SU1670548A1 - Device for assessment of slurry fluidity - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the uniformity of pulp mixing in the tank of the pulp preparation circuit. The purpose of the invention is to improve the accuracy and enhance the functionality by measuring the uniformity of mixing of the pulp in the tank. The device contains conductometric transducer and meter. New in the device is that it is equipped with a vertical pipe, lowered into a controlled capacitance, with a rotating drive, additional two conductometric converters, two gauges, a subtraction unit, a dividing unit and a comparator, with conductometric converters installed on the pipe wall evenly in height at three points of the monitored volume, flush with its outer surface, the axis of symmetry of the electrodes is oriented perpendicular to the pipe, conductometric transducers with dineny gauges with respective inputs, the outputs of the first and third meter connected to the input divider unit dividing the output of which is connected to the first input of the comparator, the second input of which is connected to a reference voltage, and the output of the comparator is the output device. 1 il.

Description

The invention relates to a measurement technique and can be used to assess the uniformity of pulp mixing in the tank of a pulp preparation circuit of a hydrotransport system.

The purpose of the invention is to improve the accuracy of pulp density measurement and enhance the functionality by assessing the uniformity of pulp mixing in the tank.

FIG. 1 is a block diagram of the device.

The device for the evaluation of fluidity contains identical conductometric transducers 1, 2. 3, evenly spaced at three points of the monitored volume, mounted flush with the surface of the rod 4, lowered into the controlled reservoir 5 with pulp b. The rotation of the rod 4 is performed with the aid of the actuator 7. For mixing

about xj

about ate

4 00

pulp 6 in tank 5 (tank 5) the device is equipped with a stirrer 8. The device contains three identical meters 9, 10, 11, each of which consists of a generator of 12 vapor-phase pulses, a demodulator 13. acting as a filter and an amplifier 14. The device also includes a subtraction unit 15, a division block 16 and a comparator 17. Conductometric transducers 1, 2, 3 are made in the form of two closely spaced metal electrodes attached to a dielectric insert.

The device works as follows.

The pulp 6, placed in the container 5, is stirred by the stirrer 8. The rod 4 with the conductivity transducers 1.2.3 is driven by the actuator 7 into rotational motion. Electrical signals from transducers 1, 2, 3, through a current collector (not shown) are fed to the inputs of meters 9,10.11 (from 1 to 9; from 2 to 10; from 3 to 11). Under the action of filler particles, the oscillation frequency of the generator 12 acquires amplitude modulation. The signal is then demodulated by a filter and amplified by amplifier 14. This signal is proportional to the intensity of fluctuation and characterizes the density of pulp 6 at three different points in the volume: upper, middle and lower. At a sufficiently high speed of rotation of the rod 4, the linear mixing speed of conductometric transducers 1,2,3 relative to the medium will be much greater than the linear velocity of the particle of the pulp 6 due to the upward flows generated by the agitator 8 and the output signals from the meters 9, 10,11 with high confidence proportional to the density of particles in the pulp 6. Signals from meters 9 and 11 (upper and lower points of volume) go to subtractor 15, where the absolute value of the difference of signals is estimated. From the output of the subtractor 15, the signal is fed to the input of the divisible division block 16, the second input of which (the divider input) receives the signal from the meter, 10 (middle point of the volume). The result of the division is compared at comparator 17c with the reference level V0n. Thus, given my device implements the following subtraction scheme:

 w -Vi-Oz VBHX dem. uЈ-.

where Vi-V / C is the magnitude of the signal at the outputs of the meters 9. 10, 11 and if V is p, where p is the pulp capacity b, then

VBMx. dump in yes

The evaluation of this expression is carried out on the comparator 17 against a predetermined threshold level proportional to the permissible density variation. If the allowable density variation is less than or equal to the measured value / OUT of block 16, then at the output of the comparator 17 a level D is set corresponding to that mixing has been performed. If Oh, then the mixing is not yet complete.

Form of invention

A device for evaluating the fluidity of the pulp, comprising a mixing tank, a conductometric transducer located in the mixing tank, and a meter electrically connected to the conductometric transducer, in order to enhance the functionality by improving the accuracy of measuring the density of the pulp and evaluating its homogeneity. structure, it is equipped with a vertical cylindrical rod with a drive and with built-in flush with its outer surface and uniformly along the height of conductometric converters, the axis of symmetry of the electrodes of which are oriented perpendicular to the rod fixed in the mixing tank, two additional meters, a subtraction unit and a dividing unit, the inputs of the meters connected to the corresponding conductometric converters, the outputs of the first and third meters are connected to the inputs a subtraction, the output of which is connected to the input of the dividend division block, the input of the divider of which is connected to the output of the second meter, and the output of the division block connected to the first input of the comparator, the second input of which is fed a reference voltage, the comparator output is an output device.

CM f

. 4V & &

lt

V

Claims (1)

Claim A device for evaluating the flow of pulp containing a mixing tank, a conductometric transducer located in the mixing tank and a meter electrically connected to a conductometric transducer, characterized in that, in order to expand the functionality by increasing the accuracy of measuring the density of the pulp and assess the uniformity of its composition. it is equipped with a vertical cylindrical rod with a drive and flush with its outer surface and uniformly in height with three conductometric transducers, the axis of symmetry of the electrodes of which is oriented perpendicular to the rod fixed in the mixing tank, two additional meters, a subtraction unit and a division unit, and the inputs the meters are connected to the corresponding conductivity converters, the outputs of the first and third meters are connected to the inputs of the subtraction unit the output of which is connected to the input of the divisible division unit, the output of the second meter is connected to the input of the divider, and the output of the division unit is connected to the first input of the comparator, the second input of which is supplied with the reference voltage, and the output of the comparator is the output of the device.