RU2597318C2 - Method of producing fine systems - Google Patents

Abstract

FIELD: physics; chemistry.

SUBSTANCE: invention relates to thermodynamics of multiphase systems and can be used for production of fine systems. Gases dissolved in water according to Henry's law are released therefrom when passing through holes in partition in form of bubbles with size of 5 mcm or more. Determined average value of electric potential in flow is 98.8 mV. Diameter of holes in partition is determined by value of particles of mechanical impurities of up to 300 mcm and is equal to 400 mcm.

EFFECT: higher efficiency of extraction of gas dissolved in water.

1 cl, 2 dwg, 2 tbl

Description

The invention relates to the field of thermodynamics of multiphase systems.

A known method of separating hydrogen sulfide from natural water by degassing. In order to simplify the process when removing hydrogen sulfide from the deep layers of natural reservoirs, degassing is carried out by exposure to water by electro-hydraulic shocks (Aut. St. USSR No. 429026, IPC C02F 1/34, publ. 25.05.1974).

The disadvantage of this method is the need to use high voltage from 5 to 100 kV while applying a vacuum of about 0.4 atmosphere. In this case, contact of water and the products (gases) obtained from it with oxygen should be excluded.

Also known is a method consisting in its heat treatment by heating in volumetric apparatus to a boiling point (Aut. St. USSR No. 426970, IPC C021F 1/02, publ. 05.05.1974).

The disadvantage of this method is that the water is subjected to heat treatment, which requires the attraction of additional energy.

There is a method of degassing a liquid by desorption of gases under the influence of the difference of their partial pressures and increasing the interface between the cavitational mechanical effects on the liquid, while desorption is carried out in the volume of the liquid having a natural free surface, and only a liquid layer within this surface is subjected to cavitation mechanical impact ( RF patent No. 2079435, IPC C02F 1/34, publ. 05.20.1997).

The disadvantage of the above methods is that they consume additional energy. And also absent: initiating mechanism of CaCO ₃ nucleation; taking into account the surface area of the interface, the main generating factor of which is the bubble system; there is no analysis of the mass transfer processes described by Henry's law.

The technical result of the invention is to increase the efficiency of extraction from a liquid of gas dissolved in it, i.e. degassing of liquids, and in particular water.

The technical result is achieved by the fact that in the method of producing microdispersed systems when a water stream passes through a membrane, gases dissolved in water in accordance with Henry's law are released from the solution when passing through holes in the partition in the form of bubbles with a size of 5 μm or more, and the average electric value determined potential in the stream is - 98.8 mV, the diameter of the holes in the septum is determined by the particle size of mechanical impurities contained in the water, up to 300 microns and is 400 microns.

Since the value of the bubble charge does not determine the essence of the application, therefore, this value is not given in the application formula.

The invention is illustrated by drawings, where in FIG. 1 is a diagram of an experimental setup; FIG. 2 - dependence of the number of air bubbles in 1 ml of microbubble fluid on their diameter.

The inventive method is implemented in a vertical or horizontal apparatus (Fig. 1), in which the septum-membrane 1 has a living cross section of 5% or more, depending on the physicochemical properties of the liquid phase, and the diameter of the holes starts from 400 microns or more, taking into account the presence particles of the solid phase, in order to avoid clogging of the septum-membrane during operation.

In the cross section of the material flow (Fig. 1), a membrane-membrane (1) with a hole size of 400 μm is installed in the casing of installation 2 in order to prevent clogging of these holes. The pressure in the system is determined by the value of the operating pressure of the network (P ₁ ). After passing through the diaphragm, the material flow entered the open system under atmospheric pressure (P ₂ ). The volumetric flow rate was determined by the difference (P ₁ ) and (P ₂ ), as well as the resistance of the membrane-membrane.

In this case, the solution of the liquid phase is degassed in accordance with Henry's law, that is, the gas dissolved in the liquid phase, accumulated over tens and hundreds of years, is released into the environment. Micro bubbles 3 are emitted from water.

During the experiment, the following indicators were recorded:

1. The size of the emitted bubbles from the solution when passing through holes in the septum.

2. The sign of the charge of the bubbles.

3. The potential difference between the installation casing and the water flow.

4. The diameter of the holes in the partition to prevent clogging of these holes with mechanical impurities.

5. The volumetric flow rate depending on the pressure of the water supply network.

6. The rate of formation of crystals of salts of temporary stiffness in the solution passed through the membrane-membrane.

7. The number of microbubbles per unit volume of the liquid phase.

8. The material of the septum membrane.

9. The chemical composition of the gas phase extracted from water upon receipt of microdispersed systems.

The electric potential E in the flow was measured with a V7-22A voltmeter.

The electrostatic field strength was measured with an IESP-7 electrostatic field strength meter.

E (E.D.S.) was measured with an instrument: pH meter-ionometer Expert 001.

The results of the studies were designed probable mechanism that increases the rate of nucleation of CaCO _3, based on the negative sign of the surface charge of the microbubble and dissociation HCO ₃ ^- to H ⁺ and CO ₃ ^2-.

As a result of the passage of the water flow through the membrane, the impurities dissolved in the electrolyte decayed according to the Gomber dissociation mechanism, pairs of free radicals appeared, the sign of the interaction energy of which with the surrounding molecules is positive (Gomberg M. Ueber die Darstellung dess Triphenyl-chlor-metanes. // Ber. Dt. Chem. Ges. - 1900, p. 3144-3149, Bargon J., Fischer H., Johnsen U. Kernresonans-Emissionslinien waehrend rascher Radikal - reaktionen. 1 Aufnahmeverfahren und Beispiele. - "Z. Naturforsch", 1967, Bd. . 22a, S. 1551-1556).

The composition of the gas obtained by degassing a water stream is significantly different from the composition of air, as evidenced by chromatographic analysis. The composition of the gas obtained after degassing and reference data on the composition of the ambient air are shown in table 1.

The ranges of the experiment: temperature T ₁ = + 1 ... + 90 ° C; system pressure P ₁ = 2 ... 2.5 atm; frequency of measurements 10 min.

The results are presented in table 1.

It was found that a gas microbubble, in contrast to a gas bubble surrounded by water with dipoles on its surface, has a negative charge in our case, which significantly changes the mechanism of formation of CaCO ₃ micronuclei on the surface of a microbubble in a liquid-gas system.

The electrical indicators of the water flow after passing through the membrane are presented in table 2.

According to experimental data, we have the volume of the gas phase in water 5-7% vol.

Based on the assumption that 1 ml (or 1 cm ³ ) contains 5-7% of gas. Then the volume of gas V _g will be

1 ml - 100%

X ml - 5%, X = V _g = 0.05 ml (cm ³ ).

Assume that the diameter d of the air bubbles is 100 μm, or 0.01 cm.

_. Then the volume of the ball of the gas bubble is V _gp $$V_{gP}=\frac{\mathrm{one}}{6}\mathrm{<figure-callout\; id="3"\; label="\pi \; d"\; filenames="00000007.png"\; state="\{\{state\}\}">\pi \; </figure-callout>}{d}^{}{}^3=0.000000523\mathrm{from}{\mathrm{<figure-callout\; id="3"\; label="m"\; filenames="00000007.png"\; state="\{\{state\}\}">m</figure-callout>}}^3$$

_.

We determine the number of gas bubbles n with a diameter of 0.01 cm.

n_0,01=95602 шт. $$n=\frac{V_g}{V_{gP}}$$

n _0.01 = 95602 pcs.

For air bubbles with a diameter of d - 50 microns, or 0.005 cm.

$$V_{gP}=\frac{\mathrm{one}}{6}\mathrm{<figure-callout\; id="3"\; label="\pi \; d"\; filenames="00000007.png"\; state="\{\{state\}\}">\pi \; </figure-callout>}{d}^{}{}^3=0.00000006542\mathrm{from}{\mathrm{<figure-callout\; id="3"\; label="m"\; filenames="00000007.png"\; state="\{\{state\}\}">m</figure-callout>}}^3$$

n _0.005 = 764292 pcs.

For air bubbles with a diameter of d - 10 microns, or 0.001 cm.

$$V_{gP}=\frac{\mathrm{one}}{6}\mathrm{<figure-callout\; id="3"\; label="\pi \; d"\; filenames="00000007.png"\; state="\{\{state\}\}">\pi \; </figure-callout>}{d}^{}{}^3=\text{0}\text{000}\text{.000}{\text{.000523 <figure-callout id="3" label="cm" filenames="00000007.png" state="{{state}}">cm</figure-callout>}}^{\text{3}}$$

n _0.001 = 95602294 pcs.

In FIG. 2 shows the dependence of the number of air bubbles in 1 ml of liquid on their diameter.

The number of microbubbles ranged from 5 to 8% of the volume of the liquid phase.

The use of materials: organic - fluoroplast-4, kapron and inorganic - brass and stainless steel (the materials selected because they do not corrode, do not change the size of the holes) as the material of the partition-membrane.

The flow rate, depending on the pressure of the water supply network, at 252 kPa, was 20 m / s in one hole, and the Reynolds criterion value increased from 1400 to 3430.

A probable mechanism is proposed that increases the rate of CaCO ₃ nucleation, based on the negative charge of the surface of the microbubble and the dissociation of HCO ₃ ^— on H ⁺ and CO ₃ ^2– .

Due to the increase in the surface area of the contact of phases, the rate of formation of crystals of salts of temporary hardness increased by 1.4 times.

Under the influence of a magnetic field, from 1.2 to 1.5 Tesla, the deviation of the microbubbles of the gas phase increased in the direction of the magnet attached to the glass beaker, which confirmed, based on the Lorentz law, the negative charge on the surface of the microbubble.

The chemical composition of the gas phase isolated from water was changed upon receipt of microdispersed systems, in contrast to the known composition in the reference literature: nitrogen rises from 78.0% to 81.2%; oxygen decreases from 20.9% to 15.9%. This is observed as a result of a general increase in the volume of emitted gases, as well as during its redistribution among the components.

Claims (1)

A method of producing microdispersed systems, characterized in that gases dissolved in water in accordance with Henry's law are released from the solution when passing through holes in the partition in the form of bubbles with a size of 5 microns or more, and the determined average electric potential in the stream is 98.8 mV, the diameter of the holes in the partition is determined by the particle size of mechanical impurities up to 300 microns and is 400 microns.

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