Vertical top entry air bag precipitator with built-in spark arrest

Abstract

This invention discloses a vertical top-inlet baghouse dust collector with built-in swirling spark trapping. The inlet duct 1 is vertically positioned at the center of the top of the clean air chamber 6, with its lower end sealed to the upper end of the central flue 2 via an inlet flange 221. The central flue 2 integrates, from top to bottom, a swirling spark trapping device 21, a perforated flue 26, and an umbrella-shaped flow equalizer 24. A rear cylinder 223 is welded to the lower end of the inlet duct 222 of the swirling spark trapping device 21. A conical expansion tube 226 is coaxially arranged inside the inlet duct 222, and swirling blades 225 are mounted on the conical expansion tube 226. The outer edge of the swirling blades 225 is connected to the rear cylinder 223. 3. The inner wall is fully welded and sealed; a central clean air short pipe 224 is set below the tapered expansion pipe 226, and the lower end of the central clean air short pipe 224 is welded to the upper end of the porous flue 26; the rear cylinder 223 and the central clean air short pipe 224 are coaxially nested; an ash gas separation channel is set on the outside of the central flue 2, which includes an ash hopper 22, a discharge pipe 23, and an ash collection pipe 25. The lower end of the ash hopper 22 is welded to the upper end of the discharge pipe 23, and the lower end of the discharge pipe 23 is connected to the ash collection pipe 25; the upper inlet of the ash hopper 22 is connected to the annular gas-solid separation chamber between the rear cylinder 223 and the central clean air short pipe 224. This invention achieves a deep integration of spark capture, airflow distribution, and uniform air distribution through a vertical top air intake structure and integrated design, completely solving the secondary hoisting problem and improving the reliability of system operation.

Description

Technical Field

[0001] This invention belongs to the field of industrial flue gas purification technology, specifically relating to a vertical top-inlet baghouse dust collector with built-in spark capture, suitable for treating high-temperature spark-containing flue gas from sintering machine heads, pellet roasting, biomass boilers, waste incineration, and electric arc furnace steelmaking. Background Technology

[0002] Top-inlet baghouse dust collectors effectively reduce secondary dust generation because the airflow direction is consistent with the dust settling direction, and are widely used in industrial flue gas treatment.

[0003] However, existing technologies have the following drawbacks when dealing with high-temperature flue gas containing sparks: First, an independent cyclone dust collector or spark catcher needs to be connected in series before the dust collector, which increases the system footprint by more than 30%, increases the resistance by 200-300Pa, and significantly increases the operating energy consumption. Secondly, although existing technologies have attempted to set up simple flow guiding structures at the air inlet of dust collectors, they cannot form a stable and strong vortex, resulting in low spark capture efficiency and the separation of particles being easily re-entrained by the main airflow, forming a secondary vortex. Third, top-inlet air intake structures generally suffer from problems such as excessive load on the upper filter bags and low utilization rate of the lower filter bags; Fourth, the functional units are scattered, the connections are complex, there are many system control points, and maintenance is difficult. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a vertical top-inlet bag filter with built-in vortex spark capture. Through the vertical top-inlet structure and integrated design, it achieves a deep integration of spark capture, airflow distribution and uniform air distribution, completely solves the problem of secondary hoisting and improves the reliability of system operation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a vertical top-inlet baghouse dust collector with built-in cyclone spark capture, comprising an inlet duct, a central flue, a middle housing, a dust hopper, a filter bag area, a clean air chamber, an outlet duct, a reverse-blowing device, and a dust discharge port. The inlet duct is vertically arranged at the top center of the clean air chamber, and its lower end is sealed to the upper end of the central flue through an inlet flange, forming a vertical top-inlet structure. The airflow direction is consistent with the natural settling direction of the dust. The central flue integrates, from top to bottom, a swirling spark catcher, a porous flue, and an umbrella-shaped flow equalizer; The swirling spark trapping device includes an air inlet duct, an inlet flange welded to the upper end of the air inlet duct, and a rear duct welded to the lower end of the air inlet duct. A conical expansion tube is coaxially arranged inside the air inlet duct, and swirling blades are arranged on the conical expansion tube. The inner edge of the swirling blades is welded to the outer wall of the conical expansion tube, and the outer edge of the swirling blades is fully welded to the inner wall of the rear duct for a seal. A central purified gas short pipe is arranged below the conical expansion tube, and the lower end of the central purified gas short pipe is welded to the upper end of the porous flue. The rear duct and the central purified gas short pipe are coaxially nested, forming a double-layer sleeve structure where the outer cavity carries gas and solid phases and the inner cavity carries purified gas. The middle of the sleeve is an annular gas-solid separation chamber. A connecting plate is arranged on the central purified gas short pipe, and the central purified gas short pipe is connected to the rear duct through the connecting plate. An ash-gas separation channel is provided outside the central flue. The ash-gas separation channel includes an ash hopper, a feeding pipe, and an ash collecting pipe. The lower end of the ash hopper is welded to the upper end of the feeding pipe, and the lower end of the feeding pipe is connected to the ash collecting pipe. The outlet of the ash collecting pipe is connected to the ash hopper. The upper inlet of the ash hopper is connected to the annular gas-solid separation chamber between the rear cylinder and the central clean air short pipe.

[0006] According to an embodiment of the present invention, the porous flue is an inverted conical cylinder with evenly distributed diversion holes on the wall surface, an open bottom, a cone angle of 6°-10°, and a bottom opening diameter of 0.4-0.5 times the inner diameter of the upper end of the porous flue; the wall surface is evenly distributed with diversion holes of φ50-70mm, the opening rate is 4.0%-5.0%, and the diversion holes are arranged in an equilateral triangle staggered along the circumference and axial direction of the cylinder.

[0007] According to an embodiment of the present invention, the swirl blades are evenly arranged circumferentially, and the number is 8-12.

[0008] According to an embodiment of the present invention, the tapered expansion tube is a hollow tapered structure with a small upper end and a large lower end, a closed upper end face and an open lower end face. The upper end face of the tapered expansion tube is flush with the upper end face of the swirl vane, and the vertical distance between the lower end face and the upper end face of the central clean air short tube is 500-800mm.

[0009] According to an embodiment of the present invention, the umbrella-shaped flow equalizer is welded and fixed to the bottom outer wall of the porous flue by three inclined support rods, and is coaxially installed directly below the opening of the bottom porous flue; the cone angle of the umbrella-shaped flow equalizer is 100°-120°, and the maximum diameter is 1.0-2.0 times the diameter of the porous flue; a 100-200mm wide annular guide slit is formed between the lower end face of the porous flue and the umbrella-shaped flow equalizer.

[0010] According to an embodiment of the present invention, the ash hopper has an inverted conical structure with a cone angle of 60°-70°, and four hoppers are evenly arranged along the circumference of the porous flue; the lower end of the ash hopper is an ash discharge port with a diameter of φ100-200mm, which is welded to the upper end of the feed pipe.

[0011] According to an embodiment of the present invention, the feeding pipe is a straight pipe with an inner diameter consistent with the inner diameter of the ash discharge port of the ash hopper, and the number of pipes is the same as that of the ash hopper. Its lower end is welded to the corresponding opening of the umbrella-shaped flow equalizer. The ash collecting pipe is a closed ring pipe with an inner diameter that is 1.05-1.15 times the distance between the outermost edges of the two diagonal feeding pipes. Its lower opening is open and discharges ash downward toward the center of the ash hopper.

[0012] According to an embodiment of the present invention, the upper end face of the central air purification short pipe is a flared mouth structure, the vertical distance between the upper end face of the flared mouth and the lower end face of the tapered expansion pipe is 500-800mm, and the lower end of the central air purification short pipe is welded to the upper end of the porous flue.

[0013] According to an embodiment of the present invention, the dust collector is used as a single module or as a modular structure, wherein the modular structure is composed of 2-20 single-module dust collectors symmetrically combined; the air inlet pipe of each single-module dust collector is connected to the air inlet main pipe with gradually decreasing diameter, and the air outlet pipe is connected to the air outlet main pipe with gradually decreasing diameter.

[0014] The central flue is a prefabricated, integrated vertical welded structure with a double-layer sleeve structure, which fundamentally prevents the clean airflow from disturbing the separated dust.

[0015] The tapered expansion tube, through its variable diameter structure, gradually increases the flow area of ​​the annular swirling channel from top to bottom. When the airflow flows in the channel, according to the principle of conservation of angular momentum, the tangential velocity continuously increases and the centrifugal force continuously strengthens, thereby enhancing the migration of sparks and coarse particles toward the wall.

[0016] The working method of the dust collector includes the following steps: S1 The spark-containing flue gas enters vertically downward through the air inlet duct into the swirling spark-catching device in the integrated central flue, where a strong rotating airflow is formed by the swirling blades. S2 Sparks and coarse particles are thrown towards the inner wall of the rear cylinder under centrifugal force, spiral down the wall to the ash hopper inlet, enter the ash hopper under gravity, enter the ash collection pipe through the feed pipe, and finally be evenly discharged into the ash hopper through the ash discharge port at the bottom of the ash collection pipe. The purified gas after pre-separation in S3 gathers in the low-pressure zone at the center of the swirl and is actively drawn into the inner tube by the flared mouth at the top of the central purified gas short pipe. It then flows downward to the middle of the porous flue inverted cone-shaped cylinder and is released into the outer cavity. After S4 is released, the gas is automatically distributed in a 7:3 ratio under the dynamic pressure generated by the contraction of the inverted cone section: 70% of the gas flows out radially through the diversion holes of the porous flue and enters the filter bag area evenly; 30% of the gas flows downward along the inverted cone cylinder, flows out from the bottom opening and hits the umbrella-shaped flow equalizer, and diffuses evenly to the bottom of the filter bag area. The two airflows from above and below S5 mix thoroughly in the filter bag area to form a uniform flow field. The air passes through the filter bag to complete fine filtration, and the purified air enters the clean air chamber and is discharged through the air outlet duct. The dust captured on the surface of the S6 filter bag falls off under the action of the pulse airflow of the back-flushing device and falls into the bottom of the ash hopper, where it is discharged through the ash discharge port along with the pre-separated dust.

[0017] Compared with the prior art, the present invention has the following significant advantages: (1) The present invention adopts a coaxial nested double-layer sleeve structure. The outer cavity carries the gas-solid two-phase flow containing dust and sparks, while the inner cavity carries the purified gas, forming a completely isolated independent ash gas separation channel. Structurally, this avoids the problem of the separated dust being re-entrained by the purified airflow. On the other hand, the integrated central flue has a built-in swirling spark capture device, which forces the flue gas to form a stable strong swirling flow field, which can efficiently capture high-temperature sparks and large dust particles in the flue gas, achieving a spark capture efficiency of over 99%. (2) The present invention adopts an integrated central flue structure, which integrates components such as cyclone spark catcher, umbrella-shaped flow equalizer, and multi-hole flue into the integrated central flue, replacing the traditional separate scheme of external spark catcher and pre-dust collector, eliminating the need for external equipment and supporting connecting flues. Compared with the traditional separate process, it significantly reduces the floor space and reduces the total system resistance by 20% to 30%. (3) The present invention adopts a combined air distribution structure of inverted cone-shaped porous flue and umbrella-shaped flow equalizer. On the one hand, the inertial interception effect of the porous flue is used to further improve the removal efficiency of coarse dust. On the other hand, by precisely controlling the ratio of the total area of ​​the diversion hole to the bottom opening area, 70% of the airflow enters the upper part of the filter bag area and 30% of the airflow is diffused to the bottom of the filter bag area after hitting the umbrella-shaped flow equalizer. Combined with the vertical top air intake direction, the airflow uniformity on the cross section of the filter bag area can reach more than 95%, which solves the problem of excessive load on the upper filter bag and low utilization rate of the lower filter bag in the traditional top air intake structure. (4) The present invention uses a single-module dust collector as the basic unit. According to the air volume requirements, 2-20 modules can be symmetrically combined and arranged to flexibly adapt to different scales of flue gas treatment scenarios containing sparks.

[0018] This invention achieves a deep integration of spark capture, airflow distribution, and uniform air distribution through a vertical top-inlet structure and integrated design, completely solving the problem of secondary winch and improving the reliability of system operation.

[0019] This invention effectively solves the industry pain points of traditional flue gas treatment systems containing sparks, such as large footprint of external equipment, high system resistance, serious secondary hoisting, and uneven air distribution. It achieves a spark capture efficiency of ≥99%, airflow uniformity of over 95% in the filter bag area, and reduces system resistance by 20%-30% compared to traditional processes. It is suitable for the purification and treatment of high-temperature spark-containing flue gas in sintering machine heads, biomass boilers, and waste incineration. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a three-dimensional schematic diagram of the present invention.

[0022] Figure 3 This is a schematic diagram of the central flue structure of the present invention.

[0023] Figure 4 This is a three-dimensional schematic diagram of the central flue of the present invention.

[0024] Figure 5 These are structural schematic diagrams and three-dimensional schematic diagrams of the swirling spark capture device of the present invention, wherein a is a side view, b is a front view, c is a three-dimensional schematic diagram, and FF is a cross-sectional view of a.

[0025] In the diagram: 1-Inlet duct, 2-Central flue, 3-Middle housing, 4-Ash hopper, 5-Filter bag area, 6-Clean air chamber, 7-Outlet duct, 8-Backflushing device, 9-Ash discharge port; 21-Swirl spark collector, 22-Ash hopper, 23-Feeding pipe, 24-Umbrella-shaped flow equalizer, 25-Ash collecting pipe, 26-Porous flue; 221-Imported flange, 222-Air inlet duct, 223-Rear duct, 224-Central clean air short pipe, 225-Swirl vane, 226-Conical expansion pipe, 227-Connecting plate. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] The vertical top-inlet baghouse dust collector with built-in cyclone spark capture includes an inlet duct 1, a central flue 2, a middle box 3, a dust hopper 4, a filter bag area 5, a clean air chamber 6, an outlet duct 7, a back-blowing device 8, and a dust discharge port 9. The inlet duct 1 is vertically arranged at the top center of the clean air chamber 6, and its lower end is sealed to the upper end of the central flue 2 through an inlet flange 221 to form a vertical top-inlet structure. The airflow direction is consistent with the natural settling direction of the dust. The central flue 2 integrates a cyclone spark capture device 21, a perforated flue 26, and an umbrella-shaped flow equalizer 24 from top to bottom. The swirling spark trapping device 21 includes an air inlet duct 222, with an inlet flange 221 welded to the upper end of the air inlet duct 222 and a rear cylinder 223 welded to the lower end. A tapered expansion tube 226 is coaxially arranged inside the air inlet duct 222, and swirling blades 225 are arranged on the tapered expansion tube 226. The inner edge of the swirling blades 225 is welded to the outer wall of the tapered expansion tube 226, and the outer edge of the swirling blades 225 is fully welded to the inner wall of the rear cylinder 223 for sealing. A central clean air short pipe 224 is installed below the porous flue 26, and the lower end of the central clean air short pipe 224 is welded to the upper end of the porous flue 26; the rear cylinder 223 and the central clean air short pipe 224 are coaxially nested to form a double-layer sleeve structure in which gas and solid phases flow in the outer cavity and purified gas flows in the inner cavity, with an annular gas-solid separation chamber in the middle of the sleeve; a connecting plate 227 is installed on the central clean air short pipe 224, and the central clean air short pipe 224 is connected to the rear cylinder 223 through the connecting plate 227; An ash-gas separation channel is provided on the outside of the central flue 2. The ash-gas separation channel includes an ash hopper 22, a feeding pipe 23, and an ash collecting pipe 25. The lower end of the ash hopper 22 is welded to the upper end of the feeding pipe 23. The lower end of the feeding pipe 23 is connected to the ash collecting pipe 25. The outlet of the ash collecting pipe 25 is connected to the ash hopper 4. The upper inlet of the ash hopper 22 is connected to the annular gas-solid separation chamber between the rear cylinder 223 and the central clean air short pipe 224.

[0028] The porous flue 26 is an inverted conical cylinder with evenly spaced diversion holes on its wall surface. The bottom is open with a cone angle of 6°-10° and the diameter of the bottom opening is 0.4-0.5 times the inner diameter of the upper end of the porous flue 26. The wall surface is evenly spaced with diversion holes of φ50-70mm, with an opening rate of 4.0%-5.0%. The diversion holes are arranged in an equilateral triangle pattern along the circumference and axial direction of the cylinder.

[0029] The swirl blades 225 are evenly arranged circumferentially, and the number of blades is 8-12.

[0030] The tapered expansion tube 226 is a hollow tapered structure with a small upper end and a large lower end, a closed upper end face and an open lower end face. The upper end face of the tapered expansion tube 226 is flush with the upper end face of the swirl vane 225, and the vertical distance between the lower end face and the upper end face of the central clean air short tube 224 is 500-800mm.

[0031] The umbrella-shaped flow equalizer 24 is welded and fixed to the bottom outer wall of the porous flue 26 by three inclined support rods, and is coaxially installed directly below the bottom opening of the porous flue 26; the cone angle of the umbrella-shaped flow equalizer 24 is 100°-120°, and the maximum diameter is 1.0-2.0 times the diameter of the porous flue 26; a 100-200mm wide annular guide slit is formed between the lower end face of the porous flue 26 and the umbrella-shaped flow equalizer 24.

[0032] The ash hopper 22 has an inverted conical structure with a cone angle of 60°-70°, and four hoppers are evenly arranged around the circumference of the porous flue 26. The lower end of the ash hopper 22 is a discharge port with a diameter of φ100-200mm, which is welded to the upper end of the feed pipe 23.

[0033] The discharge pipe 23 is a straight pipe with an inner diameter consistent with the inner diameter of the ash discharge port of the ash hopper 22. The number of pipes is the same as that of the ash hopper 22. Its lower end is welded to the corresponding opening of the umbrella-shaped flow equalizer 24. The ash collection pipe 25 is a closed ring pipe with an inner diameter that is 1.05-1.15 times the distance between the outermost edges of the two diagonal discharge pipes. Its lower opening is open and discharges ash downwards towards the center of the ash hopper 4.

[0034] The upper end face of the central air purification short pipe 224 has a flared mouth structure, and the vertical distance between the upper end face of the flared mouth and the lower end face of the tapered expansion pipe 226 is 500-800mm. The lower end of the central air purification short pipe 224 is welded to the upper end of the porous flue 26.

[0035] The dust collector can be used as a single module or as a modular structure, which is composed of 2-20 single-module dust collectors symmetrically combined; the air inlet pipe 1 of each single-module dust collector is connected to the air inlet main pipe with gradually changing diameter, and the air outlet pipe 7 is connected to the air outlet main pipe with gradually changing diameter.

[0036] Example 1: As Figure 1-3 As shown, the vertical top-inlet bag filter with built-in swirling spark capture device provided in this embodiment has a single unit processing air volume of 100,000 m³ / h, and is suitable for flue gas treatment of small and medium-sized sintering machine heads.

[0037] This embodiment adopts a vertical top-inlet air intake method to ensure that the airflow direction is in the same direction as the dust settling direction. The connection relationship of the main structure of the dust collector is as follows: The middle box 3 is a rectangular steel structure. A circular air inlet hole with a diameter of φ1500mm is opened at the center of the top of the clean air chamber. The air inlet pipe 1 is vertically welded to the air inlet hole, and a DN1500 flange is welded to the lower end. The inlet flange 221 at the upper end of the integrated central flue 2 is connected to the flange at the lower end of the air inlet duct 1 by bolts, and a high-temperature resistant fluororubber gasket is installed at the connection. Multiple reinforcing ribs are welded to the outer wall of the integrated central flue 2. The other end of the reinforcing ribs is fixed to the pre-embedded steel plate on the inner wall of the middle box 3 by bolts. The bottom of the perforated flue is 1.0m away from the top of the filter bag area 5. The lower part of the middle box 3 is welded with a flange, which is connected to the upper flange of the ash hopper 4 by bolts; The filter bag area 5 is installed inside the middle box 3 via a tube sheet, and the clean air chamber 6 is above the tube sheet. The exhaust duct 7 is welded to the top of the clean air chamber 6, and its outlet is equipped with a flange to connect to the exhaust flue. The back-blowing device 8 is installed on the side of the clean air chamber 6. The ash discharge port 9 is welded to the bottom of the ash hopper 4 and is equipped with a 400*400mm slide gate valve and a star-shaped ash discharge valve.

[0038] In this embodiment, the swirling spark catcher 21 is built into the integrated central flue (2), and the ash hopper 22, the feed pipe 23, the umbrella-shaped flow equalizer 24, the ash collection pipe 25 and the multi-hole flue (26) are integrated to form an integrated structure, realizing the functions of efficient spark catcher and uniform airflow distribution. Moreover, the present invention does not require additional independent spark catcher equipment, which greatly saves space and reduces connecting pipes.

[0039] The internal connections of the integrated central flue 2 are as follows: The swirl spark catcher 21 adopts a coaxial nested double-layer sleeve design, with a cylindrical structure. The air inlet duct 222 has a diameter of φ1500mm, with an inlet flange 221 welded to the upper end, and 10 stainless steel swirl blades 225 welded inside, with a blade thickness of 6mm; the tapered expansion pipe 226) has a cone angle of 45°, a diameter of 100mm at the upper end, and a diameter of 500mm at the lower end; the inner edge of the swirl blades 225... The outer wall of the tapered expansion tube 226 is welded to the outer edge, and the outer edge is fully welded to the inner wall of the rear cylinder 223 for sealing. The upper end of the rear cylinder 223 is welded to the lower end of the air inlet duct 222, and the lower end is welded to the upper end of the ash hopper 22. The central clean air short pipe 224 has a flared mouth structure with an upper end of φ1000mm and a lower end of φ1500mm. The vertical distance between the upper end face and the upper end face of the tapered expansion tube 226 is 600mm. The lower end of the central clean air short pipe 224 is butt-welded to the upper end of the porous flue 26.

[0040] The porous flue 26 is an inverted conical cylinder with an upper diameter of φ1500mm, a bottom opening diameter of 600mm, and a height of 6000mm. The wall surface is evenly opened with φ60mm diversion holes, with an opening ratio of 4.5%. The diversion holes are arranged in an equilateral triangle pattern along the circumference and axial direction.

[0041] The umbrella-shaped flow equalizer 24 is a conical steel plate with a cone angle of 105° and a maximum diameter of 1500mm. It is welded to the bottom outer wall of the porous flue 26 by three support rods and is located directly below the bottom opening. A 100mm wide annular guide slit is formed between the two.

[0042] This embodiment sets up an independent ash discharge path, which does not cross-interfere with the clean airflow throughout the process, and completely eliminates the phenomenon of secondary hoisting.

[0043] The connection relationships of the components in the independent ash gas separation channel are as follows: Four ash hoppers 22 are evenly arranged around the perforated flue 26. The ash hoppers 22 are inverted cone-shaped structures with a cone angle of 65°. The upper inlet is connected to the annular chamber between the rear cylinder 223 and the central clean air short pipe 224. The lower end of the ash hoppers 22 is a φ150mm ash discharge port, which is welded to the upper end of the feed pipe 23. The feed pipe 23 is a seamless steel pipe with a diameter of φ150mm, there are 4 pipes in total, with a length of 6200mm, and the lower end is welded to the corresponding opening of the umbrella-shaped flow equalizer 24; The ash collection pipe 25 is a closed annular steel pipe with a diameter of 800mm and a height of 1000mm. The bottom opening is open and the ash is discharged downwards towards the center of the ash hopper 4.

[0044] The working process of this embodiment is as follows: Sintering flue gas containing sparks (temperature 150℃, dust concentration 10g / m³) enters vertically downward through the air inlet duct 1 into the swirling spark trap 21 of the integrated central flue 2. When passing through the swirling blades 225, it is forced to rotate, forming a strong swirling airflow. Sparks and coarse particles are thrown towards the inner wall of the rear cylinder 223 under the action of centrifugal force, and spiral down along the wall to the inlet of the ash hopper 22. Under the action of gravity, it enters the ash hopper 22, enters the ash collection pipe 25 through the feed pipe 23, and is finally evenly discharged into the ash hopper 4 through the bottom of the ash collection pipe 25.

[0045] The separated purified gas gathers in the low-pressure zone at the center of the swirl and is actively drawn into the inner tube by the flared opening at the upper end of the central purified gas short pipe 224. It then flows downward to the middle of the inverted conical cylinder of the porous flue 26 and is released into the outer cavity. Under the dynamic pressure generated by the contraction of the inverted conical section, the released gas is automatically distributed in a 7:3 ratio: 70% of the gas flows out radially through the diversion holes of the porous flue 26 and enters the upper part of the filter bag area 5 evenly; 30% of the gas flows downward along the inverted conical cylinder, flows out from the bottom opening, and then impacts the umbrella-shaped flow equalizer 24 through the equal-width annular guide slit, spreading evenly to the bottom of the filter bag area 5.

[0046] The two airflows mix thoroughly in the filter bag area 5 to form a uniform flow field, pass through the filter bag to complete fine filtration, and the purified gas enters the clean air chamber 6 and is discharged through the air outlet duct 7.

[0047] The dust captured on the surface of the filter bag falls off under the action of the pulse airflow of the back-blowing device 8 and falls into the bottom of the ash hopper 4, where it is discharged through the ash discharge port 9 along with the pre-separated dust.

[0048] In this embodiment, the system resistance is ≤1000Pa, the spark capture efficiency is ≥99%, the airflow uniformity in the filter bag area is ≥95%, and the outlet dust concentration is ≤5mg / m³. All indicators are better than the national standard requirements.

[0049] Example 2: This example is based on the standardized single-module technical solution of Example 1. It adopts a double-row 5-column modular combination design with a total air volume of 1 million m³ / h, which is suitable for the treatment of flue gas from large sintering machine heads.

[0050] This embodiment consists of 10 single-module dust collectors that are exactly the same as those in Embodiment 1. They are arranged symmetrically in two rows and five columns, with five modules in each row. The dust collectors have a 1.5m horizontal maintenance passage reserved.

[0051] The main air inlet duct adopts a stepped diameter reduction design. The inlet diameter is φ4800mm. After connecting two module air inlet branch ducts, the diameter is reduced by one level, for a total of 5 stages of diameter reduction to the end φ2200mm. The air velocity in each section is controlled at 14-16m / s. Each module air inlet duct has one branch duct that is vertically connected to the main duct through an equal diameter tee.

[0052] The main exhaust duct adopts a stepped expansion design, with a front end diameter of φ2200mm. After connecting every two module exhaust branch ducts, it is expanded by one stage, for a total of 5 stages of expansion to the outlet end of φ4800mm. The wind speed in each section is controlled at 14-16m / s. The seven branch ducts of each module exhaust duct are vertically connected to the main duct through equal diameter tees.

[0053] The working process of this embodiment is as follows: Sintering flue gas containing sparks enters each individual module dust collector through the main inlet duct; the flue gas treatment process inside each module is exactly the same as in Embodiment 1: the flue gas undergoes pre-separation of sparks and coarse particles through a cyclone spark catcher, and the pre-purified gas is distributed in a 7:3 ratio in the porous flue and evenly enters the filter bag area for fine filtration; the purified gas flows from the outlet ducts of each module into the main outlet duct and is discharged into the chimney by the induced draft fan. The dust collected in the ash hoppers of each module is sent to the ash silo by the conveying device below and transported out periodically.

Claims

1. A vertical top-inlet baghouse dust collector with built-in cyclone spark capture, comprising an inlet duct (1), a central flue (2), a middle box (3), a dust hopper (4), a filter bag area (5), a clean air chamber (6), an outlet duct (7), a back-blowing device (8), and a dust discharge port (9). The inlet duct (1) is vertically arranged at the top center of the clean air chamber (6), and its lower end is sealed to the upper end of the central flue (2) through an inlet flange (221) to form a vertical top-inlet structure. The airflow direction is consistent with the natural settling direction of the dust. Its features are: The central flue (2) integrates, from top to bottom, a swirling spark catcher (21), a perforated flue (26), and an umbrella-shaped flow equalizer (24). The swirling spark trapping device (21) includes an air inlet duct (222), with an inlet flange (221) welded to the upper end of the air inlet duct (222) and a rear cylinder (223) welded to the lower end of the air inlet duct (222). A tapered expansion tube (226) is coaxially arranged inside the air inlet duct (222), and swirling blades (225) are arranged on the tapered expansion tube (226). The inner edge of the swirling blades (225) is welded to the outer wall of the tapered expansion tube (226), and the outer edge of the swirling blades (225) is welded to the rear cylinder (223). The inner wall is fully welded and sealed; a central clean air short pipe (224) is provided below the tapered expansion pipe (226), and the lower end of the central clean air short pipe (224) is welded to the upper end of the porous flue (26); the rear cylinder (223) and the central clean air short pipe (224) are coaxially nested to form a double-layer sleeve structure in which gas and solid phases flow in the outer cavity and purified gas flows in the inner cavity, and the middle of the sleeve is an annular gas-solid separation chamber; a connecting plate (227) is provided on the central clean air short pipe (224), and the central clean air short pipe (224) is connected to the rear cylinder (223) through the connecting plate (227); A gas separation channel is provided outside the central flue (2). The gas separation channel includes a hopper (22), a feed pipe (23), and a collection pipe (25). The lower end of the hopper (22) is welded to the upper end of the feed pipe (23). The lower end of the feed pipe (23) is connected to the collection pipe (25). The outlet of the collection pipe (25) is connected to the hopper (4). The upper inlet of the hopper (22) is connected to the annular gas-solid separation chamber between the rear cylinder (223) and the central clean air short pipe (224).

2. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that: The porous flue (26) is an inverted conical cylinder with evenly spaced diversion holes on the wall surface. The bottom is open with a cone angle of 6°-10°. The diameter of the bottom opening is 0.4-0.5 times the inner diameter of the upper end of the porous flue (26). Evenly spaced diversion holes of φ50-70mm are opened on the wall surface with an opening rate of 4.0%-5.0%. The diversion holes are arranged in an equilateral triangle pattern along the circumference and axial direction of the cylinder.

3. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The swirl blades (225) are evenly arranged circumferentially, and the number is 8-12.

4. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The tapered expansion tube (226) is a hollow tapered structure with a small upper end and a large lower end, a closed upper end face and an open lower end face. The upper end face of the tapered expansion tube (226) is flush with the upper end face of the swirl vane (225), and the vertical distance between the lower end face and the upper end face of the central clean air short tube (224) is 500-800mm.

5. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The umbrella-shaped flow equalizer (24) is welded and fixed to the bottom outer wall of the porous flue (26) by three inclined support rods and is coaxially installed directly below the bottom opening of the porous flue (26); the cone angle of the umbrella-shaped flow equalizer (24) is 100°-120° and the maximum diameter is 1.0-2.0 times the diameter of the porous flue (26); a 100-200mm wide annular guide slit is formed between the lower end face of the porous flue (26) and the umbrella-shaped flow equalizer (24).

6. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The ash hopper (22) has an inverted conical structure with a cone angle of 60°-70°, and four hoppers are evenly arranged around the circumference of the porous flue (26). The lower end of the ash hopper (22) is a discharge port with a diameter of φ100-200mm, which is welded to the upper end of the feed pipe (23).

7. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The discharge pipe (23) is a straight pipe with an inner diameter consistent with the inner diameter of the ash discharge port of the ash hopper (22) and the same number as the ash hopper (22). Its lower end is welded to the corresponding opening of the umbrella-shaped flow equalizer (24). The ash collection pipe (25) is a closed ring pipe with an inner diameter 1.05-1.15 times the distance between the outermost edges of the two diagonal discharge pipes. Its lower opening is open and discharges ash downwards towards the center of the ash hopper (4).

8. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The upper end face of the central clean air short pipe (224) has a flared mouth structure, and the vertical distance between the upper end face of the flared mouth and the lower end face of the tapered expansion pipe (226) is 500-800mm. The lower end of the central clean air short pipe (224) is welded to the upper end of the porous flue (26).

9. The vertical top-inlet baghouse dust collector with built-in cyclone spark capture as described in claim 1, characterized in that... The dust collector can be used as a single module or as a modular structure, which is composed of 2-20 single-module dust collectors symmetrically combined; the air inlet pipe (1) of each single-module dust collector is connected to the air inlet main pipe with gradually changing diameter, and the air outlet pipe (7) is connected to the air outlet main pipe with gradually changing diameter.

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