GB1578785A

GB1578785A - Process and apparatus for mixing immiscible liquids and one or more other substances

Info

Publication number: GB1578785A
Application number: GB33703/77A
Authority: GB
Original assignee: FUNKEN KK
Current assignee: FUNKEN KK
Priority date: 1976-09-10
Filing date: 1977-08-11
Publication date: 1980-11-12
Also published as: DE2740789C2; JPS5417329B2; JPS5334809A; FR2364055B1; DE2740789A1; FR2364055A1; CA1063597A

Description

(54) PROCESS AND APPARATUS FOR MIXING IMMISCIBLE LIQUIDS AND ONE OR MORE OTHER SUBSTANCES (71) We, KABUSHIKI KAISHA FUNKEN, a Japanese Corporation of 7-22-17 Nishigotanda, Shinagawa-ku, Tokyo, Japan, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a process and apparatus for the continuous mechanical mixing of disparate substances, such as oil, water, gas and fine particulate material, to produce evenly distributed mixtures of emulsions.

The mixtures which can be produced with the aid of the present invention, for example fuel emulsions and colloid fuel in emulsion, have conventlonally been produced using emulsification processes requiring an emulsifying agent with attendant chemical reactions and resulting impurities.

The present invention, by way of contrast, discloses a process and apparatus which continuouly and mechanically produce emulsions and suspensions more simply than, and as effectively as, the prior art emulsification processes while obviating the need for emulsifying agents.

The process and apparatus according to the present invention are modifications of and improvements upon those described in U.S. Patent Nos. 3,871,625 and 3,998,433 issued to one of the co-inventors of the present invention.

This invention is also an improvement on or modification of the invention the subject of British Patent No. 1,388,767, which claims in claim 1 a continuous flow mixer comprising a tank having an outer wall formed about a central vertical axis, a tank gential inlet into said wall, an inverted truncated overflow cone disposed in and concentric with said tank, whereby to provide an annular space within which liquid from said inlet is circulated, the overflow cone having an upper edge above the level of the tank wall inlet and having an inner conical surface and a central outlet at the tank bottom, whereby liquid circulating in said annular tank portion may rise to and overflow the upper edge of the overflow cone and descend as a film over -said inner conical surface, top central inlet means to admit downwardly into said tank along its axis a material of a type capable of being dispersed into said liquid, and means beneath said inlet and operating along said central axis to disperse and distribute such material, so admitted downwardly, centrifugally from said axis, whereby to cause its continuous and even intermixture into such liquid film descending on the said inner conical surface.

The present invention, however, involves the creation in a suitable apparatus of a dual-layer liquid film, composed of upper and lower layers of immiscible liquids such as oil and water, into which film one or more substances in the gas, liquid, powder, or a combined phase are dispersed, and the resulting dispersed mixture is emulsified by mixing under shearing.

The invention therefore provides a process for mechanically mixing two immiscible liquids with at least one other substance, wherein the two liquids are separately andcontrollably fed towards a mixing zone so as to create a flowing, dual-layer film of the two liquids through the zone, and the at least one other substance is dispersed into the liquids, to produce the requisite mixture, by centrifugally projecting the substance(s) into the mixing zone and into the film flowing therethrough.

In accordance with another aspect of the invention, there is provided a process for mechanically mixing two immiscible liquids and another substance comprising the steps of feeding two immiscible liquids into a first chamber containing an -inverted trun cated conical surface; causing the immiscible liquids to flow over the conical surface for creating a continuous, downwardly flowing dual-layer liquid film thereon; feeding a flow of the other substance into the first chamber and centrifugally dispersing the other substance into the - do,wnwardly flowing dual-layer liquid film; and receiving the downwardly flowing dual-layer liquid film containing the said substance dispersed therein in a second chamber beneath the truncated conical surface.

In accordance with another aspect of the invention, there is provided a continuous flow mixer comprising a tank for receiving two immiscible liquids therein; means forming an inverted truncated conical surface with an open lower end coaxially disposed within sa'id tank; means for feeding two immiscible liquids into said tank to create a continuous downwardly flowing dual-layer liquid film on said conical surface; means for feeding another substance into said tank; and means for centrifugally dispersing said other substance into said liquid film.

The mixing apparatus forming a preferred embodiment of the invention comprises an upper mixing section in the form of à cylindrical tank containing a concentrically disposed inverted truncated overflow cone, and a lower section in the form of a mixing or emulsifying chamber containing a mixing disk. A rotatable shaft extending concentrically through the two sections is driven at its lower end and has a mixing cone' fixed to its upper end for rotation in the upper portion of the overflow cone.

The dual-layer liquid film is created on the inner surface of the overflow cone by introducing a flow of two immiscible liquids, such as oil and water, into the cylindrical tank so as to overflow across the upper rim of the overflow cone. An inlet pipe for the gas, liquid, powder; Or combinations - t6 be dispersed into the film is disposed concentrically above the mixing cone and may be adapted to conduct a swirling flow of, for example when producing a fuel, a gas, such as air, premixed with a fine powder or particulate matter, such as coal, for impingement upon the rotating surface of the mixing cone. The impinging material is centrifugally dispersed by the mixing cone into the dual-layer liquid film.The film dispersed with the gas and particulate solids then passes through the lower open end of the overflow corie into a shear-acting mixing compartment. A mixing disk in the compartment is mounted for rotation on the central portion of the rotary shaft and has circular arrays of upstanding pins on its upper surface which co-operate-with similar arrays of pins on the bottom of the stationary cylindrical tank to produce a shearing action on the incoming mixture to mix and emulsify it.Scraper blades are prdvided On the lower Surface of the mixing disk to further mix and move the resulting emulsion out through an exhaust or delivery port in the side of the mixing compartment. - An additional oil inlet may be provided in the mixing compartment to add further oil to the mixture to create - a two-step emulsification process between the oil and water.

The invention will now be described in more detail by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a sectional view in elevation of a continuous flow jet mixer in accordance with the present invention Fig. 2 is a sectional view taken along the lines II-II in Fig. 1; Fig. 3 is a sectional view taken along the lines III-III in Fig. 1.

A mixing apparatus in accordance with the present invention is shown in Fig. 1. Similar mixing apparatus is disclosed and claimed in British Patent No. 1,388,767. The upper section of the mixing apparatus comprises an upstanding cylindrical vessel or tank 8 with upper and lower concentrically apertured end wails 8a, 8b and containing a concentrically arranged inverted truncated overflow cone 9. A feed pipe 4 extends through the aperture or opening in the upper wall 8a or tank 8 into the upper portion of overflow cone 9 and acts as a flow chute or inlet for the inflow of gas, liquid, powder ot other material in a downward jet. Directly beneath pipe 4 at a level below the upper edge 9a of the overflow cone 9 is a spreader cone 10 secured to the upper end of an axially disposed rotary shaft 20.

Shaft 20 extends through the lower section of the apparatus and has a pulley 19 on its lower end by means of which it is driven in rotation through a belt 18 and pulley 17 connected to a drive motor M mounted on the mixing apparatus support frame 21. The opening in the lower wall 8b of tank 8 connects the lower portion of overflow cone 9 with the lower section of the apparatus which comprises a cylindrical mixing compartment 16.

The mixing compartment 16 contains a mixing disk 11 which is mounted for rota- tion with the shaft 20 and has a larger diameter than the opening in the lower wall 8b of tank 8, which opening is disposed immediately above it. A plurality of short pins 12 are fixed on the upper surface of the mixing disk 11 in circular arrays and project upwardly into the space between the disk and the lower wall 8b df the tank 8.

A plurality of similar short pins 13 ari: fixed on the lower wall 8b Of tank 8 in circular arrays at different radial spacirigs from the pins 12 (see Fig. 2) and project down- wardly from the lower wall 8b to substantially intermesh with the pins 12 in the space above the upper surface of mixing disk 11. Scraper blades 14 and 15 are fixed circumferentially to the underside of the mixing disk 11 for rotation therewith and the mixing compartment 16 is provided with an exhaust or delivery port 7.

In operation, the inlet pipe 4 conducts a flow of one or more substances to be mixed downwardly into the interior of tank 8, which flow impinges upon the upper surface of spreader cone 10. The impinging substance or material is centrifugally dispersed by the rotating cone 10 into the liquid film flowing downwardly on the interior surface of overflow cone 9. The liquid film with the other material dispersed therein then passes into the mixing compartment 16 for subsequent mixing by the shearing action of the mixing disk 11 and its cooperating pin structure. The resulting mixture is then passed, with the help of scraper blades 14 and 15, out through the exhaust or delivery port 7.

It will be seen that the above-described structure and operation incorporates many essential features of the mixing apparatuses disclosed in U.S. Patent Nos. 3,871,625 and 3,998,433 issued to one of the co-inventors of the present invention.

Unlike the previously-disclosed mixing apparatuses, however, the cylindrical tank 8 of the present invention is provided with two inlets 1 and 2 to permit the continuous feeding of two different immiscible liquids, such as oil and water, each at a constant feed rate into the chamber in the interior of tank 8. Inlets 1 and 2 are preferably tangential so that the two liquids, flowing into the tank chamber tangentially, circulate about the outer surface of the inverted overflow cone 9 and rise in level to the upper edge of rim 9a of cone 9. Upon reaching the level of the cone rim, the liquids flow over it and move over the inner surface of the cone 9 in a descending flow creating a continuous liquid film on the inner surface which passes downwardly through the central opening at the base of the cone 9.The form and thickness of the liquid film will be a function of the qualities of the materials to be mixed and can be determined by the skilled artisan using known factors. Similarly, the respective flow rates may be controlled to maintain a continuous film-like flow of the liquids. As the liquids are immiscible, with proper control the film may be formed of two layers.

If, for example, oil is fed through inlet 1 and water through inlet 2 at the proper rates, the liquid film will comprise two layers, a layer of water against the inner surface of cone 9, and a layer of oil over the water layer. For best results, individual metering pumps (la, 2a) are used to continuously feed the oil or other immiscible liquid through inlet 1 and to feed the water through inlet 2. It will be seen that in order to create and sustain a continuous duallayer liquid film on the internal surface of the overflow cone 9, the tank 8 is preferably first filled with water to near the rim of the overflow cone 9 prior to the subsequent simultaneous operation of the metering pumps for the water and oil.

Further, in accordance with the present invention, the feed pipe 4 is provided with a plurality of inlets, for example a gas inlet pipe 5, and an inlet pipe 6 for the introduction of particulate matter, typically fine solid powders such as pulverized coal and stabilizers. The powders may be continuously fed into the induced gas stream, typically air, from inlet 5. The gas-powder mixture will accordingly be fed to the spreader cone 10 through feed chute 4 for subsequent dispersion and mixing into the liquid film flowing downwardly on the inner surface of the overflow cone 9.

The inlet pipe 5 for introducing the gas or air into feed pipe 4 is preferably connected tangentially to pipe 4, as shown in Fig. 3, to provide a circular flow of gas which will tend to mix with the powder or particulate matter introduced from inlet pipe 6. The downwardly flowing mixture of gas and particles impinges upon the surface of the rotating spreader cone 10 which will impart a centrifugal force to the mixture that may already possess substantial energy by reason of being discharged downwardly in a circulating stream through inlet 4. The kinetic energy of the whirling powder particles aids in their intermixture with and dissolving into the dual-layer liquid film.

As the mixture of liquid, gas, and solids descends onto the roating mixing disk 11, centrifugal force expels the mixture through the pin arrays, 12 and 13, effecting a second phase of intermixture and dissolving. Also in the process the mixture is emulsified by the shearing action of the cooperating pins.

The speed of rotation of shaft 20, and thereby, of cone 10 and disk 11, may be adjusted to provide optimum mixing and emulsifying actions for the various substances used with the process, as will be undertood by those skilled in the art.

A further feature of the present invention involves the incorporation of a secondary oil inlet 3 in the mixing compartment 16 for feeding further oil to the emulsion in the chamber of the mixing compartment.

The oil or other immiscible liquid is preferably divided into two supplies to further the emulsification so that a second oil stream is supplied through inlet 3 into the mixing chamber 16. The feed rates of the oil in the two supplies depends on the feed rate of the water, desired emulsion type and other physical and chemical factors as will be familiar to the artisan.

With this arrangement the first supply of oil through inlet 1 is emulsified with the water, gas and solids before beirig mixed with the second supply of oil through inlet 3 and a more stable emulsion is ultimately produced.

As a result, the apparatus is able to continuously and mechanically produce an emulsion or emulsified particulate suspension very simply and effectively and without the, use of an emulsifying agent, which has been the conventional means for emulsification in the prior art. In the mixing compartment 16 the mixture of liquid, gas and solids is subjected to, a shearing force caused by the relative movement of the pins 12 and 13, and the mixture is discharged from the chamber through outlet or delivery port 7 b' & by the action of the scrapers 14 and 15.

EXAMPLE I Using the present mixing apparatus an extremely stable emulsion comprising 70 parts oil and 30 parts water by weight with suspended droplets of less than 3 micron diameter has been continuously produced with no emulsifying agent by feeding 30 parts of water through inlet 2 at the rate of 150 kg/hr and appropriate portions of oil through inlets 1 and 3 at the respective rates of 135 and 215 kg/hr. This emulsion remained stable for several months at room temperature.

EXAMPLE 2 Using the mixing apparatus of the present invention a stabilized colloid fuel in emulsion has been continuously produced by feeding 40 parts of oil through inlet 1 at the rate of 180 kg/hr, 20 parts of water through inlet 2 at 90 kg/hr, and 40 parts of pulverized coal through inlet 6 at 180 kg/hr. The coal was continuously dispersed into the airflow from inlet 5, which dispersion was subsequently dispersed into the dual-layer liquid film of oil and water. This emulsion also remained stable for several months at room temperature.

Thus, the apparatus and process of the present invention facilitates the mixing and emulsifying of suitable substances in the liquid, gaseous and particulate phases to produce, in appropriate cases, emulsion fuels, or colloid fuels in water-oil type emulsions by using mechanical means obviating the use of emulsifying agents.

WHAT WE CLAIM IS: 1. A continuous flow mixer comprising: a tank for receiving two immiscible liquids therein; means forming an inverted truncated conical surface with an open lower end coaxially disposed within said tank; means for feeding two immiscible liquids into said tank to create a continuous downwardly flowing dual-layer liquid film on said conical surface; means for - feeding another substance into said tank; and means for centrifugally dispersing said other substance into said liquid film.

2. A mixer according to claim 1, further comprising a compartment beneath the open lower end of said conical surface for receiving the downwardly flowing, duallayer liquid film containing the other substance dispersed therein.

3. A mixer according to claim 2 wherein said compartment includes means for producing a shearing action on the liquids and the other substance entering the compartment, for mixing and emulsifying the two immiscible liquids and the other substance dispersed therein.

4. A mixer according to claim 3, wherein the means for producing the shearing action comprises two sets of relatively movable, operatively intermeshing projections such as pin members.

5. A mixer according to any of Claims 2 to 4, further comprising means for feeding a liquid directly into said compartment for mixing with the immiscible liquids and the other substances dispersed therein.

6. A mixer according to any of claims 1 to 5, including means for premixing the said other substance with a further substance before introduction of the said other substance -to the tank.

7. A mixer according to any of claims 1 to 6, wherein the means for feeding the liquids into the tank comprise two inlets disposed tangentially in the wall of the tank.

8. A mixer according to any of claims 1 to 7, wherein the means for feeding the liquids into the tank '--includes means for feeding the two liquids at constant flow rates.

9. Apparatus for mechanically mixing two immiscible liquids and at least one other substance, comprising first and second coaxially-disposed communicating cham bers;-means for feeding two immiscible liquids and means for feeding another substance into the first chamber; means comprising a member containing a coaxially disposed inverted truncated conical surface in said first chamber, for' conducting said two liquids', in the form of a continuous dual-layer liquid film flowing downwardly over the inverted conical surface of said member, between the first and second chambers; first rotating means coaxially disposed within the said member for centrifugally dispersing the incoming other substance into the liquid film; second rotating means coaxially disposed in the second chamber; and mixing means in said second chamber, including means rotatable with the

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Claims

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of the oil in the two supplies depends on the feed rate of the water, desired emulsion type and other physical and chemical factors as will be familiar to the artisan.

With this arrangement the first supply of oil through inlet 1 is emulsified with the water, gas and solids before beirig mixed with the second supply of oil through inlet 3 and a more stable emulsion is ultimately produced.

As a result, the apparatus is able to continuously and mechanically produce an emulsion or emulsified particulate suspension very simply and effectively and without the, use of an emulsifying agent, which has been the conventional means for emulsification in the prior art. In the mixing compartment 16 the mixture of liquid, gas and solids is subjected to, a shearing force caused by the relative movement of the pins 12 and 13, and the mixture is discharged from the chamber through outlet or delivery port 7 b' & by the action of the scrapers 14 and 15.

EXAMPLE I Using the present mixing apparatus an extremely stable emulsion comprising 70 parts oil and 30 parts water by weight with suspended droplets of less than 3 micron diameter has been continuously produced with no emulsifying agent by feeding 30 parts of water through inlet 2 at the rate of 150 kg/hr and appropriate portions of oil through inlets 1 and 3 at the respective rates of 135 and 215 kg/hr. This emulsion remained stable for several months at room temperature.

EXAMPLE 2 Using the mixing apparatus of the present invention a stabilized colloid fuel in emulsion has been continuously produced by feeding 40 parts of oil through inlet 1 at the rate of 180 kg/hr, 20 parts of water through inlet 2 at 90 kg/hr, and 40 parts of pulverized coal through inlet 6 at 180 kg/hr. The coal was continuously dispersed into the airflow from inlet 5, which dispersion was subsequently dispersed into the dual-layer liquid film of oil and water. This emulsion also remained stable for several months at room temperature.

Thus, the apparatus and process of the present invention facilitates the mixing and emulsifying of suitable substances in the liquid, gaseous and particulate phases to produce, in appropriate cases, emulsion fuels, or colloid fuels in water-oil type emulsions by using mechanical means obviating the use of emulsifying agents.

WHAT WE CLAIM IS: 1. A continuous flow mixer comprising: a tank for receiving two immiscible liquids therein; means forming an inverted truncated conical surface with an open lower end coaxially disposed within said tank; means for feeding two immiscible liquids into said tank to create a continuous downwardly flowing dual-layer liquid film on said conical surface; means for - feeding another substance into said tank; and means for centrifugally dispersing said other substance into said liquid film.
2. A mixer according to claim 1, further comprising a compartment beneath the open lower end of said conical surface for receiving the downwardly flowing, duallayer liquid film containing the other substance dispersed therein.
3. A mixer according to claim 2 wherein said compartment includes means for producing a shearing action on the liquids and the other substance entering the compartment, for mixing and emulsifying the two immiscible liquids and the other substance dispersed therein.
4. A mixer according to claim 3, wherein the means for producing the shearing action comprises two sets of relatively movable, operatively intermeshing projections such as pin members.
5. A mixer according to any of Claims 2 to 4, further comprising means for feeding a liquid directly into said compartment for mixing with the immiscible liquids and the other substances dispersed therein.
6. A mixer according to any of claims 1 to 5, including means for premixing the said other substance with a further substance before introduction of the said other substance -to the tank.
7. A mixer according to any of claims 1 to 6, wherein the means for feeding the liquids into the tank comprise two inlets disposed tangentially in the wall of the tank.
8. A mixer according to any of claims 1 to 7, wherein the means for feeding the liquids into the tank '--includes means for feeding the two liquids at constant flow rates.
9. Apparatus for mechanically mixing two immiscible liquids and at least one other substance, comprising first and second coaxially-disposed communicating cham bers;-means for feeding two immiscible liquids and means for feeding another substance into the first chamber; means comprising a member containing a coaxially disposed inverted truncated conical surface in said first chamber, for' conducting said two liquids', in the form of a continuous dual-layer liquid film flowing downwardly over the inverted conical surface of said member, between the first and second chambers; first rotating means coaxially disposed within the said member for centrifugally dispersing the incoming other substance into the liquid film; second rotating means coaxially disposed in the second chamber; and mixing means in said second chamber, including means rotatable with the

second rotating means, for producing a shearing action on the liquids and the other substance in said second chamber, thereby to mix and emulsify the two immiscible liquids and the other substance dispersed therein.
10. Apparatus according to claim 9, wherein the first rotating means comprises a rotating conical surface disposed within the upper portion of the said inverted conical surface.
11. Apparatus according to claim 9 or claim 10, wherein the second rotating means comprises a rotating disk.
12. Apparatus according to claim 11, wherein the means rotatable with the second rotating means for producing the shearing action comprise a plurality of upstanding pins mounted on the said disk.
13. Apparatus according to claim 12, further including a plurality of stationary pins in the second chamber to intermesh with the upstanding pins on the rotatable disk.
14. Apparatus according to any of claims 9 to 13, wherein the means for feeding the other substance includes premixing means for producing an axial flow of the dther substance and means for producing a circulating flow of a further substance in said axial flow.
15. A process for mechanically mixing two immiscible liquids with at least one other substance, wherein the two liquids are separately and controllably fed towards a mixing zone so as to create a flowing, dual-layer film of the two liquids through the zone, and the at least one other substance is dispersed into the liquids, to produce the requisite mixture, by centrifugally projecting the substance(s) into the mixing zone and into the film flowing therethrough.
16. A process according to claim 15, wherein the mixture leaving the mixing zone is subjected to a shearing action further to mix and emulsify the constituents of the mixture.
17. A process according to claim 16, wherein more of one of the liquids is added to the mixture leaving the mixture zone, to be subjected to the shearing action with the said mixture.
18. A process for mechanically mixing two immiscible liquids and another substance comprising the steps of feeding two immiscible liquids into a first chamber containing an inverted truncated conical surface; causing the immiscible liquids to flow over the conical surface for creating a continuous, downwardly flowing dual-layer liquid film thereon; feeding a flow of the other substance into the first chamber and centrifugally dispersing the other substance into the downwardly flowing dual-layer liquid film; and receiving the downwardly flowing dual-layer liquid film containing the said substance dispersed therein in a second chamber beneath the truncated conical surface.
19. A process according to claim 18, comprising the further steps of producing a shearing action on the liquids and the other substance in the second chamber to mix and emulsify the two immiscible liquids and the other substance.
20. A process according to claim 18 or 19, comprising the further step of feeding liquid directly into the second chamber for mixing with the immiscible liquids and the other substance.
21. A process according to claim 18, 19 or 20, wherein the shearing action is produced by two sets of relatively moving operatively intermeshing pin members.
22. A process according to any one of claims 15 to 21, wherein said immiscible liquids are oil and water.
23. A process according to any of claims 15 to 22, wherein said other substance is in the form of a powder.
24. A process according to any of claims 15 to 22, wherein said third substance is pulverised coal.
25. A process according to any of claims 15 to 24, further comprising the step of premixing the said other substance with a further substance and then feeding them to the first chamber.
26. A process according to claim 25, wherein said other and further substances are mixed by producing a circulating flow of said further substance and by introducing a flow of said other substance axially into said circulating flow.
27. A process according to any of claims 15 to 26, wherein the two immiscible liquids are fed at constant flow rates.
28. A process according to any of claims 15 to 27, wherein said other substance is centrifugally dispersed by axially feeding the flow onto a rotating conical deflector surface.
29. Apparatus for mixing immiscible liquids together and with another substance, substantially as herein described with reference to and as shown in the accompanying drawings.
30. A process for mixing immiscible liquids together and with another substance, substantially as herein described wih reference o he accompanying drawings.