Double-discharge heating furnace steel charging method and steel burning process for multi-specification steel billets

Abstract

The invention relates to a double-discharge heating furnace steel charging method and a steel burning process for multi-specification steel billets. The piece weight of the steel billets is 5-18 tons, the length is 1100-4000 mm, the thickness is 135-360 mm, and the width is 1100-2000 mm. The steel charging method of the double-discharge heating furnace comprises the following steps: 1) establishing a steel charging and feeding system and a steel burning system; 2) judging whether the billet is charged or not; (3) steel billet stacking operation; 4) stacking the steel billets and charging; and the temperature difference between the upper and lower surfaces of the sintered steel billet is less than 30 DEG C. According to various plate blank specification conditions, the whole process from the heating furnace feeding process to the steel burning process is optimized, and on the premise that the rolling mill yield is met, the production flexibility is improved, the temperature uniformity of discharged steel billets is improved, and energy waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of steel billet heating, and in particular to a steel charging method and a steel burning process for a double-row heating furnace for steel billets of various specifications. Background Art

[0002] There are great differences in the specifications of the billets heated by the double-row step-beam steel rolling heating furnace. The unit weight of the raw materials is 5 to 18 tons, the average unit weight is about 8 tons, the thickness is 135 to 360 mm, the width is 1100 to 2000 mm, and the length is 1100 to 4000 mm. When heating billets of different specifications at the same time, it is difficult to find suitable control parameters, resulting in poor temperature uniformity of the billets out of the furnace and the existence of low-temperature areas on the lower surface of the billets. In order to improve the temperature uniformity of the billets, the temperature in the furnace is usually increased by increasing the amount of fuel, which increases the fuel consumption of the heating furnace and increases the operating cost; at the same time, the difference in the temperature uniformity of the billets has a great impact on the subsequent rolling process of the billets, which needs to be improved.

[0003] The Chinese patent application with application number CN 201910944706.6 discloses "a slab warehouse and heating furnace layout structure and loading method for cold slabs and hot slabs of thick plates". The slab warehouse and heating furnace layout structure include: 1# slab warehouse span and 2# slab warehouse span, which are arranged side by side; a continuous casting slab conveying roller connected to the continuous casting process is arranged at the inlet of the 2# slab warehouse span; a heating furnace span is arranged at the outlet side of the 2# slab warehouse span; more than two heating furnaces are arranged in the heating furnace span, which are arranged side by side in the 2# The slab storage span is on the exit side; the slab preparation span spans across the inlet side of the 1# and 2# slab storage spans, and the continuous casting billet conveying roller passes through the slab preparation span; the over-span trolley roller spans across the cold billet area and heating furnace span of the 1# and 2# slab storage spans; the over-span roller spans across the slab preparation span and the 1# slab storage span, and the loading roller is set between the 2# slab storage span and the heating furnace span, and spans across the 2# slab storage span and the two ends of the heating furnace span, and the loading roller is a two-way conveying structure. This method realizes the differentiated storage, stacking, loading and heating of hot and cold billets; it is energy-saving and environmentally friendly, and also solves the problems of slow rhythm, low efficiency and easy errors caused by alternating hot and cold loading.

[0004] The Chinese patent application with application number CN 201711478454.X discloses "a double-row loading method for a continuous heat treatment furnace". First, the steel plates to be treated are placed side by side in the length direction in groups of two near the roller; the two steel plates to be treated are hoisted onto the roller at one time in the length direction by a crane; the two steel plates to be treated on the roller are centered and measured, and the two steel plates to be treated are clamped in the center; the two steel plates to be treated are fed through the roller and sent into the heat treatment furnace; the two steel plates after heat treatment in the heat treatment furnace are sent to the transverse platform through the roller; the steel plates in groups of two are separated by the transverse platform; the separated steel plates are sent to the straightening machine for straightening in sequence, and the heat treatment process is completed. By loading the steel plates side by side in groups of two, the utilization rate of the heat treatment furnace is greatly improved, thereby increasing the output and reducing the cost.

[0005] The Chinese patent application with application number CN 201210134765.5 discloses a "Method for Charging Steel Billets into a Heating Furnace". First, the optimal furnace time of the steel billet is determined, and the time to stop rolling is determined. Before stopping rolling, the charging step of the steel billet is adjusted so that the sum of the conveying time of the steel billet in the heating furnace and the time to stop rolling is equal to the optimal furnace time. This method can make the furnace time of the steel billet basically the optimal furnace time, avoid the influence of insufficient or excessive heating of the steel ring on rolling, and ensure the quality of the rolled product.

[0006] The above three methods all aim to improve the efficiency of the heating furnace and enhance the quality of the steel billets, which are achieved by adjusting the layout of the slab warehouse and the heating furnace, optimizing the way of loading the steel billets into the furnace, and adjusting the time the steel billets stay in the furnace. However, they are all for slabs of a single specification, and do not involve the loading process and heating process of the heating furnace under conditions of multiple slab specifications. Summary of the invention

[0007] In order to solve the problem of poor temperature uniformity of steel billets leaving a heating furnace due to different billet specifications and sizes, the present invention provides a double-row heating furnace charging method and steel burning process for steel billets of multiple specifications. According to various slab specifications, the whole process from heating furnace loading process to steel burning process is optimized. Under the premise of meeting the output of the rolling mill, the production flexibility is improved, the temperature uniformity of the steel billets leaving the furnace is improved, and energy waste is reduced.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for charging steel in a double-row heating furnace for steel billets of multiple specifications, comprising the following steps:

[0010] 1) Establish steel loading and feeding system and steel burning system;

[0011] The steel loading system consists of a crane, 1# stack, 2# stack, 3# stack, loading roller, discharging roller and steel loader; the steel burning system adopts a double-row walking heating furnace, including a first step-in-feed beam, a second step-in-feed beam, a first feeding furnace door, a first discharging furnace door, a second feeding furnace door, a second feeding furnace door and a furnace, and the first step-in-feed beam and the second step-in-feed beam are arranged side by side in the furnace along the conveying direction when the steel billet is loaded; a first feeding furnace door is arranged at one end of the furnace corresponding to the loading end of the first step-in-feed beam, and a first discharging furnace door is arranged at the other end of the furnace corresponding to the discharging end of the first step-in-feed beam; a second feeding furnace door is arranged at one end of the furnace corresponding to the loading end of the second step-in-feed beam, and a second discharging furnace door is arranged at the other end of the furnace corresponding to the discharging end of the second step-in-feed beam;

[0012] 2) Determine whether the billet is to be loaded into the furnace;

[0013] Collect key parameters of the steel billets to be heated, including the specifications and steel types of the steel billets; first classify them according to the steel types, and then classify the same type of steel billets according to the specifications; if the steel type and specifications required by the current production plan match the classification results, and the heating process is in normal production and there is no rolling stop or waiting accident, then perform the steel billet charging operation; if the steel type and specifications required by the current production plan do not match the classification results, or the heating process is not in normal production and there is a rolling stop or waiting accident, then perform the steel billet stacking operation;

[0014] 3) Billet stacking operation;

[0015] The weight G of the steel billet is determined according to the billet number. For steel billets with G < 7t, they are directly stored in the 1# stack; for steel billets with G > 12t, they are directly stored in the 3# stack; for steel billets with 7t ≤ G ≤ 12t, the length L and thickness H are determined by the double conditions. Steel billets that meet L < 3000mm and H < 270mm are stored in the 1# stack, steel billets that meet L > 3500mm and H > 350mm are stored in the 3# stack, and the rest of the steel billets are stored in the 2# stack;

[0016] 4) Stacking steel billets and loading them into the furnace;

[0017] The crane lifts a steel billet from stack 1# to the loading roller, and transports it to the second feeding furnace door through the loading roller; the crane returns to stack 3#, lifts a steel billet from stack 3# to the loading roller, and transports it to the first feeding furnace door through the loading roller; the second feeding furnace door is opened, the loader delivers the steel billet from the second feeding furnace door to the second step-in beam, and the second feeding furnace door is closed; the first feeding furnace door is opened, the loader delivers the steel billet from the first feeding furnace door to the first step-in beam, and the first feeding furnace door is closed; the above operation is repeated until all the steel billets from stacks 1# and 3# are loaded into the furnace;

[0018] The crane returns to stack # 2, lifts a steel billet from stack # 2 to the loading roller, and transports it to the second feeding furnace door or the first feeding furnace door through the loading roller. The corresponding second feeding furnace door or the first feeding furnace door is opened, and the loader sends the corresponding steel billet to the corresponding second stepping beam or the first stepping beam; then the corresponding second feeding furnace door or the first feeding furnace door is closed; repeat the above operation until all the steel billets from stack # 2 are loaded into the furnace.

[0019] A double-row heating furnace steelmaking process for multi-specification steel billets includes the following processes:

[0020] When the fluctuation value of the fuel amount in the double-row walking beam heating furnace is less than 10%, the billet on the second walking beam stays in the furnace for 2.5 to 3.6 hours, and the billet on the first walking beam stays in the furnace for 3.6 to 4.2 hours;

[0021] When the fluctuation value of the fuel amount in the double-row walking beam heating furnace is ≥10%, the billet on the second walking beam stays in the furnace for 3.5 to 4.5 hours, and the billet on the first walking beam stays in the furnace for 4.5 to 5.5 hours.

[0022] The single weight of the steel billet is 5 to 18 tons, the length is 1100 to 4000 mm, the thickness is 135 to 360 mm, and the width is 1100 to 2000 mm; after steel firing, the temperature difference between the upper and lower surfaces of the steel billet is less than 30°C.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) It solves the problem of poor temperature uniformity of billets out of the furnace due to different billet sizes during the production process of steel rolling heating furnace;

[0025] 2) By optimizing the billet loading system and steel-burning process, the flexibility of production is improved, and billets of different specifications are evenly heated, so as to improve the heating quality and save fuel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of steel billet stacking and furnace loading according to the present invention.

[0027] Figure 2 This is a flow chart of classifying the steel billets according to specifications and matching them with stack positions according to the present invention.

[0028] Figure 3 It is a schematic diagram of charging and unloading steel billets of different specifications according to the present invention.

[0029] In the figure: 1. Loading roller 2. Double row walking beam heating furnace 21. First step of beam feeding 22. Second step of beam feeding 3. Discharging roller 4. Billet Ⅰ. 1# stack Ⅱ. 2# stack Ⅲ. 3# stack DETAILED DESCRIPTION

[0030] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0031] like Figure 1-Figure 3 As shown, the present invention provides a method for charging steel in a double-row heating furnace for steel billets of multiple specifications, comprising the following steps:

[0032] 5) Establish steel loading and feeding system and steel burning system;

[0033] The steel loading system is composed of a crane, 1# stack Ⅰ, 2# stack Ⅱ, 3# stack Ⅲ, loading roller 1, discharging roller 3 and a steel loader; the steel burning system adopts a double-row walking heating furnace 2 (referred to as heating furnace), including a first step-in-feed beam 21, a second step-in-feed beam 22, a first feeding furnace door, a first discharging furnace door, a second feeding furnace door, a second feeding furnace door and a furnace, and the first step-in-feed beam 21 and the second step-in-feed beam 22 are arranged side by side in the furnace along the conveying direction when the steel billet 4 is loaded; a first feeding furnace door is arranged at one end of the furnace corresponding to the loading end of the first step-in-feed beam 21, and a first discharging furnace door is arranged at the other end of the furnace corresponding to the discharging end of the first step-in-feed beam 21; a second feeding furnace door is arranged at one end of the furnace corresponding to the loading end of the second step-in-feed beam 22, and a second discharging furnace door is arranged at the other end of the furnace corresponding to the discharging end of the second step-in-feed beam 22;

[0034] 6) Determine whether the billet is to be loaded into the furnace;

[0035] Collect key parameters of the steel billet 4 to be heated, including the specifications and steel type of the steel billet 4; first classify according to the steel type, and then classify the same type of steel billets according to the specifications; determine whether the steel billet 4 is directly loaded into the furnace according to the classification result, if the steel type and specification required by the current production plan match the classification result, and the heating process is in normal production and there is no rolling stop or waiting accident, then perform the steel billet loading operation; if the steel type and specification required by the current production plan do not match the classification result, or the heating process is not in normal production and there is a rolling stop or waiting accident, then perform the steel billet stacking operation;

[0036] 7) Billet stacking operation;

[0037] The weight G of the steel billet 4 is determined according to the billet number. For steel billets with G < 7t, they are directly stored in the 1# stack; for steel billets with G > 12t, they are directly stored in the 3# stack; for steel billets with 7t ≤ G ≤ 12t, the length L and thickness H are determined by the double conditions. Steel billets that meet L < 3000mm and H < 270mm are stored in the 1# stack, steel billets that meet L > 3500mm and H > 350mm are stored in the 3# stack, and the remaining steel billets are stored in the 2# stack;

[0038] 8) Stacking steel billets and loading them into the furnace;

[0039] The crane lifts a steel billet from 1# stack Ⅰ to the loading roller 1, and transports it to the second feeding furnace door through the loading roller 1; the crane returns to 3# stack Ⅲ, lifts a steel billet from 3# stack Ⅲ to the loading roller 1, and transports it to the first feeding furnace door through the loading roller 1; the second feeding furnace door is opened, and the steel loader sends the steel billet from the second feeding furnace door to the second step-in beam 22, and the second feeding furnace door is closed; the first feeding furnace door is opened, and the steel loader sends the steel billet from the first feeding furnace door to the first step-in beam 21, and the first feeding furnace door is closed; the above operation is repeated until all the steel billets from 1# stack Ⅰ and 3# stack Ⅲ are loaded into the furnace;

[0040] The crane returns to 2# stack II, lifts a steel billet from 2# stack II to the loading roller 1, and transports it to the second feeding furnace door or the first feeding furnace door through the loading roller 1. The corresponding second feeding furnace door or the first feeding furnace door is opened, and the loader sends the corresponding steel billet to the corresponding second step-feed beam 22 or the first step-feed beam 21; then the corresponding second feeding furnace door or the first feeding furnace door is closed; repeat the above operation until all the steel billets from 2# stack II are loaded into the furnace.

[0041] A double-row heating furnace steelmaking process for multi-specification steel billets includes the following processes:

[0042] When the fluctuation value of the fuel amount in the double-row walking beam heating furnace 2 is less than 10%, the steel billet on the second walking beam 22 stays in the furnace for 2.5 to 3.6 hours, and the steel billet on the first walking beam 21 stays in the furnace for 3.6 to 4.2 hours;

[0043] When the fluctuation value of the fuel amount in the double-row walking beam heating furnace 2 is ≥10%, the steel billets on the second walking beam 22 stay in the furnace for 3.5 to 4.5 hours, and the steel billets on the first walking beam 21 stay in the furnace for 4.5 to 5.5 hours.

[0044] The steel billet 4 has a single weight of 5 to 18 tons, a length of 1100 to 4000 mm, a thickness of 135 to 360 mm, and a width of 1100 to 2000 mm; after steel firing, the temperature difference between the upper and lower surfaces of the steel billet 4 is less than 30°C.

[0045] The present invention optimizes the slab stacking method, the heating furnace steel charging system and the steel burning process, and realizes the flexible operation of the double-row heating furnace under the condition that the steel billets to be heated are of various different specifications, thereby effectively improving the uniformity of the heating temperature of the steel billets, improving the heating quality and reducing energy consumption.

[0046] In order to more intuitively embody the present invention, the embodiments of the present invention are further described in conjunction with examples. The following examples are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution that can be obviously obtained by a person skilled in the art within the technical scope disclosed in the present invention, including simple changes or equivalent replacements, is within the protection scope of the present invention.

[0047] [Example]

[0048] like Figure 1 , Figure 2 , Figure 3 As shown, this embodiment takes two steel billets of the same steel grade but different specifications as an example to illustrate the steel loading process and steel burning process of the double-row heating furnace; the details are as follows:

[0049] The unit weight of billet 1 is 13600kg, the length is 3550mm, the thickness is 135mm and the width is 1950mm.

[0050] The unit weight of steel billet 2 is 7400kg, the length is 3150mm, the thickness is 200mm and the width is 1550mm.

[0051] First, the two billets are classified and stacked according to their specifications:

[0052] The single weight of billet 1 is 13600kg, which belongs to the billet with G>12t, and is directly stored in the 3# stack. The billet 1 is placed in the 3# stack III of the material yard by a crane. After receiving the steel loading instruction, the billet 1 is transported to the loading roller by a crane, and the loading roller transports the billet 1 to the first feeding furnace door.

[0053] The unit weight of billet 2 is 7400kg, which belongs to the billet with 7t≤G≤12t, and does not meet the conditions of L<3000mm and H<270mm, L>3500mm and H>350mm, so it is stored in 2# stack position Ⅱ. Billet 2 is placed in the position of 2# stack position Ⅱ in the material yard by crane. After receiving the steel loading instruction, billet 2 is transported to the loading roller by crane, and the loading roller transports billet 2 to the second feeding furnace door;

[0054] After the first feeding furnace door is opened, the steel loader transports the steel billet on the loading roller to the first step feeding beam, and then the first feeding furnace door is closed.

[0055] After the second feeding furnace door is opened, the steel loader transports the steel billet on the loading roller to the second stepping beam, and then the second feeding furnace door is closed.

[0056] Through the on-site billet online temperature record, it can be known that under the normal operation of the heating furnace:

[0057] The first step of burning the billet on the beam takes 4.0 hours. After the burning is completed, the first discharge furnace door is opened, and the loader transports the billet to the discharge roller. After the billet is out of the furnace, the temperature difference between the upper and lower surfaces is 22°C, which meets the requirements.

[0058] The second steel billet on the second step beam is burned for 2.9 hours. After the burning is completed, the second discharge furnace door is opened, and the loader transports the second steel billet to the discharge roller. After the second steel billet is discharged from the furnace, the temperature difference between the upper and lower surfaces is 19°C, which meets the requirements.

[0059] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for charging steel in a double row heating furnace for steel billets of multiple specifications, characterized in that: The process includes the following: 1) Establish steel loading and feeding system and steel burning system; The steel loading system consists of a crane, 1# stack, 2# stack, 3# stack, loading roller, discharging roller and steel loader; the steel burning system adopts a double-row walking heating furnace, including a first step-in-feed beam, a second step-in-feed beam, a first feeding furnace door, a first discharging furnace door, a second feeding furnace door, a second feeding furnace door and a furnace, and the first step-in-feed beam and the second step-in-feed beam are arranged side by side in the furnace along the conveying direction when the steel billet is loaded; a first feeding furnace door is arranged at one end of the furnace corresponding to the loading end of the first step-in-feed beam, and a first discharging furnace door is arranged at the other end of the furnace corresponding to the discharging end of the first step-in-feed beam; a second feeding furnace door is arranged at one end of the furnace corresponding to the loading end of the second step-in-feed beam, and a second discharging furnace door is arranged at the other end of the furnace corresponding to the discharging end of the second step-in-feed beam; 2) Determine whether the billet is to be loaded into the furnace; Collect key parameters of the steel billets to be heated, including the specifications and steel types of the steel billets; first classify them according to the steel types, and then classify the same type of steel billets according to the specifications; if the steel type and specifications required by the current production plan match the classification results, and the heating process is in normal production and there is no rolling stop or waiting accident, then perform the steel billet charging operation; if the steel type and specifications required by the current production plan do not match the classification results, or the heating process is not in normal production and there is a rolling stop or waiting accident, then perform the steel billet stacking operation; 3) Billet stacking operation; The weight G of the steel billet is determined according to the billet number. For steel billets with G < 7t, they are directly stored in the 1# stack; for steel billets with G > 12t, they are directly stored in the 3# stack; for steel billets with 7t ≤ G ≤ 12t, the length L and thickness H are determined by the double conditions. Steel billets that meet L < 3000mm and H < 270mm are stored in the 1# stack, steel billets that meet L > 3500mm and H > 350mm are stored in the 3# stack, and the rest of the steel billets are stored in the 2# stack; 4) Stacking steel billets and loading them into the furnace; The crane lifts a steel billet from stack 1# to the loading roller, and transports it to the second feeding furnace door through the loading roller; the crane returns to stack 3#, lifts a steel billet from stack 3# to the loading roller, and transports it to the first feeding furnace door through the loading roller; the second feeding furnace door is opened, the loader delivers the steel billet from the second feeding furnace door to the second step-in beam, and the second feeding furnace door is closed; the first feeding furnace door is opened, the loader delivers the steel billet from the first feeding furnace door to the first step-in beam, and the first feeding furnace door is closed; the above operation is repeated until all the steel billets from stacks 1# and 3# are loaded into the furnace; The crane returns to stack # 2, lifts a steel billet from stack # 2 to the loading roller, and transports it to the second feeding furnace door or the first feeding furnace door through the loading roller. The corresponding second feeding furnace door or the first feeding furnace door is opened, and the loader sends the corresponding steel billet to the corresponding second stepping beam or the first stepping beam; then the corresponding second feeding furnace door or the first feeding furnace door is closed; repeat the above operation until all the steel billets from stack # 2 are loaded into the furnace.

2. A double-row heating furnace steel-burning process for multi-specification steel billets, based on a double-row heating furnace steel-charging method for multi-specification steel billets as claimed in claim 1, characterized in that: The process includes the following: When the fluctuation value of the fuel amount in the double-row walking beam heating furnace is less than 10%, the billet on the second walking beam stays in the furnace for 2.5 to 3.6 hours, and the billet on the first walking beam stays in the furnace for 3.6 to 4.2 hours; When the fluctuation value of the fuel amount in the double-row walking beam heating furnace is ≥10%, the billet on the second walking beam stays in the furnace for 3.5 to 4.5 hours, and the billet on the first walking beam stays in the furnace for 4.5 to 5.5 hours.

3. The double row heating furnace steelmaking process for multi-specification steel billets according to claim 2 is characterized in that: The single weight of the steel billet is 5 to 18 tons, the length is 1100 to 4000 mm, the thickness is 135 to 360 mm, and the width is 1100 to 2000 mm; after steel firing, the temperature difference between the upper and lower surfaces of the steel billet is less than 30°C.

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