Kaolin blending combustion system for pulverized coal boiler burning high-alkali coal

Abstract

The utility model relates to a kaolin blending combustion system for a pulverized coal boiler burning high-alkali coal, which comprises a coal hopper, a coal conveying belt, a coal mill, an air feeder I, a boiler, a burner nozzle, a Venturi tube, a kaolin hopper, a kaolin conveying belt, a steel ball mill, a screw feeder, a bent pipe, an air feeder II and a control valve. The specific surface area of kaolin is increased, the gas-phase alkali metal capturing efficiency is improved, the kaolin is added to a second-layer combustor nozzle through a Venturi injection device, and the situation that the combustion condition of the boiler is affected when lower-layer mixing is conducted and the kaolin is not reacted completely when upper-layer mixing is conducted is avoided.

Description

Technical Field

[0001] The utility model relates to the field of co - firing of pulverized coal and kaolin. Specifically, it relates to a system for co - firing kaolin in a pulverized - coal boiler burning high - alkali coal. Background Art

[0002] In the Junggar Coalfield in Xinjiang region, the coal reserves are abundant, and most of the coal - fired power plant boilers use Junggar coal. However, the Junggar coal has a high alkali - metal content, and problems such as fouling, slagging, and corrosion are likely to occur during the combustion process. Therefore, for pulverized - coal boilers burning high - alkali coal, coal types with low alkali - metal (Na, K, etc.) content or other additives are usually mixed to alleviate the slagging and fouling of the boiler heating surface.

[0003] At present, a large number of experimental studies on co - firing kaolin have been carried out. The experiments show that when co - firing kaolin, kaolin can capture the alkali - metal vapor generated during the combustion of Junggar coal, slow down the slagging and fouling of the boiler heating surface. At the same time, due to the large reserves of kaolin in Junggar and its surrounding areas, co - firing kaolin has good industrial application prospects. However, due to the different grindability indices of kaolin and coal, it is difficult to control the fineness. And after kaolin participates in combustion, only a layer of alkali - metal compounds condenses on its surface, while the interior does not react with gaseous alkali - metals. Therefore, existing kaolin blending systems all have problems such as incomplete reaction of kaolin. Summary of the Utility Model

[0004] To solve the problems existing in the process of co - firing kaolin and Junggar coal, the purpose of the utility model is to provide a system for co - firing kaolin in a pulverized - coal boiler burning high - alkali coal.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme: A system for co - firing kaolin in a pulverized - coal boiler burning high - alkali coal, including a coal hopper 1, a coal conveyor belt 2, a coal mill 3, a blower I 4, a boiler 5, a burner nozzle 6, a Venturi tube 7, a kaolin hopper 8, a kaolin conveyor belt 9, a ball mill 10, a screw feeder 11, an elbow 12, a blower II 13, and a control valve 14.

[0006] The coal in the coal hopper 1 enters the coal mill 3 through the coal conveyor belt 2. The blower I 4 extracts air and enters the coal mill 3, carrying the pulverized coal and entering the four - layer burner nozzles 6 of the boiler 5 in four paths respectively.

[0007] The kaolin conveyor belt 9 is installed below the kaolin hopper 8. The kaolin conveyor belt 9 transports kaolin to the ball mill 10 for grinding, and the ground kaolin powder is sent to the screw feeder 11.

[0008] The screw feeder 11 conveys the kaolin powder to the elbow 12. Air enters the elbow 12 through the blower II 13 and the control valve 14, carrying the kaolin powder into the Venturi tube 7.

[0009] The Venturi tube 7 is installed on the pipeline corresponding to the burner nozzle 6 on the second layer of the boiler 5, and the kaolin powder and pulverized coal are mixed in the Venturi tube and then enter the burner nozzle 6 on the second layer of the boiler 5.

[0010] Compared with the existing kaolin blending method, the present utility model has the following advantages.

[0011] A system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal of the present utility model separately grinds kaolin, reduces the particle size of kaolin, increases the specific surface area of kaolin, and improves the capture efficiency of gaseous alkali metals.

[0012] A system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal of the present utility model uses a Venturi tube to add kaolin to the burner nozzle on the second layer, avoiding the influence on the combustion condition of the boiler when adding it to the lower layer and incomplete reaction of kaolin when adding it to the upper layer. Description of the Drawings

[0013] Figure 1 It is a system flow chart of a system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal of the present utility model.

[0014] Figure 2 It is a schematic structural diagram of the Venturi tube of a system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal of the present utility model. Detailed Embodiment

[0015] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0016] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "top", "bottom", "one side", "the other side", "front", "rear", "middle part", "inside", "top end", "bottom end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present utility model; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0017] The present utility model will be further described in detail below with reference to the drawings.

[0018] As Figure 1 、 Figure 2 shown, the present utility model provides a system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal, which includes a coal hopper 1, a coal conveyor belt 2, a coal mill 3, a blower I 4, a boiler 5, a burner nozzle 6, a Venturi tube 7, a kaolin hopper 8, a kaolin conveyor belt 9, a ball mill 10, a screw feeder 11, an elbow 12, a blower II 13, and a control valve 14.

[0019] The coal in the coal hopper 1 enters the coal mill 3 through the coal conveyor belt 2. The blower I 4 extracts air and enters the coal mill 3, carrying pulverized coal and respectively entering the four - layer burner nozzles 6 of the boiler 5 in four paths.

[0020] The kaolin conveyor belt 9 is installed below the kaolin hopper 8. The kaolin conveyor belt 9 transports kaolin to the ball mill 10 for grinding, and the ground kaolin powder is sent to the screw feeder 11.

[0021] The screw feeder 11 transports the kaolin powder to the elbow 12. Air enters the elbow 12 through the blower II 13 and the control valve 14, carrying the kaolin powder into the Venturi tube 7. The elbow 12 plays an ejector role to prevent the blockage of the kaolin powder conveying pipeline.

[0022] The Venturi tube 7 is installed on the pipeline corresponding to the second - layer burner nozzle 6 of the boiler 5. The kaolin powder and pulverized coal are mixed in the Venturi tube and then enter the second - layer burner nozzle 6 of the boiler 5.

[0023] Furthermore, the system can supply multiple boilers 5 for simultaneous use, control the kaolin conveying volume through the screw feeder 11, and control the air volume for conveying kaolin through the control valve 14.

[0024] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present utility model. Any reference signs in the claims should not be construed as limiting the claims involved.

[0025] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal, comprising a coal hopper (1), a coal conveyor belt (2), a coal mill (3), a blower Ⅰ (4), a boiler (5), a burner nozzle (6), a Venturi tube (7), a kaolin hopper (8), a kaolin conveyor belt (9), a steel ball mill (10), a screw feeder (11), an elbow (12), a blower Ⅱ (13), and a control valve (14). The coal in the coal hopper (1) enters the coal mill (3) through the coal conveyor belt (2). The blower Ⅰ (4) extracts air and enters the coal mill (3), carrying pulverized coal and entering the four - layer burner nozzles (6) of the boiler (5) in four paths respectively. The kaolin conveyor belt (9) is installed below the kaolin hopper (8), and the kaolin conveyor belt (9) transports kaolin to the steel ball mill (10) for grinding. The ground kaolin powder is sent to the screw feeder (11). The screw feeder (11) conveys the kaolin powder to the elbow (12), and air enters the elbow (12) through the blower Ⅱ (13) and the control valve (14), carrying the kaolin powder into the Venturi tube (7). The Venturi tube (7) is installed on the corresponding pipeline of the second - layer burner nozzle (6) of the boiler (5). The kaolin powder and the pulverized coal are mixed in the Venturi tube and then enter the second - layer burner nozzle (6) of the boiler (5).

2. The system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal according to claim 1, characterized in that Both the elbow (12) and the Venturi tube (7) are made of wear - resistant materials.

3. A system for co - firing kaolin in a pulverized coal boiler burning high - alkali coal according to claim 1, characterized in that This system can be used for co - firing kaolin in multiple boilers (5) simultaneously.

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