An air-powder mixing injection device and a pulverized coal transport flow control system

Abstract

The present invention relates to an air-powder mixing injection device and a coal powder transportation flow control system, and belongs to the field of fuel transportation equipment. The air-powder mixing injection device includes: an air supply duct, a mixing duct and an air-powder duct; the air supply duct includes an inner tube and an outer tube; the outer tube is sleeved on the outside of the inner tube, and one end of the inner tube and one end of the outer tube are both connected to the air supply device; the other end of the inner tube and the other end of the outer tube are both connected to one end of the mixing duct; the air supply duct is used to transmit air and coal powder; the other end of the mixing duct is connected to the air-powder duct; the mixing duct is used to mix the air and coal powder transmitted by the air supply duct; the air-powder duct includes a second straight tube, a gradually expanding tube and a third straight tube connected in sequence; one end of the second straight tube is connected to the other end of the mixing duct; the diameter of the third straight tube is larger than the diameter of the second straight tube; the air-powder duct is used to inject the mixed air and coal powder into the furnace. The present invention improves the uniformity of the mixing of coal powder and air.

Description

Technical Field

[0001] The present invention relates to the field of fuel conveying equipment, in particular to an air-powder mixing injection device and a coal powder conveying flow control system. Background Art

[0002] Currently, coal dust is typically emitted by directly crushing the delivered coal using a coal crusher. Larger lumps of coal are then ground into coal dust, which is then carried by air into the furnace. During this process, the coal dust is blown into the furnace. Due to its own gravity, the coal dust is distributed within the air duct, with more coal dust in the lower portion and less in the middle and upper portions. When the wind speed of the fan conveying the coal dust falls below a certain value, coal dust accumulates within the duct. Prolonged accumulation can cause blockage in the duct. Existing technologies have not effectively addressed the problem of uneven coal dust distribution within the duct. Summary of the Invention

[0003] The purpose of the present invention is to provide an air-powder mixing injection device and a coal powder transport flow control system to solve the problem of uneven distribution of coal powder in the pipeline during the air-powder mixing process in the prior art.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] An air-powder mixing and spraying device comprises: an air supply duct, a mixing duct and an air-powder duct;

[0006] The air supply duct includes an inner tube and an outer tube; the outer tube is sleeved on the outer side of the inner tube, one end of the inner tube and one end of the outer tube are both connected to the air supply device; the other end of the inner tube and the other end of the outer tube are both connected to one end of the mixing duct; the air supply duct is used to transmit air and coal powder;

[0007] The other end of the mixing pipe is connected to the air-powder pipe; the mixing pipe is used to mix the air and coal powder transmitted by the air supply pipe;

[0008] The air-powder duct includes a second straight pipe, a gradually expanding pipe and a third straight pipe connected in sequence; one end of the second straight pipe is connected to the other end of the mixing pipe; the diameter of the third straight pipe is larger than the diameter of the second straight pipe; the air-powder duct is used to spray the mixed air and coal powder into the furnace.

[0009] Optionally, the inner tube includes a first reducer and a first straight tube; the first end of the first reducer is connected to the air supply device; the second end of the first reducer is connected to the first straight tube;

[0010] The diameter of the first end of the first reducer is equal to the diameter of the outer tube, and the first end of the first reducer is connected to one end of the outer tube, so that a coal powder chamber is formed between the inner tube and the outer tube; the diameter of the first end of the first reducer is greater than the diameter of the second end of the first reducer; the diameter of the first straight tube is equal to the diameter of the second end of the first reducer.

[0011] Optionally, the mixing pipe includes a second reducer; the diameter of one end of the second reducer is larger than the diameter of the other end; the diameter of one end of the second reducer is equal to the diameter of the outer pipe; the diameter of the other end of the second reducer is equal to the diameter of the second straight pipe.

[0012] Optionally, the third straight pipe includes a plurality of branch pipes; the plurality of branch pipes are arranged around the axis of the third straight pipe.

[0013] A pulverized coal transport flow control system, comprising any of the above-mentioned air-powder mixing and injection devices, a coal storage bin, a transport bin, a conveyor belt, a pulverized coal supply device, and a control host;

[0014] The coal storage bin is connected to the transport bin via the conveyor belt; the transport bin is connected to the air supply duct of the air-powder mixing and injection device via the pulverized coal supply device; the conveyor belt is used to transfer the pulverized coal from the coal storage bin to the transport bin; the pulverized coal supply device is used to control the flow rate of the pulverized coal fed into the air supply duct;

[0015] The transport bin is connected to the input end of the control host; the output end of the control host is respectively connected to the coal storage bin, the conveyor belt and the pulverized coal supply device.

[0016] Optionally, a space is provided at the bottom of the coal storage bin, one end of the conveyor belt is embedded in the space, a hole is provided at the top of the space, and a hole cover is provided on the hole; the hole cover is connected to the output end of the control host.

[0017] Optionally, a distance measuring sensor is provided on the top of the transport bin; the distance measuring sensor is connected to the input end of the control host.

[0018] Optionally, the pulverized coal supply device includes a pulverized coal conveying pipeline, a rising stem gate valve and an impeller powder feeder; the rising stem gate valve and the impeller powder feeder are arranged on the pulverized coal conveying pipeline; the rising stem gate valve and the impeller powder feeder are both connected to the output end of the control host.

[0019] Optionally, the control host is used to control the hole cover and the conveyor belt according to the signal collected by the distance measuring sensor, and the control host is also used to control the start and stop of the rising stem gate valve and the impeller powder feeder.

[0020] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0021] The present invention provides an air-powder mixing and injection device. When jet air enters a mixing duct through an air supply duct, a negative pressure is created within the duct, drawing the pulverized coal at the duct opening on the right side of the pulverized coal chamber into the duct. The air and pulverized coal are then fully and evenly mixed within the duct. Driven by the air, the mixed air and pulverized coal then enter the air-powder duct and are subsequently delivered to the furnace. Air-powder mixing occurs as the pulverized coal falls, preventing accumulation of pulverized coal at the bottom of the duct and improving the uniformity of the pulverized coal and air mixing.

[0022] In addition, a pulverized coal transport flow control system is provided. This system uses a transport bin to achieve secondary storage of pulverized coal. The pulverized coal supply device controls the flow of pulverized coal, evenly transporting it to the air-powder mixing and injection device, achieving balanced flow control of the pulverized coal. By evenly transporting pulverized coal to the air-powder mixing and injection device, a more uniform mixing of pulverized coal and air is further achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of an air-powder mixing and spraying device provided by the present invention;

[0025] Figure 2 A schematic diagram of a pulverized coal transport flow control system provided by the present invention;

[0026] Figure 3 The present invention provides Figure 1 AA cross-sectional diagram of the third straight section of the stroke powder pipeline;

[0027] Figure 4 Schematic diagram of the arrangement of infrared ranging sensors in an embodiment of the present invention.

[0028] Explanation of symbols: 1. Coal storage bin; 2. Hole; 3. Hole cover; 4. Conveyor belt; 5. Upper opening; 6. Infrared distance sensor; 7. Transport bin; 8. Rising-stem gate valve; 9. Impeller powder feeder; 10. Air supply duct; 11. Mixing duct; 12. Air-powder duct; 13. Control host. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The purpose of the present invention is to provide an air-powder mixing injection device and a coal powder transport flow control system to solve the problem of uneven distribution of coal powder in the pipeline during the air-powder mixing process in the prior art.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 A schematic diagram of an air-powder mixing and spraying device provided by the present invention is shown in FIG. Figure 1 As shown, an air-powder mixing and spraying device includes: an air supply duct 10, a mixing duct 11 and an air-powder duct 12.

[0033] The air supply duct 10 includes an inner tube and an outer tube; the outer tube is sleeved outside the inner tube, and one end of the inner tube and one end of the outer tube are both connected to an air supply device; the other ends of the inner tube and the other ends of the outer tube are both connected to one end of the mixing duct 11. The air supply duct 10 is used to transport air and pulverized coal. The air supply device is not shown in the figure.

[0034] Furthermore, the inner tube includes a first reducer and a first straight tube; the first end of the first reducer is connected to the air supply device; and the second end of the first reducer is connected to the first straight tube.

[0035] The diameter of the first end of the first reducer is equal to the diameter of the outer tube. The first end of the first reducer is connected to one end of the outer tube, so that a coal powder chamber is formed between the inner tube and the outer tube. The diameter of the first end of the first reducer is greater than the diameter of the second end of the first reducer. The diameter of the first straight tube is equal to the diameter of the second end of the first reducer. In actual application, the inner tube and the outer tube of the air supply duct 10 are arranged in concentric circles. The left end of the inner tube has a trumpet-shaped flared structure and is sealed with the outer tube. The outer tube is provided with a coal powder supply device connected to the coal powder chamber, and the right end of the coal powder chamber is connected to the mixing duct 11.

[0036] The other end of the mixing pipe 11 is connected to the air-powder pipe 12 ; the mixing pipe 11 is used to mix the air and coal powder transmitted by the air supply pipe 10 .

[0037] Furthermore, the mixing pipe 11 includes a second reducer; the diameter of one end of the second reducer is larger than the diameter of the other end; the diameter of one end of the second reducer is equal to the diameter of the outer pipe; the diameter of the other end of the second reducer is equal to the diameter of the second straight pipe.

[0038] In actual application, the mixing pipe 11 is a convergent pipe (second convergent pipe), the large end of the mixing pipe 11 is connected to the outer pipe of the air supply pipe 10, and the small end of the mixing pipe 11 is connected to the air-powder pipe 12, forming a mixing cavity inside the convergent pipe (second convergent pipe).

[0039] The air-powder duct 12 includes a second straight pipe, a gradually expanding pipe and a third straight pipe connected in sequence; one end of the second straight pipe is connected to the other end of the mixing pipe 11; the diameter of the third straight pipe is larger than the diameter of the second straight pipe; the air-powder duct 12 is used to spray the mixed air and coal powder into the furnace.

[0040] Furthermore, the third straight pipe includes a plurality of branch pipes; the plurality of branch pipes are arranged around the axis of the third straight pipe. Figure 3 shown.

[0041] In practice, the air-powder duct 12 is formed by coaxially docking a small-diameter straight section (the second straight section), a gradually expanding section, and a large-diameter straight section (the third straight section). The left end of the small-diameter straight section docks with the small-mouth end of the mixing duct 11. The large-diameter straight section is circumferentially divided into multiple branch sections. The branch sections are evenly arranged around the center of the large-diameter straight section. The branch sections have a circular cross-section, and the large-diameter straight section is sealed outside the branch sections. Four branch sections are provided.

[0042] The working principle of the air-powder mixing and injection device of this embodiment is as follows: the air supply device uses a jet air supply method. When the jet air enters the mixing cavity, a negative pressure is formed in the mixing cavity, which draws the coal powder located at the pipe opening on the right side of the coal powder chamber into the mixing cavity. The air and coal powder are fully and evenly mixed in the mixing cavity. Driven by the wind, the mixed air and coal powder then enter the air-powder pipe 12, and then pass through a gradually expanding pipe. Four branch pipes are separated from the rear side of the gradually expanding pipe, and each branch pipe is arranged in a "diamond" shape. When passing through the gradually expanding pipe, the mixture of air and coal powder (hereinafter referred to as the mixture) is injected into the four branch pipes. The mixture is injected into the gradually expanding pipe section to form a surface. The mixture is evenly distributed on this surface. When the mixture is injected into each branch pipe, the mixture is evenly distributed.

[0043] The air-powder uniform mixing and injection device of this embodiment can mix the coal powder and air evenly, prevent the air from flowing back, make the distribution of the coal powder inside the pipeline more uniform, reduce the accumulation of coal powder in the pipeline, and allow the coal powder to be evenly delivered to multiple branch pipelines.

[0044] Figure 2 A schematic diagram of a pulverized coal transport flow control system provided by the present invention is shown in FIG. Figure 2 As shown, a pulverized coal transportation flow control system includes an air-powder mixing and injection device, a coal storage bin 1, a transportation bin 7, a conveyor belt 4, a pulverized coal supply device and a control host 13.

[0045] The coal storage bin 1 is connected to the transport bin 7 through the conveyor belt 4; the transport bin 7 is connected to the air supply duct 10 of the air-powder mixing injection device through the coal powder supply device; the conveyor belt 4 is used to transfer the coal powder in the coal storage bin 1 to the transport bin 7; the coal powder supply device is used to control the flow rate of coal powder fed into the air supply duct 10.

[0046] Furthermore, a space is provided at the bottom of the coal storage bin 1, into which one end of the conveyor belt 4 is embedded. A hole 2 is provided at the top of the space, which is covered with a cover 3. The cover 3 is connected to the output of the control host 13. In actual use, the coal storage bin 1 has a space near the transport bin 7. The top of the space is provided with a hole 2, which is equipped with a cover 3 that automatically opens and closes. Pulverized coal flows through the hole 2 into the starting end of the conveyor belt 4, and the end of the conveyor belt 4 is connected to the upper opening 5 of the transport bin 7.

[0047] The transport bin 7 is connected to the input of the control host 13; the output of the control host 13 is respectively connected to the coal storage bin 1, the conveyor belt 4, and the pulverized coal supply device. In this embodiment, the transport bin 7 is shaped like an upper cone, and the connection between the upper square and the lower cone is welded, which improves sealing.

[0048] Furthermore, a distance measuring sensor is provided on the top of the transport bin 7; the distance measuring sensor is connected to the input terminal of the control host 13. In actual application, thirteen infrared distance measuring sensors 6 are installed on the top of the transport bin 7 in a "cross" shape. Figure 4 As shown; when the pulverized coal in the transport bin 7 is lower than a certain amount, the coal storage bin 1 will transport the pulverized coal to the transport bin 7 through the conveyor belt 4, so that the amount of pulverized coal in the transport bin 7 is maintained at a certain amount.

[0049] Furthermore, the pulverized coal supply device includes a pulverized coal conveying pipeline, a rising-stem gate valve 8, and an impeller pulverizer 9; the rising-stem gate valve 8 and the impeller pulverizer 9 are disposed on the pulverized coal conveying pipeline and are both connected to the output of the control host 13. In actual use, the rising-stem gate valve 8 and the impeller pulverizer 9 are sequentially arranged on the pulverized coal conveying pipeline to form the pulverized coal supply device.

[0050] The rising stem gate valve 8 can make the upper transport bin 7 achieve the purpose of storing coal in a short time, and can also achieve the function of quickly stopping the coal transportation. The lower part of the rising stem gate valve 8 is installed with an impeller powder feeder 9, which can make the coal powder fall continuously and maintain the same speed.

[0051] The control host 13 is used to control the hole cover 3 and the conveyor belt 4 according to the signal collected by the distance sensor. The control host 13 is also used to control the start and stop of the rising stem gate valve 8 and the impeller powder feeder 9.

[0052] Each of the above components is connected to a control host 13 via wired or wireless connections. This control host 13 controls the start and stop of all devices in the system, and displays all device start, stop, and fault information on the host 13. Specifically, the infrared distance sensor 6 is connected to the signal input of the control host 13, while the signal output of the control host 13 is connected to the hole cover 3, the conveyor belt 4, the rising-stem gate valve 8, and the impeller powder feeder 9.

[0053] When the amount of pulverized coal in the transport bin 7 is lower than a certain level, the coal storage bin 1 will automatically transport the pulverized coal to the transport bin 7 through the conveyor belt 4 through feedback control, so that the amount of pulverized coal in the transport bin 7 is maintained at a certain level. The infrared distance sensor 6 emits infrared light, which forms a reflection process after being irradiated by the object. After being reflected to the sensor, it receives the signal, and then processes the data of the time difference between the emission and reception. After processing by the signal processor, the distance of the object is calculated. When all the data measured by the infrared distance sensor 6 are transmitted to the control host 13, the control host 13 automatically takes the average value of all the values ​​after receiving all the values ​​at the same time (hereinafter referred to as the average value), and then compares the average value with the specified value in the user program memory, namely the vertical height of the upper square of the transport bin 7 (hereinafter referred to as the vertical height) and the vertical distance from the bottom end of the upper opening 5 of the transport bin 7 to the top of the transport bin 7 (hereinafter referred to as the vertical distance). When the average value is higher than the vertical height, the control host 13 directly sends a control signal to automatically control the opening of the hole cover 3 and the conveyor belt 4, and the coal powder flows into the starting end of the conveyor belt 4 through the hole cover 3. After the conveyor belt 4 is opened, it starts to transport the coal powder into the transport bin 7. The infrared distance measuring sensor 6 performs real-time monitoring. When the average value is lower than the vertical distance, the control host 13 sends a control signal to close the hole cover 3 and the conveyor belt 4. The control signal first controls the closing of the hole cover 3 and then the conveyor belt 4.

[0054] The manhole cover 3 and the conveyor belt 4 are linked together. When the conveyor belt 4 is forced to stop running due to a fault, the manhole cover 3 is directly closed through the linkage control to stop the coal powder from falling. The fault information is also displayed on the control host 13.

[0055] The working principle of the coal powder transport flow control system of this embodiment is as follows: when the system is started, the rising stem gate valve 8 and the impeller powder feeder 9 are opened, the coal powder in the transport bin 7 begins to fall, and the air in the inner pipe of the air supply duct 10 begins to be transported, forming a negative pressure in the mixing duct 11, sucking the coal powder into the mixing cavity to mix with the air, and the mixture enters the air-powder duct 12, and then enters each branch duct in the form of injection through the gradually expanding pipe.

[0056] During continuous system operation, infrared distance sensor 6 continuously monitors the continuous decrease in pulverized coal in transport bin 7. Once the amount reaches a certain level, the measured value from infrared distance sensor 6 triggers control host 13 to issue a control signal, activating cover 3 and conveyor belt 4 in coal storage bin 1 to begin conveying pulverized coal into transport bin 7. When the pulverized coal in transport bin 7 reaches a specified level, the conveyor belt stops. This method ensures that pulverized coal is always stored in transport bin 7. To stop the system, simply close rising-stem gate valve 8 and impeller feeder 9.

[0057] The beneficial effects of the pulverized coal transport flow control system of the present invention are:

[0058] (1) Pulverized coal can be stored for a secondary purpose during transportation.

[0059] (2) The coal powder can be transported to the air supply duct in a quantitative manner.

[0060] (3) The pulverized coal and air are fully mixed in the mixing cavity to prevent the wind from flowing back into the pulverized coal conveying pipeline.

[0061] (4) After the pulverized coal and the air are fully mixed, they are evenly injected into the subsequent branch pipes through the gradually expanding pipe to achieve uniform distribution of the flow rate.

[0062] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0063] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An air-powder mixing and spraying device, characterized in that: include: Air supply ducts, mixing ducts and air-powder ducts; The air supply duct includes an inner tube and an outer tube; the outer tube is sleeved on the outer side of the inner tube, one end of the inner tube and one end of the outer tube are both connected to the air supply device; the other end of the inner tube and the other end of the outer tube are both connected to one end of the mixing duct; the air supply duct is used to transmit air and coal powder; The other end of the mixing pipe is connected to the air-powder pipe; the mixing pipe is used to mix the air and coal powder transmitted by the air supply pipe; The air-powder duct includes a second straight pipe, a gradually expanding pipe, and a third straight pipe connected in sequence; one end of the second straight pipe is connected to the other end of the mixing pipe; the diameter of the third straight pipe is larger than that of the second straight pipe; the air-powder duct is used to spray the mixed air and coal powder into the furnace; The third straight pipe includes a plurality of branch pipes; the plurality of branch pipes are arranged around the axis of the third straight pipe; the cross section of the branch pipes is circular, and the third straight pipe is sealed outside the branch pipes; The mixing pipe includes a second reducer; the diameter of one end of the second reducer is larger than the diameter of the other end; the diameter of one end of the second reducer is equal to the diameter of the outer pipe; the diameter of the other end of the second reducer is equal to the diameter of the second straight pipe.

2. The air-powder mixing spraying device according to claim 1, characterized in that: The inner tube includes a first reducer and a first straight tube; the first end of the first reducer is connected to the air supply device; the second end of the first reducer is connected to the first straight tube; The diameter of the first end of the first reducer is equal to the diameter of the outer tube, and the first end of the first reducer is connected to one end of the outer tube, so that a coal powder chamber is formed between the inner tube and the outer tube; the diameter of the first end of the first reducer is greater than the diameter of the second end of the first reducer; the diameter of the first straight tube is equal to the diameter of the second end of the first reducer.

3. A pulverized coal transport flow control system, characterized in that: It comprises the air-powder mixing and injection device according to any one of claims 1 to 2, a coal storage bin, a transport bin, a conveyor belt, a pulverized coal supply device and a control host; The coal storage bin is connected to the transport bin via the conveyor belt; the transport bin is connected to the air supply duct of the air-powder mixing and injection device via the pulverized coal supply device; the conveyor belt is used to transfer the pulverized coal from the coal storage bin to the transport bin; the pulverized coal supply device is used to control the flow rate of the pulverized coal fed into the air supply duct; A space is provided at the bottom of the coal storage bin, one end of the conveyor belt is embedded in the space, a hole is provided at the top of the space, and a hole cover is provided on the hole; the hole cover is connected to the output end of the control host; The transport bin is connected to the input end of the control host; the output end of the control host is respectively connected to the coal storage bin, the conveyor belt and the pulverized coal supply device.

4. The pulverized coal transport flow control system according to claim 3, characterized in that: A distance measuring sensor is provided on the top of the transport bin; the distance measuring sensor is connected to the input end of the control host.

5. The pulverized coal transportation flow control system according to claim 4, characterized in that: The pulverized coal supply device includes a pulverized coal conveying pipeline, a rising stem gate valve and an impeller pulverizer; the rising stem gate valve and the impeller pulverizer are arranged on the pulverized coal conveying pipeline; the rising stem gate valve and the impeller pulverizer are both connected to the output end of the control host.

6. The pulverized coal transportation flow control system according to claim 5, characterized in that: The control host is used to control the hole cover and the conveyor belt according to the signal collected by the distance measuring sensor. The control host is also used to control the start and stop of the rising stem gate valve and the impeller powder feeder.

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