JP4835142B2 - Heating furnace charging table and heating furnace charging method - Google Patents

Description

  The present invention relates to a heating furnace charging table and a heating furnace charging method for charging a rolling material into a heating furnace installed in a hot rolling line.

  When a rolling material (for example, a slab) is charged into a heating furnace installed in a rolling line, the slab is piled up in a slab yard according to a predetermined charging order and placed on the charging table in the charging order. After being transported on the charging table, it is charged into the heating furnace by a pusher (see, for example, Patent Document 1).

  In this case, if there are multiple heating furnaces, depending on the method of simply circulating the furnace number of multiple heating furnaces, the slab attributes and rolling conditions There are many methods such as using different heating furnaces.

  A typical method of using different heating furnaces according to the slab attributes (hereinafter referred to as “furnace separation”) is to operate a plurality of heating furnaces as a heating furnace for a hot piece slab and a heating furnace for a cold piece slab. Is. In the case where the cold piece slab is heated to the temperature necessary for rolling and the case where the hot piece slab is heated to the temperature necessary for rolling, of course, the necessary furnace temperature set value is also determined as the heating time, that is, the furnace. The internal transfer speed is also different. Therefore, it is generally performed to reduce the manufacturing cost by charging each in a different furnace and operating at an appropriate furnace temperature set value and in-furnace transfer speed. Such furnace division is carried out in various forms for reducing the manufacturing cost, such as the above-mentioned hot piece slab and cold piece slab, as well as similar steel types and similar dimensions.

  Each of the plurality of heating furnaces is extracted at the extraction end (extraction table side) in the charging order when charged from the charging end (the charging table side). Transfer in the heating furnace is performed by a pusher or a walking beam, and in both cases, the slab in the furnace from the charging to the extraction moves simultaneously. Normally, a heating furnace loads slabs densely in order to maximize heating efficiency. However, if the slab supply on the charging side is not in time for the transfer in the furnace, the slabs in the furnace do not become dense and heating is performed. It causes a decrease in efficiency.

As a countermeasure for preventing the collapse of the dense charging, charging side of the furnace walking beam, 2 minutes devoted or extraction side, there is a long arm of the loading pusher. According to these devices, some time, even when charging pitch of Tsu want late to extract pitch, can be previously filled asynchronously with extracts pitch slabs SoIrigawa.

In the [Problems to be Solved by the Invention] column, the following Non-Patent Document 1 is cited, which is also described here.
JP 61-166915 A Japan Iron and Steel Institute, “Recent Hot Strip Manufacturing Technology in Japan,” Second Edition, August 10, 1987, p. 42, p. 51

  However, even if the measures described above are taken, the slab supply on the charging side may be delayed to the extraction pitch. Dividing the previous walking beam into two parts and increasing the length of the charging pusher are measures against differences in charging and extraction pitches in one heating furnace. Usually, a plurality of heating furnaces are provided, and their inlets are arranged along a single charging table. Therefore, if there is no charging space at the charging end of a certain heating furnace, and the slab to be charged into the furnace is waiting to be charged on the charging table, it is charged into the downstream heating furnace. Even if the space is secured, the scheduled slab cannot be transported to the downstream furnace, and an empty furnace of the heating furnace is generated, resulting in a reduction in heating efficiency.

  For example, as shown in FIG. 8, three heating furnaces of No. 1 furnace 31, No. 2 furnace 32, and No. 3 furnace 33 are installed, and their inlets are arranged along the charging table 20. In this case, when there is no charging space in the No. 2 furnace 32 and the slab 11 to be charged into the No. 2 furnace 32 is waiting to be charged on the charging table 20, the charging space in the No. 3 furnace 33 on the downstream side. However, due to the slab 11 scheduled to be charged into the No. 2 furnace 32, the slab 12 scheduled to be charged into the No. 3 furnace 33 cannot be conveyed, and an empty furnace of the No. 3 furnace 33 is generated. Heating efficiency decreases.

  In particular, in the above-described furnace division operation, the furnace transportation speed of each furnace divided differs, so even if a charging space can be secured in the heating furnace on the downstream side of the charging table, to the downstream furnace. The above-mentioned situation that the slab scheduled to be loaded cannot be transported constantly occurs.

In recent years, in order to improve productivity, it is common to synchronize the continuous casting process, which is an upstream process of the rolling line, with the rolling process. This synchronization method is described in Non-Patent Document 1 (p.41). To summarize, HDR (Hot Direct Rolling), which supplies slab directly to the rolling line without going through the heating furnace, DHCR (Direct Hot Charge Rolling), which slab is loaded directly into the heating furnace without passing through the slab yard after casting, and slab Temporarily put out to the yard, but do not change the slab order in the yard. Temporary placement H C R to be charged into the heating furnace, change the slab order in the yard with a hot piece, and charge into the heating furnace. It can be divided into HCR and CCR (Cold Charge Rolling), in which slabs that have been made into cold pieces after being maintained in a slab yard are inserted.

  Among these, one of the problems in DHCR and temporary placement HCR is a mismatch between the restriction condition of the casting order and the restriction condition of the rolling order. That is, in the normal continuous casting process and the hot rolling process, it is rare to continuously manufacture the same product, and it is necessary to determine the manufacturing order of various types of products according to the capacity of the equipment. For example, a continuous casting machine can change a slab steel grade only in the steelmaking pan unit of the steelmaking factory of the further upstream process. Further, the slab width can only be changed by about several tens of mm per slab, and the cutting of the slab length across the casting pan has a problem in quality. Also, when laying slabs on the yard with temporary HCR, if the upper slab is longer than the lower slab, the posture when placed will be unstable. There are also restrictions. Furthermore, in the hot rolling process, if the product thickness is significantly different from the thickness of the preceding material, the product thickness may change little by little due to technical issues in the precision of changing the setting of the rolling mill. It is desirable that the rolling order be a proper one. This is also described in Non-Patent Document 1 (p. 51).

  As described above, since the continuous casting process and the rolling process are asynchronous, the CCR determines the manufacturing order so that only the casting side restrictions are satisfied during continuous casting and the rolling side restrictions are satisfied during rolling. Is absorbed by replacement at the slab yard. However, in DHCR and temporary placement HCR, since there is no replacement process like CCR, the rolling order has to be determined according to the casting order, and as a result, there is a problem that DHCR and temporary placement HCR cannot be carried out much. .

  The present invention has been made to solve the above problems, and in a heating furnace charging table for charging a rolling material into a heating furnace, there is a rolling material waiting to be charged on the table. However, it is possible to maintain the heating efficiency by avoiding the occurrence of an empty furnace in the downstream heating furnace, or to satisfy the restrictions on the rolling side with the rolling materials arranged on the table according to the casting order. It is an object of the present invention to provide a heating furnace charging table and a heating furnace charging method capable of expanding the implementation of DHCR and temporary placement HCR by rearranging in this manner.

  In order to solve the above problems, the present invention has the following features.

[ 1 ] A heating furnace charging table for charging a rolling material into a plurality of heating furnaces installed in a hot rolling line, wherein the rolling material is temporarily retracted from the table. An apparatus is provided at each inlet position of the plurality of heating furnaces or at an intermediate position between adjacent inlets , and the preceding rolling material is temporarily retracted from the table by the rolling material retracting device, and the subsequent rolling material is Can overtake the preceding rolling material. However, the rolling material retracting device is not provided at the most downstream position in the rolling material conveyance direction.

[ 2 ] The preceding rolling material on the heating furnace charging table for charging the rolling material into a plurality of heating furnaces is temporarily evacuated from the table using the rolling material evacuation device described in [1]. A heating furnace charging method characterized by changing the order of charging the rolling material into the heating furnace by allowing the subsequent rolling material to pass through and then returning it to the table.

  In the present invention, since the rolling material retracting device for temporarily retracting the rolling material on the table from the table is provided, even if the rolling material is waiting to be charged on the table, the downstream heating is performed. The subsequent rolled material can be charged into the furnace, and it is possible to maintain the heating efficiency by avoiding the occurrence of an empty furnace in the downstream heating furnace. In addition, even if the rolled materials are arranged on the table in the order of casting, they can be rearranged in the order of restrictions on the rolling side by replacing the preceding rolled material and the succeeding rolled material. Implementation can be expanded.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a view showing a heating furnace charging table according to an embodiment of the present invention. As shown in FIG. 1, the heating furnace charging table 20 according to this embodiment includes a roller table 21 and a slab tongue 22 above the roller table 21.

  Thus, the rolled material (here, slab) 10 on the roller table 21 can be lifted by the slab tongue 22 and temporarily retracted from the roller table 21.

  And the operation example in this heating furnace charging table 20 is shown in FIG.

  As shown in FIG. 2 (a), the succeeding slab 12 to be charged in the downstream heating furnace (not shown) is placed on the roller table 21 where the preceding slab 11 is waiting to be charged. When it has been conveyed, as shown in FIG. 2B, the preceding slab 11 is lifted by the slab tongue 22 and temporarily retracted from the roller table 21, and the succeeding slab 12 is conveyed downstream. When the succeeding slab 12 passes the preceding slab 11, the preceding slab 11 is returned to the roller table 21 as shown in FIG.

  3 and FIG. 4, three heating furnaces of No. 1 furnace 31, No. 2 furnace 32, and No. 3 furnace 33 are installed, and their inlets are arranged along the heating furnace charging table 20. This is an example. In the figure, 34 is an extraction table.

  In the heating furnace charging table 20 shown in FIG. 3, a slab tongue 22 a is installed above the roller table 21 near the charging inlet of the No. 1 furnace 31, and a slab tongue 22 b is set above the roller table 21 near the charging inlet of the No. 2 furnace 32. Has been.

  Thus, when it is desired to overtake the slab waiting for the charging of the first furnace 31, the slab waiting for the charging is evacuated by the slab tong 22a and the slab waiting for the charging of the second furnace 32 is to be overtaken. Sometimes, the slab waiting to be loaded is evacuated by the slab tongue 22b.

  In addition, in the heating furnace charging table 20 shown in FIG. 4, a slab tongue 22 c is installed above the roller table 21 at an intermediate position between the charging inlet of the first furnace 31 and the charging inlet of the second furnace 32.

  As a result, when it is desired to overtake the slab waiting to be charged in the No. 1 furnace 31, the slab waiting to be charged is moved downstream and evacuated by the slab tong 22c. When it is desired to overtake the existing slab, the slab waiting for loading is moved upstream and retracted by the slab tongue 22c.

  Thus, in this embodiment, since the slab tongue 22 for temporarily retracting the slab on the roller table 21 from the roller table 21 is provided, the slab 11 waits for loading on the roller table 21. Even if it becomes, the succeeding slab 12 can be charged in the downstream heating furnace, and it can avoid that an empty furnace generate | occur | produces in a downstream heating furnace, and can maintain heating efficiency.

  In this embodiment, the slab tong 22 is used as the slab retracting device. Instead, as shown in FIG. 5, every other roll of the roller table 21 is raised while the slab is mounted. The table roll 23 may be used. Further, as shown in FIG. 6, a skid lifter 24 for lifting the slab with a skid between table rolls may be provided, or as shown in FIG. 7, pushers 25a and 25b capable of retracting and returning the slab may be provided. Good.

  Furthermore, in the above embodiment, when the preceding slab 11 is waiting to be loaded, this is temporarily retracted from the roller table 21 and the succeeding slab 12 is overtaken. It is not limited to this. In DHCR and temporary HCR operations, when the slabs are arranged on the roller table according to the casting order, according to the heating furnace charging table of the present invention, the succeeding slab can overtake the preceding slab, The slabs on the table can be rearranged so as to satisfy the restrictions on the rolling side. The configuration of the slab evacuation device and the specific method for overtaking may be the same as in the above-described embodiment.

It is explanatory drawing of one Embodiment of this invention. It is a figure which shows the operation example in one Embodiment of this invention. It is a figure which shows an example in case there are three heating furnaces. It is a figure which shows the other example in the case of three heating furnaces. It is explanatory drawing of other embodiment of this invention. It is explanatory drawing of other embodiment of this invention. It is explanatory drawing of other embodiment of this invention. It is explanatory drawing of a prior art.

Explanation of symbols

10 Slab
DESCRIPTION OF SYMBOLS 11 Leading slab 12 Subsequent slab 20 Loading table 21 Roller table 22, 22a, 22b, 22c Slab tong 23 Table roll 24 Skid lifter 25 Pusher 31 No. 1 furnace 32 No. 2 furnace 33 No. 3 furnace 34 Extraction table

Claims (2)

A heating furnace charging table for charging a rolling material into a plurality of heating furnaces installed in a hot rolling line, a rolling material retracting device for temporarily retracting the rolling material on the table from the table , Provided at the position of each charging inlet of the plurality of heating furnaces or at an intermediate position between the adjacent charging inlets , the preceding rolled material is temporarily retreated from the table by the rolled material retracting device, and the subsequent rolled material is preceded by the preceding rolled material. A heating furnace charging table characterized by being able to overtake the rolled material. However, the rolling material retracting device is not provided at the most downstream position in the rolling material conveyance direction. The preceding rolling material on the heating furnace charging table for charging the rolling material into a plurality of heating furnaces is temporarily retracted from the table using the rolling material retracting device according to claim 1, A heating furnace charging method characterized by changing the order of charging the rolling material into the heating furnace by passing the rolling material and then returning it to the table.

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