Method for improving operation efficiency of automatic heat preservation pit of profile hot blank

Abstract

The invention discloses a method for improving the operating efficiency of an automatic heat preservation pit of a profile hot blank, which comprises the following steps of: feeding a blank of which the boundary dimension in the pit accords with the rolling into a heating furnace for rolling, and feeding a blank of which the boundary dimension does not accord with the current rolling into the heat preservation pit for heat preservation while feeding the steel-making hot blank into the heat preservation pit for heat preservation; hot billets output by a steelmaking casting machine are prevented from being discharged to a steelmaking blank field to be stacked, and heat loss of the billets is effectively reduced; the balance of direct hot charging in the furnace and charging of the hot blank into the heat preservation pit in the hot conveying process is gradually realized through the blank hot conveying and hot charging rhythm and the matching problem, so that the blank which cannot be directly subjected to hot charging enters the heat preservation pit to be subjected to heat preservation as much as possible, and the hot charging efficiency of the heating furnace is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel forging, and particularly relates to a method for improving the operation efficiency of an automatic heat preservation pit for hot billets of profiles. Background Art

[0002] The No. 1 continuous caster in the steelmaking plant is matched with the rolling profile line. Approximately 40% of the billets are directly transported into the furnace through the hot charging roller path line connecting the billet discharging roller path of the No. 1 continuous caster and the charging roller path of the profile heating furnace; the remaining approximately 60% of the billets are stacked offline in the continuous casting billet discharging bay and enter the profile raw material bay through the transfer car. The overall hot charging rate and hot charging temperature are not high. Moreover, the billets entering the furnace have 4 cross-sectional size specifications, and the billet length fluctuates from 5.8 to 8.8 meters, increasing the difficulty of organizing hot charging production.

[0003] Affected by factors such as the mismatch between the rolling production capacity and the continuous casting production capacity and the large variety of rolled products in the profile line, it is impossible to further improve the hot charging rate of the profile line only through production organization and coordination. Currently, the billets that are not directly transported into the furnace hot are stacked offline in continuous casting, transferred across bays, and then reloaded into the furnace manually or by hoisting. There are not only large temperature drops, low automation levels, and inconvenient information exchange. The following problems exist: 1) A large amount of energy is wasted, and a large amount of physical heat of the billets is lost during the transfer process, which does not meet the requirements of energy conservation and consumption reduction; 2) The production cost is high. Manpower and equipment facilities need to be invested in hoisting, transportation, heating, etc., resulting in an increase in production cost; 3) The automation level is low. The information of the billets offline depends on manual transmission, which does not meet the requirements of modern large-scale production; 4) A large amount of gas is consumed for heating the billets in rolling steel, increasing carbon emissions, which does not meet the current development trend of carbon emission reduction and carbon neutrality.

[0004] The present invention aims to provide a method for improving the operation efficiency of an automatic heat preservation pit for hot billets of profiles that can achieve the "side-in and side-out" operation function of the billets, so as to improve the hot charging rate of the billets and the temperature of the billets entering the furnace and reduce gas consumption. Summary of the Invention

[0005] The object of the present invention is to provide a method for improving the operation efficiency of an automatic heat preservation pit for hot billets of profiles.

[0006] The object of the present invention is achieved as follows. A method for improving the operation efficiency of an automatic heat preservation pit for hot billets of profiles. When continuous casting is carried out, in the case where the cast billets are different from the rolled billets, all the billets coming out of the continuous caster pass through the ejection pusher and the sorting roller path arranged on the cold billet and sorting roller path table, and after sorting, they are transported to the billet collecting roller path, and then clamped by the billet taking machine and sent into the pit body in the heat preservation pit for heat preservation; in the case where the cast billets are different from the rolled billets, after the billet taking machine puts down the hot billets, then the billets that meet the rolling conditions in terms of grade and specification are taken out of other pit bodies in the heat preservation pit and sent to the hot billet table for charging into the furnace.

[0007] The beneficial effects of the present invention are as follows: (1)This invention, compared with the original production process ( Figure 1 ), realizes the "side-in and side-out" of billets by adding a loading bench and a grouping roller table and transforming the old loading bench, improving the running efficiency of hot billets and the hot charging rate of billets. The hot charging rate of billets (counted as hot charging when the billet temperature ≥ 400°C) has increased from 50% to 80% after the implementation of the invention, and the gas consumption of the heating furnace has been reduced by 50 m 3 / t, effectively reducing fuel consumption; (2)This invention solves the problem that the billet supply capacity of steelmaking and the billet supply and receiving capacity of the rolling mill do not match, resulting in the offline of hot billets and a large amount of heat loss of billets. Through this invention, the energy consumption of reheating billets is effectively reduced; (3)This invention sends billets with external dimensions conforming to rolling inside and outside the pit into the heating furnace for rolling, while loading billets with external dimensions not conforming to the current rolling sent from the hot steelmaking into the heat preservation pit for heat preservation, reducing the offline of hot billets output by the steelmaking casting machine to the steelmaking billet yard for stacking, and effectively reducing the heat loss of the steel billets themselves; (4)This invention gradually realizes the balance between directly hot charging into the furnace and loading hot billets into the heat preservation pit during the hot delivery process by solving the problem of the rhythm and matching of hot billet hot delivery and hot charging, enabling billets that cannot be directly hot charged currently to enter the heat preservation pit for heat preservation as much as possible, thereby further improving the hot charging efficiency of the heating furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is the original hot charging process flow chart when the cast steel billets and the rolled steel billets are the same; Figure 2 is the hot charging process flow chart of this invention when the cast steel billets and the rolled steel billets are the same; Figure 3 is the layout drawing of the automatic heat preservation pit for hot profiles of this invention, where 1 - rejection pusher, 2 - grouping roller table, 3 - billet collecting roller table, 4 - heat preservation pit, 5 - hot billet bench. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following further elaborates on the present invention in conjunction with embodiments, but does not limit the present invention in any way. Any transformation or improvement made based on the teachings of the present invention falls within the protection scope of the present invention.

[0010] A method for improving the operation efficiency of the automatic hot billet insulation pit of profiles. When continuous casting is carried out, in the case where the cast billets are different from the rolled billets, all the billets coming out of the continuous caster pass through the ejection pusher 1 and the sorting roller table 2 arranged on the cold billet and sorting roller table. After sorting, they are transported to the billet collecting roller table 3, and then clamped by the billet taking machine 7 and sent into the pit body of the insulation pit 4 for heat preservation; in the case where the cast billets are different from the rolled billets, after the billet taking machine puts down the hot billets, then the billets meeting the rolling conditions in terms of grade and specification are taken out of other pit bodies in the insulation pit 4 and sent to the hot billet table 5 for charging into the furnace.

[0011] The automatic insulation pit is provided with 9 pit bodies, 1 billet taking machine 7 and 2 cover lifting machines.

[0012] To meet the characteristics of the operation of billets with various cross-sectional dimensions of profiles, according to the current cross-sectional dimensions of the produced billets and combined with the clamping capacity of the billet taking machine's tongs, through calculation (see Table 1), the number of billets clamped for 4 types of cross-sections is set. A billet taking machine with the maximum opening size of the tongs being 1600 mm is selected to achieve the effect of sharing the billet taking machine's tongs under the operation conditions of various cross-sectional dimensions, so as to realize the efficient operation of the billet taking machine under the conditions of various billet cross-sectional dimensions (200×200 mm, clamping 7 pieces / group; 230×230 mm, clamping 6 pieces / group; 230×350 mm, clamping 4 pieces / group; 320×410 mm, clamping 3 pieces / group).

[0013] Table 1 Billet cross-section parameters and the setting of the number of billets clamped by the billet taking machine Blank cross-sectional dimension (mm) Width of the blank horizontal cross-section (mm) Number of grouped bars (bars) Total width of the horizontal cross-section (mm) Maximum size of the clamp opening (mm) 200×200 200 7 1 400 1 600 230×230 230 6 1 380 1 600 230×350 350 4 1 400 1 600 320×410 410 3 1 230 1 600 In the case where the cast billets are the same as the rolled billets, the billets that cannot be charged into the furnace in time coming out of the continuous caster stop on the previous group of rollers of the charging table, and are pushed by the ejection pusher 1 to the billet collecting roller table 3. When a full crane load is collected on the billet collecting roller table 3, the automatic clamping crane of the insulation pit clamps the billets and sends them to the pit body of the insulation pit for heat preservation.

[0014] When the continuous caster stops casting, the continuous caster does not produce billets. The billet taking machine of the insulation pit lifts the billets from the pit body and transfers them to the hot billet table 5, and the charging table sends the billets to the furnace front charging roller table one by one for charging the billets into the furnace.

[0015] Example 1 1. During the normal production process (when the cast billets are the same as the rolled billets), the collection of hot billets is as Figure 2 shown. Affected by the production capacity of billet continuous casting and rolling, about 40% of the hot billets for hot delivery directly enter the heating furnace through the charging roller table, and about 40% of the remaining 60% of the hot billets are collected into the insulation pit through the sorting roller table 2, and the remaining lower part of the hot billets is taken offline to the on-site billet storage.

[0016] 2. When the No. 1 continuous caster stops casting, no billets are discharged from the continuous caster. The billet-taking machine in the soaking pit lifts the billets from the soaking pit and transfers them to the hot billet table 5, and the hot billet table 5 sends the billets to the furnace front charging roller table one by one for charging the billets into the furnace.

[0017] 3. When the specifications and grades of the billets cast by the continuous caster are inconsistent with those of the rolled billets, such as Figure 3 , all the billets coming out of the continuous caster pass through the rejection pusher 1 of the cold billet and sorting roller table and the sorting roller table 2. After sorting, they are transported to the billet collecting roller table 3, then the first cover-opening machine is opened, and the billet-taking machine clamps and sends them into the soaking pit 4. The soaking pit 4 is designed with 9 pits (compartments). After the billet-taking machine discharges the hot billets, the second cover-opening machine is opened, and the billets with specifications and grades meeting the rolling conditions are taken out of the other pits (compartments) in the soaking pit 4 and sent to the hot billet table 5 for charging into the furnace, thus realizing the functions of hot billet collection and heat preservation when the billets for steelmaking and the rolled billets have different specifications and grades, further increasing the billet charging temperature into the furnace and reducing energy consumption.

[0018] After the method was organized and implemented in the heating furnace area of the section bar production line of Kunming Iron and Steel from December 2023 to December 2024, the hot charging rate of the billets (counted as hot charging when the billet temperature ≥ 400 °C) increased from 50% before the implementation of the invention to 80% after the implementation of the invention, and the gas consumption of the heating furnace decreased by about 50 m 3 / t, achieving energy conservation and consumption reduction.

Claims

1. A method for improving the operating efficiency of an automatic heat preservation pit for hot billets of profiles, characterized in that: The method comprises the following steps: when the cast steel billet is different from the rolled steel billet during continuous casting, all the steel billets coming out of the continuous casting machine are passed through a steel-removing pusher (1) and a marshaling roller table (2) arranged on a cold billet and marshaling roller table frame, and after being marshaled, are transported to a billet-collecting roller table (3), and are then taken by a steel-taking machine and sent to a pit body in a heat-insulating pit (4) for heat-insulating; when the cast steel billet is different from the rolled steel billet, after the steel-taking machine has put out the hot billet, steel billets of grades and specifications that meet the rolling conditions are taken out of the other pit bodies in the heat-insulating pit (4), and are sent to a hot billet stand (5) for entry into a furnace.

2. The method for improving the operating efficiency of the automatic heat preservation pit for hot billets of profiles according to claim 1, characterized in that: The automatic heat-insulating pit is provided with 9 pit bodies, 1 steel taking machine and 2 cover-opening machines, and the cover-opening machines are arranged on both sides of the steel taking machine.

3. The method for improving the operating efficiency of the automatic heat preservation pit for hot billets of profiles according to claim 1 is characterized in that: The maximum size of the steel taking machine clamp opening is 1600 mm.

4. The method for improving the operating efficiency of the automatic heat preservation pit for hot billets of profiles according to claim 1, characterized in that: The number of steel strips clamped by the steel taking machine is set as follows: cross-sectional size is 200×200 mm, clamping 7 strips / group; cross-sectional size is 230×230 mm, clamping 6 strips / group; cross-sectional size is 230×350 mm, clamping 4 strips / group; cross-sectional size is 320×410 mm, clamping 3 strips / group.

5. The method for improving the operating efficiency of the automatic heat preservation pit for hot billets of profiles according to claim 1, characterized in that: Under the same conditions as for casting and rolling billets, billets that come out of the continuous casting machine and cannot be put into the furnace in time stop on a group of rollers in front of the loading platform and are pushed onto the billet collection roller (3) by the steel-removing pusher (1). When a full load of billets is collected on the billet collection roller (3), the steel-removing machine clamps the billets and sends them to the insulation pit for insulation.

6. The method for improving the operating efficiency of the automatic heat preservation pit for hot billets of profiles according to claim 1, characterized in that: About 40% of the hot billets from the continuous casting machine that cannot be put into the furnace in time are collected by the grouping roller table (2) and enter the holding pit (4), and the remaining hot billets are taken off the line to the on-site billet warehouse.

7. The method for improving the operating efficiency of the automatic heat preservation pit for hot billets of profiles according to claim 1, characterized in that: When the continuous casting machine stops casting, the continuous casting machine does not produce steel billets. The steel taking machine lifts the steel billets from the pit body and transfers them to the hot billet stand (5). The loading stand then delivers the steel billets one by one to the furnace feeding roller table in front of the furnace for the billets to be fed into the furnace.

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