Low-temperature denitration device for hazardous waste incineration flue gas

Abstract

The utility model discloses a low-temperature denitration device for hazardous waste incineration flue gas, which comprises a denitration tower body, and a plurality of pipelines are arranged on the denitration tower body; the reaction shell is arranged inside the denitration tower body, and an air inlet and an air outlet are respectively formed in the upper end and the lower end of the reaction shell; the liquid storage shell is arranged in the reaction shell, the end part of the liquid storage shell extends to the outside of the denitration tower body, and a discharge flue is formed in the reaction shell; the spraying mechanism comprises a spraying end, a backflow end and a stirring end, one end of the spraying end is communicated with the liquid storage shell, and the other end of the spraying end is arranged in the discharge flue and used for spraying flue gas; and the backflow end is arranged at the bottom of the denitration tower body. The low-temperature denitration device disclosed by the utility model has the beneficial effects that the technical problems that in a low-temperature denitration device in the prior art, after flue gas enters a tower body, the flue gas cannot be in full contact with a calcium carbonate solution, and meanwhile, spraying liquid cannot be reutilized, so that the flue gas filtering efficiency is relatively low are solved.

Description

Technical Field

[0001] This utility model relates to the field of flue gas treatment technology, specifically to a low-temperature denitrification device for hazardous waste incineration flue gas. Background Technology

[0002] In recent years, with increasingly stringent environmental protection requirements, SCR (Selective Catalytic Reduction) flue gas denitrification is generally chosen to reduce nitrogen oxide emissions in flue gas. Due to its high efficiency and stable performance, it is widely used in engineering projects both domestically and internationally. However, SCR flue gas denitrification requires the flue gas to reach relatively high temperatures, limiting its application range. In low-temperature denitrification, ozone is first used to react with the flue gas, followed by mixing with calcium carbonate for denitrification. Currently, flue gas denitrification devices cannot fully contact the flue gas with the calcium carbonate solution, resulting in poor treatment efficiency. Furthermore, the sprayed liquid cannot be reused, indirectly affecting the working efficiency of the low-temperature denitrification device. Utility Model Content

[0003] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a low-temperature denitrification device for hazardous waste incineration flue gas, solving the technical problem that in the existing low-temperature denitrification devices, the flue gas cannot fully contact the calcium carbonate solution after entering the tower body, and the spray liquid cannot be reused, resulting in low flue gas filtration efficiency.

[0004] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0005] In a first aspect, this utility model provides a low-temperature denitrification device for hazardous waste incineration flue gas, comprising:

[0006] The denitrification tower body has multiple pipelines installed on it;

[0007] The reaction shell is disposed inside the denitrification tower body, and has an air inlet and an air outlet at its upper and lower ends, respectively.

[0008] A liquid storage tank is disposed inside the reaction tank, with its end extending to the outside of the denitrification tower body, and forming a flue gas duct inside the reaction tank;

[0009] The spraying mechanism includes a spraying end, a return end, and an agitation end. One end of the spraying end is connected to the liquid storage tank, and the other end is located in the flue gas duct for spraying the flue gas. The return end is located at the bottom of the denitrification tower for collecting the sprayed liquid and reintroducing it into the liquid storage tank. The agitation end is located outside the denitrification tower for agitating the liquid inside the liquid storage tank.

[0010] In some embodiments, the pipeline includes a flue gas inlet pipe, an ozone pipe, and a flue gas outlet pipe; the flue gas inlet pipe and the ozone pipe are respectively disposed on both sides of the denitrification tower body, and the flue gas outlet pipe is disposed on the top of the denitrification tower body.

[0011] In some embodiments, the exhaust duct includes a first flue and a second flue, and the first flue and the second flue are provided with a plurality of baffles inside.

[0012] In some embodiments, the spray end includes a diversion pipe, a water pump, and a water suction pipe. The water pump is connected to the liquid storage tank through the water suction pipe. The discharge end of the water pump is connected to the diversion pipe. The end of the diversion pipe extends into the first flue and the second flue. A plurality of spray heads are provided on the diversion pipe.

[0013] In some embodiments, the reflux end includes two limiting blocks, which are symmetrically arranged on the inner wall of the denitrification tower, and a filter element is provided between the two limiting blocks.

[0014] In some embodiments, the filter element includes a first filter and a second filter, which are arranged from top to bottom between the two limiting blocks.

[0015] In some embodiments, the reflux end further includes a reflux pump, a first pipe, and a second pipe; the reflux pump is disposed outside the denitrification tower body, and the first pipe and the second pipe are respectively connected to the reflux pump, the first pipe extending into the liquid storage shell, and the second pipe extending into the lower end of the inner cavity of the denitrification tower body.

[0016] In some embodiments, the agitation end includes an agitator motor, a shaft, and agitator blades; the agitator motor is disposed outside the denitrification tower body, and the output end of the agitator motor is connected to the shaft body, one axial end of the shaft body extends into the liquid storage shell, and a plurality of agitator blades are arranged circumferentially on the outer wall of the shaft body.

[0017] In some embodiments, each of the stirring blades is provided with a notch, and a rotatable rotating shaft is provided in the notch, and a plurality of rotating blades are connected to the rotating shaft.

[0018] In some embodiments, the upper and lower ends of the liquid storage shell are respectively provided with a water inlet and a drain outlet, and valves are provided on the water inlet and the drain outlet.

[0019] Compared with the prior art, the present invention provides a low-temperature denitrification device for hazardous waste incineration flue gas. This application sets up a reaction shell inside the denitrification tower and a liquid storage shell inside the reaction shell to limit the floating path of the flue gas and extend the residence time of the flue gas, so that it can fully contact and react with the calcium carbonate solution. A reflux end is set up to recycle the spray liquid, thereby reducing the consumption of fresh reagents. At the same time, an agitator is set up in the liquid storage shell to generate a vortex effect, avoid reagent precipitation, ensure uniform reagent concentration, and effectively guarantee the treatment efficiency of the reagent. Attached Figure Description

[0020] Figure 1 This is a side view of a low-temperature denitrification device for hazardous waste incineration flue gas provided in an embodiment of this utility model;

[0021] Figure 2 This is an internal structural diagram of a low-temperature denitrification device for hazardous waste incineration flue gas provided in an embodiment of this utility model;

[0022] Figure 3 This is a schematic diagram of the back of a low-temperature denitrification device for hazardous waste incineration flue gas provided in an embodiment of this utility model;

[0023] Figure 4 This is a schematic diagram of the interior of the liquid storage tank of the low-temperature denitrification device for hazardous waste incineration flue gas provided in this embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the spray end structure of a low-temperature denitrification device for hazardous waste incineration flue gas provided in an embodiment of this utility model.

[0025] Explanation of reference numerals in the attached diagram: 1. Denitrification tower body; 11. Pipeline; 111. Flue gas inlet pipe; 112. Ozone pipe; 113. Flue gas outlet pipe; 2. Reaction shell; 21. Air inlet; 22. Air outlet; 3. Liquid storage tank; 4. Flue gas duct; 41. First flue gas duct; 42. Second flue gas duct; 5. Spraying mechanism; 51. Spraying end; 511. Diverter pipe; 5111. Spray head; 512. Water pump; 51 3. Pump pipe; 52. Return end; 521. Limiting block; 522. Filter element; 5221. First filter screen; 5222. Second filter screen; 523. Return pump; 5231. First pipe body; 5232. Second pipe body; 53. Stirring end; 531. Stirring motor; 532. Shaft; 533. Stirring blade; 534. Notch; 5341. Rotating shaft; 5342. Rotating blade. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] To address the technical problem in existing low-temperature denitrification devices where flue gas cannot fully contact the calcium carbonate solution after entering the tower, and the spraying liquid cannot be reused, resulting in low flue gas filtration efficiency, this invention provides a low-temperature denitrification device for hazardous waste incineration flue gas. This device enables the flue gas to fully contact the calcium carbonate solution and allows for the recycling of the sprayed solution, ensuring spraying efficiency.

[0028] It should be noted that the low-temperature denitrification device for hazardous waste incineration flue gas described in this utility model is used in, but not limited to, the field of flue gas treatment. For ease of explanation, this utility model only uses the application of the low-temperature denitrification device for hazardous waste incineration flue gas in the field of flue gas treatment as an example. The principle of the low-temperature denitrification device for hazardous waste incineration flue gas in other types of equipment is essentially the same as that in the field of flue gas treatment, and will not be described in detail here.

[0029] Please see Figure 1 , Figure 1 This is a schematic diagram of a low-temperature denitrification device for hazardous waste incineration flue gas according to an embodiment of the present invention. The low-temperature denitrification device for hazardous waste incineration flue gas includes:

[0030] The denitrification tower body 1 has multiple pipelines 11.

[0031] The reaction shell 2 is located inside the denitrification tower 1, and its upper and lower ends are respectively provided with an air inlet 21 and an air outlet 22.

[0032] The liquid storage tank 3 is located inside the reaction tank 2, with its end extending to the outside of the denitrification tower 1, and forming a flue gas duct 4 inside the reaction tank 2;

[0033] The spraying mechanism 5 includes a spraying end 51, a return end 52, and an agitation end 53. One end of the spraying end 51 is connected to the liquid storage tank 3, and the other end is located in the flue gas duct 4 for spraying the flue gas. The return end 52 is located at the bottom of the denitrification tower 1 for collecting the sprayed liquid and reintroducing it into the liquid storage tank 3. The agitation end 53 is located outside the denitrification tower 1 and is used to agitate the liquid inside the liquid storage tank 3.

[0034] In this embodiment, the present application sets a reaction shell 2 inside the denitrification tower body 1, and a liquid storage shell 3 inside the reaction shell 2 to limit the floating path of the flue gas and extend the residence time of the flue gas, so that it can fully contact and react with the calcium carbonate solution. A reflux end 52 is set to recycle the spray liquid, thereby reducing the consumption of fresh reagents. At the same time, an agitation end 53 is set inside the liquid storage shell 3 to generate a vortex effect, avoid reagent precipitation, ensure uniform reagent concentration, and effectively guarantee the treatment efficiency of the reagent.

[0035] In one embodiment, please refer to Figures 1-4 The pipeline 11 includes a flue gas inlet pipe 111, an ozone pipe 112, and a flue gas outlet pipe 113. The flue gas inlet pipe 111 and the ozone pipe 112 are respectively located on both sides of the denitrification tower body 1, and the flue gas outlet pipe 113 is located at the top of the denitrification tower body 1. The flue gas exhaust duct 4 includes a first flue gas duct 41 and a second flue gas duct 42. Multiple baffles are installed inside the first flue gas duct 41 and the second flue gas duct 42.

[0036] In this embodiment, the ozone pipe 112 and the flue gas inlet pipe 111 are located on both sides of the denitrification tower 1, allowing the ozone to be initially mixed with the flue gas before entering the reaction zone, thus avoiding excessively high or low local concentrations. Secondly, a flue gas outlet pipe 113 is installed at the top of the denitrification tower 1. After the denitrification reaction, the density of the flue gas decreases, and the top-outlet flue gas utilizes the thermal flotation effect, reducing the energy consumption of the induced draft fan. By setting parallel flues, the flue gas is diverted to the first flue 41 and the second flue 42 after entering the tower, even if one flue is temporarily... Even with blockages, the system can still maintain more than 50% of its processing capacity, enhancing operational stability. The dual-flue structure increases the flue gas travel distance, and the tortuous path formed by the baffles theoretically extends the residence time by 40%-60%, ensuring that NOx reacts fully with ozone and spray liquid. The baffles disrupt the laminar flow of the flue gas, forming local eddies, which increases the contact area between the spray droplets and the flue gas, improving the denitrification efficiency by 10%-15%. This also prevents the droplets from "penetrating"—falling to the bottom of the tower without reacting—and improves reagent utilization.

[0037] In one embodiment, please refer to Figures 1-3 To improve the spraying efficiency of the spray end 51, the spray end 51 includes a diversion pipe 511, a water pump 512 and a water pumping pipe 513. The water pump 512 is connected to the liquid storage tank 3 through the water pumping pipe 513. The discharge end of the water pump 512 is connected to the diversion pipe 511. The end of the diversion pipe 511 extends into the first flue 41 and the second flue 42. Several spray heads 5111 are provided on the diversion pipe 511.

[0038] In this embodiment, the diversion pipe 511 extends into the first flue 41 and the second flue 42, and multiple sets of spray heads 5111 are arranged in the dual flues to form a three-dimensional spray network, ensuring no dead corners in the flue gas channels. The spray head 5111 has an orifice diameter of 2mm, which can achieve a droplet size of 50-200μm, taking into account both settling velocity and gas-liquid contact area. The water pump 512 is a centrifugal pump with a flow rate ≥50m³ / h. 3 / h, which can provide stable pressure to adapt to different flue gas loads. Under high load, the spray is fully open, and under low load, the branch flow can be adjusted by valve. The spray head 5111 has a 2mm orifice diameter to reduce the risk of scaling. The spray head 5111 is made of 316L stainless steel or silicon carbide ceramic and can withstand the pH range of 2-12.

[0039] In one embodiment, please refer to Figures 1-5 The reflux end 52 includes two limiting blocks 521, which are symmetrically arranged on the inner wall of the denitrification tower body 1. A filter element 522 is provided between the two limiting blocks 521. The filter element 522 includes a first filter screen 5221 and a second filter screen 5222. The first filter screen 5221 and the second filter screen 5222 are arranged from top to bottom between the two limiting blocks 521. The reflux end 52 also includes a reflux pump 523, a first pipe body 5231 and a second pipe body 5232. The reflux pump 523 is located outside the denitrification tower body 1, and the first pipe body 5231 and the second pipe body 5232 are respectively connected to the reflux pump 523. The first pipe body 5231 extends into the liquid storage shell 3, and the second pipe body 5232 extends to the lower end of the inner cavity of the denitrification tower body 1.

[0040] In this embodiment, two limiting blocks 521 are symmetrically welded to the inner wall of the tower body to form a slotted installation frame, ensuring that the filter screen does not deform under liquid impact and supporting quick pull-out replacement. The first filter screen 5221 is an 80-mesh screen used to intercept large particulate impurities, such as unreacted CaCO3 and CaSO4 crystals. The second filter screen 5222 is a 200-mesh screen used to capture fine suspended matter, such as smoke particles, forming a stepped filtration system with a filtration accuracy of less than 50μm, reducing liquid turbidity by more than 90%, ensuring the cleanliness of the recycled liquid, preventing the spray head 5111 from clogging (clogging rate <3%), and extending the life of the spray system. The return pump 523 has a flow rate ≥30m³. 3 / h, waste liquid from the bottom of the tower is extracted through the second pipe 5232 and pumped back to the storage tank 3 through the first pipe 5231, forming a closed loop: liquid recovery rate ≥95%, reducing fresh reagent consumption by more than 30%, and the pump body is placed outside the tower to avoid damage from the corrosive environment inside the tower. There is no need to stop the machine during maintenance. The reflux pump 523 continuously circulates to prevent the accumulation of sediment at the bottom of the tower. With the mixing action of the stirring end 53, the liquid uniformity is maintained and the concentration deviation is ≤3%.

[0041] In a preferred embodiment, please refer to Figures 1-5 To improve the storage efficiency of the liquid storage tank 3, the stirring end 53 includes a stirring motor 531, a shaft 532, and stirring blades 533. The stirring motor 531 is located outside the denitrification tower body 1, and the output end of the stirring motor 531 is connected to the shaft 532. One end of the shaft 532 extends axially into the liquid storage tank 3. Several stirring blades 533 are arranged circumferentially on the outer wall of the shaft 532. A notch 534 is opened on any stirring blade 533. A rotatable rotating shaft 5341 is installed in the notch 534. Several rotating blades 5342 are connected to the rotating shaft 5341. The upper and lower ends of the liquid storage tank 3 are respectively provided with a water inlet and a water outlet, and valves are provided on the water inlet and the water outlet.

[0042] In this embodiment, a radial flow is formed by the shaft 532 and the stirring blades 533 to drive a large circulation of liquid within the storage tank 3. An axial vortex is formed by the rotating shaft 5341 and the rotating blades 5342 as the shaft 5341 rotates, which disrupts the laminar boundary layer. This effectively improves mixing efficiency, ensures complete suspension of reagents such as CaCO3, and avoids fluctuations in denitrification efficiency caused by uneven local concentrations. The rotating blades 5342 autonomously adjust their rotation speed under liquid resistance to dynamically adapt to solutions of different viscosities. The stirring motor 531 is located outside the tower to avoid contact with corrosive gases and liquids. The inlet is used to support the rapid replenishment of fresh reagents or pH adjustment, and the outlet is used to periodically discharge precipitated impurities. The stirring motor 531 is equipped with a frequency converter to adjust the speed according to the liquid level.

[0043] To better understand this utility model, the following is combined with... Figures 1 to 5The technical solution of this utility model is described in detail as follows: The flue gas generated from hazardous waste incineration enters from one side of the denitrification tower 1 through the inlet pipe 111, and ozone is injected from the other side through the ozone pipe 112. The flue gas is initially mixed before entering the reaction shell 2. After entering the reaction shell 2, the flue gas is diverted to the first flue 41 and the second flue 42, forming turbulence under the action of the baffle plate, thus prolonging the residence time. The spraying mechanism 5 sprays the CaCO3 solution in the storage tank 3 into the flue through the diversion pipe 511, atomizing the droplets. The sprayed liquid carries the reaction products to the bottom of the tower, and after being filtered through the dual-stage filter screens (80 mesh and 200 mesh) at the return end 52, it is pumped back to the storage tank 3 by the return pump 523 for reuse. The stirring end 53 continuously mixes the liquid in the storage tank 3 to prevent sedimentation and maintain the activity of the reagents. The denitrified flue gas is discharged from the top outlet pipe 113. In this system, through the first flue 41 and the second flue 42, even if one flue fails, one flue can still be used, ensuring continuity. The baffle plate increases the collision frequency between flue gas and droplets, improving denitrification efficiency. The spray head 5111 forms fine droplets under a pressure of 0.4-0.6 MPa, increasing the specific surface area by 5 times. The first filter screen 5221 (80 mesh) is used to intercept particles >100μm, such as CaSO4 crystals, and the second filter screen 5222 (200 mesh) removes particles >50μm, such as unreacted CaCO3. The stirring end 53 adopts a dynamic mixing method. The stirring blade 533 is used to generate radial flow to prevent bottom deposition, and the rotating blade 5342 is used to form axial vortex to improve mixing uniformity. This device is simple to operate and has high flue gas treatment efficiency, greatly improving the working efficiency of low-temperature denitrification equipment.

[0044] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A low-temperature denitration device for hazardous waste incineration flue gas, characterized by, include: The denitrification tower body has multiple pipelines installed on it; The reaction shell is disposed inside the denitrification tower body, and has an air inlet and an air outlet at its upper and lower ends, respectively. A liquid storage tank is disposed inside the reaction tank, with its end extending to the outside of the denitrification tower body, and forming a flue gas duct inside the reaction tank; The spraying mechanism includes a spraying end, a return end, and an agitation end. One end of the spraying end is connected to the liquid storage tank, and the other end is located in the flue gas duct for spraying the flue gas. The return end is located at the bottom of the denitrification tower for collecting the sprayed liquid and reintroducing it into the liquid storage tank. The agitation end is located outside the denitrification tower for agitating the liquid inside the liquid storage tank.

2. The low-temperature denitrification device for hazardous waste incineration flue gas according to claim 1, characterized in that: The pipeline includes a flue gas inlet pipe, an ozone pipe, and a flue gas outlet pipe; the flue gas inlet pipe and the ozone pipe are respectively located on both sides of the denitrification tower body, and the flue gas outlet pipe is located at the top of the denitrification tower body.

3. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 1, characterized in that: The exhaust duct includes a first flue and a second flue, and multiple baffles are installed inside the first flue and the second flue.

4. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 3, characterized in that: The spray end includes a diversion pipe, a water pump, and a water suction pipe. The water pump is connected to the liquid storage tank through the water suction pipe. The discharge end of the water pump is connected to the diversion pipe. The end of the diversion pipe extends into the first flue and the second flue. Several spray heads are provided on the diversion pipe.

5. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 1, characterized in that: The reflux end includes two limiting blocks, which are symmetrically arranged on the inner wall of the denitrification tower, and a filter element is provided between the two limiting blocks.

6. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 5, characterized in that: The filter element includes a first filter and a second filter, which are arranged from top to bottom between the two limiting blocks.

7. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 5, characterized in that: The reflux end also includes a reflux pump, a first pipe, and a second pipe; the reflux pump is located outside the denitrification tower body, and the first pipe and the second pipe are respectively connected to the reflux pump, the first pipe extends into the liquid storage shell, and the second pipe extends into the lower end of the inner cavity of the denitrification tower body.

8. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 1, characterized in that: The stirring end includes a stirring motor, a shaft, and stirring blades; the stirring motor is located outside the denitrification tower body, and the output end of the stirring motor is connected to the shaft body, one axial end of the shaft body extends into the liquid storage shell, and several stirring blades are arranged circumferentially on the outer wall of the shaft body.

9. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 8, characterized in that: Each of the stirring blades has a notch, and a rotatable rotating shaft is provided in the notch, with several rotating blades connected to the rotating shaft.

10. A low-temperature denitrification device for hazardous waste incineration flue gas according to claim 1, characterized in that: The liquid storage tank is provided with an inlet and a outlet at its upper and lower ends, respectively, and valves are provided on the inlet and the outlet.

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