Heating surface dust removal device and method for tail flue of circulating fluidized bed

Abstract

The invention discloses a heating surface dust removal device and method for a tail flue of a circulating fluidized bed, and relates to the technical field of pipeline dust removal. The heating surface dust removal device comprises a cylinder, a mandrel, an air receiving cylinder, a spiral flow deflector, a dust hopper, a gravity air blocking valve, a filter screen, a turbine and a dust removal assembly; the two filter screens are fixed in the cylinder through the outer ring to form a gradient filter layer; the filter screen is of a flexible structure, the middle of the filter screen moves rightwards under the action of wind resistance and deforms, a plane structure is changed into a conical structure, and particles are prevented from being embedded into filter holes to cause blockage; the dust removal assembly is provided with a plurality of dust removal plates evenly arranged in the circumferential direction of the filter screen, a turbine is driven to rotate under the action of wind power, and then the dust removal plates are driven to conduct circumferential rotating cleaning along the surface of the filter screen. The technical effects of avoiding bridging effect structural blockage caused by inertial embedding of coarse particles in smoke dust, reducing adhesive dust deposition caused by electrostatic adsorption, reducing the mechanical wear rate and improving the dust removal effect can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline dust removal, in particular to a heating surface dust removal device and method for a tail flue of a circulating fluidized bed. BACKGROUND

[0002] The circulating fluidized bed boiler is a kind of high-efficiency and low-pollution combustion equipment, which is widely used in power, chemical and other industries. In the operation process of the circulating fluidized bed boiler, fuel and air are mixed and burned violently in the furnace, generating a large amount of high-temperature flue gas, which carries a large amount of fly ash particles. When the flue gas passes through the tail flue, it will cause problems such as wear and ash accumulation on the heating surface, affecting the safe and economic operation of the boiler.

[0003] The existing dust removal for the heating surface of the flue, due to the CFB tail flue gas carrying a large amount of unburned carbon particles and ash, the coarse particles with a particle size greater than 50 μm have high kinetic energy, so when they vertically impact the heating surface, they may be embedded in the deep part of the filter hole due to inertia, forming a "bridge effect" to block the hole, causing structural damage to the filter screen, blocking the air flow channel, and reducing the dust removal effect. The charged particles in the high-temperature flue gas may be adhered to the surface of the filter screen fiber due to electrostatic adsorption, and need high-pressure back blowing to peel off. Long-term use of the soot blower to peel off the accumulated ash on the heating surface of the boiler tail flue by physical impact may cause the metal surface to repeatedly withstand thermal impact and corrosion, causing mechanical wear and even cracks, reducing the service life of the equipment. SUMMARY

[0004] The present application provides a heating surface dust removal device and method for a tail flue of a circulating fluidized bed, which solves the technical problems of structural blockage caused by the inertia embedding of coarse particles in the smoke dust, adhesive ash caused by electrostatic adsorption, increased mechanical wear rate and reduced dust removal effect in the prior art, and achieves the technical effects of avoiding structural blockage caused by the inertia embedding of coarse particles in the smoke dust, reducing adhesive ash caused by electrostatic adsorption, reducing the mechanical wear rate and improving the dust removal effect.

[0005] The present application provides a heating surface dust removal device for a tail flue of a circulating fluidized bed, which includes a cylinder, a core shaft, an air inlet tube, a spiral guide vane, a dust collector, a gravity air locking valve, a filter screen, a turbine and a dust removal assembly. The filter screen is provided with two, arranged left and right, and fixed in the cylinder by an outer ring to form a gradient filter layer. The filter screen is of a flexible structure, the middle part of which moves to the right and deforms under the action of wind resistance, changing from a plane structure to a conical structure, for reducing the normal kinetic energy of particles and promoting the sliding of particles to prevent particles from embedding in the filter hole to cause blockage. The dust removal assembly is provided with a plurality of dust removal plates arranged uniformly along the circumference of the filter screen, and after the flue gas enters the cylinder, the wind drives the turbine to rotate, and then drives the dust removal plates to rotate circumferentially along the surface of the filter screen for cleaning.

[0006] Further, the air receiving cylinder is fixed at the left end of the cylinder and is placed obliquely, and a guide vane is fixed inside the air receiving cylinder, which is welded to the inner wall of the cylinder at an angle of 120 degrees to form a centrifugal inertia separation channel, which is used in cooperation with the filter screen to sequentially separate the particles in the flue gas. The bottom of the air receiving cylinder is fixed with a dust collecting hopper, which is conical in shape and is provided with a gravity air locking valve at the bottom for collecting and periodically discharging large particle dust; the turbine is fixed at the left end of the mandrel and is driven by the flue gas pressure to continuously rotate the mandrel, which in turn drives the dust removal plates to scrape and clean along the conical surface of the filter screen.

[0007] Further, two sleeves are sleeved outside the mandrel, and the sleeves are arranged left and right and are fixed inside the cylinder, and the middle part of the filter screen is slidably connected in the corresponding sleeve through the fixing ring, and the filter screen changes from a flat structure to a conical structure by moving the fixing ring left and right.

[0008] Further, the two filter screens are used to intercept medium particles with a particle size of 50-100μm and fine particles with a particle size of 20-50μm respectively; each filter screen comprises three parts, filter screen one, filter screen two and filter screen three from inside to outside, the filter hole diameters of the filter screen one, filter screen two and filter screen three increase from inside to outside in the initial state, and the elasticity decreases from inside to outside, and the hole diameters of the filter screen one, filter screen two and filter screen three are consistent after being fully stretched.

[0009] Further, the dust removal assembly comprises a connecting ring, a connecting rod and a dust removal plate. The connecting ring is slidably connected to the mandrel; the connecting rod is provided with a plurality of connecting rods arranged uniformly along the circumference of the connecting ring and is rotatably connected to the connecting ring by a torsional spring; the dust removal plate is provided with a plurality of dust removal plates corresponding to the connecting rods and is rotatably connected to the corresponding connecting rod by a torsional spring for scraping and cleaning the filter screen.

[0010] Further, the connecting ring is connected to the fixing ring through the connecting rod, and the deformation of the filter screen is caused by moving the fixing ring, which in turn drives the connecting ring to move, so that the dust removal plate always adheres to the filter screen. The dust removal plate is provided with two groups, and the lengths of the two groups of dust removal plates are different, which are divided into long plates and short plates and are arranged alternately along the circumference of the filter screen to comprehensively clean the filter screen.

[0011] Further, the dust removal plate is provided with two layers, which are divided into a storage layer and an inflation layer from inside to outside. The storage layer is a hollow capsule structure, and the outer layer is a net structure, fixed outside the dust removal plate, and the inside is filled with smoke dust particles through the outer layer through hole, for improving the cleaning effect; the air filling layer is arranged inside the dust removal plate, communicated with the external air pump through the external pipeline, for receiving the gas filled by the air pump, and extruding the storage layer to change the hardness thereof.

[0012] Further, the pressure sensor is fixed at the left end of the turbine, for monitoring the wind resistance in real time, and transmitting the data to the external control system, and the external control system controls the external air pump in real time according to the detection data, adjusts the internal air pressure of the air filling layer, and realizes the dynamic adjustment of the hardness of the storage layer.

[0013] Further, the negative pressure grooves are symmetrically arranged on both sides of the dust removal plate, a plurality of suction holes are uniformly arranged in the negative pressure grooves, and the suction holes are communicated with the external air pump through the internal pipeline, for performing negative pressure suction and collection on the smoke dust falling into the negative pressure groove after scraping during scraping cleaning.

[0014] In addition, the technical scheme of the application also provides a heating surface dust removal method for a circulating fluidized bed tail flue, and the specific steps are as follows: Step one: first, high-concentration smoke gas enters the air inlet into the air inlet, and is forced to rotate forward along the spiral channel by the spiral guide vane, to generate centrifugal force, and the large particles in the smoke gas are thrown to the inner wall of the air inlet due to large mass and large centrifugal force, and fall into the dust collecting hopper; Step two: then, the smoke gas containing small and medium particles continues to advance along the spiral channel, enters the cylinder, and passes through two filter screens with different hole diameters in sequence, and the medium particles and the small particles in the smoke gas are intercepted respectively; Step three: as the filtering proceeds, the accumulated smoke dust on the filter screen gradually increases, the wind resistance increases, the filter screen deforms in a conical shape, the turbine is driven by the smoke gas pressure, continuously rotates the shaft, and further drives the dust removal plate to rotate circumferentially along the conical surface of the filter screen, the dust removal plate is attached to the surface of the filter screen under the action of the torsion spring pre-tightening force, and scraping cleaning and collection are carried out, so that the filter screen is prevented from being blocked; Step four: the large particles in the dust collecting hopper gradually accumulate, when the accumulated weight reaches a set value, the gravity air lock valve is pressed open, and the dust is discharged; after the ash is discharged, the valve plate of the gravity air lock valve is automatically closed under the action of the counterweight, so that air leakage is prevented; Step five: finally, the filtered smoke gas is discharged through the air outlet at the right end of the cylinder.

[0015] One or more technical schemes provided in the application have at least the following technical effects or advantages: By adopting multi-stage gradient filtration and pre-separation treatment of large particles, the number of particles entering the main filtration area is significantly reduced, thereby reducing the risk of structural blockage caused by bridging effect; by using flexible net structure and conical deformation, the airflow flows tangentially, reducing the vertical embedding of particles, further reducing the risk of bridging effect, and by the centrifugal force, the particles slide down, reducing electrostatic adsorption, prolonging the service life of the filter screen; by double-layer dust removal plate and air adjustment, the scraping hardness is dynamically adjusted, the particles are effectively scraped, and mechanical wear caused by excessive scraping is avoided; by adopting negative pressure groove and suction hole, the smoke dust after scraping is removed in time, secondary adhesion is prevented, electrostatic adsorption is reduced, mechanical wear rate is reduced, and dust removal effect is significantly improved; the technical problems of structural blockage caused by "bridging effect" of coarse particles in smoke dust due to inertia embedding, adhesive dust caused by electrostatic adsorption, and reduced dust removal effect caused by increased mechanical wear rate are effectively solved, and the technical effects of avoiding "bridging effect" caused by coarse particles in smoke dust due to inertia embedding, reducing adhesive dust caused by electrostatic adsorption, reducing mechanical wear rate, and improving dust removal effect are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the heating surface dust removal device of the tail flue of the circulating fluidized bed.

[0017] Figure 2 It is a partial three-dimensional structural cross-sectional view of the heating surface dust removal device of the tail flue of the circulating fluidized bed.

[0018] Figure 3 It is a partial structural view of the dust removal assembly of the heating surface dust removal device of the tail flue of the circulating fluidized bed.

[0019] Figure 4 It is a partial three-dimensional structural cross-sectional view of the heating surface dust removal device of the tail flue of the circulating fluidized bed when the smoke gas is introduced.

[0020] Figure 5 It is a schematic diagram of the state of the dust removal assembly of the heating surface dust removal device of the tail flue of the circulating fluidized bed when the filter screen is cleaned after the smoke gas is introduced.

[0021] Figure 6 It is a three-dimensional structural view of the filter screen of the heating surface dust removal device of the tail flue of the circulating fluidized bed when it is conically deformed under the action of wind resistance after the smoke gas is introduced.

[0022] Figure 7 It is a three-dimensional structural view of the dust removal plate of the heating surface dust removal device of the tail flue of the circulating fluidized bed.

[0023] Figure 8 It is aFigure 7 Figure A-A is a full cross-sectional view.

[0024] In the figure: 100, cylinder; 101, mandrel; 102, smoke dust particles; 103, outer ring; 110, wind cylinder; 111, guide vane; 112, dust hopper; 120, gravity airlock valve; 130, filter screen; 131, filter screen one; 132, filter screen two; 133, filter screen three; 140, connecting rod; 150, turbine; 160, sleeve; 170, fixed ring; 180, pressure sensor; 200, dust removal assembly; 210, connecting ring; 220, connecting rod; 230, dust removal plate; 231, storage layer; 232, aeration layer; 233, negative pressure groove; 234, suction hole. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present application, the present application will be described in more detail below with reference to the relevant drawings; the preferred embodiments of the present application are shown in the drawings, but the present application can be implemented in many different forms and is not limited to the embodiments described herein; on the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0026] It should be noted that the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only embodiment.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] Please refer to Figure 1, which is a schematic diagram of the overall structure of a heated surface dust removal device for the tail flue of a circulating fluidized bed of the present invention; the heated surface dust removal device for the tail flue of a circulating fluidized bed of the present application significantly reduces the number of particles entering the main filtration area by adopting multi-stage gradient filtration and pre-separation and treatment of large particles, thereby reducing the risk of structural blockage caused by the bridging effect; the flexible mesh structure and conical deformation are used to make the airflow flow tangentially, reduce the vertical embedding of particles, further reduce the risk of the bridging effect, and make the particles slide down by centrifugal force, reduce electrostatic adsorption, and extend the service life of the filter 130; the scraping hardness is dynamically adjusted by the double-layer dust removal plate 230 and inflation adjustment, effectively scraping off particles and avoiding mechanical wear caused by excessive scraping; the negative pressure groove 233 and the suction hole 234 are used to promptly remove the scraped smoke and prevent secondary attachment; the technical effects of avoiding the "bridging effect" structural blockage caused by the inertial embedding of coarse particles in the smoke, reducing the adhesive dust accumulation caused by electrostatic adsorption, reducing the mechanical wear rate and improving the dust removal effect are achieved.

[0029] Example 1: Figures 1 to 6 As shown, the present application discloses a dust removal device for the heated surface of the tail flue of a circulating fluidized bed, comprising a cylinder 100, a core shaft 101, an air receiving tube 110, a spiral guide vane 111, a dust collecting hopper 112, a gravity air lock valve 120, a filter screen 130, a turbine 150 and a dust removal assembly 200; Two filter screens 130 are provided, arranged on the left and right, and are fixed to the inside of the cylinder 100 by the outer ring 103, forming a gradient filtration layer. The filter screen 130 is a flexible structure. The middle part moves to the right under the action of wind resistance and deforms, changing from a flat structure to a conical structure, which is used to reduce the normal kinetic energy of particles and promote particle sliding, thereby preventing particles from embedding into the filter holes and causing clogging. The dust removal assembly 200 has multiple dust removal plates 230 evenly arranged along the circumference of the filter 130. After the flue gas enters the cylinder 100, the wind drives the turbine 150 to rotate, thereby driving the dust removal plates 230 to rotate circumferentially along the surface of the filter 130 for cleaning.

[0030] The air receiving tube 110 is fixed at the left end of the cylinder 100, placed at an angle and a guide plate 111 is fixed inside it. The guide plate 111 is welded to the inner wall of the cylinder 100 at a spiral angle of 120° to form a centrifugal inertial separation channel, which is used to cooperate with the filter 130 to pre-separate the particles in the flue gas in turn; a dust collecting hopper 112 is fixed at the bottom of the air receiving tube 110, and the dust collecting hopper 112 is conical, and a gravity air lock valve 120 is provided at the bottom to collect and regularly discharge large particles of smoke; the turbine 150 is fixed at the left end of the core shaft 101, and is driven by the flue gas pressure to drive the core shaft 101 to rotate continuously, thereby driving the dust removal plate 230 to perform circumferential scraping and cleaning along the conical surface of the filter 130.

[0031] The core shaft 101 is sleeved with two sleeves 160, which are arranged left and right and fixed inside the cylinder 100, and the middle part of the filter screen 130 is slidably connected in the corresponding sleeve 160 through the fixing ring 170, and the filter screen 130 is driven to change from a planar structure to a conical structure by moving the fixing ring 170 left and right.

[0032] The dust removal assembly 200 comprises a connecting ring 210, a connecting rod 220 and a dust removal plate 230. The connecting ring 210 is slidably connected on the core shaft 101; the connecting rod 220 is provided with a plurality of connecting rods, which are evenly arranged circumferentially along the connecting ring 210 and are rotatably connected to the connecting ring 210 through torsional springs; the dust removal plate 230 is provided with a plurality of dust removal plates corresponding to the connecting rod 220, and is rotatably connected to the corresponding connecting rod 220 through torsional springs, and is used for scraping and cleaning the filter screen 130.

[0033] Further, the connecting ring 210 is connected to the fixing ring 170 through the connecting rod 140, and the filter screen 130 is deformed by moving the fixing ring 170, thereby driving the connecting ring 210 to move, so that the dust removal plate 230 is always in close contact with the filter screen 130. The dust removal plate 230 is provided with two groups, and the lengths of the two groups of dust removal plates 230 are different, which are divided into long plates and short plates, and are arranged alternately along the circumference of the filter screen 130, and are used for cleaning the filter screen 130 comprehensively. The dust removal plate 230 is attached to the conical surface of the filter screen 130 by the centrifugal force and the pre-tightening force of the torsional spring.

[0034] Further, as shown in Figures 2 to 6 The two filter screens 130 are respectively used for intercepting medium particles with a particle size of 50-100 μm and small particles with a particle size of 20-50 μm; each filter screen 130 comprises three parts, which are filter screen one 131, filter screen two 132 and filter screen three 133 from inside to outside, and the filter hole diameters of the filter screen one 131, the filter screen two 132 and the filter screen three 133 increase from inside to outside in the initial state, and the elasticity decreases from inside to outside, and the hole diameters of the filter screen one 131, the filter screen two 132 and the filter screen three 133 are consistent after being fully stretched.

[0035] When the wind resistance increases to a certain extent, the filter screen 130 will change from a planar circle to a conical structure. This deformation is naturally formed by the filter screen 130 under the action of wind resistance, without the need for additional external force to drive. The deformed filter screen 130 not only maintains the function of gradient filtering, but also naturally forms a particle sliding channel, which helps to reduce the vertical embedding of particles on the filter screen 130 and improve the service life of the filter screen 130. Through the conical deformation of the flexible filter screen 130 under the action of wind resistance, the filtering area is significantly increased, the wind resistance increase is reduced, and the dust removal efficiency is improved and the service life of the filter screen 130 is prolonged.

[0036] As Figure 7 With Figure 8 As shown in the drawings, the dust removal plate 230 is provided with two layers, which are sequentially divided into a storage layer 231 and an air-filled layer 232 from inside to outside; The storage layer 231 is a hollow capsule structure, and its outer layer is a mesh structure, fixed on the outside of the dust removal plate 230, and its inside is filled with smoke dust particles 102 through the outer layer through hole, for strengthening the cleaning effect; The air-filled layer 232 is arranged inside the dust removal plate 230, and is communicated with the external air pump through the external pipeline, for receiving the gas filled by the air pump and extruding the storage layer 231 to change its hardness.

[0037] The left end of the turbine 150 is fixed with a pressure sensor 180, for real-time monitoring of the wind resistance, and transmitting the data to the external control system, and the external control system controls the external air pump in real time according to the detection data, adjusts the internal air pressure of the air-filled layer 232, and realizes the dynamic adjustment of the hardness of the storage layer 231.

[0038] Further, the dust removal plate 230 is symmetrically provided with a negative pressure groove 233 on both sides, a plurality of suction holes 234 are uniformly arranged in the negative pressure groove 233, and the suction holes 234 are communicated with the external air pump through the internal pipeline, for negative pressure suction and collection of the smoke dust falling into the negative pressure groove 233 after scraping.

[0039] Through the two-layer structure design and air pressure regulation mechanism of the dust removal plate 230, the internal air pressure of the air-filled layer 232 is dynamically adjusted by real-time monitoring of the wind resistance, and the dynamic adjustment of the hardness of the storage layer 231 is realized, so that the damage to the filter screen 130 is minimized while the cleaning effect is ensured. In the scraping cleaning process, the scraped smoke dust directly falls into the negative pressure groove 233 and is quickly sucked and collected through the suction hole 234, avoiding the secondary adhesion of the smoke dust; at the same time, from the microscopic point of view, by arranging the negative pressure groove 233 and the suction hole 234 in the dust removal plate 230, combined with the negative pressure suction function of the external air pump, the suction hole 234 forms a local vortex flow field under negative pressure, the scraped particles are sucked into the hole under the action of turbulent diffusion, the charge transfer occurs when the metal inner wall of the negative pressure groove 233 contacts with the charged dust, the surface potential of the particles is reduced, the secondary adsorption is fundamentally inhibited, and the dust removal efficiency is improved.

[0040] The gravity lock valve 120 periodically discharges dust by using the self-weight of the dust, when the large particles in the dust collecting hopper 112 accumulate to a certain weight, the gravity lock valve 120 is pressed open, the dust is discharged, and then automatically closed to prevent air leakage; the turbine 150 is driven by the flue gas pressure to drive the mandrel 101 to continuously rotate, and then drive the dust removal plate 230 to clean the conical surface of the filter screen 130 in the circumferential direction; the pressure sensor 180 is used to monitor the wind resistance in real time, and is preferably a high-temperature sputtering thin film piezoresistive pressure sensor; all are prior art, and will not be described here.

[0041] The use method of the heating surface dust removal device of the tail flue of the circulating fluidized bed (the heating surface dust removal method of the tail flue of the circulating fluidized bed) of the embodiment of the application is as follows: Step one: first, high-concentration flue gas enters the air inlet into the air inlet cylinder 110, and is forced to rotate forward along the spiral channel by the spiral guide vane 111, to generate centrifugal force, and the large particles in the flue gas are thrown to the inner wall of the air inlet cylinder 110 due to large mass and large centrifugal force, and fall into the dust collecting hopper 112; Step two: then, the flue gas containing small and medium particles continues to advance along the spiral channel, enters the cylinder 100, and passes through two filter screens 130 with different hole diameters in sequence, and the medium particles and the small particles in the flue gas are intercepted respectively; Step three: as the filtering proceeds, the accumulated dust on the filter screen 130 gradually increases, the wind resistance increases, the filter screen 130 deforms in a conical shape, the turbine 150 is driven by the flue gas pressure to drive the mandrel 101 to continuously rotate, and then drive the dust removal plate 230 to rotate in the circumferential direction along the conical surface of the filter screen 130, the dust removal plate 230 is attached to the surface of the filter screen 130 under the action of the torsional spring pre-tightening force, to scrape and clean, and prevent the filter screen 130 from being blocked; Step four: the large particles in the dust collecting hopper 112 gradually accumulate, when accumulated to a certain weight, the gravity lock valve 120 is pressed open, and the dust is discharged; after the dust is discharged, the valve plate of the gravity lock valve 120 is automatically closed under the action of the counterweight, to prevent air leakage; Step five: finally, the filtered flue gas is discharged through the air outlet at the right end of the cylinder 100.

[0042] The technical solutions in the above embodiment of the application have at least the following technical effects or advantages: The centrifugal force generated by the helical guide vane 111 in this embodiment can pre-separate large particles in flue gas, significantly reducing the load of the main filter screen 130 and prolonging the service life of the device. Meanwhile, the two filter screens 130 with different pore sizes form a gradient filter layer, effectively intercepting medium particles and fine particles. The pre-separation process significantly reduces the number of particles entering the main filter area, thereby reducing the risk of structural blockage caused by the bridging effect. The design of the gradient filter layer allows particles of different sizes to be effectively intercepted, thereby improving the overall dust removal effect, reducing the chance of particles coming into contact with the surface of the filter screen 130, and further reducing the phenomenon of adhesive dust caused by electrostatic adsorption. The impact of particles on the filter screen 130 is reduced, effectively reducing the mechanical wear rate and prolonging the service life of the filter screen 130.

[0043] By setting the filter screen 130 as a flexible mesh structure, the flexible mesh structure can naturally deform under the action of wind resistance, reducing the direct impact of particles on the filter screen 130. Therefore, after being transformed from a flat surface to a conical structure under the action of wind resistance, the airflow can flow tangentially, reducing the vertical embedding of particles and thereby reducing the risk of blockage caused by the bridging effect. The conical structure of the filter screen 130 makes it easier for particles to slide under the action of centrifugal force, reducing the possibility of electrostatic adsorption.

[0044] By setting the dust removal plate 230 in two layers, namely the aeration layer 232 and the storage layer 231, the aeration amount of the aeration layer 232 can be controlled to adjust the scraping hardness of the external storage layer 231, thereby more effectively removing particles and reducing blockage caused by the bridging effect. The adjustment of the aeration layer 232 provides a more appropriate scraping force, which helps to reduce the dust accumulation phenomenon caused by electrostatic adsorption and reduce adhesive dust caused by electrostatic adsorption. The dynamic adjustment of the scraping hardness avoids excessive scraping caused by mechanical wear, reduces the mechanical wear rate, and prolongs the service life of the dust removal plate 230.

[0045] Negative pressure suction can prevent the scraped flue dust from re-attaching to the filter screen 130, thereby reducing the possibility of electrostatic adsorption, helping to reduce the residue of particles on the surface of the filter screen 130, and reducing the mechanical wear rate, thereby more thoroughly removing flue dust and significantly improving the dust removal effect. It achieves the technical effects of avoiding structural blockage caused by the "bridging effect" of inertial embedding of coarse particles in flue dust, reducing adhesive dust caused by electrostatic adsorption, reducing the mechanical wear rate, and improving the dust removal effect.

[0046] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A dust removal device for the heated surface of the tail flue of a circulating fluidized bed, characterized in that: It comprises a cylinder (100), a core shaft (101), an air receiving tube (110), a spiral guide plate (111), a dust collecting hopper (112), a gravity air lock valve (120), a filter (130), a turbine (150) and a dust removal assembly (200); Two filter screens (130) are provided, arranged on the left and right, and are fixed inside the cylinder (100) via an outer ring (103) to form a gradient filter layer; the filter screen (130) is a flexible structure, the middle portion of which moves to the right and deforms under the action of wind resistance, changing from a planar structure to a conical structure, so as to reduce the normal kinetic energy of particles and promote particle sliding, thereby preventing particles from embedding into the filter holes and causing blockage; The dust removal assembly (200) has a plurality of dust removal plates (230) uniformly arranged along the circumference of the filter screen (130). After the smoke enters the cylinder (100), the wind drives the turbine (150) to rotate, thereby driving the dust removal plates (230) to rotate circumferentially along the surface of the filter screen (130) for cleaning.

2. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 1, characterized in that: The air receiving tube (110) is fixed to the left end of the cylinder (100), placed at an angle, and a guide plate (111) is fixed inside the air receiving tube. The guide plate (111) is welded to the inner wall of the cylinder (100) at a 120° spiral angle to form a centrifugal inertial separation channel for cooperating with the filter screen (130) to sequentially perform pre-separation treatment on particles in the smoke. A dust collecting hopper (112) is fixed at the bottom of the air receiving tube (110). The dust collecting hopper (112) is conical and has a gravity air lock valve (120) at the bottom for collecting and regularly discharging large particles of smoke. The turbine (150) is fixed to the left end of the core shaft (101) and is driven by the smoke pressure to drive the core shaft (101) to rotate continuously, thereby driving the dust removal plate (230) to perform circumferential scraping and cleaning along the conical surface of the filter screen (130).

3. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 2, characterized in that: Two sleeves (160) are sleeved on the outer side of the core shaft (101). The sleeves (160) are arranged on the left and right and are fixed inside the cylinder (100). The middle part of the filter screen (130) is slidably connected to the corresponding sleeve (160) through a fixing ring (170). The fixing ring (170) moves left and right to drive the filter screen (130) to change from a planar structure to a conical structure.

4. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 1, characterized in that: The two filter screens (130) are respectively used to intercept medium particles with a particle size of 50-100 μm and fine particles with a particle size of 20-50 μm; each filter screen (130) includes three parts, which are filter screen one (131), filter screen two (132) and filter screen three (133) from the inside to the outside. The filter pore diameters of the filter screen one (131), filter screen two (132) and filter screen three (133) in the initial state increase from the inside to the outside, and their elasticity decreases from the inside to the outside. The filter screen one (131), filter screen two (132) and filter screen three (133) have the same pore diameter after being fully stretched.

5. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 1, characterized in that: The dust removal assembly (200) comprises a connecting ring (210), a connecting rod (220) and a dust removal plate (230); The connecting ring (210) is slidably connected to the core shaft (101); a plurality of connecting rods (220) are provided, which are evenly arranged along the circumference of the connecting ring (210) and are all rotatably connected to the connecting ring (210) via torsion springs; a plurality of dust removal plates (230) are provided, which correspond one to one with the connecting rods (220) and are all rotatably connected to the corresponding connecting rods (220) via torsion springs, and are used to scrape and clean the filter screen (130).

6. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 5, characterized in that: The connecting ring (210) is connected to the fixing ring (170) via a connecting rod (140), and the filter screen (130) is deformed by the movement of the fixing ring (170), thereby driving the connecting ring (210) to move, so that the dust removal plate (230) is always in close contact with the filter screen (130); The dust removal plates (230) are provided in two groups. The two groups of dust removal plates (230) have different lengths and are divided into long plates and short plates. They are arranged alternately along the circumference of the filter screen (130) and cooperate with each other to perform comprehensive circumferential cleaning on the filter screen (130).

7. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 6, characterized in that: The dust removal plate (230) is provided with two layers, which are divided into a storage layer (231) and an inflation layer (232) from the inside to the outside; The storage layer (231) is a hollow capsule structure and its outer layer is a mesh structure, fixed to the outside of the dust removal plate (230), and its interior is filled with smoke particles (102) through the outer layer through holes, so as to improve the cleaning effect; the inflation layer (232) is arranged inside the dust removal plate (230), and is connected to the external air pump through an external pipe, and is used to receive the gas charged by the air pump and squeeze the storage layer (231) to change its hardness.

8. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 7, characterized in that: A pressure sensor (180) is fixed to the left end of the turbine (150) for real-time monitoring of wind resistance and transmitting data to an external control system. The external control system controls the external air pump in real time based on the detection data, adjusts the internal air pressure of the inflation layer (232), and realizes dynamic adjustment of the hardness of the storage layer (231).

9. The dust removal device for the heated surface of the tail flue of a circulating fluidized bed according to claim 8, characterized in that: Negative pressure grooves (233) are symmetrically provided on both sides of the dust removal plate (230), and a plurality of suction holes (234) are evenly provided inside the negative pressure grooves (233). The suction holes (234) are connected to an external air pump through internal pipes, and are used for negative pressure suction and collection of smoke and dust that falls into the negative pressure grooves (233) after scraping and cleaning.

10. A method for removing dust from the heated surface of the tail flue of a circulating fluidized bed, characterized in that: A dust removal device for the heated surface of a tail flue of a circulating fluidized bed according to any one of claims 1 to 7 is provided, wherein the specific steps are as follows: Step 1: First, high-concentration flue gas enters the air receiving tube (110) from the air inlet, passes through the spiral guide vane (111), and is forced to rotate and advance along the spiral channel, generating centrifugal force. Large particles in the flue gas are thrown toward the inner wall of the air receiving tube (110) due to their large mass and large centrifugal force, and fall into the dust collecting hopper (112); Step 2: Then, the smoke containing small and medium particles continues to move along the spiral channel, enters the cylinder (100), and passes through two filter screens (130) with different pore sizes in sequence, where the medium particles and small particles in the smoke are respectively intercepted; Step 3: As the filtration proceeds, the smoke and dust accumulated on the filter (130) gradually increases, the wind resistance increases, the filter (130) undergoes a conical deformation, the turbine (150) is driven by the smoke pressure, and the core shaft (101) is driven to rotate continuously, thereby driving the dust removal plate (230) to rotate along the circumference of the conical surface of the filter (130). The dust removal plate (230) is attached to the surface of the filter (130) under the action of the torsion spring preload force, and performs scraping, cleaning and collection to prevent the filter (130) from being blocked; Step 4: Large particles in the dust collecting hopper (112) gradually accumulate. When the accumulated weight reaches a set value, the gravity air lock valve (120) is pressed open and the dust is discharged. After the dust is discharged, the valve plate of the gravity air lock valve (120) is automatically closed under the action of the counterweight to prevent air leakage. Step 5: Finally, the filtered smoke is discharged through the air outlet at the right end of the cylinder (100).

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