SU1740062A1 - System for monitoring diameters of balls in mill - Google Patents

Abstract

The invention relates to the automatic control of ball drum mills, can be used in heat and power, construction and other industries of the industry and improves the accuracy of control of the diameter of the balls. The system contains an acoustic sensor 1, a band-pass filter 2, an amplitude detector 3, an extreme controller 4, a frequency equalizer 5, a dial gauge 6 of the millimeter in the light, a mill speed sensor 7, a mill chamber setting knob 8, a multiplier unit 9, dividing block 10 , block 11 summation, block 12 multiplying, block 13 extracting the square root, block 14 subtraction, recording device 15.1 Il.

Description

Where

Tsn

1 -k V

kR2

Ri

RI - mill radius in the world, m;

R2 — internal loading radius, m; (p - filling mill;

n is the frequency of rotation of the mill rpm;

Tsh.z. - circulation period of the ball load, s;

Tm is the period of rotation of the mill drum, s;

Cn is the mill circulation feedrate.

When the ball load is applied directly to the body, only the outer layer of the balls interacts, therefore the number of balls in the outer layer can be calculated by the formula

f

Gsp

where M is the number of balls in the outer layer;

L is the length of the camera in the light, m;

rs is the volume density of the balls, kg / m;

tsh - the mass of the ball of average diameter, kg.

The frequency of collisions of the outer layer of balls on the body of the mill, can be determined from the ratio

M

f

Ty

-one

where f is the frequency, s

Thus, we get

f 0, W

where - the average diameter of the balls, m;

Do is the diameter of the mill drum in the light, m;

/ Em steel density (ball material),

kg / m3.

Accepting a 0.1, we get the end / / M

the exact form of the ratio that determines

0

five

0

five

0

five

0

five

15

dm -

1 L n (, 2 (f (

Ln + 4Do -itn)

f

(five)

By controlling the change in the frequency of rotation of the mill, the length of the chamber, the diameter of the chamber in the light, they increase the accuracy of the automatic control of the diameter of the balls.

The drawing shows the block diagram of the control system of the diameter of the balls in the mill.

The control system for the diameter of the balls in the mill contains an acoustic sensor 1, a band-pass filter 2, an amplitude detector 3, an extreme controller 4, a frequency equalizer 5, a dial gauge 6 of the quadruple mill diameter, a mill drum spin speed sensor 7, a chamber length adjuster 8, the first block 9 multiplication unit 10 division, summation unit 11, second multiplication unit 12, square root extraction unit 13, subtraction unit 14, recording device 15.

Acoustic sensor 1 senses the noise of the mill, the noise signal arrives at the first input of the tunable band-pass filter 2, which from the entire frequency spectrum selects the frequency determined by the feedback target consisting of amplitude detector 3, extreme regulator 4 and frequency corrector 5 and which is the maximum frequency of the acoustic signal. The frequency equalizer signal is fed to the input of dividing unit 10 and is the denominator. To the other input of block 10, i.e. the numerator, the value of the mill rotation frequency correction signal is received, which is detected by the mill 7 rotation frequency sensor 7. The output signal of the division unit 10 is fed to the input of the summation unit 11, to another input of which a signal is supplied from the setting unit 6 of the quadruple chamber diameter in the light. The sum signal is fed to the input of the multiplication unit 12, the second input of which receives the signal from the output of the division unit 10. Of

obtained at the output of the signal multiplying unit 12 using the square root extraction unit 13, the root value is extracted and fed to the input of the subtraction unit 14. The signal from block 10 is supplied to another input. The difference between these two signals determines the average diameter of the ball in the mill. A difference signal is applied to the recording device 15.

Using the system of automatic control of the diameter of the balls in the mill provides an increase in the accuracy of control when the average diameter of the balls changes from 0.085 to 0.065 m. Moreover, as the balls wear, the accuracy of control of the degree of wear increases.

Claims (1)

The invention The system for monitoring the diameter of balls in a mill, including an acoustic sensor, a band-pass filter, an amplitude detector, an extreme controller, a frequency corrector and a recording device, is characterized in that it is equipped with a unit for quadrupled diameter of the mill chamber in order to increase the accuracy of control of the diameter of balls in the world, a mill drum speed sensor, a mill chamber length adjuster, two multiplication blocks, a dividing unit, a summation unit, a square root extraction unit and a block m subtraction, with the acoustic sensor connected to the first input of a bandpass filter, the second the input of which is connected to the output of the frequency equalizer, and the output of the bandpass filter is connected through an amplitude detector connected in series, an extremal controller with a frequency equalizer input, the output of the frequency corrector is connected to the first input of the division unit, the second input of which is connected to the output of the first multiplication unit, to the inputs of which the mill drum speed sensor and the mill chamber length adjuster are connected, the output of the dividing unit is connected to the first input of the summation unit, the second input of which is under It is connected to the output of the sensor of the quadruple chamber diameter. mills in the light, and the output of the summation unit is connected to the first input of the second multiplication unit, the second input of which is connected to the output of the division unit, the output of the second multiplication unit is connected through the square root extraction unit to the first input of the subtraction unit, the second input of which is connected to the output of the division unit, and the output of the subtraction unit is connected to the input of the recording device.