High-air-temperature top combustion type hot blast stove

Abstract

The utility model relates to the technical field of blast furnace hot blast stoves in the metallurgical industry, in particular to a high-air-temperature top combustion type hot blast stove which comprises a stove body, a pre-combustion chamber, a combustion chamber and a heat storage chamber filled with heat storage bodies, a plurality of mixing nozzles are formed in the inner wall of the pre-combustion chamber wall body, and at least one layer of mixing nozzles is arranged; the mixing nozzle comprises a central air channel filled with air and a coal gas channel filled with coal gas, the outermost layer is a second air channel filled with air, and the channels are concentric; cooling pipes are arranged at the air inlet and the coal gas inlet; the furnace column is of a sandwich structure; and an air preheater and a coal gas preheater are arranged on the flue pipeline. By adopting an efficient nozzle combustion technology, a pre-combustion chamber thermal shock reducing technology and a high-temperature-resistant furnace column technology, low-heating-value gas is effectively utilized, and single blast furnace gas is burnt, so that the air temperature of the hot blast stove reaches 1200 DEG C or above.

Description

TECHNICAL FIELD

[0001] The utility model relates to metallurgical industry blast furnace hot blast stove technical field especially a kind of high wind temperature top combustion hot blast stove. BACKGROUND

[0002] Hot blast stove is the device to provide hot blast to blast furnace, to ensure the normal smelting of blast furnace. For blast furnace, every 100 ℃ wind temperature is increased, can reduce coke ratio 10-15 kg / t Fe, increase output 5%, while increase blast furnace coal injection amount, reduce CO2 emission, make blast furnace efficiency increase, reduce ironmaking cost;Therefore, the high wind temperature and high-efficiency stable operation of hot blast stove have important significance to reduce energy consumption. The technology of realizing high wind temperature at home and abroad mainly has the following three kinds: mixing high calorific value coal gas (such as coke oven gas), improving combustion air and coal gas temperature, at present, steel plant coke oven gas is generally lack and blast furnace gas is surplus, therefore, how to use single blast furnace gas to realize hot blast stove 1200 ℃ above wind temperature is the subject of concern of enterprise. Blast furnace gas heating value is low, to reach 1200 ℃ above wind temperature, hot blast stove needs to have high-efficiency stable long-life nozzle (burner), and high-efficiency simple preheating combustion air, coal gas temperature to higher temperature.

[0003] Hot blast stove used in China mainly has internal combustion type, external combustion type and top combustion type three kinds, wherein top combustion type hot blast stove gradually becomes mainstream furnace type because of its stable structure, high wind temperature, long life, investment saving and other advantages.

[0004] The nozzle structure of top combustion type hot blast stove precombustion chamber (burner) mainly has the following technical solutions:

[0005] First, the coal gas nozzle and air nozzle on the side wall of precombustion chamber are arranged in layers, and in order to improve the mixing effect of coal gas and air, the coal gas nozzle and / or air nozzle are arranged at a certain angle in radial and axial direction, such as patent CN100344772C and CN2861169Y;Further, in order to solve the problem of poor mixing of coal gas and air, incomplete or unstable combustion, such as patent CN201373398Y, multiple coal gas nozzles and air nozzles are arranged in staggered layers, and the outlet direction of air nozzle is inclined upward, and the outlet direction of coal gas nozzle is horizontal or inclined downward. The multiple nozzles of air and multiple nozzles of coal gas in this technical solution are layered mixed as a whole, forming a premixed long flame combustion mode, which needs a large mixing and combustion space, a long distance and a long flame, so that a large enough mixing and combustion space of precombustion chamber and combustion chamber is needed to realize complete combustion, and the excess air ratio is greater than 1.1.

[0006] Furthermore, during combustion in this type of hot blast furnace, the air and gas are stratified, with combustion occurring in the lower portion. Consequently, the pre-combustion chamber temperature is low when the furnace is burning; however, when the furnace is delivering hot air, the high-temperature hot air significantly increases the pre-combustion chamber temperature. These two states alternate as the furnace transitions between combustion and air delivery. The large, periodic temperature fluctuations in the pre-combustion chamber can adversely affect the pre-combustion chamber, damaging the refractory materials and shortening their lifespan. To extend the lifespan of the pre-combustion chamber, refractory materials with high thermal shock resistance, such as mullite-cordierite bricks, are typically used in areas of the pre-combustion chamber where the temperature fluctuates dramatically. This approach increases investment in refractory materials and does not fundamentally eliminate the factors that shorten the pre-combustion chamber's lifespan.

[0007] Secondly, the gas nozzles and air nozzles are staggered on an annular surface perpendicular to the axis of the pre-combustion chamber, such as patents CN100523610C and CN2687573Y. This technical solution forms a short flame combustion mode, which does not require a pre-combustion chamber or a large combustion chamber. It can meet the technical requirements of high efficiency and high wind temperature, and at the same time shorten the time required for complete combustion of air and gas, effectively increase the flame temperature during combustion, and the excess air coefficient is generally 1.05-1.1.

[0008] At the same time, long-term practice has proven that top-fired hot blast furnaces using short-flame mixed combustion do not damage the pre-combustion chamber nozzle during combustion, indicating no detonation. However, hot blast furnaces using premixed long-flame swirl flow experience phenomena such as gas nozzle peeling, fracture, and displacement, indicating the presence of detonation. In summary, short-flame mixed combustion is better, safer, and more uniform, but short-flame combustion technology still leaves some unburned gas in the mixed combustion flame at the nozzle.

[0009] A hot blast furnace's operating cycle consists of a combustion phase and an air supply phase, which alternate repeatedly. During the combustion phase, gas and combustion air continuously flow through the pre-combustion chamber's airflow channels, resulting in surface temperatures comparable to those of the heated gas and combustion air. When combustion is complete and the hot blast furnace enters the air supply phase, gas and combustion air no longer flow through the pre-combustion chamber, effectively stopping their cooling effect on the pre-combustion chamber's airflow channel lining. The hot blast, which can reach temperatures of 1200-1350°C, heats the channel lining, particularly at the nozzle outlet, rapidly reaching temperatures approaching these highs. Consequently, the pre-combustion chamber lining temperature can fluctuate by as much as 800-1000°C within a single hot blast furnace cycle. These frequent and drastic temperature fluctuations can rapidly cause the ceramic burner lining to flake, crack, and become damaged, shortening the burner's lifespan.

[0010] The top combustion hot blast stove is limited by the grate, the column and the like structure at the lower part of the regenerator and the heat resistance temperature, and the exhaust gas temperature is generally up to 450 DEG C. Due to the low exhaust gas temperature, after the air and the gas preheater are arranged at the rear of the flue, the preheating temperature of the air and the gas can only reach about 180 DEG C, and when the preheated air and the gas enter the precombustion chamber for combustion, the combustion temperature is limited, and it is difficult to realize that only the low calorific value blast furnace gas is burned, and the blast temperature is kept above 1200 DEG C. In order to burn only the low calorific value fuel to obtain the high blast temperature above 1200 DEG C, it is necessary to find a way to increase the combustion air of the hot blast stove to 400-550 DEG C and the gas temperature to above 180 DEG C, and the main ways are as follows: 1. adding a small hot blast stove for preheating the combustion air, such as patents CN200410009644.3 and

[0011] CN200920172956.4, which has the disadvantages of increasing the floor area, high investment cost, complex operation and the like; 2. increasing the temperature of the flue gas for preheating the combustion air and the gas, 1. adding a combustion furnace or a burner to increase the flue gas temperature, such as CN201110387988.8 and CN201921401842.2, but there are the disadvantages of large floor area, high investment, complex operation and the like; 2. directly increasing the exhaust gas temperature of the hot blast stove, which needs to select the high-temperature resistant metal material for the grate, the column and the like, and the cost of the hot blast stove is increased. Practical new type content

[0012] In view of the defects in the prior art, the purpose of the present application is to provide a high blast temperature top combustion hot blast stove which uses the high-efficiency nozzle combustion technology, the precombustion chamber thermal shock reduction technology and the high-temperature resistant column technology, effectively utilizes the low calorific value gas, and realizes that the hot blast stove burns only the single blast furnace gas to reach the blast temperature above 1200 DEG C. The problems such as the incomplete combustion of the gas, the detonation combustion, the large periodic temperature difference change of the precombustion chamber and the blast temperature not being kept above 1200 DEG C can be effectively solved, and the production efficiency and the service life are improved.

[0013] In order to realize the above-mentioned purpose, the present application is realized by the following technical scheme:

[0014] The present application provides a high blast temperature top combustion hot blast stove, which comprises:

[0015] The furnace body is provided with the precombustion chamber, the combustion chamber and the regenerator chamber filled with the regenerator arranged in sequence from top to bottom, and the precombustion chamber is arranged above the combustion chamber, and the regenerator chamber is arranged below the combustion chamber;

[0016] The inner wall of the pre-combustion chamber is provided with a plurality of mixing nozzles, and at least one layer is provided. The mixing nozzles include a central air channel for air, a gas channel for gas, and an outermost layer of a second air channel for air. The central air channel, the gas channel, and the second air channel are concentric. In this way, the air and gas instantly converge and burn at the nozzle outlet, forming short-flame combustion. Short-flame combustion does not require a pre-combustion chamber, and the combustion chamber has a larger space, which can not only meet the technical requirements of high efficiency and high air temperature, but also shorten the time required for complete combustion of air and gas, effectively increase the flame temperature during combustion, and reduce the excess air coefficient to 1.05-1.1. After the secondary air is added, the flame leaving the nozzle is surrounded by a layer of oxygen, so that the gas is completely mixed with the air and burned without dispersing, thereby improving the combustion efficiency and heat production, and eliminating excess gas in the hot blast furnace, solving the problem of some gas not being completely burned in other short-flame combustion technologies.

[0017] The air inlet is connected to the central air channel and the second air channel respectively through the air ring cavity, and the gas inlet is connected to the gas channel through the gas ring cavity.

[0018] The air and gas inlets are equipped with cooling pipes and are connected. During the air supply period, cooling air from the cooling pipes is delivered into the furnace through the pre-combustion chamber's gas and air channels. This cooling air not only continues to cool the pre-combustion chamber lining during the burn-up period but also prevents high-temperature hot air from entering the pre-combustion chamber's interior, preventing temperature increases in the central air channel, gas channel, secondary air channel, and air and gas annular cavities. This reduces pre-combustion chamber temperature fluctuations to 100-200°C, thereby extending the pre-combustion chamber's lifespan.

[0019] The furnace column has a sandwich structure. The cooling medium is passed into the sandwich to cool the furnace column so that it can withstand the flue gas temperature of 600-800℃, thereby increasing the exhaust temperature of the hot blast furnace.

[0020] The hot blast furnace flue gas outlet is connected to the air preheater's flue gas inlet via flue duct 1. The air preheater's flue gas outlet is connected to the gas preheater's flue gas inlet via flue duct 2. The gas preheater's flue gas outlet is connected to the chimney via flue duct 3. The air preheater is equipped with a preheater air inlet and outlet pipes, which are connected to the hot blast furnace's air inlet via the preheater air outlet pipe. The gas preheater is equipped with a preheater gas inlet and outlet pipes, which are connected to the hot blast furnace's gas inlet via the preheater gas outlet pipe. The temperature of the hot blast furnace flue gas outlet is 600-800℃. It passes through the air preheater and gas preheater installed on the flue in sequence, which can preheat the air to 400-550℃ and the gas to 190-220℃. The two preheated gases are transported to the precombustion chamber for mixed combustion, so that only low calorific value blast furnace gas is burned, and the air supply temperature can reach 1250-1350℃. It is simple, safe, low-investment and low-energy consumption.

[0021] Specifically, when the pre-chamber side wall is provided with one layer of the mixed nozzle, the radial angle β between the mixed nozzle and the pre-chamber is 5°≤β≤35°.

[0022] Specifically, when the pre-chamber side wall is provided with more than one layer of the mixed nozzle, in addition to the lowermost layer of the mixed nozzle facing the furnace body axis, the radial angle β of the remaining mixed nozzles is set to 5°≤β≤35°. The setting of the swirl angle of the nozzle can make the air and gas mixture uniform, the airflow of the lowermost nozzle without swirl angle will disperse the high-speed rotating airflow of the upper nozzle, weaken the airflow backflow range of the combustion chamber, eliminate the central vortex, make the combustion in the combustion chamber more sufficient, the high-temperature flue gas distribution more uniform, the heat storage effect of the heat storage body improved, and the energy utilization rate improved.

[0023] Specifically, the central air passage and the gas passage are separated by an inner partition wall; the gas passage and the second air passage are separated by an outer partition wall. The partition wall prevents air and gas from mixing in advance.

[0024] Specifically, the inner swirl plate is arranged in the gas passage, and the outer swirl plate is arranged in the second air passage, to support the partition wall and make the fluid rotate.

[0025] Specifically, the inner swirl plate and the outer swirl plate have a set angle α1, α2 with the length direction of the mixed nozzle, and α2≥α1. So that the air and gas are spirally ejected, which can improve the mixing effect of air and gas.

[0026] Specifically, the furnace column is a double-jacket structure, including an inner jacket and an outer jacket, and a cooling medium is passed through the jacket. The medium is a liquid or a gas, and the liquid includes but is not limited to water, and the gas includes but is not limited to air. When the medium is air, it can be sent to the inlet of the air preheater after heat exchange through the jacket. By passing the cooling medium through the inner and outer jackets of the furnace column to cool the furnace column, the disadvantages of steel furnace columns not suitable for high-temperature environments are overcome, and the furnace column can be made of ordinary metal materials and can withstand 600-800℃ flue gas temperature, saving the investment of the furnace column. And the high temperature of the heat storage body is moved downward, increasing the heat storage amount of the high temperature in the heat storage body, improving the heat storage capacity and heat exchange capacity of the heat storage body and the utilization rate, prolonging the blast furnace blowing time, and achieving the effect of energy saving and emission reduction.

[0027] It also includes an air inlet, a gas inlet, a cold air inlet, a smoke outlet, a hot air outlet, a grate, a furnace pillar, and a heat storage body. The cold air inlet and the smoke outlet are arranged at the lower part of the furnace body, the furnace pillar is arranged at the lower part of the interior of the furnace body and supports the grate and the heat storage body above it, the hot air outlet is arranged at the upper middle part of the furnace body, and the air inlet and gas inlet are arranged at the upper part of the furnace body.

[0028] The beneficial effects of the above utility model are as follows:

[0029] 1. The mixing nozzles on the side walls of the pre-combustion chamber of this utility model utilize short-flame combustion technology. The three-channel arrangement of air, gas, and air shortens the time required for complete combustion of the air and gas, effectively raising the flame temperature during combustion, with an excess air coefficient as low as 1.05-1.1. The addition of secondary air surrounds the flame exiting the nozzles with a layer of oxygen, allowing the gas and air to completely mix and burn without dispersing. This improves combustion efficiency and heat production, while also eliminating excess gas within the hot blast furnace, solving the problem of unburned gas found in other short-flame combustion technologies.

[0030] 2. When there are multiple layers of mixing nozzles, the airflow ejected from the lowest layer of swirl angle mixing nozzles on the side wall of the pre-combustion chamber of the utility model disperses the high-speed rotating airflow ejected from the upper mixing nozzles on the side wall of the pre-combustion chamber, which can weaken the airflow backflow range in the combustion chamber, making the combustion in the combustion chamber more complete and more uniform, the high-temperature flue gas distribution more uniform, the heat storage effect of the heat storage body good, and the energy utilization rate high.

[0031] 3. The utility model is equipped with an inner swirl plate in the gas channel and an outer swirl plate in the second air channel. The swirl plate and the mixing nozzle have a set angle in the length direction so that the air and gas are ejected in a spiral shape, which can improve the mixing effect of air and gas.

[0032] 4. During the air supply period, the utility model introduces cold air to cool the pre-combustion chamber, reducing the temperature fluctuation of the pre-combustion chamber to 100-200°C, thereby extending the life of the pre-combustion chamber. It can also be used for the construction of new top-fired hot blast furnaces and for the renovation and update of top-fired hot blast furnaces.

[0033] 5. The furnace pillars of this utility model have a sandwich structure. By passing a cooling medium through the inner and outer interlayers of the furnace pillars to cool them, the furnace pillars can be made of ordinary metal and can withstand flue gas temperatures of 600-800°C, saving investment. The high temperature of the heat storage body is also transferred downward, increasing the heat storage capacity and heat exchange capacity of the heat storage body, as well as its utilization rate, and extending the blast furnace air supply time, thereby achieving the effect of energy conservation and emission reduction.

[0034] 6. The utility model adopts dual preheating of air and gas. Since the temperature of the hot blast furnace flue gas outlet can be as high as 600-800℃, the air can be preheated to 400-550℃ and the gas can be preheated to 190-220℃. The two preheated gases are transported to the hot blast furnace precombustion chamber for mixed combustion, so that only low calorific value blast furnace gas is burned so that the air supply temperature can reach 1250-1350℃. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0036] Figure 1 This is a schematic structural diagram of a high-temperature top-fired hot blast furnace in Example 1 of the present invention;

[0037] Figure 2 yes Figure 1 Enlarged view at point A in the middle;

[0038] Figure 3 yes Figure 1 Middle BB section;

[0039] Figure 4 yes Figure 1 Mid-CC section;

[0040] Figure 5 yes Figure 2 mid-DD section;

[0041] Figure 6 yes Figure 5 Middle EE section;

[0042] Figure 7 yes Figure 5 Middle FF section;

[0043] Figure 8 yes Figure 1 Enlarged view at G in the middle;

[0044] Figure 9 yes Figure 8 mid-HH section;

[0045] Figure 10 It is a schematic structural diagram of a high-temperature top-fired hot blast furnace in Example 2 of the present invention.

[0046] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0047] Among them: 1. Cold air inlet; 2. Heat storage body; 3. Furnace body; 4. Hot air outlet; 5. Combustion chamber; 6. Air ring cavity; 7. Gas ring cavity; 8. Mixing nozzle; 9. Central air channel; 10. Gas channel; 11. Second air channel; 12. Inner swirl plate; 13. Outer swirl plate; 14. Inner partition wall; 15. Outer partition wall; 16. Pre-combustion chamber; 17. Air inlet; 18. Gas inlet; 1 9. Cooling pipe; 20. Flue gas outlet; 21. Grate; 22. Furnace column; 22-1. Inner interlayer; 22-2. Outer interlayer; 23. Flue 1; 24. Air preheater; 25. Flue 2; 26. Gas preheater; 27. Flue 3; 28. Preheater gas inlet pipe; 29. ​​Preheater gas outlet pipe; 30. Preheater air inlet pipe; 31. Preheater air outlet pipe; 32. Chimney. DETAILED DESCRIPTION

[0048] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0049] Example 1

[0050] In a typical embodiment of the present invention, reference is made to Figure 1 As shown, a high-temperature top-fired hot blast furnace includes a cold air inlet 1, a heat storage body 2, a furnace body 3, a hot air outlet 4, a combustion chamber 5, a pre-combustion chamber 16, a cooling pipe 19, a flue gas outlet 20, a grate 21, a furnace column 22, an air preheater 24, a gas preheater 26 and a mixing nozzle 8.

[0051] The cold air inlet 1 and the flue gas outlet 20 are arranged at the lower part of the furnace body 3, the furnace pillar 22 is arranged at the lower part of the furnace body 3 and supports the grate 21 and the heat storage body 2 above it, the hot air outlet 4 is arranged in the middle and upper part of the furnace body 3, and the air inlet 17 and the gas inlet 18 are arranged in the upper part of the furnace body 3; the combustion chamber 5 is the arched space in the middle and upper part of the furnace body 3, the pre-combustion chamber 16 is the top space in the furnace body 3, and the heat storage chamber is the space in the lower part of the furnace body 3 filled with the heat storage body 2. The pre-combustion chamber 16, the combustion chamber 5 and the heat storage chamber are arranged up and down, and the combustion chamber 5, the pre-combustion chamber 16 and the heat storage chamber are arranged coaxially.

[0052] The mixing nozzles 8 are arranged on the inner wall of the pre-combustion chamber 16, and at least one layer of mixing nozzles 8 is provided; Figure 2 and Figure 5As shown, the mixing nozzle 8 includes a central air channel 9 for air, a gas channel 10 for gas, and an outermost layer of a second air channel 11 for air. The three channels are concentric, and the mixing nozzle 8 is evenly arranged circumferentially on the inner wall of the pre-combustion chamber 16. The three-channel arrangement of air-gas-air allows the air and gas to instantly converge and burn at the nozzle outlet, forming short-flame combustion. Short-flame combustion has a short flame, which can reduce the space in the pre-combustion chamber 16 and the combustion chamber 5, saving investment. At the same time, it can shorten the time required for complete combustion of air and gas, effectively increase the flame temperature during combustion, and reduce the air excess coefficient to 1.05-1.1. After the outer layer of secondary air is added, the flame leaving the mixing nozzle 8 is surrounded by a layer of oxygen, allowing the gas to completely mix with the air and burn without dispersing, thereby improving combustion efficiency and heat production, and eliminating excess gas in the hot blast furnace, solving the problem of some gas not being completely burned in other short-flame combustion technologies.

[0053] When more than one layer of mixing nozzles 8 are provided on the inner wall of the pre-combustion chamber 16 (e.g. Figure 1 As shown, the mixing nozzles 8 are provided in two layers, except for the mixing nozzles 8 in the bottom layer which are facing the axis of the furnace body 3 (as shown in FIG. Figure 4 As shown), the radial angle between the remaining mixing nozzles 8 and the pre-combustion chamber 16 is set to β (as shown Figure 3 As shown in the figure, the value range of β is 5°≤β≤35°. Setting the swirl angle of the mixing nozzle 8 allows the air and gas to be mixed and tangled on the inner wall of the pre-combustion chamber 16, forming a high-speed rotating airflow close to the side wall of the pre-combustion chamber 16, accelerating the mixing effect of the air and gas. The airflow without a swirl angle from the bottom nozzle disperses the high-speed rotating airflow from the upper nozzle, weakening the airflow recirculation range in the combustion chamber, compensating for the reduced central airflow distribution caused by the vortex, and distributing the high-temperature flue gas more evenly on the heat storage body, thereby improving the utilization rate of the heat storage body 2 and the energy utilization rate.

[0054] The side wall of the pre-combustion chamber 16 is provided with an annular cavity through which gas or air is passed. Figure 1 、 Figure 2 、 Figure 3 ,and Figure 4 As shown, the side wall of the pre-combustion chamber 16 is provided with an air annular cavity 6, a gas annular cavity 7 and a mixing nozzle 8. The air inlet 17 is connected to the central air channel 9 and the second air channel 11 through the air annular cavity 6; the gas inlet 18 is connected to the gas channel 10 through the gas annular cavity 7. Figure 5 As shown, the outlet of the mixing nozzle 8 is connected to the pre-combustion chamber 16. The mixing nozzle 8 is a multi-layer nested structure, including a central air channel 9, a gas channel 10, and a second air channel 11. The central air channel 9 and the gas channel 10 are separated by an inner partition wall 14; the gas channel 10 and the second air channel 11 are separated by an outer partition wall 15.

[0055] like Figure 5 、 Figure 6As shown, an inner swirl plate 12 is provided in the gas channel 10 to support the inner partition wall 14 and to make the gas swirl; Figure 5 and Figure 7 As shown, external swirl blades 13 are installed within the second air passage 11 to support the outer partition wall 15 and to induce air rotation. In this example, there are four internal and external swirl blades, respectively, arranged above, below, and to the left and right of the air-coal passage. The internal and external swirl blades 12, 13 form an angle with the length of the mixing nozzle 8. The angle α2 of the external swirl blades 13 is 10-20°, while the angle α1 of the internal swirl blades 12 is 5-15°. This angle creates a spiral motion and mixing of the air and gas during ejection. The outer airflow rotates at a greater angle than the inner airflow, enhancing the mixing effect of the air and gas.

[0056] like Figure 1 As shown, the cooling pipe 19 is respectively connected to the air inlet 17 and the gas inlet 18. During the air supply period, cold air is introduced to cool the pre-combustion chamber, so that the temperature fluctuation of the pre-combustion chamber is reduced, the thermal shock effect is reduced, and the life of the pre-combustion chamber is extended.

[0057] like Figure 1 As shown, the hot blast stove flue gas outlet 20 is connected to the smoke inlet of the air preheater 24 via flue 1 23. The smoke outlet of the air preheater 24 is connected to the smoke inlet of the gas preheater 26 via flue 2 25. The smoke outlet of the gas preheater 26 is connected to the chimney 32 via flue 3 27. The air preheater 24 is provided with a preheater air inlet pipe 30 and a preheater air outlet pipe 31, which are connected to the hot blast stove air inlet 17 via the preheater air outlet pipe 31. The gas preheater 26 is provided with a preheater gas inlet pipe 28 and a preheater gas outlet pipe 29, which are connected to the hot blast stove gas inlet 18 via the preheater gas outlet pipe 29.

[0058] like Figure 8 and Figure 9 As shown, the furnace column 22 is a double-layer structure, comprising an inner layer 22-1 and an outer layer 22-2. A cooling medium, which is air, passes through the interlayers.

[0059] The hot blast stove is a regenerative heat exchanger that works periodically. Each hot blast stove has a working cycle that includes a combustion period and an air supply period, which alternate with each other over and over again.

[0060] The combustion period is as follows: the combustion-supporting air at room temperature required for hot blast furnace combustion enters the air preheater 24 from the preheater air inlet pipe 30 for heat exchange, then flows out from the preheater air outlet pipe 31 with the air temperature rising to 400-550°C. It is then delivered to the hot blast furnace air inlet 17, enters the air annulus 6, passes through the central air channel 9 and the second air channel 11, enters the precombustion chamber 16, and is mixed with the coal gas at the outlet of the mixing nozzle 8 for combustion. The coal gas required for hot blast furnace combustion enters the gas preheater 26 from the preheater gas inlet pipe 28 for heat exchange, then flows out from the preheater gas outlet pipe 29 with the gas temperature rising to 190-220°C. It is then delivered to the hot blast furnace gas inlet 18, enters the gas annulus 7, passes through the gas channel 10, enters the precombustion chamber 16, and is mixed with the air at the outlet of the mixing nozzle 8 for combustion. Because the air and gas are preheated, the theoretical combustion temperature can reach 1450-1500°C, and the actual combustion temperature is 1380-1430°C. The high-temperature flue gas flows from the precombustion chamber 16 through the combustion chamber 4 to the heat storage body 2. After heat exchange, the flue gas temperature drops to 600-800°C. It then passes through the grate 21 and the furnace pillars 22 and is discharged from the hot blast furnace flue gas outlet 20. It then passes through the air preheater 24 and the gas preheater 26 for heat exchange and cooling, and is discharged to the chimney 32. Air is passed into the interlayer of the grate to cool it, and then the air is sent to the air preheater inlet 30 for use.

[0061] The specific process of the air supply period is as follows: the cold air required by the blast furnace enters the hot blast furnace from the cold air inlet 1, passes through the furnace pillars 22 and the grate 21, and reaches the heat storage body 2. At this time, the heat storage body 2 is in a high-temperature state having just exchanged heat with the high-temperature flue gas. After the cold air exchanges heat with the high-temperature heat storage body 2, its temperature rises to 1300-1350℃, and then it is discharged through the hot air outlet 4 and sent to the blast furnace for smelting. Before the start of the air supply period, cooling air is introduced into the cooling pipe 19. The cooling air enters the air annulus 6 and the gas annulus 7 through the air inlet 17 and the gas inlet 18 respectively, and then enters the pre-combustion chamber 16 through the central air channel 9, the gas channel 10, and the second air channel 11 respectively. Finally, it is discharged through the hot air outlet 4 and sent to the blast furnace. During the air supply period, the cold air blown in has a cooling effect on the furnace pillars 22. No cooling medium is introduced into the interlayer during this period.

[0062] Example 2

[0063] like Figure 10 As shown, the difference from Example 1 is that only one layer of mixing nozzles 8 is provided on the inner wall of the pre-combustion chamber 16 of this embodiment. At this time, the mixing nozzles 8 located on the inner wall of the pre-combustion chamber 16 form a set angle β with the radial direction of the pre-combustion chamber 16 (as shown in FIG. Figure 3 As shown), the angle β of this embodiment ranges from 5°≤β≤35°, so that the air and gas are mixed and spun inside the pre-combustion chamber 16 to form a high-speed rotating airflow close to the side wall of the pre-combustion chamber, so as to optimize the mixing effect of the air and gas.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A high-temperature top-fired hot blast stove, characterized in that: include: The furnace body (3) is provided with a pre-combustion chamber (16) arranged up and down, a combustion chamber (5), and a heat storage chamber filled with a heat storage body (2); A plurality of mixing nozzles (8) are provided on the inner wall of the pre-combustion chamber (16), and at least one layer is provided; the mixing nozzles (8) include a central air channel (9) for passing air, a gas channel (10) for passing gas, and an outermost layer of a second air channel (11) for passing air, and the channels (9), (10), (11) are concentric; The air inlet (17) and the gas inlet (18) are provided with a cooling pipe (19) and are in communication with each other; The furnace pillar (22) is a sandwich structure; An air preheater (24) and a gas preheater (26) are provided on the flue pipe.

2. A high-temperature top-fired hot blast stove according to claim 1, characterized in that: When a layer of the mixing nozzles (8) is provided on the inner wall of the pre-combustion chamber (16), a radial angle β between the mixing nozzles (8) and the pre-combustion chamber (16) is 5°≤β≤35°.

3. The high-temperature top-fired hot blast stove according to claim 1, characterized in that: When more than one layer of the mixing nozzles (8) is provided on the inner wall of the pre-combustion chamber (16), except for the mixing nozzles (8) in the lowest layer facing the axis of the furnace body (3), the radial angle β between the remaining mixing nozzles (8) and the pre-combustion chamber (16) is set, and the value range of β is 5°≤β≤35°.

4. The high-temperature top-fired hot blast stove according to claim 1, characterized in that: The central air channel (9) and the gas channel (10) are separated by an inner partition wall (14); the gas channel (10) and the second air channel (11) are separated by an outer partition wall (15).

5. The high-temperature top-fired hot blast stove according to claim 1, characterized in that: An inner swirl plate (12) is provided in the gas channel (10), and an outer swirl plate (13) is provided in the second air channel (11).

6. The high-temperature top-fired hot blast stove according to claim 5, characterized in that: The inner swirl plate (12), the outer swirl plate (13) and the mixing nozzle (8) have set angles α1 and α2 in the length direction, and α2 ≥ α1.

7. The high-temperature top-fired hot blast stove according to claim 1, characterized in that: The air preheater (24) is provided with a preheater air inlet pipe (30), and the air preheater (24) is connected to the air inlet (17) through a preheater air outlet pipe (31). The gas preheater (26) is provided with a preheater gas inlet pipe (28), and the gas preheater (26) is connected to the gas inlet (18) through a preheater gas outlet pipe (29).

8. The high-temperature top-fired hot blast stove according to claim 1, characterized in that: The furnace column (22) is a double-layer structure, comprising an inner layer (22-1) and an outer layer (22-2), wherein a cooling medium is passed through the interlayer, and the medium is liquid or gas.

9. The high-temperature top-fired hot blast stove according to claim 1, characterized in that: The invention also comprises an air inlet (17), a gas inlet (18), a cold air inlet (1), a smoke outlet (20), a hot air outlet (4), a grate (21), a furnace column (22), and a heat storage body (2). The cold air inlet (1) and the smoke outlet (20) are arranged at the lower part of the furnace body (3). The furnace column (22) is arranged at the lower part of the interior of the furnace body (3) and supports the grate (21) and the heat storage body (2) thereon. The hot air outlet (4) is arranged at the upper middle part of the furnace body (3). The air inlet (17) and the gas inlet (18) are arranged at the upper part of the furnace body (3).

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