Coal grinding assembly and coal grinding machine

Abstract

The present invention provides a coal grinding assembly and a coal mill, and relates to the technical field of coal mills. The coal grinding assembly includes a grinding bowl mechanism and a grinding roller mechanism. The grinding bowl mechanism includes a base and a grinding bowl, and the grinding bowl is provided with an annular bowl rim extending obliquely upward, the diameter of the grinding bowl is D, the width of the annular bowl rim is L, and the parameter L / D is 0.2-0.3. The grinding roller mechanism includes a grinding roller, which is a geometric body with a truncated cone profile, the large end diameter of the grinding roller is A, the high position of the grinding roller is H, and the parameter H / A is 0.2-0.4. A coal grinding gap is formed between the annular bowl rim and the grinding roller, and the rotation of the grinding bowl can drive the grinding roller to rotate to grind the raw coal located in the coal grinding gap. The coal mill includes the above-mentioned coal grinding assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mills, and in particular to a coal mill assembly and a coal mill. Background Art

[0002] A coal mill is a device that grinds raw coal into coal powder and then sends the coal powder to the furnace of the boiler for combustion and power generation. The coal mill assembly includes a grinding bowl mechanism, a grinding roller mechanism, and an impeller mechanism. The grinding roller mechanism and the grinding bowl mechanism can grind the raw coal into coal powder. The hot air from the primary air duct can generate an upward lift through the impeller mechanism, which can separate the coal powder into a primary level.

[0003] At present, with the large-scale mining and application of coal mines, the quality of many raw coals is rapidly decreasing, such as: the total moisture content of raw coal, the Hardgrove grindability coefficient, and the raw coal ash content and coal powder fineness and other parameters are also getting lower and lower. However, the amount and quality of coal ground by the coal mill will be greatly affected by the total moisture content of the raw coal, the Hardgrove grindability coefficient, and the raw coal ash content and coal powder fineness and other parameters. As a result, the current coal mill not only has a reduced coal grinding capacity but also cannot meet the existing needs. In view of this, the inventors specially proposed this application after studying the existing technology. Summary of the invention

[0004] The present invention provides a coal grinding assembly and a coal grinding machine, aiming to improve the coal grinding machine in the prior art, which has the problem that the amount and quality of ground coal are not good due to the reduction of the quality of raw coal.

[0005] In order to solve the above technical problems, the present invention provides a coal grinding assembly, comprising:

[0006] A grinding bowl mechanism, comprising a base, and a grinding bowl rotatably arranged on the base, the grinding bowl being provided with an annular bowl edge extending obliquely upward, the diameter of the grinding bowl being D, the width of the annular bowl edge being L, wherein the value of L / D is 0.2-0.3;

[0007] A grinding roller mechanism, comprising a grinding roller rotatably and tiltedly supported above the annular bowl edge, the grinding roller being a geometric body with a truncated cone profile, the large end diameter of the grinding roller being A, the high position of the grinding roller being H, wherein the value of H / A is 0.2-0.4;

[0008] A coal grinding gap for grinding raw coal is formed between the annular bowl edge and the grinding roller; the rotation of the grinding bowl can drive the grinding roller to rotate, so as to grind the raw coal located in the coal grinding gap.

[0009] As a further optimization, the grinding bowl mechanism also includes a lining plate arranged on the upper surface of the annular bowl edge, and the side surface of the grinding roller is roughly parallel to the lining plate.

[0010] As a further optimization, the angle β between the edge of the annular bowl and the horizontal plane is 10° to 25°, and the angle α between the two side surfaces of the grinding roller is 10° to 20°.

[0011] As a further optimization, the value of L / D is 0.22, the value of H / A is 0.3, β is 23°, and α is 14°.

[0012] As a further optimization, the coal grinding assembly also includes an impeller mechanism, which includes an inner ring arranged around the grinding bowl, an outer ring arranged around the inner ring, and a plurality of guide plates; the inner ring is arranged on the grinding bowl, a guide gap is formed between the inner ring and the outer ring, and the plurality of guide plates are respectively inclined in the guide gaps, the inner ring, the outer ring, and the plurality of guide plates form a plurality of guide cavities, and the air outlets of the guide cavities are higher than the grinding bowl.

[0013] As a further optimization, the top of the base is provided with an upwardly protruding limiting boss, the side wall of the base is provided with an outwardly extending supporting flange, the grinding bowl is sleeved on the limiting boss and supported on the supporting flange; the limiting boss is a frustum geometric body with a smaller diameter, and the inner annular surface of the grinding bowl is an inclined surface adapted to the side surface of the limiting boss.

[0014] As a further optimization, the angle J between the side surface of the limiting boss and the upper surface of the supporting flange is 90° to 120°.

[0015] As a further optimization, the grinding bowl is connected to the base by bolts, and the grinding bowl is provided with a nut groove, and the nut of the bolt can be accommodated in the nut groove to be lower than the upper surface of the grinding bowl.

[0016] The present application further provides a coal pulverizer, comprising any of the coal pulverizing assemblies described above.

[0017] By adopting the above technical solution, the present invention can achieve the following technical effects:

[0018] 1. The coal grinding assembly of the invention can ensure that the coal grinding assembly can increase the coal grinding amount of the coal grinding assembly as much as possible under safe and reliable working conditions by setting the parameters L / D and H / A. Specifically, the larger the value of the parameter L / D, the larger the area of ​​the annular bowl edge can be. In addition, the heating area of ​​the raw coal can be increased, which is beneficial to the removal of moisture from the raw coal. The larger the value of the parameter H / A, the larger the side area of ​​the grinding roller can be. Therefore, increasing the parameters L / D and H / A can effectively increase the length of the coal grinding gap and greatly improve the efficiency of coal grinding. Of course, the larger the value of L / D, the greater the force borne by the annular bowl edge 111, which will affect the structural strength of the grinding bowl mechanism. Correspondingly, the larger the value of H / A, on the one hand, it will increase the load-bearing capacity of the grinding roller mechanism and the force borne by the annular bowl edge, and at the same time, it will increase the rotation speed of the grinding roller, which will affect the stable operation of the grinding roller mechanism. In this case, the L / D value is 0.2-0.3, and the H / A value is 0.2-0.4, which can ensure that the coal grinding assembly can work safely and reliably and increase the coal grinding capacity of the coal grinding assembly as much as possible.

[0019] 2. The impeller mechanism of the present invention can greatly improve the air outlet speed of the impeller mechanism through the inclined guide plate and the uniformly distributed guide cavity. At the same time, the air outlet of the guide cavity is higher than the grinding bowl, which can ensure that large particles of coal or impurities in the raw coal will not accumulate at the air outlet of the impeller mechanism, thereby affecting the air outlet of the impeller mechanism and the separation of coal powder.

[0020] 3. The impeller mechanism of the present invention, by providing the limiting boss and the limiting flange, is not only convenient for the installation of the grinding bowl on the base, but also convenient for ensuring the concentricity of the grinding bowl and the base, and avoiding vibration caused by eccentric rotation. At the same time, the matching of the limiting boss and the conical surface of the inner ring surface of the grinding bowl makes the grinding bowl and the limiting boss have the characteristics of self-locking, which effectively improves the stability of the matching between the grinding bowl and the base.

[0021] 4. The present invention also provides a coal grinding assembly. By configuring the coal grinding assembly of this case, the coal grinding capacity of the coal mill can be greatly increased to adapt to the current situation of reduced quality of raw coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of a coal grinding assembly according to an embodiment of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a grinding bowl mechanism according to an embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of a grinding roller mechanism according to an embodiment of the present invention;

[0026] Figure 4 It is the first structural schematic diagram of the coal grinding assembly in the prior art;

[0027] Figure 5 It is a second structural schematic diagram of a coal grinding assembly in the prior art;

[0028] Markings in the figure: 100-grinding bowl mechanism; 200-impeller mechanism; 300-grinding roller mechanism; 110-grinding bowl; 120-lining plate; 130-base; 111-annular bowl rim; 131-limiting boss; 132-support flange; 140-bolt; 112-nut groove; 210-inner ring; 220-guide plate; 230-outer ring; 240-guide chamber; 310-grinding roller. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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 work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and 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 a limitation on the present invention.

[0031] 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 one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] 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 connection; it can be a mechanical connection or an electrical connection; 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0035] Depend on Figure 1 , Figure 2 and Figure 3 As shown, this embodiment provides a coal grinding assembly, including a grinding bowl mechanism 100 and a grinding roller mechanism 300, specifically:

[0036] like Figure 1 and Figure 2 As shown, the grinding bowl mechanism 100 includes a base 130, a grinding bowl 110 and a liner 120. The grinding bowl 110 is rotatably arranged on the base 130, and the grinding bowl 110 is provided with an annular bowl edge 111 extending obliquely upward. The liner 120 is arranged on the upper surface of the annular bowl edge 111. The diameter of the grinding bowl 110 is D, the width of the annular bowl edge 111 is L, and the value of L / D is approximately 0.22. Of course, in another embodiment, L / D can be taken as 0.2 to 0.3.

[0037] like Figure 1 and Figure 2 As shown, the grinding roller mechanism 300 includes a grinding roller 310 rotatably and tiltably supported above the annular bowl edge 111. The grinding roller 310 is a geometric body with a truncated cone profile, and the side of the grinding roller 310 is substantially parallel to the liner 120. The diameter of the large end of the grinding roller 310 is A, the high position of the grinding roller 310 is H, and the value of H / A is 0.3. Of course, in another embodiment, H / A can be taken as 0.2-0.4.

[0038] like Figure 1 As shown, a coal grinding gap for grinding raw coal is formed between the annular bowl edge 111 and the grinding roller 310. In specific operation, the grinding bowl 110 is driven to rotate, and the raw coal on the surface of the liner 120 is spread on the surface of the liner 120 by centrifugal force and enters the coal grinding gap. When there is raw coal in the coal grinding gap, the rotating grinding bowl 110 can drive the grinding roller 310 to rotate through the action of the raw coal, thereby achieving the purpose of grinding the raw coal spread on the surface of the liner 120.

[0039] The coal grinding assembly of this embodiment can further improve the coal grinding amount of the coal grinding assembly compared with the coal grinding assembly of the prior art. The larger the value of the parameter L / D, the larger the area of ​​the annular bowl edge 111 can be. In addition, the heating area of ​​the raw coal can be increased, which is beneficial to the removal of moisture from the raw coal. The larger the value of the parameter H / A, the larger the side area of ​​the grinding roller 310 can be. Therefore, increasing the parameters L / D and H / A can effectively increase the length of the coal grinding gap, increase the grinding area, and thus greatly improve the efficiency of coal grinding. Of course, the larger the value of L / D, the greater the force borne by the annular bowl edge 111, which will affect the structural strength of the grinding bowl mechanism 100. Correspondingly, the larger the value of H / A, on the one hand, the load-bearing capacity of the grinding roller mechanism 300 will be increased, the force borne by the annular bowl edge 111 will be increased, and at the same time, the rotation speed of the grinding roller 310 will be increased, which will affect the stable operation of the grinding roller mechanism 300. In the coal grinding assembly of the present embodiment, the parameter L / D takes a value of 0.22, and the parameter H / A takes a value of 0.3, which can well ensure that the coal grinding assembly works safely and reliably and maximize the coal grinding amount of the coal grinding assembly.

[0040] It should be noted that the coal mill of the prior art does not need to be redesigned. It only needs to change the values ​​of the parameters L / D and H / A to greatly increase the coal grinding capacity of the coal grinding assembly, which is suitable for the current situation where the quality of raw coal is rapidly decreasing. At the same time, it can extend the service life of old equipment and reduce the cost of enterprise equipment, which has good practicality.

[0041] like Figure 2 and Figure 3As shown, in this embodiment, the angle β between the annular bowl edge 111 and the horizontal plane is 23°, and the angle α between the two side surfaces of the grinding roller 310 is 14°. In another embodiment, β can be 10° to 25°, and α can be 10° to 20°. In the case of H being constant, increasing α can increase the side surface area of ​​the grinding roller 310; in the case of D being constant, increasing β can increase the upper surface area of ​​the annular bowl edge 111, thereby further increasing the coal grinding amount of the coal grinding assembly.

[0042] like Figure 1 and Figure 2 As shown, in this embodiment, the coal mill assembly further includes an impeller mechanism 200, which includes an inner ring 210 arranged around the grinding bowl 110, an outer ring 230 arranged around the inner ring 210, and a plurality of guide plates 220. The inner ring 210 is arranged on the grinding bowl 110, a guide gap is formed between the inner ring 210 and the outer ring 230, and a plurality of guide plates 220 are respectively arranged obliquely in the guide gap. The inner ring 210, the outer ring 230, and the plurality of guide plates 220 surround a plurality of uniformly distributed guide cavities 240, wherein the air outlet of the guide cavity 240 is higher than the grinding bowl 110. It can be ensured that large particles of coal or impurities in the raw coal will not accumulate at the air outlet of the impeller mechanism 200, thereby affecting the air outlet of the impeller mechanism 200 and the separation of coal powder.

[0043] On the contrary, Figure 4 and Figure 5 As shown, in the prior art, the air outlet of the guide cavity 240 is lower than the grinding bowl 110. In actual operation, large particles of coal or impurities in the raw coal will accumulate here, which will quickly wear out the impeller mechanism 200 on the one hand, and affect the air outlet of the impeller mechanism 200 on the other hand, thereby affecting the separation of coal powder.

[0044] like Figure 1 and Figure 2As shown, in this embodiment, the top of the base 130 is provided with a limiting boss 131 protruding upward, the side wall of the base 130 is provided with a supporting flange 132 extending outward, and the grinding bowl 110 is sleeved on the limiting boss 131 and supported on the supporting flange 132. The limiting boss 131 is a truncated cone geometry with a smaller diameter, and the inner annular surface of the grinding bowl 110 is an inclined surface adapted to the side of the limiting boss 131. Among them, the angle J between the side of the limiting boss 131 and the upper surface of the supporting flange 132 is 98°. In another embodiment, J can be 90° to 120°. Through the above-mentioned setting of the limiting boss 131 and the limiting flange, it is not only convenient to install the grinding bowl 110 on the base 130, but also convenient to ensure the concentricity of the grinding bowl 110 and the base 130, avoiding vibration caused by eccentric rotation. At the same time, the matching of the limiting boss 131 and the conical surface of the inner ring surface of the grinding bowl 110 allows the grinding bowl 110 and the limiting boss 131 to have a self-locking feature, effectively improving the stability of the matching between the grinding bowl 110 and the base 130.

[0045] On the contrary, Figure 4 and Figure 5 As shown, in the prior art, the limiting boss 131 is a roughly cylindrical geometric body, and the angle J between the side surface of the limiting boss 131 and the upper surface of the supporting flange 132 is 90°. This is not only not conducive to the installation of the grinding bowl 110 on the base 130, but also difficult to ensure the concentricity of the grinding bowl 110 and the base 130, which will lead to the problem of vibration caused by eccentric rotation.

[0046] like Figure 2 As shown, in this embodiment, the grinding bowl 110 is connected to the base 130 by a bolt 140, and the grinding bowl 110 is provided with a nut groove 112, and the nut of the bolt 140 can be accommodated in the nut groove 112 to be lower than the upper surface of the grinding bowl 110. Through the above-mentioned arrangement, it is possible to minimize the intense friction between the nut of the bolt 140 and the raw coal located on the annular bowl edge 111 during operation, which causes the bolt 140 to wear quickly and affects the fixation of the grinding bowl 110. It should be noted that once the coal mill assembly is installed in place, the grinding bowl mechanism 100 is located inside the coal mill, and it is not convenient to maintain the coal mill assembly, nor is it convenient to replace the bolt 140.

[0047] The present application further provides a coal pulverizer, which includes the coal pulverizing assembly described above in this embodiment.

[0048] Through the above scheme of this embodiment, the coal mill assembly of this case can ensure that the coal grinding amount of the coal mill assembly is increased as much as possible under safe and reliable working conditions by changing the parameters L / D and H / A. In the prior art, the old coal mill can improve the coal output and coal quality of the coal mill according to the scheme of this embodiment, which is suitable for the current situation where the quality of raw coal is rapidly decreasing. At the same time, the service life of the old equipment can be extended and the cost of enterprise equipment can be reduced.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coal grinding assembly, characterized in that: Include: A grinding bowl mechanism (100) comprises a base (130) and a grinding bowl (110) rotatably arranged on the base (130), wherein the grinding bowl (110) is provided with an annular bowl edge (111) extending obliquely upward, the diameter of the grinding bowl (110) is D, and the width of the annular bowl edge (111) is L, wherein the value of L / D is 0.2-0.3; A grinding roller mechanism (300), comprising a grinding roller (310) rotatably supported above the annular bowl edge (111), the grinding roller (310) being a geometric body with a truncated cone profile, the large end diameter of the grinding roller (310) being A, the high position of the grinding roller (310) being H, wherein the value of H / A is 0.2-0.4; A coal grinding gap for grinding raw coal is formed between the annular bowl edge (111) and the grinding roller (310); the rotation of the grinding bowl (110) can drive the grinding roller (310) to rotate, so as to grind the raw coal located in the coal grinding gap; The angle β between the annular bowl edge (111) and the horizontal plane is 10° to 25°, and the angle α between the two side surfaces of the grinding roller (310) is 10° to 20°; Furthermore, the top of the base (130) is provided with an upwardly protruding limiting boss (131), the side wall of the base (130) is provided with an outwardly extending supporting flange (132), and the grinding bowl (110) is sleeved on the limiting boss (131) and supported on the supporting flange (132); wherein, the angle J between the side surface of the limiting boss (131) and the upper surface of the supporting flange (132) is 90° to 120°.

2. A coal grinding assembly according to claim 1, characterized in that The grinding bowl mechanism (100) further includes a lining plate (120) disposed on the upper surface of the annular bowl edge (111), and the side surface of the grinding roller (310) is substantially parallel to the lining plate (120).

3. A coal grinding assembly according to claim 1, characterized in that , the value of L / D is 0.22, the value of H / A is 0.3, β is 23°, and α is 14°.

4. A coal grinding assembly according to claim 1, characterized in that The coal grinding assembly further comprises an impeller mechanism (200), the impeller mechanism (200) comprising an inner ring (210) arranged around the grinding bowl (110), an outer ring (230) arranged around the inner ring (210), and a plurality of guide plates (220); the inner ring (210) is arranged on the grinding bowl (110), a guide gap is formed between the inner ring (210) and the outer ring (230), the plurality of guide plates (220) are respectively arranged obliquely in the guide gap, the inner ring (210), the outer ring (230), and the plurality of guide plates (220) surround a plurality of uniformly distributed guide cavities (240), and the air outlet of the guide cavity (240) is higher than the grinding bowl (110).

5. A coal grinding assembly according to claim 1, characterized in that The limiting boss (131) is a truncated cone geometry with a smaller diameter, and the inner annular surface of the grinding bowl (110) is an inclined surface adapted to the side surface of the limiting boss (131).

6. A coal grinding assembly according to claim 1, characterized in that The grinding bowl (110) is connected to the base (130) via a bolt (140), and the grinding bowl (110) is provided with a nut groove (112), and the nut of the bolt (140) can be accommodated in the nut groove (112) to be lower than the upper surface of the grinding bowl (110).

7. A coal mill, characterized in that: A coal grinding assembly comprising any one of claims 1 to 6.

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