Loosening and pneumatic material stirring device for sludge blending combustion in dense-phase region of circulating fluidized bed boiler
By designing loosening and pneumatic feeding devices such as compressed air storage tanks and venturi tubes in circulating fluidized bed boilers, the clogging problem during sludge co-firing was solved, achieving continuous and efficient sludge feeding and combustion stability, and reducing energy consumption and maintenance costs.
Patent Information
- Application Number
- CN202511229245.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-29
- Publication Date
- 2025-12-05
AI Technical Summary
In existing circulating fluidized bed boilers, during the sludge co-firing process, strip-shaped sludge can easily cause blockage of the fuel chamber air cap and slag discharge port, affecting material fluidization and slag discharge, leading to unstable combustion.
A loosening and pneumatic material-dispensing device was designed, comprising a compressed air storage tank, a venturi tube, a hot primary air inlet pipe, a sludge feed pipe, and a material-dispensing air duct. The device forms a high-temperature material-dispensing air by mixing hot primary air and compressed air, and uses the material-dispensing air duct to spray the sludge comprehensively and continuously, breaking up the strip-shaped sludge structure and preventing it from adhering to the rear wall of the combustion chamber.
It achieves continuous and efficient sludge feeding, prevents clogging, ensures combustion stability, reduces energy consumption, adapts to different working conditions, has a simple structure and low cost, and is easy to promote industrially.
Smart Images
Figure CN121067337A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of circulating fluidized bed boiler sludge blending combustion, in particular to a loose and pneumatic raking device for sludge blending combustion in the dense phase zone of a circulating fluidized bed boiler. BACKGROUND
[0002] A circulating fluidized bed boiler mainly includes a combustion chamber, a gas-solid separator and a material return system. Its working principle is based on fluidized combustion technology, and its core is to suspend and strongly mix fuel particles through high-speed airflow. In the combustion chamber, fuel is mixed with high-temperature solid particles to form a fluidized state, ensuring that the fuel ignites quickly and burns fully. Fine particles produced by combustion are separated by a gas-solid separator and returned to the combustion chamber for continuous combustion, forming a cycle to achieve efficient combustion.
[0003] To achieve sludge reduction, harmlessness, resource utilization and large-scale disposal. At the same time, reduce fuel operating costs. The power plant mixes and burns the sludge of different degrees of drying with fuel in the form of self-feeding coal system, coal feeding system or directly into the combustion chamber.
[0004] The existing boiler used in the power plant is a circulating fluidized bed boiler, and its sludge blending combustion system uses the method of entering the furnace in the dense phase zone of the combustion chamber. Because the height difference between the blending combustion point and the air distribution plate of the circulating fluidized bed combustion chamber is only 2.72m. Therefore, after the strip-shaped sludge enters the combustion chamber from the blending port, part of the unfluidized and burned-out sludge will cause problems such as blockage of the fuel chamber air cap eye and the slag discharge port, thereby affecting the normal material fluidization and slag discharge of the circulating fluidized bed boiler. In view of the above status, it is urgent to provide a loose and pneumatic raking device for sludge blending combustion in the dense phase zone of a circulating fluidized bed boiler to overcome the deficiencies in current actual applications. SUMMARY
[0005] The purpose of the present application is to provide a loose and pneumatic raking device for sludge blending combustion in the dense phase zone of a circulating fluidized bed boiler, which aims to solve the problems in the background art.
[0006] The present application is realized as follows: a loose and pneumatic raking device for sludge blending combustion in the dense phase zone of a circulating fluidized bed boiler, comprising a compressed air storage tank;
[0007] It also includes a Venturi tube, a hot primary air introduction pipe, a sludge feeding pipe, a raking air pipe and a fixing rib;
[0008] The compressed air storage tank is connected with an air inlet pipe and an air outlet pipe for storing and outputting compressed air;
[0009] The inlet section of the Venturi tube is connected with the air outlet pipe of the compressed air storage tank, the throat of the Venturi tube is connected with the hot primary air introduction pipe, and the outlet section of the Venturi tube is connected with the raking air pipe;
[0010] The sludge feeding pipe is fastened with the start-up burner sleeve through a flange, and the outlet side of the sludge feeding pipe is welded and fixed with the inner wall of the start-up burner sleeve through a positioning rib plate.
[0011] The stirring air pipe penetrates into the sludge feeding pipe and extends to the discharge port of the sludge feeding pipe.
[0012] The fixing rib is installed between the stirring air pipes and between the stirring air pipes and the sludge feeding pipe.
[0013] As a further scheme of the present application, the outlet section of the Venturi tube is provided with a distributor.
[0014] As a further scheme of the present application, the stirring air pipe is provided with a root.
[0015] As a further scheme of the present application, the distributor comprises one main pipe interface and eight small pipe interfaces, the main pipe interface is connected with the outlet section of the Venturi tube, and the eight small pipe interfaces are respectively welded with the eight stirring air pipes in one-to-one correspondence.
[0016] As a further scheme of the present application, the throat of the Venturi tube is connected with the hot primary air introduction pipe, so that the hot primary air with a temperature of 260 DEG C introduced after being heated by the boiler air preheater is mixed with the compressed air with a temperature of 40 DEG C output by the compressed air storage tank in the Venturi tube to form the stirring air with a temperature between 40 DEG C and 260 DEG C.
[0017] As a further scheme of the present application, the front section of the sludge feeding pipe close to the sludge inlet end is provided with a penetrating section, eight through holes are uniformly arranged in the circumferential middle position of the penetrating section, the diameters of the eight through holes are adapted to the outer diameters of the stirring air pipes, and the eight stirring air pipes penetrate into the sludge feeding pipe through the eight through holes respectively.
[0018] As a further scheme of the present application, the sludge inlet end of the sludge feeding pipe is provided with a flange.
[0019] As a further scheme of the present application, the stirring air pipes are equidistantly distributed in the circumferential direction at the outlet position of the sludge feeding pipe.
[0020] As a further scheme of the present application, the fixing rib is provided with two places, the first fixing rib is installed at the middle position of the sludge feeding pipe, and the second fixing rib is installed at the sludge outlet position of the sludge feeding pipe.
[0021] As a further scheme of the present application, the material of the stirring air pipe is high-temperature-resistant stainless steel.
[0022] Compared with the prior art, the present application has the following beneficial effects:
[0023] 1. Achieve continuous and efficient raking: Through 8 circumferentially equidistantly distributed raking air pipes, combined with the airflow distribution structure of the Venturi tube, the strip-shaped sludge in the sludge feeding pipe can be fully and continuously sprayed by airflow, completely breaking the structure of the strip-shaped sludge and avoiding sludge accumulation, and the raking efficiency is significantly improved compared with existing intermittent injection devices.
[0024] 2. Reduce the interference of combustion conditions: The hot primary air is mixed with compressed air by the Venturi tube to increase the temperature of the raking air to close to the ambient temperature of the combustion chamber, greatly reducing the temperature difference between the raking air and the combustion chamber, effectively reducing the influence on the combustion stability of the circulating fluidized bed boiler, and ensuring the normal combustion conditions of the boiler.
[0025] 3. Prevent clogging: The strip-shaped sludge is fully loosened and dispersed into clusters or flocs, and enters the middle of the combustion chamber with the airflow to participate in fluidized combustion, which fundamentally solves the problem of clogging of the air cap eye and the slagging port, and ensures the normal material fluidization and slagging of the boiler.
[0026] 4. Reduce energy consumption and cost: The introduction of hot primary air is realized by the negative pressure suction principle of the Venturi tube, without the need for additional power equipment, thereby reducing energy consumption; at the same time, the device structure is simple, and conventional high-temperature resistant materials are used, so the manufacturing and maintenance costs are low, and it is easy to industrialize and popularize.
[0027] 5. Adapt to different working conditions: The pressure regulating valve of the compressed air storage tank inlet pipe can flexibly adjust the compressed air pressure according to the coal quality used by the boiler, the sludge feeding amount and the boiler load, and then adjust the raking airflow intensity, so that the device can adapt to different operating conditions and improve the versatility of the device. BRIEF DESCRIPTION OF DRAWINGS
[0028] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.
[0029] Figure 1 It is a schematic diagram of the overall structure of the present application.
[0030] Figure 2 It is a schematic diagram of the structure of the hot primary air introduction pipe, the Venturi tube and the raking air pipe in the present application.
[0031] Figure 3 It is a schematic diagram of the structure of the sludge feeding pipe in the present application.
[0032] Figure 4 It is a schematic diagram of the structure of the hot primary air introduction pipe and the raking air pipe in the present application.
[0033] In the drawings: 1 - compressed air tank, 2 - venturi, 21 - distributor, 3 - hot primary air introduction pipe, 4 - sludge feeding pipe, 41 - flange, 42 - penetration section, 5 - raking air pipe, 6 - fixing rib, 7 - start-up burner sleeve. DETAILED DESCRIPTION
[0034] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0035] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.
[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application should be understood according to the specific circumstances.
[0037] The present application will be further explained and described below in conjunction with specific embodiments.
[0038] Please refer to Figures 1-4 The loose and pneumatic raking device for sludge blending in the dense phase zone of a circulating fluidized bed boiler provided by the embodiments of the present application comprises a compressed air tank 1, a venturi 2, a hot primary air introduction pipe 3, a sludge feeding pipe 4, a raking air pipe 5, and a fixing rib 6.
[0039] The compressed air tank 1 is connected with an air inlet pipe and an air outlet pipe. The inlet section of the Venturi tube 2 is connected with the compressed air tank, the throat section is connected with the hot primary air introduction pipe 3, and the outlet section is connected with the stirring air pipe. The sludge feeding pipe 4 is connected with the start-up burner sleeve 7 through a flange. The outlet side of the sludge feeding pipe 4 is fastened with the inner wall of the start-up burner sleeve 7 through a positioning rib plate. The stirring air pipe 5 is connected with the diffusion section of the Venturi tube 2. The fixing rib 6 is installed between the stirring air pipes 5 and between the stirring air pipe 5 and the sludge feeding pipe 4. The material of the stirring air pipe 5 is high-temperature-resistant stainless steel.
[0040] The throat section of the Venturi tube 2 is connected with the hot primary air introduction pipe 3. The hot primary air heated by the boiler air preheater is sucked by the negative pressure to mix the hot primary air at about 260 DEG C with the compressed air at about 40 DEG C, so as to increase the stirring air temperature entering the combustion chamber, reduce the temperature difference between the stirring air and the combustion chamber, and reduce the influence on the boiler combustion condition. The outlet section of the Venturi tube 2 is provided with a distributor 21, which is divided into eight small pipes and is welded with the stirring air pipe 5, for providing the air source for stirring.
[0041] One end (the sludge inlet end) of the sludge feeding pipe 4 is provided with a flange 41, so as to be fastened and connected with the start-up burner sleeve 7. The other end (the sludge outlet end) is positioned with the inner wall of the start-up burner through a positioning rib plate to avoid shaking and displacement. The front section of the sludge inlet end of the sludge feeding pipe 4 is provided with a penetrating section 42. Eight holes are arranged in the middle position of the penetrating section 42 in the circumferential direction, for penetrating the stirring air pipe 5. The sludge inlet side of the penetrating section 42 is provided with a flange, for connecting with the expansion joint of the sludge conveying pipe.
[0042] The stirring air pipe 5 is provided with eight pipes, which are welded with the distributor 21 of the Venturi tube 2 at the air inlet side. The stirring air pipe penetrates into the inside of the sludge feeding pipe from the penetrating section 42 of the sludge feeding pipe, is distributed equidistantly in the circumferential direction, and extends to the sludge outlet along the sludge feeding pipe.
[0043] The fixing rib 6 has two positions, one of which is installed in the middle of the sludge feeding pipe 4, and the other of which is installed at the sludge outlet of the sludge feeding pipe 4, for fixing the stirring air pipe 5 and keeping the relative positions between the eight stirring air pipes 5 and between the stirring air pipe 5 and the sludge feeding pipe 4.
[0044] In the embodiment of the present application, the stirring air pipe 5 is arranged equidistantly in the circumferential direction in the inside of the sludge feeding pipe 4, and is connected and positioned through the fixing rib 6, so as to play a role of loosening the strip-shaped sludge.
[0045] The outlet of the sludge feeding pipe 4 is circumferentially equidistantly distributed with 8 stirring air pipes 5, and the sludge conveyed into the combustion chamber can be scattered and blown into the middle of the combustion chamber to participate in fluidized combustion under the action of pneumatic conveying, so as to improve the combustion efficiency and avoid that the strip-shaped sludge structure cannot be scattered, flows to the circulating fluidized bed air cap and the slag discharge port after sticking to the back wall of the combustion chamber, and causes the blockage of the air cap eye and the slag discharge port.
[0046] The hot primary air at about 260 DEG C is mixed into the sludge pneumatic stirring compressed air through the Venturi tube 2, the temperature of the stirring air source is increased to reduce the temperature difference between the sludge stirring medium and the combustion chamber, so as to reduce the influence on the combustion working condition of the circulating fluidized bed boiler.
[0047] The strip-shaped sludge can be loosened and the sludge can be fully and continuously stirred into the furnace for mixing and burning through the stirring air pipe 5, so as to improve the combustion efficiency of the mixed and burned sludge.
[0048] In summary, the working principle of the present application is as follows:
[0049] When the sludge mixing and burning system is put into operation, the sludge is injected into the boiler combustion chamber in the form of strips under the action of the screw pump through the sludge feeding pipe 4. The compressed air in the compressed air storage tank 1 is mixed into the hot primary air of the boiler through the Venturi tube 2 to provide the pneumatic stirring air source for the stirring air pipe 5. The stirring air pipe 5 uniformly distributed at the outlet of the sludge feeding pipe 4 blows the strip-shaped sludge into clusters, flocs and blows it to the middle of the combustion chamber to participate in fluidized combustion, improves the combustion efficiency, and avoids that the strip-shaped sludge structure cannot be scattered, flows to the circulating fluidized bed air cap and the slag discharge port after sticking to the back wall of the combustion chamber, and causes the blockage of the air cap eye and the slag discharge port.
[0050] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A loose and pneumatic raking device for sludge mixing in the dense phase zone of a circulating fluidized bed boiler, comprising a compressed air tank (1), characterized in that, Venturi tube (2), hot primary air introduction pipe (3), sludge feeding pipe (4), stirring air pipe (5) and fixing rib (6) are further included; The compressed air storage tank (1) is connected with an air inlet pipe and an air outlet pipe for storing and outputting compressed air; The inlet section of the venturi tube (2) is connected with the air outlet pipe of the compressed air storage tank (1), the throat of the venturi tube (2) is connected with the hot primary air introduction pipe (3), and the outlet section of the venturi tube (2) is connected with the stirring air pipe (5); The sludge feeding pipe (4) is fastened and connected with the start-up burner sleeve (7) through a flange, and the outlet side of the sludge feeding pipe (4) is welded and fixed with the inner wall of the start-up burner sleeve (7) through a positioning rib plate; The stirring air pipe (5) penetrates into the inside of the sludge feeding pipe (4) and extends to the discharge port of the sludge feeding pipe (4); The fixing rib (6) is installed between the stirring air pipes (5) and between the stirring air pipes (5) and the sludge feeding pipe (4).
2. The circulating fluidized bed boiler dense zone sludge blending and loose and pneumatic raking device according to claim 1, characterized in that, The outlet section of the venturi tube (2) is provided with a distributor (21).
3. A fluidized bed boiler dense zone sludge blending and pneumatic raking device according to claim 2, characterized in that, The stirring air pipe (5) is provided with 8.
4. The circulating fluidized bed boiler dense zone sludge blending and loose and pneumatic raking device according to claim 3, characterized in that, The distributor (21) includes 1 main pipe interface and 8 small pipe interfaces, the main pipe interface is connected with the outlet section of the venturi tube (2), and the 8 small pipe interfaces are respectively welded and connected with the 8 stirring air pipes (5) one by one.
5. The circulating fluidized bed boiler dense zone sludge blending and fluidizing device according to claim 1, characterized in that, The venturi tube (2) is connected with the hot primary air introduction pipe (3) to mix the hot primary air with a temperature of 260 DEG C heated by the boiler air preheater and the compressed air with a temperature of 40 DEG C output by the compressed air storage tank (1) in the venturi tube (2) to form the stirring air with a temperature between 40 DEG C and 260 DEG C.
6. The circulating fluidized bed boiler dense zone sludge blending and fluidization means according to claim 1, characterized in that, The front section of the sludge feeding pipe (4) close to the sludge inlet end is provided with a penetrating section (42), 8 perforations are uniformly arranged in the circumferential middle position of the penetrating section (42), the diameters of the 8 perforations are matched with the outer diameters of the 8 stirring air pipes (5), and the 8 stirring air pipes (5) penetrate into the inside of the sludge feeding pipe (4) through the 8 perforations respectively.
7. A fluidized bed boiler dense zone sludge blending and pneumatic raking device according to claim 6, characterized in that, The sludge inlet end of the sludge feeding pipe (4) is provided with a flange (41).
8. The circulating fluidized bed boiler dense zone sludge blending and fluidizing device according to claim 1, characterized in that, The stirring air pipes (5) are equally distributed in the circumferential direction at the outlet position of the sludge feeding pipe (4).
9. The circulating fluidized bed boiler dense zone sludge blending and fluidization means according to claim 1, characterized in that, The fixing rib (6) is provided in two positions, the first fixing rib (6) is installed at the middle position of the sludge feeding pipe (4), and the second fixing rib (6) is installed at the sludge outlet position of the sludge feeding pipe (4).
10. The circulating fluidized bed boiler dense zone sludge blending and fluidization means according to claim 1, characterized in that, The material of the stirring air pipe (5) is high-temperature-resistant stainless steel.