A circulating fluidized bed boiler back pass fly ash conveying system

Abstract

The present application belongs to the technical field of biomass boiler, in particular to a circulating fluidized bed boiler tail flue fly ash conveying system, which comprises a bin pump and a fly ash conveying pipeline, the bin pump is arranged at the bottom of the discharge pipe of the tail flue ash bucket; a flow zone is arranged at the middle part of the discharge pipe, a flow bin is arranged inside the flow zone, and the flow bin is communicated with the bin pump through a mixing pipe arranged at the middle part; the accumulated ash and the airflow are mixed in advance to form a gas-solid mixture which is sent into the bin pump and flows to the ash storage, so that the flowability of the ash is improved, the short-time concentrated release of the ash is converted into the continuous release of the gas-solid mixture, and the load on the bin pump is reduced; and the process of forming the gas-solid mixture from the accumulated ash expands the gap between the cinder, so that the cinder is diffused, the excessive concentration of the cinder through the bin pump is avoided, the blockage of the upper opening or the valve of the bin pump is avoided, the failure rate of the bin pump is reduced, and the smooth transfer of the accumulated ash of the boiler tail flue is ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomass boiler, and particularly relates to a fly ash conveying system for a tail flue of a circulating fluidized bed boiler. BACKGROUND

[0002] A biomass circulating fluidized bed boiler is referred to as a CFB boiler. The circulating fluidized bed combustion technology is gradually attracting the attention of various countries due to its unique advantages in replacing fuel, treating various wastes and protecting the environment. As a kind of thermal equipment taking biomass fuel (such as crop straw, wood chips, rice husk, etc.) as the main energy source, it is widely used in the fields of biomass power generation, heating and the like. Its working principle is based on the circulating fluidized bed combustion technology, and high-speed flowing material (bed material is usually quartz sand, limestone, etc.) is fully mixed with fuel to achieve efficient combustion and heat transfer.

[0003] Because the biomass fuel contains alkali metal elements such as potassium and sodium, the oxides generated after combustion are easy to react with components such as silicon and aluminum in the ash to form low-melting eutectic (such as potassium silicate aluminate), which is mutually adhered in the molten state in the low-temperature region of the tail flue to form large particle agglomerates, which can easily hinder the flow of flue gas and reduce the heat transfer efficiency, so frequent shutdown for ash removal is required, which affects the continuous operation of the boiler and increases the maintenance cost.

[0004] Because the ash and impurities in the flue are temporarily stored in the tail flue hopper, the specific cleaning method is to release the internal ash when the ash accumulated in the hopper reaches a certain amount by opening the unloading valve arranged at the bottom of the discharge pipe of the hopper, and the cleaning personnel push the trolley to the lower side of the discharge pipe to catch the released ash, and then push it to the ash storage for storage. This ash conveying method relies on manual operation and has low efficiency. SUMMARY

[0005] In order to make up for the shortcomings of the prior art and solve the above technical problems, the present application provides a fly ash conveying system for a tail flue of a circulating fluidized bed boiler, which comprises a bin pump and a fly ash conveying pipeline, and the bin pump is arranged at the bottom of the discharge pipe of the tail flue hopper.

[0006] A flow zone is arranged at the middle part of the discharge pipe, and the discharge pipe is arranged with an unloading valve above the flow zone. A flow bin is arranged inside the flow zone and is arranged on the fixed frame arranged on the inner wall of the flow zone. The flow bin is communicated with the bin pump through a mixing pipe arranged at the middle part.

[0007] The flow bin is communicated with the external gas supply device through the gas charging pipe. The top opening of the mixing pipe is higher than the top of the flow bin, and a closed cap is arranged at the top of the mixing pipe. The bottom outer circle of the closed cap is uniformly provided with a feeding port communicated with the inside of the mixing pipe.

[0008] Preferably, the flow bin is internally provided with a dispersion pipe, the dispersion pipe vertically extends downward, and the bottom opening of the dispersion pipe is close to the bottom of the flow bin, and the dispersion pipe is communicated with the gas supply device outside through the inflation pipe.

[0009] Preferably, the inflation pipe is communicated with the bottom opening of the mixing pipe through a branch pipe, and the branch pipe is internally provided with a control valve.

[0010] Preferably, the flow bin is circular in cross section, and the mounting ring provided at the top of the flow bin is rotationally connected with the fixed frame, the fixed frame is provided with a rotating device to drive the flow bin to rotate relative to the fixed frame.

[0011] Preferably, the mixing pipe is fixedly connected with the fixed frame, and the mixing pipe is rotationally connected with the flow bin.

[0012] The area close to the bottom of the flow bin is provided with a bottom plate, and the bottom plate is rotationally connected with the outer surface of the mixing pipe.

[0013] Preferably, the bottom surface of the flow bin is provided with a separation inner net around the mixing pipe, and the area between the separation inner net and the mixing pipe is a inflation area.

[0014] The inner wall of the fixed frame located at the lower side of the separation inner net is provided with a separation outer net, the area between the separation inner net and the separation outer net forms a separation gap, the side wall of the mixing pipe is provided with an air outlet hole corresponding to the inflation area, and the separation inner net and the separation outer net are both conical.

[0015] Preferably, the bottom of the separation inner net and the separation outer net is provided with an annular partition plate, the annular partition plate extends horizontally to the outside of the mixing pipe, the inner circle of the annular partition plate at the bottom of the separation inner net is provided with a cleaning ring, and the cleaning ring extends downward and is rotationally connected with the mixing pipe.

[0016] The upper surface of the annular partition plate at the bottom of the separation inner net is uniformly provided with a communication port, the communication port realizes the communication between the inflation area and the separation gap; the outer surface of the cleaning ring is uniformly provided with a cleaning block, and the conical end of the cleaning block points to the inner area of the separation gap.

[0017] Preferably, the outer surface of the cleaning ring is provided with a cleaning hole in the gap between the cleaning blocks, and the side wall of the mixing pipe is provided with an inflation hole corresponding to the cleaning hole; the inside of the mixing pipe is provided with an interception net between the air outlet hole and the cleaning hole.

[0018] Preferably, the positioning rod of the bottom surface of the bottom plate is slidingly embedded into the positioning hole corresponding provided on the bottom surface of the flow bin, and an elastic element is provided between the positioning rod and the positioning hole.

[0019] The bottom surface of the flow bin is provided with a flow guide groove, the flow guide groove is located in the gap area between the bottom plate and the flow bin, the side wall of the mixing pipe is provided with a flow guide hole corresponding to the flow guide groove, the surface of the bottom plate is uniformly provided with an impact hole, and the bottom of the impact hole is communicated with the flow guide groove.

[0020] Preferably, the bottom plate upper surface is provided with a mounting groove corresponding to the impact hole, a push plate is rotatably arranged in the mounting groove, and the impact hole top opening is communicated with the mounting groove interior; the push plate lower surface is uniformly provided with a drainage groove extending to the push plate end.

[0021] The beneficial effects of the present application are as follows:

[0022] The circulating fluidized bed boiler tail flue fly ash conveying system mixes the accumulated ash and airflow in advance to form a gas-solid mixture, and then the gas-solid mixture is sent into the warehouse pump and flows to the ash storage, thereby improving the flowability of the ash, converting the short-time concentrated release of the ash into the sustained release of the gas-solid mixture, reducing the load on the warehouse pump, expanding the gap between the flue ash during the process of forming the gas-solid mixture, and making the flue ash diffuse, avoiding the excessive concentration of the flue ash passing through the warehouse pump, causing the opening or valve of the warehouse pump to be blocked, thereby reducing the failure rate of the warehouse pump and ensuring the smooth transfer of the boiler tail flue accumulated ash. BRIEF DESCRIPTION OF DRAWINGS

[0023] The present application will be further described below in conjunction with the drawings.

[0024] Figure 1 is a front view of the present application;

[0025] Figure 2 is a sectional view of the discharge pipe in the present application;

[0026] Figure 3 is Figure 2 is a local enlarged view of A in the present application;

[0027] Figure 4 is Figure 2 is a local enlarged view of B in the present application;

[0028] Figure 5 is a perspective view of the fixed frame in the present application;

[0029] Figure 6 is a perspective view of the bottom plate in the present application;

[0030] Figure 7 is a perspective view of the combination of the separation inner net and the annular partition plate in the present application.

[0031] In the figure: bin pump 1, fly ash conveying pipeline 2, ash bucket 3, discharge pipe 31, flow bin 4, fixed frame 41, air mixing pipe 42, feed inlet 421, air outlet 422, air charging hole 423, flow guide hole 424, air charging pipe 43, dispersion pipe 431, branch pipe 432, mounting ring 44, bottom plate 45, positioning rod 451, positioning hole 452, flow guide groove 453, impact hole 454, mounting groove 455, push plate 456, drainage groove 457, separation inner net 46, air charging area 461, separation outer net 47, separation gap 471, annular partition 48, cleaning ring 481, communication port 482, cleaning block 483, cleaning hole 484. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only 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.

[0033] Embodiment one:

[0034] As shown in the drawings of the specification Figures 1-7 The present application proposes a fly ash conveying system of the tail flue of a circulating fluidized bed boiler, which comprises a bin pump 1 and a fly ash conveying pipeline 2. The bin pump 1 is arranged at the bottom of the discharge pipe 31 of the tail flue ash bucket 3, and a manual plug valve and a pneumatic feeding valve are arranged at the joint between the discharge pipe 31 and the bin pump 1. One end of the fly ash conveying pipeline 2 is communicated with the discharge port of the bin pump 1, and the other end is communicated with an ash storage.

[0035] An intermediate part of the discharge pipe 31 is provided with a flow zone. A discharge valve is arranged on the upper side of the discharge pipe 31 in the flow zone. A flow bin 4 is arranged in the flow zone and is arranged on the fixed frame 41 arranged on the inner wall of the flow zone. The flow bin 4 is communicated with the bin pump 1 through an air mixing pipe 42 arranged at the intermediate part.

[0036] The flow bin 4 is communicated with the external gas supply equipment through an air charging pipe 43. The gas supply equipment can be an external high-power fan air pump equipment. The top opening of the air mixing pipe 42 is higher than the top of the flow bin 4, and a closed cap is arranged at the top of the air mixing pipe 42. The bottom outer circle part of the closed cap is uniformly provided with a feed inlet 421 communicated with the inside of the air mixing pipe 42.

[0037] Specific workflow: the existing biomass circulating fluidized bed boiler uses biomass material as fuel to work and output heat, a large amount of ash is generated during the combustion process, and is transported to the ash hopper 3 at the tail for temporary storage; when the accumulated ash in the ash hopper 3 reaches a certain amount, the unloading valve provided at the bottom of the discharge pipe 31 of the ash hopper 3 can be opened to discharge the internal ash, and the cleaning personnel pushes the trolley to the lower side of the discharge pipe 31 to catch the discharged ash, and then pushes it to the ash storage for storage; considering that this ash conveying method relies on manual operation and has low efficiency, an automatic fly ash conveying system is provided in the application;

[0038] The bottom opening of the discharge pipe 31 is communicated with the bin pump 1, the accumulated ash is mixed with the gas flow to form flue gas and automatically flows to the ash storage along the fly ash conveying pipeline 2 by starting the bin pump 1 and inputting the compressed gas flow, realizing automatic cleaning of the accumulated ash in the internal flue of the biomass circulating fluidized bed boiler, reducing the manual input and improving the cleaning efficiency of the accumulated ash;

[0039] And in order to avoid the blockage of the bin pump 1 caused by the accumulated ash and improve the fluidity of the ash, a flow bin 4 is arranged in the middle region of the discharge pipe 31, when the accumulated ash at the bottom of the ash hopper 3 needs to be discharged, the unloading valve is opened to discharge the ash, and the ash falls along the discharge pipe 31 into the flow bin 4, a material level meter is arranged on the fixed frame 41, and when it is detected that the flow bin 4 is about to be filled, the unloading valve is automatically closed;

[0040] Then the compressed gas flow generated by the external gas supply device is sent into the flow bin 4 through the air charging pipe 43, so that the ash in the flow bin 4 is blown up and fluidized, and the mixture of the ash and the gas flow makes the accumulated ash form a gas-solid mixture with strong fluidity; the bin pump 1 is started, and the manual plug valve and the pneumatic feeding valve communicated with the feeding port 421 of the bin pump 1 are opened, the inside of the discharge pipe 31 is pumped, and the gas-solid mixture generated by the flow bin 4 flows into the gas mixing pipe 42 communicated therewith, and flows to the bin pump 1 along the gas mixing pipe 42 through the flow bin 4;

[0041] The application sends the accumulated ash mixed with the gas flow into the bin pump 1 to form a gas-solid mixture and flows to the ash storage, which improves the fluidity of the ash, converts the concentrated release of the ash into a sustained release of the gas-solid mixture, and reduces the load on the bin pump 1; and the process of forming a gas-solid mixture from the accumulated ash expands the gap between the flue gas, so that the flue gas diffuses, avoids the too concentrated flue gas through the bin pump 1, causing the blockage of the opening or valve of the bin pump 1, thereby reducing the failure rate of the bin pump 1;

[0042] Further, through the continuous mixing of the airflow and the accumulated ash, part of the large particle ash with large diameter and density is difficult to mix into the airflow and is left in the flow bin 4. This part of the large particle ash has poor fluidity, so its entry into the fly ash conveying system can cause the abrasion of the pipeline or valve to be intensified or even cause the blockage problem. Therefore, it is separated from the accumulated ash and left in the flow bin 4. After the other required ash fully flows out, the unloading valve at the bottom of the ash bucket 3 is opened to continue to release the accumulated ash, and the above process is repeated. Until the large particle ash accumulated in the flow bin 4 reaches a certain degree, the maintenance door provided on the side wall of the discharge pipe 31 can be opened, and the fixed frame 41 is taken out to clean the large particle ash accumulated in the flow bin 4, facilitating the normal operation of the subsequent cleaning ash work.

[0043] Embodiment two:

[0044] On the basis of embodiment one, as to how the air supply device sends the airflow into the flow bin 4 through the charging pipe 43 to mix with the ash to form the gas-solid mixture, the application provides a possible technical solution. Specifically, the flow bin 4 is provided with a dispersion pipe 431 extending vertically downward, and the bottom opening of the dispersion pipe 431 is close to the bottom of the flow bin 4. The dispersion pipe 431 is communicated with the air supply device outside through the charging pipe 43. The charging pipe 43 is communicated with the bottom opening of the mixing pipe 42 through a branch pipe 432, and the branch pipe 432 is provided with a control valve inside.

[0045] Specific working process: on the basis of the specific working process in embodiment one, when the ash in the ash bucket 3 falls into the flow bin 4, the bottom opening of the dispersion pipe 431 is covered by the falling ash because the bottom of the annularly distributed dispersion pipe 431 extends into the flow bin 4. In this way, when the air supply device is started, the airflow flows into the dispersion pipe 431 through the charging pipe 43 and is dispersed into the uniformly distributed dispersion pipe 431, and then flows out of the bottom opening of the dispersion pipe 431 and is filled into the flow bin 4, so that the accumulated ash is subjected to the impact action from inside to outside, promoting the airflow and the accumulated ash to be fully mixed to form the gas-solid mixture, improving the fluidity of the ash, and facilitating the gas-solid mixture formed by the mixing of the ash and the airflow to be sucked into the feeding port 421 on the mixing pipe 42 to realize the transmission of the ash.

[0046] The opening of the dispersion pipe 431 is in the shape of a horn. After the transfer of the accumulated ash is completed, the large particle ash separated and left in the flow bin 4 can be connected to the suction pump through the dispersion pipe 431, so that the large particle ash is sucked into the dispersion pipe 431, and then flows reversely through the charging pipe 43 to the outside to realize the automatic cleaning of the accumulated large particle ash.

[0047] Further, one branch pipe 432 of the air charging pipe 43 is communicated to the bottom of the mixed gas pipe 42, so that after the ash accumulated in the flow bin 4 is fully blown up and transported to the lower bin pump 1, the control valve in the branch pipe 432 is opened, and the control valve of the air charging pipe 43 close to the dispersion pipe 431 is closed, so that the air flow flowing into the air charging pipe 43 enters the branch pipe 432, and then flows into the mixed gas pipe 42 along the branch pipe 432, and the reverse air flow flushing effect flushes the mixed gas pipe 42 and the feed inlet 421 on the end, reduces the suction of the gas-solid mixture, and causes the ash agglomeration to adhere to the inner wall of the mixed gas pipe 42, causing the mixed gas pipe 42 to be blocked and unable to work normally.

[0048] Embodiment three:

[0049] On the basis of embodiment two, the cross section of the flow bin 4 is circular, and the mounting ring 44 provided at the top of the flow bin 4 is rotationally connected with the fixed frame 41, and the fixed frame 41 is provided with a rotating device to drive the flow bin 4 to rotate relative to the fixed frame 41. The specific structure of the rotating device can be that a gear ring is provided on the outer side surface of the mounting ring 44, and a drive gear is provided in the corresponding position of the fixed frame 41, and the drive gear is connected with the output end of a drive motor, so that the drive motor can be controlled by an external controller to drive the gear ring to rotate, thereby driving the flow bin 4 to rotate.

[0050] Specific working process: on the basis of the specific working process in embodiment two, in order to make the flowing air and the ash entering the flow bin 4 mix more uniformly, the flow bin 4 is driven to rotate by the controller, thereby driving the ash accumulated inside to rotate; the flowability of the rotating ash is enhanced, and the gap between the ash particles is increased, so that the flowing air can enter the gap between the ash particles, so that the ash and the air flow mix more fully, and the gas-solid mixture is formed more thoroughly and flows into the mixed gas pipe 42 through the feed inlet 421 on the closure cap, thereby improving the efficiency of converting the accumulated ash into a gas-solid mixture through the rotation of the flow bin 4, thereby improving the conveying efficiency of the ash in the ash chute 3.

[0051] And with the blowing separation of the accumulated ash, so that the large particle ash remains in the flow bin 4, because the large particle ash gap is larger, and in the mixed flow with fine ash, large particle ash has greater kinetic energy and impact, so in the process of rotating around the gas mixing pipe 42 impact and stir the accumulated ash, so that it is fully driven and mixed with the flow of gas; ash because of the extrusion effect and gather together to form an agglomeration in the process of rotation, the impact of the large particle ash, so that it is broken by the impact of the fine, the ash adhering to the inner wall of the flow bin 4 is also under the action of the rolling large particle ash impact scraping and falling, mixed into the gas flow to form a gas-solid mixture, into the fly ash conveying system, further improve the flow state conversion efficiency of the accumulated ash, and reduce the agglomeration of the ash, so that the ash mixed into the gas flow dispersion is more uniform, reduce the wear and tear of the pipeline and valve parts in the fly ash conveying system.

[0052] Example four:

[0053] On the basis of example three, the gas mixing pipe 42 and the fixed frame 41 are fixedly connected, and the gas mixing pipe 42 and the flow bin 4 are rotatably connected; the bottom plate 45 is arranged in the area close to the bottom of the flow bin 4, the bottom plate 45 is rotatably connected with the outer surface of the gas mixing pipe 42, and the bottom plate 45 and the bottom of the flow bin 4 are elastically connected, so that the bottom plate 45 can move vertically relative to the flow bin 4 while rotating with the flow bin 4.

[0054] Specific working process: on the basis of the specific working process in example three, the rotating device is started, the flow bin 4 rotates relative to the gas mixing pipe 42, the dispersion pipe 431 located in the flow bin 4 rotates relative to the flow bin 4, and plays a stirring role on the accumulated ash in the flow bin 4, so that the dispersion pipe 431 can stir the ash in the flow bin 4 while the flow bin 4 rotates, and release the impact gas flow, promote the flow of ash, so that the inflow gas flow and ash are mixed more uniformly;

[0055] The bottom plate 45 is arranged in the flow bin 4, and the bottom plate 45 vibrates elastically relative to the flow bin 4 under the action of external force while rotating with the flow bin 4, so that the bottom plate 45 transmits the vibration to the bottom area of the ash, which on the one hand reduces the adhesion of the ash to the bottom of the flow bin 4, so that the entering ash fully participates in the rotating flow; on the other hand, with the rotation and impact of the remaining large particle ash in the flow bin 4, the bottom plate 45 shields the bottom of the flow bin 4, avoiding the wear and tear of the rolling large particle ash to the inner wall of the bottom of the flow bin 4, thereby ensuring the service life of the flow bin 4, and the bottom plate 45 can also transmit the elastic vibration to the upper rolling large particle ash, promote its rolling impact on the accumulated ash, and further accelerate the mixing of the ash and the gas flow, improve the ash flow conversion efficiency.

[0056] Embodiment five:

[0057] On the basis of embodiment four, the bottom lower surface of the flow bin 4 is provided with a separation inner net 46 around the gas mixing pipe 42, and the area between the separation inner net 46 and the gas mixing pipe 42 is a gas charging area 461;

[0058] The inner wall of the fixed frame 41 is provided with a separation outer net 47 below the separation inner net 46, and the area between the separation inner net 46 and the separation outer net 47 forms a separation gap 471. The side wall of the gas mixing pipe 42 is provided with a gas outlet hole 422 corresponding to the gas charging area 461. Both the separation inner net 46 and the separation outer net 47 are conical.

[0059] Specific working process: on the basis of the specific working process of embodiment four, because part of the components in the ash aggregate and adhere to form aggregates during the flow process, in order to further separate the large particle aggregates that do not meet the application range of the bottom bin pump 1, the separation inner net 46 and the separation outer net 47 are arranged at the bottom of the flow bin 4. The gas-solid mixture entering the inside of the gas mixing pipe 42 flows out from the gas outlet hole 422 inside the gas mixing pipe 42 located in the gas charging area 461, so that the gas-solid mixture fills the inside of the gas charging area 461, and then successively passes through the separation outer net 47 and the separation inner net 46 from the inside to the outside, so that the gas-solid mixture that meets the application range of the bin pump 1 smoothly passes through and enters the bin pump 1 below and flows into the fly ash conveying system;

[0060] The pore size of the separation inner net 46 and the separation outer net 47 refers to the application range of the bin pump 1. For example, when the bin pump 1 is applied to conveying fly ash with particles of 0.1-5mm, the pore size of the separation outer net 47 can be set to 5mm, and the pore size of the separation inner net 46 can be set to 8mm. In this way, particles that meet the particle size requirements pass through the separation inner net 46 and the separation outer net 47 and enter the bin pump 1, reducing the problem of blockage and damage of the bin pump 1. Different separation inner nets 46 and separation outer nets 47 with different filter hole sizes can intercept different particles of ash into the gas charging area 461 and the separation gap 471, avoiding excessive concentration of large particle aggregates and affecting the passability of the gas-solid mixture;

[0061] And because the separation inner net 46 is fixed with the flow bin 4, the separation inner net 46 rotates relative to the separation outer net 47 with the flow bin 4, so that the large particle aggregates intercepted in the separation gap 471 are subjected to the friction of the relatively rotating separation inner net 46 and the separation outer net 47 on both sides, promoting the large particle aggregates in the separation gap 471 to be broken down into small particle fly ash under the action of rotation and friction, and passing through the separation outer net 47, so that the particles in the gas-solid mixture are more evenly distributed;

[0062] Further, the separation inner net 46 and the separation outer net 47 are both conical, which increases the contact surface of the gas-solid mixture with the separation inner net 46 and the separation outer net 47, improves the passing efficiency; and the separation gap 471 extends obliquely, so that the large particle agglomerates intercepted in the gas-solid mixture flowing into the separation gap 471 continuously receive the relative scraping action of the rotating separation inner net 46 while rolling down along the oblique surface of the separation gap 471, which accelerates the decomposition and refinement of the large particle agglomerates, improves the passing rate of the gas-solid mixture, reduces the residue of the large particle agglomerates, and promotes the full transfer of the gas-solid mixture.

[0063] Embodiment six:

[0064] On the basis of embodiment five, the separation inner net 46 and the separation outer net 47 are both provided with annular baffles 48 at the bottom, the annular baffles 48 both extend horizontally to the outside of the gas mixing pipe 42, and the inner ring of the annular baffle 48 at the bottom of the separation inner net 46 is provided with a cleaning ring 481, which extends downward and is rotationally connected with the gas mixing pipe 42;

[0065] The upper surface of the annular baffle 48 at the bottom of the separation inner net 46 is uniformly provided with communication openings 482, which realize the communication between the aeration area 461 and the separation gap 471; and the outer surface of the cleaning ring 481 is uniformly provided with cleaning blocks 483, and the conical end of the cleaning block 483 points to the inner region of the separation gap 471;

[0066] The region of the outer surface of the cleaning ring 481 between the gaps of the cleaning blocks 483 is provided with cleaning holes 484, and the side wall of the gas mixing pipe 42 is provided with aeration holes 423 corresponding to the cleaning holes 484; and the inside of the gas mixing pipe 42 is provided with an interception net between the gas outlet hole 422 and the aeration hole 423, which prevents the ash in the gas-solid mixture flowing from top to bottom in the inside of the gas mixing pipe 42 from flowing down to the aeration hole 423 region, reducing the plugging probability of the aeration hole 423.

[0067] Specific working process: on the basis of the specific working process in embodiment five, the gap formed between the annular baffles 48 at the bottom of the separation inner net 46 and the separation outer net 47 constitutes the bottom region of the separation gap 471, and the large particle agglomerates intercepted by the separation outer net 47 roll down along the surface of the separation outer net 47 to the bottom region and enter the bottom region of the separation gap 471 through the communication openings 482 at the bottom; similarly, the large particle agglomerates intercepted by the separation inner net 46 in the separation gap 471 also roll down to the bottom region along the inclined surface, so that the large particle agglomerates in the gas-solid mixture are concentrated in the bottom region, without affecting the passing property of other regions of the separation inner net 46 and the separation outer net 47;

[0068] For the agglomerates gathered in the bottom area, the separation inner net 46 rotates to drive the cleaning blocks 483 on the bottom cleaning ring 481 to rotate, the end of the cleaning blocks 483 extends into the bottom area, and the large particle agglomerates are broken and refined by the impact during the rotation, so that the large particle agglomerates are broken and refined into small particle ash slag while being impacted outward; and because the cleaning ring 481 rotates around the gas mixing pipe 42, when the cleaning holes 484 on the cleaning ring 481 coincide with the inflation holes 423 inside the gas mixing pipe 42, part of the airflow flowing along the inside of the gas mixing pipe 42 can flow out from the gap between the cleaning blocks 483 through the inflation holes 423 and the cleaning holes 484, which cooperates with the cleaning blocks 483 to improve the agitation and fragmentation effect on the large particle agglomerates accumulated in the bottom area, and also prevents the agglomerates from entering the gap between the cleaning blocks 483 to cause blockage; the outward impact airflow mixes with the ash slag broken into small particles while entering the upper side of the separation gap 471, forming a new gas-solid mixture passing through the separation inner net 46 and flowing to the bin pump 1 to participate in the fly ash conveying system.

[0069] Embodiment seven:

[0070] On the basis of embodiment six, regarding the elastic connection mode between the bottom plate 45 and the bottom of the flow bin 4, a possible technical solution is provided here. Specifically, the positioning rods 451 on the lower surface of the bottom plate 45 are slidingly embedded in the positioning holes 452 correspondingly arranged on the bottom surface of the flow bin 4, and an elastic member is arranged between the positioning rods 451 and the positioning holes 452. The elastic member here can be selected as a spring;

[0071] The bottom surface of the flow bin 4 is provided with a flow guide groove 453, which is annular around the gas mixing pipe 42. The flow guide groove 453 is located in the gap region between the bottom plate 45 and the flow bin 4, thereby increasing the gap between the upper surface of the bottom of the flow bin 4 and the bottom plate 45. The side wall of the gas mixing pipe 42 is provided with a flow guide hole 424 corresponding to the flow guide groove 453. The inner side opening of the flow guide hole 424 can be provided with a filter screen to prevent the ash impurities in the gas-solid mixture flowing through the gas mixing pipe 42 from entering the flow guide groove 453 through the flow guide hole 424. The surface of the bottom plate 45 is uniformly provided with impact holes 454, and the bottom of the impact holes 454 is communicated with the flow guide groove 453. The upper surface of the bottom plate 45 is provided with a mounting groove 455 corresponding to the impact holes 454, and a push plate 456 is rotatably arranged in the mounting groove 455. The top opening of the impact holes 454 is communicated with the inside of the mounting groove 455. The lower surface of the push plate 456 is uniformly provided with drainage grooves 457, and the drainage grooves 457 extend to the end of the push plate 456.

[0072] Specific work flow: on the basis of the specific work flow in example six, in order to make the ash accumulated in the flow bin 4 fully converted into gas-solid mixture and participate in the fly ash conveying, after the dispersion pipe 431 continuously outputs the gas flow to impact the accumulated ash for a period of time, the control valve of the branch pipe 432 is opened, so that the gas flow flows from the inside of the mixing pipe 42 from bottom to top, which on the one hand promotes the gas flow to reverse flush the inner wall of the mixing pipe 42 and spurt outwards from the feed port 421, and on the other hand, promotes part of the gas flow to flow out from the guide hole 424 into the guide groove 453 at the bottom of the flow bin 4, so that the air pressure in the gap area between the bottom plate 45 and the bottom of the flow bin 4 increases, and the bottom plate 45 is pressed to move upwards, and the vibration is transmitted to the ash adhered to the upper surface of the bottom plate 45, so as to promote it to fall off;

[0073] And the gas flow in the gap area flows upwards into the impact hole 454, and impacts the push plate 456 in the installation groove 455 vertically upwards along the impact hole 454, so that the push plate 456 is turned upwards, pushes the residual ash on the upper side of the bottom plate 45, and the impact gas flow impacts along the drainage groove 457 on the surface of the push plate 456 after the installation groove 455 is opened by the rotation of the push plate 456, so that the ash accumulated on the upper surface of the bottom plate 45 is subjected to the impact action from bottom to top and from inside to outside, and the adhesion between the ash accumulated on the upper side of the bottom plate 45 and the bottom plate 45 is accelerated to be removed, so as to promote the ash in the flow bin 4 to be fully dispersed into the flowing gas flow to form a gas-solid mixture and participate in the fly ash conveying.

[0074] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A circulating fluidized bed boiler backpass fly ash conveying system comprising a silo pump (1) and a fly ash conveying pipe (2), characterized in that: The bin pump (1) is arranged at the bottom of the discharge pipe (31) of the tail flue ash hopper (3); The middle part of the discharge pipe (31) is provided with a flow area, the discharge pipe (31) is provided with a discharge valve on the upper side of the flow area, the flow area is internally provided with a flow bin (4), the flow bin (4) is arranged on the fixed frame (41) arranged on the inner wall of the flow area, and the flow bin (4) is communicated with the bin pump (1) through the mixing pipe (42) arranged at the middle part. The flow bin (4) is communicated with the external gas supply equipment through the gas filling pipe (43), the top opening of the mixing pipe (42) is higher than the top of the flow bin (4), and the top of the mixing pipe (42) is provided with a closed cap, and the outer circle part of the bottom of the closed cap is uniformly provided with a feeding port (421) communicated with the inside of the mixing pipe (42).

2. A circulating fluidized bed boiler backpass fly ash transport system according to claim 1, characterized in that: The flow bin (4) is internally provided with a dispersion pipe (431), the dispersion pipe (431) extends vertically downward, and the bottom opening of the dispersion pipe (431) is close to the bottom of the flow bin (4), and the dispersion pipe (431) is communicated with the external gas supply equipment through the gas filling pipe (43).

3. A circulating fluidized bed boiler backpass fly ash transport system according to claim 1, characterized in that: The gas filling pipe (43) is communicated with the bottom opening of the mixing pipe (42) through the branch pipe (432), and the branch pipe (432) is internally provided with a control valve.

4. A circulating fluidized bed boiler backpass fly ash transport system according to claim 1, characterized in that: The cross section of the flow bin (4) is circular, and the mounting ring (44) arranged at the top of the flow bin (4) is rotatably connected with the fixed frame (41), and the fixed frame (41) is provided with a rotating device to drive the flow bin (4) to rotate relative to the fixed frame (41).

5. A circulating fluidized bed boiler backpass fly ash transport system according to claim 4, characterized in that: The mixing pipe (42) and the fixed frame (41) are fixedly connected, and the mixing pipe (42) and the flow bin (4) are rotatably connected; The area close to the bottom of the flow bin (4) is provided with a bottom plate (45), and the bottom plate (45) is rotatably connected with the outer surface of the mixing pipe (42).

6. A circulating fluidized bed boiler backpass fly ash transport system according to claim 5, characterized in that: The lower surface of the bottom of the flow bin (4) is provided with a separation inner net (46) around the mixing pipe (42), and the area between the separation inner net (46) and the mixing pipe (42) is a gas filling area (461); The inner wall of the fixed frame (41) is provided with a separation outer net (47) below the separation inner net (46), and the area between the separation inner net (46) and the separation outer net (47) forms a separation gap (471), and the side wall of the mixing pipe (42) is provided with a gas outlet (422) corresponding to the gas filling area (461), and the separation inner net (46) and the separation outer net (47) are both conical.

7. A circulating fluidized bed boiler backpass fly ash transport system according to claim 6, characterized in that: The bottom of the separation inner net (46) and the separation outer net (47) is provided with an annular partition (48), the annular partition (48) extends horizontally to the outside of the mixing pipe (42), the inner circle of the annular partition (48) at the bottom of the separation inner net (46) is provided with a cleaning ring (481), the cleaning ring (481) extends downward and is rotatably connected with the mixing pipe (42); The upper surface of the annular partition (48) at the bottom of the separation inner net (46) is uniformly provided with a communication port (482), the communication port (482) realizes the communication between the gas filling area (461) and the separation gap (471); the outer surface of the cleaning ring (481) is uniformly provided with a cleaning block (483), and the conical end of the cleaning block (483) points to the inner area of the separation gap (471).

8. A circulating fluidized bed boiler backpass fly ash transport system according to claim 7, characterized in that: The area of the outer surface of the cleaning ring (481) located between the gaps of the cleaning blocks (483) is provided with cleaning holes (484), and the part of the side wall of the mixed gas pipe (42) corresponding to the cleaning holes (484) is provided with air charging holes (423); the inside of the mixed gas pipe (42) between the air outlet holes (422) and the air charging holes (423) is provided with a blocking net.

9. A circulating fluidized bed boiler backpass fly ash transport system according to claim 8, characterized in that: The positioning rod (451) on the lower surface of the bottom plate (45) is slidingly embedded into the positioning hole (452) correspondingly arranged on the bottom surface of the flow bin (4), and an elastic member is arranged between the positioning rod (451) and the positioning hole (452); The bottom surface of the flow bin (4) is provided with a flow guide groove (453), the flow guide groove (453) is located in the gap area between the bottom plate (45) and the flow bin (4), and the part of the side wall of the mixed gas pipe (42) corresponding to the flow guide groove (453) is provided with a flow guide hole (424), and the surface of the bottom plate (45) is uniformly provided with impact holes (454), and the bottom of the impact holes (454) is communicated with the flow guide groove (453).

10. A circulating fluidized bed boiler backpass fly ash transport system according to claim 9, characterized in that: The part of the upper surface of the bottom plate (45) corresponding to the impact holes (454) is provided with a mounting groove (455), the mounting groove (455) is internally rotatably provided with a push plate (456), the top opening of the impact hole (454) is communicated with the inside of the mounting groove (455); the lower surface of the push plate (456) is uniformly provided with a drainage groove (457), and the drainage groove (457) extends to the end of the push plate (456).

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