Environment-friendly smoke dust treatment device for steelmaking plant area

Abstract

This utility model relates to the field of metallurgical environmental protection technology, specifically a dust control device for steelmaking plants. It includes a dust collection hood, a cyclone dust collector, a spray cooling tower, and a bag filter, connected sequentially along the dust flow direction. A flue gas emission pipe is connected to the side wall at the top of the bag filter, and an installation cylinder is connected to the flue gas emission pipe. This utility model adopts a three-stage treatment process of "cyclone dust collection + spray cooling + bag filtration." The cyclone dust collector first removes larger coarse dust particles, reducing the load on subsequent equipment. The spray cooling tower lowers the temperature of the high-temperature flue gas to the suitable operating range of the bag filter (usually below 200℃), while simultaneously capturing some fine particles through water mist. The bag filter performs final fine filtration to ensure that the outlet dust concentration meets ultra-low emission standards. A settling tank and circulating water pump are installed at the bottom of the spray cooling tower to achieve the recycling of spray water, reducing wastewater discharge and external water replenishment.

Description

Technical Field

[0001] This utility model relates to the field of metallurgical environmental protection technology, specifically to an environmental dust control device for steelmaking plants. Background Technology

[0002] During the steelmaking process, converters, electric furnaces, and refining furnaces generate a large amount of high-temperature dusty flue gas during the smelting stage. These flue gases are characterized by high temperature (up to 800℃-1200℃), high dust concentration, and drastic fluctuations in flue gas volume. The dust in the flue gas mainly consists of metal oxide particles such as iron oxide and calcium oxide. Direct emission of these particles would cause serious pollution to the atmospheric environment and also waste metal resources.

[0003] Currently, dry or semi-dry dust removal technologies are commonly used for steelmaking flue gas treatment. However, traditional dust removal equipment has the following problems when dealing with high-temperature flue gas:

[0004] 1. Excessively high flue gas temperature can easily damage fine filtration elements such as filter bags, resulting in poor system stability;

[0005] 2. A single dust removal method is difficult to achieve the same efficiency in removing both large dust particles and fine particulate matter, and the emission concentration is difficult to meet the increasingly stringent ultra-low emission standards.

[0006] 3. Some devices lack intelligent monitoring methods and cannot monitor emission status in real time.

[0007] Therefore, there is an urgent need to develop an environmentally friendly dust control device that can adapt to the high temperature and high dust characteristics of steelmaking flue gas, and has high dust removal efficiency and stable operation. Utility Model Content

[0008] The purpose of this utility model is to provide an environmental protection dust control device for steelmaking plants, so as to solve the problems of low efficiency and poor stability of existing steelmaking dust control devices when dealing with high-temperature and high-concentration flue gas.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] An environmental dust control device for steelmaking plants includes a dust collection hood, a cyclone dust collector, a spray cooling tower, and a bag filter, which are connected sequentially along the dust flow direction. A flue gas emission pipe is connected to the side wall at the top of the bag filter, and an installation cylinder is connected to the flue gas emission pipe. An induced draft fan is installed inside the installation cylinder.

[0011] The spray cooling tower is arranged from top to bottom as follows: a demisting chamber, a second spraying chamber, a first spraying chamber, and a settling tank. The outlet of the cyclone dust collector is connected to the bottom wall of the first spraying chamber. A permeable baffle is provided between the demisting chamber, the second spraying chamber, the first spraying chamber, and the settling tank. A filling layer is provided on the permeable baffle on the first and second spraying chambers. A baffle plate demisting device is provided on the permeable baffle on the demisting chamber. A filter baffle is vertically installed at the center of the settling tank. A clean water tank is provided at the other end of the settling tank through the filter baffle. The permeable baffle above the clean water tank is in a sealed state. A spray assembly is provided at the clean water tank. A sewage discharge assembly is also provided at the bottom of the settling tank. The sewage discharge assembly includes a sewage discharge pipe connected to the settling tank. An exhaust pipe is provided at the top of the demisting chamber.

[0012] The bag filter is equipped with a tube sheet, the top of which is a clean air chamber and the bottom of which is a filter chamber. An air injection pipe is connected to the side wall of the filter chamber and is connected to an exhaust pipe. A dust hopper connected to the filter chamber is located at the bottom of the bag filter. Multiple filter bags are evenly clamped on the tube sheet. A dust removal assembly is installed inside the bag filter.

[0013] Preferably, a high-temperature resistant pipe is connected between the dust collection hood and the cyclone dust collector, the inner wall of the high-temperature resistant pipe is provided with a refractory castable layer, and an airlock ash discharge valve is provided at the bottom of the cyclone dust collector.

[0014] Preferably, the spray assembly includes a circulating water pump disposed at the bottom of the spray cooling tower, the inlet of the circulating water pump extending to the bottom of the water purification tank, the outlet of the circulating water pump being connected to a conduit, and the other end of the conduit extending to the top of the first spray chamber and the second spray chamber respectively and connected to a spray nozzle.

[0015] Preferably, a spiral conveying roller is installed inside the sewage pipe, a motor for controlling the rotation of the spiral conveying roller is fixedly installed on the side wall of the sewage pipe, and a slag discharge pipe with a valve is connected to the bottom end of the sewage pipe.

[0016] Preferably, the dust removal assembly includes an air pump installed on the side wall of the bag filter, the air pump outlet is connected to a connecting frame, the bottom end of the connecting frame is evenly connected to multiple blow pipes, and the air pump outlet is also equipped with an electromagnetic pulse valve.

[0017] Preferably, the opening of the filter bag is located in the clean air chamber, and the bottom end of the blow pipe extends into the filter bag.

[0018] Preferably, the flue gas emission pipe is further equipped with a dust concentration sensor, a temperature sensor, and a flow rate sensor, which are electrically connected to the controller.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0020] 1. Multi-stage gradient purification: This utility model adopts a three-stage treatment process of "cyclone dust collection + spray cooling + bag filter". The cyclone dust collector first removes coarse dust particles with larger particle sizes, reducing the load on subsequent equipment; the spray cooling tower reduces the temperature of the high-temperature flue gas to the suitable working range of the bag filter (usually below 200°C), while capturing some fine particles through water mist; the bag filter performs final fine filtration to ensure that the outlet dust concentration meets the ultra-low emission standard.

[0021] 2. Stable system operation: The precise temperature control of the spray cooling tower effectively avoids the risk of high-temperature flue gas burning the filter bags, extending the service life of the filter bags. At the same time, the pre-installation of the cyclone dust collector reduces the wear of coarse particles on the filter bags, ensuring the long-term stable operation of the system.

[0022] 3. Water-saving and environmentally friendly: The bottom of the spray cooling tower is equipped with a sedimentation tank and a circulating water pump to realize the recycling of spray water, reduce wastewater discharge and external water replenishment, and the sludge in the sedimentation tank can be automatically and regularly cleaned by the sewage discharge component, which is beneficial to the filtration of sewage.

[0023] 4. Intelligent monitoring: An online monitoring system is installed on the flue gas emission pipe to monitor dust concentration, temperature and flow rate in real time, which allows operators to adjust operating parameters in a timely manner to ensure that emissions meet standards. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0025] Figure 2 This is a cross-sectional structural diagram of the spray cooling tower in an embodiment of this utility model;

[0026] Figure 3 This is a cross-sectional structural diagram of the bag filter in an embodiment of the present utility model;

[0027] Figure 4 This is a schematic diagram of the top of the bag filter in an embodiment of the present invention.

[0028] In the diagram: 1. Dust collection hood; 2. Cyclone dust collector; 21. Airlock ash discharge valve; 3. Spray cooling tower; 31. First spray chamber; 32. Second spray chamber; 33. Demisting chamber; 331. Baffle plate demister; 34. Settling tank; 341. Filter baffle; 342. Clean water tank; 35. Circulating water pump; 351. Pipe; 352. Spray nozzle; 36. Sewage pipe; 361. Motor; 362. Slag discharge pipe; 363. Screw conveyor roller; 37. Breathable baffle. 38. Filling layer; 39. Exhaust pipe; 4. Baghouse dust collector; 41. Tube sheet; 42. Air injection pipe; 43. Clean air chamber; 44. Filter chamber; 45. Filter bag; 46. Dust hopper; 47. Air pump; 471. Electromagnetic pulse valve; 472. Connecting frame; 473. Pulse jet pipe; 48. Flue gas exhaust pipe; 481. Dust concentration sensor; 482. Temperature sensor; 483. Flow rate sensor; 5. Mounting cylinder; 51. Exhaust fan; 6. High temperature resistant pipe. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0031] Please see Figures 1 to 4 An environmental dust control device for steelmaking plants includes a dust collection hood 1, a cyclone dust collector 2, a spray cooling tower 3, and a bag filter 4, which are connected sequentially along the dust flow direction. A flue gas emission pipe 48 is connected to the side wall at the top of the bag filter 4, and an installation cylinder 5 is connected to the flue gas emission pipe 48. An induced draft fan 51 is installed inside the installation cylinder 5.

[0032] Among them, the dust collection hood 1 is installed above the steelmaking converter or electric furnace to capture the flue gas generated during the smelting process;

[0033] The spray cooling tower 3 contains, from top to bottom, a demisting chamber 33, a second spray chamber 32, a first spray chamber 31, and a settling tank 34. The outlet of the cyclone dust collector 2 is connected to the bottom wall of the first spray chamber 31. A permeable baffle 37 is installed between the demisting chamber 33, the second spray chamber 32, the first spray chamber 31, and the settling tank 34. A filling layer 38 is installed on the permeable baffle 37 on the first spray chamber 31 and the second spray chamber 32. A filling layer 38 is installed on the permeable baffle 37 on the demisting chamber 33. A baffle plate demister 331 is provided. A filter baffle 341 is vertically installed at the center of the settling tank 34. A water purification tank 342 is provided at the other end of the settling tank 34 through the filter baffle 341. The air vent 37 above the water purification tank 342 is in a sealed state. A spray assembly is provided at the water purification tank 342. A sewage discharge assembly is also provided at the bottom of the settling tank 34. The sewage discharge assembly includes a sewage discharge pipe 36 connected to the settling tank 34. An exhaust pipe 39 is provided at the top of the demister 33.

[0034] The bag filter 4 is equipped with a tube sheet 41. The top of the tube sheet 41 is a clean air chamber 43, and the bottom of the tube sheet 41 is a filter chamber 44. An air injection pipe 42 is connected to the side wall of the filter chamber 44 and is connected to the exhaust pipe 39. The bottom of the bag filter 4 is equipped with a dust hopper 46 connected to the filter chamber 44. Multiple filter bags 45 are evenly clamped on the tube sheet 41. The bag filter 4 is equipped with a dust removal assembly.

[0035] As one embodiment of this utility model, please refer to Figure 1 A high-temperature resistant pipe 6 is connected between the dust collection hood 1 and the cyclone dust collector 2. The inner wall of the high-temperature resistant pipe 6 is provided with a refractory castable layer. An airlock ash discharge valve 21 is provided at the bottom of the cyclone dust collector 2.

[0036] In this embodiment, the refractory castable layer on the inner wall of the high-temperature resistant pipe 6 can withstand the impact of high-temperature flue gas above 800°C. After the flue gas enters the cyclone dust collector 2, under the action of centrifugal force, the larger dust particles are thrown to the wall of the collector and settle to the bottom, and are periodically discharged through the airlock ash discharge valve 21. These coarse dust particles are mainly iron oxide scale, which can be directly recycled back to the furnace for smelting.

[0037] As one embodiment of this utility model, please refer to Figure 2 The spray assembly includes a circulating water pump 35 located at the bottom of the spray cooling tower 3. The inlet of the circulating water pump 35 extends to the bottom of the water purification tank 342. The outlet of the circulating water pump 35 is connected to a conduit 351. The other end of the conduit 351 extends to the top of the first spray chamber 31 and the second spray chamber 32 respectively and is connected to a nozzle 352.

[0038] In this embodiment, after the high-temperature flue gas enters the spray cooling tower 3, it comes into full contact with the atomized water sprayed from the nozzle 352. The water absorbs the heat of the flue gas through vaporization, causing the flue gas temperature to drop rapidly to 150℃-180℃. At the same time, the water mist can capture fine particulate matter in the flue gas. Water droplets carrying dust fall into the bottom settling tank 34. The upper clear liquid is further purified by the filter baffle 341 and flows into the clean water tank 342. It is then sent back to the first spray chamber 31 and the second spray chamber 32 for recycling by the circulating water pump 35. The cooled flue gas passes through the baffle demister 331 in the demister chamber 33 to remove the entrained droplets, preventing the wet flue gas from entering the subsequent equipment.

[0039] As one embodiment of this utility model, please refer to Figure 2 A spiral conveying roller 363 is installed inside the sewage pipe 36, and a motor 361 for controlling the rotation of the spiral conveying roller 363 is fixedly installed on the side wall of the sewage pipe 36. A slag discharge pipe 362 with a valve is connected to the bottom end of the sewage pipe 36.

[0040] In this embodiment, large sludge particles settle at the bottom of the sedimentation tank 34. After the motor 361 drives the spiral conveyor roller 363 to rotate, the sludge in the sedimentation tank 34 moves with the spiral conveyor roller 363. The sludge can be cleaned regularly through the sludge discharge pipe 362 on the bottom wall of the sewage discharge pipe 36, which is beneficial to the filtration of sewage.

[0041] As one embodiment of this utility model, please refer to Figure 2 The dust removal assembly includes an air pump 47 installed on the side wall of the bag filter 4. The air outlet of the air pump 47 is connected to a connecting frame 472. Multiple blow pipes 473 are evenly connected to the bottom end of the connecting frame 472. The air outlet of the air pump 47 is also equipped with an electromagnetic pulse valve 471.

[0042] The opening of the filter bag 45 is located inside the clean air chamber 43, and the bottom end of the blow pipe 473 extends into the filter bag 45.

[0043] In this embodiment, when the dust layer attached to the surface of the filter bag 45 reaches a certain thickness, the electromagnetic pulse valve 471 is opened, and the air outlet of the air pump 47 instantly releases high-pressure gas. The high-pressure gas is transported along the connecting frame 472 to the blow pipe 473, and further blown into the interior of the filter bag 45 in reverse, causing the filter bag 45 to shake violently. The surface dust falls off and into the ash hopper 46, which can prevent dust from accumulating on the filter bag 45 and ensure the filtration effect of the filter bag 45.

[0044] As one embodiment of this utility model, please refer to Figure 3 The flue gas emission pipe 48 is also equipped with a dust concentration sensor 481, a temperature sensor 482 and a flow rate sensor 483, which are electrically connected to the controller.

[0045] In this embodiment, dust concentration, temperature and flow rate can be monitored in real time by dust concentration sensor 481, temperature sensor 482 and flow rate sensor 483, which makes it easy for operators to adjust operating parameters in a timely manner to ensure that emissions meet standards.

[0046] Working principle: First, the induced draft fan 51 inside the installation cylinder 5 is started. At this time, negative pressure is generated in the cyclone dust collector 2, the spray cooling tower 3, and the bag dust collector 4. The flue gas generated during the smelting process is captured by the dust collection hood 1 installed above the steelmaking converter or electric furnace. The refractory castable layer on the inner wall of the high-temperature resistant pipe 6 can withstand the impact of high-temperature flue gas above 800℃. After the high-temperature flue gas enters the cyclone dust collector 2, under the action of centrifugal force, the larger dust particles are thrown to the wall of the device and settle to the bottom. They are periodically discharged through the airlock ash discharge valve 21. These coarse dust particles are mainly iron oxide scale, which can be directly returned to the furnace for smelting. The pre-treated flue gas enters the spray cooling tower 3.

[0047] After the high-temperature flue gas enters the spray cooling tower 3, the circulating water pump 35 starts working. The circulating water pump 35 first introduces external water into the conduit 351, and then sprays it evenly into the first spray chamber 31 and the second spray chamber 32 through the nozzle 352. The water comes into full contact with the atomized water sprayed from the nozzle 352. The water absorbs heat from the flue gas through vaporization, so that the flue gas temperature drops rapidly to 150℃-180℃. At the same time, the water mist can capture fine particulate matter in the flue gas. The water droplets carrying dust fall into the bottom settling tank 34. The upper clear liquid is further purified by the filter baffle 341 and flows into the clean water tank 342. It is then sent back to the first spray chamber 31 and the second spray chamber 32 by the circulating water pump 35 for recycling. The cooled flue gas enters the bag filter 4 through the exhaust pipe 39. The baffle plate demister 331 in the demisting chamber 33 can remove the entrained droplets and prevent the wet flue gas from entering the subsequent equipment.

[0048] The water that has absorbed the dust in the first spray chamber 31 and the second spray chamber 32 falls into the settling tank 34 through the breathable baffle 37. In the settling tank 34, large particles of sludge settle at the bottom. After the motor 361 drives the screw conveyor roller 363 to rotate, the sludge in the settling tank 34 moves with the screw conveyor roller 363. The sludge can be cleaned regularly through the sludge discharge pipe 362 on the bottom wall of the sewage pipe 36, which is beneficial to the filtration of sewage.

[0049] The flue gas entering the bag filter 4 first enters the filter chamber 44, and after being filtered by the filter bags 45 on the tube sheet 41, the flue gas enters the clean air chamber 43. Then, driven by the induced draft fan 51, it is discharged into the atmosphere through the flue gas discharge pipe 48. The dust concentration, temperature and flow rate can be monitored in real time by the dust concentration sensor 481, temperature sensor 482 and flow rate sensor 483, which makes it easy for operators to adjust the operating parameters in a timely manner to ensure that the emission meets the standards.

[0050] When the dust layer on the surface of the filter bag 45 reaches a certain thickness, the electromagnetic pulse valve 471 is opened, and the air outlet of the air pump 47 releases high-pressure gas instantly. The high-pressure gas is transported along the connecting frame 472 to the blow pipe 473, and further blown into the interior of the filter bag 45 in reverse, causing the filter bag 45 to shake violently. The surface dust falls off and into the ash hopper 46, which can prevent dust from accumulating on the filter bag 45 and ensure the filtration effect of the filter bag 45.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A dust control device for steelmaking plants, comprising a dust collection hood (1), a cyclone dust collector (2), a spray cooling tower (3), and a bag filter (4) connected sequentially along the dust flow direction, wherein a flue gas emission pipe (48) is connected to the side wall at the top of the bag filter (4), an installation cylinder (5) is connected to the flue gas emission pipe (48), and an induced draft fan (51) is installed inside the installation cylinder (5), characterized in that, The spray cooling tower (3) is provided with a demisting chamber (33), a second spraying chamber (32), a first spraying chamber (31), and a settling tank (34) arranged sequentially from top to bottom. The outlet of the cyclone dust collector (2) is connected to the bottom wall of the first spraying chamber (31). A permeable baffle (37) is provided between the demisting chamber (33), the second spraying chamber (32), the first spraying chamber (31), and the settling tank (34). A filling layer (38) is provided on the permeable baffle (37) on the first spraying chamber (31) and the second spraying chamber (32). The permeable baffle (38) on the demisting chamber (33) is also provided with a filling layer (38). 7) A baffle plate demister (331) is provided on the top. A filter baffle (341) is vertically provided at the center of the sedimentation tank (34). A water purification tank (342) is provided at the other end of the sedimentation tank (34) through the filter baffle (341). The air-permeable baffle (37) above the water purification tank (342) is in a sealed state. A spray assembly is provided at the water purification tank (342). A sewage discharge assembly is also provided at the bottom of the sedimentation tank (34). The sewage discharge assembly includes a sewage discharge pipe (36) connected to the sedimentation tank (34). An exhaust pipe (39) is provided at the top of the demister (33). The bag filter (4) is provided with a tube sheet (41), the top of the tube sheet (41) is a clean air chamber (43), the bottom of the tube sheet (41) is a filter chamber (44), an air injection pipe (42) is connected to the side wall of the filter chamber (44), the air injection pipe (42) is connected to the exhaust pipe (39), the bottom of the bag filter (4) is provided with a dust hopper (46) connected to the filter chamber (44), a plurality of filter bags (45) are evenly clamped on the tube sheet (41), and a dust removal assembly is provided inside the bag filter (4).

2. The environmental dust control device for steelmaking plants according to claim 1, characterized in that: A high-temperature resistant pipe (6) is connected between the dust collection hood (1) and the cyclone dust collector (2). The inner wall of the high-temperature resistant pipe (6) is provided with a refractory castable layer. An airlock ash discharge valve (21) is provided at the bottom of the cyclone dust collector (2).

3. The environmental dust control device for steelmaking plants according to claim 1, characterized in that: The spray assembly includes a circulating water pump (35) installed at the bottom of the spray cooling tower (3). The inlet of the circulating water pump (35) extends to the bottom of the water purification tank (342). The outlet of the circulating water pump (35) is connected to a conduit (351). The other end of the conduit (351) extends to the top of the first spray chamber (31) and the second spray chamber (32) respectively and is connected to a nozzle (352).

4. The environmental dust control device for steelmaking plants according to claim 1, characterized in that: The drain pipe (36) is equipped with a spiral conveying roller (363) that rotates in a spiral motion. A motor (361) that controls the rotation of the spiral conveying roller (363) is fixedly installed on the side wall of the drain pipe (36). The bottom end of the drain pipe (36) is connected to a slag discharge pipe (362) with a valve.

5. The environmental dust control device for steelmaking plants according to claim 1, characterized in that: The dust removal assembly includes an air pump (47) installed on the side wall of the bag filter (4). The air outlet of the air pump (47) is connected to a connecting frame (472). The bottom end of the connecting frame (472) is evenly connected to multiple blow pipes (473). The air outlet of the air pump (47) is also equipped with an electromagnetic pulse valve (471).

6. The environmental dust control device for steelmaking plants according to claim 5, characterized in that: The opening of the filter bag (45) is located inside the clean air chamber (43), and the bottom end of the blow pipe (473) extends into the filter bag (45).

7. The environmental dust control device for steelmaking plants according to claim 1, characterized in that: The flue gas emission pipe (48) is also equipped with a dust concentration sensor (481), a temperature sensor (482) and a flow rate sensor (483), which are electrically connected to the controller.

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