SU282206A1 - DEVICE FOR AUTOMATIC CONTROL OF THE PROCESS OF PURCHASING SORTING OF MINERAL RAW MATERIALS - Google Patents

Description

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Devices are known for automatically controlling the process of picking mineral raw materials, comprising a radiation source, a unit for recording the residence time of a piece in the measurement zone, and a radiometric unit consisting of a radiation detector, a former, a measuring circuit, a threshold circuit, and an execution stage.

The proposed device is characterized in that the unit for recording the residence time of a piece in the measurement zone is designed as an integrating RC circuit and connected to its output of the amplitude normalizer, the integrating RC circuit being connected to the output of the driver, and the output of the normalizer of amplitudes is connected to the measuring and threshold circuits radiometric unit.

This improves the sorting efficiency and increases the reliability of the device.

FIG. 1 shows schematically the proposed device operating with the use of gamma (neutron, X-ray) - absorption pusk. Or batch - pokuskov sorting of mineral raw materials; in fig. 2 is a diagram of a radiometric unit; in fig. 3 - voltage plots showing the operation of the device.

3, the radiation source 4 of the radiometric unit 5 with the detector 6 and the gate device 7. The radiometric unit consists of the radiation detector 6, the amplifier and the former 7, the measuring circuit 8, the threshold circuit 9, the executive stage 10, the integrating RC circuit 11 and the amplitude normalizer 12.

The device for automatic control of the process of picking raw materials works as follows. The classified ore from the hopper / (see Fig. 1) is fed by a vibratory feeder and a pick-up spreader 2 to the conveying device 3.

On the conveyor device, the sorted material is arranged in a row with intervals between pieces (portions). The number of such rows (channels) is determined by the type of separator (single channel

or multichannel). Using a transporting device, 3 pieces (portions) are delivered to the measurement zone, which consists of the radiation source 4, the detector 6 and the radiometric unit 5. The pieces alternately block the beam of gamma rays from the neutron, X-ray source 4. In the absence of a piece in the measurement zone at the detector output the maximum pulse frequency is obtained. When a piece appears in the measurement area

quanta) is absorbed (absorbed) by the piece. The degree of absorption depends on the content of the useful component in the piece and its size. Absorption by a piece of radiation leads to a decrease in the frequency of pulses taken from the detector. The content of the useful component in the piece (portions) is determined by the value of the pulse frequency difference using radiometric equipment 7. Radiometric equipment is pre-set to a predetermined pulse frequency difference (or to a predetermined frequency), which corresponds to the threshold (boundary) content of the useful component in the piece. If the content of the useful component in the piece (portions) is higher than the boundary component, then the radiometric equipment issues a command to change the position of the slide device. Then the piece (portion) enters the concentrate or tail estrus.

When passing through the measurement zone of a piece with the content of the useful component is much less than the threshold (boundary) value, or even completely, the empty frequency difference from the radiation detector is always significant (at least several tens of percent) and easily measurable.

The signal about the approach time and the time the piece stays in the measurement zone from the information taken from the radiation detector is obtained by separating the frequency difference using an RC circuit with a constant integration time equal to about 0.1 of the average duration of the piece in the measurement zone.

The frequency of the pulses taken from the driver (see FIG. 2) is distributed in time, for example, as indicated in FIG. Behind. In the to-ti, tz-sections, there is nothing in the measurement zone. The ti-tz sites show that pieces have passed through the zone. The plot corresponds to the passage of the piece with the content of the useful component exceeding the threshold (boundary) value ().

The plot shows that a piece passed through the zone either “empty, or with a content not exceeding the threshold (boundary) value ().

The signal allocated on the RC circuit about the approach time and the time the piece is in the measurement zone is a variable plot, an approximate graph of which is shown in FIG. 36

To simplify the control circuit, this signal is normalized in amplitude. On the amplitude normalizer output, signals are obtained, an approximate graph of which is shown in FIG. 30. As a result of the transformation, delays of the front and rear footage appear (see FIG. 3), etc.

The magnitude of the delays is determined by the time constant of the transforming RC circuit and the level of the limitation Ui (see Fig. 36). Therefore, for each specific case, these two values are chosen from the following values: the smallest admissible fronts delay.

Thus, at the output of the amplitude normalizer, a U-shaped impulse voltage is obtained, the duration of which is equal to the duration of the piece in the measurement zone, and the leading edge - to the moment of the appearance of the piece in this zone.

The received pulses are controlled by the measuring channel of the radiometer. In the measuring device, the leading and trailing edges of the pulse determine the beginning and the end of the measurement of the content of the useful component in the piece. The duration of the pulse is introduced by the correction of the measurement of the content depending on the size of the piece. At a constant speed of movement of the piece in the measurement zone, the pulse duration exactly corresponds to the linear size of the piece along the line of motion. The weight of a piece of Carrel depends on its linear size; therefore, the correction of the obtained data on the pulse duration, i.e., on the linear size of the piece, significantly improves the technological performance of the separator.

Subject invention

A device for automatic control of the mineral raw material by-step sorting process, comprising a radiation source, a unit for recording the residence time of a piece in the measurement zone, and a radiometric unit consisting of the radiation detector, a former, a measuring circuit, a threshold circuit and an execution stage, increasing the sorting efficiency and increasing the device operation allotment; the unit for recording the time of a nahol: piece in the measurement zone is designed as an integrating RC circuit and nennogo with its output amplitude normalizer, wherein the integrating RC-circuit is connected to the output of the shaper and the output of the normalizer coupled to the amplitudes -sv measuring radiometric and threshold circuitry block.

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