Lump ore drying and circular cooler coupled near-zero emission system

Abstract

A lump ore drying and circular cooler coupled near-zero emission system comprises a circular cooler and a drying machine. And smoke hoods are respectively arranged above the circular cooler and the dryer. According to the material trend, the flue gas cover above the circular cooler is sequentially divided into a high-temperature area, a medium-temperature area and a low-temperature area. And the air outlet of the high-temperature area is connected to the air inlet of the high-temperature area through a high-temperature flue gas pipeline. And a medium-temperature flue gas pipeline led out from the medium-temperature area and a low-temperature flue gas pipeline led out from the low-temperature area are combined and then are connected to an air inlet of the drying machine through a mixed flue gas pipeline. And a circulating flue gas pipeline led out from an air outlet of a flue gas cover above the drying machine is connected to air inlets of a medium-temperature area and a low-temperature area of the circular cooler. According to the system, lump ore drying is coupled with the circular cooler, the lump ore is dried by fully utilizing waste gas waste heat of a low-temperature area in the circular cooler, and meanwhile near-zero emission of the system is achieved.

Description

Technical Field

[0001] This utility model relates to the utilization of waste heat resources from the exhaust gas of an annular cooler, specifically to a near-zero emission system that couples lump ore drying with an annular cooler, belonging to the fields of metallurgy and environmental protection technology. Background Technology

[0002] Natural lump ore is a major component of blast furnace feed, with its addition reaching up to 30%. Currently, however, the proportion of lump ore in the blast furnace is generally 5-15%, a relatively low percentage. This is primarily due to the high powder and moisture content of the lump ore. The moisture content is typically 8-15%, and in some port steel mills, it even exceeds 20% during the rainy season. Drying high-moisture lump ore requires energy and time, increasing the coke ratio in the blast furnace, leading to higher smelting costs and impacting normal blast furnace production. This significantly affects the smooth operation of the steelmaking process and the economic benefits of steel mills. Therefore, reducing the moisture content of lump ore is crucial for lowering ironmaking costs and enhancing furnace stability. Currently, lump ore drying systems face challenges such as high construction costs, low drying efficiency, and high energy consumption.

[0003] Currently, domestic annular cooler exhaust gases have largely recovered the high-temperature waste heat resources from the first and second stages. However, the waste heat resources in the later stages of the annular cooler are difficult to utilize due to the excessively low exhaust gas temperature. Furthermore, domestic annular coolers generally do not achieve zero emissions, resulting in large amounts of high-temperature, dust-laden exhaust gas being directly released into the atmosphere, polluting the environment. For the low-temperature exhaust gas after the first and second stages of the annular cooler, some domestic sintering plants have adopted exhaust gas recirculation to generate steam to recover this waste heat. However, after recirculation, the exhaust gas temperature remains too high, making it impossible to cool the annular cooler discharge temperature to the design value. This forces the sintering system to operate at reduced load, impacting sinter production. Utility Model Content

[0004] In view of the problems of high construction cost, low drying efficiency and high energy consumption in the existing lump ore drying system, as well as the difficulty in utilizing the waste heat of the low-temperature section of the annular cooler and the difficulty in achieving zero emissions, this utility model couples the drying of lump ore with the utilization of waste heat of the low-temperature section of the annular cooler, and proposes a near-zero emission system that couples lump ore drying with an annular cooler. In the technical solution of this utility model, the high-temperature hot air discharged from the high-temperature zone of the annular cooler is drawn back to the high-temperature zone to circulate and cool the sinter in that area. At the same time, the mixed hot air discharged from the low-temperature zone of the annular cooler is transported to the dryer to dry the lump ore, thus making full use of the waste heat of the exhaust gas in the low-temperature zone of the annular cooler. After drying, the dried air discharged from the dryer is drawn back to the low-temperature zone of the annular cooler for circulating and cooling the sinter. That is, through the air volume balance and heat balance between the sinter annular cooler and the lump ore dryer, the near-zero emission of the lump ore drying and annular cooler coupling is finally achieved. This effectively solves the problem that the waste heat of the exhaust gas in the low-temperature zone of the existing annular cooler is difficult to utilize and that it is difficult to achieve zero emissions. At the same time, it reduces the investment cost of lump ore drying and improves the drying efficiency of lump ore.

[0005] According to the embodiments of this utility model, a near-zero emission system coupling lump ore drying and an annular cooler is provided.

[0006] A near-zero emission system coupling lump ore drying with an annular cooler is disclosed. The system includes an annular cooler and a dryer. Each annular cooler and dryer is equipped with a flue gas hood. Following the material flow, the flue gas hood above the annular cooler is sequentially divided into a high-temperature zone, a medium-temperature zone, and a low-temperature zone. The outlet of the high-temperature zone is connected to the inlet of the high-temperature zone via a high-temperature flue gas duct. A medium-temperature flue gas duct drawn from the medium-temperature zone and a low-temperature flue gas duct drawn from the low-temperature zone are combined and connected to the inlet of the dryer via a mixed flue gas duct. A circulating flue gas duct drawn from the outlet of the flue gas hood above the dryer is connected to the inlets of the medium-temperature and low-temperature zones of the annular cooler.

[0007] In this invention, both the annular cooler and the dryer are annular structures. The dryer is disposed within the inner annular space of the annular cooler. Preferably, the dryer and the annular cooler are coaxially arranged.

[0008] In this invention, a condenser is also provided on the circulating flue gas duct. The air outlet of the dryer is connected to the condenser via the circulating flue gas duct. The condenser is connected to the air inlets of the medium and low temperature zones of the circulating cooler via the medium and low temperature zone air inlet duct.

[0009] In this invention, a waste heat recovery device is also provided on the high-temperature flue gas duct. The air outlet of the high-temperature zone is connected to the waste heat recovery device via the high-temperature flue gas duct. The waste heat recovery device is connected to the air inlet of the high-temperature zone via the high-temperature zone air inlet duct.

[0010] Preferably, the waste heat utilization device is a high-temperature waste heat boiler.

[0011] In this invention, a first circulating fan is installed on the air inlet duct in the high-temperature zone. A second circulating fan is installed on the air inlet duct in the medium- and low-temperature zone. A third circulating fan is installed on the mixed flue gas duct.

[0012] Preferably, a mixer is also provided on the flue gas mixing duct. The mixer is located upstream of the third circulating fan.

[0013] In this invention, a first natural air duct is also connected to the high-temperature zone air inlet duct. The connection point between the first natural air duct and the high-temperature zone air inlet duct is located upstream of the first circulating fan.

[0014] In this invention, a second natural air duct is also connected to the air inlet duct for the medium-low temperature zone. The connection point between the second natural air duct and the air inlet duct for the medium-low temperature zone is located upstream of the second circulating fan.

[0015] As a preferred option, a high-temperature zone solenoid valve is installed on the first natural air duct.

[0016] As a preferred option, the second natural air duct is equipped with a medium-low temperature zone solenoid valve.

[0017] In view of the problems of high construction cost, low drying efficiency and high energy consumption in the existing lump ore drying system, as well as the difficulty in utilizing the waste heat of the low-temperature section of the annular cooler and the difficulty in achieving zero emissions, this utility model couples the drying of lump ore with the utilization of waste heat of the low-temperature section of the annular cooler, and proposes a near-zero emission system that couples lump ore drying with an annular cooler. In the technical solution of this utility model, the high-temperature hot air discharged from the high-temperature zone of the annular cooler is drawn back to the high-temperature zone to circulate and cool the sinter in that area. At the same time, the mixed hot air discharged from the low-temperature zone of the annular cooler is transported to the dryer to dry the lump ore, thus making full use of the waste heat of the exhaust gas in the low-temperature zone of the annular cooler. After drying, the dried air discharged from the dryer is drawn back to the low-temperature zone of the annular cooler for circulating and cooling the sinter. That is, through the air volume balance and heat balance between the sinter annular cooler and the lump ore dryer, the near-zero emission of the lump ore drying and annular cooler coupling is finally achieved. This effectively solves the problem that the waste heat of the exhaust gas in the low-temperature zone of the existing annular cooler is difficult to utilize and that it is difficult to achieve zero emissions. At the same time, it reduces the investment cost of lump ore drying and improves the drying efficiency of lump ore.

[0018] As a preferred embodiment, both the annular cooler and the dryer described in this utility model have annular structures, i.e., as shown in the figure below. Figure 2As shown, the dryer used for drying lump ore can also adopt a ring structure similar to that of an annular cooler. Preferably, this invention arranges the dryer within the inner ring space of the annular cooler; that is, the inner ring dryer is used to dry lump ore, and the outer ring annular cooler is used to cool sintered ore. The dryer and annular cooler arranged in the inner and outer rings can better utilize each other's waste heat from flue gas. The inner ring dryer arrangement also makes full use of the inner space of the traditional annular cooler, reducing the construction cost of lump ore drying. To further ensure the dryer's full and uniform utilization of the waste heat from the low-temperature zone of the annular cooler, this invention preferably arranges the dryer and annular cooler coaxially. It should be noted that the annular cooler includes a cooling zone and a non-cooling zone, and the cooling zone is further divided into a high-temperature zone, a medium-temperature zone, and a low-temperature zone. Figure 2 In the annular cooler, the unmarked parts correspond to the non-cooled areas.

[0019] In this invention, the mixed hot air discharged from the low-temperature zone of the annular cooler is transported to the dryer for drying lump ore. For lump ore, the moisture content entering the blast furnace is generally required to be below 2%. Since the hot air for drying lump ore circulates within the system, without condensation and dehydration, the system's moisture content will increase, eventually leading to an imbalance. Therefore, this invention adds a condenser to the circulating flue gas duct between the dryer and the air inlet of the low-temperature zone of the annular cooler for dehydration. Generally, considering the condenser's efficiency, the condenser's inlet temperature (i.e., the temperature of the drying air discharged from the dryer) should be controlled between 70 and 90°C.

[0020] For sintered ore, the temperature of the cooled sintered ore generally needs to be controlled below 120℃ to ensure smooth production, protect equipment, meet the needs of subsequent blast furnaces, and achieve energy conservation and environmental protection. Furthermore, this invention delivers the mixed hot air discharged from the low-temperature zone of the annular cooler to the dryer for drying the lump ore. Therefore, to achieve drying of the lump ore, ensure drying efficiency, and prevent the lump ore from cracking due to excessive temperature, this invention preferably controls the temperature of the mixed hot air discharged from the low-temperature zone between 150 and 250℃.

[0021] This invention also includes a waste heat recovery device (e.g., a high-temperature waste heat boiler) installed on the high-temperature flue gas duct. The high-temperature hot air discharged from the high-temperature zone of the annular cooler is recycled back to the high-temperature zone of the annular cooler after waste heat recovery (e.g., through power generation via the high-temperature waste heat boiler). Based on the waste heat recovery of the high-temperature hot air discharged from the high-temperature zone, for example, according to the thermal efficiency requirements of the high-temperature waste heat boiler, the average temperature of the high-temperature hot air discharged from the high-temperature zone should be ≥350℃ (e.g., the average temperature of the high-temperature hot air is between 350 and 450℃), thereby maximizing the waste heat recovery rate of the high-temperature zone of the annular cooler.

[0022] Preferably, a first natural air duct is connected to the high-temperature zone air inlet duct, and further, a high-temperature zone solenoid valve is installed on the first natural air duct. At the initial startup of the system, the cooling air entering the high-temperature zone of the annular cooler (i.e., the initial cooling air) is supplied by the first natural air duct, and the high-temperature zone solenoid valve is in the open state at this time; when the required high-temperature zone cooling air volume is supplied, the high-temperature zone solenoid valve is closed. Correspondingly, the drying air discharged from the dryer is condensed by the condenser and circulated to the medium-temperature and low-temperature zones of the annular cooler through the medium-low temperature zone air inlet duct. A second natural air duct is connected to the medium-low temperature zone air inlet duct, and further, a medium-low temperature zone solenoid valve is installed on the second natural air duct. At the initial startup of the system, the cooling air entering the medium-temperature and low-temperature zones of the annular cooler (i.e., the initial cooling air) is supplied by the second natural air duct, and the medium-low temperature zone solenoid valve is in the open state at this time; when the required medium-temperature and low-temperature zone cooling air volume is supplied, the medium-low temperature zone solenoid valve is closed.

[0023] It should be noted that the cooling air required for the high-temperature zone and the medium-low temperature zone of the annular cooler is only initially supplied by the first natural air duct and the second natural air duct, respectively. In the subsequent operation of the system, the cooling air for the high-temperature zone is supplied by the high-temperature hot air discharged from the high-temperature zone after waste heat utilization, and the cooling air for the medium-low temperature zone is supplied by the dry air discharged from the dryer after condensation, thereby achieving near-zero emissions of lump ore drying coupled with the annular cooler.

[0024] To further control or adjust the cooling airflow in the high-temperature and medium-low-temperature zones of the annular cooler, this invention includes a first circulating fan on the high-temperature zone inlet duct and a second circulating fan on the medium-low-temperature zone inlet duct. Correspondingly, to control or adjust the drying airflow in the dryer, this invention mixes the medium- and low-temperature hot air discharged from the medium-temperature and low-temperature zones of the annular cooler via a mixer and then delivers it to the dryer through a mixed flue gas duct, on which a third circulating fan is installed. When the system needs to change the airflow, the high-temperature zone solenoid valve and the medium- and low-temperature zone solenoid valve are opened, the pressure heads of the three circulating fans are adjusted to achieve the required airflow change, and then the two solenoid valves are closed to achieve the circulation of fresh air and near-zero emissions.

[0025] In this application, the terms "high temperature zone" and "high temperature section," "medium temperature zone" and "medium temperature section," and "low temperature zone" and "low temperature section" for the annular cooler are used interchangeably. "Medium and low temperature zone" and "medium temperature zone and low temperature zone" have the same meaning and are used interchangeably.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. This utility model couples lump ore drying with an annular cooler, thereby making full use of the waste heat of the exhaust gas in the low-temperature zone of the annular cooler.

[0028] 2. This utility model utilizes the waste heat of the high-temperature air discharged from the high-temperature zone of the annular cooler and then draws it back to the high-temperature zone of the annular cooler to circulate and cool the sinter in that area. At the same time, the mixed hot air discharged from the low-temperature zone of the annular cooler is transported to the dryer to dry the lump ore. After drying, the dried air discharged from the dryer is drawn back to the low-temperature zone of the annular cooler for circulating and cooling the sinter. That is, by balancing the air volume and heat between the sinter annular cooler and the lump ore dryer, near-zero emissions are achieved by coupling the lump ore drying and the annular cooler.

[0029] 3. This utility model uses a ring dryer with a structure similar to that of a ring cooler to dry lump ore, and places the lump ore dryer in the inner ring position of the ring cooler, making full use of the inner ring space of the existing ring cooler, thereby reducing the investment cost of lump ore drying and improving the drying efficiency of lump ore. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a near-zero emission system for coupling lump ore drying and an annular cooler according to the present invention;

[0031] Figure 2 This is a schematic diagram showing the arrangement of the central ring chiller and dryer in this utility model.

[0032] Figure label:

[0033] 1: Circular cooler; 101: High-temperature zone; 102: Medium-temperature zone; 103: Low-temperature zone; 2: Dryer; 3: Condenser; 4: Waste heat recovery device; 501: First circulating fan; 502: Second circulating fan; 503: Third circulating fan; 6: Mixer; 701: High-temperature zone solenoid valve; 702: Medium-low temperature zone solenoid valve;

[0034] L1: High-temperature flue gas duct; L2: Medium-temperature flue gas duct; L3: Low-temperature flue gas duct; L4: Mixed flue gas duct; L5: Circulating flue gas duct; L6: Medium-low temperature zone air inlet duct; L7: High-temperature zone air inlet duct; L8: First natural wind duct; L9: Second natural wind duct. Detailed Implementation

[0035] The technical solution of this utility model is illustrated below. The scope of protection of this utility model includes, but is not limited to, the following embodiments.

[0036] According to the embodiments of this utility model, a near-zero emission system coupling lump ore drying and an annular cooler is provided.

[0037] A near-zero emission system coupling lump ore drying with an annular cooler is disclosed. The system includes an annular cooler 1 and a dryer 2. Both the annular cooler 1 and the dryer 2 are equipped with flue gas hoods. Following the material flow, the flue gas hood above the annular cooler 1 is sequentially divided into a high-temperature zone 101, a medium-temperature zone 102, and a low-temperature zone 103. The outlet of the high-temperature zone 101 is connected to its inlet via a high-temperature flue gas duct L1. A medium-temperature flue gas duct L2, originating from the medium-temperature zone 102, and a low-temperature flue gas duct L3, originating from the low-temperature zone 103, are combined and connected to the dryer 2's inlet via a mixed flue gas duct L4. A circulating flue gas duct L5, originating from the outlet of the flue gas hood above the dryer 2, connects to the inlets of the medium-temperature zone 102 and the low-temperature zone 103 of the annular cooler 1.

[0038] In this invention, both the annular cooler 1 and the dryer 2 are annular structures. The dryer 2 is disposed within the inner annular space of the annular cooler 1. Preferably, the dryer 2 and the annular cooler 1 are coaxially arranged.

[0039] In this invention, a condenser 3 is also provided on the circulating flue gas duct L5. The air outlet of the dryer 2 is connected to the condenser 3 via the circulating flue gas duct L5. The condenser 3 is connected to the air inlets of the medium temperature zone 102 and the low temperature zone 103 of the circulating cooler 1 via the medium and low temperature zone air inlet duct L6.

[0040] In this invention, a waste heat recovery device 4 is also provided on the high-temperature flue gas duct L1. The air outlet of the high-temperature zone 101 is connected to the waste heat recovery device 4 via the high-temperature flue gas duct L1. The waste heat recovery device 4 is connected to the air inlet of the high-temperature zone 101 via the high-temperature zone air inlet duct L7.

[0041] Preferably, the waste heat utilization device 4 is a high-temperature waste heat boiler.

[0042] In this invention, a first circulating fan 501 is installed on the high-temperature zone air inlet duct L7. A second circulating fan 502 is installed on the medium-low temperature zone air inlet duct L6. A third circulating fan 503 is installed on the mixed flue gas duct L4.

[0043] Preferably, a mixer 6 is also provided on the flue gas mixing duct L4. The mixer 6 is located upstream of the third circulating fan 503.

[0044] In this invention, a first natural air duct L8 is also connected to the high-temperature zone air inlet duct L7. The connection point between the first natural air duct L8 and the high-temperature zone air inlet duct L7 is located upstream of the first circulating fan 501.

[0045] In this invention, a second natural air duct L9 is also connected to the low-temperature zone air inlet duct L6. The connection point between the second natural air duct L9 and the low-temperature zone air inlet duct L6 is located upstream of the second circulating fan 502.

[0046] As a preferred option, a high-temperature zone solenoid valve 701 is installed on the first natural air duct L8.

[0047] As a preferred option, the second natural air duct L9 is equipped with a medium-low temperature zone solenoid valve 702.

[0048] Example 1

[0049] like Figure 1 As shown, a near-zero emission system coupling lump ore drying with an annular cooler is disclosed. The system includes an annular cooler 1 and a dryer 2. Flue gas hoods are respectively installed above the annular cooler 1 and the dryer 2. According to the material flow direction, the flue gas hood above the annular cooler 1 is sequentially divided into a high-temperature zone 101, a medium-temperature zone 102, and a low-temperature zone 103. The outlet of the high-temperature zone 101 is connected to the inlet of the high-temperature zone 101 via a high-temperature flue gas duct L1. The medium-temperature flue gas duct L2, drawn from the medium-temperature zone 102, and the low-temperature flue gas duct L3, drawn from the low-temperature zone 103, are combined and connected to the inlet of the dryer 2 via a mixed flue gas duct L4. A circulating flue gas duct L5, drawn from the outlet of the flue gas hood above the dryer 2, is connected to the inlets of the medium-temperature zone 102 and the low-temperature zone 103 of the annular cooler 1.

[0050] Example 2

[0051] like Figure 2 As shown, Embodiment 1 is repeated, except that both the annular cooler 1 and the dryer 2 are annular structures. The dryer 2 is located within the inner annular space of the annular cooler 1.

[0052] Example 3

[0053] Repeat Example 2, except that the dryer 2 and the annular cooler 1 are arranged coaxially.

[0054] Example 4

[0055] The embodiment 3 is repeated, except that a condenser 3 is also provided on the circulating flue gas duct L5. The air outlet of the dryer 2 is connected to the condenser 3 via the circulating flue gas duct L5. The condenser 3 is connected to the air inlets of the medium temperature zone 102 and the low temperature zone 103 of the circulating cooler 1 via the medium and low temperature zone air inlet duct L6.

[0056] Example 5

[0057] Example 4 is repeated, except that a waste heat recovery device 4 is also provided on the high-temperature flue gas duct L1. The air outlet of the high-temperature zone 101 is connected to the waste heat recovery device 4 via the high-temperature flue gas duct L1. The waste heat recovery device 4 is connected to the air inlet of the high-temperature zone 101 via the high-temperature zone air inlet duct L7. The waste heat recovery device 4 is a high-temperature waste heat boiler.

[0058] Example 6

[0059] Example 5 is repeated, except that a first circulating fan 501 is installed on the high-temperature zone air inlet duct L7. A second circulating fan 502 is installed on the medium-low temperature zone air inlet duct L6. A third circulating fan 503 is installed on the mixed flue gas duct L4.

[0060] Example 7

[0061] Example 6 is repeated, except that a mixer 6 is also provided on the flue gas mixing duct L4. The mixer 6 is located upstream of the third circulating fan 503.

[0062] Example 8

[0063] The same method as Embodiment 7 is used, except that a first natural air duct L8 is also connected to the high-temperature zone air inlet duct L7. The connection point between the first natural air duct L8 and the high-temperature zone air inlet duct L7 is located upstream of the first circulating fan 501.

[0064] Example 9

[0065] Example 8 is repeated, except that a second natural air duct L9 is also connected to the low-temperature zone air inlet duct L6. The connection point between the second natural air duct L9 and the low-temperature zone air inlet duct L6 is located upstream of the second circulating fan 502.

[0066] Example 10

[0067] Repeat Example 9, except that a high-temperature zone solenoid valve 701 is provided on the first natural air duct L8.

[0068] Example 11

[0069] The same example as Example 10 is repeated, except that a medium-low temperature zone solenoid valve 702 is provided on the second natural air duct L9.

[0070] The method using the near-zero emission system of lump ore drying and annular cooler coupling described in this embodiment includes the following steps:

[0071] 1) The sinter to be cooled enters the annular cooler 1 and passes through the high temperature zone 101, the medium temperature zone 102 and the low temperature zone 103 in sequence for cooling. The cooled sinter is discharged from the outlet of the annular cooler 1.

[0072] 2) The lump ore to be dried enters the dryer 2 for drying, and the dried lump ore is discharged from the outlet of the dryer 2.

[0073] 3) Cooling air enters the high-temperature zone 101 of the annular cooler 1 and exchanges heat with the sinter to be cooled in the high-temperature zone 101. After the heat exchange, the temperature of the cooling air rises to form high-temperature hot air, which is discharged from the air outlet of the high-temperature zone 101. The high-temperature hot air is then drawn back to the high-temperature zone 101 to circulate and cool the sinter to be cooled after being generated by the high-temperature waste heat boiler through the high-temperature zone air inlet pipe L7.

[0074] 4) The cooling air entering the medium-temperature zone 102 and low-temperature zone 103 of the annular cooler 1 continues to cool the sinter. After heat exchange with the sinter, the temperature of the cooling air rises to form medium- and low-temperature hot air, which is discharged from the air outlets of the medium-temperature zone 102 and low-temperature zone 103, respectively. The medium- and low-temperature hot air is mixed by the mixer 6 and then sent to the air inlet of the dryer 2. The mixed hot air dries the lump ore in the dryer 2. The dried air discharged from the dryer 2 is condensed by the condenser 3 and then drawn back to the medium-temperature zone 102 and low-temperature zone 103 through the medium- and low-temperature zone air inlet pipe L6 to circulate and cool the sinter, realizing the circulation of system air volume and near-zero emissions.

[0075] The initial cooling air entering the high-temperature zone 101 of the annular cooler 1 is supplied by the first natural air duct L8. After the initial cooling air supply to the high-temperature zone 101 is completed, the high-temperature zone solenoid valve 701 installed on the first natural air duct L8 is closed. Correspondingly, the initial cooling air entering the medium-temperature zone 102 and the low-temperature zone 103 of the annular cooler 1 is supplied by the second natural air duct L9. After the initial cooling air supply to the medium-temperature zone 102 and the low-temperature zone 103 is completed, the medium- and low-temperature zone solenoid valve 702 installed on the second natural air duct L9 is closed.

Claims

1. A near-zero emission system for coupling lump ore drying with an annular cooler, characterized in that: The system includes a ring cooler (1) and a dryer (2); a flue gas hood is provided above the ring cooler (1) and the dryer (2); according to the material flow, the flue gas hood above the ring cooler (1) is divided into a high temperature zone (101), a medium temperature zone (102), and a low temperature zone (103); the outlet of the high temperature zone (101) is connected to the inlet of the high temperature zone (101) via a high temperature flue gas pipe (L1); the medium temperature flue gas pipe (L2) drawn from the medium temperature zone (102) and the low temperature flue gas pipe (L3) drawn from the low temperature zone (103) are combined and then connected to the inlet of the dryer (2) via a mixed flue gas pipe (L4); the circulating flue gas pipe (L5) drawn from the outlet of the flue gas hood above the dryer (2) is connected to the inlets of the medium temperature zone (102) and the low temperature zone (103) of the ring cooler (1).

2. The near-zero emission system according to claim 1, characterized in that: Both the annular cooler (1) and the dryer (2) are annular structures; the dryer (2) is located in the inner annular space of the annular cooler (1).

3. The near-zero emission system according to claim 2, characterized in that: The dryer (2) and the annular cooler (1) are set coaxially.

4. The near-zero emission system according to claim 1, characterized in that: A condenser (3) is also provided on the circulating flue gas duct (L5); the outlet of the dryer (2) is connected to the condenser (3) via the circulating flue gas duct (L5); the condenser (3) is connected to the inlet of the medium temperature zone (102) and the low temperature zone (103) of the circulating cooler (1) via the medium and low temperature zone inlet duct (L6).

5. The near-zero emission system according to any one of claims 1-4, characterized in that: The high-temperature flue gas duct (L1) is also equipped with a waste heat utilization device (4); the air outlet of the high-temperature zone (101) is connected to the waste heat utilization device (4) via the high-temperature flue gas duct (L1); the waste heat utilization device (4) is connected to the air inlet of the high-temperature zone (101) via the high-temperature zone air inlet duct (L7).

6. The near-zero emission system according to claim 5, characterized in that: The waste heat utilization device (4) is a high-temperature waste heat boiler.

7. The near-zero emission system according to claim 5, characterized in that: The high-temperature zone air inlet duct (L7) is equipped with a first circulating fan (501); the medium-low temperature zone air inlet duct (L6) is equipped with a second circulating fan (502); and the mixed flue gas duct (L4) is equipped with a third circulating fan (503).

8. The near-zero emission system according to claim 7, characterized in that: A mixer (6) is also provided on the flue gas mixing duct (L4); the mixer (6) is located upstream of the third circulating fan (503).

9. The near-zero emission system according to claim 7, characterized in that: The high-temperature zone air inlet duct (L7) is also connected to the first natural air duct (L8); the connection point between the first natural air duct (L8) and the high-temperature zone air inlet duct (L7) is located upstream of the first circulating fan (501).

10. The near-zero emission system according to claim 9, characterized in that: The low-temperature zone air inlet duct (L6) is also connected to a second natural air duct (L9); the connection point between the second natural air duct (L9) and the low-temperature zone air inlet duct (L6) is located upstream of the second circulating fan (502).

11. The near-zero emission system according to claim 10, characterized in that: A high-temperature zone solenoid valve (701) is installed on the first natural ventilation duct (L8); and / or The second natural air duct (L9) is equipped with a medium and low temperature zone solenoid valve (702).

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