DEVICE AND METHOD FOR DISPERSITING GASES IN LIQUIDS

Description

[0001] The invention relates to a device and a method for dispersing gases in liquids.

[0002] The introduction of gases into liquids is an important component of process engineering. In wastewater treatment, for example, oxygen is introduced to improve treatment efficiency, and in neutralization, carbon dioxide is used to regulate the water's pH. It is advantageous, particularly from an energy perspective, to introduce the gases into the liquid being treated by generating the smallest possible gas bubbles and distribute them evenly.

[0003] The gases are often introduced via porous bodies, such as sintered ceramics or metals, or via perforated tubes. While perforated tubes are a relatively inexpensive way to introduce gases into a liquid, the resulting gas bubbles are usually quite large and can only be manipulated to a limited extent. Due to the rapid flotation of larger gas bubbles and the small surface area available for the gas to dissolve in the liquid (mass transfer), large amounts of gas reach the surface and are thus lost to the process. Such tube systems are therefore only suitable for very deep water tanks.

[0004] Sintered materials are somewhat more suitable than perforated tubes in terms of the achievable bubble size. However, this requires a relatively high level of construction effort. In the case of flat feed systems, inaccurate alignment also leads to uneven gas discharge. Furthermore, during extended periods of downtime, there is a risk that solids contained in the liquid will penetrate the pores of the material and clog them.

[0005] As an alternative to the methods mentioned, injectors have proven successful. These involve a liquid being passed through a pipe and mixed with a gas. The resulting mixture is then fed to a treatment area, for example a container or a basin filled with the liquid. The gas is introduced, for example, via a Venturi system arranged in the pipe, in which a flow generated in the liquid automatically sucks in the gas. The liquid in the pipe can be, for example, liquid from the treatment area itself, which is circulated by a pump, or it can come from a separate container or pipe. Systems of this type are known, for example, from the documents EP 2 327 298 A1, EP 0 477 846 A1, EP 0 322 925 A2 or FR 2 825 996 A1.

[0006] When using an injector with a Venturi nozzle, it was observed that the liquid-gas mixture formed in the Venturi system tends to separate into a two-phase flow due to the buoyancy of the gas. The widened cross-section at the outlet, typical of a Venturi system, also reduces the flow velocity. Turbulence, which briefly provided relatively good mixing in the narrowest cross-section, dissipates, and further along the pipeline, a separation of liquid and undissolved gas components occurs. These components collect in the upper sections of the pipeline and coagulate to form larger gas bubbles. While attempts can be made to promote the introduction or dissolution of the gas using mixing tubes, these systems still have room for improvement in terms of efficiency.

[0007] Furthermore, it has been proposed to generate fine gas bubbles, so-called "microbubbles," using a swirl chamber. The liquid to be treated is introduced tangentially into a cylindrical or conical chamber, causing the liquid therein to rotate. The gas supplied to the liquid in front of or in the swirl chamber concentrates along the axis due to the centrifugal forces acting in the swirl chamber, while the denser liquid collects radially on the outside. The liquid-gas mixture emerges in a swirl pattern from a bore centrally inserted into one end face of the swirl chamber. At sufficiently high flow velocities and rotational speeds, the gas is finely dispersed in the liquid by turbulence and shear forces. Systems of this type are known, for example, from EP 0 963 784 A1, WO 2014 192 896 A1, or WO 2016 083 043 A1.

[0008] These systems are similar to a hydrocyclone with the individual phases separated according to density: The fluid with the lowest density rotates in the center along the axis, while denser components, such as solids contained in the liquid, are pushed out to the outer region and concentrate there. When operating with liquids laden with solids, this leads to overloading of the swirl chamber and ultimately to blockage of the outlet opening. This is especially true if additional static devices for swirl generation are provided within the swirl chamber, as is the case, for example, in the subject matter of WO 2014 192 896 A1. Therefore, these systems are also unsuitable for use with suspensions, i.e., liquids containing solid-state contaminants.

[0009] EP 2 540 387 A1 discloses a device according to the preamble of claim 1 and a method according to the preamble of claim 9.

[0010] The invention is therefore based on the object of providing a possibility for dispersing a gas in a liquid which overcomes the disadvantages of the prior art.

[0011] The object is achieved by a device having the features of patent claim 1 and by a method having the features of patent claim 9. Advantageous embodiments of the invention are specified in the subclaims.

[0012] A device according to the invention for dispersing a gas in a liquid comprises a liquid volume and a nozzle for introducing a liquid into the liquid volume. The nozzle has a conical annular gap arranged between a conical inner surface of a nozzle casing and a guide cone and opening into the liquid volume at its tip with a nozzle opening, as well as a liquid supply opening tangentially into the conical annular gap. Furthermore, the device comprises a gas supply for a gas to be dispersed in the liquid volume, which opens into the liquid supply and / or into the annular gap and / or in the region of the nozzle opening, i.e. directly at the nozzle opening itself or downstream (seen in the direction of the exiting liquid) of the nozzle opening in the liquid volume.

[0013] The width of the annular gap, i.e., the distance between the inner wall of the nozzle shell and the outer wall of the guide cone, should at no point be larger than the inner diameter of the fluid supply at its junction with the annular gap. The annular gap can have an acute or obtuse opening angle. For example, the opening angle is between 30° and 180°, preferably between 45° and 170°, and particularly preferably between 60° and 135°. The annular gap forces the tangentially entering fluid to move in a spiral motion.The radial distance between the conical inner surface of the nozzle shell and the outer surface of the guide cone is constant between the inlet of the liquid supply and the tip of the guide cone, or decreases continuously towards the nozzle opening; a widening of the distance between the boundary surfaces of the annular gap between the inlet of the liquid supply and the nozzle opening, for example to form a mixing chamber, is not provided for in the invention. Therefore, the volume available to the liquid in the annular gap decreases continuously up to the nozzle opening, whereby the axial velocity, as well as the rotational speed, continuously increases. In particular, the rotational speed is higher due to the guidance of the liquid through an annular gap than with an otherwise equally sized hollow-conical nozzle body.Due to the high rotation speed, the liquid is introduced at the nozzle opening into the surrounding liquid volume as a highly swirling liquid jet, along whose axis a zone of greatly reduced pressure exists. The gas, simultaneously introduced via the gas supply, enters the liquid jet, is introduced with it into the surrounding liquid volume, and only there, i.e., before the nozzle opening, does it intensively mix with the liquid, forming tiny bubbles.

[0014] It has surprisingly been shown that the presence of mixing chambers and the like within the nozzle actually leads to a separation of liquid, gas, and any solids present in the liquid due to the pressure conditions prevailing there. The strictly conical annular gap provided by the invention, with a constant or steadily decreasing radial distance between the inner surface of the nozzle shell and the guide cone towards the nozzle outlet, prevents a separation of liquid and the solids contained therein within the nozzle. The mixture of liquid and gas is thus introduced into the liquid volume.

[0015] There are three basic options for introducing the gas. Firstly, the gas can be injected into the liquid at the liquid feed point, i.e. upstream of the nozzle. In this case, the injected gas reduces the viscosity of the liquid, and a considerable amount of gas can be injected at a volume flow ratio of 1:1 to the liquid or more, without - compared to the case without gas injection - a reduction in the liquid's throughput despite an overall increase in volume flow. In addition, the strong shear forces in the annular gap promote the mixing of gas and liquid. The disadvantage of this, however, is that the gas must be injected at the same pressure as the liquid, which corresponds to the inlet pressure of the liquid at the nozzle, otherwise the more highly compressed medium will enter the other's feed lines.

[0016] Secondly, the gas can be fed into the annular gap via one or more gas outlet openings from a gas supply line arranged in the nozzle jacket or the guide cone. In the simplest case, the gas outlet opening of the gas supply is a bore; however, it can also be a nozzle or a body made of a porous material, for example a sintered material made of plastic, ceramic, or metal, in which the gas is introduced into the surrounding liquid through a large number of outlet openings, resulting in a particularly fine-beaded introduction of the gas. The entire guide cone or parts of it can also be designed as a porous sintered material body through which the gas is introduced. However, even in this variant, the pressure of the supplied gas is limited to the pressure value of the liquid in the annular gap.

[0017] Thirdly, the gas can be introduced into the liquid at a gas outlet opening or gas outlet nozzle located centrally in the tip of the guide cone or at least one gas outlet opening or gas outlet nozzle arranged laterally to the nozzle jacket, in the direction of the swirling liquid jet. The supplied gas is sucked into the zone of reduced pressure in the liquid jet and, together with the introduced liquid, is distributed deep into the liquid volume. The high pressure difference between the pressure of the supplied gas and the pressure within the zone of reduced pressure in the liquid jet enables a high mass throughput. In particular, in advantageous embodiments of the invention, the gas can also be introduced at the speed of sound or supersonic speed. In addition, a suction is created on the escaping liquid, which assists in the conveyance of the liquid.In this design, there is no mixing of gas and liquid within the nozzle, and both media can be supplied at different pressures, for example, the gas is supplied at a pressure of 10-20 bar and the liquid at a pressure of 2-3 bar.

[0018] In a preferred embodiment, two or more gas discharge nozzles can be arranged laterally to the nozzle opening and preferably symmetrically to it. The gas discharge nozzle or nozzles can, for example, be aligned axially parallel to the conical annular gap, so that the gas jet(s) emerging from the gas discharge nozzle(s) is / are introduced into the liquid volume parallel to the swirled liquid jet. A particularly advantageous embodiment of the invention, however, provides that the at least one gas supply ends at a gas discharge nozzle or gas discharge opening which is angled, preferably at an acute angle, to the nozzle opening, so that the gas jet emerging from the gas supply is discharged in the direction of the swirled liquid jet. This results in particularly intensive mixing of gas and liquid in the liquid jet.

[0019] An advantageous embodiment of the invention provides for a ramp in the annular gap, beginning at the inlet of the liquid supply and spiraling toward the cone tip. The ramp is designed such that, after one revolution in the annular gap, it guides the liquid entering through the tangential liquid supply by at least the diameter of the liquid supply toward the nozzle opening. As a result, after completing one revolution in the annular gap, the liquid does not, or only to a limited extent, encounter the flow of liquid just entering from the liquid supply, and turbulent flows that could lead to a reduction in the rotational speed are effectively avoided.

[0020] The liquid volume is preferably a liquid-filled, preferably closed, container or a liquid-conducting conduit; however, this can be an open container, a basin, or a body of water, such as a pond or a fish farm. In the case of a liquid-conducting conduit, such as a pipeline through which the liquid flows, the strongly swirling flow prevents a flow of two separate phases from forming again quickly after the initial dispersion of a gas.

[0021] If the liquid volume is located within a container, it is recommended, especially for flowless and / or large-volume containers such as pools or ponds, to provide additional means for generating a flow within the liquid to promote the distribution of the gas bubbles. These additional means could be, for example, a stirring device or a circulation pump. Furthermore, the nozzle can be located within a mixing tube located within or fed from the liquid volume, or in a circulation line fluidly connected to the liquid volume.

[0022] In a suitable further development of the invention, the nozzle guide cone is designed to be axially adjustable to accommodate varying requirements regarding the amount of fluid flowing through the nozzle. Furthermore, a cylindrical front section can be provided at the nozzle orifice, downstream of the tip of the guide cone, which focuses the swirled fluid jet without, however, reducing the axial or radial velocity of the fluid exiting the nozzle opening.

[0023] The nozzle opening is preferably designed as a flat jet nozzle, i.e., it has a greater width horizontally than vertically. For example, the nozzle opening has an oval shape, with a greater width than height. This reduces the agglomeration of gas bubbles because there are fewer gas bubbles vertically. A preferred embodiment of the invention provides for a liquid recirculation system. For this purpose, the nozzle is connected to a return line for recirculating the liquid from the liquid volume. A conveying device, for example an electric pump, is preferably arranged in the return line, by means of which liquid is continuously withdrawn from the liquid volume and introduced into the nozzle.

[0024] The object of the invention is also achieved by a method having the features of patent claim 9.

[0025] In a method according to the invention for dispersing a gas in a liquid, liquid is fed to a nozzle of the type described above, equipped with a conical annular gap, wherein the liquid is fed tangentially via a liquid feed opening tangentially into the annular gap. In the annular gap, the liquid is forced into a spirally narrowing path and exits in the form of a swirling liquid jet from a nozzle opening arranged at the tip of the conical annular gap below the liquid level of a liquid volume. The gas to be dispersed is introduced into the liquid feed and / or into the nozzle and / or into the swirling liquid jet upstream of the nozzle opening.

[0026] Preferably, the gas to be dispersed is introduced at least partially in the form of a gas jet directed at the swirled jet of liquid emerging from the nozzle opening into the liquid volume. For example, the gas is introduced either centrally into the swirled liquid jet and / or via gas discharge nozzles arranged laterally on the nozzle and directed at the swirled jet.

[0027] The liquid passed through the nozzle may be liquid that is introduced into the liquid volume from a reservoir, a tank or a pipe, or liquid from the liquid volume itself that is circulated and fed to the nozzle by means of a pump or a similar conveying device.

[0028] In order to disperse the gas as finely as possible in the liquid, a ratio of liquid passed through the nozzle to gas to be dispersed of between 5:1 and 1:2 is particularly suitable.

[0029] A further improvement in the distribution of the gas can be achieved by ionizing the gas before it is fed to the liquid, as this stabilizes the gas bubbles and prevents rapid agglomeration.

[0030] The liquid can be, for example, water or an aqueous solution or suspension, especially wastewater or cooling water. The introduced gas can be, for example, air, pure oxygen, or carbon dioxide.

[0031] Typically, the gas is supplied in a gaseous state. However, in order to achieve a cooling effect in the liquid volume in addition to dispersing the gas, an advantageous embodiment of the process according to the invention provides for the gas to be dispersed to be supplied in a cold-liquefied or pressure-liquefied state. In this case, a design of the nozzle according to the invention is recommended in which the gas is introduced via one or more gas outlet openings arranged at the tip of the guide cone and / or laterally at the nozzle opening in the direction of the swirling liquid jet in the liquid volume.This not only allows the gas to be introduced at a pressure independent of the liquid pressure, but the high velocity of the escaping liquefied gas and the vigorous movement of the surrounding liquid also ensure intensive mixing and prevent freezing of the gas outlet opening. For example, this method can be used to introduce carbon dioxide in its liquid state, for example, at a pressure of 6 to 10 bar, into a volume of liquid consisting of water.

[0032] Using the method and device according to the invention, bubbles of the gas to be dispersed can be produced in the liquid volume in the micrometer range, i.e., with a size of 1 micrometer to 100 micrometers, preferably 1 micrometer to 10 micrometers ("microbubbles") or smaller, i.e., for example, between 0.1 micrometer and 1 micrometer ("nanobubbles"). Due to their low buoyancy, these bubbles can be widely distributed throughout the liquid volume. Very small-volume gas bubbles can be generated, particularly with high liquid content (liquid-to-gas volume flow ratio of 5:1 or more).

[0033] The device and method according to the invention can be used for various applications, particularly in the field of wastewater treatment. A preferred application is the introduction of air, oxygen-enriched air, or oxygen (with a purity of over 95 vol%) into wastewater to improve treatment efficiency, or the introduction of carbon dioxide to regulate the pH of wastewater.

[0034] Embodiments of the invention will be explained in more detail with reference to the drawings. The schematic views show: Fig. 1a: A device according to the invention in a first embodiment in longitudinal section, Fig. 1b: The device from Fig. 1 a in cross-section along a section line BB in Fig. 1a , Fig. 2a: A device according to the invention in a second embodiment in longitudinal section. Fig. 2b: The device from Fig. 2a in cross-section along a section line BB in Fig. 2a, Fig. 2c:The device from Fig. 2a in cross-section along a section line CC in Fig. 2a , Fig. 3: A device according to the invention for treating a liquid in a container.

[0035] The Fig. 1a and Fig. 1bThe device 1 shown comprises a nozzle 3 accommodated within a liquid volume 2. The nozzle 3 comprises a nozzle casing 4 with a conical inner surface, into which a liquid supply 5 opens tangentially. Within the nozzle casing 4, a likewise conically shaped guide cone 6 is arranged such that a conical annular gap 7 is open between the inner wall of the nozzle casing 4 and the outer wall of the guide cone 6, and preferably such that the cone tip 8 of the guide cone 6 is substantially aligned with a nozzle opening 9 of the nozzle 3. The nozzle opening 9 is preferably dimensioned such that its flow cross-section is substantially equal to or smaller than the flow cross-section of the liquid supply 5.The inner surface of the conical nozzle jacket 4 and the outer surface of the guide cone 6 can have the same opening angle, but it is also conceivable that the opening angle of the outer surface of the guide cone 6 is more acute than the opening angle of the inner surface of the nozzle jacket 4, the distance between the nozzle jacket 4 and the guide cone 6 is reduced in the direction of the nozzle opening 9, as in . fig. 1a shown.

[0036] The nozzle opening 9 can have a circular cross-section or, as explained in more detail below, a horizontally widened cross-section. The guide cone 6 can be fixedly mounted within the nozzle casing 4 or—not shown here—can be accommodated for axial movement.

[0037] A gas supply 10 runs along a central axis of the guide cone 6 and is connected to a gas source (not shown here), such as a compressed gas cylinder or a pressure tank. The gas supply 10 opens into the nozzle opening 9 via a gas outlet opening 11, which can also be designed as a nozzle, at the cone tip 8 of the guide cone 6.

[0038] During operation of the device 1, a liquid to be treated is introduced into the annular gap 7 at a pressure of, for example, 2-3 bar via the liquid supply line 5 in the direction of arrow 12. In the annular gap 7, the liquid is set into a rapid rotational movement, the angular velocity of which increases due to the radius of the annular gap 7 decreasing in the flow direction up to the nozzle opening 9. For the same reason, the linear velocity component directed towards the nozzle opening 9 also increases. The liquid leaves the nozzle 3 at the nozzle opening 9 and is introduced into the liquid volume 2 as a strongly swirled jet 13 at high speed in the direction of arrow 14. Due to the high rotational speed, a zone of greatly reduced pressure is created along a central axis 15 of the jet 13.

[0039] A gas to be dispersed in the liquid volume 2 is introduced via the gas supply 10 in the direction of arrow 16 at a high pressure of, for example, 10 bar to 20 bar. The gas exits the gas outlet opening 11 at high velocity and from there enters the interior of the swirling liquid jet 13. Together with the gas, the gas is drawn deep into the liquid volume 2 and, due to the forces acting within the swirling jet 13, is gradually broken up into fine bubbles, for example, a few micrometers in diameter, and finely distributed (dispersed) in the liquid volume 2. A cylindrical front section 17, optionally arranged at the nozzle opening 9 in front of the cone tip 8, leads to increased focusing of the liquid jet 13.

[0040] The Fig. 2a, 2b and 2cThe device 20 shown also comprises a nozzle 22 accommodated within a liquid volume 21. The nozzle 22 has a nozzle casing 23 with a conical inner surface, into which a liquid supply 24 opens tangentially. Within the nozzle casing 23, a likewise conically shaped guide cone 25 is arranged such that a conical annular gap 26 is open between the inner wall of the nozzle casing 23 and the outer wall of the guide cone 25 and such that the cone tip 27 of the guide cone 25 is substantially aligned with a nozzle opening 28 of the nozzle 22. In this exemplary embodiment, the opening angles of the inner surface of the nozzle casing 23 and the outer surface of the guide cone 25 are the same.

[0041] In the embodiment according to Fig. 2a-2c the nozzle opening 28 has a horizontally widened cross-section, for example the one in Fig. 2cshown oval cross-section, in which the horizontal width a of the nozzle opening 28 is greater than the vertical height b.

[0042] The gas to be dispersed in the liquid volume 21 is introduced into the device 20 via a gas supply 29 which - as shown here - is arranged inside the nozzle casing 23 or outside the nozzle casing 23 and exits at a gas outlet opening 30 laterally to the nozzle opening 28, but inclined in the direction of a central axis 31 of the nozzle 22.

[0043] During operation of the device 20, a liquid to be treated is introduced into the annular gap 26 at a pressure of, for example, 2 bar to 3 bar via the liquid supply line 24 in the direction of arrow 32. In the annular gap 26, the liquid is set into a rapid rotational movement, the angular velocity of which increases due to the radius of the annular gap 26 decreasing in the flow direction up to the nozzle opening 28. For the same reason, the linear velocity component directed towards the nozzle opening 28 also increases. The liquid leaves the nozzle 22 at the nozzle opening 28. Due to the horizontally widened nozzle opening 28, a flat jet pattern 33 is generated within the liquid volume 21.For example, two co-rotating primary jets form in the liquid entering the liquid volume 21, between which a counter-rotating secondary jet forms, with a zone of greatly reduced pressure forming in each of the jets due to the high rotation speed.

[0044] A gas to be dispersed in the liquid volume 21 is introduced via the gas inlet 29 in the direction of arrow 34 at a high pressure of, for example, 10 bar to 20 bar. The gas exits the gas outlet opening 30 at high velocity and from there enters the interior of the swirled liquid jets in the jet pattern 33. The gas is introduced deep into the liquid volume 21 and, due to the forces acting within the swirled jets, is gradually broken down into fine bubbles, for example, a few micrometers in diameter, and finely dispersed in the liquid volume 21.

[0045] In order to ensure the most efficient rotational acceleration of the liquid introduced into the nozzle 20, a ramp 35 is provided in the annular gap 26. Due to the ramp 35, the base area of ​​the annular gap 26 does not describe a flat circular ring, but rather a winding of a helical surface rising in the direction of the nozzle opening 28, which at its ramp end 36 is located a distance corresponding to the diameter of the liquid feed line 24 further in the direction of the nozzle opening 28 than at the entry point 37 of the liquid feed line 24 into the annular gap 26. In this way, after passing through the ramp 35, the liquid does not hit the flow of liquid introduced via the liquid feed line 24 from the side, but offset from it, thereby avoiding turbulence that would limit the acceleration of the liquid.

[0046] Furthermore, a nozzle 22 with an acute-angled gas supply 29 does not necessarily have to have a horizontally widened nozzle opening 28; of course, the nozzle opening 28 can also have a circular cross-section, or the nozzle opening 9 of the nozzle 3 can have a horizontally widened cross-section. Likewise, a ramp 35 can also be provided in an arrangement corresponding to the nozzle 1.

[0047] In Fig. 3 An embodiment is shown in which a volume of liquid is continuously circulated by means of a device according to the invention and is thereby mixed with gas.

[0048] The Fig. 3The device 40 shown comprises a nozzle 41 according to the invention, which is, for example, a nozzle 3, 22 of the type described above. The nozzle 41 is accommodated below a liquid level 42 in a liquid volume 43 contained in a container 44. For example, the container 44 is a largely closed container, a settling tank for receiving wastewater, or a fish farm.

[0049] The device 40 has a liquid supply 45, which is fluidly connected to a return line 46 immersed in the liquid volume 43. A conveying device 47, for example a pump, is arranged in the return line 46. By means of the conveying device, liquid is continuously withdrawn from the liquid volume 43 and fed into the nozzle 41.

[0050] The gas to be dispersed into the liquid volume 43 is taken from a gas source 48, for example, a pressure vessel or a pressure line, fed to the nozzle 41 via a gas supply 29, and dispersed in the liquid in the manner described above. The gas is, for example, oxygen or carbon dioxide. For example, gas and liquid are introduced via the nozzle 41 in a gas-to-liquid volume flow ratio of 2:1. To improve mixing, particularly in large vessels, means (not shown here) for generating an additional flow 50, such as a circulation pump, can be provided in the vessel.

[0051] Due to the special nozzle design, the device 40 according to the invention is suitable for dispersing the gas even when the liquid fed into the nozzle 41 via the return line 46 is heavily permeated with solid components. Since the nozzle 41 contains neither dead spaces, such as mixing chambers, nor static mixing elements, such components do not accumulate within the nozzle 41 and therefore cannot impair the functionality of the device 40. Rather, the conical design of the annular gap 7, 26, due to the cross-sectional constriction, causes a high velocity of the introduced liquid, even in the axial direction, which promotes the discharge and distribution of the solids (or, more generally, substances with a higher density than the liquid itself) in the liquid volume. List of reference symbols 1 device 26 Annular gap 2 Liquid volume 27 cone tip 3 nozzle 28 nozzle opening 4 nozzle jacket 29 Gas supply 5 Fluid supply 30 Gas outlet opening 6 Guide cone 31 axis 7 Annular gap 32 Arrow 8 cone tip 33 Beam pattern 9 nozzle opening 34 Arrow 10 Gas supply 35 ramp 11 Gas outlet opening 36 Ramp end 12 Arrow 37 Entry point 13 beam 38 - 14 Arrow 39 - 15 axis 40 device 16 Arrow 41 nozzle 17 Cylindrical anterior section 42 fluid level 18 - 43 Liquid volume 19 - 44 container 20 device 45 Fluid supply 21 Liquid volume 46 Return line 22 nozzle 47 conveyor system 23 nozzle jacket 48 Gas source 24 Fluid supply 49 Gas supply 25 Guide cone 50 flow

Claims

1. Device for dispersing a gas into a liquid, having a liquid volume (2, 21, 43) and a nozzle (3, 22, 41) for feeding a liquid into the liquid volume (2, 21, 43), which nozzle has a conical annular gap (7, 26) that is disposed between a conical internal face of a nozzle casing (4, 23) and a guide cone (6, 25) and on the tip of said annular gap at a nozzle opening (9, 28) opens out into the liquid volume (2, 21, 43) below a liquid level (42), and a liquid infeed (5, 24) which opens tangentially into the conical annular gap (7, 26), and having at least one gas infeed (10, 29, 49) for a gas to be dispersed into the liquid volume (2, 21, 43), characterized in that the at least one gas infeed opens out into the liquid infeed (5, 24) and / or is guided through the guide cone (6, 25) or the nozzle casing (4, 23) and opens out into the annular gap (7, 26) at a gas exit opening (11, 30), and / or in the liquid volume (2, 21, 43) opens out laterally to the nozzle opening (9, 28) and at an angle to a central axis (31) of the conical annular gap (7, 26).

2. Device according to Claim 1, characterized in that at least one gas infeed (10, 29, 49) is guided through the guide cone (6, 25), and at a gas exit opening (11, 30) disposed in the tip (8, 27) of the guide cone (6, 25) opens out into the nozzle opening (9, 28).

3. Device according to Claim 1 or 2, characterized in that a ramp (35) which starts at the mouth of the liquid infeed (5, 24) and ascends helically in the direction of the nozzle opening (9, 28) is provided in the annular gap (7, 26).

4. Device according to one of the preceding claims, characterized in that a vessel (44) filled with liquid, or a liquid-conducting line, is provided as the liquid volume (2, 21, 43).

5. Device according to one of the preceding claims, that a vessel (44) filled with liquid is provided as the liquid volume (2, 21, 43), and additional means for generating a flow (50) in the liquid are disposed in the vessel (44).

6. Device according to one of the preceding claims, characterized in that the guide cone (6, 25) of the nozzle (3, 22, 41) is axially adjustable in relation to the conical internal face of the nozzle casing (4, 23).

7. Device according to one of the preceding claims, characterized in that the nozzle opening (9, 28) is configured as a flat-jet nozzle.

8. Device according to one of the preceding claims, characterized in that the nozzle (3, 22, 41) is connected to a return line (46) for circulating the liquid from the liquid volume (2, 21, 43).

9. Method for dispersing a gas into a liquid, in which method a. a liquid is fed to a nozzle (3, 22, 41) which has a conical annular gap (7, 26), wherein the liquid is supplied into the annular gap (7, 26) by way of a liquid infeed (5, 24) that opens tangentially into the annular gap (7, 26), b. the liquid in the annular gap (7, 26) is forced into a path constricted in the shape of a spiral, and at a nozzle opening (9, 28) disposed on the tip of the conical annular gap (7, 26), below a liquid level (42) of a liquid volume (2, 21, 43), is ejected in the form of a swirled liquid jet (13) into the liquid volume (2, 21, 43), characterized in that c. a gas to be dispersed is introduced into the liquid infeed (5, 24) and / or into the conical annular gap (7, 26) of the nozzle (3, 22, 41) and / or by way of gas exit nozzles (30), which are disposed laterally on the nozzle (3, 22, 41) and directed onto the swirled jet (13), into a gas jet directed toward the swirled jet (13) of the liquid exiting into the liquid volume (2, 21, 43) at the nozzle opening (9, 28).

10. Method according to Claim 9, characterized in that the volumetric flow ratio of liquid guided through the nozzle (3, 22, 41) to the fed gas to be dispersed is between 5:1 and 1:2.

11. Method according to one of Claims 9 or 10, characterized in that the gas is ionized prior to being fed to the liquid.

12. Method according to one of Claims 9 to 11, characterized that the gas is fed in a liquefied state into the swirled liquid jet (13) ahead of the nozzle opening (9, 28).