APPARATUS AND METHOD FOR SEPARATING FLUID MIXTURES

Abstract

The invention relates to an apparatus for separating fluid mixtures, being equipped with a nozzle for feeding a fluid mixture composed of a number of components of different density into a volume. The nozzle has a conical annular gap located between a conical inner face of a nozzle casing and a guide cone and opening out at its tip at a nozzle opening into the volume, and a fluid feed leading tangentially into the conical annular gap. Furthermore, the apparatus has a separator, which has a separation portion located in the volume and fluidically connected to a discharge line, and has an inlet opening arranged concentrically to the nozzle opening and axially spaced therefrom. The apparatus according to the invention enables an efficient and trouble-free separation of fluid mixtures, in particular the separation of dissolved gases from a liquid or suspension.

Claims

1. An apparatus for separating fluid mixtures, the apparatus comprising: a nozzle for feeding a fluid mixture composed of a plurality of components into a volume, the nozzle comprising: a conical annular gap that is disposed between a conical inner face of a nozzle casing and a guide cone, and at a nozzle opening at the tip of said nozzle opens into the volume; and a fluid feed opening tangentially into the conical annular gap; and a separator comprising: a separation portion that is disposed in the volume and is fluidically connected to a discharge line; and an inlet opening disposed concentrically with the nozzle opening and axially spaced apart from the latter.

2. The apparatus as claimed in claim 1, wherein the separation portion had an end portion which faces the nozzle and has the shape of a tubular cylinder, of a perforated disk, or of a funnel.

3. The apparatus as claimed in claim 1, wherein a pump for conveying the fluid mixture to the nozzle is integrated in the fluid feed.

4. The apparatus as claimed in claim 1, wherein a container filled with a fluid, or a fluid-conducting line, is provided as the volume.

5. The apparatus as claimed in claim 1, wherein a phase separator which is fluidically connected to the fluid feed by way of a return line is integrated in the discharge line of the separator.

6. The apparatus as claimed in claim 1, wherein the axial spacing between the nozzle opening and the inlet opening of the separator and/or the axial position of the guide cone of the nozzle relative to the conical inner face of the nozzle casing is adjustable.

7. The apparatus as claimed in claim 1, wherein a heating device is provided in the fluid feed, in the nozzle casing and/or in the guide cone.

8. The apparatus as claimed in claim 1, wherein a feed line for a sparging gas opens into the fluid feed and/or into the annular gap.

9. The apparatus as claimed in claim 1, wherein the separator is equipped with means for actively reinforcing radial separation of components of dissimilar density in the fluid mixture.

10. The apparatus as claimed in claim 1, wherein the nozzle is equipped with a demixing chamber between the tip of the guide cone and the nozzle opening.

11. The apparatus as claimed in claim 1, further comprising an ultrasonic device for generating short-term local pressure gradients in the fluid mixture.

12. A method for separating fluid mixtures, in which a. a fluid mixture composed of a plurality of components is fed to a nozzle which has a conical annular gap, wherein the fluid mixture is fed into the conical annular gap by way of a fluid feed that opens tangentially into the annular gap; b. the fluid mixture in the conical annular gap is forced into a helically constricted path and, at a nozzle opening disposed at the tip of the conical annular gap, ejected in the form of a twisted jet into a volume, wherein a zone of reduced pressure is formed in the twisted jet, and components of dissimilar density in the fluid mixture are at least partially demixed in the radial direction; and c. fluid mixture is extracted from the zone of reduced pressure and separated from the remaining fluid mixture with the aid of a separator, which is disposed in front of the nozzle opening in the volume.

13. The method as claimed in claim 12, wherein the volume before or during the introduction of the fluid mixture is filled with an identical fluid mixture or with an inert gas.

14. The method as claimed in claim 12, wherein the fluid mixture extracted from the zone is subjected to phase separation, and a denser phase which is separated in the process is again fed to the nozzle.

15. The use of a method as claimed in claim 12, for degassing liquids or suspensions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Exemplary embodiments of the invention are to be explained in more detail by means of the drawings. In schematic views in the drawings:

[0036] FIG. 1a shows an apparatus according to the invention in a first embodiment, in a longitudinal sectional view;

[0037] FIG. 1b shows the apparatus from FIG. 1a in the cross section along the section line B-B in FIG. 1a;

[0038] FIGS. 2a-2d show different design embodiments of a separator of an apparatus according to the invention;

[0039] FIG. 3a shows an apparatus according to the invention in another embodiment, in a longitudinal sectional view;

[0040] FIG. 3b shows the apparatus from FIG. 3a in the cross section along the section line B-B in FIG. 3a; and

[0041] FIG. 4 shows an apparatus according to the invention in a further embodiment.

DETAILED DESCRIPTION

[0042] The apparatus 1 shown in FIG. 1a and FIG. 1b comprises a nozzle 2 and, spaced apart therefrom, a separator 3. The nozzle 2 comprises a nozzle casing 4 which has a conical inner face into which a fluid feed 5 opens tangentially. A likewise conically shaped guide cone 6 is disposed within the nozzle casing 4 in such a manner that a conical annular gap 7 lies opening between the inner wall of the nozzle casing 4 and the outer wall of the guide cone 6, preferably in such a manner that the cone tip 8 of the guide cone 6 is substantially co-aligned with a nozzle opening 9 of the nozzle 2. The flow cross sections of the nozzle opening 9, annular gap 7 and fluid feed 5 are preferably chosen to be of substantially identical size. The inner face of the conical nozzle casing 4 and the outer face of the guide cone 6 herein can have the same opening angle; however, it is also conceivable that the opening angle of the outer face of the guide cone 6 is more acute than the opening angle of the inner face of the nozzle casing 4, and the spacing of the nozzle casing 4 and the guide cone 6 decreases in the direction toward the nozzle opening 9, as is shown in FIG. 1a.

[0043] The nozzle 2 and the separator 3 are received within a volume 10, the latter being, for example, a container or a line. In the exemplary embodiment shown here, the volume 10 is filled with the same medium as is introduced by way of the nozzle 3. The medium is a fluid mixture composed of a plurality of components, such as for instance a suspension, a mixture of two liquids, or a solution. This is, for example, a liquid such as water, in which a gas, for instance oxygen, is dissolved, the latter to be at least partially separated from the liquid with the aid of the apparatus according to the invention.

[0044] In order to guarantee an ideally efficient rotational acceleration of the medium introduced into the nozzle 3, a rampnot shown herecan moreover be provided in the annular gap 7, by way of which ramp the base area of the annular gap 7 does not define a flat annulus but a turn of a helical face which ascends in the direction toward the nozzle opening 9 and which at the ramp end thereof terminates in the direction of the nozzle opening 9 at a height corresponding to the diameter of the fluid feed 5. In this way, after having passed the ramp, the medium does not laterally impact the flow of the medium simultaneously being introduced by way of the fluid feed 5, but is guided past the latter medium so as to be offset in the direction toward the nozzle opening 9, as a result of which turbulences counteracting the acceleration of the medium are avoided.

[0045] The guide cone 6 can be fixedly assembled within the nozzle casing 4, or be received so as to be movable axially by means of a manual or motorized displacement device 11, as is shown here, so as to adapt the apparatus 1 to the characteristics of the treated medium and/or to the respective operative task.

[0046] During the operation of the nozzle 2, a fluid mixture to be treated, for example a liquid to be degassed, is introduced in the direction of the arrow 12 into the annular gap 7 at a pressure of, for example, 2 to 5 bar by way of the fluid feed 5. The fluid mixture in the annular gap 7 is set in rapid rotating movement, the angular velocity of the latter, owing to the radius of the annular gap 7 decreasing in the flow direction, increasing up to the nozzle opening 9. For the same reason, the linear speed component directed in the direction of the nozzle opening 9 also increases. The fluid mixture exits the nozzle 2 at the nozzle opening 9, and is introduced into the volume 10 in the direction of the arrow 14 as a highly twisted jet 13 with a high torque and a high axial velocity. By virtue of the high rotating speed, a zone 16 of highly reduced pressure is created along a central axis 15 of the jet 13, this at the same time being the symmetry axis of the annular gap 7. Components with a comparatively low density from the fluid mixture accumulate in the zone 16. For example, gas dissolved in the liquid degasses and accumulates in the form of a multiplicity of small gas bubbles, or as a single gas bubble, in the zone 16.

[0047] For example, in an experimental device corresponding to the apparatus 1, a pressure of 350 mbar and below was measured in front of the nozzle opening 9 in the volume 10 at a pressure of 5 bar in the fluid feed, a volumetric flow rate of 1.2 l/h of an aqueous solution and an opening cross section of the nozzle opening 9 of 7 mm. The negative pressure generated can be varied within a wide range as a result of different delivery pressures, volumetric flow rates and nozzle dimensions.

[0048] The separator 3 by way of a separation portion 18 is immersed in the zone 16. The separation portion 18 in the exemplary embodiment shown in FIG. 1a is a tubular cylinder which is disposed so as to be radially symmetrical to the axis 15 in the volume 10, the front inlet opening 19 of said tubular cylinder being spaced apart axially from the nozzle opening 8. The cross-sectional area of the inlet opening 19 in the exemplary embodiment is approximately equal to that of the nozzle opening 9, but it may also be chosen to be larger or smaller. The separation portion 18 is fluidically connected to a discharge line 20 by way of which fluid mixture from the volume 10 that invades the separation portion 18 is extracted.

[0049] In the example of a liquid loaded with dissolved gas as the fluid mixture already mentioned several times herein, gas or a gas-rich fraction accumulates in the zone 16, said gas having previously been dissolved in the liquid introduced by way of the nozzle 2. Constituent parts of the fluid with a comparatively high density, for example a liquid phase or a phase with a minor proportion of gas, are to be found at a comparatively large radial spacing from the axis 15. All constituent parts of the fluid move at a high speed in the axial direction and have a correspondingly high kinetic energy. Since a considerable negative pressure is prevalent in the zone 16, the retrieval of the constituent parts of the fluid from this region usually requires an even higher negative pressure downstream of the separation portion 18, the latter negative pressure being generated by a vacuum pump, for example, which is disposed in the discharge line 20 (not shown here). Such a vacuum pump is typically required if gas is to be extracted substantially exclusively from the center of the twisted jet 13.

[0050] However, a vacuum pump can be dispensed with in certain circumstances. If the diameter of the separation portion 18 is enlarged, constituent parts of the fluid with a comparatively high density increasingly make their way into the separation portion 18, as a result of which the kinetic energy density of all of the constituent parts of the fluid introduced into the separation portion 18, and thus the backpressure, is increased. If the backpressure exceeds the negative pressure in the separation portion 18, no additional means are required for extracting the constituent parts of the fluid located in the separation portion.

[0051] The constituent parts of the fluid present in the separation portion 18 are extracted by way of the discharge line 20, while the remaining constituent parts of the fluid remain in the volume 10 and are fed to another kind of use.

[0052] If the assembly from FIG. 1a, 1b is used for degassing liquids or suspensions, said assembly is moreover preferably disposed vertically, i.e. having a nozzle 2 which by way of its tip points upward, and a separator 3 disposed above the latter. As a result of a vertical assembly, the separated gas can escape upward in a gas phase separator (not shown in FIG. 1a) disposed downstream of the discharge line 20, while the remaining liquid, or the remaining suspension, in the gas phase separator can be returned to the fluid feed 5.

[0053] Various embodiments of a separator which can be used in the invention are shown in FIGS. 2a to 2d.

[0054] Visualized once more in FIG. 2a is a separator 3a of the type of separator 3 shown in FIG. 1a. The separator 3a has a tubular separation portion 18a which is disposed so as to be rotationally symmetrical about an axis 15, which is shared with the nozzle 2 (only indicated in FIGS. 2a to 2d), and by way of an inlet opening 19a is disposed so as to be spaced apart from the nozzle opening 9.

[0055] The separator 3b shown in FIG. 2b has a separation portion 18b which in the region of the inlet opening 19b thereof has an outer casing 21 that widens conically in the direction from the nozzle opening 9. Owing to the conical outer casing 21, the flow exiting the nozzle opening 9 is deflected radially outward, as a result of which the pressure in a region proximal to the axis 15 at the inlet opening 19b is further reduced.

[0056] In FIG. 2c, the separation portion 18c of a separator 3c has an aperture in the form of a perforated disk 22 which is disposed in a circular manner about the inlet opening 19c and is perpendicular to the axis 15. Owing to the perforated disk 22, the medium exiting the nozzle opening 9 is radially deflected, while only a comparatively small proportion of the medium makes its way through the inlet opening 19c into the interior of the separation portion 18c. This variant also contributes toward an amplification of the pressure difference between a region proximal to the axis 15 and the regions lying radially outward in comparison.

[0057] Shown in FIG. 2d is a separator 3d which on the inlet opening 19d of the separation portion 18d of the former has a funnel 23. In comparison to the embodiment shown in FIG. 2a, the funnel 23 increases the proportion of the medium exiting the nozzle opening 9, said medium being introduced into the interior of the separation portion 18d, in comparison to the proportion that is guided past the separation portion 19d on the outside, this however being at the expense of the negative pressure prevalent in the region of the axis 15 relative to the other regions in the volume 10.

[0058] FIG. 3a shows an apparatus 25 according to the invention of another embodiment. In a manner similar to that of the apparatus 1, the apparatus 25 shown in FIG. 3a has a nozzle 26 having a guide cone 28, which is disposed so as to be movable axially while forming an annular gap 27, and a fluid feed line 29 opening into the annular gap 27. In the apparatus 25, a heating element 30, for example an electric heating device, by means of which the fluid mixture can be heated and the viscosity of the latter thus reduced, is additionally disposed in the fluid feed 29. Furthermore, a tubular demixing chamber 32, which facilitates the separation of the fluid mixture exiting the nozzle 26, is disposed downstream of the nozzle opening 31 of the nozzle 26. The length and the cross section of the demixing chamber 32 herein may vary so as to achieve a positive separation effect for the respective fluid mixture.

[0059] The apparatus 25 moreover has a separator 33 having a tubular-cylindrical separation portion 34, the end side of the latter lying opposite the nozzle 27 having an inlet opening 35. A perforated disk 36 is mounted on this end side so as to be rotatable about a longitudinal axis 37, said perforated disk 36 being able to be set in rapid rotation by a drive apparatus not shown here. Blades 38 are disposed on that side of the perforated disk 36 that faces the nozzle 26.

[0060] During the operation of the apparatus 25, the perforated disk 36 is set in rotating movement about the longitudinal axis 37, the rotating speed of said rotating movement even exceeding the rotating speed of the fluid jet being formed in front of the demixing chamber 32. An additional separation of components of dissimilar density in the treated fluid mixture is caused as a result.

[0061] Furthermore, the apparatus 25 is equipped with an ultrasonic generator 39, by means of which the guide cone 28 can be set in vibration of very high frequency (ultrasonic vibrations), for example. Generated as a result are cavitations in the fluid mixture to be treated downstream of the nozzle opening 31, dissolved gas from the fluid mixture being able to degas into said cavitations. The efficiency of the apparatus 25 is further increased as a result. Moreover, instead of the guide cone 28, the entire nozzle 25 or the nozzle casing enclosing the guide cone 28 can also be set in ultrasonic vibration, for example.

[0062] The apparatus 40 according to the invention shown in FIG. 4 is integrated in a pipeline 41 and specified, for example, to continuously degas a liquid routed through the pipeline 41. The apparatus 40 comprises a nozzle 42 having a fluid feed 43, annular gap 44, guide cone 45 and nozzle opening 46 and a separator 47 which by way of a separation portion 48 is disposed within the pipeline 41 downstream of the nozzle opening 46 and has an inlet opening 49 that is axially spaced apart from the nozzle opening 46. The separation portion 48 is connected to a gas phase separator 51 by way of a discharge line 50.

[0063] During the operation of the apparatus 40, a liquid loaded with gas, for example process water in which oxygen is dissolved, is guided by means of a pump 52 through an upstream portion 53 of the pipeline 41 to the nozzle 42. The liquid in the nozzle 42 is set in intense rotation and, while forming a heavily twisted liquid jet, exits the nozzle opening 46 at a high axial velocity into a downstream portion 54 of the pipeline 41. Owing to the intense rotating movement, a negative pressure which is sufficient to allow the gas dissolved in the liquid to degas, while forming gas bubbles 55, is generated in the center of the twisted liquid jet. The separation portion 48 of the separator 47, disposed so as to be centric in the portion 54 of the pipeline 41, at the inlet opening 49 thereof is immersed in the center of the highly twisted liquid jet, and as a result separates a gas-rich phase from the liquid. Owing to the high backpressure in the separation portion 48, the gas-rich phase of the liquid is fed to the gas phase separator 51 by way of the discharge line 50, in which gas phase separator 51 the already degassed phase is separated from the remaining gas-rich liquid and discharged by way of a gas discharge line 56. The remaining gas-rich liquid is discharged by way of a liquid discharge line 57 and can optionally be returned to the pipeline portion 53 upstream of the pump 52, or fed to another kind of use. The liquid flow remaining in the pipeline portion 54 has a highly reduced proportion of gas.

[0064] The invention is moreover not restricted to the exemplary embodiments shown here. Rather, various features of the apparatuses 1, 25, 40 can be combined with one another in an arbitrary manner, or the apparatuses 1, 25, 40 can be enhanced with further features. For example, a heating device or an ultrasonic generator can also be provided in the apparatuses 1, 40, or a gas feed line, not shown here, opens into the fluid feed 5, 29, 43 so as to reduce the viscosity of the fluid mixture to be treated with a fed sparging gas. Likewise, various operating parameters of an apparatus according to the invention such as, for example, the heating output of the heating element 30, the width of the annular gap 7, 27, 44, the spacing of the separator 3, 3a, 3b, 3c, 3d, 33, 47 from the nozzle 2, 26, 42, or the pressure of a pump conveying the fluid mixture to be treated to the nozzle 2, 26, 42 can be feedback-controlled by means of an electronic controller, not shown here, as a function of continuously measured parameters such as, for example, the temperature or the viscosity of the fluid mixture.

LIST OF REFERENCE SIGNS

[0065] 1 Apparatus [0066] 2 Nozzle [0067] 3, 3a, 3b, 3c, 3d Separator [0068] 4 Nozzle casing [0069] 5 Fluid feed [0070] 6 Guide cone [0071] 7 Annular gap [0072] 8 Cone tip [0073] 9 Nozzle opening [0074] 10 Volume [0075] 11 Displacement device [0076] 12 Arrow [0077] 13 Jet [0078] 14 Arrow [0079] 15 Axis [0080] 16 Zone [0081] 17 - [0082] 18, 18a, 18b, 18c, 18d Separation portion [0083] 19, 19a, 19b, 19c, 19d Inlet opening [0084] 20 Discharge line [0085] 21 Outer casing [0086] 22 Perforated disk [0087] 23 Funnel [0088] 24 - [0089] 25 Apparatus [0090] 26 Nozzle [0091] 27 Annular gap [0092] 28 Guide cone [0093] 29 Fluid feed [0094] 30 Heating element [0095] 31 Nozzle opening [0096] 32 Demixing chamber [0097] 33 Separator [0098] 34 Separation portion [0099] 35 Inlet opening [0100] 36 Perforated disk [0101] 37 Longitudinal axis [0102] 38 Blades [0103] 39 Ultrasonic generator [0104] 40 Apparatus [0105] 41 Pipeline [0106] 42 Nozzle [0107] 43 Fluid feed [0108] 44 Annular gap [0109] 45 Guide cone [0110] 46 Nozzle opening [0111] 47 Separator [0112] 48 Separation portion [0113] 49 Inlet opening [0114] 50 Discharge line [0115] 51 Gas phase separator [0116] 52 Pump [0117] 53 Portion (of the pipeline) [0118] 54 Portion (of the pipeline) [0119] 55 Gas bubble [0120] 56 Gas discharge line [0121] 57 Liquid discharge line