving as an outlet. The chamber includes a first rectifying wall(14) having a first air through-hole(14a) such that first and second uniform pressure spaces(A1,A2) are formed in the chamber.

Description

Air Knife in Continuous Galvanizing Line

1 is a perspective view showing a galvanizing facility

2 is a perspective view showing an example of a conventional air knife

3 is a perspective view of an air knife according to the present invention;

4 is an exploded perspective view of FIG.

5 is a side structural view of FIG.

Figure 6 is a schematic diagram showing the air discharge amount profile and plating deposition amount when the air supply pipe is connected to only one side of the chamber

7 is a side structural view showing an air knife according to another embodiment of the present invention corresponding to an air discharge amount profile;

8 is a plan view showing an operating state of the present invention air knife of FIG.

9 is a side structural view showing a modification of the air knife of FIG. 7 according to the present invention;

10 is a plan view showing an operating state of the air knife of the present invention of FIG.

11 is a side structural view showing an air knife according to another embodiment of the present invention in which the air passage hole of the lip support rectifying wall is varied.

FIG. 12 is a perspective view illustrating an inner diameter reducing tube inserted into a rectifying wall air passing hole in FIG. 11; FIG.

Explanation of symbols on the main parts of the drawings

1,1 '.... Air Knife 10 .... Chamber

12 .... Chamber opening 14 .... First commutation wall

14a .... 1st air through hole 16 .... air supply line

18 .. Vertical bulkhead 20 .... Air discharge profile adjustment means

22 .... Driving means 30 .... Lip support

32 .... upper support 34 .... lower support

36 .... 2nd commutation wall 36a .... 2nd air through hole

50 .... Upper lip 60 .... Air outlet

70 .... Lower lip 80 .... Side cover

90 .... Inner diameter reduction tube

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air knife (Knife) for adjusting the coating amount of a steel plate as one of the steel plate plating equipment for plating molten metal such as zinc on the surface of the steel plate, and more specifically, multistage equalization in the space between the chamber and the lip. Hot-melt steel sheet with excellent uniform ejection property to form a space and to ensure uniform air discharge at all times corresponding to the air discharge amount profile according to the chamber connection of the air supply pipe, thereby preventing the plating deviation in the width direction of the plated steel sheet. It relates to an air knife of a plating line.

Among the cold-rolled steel sheets manufactured in steel mills, galvanized steel sheets for plating certain molten metals, in particular molten zinc, on the surface not only improve the corrosion resistance of the steel sheet, but also enhance the appearance of the steel sheet.

In particular, in recent years, such a plated steel sheet is being used as a steel sheet for electronic products or automobiles, and the development of technology for manufacturing high quality steel sheets is concentrated.

On the other hand, the plating process of the steel sheet is carried out by passing the steel sheet through the plating bath in which the molten metal is stored, a typical galvanizing process of the steel sheet.

For example, the production line of the cold-rolled coil galvanized steel sheet is not shown in a separate drawing, but the coiled steel sheet released from the pay off reel is heat treated in a heat treatment furnace through a welder and a side looper. After adjusting the snout and the plating bath, adjust the proper amount of plating on the air knife.

Then, the plated steel sheet with the plated coating amount adjusted is cooled by air cooling and water cooling facilities, and then the plated coating amount is measured by the coating weight measuring instrument, and then the shape correction and the internal stress are removed in the temper rolling mill, and the corrosion resistance in the chromium plating equipment. For further improvement, the plated steel sheet is finally produced by being chemically treated, dried in a dryer, and passed through the exit looper into a coil in a tension reel.

As shown in FIG. 1, the steel sheet hot-dip plating line, after the molten zinc 120 is fused to the surface of the steel sheet S while the steel sheet S passes through the galvanizing bath 110, is applied to the plated amount. In order to meet the demand plating amount of the demand, the air knife 200 installed above the hot water surface of the galvanizing bath 110 is referred to as air A (or inert gas such as nitrogen) (hereinafter referred to as 'air') on both surfaces of the steel sheet. Spray) so that the amount of zinc deposited is properly cut.

Next, the plating deposition amount of the steel sheet is measured by the plating deposition amount measurement gauge, and the measured value is fed back to adjust the air discharge pressure of the air knife 200 or the gap between the steel sheet S and the air knife 200 to adjust the plating steel sheet. Control the plating amount.

In this case, reference numerals 112 and 114, which are not described in FIG. 1, are sink rolls and stabilizing rolls for guiding the steel sheet, guiding its progress, and adjusting tension.

Accordingly, as shown in FIG. 1, the air knife 200, which is a facility for controlling the coating amount of the steel sheet during the hot-dip galvanizing of the steel sheet, that is, the galvanized steel sheet, determines the plating thickness of the steel sheet in accordance with the demand of the consumer. It is an important facility.

On the other hand, Figure 2 shows a conventional air knife disclosed in the Republic of Korea Patent Application Publication No. 2004-0110831 filed by the applicant of the present invention.

Such a conventional air knife 200, the chamber 210 and the chamber 210 is connected and fixed to the rectifying wall 222, the air passage hole 222a is formed and the upper and lower lip support 224 ( The upper and lower lip 240 forming the air discharge port 230 (gap G) is fixed to the lip support 220 and the lip support 220, respectively, to constitute a 226 and maintain a predetermined thickness for maintaining rigidity It consists of 250.

Therefore, in the conventional air knife 200, the lip support 220 is provided as a rigid retainer of the entire air knife, and the front and rear sides thereof have a chamber having a reduced thickness than the conventional air knife and the upper and lower parts of which strength is easily maintained. It is characterized by the fact that the lip is fixed.

However, in the conventional air knife 200, when the air is supplied from an air supply pipe (not shown) connected to the chamber, the amount of air discharged through the actual air discharge port is not uniform in the longitudinal direction, thereby causing plating deviation. cause.

That is, the conventional air knife 200 is not designed to correspond to the air discharge amount profile.

In addition, it is preferable to install a partition member on the chamber side to further secure the equalization space through which air flows, thereby enabling more uniform discharge.

Accordingly, the applicant of the present application, which is the applicant of the conventional air knife disclosed in the above patent publication, has proposed an improved air knife to solve the above problem.

The present invention has been made to solve the above-mentioned conventional problems, the object of which is to form a multi-stage equalization space in each space between the chamber and the lip, and more particularly in response to the air discharge amount profile according to the chamber connection of the air supply pipe It is an object of the present invention to provide an air knife of a steel plate hot-dip plating line which prevents the plate width deviation of the steel plate by enabling one air discharge.

In addition, another object of the present invention is to change the inner diameter of the air passage hole of the rectifying wall to suppress the vortex generation of the air immediately after passing through the rectifying wall to further improve the air uniformity of the steel plate hot-dip plating line To provide.

As a technical aspect for achieving the above object, the present invention, a chamber for receiving and discharging the supplied air or gas and constituting a multi-stage equalization space therein, and is formed in connection with the front of the chamber to form another equalization space A lip support, through which air or gas is passed and composed of the strength holder of the air knife; And an upper and a lower lip installed in association with each other in front of the lip support to provide an outlet for forming a gap.
The chamber has a first rectifying wall configured to form first and second equalizing spaces in the chamber by having the first air through holes discharging the air or the gas uniformly and installed in the transverse direction. The air knife of the steel plate hot-dip plating line excellent in uniform discharge property is connected to the first equalization space side by the first rectifying wall.

delete

delete

delete

delete

Preferably, the first rectifying wall is formed of a bent metal plate material while the bent portion is fixed to the upper support of the lip support, and the first air through holes are integrally arranged at regular intervals in the longitudinal direction opposite to the bent portion of the metal plate material. It is constructed by perforating.

Here, the lip support is an upper support that the upper end of the opening provided in the chamber and the upper lip is connected to both sides, a lower support to which the lower end and the lower lip of the opening provided in the chamber, respectively, and the It comprises a second rectifying wall integrally formed between the upper and lower supporters, and having a second air through hole arranged at regular intervals through which air or gas passes and forming a third equalization space.

Preferably, the chamber further comprises air or gas profile adjusting means provided to open and close the first air passage holes on the first rectifying wall so that the air discharge amount profile can be uniformly flowed in the steel plate width direction when a single supply pipe is connected. do.

In addition, the profile adjusting means may be composed of a metal plate for variably opening and closing the first air through-holes in the longitudinal direction while flowing in conjunction with the drive means installed on the first rectifying wall.

Here, the drive means is composed of an air, hydraulic or electrically operated actuator, the profile adjustment metal plate is characterized in that the front end is inclined and the plurality of actuators are connected to the rear end and flow back and forth.

Alternatively, the profile adjusting means is provided as a square plate pivoted around the center of the first rectifying wall and pivoted around the center of the first rectifying wall, the driving means of the actuator, which is air, hydraulic or electrically operated is connected to one side of the rear end.

In this case, the second equalization space side of the chamber with the profile adjusting means is further provided with vertical partitions vertically installed at regular intervals in the longitudinal direction to maintain the air discharge amount profile up to the air discharge port in the longitudinal direction.

More preferably, the second rectifying wall second air passage hole of the lip support is further provided with an inner diameter reducing pipe for adjusting the discharge direction of air or gas to minimize the generation of air or gas vortex passing through the passage hole will be.

In this case, the inner diameter reduction tube may be configured as a lower end type or an upper end type in cross-section, respectively disposed on the lower side or the upper side of the second air passage hole arranged in the second rectifying wall.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, FIG. 3 to FIG. 5 illustrate an air knife 1 of a molten steel plate having excellent discharge uniformity according to the present invention. The pressure equalizing space described below is an air before and after passing through a rectifying wall. It should be noted that is a uniformly distributed flow space.

As shown in Figs. 3 to 5, the air knife 1 of the present invention includes an opening 12 for accommodating and discharging the supplied high pressure air or gas, and the first and second equalization spaces A1 and A2 therein. Lip support 30, which is installed in association with the front of the opening of the chamber 10 and forms a third equalizing space A3, through which air or gas is passed and the strength retainer of the air knife. And upper and lower ribs 50 and 70 which are installed to cooperate with each other in front of the lip support 30 to form an air discharge port 60 having a predetermined gap.

That is, in the air knife 1 of this invention, as shown in FIG. 5, when high pressure air is supplied to the 1st equalizing space A1 of the chamber 10, it rips through the 1st rectifying wall 14 It is discharged to the second equalization space A2 on the side of the support 30, passes through the second rectifying wall 36 to the third equalization space A3, and finally through the air discharge port 60 of the steel sheet. It is characterized in that it is uniformly discharged in the width direction so that the plating adhesion amount of the steel plate plating is uniformly maintained in the width direction of the steel plate.

For example, as shown in FIGS. 3 and 5, in the air knife 1 of the present invention, the chamber 10 is formed inside the chamber to form the first and second equalizing spaces A1 and A2 described above. A first rectifying wall 14 is installed to be sealed in the lateral direction (horizontally).

In addition, the chamber 10 has an opening 12 for accommodating the supplied air to flow the high pressure air to the air discharge port 20, and the chamber 10 of the present invention has an empty inside. The hollow member is shown as a rectangular chamber in the figure, but a circular chamber or other various forms are possible.

In this case, the first rectifying wall 14 includes first air through holes 14a for uniformly discharging the supplied air or gas.

3 and 5, the important thing is that the air or gas supply pipe 16 should be connected to the first equalizing space A1 side above the first rectifying wall.

Therefore, as shown in FIG. 5, when air is primarily supplied to the first equalization space A1 at a predetermined pressure, the air is filled in the first air passage hole of the first rectifying wall 14 ( Since it must pass through 14a), the flow distribution is arranged, and then through the first air through hole 14a of the next first rectifying wall, to the second rectifying wall 36 of the lip support 30 which will be described in detail below. It flows into the 2nd equalization space A2 in a chamber.

3 and 4, the first rectifying wall 14 is manufactured by bending a metal plate, and one side bent portion 14b is formed on the upper support 32 of the lip support 30. It is fixed with the bolt B3 like the upper end part 12a of the opening 12 of a chamber.

The first air passage holes 14a of the first rectifying wall 14 are integrally formed at equal intervals at predetermined intervals in the rectifying wall longitudinal direction opposite to the bent portion 14b of the metal plate. The first air passage hole 14a may be simply formed by the punching process after the bending of the first rectifying wall which is a metal plate.

On the other hand, the first rectifying wall may be coupled to the chamber inner wall on one side, and the lip support on the other side, in this case, as shown in Figure 5, to provide the chamber of the present invention in the form of a flange fastening assembly. desirable.

3 to 5 show the lip support 30 of the air knife 1 of the present invention in detail.

That is, as shown in Figures 3 and 4, the lip support 30 of the present invention, and the upper support 32, the upper end portion 12a of the chamber and the upper lip 50 is connected to both sides, respectively; A lower support 34 to which the lower end portion 12b of the chamber and the lower lip 70 are connected, and vertically integrally formed between the upper and lower supports and arranged at predetermined intervals through which air or gas passes; A second rectifying wall 36 is provided between the second equalization space A2 and the third equalization space A3 while having the second air passage holes 36a.

Thus, as shown in FIG. 5, the high pressure air passing through the first air passage holes 14a of the first rectifying wall 14 in the first equalizing space A1 is the second rectifying wall 36 of the lip support. Filled in the second equalization space A2 while being uniformly distributed and flowed therebetween, and then the air flows more uniformly through the second air through holes 36a of the second rectifying wall 36 between the upper and lower ribs. It flows to the equalization space A3 and is discharged uniformly through the air discharge port 60 finally.

In particular, the lip support 30 of the present invention is implemented as a rigid retainer of the air knife 1, which is produced by a lip support with a predetermined thickness and excellent rigidity, so the lip support is an air knife instead of a bulky chamber. It is provided as a rigid retainer.

For example, conventional air knives known to date have a form in which the chamber and the ribs are directly connected, in which case the chamber is a rigid retainer of the air knife, in which the thickness must be kept above a certain amount to maintain the rigidity, in which case the bulky chamber It was to increase the overall weight of the air knife while making the production difficult.

However, in the air knife of the present invention, the lip support serves as a skeleton of the air knife and does not need to maintain the rigidity of the chamber 10 fixed thereto, which serves to reduce the manufacturing or the overall weight of the air knife.

At this time, the upper support 32 of the lip support 30 includes an inclined support surface 32a to allow the upper lip 50 to be fixed inclined to prevent zinc adhesion from scattering.

3 to 5, the upper lip 50 is fastened to the inclined surface 32a of the upper support 32 of the lip support 32 by the fastening bolt B1 through the long hole 50a, and thus the long hole 50a. The upper lip 32 by the length of the upper support can be installed to enable the flow operation in accordance with the operation of the fastening bolt.

At this time, the inclined surface of the upper support 32 is integrally provided with a protrusion 32b to which the other fastening bolt B2 for pressing the rear end surface of the upper lip 50 is fastened.

In addition, the lower lip 70 of the present invention is formed on the fastening bolt (B1) and the lower support portion which is screwed to the lower support 34 of the lip support while forming a long hole (70a) similarly to the upper lip 50 The fastening bolt (B2) for pressing the rear end surface of the lower lip while being fastened to the protrusion (34a) it is possible to install the flow of the lower lip.

Accordingly, the gap G between the ends of the upper and lower ribs 50 and 70 forms the air discharge port 60.

Next, in FIG. 6, when the air supply pipe 16 is connected to only one side of the chamber, the air discharge amount profile P discharged through the air discharge port 60 between the chamber 10 and the upper and lower ribs 50 and 70. )

That is, as shown in FIG. 6, the air discharge amount profile is larger in the opposite side to the heat connection portion of the air supply pipe and gradually decreases in the discharge amount toward the air connection portion, which means that the plating amount thickness t of the steel sheet S is the air supply pipe. The opposite side of the connection becomes thinner.

For example, as the amount of air discharge increases, the amount of chipping of zinc (molten metal) by the air knife increases, so that the plating thickness becomes thinner.

By the way, in order to solve such a deviation of the air discharge amount profile, it is known that the air supply pipes are connected to both sides of the chamber as in FIG. 10 to solve the air pressure adjustment. In order to avoid collision / vortex generation in the chamber, the air supply pipe has a single connection structure, but it is not known to solve the air discharge amount profile deviation.

7,8, 9, and 10, in the air knife 1 of the present invention, the chamber 10 opens and closes the first air passage holes 14a on the first rectifying wall to determine the air discharge amount profile. Another configuration feature is provided with the profile adjustment means 20 provided to be able to flow uniformly in the width direction.

For example, in Figures 7 to 10 several embodiments of the present invention profile adjustment means 20 are presented.

First, as shown in Figs. 7 and 8, the (air discharge amount) profile adjusting means 20 of the first aspect of the present invention, while flowing in association with the drive means 22 provided on the first rectifying wall 1 may be provided as a metal plate to variably open and close the air through holes (14a) in the longitudinal direction.

In addition, the metal plate of the profile adjusting means 20 has a shape opposite to that of the air discharge amount profile P of FIG. 6 because the tip portion 20a of FIG. 8 is inclined from the portion to which the air supply pipe 16 is connected to the opposite side thereof. Is provided.

At this time, the driving means 22 is composed of an actuator that is air, hydraulic or electrically operated, the profile adjustment metal plate is the front end is inclined and a plurality of actuators are connected to the rear end flows before and after.

By the way, the drive means 22 installed in the chamber is most preferably an actuator that is electrically operated (because only the electric wire is connected) for the auxiliary equipment for operation, as shown in Figure 8, the drive means 22 When this operation is performed (forward operation), the air discharge amount profile adjusting means 20 of the metal plate material having the inclined tip portion causes the first air passage hole 14a of the first rectifying wall 14 to move from the air supply pipe connection side to the opposite side. The discharge amount is reduced.

Therefore, the air discharge amount in the air knife 1 of the present invention is adjusted from passing through the first rectifying wall.

Next, FIG. 9 and FIG. 10 show the air discharge amount profile adjusting means 20 'of another form of the air knife 1 of the present invention.

That is, as shown in Figs. 9 and 10, the metal plate, which is another profile adjusting means 20 'of the present invention, is provided as a square plate which is pivoted 24' at the center of the rectifying wall and has a single actuator 22 at the rear end. ') Is connected to pivot about the pivot 24'.

In this case, as described above, the driving means 22 ′ may be provided as an actuator that is air, hydraulic or electrically operated, most preferably an actuator that is electrically operated.

Accordingly, as shown in FIG. 10, the rectangular metal plate of the profile adjusting means 20 ′ is connected to one corner of the actuator so that the first air passage hole of the first rectifying wall 14 is neutral when the actuator is stopped. No part of 14a is opened or closed, and the opening and closing of the first air passage hole 14a is gradientd to one side or the opposite side when the actuator is moved forward or backward.

Therefore, the other profile adjusting means 24 'of the present invention operates normally by connecting the air supply pipes 16 to both sides of the chamber 10, and then the other air supply pipes 16 beyond the facilities of one air supply pipe 16. If air is supplied only to (right side of FIG. 10), the actuator is reversed so that the metal plate pivots about the pivot 24 'to the position of' S1 '(FIG. 10), whereby the air discharge amount profile is made uniform.

On the contrary, when the operation of the left air supply pipe 16 is stopped, the driving means 22, which is an actuator, moves forward, and the metal sheet is brought to the position of 'S2' (Fig. 10). As a result, the air discharge amount profile is made constant in the steel plate width direction. .

Therefore, the air discharge amount profile adjusting means 20 'of another form of the present invention is continuously used when the single air supply pipe is connected, and if the air supply pipe is connected to both sides of the chamber, the air discharge amount profile adjusting means 20' is uniformly operated while operating according to its operation state. To be able to adjust

At this time, as shown in Figs. 3 to 10, the second equalization space side of the chamber with the profile adjusting means 20, 20 'is installed vertically at a predetermined interval in the longitudinal direction, so that the air discharge amount profile is air in the longitudinal direction. It is preferable to further have vertical partitions 18 to be held up to the discharge port.

That is, in the air knife according to the present invention, since the profile adjusting means 20 is provided, the air discharge amount adjusts the profile according to the connection operation state of the air supply pipe. This will prevent the non-uniform deviation.

At this time, as shown in FIG. 10, the actuator 22 'is fitted with a connecting block 26', and the projections 26'a of the block are fitted with a long groove 20'a formed in the profile adjusting plate made of a metal plate. The bolt (b) is fastened.

That is, the turning of the metal plate, which is the profile adjusting means 20 ', is possible because the protrusion can slide in the long groove.

Next, Figure 11 and Figure 12, shows another embodiment of the air knife 1 of the present invention, in addition to the implementation of the multi-stage equalization space by the first and second rectifying walls 14, 36, air through hole It is characteristic that the air discharge direction which passes through this is arbitrarily adjusted and the more uniform air discharge was possible in the steel plate width direction.

For example, in the second air passage hole 36a of the lip support second rectifying wall 36, vortices due to air collision when passing through the rectifying wall to minimize vortex generation of air or gas passing through the passage hole (FIG. 11). 'V' part) is characterized by having an inner diameter reduction tube 90 to suppress the occurrence of.

That is, as shown in FIGS. 11 and 12, the second air passage hole 36a of the second rectifying wall 36 is formed at predetermined intervals by about three rows in the rectifying wall longitudinal direction (vertical direction), The inner diameter reduction tube 90 is inserted therein.

Therefore, as shown in FIG. 11, the air passing through the rectifying wall second air passing hole 36a of the lip support 30 is upstream a1 and the central flow a2 to avoid the vortex space V caused by the air collision. ), It is discharged downstream (a3), which enables uniform discharge of the air passing through the air discharge port (60).

At this time, the inner diameter reduction tube 90 of the present invention as shown in Figures 11 and 12. It can be provided as a bottom reduction type (90a) and a top reduction type (90b) on the cross section to forcibly implement the air flow of the upstream (a1) and downstream (a3), and a separate in the central side second air through hole (36a) There is no need to use an internal shrinkage tube.

By the way, in view of the fact that the use space of the air knife is high in heat shrinkable tube 90 as described above, a refractory molded article or a synthetic resin molded article having heat resistance may be used.

Thus, according to the air knife of the steel plate hot-dip plating line of the present invention, a multi-stage equalization space is formed in each space between the chamber and the lip, and in particular, more uniform air discharge is possible in response to the air discharge amount profile according to the chamber connection of the air supply pipe. It is effective to prevent the plating deviation in the width direction of the steel sheet.

In addition, it is possible to provide an excellent effect of changing the inner diameter of the air passage hole of the rectifying plate to suppress vortex generation of air passing through the rectifying plate, thereby preventing the steel plate width direction plating variation at the air discharge port.

While the invention has been shown and described in connection with specific embodiments so far, it will be appreciated that the invention can be varied and modified without departing from the spirit or scope of the invention as set forth in the claims below. It will be appreciated that those skilled in the art can easily know.

Claims (11)

A chamber for accommodating and discharging the supplied air or gas and constituting a multistage equalization space therein; and a lip support configured to be connected to the front of the chamber and to form another equalization space while the air or gas is passed through and to maintain the strength of the air knife. ; And an upper and a lower lip installed in association with each other in front of the lip support to provide an outlet for forming a gap. The chamber has a first rectifying wall configured to form first and second equalizing spaces in the chamber by having the first air through holes discharging the air or the gas uniformly and installed in the transverse direction. The air knife of the steel plate hot-dip plating line excellent in uniform discharge property is connected to the first equalization space side by the first rectifying wall. delete The method of claim 1, wherein the first rectifying wall is formed of a bent metal plate material, the bent portion is fixed to the upper support of the lip support, the first air through holes are spaced in the longitudinal direction opposite to the bent portion of the metal plate material Air knife, characterized in that perforated integrally. The method of claim 1, wherein the lip support, An upper supporter having an upper end of the opening provided in the chamber and the upper lip connected to both sides thereof; A lower supporter to which the lower end of the opening provided in the chamber and the lower lip are respectively connected; And, A second rectifying wall integrally formed between the upper and lower supports and having second air passage holes arranged at regular intervals through which air or gas passes, and forming a third equalizing space; Air knife, characterized in that configured to include. The air conditioner according to claim 1, wherein the chamber further comprises air or gas profile adjusting means provided to open and close the first air passage holes on the first rectifying wall so that the air discharge amount profile can be uniformly flowed in the steel plate width direction when a single supply pipe is connected. Air knife characterized in that provided with. 6. The air knife according to claim 5, wherein the profile adjusting means is made of a metal plate that is variably opened and closed to firstly space the first air through holes in a longitudinal direction while being flown in association with the driving means installed on the first rectifying wall. . 7. The air knife according to claim 6, wherein the driving means comprises air, hydraulic or electric actuators, and the profile adjusting metal plate is inclined at the front end and plural actuators are connected to the rear end to flow back and forth. The method of claim 5, wherein the profile adjusting means is provided as a square plate pivoted around the center of the first rectifying wall and pivoting around it, one side of the rear end is connected to the driving means of the air, hydraulic or electrically operated actuator Featuring an air knife. 6. The method of claim 5, wherein the second equalization space side of the chamber having the profile adjusting means is further provided with vertical partitions vertically installed at regular intervals in the longitudinal direction such that the air discharge amount profile is maintained up to the air discharge port in the longitudinal direction. Featuring an air knife. 5. The inner diameter reduction tube of claim 4, wherein the second rectifying wall second air through hole of the lip support further includes an inner diameter reducing pipe configured to adjust a discharge direction of air or gas to minimize vortex generation of air or gas passing through the through hole. Air knife characterized in that it became. The air knife according to claim 10, wherein the inner diameter reducing tube has a lower end type or a lower end type in cross-section disposed respectively below or above the second air passing air arranged on the second rectifying wall.

Images