KR101890146B1 - Condition detecting method and device for trouble diagnosis of ball mill - Google Patents

Abstract

An object of the present invention is to provide a condition detecting method for the trouble diagnosis of a ball mill, which measures the vibration and noise of a ball mill in real time using a vibration and acoustic sensor and analyzes measurement values to detect the condition of the ball mill and diagnoses trouble. More specifically, it is possible to quantitatively set a warning value suitable for a type of ball mill, the operating condition of the ball mill and the like, by using vibration and noise measurement values measured in real time.

Description

Technical Field [0001] The present invention relates to a condition detecting method and apparatus for a pulverizer abnormality diagnosis,

More particularly, the present invention relates to a ball mill for grinding a sample by an impact caused by ball motion by receiving and rotating a plurality of balls and a sample together, And more particularly, to a method and apparatus for detecting a state of a pulverizer abnormality.

The ball mill is widely used for crushing a sample. In general, a ball mill is rotated by receiving a plurality of balls and a sample in a cylindrical body rotating on a horizontal axis, To thereby crush the sample. The balls contained in the ball mill are made of materials such as cast iron, cold racing, flint, and natural stone that are strong enough to crush the sample by crushing it. The performance of the milling operation of the ball mill is varied depending on the material / amount of the sample, the material / diameter / weight of the ball, and the rotational speed of the drum.

The ball mill is divided into a continuous type and a non-continuous type. An example of a continuous ball mill is disclosed in Korean Utility Model Application No. 1995-0026834 ("Continuous Vibrating Ball Mill ", Oct. 16, 1995), in which a plurality of pulverizing drums are vertically arranged, So that the sample pulverized in one drum flows into the other drum to be continuously pulverized in stages. The non-continuous ball mill grinder is similar in that grinding a sample using a grinding drum is different, except that the grinding is carried out by charging the sample and then the sample is again removed from the ball mill.

In ball mill grinder, many balls continuously move in the drum during operation, and impact is generated in the process of crushing and colliding with the sample, so that noise and vibration are considerably generated during operation. On the other hand, when abnormal conditions such as excessively hard or too large samples are not properly crushed or a failure occurs in the apparatus itself, considerable noise and vibration are generated even when the ball mill is normally operated as described above , It is not easy for the operator to detect such an abnormal state.

Conventionally, in order to detect the abnormal state of the ball mill, the operator diagnoses the abnormality based on the subjective judgment or the abnormality is diagnosed based on the vibration standard unilaterally proposed by the pulverizer manufacturer. Since such a conventional method has a considerably low reliability, accuracy and reproducibility, there is a need for a method of diagnosing abnormality of the ball mill with a higher reliability. In particular, as described above, continuous and discontinuous ball milling machines require different methods of diagnosing abnormal conditions because of different operating modes and device characteristics.

1. Korean Utility Model No. 1995-0026834 ("Continuous Vibrating Ball Mill ", Oct. 16, 1995)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a vibrating and acoustic sensor for measuring vibration and noise of a crusher in real time, The present invention also provides a method and an apparatus for detecting a state of a pulverizer for detecting a state and diagnosing an abnormality. More particularly, the present invention relates to a state detection method for a pulverizer abnormality diagnosis, which can quantitatively set an alarm value appropriately corresponding to each operation condition of a pulverizer, a kind of a pulverizer, etc. using vibration and noise measurement values measured in real time And an apparatus.

According to an aspect of the present invention, there is provided a method for detecting a state of a pulverizer abnormality, comprising: operating a pulverizer (500) to detect a state change from a measurement sensor (110) installed in the pulverizer A measurement value acquisition step in which a vibration or noise measurement value is obtained; A measurement value correction step in which the measurement value is corrected according to an operation condition; A measurement statistical analysis step in which measurement values for a predetermined period are statistically analyzed to derive a probability density function and a statistical characteristic value; An alarm value setting step of setting an alarm value using a statistical property value of measurement values; . ≪ / RTI >

At this time, the measurement value correcting step is a step of correcting the measured value by at least one of the sample material, the sample loading amount, the ball material, the ball diameter, the ball weight and the drum rotation speed, So that the measured value can be corrected.

In addition, the state detection method for the pulverizer abnormality diagnosis may include a pulverizer type determination step of determining whether the pulverizer 500 is continuous or non-continuous, between the measurement value correction step and the measurement statistical analysis step; A measurement value addition correction step in which, when the pulverizer (500) is a non-continuous type, the measurement value is further corrected according to the pulverization progress; And when the grinder 500 is a continuous type, the measurement statistical analysis step may be performed immediately after the grinder type determination step.

Further, at this time, in the measurement addition correction step, further correction may be performed by normalizing the measurement values for each grinding operation, which are performed discontinuously. Alternatively, the measurement addition correction step may be further corrected by using a ratio between measurement values for each grinding operation which is discontinuous.

In addition, the measurement statistical analysis step may be performed such that at least one selected from an average value, a median value, and a standard deviation is derived as statistical characteristic values.

In addition, the state detection method for the pulverizer abnormality diagnosis may include: generating an alarm after the alarm value setting step, when the measurement value acquiring step is performed again, when the measured value becomes equal to or greater than the warning value; As shown in FIG.

In addition, the state detecting apparatus for diagnosing a pulverizer abnormality according to the present invention is a state detecting apparatus (100) for pulverizer abnormality diagnosis using the state detecting method for pulverizer abnormality diagnosis as described above, One measurement sensor 110; An alarm unit 120 for generating an alarm; A controller 130 for receiving a measurement value from the measurement sensor 110 to perform a statistical analysis, and operating the warning unit 120 when the measured value is equal to or greater than a warning value; . ≪ / RTI >

Also, the measurement sensor 110 may be at least one selected from a vibration sensor or a noise sensor.

According to the present invention, it is possible to quantitatively diagnose abnormalities of the pulverizer in a pulverizer, particularly a ball mill pulverizer. Conventionally, a state abnormality was diagnosed based on the subjective judgment of the operator or the vibration reference value provided by the manufacturer. As the operating conditions of the crusher such as the material / amount of the sample, the material / diameter / weight of the ball, the rotation speed of the drum and the type of crusher such as continuous / In the past, there was a problem because it diagnosed the state abnormality with a single warning criterion determined without such precise grounds. However, according to the present invention, the alarm value is quantitatively derived from the vibration and noise measurement values measured in real time, and the status abnormality is diagnosed by using the warning value thus derived, so that the reliability, accuracy and reproducibility There is a big effect.

1 is a schematic view of a ball mill.
2 is a schematic diagram of a state sensing device of the present invention.
3 is a flow chart of a state detection method of the present invention.
FIG. 4 is an example of statistical analysis and warning value derivation in the state detection method of the present invention. FIG.
Figure 5 is an example of measurements of a non-continuous mill.
Figure 6 is an example of measurements of a continuous mill.
7 is an example of measurement correction in the state detection method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and apparatus for detecting a state of a pulverizer according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows a schematic view of a ball mill. As shown in the figure, the ball mill has a plurality of balls and a sample accommodated in a drum that rotates about a horizontal axis. In the process of rotating the ball and the sample together by the drum rotation, So that the sample is crushed by the action of the crushing of the sample. In general, the degree of crushing of a sample is determined by the diameter of the ball. However, the crushing condition of the crusher such as material / loading amount of the sample, material / diameter / weight of the ball, The degree of noise and vibration generated varies depending on the type.

Conventionally, in order to diagnose abnormality of the state of the ball mill, it is used based on the subjective judgment of the operator or the vibration reference value provided by the manufacturer. However, as described above, since the degree of generated noise and vibration varies depending on the operating condition of the crusher, the kind of the crusher, etc., it is not accurate to judge the state anomaly based on only one criterion. Accordingly, the present invention is intended to provide a method and apparatus for detecting the state of a pulverizer capable of more quantitatively diagnosing an abnormality without being limited to the operating condition or the device type.

FIG. 2 is a schematic diagram of a state sensing apparatus of the present invention. As shown in FIG. 2, the state sensing apparatus of the present invention includes at least one measurement sensor 110 installed in the crusher 500, a warning unit 120 for generating a warning, And a controller 130 for receiving a measurement value from the measurement sensor 110 to perform a statistical analysis and operating the warning unit 120 when the measured value is equal to or greater than a warning value. In this case, the measurement sensor 110 may be a vibration sensor or a noise sensor, so that the measurement value measured by the measurement sensor 110 becomes a vibration or noise value.

3 shows a flow chart of the state detection method of the present invention. The state detection method for the pulverizer abnormality diagnosis of the present invention can basically include a measurement value acquisition step, a measurement value correction step, a measurement statistical analysis step, and an alarm value setting step. The method may further include determining a type of a pulverizer and determining a type of the pulverizer to reflect the type of the pulverizer, and further correcting the measurement value. Further, after the alarm value is set by these steps, an alarm generating step may be further performed to generate the alarm using the warning value thus quantitatively calculated. Hereinafter, a basic embodiment, a further embodiment and an optimum embodiment will be separately described.

Basic embodiment

The basic embodiment may include a measurement acquisition step, a measurement correction step, a measurement statistical analysis step, and an alarm value setting step.

In the measurement value acquisition step, vibration or noise measurement values varying with time are obtained from the measurement sensor 110 installed in the crusher 500 while the crusher 500 is operating.

In the measurement value correction step, a measurement value corrected in accordance with the operation condition is derived. Here, the operating condition refers to variables such as a sample material, a sample loading amount, a ball material, a ball diameter, a ball weight, and a drum rotation speed. For example, even if pulverization is carried out using the same balls and drums, the vibrations naturally occurring in pulverizing the sample A, which is a hard material, and the sample B, which are relatively soft, are different. Alternatively, even if the same sample A is pulverized, the vibrations generated even when pulverizing a small amount and pulverizing a relatively large amount are different. In consideration of these points, the measurement value is corrected using a function or table (s) calculated in advance according to the operating condition through grasping the characteristics of the crusher, so that statistical analysis can be smoothly performed. The characteristics of the crusher according to the operating conditions can be identified through a number of experiments prior to mass production through a crusher, and they can be used for function calibration or tabulation and correction of the measured values through curve fitting. For example, the magnitude of the vibration according to the rotational speed of the ball mill (drum) can be curved by a quadratic function.

Where v is the magnitude of the vibration and Ω is the rotational speed. The coefficients a, b, and c are values previously determined through a number of experiments.

In the measurement statistical analysis step, the measurement values for a predetermined period are statistically analyzed to derive a probability density function and a statistical characteristic value. The period may be appropriately determined according to the operating conditions and the like. FIG. 4 shows an example of statistical analysis and warning value derivation in the state detection method of the present invention. As shown in FIG. 4A, the vibration measurement value with time (in the example of FIG. ), And can be expressed in a distribution form for statistical analysis as shown in FIG. 4 (B). A probability density function can be derived from the distribution of FIG. 4 (B), and an average value, a median value, a standard deviation, and the like can be derived as statistical characteristic values.

In the alarm value setting step, the alarm value is set using the statistical property value of the measured value values. As a concrete example, in FIG. 4 (B), the value 2.33 times the standard deviation is set as a warning value. Of course, this is merely an example, and the warning value may be appropriately set according to the operating condition or the like, such as a value twice the standard deviation or a value three times the average value.

As described above, it is obvious that the criterion that can be diagnosed to be abnormal according to the various operating conditions and the kind of the crusher should be changed. However, in the past, the faulty diagnosis was made according to the subjective judgment of the operator or only one standard provided by the manufacturer There were a lot of problems. However, in the present invention, as described above, the warning value to be a reference is set according to various operating conditions, and accordingly, the reliability, accuracy, and reproducibility of the pulverizer abnormality diagnosis can be improved much more.

Additional Embodiment

In a further embodiment, a step of further correcting the measurement according to the type of grinder is added. That is, in the basic embodiment, only the warning value is set according to the operating condition. However, in the additional embodiment, the warning value can be set in consideration of the type of the pulverizer in addition to the operating condition.

Fig. 5 shows an example of measured values of a discontinuous pulverizer, and Fig. 6 shows an example of measured values of a continuous pulverizer. As shown in Fig. 5, in the case of the discontinuous pulverizer, a certain amount of the sample is pulverized and a new sample is charged again. At this time, as the crushing of the sample progresses, the magnitude of vibration tends to decrease. In the case of a device in which the magnitude of the vibration greatly changes as described above, it is difficult to set the warning value in order to diagnose the abnormal condition, so an additional correction step is necessary.

Fig. 6 is a measurement example of a continuous pulverizer. Unlike the non-continuous type ball mill, since the sample is continuously charged, pulverized and removed, the state of the sample inside the ball mill is constant with time. Accordingly, the measurement result is also small with time, and the alarm value setting by the statistical analysis described in FIG. 4 can be applied without an additional correction step.

Figure 7 illustrates a measure correction example for a discontinuous mill of the present invention. As shown in FIG. 5, since the magnitude of the measured value changes according to the grinding progress, additional correction is performed to reduce the amount of change. As a further correction, a method of determining the ratio of two measurement values that change with time may be used. That is, if one measurement value (FIG. 7 (A)) that varies with time is similarly divided by another measurement value that varies with time, the degree of change with time can be reduced as shown in FIG. 7 (B). Accordingly, the measurement value of the non-continuous type pulverizer can be processed similarly to the measurement value of the continuous type pulverizer, and the warning value setting by statistical analysis can be applied.

Optimal Embodiment

As described above, after the warning value is optimized in accordance with the operation condition, the type of the crusher, and the like, it is possible to perform the fault diagnosis in real time while operating the crusher by using the warning value thus set.

After setting the warning value through the above-described basic embodiment or further embodiment, as shown by a dotted line in FIG. 2, the operation of the grinder 500 and the operation of the measurement sensor 110 installed in the grinder 500 The measurement acquiring step in which a time-varying vibration or noise measurement is obtained for the state detection is performed again.

When the measured value is equal to or greater than the warning value, the alarm generating step for generating a warning is performed. Thus, the operator can easily recognize that the abnormality has occurred in the crusher.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It goes without saying that various modifications can be made.

100: status detecting device 110: measuring sensor
120: warning part 130:
500: crusher

Claims (9)

Obtaining a vibration or noise measurement value varying with time for sensing the state from a measurement sensor installed in the crusher while operating the crusher;
A measurement value correction step in which the measurement value is corrected according to an operation condition;
A measurement statistical analysis step in which measurement values for a predetermined period are statistically analyzed to derive a probability density function and a statistical characteristic value;
An alarm value setting step of setting an alarm value using a statistical property value of measurement values;
, ≪ / RTI >
Between the measurement correction step and the measurement statistical analysis step,
Determining whether the pulverizer is continuous or non-continuous;
A measurement value addition correction step in which, when the pulverizer is discontinuous, the measurement value is further corrected according to the pulverization progress;
Further comprising:
Wherein when the grinder is a continuous type, the measurement statistical analysis step is performed immediately after the grinder type determination step.
2. The method according to claim 1,
Wherein the operating condition is at least one selected from among a sample material, a sample loading amount, a ball material, a ball diameter, a ball weight, and a drum rotational speed,
And a measurement value is corrected using a function or a data table calculated in advance according to the operation condition.
delete 2. The method according to claim 1,
Characterized in that the measurement values for each of the grinding operations which are carried out discontinuously are normalized so that further correction is made.
2. The method according to claim 1,
Wherein further correction is made by using a ratio between measurement values for each of the grinding operations which is performed discontinuously.
2. The method according to claim 1,
Wherein at least one of an average value, a median value, and a standard deviation is derived as a statistical characteristic value.
The method according to claim 1,
After the warning value setting step, the measurement value acquiring step is performed again,
An alarm generating step of generating a warning when the measured value becomes equal to or greater than the warning value;
Further comprising the steps of: detecting a state of the pulverizer;
A state detection apparatus for a pulverizer abnormality diagnosis using a state detection method for pulverizer abnormality diagnosis according to any one of items 1, 2, 4, 5, 6, and 7,
At least one measuring sensor installed in the crusher;
An alarm unit for generating an alarm;
A controller for receiving a measurement value from the measurement sensor to perform statistical analysis, and operating the warning unit when the measured value is equal to or greater than a warning value;
And a state detector for detecting the pulverizer abnormality.
9. The apparatus according to claim 8,
A vibration sensor, and a noise sensor.

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