Positive-pressure coal feeding device for coal drop pipe of circulating fluidized bed boiler

Abstract

The utility model discloses a positive-pressure coal feeding device for a coal drop pipe of a circulating fluidized bed boiler, and relates to the technical field of coal feeding devices. The sealing device comprises a sealing box, a fire observation hole is formed in the sealing box, and the sealing box is communicated with a hearth; the coal dropping tee joint is fixedly inserted into the sealing box, a coal spreading air nozzle is arranged on the coal dropping tee joint, and a straight pipe is fixedly mounted at the top end of the coal dropping tee joint. According to the utility model, flue gas is prevented from flowing back while reducing atmosphere at the bottom of the hearth is ensured through the sealing device, coal channeling of the coal feeder is avoided, and coal spreading air is blown through the coal spreading air nozzle in the falling process of the coal in order to ensure that the coal is uniformly scattered in the hearth, so that the uniform distribution of the coal is further promoted; and hot spots or insufficient combustion areas are prevented from being formed in the hearth, the auxiliary effect of the coal spreading air is beneficial for improving the combustion efficiency and reducing the generation of pollutants such as nitrogen oxides, and therefore the combustion efficiency and the environmental protection performance of the boiler are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to coal feeder technical field, concretely is a kind of circulating fluidized bed boiler coal chute positive pressure coal feeder. BACKGROUND

[0002] Circulating fluidized bed boiler can be divided into two parts: the first part is by hearth, i.e. fast fluidized bed, gas-solid separator, solid material recirculation equipment and external heat exchanger etc., above-mentioned component forms a solid material circulation loop, the second part is for convection flue, is arranged with superheater, reheater, economizer and air preheater etc., similar with other conventional boiler, the primary air and secondary air required by circulating fluidized bed boiler combustion are sent from the bottom and side wall of hearth respectively, and the combustion of fuel is mainly completed in hearth, water-cooled wall is arranged around hearth for absorbing part of heat generated by combustion, large particles on fluidized bed are blown up by primary air, in suspended state, this part has the nature of fluid, small particles are blown away, solid material taken out of hearth by airflow is collected in gas-solid separator and sent back to hearth by return device, this part becomes circulating combustion, which is the basic working principle of circulating fluidized bed boiler.

[0003] In the operation process of circulating fluidized bed boiler, the delivery and distribution of coal have a crucial influence on the combustion efficiency and environmental performance of the boiler, and the traditional coal chute feeding mode has some deficiencies, for example, the coal is not evenly distributed when falling into the hearth, which is easy to form hot spots or insufficient combustion areas at the bottom of the hearth, which not only affects the thermal efficiency of the boiler, but also may cause excessive generation of pollutants such as nitrogen oxides (NOX). In addition, the poor sealing of the coal chute may cause backflow of flue gas in the hearth, increasing the safety risk and maintenance cost during maintenance. SUMMARY

[0004] The utility model aims at providing a circulating fluidized bed boiler coal chute positive pressure coal feeder to solve the problems raised in the above background.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a circulating fluidized bed boiler coal chute positive pressure coal feeder, comprising: a sealing box, the sealing box is provided with a fire observation hole, and the sealing box is in communication with the hearth; a coal falling tee, the coal falling tee is fixedly inserted into the sealing box, the coal falling tee is provided with a coal blowing nozzle, a straight pipe is fixedly installed at the top of the coal falling tee, a bend pipe is fixedly installed at the top of the straight pipe, and the bend pipe is connected with the coal chute; a sealing device, the sealing device is installed between the bend pipe and the coal chute, and is used to close or open the space connected with the bend pipe and the coal chute.

[0006] As a further preferred embodiment of the present technical solution, the sealing device includes a sealing frame fixedly installed between the bent pipe and the coal drop pipe, and two semicircular plates are slidably installed between the two sides of the inner wall of the sealing frame. The two semicircular plates are symmetrically distributed, and a moving component is installed on the sealing frame for driving the two semicircular plates to move closer to or away from each other.

[0007] As a further preferred embodiment of the present technical solution, the moving component includes a bidirectional threaded rod rotatably installed between the two sides of the inner wall of the sealing frame, and a driving motor for driving the bidirectional threaded rod to rotate is fixedly installed on one side of the sealing frame, and the two semicircular plates are both threadedly connected to the bidirectional threaded rod.

[0008] As a further preferred embodiment of the present technical solution, sealing gaskets are fixedly installed on the top and bottom of the two semicircular plates, and the outer surface of the sealing gaskets is in contact with the inner wall of the sealing frame.

[0009] As a further preferred embodiment of the present technical solution, the coal dropping tee includes a main pipe and two lateral pipes. The main pipe is connected to the straight pipe. The two lateral pipes are fixedly inserted on both sides of the main pipe, and are used to guide the burning coal to be distributed to both sides of the furnace. The coal spreading air nozzle is inserted on the main pipe.

[0010] As a further preferred embodiment of the present technical solution, a rotating plate is rotatably installed between the two sides of the inner wall of the sealing box, at least three closing plates are fixedly installed on the bottom of the rotating plate, and an adjustment component for driving the rotating plate to rotate is installed on the sealing box.

[0011] As a further preferred embodiment of the present technical solution, the adjustment assembly includes a rotating motor fixedly mounted on one side of the sealing box, a rotating rod is fixedly mounted on the output end of the rotating motor, and the rotating plate is fixedly sleeved on the outer surface of the rotating rod.

[0012] The utility model provides a positive pressure coal feeding device for a coal drop pipe of a circulating fluidized bed boiler, which has the following beneficial effects:

[0013] (1) The utility model uses a sealing device to ensure a reducing atmosphere at the bottom of the furnace while preventing the backflow of flue gas, thereby ensuring that the coal feeder does not leak coal. In order to ensure that the coal is evenly spread in the furnace, the coal spreading air is blown through the coal spreading nozzle during the falling process of the coal, further promoting the uniform distribution of the coal and avoiding the formation of hot spots or insufficient combustion areas in the furnace. The auxiliary effect of the coal spreading air helps to improve the combustion efficiency and reduce the generation of pollutants such as nitrogen oxides, thereby improving the combustion efficiency and environmental performance of the boiler.

[0014] (2) The utility model can adjust the size of the upper discharge port of the coal dropping tee by coordinating the rotating plate, the closing plate and the adjusting assembly, thereby preventing a large amount of coal from falling quickly into the furnace and causing insufficient coal burning. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a three-dimensional structural diagram of the utility model;

[0016] Figure 2 This utility model Figure 1 A side-view sectional perspective structural diagram;

[0017] Figure 3 This utility model Figure 1 A sectional three-dimensional structural diagram from the front;

[0018] Figure 4 This utility model Figure 1 A sectional three-dimensional structural diagram from a top view;

[0019] Figure 5 This utility model Figure 1 Another three-dimensional structural diagram;

[0020] In the figure: 1. Sealing box; 2. Coal drop tee; 21. Main pipeline; 22. Lateral pipeline; 3. Coal spreading air nozzle; 4. Straight pipe; 5. Bend pipe; 6. Sealing device; 61. Sealing frame; 62. Semicircular plate; 63. Moving assembly; 631. Bidirectional threaded rod; 632. Driving motor; 7. Sealing gasket; 8. Closing plate; 9. Adjusting assembly; 91. Rotating motor; 92. Rotating rod; 10. Rotating plate. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0022] The utility model provides a technical solution: Figures 1-5 As shown, in this embodiment, a positive pressure coal feeding device for a coal drop pipe of a circulating fluidized bed boiler comprises: a sealed box 1, wherein the sealed box 1 is provided with a fire viewing hole, and the sealed box 1 is connected to the furnace;

[0023] The coal dropping tee 2 is fixedly inserted in the sealing box 1, and a coal spreading air nozzle 3 is provided on the coal dropping tee 2. A straight pipe 4 is fixedly installed on the top of the coal dropping tee 2, and a bent pipe 5 is fixedly installed on the top of the straight pipe 4, and the bent pipe 5 is connected to the coal dropping pipe; the coal dropping tee 2 includes a main pipe 21 and two lateral pipes 22, the main pipe 21 is connected to the straight pipe 4, and the two lateral pipes 22 are fixedly inserted on both sides of the main pipe 21, which are used to guide the burning coal to be distributed to both sides of the furnace, and the coal spreading air nozzle 3 is inserted on the main pipe 21.

[0024] A sealing device 6 is installed between the elbow pipe 5 and the coal drop pipe, which is used to close or open the space connected by the elbow pipe 5 and the coal drop pipe. The sealing device 6 includes a sealing frame 61 fixedly installed between the elbow pipe 5 and the coal drop pipe, and two semicircular plates 62 slidingly installed between the inner walls of the sealing frame 61. The two semicircular plates 62 are symmetrically distributed, and the sealing frame 61 is provided with a moving assembly 63 for driving the two semicircular plates 62 to move closer to or away from each other. The coal drop pipe uses positive pressure coal feeding, a reasonable elevation is selected, the angle of the elbow pipe 5 is between 120-160°, which makes it not easy to be blocked, and the sealing device 6 is added. In this way, the reducing atmosphere at the bottom of the hearth is ensured, and the coal feeder is also prevented from coal leakage. In order to ensure that the coal is evenly scattered in the hearth, the coal drop tee 2 is provided with a coal spreading air nozzle 3, so as to achieve uniform spreading and combustion of the fuel.

[0025] Firstly, the sealing box 1 is located at the connection of the hearth, and is provided with a fire observation hole for observing the internal condition of the hearth. The main function of the sealing box 1 is to form a sealed connection with the hearth, prevent the backflow of flue gas, and ensure the stability of the pressure in the hearth. The inside of the sealing box 1 is connected with the coal drop tee 2, and the coal drop tee 2 is fixedly inserted into the sealing box 1. The structure design allows the coal to flow smoothly from the sealing box 1 into the coal drop tee 2.

[0026] The coal drop tee 2 is the core part of the device, which includes a main pipe 21 and two lateral pipes 22. The main pipe 21 is connected with the straight pipe 4, and the top end of the straight pipe 4 is connected with the coal drop pipe through the elbow pipe 5, forming a downward conveying path of the coal. The lateral pipes 22 are fixedly arranged on the two sides of the main pipe 21, and are used to guide the coal to distribute to the two sides of the hearth, realizing the horizontal diffusion of the coal.

[0027] The coal spreading air nozzle 3 is inserted into the main pipe 21, which is used to further promote the uniform distribution of the coal by blowing the coal spreading air during the falling process of the coal, and avoid the formation of hot spots or insufficient combustion areas in the hearth. The auxiliary function of the coal spreading air helps to improve the combustion efficiency and reduce the generation of pollutants such as nitrogen oxides.

[0028] The sealing device 6 is installed between the elbow pipe 5 and the coal drop pipe, and its main function is to realize the closing or opening of the space connected by the elbow pipe 5 and the coal drop pipe. The sealing device 6 is composed of a sealing frame 61 and two semicircular plates 62. The semicircular plates 62 slide in the sealing frame 61, and are driven by the moving assembly 63 to move closer to or away from each other, so as to control the flow of the coal. When the coal needs to be fed, the two semicircular plates 62 are separated, the space connected by the elbow pipe 5 and the coal drop pipe is opened, and the coal is allowed to pass through. When the coal does not need to be fed or needs to be maintained, the two semicircular plates 62 are closed, the space is sealed, and the backflow of flue gas is prevented.

[0029] As shown in the drawings, Figure 4As shown, the moving assembly 63 includes a bidirectional threaded rod 631 rotatably mounted between the two sides of the inner wall of the sealing frame 61, one side of the sealing frame 61 is fixedly provided with a driving motor 632 for driving the bidirectional threaded rod 631 to rotate, and the two semicircular plates 62 are threadedly connected with the bidirectional threaded rod 631. The two semicircular plates 62 are threadedly connected with two symmetrical threads on the bidirectional threaded rod 631, and the driving motor 632 is a reversible motor and is electrically connected with an external power supply and a control switch.

[0030] The bottom end of the coal falling pipe penetrates through and is inserted into the top of the sealing frame 61, the top of the elbow pipe 5 penetrates through and is inserted into the bottom of the sealing frame 61, the driving motor 632 is started to drive the bidirectional threaded rod 631 to rotate in the forward and reverse directions, so as to drive the two semicircular plates 62 threadedly connected with the bidirectional threaded rod 631 to move close to or away from each other, so that the opening of the bottom end of the coal falling pipe and the opening of the top end of the elbow pipe 5 can be opened or blocked.

[0031] As shown in Figure 3 The top and bottom of the two semicircular plates 62 are fixedly provided with sealing pads 7, and the outer surfaces of the sealing pads 7 are attached to the inner wall of the sealing frame 61.

[0032] The sealing pads 7 are used to increase the sealing performance of the two semicircular plates 62 on the coal falling pipe and the elbow pipe 5.

[0033] As shown in Figure 2 The sealing box 1 is rotatably provided with a rotating plate 10 between the two sides of the inner wall, the bottom of the rotating plate 10 is fixedly provided with at least three closing plates 8, and the sealing box 1 is provided with an adjusting assembly 9 for driving the rotating plate 10 to rotate. The adjusting assembly 9 includes a rotating motor 91 fixedly provided on one side of the sealing box 1, a rotating rod 92 fixedly provided at the output end of the rotating motor 91, and the rotating plate 10 is fixedly sleeved on the outer surface of the rotating rod 92. The three closing plates 8 are used to close the discharge ports of the main pipeline 21 and the two lateral pipelines 22. The rotating rod 92 extends through the sealing box 1 to the inside of the sealing box 1.

[0034] The rotating motor 91 is started to drive the rotating rod 92 to rotate, so as to drive the rotating plate 10 to rotate, and then drive the three closing plates 8 to rotate, gradually open the discharge ports of the main pipeline 21 and the two lateral pipelines 22, and adjust the size of the opened discharge ports according to actual needs, so as to avoid that a large amount of coal is rapidly falling into the furnace, causing insufficient combustion of the coal.

[0035] The utility model provides a kind of circulating fluidized bed boiler coal falling pipe positive pressure coal feeder, specific working principle as follows:

[0036] The coal is first fed into the sealing box 1 through the coal falling pipe, the elbow pipe 5 and the straight pipe 4, and is distributed to both sides of the furnace through the guidance of the main pipe 21 and the lateral pipe 22, and the coal distribution nozzles 3 play a role in the process, and the uniform distribution of the coal in the furnace is ensured through the blowing of the coal distribution air, the two semicircular plates 62 are driven by the moving assembly 63 to move close to or away from each other, the space connected with the elbow pipe 5 and the coal falling pipe is closed or opened, the flow of the coal is controlled according to the need, the pressure in the furnace is ensured to be stable, the backflow of the flue gas is prevented, through the arrangement, the problem of the traditional coal falling pipe being blocked is solved, the amount of NOX generated by the combustion of the coal is reduced, the uniform combustion of the coal is ensured, and the combustion efficiency and the environmental protection performance of the boiler are improved.

[0037] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and modifications can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe, characterized in that: include: A sealed box (1), wherein a fire viewing hole is provided on the sealed box (1), and the sealed box (1) is connected to the furnace; A coal drop tee (2), the coal drop tee (2) is fixedly inserted into the sealing box (1), a coal spreading air nozzle (3) is provided on the coal drop tee (2), a straight pipe (4) is fixedly installed at the top end of the coal drop tee (2), a curved pipe (5) is fixedly installed at the top end of the straight pipe (4), and the curved pipe (5) is connected to the coal drop pipe; A sealing device (6) is installed between the bent pipe (5) and the coal drop pipe, and is used to close or open the space connecting the bent pipe (5) and the coal drop pipe.

2. The positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe according to claim 1, characterized in that: The sealing device (6) comprises a sealing frame (61) fixedly mounted between the bent pipe (5) and the coal drop pipe, two semicircular plates (62) being slidably mounted between the two sides of the inner wall of the sealing frame (61), the two semicircular plates (62) being symmetrically distributed, and a moving assembly (63) for driving the two semicircular plates (62) to move closer to or away from each other being mounted on the sealing frame (61).

3. The positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe according to claim 2, characterized in that: The moving assembly (63) comprises a bidirectional threaded rod (631) rotatably mounted between two sides of the inner wall of the sealing frame (61); a driving motor (632) for driving the bidirectional threaded rod (631) to rotate is fixedly mounted on one side of the sealing frame (61); and both of the two semicircular plates (62) are threadedly connected to the bidirectional threaded rod (631).

4. The positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe according to claim 2, characterized in that: Sealing pads (7) are fixedly mounted on the top and bottom of the two semicircular plates (62), and the outer surface of the sealing pads (7) is in contact with the inner wall of the sealing frame (61).

5. The positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe according to claim 1, characterized in that: The coal drop tee (2) comprises a main pipe (21) and two lateral pipes (22), wherein the main pipe (21) is connected to the straight pipe (4), and the two lateral pipes (22) are respectively fixedly inserted on both sides of the main pipe (21) and used to guide the burning coal to be distributed to both sides of the furnace, and the coal spreading air nozzle (3) is inserted on the main pipe (21).

6. The positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe according to claim 1, characterized in that: A rotating plate (10) is rotatably mounted between two sides of the inner wall of the sealing box (1), at least three closing plates (8) are fixedly mounted on the bottom of the rotating plate (10), and an adjusting component (9) for driving the rotating plate (10) to rotate is mounted on the sealing box (1).

7. The positive pressure coal feeding device for a circulating fluidized bed boiler coal drop pipe according to claim 6, characterized in that: The adjustment assembly (9) comprises a rotating motor (91) fixedly mounted on one side of the sealing box (1), a rotating rod (92) fixedly mounted on the output end of the rotating motor (91), and the rotating plate (10) fixedly sleeved on the outer surface of the rotating rod (92).

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