SU1613167A1 - Method of controlling jigging machine having movable screen - Google Patents

Abstract

The invention relates to the enrichment of minerals by the method of hydraulic jigging and can be used in jigging machines with a movable reagent, in particular, for pre-breeding. The purpose of the invention is to improve the accuracy of control of the jigging machine. For this, the height of heavy fractions (TF) is determined in proportion to the height and mass of the bed in a cohesive state at the top of the sieve oscillation (CR) in the pause between the sieve lifting and lowering in each jigging cycle. The degree of compaction of the bed is determined. The flow rate of the starting material is measured. Adjust the measured value of the mass of the bed in a cohesive state at the upper point of the RC in the pause between raising and lowering the sieve in each jigging cycle by subtracting the mass of the empty box and is proportional to the consumption of the source material. Correct the measured value of the bed height in proportion to the SUP. The height of the TF layer is determined. According to the adjusted value of the mass of the bed, adjust the amplitude and frequency of the CR. Over a specific TF height, the TF discharge rate of the enriched material is changed. The method has fewer errors and is simpler to implement, which ensures a higher quality of material separation. 3 il.

Description

jigging cycle, empty sieve mass, bed compaction degree, raw material consumption is measured, and the measured bed mass is adjusted in a cohesive state at the top of the sieve oscillation in the pause between lifting and lowering the sieve in: each jigging cycle by subtracting the value the mass of the empty box and, in proportion to the consumption of the source material, adjust the limiting value of the bed height in proportion to the degree of compaction, determine the height of the bed, heavy fractions during the jigging The magnitude of the mass of the bed is adjusted to the amplitude and frequency of sieve oscillations, and over a certain height of heavy fractions - the rate of unloading of heavy fractions of the enriched material.

The method is carried out as follows.

The sieve box oscillates in the water bath in accordance with the diagram in figa, a portion of the graph is 1S, 2S, 3S, 4S, and the bed in accordance with the same diagram, part 1S, 2S, 3S, 5S.- In this case, the bed is in a cohesive state in the area, 1S, 2S, 3Ss and in the loosened, where the jigging process takes place, in the area 3S, 5S, 1S. The diagram in figure 1 reflects the effort required to swing the sieve. When lifting the box (section 1F, 2F), the force is composed of the force of water resistance to the movement of the sieve Fj, bed mass in water G, the weight of the box with the sieve in water G. When the sieve stops at the top point (section 2F, 3F), the water resistance force is to zero. Thus, the force P on the meter is equal to

R. G + RT-.

In the plot of the 3F, 5F sieve; goes to the lower position and the meter measures the mass of the box with the G.J .. sieve. At point 5F, occurs: -: a surge in the force diagram associated with hitting the bed against the sieve. Then, in the section 5F, 1F, a smooth increase in the force occurs in accordance with the bed deposition rate. Then the cycle repeats. The bed speed in the jigging process is displayed by a graph in fig. 1b, where, in section IV, 2V, the bed is raised at a constant speed, on section 2V,

3V speed drops to zero (pause at the top of the sieve swing), Bed deposition on the sieve is displayed as part of the 3V, 5V graph (the dotted line shows the light fraction deposition). At point IV, the bed speed is zero, and the process is repeated. The bed height measurement is shown in fig. 1g, where the 1H, 2H, 3N area corresponds to the sensor measuring the damage of the moving bed in a cohesive state, and the 3N section, 1H, indicates the lack of contact of the sensor with the bed in the process of its precipitation.

Measurements are made at site 2H, 3N. According to the proposed method, all measurements are performed at the top of the sieve swing, which corresponds to points 2 and 3 of the graphs. Moreover, to reduce the effect of transient processes, it is necessary to set the measurement moment t closer to points 3.

The height of the heavy fractions is calculated in accordance with the design scheme (FIG. 2) using the formula

city (1)

de Н is the height of heavy fractions of the bed; C is the mass of the bed in the water;

G P -

P - the tester strength meter; G - tare mass (movable box with a sieve) in water; S is the sieve area;

- density difference t

and light fractions; H - bed height (indications

 level sensor);

UH is the bed height above the dividing element; YN N - Nd;

ND - the height of the installation of the dividing element; a is the density coefficient;

(2)

Mr. V

fl А - 3 В „.„ „.„. „., ..,„ „„ „.

For Г is the density of the heavy fraction; JCft is the light fraction density; {d - the density of water; b - area ratio;

b

.§one. S

c is the material stacking factor for height; k is the load factor. This formula is obtained, the outcome of the short-circuit following considerations.

In the case when the volume of the sieve is filled with the light fraction of the material to be separated, the mass of the bed is equal to 5Нл,

If a part of the specified volume is filled with material density) p N,

on

the height is n, then the mass of the bed is increased by the amount of ut and is equal to

G.J, SH | f, + SH (Ut-Ul) -

In this case, it is also necessary to take into account the mass of the material on the separating element.

G, S (H - Nd) (p-Vb) Next, the necessary corrections are made and simplifications are made, resulting in the calculated formula (1).

For calculations, the constant values involved in the formula and the design parameters: С „3.8 ,,, ud,., A, b, cD, and also the values determined by means of the sensors: Р, Н, А where A is the amplitude of the sieve swing. The heights of heavy fractions H are calculated by the results of which the discharge speed of the heavy fractions is determined. The sieve flashes are controlled depending on the height of the postmark H and its mass G. With an increase in the mass of the bed, its amplitude increases. However, this may result in a machine being overloaded to a state where the bed in the box comes out of the water and the jigging process does not occur. To prevent such an occurrence, the amplitude of sieve oscillations is limited depending on the height of the bed, so that the bed is in water at any position of the box. The coefficients a, b are constant and are intended to simplify calculations. The coefficients c, k are corrective, where c takes into account the pliability of laying the material along the bed height, and 1 - the effect of the supplied material on the sieve in the process of measuring the bed mass.

The implementation of the method is carried out in the device shown in Fig. 3, Sett.

ig

- ten

15

20

25

f 30, et 45 50 55 35

40

The solution includes a jigging bath 1,. box 2 fixed in a bath on hangers 3, having a sieve 4 and a separating element 5, sieve oscillation drive 6 (hydraulic or pneumatic), unloader 7 drive, unloader 8, sieve lift control valve 9, sieve lowering control valve 10, force sensor 11 , sieve position sensor 12 (amplitude sensor), bed level sensor 13, microprocessor 14. Unloader 7 drive feeds to mic-. The processor 14 is a signal proportional to the speed of unloading heavy fractions, which is necessary for performing feedback.

The force sensor 11 is a dynamometric device with an electrical output signal and has no fundamental features. The sieve position sensor 12 may be, for example, a resolver or any other design that provides the required measurement accuracy. The bed level sensor 13 has a probe that touches the bed surface and can freely move up with the bed, as well as down with a speed several times slower than the light fraction of the bed, which determines the height of the bed at the highest point of the sieve oscillations and prevents it from settling. Feeds filling the probe material bed.

The microprocessor 14 is a general-purpose microprocessor device including a price; central processing unit, read-only memory, analog-to-digital converters of sensor signals, interface devices with drives, display. The microprocessor has no fundamental features of software and hardware, and can be implemented, for example, on the basis of sets of the 580 or 1820 series and the like.

The device works as follows.

The microprocessor 14 receives a discharge speed signal, a bed height signal, a sieve position signal. The required constants and agglomerate computations are sampled from the memory. The microprocessor processes these signals, calculates the control values and controls the unloading, as well as lifting and lowering the sieve. Thus, to implement the control, the microprocessor receives the following input parameters: concentrate density,}, tail density, bed mass, bed height, measurement time, constants. However, during the operation of the jigging machine, the sensor signals contain errors and interferences that can affect the control accuracy. Therefore, before calculating, the input signals in the microprocessor are digitally filtered by software. According to the results of calculations, the output parameters are formed: the height of heavy fractions, the discharge rate, the amplitude and frequency of oscillations of the sieve, and the load on the machine. These parameters control the jigging machine and can be displayed in the process of operation on the display using the Monitor program.

Claims (1)

The invention makes it possible to improve the control accuracy, has less metrological: errors and is simpler to implement, which provides higher quality material separation, especially in pre-rock-separation operations during coal preparation. Formula of about - and E and the Method of control of the jigging machine with a mobile sieve, based S measuring the mass of the bed of the enriched material, measuring the frequency and amplitude of the sieve oscillation and the discharge rate of heavy factions, characterized in that, in order to improve the control accuracy of the jigging machine, the height of the heavy fractions is determined in proportion to the height and weight of the bed in a cohesive state in the upper the sieve oscillation point in the pause between raising and lowering the sieve in each jigging cycle, set the mass of the empty sieve, the degree of compaction of the bed, measure the flow rate of the source material and correct the measured the size of the bed mass in a cohesive state at the top of the sieve oscillation in the pause between lifting and lowering the sieve in each jigging cycle by subtracting the mass of the empty box and proportionally to the consumption of the source material, correct the measured bed height directly proportional to the degree of compaction, determine the bed height heavy fractions in the process of jigging, adjust the amplitude and frequency of sieve oscillations by the corrected mass of the bed, and soon after a certain height of heavy fractions be unloading heavy fractions enriched material. Fractional Sensor Sieve Double / Black zlvnvnt 7 T / Kelaa J France france at   ( FIG. 2 FIG. five