GB2326356A

GB2326356A - Preparing emulsions by reflecting a liquid mixture

Info

Publication number: GB2326356A
Application number: GB9805999A
Authority: GB
Inventors: Sergevi Voronov
Original assignee: SOBEGINA TRADING Ltd
Current assignee: SOBEGINA TRADING Ltd
Priority date: 1998-03-21
Filing date: 1998-03-21
Publication date: 1998-12-23
Also published as: GB9805999D0

Abstract

A mixture of liquids such as oil and water is ejected through two nozzles against two concave reflectors 8, 9 to produce an emulsion. The main liquid fraction, oil for example, flows from 1 into a diffuser 2 where the second liquid fraction, usually water, is added. The mixture is then directed along parallel channels (Figure 2) which form the nozzles to be ejected onto the reflectors. After hitting the reflectors the mixture is reflected at an angle to the direction of its initial flow thereby intersecting with the incident flow from the nozzles. This generates pressure oscillations at an ultrasonic frequency causing the formation and collapse of cavities in the mixture which breaks down the droplets of the second fraction to produce a stable emulsion. The frequencies of the oscillations produced depends upon the radii of the reflectors, their distance from the nozzles and their relative displacement d. These parameters are adjustable to enable the production of emulsions from a variety of different viscosity liquids.

Description

A METHOD FOR THE PREPARATION OF EMULSIONS This invention relates to a process for the preparation of stable water-fuel and other emulsions from liquids that do not normally mix.

Emulsions are used in many applications in the chemical industry, in the machining and metal cutting industry, in plants using fuel as an energy source. There are a number of methods for preparing emulsions, but none of which can produce droplets of emulsifying liquid small enough for an emulsion that is stable for long periods of time, and over changing environmental conditions.

The present invention enables the production of emulsions of high stability over long periods of time and varying environmental conditions, in an effective and economic way. The capability to adjust the process enables the production of emulsions from various liquids including viscous liquids such as crude oil.

The principle of this method is generation of high and low frequency oscillations in a hydrodynamic cavitation ejector where the mixed liquid pass to be ejected through a nozzle, against specially formulated concave reflectors placed at a set distance from the nozzle.

The method is described hereinafter with reference to the accompanying drawing in which: Figure 1 shows a longitudinal cross-sectional view of the hydrodynamic cavitation radiator; Figure 2 shows a cross-section of the radiator in the zone of the ejector.

With reference to the drawing the method is described below: 1. The main fraction of the liquid, oil for example, flows into the radiator through contractor (1). A pump provides the necessary head of up to 1 OBAR.

2. From the contractor, the liquid passes to the diffuser (2), where the second liquid fraction - usually water- is added. The added fraction is controlled by a regulator (4), and can reach a maximum of 33% of total volume. In this zone the preliminary rough mixing of the different fractions of liquid happens and large droplets are generated.

3. The mixture is directed to two parallel channels of cavitators made from elastic slices in the form of Naval's nozzle.

4. Opposite to the nozzles, there are two spherical concave reflectors (7) & (9),whose radii is equal to the slot of the nozzle. The reflectors are positioned on the axis of the direction of flow from each nozzle at a distance L, from each nozzle. The two distances, however, are not equal and there is a relative distance (d).

5. The liquid mixture as it leaves each nozzle, hits the corresponding reflector and is reflected at an angle to the axis of the initial flow direction.

6. The reflected liquid intersects the incident flow, displacing outside the spherical zone of the reflector, and causing a pressure drop within that spherical zone. When this happens, the incident flow resumes its initial direction thus falling onto the reflector. This phenomenon creates pressure oscillations at ultrasonic frequency.

These oscillations cause the generation and at the same time, the destruction of cavities in the liquid mixture inside the cavitators. The non-symmetrical collapse of the cavities in a way similar to a micro-explosion, generates multiple jets of liquid which in turn break further the fraction droplets in the mixture.

7. The relative displacement (d) of the reflectors, means that the frequencies of oscillations at each cavitator and reflector are not equal. The superposition of the two oscillating pressure waves of slightly different frequencies fl & :12, creates a new oscillation of low frequency (f2-fl). This increases the number of cavities generated in the mixture and increases the total power of micro-explosions per unit time.

8. The frequency of oscillations from each reflector depends on the radii of the spherical reflectors and their distance from the nozzle. The low frequency oscillation depends on the relative displacement of the two reflectors. These parameters are adjustable, and together with a varying size of the nozzles to adjust the amplitude of the oscillations, allows very fine adjustment of the process which enables the method to produce stable emulsions of a number of liquids of different viscosity.

Claims

1. A method for the production of emulsions of liquids not normally mixing, which utilises pressure oscillations generated as the liquid is ejected onto a reflector, and which create and crash cavities in the ejector to further break to smaller sizes droplets in the liquid.

2. A method as claimed in Claim 1, wherein the pressure of the main liquid fraction used is no higher than 1 OBAR.

3. A method as claimed in Claim 1 and Claim 2, in which the additional fractions are added and mix with the main fraction in a zone between the contractor and diffuser.

4. A method as claimed in Claim 1 or Claim 3 wherein the additional fraction is no higher than 1/3 of the total volume or 50% of the volume of the main fraction.

5. A method as claimed in Claim 1, wherein the liquid mixture is directed to two or more parallel cavitators - ejectors- and is ejected through Laval's nozzles.

6. A method as claimed in Claim 5 wherein the cavitators are made of elastic slices.

7. A method as claimed in Claim 1, Claim 5, and Claim 6 wherein the liquid is ejected onto spherical concave reflectors placed opposite the nozzles.

8. A method as claimed in Claim 7 wherein the two or more reflectors are not at the same distance from the nozzles, but have a relative displacement along the axis of the liquid jet flow.

9. A method as claimed in Claim 7 wherein the radii of the reflectors is equal to the size of the Laval's nozzle.

10. A method as claimed in Claim 8 wherein the relative displacement of the reflectors does not exceed 1/2 the radii of the hemispherical reflectors.

1 1.A method as claimed in Claims 1-10 wherein the amplitude of the high frequency oscillations is adjusted by a selection of the combination of the distance of the reflectors from the nozzles, and the nozzle size.

12. A method as claimed in Claims 1-10 wherein the amplitude and frequency of the low frequency oscillations is adjusted by changing the relative displacement of the reflectors.

13.A method as herein described with the specified conditions, and with reference to and as shown in Figure 1 of the accompanying drawing.