Judgment method and processing method of blast furnace material suspension part

Abstract

The invention relates to a judging method and a processing method for a blast furnace material suspension part, and the judging method for the blast furnace material suspension part is used for judging the position where material suspension occurs in a blast furnace. Comprising the following steps: if the material is suspended at the upper part, controlling the wind speed and increasing coke for maintaining the shape of the material surface, selecting different modes according to different material suspending parts to perform wind reduction'material setting ', quantitatively calculating and supplementing the weight of net coke, and determining a material distribution mode for increasing the net coke. The method has the advantages that different furnace condition recovery methods, parameter setting rules and coke adding methods are invented according to different material suspension parts, and the recovery speed of the blast furnace after material suspension is increased; in the upper suspended material, the follow-up air adding process can be accelerated by maintaining the shape of the material surface, and the possibility of secondary material collapsing and material sliding accidents is reduced; different modes are selected according to different material suspension parts to carry out air reduction'material setting ', corresponding air reduction methods are adopted according to different material suspension parts, the furnace condition recovery process can be accelerated as much as possible, and optimization of the material suspension recovery process is achieved.

Description

Technical Field

[0001] The invention relates to the field of iron and steel metallurgy, and in particular to a method for determining and treating a blast furnace hanging material position. Background Art

[0002] It is of great significance to keep the blast furnace smelting process stable and smooth. Accidents such as pipeline travel, collapse and hanging material seriously affect the stable production of blast furnaces, and in severe cases will cause major accidents. Hanging material is one of the common serious abnormal furnace conditions caused by the deterioration of furnace conditions in blast furnace production. It is manifested by the stagnation of the probe and the sharp increase in hot air pressure. In essence, the gravity of the descending charge is less than the upward combined force of the local gas buoyancy and the friction of the furnace wall, causing the charge to stop falling. The cause of hanging material is a series of complex factors such as the deterioration of furnace conditions, abnormal distribution of gas flow in the furnace, violent fluctuations in the soft melting range, slag skin shedding, blockage of the passage after the local pipeline travel, and deterioration of the physical and chemical properties of the charge. In actual operation, a large amount of air reduction must be carried out after the occurrence of hanging material, and the smelting intensity must be reduced and then slowly recovered. It has a huge impact on the pig iron production capacity and fuel consumption of the blast furnace. Secondary hanging material or secondary air reduction caused by errors in continuous hanging material or recovery process may lead to long-term abnormal furnace conditions and huge economic losses.

[0003] The traditional blast furnace hanging material treatment mainly relies on the operator's operating experience to manually "sit the material" according to the state of the probe (sitting the material means reducing the wind to restore the stagnant material surface). The treatment of hanging materials is mainly divided into two processes: "sitting the material" and "recovery". The previous methods of handling hanging materials have great disadvantages:

[0004] 1. Lack of accurate judgment on the location of overhanging materials. Overhanging materials in blast furnaces can be divided into upper overhanging materials and lower overhanging materials. The causes and characteristics of the two are inconsistent, and the corresponding treatment methods are also different. Operators usually take a large amount of air reduction for both upper and lower overhanging materials, and lack the possibility of optimizing the air volume and recovery progress;

[0005] 2. During the "sitting" and "recovery" process of suspended materials, the control of parameters depends entirely on the operator's experience. Summary of the invention

[0006] The purpose of the present invention is to provide a method for judging and treating the position of suspended material in a blast furnace, thereby improving the accuracy of judging the position of suspended material, performing differentiated treatment according to the position of suspended material, realizing rapid and stable recovery of the furnace condition after suspended material, and reducing the adverse effects of suspended material on the furnace condition of the blast furnace.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A method for determining a blast furnace overhanging material position, comprising:

[0009] 1) If one or more of the following features appear, it is used to determine that the location of suspended material in the blast furnace is located at the upper part of the blast furnace body, as follows:

[0010] a. The static pressure at one or more points on the upper part of the blast furnace body increases to a peak value, the pressure increase rate is >0.5KPa / s, and the peak time appears earlier than the hot blast pressure increase time;

[0011] b. Both the static pressure on the upper part of the blast furnace shaft and the static pressure on the blast furnace bosh appear at peak values, but the peak value of the static pressure on the upper part of the blast furnace shaft appears earlier than the time when the static pressure on the blast furnace bosh increases;

[0012] c. The static pressure on the upper part of the blast furnace shaft and the static pressure on the blast furnace bosh both reach peak values, but the rate of increase of the static pressure on the upper part of the blast furnace shaft is greater than the rate of increase of the static pressure on the blast furnace bosh;

[0013] 2) The following features appear, which are used to judge that the location where the blast furnace has suspended material is located at the lower part of the blast furnace body, as follows:

[0014] The static pressure of the blast furnace bosh or the hot blast pressure increases to a peak value, and the pressure increase rate is >0.5KPa / s, while the static pressure of the blast furnace body decreases or has no obvious change.

[0015] The method for treating the suspended material part of the blast furnace where the current blast furnace operation status is determined to be suspended material phenomenon includes:

[0016] S1. If it is upper hanging material, control the wind speed and increase the coke to maintain the shape of the material surface;

[0017] S2. Choose different ways to reduce wind and "sit on the material" according to the different parts of the hanging material;

[0018] S3. Quantitative calculation of the net coke weight to be supplemented;

[0019] S4. Determine the material distribution method to increase the net focus.

[0020] In S1, the wind speed is controlled as follows:

[0021] Reduce the blast furnace inlet air volume, the value is: 100 ~ 500m3 / min, the blast furnace top pressure setting value decreases with the reduction of air volume, and the top setting value is reduced to P2. The formula is as follows:

[0022]

[0023] In formula ①, P2 represents the set value of the top pressure of the blast furnace after the air reduction, in kPa, and P1 represents the set value of the top pressure of the blast furnace before the air reduction, in kPa; P 热2 It indicates the hot air pressure value after the blast furnace is reduced, in kpa; It indicates the hot blast pressure value before blast reduction in the blast furnace, in kPa; η indicates the top pressure coefficient of the suspended material furnace condition, in dimensionless units, with a value of 0.3 to 0.8.

[0024] In S1, the method of increasing the coke to maintain the shape of the material surface includes method 1 and method 2, and the contents are as follows:

[0025] Method 1: The single-ring charging method is adopted for the net coke charging side. The tilting angle of the single-ring charging is the weighted average of the tilting angles and the number of charging circles of all the rings except the center coke in the current charging matrix of the blast furnace.

[0026] Method 2: The single-ring material distribution method is adopted for the net coke distribution, and the tilting angle of the single-ring material distribution is α:

[0027] Firstly, based on the infrared imaging of the furnace top material surface, determine the location of point Q where the temperature drop before and after the material is suspended is the largest in the circumferential section of the furnace throat;

[0028] The distance r between point Q and the center of the furnace throat is obtained according to the material placement formula as follows:

[0029]

[0030] In formula ②: t is the falling time of the charge after leaving the chute, in seconds; v2 is the speed of the charge when leaving the chute, in meters / seconds; l is the effective length of the chute, in meters; α is the inclination angle of the chute, in degrees; w is the angular velocity of the chute, in rad / s;

[0031]

[0032] In formula ③: v0 is the initial velocity of the charge after it falls into the chute, in m / s; λ is the velocity loss coefficient; v2 is the velocity of the charge when it leaves the chute, in m / s; g is the acceleration of gravity, in m / s2; l is the effective length of the chute, in m; α is the inclination angle of the chute, in degrees; μ is the friction coefficient between the charge and the chute; w is the angular velocity of the chute, in rad / s;

[0033]

[0034] In formula ④: v0 is the material flow velocity before falling into the chute, in m / s; F is the measured flow rate of the furnace charge when it leaves the throttle valve, in m3 / s; S is the projection area of ​​the throttle valve, in m2; l S is the length of the throttle valve perimeter, in m; d0 is the average particle size of the charge, in m;

[0035] Calculate the tilt angle α corresponding to the landing radius r of point Q;

[0036] Finally, according to the tilting angle α, the single ring of coke is distributed on the ring where the point with the maximum temperature drop value (i.e., point Q) is located.

[0037] In S2, during the "charging" process, the blast furnace top pressure is maintained 10% to 30% higher than the top pressure during conventional charging and reducing air flow by reducing the manual opening of the TRT bypass valve group on the blast furnace top;

[0038] According to the different positions of the hanging materials, different methods of reducing the air flow when sitting are adopted to speed up the process of returning the air to the blast furnace. The contents are as follows: 1) When the hanging material position is the upper hanging material:

[0039] Change the blast furnace top pressure regulation to manual, and set the valve position opening to 55%-85% of the TRT manual valve position opening when the blast furnace is in the non-accident wind down state;

[0040] Use the vent valve to reduce the air volume to 30%-80% of the full air state at one time, and end when the stagnant probe shows material collapse;

[0041] After the material collapse, quickly return air at 200-400m3 / min to speed up the recovery of furnace conditions, and then gradually add air to restore the air volume;

[0042] 2) When the suspension part is the lower suspension:

[0043] Change the blast furnace top pressure regulation to manual, and set the valve position opening to 40% to 60% of the TRT manual valve position opening when the blast furnace is in a non-accidental wind-down and wind-reduction state;

[0044] Use the vent valve to reduce the air volume to 30%-80% of the full air state at one time, and end when the stagnant probe shows material collapse;

[0045] Do not return air directly after material collapse. Wait until the probe descends evenly without stagnation and the material slides for more than 5-10 minutes before gradually adding air to restore the air volume.

[0046] In S3, the net coke weight is quantitatively calculated as follows:

[0047]

[0048] In formula ⑤, M 焦It indicates the total mass of net coke to be replenished after the suspension, in tons (t); L2 indicates the deepest material line detected by each probe after the collapse, in meters (m); L1 indicates the normal set material line of the blast furnace, in meters (m); T2 indicates the maximum value of the blast furnace top temperature point during the blast furnace collapse, in degrees Celsius (℃); T1 indicates the maximum value of the blast furnace top temperature point before the blast furnace collapse, in degrees Celsius (℃); a indicates the collapse depth coke replenishment coefficient, which is determined by the daily fuel ratio of the blast furnace and the quality of coke, with a value range of 0.5-1.5, and a dimensionless unit; b indicates the pipeline stroke coke replenishment coefficient, which is determined by the daily fuel ratio of the blast furnace and the quality of coke, with a value range of 0.5-1.7, and a dimensionless unit; m1 indicates the batch weight of coke charged to the blast furnace before the collapse, in tons / batch;

[0049] Through formula ⑤, the number of net coke batches is obtained, and the formula is as follows:

[0050] N=M 焦 / m1 ⑥

[0051] In formula ⑥, N represents the number of net coke batches, N is an integer, and the unit is batch; the net coke weight of each batch is set to M 焦 / N tons, so that the total weight of N batches of net coke is M 焦 .

[0052] In S4, the calculation formula for adding net coke in formula ④ is as follows:

[0053] M 焦 =A+B ⑦

[0054] A=(L2-L1) / 0.5·a·m1⑧

[0055] B=(T2-T1) / 150·b·m1 ⑨

[0056] In formulas ⑦-⑨, A represents the net coke of the replenishment line of collapsed material, and B represents the net coke of the pipeline journey heat source;

[0057] Add the net focus distribution method, the content is as follows:

[0058] 1) Upper hanging material, the calculation formula is as follows:

[0059] NA=A / m1 ⑩

[0060] In formula ⑩, NA represents the number of batches of net coke of the collapsing material replenishment line, that is, it represents how many batches or tank net cokes are needed to be added to the collapsing material replenishment line. NA is an integer, and the unit is batch. The net coke of the tank of the net coke of the collapsing material replenishment line is distributed according to the coke ring position inclination of the original distribution matrix of the blast furnace. The net coke B part of the pipeline stroke supplementary heat source is distributed according to the original matrix ring position of the blast furnace minus the center ring position. The net coke B part of the pipeline stroke supplementary heat source is distributed in the annular belt area of ​​the blast furnace.

[0061] 2)Lower hanging material

[0062] When N≥3, take 1-2 batches of clean coke and place them at the center angle, and the rest of the clean coke shall be placed in the original matrix ring position;

[0063] When N<3, each batch of clean coke is distributed according to the original distribution matrix.

[0064] The center angle is the tilt angle of the ring where the center of the fabric matrix is ​​focused.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] 1. Determine the location of overhanging materials in the blast furnace (the overhanging materials include the upper overhanging materials and the lower overhanging materials), identify the overhanging materials, and take targeted measures to speed up the furnace condition recovery process and the stability and economy of the furnace condition after recovery. Determining the overhanging materials location is a necessary condition for analyzing the causes of overhanging materials and taking correct and targeted measures to adjust the furnace condition in the future;

[0067] 2. According to different parts of suspended materials, different furnace condition recovery methods, parameter setting rules and coke adding methods are invented to minimize the loss of suspended materials and improve the recovery speed of blast furnace after suspended materials;

[0068] 3. In the upper hanging material, maintaining the material surface shape can speed up the subsequent air addition process, reduce the loss of pig iron production, and reduce the possibility of secondary collapse and sliding accidents;

[0069] 4. Choose different ways to reduce air flow and "sit on the material" according to the different parts of the suspended material. According to the different parts of the suspended material and their different characteristics, adopt corresponding air reduction methods to speed up the furnace condition recovery process as much as possible and optimize the suspended material recovery process;

[0070] 5. According to the specific collapse depth L2-L1, the weight of net coke to be supplemented is quantified and calculated. According to the change in furnace top temperature T2-T1, the degree of gas flow pipeline is quantified, and the net coke weight required for pipeline travel is calculated. The net coke weight to be supplemented is calculated comprehensively to avoid excessive or insufficient fuel caused by adding too much or too little coke, and the secondary fluctuations in the subsequent furnace conditions caused by this;

[0071] 6. Determine the method of placing additional net coke, innovatively differentiate between net coke A for replenishing collapsed materials and net coke B for replenishing heat source in pipeline travel. The placing method is more scientific, effectively improves the actual effect of coke, and maximizes the effect of net coke on replenishing blast furnace heat and improving the permeability of the material layer;

[0072] 7. Reduce the adverse effects of suspended materials on the blast furnace condition and avoid long-term abnormal condition of the blast furnace. DETAILED DESCRIPTION

[0073] The present invention is described in detail below, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0074] The following examples are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0075] [Example 1]

[0076] Take a steel plant with a height of 3200m 3 Take the blast furnace as an example. When the hot air pressure of the blast furnace increases from 413kpa to 417kpa, hanging material occurs and the probe stops. The method for judging the location of hanging material in the blast furnace is as follows:

[0077] Determine the location of the hanging material

[0078] Analysis of the static pressure value of the blast furnace body: It was found that there were 4 detection points for the static pressure of the furnace body, which were located at the 10th cooling wall and the lower part of the furnace body. Among them, 3 detection points of the static pressure of the furnace body increased from 280kpa to 283kpa, which met the following characteristics:

[0079] ① The static pressure of the furnace body peaks, with a rising rate of 0.6 kpa / s, 0.6 kpa / s>0.5 kPa / s, and the static pressure of the furnace body rises earlier than the wind pressure.

[0080] ② Both the static pressure on the upper part of the furnace body and the static pressure on the furnace belly reach peak values, but the peak value of the static pressure on the upper part of the furnace body occurs earlier than the time when the static pressure on the furnace belly increases.

[0081] ③ The static pressure increase rate of the upper part of the furnace body is greater than the static pressure increase rate of the furnace bosh. Among the two static pressure curves, the increasing slope of the static pressure curve of the furnace body is obviously greater than that of the static pressure curve of the furnace bosh, or the pressure increase rate is calculated by the pressure increase value / pressure increase time.

[0082] As long as the static pressure of the furnace body meets one of the three characteristics, it can be determined that the suspended material is the upper suspended material.

[0083] If the static pressure of the furnace belly or the hot air pressure increases to a peak value, and the pressure increase rate is >0.5KPa / s, while the static pressure of the furnace body decreases or has no obvious change, it can be clearly determined that there is hanging material at the bottom.

[0084] The treatment method of the suspended material part of the blast furnace is as follows:

[0085] Step 1:

[0086] Suspended material on top, controls wind speed and increases the surface shape of the material. Coke:

[0087] After determining the location of the suspended material, the blast furnace immediately uses the electric fan to reduce the blast furnace inlet air volume by 400m 3 / min, the blast furnace air pressure dropped from 417kpa to 392kpa; the current furnace top pressure is in automatic adjustment state, the set value is 235kpa, and the blast furnace is reduced by 400m 3 The top pressure setting value of the blast furnace inlet air volume should be reduced by 18kpa according to the conventional material sitting and reducing air operation, and is set to 217kpa; the drop value of the furnace top pressure after reducing air by the patent method is only 30-80% of the drop value of the conventional material sitting and reducing air. The top pressure coefficient is selected as 0.5, then according to formula ①, as shown below:

[0088]

[0089] In formula ①, P2 represents the set value of the furnace top pressure after the blast furnace is reduced, in kPa, and P1 represents the set value of the blast furnace top pressure before the blast furnace is reduced, in kPa. In this example, P1 = 235 kPa; P 热2 It indicates the hot air pressure value after the blast furnace is reduced, in kpa; P 热1 It indicates the hot blast pressure value before blast reduction in the blast furnace, in kPa; η indicates the top pressure coefficient of the suspended material furnace condition, in dimensionless units, with a value of 0.3 to 0.8.

[0090] According to formula ①, P2=235(1-0.5+0.5*392 / 417)=227kpa, the furnace top pressure is set to 227kpa.

[0091] Since the suspended material is located at the upper part, 1 to 2 batches of coke are needed to maintain the material surface shape, so as to accelerate the subsequent recovery of the blast furnace condition.

[0092] The method of adding coke to maintain the shape of the material surface can be method 1 or method 2:

[0093] Method 1: Use single ring fabric

[0094] The tilting angle is the weighted average of the tilting angles and number of distribution circles of all rings except the center focus in the current distribution matrix of the blast furnace, see Table 1.

[0095] Table 1 The material distribution matrix used when suspending material in a 3200m3 blast furnace of a steel plant

[0096]

[0097] According to the above matrix method 1, the single-ring distribution tilting angle is: (41.8°*6+39.2°*7+36.5°*5+33.7°*4+30.8°*4) / 26=37.1°. The batch of net coke is distributed into the furnace in a single-ring at a tilting angle of 37.1°.

[0098] Method 2: Single ring fabric method

[0099] The tilting angle is: based on the infrared imaging of the furnace top material surface, first determine the position of the point (Q point) where the temperature value drops the most before and after the suspended material in the circular material surface of the furnace throat; then calculate the chute tilting angle corresponding to L based on the radius distance L between the Q point position and the furnace throat center; finally, according to the chute tilting angle, distribute the single ring of coke on the circular ring where the point with the maximum temperature drop is located.

[0100] The specific operations are as follows:

[0101] The infrared imaging of the blast furnace roof shows that the temperature at the location with a radius of r = 3.6m from the center of the furnace throat drops from 132°C to 71°C, with the largest temperature drop; according to the material placement formula, it is as follows:

[0102] The distance r between point Q and the center of the furnace throat is obtained according to the material placement formula as follows:

[0103]

[0104] In formula ②: t is the falling time of the charge after leaving the chute, in seconds; v2 is the speed of the charge when leaving the chute, in meters / seconds; l is the effective length of the chute, in meters; α is the inclination angle of the chute, in degrees; w is the angular velocity of the chute, in rad / s;

[0105]

[0106] In formula ③: v0 is the initial velocity of the charge after it falls into the chute, in m / s; λ is the velocity loss coefficient; v2 is the velocity of the charge when it leaves the chute, in m / s; g is the acceleration of gravity, in m / s2; l is the effective length of the chute, in m; α is the inclination angle of the chute, in degrees; μ is the friction coefficient between the charge and the chute; w is the angular velocity of the chute, in rad / s;

[0107]

[0108] In formula ④: v0 is the material flow velocity before falling into the chute, in m / s; F is the measured flow rate of the furnace charge when it leaves the throttle valve, in m3 / s; S is the projection area of ​​the throttle valve, in m2; l S is the length of the throttle valve perimeter, in m; d0 is the average particle size of the charge, in m;

[0109] It is calculated that the corresponding tilting angle α when the landing point radius r = 3.6m is 35°. The tilting angle of the blast furnace chute is manually set to 35°, and the clean coke is distributed in a single ring into the blast furnace, so that the coke that maintains the shape of the material surface is accurately distributed in the circular area where the Q point in the maximum temperature drop area is located.

[0110] In this case, since the infrared imaging of the furnace top showed an obvious temperature drop area, we specifically chose to add one batch of coke to maintain the shape of the material surface, and adopted method 2 to add it.

[0111] Step 2:

[0112] According to the upper hanging material, the wind reduction "sitting material" is carried out:

[0113] Change the furnace top pressure regulation to manual. When the blast furnace is not shut down or reduced due to accidents, the valve opening of the TRT bypass valve group is set to 100; therefore, after reducing the air, the blast furnace TRT bypass valve group needs to be manually opened to 55% to 85% of the normal opening, so the valve opening is set to 60 to ensure that the actual flow rate in each area of ​​the furnace is greatly reduced during the material sitting process. After stopping oxygen enrichment, coal injection, and water pumping on the furnace top according to the normal material sitting procedure, use the vent valve to reduce the air volume to 30% to 0% of the full air state at one time, until the stagnant probe shows the end of the material collapse. After the material collapse, quickly return the air for 200 to 400 m 3 / min to speed up the air adding process and then gradually add air to restore the air volume.

[0114] Step 3:

[0115] Determine the increase in net coke weight by calculation:

[0116] The increase in net coke volume is determined by formula ②. After the blast furnace is “stood” and the air is reduced, the maximum depth of the material line is 3 # The probe is 4.6m, the material line depth before air reduction is 1.5m, and there is an obvious pipeline travel during the collapse. The highest temperature of the four-point furnace top increases from 133℃ before the collapse to 389℃. According to formula ②, L2=4.6m(m); L1=1.5m(m); T2=389℃; T1=133℃; the batch weight of coke charged to the blast furnace is 15.37 tons(t); the blast furnace increases the net coke weight based on the empirical collapse and pipeline coke supplement coefficients of a=0.6 and b=0.7, respectively, and the formula is as follows:

[0117]

[0118]

[0119] Calculate the required increase in net focal length M 焦 is 75.5 tons, then the number of net coke batches is N = 75.5 / 15.37 = 4.9, rounded to 5 batches,

[0120] N=M 焦 / m1 ⑥

[0121] Calculated by N=5, the net coke weight of each batch is set to M 焦 / N tons, then the net coke batch weight of each batch is 75.5 / 5=15.1 tons;

[0122] The actual increase in net coke was 5 batches, each batch was 15.1 tons, with a total weight of 75.5 tons.

[0123] Step 4:

[0124] Determine the material distribution method to increase net focus:

[0125] The net coke weight M calculated in formula ② is 焦 It is divided into two parts:

[0126] A=(L2-L1) / 0.5·a·m1=3.72×15.37=57.18 tons

[0127] B = (T2-T1) / 150·b·m1=18.36 tons

[0128] The specific distribution method of upper suspended material net coke is:

[0129] Upper hanging material: N A =A / m1=57.18 / 15.37=3.72, N A Take the integer and take 4 batches; divide part A into N A Net coke in the tank, according to the original blast furnace distribution matrix (Table 1), part B N B =NN A =5-4=1 batch of clean coke is deducted from the center ring position according to the matrix ring position in Table 1 (converted to Table 2); the clean coke part B (1 batch) is distributed in the annular belt area of ​​the blast furnace.

[0130] Table 2 Net coke distribution matrix of supplementary heat source in pipeline travel of 3200m3 blast furnace in a steel plant

[0131]

[0132] If the lower hanging material occurs: Since N≥3, the distribution method of the clean coke can be to distribute 1 to 2 batches of clean coke at the tilted position at the center angle (10°), and the remaining clean coke can be distributed according to the normal matrix in Table 1.

[0133] There are 3 to 10 batches of ore between the above batches of clean coke, and then the air is returned according to the normal return air procedure of the blast furnace.

[0134] The present invention determines the suspended material position of the blast furnace (the suspended material position includes the upper suspended material and the lower suspended material), clarifies the suspended material position, and takes different targeted air-adding recovery measures to accelerate the furnace condition recovery process and the furnace condition stability and economy after recovery. The clear determination of the suspended material position is a necessary condition for analyzing the cause of the suspended material and taking correct targeted measures to adjust the furnace condition later. Different furnace condition recovery methods, parameter setting rules, and coke adding methods are invented for different suspended material positions to minimize the suspended material loss and improve the recovery speed of the blast furnace after suspended material. In the upper suspended material, maintaining the material surface shape can accelerate the subsequent air-adding process, reduce the pig iron production loss, and reduce the possibility of secondary collapse and sliding accidents. Different methods are selected according to different suspended material positions to reduce air flow and "sit on the material". According to different suspended material positions, corresponding air-reduction measures are taken according to their different characteristics. The method can speed up the furnace condition recovery process as much as possible and optimize the suspended material recovery process; according to the specific collapsed material depth L2-L1, the weight of the net coke for supplementary collapsed material is quantitatively calculated, according to the furnace top temperature change T2-T1, the degree of the gas flow pipeline is quantified, and the net coke weight required for the pipeline stroke is calculated, and the net coke weight for supplementary net coke is comprehensively calculated, so as to avoid excessive or insufficient fuel caused by adding too much or too little coke, and secondary fluctuations of a series of subsequent furnace conditions caused by this; determine the distribution method for increasing net coke, innovatively distinguish between the net coke A for supplementary collapsed material and the net coke B for supplementary heat source in the pipeline stroke, the distribution method is more scientific, effectively improves the actual effect of coke, and maximizes the effect of net coke on supplementing blast furnace heat and improving the permeability of the material layer; reduce the adverse effect of suspended materials on the blast furnace condition, and avoid long-term abnormal condition of the blast furnace.

Claims

1. A method for determining the location of suspended material in a blast furnace, characterized in that: include: 1) If one or more of the following features appear, it is used to determine that the location of suspended material in the blast furnace is located at the upper part of the blast furnace body, as follows: a. The static pressure at one or more points on the upper part of the blast furnace body increases to a peak value, the pressure increase rate is >0.5KPa / s, and the peak time is earlier than the hot blast pressure increase time; b. Both the static pressure on the upper part of the blast furnace shaft and the static pressure on the blast furnace bosh appear at peak values, but the peak value of the static pressure on the upper part of the blast furnace shaft appears earlier than the time when the static pressure on the blast furnace bosh increases; c. The static pressure on the upper part of the blast furnace shaft and the static pressure on the blast furnace bosh both reach peak values, but the rate of increase of the static pressure on the upper part of the blast furnace shaft is greater than the rate of increase of the static pressure on the blast furnace bosh; 2) The following features appear, which are used to judge that the location where the blast furnace has suspended material is located at the lower part of the blast furnace body, as follows: The static pressure of the blast furnace bosh or the hot blast pressure increases to a peak value, and the pressure increase rate is >0.5KPa / s, while the static pressure of the blast furnace body decreases or has no obvious change.

2. A method for processing a blast furnace suspended material portion where the current blast furnace operation status is determined as a suspended material phenomenon by the judgment method according to claim 1, characterized in that: include: S1. If it is upper hanging material, control the wind speed and increase the coke to maintain the shape of the material surface; S2. Choose different ways to reduce wind and "sit material" according to different parts of the hanging material; S3. Quantitative calculation of the net coke weight to be supplemented; S4. Determine the material distribution method to increase the net focus.

3. The method for treating the suspended material part of a blast furnace according to claim 2, characterized in that: In S1, the wind speed control is as follows: Reduce the blast furnace inlet air volume, the value is: 100 ~ 500m3 / min, the blast furnace top pressure setting value decreases with the reduction of air volume, and the top setting value is reduced to P2. The formula is as follows: In formula ①, P2 represents the set value of the top pressure of the blast furnace after the air reduction, in kPa, and P1 represents the set value of the top pressure of the blast furnace before the air reduction, in kPa; P 热2 It indicates the hot air pressure value after the blast furnace is reduced, in kpa; P 热 1 represents the hot air pressure value before blast furnace air reduction, in kPa; η represents the top pressure coefficient of suspended material furnace condition, in dimensionless unit, with a value of 0.3 to 0.

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4. The method for treating the suspended material portion of a blast furnace according to claim 2, characterized in that: In S1, the method of increasing the coke to maintain the shape of the material surface includes method 1 and method 2, and the contents are as follows: Method 1: The single-ring charging method is adopted for the net coke charging side. The tilting angle of the single-ring charging is the weighted average of the tilting angles and the number of charging circles of all the rings except the center coke in the current charging matrix of the blast furnace. Method 2: The single-ring material distribution method is adopted for the net coke distribution, and the tilting angle of the single-ring material distribution is α: Firstly, based on the infrared imaging of the furnace top material surface, determine the location of point Q where the temperature drop before and after the material is suspended is the largest in the circumferential section of the furnace throat; The distance r between point Q and the center of the furnace throat is obtained according to the material placement formula as follows: In formula ②: t is the falling time of the charge after leaving the chute, in seconds; v2 is the speed of the charge when leaving the chute, in meters / seconds; l is the effective length of the chute, in meters; α is the inclination angle of the chute, in degrees; w is the angular velocity of the chute, in rad / s; In formula ③: v 0 is the initial velocity of the charge after it falls into the chute, in m / s; λ is the velocity loss coefficient; v2 is the velocity of the charge when it leaves the chute, in m / s; g is the acceleration of gravity, in m / s2; l is the effective length of the chute, in m; α is the inclination angle of the chute, in degrees; μ is the friction coefficient between the charge and the chute; w is the angular velocity of the chute, in rad / s; In formula ④: v 0 is the material flow velocity before falling into the chute, in m / s; F is the measured flow rate of the furnace charge when it leaves the throttle valve, in m3 / s; S is the projection area of ​​the throttle valve, in m2; l S is the side length of the throttle valve, in m; d0 is the average particle size of the charge, in m; Calculate the tilt angle α corresponding to the landing radius r of point Q; Finally, according to the tilting angle α, the coke single ring is distributed on the ring where the point with the maximum temperature drop value (i.e., point Q) is located.

5. The method for treating the suspended material portion of a blast furnace according to claim 2, characterized in that: In S2, during the "seating material" process, the blast furnace top pressure is maintained 10% to 30% higher than the top pressure during conventional sitting material and reducing wind by reducing the manual opening of the TRT bypass valve group at the blast furnace top; According to the different positions of the hanging materials, different methods of reducing the air flow during the material sitting are adopted to speed up the blast furnace return air process, as follows: 1) When the suspension part is the upper suspension: Change the blast furnace top pressure regulation to manual, and set the valve position opening to 55%-85% of the TRT manual valve position opening when the blast furnace is in the non-accident wind down state; Use the vent valve to reduce the air volume to 30%-80% of the full air state at one time, and end when the stagnant probe shows material collapse; After the material collapse, quickly return air at 200-400m3 / min to speed up the recovery of furnace conditions, and then gradually add air to restore the air volume; 2) When the suspension part is the lower suspension: Change the blast furnace top pressure regulation to manual, and set the valve position opening to 40% to 60% of the TRT manual valve position opening when the blast furnace is in a non-accidental wind-down and wind-reduction state; Use the vent valve to reduce the air volume to 30%-80% of the full air state at one time, and end when the stagnant probe shows material collapse; Do not return air directly after material collapse. Wait until the probe descends evenly without stagnation and the material slides for more than 5-10 minutes before gradually adding air to restore the air volume.

6. The method for treating the suspended material portion of a blast furnace according to claim 2, characterized in that: In S3, the quantitative calculation of the net coke weight is as follows: In formula ⑤, M 焦 It indicates the total mass of net coke to be replenished after the suspension, in tons (t); L2 indicates the deepest material line detected by each probe after the collapse, in meters (m); L1 indicates the normal set material line of the blast furnace, in meters (m); T2 indicates the maximum value of the blast furnace top temperature point during the blast furnace collapse, in degrees Celsius (℃); T1 indicates the maximum value of the blast furnace top temperature point before the blast furnace collapse, in degrees Celsius (℃); a indicates the collapse depth coke replenishment coefficient, which is determined by the daily fuel ratio of the blast furnace and the quality of coke, with a value range of 0.5-1.5, and a dimensionless unit; b indicates the pipeline stroke coke replenishment coefficient, which is determined by the daily fuel ratio of the blast furnace and the quality of coke, with a value range of 0.5-1.7, and a dimensionless unit; m1 indicates the batch weight of coke charged to the blast furnace before the collapse, in tons / batch; Through formula ⑤, the number of net coke batches is obtained, and the formula is as follows: N=M 焦 / m1 ⑥ In formula ⑥, N represents the number of net coke batches, N is an integer, and the unit is batch; the net coke weight of each batch is set to M 焦 / N tons, so that the total weight of N batches of net coke is M 焦 .

7. The method for treating the suspended material portion of a blast furnace according to claim 2, characterized in that: In S4, the calculation formula for adding net coke in formula ④ is as follows: M 焦 =A+B ⑦ A= (L2-L1) / 0.5·a·m1⑧ B= (T2-T1) / 150·b·m1 ⑨ In formulas ⑦-⑨, A represents the net coke of the replenishment line of collapsed material, and B represents the net coke of the pipeline journey heat source; The material distribution method for increasing the net coke is as follows: 1) Upper hanging material, the calculation formula is as follows: NA=A / m1 ⑩ In formula ⑩, NA represents the number of batches of net coke of the collapsing material replenishment line, that is, it represents how many batches or tank net cokes are needed to be added to the collapsing material replenishment line. NA is an integer, and the unit is batch. The net coke of the tank of the net coke of the collapsing material replenishment line is distributed according to the coke ring position inclination of the original distribution matrix of the blast furnace. The net coke B part of the pipeline stroke supplementary heat source is distributed according to the original matrix ring position of the blast furnace minus the center ring position. The net coke B part of the pipeline stroke supplementary heat source is distributed in the annular belt area of ​​the blast furnace. 2)Lower hanging material When N≥3, take 1-2 batches of clean coke and place them at the center angle, and the rest of the clean coke shall be placed in the original matrix ring position; When N<3, each batch of clean coke is distributed according to the original distribution matrix.

8. The method for treating the suspended material area of ​​a blast furnace according to claim 7, characterized in that: The center angle is the tilt angle of the ring position where the center of the cloth matrix is ​​focused.

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