Treatment system and treatment method for coal gasification slag

Abstract

The invention discloses a coal gasification slag treatment system and method, and belongs to the technical field of coal gasification slag treatment.The coal gasification slag treatment system comprises a three-waste furnace, high-temperature flue gas generated by the three-waste furnace is connected with a boiler system through a high-temperature flue gas pipeline, the boiler system comprises a boiler, and a plurality of inlets are formed in the lower end of the boiler; the inlet is used for feeding and feeding gas into the boiler; one end of the boiler is connected with the cyclone separator, one end of the cyclone separator is connected with the superheater, one end of the superheater is connected with an economizer in the pulverized coal boiler, one end of the economizer is connected with the air pre-heater, one end of the air pre-heater is connected with the dust remover, one end of the dust remover is connected with the induced draft fan, and the other end of the induced draft fan is connected with the cyclone separator. And one end of the induced draft fan is connected with the desulfurization tower. Efficient treatment of the coal gasification slag can be achieved, the process is simplified, and the cost is effectively controlled.

Description

Technical Field

[0001] This invention belongs to the field of coal gasification slag treatment technology, specifically relating to a coal gasification slag treatment system and method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In the modern coal chemical industry, the core processes such as coal gasification furnaces for producing syngas all generate coal gasification slag, a solid waste. Its annual output is enormous, but the current comprehensive utilization rate is low. A large amount of coal gasification slag that is not effectively treated has become a prominent problem for industrial development and environmental governance.

[0004] Coal gasification slag contains various harmful substances, and improper disposal can cause serious environmental pollution and health risks, placing enormous environmental pressure on enterprises. At the same time, increasingly stringent environmental policies mean that enterprises not only face policy constraints on the compliant disposal of coal gasification slag, but also bear the ever-increasing environmental disposal costs, making traditional disposal methods insufficient to meet actual needs.

[0005] From a recycling perspective, the characteristics of coal gasification slag prevent it from being directly co-fired in conventional coal-fired boilers. After the initial high-temperature gasification process, the coal gasification slag no longer possesses the volatile matter required for combustion, has a low content of remaining combustible components, and exhibits poor combustion performance. Furthermore, some combustible components are coated with other substances, further hindering the combustion reaction. Conventional coal-fired boilers have limitations in terms of combustion temperature, oxygen concentration, and combustion time in the high-temperature zone. Forcing co-firing would lead to incomplete combustion, failing to achieve resource utilization and wasting energy, which does not meet the requirements of economical and efficient development.

[0006] Currently, patents related to specialized equipment for the clean conversion of gasification slag have been published. This equipment, by maintaining a stable and suitable reaction temperature, can achieve the removal of harmful substances, moisture removal, and combustion of combustible components from coal gasification slag, providing equipment support for centralized treatment of coal gasification slag. Simultaneously, related solutions for boiler coupling have emerged in the technical field, such as biomass pyrolysis coupled with direct-fired boilers and boiler denitrification coupled with flue gas waste heat utilization systems. These solutions provide ideas for energy cascade utilization and system optimization, but they do not form a dedicated treatment system for the characteristics of coal gasification slag. Existing technologies lack a coal gasification slag treatment process that can efficiently coordinate with the existing production systems of coal chemical enterprises, with low investment and low cost, making it difficult to simultaneously address the multiple needs of harmless disposal, resource utilization, and energy consumption reduction of coal gasification slag. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a coal gasification slag treatment system and method that enables efficient treatment of coal gasification slag, simplifies the process, and effectively controls costs.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A coal gasification slag treatment system includes a three-waste furnace, characterized in that the high-temperature flue gas generated by the three-waste furnace is connected to a boiler system through a high-temperature flue gas pipeline, the boiler system includes a boiler, and the lower end of the boiler is provided with a plurality of inlets for feeding materials and gas into the boiler. One end of the boiler is connected to a cyclone separator, one end of the cyclone separator is connected to a superheater, one end of the superheater is connected to an economizer inside the boiler, one end of the economizer is connected to an air preheater, one end of the air preheater is connected to a dust collector, one end of the dust collector is connected to an induced draft fan, and one end of the induced draft fan is connected to a desulfurization tower.

[0009] As a further technical solution, the three-waste boiler includes a main boiler and an auxiliary boiler. The auxiliary boiler is connected to the superheater through a high-temperature flue gas pipeline. The cyclone separator and the superheater are connected by a convection tube bundle. The economizer is installed in the boiler flue.

[0010] As a further technical solution, a first inlet is provided at the lower end of the boiler. One end of the first inlet is connected to the inside of the boiler, and the other end is connected to the air outlet of the second fan through a second fan duct. The second fan duct passes through an air preheater.

[0011] As a further technical solution, a second inlet is provided at the lower end of the first interface. One end of the second inlet is connected to the inside of the boiler, and a feed port is provided at the other end of the second inlet. A feeding conveyor is provided at one end of the feeding port, and a hopper is provided at the upper end of the feeding conveyor. The material in the hopper is transported to the feeding port through the feeding conveyor and enters the inside of the boiler.

[0012] As a further technical solution, the side of the second inlet is connected to the air outlet of the first fan via a pipe.

[0013] As a further technical solution, a third inlet is also provided at the lower part of the boiler. One end of the third inlet is connected to the interior of the boiler, and the other end of the third inlet is connected to the air outlet of the first fan through the first fan duct; the first fan duct passes through the air preheater.

[0014] As a further technical solution, a bottom slag discharge port is provided at the bottom of the boiler, and a fourth inlet is provided on one side of the bottom slag discharge port. One end of the fourth inlet is connected to the interior of the boiler, and the other end of the fourth inlet is connected to the air outlet of the first fan through a first fan pipe.

[0015] As a further technical solution, several cyclone separators are provided, a return feeder is provided at the lower end of the cyclone separator, a high-pressure fluidizing fan is provided on one side of the return feeder, and the air outlet of the high-pressure fluidizing fan is connected to the return feeder through a pipe.

[0016] As a further technical solution, the dust collector and the air preheater are connected by a boiler flue gas duct, and a chimney is installed at the upper rear of the desulfurization tower.

[0017] A method for treating coal gasification slag includes the following steps: The coal gasification slag first enters the three waste furnace, where it undergoes preliminary treatment in a suitable high-temperature environment, ultimately generating high-temperature flue gas, which is then discharged from the auxiliary furnace to the high-temperature flue gas pipeline. High-temperature flue gas enters the boiler system through a high-temperature flue gas duct. For circulating fluidized bed boilers, the flue gas enters from between the high-temperature and low-temperature sections of the steam superheater; for pulverized coal boilers, the flue gas enters from before the economizer. The fuel in the silo is transported to the feed port by the feed conveyor and enters the boiler through the second inlet of the boiler. The first and second blowers are started, and the air is transported through the first blower pipe and the second blower pipe respectively. It is preheated when passing through the air preheater and then sent into the furnace through the first inlet, third inlet and fourth inlet of the boiler. It is fully mixed and burned with the fuel to further supplement the flue gas volume and increase the flue gas heat. After the mixed flue gas flows out of the boiler, it enters the cyclone separator, where the solid particles in the flue gas are separated by centrifugal force. The separated solid particles are returned to the boiler for re-combustion via the return feeder at the lower end. The high-pressure fluidizing blower provides stable power for the return process. The purified flue gas then enters the superheater, economizer, and air preheater sequentially through the convection tube bundle, gradually releasing heat to heat steam, preheat feedwater, and air, respectively, thus achieving cascade recovery and utilization of heat. The flue gas that has completed heat recovery enters the dust collector through the boiler exhaust pipe to remove dust particles. Then, under the traction of the induced draft fan, it is sent to the desulfurization tower through the dust removal pipe to remove pollutants such as sulfur oxides.

[0018] Compared with the prior art, the advantages and positive effects of this invention are: The three-waste furnace of this invention first performs high-temperature preliminary treatment on coal gasification slag. The generated high-temperature flue gas is introduced into the boiler system through a high-temperature flue gas pipeline, where it mixes with the flue gas generated by fuel combustion in the boiler. The multi-inlet design at the bottom of the boiler works in conjunction with the first and second blowers, and the air preheated by the air preheater is sent into the furnace at multiple points to ensure that the fuel and air are fully mixed and burned. This not only thoroughly removes harmful substances from the coal gasification slag but also fully combusts the residual combustible components, achieving efficient and harmless treatment and resource utilization of the coal gasification slag. The mixed flue gas is separated into solid particles by a cyclone separator and returned to the boiler for re-combustion under the drive of a high-pressure fluidizing blower, avoiding waste of combustible components. The purified flue gas flows sequentially through the heat exchanger, economizer, and air preheater through convection tube bundles, gradually releasing heat, which is used to heat steam, preheat feedwater, and air, respectively, forming heat recovery and utilization, achieving efficient energy circulation, reducing the overall energy consumption of the enterprise, and eliminating the need for an additional dedicated treatment system, thus simplifying the coal gasification slag treatment process. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a diagram of the coal gasification slag treatment system of the present invention; In the diagram: 1. Main furnace; 2. Auxiliary furnace; 3. High-temperature flue gas duct; 4. Boiler; 5. Bin; 6. Feed conveyor; 7. First inlet; 8. Second inlet; 9. Feed port; 10. Third inlet; 11. Slag discharge port at the bottom of the furnace; 12. Fourth inlet; 13. High-pressure fluidizing blower; 14. Return feeder; 15. Second blower; 16. Second blower duct; 17. First blower; 18. First blower duct; 19. Air preheater; 20. Economizer; 21. Convection tube bundle; 22. Superheater; 23. Boiler flue gas duct; 24. Dust collector; 25. Dust collection duct; 26. Induced draft fan; 27. Desulfurization tower; 28. Chimney; 29. ​​Cyclone separator. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] Example 1: The present invention will now be described in detail with reference to the accompanying drawings. This embodiment discloses a coal gasification slag treatment system, such as... Figure 1As shown, it includes a three-waste furnace, characterized in that the high-temperature flue gas generated by the three-waste furnace is connected to the boiler system through a high-temperature flue gas pipe 3. The boiler system includes a boiler 4, and several inlets are provided at the lower end of the boiler 4. The inlets are used for feeding materials and air into the boiler 4. One end of boiler 4 is connected to cyclone separator 29, one end of cyclone separator 29 is connected to superheater 22, one end of superheater 22 is connected to economizer 20, one end of economizer 20 is connected to air preheater 19, one end of air preheater 19 is connected to dust collector 24, one end of dust collector 24 is connected to induced draft fan 26, and one end of induced draft fan 26 is connected to desulfurization tower 27.

[0023] Specifically, the waste gasifier first performs high-temperature preliminary treatment on the coal gasification slag. The generated high-temperature flue gas is introduced into the boiler system through high-temperature flue gas pipe 3, where it mixes with the flue gas generated by fuel combustion in boiler 4. The lower end of boiler 4 has a multi-inlet design that works in conjunction with the first blower 17 and the second blower 15. Air preheated by air preheater 19 is sent into the furnace at multiple points to ensure that the fuel and air are fully mixed and burned. This not only thoroughly removes harmful substances from the coal gasification slag but also fully combusts the residual combustible components, achieving efficient and harmless treatment and resource utilization of the coal gasification slag.

[0024] The mixed flue gas is separated into solid particles by the cyclone separator 29 and then returned to the boiler 4 for re-combustion by the return feeder 14 under the drive of the high-pressure fluidizing blower 13, thus avoiding the waste of combustible components. The purified flue gas flows through the convection tube bundle 21 in sequence through the heat exchanger 22, the economizer 20, and the air preheater 19, gradually releasing heat, which is used to heat steam, preheat feedwater, and air, respectively, forming heat recovery and utilization, realizing efficient energy circulation, reducing the overall energy consumption of the enterprise, and eliminating the need to build an additional dedicated treatment system, thus simplifying the coal gasification slag treatment process.

[0025] The three-waste furnace includes a main furnace 1 and an auxiliary furnace 2. The auxiliary furnace 2 is connected to the superheater 22 through a high-temperature flue gas duct 3. The cyclone separator 29 and the superheater 22 are connected through a convection tube bundle 21. The economizer 20 is installed in the flue.

[0026] Specifically, the three waste furnace consists of a main furnace 1 and an auxiliary furnace 2. The main furnace 1 is used to calcine and decompose the coal gasification slag at high temperature, so that the harmful substances in the coal gasification slag are initially decomposed and the combustible components are converted into gaseous form. The auxiliary furnace 2 is responsible for guiding and stabilizing the flow of the treated high-temperature flue gas.

[0027] The outlet of the auxiliary furnace 2 of the three-waste furnace is fixedly connected to the superheater 22 through the high-temperature flue gas pipe 3. The high-temperature flue gas pipe 3 adopts a sealed design to ensure that all the high-temperature flue gas exported from the auxiliary furnace 2 can be delivered to the superheater 22, avoiding heat loss and flue gas leakage.

[0028] The cyclone separator 29 and the superheater 22 are connected by a convection tube bundle 21. The convection tube bundle 21 is precisely matched according to the equipment interface size, so that the flue gas purified by the cyclone separator 29 can flow smoothly into the superheater 22 for heat exchange.

[0029] A first inlet 7 is provided at the lower end of the boiler 4. One end of the first inlet 7 is connected to the interior of the boiler 4, and the other end is connected to the air outlet of the second fan 15 via a second fan duct 16. The second fan duct 16 passes through an air preheater 19. A second inlet 8 is provided at the lower end of the first inlet 7. One end of the second inlet 8 is connected to the interior of the boiler 4, and the other end of the second inlet 8 is provided with a feed port 9. A feed conveyor 6 is provided at one end of the feed port 9, and a hopper 5 is provided at the upper end of the feed conveyor 6. The material in the hopper 5 is conveyed to the feed port 9 via the feed conveyor 6 and enters the interior of the boiler 4. The side of the second inlet 8 is connected to the air outlet of the first fan 17 via a pipe.

[0030] Specifically, a first inlet 7 is provided at the lower end of boiler 4. The inner end of the first inlet 7 is connected to the combustion chamber of boiler 4, and the outer end is sealed to the air outlet of the second fan 15 through the second fan duct 16. The second fan duct 16 is laid along a preset path and passes through the interior of the air preheater 19. The contact area between the duct and the air preheater 19 is treated with heat insulation and sealing to ensure that the air can fully absorb heat when flowing through the air preheater 19 in the duct.

[0031] A second inlet 8 is located directly below the first inlet 7. The inner end of the second inlet 8 is connected to the combustion chamber of the boiler 4, and the outer end is welded to a feed port 9. The feed port 9 adopts a funnel-shaped structure design to facilitate the smooth introduction of materials. The feed end of the feed port 9 is rigidly connected to the discharge end of the feeding conveyor 6. The upper end of the feeding conveyor 6 is fixedly installed with a hopper 5 via a bracket. The discharge port of the hopper 5 is precisely aligned with the feed end of the feeding conveyor 6. Under the action of gravity and the conveying force of the feeding conveyor 6, the material can stably enter the interior of the boiler 4 through the feed port 9 and the second inlet 8.

[0032] Meanwhile, an interface is reserved on the side of the second inlet 8, which is connected to the air outlet of the first fan 17 through a branch pipe. The branch pipe is connected to the second inlet 8 and the air outlet of the first fan 17 with flange sealing to ensure the airtightness of the air supply process.

[0033] The lower part of the boiler 4 is also provided with a third inlet 10. One end of the third inlet 10 is connected to the interior of the boiler 4, and the other end of the third inlet 10 is connected to the air outlet of the first fan 17 through the first fan duct 18. The first fan duct 18 passes through the air preheater 19.

[0034] Specifically, a third inlet 10 is opened in the side area of ​​the lower part of the boiler 4. The inner end of the third inlet 10 extends to the middle and lower part of the combustion chamber of the boiler 4, and the outer end is connected to the air outlet of the first fan 17 through the first fan duct 18. The first fan duct 18 also passes through the air preheater 19. The duct route is coordinated with the second fan duct 16 to avoid pipeline interference.

[0035] Boiler 4 is provided with a bottom slag discharge port 11. A fourth inlet 12 is provided on one side of the bottom slag discharge port 11. One end of the fourth inlet 12 is connected to the inside of boiler 4, and the other end of the fourth inlet 12 is connected to the air outlet of the first fan 17 through the first fan pipe 18.

[0036] Specifically, a bottom ash discharge port 11 is provided at the bottom of boiler 4 to discharge the waste ash after combustion. A fourth inlet 12 is opened on the side of the bottom ash discharge port 11 near the combustion chamber of boiler 4. The inner end of the fourth inlet 12 is connected to the bottom area of ​​the combustion chamber of boiler 4 to ensure that the supplied air can act on the material at the bottom of the furnace. The outer end of the fourth inlet 12 is connected to the air outlet of the first fan 17 through another branch first fan pipe 18. This branch pipe is connected to the main first fan pipe 18 through a tee joint to realize the diversion and transportation of the air output from the first fan 17.

[0037] Several cyclone separators 29 are provided. A return feeder 14 is installed at the lower end of each cyclone separator 29. A high-pressure fluidizing blower 13 is installed on one side of the return feeder 14. The outlet of the high-pressure fluidizing blower 13 is connected to the return feeder 14 through a pipe. The dust collector 24 and the air preheater 19 are connected through a boiler flue gas pipe 23. A chimney 28 is installed at the upper end of the desulfurization tower 27.

[0038] Specifically, based on the processing scale requirements, several cyclone separators 29 are arranged in parallel at the flue gas outlet of boiler 4. The air inlet of the cyclone separator 29 is connected to the flue gas outlet of boiler 4 through a pipeline. The arrangement of multiple cyclone separators 29 can improve the separation efficiency of solid particles. The lower discharge port of each cyclone separator 29 is connected to the feed end of the return feeder 14. The return feeder 14 adopts a closed structure, and its discharge end extends to the feed area of ​​boiler 4 through a pipeline to realize the return of the separated solid particles.

[0039] A high-pressure fluidizing fan 13 is installed on the side of the return feeder 14. The outlet of the high-pressure fluidizing fan 13 is connected to the fluidizing air inlet of the return feeder 14 through a high-pressure pipeline. A pressure regulating valve is installed on the high-pressure pipeline, which can adjust the fluidizing air pressure according to the return material requirements, so as to provide stable power for the return of solid particles from the return feeder 14 to the boiler 4.

[0040] The inlet of the dust collector 24 is connected to the exhaust port of the air preheater 19 via the boiler exhaust pipe 23. The boiler exhaust pipe 23 can be made of corrosion-resistant material to ensure the stability of the flue gas transportation process. The inlet of the desulfurization tower 27 and the outlet of the induced draft fan 26 are connected via the dust collection pipe 25. The induced draft fan 26 provides traction force for transporting flue gas from the dust collector 24 to the desulfurization tower 27. A chimney 28 is installed at the rear of the desulfurization tower 27. The height and diameter of the chimney 28 are designed according to environmental emission requirements. The treated clean flue gas is discharged through the chimney 28 in compliance with standards.

[0041] Example 2: A method for treating coal gasification slag includes the following steps: The coal gasification slag first enters the three waste furnace, where it undergoes preliminary treatment in a suitable high-temperature environment, ultimately generating high-temperature flue gas, which is then discharged from the auxiliary furnace 2 to the high-temperature flue gas pipeline 3. High-temperature flue gas enters the boiler system through high-temperature flue gas pipe 3. In boiler 4, flue gas is introduced between the high-temperature section and the low-temperature section of superheater 22. Pulverized coal boiler is introduced from before economizer 20. Fuel in silo 5 is conveyed to feed port 9 by feed conveyor 6 and enters boiler 4 through second inlet 8. First fan 17 and second fan 15 are started, and air is conveyed through first fan pipe 18 and second fan pipe 16 respectively. It is preheated when passing through air preheater 19, and then sent into the furnace through first inlet 7, third inlet 10 and fourth inlet 12 of boiler 4. It is fully mixed and burned with fuel to further supplement the flue gas volume and increase the flue gas heat. After the mixed flue gas flows out of the boiler 4, it enters the cyclone separator 29, where the solid particles in the flue gas are separated by centrifugal force. The separated solid particles are returned to the boiler 4 for re-combustion via the return feeder 14 at the lower end. The high-pressure fluidizing blower 13 provides stable power for the return process. The purified flue gas then enters the superheater 22, economizer 20 and air preheater 19 in sequence through the convection tube bundle 21, gradually releasing heat to heat the steam, preheat the feedwater and air respectively, thus realizing the cascade recovery and utilization of heat. The flue gas that has completed heat recovery enters the dust collector 24 through the boiler exhaust pipe 23 to remove dust particles. Then, under the traction of the induced draft fan 26, it is sent to the desulfurization tower 27 through the dust removal pipe 25 to remove pollutants such as sulfur oxides.

[0042] Specifically, the coal gasification slag produced in the coal chemical industry is transported to the main furnace 1 of the three-waste furnace. A suitable high-temperature environment is maintained within the main furnace 1 to decompose the coal gasification slag at high temperatures, causing the harmful substances to initially crack and the combustible components to be converted into gaseous form, ultimately forming high-temperature flue gas. The high-temperature flue gas treated in the main furnace 1 enters the auxiliary furnace 2 for flow stabilization and guidance, and is then discharged through a sealed high-temperature flue gas pipeline 3 into the subsequent boiler system.

[0043] High-temperature flue gas is precisely delivered to the boiler system through high-temperature flue gas pipeline 3. Among them, part of the flue gas connected to boiler 4 enters from the preset interface between the high-temperature section and the low-temperature section of superheater 22, and forms a synergy with the flue gas generated by combustion in boiler 4; part of the flue gas connected to pulverized coal boiler is integrated from in front of economizer 20 of pulverized coal boiler, so as to achieve seamless connection with the existing pulverized coal boiler 30 system without the need for additional adjustment of the original equipment operating parameters.

[0044] Auxiliary fuel stored in silo 5 is uniformly conveyed to feed port 9 by feed conveyor 6, and continuously fed into the combustion chamber of boiler 4 through second inlet 8. Simultaneously, first fan 17 and second fan 15 are started, and outside air enters first fan duct 18 and second fan duct 16 respectively. Both types of ducts pass through air preheater 19. After preheating by absorbing waste heat in air preheater 19, the air is fed into the combustion chamber through multiple points via first inlet 7, third inlet 10, and fourth inlet 12 of boiler 4. The air supplied by first fan 17, which is connected to the side of second inlet 8, can directly contact the fuel to promote initial combustion. The preheated air supplied by the other inlets supplements oxygen from different directions, ensuring thorough mixing of fuel and air, achieving oxygen-rich combustion, which improves combustion efficiency, further supplements flue gas volume, and increases the overall heat of the flue gas.

[0045] The mixed flue gas, carrying solid particles produced by combustion, flows out of the boiler 4 outlet and enters several parallel cyclone separators 29. Inside the cyclone separators 29, centrifugal force separates the incompletely burned solid particles from the flue gas. The separated solid particles fall into the return feeder 14 at the lower end of the cyclone separator 29. The high-pressure fluidizing fan 13 is activated, supplying high-pressure fluidizing air through pipes to the return feeder 14, providing stable conveying power for the solid particles. This allows the solid particles to flow back to the boiler 4 combustion chamber for re-combustion, avoiding waste of combustible components and maximizing resource utilization.

[0046] The flue gas, purified by the cyclone separator 29, sequentially enters the superheater 22, economizer 20, and air preheater 19 through the convection tube bundle 21. In the superheater 22, the flue gas releases heat to heat the steam generated by the boiler, improving steam parameters. After entering the economizer 20, the waste heat of the flue gas is used to preheat the boiler feedwater, reducing boiler energy consumption. Finally, as it flows through the air preheater 19, the remaining heat of the flue gas is used to preheat the air entering the system, providing favorable conditions for the subsequent combustion process, thus achieving the cascade recovery and efficient utilization of flue gas heat.

[0047] After heat recovery, the flue gas enters the dust collector 24 through the boiler exhaust pipe 23, where particulate matter is removed, reducing pollutant levels. Subsequently, driven by the induced draft fan 26, the flue gas is sent to the desulfurization tower 27 through the dust collection pipe 25, where sulfur oxides and other harmful pollutants are removed through a desulfurization process. The cleaned flue gas, after multi-stage purification, is finally discharged through the chimney 28 downstream of the desulfurization tower 27, meeting emission standards.

[0048] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A coal gasification slag treatment system, comprising a three-waste furnace, characterized in that, The high-temperature flue gas generated by the three waste furnace is connected to the boiler system through a high-temperature flue gas pipeline. The boiler system includes a boiler, and several inlets are provided at the lower end of the boiler for feeding materials and air into the boiler. One end of the boiler is connected to a cyclone separator, one end of the cyclone separator is connected to a superheater, one end of the superheater is connected to an economizer inside the boiler, one end of the economizer is connected to an air preheater, one end of the air preheater is connected to a dust collector, one end of the dust collector is connected to an induced draft fan, and one end of the induced draft fan is connected to a desulfurization tower.

2. The coal gasification slag treatment system as described in claim 1, characterized in that, The three-waste boiler includes a main boiler and an auxiliary boiler. The auxiliary boiler is connected to the superheater through a high-temperature flue gas duct. The cyclone separator and the superheater are connected by a convection tube bundle. The economizer is installed in the boiler flue.

3. The coal gasification slag treatment system as described in claim 1, characterized in that, The lower end of the boiler is provided with a first inlet. One end of the first inlet is connected to the inside of the boiler, and the other end is connected to the air outlet of the second fan through a second fan duct. The second fan duct passes through an air preheater.

4. The coal gasification slag treatment system as described in claim 3, characterized in that, A second inlet is provided at the lower end of the first interface. One end of the second inlet is connected to the inside of the boiler, and the other end of the second inlet is provided with a feed port. A feed conveyor is provided at one end of the feed port, and a hopper is provided at the upper end of the feed conveyor. The material in the hopper is transported to the feed port through the feed conveyor and enters the boiler.

5. The coal gasification slag treatment system as described in claim 4, characterized in that, The side of the second inlet is connected to the air outlet of the first fan via a pipe.

6. The coal gasification slag treatment system as described in claim 1, characterized in that, The lower part of the boiler is also provided with a third inlet. One end of the third inlet is connected to the interior of the boiler, and the other end of the third inlet is connected to the air outlet of the first fan through the first fan duct. The first fan duct passes through the air preheater.

7. The coal gasification slag treatment system as described in claim 1, characterized in that, The boiler is provided with a bottom slag discharge port, and a fourth inlet is provided on one side of the bottom slag discharge port. One end of the fourth inlet is connected to the inside of the boiler, and the other end of the fourth inlet is connected to the air outlet of the first fan through the first fan pipe.

8. The coal gasification slag treatment system as described in claim 1, characterized in that, Several cyclone separators are provided, and a return feeder is provided at the lower end of the cyclone separator. A high-pressure fluidizing fan is provided on one side of the return feeder, and the outlet of the high-pressure fluidizing fan is connected to the return feeder through a pipe.

9. The coal gasification slag treatment system as described in claim 1, characterized in that, The dust collector and the air preheater are connected by a boiler exhaust pipe, and a chimney is installed at the rear of the desulfurization tower.

10. A method for treating coal gasification slag according to any one of claims 1-9, characterized in that, Includes the following steps: The coal gasification slag first enters the three waste furnace, where it undergoes preliminary treatment in a suitable high-temperature environment, ultimately generating high-temperature flue gas, which is then discharged from the auxiliary furnace to the high-temperature flue gas pipeline. High-temperature flue gas enters the boiler system through a high-temperature flue gas pipeline. In a circulating fluidized bed boiler, the flue gas is introduced from between the high-temperature section and the low-temperature section of the superheater. In a pulverized coal boiler, the flue gas is introduced from the economizer. The fuel in the silo is transported to the feed port by the feed conveyor and enters the boiler through the second inlet of the boiler. The first and second blowers are started, and the air is transported through the first blower pipe and the second blower pipe respectively. It is preheated when passing through the air preheater and then sent into the furnace through the first inlet, third inlet and fourth inlet of the boiler. It is fully mixed and burned with the fuel to further supplement the flue gas volume and increase the flue gas heat. After the mixed flue gas flows out of the boiler, it enters the cyclone separator, where the solid particles in the flue gas are separated by centrifugal force. The separated solid particles are returned to the boiler for re-combustion via the return feeder at the lower end. The high-pressure fluidizing blower provides stable power for the return process. The purified flue gas then enters the superheater, economizer, and air preheater sequentially through the convection tube bundle, gradually releasing heat to heat steam, preheat feedwater, and air, respectively, thus achieving cascade recovery and utilization of heat. The flue gas that has completed heat recovery enters the dust collector through the boiler exhaust pipe to remove dust particles. Then, under the traction of the induced draft fan, it is sent to the desulfurization tower through the dust removal pipe to remove pollutants such as sulfur oxides.

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