Vertical roller mill

Abstract

The present application provides a vertical roller mill in which unevenness in flow velocity of inward airflow in a classification rotor of a separator is improved. The vertical roller mill has a rotating table, a pulverizing roller disposed on an upper surface of the rotating table, a separator that classifies pulverized material conveyed by flow of gas, and a mill housing having an exhaust port disposed above the separator. The separator includes a classification rotor and guide vanes disposed around the classification rotor. The guide vanes have a plurality of layers of guide vane rows in the up-down direction. The plurality of layers of guide vane rows include a first layer of guide vane rows having first layer guide vanes arranged in a ring shape around the classification rotor with a rotor shaft as a center, and a second layer of guide vane rows having second layer guide vanes arranged in a ring shape around the classification rotor with the rotor shaft as a center, the passage cross-sectional area of gas in the first layer of guide vane rows being smaller than the passage cross-sectional area of gas in the second layer of guide vane rows.

Description

Technical Field

[0001] This disclosure relates to a vertical roller mill with a separator. Background Technology

[0002] Traditionally, vertical roller mills have been used for crushing solid fuels such as coal and cement raw materials such as limestone or clay. Hereinafter, the material being crushed in a vertical roller mill will be referred to as raw material, and the crushed raw material will be referred to as pulverized material. Among vertical roller mills, there are those equipped with a separator that classifies the pulverized material to adjust the particle size of the product. Such a vertical roller mill is disclosed in Patent Document 1.

[0003] Patent Document 1 describes a vertical pulverizing mechanism comprising a pulverizing roller and a rotating worktable. The pulverizing roller pulverizes the raw material fed onto the rotating worktable, and the pulverized material is blown up by gas supplied from below the rotating worktable and removed from the upper outlet along with the gas through a separator located above the rotating worktable. The separator has a classifying rotor consisting of rotating blades arranged in a ring and fixed blades arranged in a ring around the outer periphery of the classifying rotor. The classifying rotor causes the airflow rectified by the fixed blades to swirl, thereby classifying the pulverized material.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-1055

[0005] In a separator with a classifying rotor as described above, the pulverized material is classified into fine and coarse powders by balancing the centrifugal force generated by the rotation of the classifying rotor with the attractive force generated by the inward airflow passing through the classifying rotor towards the center of rotation. Therefore, the non-uniformity (i.e., flow deviation) of the inward airflow velocity in the classifying rotor affects the classification performance of the separator. Summary of the Invention

[0006] This disclosure was made in view of the above circumstances, and its purpose is to improve the non-uniformity of the inward airflow velocity in the classifying rotor of the separator in a vertical roller mill.

[0007] To address the aforementioned issues, one embodiment of the vertical roller mill disclosed herein includes: a rotary table; a crushing roller disposed on the upper surface of the rotary table; a separator disposed above the rotary table, comprising a classifying rotor rotating about a rotor shaft extending in a vertical direction and guide vanes disposed around the classifying rotor, for classifying the crushed material transported by a gas flow after being crushed by the rotary table and the crushing roller; and a mill housing housing the rotary table, the crushing roller, and the separator, having an exhaust port disposed above the separator, wherein the guide vanes comprise multiple layers of guide vanes in the vertical direction, the multiple layers of guide vanes comprising: a first layer of guide vanes having first layer guide vanes arranged in a ring around the classifying rotor about the rotor shaft; and a second layer of guide vanes having second layer guide vanes arranged in a ring around the classifying rotor about the rotor shaft, wherein the cross-sectional area of ​​the gas passing through the first layer of guide vanes is smaller than the cross-sectional area of ​​the gas passing through the second layer of guide vanes.

[0008] According to this disclosure, it is possible to improve the non-uniformity of the inward airflow velocity in the staged rotor of the separator in a vertical roller mill. Attached Figure Description

[0009] Figure 1 This is a diagram illustrating a schematic structure of a vertical roller mill according to one embodiment of the present disclosure.

[0010] Figure 2 This diagram illustrates the support structure of the guide wing.

[0011] Figure 3 It is a graph showing the distribution of inward gas velocity in the vertical direction of the staged surface of the staged rotor.

[0012] Figure 4 This is a diagram showing the upper and lower guide wing arrays of the first example from above.

[0013] Figure 5 This is a diagram showing the upper and lower guide wing arrays of the modified example 1 from above.

[0014] Figure 6 This is a diagram showing the upper and lower guide wing arrays of the modified example 2 from above.

[0015] Label Explanation

[0016] 1: Vertical roller mill; 2: Rotary worktable; 3: Crushing roller; 7: Mill casing; 9: Separator; 71: Mill outlet (exhaust port); 91: Stager rotor; 92: Guide vane; 94: Rotor shaft; 96: Upper guide vane (an example of the first layer of guide vanes); 96C: Upper guide vane array (an example of the first layer of guide vanes); 96C: Guide vane array; 97: Lower guide vane (an example of the second layer of guide vanes); 97C: Lower guide vane array (an example of the second layer of guide vanes); 97C: Guide vane array. Detailed Implementation

[0017] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

[0018] [Simplified structure of vertical roller mill 1]

[0019] Figure 1 This is a diagram illustrating a schematic structure of a vertical roller mill 1 according to one embodiment of the present disclosure. Figure 1 As shown, the vertical roller mill 1 has a rotating worktable 2, crushing rollers 3 rolling on the upper surface of the rotating worktable 2, and a separator 9 disposed above the rotating worktable 2. The rotating worktable 2, the multiple crushing rollers 3, and the separator 9 are covered by the mill housing 7.

[0020] The rotary table 2 is driven to rotate about a vertical axis of rotation passing through its center by a table drive unit 5. The table drive unit 5 includes a mill motor 51 and a reducer 52 that amplifies the rotational torque of the mill motor 51 and transmits it to the rotary table 2. Raw materials are supplied to the upper surface of the rotary table 2 through a raw material feed chute 8. The inlet of the raw material feed chute 8 is located outside the mill housing 7, and raw materials are metered into the inlet of the raw material feed chute 8 by a feeder 14.

[0021] A ring-shaped or annular hot air outlet is provided between the outer periphery of the rotary table 2 and the mill housing 7. A hot air inlet 72, located below the rotary table 2, is connected to a hot air source via piping or the like. Hot air supplied from the hot air source to the hot air inlet 72 is blown upwards from the hot air outlet.

[0022] Multiple crushing rollers 3 are arranged at equal angular intervals on a circumferential track centered on the rotation axis of the rotary table 2. Figure 1 The example shows two of a plurality of crushing rollers 3. The plurality of crushing rollers 3 are elastically pressed onto the rotary table 2 by roller pressing devices 4 having a drive source such as a hydraulic cylinder.

[0023] A funnel-shaped internal cone 11 is disposed above the rotary table 2. The outlet of the internal cone 11 is located above the center of the rotary table 2. Inside the mill housing 7, a separator 9 is disposed above the internal cone 11.

[0024] Separator 9 classifies the pulverized material, which is transported by the airflow along with the blown hot air, into fine powder and coarse powder. The construction of separator 9 will be described in detail later.

[0025] A mill outlet 71, serving as the exhaust port for the mill housing 7, is provided above the separator 9. An exhaust passage 31 is connected to the mill outlet 71. A collection device 33 is provided in the exhaust passage 31 to collect the pulverized material accompanying the mill exhaust. The collection device 33 can be, for example, a bag filter or a cyclone separator. Additionally, an exhaust fan 34 is provided in the exhaust passage 31. The flow rate of the mill exhaust can be adjusted by varying the rotational speed of this exhaust fan.

[0026] Next, the crushing operation of the vertical roller mill 1 with the above-described structure will be explained. Multiple crushing rollers 3 are driven by the rotation of the rotary table 2 and roll on the rotary table 2. Furthermore, when raw material is supplied to approximately the center of the rotary table 2 via the raw material feeding chute 8, the raw material moves towards the outer edge of the rotary table 2 due to centrifugal force driven by the rotation of the rotary table 2, and is bitten between the rotary table 2 and the crushing rollers 3 and crushed.

[0027] The pulverized material moves further toward the outer edge of the rotating table 2 due to centrifugal force, is dried by the hot air blown from around the rotating table 2, and is transported upwards by the airflow. In addition, pulverized material, gravel, metal fragments, and other spillages that are not on the hot airflow fall from the outer periphery of the rotating table 2 and are recovered due to centrifugal force.

[0028] The pulverized material rising within the mill casing 7, accompanied by the flow of hot air, is separated into coarse and fine particles by the separator 9. The fine particles separated by the separator 9 are conveyed to the mill outlet 71 by the airflow and flow out through the exhaust path 31. The fine particles flowing out of the exhaust path 31 are separated from the airflow by the collection device 33 and are recovered as product. On the other hand, the coarse particles separated by the separator 9 slide down in the inner cone 11 and return to the rotary table 2, where they are pulverized again along with the raw material.

[0029] [Structure of Separator 9]

[0030] Here, the structure of the separator 9 will be described in detail. The separator 9 has a staged rotor 91, guide vanes 92 disposed on the outer periphery of the staged rotor 91, and a separator drive device 93 for rotating the staged rotor 91.

[0031] The stage rotor 91 has a rotor shaft 94 and a rotor blade array 98C consisting of multiple rotating blades 98 arranged in a ring around the rotor shaft 94. The rotor shaft 94 hangs down from the upper part of the mill housing 7 and is supported by the mill housing 7 to be rotatable. The rotor shaft 94 and the rotor blade array 98C are connected by a rim 95, and the rotor blade array 98C rotates integrally with the rotor shaft 94. The separator drive unit 93 is disposed outside the mill housing 7. The separator drive unit 93 includes a stage motor M and a power transmission mechanism that transmits the rotation of the stage motor M to the rotor shaft 94. Driven by the stage motor M, the rotor shaft 94, i.e., the stage rotor 91, rotates.

[0032] The guide vane 92 has multiple guide vanes 96C and 97C in the vertical direction, including the upper guide vane 96C and the lower guide vane 97C. The guide vane 92 of this embodiment has two layers of guide vanes 96C and 97C, but in addition to the upper guide vane 96C and the lower guide vane 97C, more than one layer of guide vanes may be configured.

[0033] The upper guide wing array 96C consists of multiple upper guide wings 96 arranged in a ring around the rotor shaft 94. The wing angle of the upper guide wings 96 is variable. Similarly, the lower guide wing array 97C consists of multiple lower guide wings 97 arranged in a ring around the rotor shaft 94. The wing angle of the lower guide wings 97 is variable. Here, the wing angle refers to the inclination of the chord line of the guide wings 96 and 97 relative to the radial direction centered on the rotor shaft 94 (i.e., the radial direction of the guide wing arrays 96C and 97C).

[0034] The wing angles of multiple upper guide vanes 96 can be the same or different. The wing angles of multiple lower guide vanes 97 can be the same or different. Furthermore, if the rotor 98 has a vertically segmented structure, and there is a deviation in the wing angles of the rotor 98 in the rotor train 98C, the rotational balance of the staged rotor 91 may collapse. However, since the operating guide vanes 96 and 97 are stationary, even if there is a deviation in the wing angles of the guide vanes 96 and 97 in the guide trains 96C and 97C, the aforementioned problem will not occur.

[0035] When the number of divisions is two, the vertical dimension of the upper guide wing 96 is smaller than the vertical dimension of the lower guide wing 97. The vertical dimension of the upper guide wing 96 is preferably less than 1 / 2 of the vertical dimension of the guide vane 92, and more preferably less than 1 / 3.

[0036] Figure 2 This diagram illustrates the support structure of the upper guide wing 96 and the lower guide wing 97. Figure 2The diagram shows a set of upper guide wing 96 and lower guide wing 97 support structures, but other upper guide wing 96 and lower guide wing 97 also have the same support structures.

[0037] like Figure 2 As shown, the upper guide vane 96 and the lower guide vane 97 are supported on the mill housing 7. The inner cylinder 82 penetrates the mill housing 7, and the support shaft 81 is rotatably inserted through the inner cylinder 82. The support shaft 81 is longer than the inner cylinder 82, and the support shaft 81 extends upward and downward beyond the inner cylinder 82.

[0038] The lower part of the inner cylinder 82 and the portion of the support shaft 81 that extends downward beyond the inner cylinder 82 are exposed inside the mill housing 7. Inside the mill housing 7, an upper guide wing 96 is fixed to the inner cylinder 82, and a lower guide wing 97 is fixed to the support shaft 81.

[0039] An outer cylinder 83 is fixed to the outer surface of the mill housing 7, and an inner cylinder 82 is rotatably inserted into the outer cylinder 83. An upper guide plate 86 is fixed to the upper end of the outer cylinder 83. The inner cylinder 82 extends upward from the outer cylinder 83 beyond the upper guide plate 86, and an upper rod 84 is fixed to this extended portion of the inner cylinder 82. An arc-shaped guide hole 86a is provided in the upper guide plate 86 to guide and restrict the rotation of the upper rod 84. A bolt 88 passing through the upper rod 84 can move within the guide hole 86a. A lower guide plate 87 is disposed above the upper guide plate 86 via a support body. The upper end of a support shaft 81 extends upward from the inner cylinder 82 beyond the lower guide plate 87, and a lower rod 85 is fixed to this extended portion of the support shaft 81. A guide hole 87a is provided in the lower guide plate 87 to guide and restrict the rotation of the lower rod 85. The bolt 89 passing through the lower rod 85 can move within the guide hole 87a of the lower guide plate 87.

[0040] When the upper rod 84 is rotated, the inner cylinder 82 rotates relative to the support shaft 81. The upper guide wing 96, fixed to the inner cylinder 82, rotates around the support shaft 81, changing its wing angle. The upper rod 84 is secured to the upper guide plate 86 using bolts 88 and nuts, thereby fixing the wing angle of the upper guide wing 96. Similarly, when the lower rod 85 is rotated, the support shaft 81 rotates relative to the inner cylinder 82. The lower guide wing 97, fixed to the support shaft 81, rotates around the support shaft 81, changing its wing angle. The lower rod 85 is secured to the lower guide plate 87 using bolts 89 and nuts, thereby fixing the wing angle of the lower guide wing 97.

[0041] In separator 9, the wing angles of each upper guide wing 96 of upper guide wing column 96C and the wing angles of each lower guide wing 97 of lower guide wing column 97C are adjusted before operation or preset during construction of vertical roller mill 1.

[0042] In separator 9, all upper guide vanes 96 and lower guide vanes 97 have equal wing angles. CFD analysis (numerical fluid dynamics analysis) of the airflow flowing into separator 9 is performed under the condition that the upper guide vanes 96 and lower guide vanes 97 are regarded as a single guide vane. The results show that the gas flow is concentrated in the upper part of separator 9 due to the exhaust from the mill outlet 71 located above separator 9, and the gas flow is concentrated in the upper part of separator 9 due to the centrifugal force caused by the abrupt change in direction of the gas flow at the inlet of separator 9 from upward to lateral towards the center of the stage rotor 91.

[0043] Figure 3 This is a graph showing the distribution of inward gas velocity in the vertical direction of the stage surface S of the stage rotor 91. The stage surface S of the stage rotor 91 is the outer peripheral surface of the rotating blade array 98C. The vertical axis of the graph represents the vertical position in the stage surface S, and the horizontal axis represents the inward gas velocity in the stage surface S. The inward gas velocity refers to the speed of the gas flowing laterally from the stage surface S of the stage rotor 91 towards the center of rotation. In this graph, the relationship between the vertical position of the stage surface S and the inward gas velocity when all the upper guide vanes 96 and lower guide vanes 97 have equal airfoil angles and are considered as a single guide vane is shown as a "comparative example" using a dashed line. Furthermore, the relationship between the vertical position of the stage surface S and the inward gas velocity when the vertical dimensions of the upper guide vanes 96 and lower guide vanes 97 are set to a 1:1 ratio is shown as an "exemplary example" using a solid line. In the comparative example, the gas flow is concentrated in the upper part of the separator 9. As a result, the gas flow is concentrated in the upper part of the classifying rotor 91, and the inward gas velocity in the classifying surface S of the classifying rotor 91 becomes uneven in the vertical direction. Specifically, in the comparative example, the inward gas velocity in the upper part of the classifying surface S of the classifying rotor 91 is greater than the inward gas velocity in the lower part of the classifying surface S, and there is a localized portion in the upper part of the classifying surface S where the inward gas velocity is greater than in other parts.

[0044] The grading diameter of the separator 9 is adjusted by the rotational speed and airflow of the grading rotor 91. Conventionally, when there is a deviation in the inward gas velocity in the grading surface S of the grading rotor 91, the grading rotor 91 is rotated at a speed matching the larger value of the inward gas velocity. Therefore, when there is a deviation in the inward gas velocity in the grading surface S of the grading rotor 91, the energy required to rotate the grading rotor 91 increases, and proper grading cannot be performed in the grading surface S with an inward gas velocity that does not match the rotational speed of the grading rotor 91, resulting in reduced grading efficiency. Therefore, in the separator 9 of this disclosure, the guide vanes 92 are configured in multiple layers in the vertical direction, including the upper guide vane 96C and the lower guide vane 97C, with the gas passage cross-sectional area of ​​the upper guide vane 96C being smaller than that of the lower guide vane 97C. The gas passage cross-sectional area of ​​the upper guide wing array 96C is the sum of the cross-sectional areas of the passages between adjacent upper guide wings 96, and the cross-sectional area of ​​each passage can be the smallest cross-sectional area in that passage. Similarly, the gas passage cross-sectional area of ​​the lower guide wing array 97C is the sum of the cross-sectional areas of the passages between adjacent lower guide wings 97, and the cross-sectional area of ​​each passage can be the smallest cross-sectional area in that passage.

[0045] As described above, when the gas passage cross-sectional area of ​​the upper guide vane 96C is smaller than that of the lower guide vane 97C, the gas flows more actively to the lower guide vane 97C compared to the upper guide vane 96C. In other words, because the gas passage cross-sectional area of ​​the upper guide vane 96C is smaller than that of the lower guide vane 97C, the upper guide vane 96C significantly impedes the flow of gas toward the staged rotor 91 compared to the lower guide vane 97C. Consequently, the amount of gas passing through the upper part of the guide vane 92 decreases, while the amount of gas passing through the lower part of the guide vane 92 increases. Therefore, as in Figure 3 As shown by the solid line, the vertical deviation of the inward gas velocity in the grading surface S of the grading rotor 91 is reduced, and the unevenness of the inward gas velocity in the grading surface S of the grading rotor 91 is mitigated.

[0046] Figure 4 This is a diagram showing the upper guide wing array 96C and the lower guide wing array 97C of Example 1 from above. Figure 4 In the example shown, the upper guide wing 96 and the lower guide wing 97 have different wing angles. The upper guide wing 96 has a larger wing angle compared to the lower guide wing 97. Therefore, the inter-wing passage of the upper guide wing 96 is narrower than that of the lower guide wing 97. Consequently, the gas passage cross-sectional area of ​​the upper guide wing array 96C is smaller than that of the lower guide wing array 97C. Furthermore, the wing angles of all the upper guide wings 96 can also be different. For example, they can also be as follows: Figure 5As shown in the modified example, a portion of the wing angle of the upper guide wing 96 is the same as the installation angle of the lower guide wing 97, while the remaining portion has a larger wing angle than the lower guide wing 97. Additionally, a portion of the inter-wing passageway of the upper guide wing array 96C can be closed or reduced.

[0047] exist Figure 4 and Figure 5 In the example shown, the average value of the wing angles of the multiple upper guide vanes 96 of the upper guide vane column 96C is greater than the average value of the wing angles of the multiple lower guide vanes 97 of the lower guide vane column 97C. Thus, by narrowing the inter-wing passage of the upper guide vane column 96C, the flow path cross-sectional area of ​​the upper guide vane column 96C is reduced, hindering the flow of gas passing through the upper guide vane column 96C. Therefore, the gas flow concentrates in the lower guide vane column 97C. Moreover, in the gas flow passing through the lower guide vane column 97C, an upward force is exerted by the attraction force generated at the mill outlet 71, and the gas flow is dispersed in the vertical direction of the classification surface S of the classification rotor 91. As a result, the vertical deviation of the inward gas velocity in the classification surface S of the classification rotor 91 is reduced, and the non-uniformity of the inward gas velocity in the classification surface S of the classification rotor 91 is mitigated.

[0048] However, due to the circumferential position of the mill outlet 71 and the presence of components that impede gas flow, there are sometimes circumferential deviations or locally larger areas in the inward gas velocity of the staged rotor 91's staged surface S. In cases where there is a circumferentially concentrated flow deviation R1, the angle of the lower guide vane 97 is adjusted so that it significantly impedes the gas flow toward the circumferentially concentrated flow deviation R1 in the staged rotor 91 compared to other areas within the guide vane 92. Here, in addition to the lower guide vane 97, the angle of the upper guide vane 96 can also be adjusted.

[0049] Figure 6 This is a diagram showing the upper guide wing array 96C and the lower guide wing array 97C of the second example from above. Figure 6 In the example shown, the lower guide vane 97 of the circumferentially deflecting section R1 has a larger vane angle than the other lower guide vanes 97, thus closing or narrowing the passage between the lower guide vanes 97 of the deflecting section R1. In this way, in the lower guide vane array 97C, by making the vane angle of the lower guide vane 97 of the deflecting section R1 larger than the other lower guide vanes 97, the flow of gas through the deflecting section R1 is hindered. As a result, the circumferential deviation of the inward gas velocity in the staged surface S of the staged rotor 91 is reduced.

[0050] Furthermore, in the separator 9 of the vertical roller mill 1 of the present invention, the blade angles of both the upper guide vane 96 and the lower guide vane 97 are variable, but it is also possible that the blade angle of at least one of the upper guide vane 96 and the lower guide vane 97 is variable. For example, the upper guide vane 96 and the lower guide vane 97 may also be fixed blade angles. Alternatively, for example, the blade angle of the upper guide vane 96 may be variable, while the blade angle of the lower guide vane 97 may be fixed. In the case of using a fixed blade angle, the inward gas velocity of the stage surface S of the stage rotor 91 (where the function of the guide vane 92 is omitted) is predicted in advance by simulation, and the fixed blade angle of the upper guide vane 96 and the lower guide vane 97 is determined based on the predicted non-uniformity of the inward gas velocity, thereby fixing the upper guide vane 96 and the lower guide vane 97 to the mill housing 7 in a manner that achieves the fixed blade angle.

[0051] 〔Summarize〕

[0052] The vertical roller mill 1 of the first item of this disclosure includes: a rotary table 2; a crushing roller 3 disposed on the upper surface of the rotary table 2; a separator 9 disposed above the rotary table 2, comprising a classifying rotor 91 rotating around a rotor shaft 94 extending in the vertical direction and guide vanes 92 disposed around the classifying rotor 91, for classifying the crushed material transported by the flow of gas after being crushed by the rotary table 2 and the crushing roller 3; and a mill housing 7 housing the rotary table 2, the crushing roller 3 and the separator 9, having an exhaust port disposed above the separator 9, the guide vanes 92 comprising multiple layers of guide vanes 96C, 97C in the vertical direction. The multi-layer guide vane arrays 96C and 97C include: a first-layer guide vane array (equivalent to the upper guide vane array 96C in the above embodiment), which has first-layer guide vanes (equivalent to the upper guide vane 96 in the above embodiment) arranged in a ring around the stage rotor 91 with the rotor shaft 94 as the center; and a second-layer guide vane array (equivalent to the lower guide vane array 97C in the above embodiment), which has second-layer guide vanes (equivalent to the lower guide vane 97 in the above embodiment) arranged in a ring around the stage rotor 91 with the rotor shaft 94 as the center, wherein the gas passage cross-sectional area in the first-layer guide vane array is smaller than the gas passage cross-sectional area in the second-layer guide vane array.

[0053] In the vertical roller mill 1 with the above-described structure, the gas flow through the first layer of guide vanes 92 is more obstructed than the gas flow through the second layer of guide vanes, thus concentrating the gas flow through the guide vanes 92 into the second layer of guide vanes. In this way, by utilizing the different sizes of the inter-vane passages of the guide vanes, the vertical deviation of the inward gas velocity in the grading surface S of the grading rotor 91 can be reduced. Therefore, according to the vertical roller mill 1 of this disclosure, the non-uniformity of the inward airflow velocity in the grading rotor 91 of the separator 9 can be improved.

[0054] The vertical roller mill 1 of the second item of this disclosure is based on the vertical roller mill 1 of the first item, wherein the first layer of guide vanes 96C is located above the second layer of guide vanes 97C.

[0055] According to the above structure of the vertical roller mill 1, the gas passing through the guide vane 92 diffuses upward due to the attraction of the mill outlet 71, resulting in a reduction in the vertical deviation of the inward gas flow velocity in the grading surface S of the grading rotor 91.

[0056] The vertical roller mill 1 of the third item of this disclosure is based on the vertical roller mill 1 of the first or second item, wherein the average value of the wing angle of the first layer guide wing 96 of the first layer guide wing row 96C is greater than the average value of the wing angle of the second layer guide wing 97 of the second layer guide wing row 97C.

[0057] In the vertical roller mill 1 of Project 3, by adjusting the wing angle of the first layer guide vane 96, it is possible to make the cross-sectional area of ​​the gas passing through the first layer guide vane column 96C smaller than the cross-sectional area of ​​the gas passing through the second layer guide vane column 97C.

[0058] The vertical roller mill 1 of the fourth item of this disclosure is based on the vertical roller mill 1 of any one of the first to third items, wherein the vertical dimension of the first layer guide vane 96C is smaller than the vertical dimension of the second layer guide vane 97C.

[0059] In the vertical roller mill 1 of the fourth item, the vertical proportion occupied by the first layer of guide vanes 96C in the guide vanes 92 can be suppressed. Since the passage of gas is restricted in the first layer of guide vanes 96C, it is preferable that the vertical dimension of the first layer of guide vanes 96 is smaller if the local increase in inward gas velocity can be suppressed.

[0060] The vertical roller mill 1 of the fifth item of this disclosure, according to any one of the vertical roller mills 1 of items 1 to 4, wherein the wing angle of at least one of the first layer guide vane 96 and the second layer guide vane 97 is variable.

[0061] In the vertical roller mill 1 of Project 5, the gas passage cross-sectional area of ​​the first guide vane 96C and the gas passage cross-sectional area of ​​the lower guide vane 97C can be adjusted after the separator 9 is installed. Therefore, the gas passage cross-sectional areas of the first guide vane 96C and the second guide vane 97C can be adjusted according to the operating conditions of the vertical roller mill 1.

[0062] The foregoing discussion of this disclosure is for illustrative purposes and is not intended to limit this disclosure to the manner disclosed in this specification. For example, in the foregoing detailed description, various features of this disclosure are summarized into one embodiment for the purpose of rationalizing this disclosure, but several of the multiple features may also be combined. In addition, the multiple features included in this disclosure may also be combined with alternative embodiments, structures, or methods other than those discussed above.

Claims

1. A vertical roller mill, comprising: Rotary worktable; A crushing roller is disposed on the upper surface of the rotary table; A separator, disposed above the rotary table, includes a grading rotor that rotates around a rotor shaft extending in the vertical direction and guide vanes disposed around the grading rotor, for grading the pulverized material transported by the flow of gas after being pulverized by the rotary table and the pulverizing roller. as well as The mill housing, which houses the rotary table, the crushing roller, and the separator, has an exhaust port positioned above the separator. The guide vanes comprise multiple layers of guide vanes in the vertical direction. The multi-layered guide wing array includes: The first layer of guide vanes has first layer guide vanes arranged in a ring around the staged rotor with the rotor shaft as the center; as well as The second layer of guide vanes has second-layer guide vanes arranged in a ring around the staged rotor with the rotor shaft as the center. The cross-sectional area through which the gas passes in the first layer of guide wing array is smaller than that of the gas in the second layer of guide wing array.

2. The vertical roller mill according to claim 1, wherein, The first layer of guide wing array is located above the second layer of guide wing array.

3. The vertical roller mill according to claim 1, wherein, The average wing angle of the first layer of the first layer of the guide wing is greater than the average wing angle of the second layer of the second layer of the guide wing.

4. The vertical roller mill according to any one of claims 1 to 3, wherein, The vertical dimension of the first layer of guide wing array is smaller than the vertical dimension of the second layer of guide wing array.

5. The vertical roller mill according to any one of claims 1 to 3, wherein, The wing angle of at least one of the first-layer guide wing and the second-layer guide wing is variable.

Images