SU1237252A1 - System for controlling tray vibratory weigher of ball mills - Google Patents

Description

This invention relates to the dosing of bulk materials.

The aim of the invention is to improve the control accuracy.

The drawing shows a control system for a tray vibratory feeder.

The tray vibration control system contains a hopper 1 of the source bulk material, an actuator 2 of a tray vibropit l 3, suspended on a spring suspension 4 to the bunker 1. Next to the bunker 1, a single-ball loading of the grinding bodies is installed, consisting of a hopper 5 of a ball with electromagnetic the actuator 6 of the sharopite bodies for single-ball feeding of grinding bodies into the tray 7. The dispenser tray 7 is installed with a constant angle of inclination and is suspended on a spring hanger S. Tray oscillations are created by the unbalanced vibratory alarm 9. In addition, the vibrating drum contains a vibration sensor 10

 Software time relay 11, -integrators 12, 13 and 14, keys 15, 16 and 17, weight converter 18, linear potentiometer 19, power sensor 20, subtraction unit 21, operational amplifier 22, reversing motor 23, secondary device 24, controller 25 with a setting device 26. The vibrating dispenser also contains a ball detector 27 at estrus 28, unbalanced pathogens 29. The tilt of the tray is effected relative to the semi-axes 30.

The control system of a trough vibratory dosing unit for ball mills operates as follows.

Adjustable hopper feed

The 1 std material is carried out by changing the angle of inclination of the vibrating feeder 3 by an actuator

2 depending on the signal of the controller 25 performance. Bulk material is fed into the vibrating drum tray 7, the passage through which falls into the outlet 28. The capacity Q of the dispenser is defined by the formula

, 6 - 3.6. (t / h)

Q - consumption of bulk material

t / h;

G is the weight of the material on the tray, kg; V - linear velocity of bulk

material, m / s; L is the length of the tray, m; t is the time of movement of the material along the tray, p.

15

20

five

YU

2372521

Thus, the task of determining the flow rate of the bulk material is reduced to the simultaneous measurement of the material's chests on the tray and its speed, or the time of movement of the material flow through the tray. The weight of the bulk material that is on the vibrating dispenser tray-flow sensing element can be determined simply by using a weight sensor or by the amplitude of the vibration of the tray, which is proportional to the amount of material on the tray and measured by the vibration sensor 0. As a flow-sensitive element, A metal ball is used to determine the flow rate of the material in the tray.

It is known that in ball mills material grinding occurs due to the energy of falling balls, which are subject to intense abrasion during operation.

The most effective is the continuous single-ball loading of balls into the mill as they occur. wear, and not a one-time after several days, for example, by the indirect wear parameter — the power consumed by the electric drive of the mill, which is proportional to ball filling.

To determine the flow rate of the material, the sharpener of the 5 ball hopper is fed into the dispenser tray using a ballooning tool, and its passage is recorded at the exit of the tray using a balloon detector 27, which is, for example, an inductive coil or capacitor 9 a The flow rate of the material is determined by the time of the passage through the tray. The ball in the flow of bulk material moves at the same speed as it. The trigger time of the charger is set either by only the programmed time relay 1i with the same calculated duty cycle, or is additionally adjusted by the sensor for monitoring the wear of grinding media, for example, the sensor 20 for the electric drive of the mill.

25

35

40

45

50

The performance measurement circuit of the trough vibratory doser works as follows.

Initial state. The key 5 is locked - 55 nuts and passes the signal from the converter 8, proportional to the weight G, to the input of the integrator 12, realizing the average value by the formula

I /

I X (T-t) d.

five

ten

i-t

where T is the integration time constant;

t is the current time; T is variable integration; X is a proportional voltage

weight G.

The key 17 is open and the average value of the weight M (G) is not supplied to the subtractor 21. Key 16 is open. Output voltage integrate ora 13 equal-. but zero.

Work performance measurement scheme. At the command of the software time relay, the scatter feeder periodically resets the standard metal ball from the hopper 5 to the input of the tray 7 of the dispenser, simultaneously the integrator 13 is started and the keys 15 16 16 and 17 trigger a pulse from the software time relay confirming them

the initial states, namely: the key 15 is open, the keys 16 and 17 are closed. 25 As soon as a pulse arrives from the ball detector 27, which: stops the integrator 13 (the output voltage of which is proportional to time and), opens the key 16 (thus, the integrator 13 voltage to the input of the linear potentiometer I9) and opens the key 17, a voltage proportional to the average value of the weight M (G) is passed to the input 35 of the subtracting unit 21. The key 17, triggered, acts on the key G5, which turns off the power converter 18 from the integrator 12. Next, the operational amplifier 22 with the luminous potentiometer 19 in the feedback circuit divides two constant values

Umwi

and 45

where and is the voltage of the integrator 13,

time proportional; and - the voltage of the integrator 12,

proportional to the average Q value of the weight G. The division process is carried out as follows. Two voltages UQ U are supplied to subtractor 21. At the output of the subtractor

five

ten

.

37252

an error signal is generated equal to the difference Ug.

, (GV

This signal, the passage of the operational amplifier 22, affects the reversing motor 23, which mixes the moving contact of the linear potentiometer 19, working off the error signal to zero. If equal, the motor 23 also stops from the midpoint of the contact of the linear potentiometer according to the expression

(} Ut-UM (a)

the voltage is proportional to the quotient of the division

,, UMC)

V u; .

This signal is recorded on the secondary device 24. The voltage from the feedback sensor of the secondary device 2 is fed to the input of the controller 25, which compares the current value of the parameter (the amount of bulk material on the tray 7 of the dispenser) with the preset setting of the setting device 26 and the mismatch sign of the current value of the controller 25 controls the actuator 2 by varying the dispenser capacity with the help of the inclination angle of the vibrating feeder 3.

The adjustment of the time for feeding the balls to the mill is carried out as follows.

From the power sensor 20, a signal proportional to the drive power of the mills is fed to integrator 14. At the time the voltage at the integrator output 14 equals the threshold value, the latter triggers a pulse to software time relay 11 to correct the feed time of the shche to the mill through the metering tray.

Thus, the control system of the grinding mill dosing system into the mill through the vibrating drum tray not only allows determining the average rate of vibration of the material with high accuracy and reliability, but also stimulates continuous single-ball loading of the ball mill in enterprises.

VNIIPI Order 3222/8

Random polygons pr-tie, Uzhgorod, st. Project, 4

Circulation 582 Subscription

Claims (1)

TRAY VIBRATOR CONTROL SYSTEM FOR BALL MILLS, including a performance regulator with a setter, a tray vibration sensor and an actuator for the angle of inclination of the vibrator, due to the fact that, in order to improve the accuracy of control, it is equipped with a power sensor and program relay time, three integrators, three keys, a weight converter, a linear potentiometer with a reversing motor, a subtraction unit, an operational amplifier, a secondary device, a ball detector and an actuator a vibrator through a weight converter connected to the first input of the first key, the output of which through the first integrator is connected to the first input of the second key, the output of which is connected to the second input of the first key and the first input of the subtraction unit, the output of which is connected through the operational amplifier with a reversible motor, the output of the program timer is connected to the ball mechanism actuator, the second input of the second key,. the third input of the first key, the first input of the second integrator and the first input of the third key, the output of which is connected to a linear potentiometer, a regulating contact of a linear potentiometer and a secondary device, the output of which is connected via a performance regulator to the actuator of the angle of inclination of the vibrator, the linear potentiometer is connected with feedback with the second input of the subtraction unit, the output of the second integrator is connected to the second input of the third key, the output of the ball detector is connected to the second Input of the first egratora and third inputs of the first and third keys, and a power sensor via a third integrator coupled to an input of a software timer. TTS> 1 1237252