Boiler flue gas treatment device

Abstract

The invention discloses a boiler flue gas treatment device which comprises a flue gas inlet pipe and a flue gas outlet pipe which are used for guiding flue gas generated by boiler combustion, the flue gas inlet pipe is sequentially connected with a heat energy recovery assembly and a dust removal, desulfurization and denitrification assembly, and a primary treatment assembly is arranged between the heat energy recovery assembly and the flue gas inlet pipe. Through the heat exchanger, the steam generator and the waste heat recovery pipe additionally arranged at the top end in the heat exchanger, heat energy in boiler flue gas is fully recovered, and the energy utilization rate is increased; the flue gas subjected to heat energy recovery passes through the dust removal, desulfurization and denitrification assembly, pollutants in the flue gas can be effectively removed, tail gas emission reaches strict environmental protection standards, and pollution to the environment is reduced; the primary treatment assembly is additionally arranged, large dust particles in flue gas are intercepted through an interception filter screen plate, dust attached to the interior of the heat exchanger is reduced, meanwhile, the dust in the heat exchanger is effectively removed by adding cleaning liquid, and long-term stable operation of the device is guaranteed.

Description

Technical Field

[0001] The present invention relates to a soot treatment device, in particular to a boiler flue gas treatment device, belonging to the technical field of boiler soot treatment. Background Art

[0002] A boiler is an energy conversion device that outputs steam, high-temperature water or organic heat carrier with a certain amount of thermal energy. In the combustion equipment part, the combustion of fuel continuously releases heat and generates high temperatures. Boiler flue gas refers to a mixture of various gases and particulate matter produced by the boiler during the combustion of fuel.

[0003] After searching, Chinese patent number CN111853735B discloses an industrial flue gas heat recovery boiler based on spiral spraying. When industrial flue gas enters the spiral flue gas pipe, the temperature of the spiral flue gas pipe increases, and at the same time, the water in the water tank is sprayed out through the outlet of the water outlet pipe. The sprayed water contacts the spiral flue gas pipe, vaporizes the water, and produces a large amount of water vapor, thereby realizing heat recovery from the industrial flue gas, thereby saving a large amount of energy and reducing environmental pollution. By setting up the spiral flue gas pipe, the contact area between the industrial flue gas and the spiral flue gas pipe is increased, and the contact area between the industrial flue gas and the water is increased, thereby increasing the speed of water conversion to water vapor per unit time, thereby improving the efficiency of water conversion to water vapor. However, the above patented product only recovers heat from the flue gas. The flue gas also contains pollutants such as dust, sulfides, and nitrogen oxides. Direct discharge will cause serious pollution to the environment and endanger the ecological balance and human health. Summary of the Invention

[0004] The purpose of the present invention is to provide a boiler flue gas treatment device in order to solve the above problems.

[0005] The present invention achieves the above-mentioned object through the following technical solutions: a boiler flue gas treatment device, comprising a flue gas discharge pipe and a flue gas discharge pipe for draining flue gas generated by boiler combustion, the flue gas discharge pipe being sequentially connected to a heat recovery component and a dust removal, desulfurization and denitrification component, and a preliminary treatment component being provided between the heat recovery component and the flue gas discharge pipe;

[0006] The heat recovery component is used to recover and reuse the heat in the soot, and the heat recovery component includes a heat exchanger, a steam generator and a waste heat recovery pipe;

[0007] The dust removal, desulfurization and denitrification component is used to intercept and clean impurities and pollutants in the flue gas after heat exchange. The dust removal, desulfurization and denitrification component includes a bag filter, a desulfurization tower and a denitrification reactor;

[0008] The preliminary treatment component is used to preliminarily intercept impurities in the flue gas, alleviate the adhesion of impurities in the flue gas inside the heat exchanger, and improve the utilization efficiency of the heat exchanger. An interception filter plate is provided between the flue gas discharge pipe and the heat exchanger.

[0009] Preferably, the flue gas discharge pipe and the interception filter plate are both arranged in a semicircular shape, a rotating rod is connected to the center position of the interception filter plate, a scraper plate is connected to the rotating rod close to the side of the flue gas discharge pipe, the rotating rod is located inside the shell of the heat exchanger and a conveyor belt is provided, the flue gas discharge pipe is provided with a collecting pipe near the bottom end of the interception filter plate, a limiting block is provided at one end of the collecting pipe close to the interception filter plate, a driving motor is provided on the limiting block, the execution end of the driving motor is engaged with the internal end of the conveyor belt away from the rotating rod, and a recovery box is provided at the end of the collecting pipe away from the interception filter plate.

[0010] Preferably, a rotating tube is provided inside the heat exchanger, and the rotating tube is vertically arranged inside the heat exchanger, and the upper and lower ends of the rotating tube are respectively connected to the water inlet and the water outlet.

[0011] Preferably, a waste heat recovery pipe is provided inside the top end of the heat exchanger, and the waste heat recovery pipes are arranged in multiple horizontal directions at the top end of the heat exchanger. A diversion pipe is provided in the middle of the multiple waste heat recovery pipes, and a waste heat inlet pipe is provided at the top end of the diversion pipe and on the side of the water inlet. A water outlet pipe is provided on the side of the top end of the heat exchanger and at the connection with the waste heat recovery pipe.

[0012] Preferably, the water outlet and the end of the water outlet pipe away from the heat exchanger are connected to the steam generator.

[0013] Preferably, a cleaning liquid inlet pipe is provided at the top of the heat exchanger, and a cleaning liquid discharge pipe is provided at the bottom of the heat exchanger. Both the cleaning liquid inlet pipe and the cleaning liquid discharge pipe are provided with electric control valves, and the cleaning liquid discharge pipe is connected to a collection box.

[0014] Preferably, the flue gas discharge pipe is arranged at the top of the heat exchanger, and a connecting pipe is provided at the bottom end of the heat exchanger away from the flue gas discharge pipe, and the connecting pipe is connected to the top side of the bag filter.

[0015] Preferably, a plurality of filter bags are provided inside the bag dust collector, and a pulse cleaning device is provided at the top of the bag dust collector.

[0016] Preferably, the bag filter is connected to the desulfurization tower on a side away from the connecting pipe, a denitrification reactor is provided on a side of the desulfurization tower away from the bag filter, and the flue gas exhaust pipe is provided on a side of the denitrification reactor away from the desulfurization tower.

[0017] The present invention has the following beneficial effects:

[0018] 1. Through the heat exchanger, steam generator and the waste heat recovery pipe installed at the top of the heat exchanger, the heat energy in the boiler flue gas is fully recovered, the energy utilization rate is improved, and the energy consumption cost of the enterprise is reduced.

[0019] 2. The flue gas after heat recovery passes through the dust removal, desulfurization and denitrification components, which can effectively remove dust, sulfide, nitrogen oxides and other pollutants in the flue gas, so that the exhaust emissions meet strict environmental protection standards and reduce pollution to the environment.

[0020] 3. A preliminary treatment component is added at the position where the flue gas enters the heat exchanger. The larger dust particles in the flue gas are intercepted by the interception filter plate to reduce the dust adhesion inside the heat exchanger. At the same time, the addition of cleaning fluid can effectively remove the dust inside the heat exchanger, reducing the difficulty and cost of equipment maintenance and ensuring the long-term stable operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a front perspective view of the overall structure of a boiler flue gas treatment device proposed by the present invention;

[0022] Figure 2 This is a rear perspective view of the overall structure of a boiler flue gas treatment device proposed by the present invention;

[0023] Figure 3 This is a three-dimensional diagram of the heat exchanger structure of a boiler flue gas treatment device proposed by the present invention;

[0024] Figure 4 This is a schematic structural diagram of a heat exchanger for a boiler flue gas treatment device proposed by the present invention;

[0025] Figure 5 This is a three-dimensional diagram of the structure of the waste heat water inlet pipe of a boiler flue gas treatment device proposed by the present invention;

[0026] Figure 6 This is a schematic structural diagram of a preliminary treatment component of a boiler flue gas treatment device proposed in the present invention;

[0027] Figure 7 This is a schematic diagram of the internal structure of a bag filter for a boiler flue gas treatment device proposed in the present invention.

[0028] Figure: 1. Flue gas inlet pipe; 2. Flue gas outlet pipe; 3. Heat recovery component; 301. Heat exchanger; 302. Steam generator; 303. Waste heat recovery pipe; 304. Rotating pipe; 305. Water inlet; 306. Water outlet; 307. Waste heat water inlet pipe; 308. Diverter pipe; 309. Water outlet pipe; 4. Dust removal, desulfurization and denitrification components; 401. Bag filter; 402. Filter bag; 403. Pulse Cleaning device; 404, desulfurization tower; 405, denitrification reactor; 5, preliminary treatment component; 501, interception filter plate; 502, collection pipe; 503, recovery box; 504, drive motor; 505, conveyor belt; 506, scraper plate; 507, rotating rod; 508, limit block; 6, cleaning liquid inlet pipe; 601, cleaning liquid discharge pipe; 602, electric control valve; 603, collection box; 7, connecting pipe. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] Example 1:

[0031] Reference Figure 1-6 A boiler flue gas treatment device includes a flue gas discharge pipe 1 and a flue gas discharge pipe 2 for draining flue gas generated by boiler combustion. The flue gas discharge pipe 1 is sequentially connected to a heat recovery component 3 and a dust removal, desulfurization and denitrification component 4. A preliminary treatment component 5 is provided between the heat recovery component 3 and the flue gas discharge pipe 1.

[0032] The heat recovery component 3 is used to recover and reuse the heat in the soot. The heat recovery component 3 includes a heat exchanger 301 , a steam generator 302 and a waste heat recovery pipe 303 .

[0033] A rotating tube 304 is provided inside the heat exchanger 301. The rotating tube 304 is vertically arranged inside the heat exchanger 301. The upper and lower ends of the rotating tube 304 are respectively connected to the water inlet 305 and the water outlet 306. A waste heat recovery pipe 303 is provided inside the top of the heat exchanger 301. The waste heat recovery pipes 303 are arranged in multiple horizontal directions at the top of the heat exchanger 301. A diversion pipe 308 is provided in the middle of the multiple waste heat recovery pipes 303. A waste heat inlet pipe 307 is provided at the top of the diversion pipe 308 and on the side of the water inlet 305. A water outlet pipe 309 is provided on the side of the top of the heat exchanger 301 and at the connection with the waste heat recovery pipe 303.

[0034] In this embodiment, it should be noted that: the flue gas discharge pipe 1 is connected to the chimney of the boiler, so that the flue gas of the boiler enters the heat exchanger 301 along the flue gas discharge pipe 1. The spiral pipe design of the spiral pipe 304 causes the flue gas to continuously change direction during the flow process, increasing the friction with the pipe wall, thereby extending the residence time and enhancing the heat transfer effect.

[0035] At the same time, in order to reduce dust adhesion, the pipe surface of the spiral tube 304 is designed to be smoother, and an air flow uniformity distribution device is added to make the flow of flue gas in the heat exchanger more uniform.

[0036] The heat exchange medium (such as water) enters the spiral tube 304 through the water inlet 305 and interacts thermally with the flue gas. The heat exchange medium (such as water) in the spiral tube 304 in the heat exchanger 301 absorbs heat from the flue gas and heats up. It enters the steam generator 302 through the water outlet 306 at the bottom and is converted into high-temperature and high-pressure steam. The steam can be used for industrial production or domestic heating, thereby realizing the recovery and utilization of heat energy.

[0037] Due to the difference in gas density, part of the hot gas in the flue gas rises and accumulates at the top of the heat exchanger 301. Therefore, the waste heat recovery pipe 303 arranged at the top of the heat exchanger 301 can further recover the remaining low-temperature heat energy in the flue gas.

[0038] The waste heat recovery pipe 303 is a metal pipe that is sealed internally and filled with a specific working medium (such as water, ammonia, etc.). Fins can be added to the waste heat recovery pipe 303 as needed to increase the contact area with the flue gas and improve the heat absorption efficiency.

[0039] The water outlet pipe 309 and the water outlet 306 of the waste heat recovery pipe 303 enter the steam generator 302 and are converted into high-temperature and high-pressure steam, thereby improving the recovery and utilization of heat energy.

[0040] Example 2:

[0041] The difference from the first embodiment is that, referring to Figure 1-2 as well as Figure 7 This embodiment also has the following further contents: the dust removal, desulfurization and denitrification component 4 is used to intercept and clean impurities and pollutants in the flue gas after heat exchange. The dust removal, desulfurization and denitrification component 4 includes a bag filter 401, a desulfurization tower 404 and a denitrification reactor 405. The water outlet 306 and the water outlet pipe 309 are connected to the steam generator 302 at one end away from the heat exchanger 301.

[0042] The flue gas discharge pipe 1 is arranged at the top of the heat exchanger 301 . A connecting pipe 7 is provided at the bottom end of the heat exchanger 301 away from the flue gas discharge pipe 1 . The connecting pipe 7 is connected to one side of the top of the bag filter 401 .

[0043] A plurality of filter bags 402 are provided inside the bag-type dust collector 401, a pulse cleaning device 403 is provided at the top of the bag-type dust collector 401, the side of the bag-type dust collector 401 away from the connecting pipe 7 is connected to the desulfurization tower 404, a denitrification reactor 405 is provided on the side of the desulfurization tower 404 away from the bag-type dust collector 401, and the flue gas exhaust pipe 2 is arranged on the side of the denitrification reactor 405 away from the desulfurization tower 404.

[0044] In this embodiment, it should be noted that the bag filter 401 removes dust particles from the flue gas by filtering through the internal filter bags 402 .

[0045] Filter bag 402 utilizes a new type of coated filter media. The microporous polytetrafluoroethylene film on its surface effectively traps fine dust and improves dust removal efficiency. Filter bag 402 utilizes a modular design for easy installation and replacement. It also features a pulse cleaning device 403, which automatically cleans based on dust accumulation on the bag's surface, ensuring air permeability and dust removal effectiveness.

[0046] After dust removal, the flue gas enters desulfurization tower 404, which uses a spray absorption method. An alkaline absorbent (such as lime slurry) reacts with the sulfides in the flue gas, converting them into harmless sulfates. Multiple spray layers are installed within desulfurization tower 404 to evenly distribute the absorbent and maximize its contact area with the flue gas. A high-efficiency demister is also installed within the tower to remove absorbent droplets carried in the flue gas, preventing secondary contamination. The optimized airflow distribution structure within the tower ensures sufficient contact and reaction between the flue gas and the absorbent.

[0047] Desulfurized flue gas enters the denitrification reactor 405. Using selective catalytic reduction (SCR) technology, the denitrification agent (such as ammonia) reacts with nitrogen oxides over a catalyst to produce nitrogen and water, effectively reducing the pollutant content in the flue gas. The use of highly active, highly selective, and poisoning-resistant catalysts, along with a rationally designed catalyst loading method and internal flow field within the reactor, improves denitrification efficiency and extends catalyst life.

[0048] Finally, the flue gas after dust removal, desulfurization and denitrification is discharged. The bag filter 401, desulfurization tower 404 and denitrification reactor 405 can effectively remove pollutants such as dust, sulfide, nitrogen oxides and so on in the flue gas, so that the exhaust gas emissions meet the strict environmental protection standards and reduce the pollution to the environment.

[0049] Example 3:

[0050] Reference Figure 1-6Compared with the first and second embodiments, in this embodiment: the preliminary treatment component 5 is used to preliminarily intercept impurities in the flue gas, alleviate the attachment of impurities in the flue gas to the inside of the heat exchanger 301, and improve the use efficiency of the heat exchanger 301. An interception filter plate 501 is provided between the flue gas discharge pipe 1 and the heat exchanger 301. The flue gas discharge pipe 1 and the interception filter plate 501 are both semicircular. A rotating rod 507 is connected to the center of the interception filter plate 501. The rotating rod 507 is connected to the side of the flue gas discharge pipe 1. There is a scraper plate 506, a rotating rod 507 located inside the shell of the heat exchanger 301, and a conveyor belt 505 is provided. A collecting pipe 502 is provided at the bottom end of the flue gas discharge pipe 1 near the intercepting filter plate 501, and a limit block 508 is provided at one end of the collecting pipe 502 near the intercepting filter plate 501. A driving motor 504 is provided on the limit block 508. The execution end of the driving motor 504 is internally engaged with the end of the conveyor belt 505 away from the rotating rod 507, and a recovery box 503 is provided at the end of the collecting pipe 502 away from the intercepting filter plate 501.

[0051] A cleaning liquid inlet pipe 6 is provided at the top of the heat exchanger 301, and a cleaning liquid discharge pipe 601 is provided at the bottom of the heat exchanger 301. Both the cleaning liquid inlet pipe 6 and the cleaning liquid discharge pipe 601 are provided with an electric control valve 602, and the cleaning liquid discharge pipe 601 is connected to a collection box 603.

[0052] In this embodiment, it should be noted that an interception filter plate 501 is added at the connection between the flue gas discharge pipe 1 and the heat exchanger 301 to preliminarily intercept larger dust impurities in the flue gas and reduce the adhesion of flue gas impurities on the spiral tube 304 inside the heat exchanger 301.

[0053] The driving motor 504 and the electric control valve 602 are both connected to the PLC controller of model "Siemens S7-1200". The timing drive of the driving motor 501 is set through the PLC controller. The driving motor 504 starts at a fixed time to drive the conveyor belt 505, and then drives the rotating rod 507 to rotate, so that the scraping plate 506 scrapes the intercepting filter plate 501, scraping the dust and impurities attached to the intercepting filter plate 501. The scraped dust falls by gravity and enters the recovery box 503 through the collection pipe 502 for collection.

[0054] When the flue gas does not need to be treated, the corresponding cleaning agent is selected according to the material of the heat exchanger 301. After selecting a suitable chemical cleaning agent, it is allowed to enter the heat exchanger 301 through the cleaning liquid inlet pipe 6 for soaking, so that the cleaning agent is fully in contact with the dust in the heat exchanger 301, a chemical reaction occurs, and the dust is dissolved or softened. After the electric control valve 602 located on the cleaning liquid discharge pipe 601 is opened to discharge the cleaning liquid, clean water is connected to the cleaning liquid inlet pipe 6 and enters the heat exchanger 301 for flushing.

Claims

1. A boiler flue gas treatment device, comprising a flue gas inlet pipe (1) and a flue gas outlet pipe (2) for draining flue gas generated by boiler combustion, characterized in that: The flue gas discharge pipe (1) is sequentially connected to a heat recovery component (3) and a dust removal, desulfurization and denitrification component (4); a preliminary treatment component (5) is provided between the heat recovery component (3) and the flue gas discharge pipe (1); The heat recovery component (3) is used to recover and reuse the heat in the soot, and the heat recovery component (3) comprises a heat exchanger (301), a steam generator (302), and a waste heat recovery pipe (303); The dust removal, desulfurization and denitration component (4) is used to intercept and clean impurities and pollutants in the flue gas after heat exchange, and the dust removal, desulfurization and denitration component (4) includes a bag filter (401), a desulfurization tower (404) and a denitration reactor (405); The preliminary treatment component (5) is used to preliminarily intercept impurities in the flue gas, alleviate the adhesion of impurities in the flue gas inside the heat exchanger (301), and improve the use efficiency of the heat exchanger (301). An interception filter plate (501) is provided between the flue gas discharge pipe (1) and the heat exchanger (301).

2. The boiler flue gas treatment device according to claim 1, characterized in that: The flue gas discharge pipe (1) and the interception filter plate (501) are both arranged in a semicircular shape. A rotating rod (507) is connected to the center of the interception filter plate (501). A scraping plate (506) is connected to the rotating rod (507) near the side of the flue gas discharge pipe (1). The rotating rod (507) is located inside the shell of the heat exchanger (301). A conveyor belt (505) is provided. The flue gas discharge pipe (1) is close to the interception filter plate (501). A collecting pipe (502) is provided at the bottom end of the collecting pipe (502), a limiting block (508) is provided at one end of the collecting pipe (502) close to the intercepting filter plate (501), a driving motor (504) is provided on the limiting block (508), an execution end of the driving motor (504) is internally engaged with an end of the conveyor belt (505) away from the rotating rod (507), and a recovery box (503) is provided at one end of the collecting pipe (502) away from the intercepting filter plate (501).

3. The boiler flue gas treatment device according to claim 1, characterized in that: A rotating tube (304) is provided inside the heat exchanger (301). The rotating tube (304) is vertically arranged inside the heat exchanger (301). The upper and lower ends of the rotating tube (304) are respectively connected to a water inlet (305) and a water outlet (306).

4. The boiler flue gas treatment device according to claim 3, characterized in that: A waste heat recovery pipe (303) is provided inside the top end of the heat exchanger (301), and the waste heat recovery pipes (303) are arranged in multiple horizontal positions at the top end of the heat exchanger (301). A diversion pipe (308) is provided in the middle of the multiple waste heat recovery pipes (303). A waste heat water inlet pipe (307) is provided at the top end of the diversion pipe (308) and on one side of the water inlet (305). A water outlet pipe (309) is provided on one side of the top end of the heat exchanger (301) and at a connection with the waste heat recovery pipe (303).

5. The boiler flue gas treatment device according to claim 4, characterized in that: The water outlet (306) and one end of the water outlet pipe (309) away from the heat exchanger (301) are connected to the steam generator (302).

6. The boiler flue gas treatment device according to claim 5, characterized in that: A cleaning liquid inlet pipe (6) is provided at the top end of the heat exchanger (301), and a cleaning liquid discharge pipe (601) is provided at the bottom end of the heat exchanger (301). Both the cleaning liquid inlet pipe (6) and the cleaning liquid discharge pipe (601) are provided with an electric control valve (602), and the cleaning liquid discharge pipe (601) is connected to a collection box (603).

7. The boiler flue gas treatment device according to claim 1, characterized in that: The flue gas discharge pipe (1) is arranged at the top end of the heat exchanger (301), and a connecting pipe (7) is provided at the bottom end of the heat exchanger (301) away from the flue gas discharge pipe (1), and the connecting pipe (7) is connected to the top side of the bag dust collector (401).

8. The boiler flue gas treatment device according to claim 7, characterized in that: A plurality of filter bags (402) are provided inside the bag filter (401), and a pulse dust cleaning device (403) is provided at the top of the bag filter (401).

9. The boiler flue gas treatment device according to claim 8, characterized in that: The side of the bag filter (401) away from the connecting pipe (7) is connected to the desulfurization tower (404), the side of the desulfurization tower (404) away from the bag filter (401) is provided with a denitration reactor (405), and the flue gas exhaust pipe (2) is provided on the side of the denitration reactor (405) away from the desulfurization tower (404).

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