Control method based on copper rod casting

Abstract

The invention relates to the technical field of copper rod casting, and provides a control method based on copper rod casting, which comprises the following steps: step 1, a shaft furnace receives a tool changing instruction of a casting machine, and starts to reduce the air inlet pressure of an A row of burners, a B row of burners and a C row of burners of the shaft furnace so as to reduce the combustion power; secondly, according to the time interval of the semicircular pipe entering the copper inlet of the heat preservation furnace, the downtime of a casting machine is determined; 3, after the casting machine is shut down, seven burners in the row A in the shaft furnace are kept normally open, four burners in the row B are closed in a crossed mode, two burners in the row C are closed in a crossed mode, and then the casting machine begins to change tools; the effect of prolonging the service life of the shaft furnace refractory material is achieved by not stopping the furnace and prolonging the service time of the shaft furnace working layer bricks, meanwhile, slag can be reduced, copper loss can be reduced, and the quality of a copper rod is improved; and the oxygen content of the copper liquid is low, and compared with furnace shutdown, the rolling time is shortened, the pendulum shearing time is shortened, and the natural gas loss is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of copper rod casting, and in particular to a control method based on copper rod casting. Background Art

[0002] Due to the limitation of steel strip usage time, the casting machine of Contirod copper rod continuous casting and rolling production line needs to clean the tundish, replace the pouring nozzle tip, upper and lower steel strips and block every 3-5 days, which is called tool change in the industry. Because the tonnage capacity of the holding furnace is limited, the vertical furnace must be stopped when the casting machine changes tools, and the copper plate cannot be melted any more.

[0003] When the vertical furnace is shut down, there are mainly the following disadvantages: 1. When the vertical furnace is shut down, the maximum amount of air must be blown and cooled first to quickly cool the copper plate in the furnace. The working layer bricks in the vertical furnace will oxidize on the surface due to the high temperature and large amount of air blowing, which will reduce the service life of the vertical furnace; the oxides of the working layer bricks will combine with the copper liquid to produce impurities. In the actual production process, if they cannot be effectively removed, they will enter the casting machine and finally remain inside the copper rod, affecting the production quality of the copper rod.

[0004] 2. When the vertical furnace is shut down, the copper liquid in the upper and lower chutes must be discharged, generating a large amount of scrap copper, thus causing copper loss.

[0005] 3. When the vertical furnace is shut down, the oxygen content of the copper plates in the vertical furnace and the copper liquid in the holding furnace increases sharply due to a large amount of air purge. After the casting machine is started again, the oxidation amount of the copper rod in the early stage will also be very high, which reduces the quality of the copper rod. When the oxygen content of the copper rod returns to normal, charcoal needs to be put into the holding furnace to reduce the oxygen content of the copper liquid, which is a slow process. If the oxygen content of the copper rod is high when the rolling mill is rolling, it will also cause the rolling to fail.

[0006] 4. When the vertical furnace is shut down, the natural gas used for preheating and insulation of the insulation furnace and the upper and lower chutes is equivalent to not producing any products, which is equivalent to doing useless work and is a waste of production costs. Summary of the invention

[0007] The invention provides a control method based on copper rod casting, which solves the problem that the vertical furnace must be stopped in the prior art.

[0008] The technical solution of the present invention is as follows: A control method based on copper rod casting comprises the following steps: Step 1: The vertical furnace receives a tool change instruction from the casting machine and starts to reduce the air inlet pressure of the A row burners, the B row burners and the C row burners of the vertical furnace burners to reduce the combustion power; Step 2: Determine the downtime of the casting machine according to the time interval when the semicircular tube enters the copper inlet of the holding furnace; Step 3: After the casting machine is shut down, 7 burners in row A of the vertical furnace are kept open, 4 burners in row B are closed crosswise, and 2 burners in row C are closed crosswise, and then the casting machine starts to change tools; Step 4. After the casting machine has finished changing tools, the vertical furnace receives the tool instruction from the casting machine that it is ready to start pouring. The air inlet pressure of the A, B, and C rows of burners is restored to increase the combustion power of the A row of burners. The power of the B and C rows of burners is gradually adjusted according to the melting speed of the copper plate in the vertical furnace until each row of burners returns to its initial optimal working state.

[0009] Preferably, in step 1, the air inlet pressure of the burners in row A is adjusted to 30 mbar, the air inlet pressure of the burners in row B is adjusted to 30 mbar, and the air inlet pressure of the burners in row C is adjusted to 30 mbar, the λ value of the burners in row A is adjusted to 0.9, the λ value of the burners in row B is adjusted to 0.9, and the λ value of the burners in row C is adjusted to 0.9.

[0010] Preferably, in step three, there are 7 burners in row A, 8 burners in row B, and 4 burners in row C, and the burners in row A, row B, and row C are alternately arranged along the length direction of the vertical furnace.

[0011] Preferably, in step three, the 7 burners in row A, the 8 burners in row B and the 4 burners in row C are all spirally and equidistantly arranged on the vertical furnace.

[0012] Preferably, the 7 burners in row A are A1-A7 burners from top to bottom, the 4 burners in row B are B1-B8 burners from top to bottom, and the 4 burners in row C are C1-C4 burners from top to bottom.

[0013] Preferably, in step three, the λ value of the burners in row A is maintained at 0.90, the λ value of the burners in row B is adjusted to 0.88, and the λ value of the burners in row C is adjusted to 0.88.

[0014] Preferably, the total flow rate of the burner fan in row A in step 3 is 1726Nm 3 / h adjusted to 1104Nm 3 / h, the power coefficient is maintained at 13.6%, and the total flow rate of the burner fan in row B is increased from 1936Nm 3 / h adjusted to 487Nm 3 / h, the power coefficient is maintained at 13.6%, and the total flow rate of the C row burner fan is increased from 498Nm 3 / h adjusted to 307Nm 3 / h, and the power factor remains at 17.6%.

[0015] The beneficial effects of the present invention are: 1. The present invention prolongs the service life of the vertical furnace working layer bricks by not stopping the furnace, thereby achieving the effect of prolonging the service life of the vertical furnace refractory materials, while reducing slag, reducing the generation of copper loss, and improving the quality of copper rods; 2. Since the present invention does not stop the furnace, the oxygen content of the copper liquid is low. Compared with stopping the furnace, the rolling time is shortened, the swing shear time is reduced, and the natural gas loss is reduced by about; 3. Since the present invention does not stop the furnace, the oxygen content of the copper liquid will be normal, and there is no need to use charcoal to reduce the oxygen content, thereby reducing the use of charcoal in the insulation furnace and improving the success rate of the rolling mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0017] Figure 1 A schematic diagram of a control method based on copper rod casting proposed by the present invention; Figure 2 This is a schematic diagram of the overall distribution structure of the A, B, and C rows of burners in a vertical furnace proposed by the present invention; Figure 3 This is a schematic diagram of the distribution structure of the A-row burners in the vertical furnace proposed by the present invention; Figure 4 This is a schematic diagram of the distribution structure of the B row burners in the vertical furnace proposed by the present invention; Figure 5 This is a schematic diagram of the distribution structure of the C row burners in the vertical furnace proposed by the present invention; Figure 6 This is a diagram of various parameters after the primary and secondary adjustments of the A-row burners proposed by the present invention; Figure 7 This is a diagram of various parameters after the primary and secondary adjustments of the B-row burners proposed by the present invention; Figure 8 This is a diagram of various parameters after the first and second adjustments of the C-row burner proposed by the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The present invention is based on the Contirod copper rod continuous casting and rolling production line. The vertical furnace is a supporting vertical furnace for the Contirod copper rod continuous casting and rolling production line, with a rated melting rate of 35t / h, the number and power of the burners of the vertical furnace (A row burners: 7×570KW; B row burners: 8×750KW; C row burners 4×650KW), the capacity of the insulation furnace: 20T; the model of the casting machine: CR3700, the casting capacity: 35t / h. The existing production line has the following process flow for continuous casting and rolling of copper rods: electrolytic copper and part of the return material → batching → furnace loading → vertical furnace melting → insulation in the insulation furnace → continuous casting of the casting machine → secondary cooling of the casting machine → straightening → edge milling → continuous rolling of the rolling mill → cooling, cleaning → flaw detection, diameter detection → wax coating → coiling → inspection sampling → compaction, banding → packaging → weighing.

[0020] See also Figure 1 The present invention provides a technical solution: a control method based on copper rod casting, comprising the following steps: Step 1: When the vertical furnace receives the tool change command from the casting machine, it starts to reduce the air intake pressure of the A row burners, B row burners and C row burners of the vertical furnace burners to reduce the combustion power. The shorter the time interval between the semi-circular tubes entering the copper inlet of the holding furnace, the better. At the same time, attention should be paid to the condition of the circular tubes to ensure the continuity of production. Generally, when the tonnage of the holding furnace drops to 7 tons, the casting machine can be shut down and the casting machine starts to change tools, which takes about 2 hours. Step 2: Determine the downtime of the casting machine according to the time interval when the semicircular tube enters the copper inlet of the holding furnace; Step 3: After the casting machine is shut down, 7 burners in row A of the vertical furnace are kept open, 4 burners in row B are closed crosswise, and 2 burners in row C are closed crosswise, and then the casting machine starts to change tools; Step 4. After the casting machine has finished changing tools, the vertical furnace receives the tool instruction from the casting machine that it is ready to start pouring. The air inlet pressure of the A, B, and C rows of burners is restored to increase the combustion power of the A row of burners. The power of the B and C rows of burners is gradually adjusted according to the melting speed of the copper plate in the vertical furnace until each row of burners returns to its initial optimal working state.

[0021] In step 1, the air inlet pressure of the burners in row A is adjusted to 30 mbar, the air inlet pressure of the burners in row B is adjusted to 30 mbar, and the air inlet pressure of the burners in row C is adjusted to 30 mbar. The λ value of the burners in row A is adjusted to 0.9, the λ value of the burners in row B is adjusted to 0.9, and the λ value of the burners in row C is adjusted to 0.9. The λ value represents the ratio of the heat load of the combustion chamber to the effective area of ​​the vertical furnace.

[0022] See also Figure 2 , Figure 3 , Figure 4 and Figure 5In step 3, the burners in rows A, B and C are arranged alternately along the length of the vertical furnace. The 7 burners in row A, the 8 burners in row B and the 4 burners in row C are all arranged spirally and equidistantly on the vertical furnace. The 7 burners in row A are A1-A7 burners from top to bottom, the 4 burners in row B are B1-B8 burners from top to bottom, and the 4 burners in row C are C1-C4 burners from top to bottom. This design can ensure that the burners in rows A, B and C can evenly transport air and gas into the vertical furnace, so that the air and gas are burned in the vertical furnace, and each section in the vertical furnace can fully burn and maintain a balanced temperature.

[0023] See also Figure 6 , Figure 7 and Figure 8 In step 3, the lambda value of burners in row A is kept at 0.90, the lambda value of burners in row B is adjusted to 0.88, and the lambda value of burners in row C is adjusted to 0.88. In step 3, the total flow rate of burner fans in row A is increased from 1726Nm 3 / h adjusted to 1104Nm 3 / h, the power coefficient remains at 13.6%, the total flow rate of the burner fan of row B is adjusted from 1936Nm3 / h to 487Nm3 / h, the power coefficient remains at 13.6%, the total flow rate of the burner fan of row C is adjusted from 498Nm3 / h to 307Nm3 / h, the power coefficient remains at 17.6%.

[0024] It should be noted that when executing the control method of the present invention, it is necessary to strictly control the tonnage of the holding furnace during the shutdown of the casting machine, and the tonnage cannot exceed 25 tons. From the 7 tons of the holding furnace when the casting machine is shut down to the 25 tons when it is restarted again, the speed of melting the copper plate in the vertical furnace must be controlled within 2 hours, so as to keep the melting rate of the copper plate at 29% of normal production. Since the melting rate of the copper plate in the vertical furnace is very slow, the operation control requirements are very high. First, prevent the partially closed burner from tempering due to the high temperature in the furnace; secondly, the firepower of the entire vertical furnace burner is too small to prevent the low temperature of the copper outlet of the vertical furnace from causing the copper liquid to condense and block the copper outlet. Therefore, the vertical furnace operator must constantly inspect the vertical furnace burner and copper outlet to prevent sudden accidents.

[0025] Through the above embodiments, the present invention has the following implementation benefits: 1. The present invention can improve the work efficiency of each position, shorten the casting time of the casting machine, and reduce the natural gas usage in the insulation stage of the upper and lower chutes and the insulation furnace in the vertical furnace area because the furnace does not stop. It can save 500 cubic meters of natural gas in 2 hours, saving 2,000 yuan; 2. Because the furnace is not stopped, the oxygen content of copper liquid is low. Compared with stopping the furnace, the rolling time is shortened by about 20 minutes, the swing shear time is reduced, and the natural gas loss is reduced by about 400 cubic meters, about 17,000 yuan; 3. When the vertical furnace is stopped, the upper and lower chutes need to scoop out the copper liquid, and the pure copper will be downgraded to scrap copper. If the vertical furnace is not stopped, this work does not need to be done, thereby achieving the purpose of reducing copper loss and saving copper loss of about 2,000 yuan; 4. Reduce the amount of charcoal used. If the furnace is not shut down, the oxygen content of the copper liquid will be normal, and there is no need to use charcoal to reduce the oxygen content. This can save 7,000 yuan of charcoal. 5. Avoid the unstable oxygen content of copper rod after rolling, which increases the output rate of high-end copper rod.

[0026] 6. When the vertical furnace is stopped, a large amount of air is needed for cooling. In a high temperature environment, the furnace bricks will be oxidized more rapidly. If the vertical furnace is not stopped, the number of air cooling will be reduced, thus extending the service life of the vertical furnace refractory materials.

[0027] When the casting machine tool is changed by the control method of the present invention, the furnace is kept in vertical operation, which can directly save 6,400 yuan per time and 384,000 yuan in production cost per year, thus having positive implementation significance.

[0028] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A control method based on copper rod casting, characterized in that: The following steps are involved: Step 1: The vertical furnace receives a tool change instruction from the casting machine and starts to reduce the air inlet pressure of the A row burners, the B row burners and the C row burners of the vertical furnace burners to reduce the combustion power; Step 2: Determine the downtime of the casting machine according to the time interval when the semicircular tube enters the copper inlet of the holding furnace; Step 3: After the casting machine is shut down, 7 burners in row A of the vertical furnace are kept open, 4 burners in row B are closed crosswise, and 2 burners in row C are closed crosswise, and then the casting machine starts to change tools; Step 4. After the casting machine has finished changing tools, the vertical furnace receives the tool instruction from the casting machine that it is ready to start pouring. The air inlet pressure of the A, B, and C rows of burners is restored to increase the combustion power of the A row of burners. The power of the B and C rows of burners is gradually adjusted according to the melting speed of the copper plate in the vertical furnace until each row of burners returns to its initial optimal working state.

2. A control method based on copper rod casting according to claim 1, characterized in that: In the step 1, the air inlet pressure of the burners in row A is adjusted to 30 mbar, the air inlet pressure of the burners in row B is adjusted to 30 mbar, and the air inlet pressure of the burners in row C is adjusted to 30 mbar. The λ values ​​of the burners in row A are adjusted to 0.9, the λ values ​​of the burners in row B are adjusted to 0.9, and the λ values ​​of the burners in row C are adjusted to 0.

9.

3. A control method based on copper rod casting according to claim 1, characterized in that: In the step 3, there are 7 burners in row A, 8 burners in row B, and 4 burners in row C, and the burners in row A, row B, and row C are alternately arranged along the length direction of the vertical furnace.

4. A control method based on copper rod casting according to claim 3, characterized in that: In the step 3, the 7 burners in row A, the 8 burners in row B and the 4 burners in row C are all spirally and equidistantly arranged on the vertical furnace.

5. A control method based on copper rod casting according to claim 4, characterized in that: The 7 burners in row A are A1-A7 burners from top to bottom, the 4 burners in row B are B1-B8 burners from top to bottom, and the 4 burners in row C are C1-C4 burners from top to bottom.

6. A control method based on copper rod casting according to claim 1, characterized in that: In the step 3, the lambda value of the burners in row A is maintained at 0.90, the lambda value of the burners in row B is adjusted to 0.88, and the lambda value of the burners in row C is adjusted to 0.

88.

7. A control method based on copper rod casting according to claim 1, characterized in that: In step 3, the total flow rate of the burner fan in row A is 1726Nm 3 / h adjusted to 1104Nm 3 / h, the power coefficient is maintained at 13.6%, and the total flow rate of the burner fan in row B is increased from 1936Nm 3 / h adjusted to 487Nm 3 / h, the power coefficient is maintained at 13.6%, and the total flow rate of the C row burner fan is increased from 498Nm 3 / h adjusted to 307Nm 3 / h, and the power factor remains at 17.6%.

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