Method for improving the ability of a blast furnace to charge under the trough

Abstract

The present application belongs to the technical field of blast furnace charging, and specifically discloses a method for improving the charging capacity of a blast furnace, aiming at the problem of insufficient capacity of the traditional charging system and the restriction of blast furnace productivity. The present application optimizes the pressure maintaining and delay action parameters of the top valve, configures the ore and coke discharge process parameters, sets the belt conveying speed and calculates the conveying time, calculates the material flow parameters, calibrates the ore gate adjustment gear, integrates the standardized charging cycle timing of 450 seconds / batch, builds a linkage monitoring system to realize working condition early warning and discharge error compensation, realizes efficient linkage and accurate control of the whole charging link, improves the charging capacity of the blast furnace from 6.5 batches / hour to 7.5 batches / hour, effectively matches the high smelting intensity demand of the blast furnace, realizes long-term stable improvement of the charging capacity, and releases the blast furnace productivity.

Description

Technical Field

[0001] This invention relates to the field of blast furnace charging technology, and more specifically to a method for improving the charging capacity under the blast furnace trough. Background Technology

[0002] The blast furnace undercharging system is the core feeding link in blast furnace smelting, and its charging capacity directly determines the smelting intensity and production efficiency. Traditional blast furnace undercharging systems suffer from multiple technical defects, with a charging capacity of only 6.5 batches / hour, which cannot meet the high-intensity production demands of blast furnaces. Specifically: the timing of valve actions at the furnace top is unreasonable, with redundant pressure holding and delay parameters, gaps in action connections, and excessively long valve action times per batch; the ore and coke discharge process lacks optimization, resulting in low discharge speeds and unscientific discharge sequence within the hopper, with ore and coke discharge times reaching 2.33 minutes and 2.11 minutes respectively, directly hindering overall charging efficiency; the belt conveyor system's discharge speed is mismatched with belt capacity and conveying efficiency, resulting in gaps in the transfer process and significant differences in ore and coke transport times, with an overall excessively long duration; simultaneously, the ore gate opening lacks clearly defined speed matching levels, and material flow pattern control is inadequate, easily leading to spillage and overload problems, further reducing charging continuity.

[0003] The aforementioned defects create a vicious cycle of inefficient valve operation → time-consuming material conveying → lack of material flow control → insufficient feeding capacity, resulting in a lag in blast furnace feeding rhythm, inability to improve smelting intensity, and severe constraints on capacity release. Summary of the Invention

[0004] The purpose of this invention is to provide a method for improving the charging capacity of blast furnace troughs, so as to solve the problem that the existing blast furnace trough charging system has a lagging charging rhythm during the charging process, which makes it impossible to improve the smelting intensity and severely restricts the release of production capacity.

[0005] To achieve the above objectives, the basic solution provided by this invention is as follows: The blast furnace trough charging capacity is improved by optimizing the furnace top valve action parameters, coke and ore discharge process configuration, belt conveyor system parameters, integrating the charging cycle sequence, implementing linkage monitoring and error compensation, controlling the coke and ore discharge speed and material flow parameters, and calibrating the ore gate position; specifically as follows: a. Set the pressure holding time for the furnace top vent valve, sealing valve, dust recovery valve, and pressure equalization valve, and simultaneously formulate the delay action rules for the charging gate, discharging gate, and probe; b. Set the batch weight of ore to 70 tons / batch and coke to 15.2 tons / batch, the initial discharge speed of ore to 500 kg / s and the initial discharge speed of coke to 120 kg / s, and set the remaining weight of coke silo discharge to 500 kg. c. Set the belt running speed to 2m / s, and calculate the conveying length and corresponding conveying time of each belt according to the number of coke bins used; d. Based on the mass flow rate of the material, the belt speed, and the density of the ore, calculate the cross-sectional area and height of the material flow for sinter and pellets, and set a height control threshold; e. Set 5 adjustment positions for the ore gate, calibrate the discharge speed corresponding to each position, and establish a matching relationship between the maximum opening and the speed; f. With a target of 8 batches / hour and 0 seconds as the time node for opening the silo door, integrate the time nodes of the entire process of ore and coke discharge, belt conveyor, furnace top valve operation, probe release and silo pressure equalization, set the time limit for each link, and form a standardized feeding cycle sequence. g. Monitor the operation of furnace top valves, ore and coke discharge, and belt conveyor status through a linkage monitoring system. Collect time parameters and material flow status of each link in real time, issue early warnings for overdue links, monitor the remaining weight of ore and coke bins in real time, establish a cumulative error compensation mechanism, and calibrate the remaining weight after each batch of material discharge.

[0006] The beneficial effects of this invention are as follows: It optimizes the valve action parameters at the furnace top, precisely sets the pressure holding and delay times, eliminates gaps in equipment action connections, significantly shortens the valve action time for a single batch, and improves the initial efficiency of the feeding cycle; it plans the ore and coke discharge sequence and batch weight, increases the discharge speed, and simultaneously sets the remaining weight in the coke bin to ensure the uniformity and accuracy of ore and coke discharge, reducing ineffective time consumption in the discharge process; based on the belt running speed, it calculates the belt conveying time under different bin usage conditions, optimizes the belt hardware structure, and reduces transfer gaps and material spillage; it calculates material flow parameters based on material characteristics, sets height control thresholds, and achieves control over material flow patterns, avoiding belt overload and spillage problems, thus ensuring improved discharge speed; it integrates the entire process feeding sequence with a target of 8 batches / hour, sets time limits for each stage, and achieves synchronization of ore and coke discharge, belt conveying, and furnace top actions; simultaneously, it monitors the operating status of each stage in real time through a linkage monitoring system, promptly warns of abnormal conditions, calibrates the remaining weight error of the discharge, ensures the stability of the feeding process, and achieves long-term stable improvement in feeding capacity.

[0007] Option 2, which is the preferred option of the basic option, in option a, the venting valve, pressure equalizing valve and dust recovery valve are closed and pressure is maintained for 1 second, the upper sealing valve is tightened and pressure is maintained for 1.5 seconds, the lower sealing valve is loosened / tightened and pressure is maintained for 0.5 seconds, and the discharge gate is closed and pressure is maintained for 0 seconds.

[0008] Option 3, which is the preferred option of the basic option, in option a, the delay action rules of the loading gate, unloading gate and probe are as follows: the loading gate is delayed by 3 seconds, the unloading gate is closed 5 seconds after the signal of opening to the position, and the probe is automatically released with a delay of 2 seconds.

[0009] Option 4, the preferred option of the basic option, in d, the formulas for calculating the cross-sectional area and height of the sinter and pellet flow are: In the formula, Mass of material flow per unit length; Mass flow rate of material; The belt running speed; In the formula, The volume of material flow per unit length; Bulk density of the ore; In the formula, It is the cross-sectional area of ​​the material flow; The volume of material flow per unit length; In the formula, Material flow height; This refers to the width of the material flow.

[0010] Option 5 is the preferred option of the basic option. In option e, the discharge speed corresponding to the maximum opening is 500 kg / s.

[0011] Option 6, the preferred option of the basic option, specifies the following time nodes for the standardized feeding cycle sequence: 0s to open the ore and coke bin gate, 1~T1 stage to complete ore and coke discharge, T1~T2 stage to complete belt conveying, T2~350s to complete the entire process of furnace top valve operation, 350~450s to complete probe release and pressure equalization of material tank, 450s to complete a single feeding cycle and prepare for the next batch of material bin gate to open.

[0012] Option 7, which is the preferred option of the basic option, in g, the rules for early warning and error compensation of the linkage monitoring system for the working conditions are as follows: when the belt conveyor time deviates from the benchmark value by more than 10 seconds, the material flow height exceeds the control threshold, or the valve action time exceeds 350 seconds, a linkage early warning is triggered; when the remaining weight in the coke bin deviates from the set value of 500 kg by more than 50 kg, error compensation is initiated, and the batch weight is corrected by adjusting the discharge time of the next batch. Detailed Implementation

[0013] The present invention will be further described in detail below through specific embodiments: A method for improving the blast furnace trough charging capacity is proposed, which involves optimizing the furnace top valve action parameters, coke and ore discharge process configuration, belt conveyor system parameters, integrating the charging cycle sequence, linkage monitoring and error compensation, controlling the coke and ore discharge speed and material flow parameters, and calibrating the ore gate position to achieve the improvement of the blast furnace trough charging capacity; the details are as follows: a. Set the pressure holding time for the furnace top vent valve, sealing valve, dust recovery valve, and pressure equalization valve: vent valve, pressure equalization valve, and dust recovery valve hold pressure for 1 second when closed; upper sealing valve holds pressure for 1.5 seconds when tightened; lower sealing valve holds pressure for 0.5 seconds when loosened / tightened; and discharge gate holds pressure for 0 seconds when closed. Simultaneously, establish delay action rules: discharge gate delays by 3 seconds; upper sealing valve performs clamping action 3 seconds after closing; discharge gate closes 5 seconds after opening signal; probe automatically extends with a 2-second delay; when the pressure difference in the material tank reaches 15 kPa, pressure equalization and discharge "ok" signals are triggered with a 5-second delay to eliminate valve action gaps. b. Set the batch weight of ore to 70 tons / batch and coke to 15.2 tons / batch. Plan the 13 ore bins to discharge material in the order of bin 13 to bin 1 and the 4 coke bins to discharge material in the order of bin 4 to bin 1. Set the initial discharge speed of ore to 500 kg / s and the initial discharge speed of coke to 120 kg / s. Set the remaining weight of material discharged in each coke bin to 500 kg. Complete the basic parameter configuration for ore and coke discharge. c. Fix the operating speed of belts S101, S102, and S103 to 2 m / s. Calculate the conveying length and corresponding conveying time of each belt based on the number of ore and coke bins used. The calculations show that: bin 13 uses ore for a conveying length of 435 m and takes 217.5 s; bin 7 uses ore for a conveying length of 387 m and takes 193.5 s; bin 4 uses coke for a conveying length of 373 m and takes 186.5 s; and bin 2 uses coke for a conveying length of 357 m and takes 178.5 s. At the same time, adjust the belt protectors, optimize the shape of the material chute, reduce material spillage, and lower the belt transfer gap. d. Increase the ore discharge speed from 500 kg / s to 550 kg / s and the coke discharge speed from 120 kg / s to 130 kg / s. Based on the mass flow rate of the material, the belt running speed and the density of the ore, calculate the cross-sectional area and height of the sinter and pellets, and set the height control threshold. Given: Material flow rate is 550 kg / s; belt speed is 2 m / s; set material flow width is 1.6 m (belt body width is 1.8 m, with a 0.2 m allowance for spillage prevention); sinter density is 1800 kg / m³. 3 Pellet density 2000 kg / m³ 3 ; The calculation formula is: In the formula, Mass of material flow per unit length; Mass flow rate of material; The belt running speed; ①Sintered ore: ② Pelletized ore: In the formula, The volume of material flow per unit length; Bulk density of the ore; ①Sintered ore: ② Pelletized ore: In the formula, It is the cross-sectional area of ​​the material flow; The volume of material flow per unit length; ①Sintered ore: ② Pelletized ore: In the formula, Material flow height; The width of the material flow; Sintered ore: The calculated cross-sectional area of ​​the feed flow is 0.1528 m³. 2 The height is 0.0955m, and the control threshold is set to ≤95mm; Pelletized ore: Calculated yield cross-sectional area 0.1375 m³ 2 Height 0.0859m, set control threshold ≤85mm; e. Set 5 adjustment positions for the ore gate, calibrate the discharge speed corresponding to each position, and establish a matching relationship between the maximum opening and the speed. The discharge speed corresponding to the maximum opening is 500 kg / s. f. With a target of 8 batches / hour, the single batch feeding cycle time is set to 450 seconds, with the opening of the silo door as the 0-second time node: the ore and coke silo gates are opened at 0s, the ore discharge is completed from 1 to 127.2s, the coke discharge is completed from 1 to 116.9s, the belt conveyor stage is entered after the discharge is completed, the furnace top valve completes the entire process from the completion of the conveyor to 350s, the probe is released and the pressure equalization of the material tank is completed from 350 to 450s, and the single feeding cycle is completed at 450s. The time of each link does not exceed the set upper limit. g. The linkage monitoring system monitors the operation of the furnace top valves, the discharge of ore and coke, and the status of the belt conveyor. It collects the time parameters and material flow status of each link in real time, issues warnings for overdue links, and monitors the remaining weight of the ore and coke bin in real time. It establishes a cumulative error compensation mechanism and calibrates the remaining weight after each batch of material is discharged. The linkage monitoring system's warning and error compensation processing rules are as follows: when the belt conveyor time deviates from the benchmark value by more than 10 seconds, the material flow height exceeds the control threshold, or the valve operation time exceeds 350 seconds, a linkage warning is triggered; when the remaining weight of the ore and coke bin deviates from the set value of 500 kg by more than 50 kg, error compensation is initiated, and the batch weight is corrected by adjusting the discharge time of the next batch.

[0014] Specific implementation steps: Optimization of valve timing at the furnace top: The pressure holding and delay parameters of each valve at the furnace top are calibrated through the blast furnace central control system, and the calibration parameters are entered into the valve control system to realize the automatic execution of valve actions; the valve action connection is tested on-site to eliminate action gaps caused by manual operation. After the test, the time taken for the entire process of the furnace top valve action is reduced from more than 4 minutes to less than 3.5 minutes.

[0015] Coke and ore discharge process: The batch weight parameters of 70 tons / batch of ore and 15.2 tons / batch of coke are set through the trough batching control system. The discharge sequence of ore silo 13→1 and coke silo 4→1 is planned in the silo control system. The initial discharge speed of ore is set to 500 kg / s and coke to 120 kg / s. The shutdown threshold of 500 kg remaining weight is set in the coke silo discharge control system. The material level in the silo is monitored in real time during the discharge process to ensure the uniformity of discharge. After the initial discharge test is completed, the discharge speed of ore is gradually increased to 550 kg / s and coke to 130 kg / s, and the discharge time is reduced to 2.12 minutes and 1.94 minutes, respectively.

[0016] Belt Conveyor and Material Flow Control: The running speed of belts S101, S102, and S103 was adjusted to 2m / s and fixed. The belt sheaths were tightened and adjusted. The angle and shape of the material chute at the transfer station were optimized to reduce spillage and gaps during material flow transfer. A material flow height detection device was installed on belt S101 to monitor the material flow height of sinter and pellets in real time, ensuring that the sinter does not exceed 95mm and the pellets do not exceed 85mm. On-site testing showed that the material flow was flat and there were no spillage, overload, or overturning issues.

[0017] Ore gate calibration: On-site testing was conducted on each of the five adjustment positions of the ore gate, and the actual discharge speed corresponding to each position was recorded. A gate opening-discharge speed calibration table was created and entered into the central control system to achieve precise adjustment of the discharge speed. The test at the maximum opening position showed that the discharge speed was stable at 500 kg / s, which met the process requirements, while reserving adjustment space for the subsequent upgrade to 600 kg / s.

[0018] Charging cycle timing and monitoring: Taking the opening of the silo door as the 0-second time node, the time nodes of ore and coke discharge, belt conveyor, furnace top valve action, and probe release are recorded into the blast furnace central control system to achieve time-sequential linkage of the entire process; the established linkage monitoring system displays real-time operating data of each link on the central control platform, and provides real-time warnings for abnormal operating conditions; the remaining weight of the ore and coke in the silo is calibrated for each batch, with the cumulative error controlled within 50kg to ensure batch weight accuracy. The single batch charging cycle time is stably controlled at 7.5 minutes, and the charging capacity reaches the limit target of 8 batches / hour, and can reach 7.5 batches / hour during stable operation.

[0019] This invention optimizes and controls the entire process, including furnace top valves, discharge process, belt conveyor, and material flow management. This increases the traditional charging capacity from 6.5 batches / hour to 7.5 batches / hour, with a maximum of 8 batches / hour. The single-batch charging cycle time is reduced from 9.23 minutes to 7.5 minutes, resulting in a 23.08% increase in charging efficiency. This effectively matches the high-intensity smelting production demands of blast furnaces and releases blast furnace capacity. Precisely setting the pressure holding and delay parameters for the furnace top valves eliminates gaps in the action connections, controlling the entire process of the furnace top valves' operation time within 350 seconds, significantly reducing ineffective valve operation time and improving the overall efficiency of the charging cycle. It also increases the ore and coke discharge speed while calculating and setting material flow parameter control thresholds. A 0.2m allowance is reserved for the material flow width to prevent spillage, and the material flow height is always below 0.1m to avoid leakage. Belt conveyor time is controlled within 4 minutes, ensuring the high efficiency and safety of the discharge and conveying process.

[0020] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for improving the charging capacity under a blast furnace trough, characterized in that, The blast furnace trough charging capacity is improved by optimizing the furnace top valve operating parameters, coke and ore discharge process configuration, belt conveyor system parameters, integrating the charging cycle sequence, linking monitoring and error compensation, controlling the coke and ore discharge speed and material flow parameters, and calibrating the ore gate position; specifically as follows: a. Set the pressure holding time for the furnace top vent valve, sealing valve, dust recovery valve, and pressure equalization valve, and simultaneously formulate the delay action rules for the charging gate, discharging gate, and probe; b. Set the batch weight of ore to 70 tons / batch and coke to 15.2 tons / batch, the initial discharge speed of ore to 500 kg / s and the initial discharge speed of coke to 120 kg / s, and set the remaining weight of coke silo discharge to 500 kg. c. Set the belt running speed to 2m / s, and calculate the conveying length and corresponding conveying time of each belt according to the number of coke bins used; d. Based on the mass flow rate of the material, the belt speed, and the density of the ore, calculate the cross-sectional area and height of the material flow for sinter and pellets, and set a height control threshold; e. Set 5 adjustment positions for the ore gate, calibrate the discharge speed corresponding to each position, and establish a matching relationship between the maximum opening and the speed; f. With a target of 8 batches / hour and 0 seconds as the time node for opening the silo door, integrate the time nodes of the entire process of ore and coke discharge, belt conveyor, furnace top valve operation, probe release and silo pressure equalization, set the time limit for each link, and form a standardized feeding cycle sequence. g. Monitor the operation of furnace top valves, ore and coke discharge, and belt conveyor status through a linkage monitoring system. Collect time parameters and material flow status of each link in real time, issue early warnings for overdue links, monitor the remaining weight of ore and coke bins in real time, establish a cumulative error compensation mechanism, and calibrate the remaining weight after each batch of material discharge.

2. The method for improving the charging capacity under the blast furnace trough according to claim 1, characterized in that, In step a, the venting valve, equalizing valve, and dust recovery valve are closed and pressure is maintained for 1 second; the upper sealing valve is tightened and pressure is maintained for 1.5 seconds; the lower sealing valve is loosened / tightened and pressure is maintained for 0.5 seconds; and the discharge gate is closed and pressure is maintained for 0 seconds.

3. The method for improving the charging capacity under the blast furnace trough according to claim 1, characterized in that, In section a, the delay action rules for the loading gate, unloading gate, and probe are as follows: the loading gate is delayed by 3 seconds, the unloading gate closes 5 seconds after the signal to open to the position, and the probe automatically releases its gauge after a 2-second delay.

4. The method for improving the charging capacity under the blast furnace trough according to claim 1, characterized in that, In section d, the formulas for calculating the cross-sectional area and height of sinter and pellets are as follows: In the formula, Mass of material flow per unit length; This refers to the mass flow rate of the material. The belt running speed; In the formula, The volume of material flow per unit length; Bulk density of the ore; In the formula, It is the cross-sectional area of ​​the material flow; The volume of material flow per unit length; In the formula, Material flow height; This refers to the width of the material flow.

5. The method for improving the charging capacity under the blast furnace trough according to claim 1, characterized in that, In equation e, the discharge speed corresponding to the maximum opening is 500 kg / s.

6. The method for improving the charging capacity under the blast furnace trough according to claim 1, characterized in that, In f, the specific time nodes of the standardized feeding cycle sequence are as follows: 0s to open the ore and coke bin gate, 1~T1 stage to complete ore and coke discharge, T1~T2 stage to complete belt conveying, T2~350s to complete the full process of furnace top valve operation, 350~450s to complete probe release and material tank pressure equalization, 450s to complete a single feeding cycle and prepare for the next batch of bin door to open.

7. The method for improving the charging capacity under the blast furnace trough according to claim 1, characterized in that, In g, the linkage monitoring system's rules for early warning and error compensation of working conditions are as follows: when the belt conveyor time deviates from the benchmark value by more than 10 seconds, the material flow height exceeds the control threshold, or the valve action time exceeds 350 seconds, a linkage early warning is triggered; when the remaining weight in the coke bin deviates from the set value of 500 kg by more than 50 kg, error compensation is initiated, and the batch weight is corrected by adjusting the discharge time of the next batch.

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