JP2011245372A - Vertical mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the crushing efficiency of a vertical mill by way of efficiently crushing solid matter such as biomass.SOLUTION: A crushing table 13 is rotatably supported by a rotary shaft disposed in the vertical direction in a housing 11. A rotatable crushing roller 18 linked to the rotation of the crushing table 13 is disposed to face the upper side of the crushing table 13, and is driven/rotated by a roller driver 19, which is controlled by a controller 41 to make the rotation rate of the crushing roller 18 adjustable so as to make the peripheral speed thereof different from that of the crushing table 13.

Description

  The present invention relates to a vertical mill for pulverizing and pulverizing solids such as biomass.

In combustion facilities such as boiler power generation, fossil fuels such as coal and heavy oil are often used as fuel, but this fossil fuel causes global warming due to the problem of CO ₂ emission. Therefore, as an alternative to fossil fuels, the use of fuel using biomass is being promoted. Biomass is an organic substance resulting from photosynthesis, and includes wood, vegetation, agricultural crops, and moss. One method of using this biomass as a fuel is to pulverize and pulverize biomass solids and supply it to a pulverized coal-fired boiler for use as a fuel. This is known as a single pulverization method in which coal and biomass are separately pulverized, and a mixed pulverization method in which coal and biomass are mixed and then pulverized. In any system, a biomass crusher for crushing biomass solids is required.

  In this case, the coal was pulverized using a vertical roller mill. However, since the biomass solid has elasticity, the pulverization is worse than coal, and the vertical roller mill for coal has a predetermined size. It is difficult to grind. Therefore, conventionally, a biomass solid is pulverized using a pulverizer such as a hammer mill or a cutter mill. However, the method of pulverizing biomass solids using a hammer mill, cutter mill, etc. requires a great deal of power and not only deteriorates the pulverization efficiency but also shortens the service life and requires maintenance in a short period of time. Have difficulty.

  In addition, the following patent documents etc. are proposed as a biomass grinding | pulverization apparatus using a vertical mill. For example, the biomass pulverization apparatus described in Patent Document 1 pulverizes biomass solids supplied on a rotation-driven pulverization table by a roller that operates in conjunction with the rotation of the table, and blows up from below. The biomass pulverized product is conveyed upward by an air current and classified into coarse powder and fine powder. Moreover, the biomass crushing apparatus described in Patent Document 2 is based on the distance between the roller and the table, so that the pressing force of the roller and the rotation speed of the table are within a certain range that promotes the mutual grinding between the biomass chips. Is to control.

JP 2009-291692 A JP 2008-043926 A

  However, the biomass solids are fibrous and soft, and it is difficult to efficiently pulverize the biomass solids only with the compressive force of the roller, which requires a lot of power and time, and the pulverization efficiency is not good. There is.

  This invention solves the subject mentioned above, and aims at providing the vertical mill which can improve a grinding | pulverization efficiency by grind | pulverizing solids, such as biomass, efficiently.

  In order to achieve the above object, a vertical mill of the present invention is disposed in a housing so as to be opposed to the upper side of the crushing table supported by the crushing table so as to be driven to rotate with a rotation axis along the vertical direction. And a roller speed adjustment mechanism capable of adjusting the rotation speed of the crushing roller so as to have a peripheral speed different from the peripheral speed of the crushing table. is there.

  Therefore, when the crushing table is driven and rotated, and solids such as biomass are supplied onto the crushing table, the solids move outward by centrifugal force, enter between the crushing table and the crushing roller, and crush. The solid material is pulverized by rotating the pulverizing roller by the rotation of the table. At this time, the rotational speed of the pulverizing roller is adjusted by the roller speed adjusting mechanism, so that the solid material acts on the solid material to promote the pulverization. Therefore, it is possible to improve the pulverization efficiency by efficiently pulverizing solids such as biomass.

  In the vertical mill of the present invention, the roller speed adjusting mechanism includes a braking / driving device that applies a driving force or a braking force to the crushing roller.

  Therefore, when the braking / driving device applies driving force or braking force to the grinding roller, the circumferential speed of the grinding roller and the circumferential speed of the grinding table are different, and the shearing force acts on the solid material to improve the grinding efficiency. can do.

  In the vertical mill of the present invention, the roller speed adjusting mechanism has a driving device that applies a driving force to the crushing roller, and the driving device has a peripheral speed of the crushing roller higher than a peripheral speed of the crushing table. Thus, the rotational speed of the crushing roller can be adjusted.

  Therefore, by adjusting the drive device so that the peripheral speed of the grinding roller is faster than the peripheral speed of the grinding table, it becomes easier for the solid matter to bite between the grinding roller and the grinding table, improving the solid grinding efficiency. can do.

  In the vertical mill of the present invention, the roller speed adjusting mechanism has an electric motor that drives and rotates the crushing roller.

  Therefore, the circumferential speed of the grinding roller and the circumferential speed of the grinding table can be easily made different.

  The vertical mill of the present invention is characterized in that the electric motor is capable of regenerative braking.

  Therefore, by applying a regenerative brake to the crushing roller, the heat energy can be converted into electric energy by the electric motor and collected, and the collected electric power can be used effectively.

  According to the vertical mill of the present invention, the pulverization roller is disposed above the pulverization table, and the pulverization roller can be adjusted so as to be different from the peripheral speed of the pulverization table by the roller speed adjustment mechanism. It is possible to improve the pulverization efficiency by efficiently pulverizing the solid matter such as.

FIG. 1 is a front view showing a crushing roller and a driving device thereof in a vertical mill according to Embodiment 1 of the present invention. FIG. 2 is a schematic configuration diagram illustrating the vertical mill of the first embodiment. FIG. 3 is a front view illustrating a crushing roller and a driving device thereof in a vertical mill according to Embodiment 2 of the present invention.

  Exemplary embodiments of a vertical mill according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example.

  FIG. 1 is a front view illustrating a crushing roller and a driving device thereof in a vertical mill according to a first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram illustrating the vertical mill according to the first embodiment.

  The vertical mill of Example 1 grinds solids such as biomass. Here, the biomass is an organic resource derived from a renewable organism. Examples include thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuel (pellets and chips) made from these materials, and are not limited to those presented here. In addition, the vertical mill of a present Example is not limited to what grind | pulverizes biomass solid substance, It can also grind | pulverize coal and the mixture of biomass solid substance and coal.

  In the vertical mill of the present embodiment, as shown in FIGS. 1 and 2, the housing 11 has a cylindrical hollow shape, and a biomass supply pipe 12 is mounted on the top. This biomass supply pipe 12 supplies biomass solids into the housing 11 from a biomass supply device (not shown), and is arranged in the center position of the housing 11 along the vertical direction (vertical direction), with the lower end portion extending downward. It is extended.

  The housing 11 has a crushing table 13 disposed at the bottom. The crushing table 13 is disposed at the center position of the housing 11 so as to face the lower end of the biomass supply pipe 12. Further, the crushing table 13 is connected to a lower portion of a rotating shaft 14 having a rotation axis along the vertical direction, and is rotatably supported by the housing 11. A worm wheel 15 as a drive gear is fixed to the rotary shaft 14, and a worm gear 16 of a drive motor (not shown) mounted on the housing 11 is engaged with the worm wheel 15. Therefore, the crushing table 13 can be driven to rotate by the drive motor via the worm gear 16, the worm wheel 15, and the rotating shaft 14.

  The crushing table 13 has a ring-shaped table liner 17 fixed to the outer peripheral side. The table liner 17 has an inclined surface whose surface (upper surface) becomes higher as it goes to the outer peripheral side of the crushing table 13. A plurality of crushing rollers 18 are arranged facing the upper side of the crushing table 13 (table liner 17), and a roller driving device 19 for driving and rotating each crushing roller 18 is provided. The roller driving device 19 is, for example, a motor, and can apply a driving force to the crushing roller 18.

  That is, the rear end portion of the support shaft 21 is supported by the roller drive device 19, and the roller drive device 19 is supported by the mounting shaft 22 on the side wall portion of the housing 11, so that the front end portion of the support shaft 21 is vertically moved. It can swing in the direction. The support shaft 21 is disposed such that the tip portion faces the direction of the rotation axis of the crushing table 13 and is inclined downward, and the crushing roller 18 is mounted.

  Further, the roller driving device 19 (support shaft 21) is provided with an upper arm 24 extending upward, and the tip of a pressing rod 26 of a hydraulic cylinder 25 serving as a pressing device fixed to the housing 11 is connected to the upper arm 24. Connected to the tip. The roller driving device 19 (support shaft 21) is provided with a lower arm 27 extending downward, and a tip portion thereof can come into contact with a stopper 28 fixed to the housing 11. Therefore, when the pressing rod 26 is advanced by the hydraulic cylinder 25, the upper arm 24 is pressed, and the roller driving device 19 and the support shaft 21 can be rotated clockwise in FIG. . At this time, when the lower arm 27 abuts against the stopper 28, the rotational positions of the roller driving device 19 and the support shaft 21 are defined.

  That is, the crushing roller 18 crushes the biomass solids with the crushing table 13 (table liner 17), and a predetermined amount is provided between the surface of the crushing roller 18 and the surface of the crushing table 13 (table liner 17). It is necessary to secure a gap. Therefore, by defining the support shaft 21 at a predetermined rotational position by the hydraulic cylinder 25, a predetermined gap between the surface of the pulverizing roller 18 and the surface of the pulverizing table 13 for taking in and pulverizing the biomass solids is provided. Secured.

  In this case, when the crushing table 13 rotates, the biomass solids supplied onto the crushing table 13 are moved to the outer peripheral side by the centrifugal force and enter between the crushing roller 18 and the crushing table 13. Since the crushing roller 18 is pressed toward the crushing table 13, the rotational force of the crushing table 13 is transmitted through the biomass solids, and the crushing roller 18 rotates in conjunction with the rotation of the crushing table 13. Can do.

  In the present embodiment, the crushing roller 18 has a truncated cone shape with a small diameter on the tip side and the surface of the crushing roller 18 is flat. However, the present invention is not limited to this shape. For example, the grinding roller 18 may have a tire shape. In the present embodiment, a plurality of (three) crushing rollers 18 are provided and arranged at equal intervals along the rotation direction of the crushing table 13. In this case, the number and arrangement of the crushing rollers 18 may be appropriately set according to the size of the crushing table 13, the crushing roller 18, and the like.

  In the first embodiment, the control device 41 that controls the roller driving device 19 serves as a roller speed adjustment mechanism that can adjust the rotation speed of each grinding roller 18 so that the circumferential speed is different from the circumferential speed of the grinding table 13. Is provided. In addition, a detector 42 that detects the rotation speed of the crushing table 13 is provided, and this detector 42 outputs the detection result to the control device 41. The control device 41 adjusts the rotational speed of the grinding roller 18 by the roller driving device 19 based on the rotational speed of the grinding table 13.

  Specifically, the control device 41 calculates the peripheral speed at the position where the pulverizing roller 18 faces based on the rotational speed of the pulverizing table 13 detected by the detector 42, and the peripheral speed of the pulverizing roller 18 is determined by the pulverizing table 13. The rotational speed of the grinding roller 18 is set by controlling the driving of the roller driving device 19 so as to be different from the peripheral speed.

  In this case, it is desirable that the control device 41 sets the rotational speed of the grinding roller 18 by the roller driving device 19 so that the circumferential speed of the grinding roller 18 is slightly higher than the circumferential speed of the grinding table 13.

  The housing 11 is provided with an inlet port 31 at the lower part located on the outer periphery of the crushing table 13 and into which primary air is fed. Further, the housing 11 is provided with an outlet port 32 for discharging the pulverized biomass located on the outer periphery of the biomass supply pipe 12 at the top. The housing 11 is provided with a rotary separator 33 as a classification device for classifying the pulverized biomass below the outlet port 32. The rotary separator 33 is provided on the outer periphery of the biomass supply pipe 12 and can be driven and rotated by a driving device 34. In addition, the housing 11 is provided with a foreign matter discharge pipe 35 at the bottom. The foreign matter discharge pipe 35 is configured to drop and discharge foreign matters (spillage) such as gravel and metal pieces mixed in the biomass solid matter from the outer peripheral portion of the crushing table 13.

  When the solid material such as biomass is supplied from the biomass supply pipe 12 into the housing 11 in the vertical mill of Example 1 configured as described above, the solid material falls in the biomass supply pipe 12, It is supplied to the central part on the crushing table 13. At this time, since the crushing table 13 is rotating at a predetermined speed, the solid material supplied to the central portion on the crushing table 13 moves so as to be dispersed in all directions due to the centrifugal force. A certain layer is formed on the entire surface of 13. That is, solid matter such as biomass enters between the grinding roller 18 and the grinding table 13.

  Then, the rotational force of the crushing table 13 is transmitted to the crushing roller 18 through solid matter such as biomass, and the crushing roller 18 rotates with the rotation of the crushing table 13. At this time, since the crushing roller 18 is pressed and supported on the crushing table 13 side by the hydraulic cylinder 25, the crushing roller 18 presses and crushes this solid matter while rotating.

  At this time, the control device 41 drives and controls the roller driving device 19 based on the rotation speed of the crushing table 13 detected by the detector 42 to set the rotation speed of the crushing roller 18. Specifically, the control device 41 adjusts the rotation speed of the crushing roller 18 so that the peripheral speed of the crushing roller 18 is slightly faster than the peripheral speed of the crushing table 13. Therefore, a speed difference is generated between the pulverizing roller 18 and the pulverizing table 13, and a shearing force is applied to the solid matter. The pulverizing roller 18 presses and cuts the solid matter while rotating, thereby improving the efficiency. It can be crushed well.

  The solid matter pulverized by the pulverization roller 18 rises while being dried by the primary air sent into the housing 11 from the inlet port 31. The raised pulverized solid matter is classified by the rotary separator 33, and the coarse powder drops and is returned to the pulverization table 13 again to be pulverized again. On the other hand, the fine-grained powder passes through the rotary separator 33, rides on the air current, and is discharged from the outlet port 32. Further, spillage such as gravel and metal pieces mixed in solid matter such as biomass falls outward from the outer peripheral portion by the centrifugal force of the crushing table 13 and is discharged by the foreign matter discharge pipe 35.

  As described above, in the vertical mill of the first embodiment, the crushing table 13 is supported in the housing 11 so as to be capable of driving and rotating with a rotation axis along the vertical direction, and the crushing table 13 is crushed facing the upper side of the crushing table 13. A crushing roller 18 that can rotate in conjunction with the rotation of the table 13 is arranged, and the crushing roller 18 can be driven and rotated by a roller driving device 19, and the crushing table 13 is controlled by controlling the roller driving device 19 by a controller 41. The rotational speed of the grinding roller 18 can be adjusted so that the peripheral speed is different from the peripheral speed.

  Therefore, when the crushing table 13 is driven to rotate and solid matter such as biomass is supplied onto the crushing table 13, the solid matter moves outward due to centrifugal force, and between the crushing table 13 and the crushing roller 18. Get in. Then, the solid material is pulverized by rotating the pulverizing roller 18 by the rotation of the pulverizing table 13, and at this time, the rotational speed of the pulverizing roller 18 is adjusted by the control device 41 so that a shearing force acts on the solid material. The pulverization is promoted, and the pulverization efficiency can be improved by efficiently pulverizing solids such as biomass.

  In this case, by applying a roller driving device 19 that applies a driving force to the crushing roller 18 as a roller speed adjusting mechanism, the roller driving device 19 applies a driving force to the crushing roller 18 and the peripheral speed of the crushing roller 18 is increased. The peripheral speed of the pulverizing table 13 is different from that of the pulverizing table 13, so that the shearing force acts on the solid matter and the pulverizing efficiency can be improved.

  The control device 41 adjusts the rotational speed of the grinding roller 18 by the roller driving device 19 so that the circumferential speed of the grinding roller 18 is faster than the circumferential speed of the grinding table 13. Therefore, it becomes easy for the solid matter to bite between the pulverization roller 18 and the pulverization table 13, and the pulverization efficiency of the solid matter can be improved.

  In the first embodiment, the control device 41 adjusts the rotational speed of the crushing roller 18 by the roller driving device 19 so that the peripheral speed of the crushing roller 18 is faster than the peripheral speed of the crushing table 13. The rotational speed of the grinding roller 18 may be adjusted by the roller driving device 19 so that the circumferential speed of 18 is slightly slower than the circumferential speed of the grinding table 13. Further, the control device 41 may adjust the rotation direction of the crushing roller 18 by the roller driving device 19 so that the rotation direction of the crushing roller 18 is opposite to the rotation direction of the crushing table 13. Further, since the rotational force of the pulverizing table 13 is transmitted through the solid material and rotates at substantially the same speed, the pulverizing roller 18 applies a braking force (braking force) to the pulverizing roller 18 as a roller speed adjusting mechanism. Even if the roller braking device is applied and adjusted so that the peripheral speed of the crushing roller 18 and the peripheral speed of the crushing table 13 are different, that is, the peripheral speed of the crushing roller 18 is slower than the peripheral speed of the crushing table 13. Good.

  FIG. 3 is a front view illustrating a crushing roller and a driving device thereof in a vertical mill according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In the vertical mill of the second embodiment, as shown in FIG. 3, a plurality of pulverizing rollers 18 are arranged above the pulverizing table 13 (table liner 17), and each pulverizing roller 18 is driven by a roller driving device 19. The drive can be rotated. The roller driving device 19 is a motor generator, which can function as an electric motor and can function as a generator.

  That is, the roller drive device (motor generator) 19 is connected to an inverter 51, and a storage battery 52 is connected to the inverter 51, and the control device 41 can control the inverter 51. The motor generator that constitutes the roller driving device 19 converts the electric power supplied from the storage battery 52 into mechanical power and outputs it to the support shaft 21, and the mechanical power input to the support shaft 21 into electric power. It has the function of converting and collecting.

  That is, when the roller driving device (motor generator) 19 functions as a motor, the grinding roller 18 can be rotated via the support shaft 21. In this case, the control device 41 controls the roller driving device 19 so that the peripheral speed of the crushing roller 18 is slightly faster than the peripheral speed of the crushing table 13 by the inverter 51. On the other hand, when the roller drive device (motor generator) 19 functions as a generator, the rotational force of the pulverizing table 13 is transmitted to the pulverizing roller 18 through the solid material, and the support shaft 21 rotates. The rotational force of 21 can be converted into electric power and stored in the storage battery 52. In this case, the control device 41 controls the roller driving device 19 so that the peripheral speed of the pulverizing roller 18 is slightly slower than the peripheral speed of the pulverizing table 13 by the inverter 51, and functions as a power regenerative brake.

  In addition, since the effect | action of the vertical mill of a present Example is the same as that of Example 1 mentioned above, detailed description is abbreviate | omitted.

  As described above, in the vertical mill according to the second embodiment, the roller driving device 19 is a motor generator, the crushing roller 18 can be driven and rotated by the roller driving device 19, and the circumference of the crushing table 13 is controlled by the control device 41. The rotational speed of the grinding roller 18 can be adjusted so that the peripheral speed is different from the speed. Therefore, when the peripheral speed of the crushing roller 18 and the peripheral speed of the crushing table 13 are different by the control device 41, the crushing roller 18 is accelerated by crushing due to the shearing force acting on the solids, such as biomass. It is possible to improve the pulverization efficiency by efficiently pulverizing the solid matter.

  In this case, by using the roller drive device 19 as a motor generator, the circumferential speed of the grinding roller 18 and the circumferential speed of the grinding table 13 can be easily made different. Since the roller driving device (motor generator) 19 is capable of regenerative braking, the regenerative braking can be applied to the crushing roller 18 so that the heat energy can be converted into electric energy and recovered. Can be used effectively.

  The vertical mill according to the present invention is provided with a grinding roller above the grinding table and allows the rotational speed of the grinding roller to be adjusted so as to be different from the circumferential speed of the grinding table. Can be efficiently pulverized to improve the pulverization efficiency, and can be applied to an apparatus for pulverizing solids such as biomass.

DESCRIPTION OF SYMBOLS 11 Housing 12 Biomass supply pipe 13 Crushing table 17 Table liner 18 Crushing roller 19 Roller drive device (roller speed adjustment mechanism)
21 Support shaft 25 Hydraulic cylinder (pressing device)
41 Control device (roller speed adjustment mechanism)
42 Detector 51 Inverter 52 Storage battery

Claims (5)

A crushing table that is supported so as to be capable of driving and rotating with a rotation axis along the vertical direction in the housing;
A crushing roller disposed above the crushing table and rotatably supported;
A roller speed adjustment mechanism capable of adjusting the rotational speed of the grinding roller so as to have a circumferential speed different from the circumferential speed of the grinding table;
A vertical mill characterized by comprising:   The vertical mill according to claim 1, wherein the roller speed adjusting mechanism includes a braking / driving device that applies a driving force or a braking force to the crushing roller.   The roller speed adjusting mechanism includes a driving device that applies a driving force to the grinding roller, and the driving device rotates the grinding roller so that a circumferential speed of the grinding roller is higher than a circumferential speed of the grinding table. The vertical mill according to claim 1, wherein the speed is adjustable.   4. The vertical mill according to claim 1, wherein the roller speed adjusting mechanism includes an electric motor that drives and rotates the crushing roller. The vertical mill according to claim 4, wherein the electric motor is capable of regenerative braking.

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