SU759915A1 - Device for determining adhesive force of interphase films - Google Patents

Description

The invention relates to hydrometallurgy, namely, to the extraction technology, the study of the ability of interfacial films formed during extraction, stick to the walls of the equipment and clog the connecting channels. It can be used for ⁵ similar purposes in the oil refining industry.

A device for investigation of peculiarities of wetting real solids, and in particular, ψ resistance force acting on the ^10-boiling wetting line [1].

In this device, a plate tapering the sticking surface is placed at the bottom of the cuvette with plane-parallel walls. Above it podvoshivaetsya pendulum on the glass filaments ¹⁵ between it and the plate surface was placed under investigation gas bubble, and the entire volume of the cell is filled with liquid. At horizontal displacement of the cuvette pendulum deviates, and this deviation value is not difficult to calculate the specific ^Yu resistance force prevents movement of the wetting line, wherein when the displacement of the bubble fails razln2

part of the static resistance, which must be overcome to start the movement of the bubble, and the dynamic resistance that acts during the sliding of the bubble between the surface of a solid and the material. The described device cannot be effectively used for liquid-liquid systems.

The closest technical solution is a device for determining the adhesion force of interfacial films, which is a horizontally disposed capillary tube [2]. A few drops of liquid are placed in the tube, separated by gas bubbles. ; At the ends; the tubes create a pressure differential; while increasing, a drop closest to the high pressure side first comes into motion, then other drops begin to move. Delays in movement are caused by resistance at the wetting perimeter. By measuring the minimum pressure difference at which the last drop begins to move, it is possible to calculate the minimum force required to shift the wetting line from a fixed position

"Y

”Critical’

759915

force

; the so-called wetting line.

The described device cannot be used to determine similar characteristics in liquid-liquid systems. _five

The aim of the invention is to expand the scope.

For this, the tube is made 1) -shaped, with 10 rod located in its wide bend connected to the micrometer screw, and the narrow bend is provided with an eyepiece micrometer.

FIG. 1 shows the device in general 15; in fig. 2 - in the case of an opaque solid material.

The device consists of an upright I-tube 1, in the wide knee of which the rod 2 is located, connected with a micrometer screw 3. The narrow knee is equipped with an eyepiece micrometer 4, which measures the change in the position of the phase boundary. The core. made of glass, teflon or stainless steel. The price of division of the micrometric, screw 0.1 mm, eyepiece-micrometer 0.01 mm. The preferred ratio of pa- ₁ "Dyus knee -1: 4.

In the case of an opaque solid material .30, the narrow bend of the device is made of the material under study and provided with an additional reading glass capillary 5 (Fig. 2).

The device works as follows. The 11-shaped tube is filled with an aqueous solution of 35, then the organic phase is poured into the narrow knee. When the micrometric screw with the rod is raised to a height of 1 ° _C , the fluid level in the wide joint drops. The interface level of the phase (PRF) in: to

the narrow tube will fall to the same height L, if the resistance force around the wetting perimeter is ψ = 0. The relationship between LC and Ab _C in this case - the direct proportionality:

5t. '45

where is LU

L _With

⁸ <8 offset PRF in a narrow channel, measured by eyepiece micrometer, mm: '

stroke of the micrometer screw of the rod, mm; rod section area; cross-sectional area of the wide bend ^ cross-sectional area of the narrow bend. ^one

50

55

Experimental plot of LC (KLS) is a straight line passing through the origin

with the tangent of the angle of inclination to the x-axis,

equal

If the critical force of resistance to movement along the wetting line ψ is different from 0, some pressure must be applied so that the PRF miniature in the narrow knee begins to mix. The dependency graph ЛЬ = Т (ЛК _С ) in this case will have some initial section ЛК “, cut off on the abscis axis, according to which one can calculate using the following relations;

l ° C> - ^ P ^C

tsn

where r is the radius of the narrow tube.

If there is an interfacial film on the PRF, the latter adheres to the tube wall and the values of ψ turn out to be quite large and characterize this adhesion force. The critical resistance force along the wetting line of the organic phase-air-tube wall ψ ° in such cases can be neglected. Basically her. it is easy to measure on the same instrument, injecting only the organic phase into it, and calculate the differences

W 15. W - ψ °

ADC * ^ψ ·

In the case of an opaque solid material, modifications of the device shown in fig. 2 and 3. Measurements are also carried out, however, the change in the position of the interface in the opaque tube LL is determined by the value of L * - the mixing of the level of the aqueous solution in the readout capillary (Fig. 2) or by the value of L * * raising (lowering) the top projecting from the tube the edges of the reading rod - the float floating on the surface of the organic phase. In both cases, LH = LH = LH

The device allows one to measure the strength of adhesion-’adhesion of interfacial films formed on the interface surfaces of two immiscible liquids to a solid material and thus characterize their ability to clog up production devices and connecting; Channels. The obtained data serve as the basis for choosing the most suitable material of the apparatus, the cleanliness of processing its surface, give information about the feasibility and effectiveness

5 759915 $

chemical destruction of interfacial films. '

Claims (1)

Claim A device for determining the strength of adhesion of interfacial films, including a tube for the liquid under study, characterized in that, in order to expand the field of application, the tube is 11-shaped, with a rod connected to the micrometric screw in its wide bend, and a narrow knee is provided with an eyepiece micro meter.