A flue gas purification device applied to low-temperature catalytic desulfurization and denitrification integration

Abstract

The application relates to a flue gas purification device applied to low-temperature catalytic desulfurization and denitrification integration, and belongs to the technical field of flue gas purification. The flue gas purification device applied to low-temperature catalytic desulfurization and denitrification integration comprises a reaction tower, a desulfurization and denitrification agent inlet and a raw flue gas inlet are arranged at the bottom of the reaction tower, a cyclone is arranged in the reaction tower, the desulfurization and denitrification agent inlet is connected with the center hole of the cyclone through a material conveying pipeline, a dust removal assembly is fixedly arranged vertically above the cyclone, a flue gas discharging pipeline is arranged at the top of the reaction tower, and a material collecting assembly is communicated with the side wall of the upper part of the reaction tower. The device has the beneficial effects that the structure is simple, the reaction is rapid, the desulfurization and denitrification processes can be simultaneously completed in a short time, the operation and maintenance are convenient, and the investment and operation cost are low.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flue gas purification, and particularly relates to a flue gas purification device applied to low-temperature catalytic desulfurization and denitrification integration. BACKGROUND

[0002] With the continuous progress of China's industry, more and more coal-fired boilers are used, and SO2 and NOx generated by coal combustion are the main causes of air pollution. If untreated flue gas is randomly discharged into the atmosphere, it will have a very bad impact on the local ecological environment. In order to protect the ecological environment of China and realize the sustainable development of environment and economy, the boiler tail gas needs to be treated by desulfurization and denitrification.

[0003] At present, the flue gas denitrification generally adopts the SCR (selective catalytic reduction) technology, which requires a high flue gas temperature, and the activity of the catalyst can be maintained only between 300 DEG C and 400 DEG C. The flue gas desulfurization generally adopts the limestone-gypsum wet flue gas desulfurization technology, which has a high removal efficiency, but has a high energy consumption, and the value of the desulfurization byproduct calcium sulfate is low and cannot be utilized, and a large amount of accumulation will cause secondary pollution problems.

[0004] In recent years, the state environmental protection has proposed the requirement of flue gas treatment and simultaneous desulfurization and denitrification. In response to the call of the state, people continuously research new technologies and equipment to synchronously remove SO2 and NOx in the waste gas at one time. At present, the simultaneous desulfurization and denitrification integration technologies include the activated carbon method, the SNOX process, the SNRB process, the NOXSO process and the electron beam method. However, the current desulfurization and denitrification integration technology is not mature enough, and the industrial application is difficult to completely realize, so most of the power plants and industrial boilers still adopt the method of separate desulfurization and denitrification. SUMMARY

[0005] The application provides a flue gas purification device applied to low-temperature catalytic desulfurization and denitrification integration, which has a simple structure, rapid reaction, can simultaneously complete the desulfurization and denitrification process in a short time, is convenient to operate and maintain, and has low investment and operation cost.

[0006] The technical scheme for solving the above technical problems is as follows: the flue gas purification device applied to low-temperature catalytic desulfurization and denitrification integration comprises a reaction tower, a desulfurization and denitrification agent inlet and a raw flue gas inlet are arranged at the bottom of the reaction tower, a cyclone is arranged in the reaction tower, the desulfurization and denitrification agent inlet is connected with the center hole of the cyclone through a material conveying pipeline, a dust removal assembly is fixedly arranged vertically above the cyclone, a back-blowing gas assembly is arranged vertically above the dust removal assembly, a flue gas discharging pipeline is arranged at the top of the reaction tower, and a material collecting assembly is communicated with the side wall of the upper part of the reaction tower.

[0007] Beneficial effects:

[0008] 1. Compared with conventional denitration SCR and SNCR, the denitration reaction temperature is low, and there are no disadvantages such as catalyst poisoning and ammonia leakage.

[0009] 2. The structure is simple, the reaction is rapid, the desulfurization and denitration processes can be completed at the same time in a short time, operation and maintenance are convenient, and investment and operation cost are low.

[0010] 3. Sulfur dioxide and nitrogen oxides in flue gas can be efficiently removed, and the byproduct does not cause secondary pollution and is environmentally friendly.

[0011] 4. It is suitable for flue gas treatment of various coal-fired power plants and industrial kilns, and has a broad prospect.

[0012] On the basis of the above technical scheme, the application can also be improved as follows.

[0013] Further, the material collecting assembly comprises a dust collector and a bin, the inlet of the dust collector is communicated with the inside of the reaction tower through a pipeline, the outlet of the dust collector is communicated with the flue gas pipeline through a pipeline, and the bin is arranged below the dust collector.

[0014] The beneficial effect of the above further scheme is that the product after desulfurization and denitration reaction is blown into the dust collector by the back-blowing air assembly and collected in the bin after dust removal.

[0015] Further, a first valve is arranged on the pipeline between the inlet of the dust collector and the reaction tower, a second valve is arranged on the pipeline between the outlet of the dust collector and the flue gas pipeline, and a fourth valve is arranged on the flue gas pipeline.

[0016] The beneficial effect of the above further scheme is that the valves can control the timed discharge of the reaction product.

[0017] Further, the dust removal assembly comprises a high-temperature cloth bag and a perforated plate, the perforated plate is fixed in the upper part of the reaction tower, and a plurality of high-temperature cloth bags are arranged on the perforated plate at intervals.

[0018] The beneficial effect of the above further scheme is that the dust removal function is achieved, the reaction of flue gas and desulfurization and denitration agent is accelerated, and the efficiency of flue gas purification is improved.

[0019] Further, the vertical upper part of the perforated plate is provided with the back-blowing air assembly.

[0020] The beneficial effect of the above further scheme is that the product after desulfurization and denitration reaction is blown into the dust collector.

[0021] Further, the back-blowing air assembly is a gas blowing nozzle, the gas inlet of the gas blowing nozzle is connected with a compressed air device through a pipeline, and a third valve is arranged on the gas blowing nozzle.

[0022] The beneficial effect of the further scheme is that the structure is simple, and the product after reaction can be quickly blown into the dust collector along with the flue gas.

[0023] Further, the distance between the high-temperature cloth bag and the cyclone is at least greater than 1.5 m.

[0024] The beneficial effect of the further scheme is that the desulfurization and denitrification agent can be fully mixed with the flue gas.

[0025] Further, the reaction tower is provided with multiple temperature measuring points and multiple pressure measuring points.

[0026] The beneficial effect of the further scheme is that the temperature and pressure of each point can be monitored in real time.

[0027] Further, the horizontal installation height of the raw flue gas inlet is above the desulfurization and denitrification agent inlet, and the installation should be along the tangent angle of the reaction tower and connected with the reaction tower.

[0028] The beneficial effect of the further scheme is that the raw flue gas can flow upward along the material conveying pipeline after entering the reaction tower.

[0029] Further, the material of the cyclone is stainless steel, and multiple blades with a certain angle and gap are arranged on the cyclone.

[0030] The beneficial effect of the further scheme is that the desulfurization and denitrification agent and the raw flue gas can be fully mixed under the action of the cyclone. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The figure is a structural schematic diagram of the present application;

[0032] Figure 2 The figure is a movement trajectory diagram of the raw flue gas in the material conveying pipeline of the present application;

[0033] Figure 3 The figure is a structural schematic diagram of the cyclone;

[0034] Figure 4 The figure is a structural schematic diagram of the dust removal assembly;

[0035] Figure 5 The figure is a structural schematic diagram of the dust collector;

[0036] In the drawings, the components represented by each reference numeral are listed as follows:

[0037] 1. Reaction tower; 2. Desulfurization and denitrification agent inlet; 3. Raw flue gas inlet; 4. Material conveying pipeline; 5. Cyclone separator; 6. Dust collector; 7. High-temperature filter bag; 8. Orifice plate; 9. Air blowing nozzle; 10. Temperature measuring point; 11. Pressure measuring point; 12. First valve; 13. Second valve; 14. Third valve; 15. Fourth valve; 16. Silo. Detailed Implementation

[0038] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0039] Example

[0040] like Figures 1-5 As shown, this embodiment provides a flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification, including a reaction tower 1. The bottom of the reaction tower 1 is provided with a desulfurization and denitrification agent inlet 2 and a raw flue gas inlet 3. The inside of the reaction tower 1 is provided with a hydrocyclone 5. The desulfurization and denitrification agent inlet 2 is connected to the center hole of the hydrocyclone 5 through a material conveying pipe 4. A dust removal component is fixedly provided above the vertically oriented hydrocyclone 5. A backflush air component is provided above the vertically oriented dust removal component. The top of the reaction tower 1 is provided with a flue gas exhaust pipe. A material receiving component is connected to the upper side wall of the reaction tower 1.

[0041] In this embodiment, the hydrocyclone 5 is fixed inside the reaction tower 1. It has multiple blades at a certain angle to the horizontal and with certain gaps. After entering the reaction tower, the raw flue gas flows upwards and rotates around the material conveying pipe 4, exiting at high speed through the gaps in the blades of the hydrocyclone 5. The desulfurization and denitrification agent is sprayed from the central hole of the hydrocyclone, ultimately coming into close contact with the high-speed rotating flue gas outside the central hole of the hydrocyclone 5, fully mixing and undergoing a preliminary reaction. It should be noted that the rotation direction of the raw flue gas along the material conveying pipe 4 must be consistent with the rotation direction of the hydrocyclone 5 to ensure sufficient gas-solid mixing.

[0042] In this embodiment, the cyclone separator 5 is made of 201 stainless steel. Because the flue gas continuously scours the blades of the cyclone separator 5, and since the flue gas has not yet undergone desulfurization and denitrification, it is corrosive, thus requiring high-quality materials. The main function of the cyclone separator is to fully mix the flue gas with the desulfurization and denitrification agent. The quality of this mixing depends entirely on the number and angle of the blades on the cyclone separator 5. Too many blades or too small an angle will result in high resistance in the cyclone separator, and high resistance does not necessarily mean good mixing. Too few blades or too large an angle will result in weak rotational force of the flue gas passing through the cyclone separator, leading to poor mixing. Therefore, a suitable number of blades and blade angle are crucial. The preferred number of blades is 16 to 22, and the blade angle is 36° to 50°.

[0043] In this embodiment, the components of the desulfurization and denitrification agent are two or more of ammonium sulfate, ammonium sulfite, sodium sulfite, ferrous sulfate, and sodium carbonate. The horizontal installation height of the original flue gas inlet 3 is above the desulfurization and denitrification agent inlet 2 to avoid the collision of the flue gas with the transverse pipeline of the desulfurization and denitrification agent inlet 2 after entering the reaction tower 1, thereby reducing the resistance of the original flue and avoiding the erosion of the flue gas on the elbow of the desulfurization and denitrification agent inlet 2. The original flue gas inlet 3 should be connected to the reaction tower 1 along the tangent angle of the reaction tower 1 during installation, and the material conveying pipeline 4 is vertically installed at the center of the reaction tower 1 and is connected to the center hole of the cyclone 5.

[0044] In this embodiment, the material collecting assembly includes a dust collector 6 and a bin 16. The inlet of the dust collector 6 is connected to the inside of the reaction tower 1 through a pipeline, the outlet of the dust collector 6 is connected to the flue gas pipeline through a pipeline, and the bin 16 is arranged below the dust collector 6. A first valve 12 is arranged on the pipeline between the inlet of the dust collector 6 and the reaction tower 1, a second valve 13 is arranged on the pipeline between the outlet of the dust collector 6 and the flue gas pipeline, and a fourth valve 15 is arranged on the flue gas pipeline.

[0045] In this embodiment, the dust collector 6 can be one or a series connection of a cyclone dust collector, a bag dust collector, or an electric dust collector.

[0046] In this embodiment, the dust collecting assembly includes high-temperature bags 7 and a hole plate 8. The hole plate 8 is fixed in the upper part of the reaction tower 1, and a plurality of high-temperature bags 7 are arranged on the hole plate 8 at intervals. The material of the high-temperature bags 7 should be able to withstand a temperature of at least 120°C or above, and the pore size is slightly smaller than the particle size of the desulfurization and denitrification agent but larger than the pore size of the bag used in a conventional bag dust collector. The high-temperature bags 7 are the main reaction site of the flue gas and the desulfurization and denitrification agent, and the number and length of the high-temperature bags 7 are related to the material of the bags and the required flow velocity. Relatively speaking, a small flow velocity and a large filtering area can achieve better desulfurization and denitrification effects. The high-temperature bags 7 are directly above the cyclone 5, and the mixing of the desulfurization and denitrification agent and the flue gas after passing through the cyclone 5 requires a certain time and space. Therefore, the distance between the bottom of the high-temperature bags 7 and the cyclone 5 should be at least 1.5 m to ensure that the desulfurization and denitrification agent and the flue gas can be fully mixed.

[0047] In this embodiment, the vertical upper part of the hole plate 8 is provided with a back-blowing air assembly, which is a blowing nozzle 9. The air inlet of the blowing nozzle 9 is connected to a compressed air device through a pipeline, and a third valve 14 is arranged thereon.

[0048] In addition, there are many temperature measuring points 10 and pressure measuring points 11 on the flue gas purification device to monitor the temperature and pressure of each point in real time. The upper part of the high-temperature bags 7 in the tower is provided with a back-blowing assembly. When the bag pressure is too high, the bag needs to be back-blown.

[0049] When the device is running, all are in the closed state, when the high-temperature cloth bag 7 in the reaction tower 1 needs to be purged due to excessive pressure, the fourth valve 15 is closed, the first valve 12, the second valve 13 and the third valve 14 are opened, after purging, the fourth valve 15 is opened again, and the first valve 12, the second valve 13 and the third valve 14 are closed.

[0050] In the operation process of the present application, under the action of the induced draft fan and the booster fan, the original flue gas flows upwards in the reaction tower 1 from the flue inlet 3, and obtains greater rotating force after passing through the cyclone 5. At the same time, the desulfurization and denitrification agent enters the tower from the material inlet 2 and is sprayed out from the center hole of the cyclone 5. The original flue gas and the desulfurization and denitrification agent are fully mixed under the action of the cyclone 5. At this time, the reaction temperature in the reaction tower 1 is met, so the preliminary removal of sulfur dioxide and nitrogen oxides can be completed in the process of close contact between the desulfurization and denitrification agent and the flue gas. The flue gas carrying the desulfurization and denitrification agent continues to flow upwards, and finally the desulfurization and denitrification agent adheres to the surface of the high-temperature cloth bag 7 in the tower. The flue gas can only leave the reaction tower 1 by passing through the cloth bag. When the flue gas passes through the cloth bag, it is squeezed and contacted again with the desulfurization and denitrification agent adhering to the surface of the cloth bag, and a reaction occurs, finally completing the deep purification of sulfur dioxide and nitrogen oxides. As the purification device proceeds, more and more reaction materials adhere to the surface of the high-temperature cloth bag 7. At this time, the pressure in the tower will be higher and higher. When it is monitored that the pressure in the reaction tower 1 is too high, the first valve 12 and the second valve 13 are opened and the fourth valve 15 is closed, and the flue gas temporarily passes through the bypass flue. After passing through the dust collector 6, it is discharged. At the same time, the third valve 14 is opened, and compressed air is used to blow back the high-temperature cloth bag 7 in the tower through the back blowing assembly. Therefore, the materials blown off enter the dust collector 6 under the action of the flue gas, and the materials temporarily adhere to the cloth bag of the dust collector 6. After purging, the fourth valve 15, the first valve 12, the second valve 13 and the third valve 14 are opened, and the flue gas and the desulfurization and denitrification agent continue to react on the high-temperature cloth bag 6 in the reaction tower 1. The purified flue gas is discharged from the top of the tower, and the reaction materials are finally collected in the material bin 16 below the dust collector 6.

[0051] In summary, the low-temperature catalytic desulfurization and denitrification integrated flue gas purification device of the present application completes the simultaneous removal of sulfur dioxide and nitrogen oxides in flue gas, has a low reaction temperature, and can complete the desulfurization and denitrification processes in one reaction tower, greatly simplifying the separate removal systems for desulfurization and denitrification. It has a wide range of applications, is technically and economically superior, is suitable for flue gas treatment of various coal-fired power plants and industrial kilns, and has a broad prospect.

[0052] In the description of the application, it should be understood that the terms "center", "length", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "inner", "outer", "peripheral side", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0053] In the description of the application, "a plurality of" means at least two, for example two, three, etc., unless otherwise explicitly specified and limited.

[0054] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0056] The above is only the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification, characterized in that, The reaction tower (1) includes a desulfurization and denitrification agent inlet (2) and a raw flue gas inlet (3) at its bottom. A hydrocyclone (5) is installed inside the reaction tower (1). The desulfurization and denitrification agent inlet (2) is connected to the center hole of the hydrocyclone (5) via a material conveying pipe (4). A dust removal assembly is fixedly installed vertically above the hydrocyclone (5), and a backflush assembly is installed vertically above the dust removal assembly. A flue gas exhaust pipe is installed at the top of the reaction tower (1). The upper sidewall of the reaction tower (1) is... The material receiving assembly is connected; the material receiving assembly includes a dust collector (6) and a hopper (16). The inlet of the dust collector (6) is connected to the interior of the reaction tower (1) through a pipe, and the outlet of the dust collector (6) is connected to the exhaust pipe through a pipe. The hopper (16) is located below the dust collector (6). The dust collection assembly includes a high-temperature filter bag (7) and a perforated plate (8). The perforated plate (8) is fixed inside the upper part of the reaction tower (1), and multiple high-temperature filter bags (7) are spaced apart on the perforated plate (8).

2. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification as described in claim 1, characterized in that, A first valve (12) is provided on the pipe between the inlet of the dust collector (6) and the reaction tower (1), a second valve (13) is provided on the pipe between the outlet of the dust collector (6) and the exhaust pipe, and a fourth valve (15) is provided on the exhaust pipe.

3. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification as described in claim 1, characterized in that, The backflush assembly is located vertically above the orifice plate (8).

4. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification as described in claim 3, characterized in that, The backflush assembly is a blow nozzle (9), and the air inlet of the blow nozzle (9) is connected to a compressed air device through a pipe, and a third valve (14) is provided on it.

5. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification as described in claim 3, characterized in that, The distance between the high-temperature cloth bag (7) and the hydrocyclone (5) is at least greater than 1.5m.

6. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification according to any one of claims 1-5, characterized in that, The reaction tower (1) is equipped with multiple temperature measuring points (10) and multiple pressure measuring points (11).

7. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification according to any one of claims 1-5, characterized in that, The horizontal installation height of the original flue gas inlet (3) is above the desulfurization and denitrification agent inlet (2), and it should be connected to the reaction tower (1) along the tangent angle of the reaction tower (1) during installation.

8. The flue gas purification device for integrated low-temperature catalytic desulfurization and denitrification according to any one of claims 1-5, characterized in that, The hydrocyclone (5) is made of stainless steel and has multiple blades that are at a certain angle to the horizontal and have a certain gap.

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