A slurry preparation device for coal-fired boiler denitration

Abstract

The utility model discloses a kind of slurry deployment devices for coal-fired boiler denitration, including denitration agent storage tank, water storage tank, additive storage tank, deployment jar and PLC controller;Three feed ports are provided at the top of deployment jar, and denitration agent storage tank, water storage tank and additive storage tank are respectively connected with three feed ports one-to-one through feeding pipeline, and feeding pipeline is provided with feeding pump machine;Mixing mechanism is provided in deployment jar;The top of deployment jar, denitration agent storage tank, water storage tank and additive storage tank is respectively provided with pressure relief port, and pressure relief valve is provided in pressure relief port, and pressure relief port is connected with main exhaust gas conveying pipeline by communicating branch exhaust conveying pipeline, and induced draft fan is provided on main exhaust gas conveying pipeline;The output end of PLC controller is respectively connected with the controlled end of feeding pump machine, mixing mechanism, pressure relief valve and induced draft fan.

Description

Technical Field

[0001] This utility model relates to the field of denitrification technology for coal-fired boilers, specifically to a slurry preparation device for denitrification of coal-fired boilers. Background Technology

[0002] During the operation of coal-fired boilers, nitrogen oxide (NOx) emissions are a significant contributor to air pollution. To effectively reduce NOx emissions, denitrification technology has been widely adopted. The preparation of denitrification slurry is a crucial step in the denitrification process, and the accuracy of its proportions and quality directly affects the denitrification effect.

[0003] Currently, flue gas denitrification in coal-fired boilers typically uses wet ammonia or urea solution injection as a reducing agent. This requires mixing the denitrifying agent with water and additives (such as stabilizers and slow-release agents) in a specific ratio to prepare a homogeneous slurry. Traditional manual mixing methods have the following drawbacks:

[0004] Large mixing ratio error: Reliance on manual experience can easily lead to fluctuations in the concentration of the denitrifying agent, affecting the denitrification efficiency;

[0005] Uneven mixing: The slurry is prone to stratification or sedimentation, which can clog the spray gun or lead to incomplete reaction.

[0006] Air pollution: The mixing process generates waste gas, which pollutes the air and harms people's health. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a slurry preparation device for denitrification of coal-fired boilers, so as to solve the problems mentioned in the background art.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows.

[0009] A slurry preparation device for denitrification of a coal-fired boiler includes a denitrification agent storage tank for storing denitrification agent, a water storage tank for storing water, an additive storage tank for storing additives, a preparation tank for preparing the slurry, and a PLC controller. The top of the preparation tank has three feed inlets. The denitrification agent storage tank, water storage tank, and additive storage tank are connected to the three feed inlets one-to-one via feeding pipes, and feeding pumps are installed on the feeding pipes. The preparation tank is equipped with a stirring mechanism for mixing and blending. The tops of the preparation tank, denitrification agent storage tank, water storage tank, and additive storage tank are each equipped with a pressure relief port and a pressure relief valve. These pressure relief ports are connected to a main exhaust gas conveying pipe via branch exhaust gas conveying pipes, and an induced draft fan is installed on the main exhaust gas conveying pipe. The output of the PLC controller is connected to the controlled terminals of the feeding pump, stirring mechanism, pressure relief valve, and induced draft fan.

[0010] Preferably, one end of the feeding pipe extends into the bottom of the denitrifying agent storage tank, water storage tank, and additive storage tank, and the feeding pipe is sealed and assembled with the denitrifying agent storage tank, water storage tank, and additive storage tank respectively.

[0011] Preferably, the bottom of the additive storage tank is provided with an ultrasonic oscillator to prevent additive sedimentation and agglomeration.

[0012] Preferably, the denitrification agent storage tank, water storage tank, and additive storage tank each include an inner tank and an outer tank; the inner tank is equipped with a liquid level sensor and a first temperature sensor, the output terminals of which are respectively connected to the input terminal of the PLC controller; an interlayer is formed between the inner tank and the outer tank, and an electric heating wire is provided in the interlayer, the controlled end of which is connected to the output terminal of the PLC controller.

[0013] Preferably, the outer wall of the mixing tank is covered with a heating jacket, the bottom of the heating jacket is provided with a medium inlet for the heating medium to flow in, and the top of the heating jacket is provided with a medium outlet for the heating medium to flow out; the medium inlet is connected to a medium pump through a pipe, and the controlled end of the medium pump is connected to the output end of the PLC controller.

[0014] Preferably, the outer walls of the denitrification agent storage tank, water storage tank, additive storage tank, and mixing tank are all covered with an outermost heat insulation layer.

[0015] Preferably, the stirring mechanism includes a stirring motor mounted on the top of the mixing tank. The rotating shaft of the stirring motor is positioned downwards and connected to a rotating shaft whose bottom end extends into the bottom of the mixing tank. At least two rows of stirring crossbars are evenly arranged on the outer wall of the rotating shaft, perpendicular to the rotating shaft. Each row of stirring crossbars is spaced apart from top to bottom. The outer end of the stirring crossbars in the same row, away from the rotating shaft, is connected to a scraper that abuts against the inner wall of the mixing tank. Stirring longitudinal bars are arranged perpendicular to the stirring crossbars on the outer wall of the stirring crossbars, and the stirring longitudinal bars on adjacent stirring crossbars are staggered.

[0016] Preferably, the bottom of the mixing tank is provided with a viscosity sensor and a discharge port, and a second temperature sensor is provided in the discharge port. The output terminals of the second temperature sensor and the viscosity sensor are respectively connected to the input terminal of the PLC controller.

[0017] Preferably, a flow meter is installed on the feeding pipe behind the feeding pump, and the output end of the flow meter is connected to the input end of the PLC controller.

[0018] Preferably, each of the denitrification agent storage tank, water storage tank, additive storage tank, and mixing tank is equipped with a pressure sensor, and the output of the pressure sensor is connected to the input of the PLC controller.

[0019] The technological advancements achieved by this utility model are as follows, due to the adoption of the above technical solutions.

[0020] This invention ensures the precision of slurry preparation and thus guarantees denitrification efficiency through the installation of a feeding pump, flow meter, and PLC controller. The mixing mechanism ensures uniform slurry mixing, preventing stratification and sedimentation. The pressure relief port, pressure relief valve, and waste gas delivery pipeline allow waste gas to be discharged into the waste gas treatment system, preventing air pollution and harm to personnel. The electric heating wire, heating jacket, and media pump effectively maintain the temperature of the liquid and the slurry preparation temperature, facilitating slurry preparation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] The components include: 1. Denitrifying agent storage tank, 2. Water storage tank, 3. Additive storage tank, 4. Mixing tank, 5. Heating jacket, 51. Medium inlet, 52. Medium outlet, 6. Medium pump, 7. Feed inlet, 8. Stirring mechanism, 81. Stirring motor, 82. Rotating shaft, 83. Stirring crossbar, 84. Stirring longitudinal bar, 85. Scraper, 9. Discharge port, 10. Second temperature sensor, 11. Viscosity sensor, 12. Jacket, 13. Electric heating wire, 14. Feed port, 15. Sealing cover, 16. Feeding pipe, 17. Feeding pump, 18. Flow meter, 19. Ultrasonic oscillator, 20. Pressure relief port, 21. Branch exhaust gas conveying pipe, 22. Main exhaust gas conveying pipe, 23. Exhaust fan. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] A slurry preparation device for denitrification of coal-fired boilers, combined with Figure 1 As shown, the system includes a denitrification agent storage tank 1, a water storage tank 2, an additive storage tank 3, a mixing tank 4, and a PLC controller. The denitrification agent storage tank 1 is used to store denitrification agent; the water storage tank 2 is used to store water; the additive storage tank 3 is used to store additives; the mixing tank 4 is used to mix the slurry; and the PLC controller is used to control the slurry mixing process, thereby configuring a denitrification slurry that meets the requirements of the coal-fired boiler.

[0025] Each of the denitrification agent storage tank 1, water storage tank 2, and additive storage tank 3 includes an inner tank and an outer tank. The inner tank is equipped with a level sensor and a first temperature sensor. The level sensor monitors the liquid level in each of these tanks, while the first temperature sensor monitors the temperature of the liquid in each tank. The outputs of the level sensor and the first temperature sensor are connected to the input of a PLC controller. A sandwich layer 12 is formed between the inner and outer tanks, and an electric heating wire 13 is installed within this layer. The controlled end of the electric heating wire 13 is connected to the output of the PLC controller. The PLC controller controls the operation of the corresponding electric heating wire 13 based on the temperature monitored by the first temperature sensor, thereby ensuring the temperature of the liquid in each storage tank. The PLC controller also alerts operators to replenish the corresponding liquid based on the liquid level information monitored by the level sensor.

[0026] The top of the denitrification agent storage tank 1, water storage tank 2, and additive storage tank 3 are all equipped with a feeding port 14, through which personnel can replenish the corresponding liquid to the respective storage tank. The feeding port 14 is sealed with a sealing cap 15 to prevent foreign objects from entering and contaminating the liquid.

[0027] An ultrasonic oscillator 19 is provided at the bottom of the additive storage tank 3. The ultrasonic oscillator 19 is used to prevent the additive from settling and agglomerating.

[0028] The denitrifying agent storage tank 1, water storage tank 2, and additive storage tank 3 are connected to the mixing tank 4 via a feeding pipe 16. One end of the feeding pipe 16 extends into the bottom of each of the three storage tanks, and the feeding pipe 16 is sealed to each of them. A feeding pump 17 and a flow meter 18 are installed on the feeding pipe 16. The flow meter 18 is located behind the feeding pump 17. The feeding pump 17 pumps the liquid from the denitrifying agent storage tank 1, water storage tank 2, and additive storage tank 3 into the mixing tank 4, and the flow meter 18 monitors the pumping volume of the corresponding liquid. Meanwhile, the controlled end of the feed pump 17 is connected to the output end of the PLC controller, and the output end of the flow meter 18 is connected to the input end of the PLC controller. The PLC controller controls the amount of each liquid to be pumped into the mixing tank 4, thereby mixing the required concentration of slurry.

[0029] The mixing tank 4 has three feed inlets 7 at its top, which are connected to the denitrification agent storage tank 1, water storage tank 2, and additive storage tank 3 respectively via a feeding pipe 16. The mixing tank 4 also has a discharge outlet 9 at its bottom, which houses a second temperature sensor 10 for monitoring the temperature of the liquid. The outer wall of the mixing tank 4 is covered by a heating jacket 5. The bottom of the heating jacket 5 has a medium inlet 51 for the heating medium to flow into it, and the top of the heating jacket 5 has a medium outlet 52 for the heating medium to flow out. The medium inlet 51 is connected to a medium pump 6 via a pipe, which pumps the heating medium into the heating jacket 5 and provides power for the heating medium to flow out. The controlled end of the media pump 6 is connected to the output end of the PLC controller, and the output end of the second temperature sensor 10 is connected to the input end of the PLC controller. The PLC controller controls the media pump 6 according to the temperature monitored by the second temperature sensor 10, thereby realizing the heating medium to heat the liquid in the mixing tank 4, so that the temperature of the liquid meets the mixing requirements and the slurry that meets the temperature requirements is mixed.

[0030] To conserve resources and more effectively maintain temperature, the outer walls of the denitrification agent storage tank 1, water storage tank 2, additive storage tank 3, and mixing tank 4 are all covered with an insulation layer, which is located on the outermost layer and is used to achieve heat preservation.

[0031] The mixing tank 4 is equipped with a stirring mechanism 8, which is used to achieve mixing and ensure efficient mixing. Specifically, the stirring mechanism 8 includes a stirring motor 81 located at the top of the mixing tank 4. The rotating shaft of the stirring motor 81 is arranged downward and connected to a rotating shaft 82. The bottom end of the rotating shaft 82 extends into the bottom of the mixing tank 4. At least two rows of stirring crossbars 83 are evenly arranged on the outer wall of the rotating shaft 82, which are perpendicular to the rotating shaft 82. The stirring crossbars 83 in each row are spaced apart from top to bottom. The outer end of the stirring crossbars 83 in the same row away from the rotating shaft 82 is connected to a scraper 85, which abuts against the inner wall of the mixing tank 4. Stirring longitudinal bars 84 are arranged on the outer wall of the stirring crossbars 83. The stirring longitudinal bars 84 are arranged perpendicular to the stirring crossbars 83, and the stirring longitudinal bars 84 on adjacent stirring crossbars 83 are staggered. The controlled end of the stirring motor 81 is connected to the output end of the PLC controller. When the PLC controller controls the stirring motor 81 to drive the rotating shaft 82 to rotate, the stirring crossbar 83 and stirring longitudinal bar 84 rotate to achieve stirring. The horizontal and vertical stirring can ensure thorough stirring and achieve efficient mixing. At the same time, the scraper 85 rotates close to the inner wall of the mixing tank 4 to scrape off the slurry on the inner wall of the mixing tank 4.

[0032] A viscosity sensor 11 is installed at the bottom of the mixing tank 4, and the output of the viscosity sensor 11 is connected to the input of the PLC controller. The viscosity sensor 11 is used to monitor the viscosity of the slurry. When the slurry in the mixing tank 4 is prepared but not output, the viscosity sensor 11 monitors the viscosity of the slurry in real time. The PLC controller intermittently starts the stirring mechanism 8 to stir according to the monitored viscosity information.

[0033] Pressure sensors are installed inside the denitrification agent storage tank 1, water storage tank 2, additive storage tank 3, and mixing tank 4. These pressure sensors monitor the pressure within their respective tanks, and their outputs are connected to the inputs of a PLC controller. Each of the denitrification agent storage tank 1, water storage tank 2, additive storage tank 3, and mixing tank 4 has a pressure relief port 20 at its top. Each pressure relief port 20 contains a pressure relief valve, and is connected to a main exhaust gas conveying pipe 22 via a branch exhaust gas conveying pipe 21. The main exhaust gas conveying pipe 22 connects to the exhaust gas treatment system, and is equipped with an induced draft fan 23 to introduce exhaust gas into the exhaust gas treatment system. The input terminal of the PLC controller is connected to the output terminal of the pressure sensor, and the output terminal of the PLC controller is connected to the controlled terminals of the pressure relief valve and the induced draft fan 23 respectively. When the pressure information monitored by the pressure sensor exceeds the set threshold, the PLC controller controls the corresponding pressure relief valve to open and the induced draft fan 23 to draw out the exhaust gas and discharge it to the exhaust gas treatment system. After the pressure value meets the requirements, the corresponding pressure relief valve is closed.

[0034] In use, the PLC controller, based on preset information and feedback from the flow meter 18, controls the feeding pump 17 to extract raw materials, which are then injected into the mixing tank 4 via the feeding pipe 16. The control medium pump 6 maintains the temperature and drives the stirring mechanism 8 for mixing. Once the viscosity sensor 11 confirms that the slurry viscosity meets the standard, the mixing process is complete. Simultaneously, the waste gas generated during the mixing process is introduced into the waste gas treatment system via the induced draft fan 23.

Claims

1. A slurry preparation device for denitrification of coal-fired boilers, characterized in that: The system includes a denitrification agent storage tank (1) for storing denitrification agents, a water storage tank (2) for storing water, an additive storage tank (3) for storing additives, a mixing tank (4) for mixing slurry, and a PLC controller. The mixing tank (4) has three inlets (7) on its top. The denitrification agent storage tank (1), water storage tank (2), and additive storage tank (3) are connected to the three inlets (7) one-to-one via a feeding pipe (16), and a feeding pump (17) is installed on the feeding pipe (16). The mixing tank (4) is equipped with a mixing mechanism for mixing slurry. The mixing mechanism (8) is equipped with a stirring mechanism; the top of the mixing tank (4), the denitrification agent storage tank (1), the water storage tank (2) and the additive storage tank (3) are respectively provided with pressure relief ports (20), pressure relief valves are provided in the pressure relief ports (20), and the pressure relief ports (20) are connected to the main exhaust gas conveying pipe (22) through the connected branch exhaust gas conveying pipe (21), and an induced draft fan (23) is provided on the main exhaust gas conveying pipe (22); the output end of the PLC controller is respectively connected to the control end of the feeding pump (17), the stirring mechanism (8), the pressure relief valve and the induced draft fan (23).

2. The slurry preparation device for denitrification of a coal-fired boiler according to claim 1, characterized in that: The feeding pipe (16) is located at one end of the denitrifying agent storage tank (1), water storage tank (2) and additive storage tank (3) and extends into the bottom of the denitrifying agent storage tank (1), water storage tank (2) and additive storage tank (3), and the feeding pipe (16) is sealed and assembled with the denitrifying agent storage tank (1), water storage tank (2) and additive storage tank (3) respectively.

3. The slurry preparation device for denitrification of a coal-fired boiler according to claim 1, characterized in that: The bottom of the additive storage tank (3) is provided with an ultrasonic oscillator (19) to prevent additives from settling and agglomerating.

4. The slurry preparation device for coal-fired boiler denitration according to claim 1, characterized in that: The denitrification agent storage tank (1), water storage tank (2) and additive storage tank (3) each include an inner tank and an outer tank; a liquid level sensor and a first temperature sensor are provided in the inner tank, and the output terminals of the liquid level sensor and the first temperature sensor are respectively connected to the input terminal of the PLC controller; an interlayer (12) is formed between the inner tank and the outer tank, and an electric heating wire (13) is provided in the interlayer (12), and the controlled end of the electric heating wire (13) is connected to the output terminal of the PLC controller.

5. The slurry preparation device for coal-fired boiler denitration according to claim 1, characterized in that: The outer wall of the mixing tank (4) is covered with a heating jacket (5). The bottom of the heating jacket (5) is provided with a medium inlet (51) for the heating medium to flow in, and the top of the heating jacket (5) is provided with a medium outlet (52) for the heating medium to flow out. The medium inlet (51) is connected to a medium pump (6) through a pipe. The controlled end of the medium pump (6) is connected to the output end of the PLC controller.

6. The slurry preparation device for coal-fired boiler denitration according to claim 1, characterized in that: The outer walls of the denitrification agent storage tank (1), water storage tank (2), additive storage tank (3) and mixing tank (4) are all covered with an outermost heat insulation layer.

7. The slurry preparation device for denitrification of a coal-fired boiler according to claim 1, characterized in that: The stirring mechanism (8) includes a stirring motor (81) set on the top of the mixing tank (4). The rotating shaft of the stirring motor (81) is set downward and connected to a rotating shaft (82) whose bottom end extends into the bottom of the mixing tank (4). At least two rows of stirring crossbars (83) are evenly arranged on the outer wall of the rotating shaft (82) and are perpendicular to the rotating shaft (82). The stirring crossbars (83) in each row are spaced apart from top to bottom. The outer end of the stirring crossbars (83) in the same row away from the rotating shaft (82) is connected to a scraper (85) that abuts against the inner wall of the mixing tank (4). The stirring longitudinal bars (84) are set on the outer wall of the stirring crossbars (83) and are perpendicular to the stirring crossbars (83). The stirring longitudinal bars (84) on adjacent stirring crossbars (83) are staggered.

8. The slurry preparation device for coal-fired boiler denitration according to claim 7, characterized in that: The bottom of the mixing tank (4) is provided with a viscosity sensor (11) and a discharge port (9). A second temperature sensor (10) is provided in the discharge port (9). The output terminals of the second temperature sensor (10) and the viscosity sensor (11) are respectively connected to the input terminal of the PLC controller.

9. A slurry preparation device for denitrification of a coal-fired boiler according to claim 1, characterized in that: A flow meter (18) is installed on the feeding pipe (16) behind the feeding pump (17), and the output end of the flow meter (18) is connected to the input end of the PLC controller.

10. A slurry preparation device for denitrification of a coal-fired boiler according to claim 1, characterized in that: Pressure sensors are installed inside the denitrification agent storage tank (1), water storage tank (2), additive storage tank (3) and mixing tank (4), respectively, and the output end of the pressure sensor is connected to the input end of the PLC controller.

Images