Operation method after blast furnace profile improvement

Abstract

The invention belongs to the technical field of blast furnace ironmaking, and particularly discloses an operation method after blast furnace profile improvement, which comprises an initial material distribution and air supply step, a dynamic air volume regulation and control step, a heat system fine control step, an abnormal working condition treatment step and a furnace condition stable air volume callback step, improvement is mainly carried out from three aspects of material distribution system optimization, air supply parameter adjustment, heat system and emergency treatment, so that the problems of disordered gas flow distribution, non-uniform furnace burden decline and the like caused by furnace bosh diameter expansion after blast furnace profile transformation are solved, the stability of the furnace condition is improved, the material suspension frequency is reduced, and the daily average output is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of blast furnace ironmaking, in particular to an improved operation method of blast furnace furnace type. BACKGROUND

[0002] In the traditional blast furnace furnace type, the matching of the furnace waist diameter and the furnace body angle is crucial to the gas flow distribution and the smooth running of the furnace charge. After the transformation of the blast furnace furnace type, the furnace waist diameter is expanded from 12600mm to 13000mm, resulting in a 0.655° angle deviation between the lower 9th segment and the 10th segment of the furnace body (originally 83.039° adjusted to 82.384°). This geometric mutation will cause the following technical problems: Gas flow disorder: vortex is formed at the angle difference, which destroys the "center + edge" double-peak gas flow distribution, and the coal gas utilization rate decreases from 45% to 38-42%; Uneven descent of furnace charge: stress concentration in the angle difference area, increased coke crushing rate (<10mm particle size accounts for 28-33%, normal ≤15%), and increased pressure difference to 175kPa (normal ≤165kPa); Thermal load fluctuation: excessive edge gas flow, furnace wall temperature fluctuation amplitude up to ±15%, and frequent suspension of material (cumulative 3 times in the initial stage of blowing);

[0003] The existing charging method is not optimized for the geometric mutation of the furnace type, resulting in the destruction of the smooth running of the blast furnace and the increase of the fuel ratio to 630kg / t (target ≤550kg / t). Therefore, there is an urgent need for a charging method suitable for the HyCROF furnace type to solve the problem of coordinated regulation of gas flow and furnace charge. SUMMARY

[0004] The purpose of the present application is to provide an improved operation method of blast furnace furnace type to solve the problems of gas flow disorder and uneven descent of furnace charge caused by the expansion of the furnace waist.

[0005] To achieve the above-mentioned purpose, the basic scheme provided by the present application is as follows: an improved operation method of blast furnace furnace type, comprising the following steps: S1: initial material distribution and air supply Take the coke and sintered ore by mass percentage, execute the optimized distribution matrix through the top distributor, and the basis of the optimized distribution matrix is the coke distribution weighted angle of 36.2° and the ore distribution weighted angle of 37.68°, with an angle difference of 1.48°; Start the air supply system, the initial air volume is 4200m 3 / min, the top pressure is 60kPa, the air temperature is 1050℃; the tuyere diameter is 100-115mm, the tuyere area is 0.2963m 2 , the wind speed is 280m / s, and the blast kinetic energy is 85-120kJ / s; S2: dynamic air volume regulation Real-time monitoring of differential pressure and air permeability index, when the pressure difference >180kPa, the air volume is reduced to 3800m 3 / min at a rate of 50m 3 / min, and add 3 batches of clean coke; when the pressure difference <160kPa and the coal gas utilization rate >45%, gradually increase the air volume to 4500m 3 / min; S3: Fine control of thermal system Every 2h, detect the silicon content of molten iron, when Si<0.3%, the wind temperature is increased to 1130℃, and 2 batches of coke are added; when Si>0.8%, the wind temperature is reduced to 1080℃, the coal injection amount is reduced by 10kg / t, and the oxygen enrichment amount is increased by 0.5%; S4: Abnormal condition handling Emergency suspension of material: when the pressure difference >180kPa, trigger the emergency mechanism of reducing air and adding coke; S5: After the furnace condition is stable, the air volume is gradually adjusted to 4500m 3 / min, the wind temperature is reduced to 1050℃, and the conventional distribution matrix is switched to restore the standard operation process.

[0006] Further, the emergency mechanism in step S4 is: when the pressure difference >180kPa, immediately reduce the air to 3840m 3 / min, stop oxygen, add 3 batches of clean coke, and control the center temperature at 400-500℃; when the pressure difference falls to <170kPa, restore the air volume at a rate of ≤50m 3 / min.

[0007] Further, the thickness of the coke layer added in the emergency mechanism is increased by 450mm based on the original.

[0008] Further, the optimized coke distribution matrix in step S1 is 41.5° (2 rings), 39.5° (3 rings), 37.5° (3 rings), 35° (3 rings), 32.5° (2 rings), and 29.5° (2 rings); and the optimized sinter distribution matrix is 40.5° (3 rings), 38.5° (3 rings), 36.5° (3 rings), and 34° (2 rings).

[0009] Further, the coke particle size in step S1 is 25-50mm, and the TFe in the sinter is ≥55%.

[0010] Compared with the prior art, the advantages of the present application are: 1. After the implementation of this invention, the gas utilization rate will be increased from 38-42% to 45-46.8%, the fuel ratio will be reduced to 538 kg / t, the pressure difference will be reduced from 175 kPa to 160 kPa, the permeability index K value will be optimized from 5.9 to 5.4, the furnace stability will be improved, the frequency of material suspension will be reduced by 80%, and the average daily output will be restored to 5030 tons. Detailed Implementation

[0011] The present invention will be further described in detail below through specific embodiments: An operating method for an improved blast furnace includes the following steps: S1: Initial Fabric and Air Supply Coke and sinter were weighed according to mass percentage, with coke particle size of 25-50mm and TFe ≥ 55% in sinter. The optimized distribution matrix was executed through the furnace top distributor. The optimization matrix was based on a coke distribution weighted angle of 36.2° and an ore distribution weighted angle of 37.68°, with an angle difference of 1.48°. The optimized coke distribution matrix was 41.5° (2 rings), 39.5° (3 rings), 37.5° (3 rings), 35° (3 rings), 32.5° (2 rings), and 29.5° (2 rings). The optimized sinter distribution matrix was 40.5° (3 rings), 38.5° (3 rings), 36.5° (3 rings), and 34° (2 rings). The air supply system is started, with an initial air volume of 4200 m³ / h. 3 The furnace top pressure is 60 kPa, and the blast temperature is 1050℃; the tuyere diameter is 100-115 mm, and the tuyere area is 0.2963 m². 2 The wind speed is 280 m / s, and the kinetic energy of the blower is 85-120 kJ / s; S2: Dynamic airflow control Real-time monitoring of pressure difference and air permeability index; when pressure difference > 180 kPa, air volume is increased to 50 m³ / h. 3 / min amplitude decreased to 3800m 3 Increase the air volume to 4500 m³ / min and add 3 batches of clean coke; when the pressure difference is <160 kPa and the gas utilization rate is >45%, gradually increase the air volume to 4500 m³ / min. 3 / min; S3: Refined control of thermal regime The silicon content of molten iron is tested every 2 hours. When Si < 0.3%, the blast temperature is increased to 1130℃, and two batches of coke are added. When Si > 0.8%, the blast temperature is reduced to 1080℃, the coal injection rate is reduced by 10 kg / t, and the oxygen enrichment is increased by 0.5%. S4: Abnormal Operating Condition Handling Emergency Suspension Mechanism: When the pressure difference > 180 kPa, the emergency mechanism for reducing airflow and adding coke is triggered; specifically, when the pressure difference > 180 kPa, the airflow is immediately reduced to 3840 m³. 3 / min, stop oxygen, add clean coke 3 batches, coke layer thickness increased by 450 mm on the original basis, center temperature controlled at 400-500℃; when the pressure difference dropped to <170 kPa, the air volume was restored at a rate of ≤50 m 3 / min; S5: After the furnace condition is stable, the air volume is gradually adjusted back to 4500 m 3 / min, the air temperature is reduced to 1050℃; and the normal distribution matrix is switched to restore the standard operation process.

[0012] Take a 3200 m 3 HyCROF blast furnace as an example, the specific operation scheme using the above method is as follows: S1: Initial distribution and air supply Coke (particle size 25-50 mm) and sinter (TFe≥55%) are weighed according to mass percentage, and the optimized matrix is executed through the top distributor: Coke: 41.5° (2 rings), 39.5° (3 rings), 37.5° (3 rings), 35° (3 rings), 32.5° (2 rings), 29.5° (2 rings); Ore: 40.5° (3 rings), 38.5° (3 rings), 36.5° (3 rings), 34° (2 rings); Start the air supply system, initial air volume 4200 m 3 / min, top pressure 60 kPa, air temperature 1050℃; S2: Dynamic air volume control Real-time monitoring of pressure difference and gas permeability index, when the pressure difference is >180 kPa, the air volume is reduced at a rate of 50 m 3 / min to 3800 m 3 / min, and add clean coke 3 batches; when the pressure difference is <160 kPa and the coal gas utilization rate is >45%, gradually increase the air volume to 4500 m 3 / min; S3: Fine control of heat system Every 2h, detect the silicon content of molten iron, Si <0.3%: air temperature increased to 1130℃, add coke 2 batches (each batch increases 10% coke); Si >0.8%: air temperature reduced to 1080℃, coal injection amount reduced by 10 kg / t, oxygen enrichment amount increased by 0.5%.

[0013] S4: Abnormal condition handling Emergency suspension of material: immediately reduce the air volume to 3840 m 3 / min, stop oxygen, add clean coke 3 batches (coke layer + 450 mm), center temperature controlled at 450℃; when the pressure difference drops to <170 kPa, the air volume is restored at a rate of ≤50 m 3 / min.

[0014] S5: After the late parameter callback furnace stable, the air volume gradually callback to 4500m 3 / min, the air temperature dropped to 1050℃; switch to the normal distribution matrix, restore the standard operating procedures.

[0015] Table 1 is the operation scheme before and after the implementation of the data comparison table Parameter Before improvement After implementation of the application Improvement rate Gas utilization rate 38-42% 45-46.8% +14% Daily average output 4200t 5030t +19.8% Frequency of suspended material 3 times / week 0 -100% The above only is the embodiment of the present application, the specific structure and the common sense of the scheme are not described too much. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of deformation and improvement can be made, which should be considered as the protection scope of the present application, which will not affect the effect and the practicality of the patent. The protection scope of the present application should be subject to the content of its claims, the specific implementation mode and the like in the description can be used to explain the content of the claims.

Claims

1. An operating method for an improved blast furnace, characterized in that, Includes the following steps: S1: Initial Fabric and Air Supply Coke and sinter were weighed by mass percentage, and the optimized feeding matrix was executed through the furnace top feeder. The optimized feeding matrix was based on the weighted angle of coke feeding of 36.2°, the weighted angle of ore feeding of 37.68°, and the angle difference of 1.48°. The air supply system is started, with an initial air volume of 4200 m³ / h. 3 The furnace top pressure is 60 kPa, and the blast temperature is 1050℃; the tuyere diameter is 100-115 mm, and the tuyere area is 0.2963 m². 2 The wind speed is 280 m / s, and the kinetic energy of the blower is 85-120 kJ / s; S2: Dynamic airflow control Real-time monitoring of pressure difference and air permeability index; when pressure difference > 180 kPa, air volume is increased to 50 m³ / h. 3 / min amplitude decreased to 3800m 3 Increase the air volume to 4500 m³ / min and add 3 batches of clean coke; when the pressure difference is <160 kPa and the gas utilization rate is >45%, gradually increase the air volume to 4500 m³ / min. 3 / min; S3: Refined control of thermal regime The silicon content of molten iron is tested every 2 hours. When Si < 0.3%, the blast temperature is increased to 1130℃, and two batches of coke are added. When Si > 0.8%, the blast temperature is reduced to 1080℃, the coal injection rate is reduced by 10 kg / t, and the oxygen enrichment is increased by 0.5%. S4: Abnormal Operating Condition Handling Emergency suspension mechanism: When the pressure difference is greater than 180 kPa, the emergency mechanism for reducing airflow and adding coke is triggered. S5: After the furnace condition stabilizes, the air volume is gradually reduced to 4500m³. 3 / min, the air temperature drops to 1050℃; and it switches to the regular fabric matrix to restore the standard operating procedure.

2. The operating method of the improved blast furnace according to claim 1, characterized in that, The emergency mechanism in step S4 is as follows: when the pressure difference is greater than 180 kPa, immediately reduce the airflow to 3840 m. 3 / min, stop oxygen, add 3 batches of clean coke, and control the center temperature at 400-500℃; when the pressure difference drops to <170kPa, reduce to ≤50m 3 / min amplitude recovery air volume.

3. The operating method of the improved blast furnace according to claim 2, characterized in that, In the emergency mechanism, the thickness of the coke layer is increased by 450mm on the original basis.

4. The operating method of the improved blast furnace according to claim 1, characterized in that, The optimized coke fabric distribution matrix in step S1 is 41.5° (2 rings), 39.5° (3 rings), 37.5° (3 rings), 35° (3 rings), 32.5° (2 rings), and 29.5° (2 rings); the optimized sinter fabric distribution matrix is ​​40.5° (3 rings), 38.5° (3 rings), 36.5° (3 rings), and 34° (2 rings).

5. The operating method of the improved blast furnace according to claim 1, characterized in that, The coke particle size in step S1 is 25-50mm, and the TFe content in the sinter is ≥55%.