Hot blast furnace device with coal gangue calcining function and use method

Abstract

The present invention discloses a hot blast furnace device with the function of calcining coal gangue and a method for using the same, comprising a shell, an outer side of the shell being provided with an insulation layer, the interior of the shell being provided with an exhaust gas treatment section, a coal gangue feeding section, a high-temperature calcining section and a discharging section from top to bottom; wherein an exhaust gas inlet is provided on one side of the upper portion of the exhaust gas treatment section, a hot air outlet is provided on the other side of the upper portion of the exhaust gas treatment section, the coal gangue feeding section is symmetrically provided with coal gangue nozzles below the exhaust gas inlet and the hot air outlet; a flame distributor is provided at the bottom of the high-temperature calcining section, a grate is provided on the lower side of the flame distributor, and the bottom of the discharging section is connected to an ash-locking bin. The present invention adopts a hot blast furnace device with the function of calcining coal gangue of the above structure and a method for using the same, which utilizes the heat energy in the coal gangue while realizing the calcination and activation of the coal gangue, saves the amount of gas fuel used, replaces the function of the existing hot blast furnace, has high thermal energy efficiency, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of hot blast furnace equipment, and in particular to a hot blast furnace device with the function of calcining coal gangue and a use method thereof. Background Art

[0002] A hot blast furnace is a thermal equipment that integrates combustion and heat transfer processes. It burns fuel to generate high-temperature hot air, which is used to supply heat energy for industrial production, such as heating exhaust gases for drying and sintering. During the purification of exhaust gases from coke ovens or blast furnace gas, the exhaust gas temperature does not match the optimal temperature of the catalysts in the desulfurization and denitrification processes. Therefore, a hot blast furnace is required to heat the exhaust gas to control its temperature, thereby facilitating efficient desulfurization and denitrification downstream. These hot blast furnaces typically use blast furnace gas or coke oven gas as fuel. Depending on process requirements, while using only blast furnace gas, they preheat the combustion air and gas. The temperature within the hot blast furnace is controlled by adjusting burner parameters such as fuel supply, air volume, and air temperature. Ball-type hot blast furnaces and lattice brick hot blast furnaces can be categorized by combustion method: top-fired, internal-fired, or external-fired, depending on the heat storage medium within the hot blast furnace.

[0003] Traditional hot blast furnaces, as equipment that uses hot air generated by fuel combustion to heat the medium, are widely used in metallurgy, chemical industry, building materials, food processing and other fields. However, it also has some disadvantages, including: 1) High energy consumption: The energy efficiency of hot blast furnaces is generally low, and part of the fuel's energy will be discharged in the form of flue gas. This means that the hot blast furnace wastes a certain amount of energy during use. 2) Temperature control is difficult: The temperature of traditional hot blast furnaces is relatively difficult to adjust, especially for large hot blast furnaces. This may lead to large temperature fluctuations during the heating process, affecting product quality or process stability. 3) High operating costs: The operating costs of hot blast furnaces include fuel costs, maintenance costs, and labor costs. Especially for older hot blast furnaces, due to technological updates and low energy efficiency, higher operating costs may be incurred. 4) Safety hazards: Hot blast furnaces involve working environments such as high temperature and high pressure. If they are not operated properly or the equipment is not maintained in place, there may be safety hazards such as explosions and leaks.

[0004] Gangue, a mineral associated with coal, is produced during the mining and washing processes and is the primary waste product emitted during these processes. Thermal activation of gangue can transform it into usable rubber fillers, soil conditioners, or building materials. However, due to its low calorific value, gangue's activation in a kiln is difficult to achieve by relying solely on its own calorific value. Furthermore, significant heat loss occurs during the calcination and cooling process. Uneven temperatures within the furnace also result in incomplete calcination of some gangue, making it difficult to reach the ideal activation temperature, impacting product quality.

[0005] Aiming at the problems existing in the traditional hot blast furnace and the gangue calcination and activation process, the present invention discloses a hot blast furnace device with the function of calcining and activating gangue and a method for using the same. Summary of the Invention

[0006] The purpose of the present invention is to provide a hot blast furnace device with the function of calcining coal gangue and a method for using it. While realizing the calcination and activation of coal gangue, it utilizes the heat energy in the coal gangue, saves the amount of gas fuel, replaces the function of the existing hot blast furnace, has high thermal energy efficiency, and has broad application prospects.

[0007] To achieve the above-mentioned object, the present invention provides a hot blast furnace device with the function of calcining coal gangue, comprising a shell, an insulation layer is provided on the outside of the shell, an inspection hole is provided on the top of the shell, and the inside of the shell is provided with an exhaust gas treatment section, a coal gangue feeding section, a high-temperature calcining section and a discharging section from top to bottom;

[0008] A tail gas inlet is provided on one side of the upper portion of the tail gas treatment section, which is connected to the tail gas pipeline; a hot air outlet is provided on the other side of the upper portion of the tail gas treatment section, which is connected to the cyclone separator through a pipeline;

[0009] The gangue feeding section is located below the tail gas inlet and hot air outlet and is symmetrically provided with gangue nozzles;

[0010] A flame distributor is provided at the bottom of the high-temperature calcining section, which is connected to the gas pipeline through a flange. A grate is provided on the lower side of the flame distributor, and the bottom of the grate is connected to the shell through a driver.

[0011] The bottom of the discharging section is connected to the ash-closing lock bin, and the bottom of the discharging section is symmetrically provided with air inlets on both sides of the ash-closing lock bin.

[0012] Preferably, the insulation layer is an insulation brick with a thickness of 10-20 cm.

[0013] Preferably, the flame distributor is cross-shaped, grid-shaped or rotary-shaped. When the flame distributor is a cross-shaped flame distributor, the flame holes are evenly distributed on the top of the flame distributor.

[0014] Preferably, the grate is a pagoda-shaped rotating grate comprising 4-8 layers of grate blocks stacked in a stepped cone shape and a top hood.

[0015] Preferably, the upper part, the middle part, the lower part and the hot air outlet of the shell are all provided with temperature detection devices and pressure detection devices.

[0016] Preferably, the air inlet is connected to the induced draft fan through a pipeline.

[0017] Preferably, the particle size of the coal gangue after grinding is less than or equal to 50 mm.

[0018] A method for using a hot blast furnace device capable of calcining coal gangue comprises the following steps:

[0019] 1) Air enters from the air inlet, passes through the grate and reaches the flame distributor, where the fuel and air are fully mixed and ignited to produce high-temperature flue gas and flame flue gas, and the heat of the flue gas is transferred to the air;

[0020] 2) The gangue is ground and then enters the shell through the gangue nozzle. During the falling process, the gangue is calcined and activated by high-temperature flue gas and air. The gangue that is not fully activated during the falling process falls to the grate and stays there for further calcination and activation;

[0021] 3) In the tail gas treatment section, the tail gas enters the shell through the tail gas inlet, and the high-temperature flue gas and air undergo a combustion reaction during the rising process. The tail gas after combustion enters the cyclone separator through the hot air outlet for dust removal;

[0022] 4) After activation, the gangue falls into the ash lock bin below through the rotation of the grate and is discharged periodically.

[0023] Beneficial effects of the present invention:

[0024] 1. The hot blast stove device of the present invention has a simple structure and low production cost. An inspection hole is provided above the hot blast stove to facilitate equipment inspection and replacement.

[0025] 2. The hot blast furnace device of the present invention combines mechanical crushing and high-temperature calcination activation, so that the residual calorific value of the coal gangue is fully utilized. A part of it is used for its own calcination activation, and the other part is used to heat the air and exhaust gas, thereby achieving efficient utilization of energy.

[0026] 3. The hot blast furnace system of the present invention passes the hot upstream exhaust gas into the hot blast furnace for combustion reaction, removing harmful substances and generating some heat energy. The exhaust gas is heated to a certain temperature through heat exchange and then sent to the downstream desulfurization and denitrification process, achieving environmental protection and reducing pollutant emissions.

[0027] 4. The cross-shaped distributor in the hot blast stove device of the present invention can evenly distribute the flame, prevent the combustion flame from being too concentrated, make the temperature in the furnace more uniform, and avoid damage caused by uneven heating of the furnace. The flame distributor can be replaced with a grid type or a rotary type according to different needs.

[0028] 5. The hot blast furnace device of the present invention is not limited to the use of coal gangue for calcination. Other carbon-containing low calorific value raw materials can also be calcined and activated in this device, saving gas fuel consumption.

[0029] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of an embodiment of a hot blast furnace device having the function of calcining coal gangue according to the present invention;

[0031] Figure 2 The present invention is a schematic diagram of a flame distributor of a hot blast furnace device with the function of calcining coal gangue.

[0032] Reference numerals:

[0033] 1. Shell; 2. Inspection hole; 3. Insulation layer; 4. Exhaust gas inlet; 5. Hot air outlet; 6. Cyclone separator; 7. Gangue nozzle; 8. Flame distributor; 9. Flame hole; 10. Grate; 11. Ash lock bin; 12. Air inlet; 13. Driver. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the following embodiments. Unless otherwise defined, technical or scientific terms used herein shall have the same meanings as those commonly understood by persons of ordinary skill in the art to which the present invention pertains. The above-mentioned features or features described in the specific examples of the present invention may be combined in any manner. These specific embodiments are intended only to illustrate the present invention and are not intended to limit the scope of the present invention.

[0035] Example 1

[0036] The gangue material of this embodiment is provided by Datuhe Thermal Power Company. The chemical composition of the gangue is shown in Table 1.

[0037] Table 1 Chemical composition of coal gangue

[0038]

[0039] Experimental parameters: coal gangue particle size: 0-20 mm, high temperature calcination section temperature: 950 °C, coal gangue residence time in the furnace is about 1 h, hot air outlet temperature is 900 °C.

[0040] See also Figures 1 to 2 As shown in the figure, the present invention provides a hot blast furnace device capable of calcining coal gangue. The device comprises a housing 1, the outer surface of which is provided with an insulation layer 3. The insulation layer 3 is made of 10cm thick insulation bricks, which provides excellent insulation and reduces heat loss. An access hole 2 is provided at the top of the housing 1 to facilitate equipment maintenance and replacement.

[0041] The interior of the shell 1 is arranged from top to bottom as an exhaust gas treatment section, a gangue feeding section, a high-temperature calcination section and a discharging section. A exhaust gas inlet 4 is provided on one side of the upper portion of the exhaust gas treatment section, and the exhaust gas inlet 4 is connected to the exhaust gas pipeline. A hot air outlet 5 is provided on the other side of the upper portion of the exhaust gas treatment section, and the hot air outlet 5 is connected to the cyclone separator 6 through a pipeline. The pipeline connected to the hot air outlet 5 is always in a high-temperature state and needs to be built with high-quality refractory materials. The exhaust gas enters the interior of the shell 1 through the exhaust gas inlet 4, and the high-temperature flue gas and air in the shell 1 undergo a combustion reaction to remove harmful substances in the exhaust gas and generate some heat energy. Then, the exhaust gas after the harmful substances are removed, that is, the hot air, enters the cyclone separator 6 through the hot air outlet 5. The cyclone separator 6 is used to separate solid particles in the hot air, and the purified hot air enters the downstream process. The cyclone separator 6 needs to be insulated to prevent heat loss.

[0042] The gangue feeding section is located below the tail gas inlet 4 and the hot air outlet 5 and is symmetrically provided with gangue nozzles 7. The ground gangue enters the shell 1 through the gangue nozzles 7, so that the gangue particles are evenly distributed in the hot air furnace device shell 1.

[0043] A flame distributor 8 is provided at the bottom of the high-temperature calcining section. The flame distributor 8 is connected to the gas pipeline through a flange. The flame distributor 8 is a cross-shaped flame distributor 8. The flame holes 9 are evenly distributed on the top of the flame distributor 8. The cross-shaped distributor can evenly distribute the flame, prevent the combustion flame from being too concentrated, make the temperature in the furnace more uniform, and avoid damage caused by uneven heating of the furnace.

[0044] A grate 10 is provided on the lower side of the flame distributor 8. The bottom of the grate 10 is connected to the convex edge of the housing 1 via rollers and tracks. A driver 13 connected to the grate 10 is also provided on one side of the housing 1. The driver 13 mainly consists of a motor, a reducer, an eccentric sleeve assembly, and an output shaft. The reducer is connected to the variable frequency speed motor via a coupling. The output shaft of the reducer is connected to one side of the grate 10 via a connecting assembly. The variable frequency speed motor drives the reducer, which transmits power to the grate 10, providing power for the rotation of the grate 10. The driver 13 achieves precise control of the speed of the grate 10 by changing the frequency of the variable frequency speed motor to meet the needs of continuous production. The grate 10 is a pagoda-shaped rotating grate, which includes four layers of grate 10 stacked in a stepped cone shape and a top hood, totaling five layers of grate 10. The grate 10 is driven by the grate 10 driver 13. The gangue that is not fully activated during the falling process can fall to the grate 10 and stay there for a period of time to continue calcination and activation. The activated gangue falls into the ash locking bin 11 below through the rotation of the grate 10.

[0045] The bottom of the discharge section is connected to the ash lock bin 11. Air inlets 12 are symmetrically located on either side of the ash lock bin 11. These inlets are connected to induced draft fans (IDFs) via pipes. The IDFs pump air in from the bottom. The frequency of the IDFs can be adjusted to meet the requirements of downstream processes and gangue activation to provide the required air volume.

[0046] Temperature detection devices and pressure detection devices are provided at the upper, middle, lower part and hot air outlet 5 of the shell 1 to conveniently monitor the temperature and pressure conditions of the hot air furnace device.

[0047] A method for using a hot blast furnace device capable of calcining coal gangue comprises the following steps:

[0048] 1) Air enters from the air inlet 12 and passes through the grate 10 to the flame distributor 8. In the flame distributor 8, the fuel and air are fully mixed and ignited to produce high-temperature flue gas and flame flue gas, so that the heat of the flue gas is continuously transferred to the air.

[0049] 2) The coal gangue is ground and then passed through the coal gangue nozzle 7 into the housing 1, where it is calcined and activated by high-temperature flue gas and air. The particle size of the ground coal gangue is less than or equal to 20 mm. Due to its small particle size, the coal gangue is evenly distributed within the furnace when it passes through the coal gangue nozzle 7 and enters the furnace body, where it is calcined and activated by the high-temperature flue gas and air. Due to the influence of gravity, the coal gangue is fully calcined and activated as it falls. Some coal gangue that is not fully activated during the falling process falls to the grate 10 and remains there for further calcination and activation.

[0050] 3) In the tail gas treatment section, the tail gas enters the shell 1 through the tail gas inlet 4, and the high-temperature flue gas and air undergo combustion reaction during the rising process to remove harmful substances. The tail gas after combustion enters the cyclone separator 6 through the hot air outlet 5 for dust removal and is then sent to the downstream desulfurization and denitrification process.

[0051] 4) After activation, the gangue falls into the ash lock bin 11 below through the rotation of the grate 10 and is discharged periodically.

[0052] Performance Testing

[0053] The gangue powder activated by calcination in the hot blast furnace of the present invention was filled into rubber material, and the mechanical properties of the rubber material were tested. The test results are shown in Table 2. The comparative example is unactivated gangue powder and carbon black.

[0054] Table 2 Tensile properties and hardness of samples

[0055]

[0056] Example 2

[0057] The coal gangue material of this embodiment was produced in Yangquan, Shanxi Province. The chemical composition of the coal gangue is shown in Table 3.

[0058] Table 3 Chemical composition of coal gangue

[0059]

[0060] Experimental parameters: coal gangue particle size: 0-35mm, high temperature calcination section temperature: 968℃, coal gangue residence time in the furnace is about 1h, hot air outlet temperature is 905℃.

[0061] A method for using a hot blast furnace device capable of calcining coal gangue comprises the following steps:

[0062] 1) Air enters from the air inlet 12 and passes through the grate 10 to the flame distributor 8. In the flame distributor 8, the fuel and air are fully mixed and ignited to produce high-temperature flue gas and flame flue gas, so that the heat of the flue gas is continuously transferred to the air.

[0063] 2) The coal gangue is ground and then passed through the coal gangue nozzle 7 into the housing 1, where it is calcined and activated by high-temperature flue gas and air. The particle size of the ground coal gangue is less than or equal to 35 mm. Due to its small particle size, the coal gangue is evenly distributed within the furnace when it passes through the coal gangue nozzle 7 and enters the furnace body, where it is calcined and activated by the high-temperature flue gas and air. Due to the influence of gravity, the coal gangue is fully calcined and activated as it falls. Some coal gangue that is not fully activated during the falling process falls to the grate 10 and remains there for further calcination and activation.

[0064] 3) In the tail gas treatment section, the tail gas enters the shell 1 through the tail gas inlet 4, and the high-temperature flue gas and air undergo combustion reaction during the rising process to remove harmful substances. The tail gas after combustion enters the cyclone separator 6 through the hot air outlet 5 for dust removal and is then sent to the downstream desulfurization and denitrification process.

[0065] 4) After activation, the gangue falls into the ash lock bin 11 below through the rotation of the grate 10 and is discharged periodically.

[0066] Performance Testing

[0067] The gangue powder activated by calcination in the hot blast furnace of the present invention was filled into rubber material, and the mechanical properties of the rubber material were tested. The test results are shown in Table 4. The comparative example is unactivated gangue powder and carbon black.

[0068] Table 4 Tensile properties and hardness of samples

[0069]

[0070] In Examples 1-2 above, the mechanical properties of the rubber material filled with the activated coal gangue powder calcined in the hot blast furnace apparatus of the present invention were significantly improved, comparable to those of the rubber material filled with carbon black. The performance of the rubber material filled with unmodified coal gangue powder was significantly reduced. Therefore, the inexpensive coal gangue powder activated by calcining in the hot blast furnace apparatus of the present invention can be used to replace expensive carbon black, achieving high-value-added utilization of coal gangue while reducing the production cost of rubber and plastic materials. Furthermore, the activated coal gangue can be used as an adsorbent, plastic filler, and in the production of building materials, possessing broad market prospects.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A hot blast furnace device with the function of calcining coal gangue, characterized by: It includes a shell, an insulation layer is provided on the outside of the shell, an inspection hole is provided on the top of the shell, and the inside of the shell is arranged from top to bottom as an exhaust gas treatment section, a coal gangue feeding section, a high-temperature calcination section and a discharging section; A tail gas inlet is provided on one side of the upper portion of the tail gas treatment section, which is connected to the tail gas pipeline; a hot air outlet is provided on the other side of the upper portion of the tail gas treatment section, which is connected to the cyclone separator through a pipeline; The gangue feeding section is located below the tail gas inlet and hot air outlet and is symmetrically provided with gangue nozzles; A flame distributor is provided at the bottom of the high-temperature calcining section, which is connected to the gas pipeline through a flange. A grate is provided on the lower side of the flame distributor, and the bottom of the grate is connected to the shell through a driver. The bottom of the discharging section is connected to the ash-closing lock bin, and the bottom of the discharging section is symmetrically provided with air inlets on both sides of the ash-closing lock bin.

2. The hot blast furnace device with the function of calcining coal gangue according to claim 1, characterized in that: The insulation layer is made of insulation bricks with a thickness of 10-20 cm.

3. The hot blast furnace device with the function of calcining coal gangue according to claim 1, characterized in that: The flame distributor is of cross type, grid type or rotary type. When the flame distributor is of cross type, the flame holes are evenly distributed on the top of the flame distributor.

4. The hot blast furnace device with the function of calcining coal gangue according to claim 1, characterized in that: The grate is a pagoda-shaped rotating grate comprising 4 to 8 layers of grate blocks stacked in a stepped cone shape and a top hood.

5. The hot blast furnace device with the function of calcining coal gangue according to claim 1, characterized in that: Temperature detection devices and pressure detection devices are provided at the upper, middle, lower part and hot air outlet of the shell.

6. The hot blast furnace device with the function of calcining coal gangue according to claim 1, characterized in that: The air inlet is connected to the induced draft fan through a pipe.

7. A method for using a hot blast furnace device having the function of calcining coal gangue according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Air enters from the air inlet, passes through the grate and reaches the flame distributor, where the fuel and air are fully mixed and ignited to produce high-temperature flue gas and flames, and the heat of the flue gas is transferred to the air; 2) The gangue is ground and then enters the shell through the gangue nozzle. During the falling process, the gangue is calcined and activated by high-temperature flue gas and air. The gangue that is not fully activated during the falling process falls to the grate and stays there for further calcination and activation; 3) In the exhaust gas treatment section, the exhaust gas enters the shell through the exhaust gas inlet, and heat is exchanged between the high-temperature flue gas and the air during the rising process. The exhaust gas after heat exchange enters the cyclone separator through the hot air outlet for dust removal; 4) After activation, the gangue falls into the ash lock bin below through the rotation of the grate and is discharged periodically.

8. The method for using the hot blast furnace device capable of calcining coal gangue according to claim 7, characterized in that: The particle size of the coal gangue after grinding is less than or equal to 50mm.

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