Waste incineration power plant leachate concentration device and use method

Abstract

The application discloses a kind of waste incineration power plant leachate concentration device and use method, the waste incineration power plant is equipped with waste incinerator, and waste incinerator is equipped with smoke rush on, the concentration device includes the cylinder that is opened in up and down, cylinder is arranged at the exhaust port of smoke rush or is connected in series in smoke rush, filler zone is equipped in cylinder, and multiple air passages that are communicated with the upper end of cylinder are formed in filler zone, water distribution pipe with one end extending from cylinder is equipped above filler zone, multiple water outlets are equipped on water distribution pipe, water receiving mechanism is equipped below filler zone, and water receiving mechanism is connected with drain pipe;Water tank is equipped outside the cylinder, first water pump is equipped in water tank, the outlet of first water pump is connected with water distribution pipe, and the water outlet end of drain pipe is connected with water tank.The application has the advantages of reducing waste incineration power plant leachate processing cost, avoiding complaint, ensuring that flue gas emission temperature meets the standard and avoiding flue gas heat waste again.

Description

Technical Field

[0001] This invention relates to a leachate concentration device and its usage method for a waste incineration power plant. Background Technology

[0002] Waste-to-energy power plants use recycled waste as their primary fuel to generate electricity. The waste has a high moisture content, and when stored in the landfill, it produces large amounts of leachate. This leachate contains numerous bacteria and heavy metals, classifying it as hazardous waste that requires treatment before discharge. However, the primary function of a power plant is power generation, and leachate treatment is generally not a concern. Typically, the leachate is collected and transported to a wastewater treatment company for processing. This process presents several problems: First, the leachate ferments and produces a large amount of foul odor, which is emitted along the transport route, affecting residents and leading to complaints, thus hindering the plant's normal operation. Second, power plants often store large quantities of waste, resulting in significant leachate production and substantial transportation costs. Furthermore, leachate treatment is priced by volume, meaning the large volume of leachate generated results in exorbitant fees that the power plant must pay to wastewater treatment companies.

[0003] Furthermore, according to the relevant provisions of the "Air Pollution Prevention and Control Law" and the "Air Pollutant Emission Standards," the temperature of flue gas emitted by waste incineration power plants must not exceed 200℃. To meet this requirement, without intentionally increasing the height of the flue gas duct, power plants generally install heat exchangers inside the flue gas duct. These heat exchangers absorb heat from the flue gas and are generally used for two purposes: first, heating domestic water. However, due to the unavoidable odor generated by waste incineration power plants from storing waste, these plants are generally located far from residential areas. Domestic water is then transported over long distances to distant residential areas, resulting in significant temperature variations. The current method of reducing the heat output is not feasible and can only be used by power plant employees. However, the water consumption of power plant employees is far less than the amount of hot water produced, resulting in the waste of recovered heat. This is especially true in summer, when the heated domestic water is essentially left to cool naturally, leading to heat waste. Secondly, heating air and sending it into the furnace of the waste incinerator can increase the furnace temperature and thus improve power generation efficiency. However, air has a low specific heat capacity and a slow heating rate, making it difficult to reduce the flue gas temperature below 200°C. Therefore, it still needs to be used in conjunction with heating domestic water, resulting in heat waste. Thus, how to recover flue gas heat to meet emission temperature requirements and find suitable uses for the recovered heat to avoid further waste is a pressing issue that the industry needs to address. Summary of the Invention

[0004] The purpose of this invention is to provide a leachate concentration device and its usage method for waste incineration power plants. This invention has the advantages of reducing leachate treatment costs from waste incineration power plants, avoiding complaints, ensuring that flue gas emission temperatures meet standards, and preventing the further waste of flue gas heat.

[0005] The technical solution of the present invention: a leachate concentration device for a waste incineration power plant, wherein the waste incineration power plant is equipped with a waste incinerator and a flue gas flushing device, the concentration device includes a cylindrical body with openings at both the top and bottom, the flue gas flushing outlet of the cylindrical body is located at the cylindrical body or connected in series with the flue gas flushing device, a packing zone is provided inside the cylindrical body, multiple air passages are formed in the packing zone to connect the upper and lower ends of the cylindrical body, a water distribution pipe with one end extending out of the cylindrical body is provided above the packing zone, the water distribution pipe has multiple water outlets, a water receiving mechanism is provided below the packing zone, and a drain pipe extending out of the cylindrical body is connected to the water receiving mechanism.

[0006] In the aforementioned leachate concentration device for waste incineration power plants, a water tank is provided on the outside of the cylinder, and a first water pump is provided inside the water tank. The outlet of the first water pump is connected to a water distribution pipe, and the outlet of the drain pipe is connected to the water tank.

[0007] In the aforementioned leachate concentration device for waste incineration power plants, the water tank is connected to an inlet pipe and an overflow pipe, and a second water pump is connected to the inlet pipe.

[0008] In the aforementioned leachate concentration device for waste incineration power plants, the packing material in the packing zone consists of multiple spheres, with multiple evenly distributed support rods on the outer circumference of the spheres, and a mesh plate connecting the cylinder is provided at the bottom of the packing zone.

[0009] In the aforementioned leachate concentration device for waste incineration power plants, the side wall of the cylinder is provided with a material intake door and a material feeding door, which are located on the upper and lower sides of the packing area, respectively.

[0010] In the aforementioned leachate concentration device for waste incineration power plants, the water receiving mechanism includes a conical spiral water guide plate with baffles on both sides. The upper part of the water guide plate expands radially outward and connects to the inner wall of the cylinder, while the lower end of the water guide plate contracts radially inward and connects to a water receiving tray. A drain pipe is provided at the bottom of the water receiving tray. From the axial direction of the cylinder, the water receiving mechanism covers the entire inner hole of the cylinder.

[0011] In the aforementioned leachate concentration device for waste incineration power plants, a branch flue is provided on the outer side of the cylinder. The upper end of the branch flue is connected to the cylinder and located above the packing area, and the lower end of the branch flue is connected to the cylinder and located below the packing area. A valve is provided on the cylinder.

[0012] In the aforementioned leachate concentration device for waste incineration power plants, pressure sensors are installed on both sides of the valve in the branch flue pipes, and both the pressure sensors and the valves are connected to a controller.

[0013] In the aforementioned leachate concentration device for waste incineration power plants, the inner diameter of the cylinder is more than 1.5 times the inner diameter of the flue gas chute, and an annular water trough is provided at the bottom of the cylinder. The outer wall of the water trough is attached to the inner wall of the cylinder, and the inner wall of the water trough is close to the flue gas chute.

[0014] The aforementioned method of using the leachate concentration device for waste incineration power plants involves collecting the leachate in the waste incineration power plant into a container, pumping the leachate into a water tank using a second water pump, pumping the leachate from the water tank into a cylinder using a first water pump, heating the leachate with high-temperature flue gas passing through the flue, thus concentrating the leachate, and returning the concentrated leachate to the water tank. The volumetric flow rate of the second water pump is less than that of the first water pump.

[0015] When the packing area is blocked, acid is pumped into the water tank by the second water pump, and the acid in the water tank is circulated through the packing area by the first water pump to clear the blockage.

[0016] Compared with existing technologies, this invention comprehensively considers the actual conditions of waste incineration power plants. It utilizes the flue gas emitted from the incinerator to concentrate leachate. A packing zone is set up within the flue gas chute. When the leachate falls and passes through the packing zone, the packing not only slows down the descent speed of the leachate, increasing the heating time, but also allows the leachate to form a large-area water film, increasing the evaporation area. Furthermore, the packing zone counteracts the high-temperature flue gas, impacting it with the high-speed hot airflow, thereby increasing the water evaporation rate and significantly concentrating the leachate. Because the volume of the concentrated leachate is reduced, transportation costs are lowered, resulting in lower fees paid to wastewater treatment companies, and ultimately reducing the power plant's leachate treatment costs. Since the leachate is heated at high temperatures by the flue gas, odorous components in the leachate also volatilize, and bacteria in the leachate are killed. The leachate has minimal odor for a considerable period afterward, minimizing its impact on residents along the transportation route during transport, avoiding complaints, and facilitating the normal operation of the power plant. Furthermore, the leachate concentration process requires the absorption of a large amount of heat. Ensuring that the flue gas emission temperature meets standards and preventing the waste of recovered heat from the flue gas provides a new avenue for utilizing recovered flue gas heat. Therefore, this invention has the advantages of reducing leachate treatment costs at waste-to-energy incineration plants, avoiding complaints, ensuring that flue gas emission temperatures meet standards, and preventing the waste of flue gas heat.

[0017] Furthermore, through further improvements, the present invention further enhances the concentration effect of leachate, reduces the maintenance frequency, and increases the convenience of maintenance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the sphere of the present invention.

[0020] Figure 3 This is a connection diagram of the controller.

[0021] The labels in the attached diagram are as follows: 1-fume flush, 2-cylinder, 3-filling area, 4-water distribution pipe, 5-outlet, 6-drainage pipe, 7-water tank, 8-first water pump, 9-controller, 10-inlet pipe, 11-overflow pipe, 12-second water pump, 13-sphere, 14-support rod, 15-mesh plate, 16-material handling gate, 17-feeding gate, 18-water guide plate, 19-water baffle plate, 20-water receiving tray, 21-branch flue pipe, 22-valve, 23-pressure sensor, 24-water tank, 25-alarm device. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0023] Example 1. Leachate concentration device for a waste incineration power plant, wherein the waste incineration power plant is equipped with a waste incinerator, and the waste incinerator is equipped with a flue gas flush 1, such as... Figure 1 As shown, the concentration device includes a cylindrical body 2 with openings at both the top and bottom. The cylindrical body 2 is located at the exhaust port of the flue gas flush 1 or connected in series with the flue gas flush 1. Preferably, the cylindrical body 2 is connected in series with the flue gas flush 1. The flue gas flush 1 is generally equipped with a flue gas treatment device because the flue gas produced by waste incineration also contains some harmful components, which need to be treated by the flue gas treatment device to meet emission requirements. The cylindrical body 2 is located in front of the flue gas treatment device, and the flue gas first passes through the cylindrical body 2 and then through the flue gas treatment device.

[0024] The cylinder 2 is provided with a packing area 3, which forms multiple air passages that connect the upper and lower ends of the cylinder 2. A water distribution pipe 4 with one end extending out of the cylinder 2 is provided above the packing area 3. Multiple water outlets 5 are provided on the water distribution pipe 4. A water receiving mechanism is provided below the packing area 3, and a drain pipe 6 extending out of the cylinder 2 is connected to the water receiving mechanism.

[0025] A water tank 7 is provided on the outside of the cylinder 2. The water tank 7 is located on the horizontal side of the cylinder 2. A first water pump 8 is provided inside the water tank 7. The outlet of the first water pump 8 is connected to the water distribution pipe 4, and the outlet end of the drain pipe 6 is connected to the water tank 7.

[0026] The water tank 7 is connected to an inlet pipe 10 and an overflow pipe 11, and a second water pump 12 is connected to the inlet pipe 10.

[0027] The filler in the filling zone 3 consists of multiple spheres 13. Multiple evenly distributed support rods 14 are provided on the outer circumference of the spheres 13. A mesh plate 15 is provided at the bottom of the filling zone 3. A bracket fixed to the cylinder 2 can be provided at the bottom of the mesh plate 15. The mesh plate 15 rests on the bracket.

[0028] The side wall of the cylinder 2 is provided with a material taking door 16 and a material feeding door 17, which are located on the upper and lower sides of the filling area 3, respectively.

[0029] The water receiving mechanism includes a conical spiral water guide plate 18, with baffle plates 19 on both sides of the water guide plate 18. The height of the baffle plates 19 is less than the pitch of the water guide plate 18, so that a channel for flue gas to pass through is formed between the upper and lower rings of the water guide plates 18. The upper part of the water guide plate 18 expands radially outward and connects to the inner wall of the cylinder 2. The lower end of the water guide plate 18 contracts radially inward and connects to a water receiving tray 20. A drain pipe 6 is provided at the bottom of the water receiving tray 20. From the axial direction of the cylinder 2, the water receiving mechanism covers the entire inner hole of the cylinder 2.

[0030] A branch flue pipe 21 is provided on the outer side of the cylinder 2. The upper end of the branch flue pipe 21 is connected to the cylinder 2 and located above the packing area 3. The lower end of the branch flue pipe 21 is connected to the cylinder 2 and located below the packing area 3. A valve 22 is provided on the cylinder 2. The valve 22 is electric.

[0031] Both sides of the valve 22 are equipped with air pressure sensors 23 located in the branch flue pipe 21. The first water pump 8, the second water pump 12, the air pressure sensors 23 and the valve 22 are all connected to the controller 9. The controller 9 is connected to a photoelectric alarm device 25.

[0032] To facilitate the smooth passage of flue gas through the cylinder 2, the inner diameter of the cylinder 2 is more than 1.5 times the inner diameter of the flue gas 1.

[0033] The bottom of the cylinder 2 is provided with an annular water trough 24, the outer wall of the water trough 24 is attached to the inner wall of the cylinder 2, and the inner wall of the water trough 24 is close to the flue gas flush 1. During the test, it was found that although the water guide plate 18 and the water receiving plate 20 cover the entire inner hole of the cylinder 2 when viewed from above, a small amount of leachate will still escape the interception of the water receiving mechanism and enter the flue gas flush 1 under the impact of rising flue gas. In order to avoid the impact on the incinerator furnace, a water trough is set at the bottom of the cylinder 2 to intercept part of the leachate. The intercepted leachate will evaporate and disappear when heated.

[0034] Example 2. Following the method of Example 1, leachate from the waste incineration power plant is collected in a container. A second water pump 12 pumps the leachate into a water tank 7. This is a continuous pumping process. A first water pump 8 continuously pumps the leachate from the water tank 7 into the cylinder 2. Under gravity, the leachate passes through the packing zone, forming a water film that counteracts the rising hot flue gas, evaporating the water and concentrating the leachate. The flue gas is then cooled, and the concentrated leachate returns to the water tank 7. The volumetric flow rate of the second water pump 12 is set to one-third of the volumetric flow rate of the first water pump 8, ensuring that the water inlet rate to the water tank 7 is three times the rate at which the drain pipe 6 replenishes the water tank 7. The leachate passes through the packing zone 3 several times, undergoing several concentrations before being discharged from the overflow pipe 11. The discharged leachate can then be transported to a wastewater treatment company.

[0035] Because the leaked liquid contains impurities, the packing area 3 is prone to blockage when the air passage is too small. Therefore, support rods 14 are installed on the packing material in the packing area 3, i.e., the ball 13, to increase the distance between the packing materials, expand the air passage, make the packing area 3 less prone to blockage, and reduce the maintenance frequency.

[0036] Valve 22 is normally closed. Under normal circumstances, flue gas passes through cylinder 2, and the air pressure on both sides of valve 22 is similar. When controller 9 detects a certain pressure difference on both sides of valve 22 via air pressure sensor 23, it indicates that the packing area 3 is blocked. The controller stops the first water pump 8 and the second water pump 12, opens valve 22, allows flue gas to pass through branch flue pipe 21, and issues a warning through alarm device 25, prompting workers to handle the packing. There are two handling methods:

[0037] The first method involves pumping acid into the water tank 7 via the second water pump 12. To minimize waste, the acid should not overflow from the overflow pipe 11. Then, the acid in the water tank 7 is circulated through the packing zone 3 via the first water pump 8 to clear the packing zone and perform acid washing on the packing. After a certain period of acid washing, the valve 22 is closed via the controller 9. If the alarm device 25 does not issue a warning, it indicates that the packing zone 3 has been sufficiently cleared and the air pressure on both sides of valve 22 is close. The controller 9 then starts the first water pump 8 and the second water pump 12, placing the second water pump 12 into the leachate container to continue concentrating the leachate. Conversely, if the alarm device 25 still issues a warning after the controller 9 closes valve 22, and the first water pump 8 and the second water pump 12 cannot be started, it indicates that acid washing alone is insufficient to restore the clearness of the packing zone 3, and the second method is required to treat the packing. In the first method, the existing structure of the concentration device can be used to clear the packing zone 3, making operation convenient and labor-saving for workers, and simplifying maintenance.

[0038] The second method: Open the material removal door 16, remove all the packing material, and then close it. Open the material feeding door 17, add new packing material into the packing area 3, and then close it. The removed packing material can be reused by methods such as vibration pickling and high-pressure water jet rinsing, or it can be discarded directly. In actual use, it has been found that after the packing area 3 is treated 5-8 times using the first method, it needs to be treated once using the second method.

[0039] Tests showed that the leachate discharged from the overflow pipe 11 was concentrated by about 40%, meaning that every liter of leachate was concentrated to 0.4 liters.

[0040] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

Claims

1. A leachate concentration device for a waste-to-energy power plant, wherein the waste-to-energy power plant is equipped with a waste incinerator and a flue gas flushing device (1), characterized in that: The concentration device comprises a cylinder (2) which is open at both top and bottom and is arranged at the smoke outlet of the smoke rush (1) or is connected in series in the smoke rush (1), a filler area (3) is arranged in the cylinder (2), a plurality of air passages which communicate with the top and bottom of the cylinder (2) are formed in the filler area (3), a water distribution pipe (4) which extends out of the cylinder (2) is arranged above the filler area (3), a plurality of water outlets (5) are arranged on the water distribution pipe (4), a water receiving mechanism is arranged below the filler area (3), and a drain pipe (6) which extends out of the cylinder (2) is connected to the water receiving mechanism; The water receiving mechanism comprises a conical spiral water guide plate (18), water baffle plates (19) are arranged on both sides of the water guide plate (18), the upper part of the water guide plate (18) is expanded radially outwards and is connected to the inner side wall of the cylinder (2), the lower end of the water guide plate (18) is contracted radially inwards and is connected to a water receiving disc (20), the bottom of the water receiving disc (20) is provided with the drain pipe (6), and the water receiving mechanism covers the inner hole of the entire cylinder (2) as viewed in the axial direction of the cylinder (2).

2. The waste incineration plant leachate concentration device according to claim 1, characterized by: A water tank (7) is arranged on the outside of the cylinder (2), a first water pump (8) is arranged in the water tank (7), the outlet of the first water pump (8) is connected to the water distribution pipe (4), and the water outlet end of the drain pipe (6) is connected to the water tank (7).

3. The waste incineration plant leachate concentration device according to claim 2, characterized by: The water tank (7) is connected with a water inlet pipe (10) and an overflow pipe (11), and a second water pump (12) is connected to the water inlet pipe (10).

4. The waste incineration plant leachate concentration device according to claim 1, characterized by: The filler in the filler area (3) is a plurality of spherical bodies (13), a plurality of uniformly distributed support rods (14) are arranged on the outer circumferential surface of the spherical bodies (13), and a mesh plate (15) which is connected to the cylinder (2) is arranged at the bottom of the filler area (3).

5. The waste incineration plant leachate concentration device according to claim 4, characterized by: A material taking door (16) and a material adding door (17) are arranged on the side wall of the cylinder (2), and the material taking door (16) and the material adding door (17) are respectively arranged on the upper side and the lower side of the filler area (3).

6. The waste incineration plant leachate concentration device according to claim 1, characterized by: A branch smoke pipe (21) is arranged on the outside of the cylinder (2), the upper end of the branch smoke pipe (21) is connected to the cylinder (2) and is arranged above the filler area (3), the lower end of the branch smoke pipe (21) is connected to the cylinder (2) and is arranged below the filler area (3), and a valve (22) is arranged on the cylinder (2).

7. The waste incineration plant leachate concentration device according to claim 6, characterized by: Air pressure sensors (23) are arranged on both sides of the valve (22) and are arranged in the branch smoke pipe (21), and the air pressure sensors (23) and the valve (22) are both connected to a controller (9).

8. The waste incineration plant leachate concentration device according to claim 6, characterized by: The inner diameter of the cylinder (2) is more than 1.5 times the inner diameter of the smoke rush (1), an annular water groove (24) is arranged at the bottom of the cylinder (2), the outer side wall of the water groove (24) is attached to the inner side wall of the cylinder (2), and the inner wall of the water groove (24) is close to the smoke rush (1).

9. Use of a waste incineration plant leachate concentration device according to any one of claims 1-8, characterized in that: The leachate in a waste incineration power plant is collected in a container, the leachate is pumped into the water tank (7) by the second water pump (12), the leachate in the water tank (7) is pumped into the cylinder (2) by the first water pump (8), the leachate is heated by the high-temperature flue gas passing through the smoke rush (1) to concentrate the leachate, the concentrated leachate returns to the water tank (7), and the volume flow rate of the second water pump (12) is smaller than the volume flow rate of the first water pump (8). When the filler zone (3) is blocked, the acid liquid is pumped into the water tank (7) by the second water pump (12), and the acid liquid in the water tank (7) is circulated through the filler zone (3) by the first water pump (8), so as to dredge the filler zone (3).

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