Method for preventing material adhesion of connecting trolley

Abstract

The invention discloses a method for preventing material adhesion of a connecting trolley, which ensures the uniform distribution of waste steel, reduces the phenomena of material blockage and material adhesion, simultaneously controls the fluctuation of phosphorus content and ensures the product quality by optimizing the structural design, the material distribution process and the material cleaning mode of the connecting trolley, effectively solves the problem that the waste steel adheres to the bottom of the connecting trolley, and improves the production efficiency. And the material distribution efficiency and the production stability are also improved.

Description

Technical Field

[0001] The invention relates to the technical field of steel smelting, and in particular to a method for preventing a connecting trolley from sticking to materials. Background Art

[0002] In the field of steel smelting technology, the horizontal continuous charging electric furnace, as an advanced steelmaking equipment, has significant advantages over traditional top-loading electric furnaces. The horizontal continuous charging electric furnace can continuously transport scrap steel during the smelting process, eliminating the need to interrupt production for charging, significantly improving production efficiency. The continuous charging electric furnace efficiently utilizes the heat within the furnace, reducing energy waste. Through its advantages of continuous operation, uniform material distribution, optimized heat utilization, and automated control, the horizontal continuous charging electric furnace significantly improves smelting efficiency and product quality, while reducing energy consumption and environmental pollution. The connecting trolley is one of the most important equipment in the horizontal continuous charging electric furnace. In actual production, due to the diverse types and sizes of scrap steel, and the high temperature environment in which it operates, the bottom of the connecting trolley is prone to scrap steel sticking to it, resulting in poor scrap steel transportation and even scrap steel getting stuck in the channel, seriously affecting production efficiency. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a method for preventing the connecting trolley from sticking.

[0004] The present invention solves the technical problem by adopting the following technical solutions.

[0005] The present invention provides a method for preventing a connecting trolley from sticking to materials, which comprises: optimizing a bottom plate structure, a material distribution process and a material clearing mode of the connecting trolley to prevent the connecting trolley from sticking to materials.

[0006] The present invention has the following beneficial effects:

[0007] The present invention provides a method for preventing the connection trolley from sticking. By optimizing the structural design, material distribution process, and material clearing mode of the connection trolley, the present invention effectively prevents the problem of scrap steel sticking to the bottom of the connection trolley, thereby improving material distribution efficiency and production stability. DETAILED DESCRIPTION

[0008] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0009] A method for preventing the connecting carriage from sticking to materials provided by an embodiment of the present invention is described in detail below.

[0010] An embodiment of the present invention provides a method for preventing a connecting trolley from sticking to a material, comprising: optimizing a bottom plate structure, a material distributing process, and a material clearing mode of the connecting trolley to prevent the connecting trolley from sticking to a material.

[0011] An embodiment of the present invention provides a method for preventing the connecting trolley from sticking to the material. By optimizing the structural design, material distribution process and material clearing mode of the connecting trolley, the problem of scrap steel sticking to the bottom of the connecting trolley is effectively solved, thereby improving the material distribution efficiency and production stability.

[0012] In some optional embodiments, the optimization of the bottom plate structure of the connecting trolley includes: replacing the original pipe-type connecting trolley water-cooling bottom plate with a plate-type water-cooling bottom plate, and reducing the cooling water flow from 100m 3 / h increased to 120m 3 / h, with the baseplate temperature controlled below 60°C. The bottom of the connecting trolley utilizes a plate-type water-cooling structure, effectively controlling the baseplate temperature and preventing scrap from sticking at high temperatures. This plate-type water-cooling structure also effectively improves the efficiency of the connecting trolley's cleaning process, avoiding accidents involving scrap melting and sticking caused by improper scrap cleaning and prolonged exposure to high-temperature flue gas. The plate-type water-cooling structure of the connecting trolley in the present invention effectively controls the baseplate temperature, reduces damage to the equipment caused by thermal stress, and extends the equipment's service life.

[0013] In some optional embodiments, the bottom plate and the weld are laser welded, with the weld height controlled to be ≤1 mm. The bottom plate and the weld are ensured to be smooth and flat, thereby reducing friction and obstruction during the scrap steel conveying process.

[0014] In some optional embodiments, the optimization of the distribution process of the connecting trolley includes: laying different types of scrap steel in sequence and then feeding them into the furnace.

[0015] In some optional implementations, the materials are usually spread in the order of priority of fusible materials > pig iron blocks > pressed cakes and briquettes > bulk materials and fine materials, starting from the charging section close to the furnace area.

[0016] Scrap steel, also known as scrap iron, refers to steel waste that can be recycled and reused after undergoing certain processing steps. It comes from a wide range of sources, including scrap steel, scrap iron, metallurgical slag, and oxidized waste. These wastes vary in nature and form depending on their generation. While their performance is similar to that of the original finished product, they can be degraded by factors such as aging, corrosion, and fatigue. Therefore, when charging the furnace, different types of scrap must be prioritized. In our smelting process, we frequently use a variety of scrap materials, including melts, pig iron ingots, pressed cakes and briquettes, bulk material, and refined material. Bulk material and refined material account for 30-40% of the total feedstock, pig iron ingots for 10-20%, pressed cakes and briquettes for 10-30%, and the remainder is melts. When charging the furnace, the melts should be placed first to ensure they enter the furnace as early as possible to avoid melting and sticking during subsequent high-temperature baking. Pig iron ingots should be placed next to prevent fluctuations in phosphorus content caused by later additions. The pressed cakes and blocks are then laid out on the fabric, followed by the bulk material and fine material. During the laying process, the scrap steel laid out first enters the furnace as the material trough runs, and the scrap steel laid out later enters the furnace again as the material trough runs. During the whole process, scrap steel of different types and sizes is put into the furnace in sections and in an orderly manner, which effectively solves the problem of scrap steel sticking to the bottom of the connecting trolley and improves the laying efficiency and production stability.

[0017] In some optional embodiments, the fusible material includes at least one of light and thin material, crushed material, burned iron, iron oxide scale and iron filings.

[0018] In some optional implementations, for steel grades with P≤0.01%, granular pig iron blocks, scrap steel cakes, and wood shavings cakes shall not be used.

[0019] In some optional embodiments, if the added scrap steel contains large scrap pieces, the length and width of the large scrap steel pieces in the trough are controlled to be less than 1.0*0.5 meters, and the unit weight is less than 1.5 tons.

[0020] In some optional embodiments, the optimization of the material clearing mode of the connecting trolley includes: when the total amount of scrap steel fed differs from the total loading amount by 5 to 8 tons, reducing the feeding speed to below 70%.

[0021] In some optional embodiments, the process further includes: after reaching the target loading volume, the process enters a clearing mode, and the connecting trolley is used to clear the material at a vibration rate of 95% for 5 minutes. The iron-steel ratio is a core indicator for measuring the production efficiency of steel enterprises. It is defined as the ratio of the amount of molten iron entering the furnace to the amount of steel discharged. The lower the value, the higher the utilization rate of the molten iron, which directly affects the production cost. In the actual production process, a range of iron-steel ratios will be preset based on a comprehensive consideration of multiple factors. During the scrap steel feeding process, the scrap steel needs to reach the target loading volume. After reaching the target loading volume, the connecting trolley enters a clearing mode, and all the remaining scrap on the connecting trolley is poured into the furnace. That is, the amount of scrap steel entering the furnace will slightly exceed the theoretical calculated amount, but this does not affect the progress of smelting, and the smelting operation can be adjusted according to the specific situation.

[0022] The present invention will be further described below with reference to the embodiments.

[0023] Example 1

[0024] In a steel plant's horizontal continuous scrap feeding system, the connecting trolley encountered the following problems during the scrap conveying process:

[0025] Sticking problem: Due to the variety of scrap steel (including large scrap steel, fusible materials, etc.), in a high temperature environment, the scrap steel is easy to stick to the bottom of the connecting trolley, resulting in poor transportation.

[0026] Fluctuation of phosphorus content: When high-phosphorus scrap steel (such as pig iron blocks and particle steel cakes) is put into the furnace at a later stage, it is easy to cause fluctuations in the phosphorus content in the furnace, affecting product quality.

[0027] High equipment maintenance costs: Frequent sticking and jamming problems lead to high equipment maintenance frequency, with annual maintenance costs as high as 2-3 million yuan.

[0028] Low production efficiency: Due to the long cleaning time after sticking, production efficiency is greatly affected.

[0029] In order to solve the above problems, the steel plant adopted the following technical solutions:

[0030] Connecting trolley bottom modification

[0031] The modular water cooling plate design is adopted to replace the original pipe-type water cooling base plate of the trolley with a plate-type water cooling base plate. The cooling water flow rate is increased from 100m 3 / h increased to 120m 3 / h, the bottom plate temperature is controlled below 60℃.

[0032] The bottom plate and welds are welded using laser welding technology, and the weld height is ≤1mm.

[0033] Fabric process optimization

[0034] Cloth in stages:

[0035] The first stage: laying crushed materials (accounting for 20% of the total scrap steel volume) to ensure that fusible materials enter the furnace as early as possible.

[0036] The second stage: laying pig iron blocks (accounting for 15% of the total scrap steel volume) to avoid fluctuations in phosphorus content caused by later furnace entry.

[0037] The third stage: laying cakes and briquettes (accounting for 30% of the total scrap steel volume).

[0038] The fourth stage: laying bulk materials (accounting for 35% of the total scrap steel volume).

[0039] During the above-mentioned laying process, the length and width of the large pieces of scrap steel in the trough are controlled to be less than 1.0*0.5 meters, and the single weight is less than 1.5 tons.

[0040] Feeding speed control:

[0041] When the remaining feed amount is 6 tons, the feeding speed is reduced to below 70% to avoid excessive material accumulation.

[0042] After the cleaning mode is started, the connected trolley will clean the material at a vibration rate of 95% for 5 minutes to ensure that the scrap steel is completely removed.

[0043] Through actual operation tests, the steel plant's horizontal continuous scrap feeding system has achieved significant improvements:

[0044] The number of times the trolley sticks: dropped from an average of 3 times / month to 0.2 times / month, a 93% reduction in sticking failures.

[0045] Phosphorus content fluctuation: reduced from ±0.008% to ±0.003%, significantly improving product quality.

[0046] Equipment maintenance costs: reduced from an average annual 2-3 million yuan to 600,000-800,000 yuan.

[0047] Example 2:

[0048] Special steel production line (P≤0.015% steel grade)

[0049] On a special steel production line at a certain steel plant, due to the strict phosphorus content requirements of the steel grade (P ≤ 0.015%), the traditional material distribution method has the following problems:

[0050] Excessive phosphorus content: When high-phosphorus scrap steel (such as particle steel cakes) is put into the furnace at a later stage, the phosphorus content in the furnace fluctuates, and the scrap rate is as high as 8%.

[0051] High energy consumption and low efficiency: Due to the poor transportation of scrap steel, normal smelting production is greatly affected.

[0052] Short equipment life: Frequent material sticking and difficulty in clearing the material lead to severe equipment wear, and the life of the connecting trolley is only 8 months.

[0053] In order to solve the above problems, the steel plant adopted the following technical solutions:

[0054] Connecting trolley bottom modification

[0055] The modular water-cooled plate design is adopted, and the bottom plate temperature is controlled below 60°C to avoid scrap steel sticking.

[0056] The bottom plate surface is smooth and flat, which reduces friction during scrap transportation.

[0057] Fabric process optimization

[0058] High-phosphorus scrap steel should be laid first: the laying of pig iron blocks should be completed in the early stage of charging (the first 25% stage) to avoid fluctuations in phosphorus content caused by later charging.

[0059] Optimization of cleaning mode:

[0060] When the total feed amount differs by 7 tons from the total loading amount, reduce the horizontal feeding vibration speed to below 70%. After reaching the target loading amount, enter the cleaning mode and connect the trolley to clean the material at a vibration rate of 95% for 5 minutes.

[0061] Through actual operation tests, the steel plant's special steel production line has achieved significant improvements:

[0062] The qualified rate of phosphorus content increased from 92% to 98%, and the scrap rate dropped from 8% to 2%.

[0063] Equipment life: The life of the connected trolley is extended from 8 months to 16 months, and maintenance costs are reduced by 50%.

[0064] Conclusion: The present invention provides an effective structure and material distribution method for preventing the connecting trolley from sticking. By optimizing the structural design and process flow, the efficiency and quality of scrap steel transportation and distribution are significantly improved, and it has broad application prospects and economic benefits.

[0065] Comparative Example 1

[0066] The steps were similar to those in Example 1, except that the bottom of the connecting trolley was a tubular water-cooled base plate, and there were multiple raised weld scars between the water-cooled plate pipes. After the loading was completed, the material was purged. The connecting trolley was vibrated at 95% for 5 minutes. After the molten steel reached the required temperature and composition, the steel was discharged. After the next furnace was smelted, the horizontal continuous feeding was started. However, it was found that the scrap steel could not be fed into the furnace. The cover of the connecting trolley was opened, and it was found that the scrap steel in the connecting trolley of the previous furnace had not been effectively cleaned. The scrap steel remaining on the connecting trolley had melted and solidified due to the prolonged baking of the high-temperature flue gas, making it impossible to feed the next furnace and causing a furnace shutdown. The accumulated scrap steel, i.e., the melted and solidified cold steel, took a total of 5 hours to process.

[0067] Comparative Example 2

[0068] The steps are similar to those in Example 2, except that the material distribution process is not carried out in the order of priority of fusible material > pig iron block > pressed cake and pressed briquette > bulk material and fine material, and is not spread in sequence from the charging section close to the furnace area. Instead, the pig iron block and pressed cake are used as the last materials to be fed into the furnace. The feeding is completed in the later stage of smelting, and temperature measurement and sampling are carried out after the predetermined smelting power consumption and oxygen consumption are reached. The temperature reaches 1560°C, and then sampling is carried out. The carbon content is 0.12% and the phosphorus content is 0.011% (the target phosphorus content is ≤0.015%). Subsequently, the smelting is continued and the temperature is raised. After the temperature reaches 1615°C, the steel is discharged. After the molten steel is sampled and analyzed after LF refining pretreatment, the phosphorus content is 0.018%, causing the composition to be out of the norm. The main reason for the abnormal phosphorus content in molten steel is that scrap steel with high phosphorus content, such as pig iron blocks and particle cakes, are put into the furnace in the later stage of smelting. When the electric furnace process reaches the sampling temperature, the pig iron blocks and particle cakes put into the furnace have not been completely melted. After the sampling is completed, the temperature continues to rise, and the pig iron blocks and particle cakes gradually melt to release phosphorus, resulting in abnormal phosphorus content in the steel and causing waste.

[0069] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preventing the connecting trolley from sticking, characterized in that: It includes: By optimizing the bottom plate structure, material distribution process and material cleaning mode of the connecting trolley, the material sticking of the connecting trolley can be prevented.

2. The method according to claim 1, wherein: The optimization of the bottom plate structure of the connecting trolley includes: replacing the original pipe-type connecting trolley water-cooling bottom plate with a plate-type water-cooling bottom plate, and reducing the cooling water flow from 100m 3 / h increased to 120m 3 / h, the bottom plate temperature is controlled below 60℃.

3. The method according to claim 2, wherein: Also includes: The bottom plate and weld are welded by laser welding process, and the weld height is controlled to be ≤1mm.

4. The method according to claim 1, wherein: The optimization of the laying process of the connecting trolley includes: laying different types of scrap steel in sequence and then feeding them into the furnace.

5. The method according to claim 4, characterized in that: Usually, the priority order is fusible material > pig iron block > pressed cake and briquette > bulk material and fine material, and they are spread in sequence from the charging section close to the furnace area.

6. The method according to claim 5, characterized in that: The fusible material includes at least one of light and thin material, crushed material, burned iron and iron oxide scale.

7. The method according to claim 4, characterized in that: For steel grades with P≤0.01%, granular pig iron blocks, scrap steel cakes, and wood shavings cakes shall not be used.

8. The method according to claim 4, wherein: If the added scrap steel contains large pieces of scrap, control the length and width of the large pieces of scrap steel in the trough to be less than 1.0*0.5 meters, and the unit weight to be less than 1.5 tons.

9. The method according to claim 1, wherein: The optimization of the material clearing mode of the connecting trolley includes: when the total amount of scrap steel fed differs from the total loading amount by 5 to 8 tons, reducing the feeding speed to below 70%.

10. The method according to claim 9, characterized in that: Also includes: After reaching the target loading volume, it enters the cleaning mode and connects the trolley to clean the material at a vibration rate of 95% for 5 minutes.