A system for energy utilization of domestic waste and efficient control of pollutants

Abstract

This invention discloses a high-efficiency control system for the energy utilization and pollutant treatment of municipal solid waste. A pyrolysis gasification furnace is sequentially connected to a secondary combustion chamber, a two-stage water-cooled wall, a quench chamber, and a semi-dry desulfurization tower. A gravity settling chamber is installed in the middle flue gas duct of the two-stage water-cooled wall. The water pipes at the outlet of the two-stage water-cooled wall are sequentially connected to a cooling tower, a water pump, and a water supply pipe to the quench chamber. The flue gas is desulfurized and dechlorinated through the semi-dry desulfurization tower. This invention achieves ultra-low pollutant emissions. The use of semi-dry cyclone desulfurization technology increases the flue gas flow time, improves desulfurization and dechlorination efficiency, and eliminates wastewater discharge. Simultaneously, the use of a two-stage water-cooled wall with rotary ammonia injection in the later stage reduces nitrogen oxide emissions and controls the denitrification temperature, achieving a highly efficient denitrification effect.

Description

Technical Field

[0001] This invention belongs to the field of waste pollutant control and heat recovery technology, specifically relating to a system for the energy utilization of municipal solid waste and a highly efficient control system for pollutants. Background Technology

[0002] With the rapid pace of urbanization in my country, the amount of urban household waste is increasing rapidly. How to effectively dispose of this waste has become a major challenge for city managers. Due to my country's limited land and large population, traditional landfill disposal methods are facing increasing difficulties in site selection.

[0003] To achieve the goals of reducing, recycling, and harmlessly disposing of urban household waste, building waste-to-energy incineration plants is becoming the preferred option for city managers. However, when household waste is incinerated in these plants, it generates a lot of highly polluting smoke and dust, which mainly contain dust, acidic gases, and dioxins. Therefore, the control of these pollutants has received significant attention from the government. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a system for the energy utilization and efficient control of pollutants from municipal solid waste, which effectively controls the generation of nitrogen oxides, sulfur oxides and chlorides, thereby reducing the emission of air pollutants, in order to address the shortcomings of the prior art.

[0005] The present invention adopts the following technical solution:

[0006] A high-efficiency control system for the energy utilization and pollutant utilization of municipal solid waste includes a pyrolysis gasification furnace. The pyrolysis gasification furnace is connected to a semi-dry desulfurization tower via a secondary combustion chamber, a two-stage water-cooled wall, a quench chamber, and a secondary combustion chamber. A gravity settling chamber is installed in the middle flue gas duct of the two-stage water-cooled wall. The water pipes at the outlet of the two-stage water-cooled wall are connected to a cooling tower, a water pump, and a water supply pipe for the quench chamber. The semi-dry desulfurization tower includes, from top to bottom, a flue gas swirl chamber, an atomization regulating chamber, a flue gas mixing chamber, a drying desulfurization chamber, and an ash collection chamber. An ash discharge port is provided at the bottom of the ash collection chamber. The flue gas is desulfurized and dechlorinated through the semi-dry desulfurization tower.

[0007] Specifically, the front and rear sections of the two-section water-cooled wall have different sizes.

[0008] Furthermore, the rear half of the two-section water-cooled wall is equipped with multiple ammonia injection ports, which are connected to the ammonia water tank respectively.

[0009] Specifically, a flue gas inlet is tangentially located on the flue gas swirl chamber.

[0010] Specifically, a swirling device is installed between the flue gas swirl chamber and the atomization regulating chamber, and the swirling device is equipped with rotating blades with adjustable angles.

[0011] Specifically, the atomization regulating chamber is equipped with an atomizing spray gun, one end of which is connected to the limestone slurry nozzle and the compressed air inlet.

[0012] Furthermore, the atomizing spray gun can move up and down along the atomization adjustment chamber.

[0013] Specifically, four flue gas collection pipes are installed at intervals at the lower end of the drying desulfurization chamber. The four flue gas collection pipes are inclined upwards and are all connected to the flue gas collection box and the flue gas outlet pipe.

[0014] Specifically, the flue gas mixing chamber has a funnel-shaped structure.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] This invention relates to a system for the energy utilization of municipal solid waste and a highly efficient control system for pollutants. It effectively controls the emissions of nitrogen oxides, sulfur oxides, and chlorides, while reducing the adhesion of fly ash in high-temperature flue gas to the wall surface. It also achieves effective control of dioxins and reduces the emission of pollutants into the atmosphere.

[0017] Furthermore, the front and rear sections of the two-section water-cooled wall have different sizes. The front section maintains the original speed of flue gas for heat exchange, resulting in a decrease in flue gas temperature and dust accumulation. When passing through the rear section, the space is larger, and the flow rate is slower, which helps the dust settle.

[0018] Furthermore, multiple ammonia injection ports are set up to form a rotating ammonia injection, which mixes better with the flue gas, increases the reaction time, and allows for better control of the amount of nitrogen oxides.

[0019] Furthermore, the flue gas enters the swirl chamber tangentially through the flue gas inlet, forming rotating flue gas and creating a swirling airflow, which provides sufficient momentum for swirl. The flue gas then passes through the swirl device, which automatically adjusts the angle of the rotating blades according to the flue gas flow rate and temperature to match the rotation angle of the flue gas at the swirl chamber outlet, achieving a speed that matches the atomization angle.

[0020] Furthermore, the position of the atomizing spray gun in the flue gas mixing chamber can be automatically adjusted up and down according to the flow rate of the flue gas, so as to maximize the contact area between the atomized slurry and the flue gas, and avoid spraying it on the wall surface.

[0021] Furthermore, the lower end of the drying desulfurization chamber is connected to four flue gas collection pipes, which can prevent the flue gas in the drying chamber from being short-circuited, causing uneven flue gas flow field, and further ensure that the sulfur in the flue gas reacts fully with the atomized slurry. The flue gas collection pipes are inclined upwards, which allows large dust particles to slide into the ash collection chamber along the pipe wall, and more fly ash is discharged through the ash discharge port.

[0022] Furthermore, the flue gas mixing chamber is shaped like a funnel, which allows for more uniform mixing of the flue gas and the atomized slurry. It also reduces the swirling speed of the flue gas and increases its residence time, ensuring that the sulfur in the flue gas reacts fully with the atomized slurry.

[0023] In summary, this invention can achieve ultra-low emissions of pollutants. The use of semi-dry cyclone desulfurization technology increases the flue gas flow time, improves desulfurization and dechlorination efficiency, and eliminates wastewater discharge. Simultaneously, the use of a two-stage water-cooled wall with rotary ammonia injection in the latter stage reduces nitrogen oxide emissions and controls the denitrification temperature, achieving a highly efficient denitrification effect.

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the semi-dry desulfurization tower structure of the present invention.

[0027] The components are as follows: 1. Pyrolysis gasification furnace; 2. Secondary combustion chamber; 3. Two-stage water-cooled wall; 4. Gravity settling chamber; 5. Ammonia water tank; 6. Quenching chamber; 7. Semi-dry desulfurization tower; 8. Cooling tower; 9. Water pump; 10. Flue gas inlet; 11. Flue gas swirl chamber; 12. Swirl device; 13. Atomizing spray gun; 14. Limestone slurry nozzle; 15. Compressed air inlet; 16. Flue gas mixing chamber; 17. Drying desulfurization chamber; 18. Flue gas collection box; 19. Flue gas collection pipeline; 20. Ash collection chamber; 21. Ash discharge port; 22. Flue gas outlet pipeline; 23. Atomization regulating chamber. Detailed Implementation

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Please see Figure 1 The present invention discloses a system for the energy utilization and efficient control of pollutants from municipal solid waste, comprising a pyrolysis gasification furnace 1, a secondary combustion chamber 2, a two-stage water-cooled wall 3, a gravity settling chamber 4, an ammonia tank 5, a quench chamber 6, a semi-dry desulfurization tower 7, a cooling tower 8, and a water pump 9.

[0031] The pyrolysis gasification furnace 1 is connected to the semi-dry desulfurization tower 7 via the secondary combustion chamber 2, the two-stage water-cooled wall 3, and the quench chamber 6. The raw waste is stored in the pyrolysis gasification furnace 1 and burned to produce syngas, which continues to burn in the secondary combustion chamber 2. The high-temperature flue gas is cooled by passing through the two-stage water-cooled wall 3 and the quench chamber 6, and then desulfurized and dechlorinated by passing through the semi-dry desulfurization tower 7.

[0032] A gravity settling chamber 4 is installed in the middle flue gas duct of the two-section water-cooled wall 3.

[0033] The rear half of the two-section water-cooled wall 3 is equipped with an ammonia water tank 5. Ammonia water from the ammonia water tank 5 is sprayed into the rear half of the two-section water-cooled wall 3 to form a vortex and denitrify the flue gas.

[0034] The front and rear sections of the two-section water-cooled wall 3 have different sizes. The front section maintains the original speed of flue gas for heat exchange, the flue gas temperature decreases, and dust accumulates. When passing through the rear section, the space is larger and the flow rate is slower, which helps the dust settle. At the same time, multiple ammonia injection ports are set at the position where the flue gas enters the rear section to form a rotating ammonia injection, which mixes better with the flue gas, increases the reaction time, and better controls the amount of nitrogen oxides.

[0035] The water pipes at the outlet of the two-section water-cooled wall 3 are connected sequentially to the water supply pipes of the cooling tower 8, water pump 9, and quench chamber 6.

[0036] Please see Figure 2The semi-dry desulfurization tower 7, from top to bottom, includes a flue gas swirl chamber 11, an atomization regulating chamber 23, a flue gas mixing chamber 16, a drying desulfurization chamber 17, and an ash collection chamber 20. A flue gas inlet 10 is tangentially arranged on the flue gas swirl chamber 11, through which flue gas enters the flue gas swirl chamber 11. A swirl device 12 is arranged between the flue gas swirl chamber 11 and the atomization regulating chamber 23. The swirl device 12 contains adjustable rotating blades, and the flue gas is automatically swirled... The swirl device 12 with an adjustable blade angle further increases the swirl intensity; an atomizing spray gun 13 that can move up and down along the atomizing chamber 23 is provided on the atomizing chamber 23. One end of the atomizing spray gun 13 is connected to the limestone slurry nozzle 14 and the compressed air inlet 15, respectively. The limestone slurry atomized by the atomizing spray gun 13 is fully mixed with the flue gas in the flue gas mixing chamber 16; then it enters the ash collection chamber 20 through the drying desulfurization chamber 17. The bottom of the ash collection chamber 20 is provided with an ash discharge port 21.

[0037] The lower end of the drying desulfurization chamber 17 is provided with four flue gas collection pipes 19 at intervals. The four flue gas collection pipes 19 are inclined upward and are all connected to the flue gas collection box 18 and the flue gas outlet pipe 22.

[0038] The flue gas mixing chamber 16 has a funnel-shaped structure, which allows for more uniform mixing of flue gas and atomized slurry. It also reduces the swirl velocity of the flue gas and increases the residence time of the flue gas, thus ensuring that the sulfur in the flue gas reacts fully with the atomized slurry.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0040] The present invention discloses a method for controlling pollutants during the thermal utilization process of municipal solid waste, which specifically comprises:

[0041] Raw waste is stored in a pyrolysis gasifier and burned to produce syngas, which continues to burn in the secondary combustion chamber, generating high-temperature flue gas. This flue gas is then cooled by passing through a two-stage water-cooled wall and a quench chamber before being desulfurized and dechlorinated in a semi-dry desulfurization tower. Ammonia water from the ammonia tank is injected into the latter half of the two-stage water-cooled wall to control the reaction temperature and create a swirling flow for denitrification of the flue gas.

[0042] This invention discloses a system for the energy utilization of municipal solid waste and a highly efficient control system for pollutants. It is suitable for the needs of rural and urban development and has significant potential for application in both industrial and residential sectors. This technology effectively controls the formation of nitrogen oxides, sulfur oxides, and chlorides, reducing emissions of air pollutants. The advantages of this technology can be summarized as follows:

[0043] (1) Flue gas forms a vortex in the desulfurization equipment, which increases the flue gas residence time, improves the desulfurization and dechlorination efficiency, and has no wastewater discharge.

[0044] Flue gas enters the swirl chamber tangentially through the flue gas inlet, forming a rotating airflow that provides sufficient momentum for swirl. The rotating flue gas then passes through a swirl device, achieving a velocity that matches the atomization angle. The swirl device's blade angle automatically adjusts according to the flue gas flow rate to match the atomization gun's spray angle, achieving highly efficient desulfurization and dechlorination.

[0045] The lower end of the desulfurization drying chamber is equipped with multiple flue gas collection pipes. The flue gas is collected in the flue gas collection box through these pipes, which prevents short circuits in the flue gas within the drying chamber and avoids uneven flue gas flow. This further ensures the full reaction between the sulfur in the flue gas and the atomized slurry. Furthermore, the flue gas collection pipes are inclined upwards, allowing large dust particles to slide down the pipe walls into the ash collection chamber. More fly ash is discharged through the ash discharge port, resulting in no wastewater discharge and reducing secondary treatment.

[0046] (2) Ammonia is sprayed in the rear section of the two-stage water-cooled wall to improve the denitrification efficiency.

[0047] The front and rear sections of the two-section water-cooled wall have different sizes. The front section maintains the original speed of flue gas for heat exchange, the flue gas temperature decreases, and dust accumulates. When passing through the rear section, the space is larger and the flow rate is slower, which helps the dust settle. At the same time, multiple ammonia injection ports are set at the position where the flue gas enters the rear section, so that it forms a rotating ammonia injection, which mixes better with the flue gas, increases the reaction time, and better controls the amount of nitrogen oxides.

[0048] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A high-efficiency control system for the energy utilization and pollutant treatment of municipal solid waste, characterized in that, The pyrolysis gasifier (1) is connected to the semi-dry desulfurization tower (7) via a secondary combustion chamber (2), a two-section water-cooled wall (3), a quench chamber (6), and a secondary combustion chamber (2). The front and rear sections of the two-section water-cooled wall (3) are of different sizes. The flue gas in the front section cools down rapidly, while the rear section becomes larger, allowing the flue gas to settle slowly. A gravity settling chamber (4) is installed in the middle flue gas duct of the two-section water-cooled wall (3). The rear half of the two-section water-cooled wall (3) is... The section is equipped with multiple rotating ammonia injection ports, which are connected to the ammonia water tank (5) respectively. The water pipelines at the outlet of the two-section water-cooled wall (3) are connected sequentially to the water supply pipelines of the cooling tower (8), water pump (9) and quench chamber (6). The semi-dry desulfurization tower (7) includes, from top to bottom, a flue gas swirl chamber (11), an atomization regulating chamber (23), a flue gas mixing chamber (16), a drying desulfurization chamber (17), and an ash collection chamber (20). The flue gas swirl chamber (11) A swirl device (12) is provided between the flue gas swirl chamber (11) and the atomization regulating chamber (23). A flue gas inlet (10) is tangentially provided on the flue gas swirl chamber (11). An adjustable rotating blade is provided inside the swirl device (12). The flue gas mixing chamber (16) is a funnel-shaped structure. Four flue gas collection pipes (19) are provided at intervals at the lower end of the drying desulfurization chamber (17). The four flue gas collection pipes (19) are inclined upwards and are connected to the flue gas collection box (18) and the flue gas outlet pipe (22). An ash discharge port (21) is provided at the bottom of the ash collection chamber (20). The flue gas is desulfurized and dechlorinated by the semi-dry desulfurization tower (7). An atomizing spray gun (13) is provided on the atomization regulating chamber (23). One end of the atomizing spray gun (13) is connected to the limestone slurry nozzle (14) and the compressed air inlet (15). The atomizing spray gun (13) can move up and down along the atomization regulating chamber (23).

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