JP2019217454A - Vertical mill - Google Patents

Abstract

To suppress vibration generation at a start-up time in a vertical mill in which a rotation speed of a rotary table is so made as to be variable.SOLUTION: The vertical mill includes: a rotary table; a motor for rotating the rotary table; a controller which controls a rotation speed of the motor via an inverter; and plural rollers which are rotated following the rotation of the rotary table, and crushes a raw material supplied between the rotary table and the plural rollers. The controller fixes the rotation speed of the rotary table to a preset prescribed rotation speed during an oversupply period in which the raw material of a first amount per unit time is supplied immediately after supply start of the raw material, and increases or decreases the rotation speed of the rotary table following a supply amount of the raw material per unit time during a supply amount decrease period in which a supply amount per unit time is decreased to a second amount less than the first amount after the oversupply period, and a supply amount increase period in which the supply amount per unit is increased after the supply amount decrease period.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vertical pulverizer for pulverizing a solid material such as coal using a rotary table and a pulverizing roller.

  Patent Literature 1 discloses a vertical crusher that crushes supplied raw materials by the action of a rotary table rotated by a motor and a plurality of crushing rollers that rotate while being pressed on the rotary table. .

  When starting such a vertical crusher, generation of vibration is a problem. This vibration phenomenon is a kind of frictional vibration caused by the sliding of the layer of particles during the grinding and the grinding roller, and is a kind of self-excited vibration as a vibration type. One of the causes of the vibration is that at the time of start-up when the supply amount of the raw material is small, the layer of particles between the rotary table and the crushing roller is thin, so the crushing roller slips without obtaining sufficient friction, That is, the biting of the particles becomes discontinuous. If the operation is continued under the condition in which vibration occurs, the vibration may be amplified and the crusher itself and peripheral devices may be damaged.

  As a technique for suppressing the generation of vibration at the time of starting the vertical pulverizer as described above, Patent Literature 1 describes that the excessive supply of the pulverized raw material is temporarily performed. According to this technique, the rotating table and the grinding roller can stably bite the particles even at the time of startup, and the occurrence of vibration can be suppressed.

JP-A-11-147047 Japanese Patent No. 5732803

  In Patent Literature 1, the number of rotations of the rotary table is fixed, and only the supply amount of the raw material is adjusted. However, this method has poor response to a load change and a small load change width that can be handled. Therefore, in recent years, as described in Patent Literature 2, a system for increasing or decreasing the number of revolutions of a rotary table according to an increase or decrease in a supply amount (load) of a raw material has been introduced.

  However, for example, when the technique of Patent Document 2 is applied to the vertical pulverizer of Patent Document 1, the number of rotations of the rotary table also increases excessively in accordance with the excessive supply of the raw material, so that the generation of vibration cannot be suppressed. There is.

  An object of the present invention is to suppress the occurrence of vibration at the time of startup in a vertical pulverizer in which the rotation speed of a rotary table is variable.

  In order to achieve the above object, a vertical crusher of the present invention includes a rotary table, a motor for rotating the rotary table, a control device for controlling the number of rotations of the motor via an inverter, and And a plurality of rollers that rotate following the rotation, and crushes the raw material supplied between the rotary table and the plurality of rollers. The control device fixes the number of rotations of the turntable to a predetermined number of rotations in an excess supply period in which the first amount of material is supplied per unit time immediately after the start of supply of the raw material. In a supply amount decreasing period in which the supply amount per unit time decreases to a second amount smaller than the first amount after the period, and in a supply amount increasing period in which the supply amount per unit time increases after the supply amount decreasing period, The number of rotations of the rotary table is increased or decreased in accordance with the supply amount of the raw material per unit time.

  ADVANTAGE OF THE INVENTION According to this invention, the vibration generation at the time of starting can be suppressed in the vertical grinding machine which made the rotation speed of the grinding table variable. In addition, problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

It is a figure showing composition of a vertical type crusher concerning a 1st embodiment of the present invention. FIGS. 2A and 2B are partially enlarged views of the vertical pulverizer of FIG. 1, wherein FIG. 1A shows a state where vibration is unlikely to occur, and FIG. It is a timing chart at the time of starting of the vertical grinding machine concerning a 1st embodiment. It is a timing chart at the time of starting of the vertical crusher concerning an existing technology. It is a timing chart at the time of stop of the vertical type crusher concerning a 2nd embodiment of the present invention.

(1st Embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

(Overall configuration of vertical mill)
First, the overall configuration of a vertical crusher to which the present invention is applied will be described with reference to FIG. FIG. 1 is a longitudinal sectional view showing the entire structure of the vertical crusher according to the first embodiment. The housing 43 of the vertical pulverizer houses a coal supply pipe (raw material supply pipe) 1, a rotary table 2, and a plurality of pulverizing rollers 3.

  The coal feed pipe 1 is disposed above the housing 43, and supplies coal (raw material) 60 supplied from a coal feed device (supply device) (not shown) into the housing 43. The turntable 2 is arranged below the housing 43. The driving force of the motor 14 is transmitted to the rotary table 2 via the speed reducer 12 and the driving force transmission shaft 13 below the housing 43, and the rotary table 2 rotates around a rotation axis CL1 (dashed line) extending in the vertical direction. The plurality of crushing rollers 3 are arranged on the upper surface of the rotary table 2 so as to be spaced apart in the circumferential direction. The plurality of crushing rollers 3 are formed in a tire shape, and rotate around a rotation axis CL2 (two-dot chain line) extending in a direction intersecting with the rotation axis CL1 of the rotation table 2 following the rotation of the rotation table 2.

  The plurality of crushing rollers 3 are supported by a pressure frame 5 via a roller bracket (not shown). The crushing load (pressing force) is transmitted to the crushing roller 3 by the pressing device 9 pulling the pressing rod 8 connected to the pressing frame 5 downward. The pressurizing device 9 according to the first embodiment adjusts the crushing load (pressing force) by hydraulic pressure.

  That is, the plurality of crushing rollers 3 are pressed toward the rotary table 2 by the pressing device 9. In the vertical pulverizer according to the first embodiment, the rotary table 2 and the plurality of pulverizing rollers 3 are in contact (metal touch) in a state where the coal 60 is not supplied.

  The coal feed pipe 1 is arranged coaxially with the rotation axis CL1 of the turntable 2. Therefore, after the coal 60 supplied through the coal feed pipe 1 falls to the center of the rotating rotary table 2, the centrifugal force accompanying the rotation causes the spiral 60 to draw a spiral locus on the rotary table 2 in a radially outward direction. To be crushed between the rotary table 2 and the crushing roller 3.

  The pulverized coal 60 (referred to as powder 62) is blown upward while being dried by primary air (hot air) 61 introduced from the throat 4 outside the rotary table 2. Among the blown-up powders 62, those having a large particle size are returned to the rotary table 2 by the classification device 20 and the hopper 11, and are again pulverized. On the other hand, those having a small particle size are distributed to a plurality of coal feed pipes 30 together with the primary air 61 and sent to a boiler or a fine powder storage (not shown) as product fines 63.

  The classification device 20 includes a rotating shaft 22 rotatably supported by the coal feed pipe 1, a rotating fin 21 that rotates with the rotation of the rotating shaft 22, and a motor (not shown) that drives the rotating shaft 22 to rotate. It is a rotary type having The rotating fins 21 are arranged such that the longitudinal direction of the plate extends substantially parallel to the rotating shaft 22 and are arranged in large numbers at arbitrary angles. The particle size distribution of the product fine powder 63 is adjusted by the rotation speed of the rotating fin 21.

  The classification device 20 classifies the powder 62 blown up by the primary air 61 into fine particles and coarse particles. Then, the classification device 20 discharges the fine particles to the outside from the coal feeding pipe 30 as the product fine powder 63, and drops the coarse particles to the hopper 11. The hopper 11 is arranged between the classification device 20 and the turntable 2. The hopper 11 collects, among the powder 62 blown up by the primary air 61, the powder dropped by gravity and the coarse particles classified by the classification device 20, and drops the powder to the rotary table 2.

  The motor 14 is a VVVF (Variable Voltage Variable Frequency) motor whose rotation speed is controlled by an inverter 15. The inverter 15 increases or decreases the rotation speed of the motor 14 according to a control signal from the control device 16. The control device 16 controls devices such as the pressurizing device 9, the inverter 15, the classifying device 20, and a blower (not shown) for generating the primary air 61, and externally serves as a coal feeder, a downstream boiler, etc. (Not shown), and operate the vertical pulverizer in cooperation with each other.

  The control device 16 includes a CPU (Central Processing Unit) 31, a ROM (Read Only Memory) 32, and a RAM (Random Access Memory) 33. When the CPU 31 reads and executes the program code stored in the ROM 32, the control device 16 executes each process described below in cooperation with software and hardware. The RAM 33 is used as a work area when the CPU 31 executes a program. However, the specific configuration of the control device 16 is not limited to this, and may be realized by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

(Principle of suppressing vibration generation)
Next, the principle of suppressing the generation of vibration of the vertical mill will be described with reference to FIG. 2 (a) and 2 (b) are enlarged views of a part of the rotary table 2 and the crushing roller 3 in FIG. 1 and the periphery thereof, and FIG. 2 (a) shows a state in which vibration hardly occurs. FIG. 2B shows a state in which vibration is likely to occur.

  The difference between FIG. 2A and FIG. 2B is the amount of coal 60 on the turntable 2. The amount is large in FIG. 2A and small in FIG. 2B. In the state shown in FIG. 2A, the coal 60 is continuously bitten between the crushing roller 3 and the rotary table 2, so that a layer of particles being crushed is maintained at a thickness δ1 between the two, and the crushing roller 3 rotates stably.

  On the other hand, in the state of FIG. 2B, the bite of the coal 60 between the crushing roller 3 and the rotary table 2 becomes discontinuous, so that the thickness δ2 (<δ1) of the particle layer during the crushing is reduced as shown in FIG. (A) It becomes thinner. In this state, the grinding roller 3 slips irregularly, so that the grinding roller 3 starts vibrating up and down. Then, once the vibration starts, the biting of the coal 60 becomes further unstable, so that the vibration is amplified with the passage of time.

  Here, even if vibration occurs in the state of FIG. 2 (b), if the number of coals 60 is increased while the rotation speed of the turntable 2 is kept constant, a stable operation state of FIG. 2 (a) is obtained. Is transferred. However, when the number of rotations of the turntable 2 is increased in accordance with the increase in the amount of coal 60, the frequency of the slip caused by the crushing roller 3 increases, and the vibration increases. Therefore, in a system such as Patent Document 2 in which the number of revolutions of the turntable 2 is automatically increased in accordance with an increase in the amount of coal 60 supplied to the turntable 2 per unit time, the start of the Vibration cannot be suppressed even if oversupply is performed.

  In addition, if the rotation speed of the turntable 2 is kept very low in the state of FIG. 2B and both the supply amount of the coal 60 and the rotation speed of the turntable 2 are slowly increased, no vibration occurs. . However, this operation method is not practical because it takes too much time from the start of the vertical pulverizer until a sufficient amount of the product fine powder 63 is obtained. This is because, when the downstream device of the vertical pulverizer is a combustion device such as a boiler, high responsiveness to a change in combustion load is required.

(Operation of the control device 16 according to the first embodiment)
The operation of the control device 16 according to the first embodiment will be described with reference to FIG. 3 (a) to 3 (d) are timing charts in which the horizontal axis represents the same time, and the vertical axis represents operating parameters of different vertical mills. That is, the vertical axis in FIG. 3A is the coal supply C, the vertical axis in FIG. 3B is the rotational speed ω of the turntable 2, the vertical axis in FIG. 3C is the rotational speed Ns of the classifier 20, The vertical axis in FIG. 3D indicates the hydraulic pressure (operating pressure) P of the pressurizing device 9. The “coal supply amount” in this specification refers to the amount of coal supplied per unit time.

  As shown in FIG. 3A, the coal supply device starts coal supply at time t1. Information on the start time of coal supply and the amount of coal supply is transmitted from the control unit of the coal supply device to the control device 16. Since the vertical pulverizer stops after exhausting all the internal coal 60, the amount of coal 60 on the rotary table 2 is 0 before time t1.

  The coal feeder performs an excessive supply of the coal 60 indicated by a solid line between time t1 and time t2 (excess supply period). In other words, the coal supply device fixes the coal supply amount of the coal 60 to C1 (first amount) during the excessive supply period. Next, the coal supply device ends the excess supply period at time t2, and linearly decreases the coal supply amount from C1 to C2 (second amount) (supply amount reduction period). Next, the coal supply device ends the supply amount reduction period in response to the coal supply amount reaching C2, and linearly increases the coal supply amount until the coal supply amount reaches C1 at time t5 (supply Volume increase period). Further, in response to the coal supply amount reaching C1 at time t5, the coal supply device ends the supply amount increase period and maintains the coal supply amount C1 (rated coal supply amount) (supply amount maintenance period). .

  That is, the coal supply amount C1 during the excess supply period is larger than the coal supply amount C2 at the start of the supply amount increase period. Further, the coal supply amount C1 during the excessive supply period is the same as the coal supply amount C1 during the supply amount maintaining period. In the first embodiment, the coal supply amount during the excessive supply period is made to match the rated coal supply amount C1, but may be set to a smaller coal supply amount than C1. The amount of coal that can be started stably by the vertical pulverizer depends on properties such as the particle size distribution and hardness of the coal 60, and the amount of coal supplied in actual operation is determined by trial operation. In addition, the time from time t1 to time t2 is also determined by trial operation according to the properties of the coal 60.

  Further, as shown in FIG. 3B, the control device 16 rotates the turntable 2 at the rotation speed ω3 from time t0, which is a predetermined time earlier than time t1. The arrival of the time t0 may be notified from the control unit of the coal feeder, or may be instructed by the operator through an operation panel (not shown) of the vertical pulverizer. Next, the control device 16 fixes the rotation speed of the turntable 2 to ω2 (predetermined rotation speed) during the excessive supply period, and linearly decreases the rotation speed of the turntable 2 from ω2 to ω3 during the supply amount reduction period. Then, the rotation speed of the turntable 2 is linearly increased from ω3 to ω1 during the supply amount increase period, and the rotation speed of the turntable 2 is fixed at ω1 (rated rotation speed) during the supply amount maintenance period.

  In the first embodiment, the rotation speed ω of the turntable 2 satisfies ω1> ω2> ω3, and is set to ω1 × 0.5 ≦ ω2 ≦ ω1 × 0.8. In FIG. 3B, the rotation speed of the turntable 2 is increased from ω3 to ω2 over a predetermined time from time t1, but this is a mechanical delay of the motor 14. The control signal from the control device 16 to the inverter 15 indicates the rotation speed ω2 at the time t1. The rotation speed ω3 at the time t0 and the rotation speed ω3 at the start of the supply amount increasing period may be different rotation speeds.

  Here, it is very important to set the rotation speed ω between the time t1 and the time t2 (excess supply period). That is, in the first embodiment, the coal supply amount C during the excessive supply period is the rated coal supply amount C1, whereas the rotation speed ω of the turntable 2 is 0.5 to 0.8 times the rated rotation speed ω1. It is suppressed to. This is for the following reason. That is, since the rotary table 2 is empty before the time t1, even if the coal supply C is overshot to the rated coal supply C1 at the time t1, the amount of the coal 60 on the rotary table 2 at the time t1 is continuous. Is smaller than the period during which the rated coal supply is being performed (the supply amount maintaining period after time t5). If the rotational speed ω is increased from time t1 to time t2 to ω1 as shown in the conventional example of FIG. 4 in this state, the state shown in FIG. 2B occurs and vibration occurs. Therefore, the rotation speed ω from the time t1 to the time t2 needs to be smaller than ω1.

  In addition, the setting of the rotation speed ω2 in the excess supply period has a width of 0.5 to 0.8 times ω1 according to the particle size distribution, the hardness and other properties of the coal 60 to be pulverized. This is because it is necessary to determine appropriate operating conditions by trial operation.

  Further, while the rotation speed of the turntable 2 is fixed at ω2 during the excess supply period, the rotation speed ω increases and decreases following the increase and decrease of the coal supply amount C during the supply amount reduction period and the supply amount increase period. I do. That is, the control device 16 decreases the rotation speed ω following the decrease in the coal supply amount C during the supply amount reduction period, and changes the rotation speed ω following the increase in the coal supply amount C during the supply amount increase period. increase. More specifically, in the supply amount decrease period and the supply amount increase period, the coal supply amount C and the rotation speed ω have a positive correlation (proportional relation in the example of FIG. 3). Thereby, it is suppressed that the coal 60 on the turntable 2 becomes too large or too small, and the state of FIG. 2A can be maintained.

  Further, as shown in FIG. 3C, the control device 16 fixes the rotation speed Ns of the classifying device 20 to Ns3 from time t0 to time t3, and sets the classifying device between time t3 and time t4. 20, the rotation speed Ns is linearly increased from Ns3 to Ns2, and the rotation speed Ns of the classification device 20 is linearly increased from Ns2 to Ns1 from time t4 to time t5. Is fixed to Ns1.

  That is, the control device 16 fixes the rotation speed Ns of the classification device 20 to the predetermined value Ns3 during a period from the start of the excess supply period, the supply amount decrease period, and the supply amount increase period until a predetermined time elapses. . In addition, the control device 16 changes the rotation speed Ns of the classifying device 20 to the coal supply amount C in response to the lapse of a predetermined time from the start of the supply amount increase period (positive correlation, the example in FIG. 3). Then proportionally).

  As the rotation speed Ns of the classifier 20 increases, the effect of increasing the return of fine particles to the turntable 2 is increased. When the amount of coal 60 on the rotary table 2 is small, the fine particles tend to induce the slip of the grinding roller 3 and the generation of vibration. Therefore, as shown in FIG. 3 (c), when the rotation speed Ns of the classifying device 20 is increased later than the start of the increase in the coal feed amount C and the rotation speed ω of the rotary table 2, the effect of suppressing the generation of vibration is reduced. Can be enhanced.

  Here, time t3 is a time between time t2 and time t5, and time t4 is a time between time t3 and time t5. The rotation speed Ns of the classifying device 20 satisfies Ns1> Ns2> Ns3. Note that the timings of the times t3 and t4, the slopes of the straight lines between the times t3 and t4 and between the times t4 and t5, and the specific values of the rotation speeds Ns1, Ns2, and Ns3 are determined by the test operation depending on the properties of the coal 60. .

  Further, as shown in FIG. 3D, the control device 16 fixes the oil pressure P of the pressurizing device 9 to P2 from time t0 to time t3, and between the time t3 and time t5. The hydraulic pressure P of the pressure device 9 is linearly increased from P2 to P1, and the hydraulic pressure P of the pressurizing device 9 after time t5 is fixed at P1. That is, the control device 16 increases the pressing force of the pressurizing device 9 to a predetermined value (the hydraulic pressure P2) during a period from the start of the excess supply period, the supply amount decrease period, and the supply amount increase period until a predetermined time has elapsed. (Corresponding value). In addition, the control device 16 causes the pressing force of the pressurizing device 9 to follow the coal supply amount C in accordance with the elapse of a predetermined time after the supply amount increase period starts (positive correlation, the example in FIG. 3). Then proportionally).

  Since the crushing force increases as the hydraulic pressure P of the pressurizing device 9 increases, the amount of fine particles generated on the crushing roller 3 increases. When the amount of coal 60 on the turntable 2 is low, the fine particles tend to induce slipping and vibration of the grinding roller 3. Therefore, if the oil pressure P of the pressurizing device 9 is increased later than the start of the increase in the coal supply amount C and the rotation speed ω of the turntable 2, the effect of suppressing the generation of vibration can be enhanced. Here, the hydraulic pressure P of the pressurizing device 9 is P1> P2. Further, specific values of the oil pressures P1 and P2 are determined by a test run depending on the properties of the coal 60.

  Further, although not shown, the air volume of the primary air 61 may be increased or decreased following (positive correlation or proportional to) the coal supply amount C. That is, the control device 16 increases the air volume to the blower at the same timing (time t1) as the overshoot of the coal supply C, and reduces the airflow to the blower at the timing (time t2) at which the overshoot ends. The air volume may be increased by the blower following the increase in the volume C. Increasing the air volume of the primary air 61 promotes the transport of fine particles to the outside of the vertical pulverizer, so that the slip of the pulverizing roller 3 during excessive supply of the raw material can be suppressed, and the vertical pulverizer is started. It is possible to reduce the delay of coal removal at the time.

  As described above, when starting the vertical pulverizer in which the coal supply amount C and the rotation speed ω of the rotary table 2 are linked, while the coal 60 is temporarily excessively supplied, the rotation speed ω of the rotary table 2 is increased. By performing the dedicated startup control that is fixed at ω2, the vibration of the crushing roller 3 can be suppressed.

  The control device 16 may detect a change in the coal supply amount C using a sensor (not shown), or may appropriately receive information indicating the coal supply amount C from a control unit of the coal supply device. Alternatively, information indicating the transition of the coal supply amount C may be stored in the ROM 32 or the RAM 33 in advance. Then, the control device 16 may control the operation parameters based on these pieces of information, as shown in FIGS.

(Operation of the control device 16 according to the second embodiment)
Next, the operation of the control device 16 according to the second embodiment will be described with reference to FIG. 5A and 5B are timing charts in which the horizontal axis represents the same time, and the vertical axis represents operating parameters of different vertical mills. That is, the vertical axis in FIG. 5A indicates the amount of coal supply C, and the vertical axis in FIG. 5B indicates the rotation speed ω of the turntable 2. Note that detailed description of common points with the first embodiment will be omitted, and different points will be mainly described. The configuration of the vertical pulverizer according to the second embodiment is common to that of the first embodiment shown in FIG.

  As shown in FIG. 5A, the coal supply apparatus reduces the coal supply amount C from C1 to 0 in response to the arrival of the time t6 during the supply amount maintenance period. That is, at the time t6, the coal supply device stops supplying the coal 60 to the vertical mill. Further, as shown in FIG. 5B, the control device 16 linearly decreases the rotation speed ω of the turntable 2 from ω1 to ω4 from time t6 to time t7, and During this period, the rotation speed ω of the turntable 2 is fixed at ω4 (minimum rotation speed), and the rotation speed ω of the turntable 2 is set to 0 in response to the arrival of time t8.

  That is, the control device 16 changes the turntable 2 from the rated rotation speed ω1 to the minimum rotation speed ω4 over a predetermined time (time t6 to t7) in response to the stoppage of the supply of the coal 60 from the coal feeder. After that, the motor is rotated at a constant speed at the minimum rotation speed ω4 for a predetermined time (time t7-t8), and then stopped. The rotation speed ω of the turntable 2 is ω3 ≧ ω4. The timings of the times t6, t7, and t8, and the specific values of the rotation speed ω4 are determined by the test operation according to the properties of the coal 60.

  When the rotary table 2 is rotated in a state where the supply of the coal 60 from the coal feeder is stopped, the coal 60 on the rotary table 2 gradually decreases. Therefore, during the period from time t6 to time t7, the number of revolutions ω of the rotary table 2 is reduced by following (positive correlation or proportionality) the decrease of the coal 60 on the rotary table 2, thereby reducing the slip of the grinding roller 3. Can be suppressed. Further, during the period from time t7 to time t8, the rotary table 2 is rotated at a constant speed of the minimum rotation speed ω4 to discharge all the coal 60 on the rotary table 2 and then stop the vertical mill. it can. Thereby, troubles due to ignition of the coal 60 remaining in the housing 43 can be suppressed.

(Other embodiments)
Note that the present invention is not limited to the above embodiment. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above. For example, in FIG. 1, the rotary table 2 and the crushing roller 3 are illustrated as being in contact (metal touch) when the vertical crusher is empty, but a gap is provided between the two in the same state. You may. Further, a spherical grinding ball may be used instead of the tire-like grinding roller 3. Even in this case, the vibration can be similarly suppressed.

  Also, in FIG. 1, the integrated pressurizing frame 5 is drawn so as to suspend and press the plurality of crushing rollers 3 at the same time. It is also applicable to a mold grinder. Furthermore, a dam ring may be provided on the outer edge of the rotary table 2 to secure a layer of particles between the rotary table 2 and the grinding roller 3, or two or more of the above-described various structures may be combined.

  Further, in the above-described embodiment, as shown in FIGS. 3 and 5, an example in which the operation parameters of the vertical pulverizer are linearly changed has been described. However, the change characteristics of the operation parameters are not limited thereto. , A multi-order curve, an exponential curve, or a combination thereof.

  3B, the effect of suppressing vibration can be expected even if the rotary table 2 is rotated at a constant speed of ω3 from time t1 to time t2.

  Furthermore, in the above description, coal 60 is mentioned as an example of the raw material, but a specific example of the raw material is not limited to this, and may be, for example, a cement raw material.

1 Raw material supply pipe (coal supply pipe)
2 rotary table 3 crushing roller 4 throat 5 pressurizing frame 8 pressurizing rod 9 pressurizing device 11 hopper 12 reducer 13 driving force transmission shaft 14 motor 15 inverter 16 control device 20 classifier 21 rotary fin 22 rotary shaft 30 powder pipe (Coal pipe)
43 Housing 60 Raw material (coal)
61 Primary air (hot air)
62 Powder 63 Product fine powder

Claims (5)

A rotating table,
A motor for rotating the rotary table,
A control device for controlling the rotation speed of the motor via an inverter,
A plurality of rollers that rotate following the rotation of the turntable,
A vertical crusher for crushing the raw material supplied between the rotary table and the plurality of rollers,
The control device includes:
Immediately after the start of the supply of the raw material, in the excess supply period in which the first amount of the raw material is supplied per unit time, the rotation speed of the turntable is fixed at a predetermined rotation speed,
A supply amount decreasing period in which the supply amount per unit time decreases to a second amount smaller than the first amount after the excess supply period, and a supply amount increasing in which the supply amount per unit time increases after the supply amount decreasing period A vertical pulverizer wherein the number of rotations of the rotary table is increased or decreased in accordance with a supply amount of a raw material per unit time during a period. The vertical pulverizer according to claim 1,
The vertical grinding machine according to claim 1, wherein the predetermined number of revolutions in the excess supply period is larger than the number of revolutions of the turntable at the start of the supply amount increasing period. The vertical pulverizer according to claim 2,
In the supply amount maintaining period in which the supply amount per unit time is maintained at the first amount after the supply amount per unit time reaches the first amount during the supply amount increasing period, the control device may perform the rotation. The rotation speed of the table is fixed to the rotation speed at the end of the supply amount increasing period,
The vertical crusher according to claim 1, wherein the predetermined number of revolutions during the excess supply period is smaller than the number of revolutions of the rotary table during the supply amount maintaining period. The vertical pulverizer according to claim 1,
Further comprising a rotary classifier for classifying the raw material pulverized by the rotary table and the plurality of rollers,
The control device includes:
During the excess supply period, the supply amount decrease period, and the predetermined amount of time after the supply amount increase period starts, the rotation speed of the classifier is fixed to a predetermined value,
A vertical type characterized in that the number of revolutions of the classifying device is increased in accordance with the supply amount of the raw material per unit time, in accordance with the lapse of the predetermined time from the start of the supply amount increase period. Crusher. The vertical pulverizer according to claim 1,
Further comprising a pressing device for pressing each of the plurality of rollers toward the rotary table,
The control device includes:
During the excess supply period, the supply amount decrease period, and the predetermined amount of time after the supply amount increase period starts, the pressing force of the pressurizing device is fixed at a predetermined value,
The pressurizing force of the pressurizing device is increased in accordance with the supply time of the raw material per unit time in accordance with the lapse of the predetermined time from the start of the supply amount increasing period, wherein the vertical pressure is increased. Mold crusher.

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