Method for judging residual thickness of refractory after integral casting of blast furnace hearth

Abstract

The present application relates to a kind of judging methods of residual thickness of refractory after overall casting of blast furnace hearth, the method comprises the following steps: step 1: measure the residual thickness of original carbon brick, utilize the opportunity of blast furnace shutdown cleaning hearth, measure the thickness of carbon brick in different parts;Step 2: calculate heat flow intensity;Step 3: calculate the thickness of castable according to heat flow intensity;Step 4: judge whether the original carbon brick continues to be eroded;Step 5: calculate the overall thickness of carbon brick and castable.The technical scheme mainly solves the technical problem that it is difficult to judge the thickness of different refractories in the prior art, accurately judges the residual thickness of refractory after being eroded by slag iron after overall casting of blast furnace hearth, and then different measures are taken to realize the safety control of hearth.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of judging method, specifically to a kind of judging method of refractory residual thickness after whole pouring of blast furnace hearth, belong to steel metallurgy blast furnace iron-making technical field. BACKGROUND

[0002] The current blast furnace iron-making technology can realize a kind of rapid repair technology of furnace hearth after the erosion of original carbon brick, pouring a certain low thermal conductivity refractory, maintaining the original design of furnace hearth, realizing the reuse of carbon brick of blast furnace hearth. After whole pouring of furnace hearth, the different thermal conductivity of furnace hearth refractory leads to the original carbon brick erosion judgment method is no longer applicable.

[0003] The Chinese patent with authorized publication number CN110527769A discloses a kind of carbon brick residual thickness judgment method of blast furnace hearth, mainly using the difference between deep and shallow carbon brick galvanic couple temperature to judge carbon brick residual thickness, can obtain the degree of carbon brick erosion. This method can only judge the erosion thickness of pure carbon brick furnace hearth, and cannot judge the thickness of carbon brick and castable after whole pouring of furnace hearth.

[0004] The Chinese patent with authorized publication number CN102433409A discloses a kind of thermocouple embedding thickness measurement method of erosion site of blast furnace hearth, mainly using an additional carbon brick couple to make deep and shallow have two point temperature display values, and then using Fourier heat transfer formula to calculate the erosion degree of carbon brick. This method also cannot judge the thickness of carbon brick and castable after whole pouring of furnace hearth, therefore, there is an urgent need for a new solution to solve the above technical problems. SUMMARY

[0005] The present application is just for the problems existing in the prior art, and provides a kind of judgment method of refractory residual thickness after whole pouring of blast furnace hearth. The technical scheme mainly solves the technical problem that it is difficult to judge the thickness of different refractories when two different refractories are used in the furnace hearth in the prior art. After the whole pouring of blast furnace hearth, the residual thickness of refractory after being eroded by slag and iron is accurately judged, and then different measures are taken to realize the safe control of the furnace hearth.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows: a kind of judgment method of refractory residual thickness after whole pouring of blast furnace hearth, the method comprises the following steps:

[0007] Step 1: measure the residual thickness of original carbon brick, use the opportunity of blast furnace shutdown to measure the thickness of carbon brick in different parts;

[0008] Step 2: calculate the heat flow intensity;

[0009] Step 3: calculate the thickness of castable according to the heat flow intensity;

[0010] Step 4: judge whether the original carbon brick is continuously eroded;

[0011] Step 5: Calculate the overall thickness of carbon brick and castable.

[0012] As an improvement of the present application, step 2: calculate the heat flow intensity, after the start of the blast furnace, according to the temperature of two different depth inserted thermocouples in the same part of the carbon brick, calculate the heat flow intensity of the carbon brick in this part, as follows:

[0013]

[0014] In the formula:

[0015] q: heat flow intensity, unit w / m 2 ;

[0016] t2: temperature of deep thermocouple in carbon brick, unit ℃;

[0017] t1: temperature of shallow thermocouple in carbon brick, unit ℃;

[0018] h2: insertion depth of deep thermocouple, unit m;

[0019] h1: insertion depth of shallow thermocouple, unit m;

[0020] λ 炭砖 : thermal conductivity of carbon brick, unit w / (m·℃).

[0021] As an improvement of the present application, step 3: calculate the thickness of castable according to heat flow intensity, according to the principle of heat transfer, consider that the heat conduction of blast furnace hearth is steady-state heat conduction, the heat flow intensity in this direction is the same, according to the thermal conductivity and effective thickness of different materials in the whole heat transfer system, calculate the remaining thickness of castable;

[0022]

[0023] In the formula:

[0024] t 冷却水 : cooling water temperature of hearth, unit ℃;

[0025] d 浇注料 : thickness of castable, unit m;

[0026] λ 浇注料 : thermal conductivity of castable, unit w / (m·℃);

[0027] d 炭砖 : original residual thickness of carbon brick, unit m;

[0028] λ 炭砖 : thermal conductivity of carbon brick, unit w / (m·℃);

[0029] d 捣打料: ramming thickness, unit m;

[0030] λ 捣打料 : thermal conductivity of ramming, unit w / (m·℃);

[0031] d 冷却壁 : cooling wall thickness, unit m;

[0032] λ 冷却壁 : thermal conductivity of cooling wall, unit w / (m·℃)。

[0033] wherein the heat flow intensity has been calculated in step 2), the pouring thickness d 浇注料 .

[0034] As an improvement of the present application, step 4: judging whether the original carbon brick is continuously eroded, if the remaining thickness of the pouring material ≥0, the original carbon brick is not eroded; if the calculated pouring thickness <0, it means that the original carbon brick has been eroded.

[0035] As an improvement of the present application, step 5: calculating the overall thickness of the carbon brick and the pouring material, if the original carbon brick is not eroded, the overall thickness of the hearth refractory is the sum of the remaining thickness of the original carbon brick and the calculated pouring thickness; if the original carbon brick has been eroded, the remaining thickness of the carbon brick is calculated by using Fourier formula, and the overall thickness of the hearth refractory is the calculated remaining thickness of the carbon brick.

[0036] Compared with the prior art, the present application has the following advantages, the present application method cannot directly use two-point temperature interpolation method to directly calculate the thickness of the refractory after the overall pouring of the hearth, when the thermal conductivity of the refractory is different. The present method does not need to additionally increase equipment investment and cost; the present method is suitable for all blast furnaces, the remaining thickness of the refractory can be judged by using the original carbon brick inner deep and shallow couple, so as to guide the blast furnace operator to take measures beneficial to the safety of the hearth, reduce the risk of the burning-through of the hearth, and provide a scientific theoretical basis for the safety and long life of the blast furnace. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a schematic diagram of pouring hearth of blast furnace;

[0038] Figure 2 It is a top view schematic diagram of blast furnace hearth;

[0039] Figure 3 It is a schematic diagram of carbon brick couple of hearth.

[0040] Marked in the figure: 1- tuyere, 2- cooling wall, 3- ramming, 4- remaining carbon brick, 5- pouring material, 6- carbon brick couple with deeper insertion depth, 7- carbon brick couple with shallower insertion depth, 8- center point of hearth. DETAILED DESCRIPTION

[0041] In order to deepen the understanding of the present application, the following detailed description of the present embodiment is made in conjunction with the accompanying drawings.

[0042] Embodiment 1: see Figure 1 A method for judging residual thickness of monolithic cast refractory of a blast furnace hearth, the method comprising the following steps:

[0043] Step 1: measuring the original carbon brick residual thickness, taking the opportunity of blast furnace shutdown and hearth cleaning, measuring the thickness of carbon bricks at different positions;

[0044] Step 2: calculating heat flow intensity;

[0045] Step 3: calculating the thickness of castable according to heat flow intensity;

[0046] Step 4: judging whether the original carbon brick continues to be eroded;

[0047] Step 5: calculating the overall thickness of carbon brick and castable.

[0048] Step 2: calculating heat flow intensity, after starting up, according to the temperature of two different depth inserted thermocouples at the same position of carbon brick, calculating the heat flow intensity of the carbon brick at the position, specifically as follows:

[0049]

[0050] In the formula:

[0051] q: heat flow intensity, unit w / m 2 ;

[0052] t2: temperature of deep thermocouple in carbon brick, unit ℃;

[0053] t1: temperature of shallow thermocouple in carbon brick, unit ℃;

[0054] h2: insertion depth of deep thermocouple, unit m;

[0055] h1: insertion depth of shallow thermocouple, unit m;

[0056] λ 炭砖 : thermal conductivity of carbon brick, unit w / (m·℃).

[0057] The step 3: calculating the thickness of castable according to heat flow intensity, according to heat transfer principle, considering that the heat conduction of blast furnace hearth is steady-state heat conduction, the heat flow intensity in the direction of the thermocouple is the same, according to the thermal conductivity and effective thickness of different materials in the whole heat transfer system, the residual thickness of castable is calculated;

[0058]

[0059] In the formula:

[0060] t冷却水 : Cooling water temperature of hearth, unit ℃

[0061] d 浇注料 : Thickness of castable, unit m

[0062] λ 浇注料 : Thermal conductivity of castable, unit w / (m·℃)

[0063] d 炭砖 : Original residual thickness of carbon brick, unit m

[0064] λ 炭砖 : Thermal conductivity of carbon brick, unit w / (m·℃)

[0065] d 捣打料 : Thickness of ramming material, unit m

[0066] λ 捣打料 : Thermal conductivity of ramming material, unit w / (m·℃)

[0067] d 冷却壁 : Thickness of cooling wall, unit m

[0068] λ 冷却壁 : Thermal conductivity of cooling wall, unit w / (m·℃)

[0069] Wherein the heat flow intensity has been calculated in step 2), the thickness of castable d 浇注料 .

[0070] Step 4: Determine whether the original carbon brick is continuously eroded, if the remaining thickness of castable is ≥0, the original carbon brick is not eroded; if the calculated thickness of castable is <0, it indicates that the original carbon brick has been eroded.

[0071] Step 5: Calculate the overall thickness of carbon brick and castable, if the original carbon brick is not eroded, the overall thickness of hearth refractory is the sum of the residual thickness of original carbon brick and the calculated thickness of castable; if the original carbon brick has been eroded, the residual thickness of carbon brick is calculated by Fourier formula, and the overall thickness of hearth refractory is the calculated residual thickness of carbon brick.

[0072] Specific embodiment: A method for judging the residual thickness of overall cast hearth refractory of blast furnace, comprising the following steps:

[0073] Step 1: Measure the residual thickness of carbon brick 4, after the blast furnace is stopped and the hearth is cleaned, the center point 8 of the hearth is the intersection point of any two symmetric groups of tuyere connecting lines, a vertical line is made at the center point 8, the horizontal distance L from the vertical line to the carbon brick 4 is measured, and the residual thickness of the carbon brick 4 at this position is obtained by subtracting L from the radius of the outer end surface of the original carbon brick 4;

[0074] Step 2: Calculate the heat flux intensity. After the furnace is turned on, calculate the heat flux intensity q of the carbon brick 4 at that location based on the temperatures 6 and 7 of the two thermocouples inserted to different depths at the same location on the carbon brick 4.

[0075] Step 3: Calculate the thickness of the castable refractory 5 based on the heat flux intensity. According to the principle of heat transfer, the heat flux intensity is the same in the direction of the thermocouple. Based on the thermal conductivity and effective thickness of different materials in the entire heat transfer system, calculate the remaining thickness d of the castable refractory 5. 浇注料 .

[0076] Step 4: Determine if the original carbon brick 4 continues to be eroded. If the remaining thickness d of the castable refractory 5... 浇注料 If ≥0, then the original carbon brick 4 was not eroded; if the calculated thickness d of the castable 5 is... 浇注料 If the value is less than 0, it means that the original carbon brick 4 has been eroded.

[0077] Step 5: Calculate the overall thickness of carbon brick 4 and castable 5. If the original carbon brick 4 has not been eroded, the overall thickness of the hearth refractory is the original residual thickness d of the carbon brick. 炭砖 With the calculated thickness d of the castable 浇注料 The sum; if the original carbon brick 4 has been eroded, calculate the remaining thickness d' of carbon brick 4 using the Fourier formula. 碳砖残存 The overall thickness of the furnace hearth refractory is calculated as the residual thickness d' of carbon brick 4. 碳砖残存 .

[0078] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for judging a residual thickness of monolithically cast refractory of a blast furnace hearth, characterized by, The method comprises the following steps: Step 1: measuring the residual thickness of original carbon bricks, measuring the thickness of carbon bricks at different positions by taking the opportunity of furnace stoppage for cleaning hearth; Step 2: calculating heat flow intensity; Step 3: calculating the thickness of castable according to heat flow intensity; Step 4: judging whether the original carbon bricks continue to be eroded; Step 5: calculating the overall thickness of carbon bricks and castable; In step 2, the heat flow intensity is calculated according to the temperature of two inserted thermocouples with different depths at the same position of carbon bricks after the furnace is started, and the heat flow intensity of the carbon bricks at the position is calculated, which is specifically as follows: In the formula, q: heat flow strength, in w / m 2 ; t2: temperature of deep thermocouple inserted in carbon bricks, unit: ℃; t1: temperature of shallow thermocouple inserted in carbon bricks, unit: ℃; h2: insertion depth of deep thermocouple, unit: m; h1: insertion depth of shallow thermocouple, unit: m; λ 碳砖 : Carbon brick thermal conductivity, unit w / (m·℃); In step 3, the thickness of castable is calculated according to heat flow intensity, according to the heat transfer principle, the heat conduction of the hearth of the blast furnace is steady-state heat conduction, the heat flow intensity in the direction of the thermocouple is the same, and the residual thickness of the castable is calculated according to the heat conduction coefficient and effective thickness of different materials in the whole heat transfer system; In the formula, t 冷却水 : hearth cooling water temperature, unit ℃; d 浇注料 : thickness of the cast, in m; λ 浇注料 : thermal conductivity of castable, unit w / (m·℃); d 碳砖 : original carbon brick residual thickness, unit m; λ 碳砖 : Carbon brick thermal conductivity, unit w / (m·℃); d 捣打料 : ramming thickness, unit m; λ 捣打料 : thermal conductivity of rammed mass, in w / (m °C); d 冷却壁 : Cooling wall thickness, unit m; λ 冷却壁 : cooling wall thermal conductivity, unit w / (m·℃); where the heat flow intensity has been calculated in step 2, calculating the thickness d of the cast 浇注料 ; In step 4, it is judged whether the original carbon bricks continue to be eroded, if the residual thickness of the castable is greater than or equal to 0, the original carbon bricks are not eroded, and if the calculated thickness of the castable is less than 0, it is indicated that the original carbon bricks have been eroded; In step 5, the overall thickness of carbon bricks and castable is calculated, if the original carbon bricks are not eroded, the overall thickness of the hearth refractory is the sum of the residual thickness of the original carbon bricks and the calculated thickness of the castable, and if the original carbon bricks have been eroded, the residual thickness of the carbon bricks is calculated by using Fourier formula, and the overall thickness of the hearth refractory is the residual thickness of the carbon bricks.

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