RU96968U1 - DEVICE FOR DETERMINING THE CONCENTRATION OF SURFACE-ACTIVE SUBSTANCES IN AQUATIC MEDIA - Google Patents

Abstract

 A device for determining the concentration of surface-active substances in aqueous media, containing an annular bath with a working compartment, a barrier, an electric drive that moves the barrier along the working compartment of the annular bath, limit switches, used to stop the barrier at certain points of the working compartment, surface tension sensor, area sensor the working compartment of the annular bath, a mechatronic and a first control unit, characterized in that it is equipped with a second control unit, the first and second identical analog-to-digital and converters, the first inputs of which are connected to the output of the mechanotron and the sensor of the area of the working compartment of the annular bath, the second inputs of the analog-to-digital converters are connected to the first and second outputs of the second control unit, respectively, by a random-access memory, to the input data buses of which the outputs of the analog-to-digital converters are connected , to the address bus and control bus of which the third and fourth outputs of the second control unit are connected, the output data bus of which is connected to the input of the gear unit data control bus which is connected to the fifth output of the second control unit, second control unit input is connected to limit switches.

Description

The utility model relates to the field of thermal energy, in particular to devices for express quality control of aqueous media used in energy technology complexes, namely, devices for identifying and determining the concentration of surface-active substances (surfactants) in these aqueous media.

Known devices for determining the concentration of surface-active substances in aqueous media - tensiometers containing a working compartment with a sample of the studied aqueous medium, a sensor (Du Nui rings or Wilhelmy plates) and means for measuring the force of separation of the sensor from the liquid surface [see Surface phenomena and surfactants. Ref. edited by A. A. Abramzon and E. D. Schukin, L .: "Chemistry", 1984]. In the device, the surface tension force is measured by the detachment method of the sensor, according to which (using individual calibration curves for each specific surfactant) the value of the surfactant volume concentration is determined.

The disadvantages of this device is the lack of sensitivity in determining the concentration of surfactants in aqueous media

The closest in technical essence to a utility model is a device for determining the concentration of surfactants in aqueous media [see Abramenko Yu.M., Abramzon A.A., Bening G.P., Leshechko J.Ya. A device for determining the surface properties of liquids // Colloid Journal, 1987, No. 1, p.122-126], containing an annular bath with a working compartment, a barrier, an electric drive that moves the barrier along the working compartment of the annular bath, limit switches, used to stop the barrier in certain points of the working compartment, surface tension sensor, area sensor of the working compartment of the annular bath, mechatronic and control unit.

The disadvantage of this device is the large time spent on the analysis associated with the need to perform a large number of procedures for comparing experimental and reference kinetic characteristics.

The technical task of the utility model is to reduce the analysis time, as well as expand the functionality of the device by providing the ability to identify surfactants.

The essence of the utility model is illustrated in the drawing, which shows a schematic diagram of the device.

The device comprises an annular bath with a working compartment 1, a barrier 2, an electric drive 3 connected to the output of the control unit 4, limit switches 5, the output of which is connected to the second input of the first control unit 4, an area sensor 6 of the working compartment of the annular bath 1 mechanically connected to the electric drive 3 , the output of the area sensor 6 of the working compartment of the annular bath 1 is connected to the third input of the first control unit 4, the surface tension sensor 7 is connected to a mechatronic device 8, the output of which is connected to the first input of the first control unit 4, the first 9 and second 10 are identically made analog-to-digital converters, the first inputs of which are connected to the output of the mechatronic 8 and the area sensor 6 of the working compartment of the annular bath 1, the second inputs of the analog-to-digital converters are connected to the first and second outputs of the second control unit 11, respectively , random access memory 12, to the input data buses of which the outputs of the analog-to-digital converters 9 and 10 are connected, to the address bus and control bus of which the third and fourth outputs of the second block are connected control 11, the output data bus of which is connected to the input of the data transfer unit 13 to the electronic computer 14, the control bus of which is connected to the fifth output of the second control unit 11, the output of the data transfer unit 13 is connected to the electronic computer 14, the input of the second control unit 11 is connected with limit switches 5.

The first control unit 4 can be performed as described in Abramenko Yu.M., Abramzon A.A., Bening G.P., Leshechko J.Ya. A device for determining the surface properties of liquids // Colloid Journal, 1987, No. 1, p.122-126. The second control unit 11 is built as a control automaton with “hard” logic [see Kagan B.M. Electronic computers and systems: Textbook. manual for universities. - 2nd ed., Revised. and add. - M: Energoatomizdat, 1985. - 552 p., Ill.].

A device for determining the concentration of surfactants in aqueous media works as follows.

At the beginning of the operation of the device, a sample of the studied aqueous medium is poured into the working compartment of the annular bath 1 and the surface tension sensor 7 is lowered until it contacts the test sample. In this case, the barrier 2 is in the initial position - at the beginning of the working compartment of the annular bath 1. The surface tension sensor 7 is located at the end of the operating compartment of the annular bath 1.

The user turns on the control unit 4, which sends a signal to the electric actuator 3, which starts the barrier 2 in the working compartment of the annular bath 1. The barrier 2, moving along the working compartment, reduces the measuring area of the working compartment in which the surface tension sensor 7 is located, using which and the mechatronic 8 measures the surface tension force of the investigated aqueous medium. The current area of the measuring part of the working compartment is fixed by the area sensor 6. When the barrier 2 moves, the concentration of surface-active substances in the measuring part of the working compartment occurs, which leads to an increase in the surface tension force of the studied aqueous medium, which is detected by the surface tension sensor 7 and is measured by the mechatronic 8. Stop the barrier 2 in the final position is carried out according to the output signal of the control unit 4 upon reaching the specified area of the measuring part of the working compartment, fixing limit switches 5.

When the barrier 2 moves, the analog-to-digital converters 9 and 10 are digitized and the corresponding pairs of values are recorded in the RAM 12: the current value of the surface tension of the studied aqueous medium (output signal of the mechanotron 8) and the area of the measuring part of the working compartment of the annular bath 1 (output area sensor signal 6). Pairs of values are recorded in random access memory 12 at equal intervals of time generated by the second control unit 11, which also generates control signals for analog-to-digital converters 9 and 10. Start of operation and the basics of the second control unit 11 is carried out at the beginning and end of the movement of the barrier 2 at the signal of the limit switches 5.

Thus, in the random access memory 12 is recorded the first dependence of the values of the surface tension of the investigated aqueous medium from the current area of the measuring part of the working compartment when the latter decreases.

Then, in the same way, the second dependence is recorded in the random access memory 12 — the surface tension of the investigated aqueous medium on the current area of the measuring part of the working compartment when the latter increases (when the barrier 2 moves in the working compartment of the annular bath 1 in the opposite direction - from the end to the starting point) .

In conclusion, the third memory — the values of the surface tension of the investigated aqueous medium versus the adsorption / desorption of surface-active substances into the volume of the solution with a fixed barrier 2 — is recorded in the random access memory 12.

In this case, the barrier 2 is in its original position - at the beginning of the working compartment of the annular bath 1.

The second control unit 11 is started, which starts the countdown of the adsorption / desorption of surfactants in the volume of the solution. In this case, at equal intervals of time, the analog-to-digital converter 9 is digitized and the current value of the surface tension of the studied aqueous medium is recorded in the random access memory 12 (output signal of the mechanotron 8). The control signals for the analog-to-digital converter 9 and random access memory 12 are generated by the second control unit 11. The second control unit 11 is stopped after a predetermined adsorption / desorption of surface-active substances into the solution volume.

Then, the data of the removed three dependencies stored in the random access memory 12 are transmitted by the information transfer unit 13 to the electronic computer 14 (for example, to the serial or parallel data transfer port) for their processing and identification and determination of the concentration of surfactants. Management of data transmission and synchronization of the operation of the blocks of the device is carried out by control signals from the output of the second control unit 11.

An electronic computer 14 stores an information array containing data on similar three dependencies obtained for various surfactants of known composition and concentration.

Compare the received information about the removed dependencies with the reference ones, the electronic computer 14 selects the most matching dependencies. If no matches are found, a negative identification result is generated. When a match is found, the corresponding identification result is formed and the concentration of surfactants is determined, which are displayed on the monitor screen.

Various criteria can be used as a measure of coincidence of the measured and reference dependences, for example, the coincidence (up to a given limit) of the amplitude of the dependence and the angle of inclination (derivative) of the corresponding curve.

Using the utility model reduces the time it takes to perform the analysis, as well as expanding the functionality of the device by providing the ability to identify surfactants.

Claims (1)

A device for determining the concentration of surface-active substances in aqueous media, containing an annular bath with a working compartment, a barrier, an electric drive that moves the barrier along the working compartment of the annular bath, limit switches, used to stop the barrier at certain points of the working compartment, surface tension sensor, area sensor the working compartment of the annular bath, a mechatronic and a first control unit, characterized in that it is equipped with a second control unit, the first and second identical analog-to-digital and converters, the first inputs of which are connected to the output of the mechanotron and the sensor of the area of the working compartment of the annular bath, the second inputs of the analog-to-digital converters are connected to the first and second outputs of the second control unit, respectively, by a random-access memory, to the input data buses of which the outputs of the analog-to-digital converters are connected , to the address bus and control bus of which the third and fourth outputs of the second control unit are connected, the output data bus of which is connected to the input of the gear unit data control bus which is connected to the fifth output of the second control unit, second control unit input is connected to limit switches.