JPH08196935A - Method and device for judging completion of residual coal discharge for coal crusher - Google Patents

Abstract

PURPOSE: To monitor securely the residual coal discharge state in a coal crusher and judge securely the completion of residual coal discharge by providing a means of comparing the vibration value of a coal crusher in the process of discharging the residual coal with the vibration value in the state without residual coal and make a judgment. CONSTITUTION: An electric current value of a motor is measured by a current sensor 1. The electric current value of the motor in the unloading state is set in a signal setting instrument 2, and the measured current value is compared with the current design value at the time of no-loading by an operator 3, and the state that the difference is within the given value is judged by a judging instrument 4. A vibration sensor 5 is set on a casing section to which the vibration of a coal crusher, and the vibration value output from an amplifier 6 is compared with the output value of a setting instrument 7 setting the vibration value of the state without residual coal by an operator 8, and the state that the difference is within the given value is judged by a judging instrument 9. The completion of the residual coal discharge process of the coal crusher is judged accurately and with good reproducibility by the arrangement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coal-fired boiler using pulverized coal pulverized by a coal pulverizer as a fuel, and particularly for pulverizing coal when discharging residual coal in the coal pulverizer stopped with residual coal left. The present invention relates to a residual coal discharge completion determination method for a coal crusher capable of easily and accurately determining the completion timing of residual coal discharge without inspecting the inside of the machine, and an apparatus for implementing the method.

[0002]

2. Description of the Related Art As a method for discharging residual coal when a conventional coal crusher stops with residual coal remaining, a washing water or the like is injected while rotating the rotary part of the coal crusher to remove residual coal in the pyrite hopper. Was being discharged. As a method of confirming the discharge status of the residual coal inside the coal crusher, the structure that cannot confirm the presence or absence of residual coal inside the coal crusher,
Depending on the status of the residual coal discharged from the viewing window of the pyrite hopper part, it can be judged that the discharge of residual coal has been completed by confirming that pulverized coal is not mixed in the wastewater, and the crusher Conventionally, no consideration has been given to the method and means for confirming that the discharge of the residual coal inside has been completed. As a conventional technique similar to the present invention, there is, for example, Japanese Patent Laid-Open No. 4-83541, "Coal Mill Stopping Method".

[0003]

As described above, in the prior art, the determination of the completion of the residual coal discharge processing inside the coal crusher is performed by visually monitoring the discharge state of the residual coal at the pyrite hopper portion due to the cleaning water. The state of discharge of residual coal inside the coal crusher has not been confirmed, and it is judged that the discharge of residual coal has ended by washing until pulverized coal is no longer mixed in the wash water, and coal crushing is performed. Since the internal condition of the machine was not confirmed, there was a problem in terms of reliability as a reliable judgment for the end of residual coal discharge.

An object of the present invention is to eliminate the above problems in the prior art, to reliably monitor the state of discharge of residual coal inside a coal crusher, and to reliably determine the completion of discharge of residual coal. To provide a method for determining residual coal discharge completion of a high-performance coal crusher and an apparatus for implementing the method.

[0005]

In order to achieve the above-mentioned object of the present invention, a structure as set forth in the claims of the present invention is adopted. That is, according to the present invention, as described in claim 1, in a coal pulverizer that supplies pulverized coal to a coal-fired boiler that uses pulverized coal as a fuel, a residual coal discharge end determination method in the case of stopping with residual coal remaining. A means for comparing and determining the vibration value of the coal pulverizer in the process of discharging the residual coal by rotating the movable part of the coal pulverizer while injecting the non-combustible medium, and the vibration value in the state without residual coal, Using at least means for comparing and determining the current value of the electric current of the motor of the coal crusher and the current value in the state without residual coal in the process of rotating the movable part of the coal crusher and discharging residual coal, the residual coal discharge completion state This is a method for determining the end of residual coal discharge in a coal crusher. Further, as described in claim 2, the present invention uses steam or nitrogen gas as the nonflammable medium in claim 1. Further, according to the present invention, as described in claim 3, in a coal crusher for supplying pulverized coal to a coal-fired boiler that uses pulverized coal as a fuel, a residual coal discharge completion determination device when the residual coal is left and stopped. The vibration value of the coal crusher in the process of discharging the residual coal by rotating the movable part of the coal crusher while injecting the non-combustible medium is detected by the vibration detector installed in the casing part of the coal crusher. The vibration value amplified by the amplifier, the vibration value, and the output value of the setter that sets the vibration value in the state without residual charcoal are compared and calculated by the arithmetic unit, and the deviation becomes less than the predetermined value A means for determining by means of a determiner that the discharge of the is completed, a current detector for detecting the current value of the load state of the electric motor of the coal crusher in the process of discharging the residual coal by rotating the movable part of the coal crusher, Current under the above load condition And the output value of the setter that sets the current value of the motor in the state without residual coal, that is, in the no-load state, is compared and calculated, and it is determined that the deviation is less than the specified value and the discharge of residual coal is completed. The means for making a determination by means of a vessel is a residual coal discharge completion determining device in at least a coal crusher provided.

[0006]

In the method for determining the end of coal discharge in the coal crusher of the present invention, the load factor of the electric motor of the coal crusher can be substituted by the electric current value, and if the amount of the remaining coal in the coal crusher becomes small, it will rotate. The current value tends to decrease as the resistance of the part decreases, and the current value in the no-load state stabilizes. In addition, the vibration of the coal crusher tends to rise above the vibration level during coal crushing due to the slip phenomenon when the rotating part makes contact with the metal, so by monitoring these conditions quantitatively, It is possible to accurately grasp the end time of the discharge of the remaining coal. Therefore, it is possible to reliably estimate the state of residual coal without performing an overhaul of the inside of the coal crusher. That is, according to the present invention, as described in claim 1, since the load of the electric motor of the coal crusher changes depending on the amount of the residual coal in the coal crushing section, the current value of the electric motor in the process of discharging the residual coal and the residual value A means for comparing and determining the current value in the state without charcoal, that is, the current value in the no-load state, and the vibration value in the process of discharging the residual coal of the coal crusher and the vibration value in the state without residual coal are compared and determined. Since the time when the discharge of the residual coal is completed is confirmed by both of the means and the means, it is possible to determine the end of the discharge of the residual coal that is extremely accurate and highly reliable. Further, as described in claim 2, since it is performed while supplying steam or nitrogen gas as a non-combustible medium to the crushing part of the coal, the vibration of the crusher changes as compared with the case of using conventional washing water. It is possible to accurately detect a change in the load of the electric motor and accurately determine the end of discharging the residual coal. Claim 3
As described in, the vibration value of the coal crusher in the process of rotating the movable part of the coal crusher while discharging the residual coal while injecting the non-combustible medium, by the vibration detector installed in the casing part of the coal crusher. The vibration value detected and amplified by the amplifier, the vibration value, and the output value of the setter that sets the vibration value in the state without residual charcoal are compared and calculated by the calculator, and the deviation is less than the predetermined value. A means for determining with a determiner that the discharge of the residual coal is completed, and a current detector for detecting the current value of the load state of the motor of the coal crusher in the process of rotating the movable part of the coal crusher to discharge the residual coal. And the current value in the above-mentioned load state and the output value of the setter that sets the current value of the electric motor in the state without residual coal, that is, in the no-load state are compared and calculated, and the deviation becomes less than or equal to a predetermined value That the discharge of And means for determining by Joki, since use of at least residual carbon emissions end judging device provided, similarly to the claim 1, there is an effect capable of determining very accurately, and the discharge end of reliable residual carbon.

[0007]

Embodiments of the present invention will be described below in more detail with reference to the drawings. FIG. 1 is a system diagram showing an example of a residual coal discharge end determination method in the coal crusher illustrated in this embodiment. In the figure, since the load factor of the electric motor of the coal crusher changes depending on the amount of residual coal in the coal crushing unit in the crusher, the current value of the electric motor is measured by the current detector 1. The current value of the motor in the no-load state is set in the signal setter 2, and the calculator 3 compares the current value measured by the current detector 1 with the current set value 2 under no load. , The discriminator 4 that the deviation is within a certain value
Determined by Since it is difficult to measure the vibration of the coal crusher in the rotating part which is the coal crushing part, the vibration detector 5 is installed in the casing part where the vibration is well transmitted, and the vibration value output by the amplifier 6 and the residual coal The output value of the setter 7 that sets the vibration value in the state of is compared by the calculator 8 and the determiner 9 determines that the deviation is within a certain fixed value. By satisfying the above conditions, it was possible to accurately and reproducibly determine that the residual coal discharging process inside the coal crusher was completed.

[0008]

EFFECTS OF THE INVENTION According to the method and apparatus for determining residual coal discharge completion in the coal crusher of the present invention, the load factor of the electric motor of the coal crusher can be substituted by the current value, and the residual coal in the coal crusher If the amount of holding is small, the resistance of the rotating part becomes small and the current value tends to decrease, and the current value in the no-load state stabilizes. In addition, the vibration of the coal crusher tends to rise above the vibration level during coal crushing due to the slip phenomenon when the rotating part makes contact with the metal, so by monitoring these conditions quantitatively, It is possible to accurately grasp and determine the discharge end time of the remaining coal. Therefore, it is possible to reliably estimate the state of the residual coal without opening and inspecting the inside of the coal crusher, and it is possible to accurately estimate the state of the residual coal treatment inside the pulverized coal machine, which is highly reliable. It is possible to obtain the result of determining the end of the residual coal discharge.

[Brief description of drawings]

FIG. 1 is a system diagram showing a residual coal discharge completion determination method for a coal pulverizer exemplified in an embodiment of the present invention.

[Explanation of symbols]

 1 ... Current detector 2 ... Signal setter 3 ... Calculator 4 ... Determination device 5 ... Vibration detector 6 ... Amplifier 7 ... Setting device 8 ... Calculator 9 ... Determination device 10 ... Delay action device

Claims (3)

[Claims] 1. A method for determining the discharge of residual coal when a coal pulverizer that supplies pulverized coal to a coal-fired boiler that uses pulverized coal as a fuel is left with residual coal, and a non-combustible medium is injected. While rotating the movable part of the coal crusher means for comparing and determining the vibration value of the coal crusher in the process of discharging residual coal and the vibration value in the state without residual coal, and the movable part of the coal crusher. Characterized in that at least a means for comparing and determining the current value of the electric motor of the coal crusher in the process of discharging the residual coal and the current value in the state without residual coal is used to determine the residual coal discharge completion state. Method for judging the end of discharge of residual coal in a coal crusher. 2. A residual coal discharge completion determination method in a coal crusher according to claim 1, wherein steam or nitrogen gas is used as the nonflammable medium. 3. A coal crusher for supplying pulverized coal to a coal-fired boiler that uses pulverized coal as a fuel, which is a device for determining the end of residual coal discharge when the coal is stopped with remaining coal and injecting a non-combustible medium. While the vibration value of the coal crusher in the process of discharging the residual coal by rotating the movable part of the coal crusher, the vibration value detected by the vibration detector installed in the casing part of the coal crusher, and the vibration value amplified by the amplifier, The vibration value and the output value of the setter that sets the vibration value without residual coal are compared and calculated by a calculator, and it is determined that the deviation is less than a predetermined value and the discharge of residual coal is completed. And a current detector for detecting the current value of the load state of the motor of the coal crusher in the process of discharging the residual coal by rotating the movable part of the coal crusher, and the current value of the load state, State without residual coal Then, by comparing and calculating the output value of the setter that sets the current value of the electric motor in the no-load state, the deviation is equal to or less than a predetermined value, and means for determining by the determiner that the discharge of the residual coal is completed, A residual coal discharge completion determination device in a coal crusher, which is provided with at least one.