JP2661500B2 - Cooling equipment for hot rolled steel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling apparatus in a hot rolling line for steel sheets and the like, and more particularly, to cooling hot rolled steel by injecting cooling water with compressed air by a cooling header having a double inner / outer structure. The present invention relates to a hot rolled steel cooling device capable of uniform cooling in the width direction by a method.

[0002]

2. Description of the Related Art As an apparatus for cooling a steel sheet in a high temperature state while running the steel sheet following hot rolling, the apparatus is cooled on-line.
There are a spray nozzle system and a slit nozzle system. The spray nozzle type cooling device has a cooling header in which a number of cooling water injection nozzles are arranged in the plate width direction in the plate width direction of the steel plate transport line, and cools by injecting cooling water to the running steel plate. Is common. In the case of such a cooling method, the cooling water injected onto the steel sheet flows down from the edge along the surface of the steel sheet, so that the edge of the steel sheet is supercooled more than the central part, and the width of the steel sheet in the width direction is smaller than the longitudinal direction of the steel sheet. However, there is a problem that unevenness of the material occurs and the shape of the steel sheet is deteriorated.

[0003] On the other hand, the slit nozzle method is a method of cooling by a slit laminator using a slit nozzle for forming a curtain-shaped water film. As a device, a box-shaped slit nozzle is vertically provided below a cooling water header. What is done is common. In the case of this slit laminar cooling device, too, cooling of the steel plate edge cannot be avoided.

As means for preventing such non-uniform cooling in the sheet width direction, conventionally, mask members are arranged at both ends in the sheet width direction, and a part of cooling water from the header is blocked by the mask members. There is known a method of preventing overcooling of the steel sheet edge portion by doing so and eliminating uneven cooling in the sheet width direction of the steel sheet, and various cooling devices described below have been proposed.

For example, a method is disclosed in which cooling water jetted from a cooling header is blocked by a blocking member such as a mask tray provided separately from the cooling header to remove excess cooling water (Japanese Patent Laid-Open No. 62-61713). And a method of narrowing the cooling width by blocking the tip of the nozzle portion of a slit nozzle type cooling header with a stopper member provided outside the cooling header (see Japanese Utility Model Application Laid-open No. Sho 58-5709). Japanese Patent Application Laid-Open No. -152310), a method in which a dovetail groove is provided between a throat part and a nozzle part of a slit nozzle type cooling header, and a width of a water film is changed by a mask member movably provided in the dovetail groove (actual opening). 1959-10661
No. 2) is known.

[0006]

However, the method of shutting off the cooling water jetted from the cooling header with a shutoff member such as a mask tray requires a complicated structure, requires a large installation space, and reduces equipment costs. In addition to being expensive, good controllability cannot be obtained. In addition, the method of blocking the tip of the nozzle portion of the cooling header with a stopper member is such that the stopper member contacts the nozzle tip of the cooling header every time the narrow steel plate is cooled, so that the nozzle tip is significantly worn and damaged. When the cooling header is a slit nozzle type, there is a problem that formation of a water film is hindered. In addition, the method of changing the width of the water film using a mask member movably attached to the cooling header is effective only for a slit nozzle type cooling header, and the driving method is to drive the arm protruding outside from the mask member. Because it adopts a method of moving by connecting to the shaft,
There is a disadvantage that the connection between the arm and the drive shaft is easily damaged, and stable operation cannot be expected for a long time.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and is particularly suitable for a spray nozzle method and is a compact type which requires no installation space, and has good controllability of cooling water. An object of the present invention is to provide a cooling device for steel materials.

[0008]

According to the present invention, in a cooling header corresponding to the maximum sheet width of a traveling hot-rolled steel material, a plurality of cooling water injection nozzles are arranged at a predetermined pitch on a surface facing the steel material to be cooled. A double structure comprising an outer cooling header and an inner cooling header in which a plurality of compressed air injection nozzles located inside the outer cooling header and independent of the cooling water injection nozzle are arranged in pairs with the cooling water injection nozzle. A cooling header, a compressed air jet width adjusting mask member disposed at both ends in the inner cooling header and slidably in the width direction of the rolled steel material in contact with the inner surface of the header, and laterally provided in the inner cooling header. The gist of the present invention is a cooling device for hot-rolled steel, comprising a positioning mechanism for moving the mask member in the width direction of the rolled steel via a motor-driven screw rod.

[0009]

[Function] The outer cooling header and the inner cooling header
Each is connected to pressure and cooling water supply piping,
The cooling water supplied to the outer cooling header is supplied to the inner cooling header, and is jetted from the cooling water jet nozzle together with the compressed air jetted from the compressed air jet nozzle.

The mask for adjusting the compressed air injection width is movable in the longitudinal direction of the header by rotating the screw rod, and is arranged so as to block the compressed air injection nozzles at both ends of the inner cooling header. The compressed air supplied into the header cannot be ejected from the compressed air ejection nozzle blocked by the mask member. Therefore, the cooling water (mist) injected together with the compressed air is not injected from the cooling water injection nozzle paired with the compressed air injection nozzle blocked by the mask member, but is injected only from the cooling water injection nozzle communicating with the compressed air injection nozzle.

In this invention, the position of the mask member for adjusting the compressed air injection width is set in accordance with the width of the rolled steel material.
It is possible to prevent the edge portion of the rolled steel material from being excessively cooled.

[0012]

1 is a plan view partially showing an example of a device for cooling a hot-rolled steel according to the present invention, FIG. 2 is an enlarged vertical sectional side view taken along line AA in FIG. 1, and FIG. It is a longitudinal side view which expands and shows a part of mask member for compressed air injection width adjustment in an apparatus, 1 is a cooling header of a double structure, 1-1 is an outer cooling header, 1-2 is an inner cooling header, 2 is Reference numeral 3 denotes a screw rod, 4 denotes a positioning motor, 5 denotes a cooling water passage, 6 denotes a compressed air passage, 7 denotes a cooling water pipe, and 8 denotes a compressed air pipe. Here, a case where the present invention is applied to cooling of a hot-rolled steel sheet will be described as an example.

The cooling header 1 having the double structure has a length corresponding to the maximum width of the hot-rolled steel sheet running, and the inner cooling header 1-2 is independently provided inside the outer cooling header 1-1. A large number of cooling water jet nozzles 1a and compressed air jet nozzles 1b are arranged in the outer cooling header 1-1 and the inner cooling header 1-2 at a predetermined pitch so as to form a pair. The outer cooling header 1-1 and the inner cooling header 1-2 are each provided with a cooling water pipe 7,
A structure in which the cooling water supplied from the cooling water passage 5 is connected to the compressed air pipe 8 and is supplied from the compressed air passage 6 and is injected in a mist form from the cooling water injection nozzle 1a together with the compressed air ejected from the compressed air injection nozzle 1b. Has become.

The mask member 2 for adjusting the compressed air jet width is slidably fitted in the inner cooling header 1-2 in the header longitudinal direction (the plate width direction) with an appropriate contact pressure. A screw rod connection block 2-1 is protruded. As the material of the mask member, natural rubber, silicon material, urethane material, or the like is selected to maintain airtightness. Structurally, as shown in an enlarged view in FIG. 3, a metal reinforcing plate 2-2 is inserted inside the mask member to maintain the shape of the mask member, and the reinforcing plate is integrated with an adhesive with an adhesive. ing. The screw rod connection block 2-1 is welded to the reinforcing plate 2-2.

The screw rod 3 constituting the moving mechanism of the mask member 2 for adjusting the compressed air injection width has a screw in a left-right opposite direction, and the two compressed air injection width adjustments fitted inside both ends of the inner cooling header. A threaded connection with the screw rod connection block 2-1 of the mask member 2 for mounting, is provided laterally on the side wall of the inner cooling header 1-2, and is rotationally driven by a positioning motor 4 installed at one end of the header. Has become. That is, by rotating the positioning motor 4,
The structure is such that both the compressed air jet width adjusting mask members 2 can be freely reciprocated simultaneously in opposite directions via the screw rods 3. Of course, a reversible motor is used as the positioning motor 4. The moving stroke of the compressed air jet width adjusting mask member 2 may be set according to the type of the width of the steel plate.

In the above cooling device, the cooling water supplied from the cooling water pipe 7 is supplied to the cooling header 1-
1, while the compressed air supplied from the compressed air pipe 8 flows into the cooling header 1-2 through the passage 6, and together with the compressed air ejected from the compressed air injection nozzle 1b, the cooling water injection nozzle 1
The cooling water is sprayed in a mist form from a. At this time,
When a part of the compressed air injection nozzle 1b is cut off by moving the compressed air injection width adjusting mask member 2 by the positioning motor 4, the cooling water injection range is narrowed by the range cut off by the mask member.

FIG. 4 is a schematic view showing one example of the case. FIG. 4A shows a case where the compressed air jet width adjusting mask members 2 are located at both ends of the cooling header 1 and are cooled over the entire width of the steel plate 10.
(B) When the mask member 2 for adjusting the compressed air injection width is moved toward the center by the length of the mask to cool both ends of the steel sheet by narrowing the cooling water injection range by the length of the mask member, (c). Shows the case where the moving amount of the mask member 2 for adjusting the compressed air injection width is made smaller than (b) and the cutoff width of the compressed air injection is reduced to cool the steel plate.

FIG. 5 is a schematic view showing a case where the compressed air jet width adjusting mask members 2 having different lengths are exchanged and used.
(A) shows a case where the compressed air jet width adjusting mask member 2 having a short length is used, and (b) shows a case where the compressed air jet width adjusting mask member 2 having a long length is used. As described above, the nozzle blocking width can be further varied by replacing and using mask members having different lengths.

FIG. 6 is a schematic plan view showing a compressed air jet width adjusting mask member 2 having a different shape. FIG. 6 (a) shows a general mask member of a full block type, and FIG. 6 (b) shows a cut-out portion 2-3. 3 shows a partially blocked mask member. By using the partially blocking type mask member (b), the end of the steel plate can be further locally blocked and cooled.

Here, the case where the cooling header of the present invention is used as the lower cooling header arranged on the lower surface of the steel plate has been described, but it is needless to say that the cooling header can be applied to the upper cooling header arranged on the upper surface of the steel plate.

Embodiment 1 FIG. 7 is a schematic view of a test apparatus for using the above cooling header as an upper cooling header, pasting pressure-sensitive paper on a steel plate, and examining a water curtain distribution depending on the presence or absence of a mask member for adjusting a compressed air jet width. And 11 is a pressure-sensitive paper. FIG. 8 shows the results of this example. In the figure, reference numeral 12 denotes a mark indicating a water curtain distribution.

That is, FIG. 1A shows a case without a mask member (conventional example), in which a uniform water film distribution can be seen. Figure (b)
Is an embodiment (example of the present invention) using a mask member. In this case, since the injection from the header is interrupted by the compressed air, the complete mist is not injected from the cooling water injection nozzle in the portion interrupted by the mask member, but the cooling water in the outer cooling header flows out. , Pressure sensitive paper has a weaker mark than mist. However, when the introduction of the compressed air and the cooling water is reversed, the compressed air is introduced into the outer cooling header, and the cooling water is introduced into the inner cooling header, the cooling water is blocked by the mask member. As shown, the portion where the mask member is present is hardly cooled. Further, as shown in FIG. 5C, when the notch is formed in the mask member, the mask member is further partially blocked, so that the supercooling can be more finely prevented.

Example 2 A short plate (material: stainless steel) having a size of 9 mm thick × 300 mm long × 300 mm wide was used as a test steel plate.
This test steel sheet was heated to 200 to 850 ° C., placed at the end of the cooling header, and the result of examining the degree of cooling depending on the presence or absence of a mask member is shown in FIG. From the results shown in FIG. 9, there is a case where the cooling efficiency is higher or lower when the mask member is used at each temperature. Turned out to be possible.

[0024]

As described above, the device of the present invention is:
The position of the mask member that is slidably fitted in the width direction of the steel material on the inner cooling header for compressed air injection of the cooling header of the double structure corresponding to the maximum width of the traveling hot steel material is set according to the width of the hot steel material By doing so, there is an effect that overcooling of the steel material edge portion can be effectively prevented. Also,
Since the mask member can be made of a lightweight material, the positioning accuracy and controllability of the mask member are good, and more delicate and fine overcooling prevention can be performed. It is effective for Furthermore, since the mask member is pressed against the inside of the header, there is no danger of damaging the nozzle or interfering with the hot steel. In addition, since the mask member is driven via a threaded rod housed in the header, stable operation can be expected for a long time, installation space can be significantly reduced, and equipment costs can be compared. There are advantages such as cost reduction.

[Brief description of the drawings]

FIG. 1 is a plan view partially showing an example of a cooling device for hot-rolled steel according to the present invention;

FIG. 2 is an enlarged vertical sectional side view taken along line AA of FIG. 1;

FIG. 3 is a longitudinal sectional side view showing an enlarged part of a mask member for adjusting a compressed air jet width in the same device.

4A and 4B are schematic views illustrating a method of cooling a steel sheet by the above-described apparatus, in which FIG. 4A shows a case where cooling members for adjusting a compressed air jet width are positioned at both ends of a cooling header to cool over the entire width of the steel sheet, and FIG. In the case where the spray width adjusting mask member is moved toward the center by the mask length to cool both ends of the steel plate by narrowing the cooling water spray range by the length of the mask member, (c)
Shows the case where the moving amount of the mask member for adjusting the compressed air injection width is made smaller than (b), the cutoff width of the compressed air injection is reduced, and the steel plate is cooled.

FIG. 5 is a schematic view showing a case in which a mask member for adjusting a compressed air injection width having a different length is used in the same apparatus as above;
(A) shows a case where a short-length compressed air jet width adjusting mask member is used, and (b) shows a case where a long compressed air jet width adjusting mask member is used.

FIG. 6 is a schematic plan view showing a compressed air jet width adjusting mask member having a different shape in the above apparatus, wherein FIG. 6 (a) is a general mask member of a full block type, and FIG. Each shows a mask member.

FIG. 7 is a schematic diagram of a test apparatus for examining a water curtain distribution depending on the presence or absence of a mask member for adjusting a compressed air jet width, using a cooling header of the above apparatus as an upper cooling header, affixing pressure-sensitive paper on a steel plate, and using a mask member for adjusting a compressed air jet width.

8A and 8B are schematic diagrams showing a water curtain distribution according to the first embodiment of the present invention, wherein FIG. 8A shows a water film distribution without a mask member (conventional example), and FIG. 8B shows water when a mask member is used. Film distribution (Example of the present invention), (c) Water film distribution when a notched mask member is used (Example of the present invention), (d) Reverses the introduction of compressed air and cooling water, and Introduce compressed air,
It is a water film distribution (invention example) when cooling water is introduced into an inner cooling header.

FIG. 9 is a diagram showing the relationship between the test steel sheet temperature and the heat transfer coefficient in Example 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Double-layer cooling header 1-1 Outside cooling header 1-2 Inner cooling header 2 Mask member for compressed air injection width adjustment 3 Screw rod 4 Positioning motor 5 Cooling water passage 6 Compressed air passage 7 Cooling water piping 8 Compressed air piping 10 Steel plate 11 Pressure sensitive paper 12 Mark indicating water curtain distribution

Claims (1)

(57) [Claims] 1. A cooling header corresponding to a maximum sheet width of a traveling hot-rolled steel material, wherein an outer cooling header in which a plurality of cooling water injection nozzles are arranged at a predetermined pitch on a surface facing the steel material to be cooled, and the outer cooling header. A cooling header having a double structure comprising an inner cooling header which is located inside the header and in which a plurality of compressed air injection nozzles independent of the cooling water injection nozzle are arranged so as to form a pair with the cooling water injection nozzle; and At both ends in the header, a mask member for adjusting the compressed air injection width which is slidably disposed in the width direction of the rolled steel material in contact with the inner surface of the header, and a motor-driven screw rod laterally provided in the inner cooling header. And a positioning mechanism for moving the mask member in the width direction of the rolled steel material through the cooling device.