Sintered ore cooling waste heat gradient utilization device

Abstract

The invention relates to a gradient utilization device for sinter cooling waste heat. Comprising a sinter cooler and a pellet raw material dryer, and the cooler is provided with a material cooling part; the material cooling part is divided into a first-stage cooling area, a second-stage cooling area and a third-stage cooling area in the material moving direction. The pellet raw material drying machine is arranged above the second-stage cooling area and the third-stage cooling area, and the pellet raw material drying machine is sequentially divided into a first-stage drying area, a second-stage drying area and a third-stage drying area in the material moving direction; the pellet raw material drying device is installed above the second-stage cooling area and the third-stage cooling area of the sinter step type circular cooler, the waste heat of sinter is used for heating the pellet raw material drying device, then hot air generated by cooling of the sinter is led out to the pellet raw material drying device through a pipeline, pellet raw materials are fully dried, and the pellet raw material drying efficiency is improved. And the utilization rate of sinter waste heat is improved.

Description

Technical Field

[0001] This application relates to the field of waste heat recovery technology of flue gas from sintering step cooler, and in particular to a device for the cascade utilization of waste heat from sintering cooling. Background Technology

[0002] Sintered ore, as a crucial raw material for blast furnaces, requires crushing, screening, and transportation before entering the furnace. However, excessively high sinter temperatures hinder these processes. Therefore, cooling high-temperature sintered ore has become an indispensable step. Cooling reduces equipment wear and adjusts the internal structure of the ore to improve its performance. Current sintered ore cooling processes have low heat recovery efficiency, and the waste heat generated during cooling is not utilized effectively, leading to energy waste. Summary of the Invention

[0003] To address or partially address the problems existing in related technologies, this application provides a cascade utilization device for sintered ore cooling waste heat, which aims to rationally utilize the waste heat after sintering of sintered ore to reduce energy consumption.

[0004] A device for cascade utilization of waste heat from sinter cooling includes a sinter cooler and a pellet raw material dryer, wherein the cooler has a material cooling section;

[0005] The material cooling section is divided into a primary cooling zone, a secondary cooling zone, and a tertiary cooling zone along the material movement direction; the pellet ore raw material dryer is located above the secondary and tertiary cooling zones, and is also divided into a primary drying zone, a secondary drying zone, and a tertiary drying zone along the material movement direction.

[0006] The hot air in the primary cooling zone is introduced into the primary heat exchanger through primary heat exchange tubes to preheat the boiler feed water. The hot air exiting the primary heat exchanger is introduced into the primary drying zone through primary cooling tubes for drying. Part of the hot air in the primary drying zone is introduced into the tertiary drying zone through pipes for drying, and the remaining hot air is introduced into the secondary heat exchanger through pipes for cooling. The hot air in the tertiary drying zone is introduced into the secondary heat exchanger through pipes for cooling. The cold air exiting the secondary heat exchanger is introduced into the primary and tertiary cooling zones through pipes for cooling.

[0007] The hot air from the tertiary cooling zone is introduced into the secondary cooling zone through pipes for cooling; the hot air from the secondary cooling zone is introduced into the secondary drying zone through pipes for drying; part of the hot air from the secondary drying zone is introduced into the tertiary drying zone through pipes for drying, and the remaining hot air is introduced into the secondary heat exchanger through pipes for cooling.

[0008] In some designs, a temperature regulating pipe is connected between the primary heat exchange tube and the primary cooling tube, and the temperature regulating pipe is equipped with a temperature regulating valve.

[0009] In some designs, the cold source inlet of the primary heat exchanger is connected to the deaerator via a pipe, and the cold source outlet is connected to the boiler via a pipe.

[0010] In some designs, the cold source end of the secondary heat exchanger is connected to the cooling tower via pipes.

[0011] In some schemes, the hot air from the primary drying zone and the secondary drying zone is introduced into the mixing tube through pipes for mixing. Then, part of the mixed hot air is introduced into the tertiary drying zone through pipes for drying, and the remaining hot air is introduced into the secondary heat exchanger through the mixing tube for cooling.

[0012] In some designs, the cooling conveyor belt of the sinter cooler is provided with a first air inlet and a first air outlet on both sides, with the air outlet of the first air inlet facing the material on the conveyor belt.

[0013] In some designs, the conveyor belt of the pellet raw material dryer is provided with a second air inlet and a second air outlet on both sides, with the second air inlet facing the material on the conveyor belt.

[0014] The technical solution provided in this application may include the following beneficial effects:

[0015] 1. This application installs the pellet raw material drying device above the secondary and tertiary cooling zones of the sinter step-type annular cooler. The residual heat of the sinter is used to heat the pellet raw material drying device. The hot air generated by the cooling of the sinter is then piped out to the pellet raw material drying device to fully dry the pellet raw material and improve the utilization rate of the waste heat of the sinter. At the same time, according to production needs, some of the hot air is introduced into the primary heat exchanger to preheat the boiler feed water, thereby reducing the boiler fuel consumption and improving the heat recovery capacity.

[0016] 2. Utilizing the waste heat from sintered ore to dry the pellet raw materials avoids the energy consumption of separately drying the pellet raw materials in existing technologies, saving 20-30 m³ of coal gas consumed in the drying furnace. 3 / t, reducing enterprise production costs. At the same time, the drying air of the pellet raw material after heat exchange is used to cool the sinter. According to the difference in temperature gradient, the cooling air intake is reasonably configured, which improves the utilization rate of hot air under different calorific values. Meanwhile, the heat exchange between the high temperature air and the boiler feed water during the cooling of sinter effectively reduces the boiler fuel consumption.

[0017] In summary, the present invention provides a method for diverting flue gas from a step cooler for sintered ore and for drying raw materials for pelletized ore. On the one hand, it improves the efficiency of waste heat utilization and energy efficiency, and achieves a reasonable distribution of flue gas under different temperature gradients. On the other hand, it reduces unnecessary equipment space occupation, waste of resources and energy, and reduces the impact of pollutant emissions on the environment by recycling flue gas and combining different resources.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0020] Figure 1 This is a schematic diagram of the pipeline of a cascade utilization device for waste heat from sinter cooling, as shown in the embodiments of this application;

[0021] Figure label:

[0022] 1. Primary cooling zone; 2. Secondary cooling zone; 3. Tertiary cooling zone; 4. Primary drying zone; 5. Secondary drying zone; 6. Primary heat exchanger; 7. Tertiary drying zone; 8. Primary heat exchange tube; 9. Primary cooling tube; 10. Secondary heat exchanger; 11. Temperature regulating tube; 12. Temperature regulating valve; 13. Deaerator; 14. Boiler; 15. Cooling tower; 16. Mixing tube. Detailed Implementation

[0023] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0024] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0025] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0026] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] Please see Figure 1 This application provides a cascade utilization device for waste heat from sintering ore cooling, including a sintering ore cooler and a pellet raw material dryer. The sintering ore cooler includes a material sintering section and a material cooling section. The material sintering section is used for sintering the ore, and the material cooling section is used for cooling the material. The material cooling section is a chain conveyor belt. The pellet raw material dryer consists of an outer shell and a chain conveyor belt disposed within the outer shell.

[0028] During operation, the material is sintered in the sintering section to obtain sintered ore. The initial temperature of the sintered ore is on average between 700℃ and 750℃. Then, it is fed into the material cooling section for cooling. In the material cooling section, the sintered ore is conveyed forward by a conveyor belt and gradually cooled. According to the extent to which the residual heat of the sintered ore can heat the surrounding air, the material cooling section is divided into a primary cooling zone 1, a secondary cooling zone 2, and a tertiary cooling zone 3 along the material movement direction. The ambient air temperature in the primary cooling zone 1 is between 400℃ and 750℃, the ambient air temperature in the secondary cooling zone 2 is between 250℃ and 400℃, and the ambient air temperature in the tertiary cooling zone 3 is between 50℃ and 250℃.

[0029] The pellet ore dryer is positioned above the secondary cooling zone 2 and the tertiary cooling zone 3, with the secondary and tertiary cooling zones 2 and 3 forming a semi-enclosed state around the pellet ore dryer. The bottom plate of the pellet ore dryer directly serves as the top plate of the secondary and tertiary cooling zones 2 and 3, and the left side plate (feed inlet end) of the secondary and tertiary cooling zones 2 and 3 directly serves as the right side plate of the primary cooling zone 1. This design allows the temperature of the secondary and tertiary cooling zones 2 and 3 to be directly transferred to the outer shell of the pellet ore dryer, thereby increasing the internal temperature of the pellet ore dryer. This effectively utilizes the necessary heat radiation from the secondary and tertiary cooling zones 2 and 3 to raise the ambient temperature of the pellet ore dryer. At the same time, it helps to lower the temperature of the secondary and tertiary cooling zones 2 and 3, rapidly cooling the materials inside.

[0030] During the drying process of the pellet ore raw material in the pellet ore raw material dryer, according to the moisture content of the pellet ore raw material, it is divided into a primary drying zone 4, a secondary drying zone 5, and a tertiary drying zone 7 along the material movement direction. In the primary drying zone 4, the moisture content of the pellet ore raw material is approximately 10%.

[0031] The sinter cooler has a first air inlet and a first air outlet on each side of the cooling conveyor belt. The air outlet of the first air inlet faces the material on the conveyor belt. Multiple first air inlets and outlets are spaced apart along the conveying direction of the cooling conveyor belt, resulting in three to six opposing first air inlets and outlets in each cooling zone. During operation, cooling air is blown from the first air inlet towards the sinter and then exited from the first air outlet, forming a basically independent circulation of cooling air in each cooling zone. Furthermore, valves are installed on the pipes connected to each first air inlet. By controlling the opening and closing of the valves, the airflow through different cooling zones can be adjusted.

[0032] The pellet ore dryer has second air inlets and outlets on both sides of the conveyor belt. The second air inlets face the material on the conveyor belt. Multiple second air inlets and outlets are spaced apart along the conveyor belt's transport direction, resulting in three to six opposing second air inlets and outlets in each drying zone. During operation, hot air is blown from the second air inlets onto the pellet ore and then exited from the second air outlets, forming a essentially independent circulation of hot air in each drying zone. Furthermore, valves are installed on the pipes connected to each second air inlet, allowing control of the airflow through different drying zones by adjusting the opening and closing of the valves.

[0033] The hot air in the primary cooling zone 1 is introduced into the primary heat exchanger 6 through the primary heat exchange pipe 8 to preheat the water inlet of the boiler 14. Specifically, the first air inlet in the primary cooling zone 1 is connected to the cooling fan through a pipe, and the first air outlet in the primary cooling zone 1 is connected to the hot end air inlet of the primary heat exchanger 6 through a pipe. Because the temperature of the sinter in the primary cooling zone 1 is high, the surrounding air temperature can be heated to between 400℃ and 750℃. Based on the drying capacity of the pellet raw material, the waste heat in the primary cooling zone 1 is rationally allocated to the boiler 14 or the primary drying zone 4 through the temperature regulating valve 12, ensuring a reasonable distribution of the waste heat. This method effectively utilizes the waste heat of the sinter in the primary cooling zone 1, saving energy and reducing the operating cost of the boiler 14.

[0034] The hot air drawn from the primary heat exchanger 6 is introduced into the primary drying zone 4 through the primary cooling pipe 9 for drying. After passing through the primary heat exchanger 6, the temperature of the hot air is reduced. By introducing it into the primary drying zone 4, the low-temperature waste heat therein is effectively utilized to improve energy efficiency.

[0035] Part of the hot air in the primary drying zone 4 is introduced into the tertiary drying zone 7 through pipes for drying, and the remaining hot air is introduced into the secondary heat exchanger 10 through pipes for cooling. The hot air in the tertiary drying zone 7 is also introduced into the secondary heat exchanger 10 through pipes for cooling. The cold air exiting from the secondary heat exchanger 10 is introduced into the primary cooling zone 1 and the tertiary cooling zone 3 through pipes for cooling. In this way, the residual heat of the sinter in the secondary cooling zone 2 is fully utilized, and the sinter can also be cooled quickly, achieving a win-win situation.

[0036] In some specific embodiments, a moisture separator is provided at the inlet of the secondary heat exchanger 10 to remove a large amount of moisture carried in the hot air after passing through the drying zone. While removing water accumulated in the pipe, it effectively filters water vapor or particulate matter in the flue gas, ensuring normal flue gas flow while separating and discharging condensate or impurities, avoiding direct discharge of moisture and reducing environmental pollution.

[0037] The hot air from the tertiary cooling zone 3 is introduced into the secondary cooling zone 2 through pipes for cooling. The air passing through the tertiary cooling zone 3 has a certain temperature, which is lower than that of the secondary cooling zone 2. This can effectively cool the sintered ore in the secondary cooling zone 2, while enhancing the matching of the residual heat between the secondary cooling zone 2 and the tertiary cooling zone 3, reducing heat dissipation, and carrying the heat into the secondary drying zone 5. This fully utilizes the residual heat of the secondary cooling zone 2 and the tertiary cooling zone 3 to dry the pellet raw materials, which has a positive effect on the drying of pellet raw materials.

[0038] The hot air in the third-stage cooling zone 3 is introduced into the second-stage cooling zone 2 through a pipe for cooling. The air that has passed through the third-stage cooling zone 3 has a certain temperature and is then introduced into the second-stage cooling zone 2 for cooling. This reduces the temperature difference between the sinter and the cooling air, which is beneficial for the uniform cooling of the sinter.

[0039] The hot air in the secondary cooling zone 2 is introduced into the secondary drying zone 5 through a pipe for drying. Part of the hot air in the secondary drying zone 5 is introduced into the tertiary drying zone 7 through a pipe for drying, and the remaining hot air is introduced into the secondary heat exchanger 10 through a pipe for cooling.

[0040] Through the above implementation method, the residual heat after sintering of sintered ore is made reasonable use. By arranging the flow direction of each heat source, the residual heat is recovered more fully, and the energy utilization efficiency is enhanced.

[0041] In some specific embodiments, a temperature regulating pipe 11 is connected between the primary heat exchange tube 8 and the primary cooling tube 9. The temperature regulating pipe 11 is equipped with a temperature regulating valve 12. In use, the amount of hot air introduced into the primary heat exchange tube 8 can be controlled by the temperature regulating valve 12. This can be used to regulate the water inlet temperature of the boiler 14 and the temperature of the hot air introduced into the primary drying zone 4.

[0042] In some specific embodiments, the cold source inlet of the primary heat exchanger 6 is connected to the deaerator 13 through a pipe, and the cold source outlet is connected to the boiler 14 through a pipe. The primary heat exchanger 6 is used to achieve heat exchange between the boiler 14 inlet water and the hot air in the primary cooling zone 1.

[0043] In some specific embodiments, the cold source end of the secondary heat exchanger 10 is connected to the cooling tower 15 through pipes. The hot air still has a certain temperature after drying. By using water in the secondary heat exchanger 10 and the cooling tower 15, the residual temperature in the hot air is effectively removed, so that it can be basically brought to room temperature for reuse in cooling.

[0044] In some specific embodiments, the hot air from the primary drying zone 4 and the secondary drying zone 5 is introduced into the mixing pipe 16 through pipes for mixing. Subsequently, part of the mixed hot air is introduced into the tertiary drying zone 7 through pipes for drying, and the remaining hot air is introduced into the secondary heat exchanger 10 through the mixing pipe 16 for cooling.

[0045] The application process:

[0046] Sintered ore, averaging 700℃-750℃, is first fed into a step-type sintered ore cooler, and then conveyed forward by a conveyor belt at a speed of 1-4 m / min. Cooling fans draw cold air from the secondary heat exchanger 10 through the corresponding first air inlet and blow it onto the sintered ore. The sintered ore heats the air, which is then discharged from the first air outlet and introduced into the primary heat exchanger 6 to heat the boiler 14 feedwater. During this process, the airflow through the first cooling zone can be adjusted by changing the opening and closing of the valve on the pipe connected to the first air inlet. After passing through the primary heat exchanger 6, the air from the primary cooling zone 1 of the step-type sintered ore cooler is introduced into the primary drying zone 4 to dry the pellets. During this process, the opening and closing of the temperature regulating valve 12 can be adjusted according to the actual production situation to control the residual heat flowing to the primary heat exchanger 6, which can effectively regulate the boiler 14 feedwater temperature and the temperature of the hot air entering the primary drying zone 4.

[0047] The cooling fan blows the cold air drawn from the secondary heat exchanger 10 into the tertiary cooling zone 3, and then through the pipeline into the secondary cooling zone 2, and then through the pipeline into the secondary drying zone 5, for drying the pellet raw materials.

[0048] After the drying air from the primary drying zone 4 and the drying air from the secondary drying zone 5 merge, a portion of it is introduced into the tertiary drying zone 7 to dry the pellets. The drying air from the tertiary drying zone 7 is then returned and mixed with the drying air from the primary and secondary drying zones 5 before being introduced into the secondary heat exchanger 10 for cooling.

[0049] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A cascade utilization device for sintered ore cooling waste heat, comprising a sintered ore cooler and a pelletized ore raw material dryer, wherein the cooler has a material cooling part, characterized in that: The material cooling section is divided into a primary cooling zone (1), a secondary cooling zone (2), and a tertiary cooling zone (3) along the material movement direction; the pelletizing raw material dryer is arranged above the secondary cooling zone (2) and the tertiary cooling zone (3); the pelletizing raw material dryer is divided into a primary drying zone (4), a secondary drying zone (5), and a tertiary drying zone (7) in sequence along the material movement direction; The hot air in the primary cooling zone (1) is introduced into the primary heat exchanger (6) through the primary heat exchange pipe (8) to preheat the inlet water of the boiler (14); the hot air discharged from the primary heat exchanger (6) is introduced into the primary drying zone (4) through the primary cooling pipe (9) for drying; part of the hot air in the primary drying zone (4) is introduced into the tertiary drying zone (7) through a pipeline for drying, and the remaining part of the hot air is introduced into the secondary heat exchanger (10) through a pipeline for cooling; the hot air in the tertiary drying zone (7) is introduced into the secondary heat exchanger (10) through a pipeline for cooling; the cold air discharged from the secondary heat exchanger (10) is respectively introduced into the primary cooling zone (1) and the tertiary cooling zone (3) through pipelines for cooling; The hot air in the tertiary cooling zone (3) is introduced into the secondary cooling zone (2) through a pipeline for cooling; the hot air in the secondary cooling zone (2) is introduced into the secondary drying zone (5) through a pipeline for drying; part of the hot air in the secondary drying zone (5) is introduced into the tertiary drying zone (7) through a pipeline for drying; and the remaining part of the hot air is introduced into the secondary heat exchanger (10) through a pipeline for cooling.

2. The device for cascade utilization of waste heat from cooling sintered ore according to claim 1, characterized in that: A temperature regulating tube (11) is connected between the first-level heat exchange tube (8) and the first-level cooling tube (9), and a temperature regulating valve (12) is provided on the temperature regulating tube (11).

3. The device for cascade utilization of waste heat from sintering ore cooling according to claim 1 is characterized in that: The cold source water inlet end of the primary heat exchanger (6) is connected to the deaerator (13) through a pipeline, and the cold source water outlet end is connected to the boiler (14) through a pipeline.

4. The device for cascade utilization of waste heat from sintering ore cooling according to claim 1 is characterized in that: The cold source ends of the secondary heat exchangers (10) are connected to cooling towers (15) via pipelines.

5. The device for cascade utilization of waste heat from cooling sintered ore according to claim 1, characterized in that: The hot air from the primary drying zone (4) and the secondary drying zone (5) is introduced into a mixing tube (16) through pipelines for mixing, and then part of the mixed hot air is introduced into the tertiary drying zone (7) through a pipeline for drying, and the remaining hot air is introduced into the secondary heat exchanger (10) through the mixing tube (16) for cooling.

6. The device for cascade utilization of waste heat from sintering ore cooling according to claim 1 is characterized in that: A first air inlet and a first air outlet are respectively arranged on both sides of the cooling conveyor belt of the sintered ore cooler, and the air outlet direction of the first air inlet is directly facing the material on the conveyor belt.

7. The device for cascade utilization of waste heat from sintering ore cooling according to claim 1 is characterized in that: A second air inlet and a second air outlet are respectively arranged on both sides of the conveyor belt of the pellet ore raw material dryer, and the second air inlet faces the material on the conveyor belt.

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