JP2013176734A - Crusher and crushing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system which actively controls vibration of a crusher and can stop this control when the control goes out of control.SOLUTION: A crushing system 1 includes: a crusher 2 having a housing; a plurality of roller units which crush raw material, a vibration sensor 6 which outputs a detection signal corresponding to vibration of the housing, and a first control device 7 which controls a load applied on the respective roller units based on a supply amount of the raw material and the detection signal of the vibration sensor 6; a feeder 3 which supplies the raw material to the crusher 2; and a second control device 5 which determines an abnormal state of the crusher when amplitude of the detection signal of the vibration sensor exceeds a predetermined range and continues to increase, and stops control by the first control device 7 and reduces the raw material supplied from the feeder 3.

Description

  The present invention relates to a pulverizer and a pulverization system, and more particularly to a pulverizer and a pulverization system provided with a control device that suppresses vibration.

For example, in an integrated gasification combined cycle (IGCC) system or the like, a pulverizer is used to make coal as fuel into pulverized coal.
The pulverizer has a housing, and a table and a roller unit that are rotationally driven are arranged in the housing. The roller unit includes a roller for crushing coal in cooperation with the table, and is supported by the housing in a swingable manner.

  A hydraulic cylinder is attached to the housing, and the hydraulic cylinder applies a load to the roller unit. Conventionally, the load applied to the roller unit has been adjusted according to the amount of coal supplied to the pulverizer and the amount of mill roll lift, as described in Patent Document 1.

  By the way, with the recent increase in the amount of power generation, the size of the pulverizer is also increasing, and the weight reduction of the housing is required. However, when the weight of the housing is reduced, the rigidity of the housing is reduced and the housing is likely to vibrate. As a technique for suppressing vibration of a pulverizer, a control method for the pulverizer as described in Patent Document 1 is known.

JP-A-9-122517

In addition, as a countermeasure against vibration of other pulverizers, active vibration suppression that applies force in the direction opposite to the vibration direction is known. In this vibration damping method, a vibration sensor is provided in the housing, and a load applied to the roller is feedback controlled based on a detection signal of the vibration sensor.
However, in this vibration damping method, since the feedback information is only vibration, there is a risk that if a malfunction or a phase delay occurs, a very large vibration occurs due to resonance.

  The present invention has been made in consideration of such circumstances, and its purpose is to provide a crushing system that can actively control the vibration of the crusher and can stop the control when the control runs away. It is to provide.

In order to solve the above problems, the present invention provides the following means.
A pulverizer according to the present invention includes a substantially cylindrical housing, a table rotatably disposed in the housing, and having an annular pulverizing surface, and a plurality of rollers that pulverize raw materials in cooperation with the table. A roller unit; a biasing device that applies a load to the roller unit so as to bias each of the rollers toward the grinding surface of the table; and a vibration sensor that outputs a detection signal corresponding to the vibration of the housing; A first controller for controlling a load applied to each of the roller units by the urging device based on a supply amount of the raw material to the grinding surface and a detection signal of the vibration sensor, and a feeder for supplying the raw material And when the amplitude of the detection signal of the vibration sensor exceeds a predetermined range and tends to increase, it is determined as an abnormal state, and the control by the first control device is performed. Causes locked, characterized in that it comprises a second control device for reducing the raw material supplied from the feeder.

  According to the above configuration, the vibration of the pulverizer can be suppressed by controlling the load applied to the roller unit, and this control can be stopped when the amplitude of vibration is increased by the control. With these effects, the structural reliability of the pulverizer can be improved.

  In the pulverizer, it is preferable that the urging device includes a hydraulic cylinder that generates the load according to the supplied hydraulic pressure, and the first control device adjusts the hydraulic pressure supplied to the hydraulic cylinder.

  According to the above configuration, since the urging device can be configured with a simple structure using a hydraulic load, the vibration of the housing can be accurately suppressed.

  In the pulverizer, the first control device sets a target value for setting a target load value that is a common target value of a load to be applied to each of the roller units by the biasing device based on the supply amount of the raw material. A load correction amount calculation unit that calculates a correction amount of the load target value for each of the roller units based on a detection signal of the vibration sensor, and the load correction amount calculation unit includes the correction The correction amount is preferably calculated so that the average value of the amounts becomes zero.

  According to the above configuration, the load applied to the roller unit is changed from the common target value to the positive side and the negative side. In this case, the total load applied to the table by the plurality of roller units eventually becomes a common target value. For this reason, even if the load is changed, insufficient strength and wear of the table and the roller will not be a problem, and a change in grindability will not be a problem.

  The pulverizer includes a classification device for recirculating coarse particles of the pulverized material that has passed through the roller unit to the table and supplying fine particles downstream of the pulverizer, and blowing up the outer periphery of the table. A powder conveying air supply device for conveying the pulverized material pulverized in step 1 to the classifying device and conveying fine particles classified by the classifying device downstream of the pulverizer; A differential pressure measuring device that measures a pulverizer differential pressure including a pressure loss when passing through the outer periphery of the pulverizer, wherein the first control device sets a pulverizer differential pressure target value based on a supply amount of the raw material. A differential pressure target value setting unit to be set; and a deviation calculating unit for obtaining a deviation between the pulverizer differential pressure target value and the pulverizer differential pressure, wherein the load target value is corrected based on the deviation. Preferably .

  According to the above configuration, since the pulverizer differential pressure quickly converges to an appropriate value that matches the supply amount, by utilizing the deviation between the pulverizer differential pressure target value and the pulverizer differential pressure for correcting the load, The load can be controlled more appropriately.

  Further, the pulverization system of the present invention includes a pulverizer having any one of the above-described configurations, and a hopper that is disposed downstream of the plurality of pulverizers and accommodates fine particles of an object to be pulverized, and the second control device includes The supply amount of the raw material discharged from the supply machine upstream of at least one of the other pulverizers when any of the pulverizers becomes abnormal is increased. And

  According to the above configuration, in the pulverization system composed of a plurality of pulverizers, even when some of the pulverizers become abnormal, the amount of pulverized coal produced in the entire pulverization system can be kept constant.

  According to the present invention, the vibration of the pulverizer can be suppressed by controlling the load applied to the roller unit, and this control can be stopped when the amplitude of the vibration is increased by the control. Thereby, the structural reliability of the pulverizer can be improved.

1 is a schematic system diagram of a crushing system according to an embodiment of the present invention. It is a schematic block diagram of the grinder which concerns on embodiment of this invention. It is a figure which expands and shows the area | region A in FIG. It is the schematic plan view which looked at the roller unit from the upper part by making the housing of a grinder into a cross section. It is a block diagram which shows roughly the functional structure of a vibration control apparatus and a supply amount control apparatus. It is a block diagram which shows the detail of the target value setting part of a vibration control apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The pulverization system 1 of this embodiment is a system for pulverizing raw material coal into pulverized coal (fuel), for example, for a coal gasification combined power generation system. As shown in FIG. 1, a pulverization system 1 includes a plurality of pulverizers 2, a feeder 3 installed upstream of each pulverizer 2, and a hopper 4 provided downstream of each pulverizer 2. And a supply amount control device 5 (second control device) for adjusting the coal supply amount from the supply device 3.

  Each pulverizer 2 includes a vibration sensor 6 that measures vibration of a housing 13 (see FIG. 2) that constitutes the pulverizer 2, and a vibration control device 7 that processes a detection signal from the vibration sensor 6 (first Control device). The vibration sensor 6 and the vibration control device 7 are connected to the supply amount control device 5.

Coal raw materials are accommodated in the plurality of feeders 3, and the supply amount of coal can be adjusted according to a command from the supply amount control device 5.
The plurality of pulverizers 2 are devices that pulverize the raw material of coal into pulverized coal. Details of the pulverizer 2 will be described later.
The hopper 4 is a part where the pulverized coal generated from each pulverizer 2 is gathered, and a boiler 8 for burning the pulverized coal is installed downstream thereof.

  That is, the pulverization system 1 of the present embodiment is a system that generates pulverized coal, which is fuel supplied to the boiler 8, by a plurality of pulverizers 1 and aggregates the pulverized coal so as to be supplied to one boiler 8. In this crushing system 1, the vibration of each crusher 2 is controlled by the vibration control device 7, and the supply amount control device 5 controls the amount of coal supplied to the plurality of crushers 2. It has become.

Next, the pulverizer 2 will be described. As shown in FIG. 2, the pulverizer 2 of the present embodiment includes a pulverizer body 9, a vibration control device 7 indicated by a block, and a hydraulic circuit 10.
The pulverizer body 9 is installed on the foundation 11. The pulverizer body 9 has a metal housing 13, and the housing 13 has a substantially cylindrical shape. The upper lid 14 of the housing 13 is penetrated by a coal input pipe 15, and raw material coal to be pulverized is supplied into the housing 13 from above through the coal input pipe 15. The upper lid 14 is provided with a delivery hole 16 through which pulverized coal pulverized is delivered.

  Further, a propeller-shaped rotary classifier 17 is concentrically attached to the coal input pipe 15, and a motor 18 is installed on the upper lid 14. The motor 18 rotates the rotary classifier 17 via, for example, a belt 19, and the rotary classifier 17 rotates to thereby exhibit a classification function for adjusting the particle size distribution of the pulverized coal.

  The base 11 is provided with a recess 20 that opens upward. A reduction gear 21 is installed in the recess 20, and an output shaft 22 of the reduction gear 21 protrudes upward from the recess 20 in the vertical direction. The output shaft 22 passes through the bottom wall of the housing 13 and protrudes into the housing 13. A metal table 23 is concentrically fixed to the output shaft 22 so as not to rotate relative to the output shaft 22.

The table 23 is disposed coaxially with the coal input pipe 15 in the housing 13. The table 23 has an annular crushing surface 24 that is arranged concentrically with the output shaft 22 on the upper side.
When a rotational force is supplied to the reduction gear 21 from the outside, the output shaft 22 rotates integrally with the table 23. A gap between the table 23 and the bottom wall of the housing 13 is covered with a skirt 25 fixed to the table 23.

A duct 26 is attached to the lower part of the peripheral wall 38 of the housing 13. A carrier gas such as air or nitrogen gas is fed into the housing 13 through the duct 26. The carrier gas flows out from the delivery hole 16 together with the pulverized coal. That is, a carrier gas flow path extending from the duct 26 to the delivery hole 16 is defined inside the housing 13.
Further, a differential pressure gauge 27 for measuring a differential pressure between the lower part and the upper part of the table 23 is provided on the peripheral wall 38 of the housing.

  Further, for example, three roller units 28 are provided in the housing 13. In FIG. 2, the two roller units 28 are arranged at 180 ° symmetrical positions for convenience of drawing, but in reality, the roller units 28 are concentrically centered on the output shaft 22 at 120 ° intervals. Is arranged.

FIG. 3 is an enlarged view showing a region A in FIG.
The roller unit 28 has a cylindrical rod holder 29, and the base end side of the rod 30 is fixed to the rod holder 29 so as not to be relatively rotatable. The rod holder 29 is disposed outside the table 23 in the radial direction and above the table 23. The rod 30 extends toward the axis of the output shaft 22 and extends obliquely with respect to the horizontal direction so that the tip of the rod 30 is closer to the table 23 than the base end.

  A rotary cylinder 32 is fitted to the distal end side of the rod 30 via a radial bearing 31 so as to be relatively rotatable, and an annular sliding member 33 is fitted to the rotary cylinder 32 so as not to be relatively rotatable. The rotating cylinder 32 and the sliding member 33 constitute a roller 34. The outer peripheral surface of the sliding member 33 is configured by a curved surface that is convex outward in the radial direction.

  Coal falls onto the table 23 when it is introduced from the coal input pipe 15. As the table 23 rotates, the coal enters the gap between the sliding member 33 and the table 23 and is pulverized to become pulverized coal. Note that when the coal is pulverized, the roller 34 rotates around the rod 30.

  In order to adjust the gap between the table 23 and the sliding member 33, the roller unit 28 can swing. Specifically, the rod holder 29 is integrally provided with a pin 35 extending in the tangential direction of the outer periphery of the table 23. FIG. 4 is a schematic plan view of the roller unit 28 as viewed from above with the housing 13 in cross section. The roller unit 28 is supported by a peripheral wall via pins 35.

  Referring again to FIG. 3, in order to define the minimum gap between the table 23 and the sliding member 33, the rod holder 29 is integrally provided with a protrusion 37 extending downward, and is formed in the screw hole of the peripheral wall 38. The screw 39 is screwed together. When the roller unit 28 is tilted in the direction in which the gap is reduced, if the protrusion comes into contact with the tip of the screw 39, the gap is prevented from being further reduced. The screw 39 can be rotated by the rod motor 40, and the vibration control device 7 can variably control the minimum gap by controlling the rotation of the rod motor 40. In place of the screw 39 and the rod motor 40, an electric cylinder may be used.

On the other hand, in order to pulverize coal using the swingable roller unit 28, an appropriate load is applied to the roller unit 28.
Specifically, the rod holder 29 is integrally provided with an arm 42 that extends upward, and the urging device 43 applies a load to the tip of the arm 42. The urging device 43 includes a plunger 44 and a hydraulic cylinder 45, and the plunger 44 is disposed inside a port portion 46 provided on the peripheral wall 38 via a slide bearing 47. The rod 48 of the hydraulic cylinder 45 is disposed coaxially with the plunger 44, and when the rod 48 extends toward the inside of the peripheral wall 38, the plunger 44 is pressed against the arm 42.

  A hydraulic circuit 10 is connected to the hydraulic cylinder 45, and the hydraulic circuit 10 includes a pump, a motor, a pressure control valve, and the like (not shown). The vibration control device 7 can adjust the hydraulic pressure supplied from the hydraulic circuit 10 to the hydraulic cylinder 45, and the load applied to the arm 42 from the hydraulic cylinder 45 via the plunger 44 changes by adjusting the hydraulic pressure. That is, the load applied to the coal on the table 23 from the roller 34 also changes by adjusting the hydraulic pressure.

  The vibration control device 7 can adjust the hydraulic pressure according to the vibration of the housing 13, and the vibration sensor 6 is attached to the housing 13 for detection of vibration. For example, the vibration sensor 6 is attached to the outside of the peripheral wall 38 of the housing 13. The circumferential position of the vibration sensor 6 on the peripheral wall 38 matches one of the three roller units 28. As a preferable aspect, the vibration sensor 6 is an acceleration sensor whose detection direction is a horizontal direction, and a detection signal of the vibration sensor 6 is input to the vibration control device 7.

Next, the control apparatus of the crushing system 1 of this embodiment is demonstrated.
In the following description, the three roller units 28 are distinguished and referred to as a first roller unit 28a, a second roller unit 28b, and a third roller unit 28c. The hydraulic cylinders 45 of the first roller unit 28a, the second roller unit 28b, and the third roller unit 28c are also referred to as a first hydraulic cylinder 45a, a second hydraulic cylinder 45b, and a third hydraulic cylinder 45c, respectively.

The vibration control device 7 and the supply amount control device 5 are configured by, for example, a computer, and are control devices having an arithmetic device, a storage device, an input / output device and the like.
The supply amount control device 5 is a control device that determines the coal supply amount according to the demand amount of the demand destination, and is a control device that instructs the plurality of supply units 3 on the coal supply amount. The vibration control device 7 is a control device that suppresses vibration of the crusher 2 based on information such as the amount of coal supplied.

First, the vibration control device 7 will be described in detail. As shown in FIG. 5, the vibration control device 7 includes a target value setting unit 50 and a load correction amount calculation unit 52.
The target value setting unit 50 of the vibration control device 7 receives the coal supply amount 65 set by the supply amount control device 5 and the differential pressure measurement value 72 measured by the differential pressure gauge 27. The target value setting unit 50 sets a load target value 76 to be applied to each of the roller units 28 and a classification characteristic command signal 79 to be applied to the rotary classifier 17 based on the coal supply amount 65 and the differential pressure measurement value 72. To do.
The load correction amount calculation unit 52 sets a correction value for correcting the load target value 76 according to the vibration acceleration of the housing 13.

  Here, details of the target value setting unit 50 will be described. As shown in FIG. 6, the target value setting unit 50 obtains an initial load value 75 based on the differential pressure target value calculation means 55 that obtains the pulverizer differential pressure target value 71 based on the coal supply amount 65 and the coal supply amount 65. A load initial value calculating unit 56 and a classifying force target value calculating unit 57 for obtaining a classifying force target value 78 based on the coal supply amount 65 are provided as main components.

  The initial load value calculation unit 56 sets a first target value of the load to be applied to each of the roller units 28 based on the input coal supply amount 65. For example, the load initial value calculating means 56 sets the load initial value 75 using a preset function or map data based on the coal supply amount 65.

  Further, the target setting unit 50 includes a differential pressure deviation calculation means 58 for obtaining a deviation between the pulverizer differential pressure target value 71 and the differential pressure measurement value 72 measured by the differential pressure gauge 27, and load correction from the differential pressure deviation signal 73. A PI adjuster 60 that obtains a signal 74, a load target value 75, and a first adder 61 that adds the load correction signal 74 are provided, and a load target value 76 is calculated. Since the load target value 76 is common between the roller units 28, it is also referred to as a common load target value.

  The target setting unit 50 also includes a classification setting corrector 62 that obtains a classification setting correction signal 77 from the differential pressure deviation signal 73, a second adder 63 that adds the classification force target value 78 and the classification setting correction signal 77. The final classification characteristic command signal 79 is calculated.

Here, as the particle concentration in the mill rises, the table differential pressure also rises. However, if the particle concentration in the mill rises, the pulverized coal becomes less likely to rise, and eventually does not rise at all. It becomes impossible to supply.
This target value setting unit 50 pays attention to the fact that the value of the differential pressure measurement value 72 converges to an appropriate value if the load command signal of the pulverizer 2 is appropriate, and sets the load to an appropriate value of the pulverizer differential pressure. It controls by deviation from.
That is, by correcting the classification setting or controlling the load based on the differential pressure deviation signal 73 calculated by the pulverizer differential pressure target value 71 calculated by the coal supply amount 65 and the differential pressure measurement value 72. The control to keep the differential pressure properly.

  Next, the load correction amount calculation unit 52 of the vibration control device 7 will be described. As shown in FIG. 5, a vibration detection signal 66 corresponding to the vibration of the housing 13 is input from the vibration sensor 6 to the load correction amount calculation unit 52. Specifically, the vibration detection signal 66 is a signal indicating the acceleration of the housing 13 at the mounting position of the vibration sensor 6.

  The load correction amount calculation unit 52 calculates the load correction amount 67 of the load target value 76 so that the vibration of the housing 13 is reduced based on the acceleration of the housing 13. There are three calculated load correction amounts 67: a first load correction amount 67a, a second load correction amount 67b, and a third load correction amount 67c. The first load correction amount 67a, the second load correction amount 67b, The third load correction amount 67c is a correction amount for correcting the load applied to the first roller unit 28a, the second roller unit 28b, and the third roller unit 28c, respectively.

  Specifically, the load correction amount calculation unit 52 substitutes the acceleration of the housing 13 into an acceleration-load correction amount function that is a preset control function, thereby making the first load correction amount 67a and the second load correction amount. The amount 67b and the third load correction amount 67c are respectively calculated. Further, the load correction amount calculation unit 52 calculates the correction amount so that the average value of the first load correction amount 67a, the second load correction amount 67b, and the third load correction amount 67c becomes zero.

  Then, the load target value 76 calculated by the target value setting unit 50 is corrected by the load correction amount 67 calculated by the load correction amount calculation unit 52. The corrected load is input to the first hydraulic cylinder 45a, the second hydraulic cylinder 45b, and the third hydraulic cylinder 45c. In the hydraulic cylinder 45, the hydraulic pressure is adjusted according to the input load.

  For example, it is assumed that the acceleration of the housing 13 indicated by an arrow in FIG. 4 is measured. In this case, the load correction amount calculation unit 52 decreases the first load correction amount 67a and increases the second load correction amount 67b and the third load correction amount 67c. As a result, the load commanded to the first hydraulic cylinder 45a decreases and the load commanded to the second hydraulic cylinder 45b and the third hydraulic cylinder 45c increases. That is, the load applied to the first roller unit 28a decreases, and the load applied to the second roller unit 28b and the third roller unit 28c increases.

  When the load applied to the first roller unit 28a from the first hydraulic cylinder 45a decreases, the reaction force received by the first hydraulic cylinder 45a from the first roller unit 28a also decreases. The reaction force also acts on the housing 13 that supports the first hydraulic cylinder 45a. When the reaction force decreases, the displacement of the housing 13 in the same direction as the reaction force is suppressed.

  Here, in FIG. 4, the direction of the reaction force received by the first hydraulic cylinder 45a coincides with the direction of the acceleration of the housing 13 due to vibration, and the reaction force is reduced by reducing the load applied to the first roller unit 28a. By doing so, the displacement of the housing 13 due to vibration can be suppressed.

  On the other hand, when the load applied to the second roller unit 28b and the third roller unit 28c increases, the reaction force received by the second hydraulic cylinder 45b and the third hydraulic cylinder 45c increases. The reaction force also acts on the housing 13 that supports the second hydraulic cylinder 45b and the third hydraulic cylinder 45c. When the reaction force increases, the housing 13 is displaced in the direction of the reaction force.

Here, in FIG. 4, the reaction force received by the second roller unit 28b and the third roller unit 28c includes a component in the direction opposite to the direction of acceleration of the housing 13 due to vibration. If the reaction force is increased by increasing the load applied from the three hydraulic cylinders 45c to the second roller unit 28b and the third roller unit 28c, the displacement of the housing 13 due to vibration can be suppressed.
In other words, as shown in FIG. 4, the direction of the force obtained by combining the reaction forces received by each of the first hydraulic cylinder 45a, the second hydraulic cylinder 45b, and the third hydraulic cylinder 45c is the acceleration of the housing 13 due to vibration. The vibration of the housing 13 is suppressed by setting the direction opposite to the direction of.

Preferably, the acceleration-load correction function used in the initial load value calculation means 56 is set in advance so that the horizontal acceleration of the housing 13 is suppressed to half or less of the allowable value.
That is, for example, when the common load target value 76 is 90 tonf, the vibration control device 7 sets the load input to the first hydraulic cylinder 45a to 86 tonf, the load input to the second hydraulic cylinder 45b to 92 tonf, and the third The load input to the hydraulic cylinder 45c is set to 92tonf. According to such setting, one or two of the first load correction amount 67a, the second load correction amount 67b, and the third load correction amount 67c are set to positive values, and two or one is negative. By being set to a value.

  Next, the supply amount control device 5 will be described in detail. As shown in FIG. 1, the supply amount control device 5 is connected to a vibration sensor 6 of each crusher 2, and a vibration detection signal 68 corresponding to the vibration of each housing 13 is input from each vibration sensor 6. Continue to be.

  The supply amount control device 5 continuously measures the vibration detection signal 68 of each vibration sensor 6 and, in particular, measures the maximum amplitude for each period. Here, when the amplitude of the vibration detection signal 68 exceeds the predetermined range and tends to increase, the supply amount control device 5 determines that the corresponding pulverizer 2 is in an abnormal state. That is, when it is determined that the magnitude of vibration exceeds a predetermined value and the vibration does not decrease and tends to diverge (the amplitude deviation for each period increases), the crusher 2 is in an abnormal state. Judge that there is.

  For example, when the allowable maximum amplitude of vibration is set to 100 mm, when the amplitude is 100 mm or more and the amplitude deviation for each cycle is increased, the pulverizer 2 is determined to be in an abnormal state. Therefore, when the amplitude is smaller than 100 mm, or even when the amplitude is 100 mm or more, if the amplitude deviation for each cycle is reduced, the supply amount control device 5 determines that the crusher 2 is in an abnormal state. Do not judge.

Next, the supply amount control device 5 stops the vibration control device 7 of the pulverizer 2 determined to be in an abnormal state. That is, in the pulverizer 2 in an abnormal state, the vibration control by the vibration sensor 6 and the vibration control device 7 is not performed thereafter.
Then, the supply amount control device 5 issues a command to reduce the coal supply amount 65 to the supply device 3 upstream of the corresponding pulverizer 2. At the same time, the supply amount control device 5 issues a command to increase the coal supply amount 65 to the supply devices 3 of the plurality of pulverizers 2 different from the pulverizer 2 in an abnormal state. That is, the supply amount control device 5 increases the pulverized coal production amount of the pulverizers 2 other than the pulverizer 2 determined to be abnormal so that the pulverized coal production amount in the entire pulverization system 1 does not decrease.

The supply amount control device 5 may be added with a function of reducing the coal supply amount 65 of the pulverizer 2 in an abnormal state and sending a signal for reducing the load of the roller unit 28 of the pulverizer 2.
However, since it takes a predetermined time for the effect of reducing the coal supply amount 65 to appear, the pulverization efficiency may be deteriorated by reducing the load. That is, there is a concern that the amount of coal in the pulverizer 2 increases and exceeds the allowable range of the lift amount of the roller 34. In order to prevent such a situation, it is necessary to provide an emergency stop valve (not shown) in the coal supply pipe 15 of the pulverizer 2.

  According to the above embodiment, the vibration of the pulverizer 2 can be suppressed by controlling the load applied to the roller unit 28, and this control can be stopped when the amplitude of vibration is increased by the control. Due to these effects, the structural reliability of the pulverizer 2 can be improved.

  Moreover, according to the said embodiment, even when some crushers 2 become abnormal in the crushing system 1 consisting of a plurality of crushers 2, the amount of pulverized coal produced in the whole crushing system 1 is kept constant. Can do.

  Moreover, according to the said embodiment, since the urging | biasing apparatus 43 can be comprised with the simple structure using a hydraulic load, the vibration of the housing 13 can be suppressed appropriately.

  According to the above embodiment, the load applied to the roller unit 28 is changed from the common target value to the positive side and the negative side. In this case, the total load applied to the table 23 by the plurality of roller units 28 finally becomes a common target value. For this reason, even if the load is changed, insufficient strength and wear of the table 23 and the roller 34 will not be a problem, and a change in pulverization property will not be a problem.

  Further, according to the above embodiment, since the pulverizer differential pressure quickly converges to an appropriate value corresponding to the supply amount, the deviation between the pulverizer differential pressure target value and the pulverizer differential pressure is used for load correction. Thus, the load can be controlled more appropriately.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment described above, the target setting unit 50 is configured to correct the load using the differential pressure measurement value 72, but is not limited to this, and the load target is calculated only by the load initial value calculation unit 56. The value 76 may be set.

In addition, the supply amount control device 5 may perform control such as reducing the number of rotations of the table 23 as well as the supply amount of coal.
In the above embodiment, the coal pulverizer has been described. However, the control method of the present embodiment can also be applied to a pulverizer such as a biomass raw material or a pulverizer used for mixed pulverization of coal and biomass.

DESCRIPTION OF SYMBOLS 1 Crushing system 2 Crusher 3 Feeder 4 Hopper 5 Supply amount control device (second control device)
6 Vibration sensor 7 Vibration control device (first control device)
13 Housing 17 Rotating classifier (classifying device)
23 Table 24 Grinding surface 26 Duct (Air supply device for powder transfer)
27 Differential pressure gauge (Differential pressure measuring device)
28 Roller unit 34 Roller 43 Biasing device 45 Hydraulic cylinder 50 Target value setting unit 52 Load correction amount calculation unit 55 Differential pressure target value calculation unit 58 Differential pressure deviation calculation unit 65 Coal supply amount 66 Vibration detection signal 67 Load correction amount 68 Vibration Detection signal 71 Crusher differential pressure target value 72 Differential pressure measurement value 74 Load correction signal 76 Load target value

Claims (5)

A substantially cylindrical housing;
A table rotatably disposed in the housing and having an annular grinding surface;
A plurality of roller units including rollers for crushing raw materials in cooperation with the table;
A biasing device that applies a load to the roller unit so as to bias each of the rollers toward the grinding surface of the table;
A vibration sensor that outputs a detection signal corresponding to the vibration of the housing;
A first control device for controlling a load applied to each of the roller units by the biasing device based on a supply amount of the raw material to the grinding surface and a detection signal of the vibration sensor;
A feeder for supplying raw materials;
When the amplitude of the detection signal of the vibration sensor exceeds a predetermined range and tends to increase, it is determined as an abnormal state, the control by the first control device is stopped, and the raw material supplied from the feeder is A pulverizer comprising a second control device for reducing the pulverizer. The biasing device includes a hydraulic cylinder that generates the load according to a supplied hydraulic pressure,
The pulverizer according to claim 1, wherein the first control device adjusts a hydraulic pressure supplied to the hydraulic cylinder. The first controller is
A target value setting unit that sets a load target value that is a common target value of a load to be applied to each of the roller units by the biasing device based on the supply amount of the raw material;
A load correction amount calculation unit that calculates a correction amount of the load target value for each roller unit based on a detection signal of the vibration sensor;
The pulverizer according to claim 1 or 2, wherein the load correction amount calculation unit calculates the correction amount so that an average value of the correction amounts becomes zero. A classifier for recirculating coarse particles of the material to be crushed that has passed through the roller unit to the table and supplying fine particles to the downstream of the pulverizer;
An air supply device for conveying powder that blows up the outer periphery of the table and conveys the object to be crushed by the roller unit to the classifier, and also conveys the fine particles classified by the classifier to the downstream of the pulverizer. When,
A differential pressure measuring device that measures a pulverizer differential pressure including a pressure loss when the powder carrier air passes through the outer periphery of the table; and
The first controller is
A differential pressure target value setting unit for setting a pulverizer differential pressure target value based on the supply amount of the raw material;
A deviation calculating unit for obtaining a deviation between the pulverizer differential pressure target value and the pulverizer differential pressure;
The pulverizer according to claim 3, wherein the load target value is corrected based on the deviation. A plurality of pulverizers according to any one of claims 1 to 4,
A hopper disposed downstream of the plurality of pulverizers and containing fines of the material to be crushed,
The supply amount of raw materials discharged from the feeder upstream of at least one pulverizer of the other pulverizers when any of the pulverizers is in an abnormal state A crushing system characterized by increasing.

Images