SU868482A2 - Devic for determining inhomogeneity coefficient of mixture - Google Patents

Description

(54) DEVICE TO DETERMINE THE INHOMOGENEITY RATIO OF A MIXTURE The invention relates to chemical technology and can be used to control the mixing of highly viscous liquids while simultaneously determining the heterogeneity coefficient of the mixture at the outlet of the device used in the production and processing of polymeric materials. According to the main auth. W 65B 447 a device is known for determining the concentration of a substance in a mixture, comprising a housing made of a translucent material with augers connected through a speedbox with a drive, a forming tool with a tap and a man-meter. A coordinate-swivel drive for moving the light source and the photoresistance included in the balanced bridge circuit and connected through resistances to a recording device is placed on the housing. The light flux from the stabilized light source, the passage through the transparent body and the fluid flow with particles of the indicator weakens in proportion to the concentration of the latter and enters the photoresistance. The concentration of the indicator is determined from the response curve to the pulse input and the calibration graph. This device allows you to determine the value of the average volume of fluid indicator concentration fl. However, the device involves only determining the intensity of mixing, but does not make it possible to measure the concentration of the indicator at any point in the volume of the mixture necessary to determine the heterogeneity coefficient of the mixture. The purpose of the invention is to measure the coefficient of heterogeneity of the mixture in any section of the sample mixture at the outlet of the device. The goal is achieved by the fact that in the device for determining the concentration of a substance in a mixture, the device case is equipped with dividing heads, nozzles, sleeves and a group of sending and receiving light guides, while the light guide is mounted in sleeves mounted in dividing heads movably fixed in the nozzles, while sleeves are located with diametrically opposite sides of the body in different planes of sections of the body so that the inputs of the sending light guides by means of a jog-and-turn stepper drive engine linked to

light source, and the outputs of the sensing light guides - with photoresistance.

FIG. 1 shows a diagram of the device; in fig. 2 is a section A-A in FIG. 1; in fig. 3 - curves of the concentration of the indicator from time to time.

The device comprises a housing 1, screws 2, a forming tool with a cork valve 3 and a pressure gauge 4, a light source L with a diaphragm 5 enclosed in the casing b supported by direction 7, photoresistance F- / included in an electrical circuit With photoresistance f of six glass light guides 8 (sending) and 9 (receiving), enclosed in metal sleeves 10, which can be axially displaced by dividing heads 11 installed in nozzles 12 of housing 1, light source Ld, with a diagram (not shown), constant resistance R.Rg . balancing resistance Rg and a registering device 13. The casing 6 with a lamp L and photoresistance F is able to move along the guides 7 from one group of optical fibers to another by means of a stepper motor 14, its rotary actuator 15 .. The drive 16 allows smoothly in wide limits -x change the speed and direction of rotation of the screws from the counter to one-side with the help of an interchangeable box of 17 speeds.

The device works as follows.

When rotating screws 2, with the help of metering devices (not shown), a high-viscosity liquid and an indicator (distributed component) are continuously introduced into the loading opening q. The distributed component moves along with the output liquid and enters the - gap S between the optical fibers 8 and 9. The luminous flux of the stabilized light source L, the passage through the sending optical fibers 8 and the liquid with the indicator particles is attenuated in proportion to the concentration of the latter and through the sensing optical fibers 9 enters the photogenerator. F. When the light flux is attenuated, the bridge is unbalanced, and the electrical signal is recorded by a recording device 13.

The photoresistance F is set at the shoulder of the bridge and serves to detect the difference between the intensity of the luminous flux incident on it from a conventionally not shown light source and the intensity of the luminous flux incident on the photoresistance F from the light source L. The pressure gauge 4 and the plug 3 are used for

control and regulation of pressure in the mixer head. By axial movement of the light guides 8 and 9, the concentration of the indicator at any point of the flowing fluid can be measured, and the gap size can be set.

The diameter of the fibers and the size of the gap -6 are selected depending on the properties of the object of study.

To increase or decrease the intensity of the light flux, the optical fibers can be made of variable cross section, for example, their lateral surface can vary in an exponential form.

When measuring concentration in another section, the jogging drive of the stepper motor moves the casing b with the light source and photoresistance and is measured on the same principle with another pair of optical fibers.

Curves of fluctuations in the concentration of the indicator in the mixture at the outlet of the device in different sections, for different pairs of optical fibers, at steady state operation of the system are a stationary random function with ergodic properties (Fig. 3).

The order of processing the curve is as follows.

First, the expectation m is determined, the functions, and the recommended number of measurements M of the current indicator concentration with a curve ranges from 100 to 300:

from 4

  L

centering

Then the obtained values are held

After that, the variance of the function is calculated:

B - | CL / Next, the normalized correlation function pp f (f) is constructed to values p 5; 0, i.e. to such a value of f, when the correlation moment disappears.

The interval T determined in this way provides the minimum error in determining the heterogeneity of the mixture V. by the formula

5, |, CCr-c) V

where N - 100 is the number of measurements of the current concentration C of the indicator in the mixture, separated by the time interval ir calculated using the normalized

0 of the correlation function.

A computer is used for the calculations, for which a simple program is compiled.

Claims (1)

The use of the proposed device allows to continuously obtain a quantitative picture of the degree of deviation of the current concentration of the distributed component at any point in the volume of the finished mixture from its predetermined average value, which, if there is feedback, this device with the dispenser of the distributed component completely eliminates the need for sampling and laboratory analysis, thereby contributes to the effective elimination of scrap, automating the process, increasing productivity. The invention The device for determining the heterogeneity coefficient of the mixture according to the author, 658447, characterized in that, in order to measure the heterogeneity coefficient of the mixture in any section of the sample mixture at the outlet of the device, the device body is equipped with dividing heads, patruots, and sleeves vt by a group of sprinkled and perceiver1; x light guides, while the optical fibers are mounted in guillotines installed in dividing heads, movably fixed in nozzles, and the sleeves are located on diametrically opposite sides of the building ca in different planes of the housing sections so that the waveguides by sending inputs jig rotary drive stepper motor are linked to the light source, and the outputs of the sensing optical waveguides with photoresistor. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 658447, cl. G 01 N 15/06, B 29 V 1/06, 1976 (prototype). sixteen 4-l