KR102177617B1 - Apparatus for cleaning of air knife - Google Patents

Abstract

An air knife cleaning apparatus of the present invention is disclosed. According to an aspect of the present invention, there is provided an apparatus for cleaning an air knife that injects gas toward a molten metal plated material, comprising: a plurality of induction heating units provided on an outer surface of a lip of the air knife and induction heating the lip; And a control unit for applying current to the plurality of induction heating units and controlling each of the induction heating units, wherein the plurality of induction heating units may be provided with an air knife cleaning device disposed to be spaced apart from each other by a predetermined distance.

Description

Air knife cleaning device {Apparatus for cleaning of air knife}

The present invention relates to an air knife cleaning apparatus, and more particularly, to an air knife cleaning apparatus capable of easily removing impurities such as zinc chips that are scattered and adhered to an air knife lip.

In general, in a continuous hot-dip galvanizing line (CGL), zinc plating is performed to secure corrosion resistance of steel sheets.

For this galvanizing operation, molten zinc is attached to the surface and back of the strip while passing the strip from the furnace through a zinc pot containing molten zinc.

An air knife is installed at the top of the zinc reservoir to control the amount (plating amount) of zinc attached to both sides of the strip exiting the zinc reservoir, and high-pressure air or nitrogen sprayed from the air knife. An inert gas (hereinafter, collectively referred to as'gas'), such as, wipes both sides of the strip to uniformly control the amount of zinc plating in the width direction.

When controlling the amount of zinc deposited on the strip, zinc chips, etc. scattered are adhered to the outer surface of the air discharge port or the inside of the air discharge port of the air knife, so that gas is not smoothly discharged.

In particular, there is a problem that the discharge pressure of the gas is lowered due to the adhesion of the zinc chips, or the production quality of the galvanized steel sheet is deteriorated due to the uneven injection of the gas in the width direction of the strip. In order to solve this problem, Korean Patent Application Publication No. 10-2012-0008605 and Korean Patent Application Publication No. 10-2012-0140509 disclose a lip cleaning device for an air knife for removing zinc chips that are adhered to the gas outlet of the air knife. Is disclosed.

According to the disclosed literature, a removal member for removing zinc chips is inserted into an air discharge port of an air knife lip, and impurities are removed by reciprocating the removal member in the width direction.

However, when cleaning the air discharge port of the air knife through the conventional structure and method disclosed above, damage due to direct contact with the removal member and the lip is caused, and the coating layer of the lip is removed and the life of the lip is shortened. have.

In addition, there is a problem in that it is impossible to remove even zinc chips stuck in the interior of the air discharge port. Accordingly, the manager manually removes the zinc chips stuck inside the air discharge port, but there is a problem that the manager is exposed to the risk of safety accidents due to the work being performed on the top of the zinc storage tank above 450°C.

KR 10-2012-0008605 (POSCO Co., Ltd.) 2012. 02. 01. KR 10-2012-0140509 (POSCO) 2012. 12. 31.

The air knife cleaning apparatus according to an embodiment of the present invention removes not only zinc chips adhered to the outer surface of the air discharge port, but also zinc chips adhered to the interior of the air discharge port to make the discharge pressure of the gas discharged from the air discharge port uniform. It makes it possible to improve the production quality of plated steel sheets.

According to an aspect of the present invention, there is provided an apparatus for cleaning an air knife that injects gas toward a molten metal plated material, comprising: a plurality of induction heating units provided on an outer surface of a lip of the air knife and induction heating the lip; And a control unit for applying current to the plurality of induction heating units and controlling each of the induction heating units, wherein the plurality of induction heating units may be provided with an air knife cleaning device disposed to be spaced apart from each other by a predetermined distance.

In addition, the plurality of induction heating units may each include an induction coil surrounding the outer surface of the lip a plurality of times.

In addition, the plurality of induction heating units divide the lip into three regions to heat the first region at the front end side of the lip in which the gas discharge port is formed, the second region at the middle of the lip, and at the rear end side of the lip. It may be provided in the third area.

In addition, the plurality of induction heating units disposed in the three areas may be independently operated and controlled by the control unit according to the working environment according to the operation of the air knife.

In addition, a sensing unit is provided inside the air knife to measure the pressure inside the air knife, or a sensing unit is provided outside the air knife to detect changes in an external environment according to temperature and airflow, and the control unit is the sensing unit It is possible to control whether the plurality of induction heating units are operated according to the information received from.

The air knife cleaning apparatus according to an embodiment of the present invention has the effect of melting and removing zinc chips that may be adhered to the gas outlet of the lip by instantaneously heating the air knife to a high temperature through induction heating. . Accordingly, compared to the prior art, it is possible to improve the durability and service life of the air knife by removing zinc chips without damaging the lip of the air knife.

In addition, by providing a plurality of induction heating units for induction heating the air knife, it is possible to remove not only the gas outlet of the air knife, but also the zinc chips adhered to the outer surface of the air knife, and select a plurality of induction heating units depending on the working environment. By operating, there is an effect of preventing foreign substances from splashing into the lip.

The present invention will be described in detail by the following drawings, but since these drawings show preferred embodiments of the present invention, the technical idea of the present invention is limited only to the drawings and should not be interpreted.
1 is a schematic diagram showing a zinc plating facility.
2 is a side cross-sectional view showing an air knife cleaning apparatus according to an embodiment of the present invention.
3 is a view showing a state in which the air knife cleaning device of FIG. 2 is operated and controlled according to a working environment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented in order to sufficiently convey the spirit of the present invention to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the exemplary embodiments presented here, but may be embodied in other forms. In the drawings, in order to clarify the present invention, portions not related to the description may be omitted, and sizes of components may be slightly exaggerated to aid understanding.

The air knife cleaning apparatus according to the present invention is an apparatus for removing zinc chips adhered to an air knife used in a continuous hot-dip galvanizing line. Prior to the description of the air knife cleaning apparatus, a continuous hot-dip galvanizing line will be briefly described. do.

1 is a schematic diagram showing a zinc plating facility.

Referring to FIG. 1, after the strip (coil steel sheet) S unwound from the Pay Off Reel is heat treated, the zinc reservoir 20 filled with molten zinc is passed through a snout 21. Plating is performed while passing.

Further, the molten zinc on the surface of the strip (S) is appropriately discharged by the high-pressure gas sprayed on the surface of the strip (S) while the strip (S) passes between the air knife (10) installed on the top of the zinc reservoir (20). As it is cut, its plating thickness is adjusted.

Whether the plating amount of the strip (S) is appropriate is measured by the plating adhesion amount measurement gauge (30), and the measured value is fed back to the gas discharge pressure of the air knife (10) or between the strip (S) and the air knife (10). The amount of plating is controlled by adjusting the gap or by adjusting the moving speed of the strip (S).

On the other hand, unexplained reference numerals '22' and '23' refer to a sink roll and a stabilizing roll that guides the strip (S) into the zinc storage tank (20) and suppresses vibration of the strip (S). roll).

As described above, when the amount of plating is adjusted through the air knife 10, the molten zinc on the surface of the strip (S) is cut and scattered according to the high-pressure gas injected. As the scattered zinc chips flow into the outside of the lip 12 and the gas outlet 13 of the air knife 10 and are fixed, a cleaning device for removing them is provided.

2 is a side cross-sectional view illustrating an air knife cleaning apparatus according to an embodiment of the present invention, and FIG. 3 is a view showing a state in which the air knife cleaning apparatus of FIG. 2 is operated and controlled according to a working environment.

2 and 3, the air knife cleaning apparatus according to an aspect of the present invention includes an induction heating unit 110, 120, 130 and a control unit 140. At this time, the air knife 10 is a member that controls the amount of plating by injecting a high-pressure gas, and is disposed between the chamber 11 supplied with the high-pressure gas and the chamber 11 and the hot-dip plated strip (S), and the chamber ( A lip 12 forming a gas discharge port 13 for injecting the high-pressure gas supplied from 11), and a support 14 provided to support the lip 12 are provided. At this time, the lip 12 may be composed of an upper lip 12a and a lower lip 12b to be fastened to the support 14. Induction heating units 110, 120, 130 are provided on the outer surface of the air knife 10.

A plurality of induction heating units 110 120 and 130 are provided on the outer surface of the air knife 10. As shown, the induction heating units 110, 120, and 130 are provided in three and are arranged to be spaced apart from each other by a predetermined interval. Here, an induction heater may be used as an example of the induction heating units 110, 120, and 130. The induction heater may be composed of an electromagnet in which a coil is wound around a conductor. That is, when an alternating current is passed through the coil, an alternating magnetic field that changes direction over time is formed in the coil. At this time, when an AC magnetic force is applied to the conductor, an eddy current is generated in the conductor due to electromagnetic induction. And the object is heated by Joule heat generated by the eddy current. That is, the induction heating unit (110, 120, 130) heats the lip 12 as a heat source using an induced current generated by a magnetic field through the principle of induction heating described above.

Accordingly, the plurality of induction heating units 110, 120, and 130 according to the present invention cover the outer surface of the lip 12 a plurality of times in order to instantaneously heat the lip 12 to an appropriate temperature. 131) respectively. These induction coils 111, 121, 131 heat the lip 12 through a high-frequency or low-frequency AC current applied by the control unit 140.

The lip 12 generated by the induced current generates heat by itself, and this heat generates heat on the surface of the conductive lip 12 due to the skin effect, and the gas outlet of the lip 12 (13) It melts zinc chips, which are foreign substances formed on the back. At this time, the lip 12 may be heated to 420° C. or higher so that zinc can be melted.

On the other hand, the reason that the plurality of induction heating units 110, 120, 130 are provided in three is to heat the lip 12 by dividing it into three regions P1, P2, P3. Specifically, the three regions P1, P2, P3 are the first region P1, which is the front end side of the lip 12 in which the gas discharge port 13 is formed, and the second region P2, which is the middle of the lip 12. ) And a third area P3 that is a rear end side of the lip 12. Accordingly, the three induction heating units 110, 120, and 130 are disposed one by one in the first to third regions P1, P2, and P3, respectively. In this way, by dividing the lip 12 of the air knife 10 into three areas P1, P2, P3, and providing the induction heating units 110, 120, 130 in each area P1, P2, P3, the amount of plating This is to prevent unnecessary waste of electric energy by selectively operating the induction heating units 110, 120, and 130 disposed in each of the areas P1, P2, and P3 according to the environment of the adjustment operation.

For example, when the zinc chips generated when the plating amount is adjusted causes adhesion to the gas outlet 13 of the lip 12 or the zinc chips are adhered to the front end surface of the lip 12, it is located in the first area P1. The induction heating unit 110 is operated to heat the lip 12 of the portion located in the first region P1. Accordingly, the zinc chips adhered by heating of the lip 12 are melted and naturally removed by the spraying force when gas is injected.

When there is no abnormality in the gas discharge port 13 of the air knife 10, induction heating is prevented, and when an abnormality occurs in the gas discharge port 13 of the air knife 10, that is, the gas of the air knife 10 The induction heating unit 110 of the first region P1 is operated only when the discharge port 13 is clogged to some extent so that induction heating occurs. Accordingly, it is possible to prevent unnecessary loss of electrical energy.

Meanwhile, as described above, the control unit 140 is configured to selectively control the plurality of induction heating units 110, 120, and 130 to prevent unnecessary waste of electrical energy. That is, the three induction heating units 110, 120 and 130 may be independently controlled by the control unit 140, respectively. In addition, a sensor unit 150 may be further provided to select and operate one or more of the three induction heating units 110, 120, and 130 according to the work environment.

The sensor unit 150 may include a first sensor 151 provided inside the air knife 10 and a second sensor 152 provided outside the air knife 10 to detect changes in the external environment.

The first sensor 151 measures the pressure inside the air knife 10. This is to measure the change in pressure by preventing gas injection when foreign substances accumulate inside the air knife 10 by zinc chips and sticking occurs. The measured internal pressure information is transmitted to the control unit 140, and it is determined whether or not the induction heating unit 110 is operated based on the pressure information measured in real time. That is, when the pressure value measured in the normal state and the measured pressure value measured by the first sensor 151 are compared and the measured pressure value is out of the tolerance range of the preset pressure value, the gas outlet 13 is clogged. When it is determined that this has occurred, the induction heating unit 110 of the first region P1 is operated to form an induced current.

In addition, the induction heating unit 120 in the second area P2 is induction heating located in the second area P2 when zinc chips are continuously blown to the upper part of the lip 12 and sticking to the outer surface occurs. The unit 120 is operated to heat the lip 12 to reduce zinc flying, and to melt and remove the zinc chips adhered to the outer surface. At this time, it is preferable to operate the induction heating unit 110 of the first area P1 and the induction heating unit 120 of the second area P2 together, but the induction heating unit 120 of the second area P2 Can also be operated independently.

In addition, when the temperature and airflow in the upper portion of the zinc storage tank 20 fluctuate during the plating amount control operation, the second sensor 152 detects this. The sensed information is provided to the control unit 140, and the control unit 140 determines whether the induction heating units 110, 120, and 130 are operated based on the received information. For example, all three induction heating units 110, 120, and 130 provided in the first to third regions P1 to P3 are operated when the airflow above the zinc storage tank 20 changes. Accordingly, due to the hot surrounding environment, zinc chips due to zinc splash cannot fly toward the lip 12, thereby preventing contamination of the air knife 10 and adhesion of zinc chips.

As described above, although the present invention has been described by a limited embodiment and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described.

10: air knife 12: lip
13: gas outlet 20: zinc storage tank
110, 120, 130: induction heating unit 140: control unit
150: sensing unit P1: first area
P2: second area P3: third area

Claims (5)

In the apparatus for cleaning an air knife that injects a gas toward a molten metal plating material,
A plurality of induction heating units for induction heating the lip provided to surround the outer surface of the lip of the air knife; And
Including; a control unit that applies current to the plurality of induction heating units and controls each induction heating unit,
The plurality of induction heating units are arranged to be spaced apart from each other by a predetermined interval along the length direction of the air knife,
Further comprising a sensing unit including a first sensor provided inside the air knife to measure the pressure inside the air knife, and a second sensor provided outside the air knife to detect changes in the external environment according to temperature and air flow, ,
The control unit controls whether or not the plurality of induction heating units are operated according to information on the work environment according to the operation of the air knife received from the sensing unit,
The plurality of induction heating units are independently operated and controlled by the control unit. The method of claim 1,
Each of the plurality of induction heating units is an air knife cleaning apparatus having an induction coil surrounding the outer surface of the lip a plurality of times. The method of claim 1,
The plurality of induction heating units divide the lip into three regions to heat the first region at the front end side of the lip in which the gas outlet is formed, the second region at the middle of the lip, and a third at the rear end side of the lip. Air knife cleaning device provided in the area.
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