Desulfurization multi-stage reaction mechanism and flue gas desulfurization system based on carbide slag

Abstract

The invention discloses a desulfurization multistage reaction mechanism and a flue gas desulfurization system based on carbide slag, the desulfurization multistage reaction mechanism comprises a reaction unit and a desulfurization mechanism, the reaction unit comprises a first reaction zone, a second reaction zone and a gas flow separator, the gas flow separator is arranged between the first reaction zone and the second reaction zone to realize gas-liquid separation and zoning reaction, and the desulfurization mechanism is connected with the first reaction zone and the second reaction zone. The desulfurization mechanism comprises a pretreatment unit, a reaction unit arranged on one side of the pretreatment unit, a slurry circulating unit connected with the reaction unit and a byproduct treatment unit, the byproduct treatment unit is arranged at the rear end of the slurry circulating unit, and the pretreatment unit is used for pretreating carbide slag. The system has the beneficial effects that most of SO2 is quickly removed in the first reaction zone, generation of byproducts is optimized in the second reaction zone, and the system stability and byproducts are improved.

Description

Technical Field

[0001] The present invention relates to the fields of flue gas desulfurization technology and industrial solid waste resource utilization technology, in particular to a desulfurization multi-stage reaction mechanism and a flue gas desulfurization system based on carbide slag. Background Art

[0002] Traditional wet flue gas desulfurization technology (limestone-gypsum wet desulfurization process) is widely used in coal-fired power plants. Its core is to use limestone powder to react with SO2 in flue gas to produce gypsum. However, this technology has problems such as high operating costs, limited limestone resources, difficult to handle gypsum by-products, and easy scaling of reactors. Calcium carbide slag, as an industrial solid waste, has a main component of CaO and has high desulfurization potential. It can replace limestone as a desulfurizer. However, due to the fast reaction speed and easy scaling of calcium carbide slag in wet desulfurization, as well as the imperfect technology for processing the by-product gypsum, its large-scale application is limited. Therefore, how to solve the scaling and by-product problems in the application of calcium carbide slag by transforming the existing desulfurization system has become a technical problem that needs to be solved urgently. Summary of the Invention

[0003] Therefore, the technical problems to be solved by the present invention are: carbide slag reacts quickly and is prone to scaling in wet desulfurization, and the by-product gypsum processing technology is still imperfect, which limits its large-scale application.

[0004] The above technical problems are solved by the following technical solutions: The present invention proposes a multi-stage desulfurization reaction mechanism, which includes a reaction unit, wherein the reaction unit includes a first reaction zone, a second reaction zone and an air flow separator, and an air flow separator is arranged between the first reaction zone and the second reaction zone to realize gas-liquid separation and partitioned reaction.

[0005] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: a first atomizing nozzle is provided in the first reaction zone, and the first reaction zone is a slow reaction zone;

[0006] The guide plate arranged in the second reaction zone guides the airflow into the airflow separator. A high-speed stirrer and a second atomizing nozzle are also arranged in the second reaction zone. The second reaction zone is a high-speed reaction zone.

[0007] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the reaction unit further includes a feeding device, and the feeding device is arranged on the side of the second reaction zone.

[0008] The beneficial effects of the present invention are: the first reaction zone realizes rapid removal of most of the SO2, the second reaction zone optimizes the generation of by-products, and improves the stability of the system and the by-products.

[0009] Another object of the present invention is to provide a flue gas desulfurization system based on carbide slag, which aims to improve desulfurization efficiency, reduce operating costs, reduce scaling problems and optimize by-product utilization.

[0010] In order to solve the above technical problems, the present invention also provides the following technical solutions: including a desulfurization mechanism, the desulfurization mechanism includes a pretreatment unit, a reaction unit arranged on one side of the pretreatment unit, a slurry circulation unit connected to the reaction unit, and a by-product processing unit, the by-product processing unit is arranged at the rear end of the slurry circulation unit, and the pretreatment unit pretreats the calcium carbide slag.

[0011] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the pretreatment unit makes the carbide slag particle size 50-150 μm and adds 0.1% polymer anti-structuring agent.

[0012] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the slurry circulation unit prepares slurry according to a mixing ratio of 40% carbide slag to water, and adjusts the initial pH value to 12.5.

[0013] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the slurry circulation unit includes a slurry tank for accommodating slurry in sequence, a sedimentation zone is located at the lower part of the first reaction zone, the sedimentation zone removes solid impurities and adjusts the slurry concentration, the slurry filtering device filters impurities in the slurry, and the filtered slurry flows into the slurry tank. The slurry circulation pump draws the slurry out of the slurry tank and enables the slurry to circulate.

[0014] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the slurry circulation unit further includes a data sensor component, the data sensor component is arranged on the side of the first reaction zone, and a PID controller is arranged on one side of the data sensor component.

[0015] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the sensor component includes a flow sensor, a temperature sensor and a pH sensor, and the flow sensor, temperature sensor and pH sensor are arranged in sequence.

[0016] In a preferred embodiment of the desulfurization multi-stage reaction mechanism of the present invention: the by-product processing unit is separated and processed by a two-stage filter.

[0017] The beneficial effects of the present invention are: by replacing limestone with calcium carbide slag, the raw material cost is reduced by about 30%, the system scaling phenomenon is reduced by anti-scaling treatment agent and multi-stage reaction design, and the operation stability is greatly improved. After the transformation, the desulfurization efficiency of the system can be increased by more than 8%, and the desulfurization efficiency is stabilized at more than 98%. The quality of the by-product gypsum is improved, waste is reduced and resource utilization is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Among them:

[0019] Figure 1 Shows a schematic structural diagram of a desulfurization multi-stage reaction mechanism;

[0020] Figure 2 The schematic diagram of the structure of the flue gas desulfurization system based on carbide slag is shown. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0022] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0023] Reference Figure 1 This embodiment provides a desulfurization multi-stage reaction mechanism, including a reaction unit 1, the reaction unit 1 includes a first reaction zone 11, a second reaction zone 12 and an air flow separator 13, and the air flow separator 13 is arranged between the first reaction zone 11 and the second reaction zone 12 to realize gas-liquid separation and partitioned reaction.

[0024] Preferably, a first atomizing nozzle 111 is provided in the first reaction zone 11, and the first reaction zone 11 is a slow reaction zone. The first reaction zone 11 can further remove residual SO2 and in the first reaction zone 11, the particle size of the by-product (such as gypsum) can be controlled by uniform spraying of the atomizing nozzle 111, making it more uniform and convenient for subsequent separation and treatment; a guide plate 121 provided in the second reaction zone 12 guides the airflow into the airflow separator 13, and a high-speed stirrer 122 and a second atomizing nozzle are also provided in the second reaction zone 12. Nozzle 123, the second reaction zone 12 is a high-speed reaction zone. The main function of the second reaction zone 12 is to quickly remove most of the SO2 in the flue gas. The high-speed agitator 122 can prevent solid particles from settling, maintain the suspension state of the slurry, and reduce the risk of scaling. The first atomizing nozzle 111 and the second atomizing nozzle 123 can atomize the slurry into fine droplets. The first atomizing nozzle 111 and the second atomizing nozzle 123 are of dual-fluid vortex type, so that the carbide slag in the slurry and the SO2 in the flue gas can be more fully in contact.

[0025] When in use, a multi-stage reaction design is introduced on the basis of a traditional desulfurization reactor. The second reaction zone 12 is a high-speed reaction zone. The main function of the second reaction zone 12 is to quickly remove most of the SO2 in the flue gas. The high-speed agitator 122 can prevent solid particles from settling, maintain the suspension state of the slurry, and reduce the risk of scaling. The first reaction zone 11 is a slow reaction zone. The first reaction zone 11 can further remove residual SO2 and in the first reaction zone 11, the particle size of the by-product can be controlled by uniform spraying of the atomizing nozzle 111 to make it more uniform, which is convenient for subsequent separation and treatment.

[0026] As an optional embodiment, the reaction unit 1 also includes a feeding device 14, which is arranged on the side of the second reaction zone 12. The feeding speed of the feeding device 14 and the spraying intensity of the first atomizing nozzle 111 and the second atomizing nozzle 123 can be adjusted to achieve control of the generation of SO2 and by-products in the flue gas. The feeding device 14 is a screw feeder Φ200.

[0027] Reference Figure 1 and Figure 2 As an optional embodiment, it is different from the first embodiment in that: the desulfurization mechanism 2 includes a pretreatment unit 21, a reaction unit 1 arranged on one side of the pretreatment unit 21, a slurry circulation unit 22 connected to the reaction unit 1, and a by-product processing unit 23. The by-product processing unit 23 is arranged at the rear end of the slurry circulation unit 22. The pretreatment unit 21 pretreats the carbide slag, and processes the carbide slag into finer pieces through drying, crushing and screening technology, and mixes the treated carbide slag with water in proportion to form a slurry.

[0028] During use, the pretreatment unit 21 pretreats the carbide slag, and the treated carbide slag is mixed with water in proportion to form a slurry, which is sprayed into the first reaction zone 11 and the second reaction zone 12 through the first atomizing nozzle 111 and the second atomizing nozzle 123. The lower part of the first reaction zone 11 is connected to the slurry circulation unit 22, and the by-product processing unit 23 is arranged at the rear end of the slurry circulation unit 22.

[0029] As an optional embodiment, the pretreatment unit 21 uses drying, crushing and screening technology to make the particle size of the carbide slag 50-150μm, and adds 0.1% polymer anti-structuring agent. The anti-scaling agent is a high-molecular organic polycarboxylic acid dispersant, and 0.1% is added according to the dry weight of the carbide slag, that is, 1 kg of anti-scaling agent is required for every ton of carbide slag processed, and the addition process is maintained by quantitative dosing.

[0030] Preferably, the slurry circulation unit 22 prepares slurry according to a mixing ratio of 40% carbide slag to water, and adjusts the initial pH value to 12.5, that is, 40% is the mass ratio between carbide slag (in dry weight) and water, and carbide slag and water are mixed in a ratio of 4:6 to prepare slurry.

[0031] When in use, the particle size of carbide slag is 50-150μm, 0.1% polymer anti-structural agent is added, carbide slag and water are mixed in a ratio of 4:6 to make slurry, and the initial pH value is adjusted to 12.5, which is the optimal value, reducing equipment scaling and by-product generation, and ensuring slurry fluidity and reaction activity.

[0032] As an optional embodiment, the slurry circulation unit 22 includes a slurry tank 221 for accommodating slurry, a sedimentation zone 222 located at the lower part of the first reaction zone 11, the sedimentation zone 222 removes solid impurities and adjusts the slurry concentration, a slurry filtering device 223 filters impurities in the slurry, and the filtered slurry flows into the slurry tank 221. The slurry circulation pump 224 draws the slurry out of the slurry tank 221 and enables the slurry to circulate.

[0033] Preferably, the slurry circulation unit 22 further includes a data sensor assembly 225, which is arranged on the side of the first reaction zone 11. A PID controller 226 is arranged on one side of the data sensor assembly 225. The PID controller 226 is a prior art and is widely used in industrial automation and control systems. It calculates the deviation between the set value (expected value) and the actual measured value and adjusts the control amount according to a combination of three control modes: proportional (P), integral (I) and differential (D), thereby achieving precise control of the controlled object. In this embodiment, the spray intensity of the first atomizing nozzle 111 and the second atomizing nozzle 123 and the feeding speed of the feeding device 14 are controlled according to the detection data of the data sensor assembly 225.

[0034] Furthermore, the data sensor assembly 225 includes a flow sensor 2251, a temperature sensor 2252 and a pH sensor 2253. The flow sensor 2251, the temperature sensor 2252 and the pH sensor 2253 are arranged in sequence, wherein the pH sensor 2253 is of the E+H CPS11D series, the temperature sensor 2252 is of the Pt100 type, and the flow sensor 2251 is an ABB 6000 series electromagnetic flowmeter.

[0035] When in use, the flow sensor 2251, the temperature sensor 2252 and the pH sensor 2253 are arranged on the side of the first reaction zone 11, for monitoring the flow, temperature and pH value of the slurry, and sending the monitoring data to the PID controller 226. The PID controller 226 adjusts the spray intensity of the first atomizing nozzle 111 and the second atomizing nozzle 123 and the feeding speed of the feeding device 14 according to the above information. The slurry tank 221 is a container for storing slurry, receiving the filtered slurry from the slurry filtering device 223, and providing a slurry source for the slurry circulation pump 224. The slurry circulation pump 224 draws the slurry out of the slurry tank 221 and connects it to the outlet of the reaction unit 1, providing power for the entire system to ensure that the slurry can circulate. The reflux branch of the slurry circulation unit 22 is located in the sedimentation zone 222 located at the lower part of the first reaction zone 11. The sedimentation zone 222 removes solid impurities and adjusts the slurry concentration.

[0036] Real-time collection of key parameters such as slurry pH value, SO2 emission concentration, slurry circulation flow rate, etc., and continuous monitoring of 30-day operating data.

[0037] Experimental conditions:

[0038] Power plant scale: 300MW coal-fired boiler;

[0039] Flue gas SO2 concentration: 3000mg / Nm3;

[0040] Carbide slag blending ratio: 40%;

[0041] Slurry pH value: initially set to 12.5;

[0042] Flue gas flow rate: 2.0m / s;

[0043] Serum concentration: 20%;

[0044] System operation time after transformation: 30 consecutive days;

[0045] Environmental conditions: Flue gas temperature 90°C, humidity 50%.

[0046] Experimental results:

[0047]

[0048]

[0049] As an optional embodiment, the by-product processing unit 23 can reduce the water content and optimize the by-product quality through double-stage filter separation processing.

[0050] When in use, the by-product processing unit 23 optimizes the quality of the by-products by double-clicking the filter.

[0051] Finally, it should be pointed out that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. A desulfurization multi-stage reaction mechanism, characterized in that: include, A reaction unit (1) includes a first reaction zone (11), a second reaction zone (12) and an airflow separator (13). The airflow separator (13) is arranged between the first reaction zone (11) and the second reaction zone (12) to achieve gas-liquid separation and partitioned reaction.

2. The desulfurization multi-stage reaction mechanism according to claim 1, characterized in that: A first atomizing nozzle (111) is provided in the first reaction zone (11), and the first reaction zone (11) is a slow reaction zone; The guide plate (121) provided in the second reaction zone (12) guides the airflow into the airflow separator (13). The second reaction zone (12) is also provided with a high-speed stirrer (122) and a second atomizing nozzle (123). The second reaction zone (12) is a high-speed reaction zone.

3. The desulfurization multi-stage reaction mechanism according to claim 1, characterized in that: The reaction unit (1) further comprises a feeding device (14), and the feeding device (14) is arranged on the side of the second reaction zone (12).

4. A flue gas desulfurization system based on carbide slag, characterized by: The desulfurization multi-stage reaction mechanism comprises any one of claims 1 to 3; and A desulfurization mechanism (2) includes a pretreatment unit (21), a reaction unit (1) arranged on one side of the pretreatment unit (21), a slurry circulation unit (22) connected to the reaction unit (1), and a by-product processing unit (23). The by-product processing unit (23) is arranged at the rear end of the slurry circulation unit (22). The pretreatment unit (21) pre-treats carbide slag.

5. The flue gas desulfurization system based on carbide slag according to claim 4, characterized in that: The pretreatment unit (21) reduces the particle size of the carbide slag to 50-150 μm and adds 0.1% of a polymer anti-structuring agent.

6. The flue gas desulfurization system based on carbide slag according to claim 5, characterized in that: The slurry circulation unit (22) prepares slurry according to a mixing ratio of 40% carbide slag to water, and adjusts the initial pH value to 12.

5.

7. The flue gas desulfurization system based on carbide slag according to claim 4, characterized in that: The slurry circulation unit (22) includes, in sequence, a slurry tank (221) for accommodating slurry, a sedimentation zone (222) located at the lower part of the first reaction zone (11), the sedimentation zone (222) removes solid impurities and adjusts the slurry concentration, a slurry filtering device (223) filters impurities in the slurry, and the filtered slurry flows into the slurry tank (221), and a slurry circulation pump (224) draws the slurry out of the slurry tank (221) and enables the slurry to circulate.

8. The flue gas desulfurization system based on carbide slag according to claim 4, characterized in that: The slurry circulation unit (22) further includes a data sensor component (225), which is arranged on the side of the first reaction zone (11), and a PID controller (226) is arranged on one side of the data sensor component (225).

9. The flue gas desulfurization system based on carbide slag according to claim 8, characterized in that: The sensor assembly (225) includes a flow sensor (2251), a temperature sensor (2252) and a pH sensor (2253), and the flow sensor (2251), the temperature sensor (2252) and the pH sensor (2253) are arranged in sequence.

10. The flue gas desulfurization system based on carbide slag according to claim 4, characterized in that: The by-product processing unit (23) is separated and processed by a double-stage filter.

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