Partitioned construction method of hot blast stove regenerator and regenerative structure

Abstract

A method for constructing a zoned regenerator chamber in a hot blast stove and a regenerator structure are disclosed, relating to the field of iron and steel metallurgy technology. The beneficial effects of this invention are as follows: By establishing a linear temperature drop heat transfer model along the height of the regenerator chamber, and using the creep resistance temperature threshold of the refractory balls as the dividing line, the boundary height between the high-temperature zone and the medium-low temperature zone is accurately calculated. The high-temperature zone is filled with regenerator checker bricks, and the medium-low temperature zone is filled with refractory balls in combination. Simultaneously, during construction, a leveling layer ensures the flatness of the upper checker bricks, and supporting grates and load-bearing grids ensure the overall structural stability. This invention aims to fundamentally isolate the refractory balls from contact with high-temperature conditions above 1200℃ through structural layout, significantly extending the service life of the refractory balls, reducing blast energy consumption, and improving blast temperature stability without affecting the blast furnace blast temperature, while also considering the overall economy and practicality of the regenerator chamber.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and specifically relates to a zoned construction method for a regenerator of a hot-blast stove and a regenerator structure. Background Art

[0002] In the iron and steel metallurgy industry, the regenerators of hot-blast stoves supporting blast furnaces generally adopt refractory balls as the filled regenerative bodies, which are called top-fired ball-type hot-blast stoves. Compared with regenerative checker brick type hot-blast stoves, ball-type hot-blast stoves have the advantages of high heat exchange efficiency, simple structure, low investment cost, etc., so they are widely used in hot-blast stove systems such as small and medium-sized blast furnaces and pellet shaft furnaces.

[0003] However, with long-term use in the actual smelting process, ball-type hot-blast stoves have exposed the following insurmountable defects: 1. Refractory balls are stacked in a random and disordered state in the regenerator, the void channels formed between the balls are tortuous and complex, and the flow resistance of the air flow when passing through is significantly increased. In order to ensure sufficient air supply volume, the fan needs to operate at high load for a long time, resulting in persistently high blast energy consumption, and increased production power consumption and equipment maintenance costs.

[0004] 2. When refractory balls operate for a long time under high temperature conditions above 1200°C, creep deformation occurs inside the material, leading to breakage of the refractory balls and surface agglomeration. The air permeability of the agglomerated ball bed drops sharply, the temperature of the exhaust gas in the regenerator rises, the heat storage efficiency decreases, and the hot-blast stove cannot maintain the normal air supply temperature. In actual production, the replacement cycle of refractory balls is only 8 to 12 months. Frequent shutdown of the stove to replace balls not only increases maintenance costs and material consumption, but more seriously, the blast furnace air temperature drops significantly during the shutdown period, leading to an increase in fuel ratio, which has a great adverse impact on the continuous and stable production of the blast furnace and energy saving and emission reduction.

[0005] 3. The disordered stacking of refractory balls leads to uneven distribution of void ratio in the regenerator, and the air flow is prone to form local channels when passing through the ball bed, resulting in air flow segregation. During the air supply process, low-temperature regions and high-temperature regions coexist, and the temperature fluctuation at the hot air outlet is large, which is difficult to meet the requirements of the blast furnace for stable high hot air temperature. At the same time, it is difficult to clean the dust accumulated in the ball bed, which further aggravates the problem of uneven air flow distribution.

[0006] In view of the above problems, although a variety of improved solutions have been proposed in the prior art, for example, optimizing the material formula of refractory balls to improve their creep resistance, or changing the particle size gradation of refractory balls to reduce the resistance of the ball bed, none of these solutions can fundamentally solve the problem. The optimization of refractory ball materials is restricted by material cost and technical bottlenecks, and the improvement range is limited; the adjustment of particle size gradation is difficult to balance the heat exchange efficiency and air flow resistance.

[0007] Some technical solutions propose using regenerator checker bricks instead of refractory balls in the regenerator, but the cost of regenerator checker bricks is much higher than that of refractory balls. If the entire regenerator is made of checker bricks, the construction and renovation costs are too high, the economic efficiency is poor, and it is difficult to promote its application in small and medium-sized blast furnaces.

[0008] Therefore, how to overcome the shortcomings of refractory balls, such as easy creep and breakage in high-temperature areas, large ball bed resistance, and poor air temperature stability, while retaining the low-cost advantage of refractory balls, and at the same time taking into account the overall service life and heat exchange performance of the heat storage chamber, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings and defects of the existing technology by providing a method for constructing a zoned heat storage chamber for a hot blast stove and a heat storage structure.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: a method for constructing a partitioned regenerator chamber in a hot blast stove and a regenerator structure, comprising the following steps: obtaining the flue gas inlet temperature at the dome of the hot blast stove regenerator chamber. and furnace bottom exhaust gas outlet temperature And obtain the total height H of the heat storage chamber; based on the flue gas inlet temperature of the dome Furnace bottom exhaust gas outlet temperature Establish a linear temperature gradient model along the height direction of the heat storage chamber based on the total height H of the heat storage chamber, and calculate the temperature drop per unit height. Based on the creep resistance temperature threshold of refractory materials Combined with the temperature drop per unit height Calculate the temperature inside the thermal storage chamber as it drops to the creep resistance temperature threshold. The first dividing height According to the first dividing height The heat storage chamber is divided into multiple temperature zones along the height direction, including at least a high-temperature zone and a medium-low-temperature zone; A first heat storage body is filled in the high-temperature zone, and a second heat storage body is filled in the medium-low temperature zone. The high-temperature creep resistance of the first heat storage body is better than that of the second heat storage body.

[0011] Furthermore, the furnace includes a furnace shell and a heat storage body disposed within the furnace shell. The heat storage body comprises at least an upper section and a lower section along its height. The upper section corresponds to the high-temperature zone and is filled with heat storage checker bricks, while the lower section corresponds to the medium-low temperature zone and is filled with refractory balls. The interface between the upper and lower sections corresponds to the isothermal surface height at which the flue gas temperature in the heat storage chamber drops to the creep initiation temperature threshold of the refractory balls, i.e., the first boundary height. .

[0012] Furthermore, the flue gas inlet temperature of the dome The temperature of the exhaust gas outlet at the furnace bottom is 1350℃~1450℃. The temperature range is 250℃ to 350℃; the creep resistance temperature threshold is... The temperature is 1100℃, and the first dividing height is... The high-temperature zone is the area from the top of the dome down to the first dividing height y1, and the medium-low temperature zone is the area from the first dividing height y1 to the bottom of the furnace.

[0013] Furthermore, it also includes the steps for dividing the temperature range into intermediate and low temperature ranges: Let Calculate the second dividing height ; set the first dividing height To the second dividing height The area between the two is designated as the medium-temperature zone, and the area from the second dividing height y2 to the furnace bottom is designated as the low-temperature zone. Both the medium-temperature zone and the low-temperature zone are filled with refractory balls.

[0014] Furthermore, the creep resistance temperature threshold The temperature range is adjusted within the range of 1050℃ to 1150℃, depending on the temperature resistance of the refractory ball material.

[0015] Furthermore, the step of filling the high-temperature zone with heat-storing checker bricks after filling the low-temperature zone with refractory balls specifically includes: filling the heat-storing chamber with refractory balls up to the first dividing height y1; laying a leveling pad layer that can burn away at high temperatures on the top surface of the refractory balls; and building the heat-storing checker bricks on top of the leveling pad layer; the leveling pad layer is used to level the uneven top surface of the refractory balls into a horizontal reference surface during construction and burns away after being put into high-temperature operation.

[0016] Furthermore, the leveling pad is a wooden board, and the thickness of the leveling pad is 5mm to 50mm.

[0017] Furthermore, a load-bearing grid is provided between the heat storage checker bricks and the refractory balls. The load-bearing grid is fixed to the inner wall of the furnace shell and is used to support the heat storage checker bricks. A support grate is provided below the refractory balls, and the width of the opening gap of the support grate is smaller than the diameter of the smallest level of refractory balls filled with it.

[0018] Furthermore, an expansion gap is reserved between the inner wall of the furnace shell and the refractory ball, and the expansion gap is filled with a high-temperature resistant fiber buffer layer; the heat storage checker brick is a high-alumina or mullite checker brick, and its channel cross-sectional shape is any one of circular, hexagonal or rectangular.

[0019] Furthermore, it also includes a working method for a hot blast stove heat storage structure, the working method comprising: a combustion heat storage stage, in which high-temperature flue gas flows from top to bottom through heat storage checker bricks and refractory balls, wherein the heat storage checker bricks absorb heat from the high-temperature section above 1100℃, and the refractory balls absorb heat from the medium-low temperature section below 1100℃; and a blower heat exchange stage, in which cold air flows from bottom to top through the refractory balls and heat storage checker bricks and absorbs heat and rises in temperature step by step, and finally outputs hot air from the top of the stove.

[0020] After adopting the above technical solution, the beneficial effects of the present invention include at least the following points: 1. This invention physically isolates the refractory balls from the high-temperature flue gas using a temperature drop heat transfer model, ensuring that the refractory balls operate only in the medium-low temperature region below 1100℃, far below their creep initiation temperature of 1200℃. The refractory balls will not soften, stick together, or crumble at high temperatures, and the porosity of the ball layer remains stable over a long period. In actual production, the refractory balls can be used for more than five years without replacement, while traditional all-refractory ball structures can only be used for 8-12 months, increasing service life by 5-6 times. This significantly reduces the frequency of furnace shutdowns for ball replacement and the impact on continuous blast furnace production.

[0021] 2. The checker bricks have regular, straight through-hole channels, resulting in significantly less airflow resistance compared to the tortuous voids formed by randomly stacked refractory balls. Simultaneously, the refractory balls in the medium- and low-temperature zones maintain uniform and stable void spacing due to the absence of high-temperature bonding. The overall airflow resistance of the regenerator is significantly reduced compared to traditional all-refractory ball structures, effectively decreasing fan load and blower power consumption.

[0022] 3. The regular channels of the checker bricks ensure uniform airflow distribution and prevent localized airflow segregation. During the air supply process, the cold air passes through the refractory ball layer and the checker brick layer in sequence, absorbing heat and increasing in temperature step by step. The temperature drop is small and the temperature fluctuation is small, which enables the long-term stable output of high-temperature hot air, meeting the blast furnace's requirements for stable blast temperature.

[0023] 4. The material and construction costs of refractory balls are approximately one-third that of heat storage checker bricks. This invention uses heat storage checker bricks only in the high-temperature zone (approximately 1 / 4 to 1 / 3 of the total height of the heat storage chamber), while using low-cost refractory balls in the medium and low-temperature zones. This significantly reduces the material cost and modification cost of the overall heat storage structure while ensuring heat storage performance and structural stability in the high-temperature zone, demonstrating good economic viability and industrial application value.

[0024] 5. The refractory balls operate only in the medium and low temperature range, without high-temperature adhesion and clumping, and the porosity of the ball layer remains stable over a long period. Dust accumulation is evenly distributed on the surface of the refractory balls, making cleaning easy and reducing the requirements for dust removal equipment, thus helping to lower the overall operation and maintenance costs of the hot blast stove system.

[0025] 6. The bottom of the regenerator is equipped with a supporting grate, the gap width of which is smaller than the diameter of the refractory balls, effectively preventing the refractory balls from leaking into the bottom flue. A load-bearing grid fixed to the inner wall of the furnace shell is installed between the regenerator checker bricks and the refractory balls. Even after the leveling layer has burned away due to high-temperature combustion, the upper checker bricks are still reliably supported by the load-bearing grid, preventing settlement or tilting and ensuring the long-term stable operation of the regenerator. An expansion gap is reserved between the inner wall of the furnace shell and the refractory balls and filled with a high-temperature resistant fiber buffer layer, effectively absorbing the thermal expansion deformation of the refractory balls and the furnace shell under high-temperature conditions, preventing the furnace shell from cracking or the refractory balls from breaking under pressure. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figure 2 yes Figure 1 Enlarged structural diagram at point A in the middle.

[0029] Figure 3 yes Figure 1 Enlarged structural diagram at point B.

[0030] Figure 4 This is a schematic diagram of the structure of the heat storage checker brick in this invention.

[0031] Explanation of reference numerals in the attached drawings: 1. Furnace shell; 2. Heat storage checker bricks; 3. Refractory balls; 4. Leveling pad; 5. Expansion gap; 6. Supporting grate. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] In the description of this invention, the terms "upper," "lower," "top," "bottom," "longitudinal," "lateral," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Example 1: Basic Structure of Hot Blast Stove Heat Storage like Figures 1-4 As shown, the present invention provides a hot blast stove heat storage structure, including a furnace shell 1 and a heat storage body disposed within the furnace shell 1. The top of the furnace shell 1 is an arched roof, which is provided with a high-temperature flue gas inlet and a hot air outlet (not labeled in the figure), and the bottom of the furnace shell 1 is provided with a furnace bottom exhaust gas outlet and a cold air inlet (not labeled in the figure).

[0035] The heat storage body is divided into an upper section and a lower section along its height. The upper section corresponds to the high-temperature zone and is filled with heat storage checker bricks 2; the lower section corresponds to the medium-low temperature zone and is filled with refractory balls 3. The interface between the upper and lower sections corresponds to the isothermal surface height at which the flue gas temperature in the heat storage chamber drops to the creep initiation temperature threshold of the refractory balls 3, i.e., the first dividing height. .

[0036] Specifically, in this embodiment, the total height of the heat storage chamber H = 18m, and the flue gas inlet temperature at the dome is... The temperature at the furnace bottom exhaust gas outlet is 1400℃. The temperature is 310℃. Calculations using a temperature drop and heat transfer model show that the temperature drop per unit height is: = (1400 − 310) ÷ 18 ≈ 60.56℃ / m The first dividing line is between the high-temperature zone and the medium-low-temperature zone: = (1400 −1100) ÷ 60.56 ≈ 4.95m That is, the area from 0 to 4.95m below the arch is the high-temperature zone, filled with heat-storing checker bricks 2; the area from 4.95m to 18m is the medium-low temperature zone, filled with refractory balls 3.

[0037] A load-bearing grid (not shown in the figure) is provided between the heat storage grid brick 2 and the refractory ball 3. The load-bearing grid is fixed to the inner wall of the furnace shell 1 to support the heat storage grid brick 2 and prevent the upper grid brick 2 from sinking or tilting during high-temperature operation.

[0038] A support grate 6 is provided below the refractory ball 3, and the support grate 6 is fixed to the bottom inner wall of the furnace shell 1. The width of the openings and gaps in the support grate 6 is smaller than the diameter of the smallest refractory ball 3 that is filled, so as to prevent the refractory ball 3 from passing through the gaps in the grate and falling into the bottom flue under the impact of gravity and airflow.

[0039] like Figure 3 As shown, an expansion gap 5 is reserved between the inner wall of the furnace shell 1 and the refractory ball 3, and the expansion gap 5 is filled with a high-temperature resistant fiber buffer layer. This buffer layer is used to offset the thermal expansion deformation of the refractory ball 3 and the furnace shell 1 under high-temperature conditions, and to prevent the furnace shell from cracking or the refractory ball from being damaged by pressure.

[0040] The heat storage checker brick 2 is a high-alumina or mullite checker brick with regular, straight through-hole channels. The cross-sectional shape of these channels can be any of circular, hexagonal, or rectangular. For example... Figure 4 As shown, in this embodiment, the cross-sectional shape of the channels in the heat storage checker brick 2 is circular, and multiple circular channels are evenly distributed in an array within the brick. The wall thickness and pore diameter of the checker brick 2 are selected according to the heat exchange capacity and airflow resistance requirements of the heat storage chamber, and those skilled in the art can make reasonable designs according to actual needs.

[0041] The refractory ball 3 is a high-alumina refractory ball with a diameter ranging from 40mm to 80mm. In this embodiment, the refractory ball 3 selected has a diameter of 60mm and adopts a multi-stage particle size distribution filling method to improve the filling density and heat exchange efficiency.

[0042] Example 2: A method for constructing a zoned heat storage structure for a hot blast stove This embodiment provides a method for constructing a partitioned regenerator chamber in a hot blast stove, including the following steps: Step 1: Collection of basic process parameters Obtain the flue gas inlet temperature at the dome of the hot blast stove regenerator. and furnace bottom exhaust gas outlet temperature The total height H of the heat storage chamber was obtained. Simultaneously, auxiliary parameters such as the cross-sectional area S of the heat storage chamber, the specific surface area of ​​the heat storage body, and the gas flow velocity were collected for subsequent heat exchange verification.

[0043] In this embodiment, , H=18m.

[0044] Step 2: Establish a linear temperature gradient model along the height. Based on the principle of engineering iteration simplification, the flue gas cools down at a uniform rate from top to bottom, with the temperature decreasing approximately linearly along the height. A linear temperature drop model is established:

[0045] Temperature drop per unit height: The flue gas temperature at any height y, where y is the distance from the vault: In this embodiment: = (1400 − 310) ÷ 18 ≈60.56℃ / m.

[0046] Step 3: Solve for the temperature zone boundary height Based on the creep resistance temperature threshold of refractory ball 3, 1100℃ (conventional high-alumina refractory balls begin to creep above 1200℃, so 1100℃ is taken as the safety threshold), calculate the first boundary height y1: Let Solution Furthermore, let Calculate the second dividing height : .

[0047] This completes the division of temperature ranges: 0~4.95m: High-temperature zone 1100℃~1400℃ 4.95m~9.91m: Medium temperature zone 800℃~1100℃ 9.91m~18m: Low temperature zone 310℃~800℃ The medium-temperature zone and the low-temperature zone are collectively referred to as the medium-low temperature zone.

[0048] Step 4: Fill the partitions according to their results Based on the calculation results in step three, heat storage checker bricks 2 are filled in the high temperature zone (0-4.95m), and refractory balls 3 are filled in the medium and low temperature zone (4.95m-18m).

[0049] When the material of refractory ball 3 is replaced with magnesium-aluminum refractory ball with a higher creep temperature, the creep temperature threshold can be adjusted adaptively within the range of 1050℃~1150℃ according to the actual material.

[0050] Step 5: Acceptance and Verification of Zoning Structure After filling is completed, the heat storage chamber is inspected for airflow uniformity and structural stability to ensure that the structural components at the dividing height are tightly connected and the airflow channels are unobstructed.

[0051] Example 3: Installation and Construction Method of Hot Blast Stove Heat Storage Structure This embodiment provides a specific installation and construction method for a hot blast stove heat storage structure, including the following steps: I. Furnace cleaning and grate maintenance After the hot blast stove is shut down and cooled to room temperature, remove the waste refractory balls and other debris from the heat storage chamber. Conduct a comprehensive overhaul and reinforcement of the bottom support grate 6, checking the load-bearing capacity, permeability of the openings, and integrity of the fixed connections to ensure that the support grate 6 can reliably support the weight of the entire upper heat storage body.

[0052] The width of the openings in the supporting grate 6 should be smaller than the diameter of the smallest first-level refractory ball 3 to prevent the refractory balls from leaking into the bottom flue during operation. In this embodiment, the width of the openings in the supporting grate 6 is 25mm, and the minimum diameter of the refractory balls 3 is 40mm.

[0053] II. Bottom refractory ball filling Refractory balls 3 are filled into the heat storage chamber from bottom to top, and the filling continues until the first boundary height is reached. (In this embodiment, the location is 4.95m). During the filling process, a uniform material distribution method should be used to avoid excessive accumulation of refractory balls 3 in a certain local area or the formation of voids.

[0054] For newly built hot blast stoves, refractory balls 3 can be directly added through the manhole on the top of the stove and evenly distributed by a rotating material distributor; for renovated hot blast stoves, the existing loading and unloading holes can be used for filling. During the filling process, the balls should be compacted in layers to ensure uniform density.

[0055] Meanwhile, an expansion gap 5 is reserved between the inner wall of the furnace shell 1 and the refractory ball 3. The width of the expansion gap 5 is generally 20mm to 50mm (30mm in this embodiment). A high-temperature resistant fiber buffer layer 12, such as an aluminosilicate fiber blanket or a zirconium-containing ceramic fiber blanket, is filled in the expansion gap 5 to absorb the thermal expansion deformation of the refractory ball and the furnace shell under high-temperature conditions.

[0056] III. Installation of Load-Bearing Grille At the dividing height At the height of the top surface of the refractory ball 3, a load-bearing grating is installed and fixed to the inner wall of the furnace shell 1. The load-bearing grating is made of high-temperature resistant stainless steel and has sufficient creep resistance and load-bearing capacity.

[0057] The load-bearing grating is installed as follows: a load-bearing bracket or annular support is pre-installed at the corresponding height on the inner wall of the furnace shell 1. The load-bearing grating is then placed horizontally on top of the bracket and fixed by bolts or welding. The grid spacing of the load-bearing grating should ensure that the upper heat storage grating bricks 2 can be placed stably and will not fall out of the grid gaps.

[0058] IV. Leveling and Subbase Laying After the refractory balls 3 are filled, the top surface of the refractory balls 3 is uneven. If the checker bricks 2 are laid directly, problems such as brick tilting, uneven stress, air leakage between brick joints, and local stress concentration will occur. Therefore, a leveling layer 4 needs to be laid on the top surface of the refractory balls 3.

[0059] The leveling layer 4 is made of a material that can burn away at high temperatures; in this embodiment, a 20mm thick wooden board is preferred. The specific construction method is as follows: open the manhole at the top of the heat storage chamber, lay the wooden boards one by one on the top surface of the refractory ball 3, and manually level it until it covers the entire cross-section of the heat storage chamber, leveling the uneven surface of the refractory ball to form a flat and continuous horizontal reference surface.

[0060] The thickness of the leveling layer 4 is not limited to 20mm, and can be selected within the range of 5mm to 50mm depending on the actual unevenness after the refractory balls 3 are laid. The material of the leveling layer 4 is not limited to wood; any organic layer that can be completely burned at high temperatures without leaving any hard ash residue can be used as a substitute.

[0061] The advantages of using wooden boards are: the boards have moderate rigidity, allowing for uniform elevation; after being put into the production furnace, the high temperature directly melts the bottom boards, and the combustion products are carbon dioxide and water vapor, leaving no ash residue and preventing blockage of the pores of the checker bricks 2. Furthermore, the leveling layer 4 does not require removal during construction, reducing construction steps and time.

[0062] V. Checkered brick masonry Construct heat storage checker bricks 2 on top of the leveling layer 4. When constructing, lay the bricks layer by layer from the center of the heat storage chamber outwards, ensuring that the holes of each layer of checker bricks are aligned vertically and horizontally to form a continuous straight airflow channel.

[0063] The laying height of the heat storage checker brick 2 is from the dividing height Starting from the base, continue filling the entire high-temperature zone of the heat storage chamber until below the vault. During the masonry process, the levelness and verticality of the checker bricks 2 should be checked at any time to ensure that the bricks are neatly arranged, the brick joints are tight, and the channels are unobstructed.

[0064] After the masonry is completed, the leveling layer 4 serves only as a temporary leveling reference surface during construction and does not participate in the final load-bearing. When the leveling layer 4 is ablated by high temperature, the checker bricks 2 are supported by the load-bearing grid and the leveled and compacted refractory ball layer 3 below, ensuring long-term structural stability and reliability.

[0065] Example 4: Working heat exchange method of hot blast stove heat storage structure This embodiment illustrates the working heat exchange principle and specific process of the heat storage structure of the present invention in actual production.

[0066] The hot blast stove operates in a cyclical alternation mode, consisting of two working cycles: a combustion heat storage stage and an air supply heat exchange stage. The heat storage structure of this invention achieves heat storage and release in both stages, with each zone's materials leveraging their respective performance advantages.

[0067] The heat storage and absorption process in the combustion heat storage stage High-temperature flue gas is introduced into the regenerator from top to bottom through the flue gas inlet at the dome (e.g., Figure 1 (As indicated by the middle arrow), the flue gas temperature is determined by the dome temperature. (1350~1450℃) linearly and gradually decreases along the height direction to the furnace bottom temperature. (250~350℃).

[0068] The top 0~y1 high temperature zone is above 1100℃: High-temperature flue gas flows through the heat-storing checker brick 2. The heat-storing checker brick 2 has regular, straight-line through-hole channels, a large specific surface area, and excellent high-temperature resistance due to its high-alumina or mullite material (capable of withstanding temperatures above 1300℃ for extended periods). A large amount of high-temperature heat in the flue gas is rapidly absorbed and stored by the checker brick 2. Because the checker brick 2 has a rigid structure, it will not undergo creep deformation or adhesion at high temperatures, ensuring that the airflow channels remain unobstructed and the flue gas resistance is stable.

[0069] In the middle section, y1~y2, the temperature range is 800~1100℃: After heat exchange in the high-temperature zone, the flue gas temperature drops to 800~1100℃, entering the middle-temperature zone. The residual heat carried by the flue gas in the middle temperature zone is absorbed and stored by the refractory balls 3 as it passes through them. Within this temperature range, the temperature of the refractory balls 3 is far below their creep initiation temperature of 1200℃, ensuring a stable material structure that will not soften, stick together, or break.

[0070] lower part Low temperature zone 250~800℃: The flue gas temperature is further reduced to the low temperature zone of 250~800℃. The remaining low temperature heat is fully absorbed by the refractory ball 3 and then discharged from the bottom of the furnace, completing the heat storage of the whole furnace.

[0071] Throughout the combustion heat storage stage, the temperature distribution in the heat storage chamber always maintains a gradient pattern of "high at the top and low at the bottom," which is highly consistent with the linear temperature drop model.

[0072] Second stage of air supply and heat exchange After the combustion and heat storage stage is completed, the flue gas passage is closed, and the system is switched to air supply mode. Cold air is introduced into the heat storage chamber from the bottom cold air inlet in the reverse direction. Figure 1 As shown by the middle arrow, it passes through three layers of refractory balls and two layers of heat-storing checker bricks in sequence, absorbing heat and increasing temperature step by step.

[0073] Bottom low-temperature refractory ball area: The cold air at 180-250℃ first passes through the refractory ball 3 in the low-temperature zone at the bottom, absorbing the residual heat stored in the refractory ball 3 to complete the initial heating.

[0074] Central medium-temperature refractory ball section: The airflow rises and enters the refractory ball layer 3 in the medium-temperature zone, continuing to absorb medium-temperature heat, further increasing the air temperature to around 800℃.

[0075] Upper high-temperature checkered brick area: When the airflow reaches the heat storage checker brick 2 in the upper high-temperature zone, the large amount of high-temperature heat stored in the checker brick 2 is released rapidly, heating the cold air to the target hot air temperature of 1150-1300℃, and then transporting it from the hot air outlet at the top of the arch to the blast furnace for blast furnace smelting.

[0076] The overall advantages of stratified heat exchange: 1. The checker bricks have regular channels, uniform airflow distribution, small temperature drop throughout the air supply process, and stable hot air temperature, which solves the problems of messy gaps and large fluctuations in air supply temperature in traditional all-fired ball structures.

[0077] 2. The airflow resistance of the layered structure is much lower than that of a pure refractory ball bed, which reduces the blower load and lowers the power consumption of production.

[0078] 3. The refractory ball 3 only works in the medium and low temperature range, without high temperature damage and clumping. The porosity of the ball layer remains stable for a long time, the ash accumulation is uniform and easy to clean, which greatly reduces the load on the dust removal equipment.

[0079] Example 5: Implementation methods under different operating parameters The method of the present invention is also applicable when the process parameters of the hot blast stove change; only the calculation parameters need to be adjusted accordingly.

[0080] Operating Condition 1: The total height H of the regenerator chamber of a hot blast stove is 20m, and the temperature at the top of the dome is... Furnace bottom exhaust gas temperature .

[0081] The calculation is as follows: .

[0082] The high temperature zone is 0–6.36m, the medium temperature zone is 6.36m–11.82m, and the low temperature zone is 11.82m–20m.

[0083] Operating Condition 2: The total height of the regenerator chamber of a hot blast stove is H=15m, and the temperature at the top of the dome is... Furnace bottom exhaust gas temperature .

[0084] The calculation is as follows: The high temperature zone is 0–3.41m, the medium temperature zone is 3.41m–7.50m, and the low temperature zone is 7.50m–15m.

[0085] Under the aforementioned different operating conditions, after calculating and determining the boundary height according to the method of this invention, heat-storing checker bricks 2 are filled in the high-temperature zone, and refractory balls 3 are filled in the medium- and low-temperature zone. The installation and heat exchange methods are the same as those in Examples 1 to 4, indicating that the method of this invention has good adaptability and versatility under operating conditions.

[0086] Best practice Based on the above embodiments, the optimal implementation of the present invention is as follows: the total height of the heat storage chamber H = 18m, and the flue gas inlet temperature at the dome... Furnace bottom exhaust gas outlet temperature The refractory ball 3 is a conventional high-alumina refractory ball with a diameter of 40-80mm, and the heat storage checker brick 2 is a high-alumina checker brick with circular channels.

[0087] The boundary height between the high-temperature zone and the medium-low temperature zone was calculated using a temperature drop heat transfer model. In the high-temperature zone of 0–4.95m, heat-storing checker bricks 2 are filled, and in the medium-low temperature zone of 4.95m–18m, refractory balls 3 are filled. At the dividing height, a load-bearing grid is set to support the upper checker bricks. A 20mm wooden board is laid on the top surface of the refractory balls for leveling before the checker bricks are built. The bottom of the refractory balls is supported by a supporting grate 6. An expansion gap is set between the furnace wall and the refractory balls and filled with a fiber buffer layer.

[0088] Under this scheme, the service life of the heat storage chamber can reach more than five years, the hot air outlet temperature is stable at 1180-1250℃, the refractory balls do not suffer from high-temperature bonding and damage, and the overall economic benefits are the best.

[0089] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing a zoned regenerator chamber in a hot blast stove, characterized in that: Includes the following steps: Obtain the flue gas inlet temperature at the dome of the hot blast stove regenerator. and furnace bottom exhaust gas outlet temperature And obtain the total height H of the heat storage chamber; Based on the flue gas inlet temperature of the dome Furnace bottom exhaust gas outlet temperature Establish a linear temperature gradient model along the height direction of the heat storage chamber based on the total height H of the heat storage chamber, and calculate the temperature drop per unit height. ; Based on the creep resistance temperature threshold of refractory materials Combined with the temperature drop per unit height Calculate the temperature inside the thermal storage chamber as it drops to the creep resistance temperature threshold. The first dividing height ; According to the first dividing height The heat storage chamber is divided into multiple temperature zones along the height direction, including at least a high-temperature zone and a medium-low-temperature zone; A first heat storage body is filled in the high-temperature zone, and a second heat storage body is filled in the medium-low temperature zone. The high-temperature creep resistance of the first heat storage body is better than that of the second heat storage body.

2. A hot blast stove heat storage structure constructed using the method described in claim 1, comprising a furnace shell (1) and a heat storage body disposed within the furnace shell (1), characterized in that: The heat storage body includes at least an upper section and a lower section along the height direction; The upper section corresponds to the high temperature zone and is filled with heat storage grid bricks (2), while the lower section corresponds to the medium and low temperature zone and is filled with refractory balls (3). The interface between the upper and lower sections corresponds to the isothermal surface height at which the flue gas temperature in the heat storage chamber drops to the creep initiation temperature threshold of the refractory ball (3), i.e., the first boundary height. .

3. The method for constructing a zoned regenerator chamber in a hot blast stove according to claim 1, characterized in that: The flue gas inlet temperature at the dome The temperature of the exhaust gas outlet at the furnace bottom is 1350℃~1450℃. The temperature range is 250℃ to 350℃; the creep resistance temperature threshold is... The temperature is 1100℃, and the first dividing height is... The high-temperature zone is the area from the top of the dome down to the first dividing height y1, and the medium-low temperature zone is the area from the first dividing height y1 to the bottom of the furnace.

4. The method for constructing a zoned regenerator chamber in a hot blast stove according to claim 3, characterized in that: It also includes the steps for dividing the temperature zone into medium and low temperature zones: make Calculate the second dividing height ; The first dividing height To the second dividing height The area between the two is designated as the medium temperature zone, and the area from the second dividing height y2 to the bottom of the furnace is designated as the low temperature zone. Both the medium temperature zone and the low temperature zone are filled with refractory balls (3).

5. The method for constructing a zoned regenerator chamber in a hot blast stove according to claim 1, characterized in that: The creep resistance temperature threshold The temperature range of the refractory ball (3) is adjusted within the range of 1050℃~1150℃, depending on the material temperature resistance performance.

6. The method for constructing a zoned regenerator chamber in a hot blast stove according to claim 1, characterized in that: The step of filling the high-temperature zone with heat-storing checker bricks (2) after filling the refractory balls (3) in the low-temperature zone specifically includes: Fill the heat storage chamber with refractory balls (3) up to the first dividing height y1; A leveling pad (4) that can burn away at high temperature is laid on the top surface of the fire-resistant ball (3); The heat storage grid bricks (2) are laid on top of the leveling layer (11); The leveling layer (11) is used to level the uneven top surface of the fire-resistant ball (3) into a horizontal reference surface during construction, and burns away after being put into high-temperature operation.

7. The method for constructing a zoned regenerator chamber in a hot blast stove according to claim 6, characterized in that: The leveling pad (4) is a wooden board, and the thickness of the leveling pad (4) is 5mm to 50mm.

8. The heat storage structure for a hot blast stove heat storage chamber partitioned according to claim 2, characterized in that: A load-bearing grid is provided between the heat storage grid brick (2) and the refractory ball (3). The load-bearing grid is fixed to the inner wall of the furnace shell (1) and is used to support the heat storage grid brick (2). A support grate plate (6) is provided below the refractory ball (3). The width of the opening gap of the support grate plate (6) is smaller than the diameter of the smallest first-level refractory ball (3) that is filled.

9. A heat storage structure for partitioned construction of a hot blast stove heat storage chamber according to claim 2, characterized in that: An expansion gap (5) is reserved between the inner wall of the furnace shell (1) and the refractory ball (3), and the expansion gap (5) is filled with a high-temperature resistant fiber buffer layer; the heat storage grid brick (2) is a high-alumina or mullite grid brick, and its channel cross-sectional shape is any one of circular, hexagonal or rectangular.

10. A heat storage structure for partitioned construction of a hot blast stove heat storage chamber according to claim 2, characterized in that: It also includes a method for operating a hot blast stove heat storage structure, the method comprising: During the combustion and heat storage stage, high-temperature flue gas flows from top to bottom through the heat storage checker brick (2) and the refractory ball (3) from the top of the arch. The heat storage checker brick (2) absorbs heat from the high-temperature section above 1100℃, and the refractory ball (3) absorbs heat from the medium and low temperature section below 1100℃. During the air supply and heat exchange stage, cold air flows from the bottom of the furnace upward through the refractory ball (3) and the heat storage checker brick (2) and absorbs heat and heats up step by step, and finally outputs hot air from the arch.

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