Blast furnace condition evaluation method based on radial hearth temperature measurement at the tuyere plane of a blast furnace

Abstract

The present invention discloses a method for evaluating the blast furnace condition based on the radial measurement of the hearth temperature in the tuyere plane of the blast furnace. The evaluation method includes the following steps: S1. Take tuyere coke from inside the blast furnace during the blast furnace shutdown time; S2. Separate the slag and iron from the sample to obtain the tuyere coke, measure the average particle size l of the tuyere coke. l , the average particle size l2 of the charged coke is measured in advance before sampling, the mass percentage σ of the coke with a particle size less than 5 mm in the tuyere coke is measured, and the hearth activity index η of the sample is calculated; S3. Compare the hearth activity index η obtained in step S2 with the standard hearth activity index η0 measured in advance. If η < 80%η0, it is determined that the blast furnace hearth is inactive; if η ≥ 80%η0, it is determined that the blast furnace hearth is active. The present invention characterizes the hearth activity with parameters such as hearth temperature and the particle size of the dead stock column, proposes a calculation method for the hearth activity index, and quickly and accurately determines whether the hearth is active.

Description

Technical Field

[0001] The present invention relates to the field of blast furnace ironmaking, and particularly to a method for evaluating the blast furnace condition by measuring the radial temperature of the hearth at the tuyere plane of the blast furnace. Background Art

[0002] A blast furnace is a huge reactor, and physical and chemical reactions such as the coke dissolution reaction and the iron ore reduction reaction are all carried out at high temperatures. Temperature is an important parameter of the blast furnace. The theoretical combustion temperature and the hearth thermal state have crucial effects on aspects such as the position of the softening-melting zone, the fluidity of slag and iron, and the cracking of coke.

[0003] The temperature measurement related to the blast furnace is mainly carried out in the following ways: (1) Direct measurement of the top gas temperature of the blast furnace. The temperature measurement points are arranged in the rising pipe of the top gas of the blast furnace. The top temperature during normal smelting of the blast furnace is about 150°C. (2) Direct measurement of the hot metal temperature. The hot metal flows out of the blast furnace iron notch, passes through the main runner in the tapping yard, and infrared or thermocouple temperature measurement is used, and the temperature is about 1500°C. (3) Furnace temperature simulation digital simulation, calculating the theoretical combustion temperature of the tuyere raceway area, the temperature field distribution in the blast furnace, etc. through relevant parameters of the blast furnace. (4) Direct measurement of the edge temperature of the tuyere raceway area through the infrared of the blast furnace tuyere peephole. (5) Determining the graphitization degree of coke through blast furnace dissection and indirectly calculating the temperature distribution in the blast furnace. (6) Measuring the temperature of the blast furnace cooling stave.

[0004] Problems existing in the above existing measurement methods:

[0005] (1) Measurement methods such as the top gas temperature of the blast furnace and the temperature of the cooling stave can only measure the top or edge temperature in the blast furnace and cannot directly measure the temperature of the materials in the blast furnace;

[0006] (2) Calculating the temperature distribution in the blast furnace through the graphitization degree of coke belongs to indirect calculation and there are temperature calculation errors;

[0007] (3) There are also temperature calculation errors in the simulation calculation.

[0008] The research on tuyere coke sampling is one of the hotspots in blast furnace ironmaking research. It can judge the working condition of the hearth in the blast furnace and the liquid permeability of the dead stock column. The multi-point mobile blast furnace tuyere coke sampler with the patent number CN201420532030.2 takes out coke by impacting and vibrating through the coke sampling pipe, but it cannot synchronously measure the internal temperature of the blast furnace during sampling.

[0009] Therefore, it is necessary to develop a method for synchronously measuring the blast furnace temperature during tuyere coke sampling and evaluating the blast furnace condition by analyzing characteristic parameters such as the blast furnace temperature and the tuyere coke particle size. Summary of the Invention

[0010] The object of the present invention is to solve the deficiencies of the above-mentioned background technology, and provide a method for evaluating the blast furnace condition based on the radial measurement of the hearth temperature in the plane of the tuyere of the blast furnace. The temperature of the blast furnace is measured synchronously during the sampling of the tuyere coke, and the condition of the blast furnace is judged by analyzing the characteristic parameters such as the blast furnace temperature and the particle size of the tuyere coke.

[0011] The technical solution of the present invention is as follows: A method for evaluating the blast furnace condition based on the radial measurement of the hearth temperature in the plane of the tuyere of the blast furnace, characterized by including the following steps:

[0012] S1. Take tuyere coke from the blast furnace during the blast furnace shutdown time. The sampling process includes: inserting the sampling device radially along the plane of the tuyere into the hearth until the front end enters at least the center of the dead stock column. After the sample enters the sampling device, measure the temperature Tp at the center of the dead stock column and the temperature Tb at the edge of the hearth through the thermocouple pre-arranged in the sampling device. Finally, withdraw the sampling device from the blast furnace to complete the sampling.

[0013] S2. Separate the slag and iron from the sample to obtain the tuyere coke, and measure the average particle size l of the tuyere coke l , the average particle size l2 of the charged coke is measured in advance before sampling. Measure the mass percentage of coke with a particle size less than 5 mm in the tuyere coke, calculate the temperature difference ΔT between the temperature Tb at the edge of the hearth and the temperature Tp at the center of the dead stock column, calculate the average particle size l of the tuyere coke l The ratio λ of the average particle size l2 of the charged coke, then the hearth activity index η of the sample,

[0014]

[0015] λ—l l / l2, the ratio of the average particle size l of the tuyere coke l to the average particle size l2 of the charged coke;

[0016] Tp—The temperature Tp at the center of the dead stock column, unit: °C;

[0017] ΔT—Tb - Tp, the temperature difference between the temperature Tb at the edge of the hearth and the temperature Tp at the center of the dead stock column, unit: °C;

[0018] σ—The mass percentage of coke with a particle size less than 5 mm in the tuyere coke;

[0019] S3. Compare the hearth activity index η obtained in step S2 with the standard hearth activity index η0 measured in advance,

[0020] If η < 80%η0, it is judged that the hearth of the blast furnace is inactive;

[0021] If η ≥ 80%η0, it is judged that the hearth of the blast furnace is active.

[0022] Preferably, in step S1, after the sample enters the sampling device, it stays for 2 to 10 minutes, and then the central temperature Tp of the dead stock column and the temperature Tb at the hearth edge are measured by thermocouples pre-arranged in the sampling device.

[0023] Preferably, in step S3, the standard hearth activity index η0 is obtained by repeatedly performing steps S1 - S2 multiple times under normal hearth conditions to obtain the hearth activity index and taking the average of all hearth activity indices under normal hearth conditions.

[0024] Preferably, in step S1, the sampling device includes a sampling tube with a solid tip at the front end. The sampling tube has an opening at the top and an upper cover that can be opened and closed at the opening. A plurality of partitions are axially spaced in the inner cavity of the sampling tube to prevent the sample from moving when being withdrawn. A plurality of thermocouples are provided on the sampling tube for measuring the temperature at multiple radial positions of the hearth. Each thermocouple includes a hot end and a cold end connected in the front - rear direction. The cold end of each thermocouple is embedded in the wall of the sampling tube, and the hot ends of multiple thermocouples are axially spaced along the sampling tube.

[0025] Further, the hot ends of multiple thermocouples are axially spaced in the inner cavity of the sampling tube; or the hot end of one of the multiple thermocouples enters the solid tip, and the hot ends of the remaining thermocouples are axially spaced in the inner cavity of the sampling tube.

[0026] Furthermore, the hot ends entering the inner cavity of the sampling tube are correspondingly arranged inside the partition or are connected to the partition in a forward - tilted manner.

[0027] Furthermore, when the hot ends entering the inner cavity of the sampling tube are connected to the partition in a forward - tilted manner, the hot ends entering the inner cavity of the sampling tube are located inside a support rod that is forward - tilted in the inner cavity of the sampling tube, and the front end of the support rod is correspondingly connected to the partition.

[0028] Further, an auxiliary rod is provided between adjacent partitions. The hot ends entering the inner cavity of the sampling tube are correspondingly arranged inside the partition and / or the auxiliary rod, or the hot ends entering the inner cavity of the sampling tube are connected to the partition and / or the auxiliary rod in a forward - tilted manner.

[0029] Furthermore, when the hot ends entering the inner cavity of the sampling tube are connected to the partition and / or the auxiliary rod in a forward - tilted manner, the hot ends entering the inner cavity of the sampling tube are located inside a support rod that is forward - tilted in the inner cavity of the sampling tube, and the front end of the support rod is correspondingly connected to the partition and / or the auxiliary rod.

[0030] Further, a high - temperature - resistant protective layer is provided on the surface of the thermocouple, and a cooling water pipeline is provided in the wall of the sampling tube for cooling the cold end of the thermocouple.

[0031] The present invention also provides a sampling device used in the above-mentioned blast furnace condition evaluation method based on radial hearth temperature measurement at the tuyere plane of the blast furnace. The sampling device is characterized in that the sampling device includes a sampling tube with a solid pointed tip formed at the front end. The sampling tube is open at the top, and an upper cover is provided at the opening in an openable and closable manner. A plurality of partitions are axially spaced in the inner cavity of the sampling tube to prevent the sample from moving when being withdrawn. A plurality of thermocouples are provided on the sampling tube for measuring the temperature at multiple radial positions of the hearth. Each thermocouple includes a hot end and a cold end connected in the front-rear direction. The cold ends of each thermocouple are embedded in the wall of the sampling tube, and the hot ends of the multiple thermocouples are axially spaced along the sampling tube.

[0032] Preferably, the hot ends of the multiple thermocouples are axially spaced in the inner cavity of the sampling tube; or the hot end of one of the multiple thermocouples enters the solid pointed tip, and the hot ends of the remaining thermocouples are axially spaced in the inner cavity of the sampling tube.

[0033] Furthermore, the hot ends entering the inner cavity of the sampling tube are correspondingly arranged inside the partition or are connected to the partition in a forward-tilted manner.

[0034] Even further, when the hot ends entering the inner cavity of the sampling tube are connected to the partition in a forward-tilted manner, the hot ends entering the inner cavity of the sampling tube are located inside a support rod that is forward-tilted in the inner cavity of the sampling tube, and the front end of the support rod is correspondingly connected to the partition.

[0035] Furthermore, an auxiliary rod is provided between adjacent partitions. The hot ends entering the inner cavity of the sampling tube are correspondingly arranged inside the partition and / or the auxiliary rod, or the hot ends entering the inner cavity of the sampling tube are connected to the partition and / or the auxiliary rod in a forward-tilted manner.

[0036] Even further, when the hot ends entering the inner cavity of the sampling tube are connected to the partition and / or the auxiliary rod in a forward-tilted manner, the hot ends entering the inner cavity of the sampling tube are located inside a support rod that is forward-tilted in the inner cavity of the sampling tube, and the front end of the support rod is correspondingly connected to the partition and / or the auxiliary rod.

[0037] Preferably, a high-temperature resistant protective layer is provided on the surface of the thermocouple, and a cooling water pipeline is provided in the wall of the sampling tube for cooling the cold ends of the thermocouples.

[0038] The beneficial effects of the present invention are:

[0039] 1. A thermocouple is arranged in the sampling device to measure the temperature of the blast furnace hearth while sampling coke at the tuyere. The arrangement method of the thermocouple is flexible: when the solid tip of the sampling pipe corresponds to the center of the dead stock column, the hot end of one of the thermocouples can be arranged inside the solid tip, and the hot ends of the remaining thermocouples are arranged at intervals in the inner cavity of the sampling pipe. When the solid tip of the sampling pipe exceeds the center of the dead stock column, the hot ends of all thermocouples are arranged at intervals in the inner cavity of the sampling pipe. For the hot ends in the inner cavity of the sampling pipe, they can be directly arranged in the partition plate and / or the auxiliary rod, or can be tilted forward and leaned on the partition plate and / or the auxiliary rod. When tilted forward, a support rod tilted forward can also be arranged in the inner cavity of the sampling pipe, and the hot end enters the support rod and leans on the partition plate and / or the auxiliary rod.

[0040] 2. Characterize the hearth activity with parameters such as hearth temperature and dead stock particle size, and propose a calculation method for the hearth activity index to quickly and accurately judge whether the hearth is active. Since it is often difficult to effectively judge in the initial stage of hearth inactivity, this technology provides a basis for timely judging the blast furnace condition and avoiding losses. Description of the Drawings

[0041] Figure 1 Structural schematic diagram of the sampling device in Embodiment 1

[0042] Figure 2 Axial sectional view of the sampling device in Embodiment 1 (the hot end of the thermocouple enters the partition plate)

[0043] Figure 3 Axial sectional view of the sampling device in Embodiment 1 (the hot end of the thermocouple is tilted forward)

[0044] Figure 4 Structural schematic diagram of the sampling device in Embodiment 2

[0045] Figure 5 Axial sectional view of the sampling device in Embodiment 2 (the hot end of the thermocouple enters the partition plate and the auxiliary rod)

[0046] Figure 6 Axial sectional view of the sampling device in Embodiment 2 (the hot end of the thermocouple is tilted forward)

[0047] Figure 7 Axial sectional view of the sampling device in Embodiment 3

[0048] Wherein: 10 - sampling device; 1 - sampling pipe; 2 - solid tip; 3 - partition plate; 4 - thermocouple (41 - cold end, 42 - hot end); 5 - auxiliary rod; 6 - cooling water pipeline; 7 - support rod. Detailed Embodiments

[0049] The following specific embodiments further illustrate the present invention in detail.

[0050] Embodiment 1

[0051] As shown in Figures 1-3 , this embodiment provides a sampling device 10. The sampling device 10 includes a sampling tube 1 with a solid pointed tip 2 formed at the front end. The upper part of the sampling tube 1 is open, and an upper cover (not shown in the figure) is provided at the opening in a switchable manner. A plurality of partition plates 3 are axially spaced in the inner cavity of the sampling tube 1 to prevent the sample from moving during extraction. A plurality of thermocouples 4 are provided on the sampling tube 1 for measuring the temperature at multiple radial positions of the blast furnace hearth. Each thermocouple 4 includes a cold end 41 and a hot end 42 connected in the front-back direction. The cold ends 41 of each thermocouple 4 are embedded in the wall of the sampling tube 1, and the hot ends 42 of the plurality of thermocouples 4 are axially spaced along the sampling tube 1. In this embodiment, the axial direction of the sampling tube 1 is as shown in Figures 2-3 the left-right direction in Figures 2-3 , with the left end in

[0052] being the rear end of the sampling tube 1 and the right end being the front end of the sampling tube 1. The plate surface of the partition plate 3 is arranged along the radial plane of the sampling tube 1. The thermocouples 4 can be flexibly selected to be arranged only in the inner cavity of the sampling tube 1 or in both the inner cavity of the sampling tube 1 and the solid pointed tip 2: when the sampling tube 1 is short and the solid pointed tip 2 corresponds to the center of the dead stock column of the blast furnace, the hot end 42 of one of the thermocouples 4 enters the solid pointed tip 2, and the hot ends 42 of the remaining thermocouples 4 enter the inner cavity of the sampling tube 1 and are axially spaced; if the sampling tube 1 is long and the front end of the inner cavity of the sampling tube 1 can reach the center of the dead stock column of the blast furnace, there is no need to set the hot end 42 inside the solid pointed tip 2, and the hot ends 42 of all the thermocouples 4 can be directly axially spaced in the inner cavity of the sampling tube 1.

[0053] A high-temperature resistant protective layer is provided on the surface of the thermocouple 4, and a cooling water pipeline 6 is provided in the wall of the sampling tube 1 to cool the cold end 41 of the thermocouple 4. When the thermocouple 4 passes through the cooling water pipeline 6, the two are sealed to prevent the leakage of cooling water. Specifically, for the thermocouple 4 with the hot end 42 located inside the solid pointed tip 2, if the axial distance of the solid pointed tip 2 is long and part of the cold end 41 enters the solid pointed tip 2, as a preferred solution, the cooling water pipeline 6 can be extended into the solid pointed tip 2 to facilitate the cooling and protection of the cold end 41.

[0054] When the number of temperature measurement points required in the inner cavity of the sampling tube 1 is small: the hot end 42 entering the inner cavity of the sampling tube 1 is correspondingly arranged inside the partition plate 3 or is connected to the partition plate 3 in a forward-inclined manner. As shown in Figures 1-2 , the hot end 42 entering the inner cavity of the sampling tube 1 is axially correspondingly arranged inside the partition plate 3; as shown in Figure 3 , when the hot end 42 entering the inner cavity of the sampling tube 1 is correspondingly connected to the partition plate 3 in a forward-inclined manner, as a preferred solution, a support rod 7 can be fixedly arranged in a forward-inclined manner in the inner cavity of the sampling tube 1. The hot end 42 entering the inner cavity of the sampling tube is located inside the support rod 7, and the front ends 7 of each support rod are correspondingly connected to each partition plate 3. The forward-inclined angle α between the hot end 42 and the axial direction satisfies 30° ≤ α ≤ 60°.

[0055] Embodiment 2

[0056] As Figures 4-6 shown, this embodiment provides a sampling device 10. The sampling device 10 includes a sampling tube 1 with a solid tip 2 formed at the front end. The upper part of the sampling tube 1 is open, and an upper cover (not shown in the figure) is provided at the opening in a switchable manner. A plurality of partitions 3 are axially spaced in the inner cavity of the sampling tube 1 to prevent the sample from moving during extraction. A plurality of thermocouples 4 are provided on the sampling tube 1 for measuring the temperature at multiple radial positions of the blast furnace hearth. Each thermocouple 4 includes a cold end 41 and a hot end 42 connected in the front-rear direction. The cold end 41 of each thermocouple 4 is embedded in the wall of the sampling tube 1, and the hot ends 42 of the plurality of thermocouples 4 are axially spaced along the sampling tube 1. In this embodiment, the axial direction of the sampling tube 1 is as Figures 5-6 the left-right direction in Figures 5-6 the figure, with the left end in the figure being the rear end of the sampling tube 1 and the right end being the front end of the sampling tube 1. The plate surface of the partition 3 is arranged along the radial plane of the sampling tube 1.

[0057] The thermocouple 4 can be flexibly selected to be arranged only in the inner cavity of the sampling tube 1 or in both the inner cavity of the sampling tube 1 and the solid tip 2: When the sampling tube 1 is short and the solid tip 2 corresponds to the center of the dead stock column of the blast furnace, the hot end 42 of one of the thermocouples 4 enters the solid tip 2, and the hot ends 42 of the remaining thermocouples 4 enter the inner cavity of the sampling tube 1 and are axially spaced; If the sampling tube 1 is long and the front end of the inner cavity of the sampling tube 1 can reach the center of the dead stock column of the blast furnace, there is no need to set the hot end 42 inside the solid tip 2, and the hot ends 42 of all the thermocouples 4 can be directly axially spaced in the inner cavity of the sampling tube 1.

[0058] A high-temperature resistant protective layer is provided on the surface of the thermocouple 4, and a cooling water pipeline 6 is arranged in the wall of the sampling tube 1 to cool the cold end 41 of the thermocouple 4. When the thermocouple 4 passes through the cooling water pipeline 6, the two are sealed to prevent the leakage of cooling water. Specifically, for the thermocouple 4 with the hot end 42 located inside the solid tip 2, if the axial distance of the solid tip 2 is long and part of the cold end 41 enters the solid tip 2, as a preferred solution, the cooling water pipeline 6 can be extended into the solid tip 2 to facilitate the cooling and protection of the cold end 41.

[0059] When there are more temperature measurement points required in the inner cavity of the sampling tube 1: An auxiliary rod 5 can be arranged along the radial direction of the sampling tube 1 between two adjacent partitions 3. The hot end 42 entering the inner cavity of the sampling tube 1 is correspondingly arranged in the partition 3 and / or the auxiliary rod 5, or the hot end 42 entering the inner cavity of the sampling tube 1 is obliquely connected to the partition 3 and / or the auxiliary rod 5 forward. As Figures 4-5 shown, the hot end 42 entering the inner cavity of the sampling tube 1 is correspondingly arranged in the partition 3 and the auxiliary rod 5, as Figure 6As shown in the figure, when the hot end 42 entering the inner cavity of the sampling tube 1 is correspondingly connected to the partition plate 3 and the auxiliary rod 5 in a forward-tilted manner, as an optimal solution, a support rod 7 can be fixedly arranged in a forward-tilted manner in the inner cavity of the sampling tube 1. The hot end 42 entering the inner cavity of the sampling tube is located inside the support rod 7. The front ends 7 of the respective support rods are correspondingly connected to the respective partition plates 3 and the auxiliary rod 5. The angle α between the forward tilt of the hot end 42 and the axis satisfies 30° ≤ α ≤ 60°.

[0060] Example 3

[0061] As Figure 7 shown, this example is a specific application of Example 1: The diameter of the blast furnace hearth is 13.5 m. The front end of the inner cavity of the sampling tube 1 can reach the center of the dead stock column of the blast furnace. There is no need to set a temperature measurement point on the solid pointed head 2. The hot ends 42 of the thermocouples 4 are set (from the back to the front) at 1.2 m, 4.1 m, and 6.7 m axially from the rear end of the sampling tube 1. The hot ends 42 of the 3 thermocouples 4 are respectively arranged in 3 partition plates to meet the temperature measurement requirements. Apply this sampling device to the following blast furnace condition evaluation method.

[0062] Using the above sampling device 10 for the blast furnace condition evaluation method, includes the following steps:

[0063] S1. Take tuyere coke from inside the blast furnace during the blast furnace shutdown time. The sampling process includes: Insert the sampling device 10 with the upper cover closed radially along the tuyere plane into the hearth until the front end enters at least the center of the dead stock column. Open the upper cover of the sampling device 10 to allow the sample to enter the sampling device 10. After waiting for 2 - 10 min, measure the stable temperature of the center of the dead stock column Tp = 1435 °C and the temperature of the hearth edge Tb = 1505 °C through the thermocouple 4 pre-arranged in the sampling device 10 (for a blast furnace hearth diameter of 13.5 m, the thermocouple 4 at 1.2 m axially from the rear end of the sampling tube measures Tb, and the thermocouple 4 at 6.7 m axially from the rear end of the sampling tube measures Tp). Finally, withdraw the sampling device 10 from the blast furnace to complete the sampling.

[0064] S2. After separating the slag and iron from the material in the sampling tube, measure the average particle size l of the sampled tuyere coke l = 18 mm. The average particle size l2 of the charged coke was pre-measured before sampling to be 50 mm. Measure the mass percentage σ of coke with a particle size below 5 mm in the tuyere coke to be 15%. Calculate the temperature difference ΔT between the hearth edge temperature Tb and the center temperature Tp of the dead stock column, ΔT = 1505 - 1435 = 70 °C. Calculate the ratio λ of the average particle size l of the tuyere coke l to the average particle size l2 of the charged coke, λ = l l / l2 = 36%. Then the hearth activity index η of the sample,

[0065]

[0066] λ—l l / l2, the average particle size l of tuyere coke l The ratio to the average particle size l2 of the coke charged into the furnace;

[0067] Tp—the central temperature Tp of the dead stock column, unit: °C;

[0068] ΔT—Tb - Tp, the temperature difference between the edge temperature Tb of the hearth and the central temperature Tp of the dead stock column, unit: °C;

[0069] σ—the mass percentage of coke with a particle size below 5 mm in the tuyere coke;

[0070] S3. Compare the hearth activity index η obtained in step S2 with the known standard hearth activity index η0 = 50. In this embodiment, η = 49.2 ≥ 80%η0, then it is judged that the blast furnace hearth is active at this time.

[0071] If η < 80%η0, it is judged that the blast furnace hearth is inactive at this time (when the hearth is inactive, the small particles of unburned pulverized coal in coal injection and the fine-grained coke will increase the resistance to the diffusion of the coal gas flow, the heat transfer efficiency in the center of the blast furnace is low, resulting in a low central temperature of the dead stock column and an enlarged radial temperature difference in the tuyere plane). When it is judged that the hearth is inactive, by adjusting the blast furnace operation parameters, optimizing the proportion of the materials charged into the furnace, improving the quality of the original fuels such as coke and iron ore, etc., the activity of the hearth is improved, so that the hearth activity index η is maintained within a suitable range.

[0072] The standard hearth activity index η0 in this embodiment is obtained by repeating steps S1 - S2 at least 10 times under normal furnace conditions in advance to obtain multiple hearth activity indices, and taking the average value of all the hearth activity indices under normal furnace conditions.

[0073] The above shows and describes the basic principle, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A blast furnace condition evaluation method based on radial hearth temperature measurement in the tuyere plane of a blast furnace, characterized in that It includes the following steps: S1. Take tuyere coke from the blast furnace during the blast furnace shutdown. The sampling process includes: inserting the sampling device (10) radially along the tuyere plane into the hearth until the front end enters at least the center of the dead stock column. After the sample enters the sampling device (10), measure the temperature Tp at the center of the dead stock column and the temperature Tb at the hearth edge through the thermocouples pre-arranged in the sampling device (10). Finally, withdraw the sampling device (10) from the blast furnace to complete the sampling. S2. Separate slag and iron from the sample to obtain tuyere coke, and measure the average particle size l of the tuyere coke l , the average particle size l2 of the coke charged into the furnace is measured in advance before sampling. Measure the mass percentage σ of coke with a particle size below 5 mm in the tuyere coke, calculate the temperature difference ΔT between the furnace hearth edge temperature Tb and the dead stock column center temperature Tp, and calculate the average particle size l of the tuyere coke l The ratio λ to the average particle size l2 of the coke charged into the furnace, then the furnace hearth activity index η of the sample λ—l l / l2, the average particle size l of tuyere coke l The ratio to the average particle size l2 of the coke charged into the furnace; Tp—the temperature Tp at the center of the dead stock column, unit: °C; ΔT—Tb - Tp, the temperature difference between the temperature Tb at the hearth edge and the temperature Tp at the center of the dead stock column, unit: °C; σ—the mass percentage σ of particles with a diameter less than 5 mm in the tuyere coke; S3. Compare the hearth activity index η obtained in step S2 with the standard hearth activity index η0 measured in advance. If η < 80%η0, it is judged that the blast furnace hearth is inactive; If η ≥ 80%η0, it is judged that the blast furnace hearth is active; In step S1, the sampling device (10) includes a sampling tube (1) with a solid tip (2) formed at the front end. The sampling tube (1) has an opening at the top and an upper cover that can be opened and closed at the opening. A plurality of partitions (3) are axially spaced in the inner cavity of the sampling tube (1) to prevent the sample from moving when withdrawn. A plurality of thermocouples (4) are provided on the sampling tube (1) for measuring the temperature at multiple positions in the radial direction of the hearth. Each thermocouple (4) includes a hot end (42) and a cold end (41) connected in the front-back direction. The cold end (41) of each thermocouple (4) is embedded in the wall of the sampling tube (1), and the hot ends (42) of the plurality of thermocouples (4) are axially spaced along the sampling tube (1).

2. The blast furnace condition evaluation method based on the radial temperature measurement of the furnace hearth at the tuyere plane of the blast furnace according to claim 1, characterized in that In step S1, after the sample enters the sampling device (10), it stays for 2 - 10 minutes, and then measure the temperature Tp at the center of the dead stock column and the temperature Tb at the hearth edge through the thermocouples pre-arranged in the sampling device (10).

3. The blast furnace condition evaluation method based on the radial temperature measurement of the blast furnace hearth at the tuyere plane as claimed in claim 1, characterized in that, In step S3, the standard hearth activity index η0 is obtained by repeatedly performing steps S1 - S2 multiple times under normal furnace conditions to obtain the hearth activity index and taking the average value of all the hearth activity indices under normal furnace conditions.

4. The blast furnace condition evaluation method based on the radial hearth temperature measurement of the blast furnace tuyere plane according to claim 1, wherein, The hot ends (42) of the plurality of thermocouples (4) are axially spaced in the inner cavity of the sampling tube (1); or the hot end (42) of one of the plurality of thermocouples (4) enters the solid tip (2), and the hot ends (42) of the remaining thermocouples (4) are axially spaced in the inner cavity of the sampling tube (1).

5. The blast furnace condition evaluation method based on the radial temperature measurement of the blast furnace hearth at the tuyere plane according to claim 4, characterized in that, The hot ends (42) entering the inner cavity of the sampling tube (1) are correspondingly arranged inside the partition (3) or are connected to the partition (3) in a forward-tilted manner.

6. The blast furnace condition evaluation method based on the radial hearth temperature measurement of the blast furnace tuyere plane according to claim 4, wherein An auxiliary rod (5) is provided between two adjacent partitions (3). The hot ends (42) entering the inner cavity of the sampling tube (1) are correspondingly arranged inside the partition (3) and / or the auxiliary rod (5), or the hot ends (42) entering the inner cavity of the sampling tube (1) are connected to the partition (3) and / or the auxiliary rod (5) in a forward-tilted manner.

7. The blast furnace condition evaluation method based on the radial hearth temperature measurement of the blast furnace tuyere plane according to claim 1, characterized in that, A high-temperature resistant protective layer is provided on the surface of the thermocouple (4), and a cooling water pipeline (6) is provided in the wall of the sampling tube (1) for cooling the cold end (41) of the thermocouple (4).

8. A sampling device used in the blast furnace condition evaluation method based on the radial hearth temperature measurement of the blast furnace tuyere plane as described in claim 1, characterized in that, The sampling device (10) includes a sampling tube (1) with a solid tip (2) formed at the front end. The sampling tube (1) is open at the top and is provided with an openable and closable upper cover at the opening. A plurality of partitions (3) are axially spaced in the inner cavity of the sampling tube (1) to prevent the movement of the sample during extraction. A plurality of thermocouples (4) are provided on the sampling tube (1) for measuring the temperature at multiple radial positions of the hearth. Each thermocouple (4) includes a hot end (42) and a cold end (41) connected in the front-rear direction. The cold end (41) of each thermocouple (4) is embedded in the wall of the sampling tube (1), and the hot ends (42) of the plurality of thermocouples (4) are axially spaced along the sampling tube (1).

9. The sampling device used in the blast furnace condition evaluation method based on the radial temperature measurement of the blast furnace hearth at the tuyere plane as claimed in claim 8, characterized in that, The hot ends (42) of the plurality of thermocouples (4) are axially spaced in the inner cavity of the sampling tube (1); or the hot end (42) of one of the plurality of thermocouples (4) enters the solid tip (2), and the hot ends (42) of the remaining thermocouples (4) are axially spaced in the inner cavity of the sampling tube (1).

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