A near-zero emission system and method for waste gas from an annular cooler and efficient comprehensive utilization of waste heat.

Abstract

This invention discloses a near-zero emission system and method for efficient waste heat utilization of an annular cooler. The annular cooler is divided into a high-temperature zone, a medium-temperature zone, and a low-temperature zone based on the temperature of the sintered ore, from high to low. Each zone has an air inlet and an air outlet. The outlet of the high-temperature zone is connected to the inlet of the No. 1 waste heat boiler. The outlet of the No. 1 waste heat boiler merges with the outlet of the low-temperature zone and then connects to the inlet of the No. 1 circulating fan. The outlet of the No. 1 circulating fan is connected to the inlet of the medium-temperature zone. The outlet of the medium-temperature zone is connected to the inlet of the No. 2 waste heat boiler. The outlet of the No. 2 waste heat boiler merges with the outlet of the low-temperature zone and then connects to the inlet of the No. 2 circulating fan. The outlet of the No. 2 circulating fan is connected to the inlet of the high-temperature zone. The inlet of the annular cooler draws air from the outside air. The outlet of the annular cooler is connected to the inlet of the low-temperature zone. This invention achieves near-zero emissions from the annular cooler.

Description

Technical Field

[0001] This invention relates to a near-zero emission system and method for waste heat utilization of an annular cooler. Background Technology

[0002] Currently, most domestic annular coolers have recovered the high-temperature waste heat resources from the first and second stages of exhaust gas. However, the waste heat resources at the rear of the annular cooler are difficult to utilize due to the excessively low exhaust gas temperature. On the other hand, domestic annular coolers have not achieved zero emissions, resulting in a large amount of high-temperature dust-laden exhaust gas being directly released into the atmosphere, polluting the environment.

[0003] For the low-temperature exhaust gas after the first and second stages of the annular cooler, some sintering plants in China have also adopted the method of exhaust gas recirculation to generate steam to recover this part of the waste heat. However, after adopting recirculation, the exhaust gas temperature is too high, which makes it impossible to cool the discharge temperature of the annular cooler to the design value. The sintering system can only operate at reduced load, which affects the output of sintered ore. Summary of the Invention

[0004] To overcome the above problems, the present invention provides a near-zero emission system for exhaust gas from an annular cooler and a comprehensive utilization system for waste heat.

[0005] To achieve the above objectives, the near-zero emission and high-efficiency waste heat comprehensive utilization system for the annular cooler exhaust gas of the present invention includes at least an annular cooler, a No. 1 waste heat boiler, a No. 2 waste heat boiler, a No. 1 circulating fan, a No. 2 circulating fan, and an annular cooler fan.

[0006] The ring cooler is divided into high-temperature zone, medium-temperature zone and low-temperature zone according to the temperature of the sinter from high to low; each zone has an air inlet and an air outlet;

[0007] The outlet of the high-temperature zone is connected to the inlet of the No. 1 waste heat boiler; the outlet of the No. 1 waste heat boiler and the outlet of the low-temperature zone merge and are then connected to the inlet of the No. 1 circulating fan; the outlet of the No. 1 circulating fan is connected to the inlet of the medium-temperature zone.

[0008] The outlet of the medium-temperature zone is connected to the inlet of the No. 2 waste heat boiler; the outlet of the No. 2 waste heat boiler and the outlet of the low-temperature zone merge and are then connected to the inlet of the No. 2 circulating fan; the outlet of the No. 2 circulating fan is connected to the inlet of the high-temperature zone.

[0009] The inlet of the annular cooling fan draws air from the outside air; the outlet of the annular cooling fan is connected to the inlet of the low-temperature zone.

[0010] To achieve the above objectives, the near-zero emission and high-efficiency waste heat comprehensive utilization system for the annular cooler exhaust gas of the present invention includes at least an annular cooler, a No. 1 waste heat boiler, a No. 2 waste heat boiler, a No. 1 circulating fan, a No. 2 circulating fan, and an annular cooler fan.

[0011] The ring cooler is divided into five zones from high to low based on the temperature of the sinter: Zone I, Zone II, Zone III, Zone IV, and Zone V; each zone has an air inlet and an air outlet.

[0012] The outlets of the annular cooler zones I and II are connected to the inlet of the No. 1 waste heat boiler; the outlet of the No. 1 waste heat boiler merges with the outlet of the annular cooler zone V and then connects to the inlet of the No. 1 circulating fan; the outlet of the No. 1 circulating fan is connected to the inlet of the annular cooler zones III and IV.

[0013] The outlets of Zones III and IV of the annular cooler are connected to the inlet of the No. 2 waste heat boiler; the outlet of the No. 2 waste heat boiler merges with the outlet of Zone V of the annular cooler and then connects to the inlet of the No. 2 circulating fan; the outlet of the No. 2 circulating fan is connected to the inlet of Zones I and II of the annular cooler.

[0014] The inlet of the annular cooling fan draws air from the outside air; the outlet of the annular cooling fan is connected to the inlet of zone V of the annular cooler.

[0015] To achieve the above objectives, the present invention provides a method for near-zero emission of exhaust gas from an annular cooler and efficient comprehensive utilization of waste heat. The method is implemented using the aforementioned system and includes:

[0016] The annular cooler is divided into high-temperature zone, medium-temperature zone and low-temperature zone according to the temperature of the sintered ore, from high to low; each zone has an air inlet and an air outlet.

[0017] The outlet of the high-temperature zone is connected to the inlet of the No. 1 waste heat boiler; the outlet of the No. 1 waste heat boiler and the outlet of the low-temperature zone are connected to the inlet of the No. 1 circulating fan; the outlet of the No. 1 circulating fan is connected to the inlet of the medium-temperature zone.

[0018] The outlet of the medium-temperature zone is connected to the inlet of the No. 2 waste heat boiler; the outlet of the No. 2 waste heat boiler and the outlet of the low-temperature zone are merged and then connected to the inlet of the No. 2 circulating fan; the outlet of the No. 2 circulating fan is connected to the inlet of the high-temperature zone.

[0019] The inlet of the annular air cooler draws air from the outside air; the outlet of the annular air cooler is connected to the inlet of the low-temperature zone.

[0020] Furthermore, the method specifically involves: when the inlet exhaust gas temperature of the No. 1 waste heat boiler 2 is 400-500℃, after heat exchange, the exhaust gas temperature of the No. 1 waste heat boiler 2 is reduced to 50-100℃.

[0021] The low-temperature exhaust gas at 50-100℃ is pumped into the inlet of zone III and zone IV of the ring cooler 1 by circulating fan 4. After cooling the sintered ore, the temperature is raised to 200-300℃. After passing through the waste heat boiler 3, the temperature is reduced to 100-200℃. This part of the exhaust gas is then pumped into the inlet of zone I and zone II of the ring cooler 1 by circulating fan 5 to cool the sintered ore, completing a cross-circulation process of exhaust gas.

[0022] The ring-cooled fan 6 draws in cold air directly from the atmosphere and introduces it into zone V of the ring-cooled fan 1 to cool the last section of sintered ore. The exhaust gas at 50-150°C after heat exchange is introduced into the inlet of the No. 1 circulating fan 4 and the No. 2 circulating fan 5 respectively, which serves as the air volume lost during the recirculation of exhaust gas in zones I, II, III and IV, thus achieving near-zero emissions of exhaust gas from the ring-cooled fan.

[0023] This invention achieves near-zero emissions from the recirculating cooler. Furthermore, by utilizing the characteristics of a low-temperature waste heat boiler, it cross-cools sintered ore at different temperatures using recirculated waste gas at varying temperatures. This reduces the gas-solid heat exchange temperature difference, improves energy recovery, lowers the breakage rate during sinter cooling, and increases the yield of finished sintered ore. In addition, the lower temperatures of the recirculated waste gas in the third and fourth stages, combined with the sintered ore being cooled by outdoor air in the fifth stage, are sufficient to cool the sintered ore to the design temperature, ensuring that the rated capacity of the sintering machine is not reduced. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a near-zero emission and waste heat utilization system for an annular cooler.

[0025] In the diagram, 1 is the annular cooler; 2 is the No. 1 waste heat boiler; 3 is the No. 2 waste heat boiler; 4 is the No. 1 circulating fan; 5 is the No. 2 circulating fan; and 6 is the annular cooler. Detailed Implementation

[0026] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] In the description of this invention, it should be understood that the terms "center", "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. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] The present invention will now be further described with reference to the accompanying drawings.

[0030] The near-zero emission and high-efficiency waste heat comprehensive utilization system of the annular cooler exhaust gas of the present invention includes at least an annular cooler, a No. 1 waste heat boiler, a No. 2 waste heat boiler, a No. 1 circulating fan, a No. 2 circulating fan, and an annular cooler fan.

[0031] The ring cooler is divided into high-temperature zone, medium-temperature zone and low-temperature zone according to the temperature of the sinter from high to low; each zone has an air inlet and an air outlet;

[0032] The outlet of the high-temperature zone is connected to the inlet of the No. 1 waste heat boiler; the outlet of the No. 1 waste heat boiler and the outlet of the low-temperature zone merge and are then connected to the inlet of the No. 1 circulating fan; the outlet of the No. 1 circulating fan is connected to the inlet of the medium-temperature zone.

[0033] The outlet of the medium-temperature zone is connected to the inlet of the No. 2 waste heat boiler; the outlet of the No. 2 waste heat boiler and the outlet of the low-temperature zone merge and are then connected to the inlet of the No. 2 circulating fan; the outlet of the No. 2 circulating fan is connected to the inlet of the high-temperature zone.

[0034] The inlet of the annular cooling fan draws air from the outside air; the outlet of the annular cooling fan is connected to the inlet of the low-temperature zone.

[0035] Figure 1 The figure shown is an embodiment of the present invention. In this embodiment, the sinter in zones I, II, III and IV of the annular cooler 1 is cooled by waste gas recirculation. Zone V is cooled by an annular cooling fan 5 drawing cold air from the outdoor atmosphere. The exhaust gas is introduced into zones I, II, III and IV as the air volume lost during the cooling process, thereby ensuring the balance of the waste gas volume of the entire annular cooler system and achieving near-zero emissions from the annular cooler.

[0036] In addition, the waste heat utilization of the exhaust gas on the annular cooler is a low-temperature waste heat recovery, which usually adopts the steam recovery method. When the inlet exhaust gas temperature of the No. 1 waste heat boiler 2 is 400-500℃, after heat exchange, the exhaust gas temperature of the No. 1 waste heat boiler 2 will drop to 50-100℃. This low-temperature exhaust gas of 50-100℃ is then pumped into the inlet of Zone III and Zone IV of the annular cooler 1 by the No. 1 circulating fan 4. After cooling the sintered ore, the temperature rises to 200-300℃. After heat exchange by the No. 2 waste heat boiler 3, the temperature drops to 100-200℃. This part of the exhaust gas is then pumped into the inlet of Zone I and Zone II of the annular cooler 1 by the No. 2 circulating fan 5 to cool the sintered ore, completing a waste gas cross-circulation process. The annular cooling fan 6 directly draws in cold air from the atmosphere and introduces it into zone V of the annular cooler 1 to cool the last stage of sintered ore. The exhaust gas, after heat exchange at 50-150°C, is then introduced into the inlets of circulating fans 1 (4) and 2 (5) to compensate for the air volume lost during the recirculation of exhaust gas in zones I, II, III, and IV, achieving near-zero emissions from the annular cooler. In this scheme, the sintered ore in zones I and II is cooled by exhaust gas at a temperature of 100-200°C, the sintered ore in zones III and IV is cooled by exhaust gas at a temperature of 50-100°C, and the sintered ore in zone V is cooled by outdoor air at a temperature <50°C. This perfectly conforms to the principle of using high-temperature exhaust gas to cool high-temperature sintered ore and low-temperature exhaust gas to cool low-temperature sintered ore, thus achieving maximum recovery. Furthermore, this cascade cooling technology results in higher cooling efficiency, ensuring that the sintered ore is cooled to the required temperature.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A near-zero emission and high-efficiency waste heat utilization system for annular cooler exhaust gas, characterized in that: The system includes at least an annular cooler, a waste heat boiler (No. 1), a waste heat boiler (No. 2), a circulating fan (No. 1), a circulating fan (No. 2), and an annular cooler. The ring cooler is divided into high-temperature zone, medium-temperature zone and low-temperature zone according to the temperature of the sinter from high to low; each zone has an air inlet and an air outlet; The outlet of the high-temperature zone is connected to the inlet of the No. 1 waste heat boiler; the outlet of the No. 1 waste heat boiler and the outlet of the low-temperature zone merge and are then connected to the inlet of the No. 1 circulating fan; the outlet of the No. 1 circulating fan is connected to the inlet of the medium-temperature zone. The outlet of the medium-temperature zone is connected to the inlet of the No. 2 waste heat boiler; the outlet of the No. 2 waste heat boiler and the outlet of the low-temperature zone merge and are then connected to the inlet of the No. 2 circulating fan; the outlet of the No. 2 circulating fan is connected to the inlet of the high-temperature zone. The inlet of the annular cooling fan draws air from the outside air; the outlet of the annular cooling fan is connected to the inlet of the low-temperature zone.

2. A near-zero emission and high-efficiency waste heat utilization system for annular cooler exhaust gas, characterized in that: The system includes at least an annular cooler, a waste heat boiler (No. 1), a waste heat boiler (No. 2), a circulating fan (No. 1), a circulating fan (No. 2), and an annular cooler. The ring cooler is divided into five zones from high to low based on the temperature of the sinter: Zone I, Zone II, Zone III, Zone IV, and Zone V; each zone has an air inlet and an air outlet. The outlets of the annular cooler zones I and II are connected to the inlet of the No. 1 waste heat boiler; the outlet of the No. 1 waste heat boiler merges with the outlet of the annular cooler zone V and then connects to the inlet of the No. 1 circulating fan; the outlet of the No. 1 circulating fan is connected to the inlet of the annular cooler zones III and IV. The outlets of Zones III and IV of the annular cooler are connected to the inlet of the No. 2 waste heat boiler; the outlet of the No. 2 waste heat boiler merges with the outlet of Zone V of the annular cooler and then connects to the inlet of the No. 2 circulating fan; the outlet of the No. 2 circulating fan is connected to the inlet of Zones I and II of the annular cooler. The inlet of the annular cooling fan draws air from the outside air; the outlet of the annular cooling fan is connected to the inlet of zone V of the annular cooler.

3. The near-zero emission and high-efficiency waste heat comprehensive utilization system for annular cooler exhaust gas as described in claim 2, characterized in that: The sinter in Zones I and II is cooled by exhaust gas at a temperature of 100-200℃.

4. The near-zero emission and high-efficiency waste heat comprehensive utilization system for annular cooler exhaust gas as described in claim 2, characterized in that: The sinter in Zones III and IV is cooled by exhaust gas at a temperature of 50-100℃.

5. The near-zero emission and high-efficiency waste heat comprehensive utilization system for annular cooler exhaust gas as described in claim 2, characterized in that: The sinter in Zone V is cooled by outdoor air with an ambient temperature of less than 50°C.

6. A method for near-zero emission of exhaust gas and efficient comprehensive utilization of waste heat from an annular cooler, characterized in that: The method is performed using the system as described in claim 2; it includes: The annular cooler is divided into high-temperature zone, medium-temperature zone and low-temperature zone according to the temperature of the sintered ore, from high to low; each zone has an air inlet and an air outlet. The outlet of the high-temperature zone is connected to the inlet of waste heat boiler #1; the outlet of waste heat boiler #1 merges with the outlet of the low-temperature zone and is then connected to the inlet of circulating fan #1; the outlet of circulating fan #1 is connected to the inlet of the medium-temperature zone. The outlet of the medium-temperature zone is connected to the inlet of waste heat boiler #2; the outlet of waste heat boiler #2 and the outlet of the low-temperature zone are merged and then connected to the inlet of circulating fan #2; the outlet of circulating fan #2 is connected to the inlet of the high-temperature zone. The inlet of the annular air cooler draws air from the outside air; the outlet of the annular air cooler is connected to the inlet of the low-temperature zone.

7. The method for near-zero emission of exhaust gas and efficient comprehensive utilization of waste heat from an annular cooler as described in claim 6, characterized in that: The method described in detail is as follows: When the inlet exhaust gas temperature of the No. 1 waste heat boiler is 400~500℃, after heat exchange, the exhaust gas temperature of the No. 1 waste heat boiler is reduced to 50~100℃. The low-temperature exhaust gas at 50~100℃ is pumped into the inlet of Zone III and Zone IV of the ring cooler by the No. 1 circulating fan. After cooling the sintered ore, the temperature is raised to 200~300℃. After passing through the No. 2 waste heat boiler for heat exchange, the temperature is reduced to 100~200℃. This part of the exhaust gas is then pumped into the inlet of Zone I and Zone II of the ring cooler by the No. 2 circulating fan to cool the sintered ore, completing a cross-circulation process of exhaust gas. The ring-cooled fan directly draws in cold air from the atmosphere and introduces it into zone V of the ring-cooled machine to cool the last section of sintered ore. The exhaust gas at 50~150℃ after heat exchange is introduced into the inlet of the No. 1 and No. 2 circulating fans respectively, which serves as the air volume lost during the recirculation of exhaust gas in zones I, II, III and IV, thus achieving near-zero emissions of exhaust gas from the ring-cooled machine.

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