A device for stably recovering the energy of the tail gas of a rotary kiln

Abstract

The present invention discloses a device for stably recovering energy from rotary kiln tail gas, comprising a rotary kiln and a gas system, a combustion chamber, and a waste heat boiler, which are sequentially connected via pipelines. The head of the rotary kiln is connected to the combustion chamber, and the head of the rotary kiln is provided with a first feeding port, while the tail of the rotary kiln is provided with a second feeding port and a discharge port. The gas system includes a ferroalloy electric furnace, which is used to react with materials that pass through the rotary kiln and are discharged from the discharge port to generate gas. The high-pressure steam generated by the waste heat boiler is supplied to a power generation system via a pipeline, and the electricity generated by the power generation system is supplied to the ferroalloy electric furnace. The materials react with each other in the rotary kiln, and the high-temperature tail gas generated enters the combustion chamber. The heat generated in the combustion chamber is transmitted to the waste heat boiler. The materials discharged from the discharge port enter the ferroalloy electric furnace to generate gas, which is then transported to the combustion chamber, ensuring stable combustion of the combustible components in the combustion chamber, thereby ensuring the normal operation of the waste heat boiler and the power generation system.

Description

Technical Field

[0001] The present invention relates to the technical field of energy recovery, in particular to a device for stably recovering rotary kiln tail gas energy. Background Art

[0002] Rotary kilns can be used to provide direct reduction of metal minerals, heating, drying, roasting materials, etc. for ferroalloy electric furnaces. The main problem with existing rotary kiln exhaust gas energy recovery is that since the rotary kiln operation process cannot be absolutely stable and operation fluctuations are normal, the flow rate, sensible heat, and combustible gas composition of the exhaust gas are in a fluctuating state, sometimes appearing and sometimes disappearing. As a result, the exhaust gas combustion chamber cannot work normally, the waste heat boiler efficiency is extremely low, and the power generation system cannot work properly.

[0003] Existing rotary kilns process high-temperature materials for the ferroalloy furnace, while their exhaust gases are fed into a waste heat power generation system, which in turn generates electricity for the ferroalloy furnace. The rotary kiln, waste heat power generation system, and ferroalloy furnace are integrated into a single system. Failure of any one of these systems negatively impacts the others. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for stably recovering the energy of rotary kiln tail gas to solve the problems existing in the above-mentioned prior art, so as to make the tail gas burn stably in the combustion chamber and ensure the normal operation of the power generation system and the gas system.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a device for stably recovering the energy of rotary kiln tail gas, comprising a rotary kiln and a gas system, a combustion chamber and a waste heat boiler connected in sequence through pipelines, the head of the rotary kiln being connected to the combustion chamber, the head of the rotary kiln being provided with a first feeding port, the tail of the rotary kiln being provided with a second feeding port and a discharge port, the gas system comprising a ferroalloy electric furnace, the ferroalloy electric furnace being used to react with materials passing through the rotary kiln and discharged from the discharge port to generate gas, the high-pressure steam generated by the waste heat boiler being supplied to a power generation system through a pipeline, and the electricity generated by the power generation system being supplied to the ferroalloy electric furnace.

[0007] Preferably, a valve is provided between the head of the rotary kiln and the combustion chamber, and the valve can realize the connection and isolation between the combustion chamber and the rotary kiln.

[0008] Preferably, the gas system includes a sixth silo, the ferroalloy electric furnace, a gas purifier and a gas tank connected in sequence, the sixth silo is used to receive the material discharged from the discharge port, the sixth silo is connected to the ferroalloy electric furnace through a material pipe, the gas tank is connected to the gas burner arranged in the combustion chamber through a pipeline, and the pipeline connecting the gas tank and the gas burner is also provided with a fourth compressed air nozzle and a first fan.

[0009] Preferably, the rotary kiln is arranged at an angle, with the head of the rotary kiln higher than the tail of the rotary kiln; the temperature inside the rotary kiln is 800-1500°C, and the length of the rotary kiln is 20-60m; and a plurality of air nozzles are arranged inside the rotary kiln along the length direction of the rotary kiln.

[0010] Preferably, the discharge port includes a chute and a sorter that are interconnected, the chute is connected to the tail of the rotary kiln, the sorter is provided with a material outlet and a rotary kiln waste discharge port, a first conveyor is provided below the rotary kiln waste discharge port, and the material outlet is provided with a barrel for holding materials and transporting the materials to the gas system.

[0011] Preferably, it also includes a first silo, a second silo and a third silo, the first silo is used to hold mineral pellets or lumps roasted at 1300-1450°C, the second silo is used to hold anthracite, and the third silo is used to hold dolomite or limestone. The first silo is provided with a first feeder, the second silo is provided with a second feeder, and the third silo is provided with a third feeder. A belt conveyor is provided below the first feeder, the second feeder and the third feeder. The mineral pellets or lumps in the first silo pass through the first feeder, the anthracite in the second silo passes through the second feeder, and the dolomite or limestone in the third silo passes through the third feeder, all of which fall onto the belt conveyor and are transported to the feeder provided on the first feeding port to enter the rotary kiln.

[0012] Preferably, it also includes a fourth silo and a fifth silo, the fourth silo is used to hold bituminous coal powder, the fifth silo is used to hold smokeless granular coal, the fourth silo is provided with a fourth feeder, the fifth silo is provided with a fifth feeder, the fourth feeder is connected to a first mixer, the fifth feeder is connected to a second mixer, the first mixer is provided with a first compressed air nozzle, the second mixer is provided with a second compressed air nozzle, the first mixer is connected to the second feeding port through a first metal tube, and the second mixer is connected to the second feeding port through a second metal tube.

[0013] Preferably, it further comprises a gas nozzle, which is connected to the second feeding port through a third metal pipe, and a third compressed air nozzle is also provided on the third metal pipe.

[0014] Preferably, a water nozzle and a gas nozzle are provided in the combustion chamber; a combustion chamber waste outlet is provided at the lower end of the combustion chamber, and a second conveyor is provided below the combustion chamber waste outlet; and the combustion chamber is also provided with an explosion-proof valve.

[0015] Preferably, the power generation system includes a turbine and a generator, the exhaust gas of the waste heat boiler is transported to the denitrification device through a pipeline, the denitrification device is connected to the carbon dioxide collector or chimney through a pipeline, a second fan is provided on the pipeline between the denitrification device and the carbon dioxide collector or chimney, a waste heat boiler waste outlet is provided at the lower end of the waste heat boiler, a third conveyor is provided below the waste heat boiler waste outlet, a denitrification waste outlet is provided at the lower end of the denitrification device, a fourth conveyor is provided below the denitrification waste outlet, the waste of the waste heat boiler is transported to the coal ash bin through the third conveyor, and the waste of the denitrification device is transported to the coal ash bin through the fourth conveyor, the discharge port of the coal ash bin is provided with a valve, and a fifth conveyor is provided below the discharge port, and also includes a water adding nozzle, which is used to spray water to the material on the fifth conveyor.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] Materials enter the rotary kiln through the first and second feeding ports respectively, react with each other and partially burn in the rotary kiln, and the high-temperature exhaust gas generated enters the combustion chamber. The combustible components contained in the exhaust gas continue to burn in the combustion chamber. The heat generated plus the sensible heat of the high-temperature exhaust gas are transmitted to the waste heat boiler along with the flue gas. The materials discharged from the discharge port of the rotary kiln enter the ferroalloy electric furnace for smelting and generate coal gas, which is transported to the combustion chamber to ensure the stable combustion of the combustible components in the combustion chamber, thereby ensuring that the waste heat boiler can stably provide steam power to the power generation system, so that the power generation system can operate normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic structural diagram of a device for stably recovering rotary kiln tail gas energy according to the present invention;

[0020] Among them: 1-rotary kiln, 2-combustion chamber, 3-waste heat boiler, 4-chute, 5-separator, 6-water nozzle, 7-material outlet, 8-air nozzle, 9-barrel, 10-first silo, 11-second silo, 12-third silo, 13-fourth silo, 14-fifth silo, 15-sixth silo, 16-first feeder, 17-second feeder, 18-third feeder, 19-fourth feeder, 20-fifth feeder, 21-belt conveyor, 22-feeder, 23-first mixer, 24-second mixer, 25-first compressed air nozzle, 26-second compressed air nozzle , 27-the third compressed air nozzle, 28-the fourth compressed air nozzle, 29-the gas nozzle, 30-the gas burner, 31-the first metal tube, 32-the second metal tube, 33-the third metal tube, 34-the ferroalloy electric furnace, 35-the gas purifier, 36-the gas tank, 37-the valve, 38-the water nozzle, 39-the gas nozzle, 40-the first fan, 41-the second fan, 42-the explosion-proof valve, 43-the denitrification device, 44-the carbon dioxide collector, 45-the first conveyor, 46-the second conveyor, 47-the third conveyor, 48-the fourth conveyor, 49-the fifth conveyor, 50-the coal ash silo. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The purpose of the present invention is to provide a device for stably recovering the energy of rotary kiln tail gas to solve the problems existing in the above-mentioned prior art, so as to make the tail gas burn stably in the combustion chamber and ensure the normal operation of the power generation system and the gas system.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1As shown: This embodiment provides a device for stably recovering rotary kiln tail gas energy, including a rotary kiln 1 and a gas system, a combustion chamber 2 and a waste heat boiler 3 connected in sequence through pipelines. The head of the rotary kiln 1 is connected to the combustion chamber 2, the head of the rotary kiln 1 is provided with a first feeding port, and the tail of the rotary kiln 1 is provided with a second feeding port and a discharge port. The gas system includes a ferroalloy electric furnace 34, which is used to react with the material passing through the rotary kiln 1 and discharged from the discharge port to generate gas. The high-pressure steam generated by the waste heat boiler 3 is supplied to the power generation system through a pipeline, and the electricity generated by the power generation system is supplied to the ferroalloy electric furnace 34. The materials enter the rotary kiln 1 through the first and second feeding ports respectively, react with each other and partially burn in the rotary kiln 1, and the high-temperature exhaust gas generated enters the combustion chamber 2. The combustible components contained in the exhaust gas continue to burn in the combustion chamber 2. The heat generated plus the sensible heat of the high-temperature exhaust gas are transmitted to the waste heat boiler 3 along with the flue gas. The materials discharged from the discharge port of the rotary kiln 1 enter the ferroalloy electric furnace 34 for smelting and generate coal gas, which is transported to the combustion chamber 2 to ensure the stable combustion of the combustible components in the combustion chamber 2, thereby ensuring that the waste heat boiler 3 can stably provide steam power to the power generation system, so that the power generation system can operate normally.

[0025] This embodiment further includes a first silo 10, a second silo 11 and a third silo 12. The first silo 10 is used to hold mineral pellets or lumps that have been roasted at 1300-1450°C and cooled, the second silo 11 is used to hold anthracite, and the third silo 12 is used to hold dolomite or limestone. A first feeder 16 is provided on the first silo 10, a second feeder 17 is provided on the second silo 11, and a third feeder 18 is provided on the third silo 12. The first feeder 16, the second feeder 17 and the third feeder 18 are provided on the first silo 10. The feeders 18 are used to weigh and feed materials. A conveyor belt 21 is located below the first, second, and third feeders 16, 17, and 18. The mineral pellets or lumps roasted at 1300-1450°C in the first hopper 10 pass through the first feeder 16, the anthracite in the second hopper 11 passes through the second feeder 17, and the dolomite or limestone in the third hopper 12 passes through the third feeder 18. These pellets fall onto the conveyor belt 21 and are transported to the feeder 22 located at the first feeding port, where they enter the rotary kiln 1. The first, second, and third feeders 16, 17, and 18 all have weighing functions and can quantitatively feed materials according to set values.

[0026] The mineral pellets or lumps in this embodiment are roasted at 1300-1450°C and have a compressive strength of 200 kg. They have the characteristics of high strength, resistance to thermal vibration, and no cracking or pulverization when exposed to high temperatures. Therefore, the temperature in the rotary kiln 1 in this embodiment is set to 800-1500°C, and the length of the rotary kiln 1 is 20-60 m. If the mineral pellets or lumps entering the rotary kiln 1 from the first hopper 10 are not resistant to high temperatures and have low strength, the length of the rotary kiln 1 must be built to be as long as 80-120 meters, providing a long space for the mineral pellets or lumps entering the rotary kiln 1 from the first hopper 10 to slowly dry, heat, and roast. Otherwise, the mineral pellets or lumps will explode and pulverize when exposed to high temperatures, and the broken powder particles will adhere to the inner wall of the rotary kiln 1 at high temperatures. Within a week, they will seriously form rings, blocking the inner wall of the rotary kiln 1 and causing production stoppage. Therefore, this embodiment uses mineral pellets or lumps roasted at 1300-1450°C, reducing the length of rotary kiln 1, lowering equipment costs, and improving its operating efficiency and output. Furthermore, because rotary kiln 1 performs only roasting, the exhaust gas generated by roasting has a high temperature, high sensible heat, and high combustible content. This exhaust gas from rotary kiln 1 contains a high level of energy, providing high-quality energy to waste heat boiler 3 and the power generation system. Combined with the combustion of coal gas from the ferroalloy electric furnace 34, this ensures stable operating conditions for waste heat boiler 3 and the power generation system.

[0027] This embodiment also includes a fourth silo 13 and a fifth silo 14. The fourth silo 13 is used to hold bituminous coal powder, and the fifth silo 14 is used to hold anthracite granular coal. A fourth feeder 19 is provided on the fourth silo 13, and a fifth feeder 20 is provided on the fifth silo 14. A first mixer 23 is provided below the fourth feeder 19, and the fourth feeder 19 is communicated with the first mixer 23. A second mixer 24 is provided below the fifth feeder 20, and the fifth feeder 20 is communicated with the second mixer 24. A first compressed air nozzle 25 is provided on the first mixer 23, and a second compressed air nozzle 26 is provided on the second mixer 24. The first compressed air nozzle 25 and the second compressed air nozzle 26 are both used to push materials. The first mixer 23 is communicated with the second feeding port through a first metal pipe 31, and the second mixer 24 is communicated with the second feeding port through a second metal pipe 32. Pulverized bituminous coal is fed into the rotary kiln 1 for combustion via the first compressed air nozzle 25, and anthracite granular coal is thrown onto the mineral pellets or lumps in the rotary kiln 1 via the second compressed air nozzle 26. Both the fourth feeder 19 and the fifth feeder 20 have weighing functions and can quantitatively feed materials according to set values. This embodiment also includes a gas nozzle 29, which is connected to the second feed port via a third metal tube 33. The third metal tube 33 is also provided with a third compressed air nozzle 27. The gas nozzle 29 and the third compressed air nozzle 27 mix gas and air, and then inject them into the rear end of the rotary kiln 1 through the third metal tube 33 to burn the pulverized bituminous coal and anthracite granular coal. The gas nozzle 29 is used to regulate the temperature within the rotary kiln 1 and ensure the combustion of the pulverized bituminous coal.

[0028] In this embodiment, the rotary kiln 1 is tilted, with the head of the rotary kiln 1 higher than the tail of the rotary kiln 1. The material entering the rotary kiln 1 from the feeder 22 at the first feeding port slowly rotates and flows toward the tail of the rotary kiln 1. Several air nozzles 8 are arranged along the length of the rotary kiln 1. The air nozzles 8 introduce air into the rotary kiln 1 during operation. Heat and gases such as carbon monoxide generated by the combustion of coal gas, bituminous coal powder, and anthracite granular coal in the interior space of the tail of the rotary kiln 1 are absorbed by the material (mineral pellets or lump ore) entering the rotary kiln 1. The tail gas that cannot be absorbed (containing physical sensible heat and combustible components such as carbon monoxide) flows from the head of the rotary kiln 1 into the combustion chamber 2.

[0029] In this embodiment, the discharge port includes a chute 4 and a separator 5 that are interconnected. The chute 4 is connected to the tail of the rotary kiln 1. The separator 5 is provided with a material outlet 7 and a rotary kiln waste outlet. A first conveyor 45 is provided below the rotary kiln waste outlet. The material outlet 7 is provided with a bucket 9 for holding the material (mineral pellets or lump ore processed by the rotary kiln 1). The mineral pellets or lump ore from the tail of the rotary kiln 1 enter the separator 5 through the chute 4, and the mineral pellets or lump ore processed by the rotary kiln 1 are separated from the fly ash and residual carbon. The mineral pellets or lump ore processed by the rotary kiln 1 are received by the bucket 9 and conveyed to the coal gas system. The fly ash and residual carbon are discharged by the first conveyor 45.

[0030] In this embodiment, the gas system includes a sixth silo 15, a ferroalloy electric furnace 34, a gas purifier 35, and a gas tank 36, which are sequentially connected by pipelines. The sixth silo 15 is used to receive material from the hopper 9. The sixth silo 15 is connected to the ferroalloy electric furnace 34 via a pipeline. The mineral pellets or lumps processed by the rotary kiln 1 enter the ferroalloy electric furnace 34 to be smelted into liquid metal. The gas produced during the smelting process is transported via a pipeline to the gas purifier 35 for purification. The purified gas is then transported to the gas tank 36 for storage. The gas tank 36 is connected via a pipeline to the gas burner 30 located in the combustion chamber 2. The pipeline connecting the gas tank 36 and the gas burner 30 is also equipped with a fourth compressed air nozzle 28 and a first blower 40. The gas is transported via a pipeline to the gas burner 30, where it is premixed with air by the fourth compressed air nozzle 28 and then completely combusted in the combustion chamber 2. When the sensible heat and gas composition of the exhaust gas delivered from the rotary kiln 1 to the combustion chamber 2 fluctuate greatly, the gas burner 30 in this embodiment stably burns the gas from the gas tank 36, solving the problem that it is very difficult for the waste heat boiler 3 to recover the sensible heat in the exhaust gas of the rotary kiln 1 and ignite the gas composition therein. The waste heat boiler 3 can operate normally and provide a stable steam flow for the downstream power generation system.

[0031] In this embodiment, the head of the rotary kiln 1 is connected to the combustion chamber 2. A valve 37 is provided between the combustion chamber 2 and the rotary kiln 1. This valve 37 connects and isolates the combustion chamber 2 from the rotary kiln 1. When the rotary kiln 1 is operating, the valve 37 is opened to connect the combustion chamber 2 with the rotary kiln 1. When the rotary kiln 1 is stopped, the valve 37 is closed to isolate the combustion chamber 2 from the rotary kiln 1. The gas burner 30 in the combustion chamber 2 increases combustion power. The gas from the gas tank 36 allows the gas burner 30 to burn stably, providing a stable heat source for the waste heat boiler 3. This allows the entire power generation system to operate stably and without interference.

[0032] After valve 37 is closed, if the rotary kiln 1 is under maintenance and has stopped operating, the ferroalloy furnace 34 can still receive power from the power generation system and the external grid and continue to operate without interruption. At this time, the ferroalloy furnace 34 receives cold material and continues to operate. If the rotary kiln 1, combustion chamber 2, waste heat boiler 3, and power generation system are all shut down, the ferroalloy furnace 34 can still receive power from the external grid and continue to operate with cold material. If the ferroalloy furnace 34 stops operating for any reason, the combustion chamber 2, waste heat boiler 3, and power generation system can continue to operate and supply power to the external grid without interruption. At the same time, the rotary kiln 1 can continue to process material and serve as a raw material reserve, continuing to operate without interruption, and the rotary kiln 1 continues to supply high-temperature exhaust gas to the combustion chamber 2. The rotary kiln 1, ferroalloy furnace 34, gas system, waste heat boiler 3, and power generation system are connected in series to form a coordinated whole. If any one or two of these three components stop operating, the remaining components can continue to operate stably.

[0033] In this embodiment, a water nozzle 38 and a gas nozzle 39 are provided in the combustion chamber 2. When the temperature of the combustion chamber 2 is too high and exceeds the set limit, the water nozzle 38 opens to reduce the temperature in the combustion chamber 2; when the combustible components and oxygen content in the combustion chamber 2 exceed the set limit, the gas nozzle 39 blows nitrogen or water vapor into the combustion chamber 2 to prevent deflagration; a combustion chamber waste outlet is provided at the lower end of the combustion chamber 2, and a second conveyor 46 is provided below the combustion chamber waste outlet; the combustion chamber 2 is also provided with an explosion-proof valve 42. When an explosion occurs in the combustion chamber 2, the explosion-proof valve 42 is opened to release the pressure to ensure safety.

[0034] In this embodiment, the combustion chamber 2 transmits high-temperature flue gas to the waste heat boiler 3 through a pipeline, and the high-pressure steam generated by the waste heat boiler 3 is transmitted to the power generation system through a pipeline. The power generation system includes a turbine and a generator connected to each other. The exhaust gas of the waste heat boiler 3 is transmitted to the denitrification device 43 through a pipeline for purification. The denitrification device 43 is connected to the carbon dioxide collector 44 or the chimney through a pipeline. A second fan 41 is provided on the pipeline between the denitrification device 43 and the carbon dioxide collector 44 or the chimney. The purified exhaust gas is transmitted to the carbon dioxide collector 44 or the chimney under the action of the second fan 41. The lower end of the waste heat boiler 3 is provided with a A waste heat boiler waste outlet is provided, a third conveyor 47 is provided below the waste heat boiler waste outlet, a denitrification waste outlet is provided at the lower end of the denitrification device 43, and a fourth conveyor 48 is provided below the denitrification waste outlet. The waste from the waste heat boiler 3 is transported to the coal ash bin 50 through the third conveyor 47, and the waste from the denitrification device 43 is transported to the coal ash bin 50 through the fourth conveyor 48. The discharge port of the coal ash bin 50 is provided with a valve, and a fifth conveyor 49 is provided below the discharge port. It also includes a water adding nozzle 6, which is used to spray water to the waste heat boiler waste and denitrification waste on the fifth conveyor 49 to prevent fly ash from polluting the environment.

[0035] In this embodiment, the first conveyor 45 , the second conveyor 46 , the third conveyor 47 , the fourth conveyor 48 and the fifth conveyor 49 are all screw conveyors.

[0036] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A device for stably recovering rotary kiln tail gas energy, characterized by: The rotary kiln comprises a gas system, a combustion chamber, and a waste heat boiler connected in sequence via pipelines. The head of the rotary kiln is connected to the combustion chamber, and the combustion chamber is provided with a water nozzle and a gas nozzle. The head of the rotary kiln is provided with a first feeding port, and the tail of the rotary kiln is provided with a second feeding port and a discharge port. The gas system includes a ferroalloy electric furnace, which is used to react with materials passing through the rotary kiln and discharged from the discharge port to generate gas. The high-pressure steam generated by the waste heat boiler is supplied to the power generation system through a pipeline, and the electricity generated by the power generation system is supplied to the ferroalloy electric furnace. A valve is provided between the head of the rotary kiln and the combustion chamber, and the valve can realize the communication and isolation between the combustion chamber and the rotary kiln.

2. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: The gas system includes a sixth silo, the ferroalloy electric furnace, a gas purifier and a gas tank connected in sequence. The sixth silo is used to receive the material discharged from the discharge port. The sixth silo is connected to the ferroalloy electric furnace through a material pipe. The gas tank is connected to the gas burner arranged in the combustion chamber through a pipeline. The pipeline connecting the gas tank and the gas burner is also provided with a fourth compressed air nozzle and a first fan.

3. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: The rotary kiln is tilted, with the head of the rotary kiln higher than the tail of the rotary kiln; the temperature inside the rotary kiln is 800-1500°C, and the length of the rotary kiln is 20-60m; and a plurality of air nozzles are arranged inside the rotary kiln along the length direction of the rotary kiln.

4. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: The discharge port includes a chute and a separator that are interconnected. The chute is connected to the tail of the rotary kiln. The separator is provided with a material outlet and a rotary kiln waste discharge port. A first conveyor is provided below the rotary kiln waste discharge port. The material outlet is provided with a barrel for holding materials and transporting the materials to the gas system.

5. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: The rotary kiln further comprises a first silo, a second silo and a third silo, wherein the first silo is used to hold mineral pellets or lumps roasted at 1300-1450°C, the second silo is used to hold anthracite, and the third silo is used to hold dolomite or limestone. A first feeder is provided on the first silo, a second feeder is provided on the second silo, and a third feeder is provided on the third silo. A belt conveyor is provided below the first feeder, the second feeder and the third feeder. The mineral pellets or lumps in the first silo pass through the first feeder, the anthracite in the second silo passes through the second feeder, and the dolomite or limestone in the third silo passes through the third feeder, all of which fall onto the belt conveyor and are transported to the feeder provided on the first feeding port to enter the rotary kiln.

6. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: It also includes a fourth silo and a fifth silo, the fourth silo is used to hold bituminous coal powder, the fifth silo is used to hold smokeless granular coal, the fourth silo is provided with a fourth feeder, the fifth silo is provided with a fifth feeder, the fourth feeder is connected to a first mixer, the fifth feeder is connected to a second mixer, the first mixer is provided with a first compressed air nozzle, the second mixer is provided with a second compressed air nozzle, the first mixer is connected to the second feeding port through a first metal pipe, and the second mixer is connected to the second feeding port through a second metal pipe.

7. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: It also includes a gas nozzle, which is connected to the second feeding port through a third metal pipe. The third metal pipe is also provided with a third compressed air nozzle.

8. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: The lower end of the combustion chamber is provided with a combustion chamber waste discharge port, and a second conveyor is provided below the combustion chamber waste discharge port; the combustion chamber is also provided with an explosion-proof valve.

9. The device for stably recovering rotary kiln tail gas energy according to claim 1, characterized in that: The power generation system includes a turbine and a generator. The exhaust gas of the waste heat boiler is transported to the denitrification device through a pipeline. The denitrification device is connected to a carbon dioxide collector or a chimney through a pipeline. A second fan is provided on the pipeline between the denitrification device and the carbon dioxide collector or the chimney. A waste heat boiler waste outlet is provided at the lower end of the waste heat boiler. A third conveyor is provided below the waste heat boiler waste outlet. A denitrification waste outlet is provided at the lower end of the denitrification device. A fourth conveyor is provided below the denitrification waste outlet. The waste of the waste heat boiler is transported to the coal ash bin through the third conveyor and the waste of the denitrification device is transported to the coal ash bin through the fourth conveyor. The discharge port of the coal ash bin is provided with a valve. A fifth conveyor is provided below the discharge port. The system also includes a water adding nozzle for spraying water on the material on the fifth conveyor.

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