Sintering circular cooler three-section waste heat recovery system for coal gas preheating

Abstract

The invention provides a sintering circular cooler three-section waste heat recovery system for coal gas preheating, the three-section waste heat recovery system comprises an inlet coal gas pipeline, an outlet coal gas pipeline, a first preheating pipeline, a second preheating pipeline and a preheater, and a waste heat utilization three-section of a sintering circular cooler is provided with an upper gas collecting hood; one end of the inlet gas pipeline is connected with an external gas source, the other end of the inlet gas pipeline is connected with one end of the first preheating pipeline, and one end of the second preheating pipeline is connected with the outlet gas pipeline. The other end of the first preheating pipeline and the other end of the second preheating pipeline are both connected with the preheater; and the preheater is arranged at the outlet of the upper gas-collecting hood. According to the system, coal gas is preheated through three-section waste heat of the sintering circular cooler, the regional safety risk is reduced, and remarkable energy conservation and consumption reduction are achieved.

Description

Technical Field

[0001] This invention relates to the field of energy-saving technology in smelting processes, and in particular to a three-stage waste heat recovery system for sintering ring coolers used for gas preheating. Background Technology

[0002] In the sintering process of iron and steel metallurgy, a large amount of high-temperature waste gas is generated when the sinter is cooled in the annular cooler. The temperature distribution of these waste gases exhibits a gradient characteristic, with the hot waste gas generated in the third stage of the annular cooler having a relatively low temperature (typically in the medium to low temperature range). Current industrial practice faces significant technical limitations in the recovery and utilization of waste heat from the third stage of the annular cooler: A common approach is to attempt to directly introduce the exhaust gas from the three stages of the annular cooler to the sintering machine material surface for heat utilization. This technical solution has high system investment costs, requires complex exhaust gas conveying pipelines and control systems, has low heat utilization efficiency, and the actual recovery effect is unsatisfactory.

[0003] Another common practice is to use this part of the waste gas as a preheating source for the combustion air of the ignition furnace, but the actual utilization rate is extremely low. Only about 10% of the heat energy is effectively utilized, and most of the waste heat is still directly discharged and wasted, failing to achieve the cascaded and efficient utilization of waste heat resources.

[0004] In the sintering process, gas preheating is usually achieved using a separate gas preheating furnace, which requires additional gas as a heat source, leading to increased energy costs. Furthermore, it poses safety hazards such as gas leaks and explosions, and the equipment is complex and costly to maintain, resulting in low overall energy efficiency and failing to meet energy conservation and emission reduction requirements.

[0005] Given the aforementioned problems with existing technologies, there is a need for a high-efficiency, low-cost three-stage waste heat recovery system for sintering ring coolers used for gas preheating. Summary of the Invention

[0006] The purpose of this invention is to provide a three-stage waste heat recovery system for sintering ring coolers used for gas preheating, which realizes the recovery and utilization of waste heat from the three stages of sintering ring coolers, reduces regional safety risks, and reduces energy consumption.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A three-stage waste heat recovery system for a sintering ring cooler used for gas preheating, wherein the sintering ring cooler has three stages for waste heat utilization, and the three-stage waste heat recovery system includes an inlet gas pipeline, an outlet gas pipeline, a first preheating pipeline, a second preheating pipeline, and a preheater, wherein the three waste heat utilization stages of the sintering ring cooler are equipped with upper gas collection hoods; one end of the inlet gas pipeline is connected to an external gas source, the other end of the inlet gas pipeline is connected to one end of the first preheating pipeline, and one end of the second preheating pipeline is connected to the... The outlet gas pipeline is connected, and the other ends of the first preheating pipeline and the second preheating pipeline are both connected to the preheater. The gas flows sequentially through the inlet gas pipeline, the first preheating pipeline, the preheater, the second preheating pipeline, and the outlet gas pipeline. The preheater is located at the outlet of the upper gas collecting hood. The waste heat of the sintering ring cooler collected by the upper gas collecting hood is used to preheat the gas through the three-stage waste gas. The preheated gas is used for ignition furnace and denitrification process.

[0008] Furthermore, in the aforementioned three-stage waste heat recovery system for sintering ring cooler used for gas preheating, an inlet butterfly valve is installed on the first preheating pipeline. The inlet butterfly valve is used to regulate the gas flow rate entering the three-stage waste heat recovery system.

[0009] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering ring cooler used for gas preheating, an outlet butterfly valve is installed on the second preheating pipeline. The outlet butterfly valve is used to regulate and control the output flow rate of the preheated gas.

[0010] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering ring cooler used for gas preheating, an inlet blind valve is also installed on the first preheating pipeline. The inlet blind valve is located after the inlet butterfly valve and can block the flow of gas in the first preheating pipeline.

[0011] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering ring cooler used for gas preheating, an outlet blind valve is also installed on the second preheating pipeline. The outlet blind valve is located after the outlet butterfly valve and can block the flow of gas in the second preheating pipeline.

[0012] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering ring cooler used for gas preheating, the inlet gas pipeline and the outlet gas pipeline are connected by a connecting pipeline, and a bypass butterfly valve is installed on the connecting pipeline.

[0013] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering annular cooler used for gas preheating, the three waste heat utilization stages of the sintering annular cooler are equipped with an annular cooling blower. Multiple air boxes are connected to the annular cooling blower, and the air boxes are connected to the main body of the sintering annular cooler. Above the air boxes is an upper flue, and above the upper flue is a trolley material layer. The upper gas collection hood is located above the trolley material layer. Adjacent air boxes are connected through an annular flue, and two flue regulating valves are installed on the annular flue. The area between the two flue regulating valves corresponds to the position of the three waste heat utilization stages of the sintering annular cooler.

[0014] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering ring cooler used for gas preheating, two gas collecting hood partitions are provided inside the upper gas collecting hood, and the area between the two gas collecting hood partitions corresponds to the position of the three waste heat utilization stages of the sintering ring cooler; the distance between the lower edge of the gas collecting hood partition and the material layer of the trolley is less than 100mm; two upper partitions are provided inside the upper flue, and the area between the two upper partitions also corresponds to the position of the three waste heat utilization stages of the sintering ring cooler; a lower partition is provided at the lower part of the wind box.

[0015] Furthermore, in the above-mentioned three-stage waste heat recovery system for sintering ring cooler used for gas preheating, the preheater has two heat exchange units connected in series, and corrugated expansion joints are installed on both the first preheating pipe and the second preheating pipe.

[0016] Furthermore, in the aforementioned three-stage waste heat recovery system for the sintering ring cooler used for gas preheating, the outer surfaces of the inlet gas pipe, the outlet gas pipe, the first preheating pipe, and the second preheating pipe are all wrapped with an insulation layer.

[0017] Analysis reveals that this invention discloses a three-stage waste heat recovery system for sintering ring coolers used for gas preheating. This system preheats the gas using the waste heat from the three stages of the sintering ring cooler, replacing the traditional gas preheating furnace. This not only reduces regional safety risks but also achieves significant energy savings. The system, through the coordination of inlet blind flange valves, outlet blind flange valves, and bypass butterfly valves, ensures that the heat exchanger and gas can be isolated under any maintenance or abnormal conditions, without affecting main production. By setting up gas collection hoods, upper partitions, and lower partitions, the system maximizes the concentration and guidance of target hot waste gas to the preheater, reducing heat loss. By adjusting the airflow of the ring cooler blower and the opening of the flue gas regulating valve, the flow rate of the waste gas can be easily adjusted, achieving stable control of the gas preheating temperature. The preheater adopts a non-powered design, greatly reducing the system's maintenance workload and extending the maintenance cycle. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a top view of an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the front view structure of an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached drawings: 1. Inlet gas pipeline; 2. Outlet gas pipeline; 3. First preheating pipeline; 4. Second preheating pipeline; 5. Preheater; 6. Inlet butterfly valve; 7. Outlet butterfly valve; 8. Inlet blind valve; 9. Outlet blind valve; 10. Connecting pipeline; 11. Bypass butterfly valve; 12. Annular cooling blower; 13. Air box; 14. Annular flue; 15. Upper flue; 16. Cart material layer; 17. Upper gas collecting hood; 18. Gas collecting hood partition; 19. Upper partition; 20. Lower partition; 21. Flue regulating valve; 22. Sintering annular cooler. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. Indeed, those skilled in the art will recognize that modifications and variations can be made to the invention without departing from its scope or spirit. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the invention encompass such modifications and variations falling within the scope of the appended claims and their equivalents.

[0022] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected," "linked," and "set up" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; a wired connection, a radio connection, or a wireless communication signal connection. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0023] The accompanying drawings illustrate one or more examples of the invention. The detailed description uses numerals and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous parts of the invention. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0024] like Figures 1 to 2 As shown, according to an embodiment of the present invention, a three-stage waste heat recovery system for a sintering ring cooler used for gas preheating is provided. The sintering ring cooler 22 has three stages for waste heat utilization, such as... Figure 1 As shown, the three-stage waste heat recovery system includes an inlet gas pipeline 1, an outlet gas pipeline 2, a first preheating pipeline 3, a second preheating pipeline 4, and a preheater 5. The waste heat utilization stages of the sintering ring cooler 22 are equipped with upper gas collection hoods 17. One end of the inlet gas pipeline 1 is connected to an external gas source to introduce the gas to be preheated. The other end of the inlet gas pipeline 1 is connected to one end of the first preheating pipeline 3. One end of the second preheating pipeline 4 is connected to the outlet gas pipeline 2. The other end of the first preheating pipeline 3 is connected to the outlet gas pipeline 4. The other end of each of the two preheating pipes 4 is connected to the preheater 5. The gas flow path is as follows: inlet gas pipe 1, first preheating pipe 3, preheater 5, second preheating pipe 4 and outlet gas pipe 2. The preheater 5 is located at the outlet of the upper gas collection hood 17. The upper gas collection hood 17 collects the waste heat of the sintering ring cooler 22 using the waste gas from the three stages. The collected waste gas preheats the gas flowing through the preheater 5. The preheated gas is used for the ignition furnace and denitrification process, thereby effectively reducing energy consumption.

[0025] Furthermore, an inlet butterfly valve 6 is installed on the first preheating pipe 3, which is used to regulate the flow rate of the gas entering the three-stage waste heat recovery system. An outlet butterfly valve 7 is installed on the second preheating pipe 4, which is used to regulate and control the output flow rate of the preheated gas.

[0026] Furthermore, an inlet blind valve 8 is installed on the first preheating pipe 3, located after the inlet butterfly valve 6. The inlet blind valve 8 completely blocks the flow of gas within the first preheating pipe 3. An outlet blind valve 9 is installed on the second preheating pipe 4, located after the outlet butterfly valve 7. The outlet blind valve 9 also completely blocks the flow of gas within the second preheating pipe 4. When maintenance of the preheater 5 is required, closing the inlet blind valve 8 and the outlet blind valve 9 completely physically isolates the preheater 5 from the upstream inlet gas pipe 1 and the downstream outlet gas pipe 2, creating absolutely safe conditions for maintenance operations.

[0027] Furthermore, the inlet gas pipeline 1 and the outlet gas pipeline 2 are connected by a connecting pipeline 10, which is equipped with a bypass butterfly valve 11. When the preheater 5 needs maintenance or malfunctions, the bypass butterfly valve 11 is opened, while the inlet butterfly valve 6 and the outlet butterfly valve 7 are closed. The gas will flow directly from the inlet gas pipeline 1 through the connecting pipeline 10 into the outlet gas pipeline 2, thus ensuring that the gas supply and production process remain continuous and uninterrupted during the shutdown and maintenance of the preheater 5, achieving "zero-impact" maintenance.

[0028] Furthermore, such as Figure 2 As shown, the waste heat utilization section of the sintering annular cooler 22 is equipped with annular cooling blowers 12. Multiple air boxes 13 are connected to the annular cooling blowers 12, and the air boxes 13 are connected to the main body of the sintering annular cooler 22. Above the air boxes 13 is an upper flue 15, and above the upper flue 15 is a trolley material layer 16 carrying the sintered ore. An upper gas collecting hood 17 is located above the trolley material layer 16. Adjacent air boxes 13 are connected through annular flues 14. Two flue regulating valves 21 are installed in the annular flue 14, and the area between the two flue regulating valves 21 corresponds to the position of the waste heat utilization section of the sintering annular cooler 22. By adjusting the opening of the flue regulating valves 21, the flow rate of the exhaust gas entering the preheater 5 can be precisely controlled, thereby achieving the final adjustment of the gas preheating temperature. Its working principle is as follows: the ring-cooled blower 12 sends cold air into the upper flue 15 through the air box 13. The cold air passes upward through the material layer 16 of the trolley and exchanges heat with the hot sintered ore. The high-temperature flue gas formed after cooling the ore gathers upward and is collected by the upper gas collection hood 17 and guided to the preheater 5.

[0029] Furthermore, two gas collection hood partitions 18 are installed inside the upper gas collection hood 17. The gas collection hood partitions 18 are used to divide the space inside the upper gas collection hood 17. The area between the two gas collection hood partitions 18 corresponds to the position of the three waste heat utilization sections of the sintering ring cooler 22. The distance between the lower edge of the gas collection hood partition 18 and the material layer 16 of the trolley is less than 100mm. Two upper partitions 19 are installed inside the upper flue 15. The upper partitions 19 are used to divide the space inside the upper flue 15. The area between the two upper partitions 19 also corresponds to the position of the three waste heat utilization sections of the sintering ring cooler 22. The gas collection hood partitions 18 and the upper partitions 19 work together to divide and guide the airflow, ensuring that the hot waste gas generated by the three waste heat utilization sections flows to the preheater 5 and avoids bypass flow. A lower partition 20 is installed at the bottom of the wind box 13. The lower partition 20 can prevent waste gas from escaping from the bottom of the wind box 13. The combination of the gas collection hood partition 18, the upper partition 19 and the lower partition 20 can maximize the concentration and guidance of the waste gas from the three waste heat utilization stages to the preheater 5, significantly reducing heat loss.

[0030] Furthermore, the preheater 5 has two heat exchange units connected in series to increase the total heat exchange area and improve heat exchange efficiency. The preheater 5 adopts a "powerless" design, meaning it does not rely on an external power source to drive heat exchange, but instead utilizes the natural temperature difference between the waste gas and the coal gas for heat exchange. The flow of coal gas within the preheater 5 follows a "low-in, high-out" pattern, meaning the low-temperature coal gas enters from the low-temperature side inlet of the preheater 5, is heated, and then flows out from the high-temperature side outlet. Corrugated expansion joints are installed on both the first preheating pipe 3 and the second preheating pipe 4. The function of the corrugated expansion joints is to absorb the thermal expansion and contraction stress of the pipes caused by temperature changes during equipment operation, thereby protecting the pipes and the preheater 5 itself from damage.

[0031] Furthermore, the outer surfaces of the inlet gas pipeline 1, the outlet gas pipeline 2, the first preheating pipeline 3, and the second preheating pipeline 4 are all wrapped with an insulation layer to reduce heat loss in the pipelines.

[0032] Furthermore, this three-stage waste heat recovery system is also equipped with data monitoring instruments such as gas temperature gauges and pressure gauges. Gas temperature gauges and pressure gauges are installed at both the inlet and outlet of preheater 5. The data from these gauges is collected synchronously and transmitted to the centralized control room, where it is displayed on the main control screen for remote monitoring. Simultaneously, fixed gas leak alarms are installed around preheater 5. These alarms detect gas content to determine if a leak has occurred in preheater 5, ensuring safe system operation.

[0033] By utilizing the three-stage waste heat recovery system of this sintering ring cooler to preheat the gas, the gas temperature can be raised to 150℃ or higher. Practical applications show that this system can reduce gas consumption in the sintering process by approximately 7% to 10%. Operators can stably and precisely control the preheating temperature of the gas by adjusting the cooling airflow of the ring cooler blower 12 and the opening of the flue gas regulating valve 21 according to the required gas temperature.

[0034] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: A three-stage waste heat recovery system for sintering ring coolers is disclosed. This system preheats the gas using the waste heat from the three stages of the sintering ring cooler, replacing the traditional gas preheating furnace. This not only reduces regional safety risks but also achieves significant energy savings. The system, through the coordination of the inlet blind valve 8, outlet blind valve 9, and bypass butterfly valve 11, ensures that the heat exchanger and gas can be isolated under any maintenance or abnormal conditions, without affecting main production. By setting up a gas collection hood partition 18, upper partition 19, and lower partition 20, the target hot waste gas is concentrated and guided to the preheater 5 to the maximum extent, reducing heat loss. By adjusting the airflow of the ring cooler blower 12 and the opening of the flue gas regulating valve 21, the flow rate of the waste gas can be easily adjusted, achieving stable control of the gas preheating temperature. The preheater 5 adopts a non-powered design, greatly reducing the system's maintenance workload and extending the maintenance cycle.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A three-stage waste heat recovery system for a sintering ring cooler used for gas preheating, wherein the sintering ring cooler has three stages for waste heat utilization, characterized in that, The three-stage waste heat recovery system includes an inlet gas pipeline, an outlet gas pipeline, a first preheating pipeline, a second preheating pipeline, and a preheater. The waste heat utilization section of the sintering ring cooler is equipped with an upper gas collection hood. One end of the inlet gas pipeline is connected to an external gas source, the other end of the inlet gas pipeline is connected to one end of the first preheating pipeline, one end of the second preheating pipeline is connected to the outlet gas pipeline, and the other ends of the first preheating pipeline and the second preheating pipeline are both connected to the preheater. Gas flows sequentially through the inlet gas pipeline, the first preheating pipeline, the preheater, the second preheating pipeline and the outlet gas pipeline. The preheater is located at the outlet of the upper gas collecting hood. The waste heat of the sintering ring cooler collected by the upper gas collecting hood is used to preheat the coal gas through the three-stage exhaust gas. The preheated gas is used for ignition of the furnace and denitrification process.

2. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 1, characterized in that, An inlet butterfly valve is installed on the first preheating pipeline, and the inlet butterfly valve is used to regulate the gas flow rate entering the three-stage waste heat recovery system.

3. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 1, characterized in that, An outlet butterfly valve is installed on the second preheating pipeline, which is used to regulate and control the output flow rate of the preheated gas.

4. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 2, characterized in that, An inlet blind valve is also installed on the first preheating pipeline. The inlet blind valve is located after the inlet butterfly valve and can block the flow of gas in the first preheating pipeline.

5. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 3, characterized in that, An outlet blind valve is also installed on the second preheating pipeline. The outlet blind valve is located after the outlet butterfly valve and can block the flow of gas in the second preheating pipeline.

6. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 1, characterized in that, The inlet gas pipeline and the outlet gas pipeline are connected by a connecting pipe, and a bypass butterfly valve is installed on the connecting pipe.

7. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 1, characterized in that, The waste heat utilization section of the sintering ring cooler is equipped with a ring cooler blower, and multiple air boxes are connected to the ring cooler blower. The air boxes are connected to the main body of the sintering ring cooler. Above the bellows is the upper flue. Above the upper flue is the material layer of the trolley, and the upper gas collection hood is located above the material layer of the trolley. The adjacent air boxes are connected by an annular flue, on which two flue regulating valves are installed. The area between the two flue regulating valves corresponds to the position of the three waste heat utilization sections of the sintering annular cooler.

8. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 7, characterized in that, The upper gas collecting hood is equipped with two gas collecting hood partitions, and the area between the two gas collecting hood partitions corresponds to the position of the three waste heat utilization sections of the sintering ring cooler. The distance between the lower edge of the gas collection hood partition and the material layer of the trolley is less than 100mm; The upper flue is provided with two upper partitions, and the area between the two upper partitions corresponds to the position of the three waste heat utilization sections of the sintering ring cooler. The lower part of the bellows is provided with a lower partition.

9. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 1, characterized in that, The preheater has two heat exchange units connected in series. Corrugated expansion joints are installed on both the first preheating pipe and the second preheating pipe.

10. The three-stage waste heat recovery system for sintering ring cooler for gas preheating according to claim 1, characterized in that, The outer surfaces of the inlet gas pipeline, the outlet gas pipeline, the first preheating pipeline, and the second preheating pipeline are all wrapped with an insulation layer.

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