KR20220118554A - Roller mill unit and method of retrofitting roller mill unit - Google Patents

Abstract

A roller mill device according to an embodiment includes a table liner rotatable about a driving axis and a roller rotatable about a roller axis, and is pressed toward a grinding surface of the table liner to form a space between the table liner and the grinding surface. A roller mill apparatus having a roller configured to pulverize a pulverized object, wherein an outer peripheral surface of the roller is formed in a curved shape convex toward the pulverized face in a state of being pressed toward the pulverized face, and the pulverized face is flat a flat surface portion formed in a shape, and a curved surface portion formed in a curved shape concave toward the outer peripheral surface of the roller in a state of being pressed toward the grinding surface, wherein the curved surface portion passes through a central position in the width direction of the roller, , is formed in a range including at least a first position that is an intersection of a center line orthogonal to the roller axis and the grinding surface.

Description

Roller mill unit and method of retrofitting roller mill unit

The present disclosure relates to a roller mill apparatus and a method of retrofitting the roller mill apparatus.

BACKGROUND ART A roller mill apparatus is used in a boiler, a coal gasification combined cycle power plant, or the like, for fine pulverization of coal or petroleum coke, or pulverization of a biomass raw material. Moreover, it is widely used in the grinding|pulverization of a cement material, cement clinker, etc. in a cement manufacturing plant. A roller mill apparatus is a plant apparatus which grind|pulverizes, dry, classifies, and conveys an object to be pulverized. A crushing unit is constituted by a roller and a table, and the crushing object formed in a layer shape on a rotating table is pressed with a driven rotating roller, thereby generating a compressive force and a shearing force in the crushing object to pulverize the crushing object.

As the wear of rollers and table liners progresses, performance degradation occurs, such as an increase in the differential pressure between the inlet and outlet of the conveying air, which is based on an increase in electric power and a decrease in the crushing ability, so regular inspection and maintenance are required. . In Patent Document 1, by remodeling the outer circumferential surface of a conical roller whose outer circumferential surface is a truncated cone shape into a curved shape (tire type), the contact surface pressure between the outer circumferential surface of the roller and the grinding surface formed by the table top surface is equalized, and the wear resistance of the grinding surface is improved. What can be improved is described.

Reduction of the time and cost required for the maintenance of rollers and table surfaces is an important subject since it is related to an operating rate. Rollers can be repaired in a relatively short period of time by replacing and installing the rollers. However, for table side repairs, when replacing the table liner provided on the table top, removing or reinstalling the table liner by means such as cutting or fusing is not necessary. , since it is necessary to re-planarize the surface of the table base material on which the table liner is mounted so that a gap with the table liner does not occur, the air becomes long and expensive. Then, in patent document 2, the proposal of reducing the frequency of maintenance and replacement of a table liner is made by making the shape of the outer peripheral surface of a roller and a table surface into a shape which can suppress abrasion of a table liner rather than the outer peripheral surface of a roller.

Japanese Patent No. 4101709 Publication Japanese Patent Publication No. 6469343

When a roller having a truncated conical outer peripheral surface is replaced with a roller having a curved surface, it is considered that the grinding performance is improved by making the grinding surface of the table also a curved surface matching the curved surface of the roller. In this case, as described above, since the replacement of the table liner requires air for a long time and high cost, it is necessary to secure air capable of simultaneously performing replacement and mounting of the roller and the table liner. Instead of replacing and mounting the table liner, as described in Patent Document 1, it is also conceivable to form a curved surface by overlay welding over the entire grinding surface, but to realize a curved surface over the entire grinding surface For this purpose, there is a problem that a large number of pasting welding materials and a long pasting operation are required.

The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a roller mill device capable of limiting the range of forming a curved portion on the crushing surface of a table to the minimum required range while ensuring crushing performance. .

In order to achieve the above object, a roller mill device according to the present disclosure is a table liner rotatable about a driving axis, and a roller rotatable about a roller axis, wherein the A roller mill apparatus comprising a roller configured to pulverize a pulverized object between a pulverized surface, and an outer peripheral surface of the roller is formed in a curved shape convex toward the pulverized face in a state pressed toward the pulverized face, The grinding surface includes a flat surface portion formed in a flat shape, and a curved surface portion formed in a curved shape concave toward the outer circumferential surface of the roller in a state of being pressed toward the crushing surface, wherein the curved surface portion is in the width direction of the roller It is formed in the range including at least the 1st position which is the intersection point of the said grinding|pulverization surface and the center line which passes through the center position of the said roller and is orthogonal to the said roller axis line. In addition, in this specification, the "pulverized surface of the table liner" refers to a table surface in a range facing the outer peripheral surface of the roller in a state of being pressed toward the table liner among the table surfaces formed on the upper surface of the table liner.

Further, the method for retrofitting the roller mill apparatus according to the present disclosure is a table liner rotatable about a driving axis, and a roller rotatable about a roller axis, and the grinding surface is pressed against the grinding surface of the table liner. A method of remodeling a roller mill device having a roller configured to pulverize a pulverized object between the sieves, wherein the outer peripheral surface of the roller is formed in a curved shape convex toward the pulverized face in a state pressed toward the pulverized face, , The grinding surface includes a flat surface portion formed in a flat shape, and a curved surface portion formed in a curved shape concave toward the outer peripheral surface of the roller in a state of being pressed toward the crushing surface, the remodeling method of the roller mill apparatus, In a range including at least a first position that passes through a central position in the width direction of the roller and is orthogonal to the roller axis and a center line that is orthogonal to the roller axis, and a first position that is an intersection point of the crushing surface, the curved surface is formed by overlay welding A patch welding step is provided.

According to the roller mill apparatus according to the present disclosure, the grinding surface of the table liner includes a flat surface and a curved portion, and the curved portion is formed in a range including at least the first range on the grinding surface. For this reason, the range in which a curved-surface part is formed can be limited to the minimum required range, ensuring grinding|pulverization performance. Thereby, the air and cost required for formation of a curved part can be suppressed to the minimum. Further, according to the remodeling method of the roller mill apparatus, in addition to the above-mentioned effects, since the curved surface portion is formed by overlay welding, replacement of the table liner is not required. Accordingly, it is possible to shorten the period required for remodeling and reduce the cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic longitudinal sectional view of the roller mill apparatus which concerns on one Embodiment.
Fig. 2 is a schematic longitudinal cross-sectional view partially enlarged of the roller mill apparatus according to the embodiment.
3 is a schematic longitudinal cross-sectional view partially enlarged of the roller mill device according to the embodiment.
4 is a process diagram of a method for remodeling a roller mill apparatus according to an embodiment.
5 is a graph showing the pulverization efficiency of a pulverized surface according to an embodiment and a comparative example.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to an accompanying drawing, some embodiment of this invention is described. However, the dimensions, materials, shapes, and their relative arrangements, etc. of the components described in these embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, and are merely illustrative examples.

For example, expressions indicating a relative or absolute arrangement such as “in any direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly It is assumed that not only the arrangement is indicated, but also the state in which the tolerance is relatively displaced with an angle or distance sufficient to obtain the same function.

For example, expressions indicating that things are in an equivalent state, such as "same", "equal" and "homogeneous", not only indicate a strictly equivalent state, but also have a tolerance or a difference to the extent that the same function is obtained. It shall also indicate the state of existence.

For example, expressions indicating a shape such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in a geometrically strict sense, but also include irregularities and chamfers within the range where the same effect is obtained. It is assumed that the shape is also indicated.

On the other hand, expressions such as "having", "having", "having", "including", or "having" one component are not exclusive expressions except for the presence of other components.

(The overall configuration of the roller mill unit)

BRIEF DESCRIPTION OF THE DRAWINGS It relates to one Embodiment which applied the roller mill apparatus to the coal grinder, It is a schematic longitudinal sectional view which shows the whole structure of this coal grinder. The coal grinder 10 includes a housing 12, a coal supply pipe 14, a table 16, at least one roller 18, a primary air supply duct 20, a rotary classifier 22 and a pulverized coal discharge pipe ( 24) is provided. The coal supply pipe 14 penetrates into the inside of the housing 12 from the upper direction of the housing 12, and is comprised so that coal as a grinding|pulverization object may be supplied to the upper surface of the table 16. As shown in FIG. The table 16 is arranged inside the housing 12 . And the table 16 is rotatably supported centering on _the drive axis line A1 by the rotation shaft 26 arrange|positioned in the perpendicular direction.

In embodiment shown in FIG. 1, the some roller 18 is arrange|positioned above the table 16, and opposes the table 16, and is arrange|positioned at fixed intervals in the circumferential direction of the table 16. The roller 18 is configured to be able to press the crushed surface formed on the upper surface of the table 16 by its own weight or a pressing device (not shown). The pressing device applies a force for the roller 18 to press the grinding surface via the rotation shaft 19 of the roller 18 . The roller 18 is driven by the grinding surface formed on the upper surface of the table 16 rotating about the driving axis _{A 1} , and is located at the axial center of the rotating shaft 19 . rotate The coal supplied from the coal supply pipe 14 is grind|pulverized between the roller 18 and this grinding|pulverization surface, and turns into pulverized coal.

The primary air supply duct 20 supplies primary air from the side surface of the housing 12 of the lower part of the table 16 and the lower part of the table 16 to the outer peripheral side of the table 16 . An air outlet 28 is provided on the outer peripheral side of the table 16 , and the primary air supplied from the primary air supply duct 20 rises through the air outlet 28 . The pulverized coal manufactured by the table 16 and the roller 18 is conveyed by the primary air which rises from the air outlet 28. As shown in FIG. A drift plate 30 is provided above the air outlet 28 , and the primary air blown out from the air outlet 28 is given a turning force by the drift plate 30 . The primary air to which the swirling force is given by the drift plate 30 becomes an airflow indicated by an arrow in FIG. 1 , and conveys the pulverized coal to the rotary classifier 22 above the housing 12 . In addition, among the pulverized coals mixed with primary air, those having a large particle size fall without reaching the rotary classifier 22 due to their own weight, and return to the table 16 again.

The rotary classifier 22 includes a blade 32 that rotates about the central axis of the housing 12 . The pulverized coal that has reached the rotary classifier 22 together with the primary air balances the centrifugal force imparted by the rotating blade 32 and the centrifugal force flowing into the rotary classifier 22 from the outer periphery of the blade 32 . Accordingly, only the pulverized coal having a small particle size flows into the inner side of the blade 32 , and flows out from the pulverized coal discharge pipe 24 . The pulverized coal discharge pipe 24 communicates with a flow path (not shown) connected to a pulverized coal boiler (not shown).

(Configuration of crushing unit including table and roller)

2 and 3 are partially enlarged longitudinal cross-sectional views each including a table 16 and a roller 18 and showing an embodiment of a pulverizing unit that pulverizes coal as a pulverization object. The table 16 includes a table body 40 , a table liner 42 , a wedge ring 44 , a dam ring 48 , and the like. The table main body 40 is rotatably supported by the rotating shaft 26. As shown in FIG. The table main body 40 has a circular dish shape, and the upper surface of the table main body 40 comprises the inclined surface 40a which inclines so that it may become high as it goes toward the outer peripheral side.

The table liner 42 has, for example, an annular shape, and is provided on the inclined surface 40a so as to face the roller 18 . The table main body 40 has an annular weir part 41 protruding upward in the inclined surface 40a (outer peripheral side than the table liner 42). The outer periphery of the table liner 42 is inserted and fixed in a recess formed between the table main body 40 and the weir 41 . The coal loaded on the table liner 42 is pulverized between the table liner 42 and the roller 18 . The table liner 42 is used as a replaceable consumable, since it is abraded by the pulverization of coal.

The wedge ring 44 has, for example, an annular shape, and is provided along the inner periphery of the table liner 42 so as to press the inner periphery of the table liner 42 against the table body 40 . The wedge ring 44 is fixed to the rotation shaft 26 by a bolt 46 .

The dam ring 48 is fixed to the upper surface of the weir 41, pulverized by the roller 18 and the table liner 42, and the pulverized coal extruded on the table liner 42 on the outer periphery side of the roller 18. Forms a storage space for storage. The pulverized coal stored in the storage space is pulverized several times by the roller 18 and pulverized to a predetermined particle size.

In this way, the table surface St is formed in the upper surface of the table liner 42, and the coal supplied to the center side area|region of the table surface St from the coal supply pipe 14 is rotated by the table main body 40. Since the centrifugal force toward the outer peripheral side of the table main body 40 acts, it moves to the outer peripheral side gradually. And it arrives at the grinding|pulverization surface Sg. In addition, in this specification, the grinding|pulverization surface Sg says the range which faces the outer peripheral surface of the roller 18 of the state pressed toward the table surface St among the table surfaces St. The coal which has reached the pulverized surface Sg is pressed between the roller 18 and the pulverized surface Sg and pulverized. In Figs. 2 and 3, m denotes an object to be pulverized (coal) deposited on the table surface St in a layered form.

2 and 3, the outer peripheral surface 18a of the roller 18 is a curved surface shape convex toward the grinding surface Sg in a state in which the roller 18 is pressed toward the grinding surface Sg. is formed with The pulverized surface Sg includes flat surface portions 50 ( 50a , 50b , 50c , 50d ) formed in a flat shape, and curved surface portions 52 ( 52a , 52b ). The curved-surface part 52 is formed in the curved-surface shape concave toward the outer peripheral surface 18a of the roller 18 in the state pressed toward the grinding|pulverization surface Sg. In this figure, the line Lc is a center line which passes through the center position in the width direction of the roller ₁₈ , and is orthogonal to roller axis line A2. The curved-surface part 52 is formed in the range which includes at least the 1st position P ₁ which is the intersection of the center line Lc and the grinding|pulverization surface Sg. As the material of the curved portion 52, for example, a wear-resistant material having high strength and toughness is used.

Since the first position P ₁ is a central position in the width direction of the roller 18 when the roller 18 is pressed toward the grinding surface Sg, it is large with respect to the grinding object between the curved surface portion 52 and the grinding surface Sg. It is considered to be within the range where the load occurs. Therefore, by forming the curved portion 52 to include at least the first position P ₁ , it is possible to secure the minimum crushing performance and to limit the formation range of the curved portion 52 to the minimum necessary. Therefore, it is possible to minimize the amount of air and cost required for forming the curved portion 52 .

In one embodiment, in FIGS. 2 and 3 , the outer peripheral surface 18a in contact with the curved portion 52 and the surface of the curved portion 52 in contact with the outer peripheral surface 18a form a curved surface having the same radius of curvature. do. As a result, a uniform load can be applied to the object to be pulverized over the entire area of the contact surface between the outer circumferential surface 18a and the curved portion 52, so that it is possible to improve the pulverization performance of the object to be pulverized.

In one embodiment, as shown in FIGS. 2 and 3 , when the roller 18 is pressed toward the grinding surface Sg, the outer peripheral surface 18a of the roller 18 is the At a position different from the first position P ₁ in the width direction, it has the most protruding end 54 at the position furthest from the roller axis A ₂ . And, the curved surface portions 52 (52a, 52b), from at least the first position (P ₁ ) to the second position (P ₂ ) on the grinding surface (Sg) at a position facing the most protruding end (54) It is formed to include the first range (R ₁ ) up to.

The load applied to the crushing object by the outer peripheral surface 18a and the crushing surface Sg of the roller 18 is considered to be greatest at the second position P ₂ . Therefore, it is considered that the load applied to the crushing object is greatest in the first range R ₁ including the first position P ₁ and the second position P ₂ . According to this embodiment, since the curved portion 52 is formed to include at least the first range R ₁ , it is possible to increase the pulverization performance of the object to be pulverized. On the other hand, since the formation of the curved-surface portion 52 is limited to the first range R ₁ , it is possible to suppress the air and cost required for the formation of the curved-surface portion 52 .

In one embodiment, as shown in FIGS. 2 and 3 , the second position P ₂ on the grinding surface Sg facing the most protruding end 54 of the roller outer peripheral surface 18a is the first position ( It is located on the outer peripheral side of P ₁ ). Therefore, the load applied to the crushing object between the roller outer peripheral surface 18a and the crushing surface Sg increases outside the first position P ₁ in the radial direction of the table 16 . Therefore, when the crushing object m is supplied to the center side of the table 16 and directed toward the peripheral side of the table 16 through the crushing surface Sg, the crushing object m rather than the first position P ₁ . Since it is possible to increase the load on the crushing object m on the outer peripheral side in the traveling direction of Therefore, it can grind|pulverize with a predetermined particle diameter with high precision.

In one embodiment, as shown in FIG. 2 and FIG. 3, among the outer peripheral surfaces 18a of the roller 18, the area|region outside the 1st position P ₁ of the table 16 in the radial direction is a center line ( Lc) located outside the first center of curvature (C ₁ ) It is formed in a circular arc as a center. And, the most protruding end 54 is formed at a second position P ₂ where a straight line L ₁ parallel to the center line Lc passes through the first center of curvature C ₁ and intersects the grinding surface Sg. . Moreover, the outer peripheral surface 18a of the radial direction inner side of the table 16 is formed in the arc centering on the _2nd center of curvature C2 on the centerline Lc rather than the _1st position P1. And, the radius of curvature r2 of the arc centered on the second center of curvature C ₂ is greater than the radius of curvature r1 of the arc centered on the first center of curvature C ₁ .

According to this embodiment, the load which generate|occur|produces in the grinding|pulverization surface Sg can form the load distribution which increases toward the outside from the radial direction inner side of the table 16. As shown in FIG. As a result, the object to be pulverized is pulverized so that the grain size is gradually reduced from the inside to the outer side of the pulverization surface Sg, so that it can be pulverized with high precision to a predetermined grain size. Moreover, since r1<r2, the clearance gap between the roller outer peripheral surface 18a and the grinding|pulverization surface Sg in the outer peripheral side area|region of the grinding|pulverization surface Sg becomes wide. Thereby, discharge to the outer peripheral side of the crushing object m is performed smoothly.

In one embodiment, as shown in FIGS. 2 and 3 , on the pulverization surface Sg, the curved surface part 52 is formed on the inner peripheral side of the second range R ₂ rather than the first range R ₁ . ) is included. According to this embodiment, since the curved portion 52 extends more in the inner peripheral side than the first range R ₁ in the radial direction of the table 16, it is possible to further improve the crushing performance with respect to the crushing object.

In one embodiment, as shown in FIG. 3 , the curved surface portions 52 and 52b have a third range R ₃ formed on the outer periphery side of the pulverized surface Sg rather than the first range R ₁ . contains more According to this embodiment, since the curved portions 52 and 52b forming the grinding surface Sg extend outward and in the radial direction of the table 16, the grinding performance of the grinding object can be further improved. .

In one embodiment, as shown in FIG. 2 and FIG. 3, in the area|region of the grinding|pulverization surface Sg, the flat surface part 50 on both sides of the table 16 of the curved-surface part 52 (52a, 52b) in the radial direction. ) (50a to 50d). The flat surface portions 50 ( 50a , 50c ) are outer peripheral flat surface portions located on the radially outer peripheral side of the table 16 rather than the curved surface portion 52 , and the flat surface portions 50 , 50b and 50d are the curved surface portions 52 . ) is an inner peripheral-side flat surface portion located on the radially inner peripheral side of the table 16 . In this way, since the flat surface portions 50 are provided on both sides of the table 16 in the radial direction in the area of the grinding surface Sg, the formation area of the curved surface portion 52 can be limited, and the The air and cost required for formation can be suppressed.

In one embodiment, as shown in FIG. 2, the grinding|pulverization surface Sg is the outer peripheral side further than _1st range R1 from the radial direction outer peripheral edge of the table 16 of _1st range R1. The inclined surface portion 56 is formed in the range up to the formed flat surface portions 50 and 50a. According to this embodiment, since the inclined surface portion 56 is formed, the strength of the outer peripheral region of the curved portion 52 (52a) can be increased.

In one embodiment, as shown in FIG. 3, the grinding|pulverization surface Sg is the outer peripheral side further than _3rd range R3 from the radial direction outer peripheral edge of the table 16 of _3rd range R3. The inclined surface portion 56 is formed in the range up to the formed flat surface portions 50 and 50c. According to this embodiment, since the inclined surface part 56 is formed, the intensity|strength of the outer peripheral area|region of the curved-surface part 52 (52b) can be raised. In addition, in the embodiment shown in FIGS. 2 and 3, the angle θ of the inclined surface portion 56 with respect to the grinding surface Sg is appropriately selected in consideration of the strength of the curved surface portions 52 (52a, 52b). do.

In one embodiment, when the roller 18 is in a state pressed toward the grinding surface Sg, the third position ( Let P ₃ ) be 0%, and the 4th position P ₄ on the grinding|pulverization surface Sg which exists in the position facing the base end surface 18c of the roller 18 shall be 100 %. At this time, the curved surface portions 52 (52a, 52b) are formed to cover at least 40 to 60% of the range. That is, the curved-surface part 52 is formed in the whole area of 40 to 60% of range. According to this embodiment, since the curved portion 52 is formed to include the above range, it is possible to exhibit the minimum necessary grinding performance for the object to be pulverized.

In one embodiment, as shown in FIGS. 2 and 3 , the third position P ₃ is a point at which a straight line on the tip surface 18b of the roller 18 intersects the grinding surface Sg, and the fourth The position P ₄ is a point at which the straight line on the base end surface 18c of the roller 18 intersects the grinding surface Sg.

In one embodiment, the curved portion 52 is formed to cover a range of 30 to 70%. That is, the curved surface part 52 is formed in the whole area of 30 to 70% of range. As a result, since the curved portion 52 is formed in a wider range, it is possible to further increase the pulverization performance of the pulverized object.

In one embodiment, the curved portion 52 is formed to cover a range of 20 to 80%. That is, the curved-surface part 52 is formed in the whole area of 20 to 80% of range. Thereby, since the curved part 52 is formed in a wider range, the grinding|pulverization performance of the grinding|pulverization object can be improved further.

In one embodiment, the curved-surface portions 52 ( 52a , 52b ) include a reinforcement-welded portion formed on the flat-surface portion 50 by reinforcement welding. According to this embodiment, since the curved-surface part 52 is formed by adding welding, replacement and mounting of the table liner 42 is not required. Therefore, the period required for the remodeling can be shortened and the remodeling cost can be reduced.

Moreover, the remodeling method of the roller mill apparatus which concerns on one Embodiment is demonstrated below. As shown in FIG. 1, for example, the remodeling method which concerns on this embodiment is provided in the rotatable table 16 centering|focusing on the drive axis line A ₁ , The table liner which forms the grinding|pulverization surface Sg. (42) and the coal grinder 10 provided with the roller ₁₈ rotatable centering on the roller axis A2 is made into object. In the coal pulverizer 10, the roller 18 is pressed toward the pulverized face Sg formed on the table face St of the table liner 42 to pulverize the pulverized object between the pulverized face Sg and the pulverized face Sg. Consists of. The outer circumferential surface 18a of the roller 18 is formed in a curved shape convex toward the grinding surface Sg in a state in which the roller 18 is pressed toward the grinding surface Sg.

The remodeling method for the coal pulverizer 10, as shown in FIG. 4, with respect to the table surface (St) of the flat surface shape, at least the first position (P ₁ ) The curved surface portion 52 in a range including the first position (P 1 ) A layer-up welding step formed by layer-up welding is provided (step S12). Accordingly, with respect to the outer circumferential surface 18a of the curved roller, the formation of the curved portion 52 can be suppressed to the minimum range capable of ensuring the pulverization performance, so that the air and cost required for the formation of the curved portion 52 can be reduced. can be minimized. In addition, since the curved surface portion 52 is formed by gluing welding, replacement of the table liner 42 is not required, and the period required for remodeling and cost can be reduced. In addition, the remodeling method which concerns on this embodiment is not limited to the coal grinder 10, Another roller mill apparatus may be sufficient.

In addition, when the remodeling target is a conical roller whose pressing surface is a truncated cone, as shown in FIG. 4 , as a pre-process of the overlay welding step S12, the conical roller is applied to the curved outer circumferential surface 18a. A step (step S10) of replacing and attaching the roller 18 having the roller 18 is performed.

Fig. 5 shows the results of verifying the mill power ratio and the circulating particle pressure differential in the mill when combining three types of rollers and table liners in a coal pulverizer. Combinations (a) and (b) are the verification results of the comparative example, and the combination (c) is the verification result according to the present embodiment. Combination (a) is a combination in which both the outer peripheral surface of the roller and the upper surface of the table liner are flat, and the combination (b) is a combination in which the outer peripheral surface of the roller has the same curved shape as the outer peripheral surface 18a and the upper surface of the table liner is flat. Combination (c) is a combination in which the outer peripheral surface of the roller has the same curved shape as the outer peripheral surface 18a and the grinding surface Sg has the curved portion 52 .

The mill power ratio (dimensionless number) is the ratio of the mill power of each combination (b) and (c) when the mill power of the combination (a) is 1, and the larger the mill power ratio, the lower the grinding performance, and the mill power ratio It shows that the grinding|pulverization performance is so high that is small. The differential pressure of circulating particles in the mill is the differential pressure between the primary air pressure in the primary air supply duct 20 and the primary air pressure in the pulverized coal discharge pipe 24 in FIG. is a ratio of the differential pressure of each combination (b) and (c) in the case where the differential pressure of the combination (a) is set to 1. It has shown that the primary air pressure in the primary air supply duct 20 becomes large, so that this value is large. That is, it has shown that the primary air pressure in the primary air supply duct 20 becomes large, so that the residual amount of the pulverized coal on the table liner 42 is large, and the grinding|pulverization performance is low.

From Fig. 5 , the combination (b) shows that both the mill power ratio and the intramill circulating particle differential pressure ratio increase compared to the combination (a), whereas the combination (c) shows a value almost equal to that of the combination (a). From this, it can be seen that the combination (b) has a reduced pulverization efficiency, whereas the combination (c) maintains a pulverization efficiency substantially equal to that of the combination (a).

The contents described in each of the above embodiments are grasped as follows, for example.

1) A roller mill device according to an aspect is a table 16 rotatable about a drive axis A ₁ , and a roller rotatable about a roller axis A ₂ , and a grinding surface of the table ( It is a roller mill apparatus 10 having a roller 18 configured to pulverize the pulverized object m between the pulverized surface Sg by being pressed toward Sg, wherein the outer peripheral surface 18a of the roller comprises: The grinding surface Sg is formed in a convex curved shape toward the grinding surface Sg in a state pressed toward the grinding surface Sg, and the grinding surface Sg is formed in a flat surface portion 50 (50a, 50b, 50c) in a flat shape. , 50d)) and a curved surface portion 52 (52a, 52b) formed in a curved shape concave toward the outer peripheral surface 18a of the roller 18 in a state of being pressed toward the grinding surface Sg); The said curved-surface part 50 passes through the center position in the width direction of the said roller 18, and the intersection of the center line Lc and the said grinding|pulverization surface Sg orthogonal to _the said roller axis line A2. It is formed in the range which includes at least the phosphorus 1st position P ₁ .

According to this configuration, the grinding surface of the table includes a flat surface and a curved portion, and the curved portion is formed in a range including at least the first position on the grinding surface. For this reason, the range in which a curved-surface part is formed can be limited to the minimum required range, ensuring grinding|pulverization performance. Thereby, the air and cost required for formation of a curved part can be suppressed to the minimum.

2) The roller mill apparatus according to another aspect is the roller mill apparatus according to 1), wherein the curved surface portion 52 is pressed from the first position P ₁ toward the grinding surface Sg. A second position P ₂ on the grinding surface Sg at a position facing the most protruding end 54 at a position farthest from the roller axis A ₂ among the outer peripheral surface 18a of the roller 18 ) up to and including at least the first range (R ₁ ).

According to this configuration, since the construction range of the curved portion reaches from the first position to the second position facing the most protruding end of the roller to which the maximum load is applied from the table crushing surface, the crushing performance for the crushing object can be improved. While there is, since formation of a curved-surface part is limited to a 1st range, the air and cost required for formation of a curved-surface part can be suppressed.

3) The roller mill apparatus according to another aspect is the roller mill apparatus according to 2), wherein the second position P ₂ is at the outer periphery of the grinding surface Sg rather than the first position P ₁ . located on the side

According to this configuration, since the second position is located on the outer peripheral side of the grinding surface than the first position, the load generated between the roller and the grinding surface increases outside the first position in the radial direction of the table. Thereby, when the object to be crushed is supplied to the center side of the table and directed toward the peripheral side of the table through the crushing surface, the load on the object to be crushed on the downstream side in the traveling direction of the object to be crushed can be increased, so that the object to be crushed has a predetermined particle size. can be crushed with high precision.

4) The roller mill apparatus according to another aspect is the roller mill apparatus according to 3), wherein the curved surface portion 52 is located on the inner peripheral side of the grinding surface Sg rather than the first range R ₁ . A second range (R ₂ ) formed is included.

According to this configuration, since the curved portion extends more toward the inner peripheral side than the first range, it is possible to further improve the grinding performance of the object to be pulverized.

5) The roller mill apparatus according to another aspect is the roller mill apparatus according to 3) or 4), wherein the curved surface portion 52 is greater in the grinding surface Sg than the first range R ₁ . It includes a third range (R ₃ ) formed on the outer peripheral side.

According to this configuration, since the curved portion extends more toward the outer periphery than the first range, pulverization performance can be further improved.

6) The roller mill apparatus according to another aspect is the roller mill apparatus according to 5), wherein the grinding surface Sg is from the outer peripheral end of the third range R ₃ , than the third range R ₃ . It further includes an inclined surface portion 56 formed in a range up to the flat surface 50 (50a, 50c) formed on the outer peripheral side.

According to this configuration, since the inclined surface portion is further included, the strength of the outer peripheral region of the curved surface portion can be increased.

7) A roller mill device according to another aspect is the roller mill device according to any one of 1) to 6), wherein the tip surface 18b of the roller 18 is pressed toward the grinding surface Sg; The pulverization at a position facing the proximal end face 18c of the roller 18 in a state of being pressed toward the pulverization face Sg with the position on the pulverization surface Sg at the facing position being 0% When the position on the surface Sg is 100%, the curved surface portion 52 is formed so as to cover at least 40% or more and 60% or less of the range.

According to this configuration, since the curved portion is formed to include the above range, it is possible to ensure the minimum pulverization performance of the pulverized object.

8) A roller mill device according to another aspect is the roller mill device according to any one of 1) to 7), wherein the curved surface portion 52 includes a reinforcement welding portion formed on the flat surface portion by reinforcement welding. do.

According to such a structure, since a curved-surface part is formed by adding welding, replacement|exchange attachment of a table liner is not required. Accordingly, it is possible to shorten the period required for remodeling and reduce the cost.

9) A method for retrofitting a roller mill device according to an aspect is a table liner (42) rotatable about a driving axis, and a roller rotatable about a roller axis (A ₂ ), the table liner (42) A method of retrofitting a roller mill apparatus comprising a roller (18) configured to pulverize an object (m) to be pulverized between the pulverized surface (52) by being pressed toward the pulverization surface (Sg) of the roller (18) The outer circumferential surface 18a of the is formed in a curved shape convex toward the crushing surface Sg in a state pressed toward the crushing surface Sg, and the crushing surface Sg is a flat surface portion ( 50), and a curved portion 52 formed in a curved shape concave toward the outer peripheral surface 18a of the roller 18 in a state of being pressed toward the grinding surface Sg, wherein the method of remodeling the roller mill apparatus A _first position ( In a range including at least P ₁ ), a reinforcement welding step S12 in which the curved surface portion 52 is formed by reinforcement welding is provided.

According to such a configuration, with respect to the outer circumferential surface of the curved roller, the formation of the curved portion can be limited to the minimum range in which the grinding performance can be ensured, so that the time and cost required for the formation of the curved portion can be minimized. In addition, since the curved portion is formed by gluing welding, replacement of the table liner is not required. Accordingly, it is possible to shorten the period required for remodeling and reduce the cost.

10: coal grinder
12: housing
14: coal supply pipe
16: table
18: roller
18a: outer periphery
18b: front end
18c: proximal section
19, 26: axis of rotation
20: primary air supply duct
22: rotary classifier
24: pulverized coal discharge pipe
28: air vent
30: drift plate
32: blade
40: table body
40a: slope
41: Dukbu
42: table liner
44: wedge ring
46: bolt
48: dam ring
50 (50a, 50b, 50c, 50d): flat surface part
52 (52a, 52b): curved portion
54: most protruding end
56: inclined surface part
A ₁ : drive axis
A ₂ : Roller axis
C ₁ : center of first curvature
C ₂ : second center of curvature
Lc: center line
P ₁ : first position
P ₂ : second position
P ₃ : 3rd position
P ₄ : 4th position
R ₁ : first range
R ₂ : second range
R ₃ : third range
Sg: crushed side
St: table surface
m: object to be pulverized (object to be pulverized)

Claims (9)

a table liner rotatable about a drive axis;
a roller rotatable about a roller axis, the roller configured to pulverize a pulverized object between the table liner and the pulverized surface by being pressed toward the pulverizing surface of the table liner;
It is a roller mill device provided with,
The outer peripheral surface of the roller is formed in a curved shape convex toward the grinding surface in a state pressed toward the grinding surface,
The grinding surface is
A flat surface portion formed in a flat shape;
and a curved portion formed in a curved shape concave toward the outer peripheral surface of the roller in a state of being pressed toward the grinding surface,
The curved surface portion is formed in a range including at least a first position that passes through a central position in the width direction of the roller and is an intersection of a center line orthogonal to the roller axis line and the grinding surface,
roller mill device. According to claim 1, wherein the curved portion,
from the first position to a second position on the grinding surface at a position facing the most protruding end farthest from the roller axis among the outer peripheral surfaces of the roller in a state of being pressed toward the grinding surface at least comprising the first range,
roller mill device. The method according to claim 2, wherein the second position is located on the outer peripheral side of the grinding surface than the first position,
roller mill device. The method according to claim 3, wherein the curved portion includes a second range formed on the inner peripheral side of the pulverized surface rather than the first range.
roller mill device. The said curved-surface part includes the 3rd range formed in the outer peripheral side in the said grinding|pulverization surface rather than the said 1st range,
roller mill device. The method according to claim 5, wherein the grinding surface further includes an inclined surface portion formed in a range from the outer peripheral edge of the third range to the flat surface formed on the outer peripheral side of the third range,
roller mill device. The position on the grinding surface according to any one of claims 1 to 6, wherein the position on the grinding surface at a position facing the front end surface of the roller in a state of being pressed toward the grinding surface is 0%,
When the position on the grinding surface at a position facing the base end surface of the roller in a state of being pressed toward the grinding surface is 100%,
The curved portion is formed to include at least 40% or more and 60% or less of the range,
roller mill device. 8. The method according to any one of claims 1 to 7, wherein the curved surface portion comprises a reinforcement welded portion formed on the flat surface portion by reinforcement welding.
roller mill device. a table liner rotatable about a drive axis;
a roller rotatable about a roller axis, the roller configured to pulverize a pulverized object between the table liner and the pulverized surface by being pressed toward the pulverizing surface of the table liner;
A method of remodeling a roller mill device comprising:
The outer peripheral surface of the roller is formed in a curved shape convex toward the grinding surface in a state pressed toward the grinding surface,
The grinding surface is
A flat surface portion formed in a flat shape;
and a curved portion formed in a curved shape concave toward the outer peripheral surface of the roller in a state of being pressed toward the grinding surface,
The remodeling method of the roller mill apparatus includes at least a first position that passes through a central position in the width direction of the roller and is orthogonal to the roller axis line and a first position that is an intersection point of the grinding surface, A layer-up welding step of forming the curved surface portion by layer-by-layer welding is provided;
A method of retrofitting a roller mill unit.

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