US3648996A

US3648996A - Apparatus for cooling high temperature metal plates

Info

Publication number: US3648996A
Application number: US3464A
Authority: US
Inventors: Toshiya Yonezawa; Katsuya Kogumasaka; Katsuhiro Kinoshita
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 1969-01-20
Filing date: 1970-01-16
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14
Also published as: DE2002045C3; DE2002045B2; DE2002045A1; CA932566A

Abstract

An apparatus for cooling high-temperature thick steel plates comprising a transmission unit consisting of endless conveyors running rectangularly across the rolling or operation line, a unit for loading high-temperature thick steel plates onto said transmission unit and a cooling water jetting unit provided at said transmission unit to have jets directed to the upper and bottom surfaces of the high-temperature thick steel plates.

Description

United States Patent Yonezawa et al.

[4 Mar. 14, 1972 APPARATUS FOR COOLING HIGH TEMPERATURE METAL PLATES Toshiya Yonezawa; Katsuya Kogumasaka;

Katsuhiro Kinoshita, all of Kitakyushu, Ja an. 7

Inventors:

Nippon Steel Corporation, Tokyo, Japan Jan. 16, 1970 Assignee:

Filed:

Appl. No.:

Foreign Application Priority Data Jan. 20, 1969 Japan ..44/433s U.S. Cl. ..266/6 S, 72/202, 134/68 Int. Cl. ..C2ld 1/62 Field of Search ..266/6 R, 6 S; 29/8l.l; 72/40,

Primary Examiner-Gerald A. Dost Attorney-Wenderoth, Lind & Ponack [57] ABSTRACT An apparatus for cooling high-temperature thick steel plates comprising a transmission unit consisting of endless conveyors running rectangularly across the rolling -or operation line, a unit for loading high-temperature thick steel plates onto said transmission unit and a cooling water jetting unit provided at said transmission unit to have jets directed to the upper and bottom surfaces of the high-temperature thick steel plates.

7 Claims, 7 Drawing Figures PATENTEDMAR 14 I972 SHEET 1 0F 2 'l'oshiya Yonezawa,

Katsuya Kogumasaka and Katsuhiro Kinoshite y wmunnm Attorneys PATENTEDHAR 14 1972 3, 648.996

' sum 2 [1F 2 Toshiya Yonezawa, Katsuya Kogumasaka and Katsuhiro Kinoshita,

Inventors Attorneys APPARATUS FOR COOLING HIGH TEMPERATURE METAL PLATES BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates in general to an apparatus for cooling high temperature metal plates, particularly steel plates of such thickness that they are called slabs.

2. Description of the Prior Art In order to cool thick steel plates from a temperature high enoughafter rolled to room temperature, there are available two cooling methods, that is, water-cooling and air-cooling methods. However, when cooling slabs of more than 80 mm. thick with water, they warp. In order to avoid occurrence of warps, there are no other ways than to allow such slabs to cool in the air, or cool them with a cooling apparatus with a press or rolls to correct warps while cooling. However, for the former way to cool with air, it takes time to cool such slabs to the desired temperature-so long a time as 9 to hours usually to cool a slab of 190 mm. thick, 940 mm. wide and 9 m. long from 1,000 C. to 150 C., it is inefficient in terms of time, as well as uneconomical due to the requirement of a large foundation space.

If operation time is made shorter, a larger size of apparatus is required, for the latter way to cool with water hence larger investment costs. Thus, the conventional cooling method has always many demerits from the standpoints of construction and operation.

In order to solve such demerits of the method of cooling with water high temperature thick steel plates of more than 80 mm. thick, particularly to reduce the production of warps to a practical minimum without using any pressing installations, but merely by adjusting cooling water feed during operation, there is used such an improved water-cooling method that a roller table is provided on the extension of the rolling line, so as to transmit high temperature thick steel plates one directly after another or intermittently, to be subjected to a shower of cooling water both surfaces of said high temperature thick steel plates. However, the greatest demerit of this method is that high temperature thick steel plates are loaded onto the roller table one after another lengthwise, requiring a very long cooling table. Thus, the apparatus used for this method also becomes large-sized, requiring a large space for foundation and large investment costs.

SUMMARY OF THE INVENTION In the light of complications with the conventional methods, and having examined every possible means to solve them, the inventors have worked out the present invention, which is successful in making compact the cooling apparatus by installing this apparatus rectangularly across the direction of the roller table provided on the rolling line and charging high temperature metal plates into the apparatus one after another crosswise.

The special characteristics of the high temperature metal plate cooling apparatus of the present invention are that it comprises a transmission unit consisting of endless conveyors provided rectangularly across the line of rolling high temperature metal plates as they are transmitted one after another in the rolling direction, a unit provided at the junction between said endless conveyors and the rolling or operation line, to load the high temperature metal plates crosswise onto said endless conveyors and a unit for jetting cooling water provided at an appropriate position near said endless conveyors. Having also studied every possible system for transmitting high temperature metal plates in the transmission unit, the inventors have found that the demerit of the system using a roller table of conventional type, is that as each piece of high temperature metal plates is usually 0.7 to 2.4 meters in breadth, rolls of the roller table must be as wide as the widest one of such plates, requiring a great amount of investment costs even in rolls.

- Also, the transmission system of skid type, is found to have a fatal demerit of producing scars on the high temperature metal plates. Also, the with-chick chain conveyorsystem having constant spacing between chains, makes ineffective and, therefore, uneconomical operations of cooling slabs having different breadths one from another.

The inventors conclude that endless conveyors (for example, chain conveyors) are the most suited for such transmission system, which knowledge is incorporated-in the present invention.

By using such endless conveyors asv mentioned above, it becomes possible to make the foundation space and the size of the apparatus and investment cost smaller-than the cooling apparatus using the roller table of conventional type.

An object of the present invention is to provide an efficient apparatus for cooling high temperature metal plates, of watercooling type but requiring no pressing means andto be set on the rolling line. 1

Another object of the present inventionisto provide an apparatus for cooling high temperature metalplates, whereby high temperature steel plates or slabs of more than 50mm thick immediately after rolled can be cooled in short time with water with nearly no production of such. deformations. as

warps.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a plane view of the apparatus for cooling high temperature metal plates according to the present invention.

FIG. 2 shows a side view of the apparatusshown in FIG. 1.

FIG. 3 shows the cross-sectional view ofthe apparatus along the line IIIIII in FIG. I.

FIG. 4 shows a plane view of the cooling water piping according to the present invention.

FIG. 5 shows the cross-sectional view of the nozzle pipe of the present invention.

FIG. 6 and FIG. 7 show respectively an embodiment of the apparatus of the present invention using another unit than shown in the above figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT The following explains the present invention by using the preferred embodiment illustrated with drawings.

In the drawings, 1 indicates the roller table provided in the direction of the rolling or operation line; the high temperature metal plates 2 just after rolled are movedzon said roller table 1. 3 indicates the pusher to push the high temperature metal plates 2 from the roller'table I to the direction rectangular across said roller table 1. 6 indicates the endless conveyors provided in a plural number rectangularly. across the rolling direction. The high temperature metal plate 2 is loaded onto said endless conveyor 6 by the pusher 3.

There is provided an elevator 4 below one end of the transmission line of the endless conveyors; and the'top-surfaceof the elevator 4 is operated by the hydraulic press 5 to move down to the level of the upper surface of the endless conveyors 6.

A greater part of each endless conveyor 6 constitutes the cooling zone 7, in which are provided a great number-of cooling water jetting pipes 8. At the other end of the transmission line of each endless conveyors 6, it is connected with another kind of endless conveyors with clicks 10 for taking out the cooled metal plate 2. The support of said conveyors 10 on the side of the roller table for transmitting cooled metal plates is so designed as to move vertically, in order to have such plates transferred from said conveyors 10'to said roller table ll. 12 indicates a motor for driving the endless conveyors 6. 13 indicates a speed converter. 14 indicates a motor for driving the conveyors 10. I5 indicates a speed converter. 16 indicates a hood for the suction of steam produced in cooling operations.

As mentioned above, the apparatus of the present invention comprises a transmission unit consisting of endless conveyors 6 provided rectangularly across the rolling or operation line of nun-1 nan rolled high temperature metal plates 2, a unit for loading high temperature metal plates 2 onto the conveyors 6 provided near one end of the transmission line of said conveyors 6, and a cooling water jetting unit covering a greater part around the center of said conveyors 6. Said conveyors are provided in several sets preferably in the pit as shown in FIGS. 1 and 2, with the falling gradient in the cooling direction, and if they are so arranged that the outside ones have their end directed toward the cooling line to some extent, say, about a 1/200, as shown in the drawings, then the shrinkage of high temperature metal plates 2 in the long side due to cooling, can be absorbed, which, together with the falling gradient in the above-mentioned cooling direction, makes smooth transmission of high temperature metal plates 2.

The above-mentioned cooling water jetting unit makes it possible to cool high temperature metal plates 2 having a very long side, with nearly no production of warps, by the most effective adjustment of cooling water supply and arrangement of jetting nozzles, that is, by the shower onto the upper and bottom sides of high temperature metal plates 2 in an amount ranging from 0.1 to 0.6 m. /min. per m of each side, and by using nozzles 9 in a number of 8 to 40 pieces per m? of the surface of high temperature metal plates 2, these nozzles being sectioned into a number of blocks, say, four blocks in FIG. 4. Each nozzle 9 is preferred to be sized about 0.05 to 0.30 cm. and provided as shown in FIG. the shower of cooling water onto the bottom surface is better to be from the same as to by about 50 percent greater than that onto the upper surface.

The following describes how to operate the above-mentioned units to cool high temperature metal plates 2.

In FIG. I and FIG. 2, high temperature metal plate 2 stops once on the roller table 1, transferred by a pusher 3, a charging device 17 shown in FIG. 6, or the like for pushing or taking up the metal plate 2 to the elevator 4, and loaded onto the endless conveyors 6 with the elevator 4 as it is moved down by the rack or the hydraulic press 5; after loading, the pusher 3 returns to the original position 1' preparation for taking care of next metal plate 2. In this case, if said charging device 17 is used, high temperature metal plates 2 can be transferred directly onto the endless conveyors 6, making it possible to omit the elevator 4. As mentioned above, in order to be loaded on the endless conveyors 6 one after another, the metal plate 2 advances by its width and stops; and after transferring, the elevator 4 goes up in preparation for taking care of next metal plate 2. The same process is repeated for each metal plate 2.

As the high temperature metal plate 2 is transmitted on the endless conveyors 6 through the cooling zone 7, its both sides are subjected to the shower of cooling water jetted from a great number of nozzles 9 set on the cooling water jetting pipes 8.

The so cooled metal plates 2 are taken out one after another by the endless conveyors with clicks 10 provided at the end of the transmission line of the endless conveyors 6, and transported by the transporter 11 such as a roller table to the stock yard. Instead of said endless conveyors for transportation 10, a crow crane, magnet crane or extractor can be used.

In order to have the endless conveyors 6 move metal plates 2 through the cooling zone 7 not intermittently but continuously, the motor of general type for driving the conveyors 12 should be replaced by a stepless variable speed motor, otherwise a stepless converter should be used additionally.

In order to use cooling water effectively, the jetting pipes 8 should be sectioned into several blocks, each block having a flow adjusting valve 13 so as to adjust the supply of cooling water by taking into consideration the anticipated time for cooling according to the size of high temperature metal plates 2, the interval between each two of high temperature metal plates 2 and their physical properties, and, in some case, adjustment is necessary even among the so operated valves 13. In order to raise cooling effects to a maximum in the practice of the present invention, the endless conveyors 6 have a falling gradient of about H to about H50 in the cooling zone 7, and ets from the nozzles are directed toward the descending end of the conveyors, so that cooling water runs very smoothly on the surface of high temperature metal plates 2, preventing production of a cover of steam on the surface of high temperature metal plates 2 and resulting in an example of the reduction of cooling time by about 10 percent.

Again, due to the falling gradient of the endless conveyors 6 in the cooling zone 7, tension of the conveyors 6 is reduced. which is effective in raising strength of the conveyors 6; scales peeled from the surface of metal plates 2 in cooling operations, run with flows without staying on the surface of the conveyors 6. Also by arranging the conveyors 6, with the outside ones have their end directed toward the cooling line, as mentioned above, moving resistance is reduced and the position energy of metal plates 2 itself can be utilized, reducing the requirement of energy for driving the conveyors. Steam produced in cooling operations and staying in the plant, is suctioned to be let out through the hood 14 provided in the indoor part of the cooling zone 7. Because of the hood [4 and the upper jetting pipes, it is difficult to inspect the maintenance of the apparatus; it is desirable to make them removable by setting them on the rail 15 or by using a rotary joint, so as to facilitate maintenance and inspection of the apparatus. Also, use of wavy guides 18 as shown in FIG. 7 on the upper surface of the endless conveyors smoothens flows of cooling water, making possible even cooling of high temperature metal plates 2. Thus, it becomes possible to cool high temperature metal plates 2 very economically.

What we claim is:

1. An apparatus for cooling hot slabs comprising:

a transmission unit consisting of endless conveyors side by side adapted to be positioned adjacent to a slab rolling line and extending in a direction perpendicular to said rolling line and having a gradient falling away from the bend of said rolling line for conveying hot slabs in the direction of their width;

a unit adjacent the end of said transmission unit at said slab rolling line for loading hot slabs from the rolling line crosswise of the rolling line onto the endless conveyors; and

a jet cooling water unit provided around the endless conveyors for jetting cooling water toward hot slabs carried on said conveyors.

2. The apparatus as claimed in claim 1, wherein said transmission unit consists of chain conveyors.

3. The apparatus as claimed in claim 1, wherein said apparatus further comprises a pit, said conveyors being provided in the pit.

4. The apparatus as claimed in claim 1, wherein said conveyors are in several sets, the outside sets of conveyors having the ends thereof remote from the slab rolling line directed toward the inside sets in the direction in which the high temperature metal plates contact during cooling.

5. The apparatus as claimed in claim 1, wherein said cooling water jetting unit includes from eight to 40 nozzles per m? of the surface of the to-be-cooled metal plate, each nozzle having a cross sectional area of from 0.05 to 0.30 cm. the nozzles being arranged in several block-shaped groups spaced along said conveyors.

6. The apparatus as claimed in claim I, wherein said loading unit consists of an elevator and a pusher.

7. The apparatus as claimed in claim 1 wherein said loading unit consists of a charging device.

innn'l (In

Claims

1. An apparatus for cooling hot slabs comprising: a transmission unit consisting of endless conveyors side by side adapted to be positioned adjacent to a slab rolling line and extending in a direction perpendicular to said rolling line and having a gradient falling away from the bend of said rolling line for conveying hot slabs in the direction of their width; a unit adjacent the end of said transmission unit at said slab rolling line for loading hot slabs from the rolling line crosswise of the rolling line onto the endless conveyors; and a jet cooling water unit provided around the endless conveyors for jetting cooling water toward hot slabs carried on said conveyors.

5. The apparatus as claimed in claim 1, wherein said cooling water jetting unit includes from eight to 40 nozzles per m.2 of the surface of the to-be-cooled metal plate, each nozzle having a cross sectional area of from 0.05 to 0.30 cm.2, the nozzles being arranged in several block-shaped groups spaced along said conveyors.

6. The apparatus as claimed in claim 1, wherein said loading unit consists of an elevator and a pusher.