Pulverized coal conveying system

Abstract

The invention relates to the technical field of boiler powder conveying and discloses a pulverized coal conveying system which comprises a coal mill, a pulverized coal bin and a vibrating screen, the top end of the coal mill is provided with a first coal inlet, a second coal inlet and a pulverized coal outlet, the first coal inlet is used for being communicated with a coal outlet of a coal feeder, the top end of the pulverized coal bin is provided with a feeding port, and the second coal inlet is used for being communicated with a coal outlet of a coal feeder. The pulverized coal bin is provided with a feed port and a second coal inlet, the feed port is communicated with the pulverized coal outlet, the bottom end of the pulverized coal bin is provided with a first discharge port, the bin side wall of the pulverized coal bin is provided with a second discharge port, the second discharge port is communicated with the second coal inlet, and the vibrating screen is obliquely arranged in the pulverized coal bin and located below the feed port. The qualified pulverized coal meeting the particle size requirement is stored in the pulverized coal bin and is subsequently used for providing the qualified pulverized coal meeting the particle size requirement for the boiler for normal combustion of the boiler, the combustion performance of the boiler can be guaranteed, the combustion performance of the boiler can reach the standard, and the combustion reliability of the boiler can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of boiler pulverized coal conveying, and in particular to a pulverized coal conveying system. Background Art

[0002] In the related technology, the coal outlet of the coal feeder is connected to the coal inlet of the coal mill to provide coal blocks to the coal mill. The coal powder ground by the coal mill is transported to the coal powder bin for buffer storage through the powder suction machine to ensure that when the pulverizing subsystem fails or is under short-term maintenance, the coal powder in the coal powder bin can be continuously sprayed into the boiler to avoid boiler shutdown accidents. However, during the coal grinding process of the coal mill, some coal block particles that exceed the particle size standard will also be transported to the coal powder bin by the powder suction machine for storage, resulting in the coal powder particle size in the coal powder bin not meeting the standard, affecting the combustion performance of the boiler. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention provides a pulverized coal conveying system that can effectively ensure the combustion performance of a boiler.

[0004] The pulverized coal conveying system of the embodiment of the present invention includes a coal mill, a pulverized coal bin and a vibrating screen, the top of the coal mill is provided with a first coal inlet, a second coal inlet and a pulverized coal outlet, the first coal inlet is used to be connected with the coal outlet of the coal feeder; the top of the pulverized coal bin is provided with a feed inlet, the feed inlet is connected with the pulverized coal outlet, the bottom of the pulverized coal bin is provided with a first outlet, the side wall of the pulverized coal bin is provided with a second outlet, the second outlet is connected with the second coal inlet; the vibrating screen is tilted in the pulverized coal bin and is located below the feed inlet, the vibrating screen is used to screen the pulverized coal falling from the feed inlet, the small-sized pulverized coal selected by the vibrating screen is stored at the bottom of the pulverized coal bin, and the large-sized pulverized coal selected by the vibrating screen is discharged through the second outlet and returned to the coal mill through the second coal inlet.

[0005] Optionally, the angle between the vibrating screen and the horizontal plane is 30°-45°.

[0006] Optionally, a tilting rod is provided in the pulverized coal bin, and both ends of the tilting rod are respectively connected to the bin side walls of the pulverized coal bin;

[0007] The vibrating screen includes a screen body and a vibration motor. The screen body is movably connected to the tilting rod along the length direction of the tilting rod. A vibration spring is provided between the tilting rod and the screen body. The vibration motor is provided on the screen body to drive the screen body to vibrate in the length direction of the tilting rod.

[0008] Optionally, the axial direction of the output shaft of the vibration motor is perpendicular to the length direction of the tilting rod, and an eccentric rotating disk is provided on the output shaft of the vibration motor.

[0009] Optionally, the bottom end of the screen body is provided with a first slide seat and a second slide seat spaced apart along the length direction of the tilting rod, the first slide seat has a first slide hole slidably matched with the tilting rod, and the second slide seat has a second slide hole slidably matched with the tilting rod;

[0010] The vibration spring includes a first spring and a second spring, the first spring is sleeved on the tilting rod and the two ends of the first spring are respectively stopped on the side wall of the coal powder bin and the first slide seat, the second spring is sleeved on the tilting rod and the two ends of the second spring are respectively stopped on the side wall of the coal powder bin and the second slide seat.

[0011] Optionally, a first conveying pipeline is provided between the pulverized coal outlet of the coal mill and the feed inlet of the pulverized coal bin, and a pulverized coal conveyor is provided on the first conveying pipeline.

[0012] Optionally, the pulverized coal conveying system of the embodiment of the present invention further includes a stud conveyor, wherein the inlet end of the stud conveyor is connected to the second discharge port, and the outlet end of the stud conveyor is connected to the second coal inlet.

[0013] Optionally, the stud conveyor is located below the second discharge port, and a second conveying pipeline is provided between an inlet end of the stud conveyor and the second discharge port.

[0014] Optionally, the bottom end of the screen body extends into the second conveying pipeline through the second discharge port.

[0015] Optionally, the outlet end of the stud conveyor is located at the upper end of the second coal inlet.

[0016] During the use of the pulverized coal conveying system of the embodiment of the present invention, the coal feeder provides coal blocks to the coal mill through the first coal inlet for grinding in the coal mill, the pulverized coal generated in the coal mill is discharged through the pulverized coal outlet, and the pulverized coal discharged from the pulverized coal outlet enters the pulverized coal bin through the feed inlet of the pulverized coal bin. Since the vibrating screen is located below the feed inlet, the pulverized coal in the pulverized coal bin falls onto the vibrating screen. The vibrating screen vibrates and screens the pulverized coal, and the small-sized pulverized coal that meets the requirements selected by the vibrating screen falls to the bottom of the pulverized coal bin for storage. The large-sized pulverized coal that does not meet the boiler use requirements selected by the vibrating screen is discharged through the second discharge port, and the unqualified large-sized pulverized coal discharged from the second discharge port is returned to the coal mill through the second coal inlet for grinding, thereby saving coal resources and avoiding waste of coal resources.

[0017] Therefore, the coal powder stored in the coal powder bin is qualified coal powder that meets the particle size requirements, which is subsequently used to provide the boiler with qualified coal powder that meets the particle size requirements for normal combustion of the boiler, which can ensure the combustion performance of the boiler and make the boiler combustion performance meet the standard, which is beneficial to improving the combustion reliability of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a pulverized coal conveying system according to an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged view of part A.

[0020] Reference numerals:

[0021] 100. Pulverized coal conveying system; 1. Coal mill; 101. First coal inlet; 102. Second coal inlet; 103. Pulverized coal outlet; 2. Pulverized coal bin; 201. Feeding port; 202. First discharging port; 203. Second discharging port; 3. Vibrating screen; 301. Vibrating motor; 302. Screen body; 3021. First slide seat; 3022. Second slide seat; 4. Tilt rod; 5. Vibrating spring; 501. First spring; 502. Second spring; 6. Eccentric turntable; 7. First conveying pipeline; 8. Pulverized coal conveyor; 9. Stud conveyor; 10. Second conveying pipeline. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0023] The technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0024] like Figure 1 and Figure 2 As shown, the pulverized coal conveying system 100 of the embodiment of the present invention comprises a coal mill 1, a pulverized coal bin 2 and a vibrating screen 3. The top of the coal mill 1 has a first coal inlet 101, a second coal inlet 102 and a pulverized coal outlet 103, and the first coal inlet 101 is used to communicate with the coal outlet of the coal feeder.

[0025] The top of the pulverized coal bin 2 is provided with a feed port 201, which is connected to the pulverized coal outlet 103. The bottom of the pulverized coal bin 2 is provided with a first discharge port 202, and the side wall of the pulverized coal bin 2 is provided with a second discharge port 203, which is connected to the second coal inlet 102. The vibrating screen 3 is tiltedly arranged in the pulverized coal bin 2 and below the feed port 201. The vibrating screen 3 is used to screen the pulverized coal falling from the feed port 201. The small-sized pulverized coal selected by the vibrating screen 3 is stored at the bottom of the pulverized coal bin 2. The large-sized pulverized coal selected by the vibrating screen 3 is discharged through the second discharge port 203 and returned to the coal mill 1 through the second coal inlet 102.

[0026] Specifically, during the use of the pulverized coal conveying system 100 of the embodiment of the present invention, the coal feeder provides coal blocks to the coal mill 1 through the first coal inlet 101 for grinding in the coal mill 1, and the pulverized coal generated in the coal mill 1 is discharged through the pulverized coal outlet 103. The pulverized coal discharged from the pulverized coal outlet 103 enters the pulverized coal bin 2 through the feed inlet 201 of the pulverized coal bin 2. Since the vibrating screen 3 is located below the feed inlet 201, the pulverized coal in the pulverized coal bin 2 falls onto the vibrating screen 3. The vibrating screen 3 vibrates and screens the pulverized coal, and the small-sized pulverized coal that meets the requirements selected by the vibrating screen 3 falls to the bottom of the pulverized coal bin 2 for storage. The large-sized pulverized coal that does not meet the boiler use requirements selected by the vibrating screen 3 is discharged through the second discharge port 203. The unqualified large-sized pulverized coal discharged from the second discharge port 203 is returned to the coal mill 1 through the second coal inlet 102 for grinding, saving coal resources and avoiding waste of coal resources.

[0027] Therefore, the coal powder stored in the coal powder bin 2 is qualified coal powder that meets the particle size requirements, which is subsequently used to provide the boiler with qualified coal powder that meets the particle size requirements for normal combustion of the boiler, which can ensure the combustion performance of the boiler and make the boiler combustion performance meet the standards, which is beneficial to improving the combustion reliability of the boiler.

[0028] In some embodiments, the angle between the vibrating screen 3 and the horizontal plane is 30°-45°.

[0029] For example, the angle between the vibrating screen 3 and the horizontal plane can be 30°, 40° or 45°. The vibrating screen 3 is set at an angle to the horizontal plane. When the coal powder falls from the feed port 201 onto the vibrating screen 3, the coal powder can slide from the second discharge port 203 to the outside of the coal powder bin 2 by gravity, and there is no need to set up a separate conveying device to convey the large-particle-size coal powder after screening, which saves costs.

[0030] In addition, the angle between the vibrating screen 3 and the horizontal plane cannot be too small or too large. If the inclination angle of the vibrating screen 3 is too small, it is not easy for the coal powder to slide from the vibrating screen 3 to the outside of the second discharge port 203, resulting in low screening efficiency. If the inclination angle of the vibrating screen 3 is too large, the coal powder will slide off the vibrating screen 3 faster, and some coal powders with particle sizes that meet the requirements will also slide along the vibrating screen 3 to the outside of the second discharge port 203, resulting in poor screening effect.

[0031] In some embodiments, a tilting rod 4 is provided in the pulverized coal bin 2 , and both ends of the tilting rod 4 are respectively connected to the bin side walls of the pulverized coal bin 2 , for example, both ends of the tilting rod 4 are connected to the bin side walls of the pulverized coal bin 2 by welding.

[0032] The vibrating screen 3 includes a screen body 302 and a vibration motor 301. The screen body 302 is movably connected to the tilting rod 4 along the length direction of the tilting rod 4. A vibration spring 5 is provided between the tilting rod 4 and the screen body 302. The vibration motor 301 is provided on the screen body 302 to drive the screen body 302 to vibrate in the length direction of the tilting rod 4.

[0033] like Figure 1 and Figure 2 As shown, when the vibrating screen 3 is working, the vibration motor 301 drives the screen body 302 to vibrate back and forth in the length direction of the tilting rod 4. The vibration spring 5 is repeatedly extended and compressed during the reciprocating vibration of the screen body 302. The vibrating screen 3 of the embodiment of the present invention has a simple structure and is easy to install.

[0034] Optionally, the axial direction of the output shaft of the vibration motor 301 is perpendicular to the length direction of the tilt rod 4, and an eccentric rotating disk 6 is provided on the output shaft of the vibration motor 301. Figure 2 As shown, it can be understood that when the output shaft of the vibration motor 301 is rotating, the eccentric turntable 6 has a certain eccentric force. Since the screen body 302 is movable in the length direction of the tilting rod 4, the screen body 302 moves back and forth under the action of the eccentric force to achieve the vibration effect, thereby making the vibration screen 3 simple in structure and easy to process and manufacture.

[0035] In some embodiments, the bottom end of the screen body 302 is provided with a first slide 3021 and a second slide 3022 arranged at intervals along the length direction of the tilting rod 4. The first slide 3021 has a first sliding hole that slides with the tilting rod 4, and the second slide 3022 has a second sliding hole that slides with the tilting rod 4, so that the connection between the screen body 302 and the tilting rod 4 is firm and reliable, and when the screen body 302 is in the reciprocating vibration process, the operation reliability of the screen body 302 can be improved.

[0036] The vibration spring 5 includes a first spring 501 and a second spring 502. The first spring 501 is sleeved on the tilting rod 4 and the two ends of the first spring 501 are respectively stopped on the side wall of the coal powder bin 2 and the first slide seat 3021. The second spring 502 is sleeved on the tilting rod 4 and the two ends of the second spring 502 are respectively stopped on the side wall of the coal powder bin 2 and the second slide seat 3022. The first spring 501 and the second spring 502 are connected to the tilting rod 4 and the first slide seat 3021 and the second slide seat 3022 without a connecting piece, which facilitates the assembly of the first spring 501 and the second spring 502 and helps to improve the assembly efficiency of the vibration spring 5.

[0037] In some embodiments, a first conveying pipeline 7 is provided between the pulverized coal outlet 103 of the coal mill 1 and the feed port 201 of the pulverized coal bin 2, and a pulverized coal conveyor 8 is provided on the first conveying pipeline 7 to facilitate the conveyance of pulverized coal.

[0038] In some embodiments, the pulverized coal conveying system 100 of the embodiment of the present invention further includes a stud conveyor 9 , the inlet end of the stud conveyor 9 is connected to the second discharge port 203 , and the outlet end of the stud conveyor 9 is connected to the second coal inlet 102 .

[0039] It can be understood that the screw conveyor 9 is a machine that uses a motor to drive the screw to rotate and push materials to achieve the purpose of transportation. It can transport horizontally, inclined or vertically, and has the advantages of simple structure, small cross-sectional area, good sealing, convenient operation, easy maintenance, and convenient closed transportation. The use of the stud conveyor 9 to transport coal powder is beneficial to improving the reliability of coal powder transportation.

[0040] In some embodiments, the stud conveyor 9 is located below the second discharge port 203, and a second conveying pipeline 10 is provided between the inlet end of the stud conveyor 9 and the second discharge port 203, so that the coal powder discharged from the second discharge port 203 can use its own gravity to fall into the inlet end of the stud conveyor 9 through the second conveying pipeline 10, and there is no need to set up conveying equipment on the second conveying pipeline 10 between the first discharge port 202 and the inlet end of the stud conveyor 9, so as to save equipment costs, thereby facilitating a simple structure and convenient connection between the second discharge port 203 and the stud conveyor 9.

[0041] In some embodiments, the bottom end of the screen body 302 extends into the second conveying pipeline 10 through the second discharge port 203 .

[0042] like Figure 1 and Figure 2As shown, during the reciprocating vibration of the vibrating screen 3, the large-size coal powder that does not meet the requirements screened out at the upper end of the screen body 302 directly slides into the second conveying pipeline 10 through the bottom end of the screen body 302, thereby preventing the large-size coal powder that does not meet the requirements from falling to the bottom of the coal powder bin 2. This can effectively ensure the particle size quality of the coal powder after being screened by the screen body 302, thereby ensuring the quality of the coal powder supplied to the boiler, and further effectively ensuring the combustion performance of the boiler.

[0043] In some embodiments, the outlet end of the stud conveyor 9 is located at an upper end of the second coal inlet 102 .

[0044] like Figure 1 and Figure 2 As shown, when the coal powder transported by the outlet end of the stud conveyor 9 is discharged, it can fall into the second coal inlet 102 by its own gravity, and return to the coal mill 1 through the second coal inlet 102 for re-grinding. There is no need to set up conveying equipment between the outlet end of the stud conveyor 9 and the second coal inlet 102, so as to save equipment costs.

[0045] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0049] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0050] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A pulverized coal conveying system, characterized in that: include: A coal mill, wherein the top of the coal mill has a first coal inlet, a second coal inlet and a coal powder outlet, wherein the first coal inlet is used to communicate with the coal outlet of the coal feeder; A pulverized coal bin, wherein the top of the pulverized coal bin has a feed port, the feed port is connected to the pulverized coal outlet, the bottom of the pulverized coal bin has a first discharge port, and the side wall of the pulverized coal bin has a second discharge port, the second discharge port is connected to the second coal feed port; and A vibrating screen is arranged obliquely in the pulverized coal bin and below the feed port, the vibrating screen is used to screen the pulverized coal falling from the feed port, the small-sized pulverized coal selected by the vibrating screen is stored at the bottom of the pulverized coal bin, and the large-sized pulverized coal selected by the vibrating screen is discharged through the second discharge port and returned to the pulverizer through the second coal inlet.

2. The pulverized coal conveying system according to claim 1, characterized in that: The angle between the vibrating screen and the horizontal plane is 30°-45°.

3. The pulverized coal conveying system according to claim 2, characterized in that: The coal powder bin is provided with a tilting rod, and the two ends of the tilting rod are respectively connected to the bin side walls of the coal powder bin; The vibrating screen includes a screen body and a vibration motor. The screen body is movably connected to the tilting rod along the length direction of the tilting rod. A vibration spring is provided between the tilting rod and the screen body. The vibration motor is provided on the screen body to drive the screen body to vibrate in the length direction of the tilting rod.

4. The pulverized coal conveying system according to claim 3, characterized in that: The axial direction of the output shaft of the vibration motor is perpendicular to the length direction of the tilting rod, and an eccentric rotating disk is arranged on the output shaft of the vibration motor.

5. The pulverized coal conveying system according to claim 4, characterized in that: The bottom end of the screen body is provided with a first slide seat and a second slide seat arranged at intervals along the length direction of the tilting rod, the first slide seat has a first sliding hole that is slidably matched with the tilting rod, and the second slide seat has a second sliding hole that is slidably matched with the tilting rod; The vibration spring includes a first spring and a second spring, the first spring is sleeved on the tilting rod and the two ends of the first spring are respectively stopped on the side wall of the coal powder bin and the first slide seat, the second spring is sleeved on the tilting rod and the two ends of the second spring are respectively stopped on the side wall of the coal powder bin and the second slide seat.

6. The pulverized coal conveying system according to claim 1, characterized in that: A first conveying pipeline is provided between the pulverized coal outlet of the coal mill and the feed port of the pulverized coal bin, and a pulverized coal conveyor is provided on the first conveying pipeline.

7. The pulverized coal conveying system according to claim 3, characterized in that: It also includes a stud conveyor, wherein the inlet end of the stud conveyor is connected to the second discharge port, and the outlet end of the stud conveyor is connected to the second coal inlet.

8. The pulverized coal conveying system according to claim 7, characterized in that: The stud conveyor is located below the second discharge port, and a second conveying pipeline is provided between the inlet end of the stud conveyor and the second discharge port.

9. The pulverized coal conveying system according to claim 8, characterized in that: The bottom end of the screen body extends into the second conveying pipeline through the second discharge port.

10. The pulverized coal conveying system according to claim 9, characterized in that: The outlet end of the stud conveyor is located at the upper end of the second coal inlet.

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