SU1392489A1 - Method and device for ultrasonic inspection of particle composition of materials in pulp flow - Google Patents

Description

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raw materials. The aim of the invention is to verify the accuracy by controlling the variation in the concentration and the parameters of the particle size distribution in the measuring vessel. The generators are 1, 2 pulses by means of radiating transducers 3, 4, the formotote longitudinal elastic oscillations in a controlled medium, as well as Lzmba waves in a measuring plate 53 in contact with it. Pulses passed through a controlled medium received by 1 and 1 converters 5, 6 are amplified by logarithmic amplifiers 7, 8. In subtraction circuit 34, the amplitude difference is determined

signals received in both electroacoustic channels, and in the first dividing scheme 9 - the quotient of dividing this difference by the amplitude of the signal that passed through the measuring plate 53. After a selected period of time, the generator 39 is turned on, using the third radiating transducer 40 which forms powerful ultrasonic hesitation. In the second division scheme 10, the ratio of the values calculated in the first scheme 9 division without and under the influence of powerful ultrasonic vibrations of several fixed amplitudes is determined. 2 sec. f-ly, I ill.

The invention relates to an ultrasound control technique and can be used in the chemical, construction, mining and adjacent industries of the industry for automatic non-contact quality control of raw materials, etc. I

The aim of the invention is to improve

improvement of the control accuracy by providing changes in the concentration and parameters of the particle size distribution in the measuring vessel.

The drawing shows a diagram of the device for ultrasonic control of particle size distribution of materials in the pulp flow.

The device contains two electro-acoustic channels from series-connected generators 1, 2, emitters 3, 4, receivers 5, 6, and logarithmic amplifiers 7, 8, two dividing circuits 9 and 10, a control unit 11 of three one-oscillators 12, 13, 14 and connected to their outputs of a three-input circuit OR 15, four measurement circuits from successively connected lines 16, 17, 18, 19 of the delay of the input of electronic switches 20, 21, 22, 23 of amplitude detectors 24, 25, 26, 27 and output electronic switches 28, 29, 30, 31, connected to the output of the FM of logarithmic amplifiers

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7, 8 two spreaders 32 and 33 pulses, a subtraction circuit 34, inputs connected to the outputs of the spreaders 32 and 33 pulses, and an output on the input of the first dividing circuit 9, the output of which is connected to the second inputs of electronic input switches 20-23, serially connected multivibrator 35, a counter 36, a decoder 37, and a four-input OR 38 circuit, an acoustic channel from a series-connected generator 39 and an emitter 40. The control unit 11 is connected between the outputs of the decoder 37 and the input of the acoustic channel generator 39. Two delay lines 41, 42 are connected between the output of the PTI 38 four-input circuit and the generator inputs 1, 2 of electroacoustic channels. The second three-input circuit OR 43 is connected to the outputs of the decoder 37, the one-shot 44, 45 and 46 are connected between the outputs of the decoder 37 and the second inputs of the output electronic keys 28, 29 and 30, and the single-shot 47 is connected to the output of the second three-input circuit OR 43 and the second input an output electronic switch 31 connected to the input of the second dividing circuit 10, the second input of which is connected to the outputs of the electronic output switches 28, 29 and 30. The output of the second dividing circuit 10 is the output of the device. The second inputs of the amplitude detectors 24-27 are connected to the outputs decoder 37. The emitter 3 is fixed on the waveguide 48, and the receiver 5 is mounted on the waveguide 49. The waveguides are designed to be inserted into the internal cavity of the measuring vessel 50. The emitter 4 and the receiver 6 are placed on prisms 51, 52 and fixed on the measuring plate 53 intended for placement on the wall of the measuring vessel 50. The second input of the first dividing circuit 9 is connected to the output of 33 pulses widening.

The essence of the invention consists in measuring the deviation of particles of a known size from the steady-state trajectory of their movement under the influence of the dynamic effects of powerful, ultrasonic vibrations, i.e. the change in the concentration and distribution parameters of the particle size in the measuring vessel. The magnitude of the deviation of particles of a known size characterizes their specific gravity, and a comparison of this magnitude with tabular values makes it possible to estimate the degree of disclosure of the useful component, i.e. the ratio of waste rock and the desired mineral in the granule enriched raw materials.

A device for carrying out the method of ultrasound control works as follows.

The multivibrator 35 generates rectangular pulses that are applied to an electronic pulse distributor, made on a counter 36 and a decoder 37 having eight outputs. Thus, one control cycle consists of eight cycles. In the first cycle, the pulse from the first output of the decoder 37, the passage through the four-input logic circuit OR 38, the delay lines 41 and 42 starts the generators 1 and 2 pulses. In order to reduce the mutual influence of electroacoustic paths, the delay times of lines 41 and 42 are chosen in such a way as to ensure the time shift of the periods of switching on the generators 1 and 2 pulses, which in the switched on state produce a series of high-frequency electrical oscillations of fixed duration. Radiating transducers 3 and 4, for example, of the piezoelectric type, convert an electrical signal into a ctn

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Other variations in the environment. Radiation Converter 3 through the waveguide 48 emits ultrasonic oscillations into the pulp flow in the measuring vessel 50 in the direction of the receiving transducer 5, installed the waveguide 49 of the iia waveguide 49. The emitting converter 4 forms a wamb-Lamb in the measuring plate 53, which pass through the second prism 52 are received by receiver transducer 6.

When ultrasound propagates} s pulp it is absorbed and scattered. Moreover, the scattering of ultrasound significantly prevails over absorption in the case when the size of the particles is comparable with its wavelength.

The magnitude of the attenuation of high-frequency ultrasound when passing through a stream of pulp from the radiating transducer 3 to the receiving transducer 5 is determined only by the size of the particles of the solid phase and their concentration.

When the Lamb waves propagate in the measuring plate 53, their attenuation is determined only by the concentration of the ground material in the pulp.

The received elastic oscillations transmitted through the pulp flow and along the measuring plate 53 are converted by electrical transducers 5 and 6. The high frequency electric oscillations are amplified in logarithmic amplifiers 7 and 8. Since the duration of the generated pulses is short, it is increased in the expanders 32 and 33 of the pulses without changing the amplitude.

In the subtraction circuit 34, the difference of the logarithms of the received signals is determined, and the ratio

dd "with

50

,

where S, is the logarithm of the amplitude of the received signal in the first electroacoustic path; P) is the logarithm of the amplitude of the received signal in the electrical and acoustic path.

The value of S characterizes the content of the control class size of the crushed material in the pulp.

The pulse from the output of the decoder 37, the passage through the delay line 16, unlocks the electronic key 20. Its delay time by the delay line 16 is determined by the propagation time of the generated oscillations in the controlled medium and the measuring plate 53 and is chosen so that the electronic key 20 unlocks S in scheme 9 division. The amplitude detector 24 captures (remembers) the value of S. The second, third and fourth monitoring steps are judged similarly to the first, since the second, third and even

The last pulses from the outputs of Rotor 37 by means of a four-input logic circuit OR 38 also start the generators of 1 and 2 pulses. At the same time, each of these pulses is driven by one-shot 2, 13 and 14, which, through a three-input laser circuit OR 15, include a generator 39, which generates powerful sinusoidal electrical oscillations converted by the radiating converter 40 into elastic medium oscillations.

Due to the dynamic effects of the power of ultrasonic oscillations (pressure and acoustic currents), particles of crushed material, such as ore, are displaced in the pulp flow from the radiating transducer 40 in the direction of the opposite wall of the measuring vessel 50 on which the measuring is attached. plate 53.

The displacement of the particles of crushed material leads to a change in their size distribution and concentration in the region adjacent to the measuring plate 53, as well as between the waveguides 48 and 49. The redistribution of these parameters for particles of the same size located at a fixed distance from the radiating transducer 4 is determined It is only their mineral composition, i.e. the proportion of each of the components. Large particles of the same size, the size of which is much larger than the size of the ore components (inclusions) contained in them, have approximately the same specific weight

about 10

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and 11O) to that, the magnitude of smccpsplllh luix is determined by TIUIIJKO of a non-significant application of exposure.

For particles crushed to the size of ore inclusions, the magnitude of the displacement is proportional to the specific weight of each of them.

In the case of the pulsed nature of the impact of powerful ultrasonic vibrations, the degree of influence of the dynamic effects caused by them on the controlled medium depends on the pulse duration. The duration of the pulses, formed by 1X one-shot vibrators 12, 13 and 14, is chosen in such a way that the magnitude of the impact of powerful ultrasonic vibrations is sufficient to displace particles of three, and in general, a larger number of sizes. The calculated value of S for each case (s, S, s) through the electronic keys 21-23, unlocked by the signals from the outputs of the deiafrarator 37 and delayed delay lines 17-19, is fed to amplitude detectors 25-27, which fix their amplitude. The delay time of the pulses by delay lines 17-19 is determined by the same conditions as for the delay line 16.

The pulses coming from the outputs of the decoder 37, through single-shot 44, 45 and 46, are successively unlocked the electronic switches 28, 29 and 30. Moreover, each of the pulses from the outputs of the fine-breaker 37 through the second three-input logic circuit OR 43 and the fourth single-shot 47 unlocks the electronic key 31. Value 40

neither

and

41

and s, s

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. ". bj, - n ij, I - Q n L; in pairs are fed to the second dividing scheme 10, where the value of r, characterizing the degree of disclosure of the useful component, is calculated

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The pulse from the output of the decoder 37 resets the values detected by the amplitude detectors 24-27, after which the monitoring cycle repeats.

Comparing the calculated values of r with the reference values (determined by laboratory analysis methods allows us to give a numerical characteristic of the degree of disclosure of the useful component.

Thus, the method of ultrasound control and the device for its implementation allow continuous monitoring of this parameter directly in the stream of the processed raw material without removing part of it as a sample from the process stream. This allows us to simplify and speed up the monitoring process, as well as to improve the accuracy of determining the monitored parameter.

Claims (2)

1. Ultrasonic control method for the granulometric composition of materials in the pulp flow, including radiation into the pulp flow and measuring the amplitude of the ultrasonic vibrations transmitted through the ultrasound flow, which is different in that, in order to increase the control accuracy, a measuring plate is excited into the pulp flow Lamb, measuring the amplitude of oscillations of Lamb waves that have passed a fixed distance, changing the concentration and distribution parameters of pulp particles by size in the area of the measuring plate by ultrasound oscillations of several fixed amplitudes and the same measurements are made and the controlled parameter is determined by the ratio of measured values at the redistribution of pulp particles and to it. 2. An ultrasonic control device for the granulometric composition of materials in the pulp stream, containing two electro-acoustic channels from a series-connected generator, radiator, receiver and amplifier, two dividing schemes and a control unit, characterized in that, in order to improve accuracy, it is equipped with four measuring schemes from connected delay lines, input key, amplitude detector and output key, two Compiler and Editor I. Ryb enko, Tehre: dji epe Order 1887/49 Circulation 847 VNIIPI State on affairs invented 113035, Moscow, Zh-35, ifmpulse spacing: from ;, cpcnc-chop to the outputs of amplifiers of each electroacoustic channel, a subtraction circuit connected between the output and the expanders and the input of the first CXBNW division, whose output is connected to the second inputs of the electronic keys connected in series a multivibrator, a counter, a decoder and a four-input circuit I.SH1, an acoustic effect channel from a series-connected generator and radiator, a control unit connected between the output of the decoder and the input of the generator of the acoustic effect channel; it contains three single vibrators, whose inputs are the inputs of the control unit, and a three-input OR circuit, whose output is the output of the control unit, connected to the outputs of the single vibrators between the output of the four-input OR circuit and the inputs of electroacoustic channel generators, the second three-input OR circuit connected to the outputs of the decoder, four single-oscillators, three of which are connected between you by the decoder moves and the second inputs of the output electronic keys of the respective measurement circuits, the fourth one-oscillator is connected to the output of the second three-input OR circuit and the second input of the output electronic key of the fourth measurement circuit connected to the input of the second dividing circuit, the second input of which is connected to the outputs of the remaining output electronic keys , the output of the second division circuit is the output of the device, the second inputs of the amplitude detectors are connected to the outputs of the decoder, the emitter and the receiver of one of the electroacoustic the oral channels are placed on a measuring plate designed to be fixed to the wall of the measuring vessel, the second input of the first division circuit is connected to the output of the pulse expander of this channel, and the amplifiers performed logarithmic. Dasheva Korrek grr M.11 aroshi Subscription