Lead smelting bottom blowing furnace pulverized coal explosion-proof filtering device and method

Abstract

The application discloses a kind of lead smelting bottom blowing furnace coal explosion-proof filtering device and method, it is related to coal filtering technical field, the first hinged link, second hinged link are hinged in the first cage and second cage between each other in the application, cooperate torsional spring and liftable cylinder and form variable height bag cage, by means of the cooperation of pressing mechanism and spring, the active shrinkage of bag cage when dust cleaning can be realized, so that in pulse jet dust cleaning stage, the deformation amplitude and shaking acceleration of anti-static filter bag can be effectively increased, the coal dust attached to the surface of anti-static filter bag is more thoroughly stripped, so that the dust cleaning efficiency of the device is high and uniform, the filter bag resistance is quickly restored to low resistance state, not only can reduce system operation energy consumption, prolong the service life of anti-static filter bag, but also be beneficial to reduce the probability of fire and explosion, improve the safety and stability of the device to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of pulverized coal filtration technology, and in particular to an explosion-proof filtration device and method for pulverized coal in a bottom-blown furnace for lead smelting. Background Technology

[0002] During the smelting process, the bottom-blown furnace in lead smelting produces a large amount of high-temperature flue gas. The exhaust gas contains a large amount of incompletely burned pulverized coal. These pulverized coal particles are fine and combustible. At the same time, the flue gas often contains carbon monoxide. This poses a potential risk of dust explosion to the flue gas purification system, especially the bag filter.

[0003] Traditional dust removal devices often lack a systematic approach to explosion-proof design when handling such media, focusing primarily on anti-static filter bags as a single measure. They lack real-time monitoring and inerting protection for oxygen content, combustible gas concentration, and temperature, resulting in insufficient safety redundancy. Furthermore, due to the light weight and strong adhesion of pulverized coal dust, it easily forms a dense filter cake on the filter bag surface. Conventional pulse jet cleaning methods sometimes fail to completely remove this cake, leading to increased residual resistance in the filter bag, uneven cleaning, increased system energy consumption over long-term operation, and the potential for high temperatures or sparks due to localized dust accumulation, affecting the safety and stability of the filtration equipment during operation.

[0004] Therefore, a pulverized coal explosion-proof filtration device and method for bottom-blown furnaces in lead smelting are proposed to solve some of the problems existing in the above-mentioned prior art. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies, such as the single dust explosion-proof structure in bottom-blown lead smelting furnaces and the incomplete cleaning effect of pulverized coal filtration and backflushing, by proposing a pulverized coal explosion-proof filtration device and method for bottom-blown lead smelting furnaces.

[0006] To address the problems existing in the prior art, the present invention adopts the following technical solution:

[0007] An explosion-proof filtration device for pulverized coal in a bottom-blown furnace of lead smelting includes a filter chamber. A dust hopper is fixedly connected to the bottom of the filter chamber, and an air inlet is fixedly connected to the dust hopper. A discharge pipe is fixedly connected to the bottom of the dust hopper. A clean air chamber is fixedly installed at the top of the filter chamber. Multiple evenly distributed filter bag mounting holes are provided between the filter chamber and the clean air chamber, and bag cages are inserted into these holes. Anti-static filter bags are wrapped around the outside of the bag cages. A clean air outlet is fixedly connected to one side of the clean air chamber, and an explosion-proof induced draft fan is fixedly installed on the clean air outlet. An explosion-proof pulse jet cleaning device is fixedly installed on the clean air chamber. A nozzle connected to the explosion-proof pulse jet cleaning device is provided above the filter bag mounting holes. The bag cage includes a first ring, and the lower part of the first ring... A first cage is fixedly installed. The lower end of the first cage is hinged to multiple first hinge rods distributed around it, and the lower end of each first hinge rod is hinged to a second hinge rod. The lower ends of the multiple first hinge rods are all hinged to the second cage. Torsion springs are installed at the hinge points of the first cage and the first hinge rods, the hinge points of the first and second hinge rods, and the hinge points of the second hinge rod and the second cage. A cylinder is slidably installed inside the first cage. A pressing mechanism for controlling the up and down movement of the cylinder is installed in the clean air chamber. The outer dimensions of the first and second cages are adapted to the inner dimensions of the filter bag mounting holes. An antistatic filter bag is fitted over the outer side of the first ring, the first cage, the first hinge rod, the second hinge rod, and the second cage.

[0008] Preferably, the antistatic filter bag contains conductive fibers, the inner walls of the filter chamber and ash hopper are coated with an antistatic coating, the filter chamber is connected to a grounding device with a grounding resistance ≤3Ω, and the filter chamber is equipped with an intelligent measurement and control mechanism.

[0009] Preferably, a second ring located above the first ring is fixedly installed on the cylinder, and a spring that provides elastic support to the bottom of the second ring is fixedly installed on the first ring.

[0010] Preferably, the pressing mechanism includes a bearing fixedly installed in the clean air chamber, and a longitudinally arranged rotating shaft is rotatably installed in the bearing. A swing arm is fixedly installed on the rotating shaft. After the swing arm flips, it presses against the top of the corresponding second ring. A drive mechanism for driving the rotating shaft to rotate is installed in the clean air chamber.

[0011] Preferably, a roller is rotatably mounted at the end of the swing arm.

[0012] Preferably, the drive mechanism includes multiple shafts, with multiple rotating shafts in the same longitudinal row coaxially fixedly connected to the same shaft. A protective box is fixedly installed on the back of the clean air chamber. A first gear, which is rotatably connected to the shaft, is rotatably installed inside the protective box. A slide table is slidably installed inside the protective box. A horizontally arranged screw and splined shaft are rotatably installed inside the protective box. Both the screw and splined shaft are externally connected to servo motors. The screw is threadedly connected to the slide table. A splined sleeve, which is slidably sleeved on the outside of the splined shaft, is rotatably installed on the slide table. A second gear, which is adapted to the multiple first gears, is fixedly installed on the splined sleeve.

[0013] Preferably, a worm gear is coaxially fixed to the end of the shaft and installed inside the protective box, and a worm is meshed below the worm gear, with the worm being coaxially fixedly connected to the corresponding first gear.

[0014] Preferably, a plurality of vertically arranged partitions are fixedly installed in the filter chamber, and the filter chamber is divided into a plurality of independent chambers by the partitions. A first guide cover is fixedly installed at the bottom of the chamber, and a second guide cover is fixedly connected to the bottom of the first guide cover. An electrically controlled flap is rotatably installed between the first guide cover and the second guide cover. The first guide cover is configured as a funnel-shaped structure, and the second guide cover is configured as an inverted funnel-shaped structure.

[0015] Preferably, a pneumatic arch breaker is fixedly installed in the upper part of the ash hopper, a flap airlock valve is installed at the upper end of the discharge pipe, a star-shaped discharge valve is installed at the lower end of the discharge pipe, a radar level gauge is fixedly installed in the ash hopper, and a level sensor is fixedly installed in the discharge pipe.

[0016] Preferably, a method for explosion-proof filtration of pulverized coal in a bottom-blown lead smelting furnace is provided. The filtration method is applicable to explosion-proof filtration devices for pulverized coal in bottom-blown lead smelting furnaces and includes the following steps:

[0017] S1, Pre-separation:

[0018] The bottom-blown furnace discharges a gas stream containing pulverized coal. The temperature of the gas stream is 110-150℃, and the pulverized coal concentration is 0.03-0.06 kg / m³. The gas stream containing pulverized coal enters the ash hopper and filter chamber through the air inlet. More than 70% of the coarse powder in the gas stream falls into the ash hopper under gravity, completing the pre-removal and reducing the load on the filter bags.

[0019] S2, Surface filtration:

[0020] Fine powder in the coal-containing gas flow enters the filtration chamber with the gas flow, is filtered by the surface of the anti-static filter bag, and the purified gas passes through the anti-static filter bag into the clean gas chamber and is discharged from the clean gas outlet. The dust concentration at the outlet is ≤10mg / Nm³, which meets the environmental emission standards.

[0021] S3. Uniform dust removal:

[0022] The differential pressure transmitter monitors the filter differential pressure in real time. When the differential pressure rises to 800-1000Pa, the explosion-proof pulse jet cleaning device is activated. Dry nitrogen is sprayed into the corresponding antistatic filter bag through the nozzle, shaking off the dust adhering to the surface of the antistatic filter bag. The dust falls into the ash hopper. The dust cleaning unevenness is ≤5%, which can quickly restore the resistance of the antistatic filter bag to 200-400Pa.

[0023] S4. Ash removal and reuse:

[0024] The dust level in the ash hopper is monitored by radar level gauge. When the level reaches the high limit, the arch breaker, flap airlock valve and star-shaped unloading valve are activated to unload the dust into the pulverized coal recovery system and return it to the bottom blower coal injection system to realize resource reuse.

[0025] S5, Explosion-proof protection:

[0026] The intelligent monitoring and control mechanism monitors the oxygen content, CO concentration, temperature and pressure difference in the filter chamber in real time. When the oxygen content is greater than 8%, the CO concentration is greater than 50 ppm, and the temperature is greater than 150°C, the filter chamber is automatically inertized with nitrogen to suppress explosion. When the parameters exceed the limits and cannot be restored, the filter chamber is shut down by interlock to eliminate the risk of explosion.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1. In this invention, by setting a first hinge rod and a second hinge rod to be hinged between the first cage and the second cage, and in conjunction with a torsion spring and a liftable cylinder, a height-variable bag cage is formed. With the cooperation of the pressing mechanism and the spring, the bag cage can be actively contracted during dust removal. This can effectively increase the deformation amplitude and shaking acceleration of the antistatic filter bag during the pulse jet cleaning stage, so that the pulverized coal dust attached to the surface of the antistatic filter bag can be more thoroughly removed. This makes the device have high and uniform dust removal efficiency, and facilitates the rapid restoration of the filter bag resistance to a low resistance state. This not only reduces the system's operating energy consumption and extends the service life of the antistatic filter bag, but also helps to reduce the probability of fire and explosion, thus improving the safety and stability of the device to a certain extent.

[0029] 2. In this invention, by using antistatic filter bags and grounding the device in an antistatic manner, along with the coating, nitrogen-filled inertization structure, and explosion relief plate installed inside the device, as well as a comprehensive intelligent measurement and control mechanism consisting of an oxygen content sensor, a CO concentration sensor, a temperature sensor, and a differential pressure sensor, a multi-layered explosion-proof safety system combining active and passive protection can be constructed. This is beneficial for significantly eliminating the conditions required for dust explosions, thereby significantly improving the safety of the flue gas treatment process in the bottom blowing furnace of lead smelting.

[0030] 3. In this invention, by dividing the filter chamber into multiple independent chambers and equipping them with electrically controlled flaps in the air inlet direction, the filter unit can be partitioned and isolated. This allows the device to shut off the airflow in the corresponding antistatic filter bag's air inlet direction when performing local backflushing dust removal, reducing backflushing resistance and further improving the backflushing dust removal effect of the antistatic filter bag. Attached Figure Description

[0031] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0032] Figure 1 This is a perspective view of the internal structure of the filter chamber and ash hopper of the present invention;

[0033] Figure 2 This is a perspective view of the present invention;

[0034] Figure 3 This is a front sectional view of the present invention;

[0035] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0036] Figure 5 This is a top sectional view of the present invention;

[0037] Figure 6 This is a perspective view of the first and second hinge rods inside the bag cage of the present invention when they are unfolded.

[0038] Figure 7 This is a perspective view of the first and second hinge rods in the bag cage of the present invention when they are brought together.

[0039] Figure 8 This is a perspective view of the pressing mechanism and the driving mechanism of the present invention;

[0040] Figure 9 This is a perspective view of the drive mechanism of the present invention from the bottom after the protective box has been removed.

[0041] Figure 10 For the present invention Figure 9 Enlarged view of point B in the middle;

[0042] Figure 11 This is a perspective view of the first guide cover, the second guide cover, and the electrically controlled flap of the present invention.

[0043] In the picture:

[0044] 1. Filter chamber; 11. Ash hopper; 12. Air inlet; 13. Discharge pipe; 14. Clean air chamber; 15. Bag cage; 16. Antistatic filter bag; 17. Clean air outlet; 18. Explosion-proof induced draft fan;

[0045] 2. Explosion-proof pulse jet cleaning device; 21. Nozzle;

[0046] 3. First ring; 31. First cage; 32. First hinge rod; 33. Second hinge rod; 34. Second cage; 35. Cylinder; 36. Second ring; 37. Spring;

[0047] 4. Shaft seat; 41. Rotating shaft; 42. Swing arm; 43. Roller;

[0048] 5. Shaft; 51. Protective box; 52. Worm gear; 53. Worm; 54. First gear; 55. Slide table; 56. Screw; 57. Splined shaft; 58. Splined cylinder; 59. Second gear;

[0049] 6. Partition; 61. Chamber; 62. First guide cover; 63. Second guide cover; 64. Electrically controlled flap;

[0050] 7. Flip-type airlock valve; 71. Rotary star-shaped discharge valve. Detailed Implementation

[0051] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0052] Example: This example provides an explosion-proof filter device for pulverized coal in a bottom-blown furnace of lead smelting. See [link / reference]. Figure 1 - Figure 11 Specifically, the filter chamber 1 has a hopper 11 fixedly connected to its bottom, an air inlet 12 fixedly connected to the hopper 11, a discharge pipe 13 fixedly connected to the bottom of the hopper 11, a clean air chamber 14 fixedly installed at the top of the filter chamber 1, multiple evenly distributed filter bag mounting holes between the filter chamber 1 and the clean air chamber 14, a bag cage 15 inserted into the filter bag mounting holes, an anti-static filter bag 16 wrapped around the outside of the bag cage 15, a clean air outlet 17 fixedly connected to one side of the clean air chamber 14, an explosion-proof induced draft fan 18 fixedly installed on the clean air outlet 17, an explosion-proof pulse jet cleaning device 2 fixedly installed on the clean air chamber 14, and a nozzle 21 connected to the explosion-proof pulse jet cleaning device 2 above the filter bag mounting holes.

[0053] In this device, the filter chamber 1, ash hopper 11, and clean air chamber 14 are connected by sealed welding and flanges to form an integrated structure with an overall air leakage rate of ≤0.5%. The shells of the filter chamber 1, ash hopper 11, and clean air chamber 14 are made of double-layer insulation structure with an insulation layer thickness of ≥100mm. The material used is aluminum silicate and rock wool composite insulation material. The inner walls of the filter chamber 1 and ash hopper 11 are coated with an antistatic coating. The filter chamber 1 is connected to a grounding device, and the grounding resistance of the grounding device is ≤3Ω, eliminating static electricity ignition sources and helping to meet the dust explosion prevention requirements. The top of the clean air chamber 14 is equipped with a quick-opening maintenance door, and the air inlet 12 is located at the lower part of the side wall of the filter chamber 1. The air inlet 12 is equipped with a flow distribution device and an anti-backflow baffle.

[0054] In this device, the ash hopper 11 and the clean gas chamber 14 are externally connected to a nitrogen replacement device, which uses nitrogen with a purity of ≥99.9%. The ash hopper 11 is equipped with a nitrogen extinguishing interface connected to the nitrogen replacement device. Under the conditions of start-up, shutdown, and failure, nitrogen can be automatically and rapidly filled into the filter chamber 1, ash hopper 11, and clean gas chamber 14. Through nitrogen filling and dissipation, the oxygen content in the device is reduced to ≤8%, which is lower than the oxygen concentration of the pulverized coal explosion limit. For example, when the temperature in the ash hopper 11 is >150℃ or the CO concentration is >50ppm, the device will automatically open the nitrogen extinguishing interface and rapidly fill the ash hopper 11 with nitrogen to suppress the explosion and inhibit the spread of fire.

[0055] The side wall of the filter chamber 1 is equipped with 2-4 explosion relief discs. The burst pressure of the explosion relief discs is 0.08-0.12MPa. The explosion relief direction avoids densely populated areas and densely populated equipment areas, which can achieve rapid pressure relief after an explosion.

[0056] In this device, the explosion-proof pulse jet cleaning device 2 uses dry nitrogen as the gas source. The dew point of nitrogen is ≤-20℃, which realizes the uniform distribution of the cleaning air volume of each filter bag. The explosion-proof pulse jet cleaning device 2 consists of a backflush main pipe, several manifolds, pulse valves, air tanks and nozzles 21.

[0057] The backflush main pipe is horizontally arranged at the top of the clean air chamber 14. Air enters from the middle of the backflush main pipe, and the cross-sectional area of ​​both ends of the backflush main pipe gradually decreases along the airflow direction. The decrease ratio is set to 1:0.8 to balance the air volume in the backflush main pipe.

[0058] The manifolds are symmetrically arranged on both sides of the backflush main pipe, and bend towards the end of the filter chamber 1. The inlet cross-section of the manifold gradually expands away from the backflush main pipe, with an expansion ratio of 0.6:1. The cross-section of the nozzle 21 gradually shrinks away from the manifold, with a reduction ratio of 1:0.7. Through the gradual cross-section design, the dust removal air volume non-uniformity of each nozzle 21 under the same backflush main pipe is ≤5%.

[0059] The pulse valve is set to a working pressure of 0.4-0.6MPa and a pulse width of 0.10-0.15s. The pulse valve operates in an online, row-by-row cleaning manner, which will not interrupt the filtration operation of the entire device.

[0060] The gas tank is used to store dry nitrogen. In actual use, the volume of the gas tank can be flexibly matched according to the processing air volume to ensure the stability of the pulse cleaning air source.

[0061] In the specific implementation process, such as Figure 4 , Figure 6 and Figure 7As shown, the bag cage 15 includes a first ring 3, and a first cage body 31 is fixedly installed below the first ring 3. The lower end of the first cage body 31 is hinged to a plurality of first hinge rods 32 arranged in a ring, and the lower end of the first hinge rods 32 is hinged to a second hinge rod 33. The lower ends of the plurality of first hinge rods 32 are hinged to a second cage body 34. Torsion springs are installed at the hinge points of the first cage body 31 and the first hinge rods 32, the hinge points of the first hinge rods 32 and the second hinge rods 33, and the hinge points of the second hinge rods 33 and the second cage body 34. A cylinder 35 is slidably installed inside the first cage body 31. A pressing mechanism for controlling the up and down movement of the cylinder 35 is installed inside the clean air chamber 14. The outer dimensions of the first cage body 31 and the second cage body 34 are adapted to the inner dimensions of the filter bag mounting hole. An antistatic filter bag 16 is sleeved on the outside of the first ring 3, the first cage body 31, the first hinge rods 32, the second hinge rods 33, and the second cage body 34.

[0062] A second ring 36 located above the first ring 3 is fixedly installed on the cylinder 35. A spring 37 elastically supported at the bottom of the second ring 36 is fixedly installed on the first ring 3. The pressing mechanism includes a bearing 4 fixedly installed in the clean air chamber 14, and a longitudinally arranged rotating shaft 41 is rotatably installed in the bearing 4. A swing arm 42 is fixedly installed on the rotating shaft 41. After the swing arm 42 is flipped, it presses against the top of the corresponding second ring 36. A roller 43 is rotatably installed at the end of the swing arm 42. A drive mechanism for driving the rotating shaft 41 to rotate is installed in the clean air chamber 14.

[0063] In this device, the design of the bag cage 15 achieves a high degree of variability. Its core lies in the fact that the lifting and lowering movement of the cylinder 35 drives the linkage mechanism composed of the first hinge rod 32 and the second hinge rod 33 to deform. Under normal filtration conditions, with the help of the pressing mechanism, specifically the swing arm 42 presses down on the second ring 36 through the roller 43, overcoming the elastic force of the spring 37, so that the cylinder 35 is in the lower limit position. At this time, the cylinder 35 acts as an internal support, forcing the first hinge rod 32 and the second hinge rod 33 to maintain a basically vertical extension state, thereby supporting the second cage 34 to the lowest position, so that the entire bag cage 15 and the antistatic filter bag 16 covering it are fully opened, maintaining the maximum effective filtration area.

[0064] When a dust removal operation is required, the rotating shaft 41 in the drive mechanism is controlled to rotate, causing the swing arm 42 to be controlled to flip upward, releasing the pressure on the second ring 36. At this time, under the elastic recovery action of the spring 37, the second ring 36 and the cylinder 35 move upward together. As the cylinder 35 moves upward, its radial constraint on the first hinge rod 32 and the second hinge rod 33 is released. Under the torsion of the torsion springs at each hinge, the included angle between the first hinge rod 32 and the second hinge rod 33 decreases, bending and contracting towards the central axis of the bag cage 15, thereby driving the second cage body 34 to move upward, resulting in a decrease in the overall height of the bag cage 15. This contraction action causes the lower middle part of the antistatic filter bag 16 to loosen and wrinkle.

[0065] At the same time, the corresponding explosion-proof pulse jet cleaning device 2 is activated, and dry nitrogen gas is instantly injected into the top of the antistatic filter bag 16 through the nozzle 21. Since the lower part of the antistatic filter bag 16 is relatively loose due to the contraction of the bag cage 15, the pulse airflow can cause the antistatic filter bag 16 to expand and shake more violently from top to bottom, which greatly enhances the relative movement between the filter cloth fibers inside the antistatic filter bag 16 during dust removal, making it easier to completely remove the coal dust embedded deep in the filter material and attached to the surface.

[0066] After the dust removal is completed, the drive mechanism moves again, the swing arm 42 presses down, the cylinder 35 moves down, straightens the linkage mechanism again, the bag cage 15 returns to its original height, and the antistatic filter bag 16 is tightened again, ready to enter the next filtration cycle.

[0067] In the specific implementation process, the antistatic filter bag 16 contains conductive fibers, and the filter chamber 1 is equipped with an intelligent monitoring and control mechanism. In this device, the antistatic filter bag 16 is made of PPS base cloth, PTFE membrane, and conductive fiber composite antistatic filter material. Its temperature resistance range can reach 130-160℃, its instantaneous temperature resistance can reach 180℃, and its surface resistance is 10 ohms. 6 -10 8 The range of Ω, wherein the membrane porosity is ≥90%, the filtration efficiency is ≥99.999%, the adaptable working condition of the antistatic filter bag 16 is φ130×(2500~3000)mm, the air-to-cloth ratio is controlled at 0.8—1.0m / min, the plate between the filter chamber 1 and the clean air chamber 14 is called the tube sheet, and the antistatic filter bag 16 and the tube sheet are connected by an elastic expansion ring and a fluororubber sealing structure to ensure that there is no leakage between the tube sheet and the antistatic filter bag 16.

[0068] The intelligent measurement and control mechanism of this device includes a differential pressure sensor fixedly installed in the filter chamber 1 and the clean air chamber 14, and sensors such as an oxygen content sensor, a CO concentration sensor, and a temperature sensor fixedly installed in the filter chamber 1. When performing air blowing and dust removal control, a composite mode of differential pressure priority and timed assistance is adopted. When the differential pressure between the filter chamber 1 and the clean air chamber 14 rises to 800-1000 Pa, the conventional mode will be activated for back-blowing and dust removal. When the differential pressure is greater than 1200 Pa, the strong dust removal mode will be activated. By increasing the number of pulses and shortening the cycle, the dust removal effect is improved. At the same time, the device will also perform timed dust removal as an auxiliary measure to adapt to the load fluctuations of the bottom blowing furnace.

[0069] In the specific implementation process, such as Figure 8 and Figure 9 As shown, the drive mechanism includes multiple shafts 5, and multiple rotating shafts 41 in the same longitudinal row are coaxially fixedly connected to the same shaft 5. A protective box 51 is fixedly installed on the back of the clean air chamber 14. A first gear 54 that is rotatably connected to the shaft 5 is rotatably installed inside the protective box 51. A slide table 55 is slidably installed inside the protective box 51. A horizontally arranged screw 56 and a splined shaft 57 are rotatably installed inside the protective box 51. Both the screw 56 and the splined shaft 57 are externally connected to servo motors. The screw 56 is threadedly connected to the slide table 55. A splined cylinder 58 that is slidably sleeved on the outside of the splined shaft 57 is rotatably installed on the slide table 55, and a second gear 59 that is adapted to the multiple first gears 54 is fixedly installed on the splined cylinder 58.

[0070] In this device, a position sensor for detecting the position of the slide table 55 is fixedly installed inside the protective box 51. Through the aforementioned drive mechanism, sequential and grouped coordinated control of multiple rows of bag cages 15 can be achieved. During operation, the servo motor drives the screw 56 to rotate. Utilizing the threaded connection between the screw 56 and the slide table 55, the slide table 55 and its splined cylinder 58 and second gear 59 can be precisely controlled to move laterally along the splined shaft 57. Based on the requirements of air-blowing backflushing cleaning, the slide table 55 is driven to move the second gear 59 to a position aligned with a specific row of bag cages 15. The first gear 54 is engaged, and then another servo motor drives the spline shaft 57 and spline cylinder 58 to rotate. The rotational power is transmitted to the corresponding shaft 5 through the meshing of the second gear 59 and the corresponding first gear 54, thereby driving all the rotating shafts 41 in the column to rotate synchronously, realizing the unified switching of the contraction or extension state of all the bag cages 15 in the column. Through the above structural setting, the structural compactness of the drive mechanism can be effectively improved, making it easy to arrange in the limited space of the clean air chamber 14, and it can be linked and coordinated with the pulse jet cleaning strategy of partitioned dust removal.

[0071] In the specific implementation process, such as Figure 10As shown, a worm gear 52 is coaxially fixed to the end of the shaft 5 and is installed inside the protective box 51. A worm 53 is meshed below the worm gear 52. The worm 53 is coaxially fixedly connected to the corresponding first gear 54. In this device, after the first gear 54 is driven to rotate, it can drive the corresponding worm 53 to rotate. Then, by means of the meshing of the worm 53 and the worm gear 52, the rotational power is transmitted to the corresponding shaft 5. By means of the self-locking property of the meshing transmission process of the worm 53 and the worm gear 52, the deflection control of the swing arm 42 can be more stable.

[0072] In the specific implementation process, such as Figure 1 , Figure 3 and Figure 11 As shown, multiple vertically arranged partitions 6 are fixedly installed inside the filter chamber 1, dividing the interior of the filter chamber 1 into multiple independent chambers 61. A first guide cover 62 is fixedly installed at the bottom of the chamber 61, and a second guide cover 63 is fixedly connected to the bottom of the first guide cover 62. An electrically controlled flap 64 is rotatably installed between the first guide cover 62 and the second guide cover 63. The first guide cover 62 is configured as a funnel-shaped structure, and the second guide cover 63 is configured as an inverted funnel-shaped structure. During the operation of the equipment, by dividing the interior of the filter chamber 1 into multiple independent chambers 61 and equipping them with electrically controlled flaps 64, the filtration unit can be partitioned and isolated and the airflow can be controlled. When the antistatic filter bag 16 in a certain chamber 61 needs to be pulsed backflushing for cleaning, the control system can close the corresponding electrically controlled flap 64 below the chamber 61 in conjunction. This action can temporarily cut off the airflow of the filter bag group, forming a relatively closed and low-interference working environment at the moment of cleaning.

[0073] With this structural design, the continuous influx of dust-laden airflow can be cut off during backflushing, significantly reducing the front filtration pressure difference borne by the antistatic filter bag 16 during backflushing. This helps reduce the airflow resistance that needs to be overcome during dust removal. At the same time, it avoids interference from the airflow of adjacent filter units, allowing the nitrogen kinetic energy of the pulse jet to act more concentratedly on the expansion and shaking of the antistatic filter bag 16, reducing the loss of kinetic energy due to side airflow offsetting. Under the combined effect of both, the dust removal efficiency and kinetic energy utilization of the pulse jet airflow can be effectively improved, making it easier to completely remove the pulverized coal dust adhering to the surface of the antistatic filter bag 16, thereby obtaining a better dust removal effect, which helps to shorten the dust removal cycle and reduce operating energy consumption.

[0074] In the specific implementation process, such as Figure 1 and Figure 3As shown, a pneumatic arch breaker is fixedly installed in the upper part of the ash hopper 11, a flap airlock valve 7 is installed at the upper end of the discharge pipe 13, a star-shaped discharge valve 71 is installed at the lower end of the discharge pipe 13, a radar level gauge is fixedly installed in the ash hopper 11, and a level sensor is fixedly installed in the discharge pipe 13. This device, by equipping the ash hopper 11 with anti-sticking, heating, arch breaking and airlock structures, can prevent material blockage and dust backflow during the discharge of pulverized coal.

[0075] In this device, the ash hopper 11 is designed with an inverted conical structure, with a cone angle ≥60°. The inner wall of the ash hopper 11 is coated with a PTFE anti-stick coating with a thickness ≥0.5mm and a friction coefficient ≤0.15. Meanwhile, a steam heating device is installed on the outside of the ash hopper 11. The steam heating device can automatically control the temperature inside the ash hopper 11 at 95-105℃, making it 10-15℃ higher than the flue gas dew point temperature, which helps to prevent condensation and adhesion inside the ash hopper 11. By installing 2-4 pneumatic arch breakers, i.e., air cannons, on the upper part of the ash hopper 11 and setting the blasting pressure to 0.5-0.7MPa, dust bridging can be effectively broken during operation.

[0076] In this device, a double-layer airlock structure can be formed by the cooperation of the flap airlock valve 7 and the star-shaped discharge valve 71 installed in the lower discharge pipe 13 of the ash hopper 11. The radar level gauge installed in the ash hopper 11 and the level sensor installed in the discharge pipe 13 are linked with the flap airlock valve 7 and the star-shaped discharge valve 71 to realize automatic start and stop of discharge. The amount of pulverized coal in the ash hopper 11 is monitored by the radar level gauge, and the pulverized coal in the ash hopper 11 is discharged into the discharge pipe 13 by the flap airlock valve 7. Then, the amount of pulverized coal in the discharge pipe 13 is monitored by the level sensor, and the pulverized coal is discharged by the star-shaped discharge valve 71. The airlock efficiency of the entire structure can be ≥99%, which is beneficial to prevent the backflow of outside air.

[0077] Specifically, the working principle of this invention is as follows:

[0078] A method for explosion-proof filtration of pulverized coal in a bottom-blown furnace for lead smelting is provided. The filtration method is applicable to explosion-proof filtration devices for pulverized coal in bottom-blown furnaces for lead smelting and includes the following steps:

[0079] S1, Pre-separation:

[0080] The bottom-blown furnace discharges a gas stream containing pulverized coal. The temperature of the gas stream is 110-150℃, and the pulverized coal concentration is 0.03-0.06 kg / m³. The gas stream containing pulverized coal enters the ash hopper 11 and the filter chamber 1 through the air inlet 12. More than 70% of the coarse powder in the gas stream falls into the ash hopper 11 under the action of gravity, completing the pre-removal and reducing the load on the filter bags.

[0081] S2, Surface filtration:

[0082] Fine powder in the coal-containing gas flow enters the filter chamber 1 with the gas flow and is filtered by the surface of the antistatic filter bag 16. The purified gas passes through the antistatic filter bag 16 and enters the clean gas chamber 14, and is discharged from the clean gas outlet 17. The dust concentration at the outlet is ≤10mg / Nm³, which meets the environmental emission standards.

[0083] S3. Uniform dust removal:

[0084] The differential pressure transmitter monitors the filter differential pressure in real time. When the differential pressure rises to 800-1000Pa, the explosion-proof pulse jet cleaning device 2 is activated. Dry nitrogen gas is sprayed into the corresponding antistatic filter bag 16 through the nozzle 21, shaking off the dust adhering to the surface of the antistatic filter bag 16. The dust falls into the ash hopper 11. The dust cleaning unevenness is ≤5%, which can quickly restore the resistance of the antistatic filter bag 16 to 200-400Pa.

[0085] S4. Ash removal and reuse:

[0086] The dust level in the ash hopper 11 is monitored by a radar level gauge. When the level reaches the high limit, the arch breaker, flap lock valve 7, and star-shaped unloading valve 71 are activated to unload the dust into the pulverized coal recovery system and return it to the bottom blower coal injection system to achieve resource reuse.

[0087] S5, Explosion-proof protection:

[0088] The intelligent monitoring and control mechanism monitors the oxygen content, CO concentration, temperature and pressure difference in filter chamber 1 in real time. When the oxygen content is >8%, the CO concentration is >50ppm and the temperature is >150℃, nitrogen inerting is automatically purged to suppress explosion. When the parameters exceed the limits and cannot be recovered, the interlock is shut down to eliminate the risk of explosion.

[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A lead smelting bottom-blown furnace pulverized coal explosion-proof filtration device, comprising a filter chamber (1), wherein the bottom of the filter chamber (1) is fixedly connected to an ash hopper (11), and an air inlet (12) is fixedly connected to the ash hopper (11); a clean air chamber (14) is fixedly installed on the top of the filter chamber (1); a plurality of uniformly distributed filter bag mounting holes are provided between the filter chamber (1) and the clean air chamber (14); a bag cage (15) is inserted into the filter bag mounting hole; an antistatic filter bag (16) is wrapped around the outside of the bag cage (15); a clean air outlet (17) is fixedly connected to one side of the clean air chamber (14); an explosion-proof induced draft fan (18) is fixedly installed on the clean air outlet (17); an explosion-proof pulse jet cleaning device (2) is fixedly installed on the clean air chamber (14); and a nozzle (21) connected to the explosion-proof pulse jet cleaning device (2) is provided above the filter bag mounting hole, characterized in that: The filter chamber (1) is equipped with an intelligent measurement and control mechanism. The bag cage (15) includes a first ring (3), and a first cage body (31) is fixedly installed below the first ring (3). The lower end of the first cage body (31) is hinged with a plurality of first hinge rods (32) arranged in a ring. The lower end of the first hinge rods (32) is hinged with a second hinge rod (33). The lower ends of the plurality of first hinge rods (32) are hinged together with a second cage body (34). The hinge points of the first cage body (31) and the first hinge rods (32), the first hinge rods (32) and the second hinge rods (33) are connected. Torsion springs are installed at the hinge of the first cage (31) and at the hinge of the second hinge rod (33) and the second cage (34). A cylinder (35) is slidably installed inside the first cage (31). A pressing mechanism for controlling the up and down movement of the cylinder (35) is installed inside the clean air chamber (14). The outer dimensions of the first cage (31) and the second cage (34) are adapted to the inner dimensions of the filter bag mounting hole. The antistatic filter bag (16) is sleeved on the outside of the first ring (3), the first cage (31), the first hinge rod (32), the second hinge rod (33), and the second cage (34).

2. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 1, characterized in that: The antistatic filter bag (16) contains conductive fibers, and the inner walls of the filter chamber (1) and the ash hopper (11) are coated with an antistatic coating. The filter chamber (1) is connected to a grounding device, and the grounding resistance of the grounding device is ≤3Ω.

3. The explosion-proof filtration device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 1, characterized in that: A second ring (36) is fixedly installed on the cylinder (35) above the first ring (3), and a spring (37) elastically supported at the bottom of the second ring (36) is fixedly installed on the first ring (3).

4. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 3, characterized in that: The pressing mechanism includes a bearing seat (4) fixedly installed in the air purification chamber (14), and a longitudinally arranged rotating shaft (41) is rotatably installed in the bearing seat (4). A swing arm (42) is fixedly installed on the rotating shaft (41). After the swing arm (42) flips over, it presses on the top of the corresponding second ring (36). A drive mechanism for driving the rotating shaft (41) to rotate is installed in the air purification chamber (14).

5. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 4, characterized in that: A roller (43) is rotatably mounted at the end of the swing arm (42).

6. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 4, characterized in that: The drive mechanism includes multiple shafts (5), and multiple rotating shafts (41) in the same longitudinal column are coaxially fixedly connected to the same shaft (5). A protective box (51) is fixedly installed on the back of the clean air chamber (14). A first gear (54) that is drivenly connected to the shaft (5) is rotatably installed in the protective box (51). A slide table (55) is slidably installed in the protective box (51). A horizontally arranged screw (56) and a spline shaft (57) are rotatably installed in the protective box (51). Both the screw (56) and the spline shaft (57) are externally connected to servo motors. The screw (56) is threadedly connected to the slide table (55). A spline cylinder (58) that is slidably sleeved on the outside of the spline shaft (57) is rotatably installed on the slide table (55), and a second gear (59) that is adapted to multiple first gears (54) is fixedly installed on the spline cylinder (58).

7. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 6, characterized in that: A worm gear (52) is coaxially fixed to the end of the shaft (5) and is installed in the protective box (51). A worm (53) is meshed below the worm gear (52), and the worm (53) is coaxially fixedly connected to the corresponding first gear (54).

8. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 1, characterized in that: The filter chamber (1) is fixedly installed with multiple vertically arranged partitions (6). The filter chamber (1) is divided into multiple independent chambers (61) by the multiple partitions (6). A first guide cover (62) is fixedly installed at the bottom of the chamber (61), and a second guide cover (63) is fixedly connected to the bottom of the first guide cover (62). An electrically controlled flap (64) is rotatably installed between the first guide cover (62) and the second guide cover (63). The first guide cover (62) is configured as a funnel-shaped structure, and the second guide cover (63) is configured as an inverted funnel-shaped structure.

9. The explosion-proof filter device for pulverized coal in a bottom-blown furnace for lead smelting according to claim 1, characterized in that: The bottom of the ash hopper (11) is fixedly connected to the discharge pipe (13). A pneumatic arch breaker is fixedly installed in the upper part of the ash hopper (11). A flap valve (7) is installed at the upper end of the discharge pipe (13). A star-shaped unloading valve (71) is installed at the lower end of the discharge pipe (13). A radar level gauge is fixedly installed in the ash hopper (11). A level sensor is fixedly installed in the discharge pipe (13).

10. A method for explosion-proof filtration of pulverized coal in a bottom-blown furnace for lead smelting, wherein the filtration method is applicable to the explosion-proof filtration device for pulverized coal in a bottom-blown furnace for lead smelting as described in any one of claims 1-9, characterized in that, The filtering method includes the following steps: S1, Pre-separation: The bottom blower discharges a coal-containing gas stream with a temperature of 110-150℃ and a coal concentration of 0.03-0.06 kg / m³. The coal-containing gas stream enters the ash hopper (11) and filter chamber (1) through the air inlet (12). More than 70% of the coarse powder in the coal-containing gas stream falls into the ash hopper (11) under gravity, completing the pre-removal. S2, Surface filtration: Fine powder in the coal-containing gas flow enters the filter chamber (1) with the gas flow and is filtered by the surface of the antistatic filter bag (16). The purified gas passes through the antistatic filter bag (16) and enters the clean gas chamber (14), and is discharged from the clean gas outlet (17). The dust concentration at the outlet is ≤10mg / Nm³. S3. Uniform dust removal: The differential pressure transmitter monitors the filter differential pressure in real time. When the differential pressure rises to 800-1000Pa, the explosion-proof pulse jet cleaning device (2) is controlled to start, and dry nitrogen gas is sprayed into the corresponding antistatic filter bag (16) through the nozzle (21). The dust adhering to the surface of the antistatic filter bag (16) is shaken off, and the dust falls into the ash hopper (11). The dust cleaning unevenness is ≤5%, and the resistance of the antistatic filter bag (16) is quickly restored to 200-400Pa. S4. Ash removal and reuse: The dust level in the ash hopper (11) is monitored by radar level gauge. When the level reaches the high limit, the arch breaker, flap lock valve (7), and star unloading valve (71) are activated to unload the dust into the pulverized coal recovery system and return it to the bottom blower coal injection system. S5, Explosion-proof protection: The intelligent monitoring and control mechanism monitors the oxygen content, CO concentration, temperature and pressure difference in the filter chamber (1) in real time. When the oxygen content is >8%, the CO concentration is >50ppm and the temperature is >150℃, the nitrogen inerting is automatically filled to suppress explosion. When the parameters exceed the limits and cannot be recovered, the machine is interlocked and shut down.

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