A sinter cooling waste heat cascade utilization device

Abstract

The application relates to a sinter cooling waste heat cascade utilization device. The device comprises a sinter cooler and a pellet raw material dryer, the cooler has a material cooling part; the material cooling part is divided into a first cooling zone, a second cooling zone and a third cooling zone along the material movement direction; the pellet raw material dryer is arranged above the second cooling zone and the third cooling zone, and the pellet raw material dryer is sequentially divided into a first drying zone, a second drying zone and a third drying zone along the material movement direction; the pellet raw material drying device is arranged above the second cooling zone and the third cooling zone of the sinter step type ring cooler, the pellet raw material drying device is heated by the waste heat of the sinter, the hot air generated by the sinter cooling is led out to the pellet raw material drying device through a pipeline, the pellet raw material is fully dried, and the utilization rate of the sinter waste heat is improved.

Description

Technical Field

[0001] The present application relates to the technical field of flue gas waste heat recovery from sintered ore step coolers, and in particular to a cascade utilization device for sintered ore cooling waste heat. Background Art

[0002] As a key raw material for blast furnaces, sintered ore requires crushing, screening, and transportation before it can be fed into the blast furnace. However, excessively high sintered ore temperatures hinder these processes. Therefore, cooling high-temperature sintered ore has become an essential step. Cooling sintered ore reduces equipment wear and adjusts the ore's internal structure to improve its performance. However, the existing sintered ore cooling process is inefficient in recovering heat, and the waste heat generated during the cooling process is not properly utilized, resulting in wasted heat. Summary of the Invention

[0003] In order to solve or partially solve the problems existing in the related art, the present application provides a cascade utilization device for sintered ore cooling waste heat, which aims to rationally utilize the waste heat of sintered ore after sintering to reduce energy consumption.

[0004] A cascade utilization device for sintered ore cooling waste heat, comprising a sintered ore cooler and a pellet ore raw material dryer, wherein the cooler has a material cooling part;

[0005] The material cooling section is divided into a primary cooling zone, a secondary cooling zone, and a tertiary cooling zone along the direction of material movement; the pellet raw material dryer is arranged above the secondary cooling zone and the tertiary cooling zone, and the pellet raw material dryer is divided into a primary drying zone, a secondary drying zone, and a tertiary drying zone in sequence along the direction of material movement;

[0006] The hot air in the primary cooling zone is introduced into the primary heat exchanger through the primary heat exchange pipe to preheat the boiler inlet water. The hot air discharged from the primary heat exchanger is introduced into the primary drying zone through the primary cooling pipe for drying. Part of the hot air in the primary drying zone is introduced into the tertiary drying zone through a pipe for drying, and the remaining hot air is introduced into the secondary heat exchanger through a pipe for cooling. The hot air in the tertiary drying zone is introduced into the secondary heat exchanger through a pipe for cooling. The cold air discharged from the secondary heat exchanger is respectively introduced into the primary cooling zone and the tertiary cooling zone through pipes for cooling.

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

[0008] In some solutions, a temperature regulating tube is connected between the first-level heat exchange tube and the first-level cooling tube, and a temperature regulating valve is provided on the temperature regulating tube.

[0009] In some solutions, the cold source water inlet end of the primary heat exchanger is connected to the deaerator through a pipeline, and the cold source water outlet end is connected to the boiler through a pipeline.

[0010] In some embodiments, the cold source ends of the secondary heat exchangers are connected to cooling towers via pipelines.

[0011] In some embodiments, the hot air in the primary drying zone and the secondary drying zone is introduced into a mixing tube through pipes for mixing, and 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 embodiments, a first air inlet and a first air outlet are respectively provided 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.

[0013] In some solutions, a second air inlet and a second air outlet are respectively provided on both sides of the conveyor belt of the pellet raw material dryer, and the second air inlet faces the material on the conveyor belt.

[0014] The technical solution provided by this application may have the following beneficial effects:

[0015] 1. This application installs the pellet raw material drying device above the secondary and tertiary cooling zones of the sintered ore step-type ring cooler, utilizes the residual heat of the sintered ore to heat the pellet raw material drying device, and then leads the hot air generated by the cooling of the sintered ore to the pellet raw material drying device through a pipeline to fully dry the pellet raw material and improve the utilization rate of the sintered ore waste heat. At the same time, according to production needs, part of the hot air is introduced into the primary heat exchanger, and the boiler inlet water is preheated through the primary heat exchanger, which reduces the fuel consumption of the boiler and improves the heat energy recovery capacity.

[0016] 2. Using the waste heat of sintered ore to dry the pellet raw materials avoids the energy consumption of drying the pellet raw materials separately in the existing technology, and can save 20-30m3 of gas consumption in the drying furnace. 3 / t, which reduces the company's production costs. At the same time, the pellet raw material drying air after heat exchange is used to cool the sintered ore. According to the difference in temperature gradient, the cooling air inlet is reasonably configured to improve the utilization rate of hot air under different calorific values. At the same time, the heat exchange between the high-temperature air and the boiler inlet water during the cooling of the sintered ore effectively reduces the fuel consumption of the boiler.

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

[0018] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 1 Schematic diagram of the piping of the sintered ore cooling waste heat cascade utilization device shown in the embodiment of the present application;

[0021] Reference numerals:

[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 pipe; 9. Primary cooling pipe; 10. Secondary heat exchanger; 11. Temperature regulating pipe; 12. Temperature regulating valve; 13. Deaerator; 14. Boiler; 15. Cooling tower; 16. Mixing pipe. DETAILED DESCRIPTION

[0023] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. Although the accompanying drawings illustrate embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present 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 each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0026] Unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0027] See also Figure 1 This application provides a cascaded device for utilizing waste heat from sintered ore cooling, comprising a sintered ore cooler and a pelletized ore raw material dryer. The sintered ore cooler comprises a material sintering section and a material cooling section. The material sintering section is used to sinter the ore, while the material cooling section is used to cool the material. The material cooling section utilizes a chain plate conveyor. The pelletized ore raw material dryer comprises a housing and a chain plate conveyor disposed within the housing.

[0028] During operation, the material is sintered in the material sintering section to obtain sintered ore. The average initial temperature of the sintered ore is between 700℃ and 750℃, and then it is put into the material cooling section for cooling. In the material cooling section, the sintered ore is transported forward by a conveyor belt and gradually cooled. According to the extent to which the waste 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 direction of material movement; the ambient air temperature of the primary cooling zone 1 is between 400℃ and 750℃, the ambient air temperature of the secondary cooling zone 2 is between 250℃ and 400℃, and the ambient air temperature of the tertiary cooling zone 3 is between 50℃ and 250℃.

[0029] The pellet raw material dryer is arranged above the secondary cooling zone 2 and the tertiary cooling zone 3, and the secondary cooling zone 2 and the tertiary cooling zone 3 form a semi-wrapped state for the pellet raw material dryer. The bottom plate of the pellet raw material dryer directly serves as the top plate of the secondary cooling zone 2 and the tertiary cooling zone 3, and the left side plates (feed port end) of the secondary cooling zone 2 and the tertiary cooling zone 3 directly serve as the right side plate of the primary cooling zone 1. Through this design, the temperature of the secondary cooling zone 2 and the tertiary cooling zone 3 is directly transmitted to the outer shell of the pellet raw material dryer, thereby increasing the temperature inside the pellet raw material dryer, effectively utilizing the necessary heat radiation of the secondary cooling zone 2 and the tertiary cooling zone 3 to increase the ambient temperature of the pellet raw material dryer, and at the same time, it is beneficial to reduce the temperature of the secondary cooling zone 2 and the tertiary cooling zone 3, and quickly cool the internal materials.

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

[0031] The cooling conveyor belt of the sintered ore cooler is provided with a first air inlet and a first air outlet on both sides. The air outlet direction of the first air inlet is directly facing the material on the conveyor belt. Multiple first air inlets and first air outlets are provided at intervals along the conveying direction of the cooling conveyor belt, so that in each cooling zone, there are three to six first air inlets and first air outlets arranged opposite each other. During operation, cooling air is blown from the first air inlet to the sintered ore, and then discharged from the first air outlet, so as to form a basically independent circulation of cooling air in each cooling zone. Furthermore, valves are provided on the pipes connected to each first air inlet, and the opening and closing of the valves are controlled to achieve the air flow rate through different cooling zones.

[0032] The pellet raw material dryer has a second air inlet and a second air outlet on either side of the conveyor belt. The second air inlet faces the material on the conveyor belt. Multiple second air inlets and second air outlets are spaced apart along the conveying direction of the conveyor belt, resulting in three to six oppositely positioned second air inlets and second air outlets in each drying zone. During operation, hot air is blown from the second air inlets toward the pellet raw material and then discharged from the second air outlets, forming a basically independent circulation of hot air in each drying zone. Furthermore, valves are installed on the pipes connected to each second air inlet, and the opening and closing of the valves are controlled to adjust the air flow through different drying zones.

[0033] The hot air from 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. Specifically, the first air inlet in the primary cooling zone 1 is connected to the cooling fan via a pipeline, 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 via a pipeline. Since the temperature of the sintered ore in the primary cooling zone 1 is relatively high, the ambient air temperature can be heated to between 400°C and 750°C. According to the drying amount of the pelletized ore raw materials, the waste heat from the primary cooling zone 1 is reasonably allocated to the boiler 14 or the primary drying zone 4 through the temperature regulating valve 12, so that the waste heat of the primary cooling zone 1 can be reasonably distributed. In this way, the waste heat of the sintered ore in the primary cooling zone 1 is effectively utilized, energy is saved, and the operating cost of the boiler 14 is reduced.

[0034] 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. After passing through the primary heat exchanger 6, the temperature of the hot air is reduced. By introducing the hot air into the primary drying zone 4, the low-temperature waste heat therein is effectively utilized to achieve the purpose of improving energy utilization efficiency.

[0035] 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 derived from the secondary heat exchanger 10 is introduced into the primary cooling zone 1 and the tertiary cooling zone 3 through pipelines for cooling. In this way, the residual temperature of the sintered ore in the secondary cooling zone 2 is fully utilized, and the sintered ore can also be cooled quickly, which is 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, effectively filtering water vapor or particulate matter in the flue gas while removing water accumulated in the pipeline, ensuring the normal circulation of the flue gas while separating and discharging condensed water or impurities, avoiding direct discharge of moisture and reducing environmental pollution.

[0037] The hot air in the tertiary cooling zone 3 is introduced into the secondary cooling zone 2 through a pipeline for cooling. The air passing through the tertiary cooling zone 3 has a certain temperature, which is lower than the temperature of the secondary cooling zone 2. It can cool the sintered ore in the secondary cooling zone 2 very well, and at the same time, enhance the matching of the waste heat of the secondary cooling zone 2 and the tertiary cooling zone 3, reduce the dissipation of heat, and bring the heat into the secondary drying zone 5, so as to make full use of the waste 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 the pellet raw materials.

[0038] The hot air in the tertiary cooling zone 3 is introduced into the secondary cooling zone 2 through a pipeline for cooling. The air passing through the tertiary cooling zone 3 has a certain temperature and is then introduced into the secondary cooling zone 2 for cooling. The temperature difference between the sintered ore and the cooled air is reduced, which is conducive to uniform cooling of the sintered ore.

[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, the residual heat of the sintered ore after sintering is reasonably utilized, and by arranging the flow direction of each heat, the residual heat is recovered more fully, thereby enhancing the energy utilization efficiency.

[0041] In some specific embodiments, a temperature regulating tube 11 is connected between the first-level heat exchange tube 8 and the first-level cooling tube 9. The temperature regulating tube 11 is provided with a temperature regulating valve 12. When in use, the temperature regulating valve 12 can be used to control the amount of hot air introduced into the first-level heat exchange tube 8. On the one hand, it can serve the purpose of regulating the water inlet temperature of the boiler 14, and on the other hand, it can regulate the temperature of the hot air introduced into the first-level drying area 4.

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

[0043] In some specific embodiments, the cold source end of the secondary heat exchanger 10 is connected to the cooling tower 15 through a pipeline. The hot air after drying still has a certain temperature. Water is used through the secondary heat exchanger 10 and the cooling tower 15 to effectively remove almost all the residual heat in the hot air, so that it can basically reach room temperature, so that it can be used for cooling again.

[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 tube 16 through pipes for mixing, and then part of the mixed hot air 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 the mixing tube 16 for cooling.

[0045] The application process:

[0046] The sintered ore with an average temperature of 700℃-750℃ is first discharged into the step-type sintered ore cooler, and then transported forward by the conveyor belt at a conveying speed of 1-4m / min. The cooling fan introduces the cold air derived from the secondary heat exchanger 10 from the corresponding first air inlet and blows it to the sintered ore. The sintered ore heats the blown air, which is then discharged from the first air outlet and then introduced into the primary heat exchanger 6 for heating the water inlet to the boiler 14. During this process, the air flow through the first cooling zone can be adjusted by adjusting the opening and closing size of the valve on the pipe connected to the first air inlet; the air outlet from the primary cooling zone 1 of the sintered ore step cooler passes through the primary heat exchanger 6 and is introduced into the primary drying zone 4 to dry the pellets. During this process, the opening and closing size of the temperature regulating valve 12 can be adjusted according to the actual production situation to control the waste heat leading to the primary heat exchanger 6, which can effectively regulate the water inlet temperature of the boiler 14 and the temperature of the hot air entering the primary drying zone 4.

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

[0048] After the drying air flowing out of the primary drying area 4 is combined with the drying air duct flowing out of the secondary drying area 5, a portion of it is introduced into the tertiary drying area 7 to dry the pellets. The drying air flowing out of the tertiary drying area 7 is refluxed again and mixed with the drying air flowing out of the primary and secondary drying areas 5 before being introduced into the secondary heat exchanger 10 for cooling.

[0049] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not 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 selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons 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 pellet ore raw material dryer, wherein the sintered ore cooler has a material cooling section, 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 direction of material movement; the pellet raw material dryer is arranged above the secondary cooling zone (2) and the tertiary cooling zone (3), and the pellet raw material dryer is divided into a primary drying zone (4), a secondary drying zone (5), and a tertiary drying zone (7) along the direction of material movement; 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); 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 from the tertiary cooling zone (3) is introduced into the secondary cooling zone (2) through a pipeline for cooling; The hot air from the secondary cooling zone (2) is introduced into the secondary drying zone (5) through a pipeline for drying, part of the hot air from 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; 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); The hot air from the primary drying zone (4) and the secondary drying zone (5) is introduced into the mixing tube (16) through pipelines for mixing, and then part of the mixed hot air is introduced into the tertiary drying zone (7) through pipelines for drying, and the remaining hot air is introduced into the secondary heat exchanger (10) through the mixing tube (16) for cooling; The cooling conveyor belt of the sintered ore cooler is provided with a first air inlet and a first air outlet on both sides thereof, wherein the air outlet direction of the first air inlet is directly facing the material on the conveyor belt; A second air inlet and a second air outlet are respectively provided on both sides of the conveyor belt of the pellet raw material dryer, and the second air inlet faces the material on the conveyor belt.

2. The cascade utilization device for sintered ore cooling waste heat according to claim 1, 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.

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

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