High-efficiency and high-speed bar production line capable of simultaneously producing bars with different specifications

Abstract

The invention relates to the technical field of steel rolling, in particular to a high-efficiency high-speed bar production line capable of simultaneously producing bars with different specifications, which comprises a heating furnace, a roughing mill group, an intermediate mill group, a pre-finishing mill group, a finishing mill group, a water cooling system, a cooling bed and a finished product collecting device which are connected in sequence, the finishing mill group is a multi-channel finishing mill group, and the multi-channel finishing mill group comprises a first channel, a second channel and a third channel which are arranged in parallel; a plurality of rolling mills, a water cooling system, a pinch roll and a flying shear mechanism are arranged in each channel; the first channel and the third channel are provided with six rolling mills, the second channel is arranged between the first channel and the third channel, and six rolling mills and two rolling mills are arranged on the front portion and the rear portion of the second channel respectively. By the adoption of the production line, the product specification can cover all specifications of domestic straight bar delivery of phi 12-phi 50, the capacity of a single production line can break through 2 million tons, and the capacity matching of one smelting and rolling machine to the production line is achieved. The production efficiency is improved by more than 30% compared with that of a traditional production line, and the market response speed is improved while the enterprise production cost is remarkably reduced.

Description

A high-efficiency, high-speed bar production line capable of simultaneously producing bars of different specifications Technical Field

[0001] This invention belongs to the field of steel rolling technology, specifically a high-efficiency, high-speed bar production line capable of simultaneously producing bars of different specifications. Background Technology

[0002] With the sharp decline in rebar production, the consumption of rebar in regional markets has been significantly reduced, resulting in a substantial reduction in the number of rebar production lines. However, rebar producers still need to meet users' "one-stop" procurement requirements, which means that rolling mill production lines need to cover as many specifications and varieties as possible.

[0003] Currently, domestic high-speed bar production lines have several types of finishing mills, including single-pass, double-pass, and triple-pass mills, but all can only produce one specification of rebar at a time. When switching production specifications, the machine must be stopped to change the roll pass and adjust rolling parameters, a process that is time-consuming (depending mainly on the number of stands changed and whether pinch rolls and pressure rolls need to be replaced, typically taking 2-8 hours). This results in a large amount of hot billets being dumped during the continuous casting process. Furthermore, because only one specification can be produced at a time, the efficiency difference between specifications is significant, with production line efficiency closely related to the production specification, ranging from 4,500 tons to 7,500 tons per day, leading to a mismatch between casting and rolling capacity. Simultaneously, the short production time for each specification and frequent specification switching due to the single-specification rolling model result in problems such as low production efficiency, casting-rolling mismatch, high production costs, slow market response, and low competitiveness. Summary of the Invention

[0004] This invention provides a high-efficiency, high-speed bar production line capable of simultaneously producing bars of different specifications, thereby overcoming the deficiencies in the prior art.

[0005] This invention is achieved through the following technical solution: a high-efficiency, high-speed bar production line capable of simultaneously producing bars of different specifications, comprising a heating furnace, a roughing mill, an intermediate mill, a pre-finishing mill, a finishing mill, a water cooling system, a cooling bed, and a finished product collection device connected in sequence; the finishing mill is a multi-channel finishing mill, the multi-channel mill base group including a first channel, a second channel, and a third channel arranged in parallel; each channel is equipped with multiple mills, a water cooling system, pinch rolls, and a flying shear mechanism; the first and third channels are equipped with six mills, the second channel is located between the first and third channels and is equipped with six mills before and two mills before and after it respectively.

[0006] As a preferred configuration, the six rolling mills are arranged in a 4+2, 2+4, or 2+2+2 pattern.

[0007] Preferably, eight rolling mills are installed in the first and third channels, arranged in a 4+4, 4+2+2, 2+2+4 or 2+4+2 configuration.

[0008] Preferably, the cooling bed and finished product collection device are dual cooling beds and dual collection devices, with each cooling bed having a dual steel loading method, namely, steel loading on the high-speed rotating hub and steel loading on the skirt plate.

[0009] Preferably, the roughing mill and the intermediate mill adopt a shared pass system.

[0010] Preferably, the water cooling system is installed between the intermediate rolling mill and the pre-finishing rolling mill, between the pre-finishing rolling mill and the finishing rolling mill, between the various groups of finishing mills, and between the finishing rolling mill and the finished product flying shear.

[0011] The beneficial effects of this invention are as follows: By setting up a multi-channel finishing mill, configuring a dual cooling bed collection device, adopting a shared pass system, and employing flexible production organization, this invention achieves simultaneous production of rebar of different diameters and rib types within the same rolling process. This solves the problems of low single-specification rolling efficiency, long downtime and high costs associated with production changeovers in traditional production lines, and addresses the issue of coordinated matching of steel rolling efficiency. Product specifications can cover all domestic specifications from Φ12 to Φ50 delivered in straight bars, achieving a single production line capacity exceeding 2 million tons, and realizing capacity matching between the rolling mill and the entire production line. Its production efficiency is more than 30% higher than traditional production lines, significantly reducing enterprise production costs while improving market responsiveness. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 is a schematic diagram of the structure of the present invention; as shown in the figure: 1, heating furnace, 2, roughing mill, 3, flying shear, 4, finishing mill, 5, cooling system, 6, first channel, 7, second channel, 8, third channel, 9, collection system. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] A high-efficiency, high-speed bar production line capable of simultaneously producing bars of different specifications is shown in Figure 1. It includes a heating furnace 1, a roughing mill 2, an intermediate mill 3, a pre-finishing mill 4, a finishing mill 4, a water cooling system, a cooling bed, and a finished product collection device, all connected in sequence. The finishing mill 4 is a multi-channel finishing mill 4, comprising a first channel 6, a second channel 7, and a third channel 8 arranged in parallel. Each channel contains multiple mill stands, a water cooling system, pinch rolls, and a flying shear mechanism 3. The first channel 6 and the third channel 8 each have six mill stands. The second channel 7 is located between the first channel 6 and the third channel 8, with six mill stands before and two mill stands before it. The distribution of the six mill stands can be 4+2, 2+4, or 2+2+2.

[0016] In addition, eight rolling mills are installed in the first channel 6 and the third channel 8, arranged in the form of 4+4, 4+2+2, 2+2+4 or 2+4+2.

[0017] The cooling bed and finished product collection device are a double cooling bed and a double collection device. Each cooling bed is a double steel loading method, which is steel loading on the high-speed rotating hub and steel loading on the skirt plate.

[0018] Its roughing, intermediate, and pre-finishing mills adopt a traditional split rolling process layout, consisting of fourteen stands, providing suitable intermediate billets for subsequent processes. The first channel 6 and the third channel 8 are composed of three sets of two-stand modular rolling mills. The first six stands of the intermediate channel have the same structure and parameters as the left and right channels, followed by two alternating horizontal and vertical Φ350 finishing mills. Sufficiently long temperature equalization and reheating distance (generally 60m-90m) is provided behind the cooling system 5. The rolled pieces in the first channel 6 are cooled and collected by the cooling system 5 and collection device within the first channel 6. The rolled pieces in the third channel 8 are cooled and collected by the cooling system 5 and collection device within the third channel 8, or by the cooling system 5 and collection system 9 within the second channel 7. The rolled pieces in the second channel 7 can be cooled and collected by the cooling system 5 and collection device within the first channel 6, or via the cooling system 5 and collection system 9 within the second channel 7. The production line involved in this invention can adopt advanced processes such as continuous casting and direct rolling, controlled rolling and controlled cooling, and other reduced-volume clean production methods.

[0019] In this application, the product specifications cover all rebar delivered in straight bars from Φ12 to Φ50. Due to the need for cost reduction in product specifications and alloys, production is organized into three groups: small specifications from Φ12 to Φ14, intermediate specifications from Φ16 to Φ25, and large specifications from Φ28 to Φ50. Production is centrally scheduled according to these three groups. When producing all specifications, the roughing and intermediate rolling mill pass systems are completely shared, that is, 10 passes are used to roll 170mm×170mm square billets into Φ60mm to Φ66mm round rolled pieces, providing suitable intermediate billets for subsequent processes. When producing the small specifications from Φ12 to Φ14, the pre-finishing rolling adopts a three-splitting process, rolling the intermediate round material into Φ21.5mm round rolled pieces in 6 passes. On the finishing mill 4, Φ12 and Φ14 rebar are rolled in 6 passes and 4 passes respectively, that is, both Φ12 and Φ14 specifications can be produced simultaneously. Production scheduling is mainly determined by the contract order volume. Production is carried out simultaneously in three channels. Usually, the production scheduling mode is Φ12, Φ12, Φ14 or Φ12, Φ14, Φ14. If the order volume of a certain specification is particularly large within a certain period, the same specification will be scheduled for production in all three channels at the same time.

[0020] For producing intermediate specifications of Φ16~Φ25, two methods are used: First, the pre-finishing rolling uses a two-splitting process, rolling the intermediate round material into Φ31mm round pieces in 6 passes. The finishing mill 4 then rolls the finished product in 2~6 passes. Two channels produce different specifications simultaneously, with the other channel as a backup, allowing for process switching at any time. For larger specifications of Φ28~Φ50, only channel 2 is used for production, employing a single-line production process, producing only one specification at a time.

[0021] The second method: The pre-finishing rolling adopts a two-splitting process, which rolls the round material from the intermediate rolling mill into a Φ21.5mm round piece in 6 passes. The finishing mill 4 uses 4 and 6 passes to roll out Φ14 and Φ12 finished products. Two channels produce different specifications at the same time, and the other channel is used as a backup. The process can be switched at any time. By arranging the specifications through the backup channel, production can be flexibly scheduled to ensure that orders are fulfilled.

[0022] The first method has a higher hourly output when producing small-sized items, but it is not as flexible and convenient as the second method in fulfilling orders for larger items.

[0023] In summary, the production line, hole pattern system, and production scheduling method described in this invention can achieve full-specification production from Φ12 to Φ50, can produce different specifications simultaneously, can significantly reduce specification changeover time, can achieve an average daily output of over 6,000 tons, and can achieve an annual production capacity of 2 million tons, featuring high efficiency and low cost.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-efficiency, high-speed bar production line capable of simultaneously producing bars of different specifications, characterized in that: The system includes a heating furnace, a roughing mill, an intermediate mill, a pre-finishing mill, a finishing mill, a water cooling system, a cooling bed, and a finished product collection device, all connected in sequence. The finishing mill is a multi-channel finishing mill, which includes a first channel, a second channel, and a third channel arranged in parallel. Each channel is equipped with multiple mill stands, a water cooling system, pinch rolls, and a flying shear mechanism. The first and third channels each have six mill stands, and the second channel is located between the first and third channels, with six mill stands in front of it and two mill stands behind it.

2. The high-efficiency, high-speed bar production line capable of simultaneously producing different specifications according to claim 1, characterized in that: The six rolling mills are arranged in a 4+2, 2+4, or 2+2+2 configuration.

3. The high-efficiency, high-speed bar production line capable of simultaneously producing different specifications according to claim 1, characterized in that: The first and third channels are equipped with eight rolling mills, arranged in a 4+4, 4+2+2, 2+2+4 or 2+4+2 configuration.

4. The high-efficiency, high-speed bar production line capable of simultaneously producing different specifications according to claim 2 or 3, characterized in that: The cooling bed and finished product collection device are a double cooling bed and a double collection device. Each cooling bed is a double steel loading method, which is steel loading on the high-speed rotating hub and steel loading on the skirt plate.

5. The high-efficiency, high-speed bar production line capable of simultaneously producing different specifications according to claim 4, characterized in that: The roughing mill and intermediate mill use a shared pass system.

6. The high-efficiency, high-speed bar production line capable of simultaneously producing different specifications according to claim 5, characterized in that: The water cooling system is installed between the intermediate rolling mill and the pre-finishing rolling mill, between the pre-finishing rolling mill and the finishing rolling mill, between the various groups of finishing mills, and between the finishing rolling mill and the finished product flying shear.

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