RU2067028C1 - Device analyzing ash content of flow of coal on conveyer belt - Google Patents

Abstract

FIELD: mining industry. SUBSTANCE: invention caused to analyze ash content of coal and content of elements in ores directly on conveyer belts. Device has baseplate with ash content sensor incorporating radiation source and two detectors, two counters which information inputs are connected to detectors and which control inputs are linked to output of pulse generator and indication and registration unit. Device is suppliemented with programmable storage and permenent storage, averager, distance determining unit, extractor of two minimal values, buffer, unit determining tangent of mean angle, unit determining coordinates of projection of signals on graduation characteristics, unit determining two distances and unit determining ash content. Precision of analysis increases with due account of different scatterings of effective atomic number and density at different values of ash content. EFFECT: increased precision and authenticity of analysis. 3 dwg

Description

 The invention relates to mining automation and is intended for the analysis of coal ash and the content of various elements in ores.

A device is known for analyzing the composition of materials in a stream, which contains a coaxially located source of polyenergetic radiation, a screen and a detector, as well as a reversible counter, a control unit, a control unit, and an indication and recording unit, which is equipped with a two-channel amplitude analyzer and a filter from of the determined element in the form of a pipe, a pulling electromagnet, a switch, a delay element, a difference meter, a multiplication unit, an additional reversible counter and a bl the division window, the output of which is connected to the display and registration unit, the first output with the output of the multiplication unit, and the second input with the output of the difference meter, the second inputs of the multiplication unit and the difference meter connected to the output of the additional reversing counter, the first input of the multiplication unit connected to the master, the inputs of the reversible counter are connected to the outputs of the switch, the inputs of which are connected to the outputs of a two-channel amplitude analyzer, and to the control input is the first output of the control unit, the output of the detector is connected nen with the input of a two-channel amplitude analyzer, the second output of the control unit with the control inputs of the reversible counters, and the third with a pulling electromagnet, to the rod of which is attached a filter from the detected element, worn on the detector with the possibility of its vertical movement [1]
A disadvantage of the known device is the low accuracy due to the influence of fluctuations in the chemical composition and sieve composition of the material.

A device for analyzing ash content of a coal flow on a conveyor belt, comprising a board with a coal ash sensor made of a radiation source and two detectors, two counters, the information inputs of which are connected to the detectors, and the control inputs are connected to the output of the pulse generator, an indication and registration unit, which is equipped with two detectors, two absorbing plates from a controlled component of the material, two filters, reversible counters, decoupling diodes, digital-to-analog converters with a ratio meter and a zero ash setter, the output of which is connected to the first input of the multiplication unit, the output of the ratio meter is connected to the second input, the output of the first detector is connected directly to the summing input of the first reversible counter and through the first decoupling diode with the subtracting input of the second counter which is also connected to the output of the fourth detector, the output of the second detector is connected to the subtracting input of the first reversible counter directly and through the second a diode with a summing input of the second reversible counter, which is also connected to the output of the third detector, the reset inputs of the reverse counters are connected to the outputs of the pulse generator, and the outputs to the inputs of the ratio meter, the first and third detectors being installed along the board axis at equal distances at different distances the sides from the radiation source parallel to the lower cheek, and the second and fourth detectors are installed parallel to the axis of the wedge at equal distances on different sides from the radiation source parallel to the lower u ke, wherein the part of the conveyor belt before the first and second detectors are installed filters, and to the third and fourth detectors installed dividing plates of the monitored component material [2]
A disadvantage of the known device is its low accuracy due to different dispersions of the effective atomic number and density at different values of coal ash.

 The aim of the invention is to increase the accuracy of the analysis of coal ash by taking into account different dispersions of the effective atomic number and density at different ash values.

 The goal is achieved in that a device for analyzing the ash flow of coal on a conveyor belt, comprising a board with a coal ash sensor made of a radiation source and two detectors, two counters, the information inputs of which are connected to the detectors, and the control inputs are connected to the first output of the pulse generator, and a display and registration unit, equipped with a programmable storage unit and series-connected permanent storage unit, a block of average values, a unit for determining distances, an execution unit I of the two smallest distances, the buffer unit, the unit for determining the tangent of the average angle, the unit for determining the coordinates of the projection of signals to the calibration curve, and the output of the block of average values is connected to the second input of the block of the buffer, the output of which is connected to the fourth input of the block for determining the coordinates of the projection of signals to the calibration curve, and with the second input of the unit for determining two distances, while the second, third, fourth, fifth, sixth and seventh outputs of the pulse generator are connected respectively to the control the input inputs of the permanent storage unit, the unit for determining distances, the unit for average values, the unit for determining the tangent of medium coal, the unit for determining the coordinates of the projection of signals onto the calibration curve, the unit for determining two distances and the unit for determining ash content, the second input of which is connected to the first output of the programmable storage unit, and the output is connected to the input of the display and registration unit, the second output of the programmable storage unit is connected to the second input of the average determination unit Gla, and the output of the permanent storage unit is connected to the third input of the buffer unit.

 In FIG. 1 shows a plate mounted on a conveyor with a coal quality sensor in a longitudinal axial section for a better view of the structure; in FIG. 2 - functional diagram of the device; in FIG. Figure 3 shows the scattering ellipses of signals about the effective atomic number Z and density ρ for the (j-1) -th, j-th, and (j + 1) -th calibration values of coal ash.

 A device for analyzing the ash content of coal flow 1 on the conveyor belt 2 contains a board 3 with an ash sensor made from a gamma radiation source 4 and two detectors 5 and 6, two counters 7 and 8, the information inputs of which are connected to detectors 5 and 6, and the control the inputs are connected to the output of the pulse generator 9, and the display unit and registration 10.

 The device is equipped with a programmable memory unit 11 and a chain of sequentially connected permanent memory unit 12, an average value unit 13, a distance determination unit 14, a two least distance separation unit 15, a buffer unit 16, a mean angle tangent determination unit 17, and a signal projection coordinate determination unit for calibration characteristic 18, a unit for determining two distances 19 and a unit for determining ash content 20.

 The outputs of the counters 7 and 8 are connected to the inputs of the permanent storage unit 12, with the second and third inputs of the distance determination unit 14 and the unit for determining the coordinates of the projection of the signals onto the calibration curve 18. The output of the average value block 13 is connected to the second input of the buffer block 16, the output of which is connected to the fourth input of the unit for determining the coordinates of the projection of signals on the calibration curve 18 and with the second input of the unit for determining two distances 19. The second, third, fourth, fifth, sixth and seventh outputs of the imp of the pulses 9 are connected respectively to the control inputs of the permanent storage unit 12, the unit for determining distances 14, the unit for average values 13, the unit for determining the tangent of the average angle 17, the unit for determining the coordinates of the projection of signals onto the calibration curve 18, the unit for determining two distances 19, and the unit for determining ash content 20, the second input of which is connected to the first output of the programmable storage unit 11, and the output is connected to the input of the display and registration unit 10. The second output of the programmable storage unit and 11 is connected to the second input of the unit for determining the tangent of the average angle 17.

 The board is made in the form of an all-metal wedge, the tip 21 of which is directed towards the coal flow, the direction of which is shown by a double arrow in FIG. 1. The windows in front of the detectors 5 and 6 are closed by plates 22 and 23 of a material with a small atomic number, for example, plastic. The wedge on the articulated rods 24 and 25 and the hinges 26 and 27 are attached to the uprights 28 and 29, which, in turn, are fixedly mounted on the conveyor stand. The tape 2 with the coal layer 1 moves along the support rollers 30 in the direction shown by the double arrow in FIG. 1.

 The operation of the device is as follows.

 The gamma-ray flux from the gamma-ray source 4 falls onto the coal flow 1. Part of the gamma-quanta scattered by the coal goes back to the detectors 5 and 6, for example, gas-discharge Geiger counters can be used. The detector 6 is installed relative to the source 4 so that the intensity of gamma radiation incident on it practically does not change with a change in the density of coal r. In this case, the signal from detector 6 will be inversely proportional to the effective atomic number of coal Z and will not depend on the density r. The detector 5 is installed relative to the source 4 so that the intensity of the gamma-ray flux on it depends mainly on the density of coal r. Then we denote the signal from detector 5 by r, and the signal from detector 6 by Z. At the output of each of the detectors, positive voltage pulses are obtained, the average repetition rate of which (the signal from the detectors) is proportional to the intensity of the flow of gamma rays incident on the detector.

Все 2m средних значений запоминают в блоке средних значений 13, а все 2Кm значений запоминают в постоянном запоминающем блоке 12. В программируемый запоминающий блок 11 заносят значение К (число проб) и m значений зольности A $\genfrac{}{}{0ex}{}{\text{d}}{\text{1}}$ , A $\genfrac{}{}{0ex}{}{\text{d}}{\text{2}}$ , ..., A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j}}$ , A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j+1}}$ , ..., A $\genfrac{}{}{0ex}{}{\text{d}}{\text{m}}$ . На этом процесс градуировки заканчивается.The device is calibrated before being put into operation. To do this, coal samples are taken from K with different, for example, five, ash values so that in each of the K samples the ash content remains constant, and the effective atomic number and coal density are randomly changed. In each i-th sample of the j-th ash content, the density r _ji and the effective atomic number Z _ji are measured with detectors 5 and 6. These values ρ _ji and Z _ji from the counters 7 and 8 are fed to the inputs of the permanent storage unit 12 and are stored here. In the block for determining the average values of 13 for each j-th ash value, the average values of the effective atomic number and density are determined by the formulas

All 2m average values are stored in the block of average values 13, and all 2Km values are stored in a permanent storage unit 12. The value K (number of samples) and m ash values A are entered into the programmable storage unit 11 $\genfrac{}{}{0ex}{}{\text{<figure-callout id="1" label="d" filenames="00000020.png" state="{{state}}">d</figure-callout>}}{\text{1}}$ , A $\genfrac{}{}{0ex}{}{\text{d}}{}$$\genfrac{}{}{0ex}{}{}{\text{2}}$ , ..., A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j}}$ , A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j + 1}}$ , ..., A $\genfrac{}{}{0ex}{}{\text{d}}{\text{m}}$ . This completes the graduation process.

Now the device is turned on in the measurement mode. By tape 2, the flow of coal 1 is fed into the sensor operating zone. Gamma radiation scattered by the coal stream is detected by detectors 5 and 6 and positive voltage pulses are generated at their outputs, the repetition rate of which depends, respectively, on the density ρ _A and effective atomic number Z _{A of the} coal. The pulses from the first output of the pulse generator 9 start the counters 7 and 8, in which during the measurement time t the number of pulses corresponding to the values of ρ _A and Z _A are recorded.

и

из счетчиков 7 и 8 значений ρ_A и Z_A определяются все m расстояний от измеренных сигналов ρ_A и Z_A до соответствующих средних значений градуировочных сигналов. Так, например, расстояние от точки A(ρ_A, Z_A) до j-й градуировочной точки

определится по формуле

По аналогичным к (2) формулам определяются все остальные расстояния. На это в блоке 14 расходуется время в доли миллисекунд.After the measurement time t has elapsed from the third output of the pulse generator 9, a control pulse is supplied to the control input of the distance determination unit 14, under the action of which in block 14 of the average values 13 received from the block of average values

and

from the counters 7 and 8 of the values ρ _A and Z _A , all m distances from the measured signals ρ _A and Z _A to the corresponding average values of the calibration signals are determined. So, for example, the distance from the point A (ρ _A , Z _A ) to the jth calibration point

determined by the formula

By formulas similar to (2), all other distances are determined. For this, in block 14, time is spent in fractions of a millisecond.

из блока 13; передает в блок 18 из блока 13 средние значения о j-й и (j+1)-й зольностях

; передает в блок 19 из блока 13 средние значения о j-й и (j+1)-й зольностях

.After this time, in block 15 of these m calculated distances, two smallest distances are determined by comparing all m distances with each other. Let, for example, be the distances l ' _j and l' _{j + 1} to the jth and (j + 1) th calibration points, as shown in FIG. 3. The values l ' _j and l' _{j + 1} go to the first input of the buffer block 16, the other inputs of which receive the average values from block 13 and the ith values from block 12. When signals appear on all three inputs, the buffer block produces the following actions: transfers to block 17 from block 12 all i-th results about the j-th and (j + 1) -th ash levels ρ _ji , Z _ji and ρ _{(j + 1) i} and Z _{(j +1) i} , transfers in block 17 the average values of the j-th and (j + 1) -th ash levels

from block 13; transfers to block 18 from block 13 average values of the jth and (j + 1) th ash levels

; transfers to block 19 of block 13 average values of the jth and (j + 1) th ash levels

.

Затем по значениям tg2α_j и tg2α_j+1 в блоке 17 определяется тангенс среднего угла наклона по формуле

На операции по определению среднего угла наклона в блоке 17 также расходуется время в доли миллисекунд.In the block 17 for determining the tangent of the average angle, the inclination angles of the jth and (j + 1) th ellipses _{j j} and _{j j + 1 are} first determined by the formulas

Then, from the values of tg2α _j and tg2α _{j + 1} in block 17, the tangent of the average angle of inclination is determined by the formula

The operation to determine the average angle of inclination in block 17 also consumes time in a fraction of milliseconds.

Блок 18 решает совместно уравнения (6) и (7) и определяет координаты точки С по формулам

На вычисление значений ρ_c и Z_C в блоке 18 также расходуется время в доли миллисекунд.After this time, from the fifth and sixth outputs of the pulse generator to the control inputs of blocks 17 and 18 receive enable pulses. Under their action, the value of the tangent of the average angle of inclination from block 17 enters block 18, and the values ρ _A and Z _A to block 18 come from counters 7 and 8. In block 18, the coordinates of the projection of the signals ρ _A and Z _A onto the calibration characteristic are determined, then there are coordinates of the point of intersection of the lines AC and О _j O _{j + 1} . This happens according to the following algorithms. The equation of a line AC is written as the equation of a line passing through point A in the direction α, that is, in the form
r _c -ρ _A = tanα _A (Z _c -Z _A ). (6)
The equation of the line 0 _j 0 _{j + 1 is} written as the equation of the line passing through the points 0 _j and 0 _{j + 1}

Block 18 solves equations (6) and (7) together and determines the coordinates of point C using the formulas

The calculation of the values of ρ _c and Z _C in block 18 also takes time in fractions of a millisecond.

На вычисление расстояний l_j и l_j+1 также в блоке 19 расходуется время в доли миллисекунд.After this time, from the seventh output of the pulse generator 9 to the control input of block 19 receives the enable pulse, under the action of which in block 19 the calculation of two distances WITH _j and WITH _{j + 1} by the formulas

The calculation of the distances l _j and l _{j + 1} also in block 19 takes time in a fraction of milliseconds.

Значения (A^d)' и (А^d)'' определены с соответствующими погрешностями, которые обратно пропорциональны расстояниям от точки С до точек О_j и О_j+1. Поэтому в блоке 20 после этого определяется уточненное значение неизвестной зольности угля по формуле
A^d=[(A^d)′l_j+1+(A^d)″l_j](l_j+l_j+1)^-1. (13)
Это уточненное значение зольности индицируется и регистрируется в блоке 10.After this time, from the eighth output of the pulse generator 9, a resolving pulse is supplied to the control input of block 20, under the influence of which block 20 first determines from the distances l _{j + 1} and l _j and the corresponding points 0 _j and 0 _{j + 1} and the values of A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j}}$ and A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j + 1}}$ ash values

The values of (A ^d ) 'and (A ^d )''are determined with corresponding errors, which are inversely proportional to the distances from point C to points O _j and O _{j + 1} . Therefore, in block 20 after this, the specified value of the unknown ash content of coal is determined by the formula
A ^d = [(A ^d ) ′ l _{j + 1} + (A ^d ) ″ l _j ] (l _j + l _{j + 1} ) ^-1 . (thirteen)
This refined ash value is displayed and recorded in block 10.

 For sequential work on calculations according to formulas (2) - (13) in blocks 14-20, time is spent about a millisecond.

 Now the next measurement cycle begins again. From the first output of the pulse generator 9, the counters 7 and 8 are put into operation, and so on, everything happens in the sequence described above and after a measurement time t and a time of about a millisecond for all calculations in block 10, the second result is displayed and recorded.

FIG. Figure 3 illustrates the dispersion ellipses of the effective atomic number Z and density ρ for three values of coal ash A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j-1}}$ = 20%, A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j}}$ = 22% and A $\genfrac{}{}{0ex}{}{\text{d}}{\text{j + 1}}$ = 24%. If we determine the unknown ash content from the coordinates of point A, as is done in the base object [3], it will be 23% since the distances from point A to points 0 _j and 0 _{j + 1 are the} same. The true ash value, determined by formulas (1) - (13), will be 22.378%. The absolute value of the error in determining the ash content compared to the base object is reduced by 0.622%
Similarly, if the measured point has the coordinates ρ _B and Z _B , then the ash content according to the basic algorithm when using the basic object will be 21% since the distances from point B to points 0 _j-1 and 0 _{j are the} same. If, according to the coordinates of point B, the ash content is determined by the present algorithm, then the true ash content according to formulas (1) - (13) will be 21.287%. The absolute value of the error in determining the ash content of this device is reduced by 0.287%
In the general case, the present device, in comparison with the most accurate of the known devices, the error will decrease to a greater extent, the farther from the middle between adjacent ellipses there will be a measured point. If the measured point is located exactly in the middle between two scattering ellipses of signals Z and ρ, then the present device will only increase the accuracy of determining the ash content to a minimum extent. This device is also suitable for radio wave, infrared and x-ray principles of the sensor. In these cases, only the type of radiation source 4 and detectors 5 and 6 are changed. The farther the calibration points are from each other, the more the device reduces the error in comparison with the known ones. This allows you to reduce the number of calibration points, that is, to reduce the complexity of calibration. YYY2

Claims (1)

 A device for analyzing the ash flow of coal on a conveyor belt, containing a board with a coal ash sensor made of a radiation source and two detectors, two counters, the information inputs of which are connected to the detectors, and the control inputs are connected to the first output of the pulse generator, and an indication and registration unit characterized in that it is equipped with a programmable storage unit and series-connected permanent storage unit, a block of average values, a unit for determining distances, a block selection two smallest distances, a buffer unit, a distance determination unit, a two smallest distance allocation unit, a buffer unit, a mean angle tangent determination unit, a signal projection coordinate determination unit on a calibration curve, the output of the average value unit being connected to a second input of the buffer unit, the output of which is connected with the fourth input of the unit for determining the coordinates of the projection of signals on the calibration curve and with the second input of the unit for determining two distances, while the second, third, four the fourth, fifth, sixth and seventh outputs of the pulse generator are connected respectively to the control inputs of a permanent storage unit, a distance determination unit, an average value unit, an average angle tangent determination unit, a signal projection coordinate determination unit on a calibration curve, two distance determination unit, and an ash determination unit the second input of which is connected to the first output of the programmable storage unit, and the output is connected to the input of the display and registration unit, the second output Programmable memory unit coupled to a second input of the determination of the mean angle, and the DC output of the storage unit is connected to the third input buffer unit.

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