SU761007A1 - Method of automatic control of charging drum mill withmillling bodies - Google Patents

Description

The invention relates to methods for regulating the loading of drum mills with grinding bodies'i can be used to automate the processes of grinding raw materials in drum mills in the enrichment of minerals in the chemical color industry and the building materials industry. "

There is a method of automatic control of intra-celled filling with grinding bodies by the difference between the measured parameter value of the drive motor, for example, active power, and the sum of measured loading values of the original ore, water and sand load entering the mill [1].

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The disadvantage of this method is the dependence of the main measured parameter of active power on the technical condition of the drive motor, the drive of the mill, and the main bearings of the mill. When you change the 'hardness and. the particle size distribution of the original ore, the magnitude of the measured active power changes faster than the measured value of the sand load, which has a long transport delay. This leads to an error in estimating the load of the mill with grinding bodies. by

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the proposed difference when changing the mode of grinding.

ι There is another way to automatically control the loading of the drum mill 5 Tsy grinding bodies, including stabi.

“the amount of the initial pulp density inside the mill at the given values, as well as the measurement of the spread of low-frequency pulsations ^{10 of the} parameter characterizing the dynamics of movement of the intra-shallow load, comparison with the set and reloading of the grinding bodies into the mill is proportional to the deviation of the measured value from the set value [2 ]. This method is closer to the invention.

It v'kachestve parameters characterizing the dynamics of movement at the guide vnutrimelnichnoy loading, use dynamic mo ment ·· generated mill drum motor ²⁰ narwhals, and as' measurand dispersion - dispersion of the low-frequency dynamic pulsations ¹ mo ment.

25 The disadvantage of this method is the presence of interference in the instantaneous values of the component power consumption parameter, driven by the drive motor of the mill, generated by a gearbox, a gear pair and

30 main bearings of the mill.

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The aim of the invention is to increase the accuracy of the control. '^' '·

This is the "reach !! in that the load control method avtbmkticheskogo drum melnitsy.melyuschimy bodies included ⁵ 'sistent stabilizing amount -iskhod7-32 ^second power and the pulp density within the mill at zadannyh znachoniYa'h,""as 7 Taksim ^'; nizkbchastotnyh scatter measurement of pulsations pairs etro characterizing Yu' present traffic dynamics vnutrimelnichnoy

“Load, comparison with a given ..... and ..... reloading of grinding bodies into the mill is proportional to the deviation of the measured value from the specified, additionally measured 15 spread value corrects the specified value of the initial power, and the parameter characterizing the dynamics the movements of the intramill loading, are determined by the geometry of the movement of intrame- nel, 20 personal loads, and the measured distance is determined by the central point, the order of which is chosen depending on the required accuracy of "fuguliro". vaiya. ' . . -'ρ- / ’'25

FIG. 1 depicts diagrams, filling the drums with balls 'and the nature of the changes in the corresponding' dispersions of the phases of the dynamic effect of the balls on the lining of the mill; in fig. 2 30 shows the nature of the change in dispersion ·,

^; . the duration of the sensor perception of the dynamic impact of the intramill load on the lining element of the massif. at different levels of loading; by 35

FIG. 3. shows a device for the implementation of the proposed method. . /

Contour / corresponds to optimal intramill loading, ’contours 2 and

respectively, the minimum and maxi-40 mallow in-line loading. ., ·

When the drum rotates, the angle of the cortex}> ω, the ball loading under the action of friction forces, the tangential component of weight and inertia, makes 45 // //. swans around the middle position ·. With increasing “ ^l '' of the LY, the levels of ball loading decrease its oscillations. '

This "leads to a reduction in the dispersion of 50 low-frequency pulsations’ of the dynamic,

Moment on the shaft of its drive electric. -path, "taken as a parameter, character ~ d 't _(the dynamics of the' movement of intra-> mill load / ¹ 7 '/

With fluctuations in ball loading or

the number of milling bodies occur cola b ^g anija ge'ometryy / her movement, h

During the movement of the ball load "or grinding bodies" under the action of <diramiisky weight and inertia, it acts on the lining of the mill. By changing the impact on the drum's drum you can judge the change in the geometry of the movement.

ball loading.

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The geometry of the load movement at a given angular velocity of rotation of the drum and the density of the pulp inside the mill is uniquely determined by the magnitudes of the angles of incidence, the external β balls, and the internal ι load layers (Fig. 2), which are the phases of the dynamic effect of the load on the mill lining. '9' .

With an increase in the level of filling of the scholar load 3–3>17–1> 2–2 (Fig. 2) and a decrease in the oscillations of the geometry of its movement, the oscillations of the angles of incidence β ₃ , β ₂ , βι, ; Negro layers of load. Correspondingly, the dispersion of the phase impact of the intramill loading on the lining of the mill Λ ₃ <7Δ) <Α ₂ decreases. '$

The magnitude of the load can be determined by the duration of the dynamic "impact of intramill. Loading of the spindle lining element of the Mill relative to a predetermined point of origin.

The duration of the dynamic effect of the intramill loading depends on the thickness of the damping "layer" and with the wind _{: the} load is reduced. '··,

With increasing load and decrease in the geometry of its 'movement', fluctuations in the thickness of the layer from the point of fall A to the point of separation B of the balls of the outer layer in the direction of the load along a circular path are reduced.

This leads to a decrease in the oscillations' of the thickness of the damping layer A, which completely dampens the dynamic effects, and consequently, the dispersion of the duration of the dynamic effect of the intramuscular load on the lining element of the grinder relative to the predetermined amount. ment start counting ^Ο,, ΊΔ ₃ <Δι <3Δ2 ·

Obviously, the geometry of the movement of intramill loading and the parameters that characterize it do not depend on the technical condition of the drive of the mill. / </ ...;, /.

To characterize the magnitude of the oscillation or variation of the parameter A around its average value (mathematical expectation of AGI), use the centered value X ° / / '‘‘

Αθ-Α-hell, ё // - ’./ \ ./_/ ////'/,/.'.// '' ''

the numerical characteristics of which are the central moments of the lth order \ '’l'„ -ld (Hdd = '?

‘''’ ’'' With

= M (X - LDA]) “= (.Υ-- M [X]” / 'X) 4X.

7 //%,>,:. / ,,, / 7 _,? 7 _,:

, - ^G. .. V: ·. , _; .//,/,7-7'7; \ '' - '. 7. /, f

7 The most frequently used is the central moment of the 2nd order, called dy-peosia. '

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With an increase in the order n of the central moment, the sensitivity to the variation of the measured parameter increases, since

= M (X - M [X} ⁿ >...> M (X - M [X]) ³ >

'> M (XM [X \ Y> M (X - M [X]).

• This allows you to improve the control accuracy of the measured parameter variation.

The self-grinding mill 4 operates in an open loop. In the armature circuit of its drive motor, an active current sensor 5 is applied, which supplies a signal to the electronic controller 6. The regulator acts on the thyristor control units 7 and 8 of the drives of the fine 9 feeders and large 10 original ores, which are located in the corresponding bins 11 and 12, which are fed by the conveyor 13 into the mill so that the mill is optimally filled with ore.

The regulator 6 simultaneously sends a signal from the scales 14 of the belt conveyor of the initial power supply, which stabilizes the amount of the initial power for a given mill performance. The pulp density in the self-grinding mill is supported by the constant ore-water ratio controller, 15, which receives signals from the sensor 16 output. and conveyor scales 14 source power.

The pulp density of the undercutting product of the mill, [indirectly characterizing its intramill density in the specified mode of its operation, is 5.0% solid.

The local sensor 17 measures the phase of the dynamic effect of the inner layer of the load on the lining of the mill. The dispersion meter 18 continuously measures the dispersion of the low-frequency pulsations of the dynamic effect phase. The magnitude of the variance was 3.38 and was taken for the set value And _ass .

A decrease in the number of grinding bodies in the mill with the same initial feed leads to an increase in the magnitude of the dispersion A> A _ass . · .. '

The size of the dispersion is measured by the secondary device 19 and is fed as a correlating effect on the regulator 'of the initial power supply b and on the input of the regulator of the grinding bodies 20, which acts on the thyristor control unit 8 of the drive' of the large ore feeder in proportion to the deviation of the measured value. dispersion until the dispersion of low-frequency oscillations will not be equal to the specified value And _ass .

When reducing the measured value of the dispersion of the regulator 20 is proportional to its deviation from the set point reduces the load of grinding bodies in the mill.

Claims (1)

Claim The method of automatic control of the loading of the drum mill by grinding bodies, including stabilization of the amount of initial power and pulp density inside the mill at given values, as well as measurement of the magnitude of the scatter of low-frequency pulsations of the parameter characterizing the dynamics of internal load movement, comparison with the specified and dose-load of grinding bodies into the mill is proportional to the deviation of the measured value from the set value, characterized in that, in order to increase the control accuracy, it is additionally measured scatter correcting value predetermined initial power value, wherein the parameter characterizing the dynamics of movement vnutrimelnichnoy z.agruzki, determined by the geometry vnutrymelnichnoy loading movement, and the measured value of dispersion is determined through the central point, the procedure of which is selected depending on the required control accuracy. . , .................