Process and device for reducing exhaust gas of a pellet

Abstract

The present application relates to waste gas emission reduction technical field, disclose a kind of pellet waste gas emission reduction process and device, including equipment installation and debugging, equipment connection and waste gas emission reduction and utilization.The present application is produced by belt roaster or chain grate machine when producing pellet, a large amount of high-temperature flue gas is first passed through filter box and electric dust collector preliminary dust removal purification, and is led out by main exhaust fan.According to production needs, the air volume is distributed by distribution valve one, distribution valve two and distribution valve three, and the waste gas is sent to desulfurization and denitrification system, cooling system and combustion-supporting system three subsystems.Because of the shunt effect of cooling system and combustion-supporting system, the load of desulfurization and denitrification system is reduced, and the goal of waste gas emission reduction is achieved.

Description

Technical Field

[0001] This invention relates to the field of waste gas emission reduction technology, specifically to a process and apparatus for reducing waste gas emissions from pelletizing plants. Background Technology

[0002] When using belt roasters or chain grate machines to produce pellets, a large amount of hot waste gas containing harmful substances such as dust and sulfides is generated. If it is discharged directly, it cannot meet environmental protection requirements. Therefore, it must be purified before it can be discharged.

[0003] Currently, the main purification process for hot exhaust gas is as follows: the hot exhaust gas first passes through an electrostatic precipitator for preliminary ash removal, and then is introduced into a desulfurization and denitrification system by the main exhaust fan to purify dust and harmful substances. After all indicators meet environmental protection requirements, it is directly discharged into the atmosphere through a chimney. The shortcomings and deficiencies of the existing technology are as follows: 1. High investment cost for desulfurization: The total amount of waste gas to be treated is large, the scale of the desulfurization and denitrification system is large, and the investment cost is high; 2. Low utilization rate of sensible heat in exhaust gas: After being purified by the equipment, the hot exhaust gas is directly discharged into the atmosphere, and the heat it contains is basically not utilized, resulting in energy waste. Summary of the Invention

[0004] The purpose of this invention is to address the problems of high investment costs in desulfurization, large volume of waste gas to be treated, large scale of desulfurization and denitrification systems, low utilization rate of sensible heat of waste gas, and direct discharge of hot waste gas into the atmosphere after equipment purification, resulting in energy waste due to the lack of utilization of its heat content. Therefore, this invention proposes a process and device for reducing waste gas emissions from pelletizing plants.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a process for reducing emissions from pelletizing waste gas, comprising the following steps: Equipment installation and commissioning: Check the operation of the desulfurization and denitrification system, check the operation of the cooling system, check the operation of the combustion system, and test the smoothness of sliding parts and the operation of power parts. Equipment connection: Connect the exhaust gas generated by the belt roaster or chain grate machine during pellet production to the filter box; Waste gas emission reduction and utilization: The waste gas undergoes primary filtration in the filter box. After primary filtration, the waste gas enters the electrostatic precipitator and is drawn out by the main exhaust fan. By adjusting distribution valve one, distribution valve two, and distribution valve three, the waste gas is sent to the desulfurization and denitrification system, the cooling system, and the combustion system, respectively.

[0006] In a first aspect, the present invention provides a device for reducing emissions of pellet waste gas, comprising a filter box, one end of which is connected to an electrostatic precipitator, one end of which is connected to a main exhaust fan, one end of which is connected to a pipe, and the ends of the pipe are respectively connected to a distribution valve one, a distribution valve two, and a distribution valve three, one end of the distribution valve one being connected to a desulfurization and denitrification system, one end of the distribution valve two being connected to a cooling system, and one end of the distribution valve three being connected to a combustion-supporting system.

[0007] In a preferred embodiment of the present invention, the desulfurization and denitrification system includes a desulfurization and denitrification device, an induced draft fan, and a chimney. The desulfurization and denitrification device is fixed to one end of a distribution valve, the induced draft fan is fixed to one end of the desulfurization and denitrification device, and the chimney is fixed to one end of the induced draft fan. The cooling system includes a regulating valve, an annular cooling fan, and an annular cooler. The regulating valve is connected to one end of a distribution valve, the annular cooling fan is connected to one end of the regulating valve, and the annular cooler is connected to one end of the annular cooling fan. The combustion-supporting system includes a combustion-supporting fan and a hot air furnace. The hot air furnace is connected to one end of a distribution valve, and the hot air furnace is connected to one end of the combustion-supporting fan.

[0008] In a preferred embodiment of the present invention, a filter screen is fixed inside the filter box, two sliding rods are fixed inside the filter box, a sliding plate slides on the outer side of the two sliding rods, a telescopic rod is fixed on one side of the sliding plate, a cleaning brush is fixed at one end of the telescopic rod, a spring is fixed between the cleaning brush and the sliding plate, and the spring is sleeved on the outer side of the telescopic rod.

[0009] In a preferred embodiment of the present invention, a limiting groove is provided on one side of the sliding plate, a motor is fixed on one side of the filter box, a rotating shaft is fixed at the output end of the motor, and a bevel gear is fixed at one end of the rotating shaft. The rotating shaft and the bevel gear form a rotating structure through the motor.

[0010] In a preferred embodiment of the present invention, a side plate is fixed inside the filter box, and a second rotating shaft is rotatably mounted on one side of the side plate. A second bevel gear is fixed to one end of the second rotating shaft, and the first bevel gear and the second bevel gear mesh with each other. A rotating rod is fixed to the other end of the second rotating shaft, and a limiting rod rotates on one side of the rotating rod, so that the limiting rod and the limiting groove are slidably connected.

[0011] In a preferred embodiment of the present invention, a gear disk is fixed to the outer side of the rotating shaft, and a drain trough is provided on both sides of the filter box. A spiral rod is rotatably provided on the inner side of the drain trough. The upper end of the spiral rod extends to the outer side of the drain trough, and a gear disk is fixed to the upper end of the spiral rod. A toothed belt meshes between the gear disk and the gear disk.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. Desulfurization investment costs are low, some waste gas is utilized, the total amount of gas entering the desulfurization and denitrification system is reduced, the scale of the desulfurization and denitrification system is reduced, and investment costs are lowered. 2. The waste gas has a high sensible heat utilization rate. Some of the waste gas is used in the drying system, and the heat it contains is effectively utilized, which improves the heat utilization rate of the waste gas and reduces production costs. Attached Figure Description

[0013] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0014] Figure 1 This is a flowchart of a pelletizing waste gas emission reduction process according to an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of the present invention; Figure 3 This is a schematic diagram of the rear three-dimensional structure of the present invention; Figure 4 This is a schematic diagram of the internal three-dimensional structure of the filter box of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of the filter box of the present invention.

[0015] In the diagram: 1. Filter box; 2. Electrostatic precipitator; 3. Main exhaust fan; 4. Pipeline; 5. Distribution valve one; 6. Desulfurization and denitrification device; 7. Exhaust fan; 8. Chimney; 9. Distribution valve two; 10. Regulating valve; 11. Circulating cooler; 12. Circulating cooler; 13. Distribution valve three; 14. Combustion fan; 15. Hot air furnace; 16. Filter screen; 17. Sliding rod; 18. Sliding plate; 19. Telescopic rod; 20. Cleaning brush; 21. Spring; 22. Limiting groove; 23. Motor; 24. Shaft one; 25. Bevel gear one; 26. Side plate; 27. Shaft two; 28. Bevel gear two; 29. ​​Rotating rod; 30. Limiting rod; 31. Gear disc one; 32. Sewage discharge trough; 33. Spiral rod; 34. Gear disc two; 35. Toothed belt. Detailed Implementation

[0016] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0017] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0019] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] Example 1 Please see Figures 1-5 As shown, a process for reducing emissions from pelletizing waste gas includes the following steps: Equipment installation and commissioning: Check the operation of the desulfurization and denitrification system, such as the operation of the induced draft fan 7; check the operation of the cooling system, such as the operation of the ring cooler fan 11 and the ring cooler 12; check the operation of the combustion system, such as the operation of the combustion fan 14 and the hot air furnace 15; test the smoothness of sliding parts and the operation of power parts, such as the smoothness of sliding between the limit rod 30 and the limit groove 22, the operation of the motor 23, and the transmission smoothness of bevel gear 1 25 and bevel gear 2 28. Equipment connection: Connect the exhaust gas generated by the belt roaster or chain grate machine during pellet production to filter box 1; Waste gas emission reduction and utilization: The waste gas is initially filtered by the filter box 1. After the initial filtration, the waste gas enters the electrostatic precipitator 2 for secondary filtration and dust removal. It is then led out by the main exhaust fan 3. By adjusting the distribution valve 1 5, distribution valve 2 9 and distribution valve 3 13, the waste gas is sent to the desulfurization and denitrification system, the cooling system and the combustion system respectively.

[0022] Example 2 Please see Figures 1-5 As shown, a device for reducing emissions from pelletizing waste gas includes a filter box 1. One end of the filter box 1 is connected to an electrostatic precipitator 2, and one end of the electrostatic precipitator 2 is connected to a main exhaust fan 3. One end of the main exhaust fan 3 is connected to a pipe 4, and the ends of the pipe 4 are respectively connected to a distribution valve 5, a distribution valve 9, and a distribution valve 13. One end of the distribution valve 5 is connected to a desulfurization and denitrification system, one end of the distribution valve 9 is connected to a cooling system, and one end of the distribution valve 13 is connected to a combustion-supporting system. The desulfurization and denitrification system includes a desulfurization and denitrification device 6, an induced draft fan 7, and a chimney 8. The desulfurization and denitrification device 6 is fixed to one end of the distribution valve 5, the induced draft fan 7 is fixed to one end of the desulfurization and denitrification device 6, and the chimney 8 is fixed to one end of the induced draft fan 7. The cooling system includes a regulating valve 1. 0. Circular cooling fans 11 and 12, regulating valve 10 is connected to one end of distribution valve 2 9, circular cooling fan 11 is connected to one end of regulating valve 10, and circular cooling fan 12 is connected to one end of circular cooling fan 11. The combustion system includes combustion fan 14 and hot air furnace 15. Hot air furnace 15 is connected to one end of distribution valve 3 13 and hot air furnace 15 is connected to one end of combustion fan 14. When the belt roaster or chain grate machine produces pellets, a large amount of high-temperature flue gas is first pre-purified by filter box 1 and electrostatic precipitator 2, and then led out by main exhaust fan 3. According to production needs, the air volume is distributed through distribution valve 1 5, distribution valve 2 9 and distribution valve 3 13, and the exhaust gas is sent to the desulfurization and denitrification system, cooling system and combustion system respectively.

[0023] Example 3 Please see Figures 1-5As shown, a filter screen 16 is fixed inside the filter box 1. Two sliding rods 17 are fixed inside the filter box 1. A sliding plate 18 slides on the outer side of the two sliding rods 17. A telescopic rod 19 is fixed on one side of the sliding plate 18. A cleaning brush 20 is fixed to one end of the telescopic rod 19. A spring 21 is fixed between the cleaning brush 20 and the sliding plate 18, and the spring 21 is sleeved on the outer side of the telescopic rod 19. A limit groove 22 is opened on one side of the sliding plate 18. A motor 23 is fixed on one side of the filter box 1. A rotating shaft 24 is fixed to the output end of the motor 23. A bevel gear 25 is fixed to one end of the rotating shaft 24. The rotating shaft 24 and the bevel gear 25 form a rotating structure through the motor 23. A side plate 26 is fixed inside the filter box 1. A rotating shaft 27 is rotatably mounted on one side of the side plate 26. A bevel gear 28 is fixed to one end of the rotating shaft 27. The bevel gear 25 and the bevel gear 28 mesh with each other. A rotating rod 29 is fixed to the other end of the rotating shaft 27. A limiting rod 30 rotates on one side of the rotating rod 29, and the limiting rod 30 is slidably connected to the limiting groove 22. A gear disk 31 is fixed to the outside of the rotating shaft 24. Drainage troughs 32 are provided on both sides of the filter box 1. A spiral rod 33 rotates inside the drainage trough 32. The upper end of the spiral rod 33 extends to the outside of the drainage trough 32, and a gear disk 34 is fixed to the upper end of the spiral rod 33. The gear disk 31 and the gear disk 34 are connected. A toothed belt 35 meshes between the two shafts 34. A filter 16 filters dust from the exhaust gas. Motor 23 drives shaft 24 to rotate, which in turn drives bevel gear 25. Bevel gear 25 then drives bevel gear 28, which in turn drives shaft 27. Shaft 27 then drives rotating rod 29, causing limiting rod 30 to slide repeatedly within limiting groove 22. This allows limiting rod 30 to repeatedly move sliding plate 18 on sliding rod 17. The sliding adjustment allows the sliding plate 18 to repeatedly slide and adjust the telescopic rod 19 and the cleaning brush 20, enabling the cleaning brush 20 to clean the filter screen 16. The spring 21 provides elasticity to the cleaning brush 20, ensuring that the cleaning brush 20 remains in contact with the surface of the filter screen 16. Simultaneously, the rotating shaft 24 drives the gear disk 31 to rotate, which in turn drives the gear disk 34 to rotate synchronously under the action of the toothed belt 35. The gear disk 34 then drives the spiral rod 33 to rotate, allowing the cleaned dust to be transported out, simplifying the cleaning and collection of dust.

[0024] In use, when the belt calciner or chain grate machine produces pellets, a large amount of high-temperature flue gas is first purified by a filter box 1 and an electrostatic precipitator 2. The filter screen 16 filters dust from the exhaust gas. By controlling the motor 23, the motor drives the rotating shaft 24 to rotate, which in turn drives the bevel gear 25 to rotate. The bevel gear 25 then drives the meshing bevel gear 28 to rotate, which in turn drives the rotating shaft 27 to rotate. The rotating shaft 27 then drives the rotating rod 29 to rotate, causing the limiting rod 30 to repeatedly move within the limiting groove 22. The sliding adjustment allows the limiting rod 30 to repeatedly slide the sliding plate 18 on the sliding rod 17, which in turn allows the sliding plate 18 to repeatedly slide the telescopic rod 19 and the cleaning brush 20. This allows the cleaning brush 20 to clean the filter screen 16. The spring 21 provides elasticity to the cleaning brush 20, ensuring it remains in contact with the surface of the filter screen 16. Simultaneously, the rotating shaft 24 drives the gear disc 31 to rotate, which in turn, under the action of the toothed belt 35, drives the gear disc 34 to rotate synchronously. The gear disc 34 then drives the spiral rod 33 to rotate, allowing the spiral rod 33 to clean the filter screen. The dust is conveyed out and drawn out by the main exhaust fan 3. According to production needs, the air volume is distributed through distribution valve 5, distribution valve 9, and distribution valve 13, sending the exhaust gas to the desulfurization and denitrification system, cooling system, and combustion system respectively. Some of the medium-temperature exhaust gas, after passing through distribution valve 5, enters the desulfurization and denitrification device 6 to remove dust, sulfides, and other harmful substances. After all indicators meet environmental protection requirements, it is sent by the exhaust fan 7 to the chimney 8 for direct discharge into the atmosphere. To ensure production needs and save energy, the exhaust fan 7 operates with a variable frequency drive. Some of the medium-temperature exhaust gas, after passing through distribution valve 9, enters several annular cooling fans 11. The annular cooling fans 11 blow the medium-temperature exhaust gas into the annular cooler 12 to cool the sintered cake. The high-temperature exhaust gas from the sintered cake goes to the pellet preheating and roasting system. The number of annular cooling fans 11 is configured according to the needs of the annular cooler 12. Each annular cooling fan 11 is equipped with a regulating valve 10 before its inlet, which can adjust the amount of exhaust gas entering each annular cooling fan 11 according to the cooling requirements. In order to adapt to the adjustment of the cooling system and save energy, the annular cooling fan 11 is operated by frequency conversion. Some of the medium-temperature exhaust gas enters the hot air furnace 15 of the combustion fan 14 after passing through the distribution valve 13, and serves as the high-temperature combustion air for the gas combustion in the hot air furnace 15. Because the medium-temperature exhaust gas has a certain amount of heat, it can realize the hot air combustion of the gas, which can save gas. In order to adapt to the adjustment of the combustion system and save energy, the combustion fan 14 is operated by frequency conversion.

[0025] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A device for reducing emissions of pelletizing exhaust gas, characterized in that, Includes a filter box (1), one end of which is connected to an electrostatic precipitator (2), one end of which is connected to a main exhaust fan (3), one end of which is connected to a pipe (4), and the ends of the pipe (4) are respectively connected to a distribution valve one (5), a distribution valve two (9) and a distribution valve three (13), one end of the distribution valve one (5) is connected to a desulfurization and denitrification system, one end of the distribution valve two (9) is connected to a cooling system, and one end of the distribution valve three (13) is connected to a combustion-supporting system; The desulfurization and denitrification system includes a desulfurization and denitrification device (6), an induced draft fan (7), and a chimney (8). The desulfurization and denitrification device (6) is fixed at one end of the distribution valve (5), the induced draft fan (7) is fixed at one end of the desulfurization and denitrification device (6), and the chimney (8) is fixed at one end of the induced draft fan (7). The cooling system includes a regulating valve (10), an annular cooling fan (11), and an annular cooling fan (12). The regulating valve (10) is connected to one end of the distribution valve (9), the annular cooling fan (11) is connected to one end of the regulating valve (10), and the annular cooling fan (12) is connected to one end of the annular cooling fan (11). The combustion-supporting system includes a combustion-supporting fan (14) and a hot air furnace (15). The hot air furnace (15) is connected to one end of the distribution valve (3) and the hot air furnace (15) is connected to one end of the combustion-supporting fan (14). A filter screen (16) is fixed inside the filter box (1). Two sliding rods (17) are fixed inside the filter box (1). A sliding plate (18) slides on the outside of the two sliding rods (17). A telescopic rod (19) is fixed on one side of the sliding plate (18). A cleaning brush (20) is fixed at one end of the telescopic rod (19). A spring (21) is fixed between the cleaning brush (20) and the sliding plate (18), and the spring (21) is sleeved on the outside of the telescopic rod (19). A limiting groove (22) is provided on one side of the sliding plate (18), and a motor (23) is fixed on one side of the filter box (1). A rotating shaft (24) is fixed at the output end of the motor (23), and a bevel gear (25) is fixed at one end of the rotating shaft (24). The motor (23) drives the rotating shaft (24) to rotate, so that the rotating shaft (24) drives the bevel gear (25) to rotate, thereby forming a rotating structure. The filter box (1) is fixed with a side plate (26). A rotating shaft (27) is rotatably mounted on one side of the side plate (26). A bevel gear (28) is fixed at one end of the rotating shaft (27). The bevel gear (25) meshes with the bevel gear (28). A rotating rod (29) is fixed at the other end of the rotating shaft (27). A limiting rod (30) rotates on one side of the rotating rod (29), so that the limiting rod (30) is slidably connected to the limiting groove (22). A gear disk (31) is fixed on the outer side of the rotating shaft (24). A drain trough (32) is provided on both sides of the filter box (1). A screw rod (33) rotates on the inner side of the drain trough (32). The upper end of the screw rod (33) extends to the outer side of the drain trough (32), and a gear disk (34) is fixed on the upper end of the screw rod (33). A toothed belt (35) meshes between the gear disk (31) and the gear disk (34).

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