A combined denitration device for flue gas treatment

Abstract

The utility model provides a kind of for calcination flue gas treatment's combined denitration device, comprising: dust removal component, heat exchange component and combined denitration device;The dust removal component, heat exchange component and combined denitration device are sequentially communicated along flue gas direction;The heat exchange component includes condenser and heat exchanger, the inlet of the condenser is communicated with the outlet of dust removal component, the heat exchanger is provided with gas inlet, gas outlet, tail gas port and exhaust port, the gas inlet is communicated with the outlet of condenser, the gas outlet is communicated with the inlet of denitration device, the tail gas port is communicated with the outlet of denitration device;The gas inlet and gas outlet heat exchange pipeline communication, the tail gas port and exhaust port are communicated by exhaust pipeline, and the heat exchange pipeline and exhaust pipeline form heat exchange structure by the heat exchange channel in the heat exchanger shell.The utility model utilizes condenser and tubular heat exchanger to recover waste heat and reduce energy consumption, realize efficient purification and energy rational utilization.

Description

Technical Field

[0001] This utility model relates to the field of waste gas treatment, and in particular to a combined denitrification device for treating calcination flue gas. Background Technology

[0002] During the calcination (such as sintering, melting, and roasting) processes in industries such as wear-resistant materials, metallurgy, and building materials, a large amount of nitrogen oxides (NOx) are generated. x ) of the flue gas, of which NO x Concentrations can typically reach 500-1500 mg / m³ 3 Direct emissions would exacerbate environmental problems such as acid rain and photochemical smog. Therefore, denitrification treatment is necessary to meet the "Emission Standard of Air Pollutants for Industrial Furnaces and Kilns" (GB9078-1996) and local ultra-low emission requirements (such as NO in some areas). x Emission limit ≤50mg / m³ 3 Currently, among the mainstream denitrification technologies, selective non-catalytic reduction (SNCR) is adopted by some companies because it does not require a catalyst and has low initial investment. However, it relies on a high-temperature reaction window of 800-1100℃, while the temperature of the calcination flue gas flues greatly (often deviating from the optimal temperature range due to changes in material batches and combustion intensity), resulting in a denitrification efficiency of only 30%-50%. Furthermore, it is prone to ammonia escape (concentration can reach 10-20ppm) due to uneven injection of reducing agent, causing corrosion of subsequent equipment or ammonium salt deposition.

[0003] While selective catalytic reduction (SCR) can achieve denitrification efficiencies of over 80%, it has significant limitations: medium-temperature SCR (300-400℃) requires a heating device to maintain the reaction temperature, resulting in high energy consumption; low-temperature SCR (150-300℃) catalysts (such as vanadium-titanium based ones) are easily poisoned by SO2 and dust in the flue gas—the dust content in the calcination flue gas can reach 100-500 g / m³. 3 Furthermore, the dust contains a large amount of wear-resistant material debris (such as Al2O3 and SiC particles), which can directly wear down the catalyst surface or clog the pores, resulting in a shortened catalyst lifespan of 6-12 months and a surge in maintenance costs.

[0004] Existing combined denitrification technologies (such as SNCR+SCR) still have compatibility issues: On the one hand, the flue gas temperature after SNCR pretreatment often drops to 200-250℃, which does not match the temperature requirements of medium-temperature SCR, requiring additional heating (increasing energy consumption by 10%-20%). On the other hand, the structure has not been optimized for the high dust and high fluctuation characteristics of calcination flue gas. For example, incomplete dust filtration can lead to catalyst blockage, or the waste heat of high-temperature flue gas may not be recovered, resulting in energy waste. In addition, existing devices mostly rely on external quantitative addition of reducing agents (such as urea and ammonia) without adjusting the dosage according to the composition of the flue gas itself, which can easily lead to excessive or insufficient reducing agents, further affecting denitrification efficiency. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a combined denitrification device for the treatment of calcination flue gas. It uses a series of cyclone separators to efficiently remove dust to protect downstream equipment, and utilizes a condenser and tubular heat exchanger to recover waste heat and reduce energy consumption. The combined denitrification device, which combines HNCR and LSCR in series and is designed with temperature control and catalyst carrier to improve denitrification efficiency, can adapt to the characteristics of high dust and high temperature fluctuations in calcination flue gas, reduce operation and maintenance costs, and achieve efficient purification and rational energy utilization.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A combined denitrification device for treating calcination flue gas is provided, comprising: a dust removal component, a heat exchange component, and a combined denitrification device; the dust removal component, the heat exchange component, and the combined denitrification device are connected sequentially along the flue gas direction, and the dust removal component is capable of separating particulate matter in the flue gas;

[0008] The heat exchange assembly includes a condenser and a heat exchanger. The inlet of the condenser is connected to the outlet of the dust removal assembly and can separate heat and water vapor in the flue gas. The heat exchanger is provided with an air inlet, an air outlet, a tail gas outlet, and a flue gas outlet. The air inlet is connected to the outlet of the condenser, the air outlet is connected to the inlet of the denitrification device, the tail gas outlet is connected to the outlet of the denitrification device, and the flue gas outlet can discharge the purified flue gas. The air inlet and the air outlet are connected through heat exchange pipes inside the heat exchanger, and the tail gas outlet and the flue gas outlet are connected through flue gas pipes inside the heat exchanger. The heat exchange pipes and the flue gas pipes form a heat exchange structure through heat exchange channels inside the heat exchanger shell to heat up the flue gas in the heat exchange pipes.

[0009] Preferably, the combined denitrification device includes an HNCR denitrification device and an LSCR denitrification device, which are connected in series along the flue gas direction. The inlet of the HNCR denitrification device is connected to the outlet of the heat exchanger, and the outlet of the LSCR denitrification device is connected to the exhaust port of the heat exchanger.

[0010] Preferably, a temperature control valve is installed on the connecting pipeline between the HNCR denitrification device and the LSCR denitrification device. The temperature control valve can adjust the temperature of the flue gas discharged from the temperature control valve in real time according to the inlet flue gas temperature of the LSCR denitrification device.

[0011] Preferably, the HNCR denitrification device includes an incinerator, a cylinder, and a reducing agent addition device. The cylinder is wrapped around the outside of the incinerator and forms a flue gas channel with the incinerator. The two ends of the channel are respectively provided with a flue gas inlet and a flue gas outlet. The flue gas inlet is located at the top of the cylinder, and the flue gas outlet is located at the bottom of the cylinder and is connected to a temperature control valve. The reducing agent addition device is located at the top of the cylinder and can spray reducing agent into the cylinder.

[0012] Preferably, the cylinder is provided with a catalytic carrier made of special silicon carbide porous ceramic. The catalytic carrier has a honeycomb structure and is fixed in the flue gas channel inside the cylinder, so that the flue gas can pass through the honeycomb pores of the catalytic carrier and be discharged from the flue gas outlet at the lower end of the cylinder.

[0013] Preferably, the reducing agent adding device includes a reducing agent storage chamber, a delivery pipeline and a spray gun. The reducing agent storage chamber is connected to the spray gun through the delivery pipeline, and a control valve is provided on the delivery pipeline. The spray gun extends through the flange interface at the top of the cylinder into the annular flue gas channel, and an atomizing nozzle is provided at the end of the spray gun. The nozzle faces the direction of the special silicon carbide porous ceramic catalyst carrier.

[0014] Preferably, the dust removal assembly includes at least two cyclone separators connected in series, with a material cylinder at the bottom of each cyclone separator, and a butterfly valve is provided between the material cylinder and the conical bottom of the cyclone separator.

[0015] Preferably, the cyclone separator includes a primary cyclone separator and a secondary cyclone separator, which are connected in series along the flue gas direction via a guide pipe and are capable of separating particles of different sizes sequentially.

[0016] Preferably, the heat exchanger is a tubular heat exchanger, including an outer shell and several heat exchange pipes and several exhaust pipes, wherein the heat exchange pipes and exhaust pipes are arranged in a cross-flow configuration within the outer shell.

[0017] Preferably, the exhaust port of the heat exchanger is connected to a high-pressure blower via a pipe.

[0018] The beneficial effects of this utility model are:

[0019] This utility model provides a combined denitrification device for treating calcination flue gas. The dust removal component adopts a series of primary and secondary cyclone separators, combined with a bottom material cylinder and butterfly valve, which can efficiently separate particles of different sizes (including a large number of wear-resistant material fragments) in calcination flue gas, avoid shortening the life of the catalyst in the subsequent denitrification device due to dust wear or blockage, and significantly reduce operation and maintenance costs.

[0020] In the heat exchange assembly, the condenser separates water vapor and heat from the flue gas, and the tubular heat exchanger realizes waste heat recovery through the heat exchange pipelines arranged in a cross-flow manner with the flue gas pipeline. The waste heat of the purified flue gas is used to heat the flue gas to be treated, reducing additional heating energy consumption and improving energy utilization.

[0021] The combined denitrification unit adopts a series design of HNCR and LSCR. The special silicon carbide porous ceramic catalyst carrier in the HNCR, together with the precise reducing agent spray gun, enhances the contact reaction effect between flue gas and reducing agent. The temperature control valve before the LSCR can adjust the inlet flue gas temperature in real time to adapt to the low-temperature catalytic reaction. The two work together to improve the denitrification efficiency, adapt to the large temperature fluctuation of calcination flue gas, and reduce the waste of reducing agent and secondary pollution caused by ammonia escape. It takes into account both environmental protection and economy, and effectively meets the needs of calcination flue gas treatment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a combined denitrification device for treating calcination flue gas according to Embodiment 1 of this utility model.

[0023] Figure 2 This is a schematic diagram of the connection structure of the dust removal component and the heat exchange component in Embodiment 1 of this utility model.

[0024] Figure 3 This is a schematic diagram of the combined denitrification device in Embodiment 2 of this utility model.

[0025] In the diagram: 1. Dust removal assembly; 11. Primary cyclone separator; 12. Secondary cyclone separator; 2. Condenser; 3. Heat exchanger; 31. Air inlet; 32. Air outlet; 33. Tail gas outlet; 34. Flue gas outlet; 4. HNCR denitrification device; 41. Incinerator; 42. Cylinder; 43. Reducing agent addition device; 431. Reducing agent storage bin; 432. Conveying pipeline; 433. Spray gun; 434. Control valve; 5. LSCR denitrification device; 6. Temperature control valve; 7. Feed cylinder; 8. Butterfly valve.

[0026] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Example 1

[0029] like Figures 1-3 As shown, a combined denitrification device for treating calcination flue gas includes: a dust removal component 1, a heat exchange component, and a combined denitrification device; the dust removal component 1, the heat exchange component, and the combined denitrification device are connected sequentially along the flue gas direction, and the dust removal component 1 is capable of separating particulate matter in the flue gas;

[0030] The heat exchange assembly includes a condenser 2 and a heat exchanger 3. The inlet of the condenser 2 is connected to the outlet of the dust removal assembly 1 and can separate heat and water vapor in the flue gas. The heat exchanger 3 is provided with an air inlet 31, an air outlet 32, a tail gas outlet 33, and a flue gas outlet 34. The air inlet 31 is connected to the outlet of the condenser 2, the air outlet 32 ​​is connected to the inlet of the denitrification device, the tail gas outlet 33 is connected to the outlet of the denitrification device, and the flue gas outlet 34 can discharge the purified flue gas. The air inlet 31 and the air outlet 32 ​​are connected through heat exchange pipes inside the heat exchanger 3, and the tail gas outlet 33 and the flue gas outlet 34 are connected through flue gas pipes inside the heat exchanger 3. The heat exchange pipes and the flue gas pipes form a heat exchange structure through heat exchange channels inside the shell of the heat exchanger 3 to heat up the flue gas in the heat exchange pipes.

[0031] It should be noted that the device consists of a dust removal component 1, a heat exchange component, and a combined denitrification device, which are connected sequentially along the flue gas flow to form a continuous flue gas treatment path. The dust removal component 1 is responsible for separating particulate matter from the flue gas and removing impurities such as wear-resistant material debris generated during calcination, providing a clean flue gas environment for subsequent treatment. The heat exchange component includes a condenser 2 and a heat exchanger 3. The inlet of the condenser 2 is connected to the outlet of the dust removal component 1. It utilizes condensation to condense water vapor in the flue gas, thereby separating the water vapor from the flue gas and releasing some of the heat carried in the flue gas. After treatment by the condenser 2, the moisture content in the flue gas is reduced, avoiding the impact of excessive water vapor on the heat exchange efficiency of the subsequent heat exchanger 3 and the catalyst performance in the combined denitrification device, providing a more suitable flue gas environment for waste heat recovery and the denitrification reaction of the subsequent heat exchange component. The heat exchanger 3 is equipped with an inlet 31, an outlet 32, a tail gas outlet 33, and a flue gas outlet 34. The inlet 31 is connected to the condenser 2. The outlet of heat exchanger 2 is connected to allow the condensed flue gas to enter the heat exchange pipeline inside heat exchanger 3. The outlet 32 ​​is connected to the inlet of the combined denitrification device to transport the flue gas to be denitrified. The tail gas outlet 33 is connected to the outlet of the combined denitrification device to receive the purified flue gas after denitrification and allow it to enter the exhaust pipeline of heat exchanger 3. The heat exchange pipeline and the exhaust pipeline form a heat exchange structure through the heat exchange channel inside the shell of heat exchanger 3. The waste heat of the purified flue gas in the exhaust pipeline is used to raise the temperature of the flue gas to be treated in the heat exchange pipeline to meet the temperature requirements of the subsequent denitrification reaction and improve energy utilization. Finally, the purified flue gas is discharged through exhaust outlet 34. Through the synergistic effect of dust removal, heat recovery and denitrification, the high temperature flue gas characteristics are used to improve the denitrification efficiency, and the waste heat recovery is used to improve the energy utilization rate, which meets the needs of calcination flue gas treatment.

[0032] like Figure 3 As shown, the combined denitrification device includes an HNCR denitrification device 4 and an LSCR denitrification device 5. The HNCR denitrification device 4 and the LSCR denitrification device 5 are connected in series along the flue gas direction. The inlet of the HNCR denitrification device 4 is connected to the outlet 32 ​​of the heat exchanger 3, and the outlet of the LSCR denitrification device 5 is connected to the exhaust gas outlet 33 of the heat exchanger 3.

[0033] It should be noted that the combined denitrification device adopts a structure in which HNCR denitrification device 4 and LSCR denitrification device 5 are connected in series along the flue gas direction. It is a synergistic denitrification system that combines high-temperature selective non-catalytic reduction (HNCR) technology and low-temperature selective catalytic reduction (LSCR) technology. The flue gas first flows through HNCR denitrification device 4 for preliminary denitrification, and then enters LSCR denitrification device 5 for further denitrification. Through the synergistic effect of the two denitrification devices, a progressive treatment is formed, which improves the overall denitrification efficiency and meets the treatment requirements of calcination flue gas. The inlet of HNCR denitrification device 4 is connected to the outlet 32 ​​of heat exchanger 3 to receive the flue gas to be denitrified after being treated by heat exchanger 3. The outlet of LSCR denitrification device 5 is connected to the tail gas port 33 of heat exchanger 3 to transport the flue gas after two-stage denitrification treatment to heat exchanger 3, absorb the heat energy in the purified flue gas, and then discharge it through exhaust port 34.

[0034] A temperature control valve 6 is installed on the connecting pipeline between the HNCR denitrification device 4 and the LSCR denitrification device 5. The temperature control valve 6 can adjust the temperature of the flue gas discharged from the temperature control valve 6 in real time according to the inlet flue gas temperature of the LSCR denitrification device 5.

[0035] It should be noted that a temperature control valve 6 is installed on the connecting pipeline between the HNCR denitrification unit 4 and the LSCR denitrification unit 5. The core function of this temperature control valve 6 is to adjust the temperature of the flue gas discharged from the LSCR denitrification unit 5 in real time according to the inlet flue gas temperature, so as to ensure that the flue gas temperature entering the LSCR denitrification unit 5 is suitable for the temperature conditions required for its denitrification reaction. By precisely controlling the flue gas temperature, the two denitrification units can achieve efficient synergy in series treatment, ensuring the stable operation of the overall denitrification system.

[0036] The HNCR denitrification device 4 includes an incinerator 41, a cylindrical body 42, and a reducing agent addition device 43. The cylindrical body 42 is wrapped around the outside of the incinerator 41 and forms a flue gas passage with the incinerator 41. The two ends of the passage are respectively provided with a flue gas inlet and a flue gas outlet. The flue gas inlet is located at the top of the cylindrical body 42, and the flue gas outlet is located at the bottom of the cylindrical body 42 and is connected to the temperature control valve 6. The reducing agent addition device 43 is located at the top of the cylindrical body 42 and can spray reducing agent into the interior of the cylindrical body 42.

[0037] It should be noted that the incinerator 41, as a high-temperature heat source, provides the necessary high-temperature environment for the denitrification reaction (a high-temperature reaction window adapted to HNCR technology); the cylinder 42 is arranged in an enclosing manner outside the incinerator 41, forming an annular flue gas channel between itself and the outer wall of the incinerator 41. This channel provides a closed space for the flow and reaction of flue gas, ensuring the stability of the high-temperature environment and the orderly flow of flue gas; the two ends of the flue gas channel are respectively provided with a flue gas inlet and a flue gas outlet, with the inlet located at the top of the cylinder 42 and the outlet located at the bottom of the cylinder 42, forming an "upward" configuration. The bottom-outlet flue gas flow path allows the flue gas to flow fully through the reaction zone within the channel. The flue gas outlet at the bottom is connected to the temperature control valve 6, facilitating the delivery of the flue gas, which has undergone preliminary HNCR treatment, to the subsequent LSCR denitrification unit 5. The temperature control valve 6 also regulates the flue gas temperature to suit the low-temperature catalytic reaction. The reducing agent addition device 43 is located at the top of the cylinder 42, on the same side as the flue gas inlet. It can precisely spray the reducing agent (such as urea solution) into the flue gas channel inside the cylinder 42, allowing it to react with nitrogen oxides (NOx) in the flue gas under high-temperature conditions. x A preliminary reduction reaction occurs.

[0038] The cylinder 42 is equipped with a catalytic carrier made of special silicon carbide porous ceramic. The catalytic carrier has a honeycomb structure and is fixed in the flue gas channel inside the cylinder 42, so that the flue gas can pass through the honeycomb pores of the catalytic carrier and be discharged from the flue gas outlet at the lower end of the cylinder 42.

[0039] It should be noted that the catalyst support is made of special porous silicon carbide ceramic. This material, with its high temperature resistance, wear resistance and strong chemical stability, can adapt to the high temperature environment of calcination flue gas (suitable for the high temperature conditions required for HNCR reaction) and the scouring of wear-resistant material debris (such as Al2O3 and SiC particles) contained in the flue gas, avoiding structural damage or performance degradation during long-term use. In addition, the honeycomb structure can significantly increase the contact area with the flue gas, and at the same time, it can allow the flue gas to form a dispersed flow through the honeycomb pores, prolonging the residence time of the flue gas in the support, ensuring that the flue gas fully contacts and reacts with the reducing agent sprayed by the reducing agent addition device 43.

[0040] The reducing agent addition device 43 includes a reducing agent storage chamber 431, a delivery pipeline 432, and a spray gun 433. The reducing agent storage chamber 431 is connected to the spray gun 433 through the delivery pipeline 432, and a control valve 434 is provided on the delivery pipeline 432. The spray gun 433 extends through the flange interface at the top of the cylinder 42 into the annular flue gas channel. The end of the spray gun 433 is provided with an atomizing nozzle, which faces the direction of the special silicon carbide porous ceramic catalyst carrier.

[0041] It should be noted that the reducing agent storage chamber 431 is used to store the reducing agent required for the denitrification reaction. The reducing agent is stably delivered to the spray gun 433 through the delivery pipeline 432. The control valve 434 installed on the delivery pipeline 432 can dynamically adjust the amount of reducing agent delivered according to the concentration of nitrogen oxides in the flue gas, so as to avoid efficiency loss and secondary pollution caused by excessive or insufficient amount.

[0042] The dust removal assembly 1 includes at least two cyclone separators connected in series. The bottom of the cyclone separator is provided with a material cylinder 7, and a butterfly valve 8 is provided between the material cylinder 7 and the conical bottom of the cyclone separator.

[0043] It should be noted that the dust removal component 1 uses at least two cyclone separators connected in series. Through multi-stage separation, it filters a large amount of wear-resistant material debris (such as Al2O3 and SiC particles) and other particulate matter contained in the calcination flue gas in stages. The first-stage cyclone separator can separate larger-diameter particles, while the subsequent stage further separates smaller-diameter particles, significantly improving the overall dust removal efficiency. The material cylinder 7 is used to collect the separated dust. The butterfly valve 8 set between the material cylinder 7 and the conical bottom of the cyclone separator can control the timing of dust discharge by opening and closing the valve, ensuring that the dust can be discharged from the separator in a timely manner and preventing flue gas leakage during the discharge process.

[0044] like Figure 2 As shown, the cyclone separator includes a primary cyclone separator 11 and a secondary cyclone separator 12. The primary cyclone separator 11 and the secondary cyclone separator 12 are connected in series along the flue gas direction through a guide pipe and can sequentially separate particles of different sizes.

[0045] It should be noted that the cyclone separator explicitly adopts a combined structure of a primary cyclone separator 11 and a secondary cyclone separator 12. These two separators are connected in series along the flue gas flow direction via guide pipes, forming a progressive, staged dust removal path. The flue gas first enters the primary cyclone separator 11, where centrifugal force separates larger particles (such as larger wear-resistant material fragments). The flue gas after primary separation then enters the secondary cyclone separator 12 through the guide pipes, where smaller residual particles are further separated. This "primary coarse separation + secondary fine separation" staged design is suitable for calcination flue gas with high dust content (up to 100-500 g / m³). 3 Furthermore, its characteristics of containing a large amount of wear-resistant material debris of different particle sizes (such as Al2O3 and SiC particles) significantly improve the overall dust removal efficiency and avoid the problem of incomplete separation caused by excessive load on a single separator.

[0046] The heat exchanger 3 is a tubular heat exchanger 3, including an outer shell and several heat exchange pipes and several exhaust pipes, wherein the heat exchange pipes and exhaust pipes are arranged in a cross-flow manner within the outer shell.

[0047] It should be noted that the outer shell provides a supporting frame and sealed space for the overall structure, reducing heat loss during the exchange process and ensuring heat exchange efficiency. The heat exchange pipes are used to circulate the flue gas to be denitrated after being treated by condenser 2, while the exhaust pipes are used to circulate the purified flue gas after being treated by the combined denitrification device. The two types of pipes are arranged in a cross-flow configuration within the outer shell: that is, the flow direction of the flue gas to be treated and the purified flue gas is opposite. This arrangement can significantly increase the contact area and heat exchange time between the two types of flue gas, enhancing the waste heat recovery effect. Through this structure, the waste heat of the purified flue gas in the exhaust pipe can be efficiently transferred to the flue gas to be treated in the heat exchange pipe, raising the temperature of the flue gas to be treated to a range suitable for subsequent denitrification reactions, reducing additional heating energy consumption, improving energy utilization, and perfectly meeting the needs for waste heat recovery and temperature control in calcination flue gas treatment, providing suitable temperature conditions for the efficient operation of the combined denitrification device.

[0048] The exhaust port 34 of the heat exchanger 3 is connected to a high-pressure blower via a pipe.

[0049] It should be noted that the exhaust port 34 of the heat exchanger 3 is connected to the high-pressure blower via a pipeline. This structural design forms the final emission path for the purified flue gas, allowing the clean flue gas, after being treated by the combined denitrification device and having its waste heat recovered in the heat exchanger 3, to be safely and compliantly discharged through this channel. The pipeline connection ensures the continuity of flue gas emission, preventing the purified flue gas from stagnating within the device and affecting system operating efficiency. Simultaneously, the connection with the high-pressure blower ensures that flue gas emissions meet environmental protection requirements such as the "Emission Standard of Air Pollutants for Industrial Furnaces and Kilns," adapting to the end-of-pipe emission requirements of calcination flue gas treatment. This design, as the final stage of the entire flue gas treatment process, works in conjunction with the front-end dust removal, heat exchange, and denitrification components to form a complete closed loop of "treatment-purification-emission," ensuring the overall environmental friendliness and stability of the device's operation.

[0050] The working principle and usage method of a combined denitrification device for treating calcination flue gas in this embodiment are as follows:

[0051] This embodiment provides a combined denitrification device for treating calcination flue gas. The dust-laden flue gas generated during calcination first enters the dust removal component 1, where large-diameter particles (such as wear-resistant material fragments) are separated by a primary cyclone separator 11. It then enters a secondary cyclone separator 12 through a guide pipe for further separation of small-diameter dust particles. The clean flue gas after two stages of separation reduces the risk of wear and blockage to subsequent equipment. The separated dust is collected and discharged through a bottom feed cylinder 7 and a butterfly valve 8. The dust-removed flue gas enters the heat exchange component, where water vapor and some heat are first separated by a condenser 2 to prevent water vapor from affecting subsequent reactions. It then enters the heat exchange pipeline of a tubular heat exchanger 3. Simultaneously, the purified flue gas after denitrification enters the exhaust pipeline of the heat exchanger 3. The two types of pipelines are connected by a cross-flow manifold. The system utilizes the waste heat from the purified flue gas to heat the flue gas to be treated, raising it to a temperature suitable for the denitrification reaction without additional energy consumption. The heated flue gas enters the combined denitrification device, first flowing through the HNCR denitrification device 4. The cylinder 42 surrounds the incinerator 41 to form a high-temperature channel. The reducing agent addition device 43 sprays the reducing agent onto the special silicon carbide porous ceramic honeycomb catalyst carrier through the spray gun 433, where it undergoes a preliminary reaction with nitrogen oxides at high temperature. The flue gas treated by HNCR is adjusted to a suitable temperature by the temperature control valve 6 before entering the LSCR denitrification device 5 for deep denitrification. Finally, the purified flue gas re-enters the exhaust pipe of the heat exchanger 3 to complete heat exchange, and is finally discharged through the exhaust port 34 via a pipeline connected to a high-pressure blower, achieving compliant emissions.

[0052] Before use, first check the sealing of each component connection (such as the flange interface of the cyclone separator, the pipe interface of heat exchanger 3, and the channel connection of the denitrification device) to ensure there is no flue gas leakage; confirm that the bottom butterfly valve 8 of the primary and secondary cyclone separators 12 of the dust removal component 1 is in the closed state and the material cylinder 7 is empty; check that there are no debris blocking the condenser 2 and tubular heat exchanger 3 of the heat exchange component, and that the heat exchange pipeline and the flue gas pipeline are unobstructed; verify that the reducing agent of the HNCR denitrification device 4 in the combined denitrification device is sufficient and that the delivery pipe is in good condition. Control valve 434 and atomizing nozzle 433 of spray gun are functioning normally, and the catalyst module of LSCR denitrification unit 5 is installed in place; confirm that the valve connecting the exhaust port 34 of heat exchanger 3 to the high-pressure blower is open; then turn on dust removal component 1 to introduce the dust-laden flue gas generated by calcination into the first-stage cyclone separator 11, using centrifugal force to separate large-diameter particles (such as Al2O3 and SiC debris), and the separated flue gas enters the second-stage cyclone separator 12 through the guide pipe to further remove small-diameter dust. Periodically (based on dust accumulation), open the butterfly valve 8 at the bottom of the two-stage cyclone separator to discharge the dust collected in the feed cylinder 7 and prevent blockage. The dust-treated flue gas enters the condenser 2, where water vapor and some heat are separated through condensation (reducing the impact of water vapor on downstream equipment). The treated flue gas enters the heat exchange pipeline of the tubular heat exchanger 3, and the heat exchanger 3 is started simultaneously, allowing the purified flue gas after denitrification to enter the exhaust pipeline. Heat exchange is completed through the cross-flow pipeline, utilizing the waste heat of the purified flue gas to heat the waste gas. The flue gas is treated to raise its temperature; the incinerator 41 of the HNCR denitrification unit 4 is started, and the cylinder 42 is heated to the high-temperature reaction window (suitable for HNCR reaction). The reducing agent addition device 43 is turned on: the flow rate of the reducing agent (such as urea solution) is adjusted by the control valve 434 through the delivery pipeline 432, and the spray gun 433 sprays the atomized reducing agent into the special silicon carbide porous ceramic honeycomb catalyst carrier in the annular flue gas channel through the flange interface at the top of the cylinder 42. The flue gas reacts with the reducing agent at high temperature, and NO is initially removed. x The flue gas treated by HNCR passes through temperature control valve 6, and is adjusted to a suitable temperature (150-300℃) according to the inlet temperature requirements of LSCR denitrification unit 5 before entering LSCR denitrification unit 5 for deep denitrification, further reducing NO. x Concentration; finally, the purified flue gas after deep denitrification enters the exhaust pipe of heat exchanger 3, and after exchanging heat with the flue gas to be treated in the heat exchange pipe, it is connected to the high-pressure blower through the exhaust port 34 of heat exchanger 3 to achieve compliant emissions.

[0053] Finally, it should be noted that the above description is only a preferred embodiment of this utility model and is used only to illustrate the technical solution of this utility model, and is not intended to limit the protection scope of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model are included within the protection scope of this utility model.

[0054] In the description of this utility model, it should be understood that the terms "upper", "lower", "upper end", "lower end", "upper surface", "lower surface", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model 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 utility model.

[0055] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" 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 utility model based on the specific circumstances.

Claims

1. A combined denitrification device for treating calcination flue gas, comprising: The dust removal component (1), heat exchange component, and combined denitrification device are connected sequentially along the flue gas flow direction, and the dust removal component (1) is capable of separating particulate matter in the flue gas, characterized in that: The heat exchange assembly includes a condenser (2) and a heat exchanger (3). The inlet of the condenser (2) is connected to the outlet of the dust removal assembly (1) and can separate heat and water vapor in the flue gas. The heat exchanger (3) is provided with an air inlet (31), an air outlet (32), a tail gas outlet (33), and a flue gas outlet (34). The air inlet (31) is connected to the outlet of the condenser (2), the air outlet (32) is connected to the inlet of the denitrification device, and the tail gas outlet (34) is connected to the outlet of the dust removal assembly (1). 3) The exhaust port (34) is connected to the outlet of the denitrification device and can discharge the purified flue gas. The inlet (31) and outlet (32) are connected through the heat exchange pipeline inside the heat exchanger (3). The tail gas port (33) and exhaust port (34) are connected through the exhaust pipeline inside the heat exchanger (3). The heat exchange pipeline and the exhaust pipeline form a heat exchange structure through the heat exchange channel inside the heat exchanger (3) shell to heat up the flue gas in the heat exchange pipeline.

2. The combined denitrification device for treating calcination flue gas as described in claim 1, characterized in that: The combined denitrification device includes an HNCR denitrification device (4) and an LSCR denitrification device (5). The HNCR denitrification device (4) and the LSCR denitrification device (5) are connected in series along the flue gas direction. The inlet of the HNCR denitrification device (4) is connected to the outlet (32) of the heat exchanger (3), and the outlet of the LSCR denitrification device (5) is connected to the exhaust gas port (33) of the heat exchanger (3).

3. The combined denitrification device for treating calcination flue gas as described in claim 2, characterized in that: A temperature control valve (6) is installed on the connecting pipeline between the HNCR denitrification device (4) and the LSCR denitrification device (5). The temperature control valve (6) can adjust the temperature of the flue gas discharged from the temperature control valve (6) in real time according to the inlet flue gas temperature of the LSCR denitrification device (5).

4. The combined denitrification device for treating calcination flue gas as described in claim 3, characterized in that: The HNCR denitrification device (4) includes an incinerator (41), a cylinder (42), and a reducing agent addition device (43). The cylinder (42) is wrapped around the outside of the incinerator (41) and forms a flue gas passage with the incinerator (41). The two ends of the passage are respectively provided with a flue gas inlet and a flue gas outlet. The flue gas inlet is located at the top of the cylinder (42), and the flue gas outlet is located at the bottom of the cylinder (42) and is connected to the temperature control valve (6). The reducing agent addition device (43) is located at the top of the cylinder (42) and can spray reducing agent into the cylinder (42).

5. A combined denitrification device for treating calcination flue gas as described in claim 4, characterized in that: The cylinder (42) is provided with a catalytic carrier made of special silicon carbide porous ceramic. The catalytic carrier has a honeycomb structure and is fixed in the flue gas channel inside the cylinder (42), so that the flue gas can pass through the honeycomb holes of the catalytic carrier and be discharged from the flue gas outlet at the lower end of the cylinder (42).

6. The combined denitrification device for treating calcination flue gas as described in claim 5, characterized in that: The reducing agent addition device (43) includes a reducing agent storage chamber (431), a delivery pipeline (432), and a spray gun (433). The reducing agent storage chamber (431) is connected to the spray gun (433) through the delivery pipeline (432), and a control valve (434) is provided on the delivery pipeline (432). The spray gun (433) extends through the flange interface at the top of the cylinder (42) into the annular flue gas channel. The end of the spray gun (433) is provided with an atomizing nozzle, which faces the direction of the special silicon carbide porous ceramic catalyst carrier.

7. The combined denitrification device for treating calcination flue gas as described in claim 1, characterized in that: The dust removal assembly (1) includes at least two cyclone separators connected in series. The bottom of the cyclone separator is provided with a material cylinder (7), and a butterfly valve (8) is provided between the material cylinder (7) and the conical bottom of the cyclone separator.

8. A combined denitrification device for treating calcination flue gas as described in claim 7, characterized in that: The cyclone separator includes a primary cyclone separator (11) and a secondary cyclone separator (12). The primary cyclone separator (11) and the secondary cyclone separator (12) are connected in series along the flue gas direction through a guide pipe and can sequentially separate particles of different sizes.

9. A combined denitrification device for treating calcination flue gas as described in claim 1, characterized in that: The heat exchanger (3) is a tubular heat exchanger (3), including an outer shell and several heat exchange pipes and several exhaust pipes, wherein the heat exchange pipes and exhaust pipes are arranged in a cross-flow pattern within the outer shell.

10. A combined denitrification device for treating calcination flue gas as described in claim 1, characterized in that: The exhaust port (34) of the heat exchanger (3) is connected to the high-pressure blower through a pipe.

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