KR20140122502A - Apparatus and method for cooling rolled steel - Google Patents

Abstract

The present invention relates to a rolled material cooling apparatus and a rolled material cooling method, wherein the rolled material cooling apparatus comprises: a laminar bank installed at the upper side of a rolled material, having multiple coolant supply holes formed in the bottom surface thereof and supplying a coolant filing the inner space of the laminar bank to the rolled material, and having the inner space with a shape of which the cross sectional area becomes smaller downwards; a sensor part installed at the inlet of the laminar bank, and measuring and transmitting the entire width of the rolled material entering the inlet of the laminar bank; and a control part controlling the amount of the coolant injected into the laminar bank so that the coolant can fill the inner space to a height (H) which is in the laminar bank and corresponds to a coolant supply width to be supplied with the coolant among the entire width of which the information is transmitted from the sensor part.

Description

Technical Field [0001] The present invention relates to a cold rolling device,

More particularly, the present invention relates to a rolling material cooling device and a cooling method, and more particularly, to a rolling material cooling device and a cooling method for cooling a rolled material on a runout table (ROT) during hot rolling, And more particularly, to a rolling material cooling device and a cooling method capable of reducing an edge wave.

1, a hot rolling apparatus 10 includes a heating furnace 11 for heating a rolling material 1 (for example, a slab), a hot rolling furnace 11 for heating in a heating furnace 11, A roughing mill 12 for rough rolling the material 1, a finishing mill 13 for finishing the rough rolling material 1 (for example, a bar), a finishing mill 13 for finishing the rolled milled material 1 (ROT) 14 (a run out table) for transporting the rolled rolled material 11, and a winder 15 for winding the rolled rolled material 11 with a coil.

The rolled material 1 is passed through a heating furnace 11, a roughing mill 12, a finishing mill 13, an ROT 14 and a winder 15 in this order and wound into a coil. The rolling speed of the plurality of rolling mills F1 to F7 provided in the finishing mill 13 is individually controlled when the rolling mill 1 proceeds to the finishing mill 13 to finishing the rolling mill. Thus, after the rolling material 1 is heated in the heating furnace 11, all the overall work which is wound into a coil by the winder 15 is generally called "hot rolling".

During the hot rolling process, the run-out table (ROT) is a process in which the strip is fed before the final rolling of the rolled material or strip, that is, the strip rolled through the heating furnace 11 and rough rolling, Is cooled to the target temperature to determine the material and strength of the product. At this time, the plate shape defect due to the cooling deviation in the width direction, that is, the occurrence of the stripe wave, is caused by the problem of permanentity, and the mechanism of occurrence thereof is as follows.

Referring to FIG. 2, in the runout table (ROT), the cooling water dropped at the center in the width direction of the strip during cooling flows out through the edge portion of the strip, so that the temperature of the edge portion of the strip is lowered. In this process, first, the volume contraction of the cooled or subcooled strip edge portion occurs, followed by the volume contraction of the central portion of the strip to be cooled. This temperature difference causes a difference in volume contraction time, which is expressed as a wave form of the strip. In particular, in the cooling process during the hot rolling process, since the strip is cooled at a high temperature of 600 ° C or higher, a transformation period occurs during cooling depending on the type of steel. As described above, this phenomenon occurs when the strip And then occurs first in the edge portion. Therefore, when the edge transformation begins at a predetermined section, the cooled edge first expands in volume and the central portion of the high temperature that has not yet entered the transformation section is cooled, causing the volume to contract. This phenomenon causes a wave of the edge portion It is a typical mechanism.

Korean Patent Publication No. 1995-0016920 (July 20, 1995) Korean Patent Publication No. 2000-0009074 (Feb.

A problem to be solved by the present invention is to provide a hot rolled steel sheet which is capable of reducing the shape defect of the rolled material, particularly the edge wave, generated during the process of cooling the rolled material to a coiling temperature on a run out table (ROT) And a method for cooling the rolled material.

Another object of the present invention is to provide a rolling material cooling device and a cooling method capable of drastically improving the installation cost, the complicated structure and materials, and frequent failures due to a poor operating environment, .

In order to achieve the above-mentioned object, the present invention provides a rolling mill for a rolling mill, comprising: a plurality of water collecting bases provided on an upper portion of a rolling mill to provide cooling water filled in an inner space to the rolling mill, A lamina bank having a shape in which the cross-sectional area thereof decreases as it goes to the upper side; A sensor unit installed on an inlet side of the lamina bank for measuring and transmitting the entire width of the rolled material entering the inlet side of the lamina bank; And controlling the amount of cooling water injected into the lamina bank so that the cooling water is filled up to the height (H) of the lamina bank corresponding to the main water width to which the cooling water is to be injected from the entire width of the rolled material received from the sensor unit And a controller for controlling the rolling material cooling device.

At this time, the bottom surface of the lamina bank may have a 'V' shape in the width direction of the rolled material.

Further, the bottom surface of the lamina bank has a stepped shape which is symmetrical in the left and right direction.

In addition, the rolling material cooling apparatus includes a cooling water supply line connected to the lamina bank and injecting the cooling water into the lamina bank; And a solenoid valve installed in the cooling water supply line for opening and closing the cooling water supply line in accordance with the control signal transmitted from the control unit to adjust the amount of cooling water injected into the lamina bank.

The control unit may further include: a height calculating unit for calculating a height (H) on the laminar bank corresponding to the main water width to which the cooling water is to be injected; A main quantity calculation unit for calculating a discharge amount per unit time of the cooling water discharged through the main water pipe located below the height H calculated by the height calculation unit; And a solenoid valve controller for transmitting the control signal to the solenoid valve so that the inflow amount of the cooling water injected into the lamina bank per unit time becomes equal to the discharge amount per unit time of the cooling water.

The discharge amount per unit time of the cooling water may be calculated by multiplying the total area S1 of the water inlet located below the height H by the discharge speed V1 of the cooling water discharged through the water inlet.

According to another aspect of the present invention, there is provided a cooling method for cooling a rolled material placed on a lower side using a lamina bank having an inner space with a reduced cross-sectional area toward the bottom and having a plurality of counter- Wherein the cooling step comprises a measuring step in which the entire width of the rolled material entering the inlet side of the lamina bank is measured; And controlling the amount of cooling water injected into the lamina bank so that the cooling water is filled up to the height (H) of the lamina bank corresponding to the main water width to which the cooling water is to be injected from the entire width of the rolled material And a method of cooling the rolled material.

Here, the control step may control the amount of cooling water injected into the lamina bank by opening / closing a cooling water supply line for supplying the cooling water to the lamina bank.

The control step may include calculating a height (H) on the lamina bank; Calculating a discharge amount per unit time of the cooling water discharged through the main water inlet of the lamina bank located below the calculated height H; And controlling the amount of cooling water injected into the lamina bank so that the inflow amount per unit time of the cooling water injected into the lamina bank becomes equal to the discharge amount per unit time of the cooling water.

At this time, the discharge amount per unit time of the cooling water may be calculated by multiplying the total area S1 of the water inlet located below the height H by the discharge speed V1 of the cooling water discharged through the water inlet.

Effects of the rolling material cooling device and the cooling method according to the present invention will be described as follows.

First, there is an advantage that the shape defect of the rolled material occurring during the process of cooling the rolled material to the coiling temperature on the run out table (ROT) at the time of hot rolling, in particular the edge wave, can be reduced.

Second, by controlling the temperature in the width direction of the rolled material uniformly through a plurality of potholes formed on the bottom surface of the lamina bank having a V-shaped section at the bottom, the edge wave can be reduced without using mechanical equipment There is an advantage to be able to.

1 is a schematic view of a general hot rolling apparatus;
FIG. 2 is an explanatory view of an edge wave generation in a cooling process; FIG.
3 is a block diagram of a rolling material cooling apparatus using a conventional edge mask.
4 is a configuration diagram of a rolling material cooling apparatus according to an embodiment of the present invention.
5 (a) is a perspective view of a lamina bank according to an embodiment of the present invention.
5 (b) is a sectional view of the lamina bank of Fig. 5 (a). Fig.
6 (a) is a perspective view of a lamina bank according to an embodiment of the present invention.
6 (b) is a cross-sectional view of the lamina bank of Fig. 6 (a). Fig.
7 is a detailed configuration diagram of the control unit of Fig.
8 is a method for cooling a rolled material according to an embodiment of the present invention.

3 is a configuration diagram of a rolling material cooling apparatus using a conventional edge mask.

Referring to FIG. 3, there is a method for preventing sub-cooling of an edge portion as a method for preventing a wave generated at an edge portion of a conventional rolled material. An edge mask facility 52 is provided at both ends of a laminar bank 51 to reduce cooling variations generated in the width direction of the hot-rolled steel plate 50 when cooling is performed on the run- . The cooling water dropped on the central portion in the width direction of the hot-rolled steel plate 50 during cooling flows out through the edge portion of the hot-rolled steel plate 50, so that the edge portion temperature is controlled to be lower than the central portion, The installed edge mask 52 prevents the cooling water injected from the lamina bank 51 from being injected into both ends of the hot-rolled steel plate 50. The installed edge mask 52 has a maximum width of 300 mm as the entire width of the hot- Is automatically controlled so that no cooling water is injected into the space.

However, the above-mentioned method of preventing supercooling of the edge portion has a high cost and difficulty in maintaining and repairing the equipment.

In addition, the edge mask is connected to the drive shaft by the power of the motor and is moved in the width direction by being attached to the drive shaft. In the hot rolling process, since the hot strips of 600 ° C or higher generally move in the run-out table section, water vapor is generated by the cooling water and the generated steam is accompanied by the scale generated by the reaction with oxygen in the atmosphere. Scale was applied to the bearings of the motor part, the drive shaft, and the connection part connecting the drive shaft and the chain, which were corroded by the high temperature exposure, and frequent equipment failure due to motor overload occurred.

In the case of the sensor for detecting the position of the hot-rolled steel sheet, since the position detection is not smooth due to the generation of high-temperature steam, the poor control in the width direction is frequent, and the scales attached to the drive shaft and the chain connection are fixed, It takes a lot of time.

This incomplete maintenance and repair often causes incomplete failure of critical edge subcooling.

In order to solve the above problems, embodiments of the rolling material cooling apparatus and the cooling method according to the present invention will be described with reference to the accompanying drawings.

4 to 7, a rolling material cooling apparatus according to an embodiment of the present invention will be described. The rolling material cooling apparatus according to the present embodiment is for preventing an edge wave from occurring at the edge of the rolled material 1 and includes a water storage tank 100 for storing cooling water, a lamina bank 200, A cooling water supply line 300, a solenoid valve 310, a sensor unit 400, and a control unit 500.

4 is a configuration diagram of a rolling material cooling apparatus according to an embodiment of the present invention.

4, the lamina bank 200 is installed on an upper portion of the roller table 20 for transferring the rolled material 1 rolled in the finish rolling mill 10, and the cooling water filled in the inner space is passed through the rolling material 1 A plurality of water dispensers 210 are formed on the bottom surface in a lengthwise or widthwise direction at regular intervals. The inner space of the lamina bank 200 has a shape in which the cross-sectional area decreases as it goes down. By adjusting the height H of the cooling water filled in the inner space of the lamina bank 200 to be described later, 1) can be adjusted.

The laminar bank 200 is connected to the storage tank 100 through the cooling water supply line 300 and the cooling water stored in the storage tank 100 is injected into the laminar bank 200 through the cooling water supply line 300. [ do. At this time, it is preferable that the water storage tank 100 is disposed at a relatively higher position than the laminar bank 200 so that cooling water of the water storage tank 100 can be injected into the laminar bank 200 by gravity.

FIG. 5 (a) is a perspective view of a lamina bank according to an embodiment of the present invention, and FIG. 5 (b) is a sectional view of a lamina bank of FIG.

Referring to FIG. 5, one embodiment of the lamina bank 200 will be described. The cross section of the bottom of the lamina bank 200 in the width direction of the rolled material 1 has a shape of 'V'. That is, the bottom surface of the lamina bank 200 is formed so as to be inclined downward toward the center of the lamina bank 200 at both ends of the lamina bank 200 in the width direction of the rolled material 1. By doing so, the height H of the cooling water filled in the lamina bank 200 can be adjusted to adjust the main water width W of the cooling water supplied through the water inlet 210 of the lamina bank 200. That is, the main water width W of the cooling water can be adjusted so that the edge portion of the rolled material 1 is not overcooled as compared with the central portion in accordance with the entire width T of the rolled material 1. [ At this time, the main water width W of the rolled material 1 is preferably set to about 70% to 90% of the entire width T.

6 (a) is a perspective view of a lamina bank according to an embodiment of the present invention, and FIG. 6 (b) is a sectional view of a lamina bank of FIG. 6 (a).

6, the cross section of the bottom of the lamina bank 200 in the width direction of the rolled material 1 has a symmetrical step shape. That is, the bottom surface of the lamina bank 200 has a stepped shape inclined downwardly symmetrically from both ends of the rabbin bank 200 toward the center of the lamina bank 200 in the width direction of the rolled material 1. By doing so, the height H of the cooling water filled in the lamina bank 200 can be adjusted to adjust the main water width W of the cooling water supplied through the water inlet 210 of the lamina bank 200. That is, the main water width W of the cooling water can be adjusted so that the edge portion of the rolled material 1 is not overcooled as compared with the central portion in accordance with the entire width W of the rolled material 1. [ At this time, the main water width W of the rolled material 1 is preferably set to about 70% to 90% of the entire width T.

The cooling water supply line 300 is a kind of pipe connecting the storage tank 100 and the lamina bank 200. The cooling water stored in the storage tank 100 through the cooling water supply line 300 is supplied to the lamina bank 200 200). The cooling water in the reservoir tank 100 may be injected into the laminar bank 200 by gravity but may be injected into the laminar bank 200 by a separate pump (not shown) .

The electromagnetic valve 310 is installed in the cooling water supply line 300 and controls the amount of cooling water injected into the laminar bank 200 through the cooling water supply line 300. Specifically, the cooling water supply line 300 is opened according to the control signal transmitted from the control unit 500 to control the amount of cooling water injected into the laminar bank 200.

The sensor unit 400 is disposed on the entrance side of the laminar bank 200 (i.e., on the exit side of the finishing mill 10) in the traveling direction of the rolling material 1 and is rolled in the finishing mill 10, 20 to the laminar bank 200 and measures the entrance information of the rolled material 1 to the control unit 500. [ Here, the entry information of the rolled material 1 may include at least one of a width, a thickness, and an entry position of the rolled material 1. The sensor unit 400 may be an optical sensor, an ultrasonic sensor, a digital camera, have.

The control unit 500 controls the amount of cooling water injected into the laminar bank 200 in response to the entry information of the rolled material 1 transferred from the sensor unit 400. Specifically, the control unit 500 controls the laminar bank 200 (corresponding to the main water width W to which the cooling water should be injected from the entire width T of the rolled material 1) And calculates a discharge amount per unit time of the cooling water discharged through the water inlet 210 located below the calculated height H, as shown in FIG. The inflow amount per unit time of the cooling water injected into the laminar bank 200 through the cooling water supply line 300 is equal to the discharge amount per unit time of the cooling water discharged through the main water inlet 210 located below the height H The solenoid valve 310 is controlled by the solenoid valve. By doing so, only the portion corresponding to the main water width W of the rolled material 1 is supplied with cooling water, so that the rolled material 1 is uniformly cooled. The control unit 500 is electrically connected to the electromagnetic valve 310 and the sensor unit 400 so as to perform wire / wireless communication.

7 is a detailed configuration diagram of the control unit 500. As shown in FIG.

7, the control unit 500 includes a height calculating unit 510, a main quantity calculating unit 520, and a solenoid valve control unit 530. The height calculating unit 510, the main quantity calculating unit 520,

The height calculating unit 510 calculates the height H of the cooling water to be filled in the lamina bank 200 in correspondence with the width information of the rolled material 1. The width W of the rolling material 1 excluding the edge portions on both sides of the rolled material 1 may be used as the width W of the main portion of the rolled material 1, The height H of the cooling water to be filled in the lamina bank 200 corresponding to the height H of the cooling water. At this time, the main water width W of the rolled material 1 is preferably set to about 70% to 90% of the entire width T.

The main water quantity calculation unit 520 calculates the amount of water discharged per unit time of the cooling water discharged through the water inlet 210 located below the height H calculated by the height calculation unit 510. Specifically, the discharge amount per unit time of the cooling water is calculated by multiplying the total area S1 of the main water cistern 210 located below the height H by the discharge speed V1. At this time, the discharge speed V1 may be a speed at which the cooling water freely falls by gravity.

The electromagnetic valve control unit 530 controls the flow rate of the cooling water injected into the laminar bank 200 through the cooling water supply line 300 per unit time of the cooling water discharged through the water inlet 210 located below the height H And sends a control signal to the solenoid valve 310 so as to be equal to the discharge amount per unit time. By doing so, only the portion corresponding to the main water width W of the rolled material 1 is supplied with cooling water, so that the rolled material 1 is uniformly cooled.

8 is a cooling method for rolling material according to an embodiment of the present invention.

Hereinafter, a rolling material cooling method according to an embodiment of the present invention will be described with reference to FIGS.

First, when the rolled material 1 passes through the finishing mill 10 and enters the roller table 20, the sensor unit 400 measures the incoming information of the rolled material 1, (Step S10). Here, the entry information of the rolled material 1 may include at least one of the width, the thickness and the entry position of the rolled material 1.

Next, a height calculating step for calculating the height H of the cooling water to be filled in the laminar bank 200 in correspondence with the width information of the rolled material 1 transferred from the sensor unit 400 is performed by the control unit 500 (S20). The width W of the rolling material 1 excluding the edge portions on both sides of the rolled material 1 may be used as the width W of the main portion of the rolled material 1, The height H of the cooling water to be filled in the lamina bank 200 corresponding to the height H of the cooling water.

Next, the control unit 500 calculates a discharge amount per unit time of the cooling water discharged through the water inlet 210 located below the height H of the cooling water (S30). Specifically, the discharge amount per unit time of the cooling water is calculated by multiplying the total area S1 of the main water inlet located below the height H by the discharge speed V1. At this time, the discharge speed V1 may be a speed at which the cooling water freely falls by gravity.

The control unit 530 controls the flow rate of the cooling water injected into the laminar bank 200 through the cooling water supply line 300 per unit time through the water inlet 210 located below the height H of the cooling water, The control of the solenoid valve 310 is performed so that the amount of discharged cooling water is equal to the amount of discharged cooling water per unit time (S40). By doing so, only the portion corresponding to the main water width W of the rolled material 1 is supplied with cooling water, so that the rolled material 1 is uniformly cooled.

As a result, it is possible to reduce the defective shape of the rolled material, particularly the edge wave, without using mechanical equipment through the rolling material cooling device and the cooling method described above.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

1: Rolling material 10: Finishing mill
20: roller table 30: conveying roller
50: hot-rolled steel plate 52: edge mask
100: Reservoir tank 51, 200: Lamina bank
210: main water channel 300: cooling water supply line
310: Solenoid valve 400: Sensor unit
500: control unit 510: height calculating unit
520: Main quantity calculation unit 530:
540: Solenoid valve control section

Claims (10)

A lamina bank provided on an upper portion of the rolled material and having a plurality of counterflow holes on the bottom surface for injecting cooling water filled in the inner space into the rolled material,
A sensor unit installed at an entrance of the lamina bank for measuring and transmitting the entire width of the rolled material entering the entrance side of the lamina bank,
And controlling the amount of cooling water injected into the lamina bank so that the cooling water is filled up to the height (H) of the lamina bank corresponding to the main water width to which the cooling water is to be injected from the entire width of the rolled material received from the sensor unit And a control unit for controlling the rolling material cooling device. The method according to claim 1,
And the bottom surface of the lamina bank has a V shape in the width direction of the rolled material. The method according to claim 1,
Wherein the bottom surface of the lamina bank has a stepped shape symmetrical in the left and right direction. The method according to claim 1,
The rolling material cooling apparatus
A cooling water supply line connected to the lamina bank for injecting the cooling water into the lamina bank;
And a solenoid valve installed in the cooling water supply line and controlling an amount of cooling water injected into the laminar bank by opening and closing the cooling water supply line in accordance with a control signal transmitted from the control unit. Device. The method of claim 4,
The control unit
A height calculating unit for calculating a height (H) on the lamina bank corresponding to a main water width to which the cooling water is to be injected;
A main water quantity calculation unit for calculating a discharge amount per unit time of the cooling water discharged through the main water pipe located below the height H calculated by the height calculation unit;
And a solenoid valve control unit for transmitting the control signal to the solenoid valve so that an inflow amount of the cooling water injected into the lamina bank per unit time becomes equal to a discharge amount per unit time of the cooling water. The method of claim 5,
The discharge amount per unit time of the cooling water
Is calculated by multiplying the total area (S1) of the main water basin located below the height (H) by the discharge velocity (V1) of the cooling water discharged through the main water basin. And a cooling step of cooling the rolled material placed on the lower side by using a lamina bank having a plurality of counterflow holes formed on the bottom surface,
The cooling step
A measuring step of measuring the total width of the rolled material entering the mouth side of the lamina bank;
And controlling the amount of cooling water injected into the lamina bank so that the cooling water is filled up to the height H of the lamina bank corresponding to the main water width to which the cooling water is to be injected from the entire width of the rolled material The rolling material cooling method. The method of claim 7,
The control step
And cooling water supplied to the lamina bank is controlled by opening / closing a cooling water supply line for supplying the cooling water to the lamina bank. The method of claim 7,
The control step
Calculating a height (H) on the lamina bank;
Calculating a discharge amount per unit time of the cooling water discharged through the main water inlet of the lamina bank located below the calculated height H;
And controlling the amount of cooling water injected into the lamina bank so that the inflow amount per unit time of the cooling water injected into the lamina bank becomes equal to the discharge amount per unit time of the cooling water. The method of claim 9,
The discharge amount per unit time of the cooling water
Is calculated by multiplying the total area (S1) of the main water basin located below the height (H) by the discharge velocity (V1) of the cooling water discharged through the main water basin.

Images