METHOD AND APPARATUS FOR PASSIVE MIXING OF MULTIPHASE FLOW
20260070029 ยท 2026-03-12
Inventors
- Sreeramagiri Venkata Shanmukha SOURI (Bangalore, IN)
- Chungikar Abbas SOHEL (Bangalore, IN)
- Sreeramagiri SIVAKUMAR (Bangalore, IN)
- Anapat Samir (Bangalore, IN)
Cpc classification
B01F25/432
PERFORMING OPERATIONS; TRANSPORTING
B01F2101/2204
PERFORMING OPERATIONS; TRANSPORTING
B01F2215/0431
PERFORMING OPERATIONS; TRANSPORTING
B01F25/4317
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01F25/431
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Method and Apparatus for passive mixing of a multiphase flow or hydrodynamic performance that is housing a conduit/tube, which is a channel extending internally from the fluid inlet to the outlet ports, comprising axially stacked plurality of static mixers possessing structural elements or mixing elements (possessing structural elements on their inner walls), that are responsible for continuous splitting, and combining of the flow through the conduit, bringing about enhanced mixing of the contents of the flow, mass-transfer, and heat transfer. The structural elements bring about an enhanced mixing of multi-phasic systems passing through the conduit such as liquid-liquid, liquid-gas-liquid, and systems comprising immiscible and viscous liquids. The mixing elements or structural elements are responsible for splitting of flow into sections of multiple streams, followed by forced recombination of the multiple streams which is responsible for the equitable dispersion of individual components of multiphasic flow, thereby enhancing mixing of flow.
Claims
1. A method and an apparatus for the passive mixing of a multi-phase(ic) flow or hydrodynamic performance comprising a housing, having a conduit/tube or a channel extending internally from the fluid inlet to the outlet ports that comprises of stacked plurality of static-mixers possessing structural elements or mixing elements on the inner walls of the individual static mixers, that are responsible for splitting the multiphasic flow in to a number of streams and forcible recombination of the streams of the multiphasic flow through the conduit, bringing about the splitting-combining effect on the flow wherein, a) the structural elements or mixing elements are selected from a group comprising of axisymmetric cap with six limbs, axisymmetric divergent slope with a four-limbed cap, axisymmetric hubcap consisting of 3 supporting limbs, 3 arch like structures arranged around the axis of the pipe, which are present on the inner walls of individual static mixers and are responsible for splitting and combining of the flow, resulting in an enhanced mixing of the multi-phasic flow, b) The conduit comprises of a stacked plurality of, static-mixers possessing structural elements, across the length of the conduit that can allow the fluid to pass through them continuously experiencing splitting and combining, resulting in enhanced mixing, mass-transfer, and heat transfer, c) The stacking of the individual static-mixers is responsible for forced recombination of the split streams of multiphasic flow at regular intervals, d) The multiphasic flow experiences a cumulative splittingcombining effect resulting in an enhanced overall mixing efficiency due to plurality of static-mixers that are placed axially along the length of the conduit, e) The method of enhancing the mixing is by splitting the multiphasic flow into a number of streams and forcible recombination of the streams of the multiphasic flow through the conduit.
2. The apparatus as claimed in claim 1 comprising of stacked plurality of static mixers wherein each individual static mixer of the stack is possessing axisymmetric six limbed cap as the structural element or mixing element wherein, a) The 6 limbs are supporting limbs that split the flow region into 6 openings/sections, and are eccentric to the pipe central axis, b) Each opening from the cap structure directs fluid into a collecting basin that has guide vanes to split the flow further, c) The guide vanes are positioned such that fluid from adjacent openings is forced to mix after splitting, d) All the basins drain into a common central hole, that serves as a junction point for fluid from multiple channels to mix and flow out, e) The basin drain is provided with a smooth, gradual ramp, leading to the circular pipe cross-section.
3. The enhanced mixing as claimed in claim 1 when the apparatus comprises of stacked plurality of static mixers possessing axisymmetric cap with six limbs as the structural element can be further enhanced by varying, a) entry length and the exit length of the mixer according to the intended working fluid, b) The aspect ratio of the initial cross-section to the subsections in terms of Total area of the split in the upper cap/Area of initial cross-section, c) number of splits n of the upper cap where n2, d) position of the cap centre and collecting drain from eccentric or non-eccentric with the central axis, e) The cap openings' angle , where 180/n (close clutter)360/n (radially symmetric), and n is the number of splits, f) edge of the mid-vanes to a tapered edge or a flat edge, g) Mid-vane length between 0.2*r to 0.9*r, where r is the inner radius of the pipe, h) The central drain cross-sectional shape with side m3, circular, elliptical, i) angle of descent of the upper cap and basin ranging from 20<70 with the longitudinal axis of the pipe wherein the angle of descent is the angle between the central and radial extreme circumferences.
4. The apparatus as claimed in claim 1 comprising of stacked plurality of static-mixers wherein each individual static mixer of the stack is possessing axisymmetric divergent slope with a four-limbed cap as the structural element wherein, a) The cap comprises of 4 limbs, that split the flow region into 4 openings/sections and are eccentric to the pipe central axis, b) there is a central plateau that helps force fluid radially, with a through hole in the centre that provides an alternate route for fluid, c) From the convergent sloped roof, there exists an inner radial slope, that forces fluid to converge to the centre from the edges and all fluid is forced through a small central hole, d) The radial slope is provided with a smooth, gradual ramp, leading to the circular pipe cross-section.
5. The enhanced mixing as claimed in claim 1 when the apparatus comprises of stacked plurality of static-mixers possessing axisymmetric divergent slope with a four-limbed cap as the structural element can be further enhanced by varying, a) the entry length and the exit length of the mixer according to the intended working fluid, b) the aspect ratio of the initial cross-section to the subsections which is given by The total area of the slots/Area of initial cross-section, c) number of splits n of the diverging slopes where n2, d) position of the central plateau and through hole from eccentric or non-eccentric with the central axis, e) angle of the slots on the slope (cross-section splits) where 180/n (close clutter)360/n (radially symmetric), and n is the number of splits, f) the central plateau diameter from 0.4*D to 0.75*D, where D is the inner diameter of the pipe, g) the central through hole diameter from 0.2*d to 0.8*d, where d is the diameter of the plateau, h) cross-sectional shape of the central plateau and hole to side m3, circular, elliptical, i) angle of the converging and diverging slopes ranging from 20<70 with the longitudinal axis of the pipe, wherein is the angle between the central and radial extreme circumference, h) the shape of the slots and arrangement to asymmetric.
6. The apparatus as claimed in claim 1 comprising of stacked plurality of static mixers wherein each individual static mixer of the stack is possessing axisymmetric hubcap consisting of 3 supporting limbs as the structural element or mixing element wherein, a) the cap consists of 3 supporting limbs that split the flow region into 3 openings/sections and are eccentric to the pipe central axis, b) from the cap structure, each opening directs fluid into a U-ramp which reverses flow direction and causes the fluid to collide with incoming streams, c) the U-ramp is provided with relief slots, that are just below the hubcap supports, and these relief slots provide easy exit paths for fluid and prevent excess back pressure, d) a common central hole connects the relieve slots and provides an exit channel for the working fluid, e) the U-ramp is provided with a smooth, gradual slope, leading to the circular pipe cross-section.
7. The enhanced mixing as claimed in claim 1 when the apparatus comprises of stacked plurality of static-mixers possessing axisymmetric hubcap consisting of 3 supporting limbs as the structural element can be further enhanced by varying, a) The entry length and the exit length of the mixer according to the intended working fluid, b) The aspect ratio of the initial cross-section to the subsections as given by, Total area of the split in the hubcap/Area of initial cross-section, c) number of splits n of the hub cap where n2, d) position of the hubcap centre and central drain from eccentric to non-eccentric with the central axis, e) angle between the relief slots and supporting limbs, where 180/n (close clutter)360/n (radially symmetric), and n is the number of limbs, f) edge of the supporting limbs from a tapered edge to a straight one, g) angle of the supporting limbs with the longitudinal axis, where 2070, h) height h of the U-ramp where 0.1*Hh0.6*H, where H is the total length of the static mixer, i) trailing edge slope angle of the U-ramp with the longitudinal axis, with 2090.
8. The apparatus as claimed in claim 1 comprising of stacked plurality of static mixers wherein each individual static mixer of the stack is possessing 3 arch like structures arranged around the axis of the pipe as the structural element or mixing element wherein, a) 3 Nozzle like components are arranged around the axis of the pipe internally, b) The mixer consists of 3 arch like structures that split the flow and then proceed to taper down to smaller arch like structures, c) The reduction of the cross-section areas of the arches causes the flow to be squeezed and jet out the exit of the mixer.
9. The enhanced mixing as claimed in claim 1 when the apparatus comprises of stacked plurality of static mixers possessing 3 arch like structures arranged around the axis of the pipe as the structural element can be further enhanced by varying, a) the length of each Cusp structure, b) The angle of rotation about the axis of the pipe of the edges 3 and 4 edges to 3 and 4 respectively where 0180, c) The surfaces 6 and 6 to get perforated, d) The edges 3, 4, 3, and 4 to take the form of an arch of n sided polygon where n3, e) number of cusp structures x, where x2, f) direction of the fluid in either axial direction where n3.
10. The multiphase(ic) flow as claimed claim 1 selected from a group comprising of liquid-liquid, liquid-gas, liquid-liquid-gas, immiscible solvent systems, highly viscous liquids, liquid-solid, ternary systems, solvent-extraction-systems.
11. The apparatus as claimed in claim 1 for enhanced mixing of a multi-phasic flow that ensures enhanced mass-transfer, heat-transfer and improved dispersion in case of gas-liquid systems with minimal pressure head loss downstream of the injection site.
Description
BRIEF DESCRIPTION OF FIGURES
[0014] Various aspects of the embodiments are discussed below with reference to the accompanying figures, which are not necessarily drawn to scale, The figures are included to provide an illustration and a further understanding of the various aspects and embodiments, and are incorporated in, and constitute a part of this specification, but are not intended as a definition of the limits of any particular embodiment. The figures, together with the remainder of the specification, serve only to explain principles and operations of the described and claimed aspects and embodiments, but are not to be construed as limiting embodiments. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labelled in every figure.
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OBJECTIVES OF THE INVENTION
[0038] 1. To come out with an apparatus for the intensification of passive mixing of a multiphasic flow, by way of introducing structural elements or mixing elements on the inner walls of the static mixer that can enhance the passive mixing, of a multiphasic flow by splitting the flow into various streams and recombining them, ensuring a thorough mixing of the multiphasic flow. [0039] 2. To come out with an apparatus and a method for the intensification of passive mixing of a multiphasic flow by way of introducing limbed structural elements on the inner walls of the individual static mixers wherein the structural elements split and combine the multiphasic flow passively in such a way that the multiphasic flow experiences alternate splitting and combining in a conduit all along from the inlet port to the outlet port in a housing. [0040] 3. To come out with an apparatus for the intensification of passive mixing of multi-phasic systems such as liquid-liquid, liquid-liquid-gas, immiscible solvent systems etc to achieve higher yields, maximum purity of the final product by way of introduction of structural elements in individual static mixers that can be stacked in a conduit or tube responsible for splitting and combining of the multiphasic flow.
SUMMARY OF THE INVENTION
[0041] The exemplary embodiment of the invention discloses a method and apparatus for passive mixing of a multi-phase flow or hydrodynamic performance by way of splitting and combining the multiphasic flow, that is housing a conduit/tube, which is a channel extending internally from the fluid inlet to the outlet ports, comprising stacked plurality of static mixers possessing structural elements or mixing elements on the inner walls of the individual static mixers that are responsible for alternate splitting and combining of flow through the conduit, bringing about a cumulative splitting and combining effect on the flow. The cumulative splitting and combining effect results in enhanced mixing of the multi-phasic flow. The conduit comprises of a plurality of axially stacked static mixers across the length of the conduit that can allow the fluid to pass through them continuously experiencing splitting and combining effect resulting in improved mixing, mass-transfer, and heat transfer.
[0042] One embodiment of the invention discloses stacked plurality of monolith static mixers possessing structural elements, in channel or conduit in a housing for the intensification of mixing in a multiphase flow in split and combine mode of operating for better mass-transfer, heat-transfer, better yield and purity of the end product resulting in an improved performance.
[0043] An exemplary embodiment of the invention discloses a stacked plurality of static mixers in a conduit wherein individual static-mixer possesses an axisymmetric cap with six limbs as the structural element, that splits the flow area for intensification of mixing of multiphase flow wherein the openings on the cap direct fluid after splitting into a collecting basin, that has guide vanes that induce further splitting which is followed by thorough mixing.
[0044] Yet another important embodiment of the invention discloses a stacked plurality of monolith static mixers in a conduit for mixing multiphase flow wherein individual static-mixer possesses an axisymmetric divergent slope with a four-limbed cap as the structural element that forces fluid towards the edges and into dedicated slots that split the flow region into 4 openings/sections and are eccentric to the pipe central axis.
[0045] One more embodiment of the invention discloses a stacked plurality of monolith static mixers in a conduit for mixing multiphase flow wherein each individual static-mixer possesses an axisymmetric hubcap consisting of 3 supporting limbs as the structural element that split the flow region into 3 openings/sections and are eccentric to the pipe central axis wherein each opening directs fluid into a U-shaped ramp that reverses the flow direction and causes the fluid to collide with incoming streams.
[0046] Yet another exemplary aspect of the invention discloses a stacked plurality of static mixers in a conduit for multiphase flow wherein individual static mixer consisting of 3 arch like structures arranged around the axis of the pipe as the structural element that splits the flow and then proceed to reduce down to smaller arch like structures which cause the flow to be squeezed and jet out of the exit of the mixer.
[0047] One important aspect of the invention discloses stacking of plurality of the static-mixers possessing structural elements on the inner walls of the individual static mixers that are responsible for the splitting of the multiphasic flow in a conduit in a housing.
[0048] One more aspect of the invention discloses the individual static mixer possessing structural elements responsible for splitting the multiphasic flow in a conduit according to any of the embodiments in the form of an insert for intensification of mixing of multiphase flow.
[0049] The various embodiments of the instant invention are described in details with the help of the accompanying drawings drawing inferences to the specific aspects of the individual embodiments of the invention in the following sections. The various embodiments of the instant invention of Method and Apparatus for passive-mixing of multiphase flow are described in detail drawing reference to the accompanying figures in the following paragraphs. The various embodiments of the invention clearly stress upon the novelty, inventorship and utility aspects of the instant invention compared to the prior art reported hitherto. A person with ordinary skill can easily understand and perform the invention easily. The different aspects of the instant invention as disclosed herein are only illustrative in nature and various other embodiments and working of the invention are possible within the scope of the invention without deviating from the essence of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0050] The examples of the apparatus discussed herein are not limited in application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. It will be understood by one of skill in the art that the apparatus is capable of implementation in other embodiments and of being practiced or carried out in various ways. Examples of specific embodiments are provided herein for illustrative purposes only and are not intended to be limiting. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0051] Any references to examples, embodiments, components, elements or acts of the apparatus herein referred to in the singular may also embrace embodiments including a plurality, and any references in plural to any embodiment, component, element, or act herein may also embrace embodiments including only a singularity (or unitary structure). References in the singular or plural form are not intended to limit the presently disclosed apparatus, its components, acts, or elements.
[0052] The use herein of including, comprising, having, containing, involving, and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. References to or may be construed as inclusive so that any terms described using or may indicate any of a single, more than one, and all of the described terms. The various embodiments of invention are described in detail herein and the various aspects of the invention are disclosed below.
[0053] Drawing reference to
[0054] Drawing reference to
Description of the Embodiment of the Invention as Depicted in
Description of Individual Static Mixer
[0055] The individual static mixer forming a part of the embodiment of the invention contained in
Description of Flow
[0056] The flow regime initially gets split into the openings between the supports, when it encounters the cap. The circular flow cross-section is split into 6 smaller pockets by the cap and then opens into a collecting basin. Fluid from each of the openings is further split into 2 halves by centrally located vanes. Fluid split by adjacent vanes is forced to combine in shared collecting basins. Finally, all the fluid from various shared basins is forced to converge into the central drain hole, where they mix and flow out. The specific aspects of the invention as first depicted in
Description of Figures Related to the Embodiment of the Invention Comprising of an Axisymmetric Cap with Six Limbs as First Depicted in
[0057] The labels are common for all further images and represent the stated features for every static mixing unit as given hereunder. (Reference convention: feature labelled as 3 in
[0067] One aspect of the invention as first depicted in
[0068] Another aspect of the invention as first depicted in
[0069] One aspect of the invention as first depicted in
[0070] One aspect of the embodiment of the invention as first depicted in
[0071] One aspect of the embodiment of the invention as first depicted in
[0072] Additional embodiments of the invention as first depicted in
Description of the Embodiment of the Invention as First Depicted in
[0073] Drawing reference to
Description of the Static Mixer Possessing an Axisymmetric Divergent Slope with a Four-Limbed Cap as the Structural Element
[0074] A monolith static mixer for mixing multiphase flow comprising an axisymmetric divergent slope that forces fluid towards the edges and into dedicated slots. This cap comprises of 4 limbs, that split the flow region into 4 openings/sections and are eccentric to the pipe central axis. Furthermore, there is a central plateau that helps force fluid radially, with a through hole in the centre that provides an alternate route for fluid. From the convergent sloped roof, there exists an inner radial slope, that forces fluid to converge to the centre from the edges. All fluid is forced through a small central hole. Multiple Static mixers can be stacked axially to enhance the mixing and dispersion of the multiphase flow elements. Each successive mixer that is stacked can be oriented with the openings and supports at an angular offset, to enhance the mixing. The radial slope is provided with a smooth, gradual ramp, leading to the circular pipe cross-section.
Description of Flow
[0075] The flow regime initially gets split into the slots between the supports, when it encounters the divergent slope, additionally, some fluid flows straight through the hole located on the central plateau. The circular flow cross-section is split into 5 smaller pockets by the slope and then opens into a convergent slope. Fluid from each of the openings is made to interact by the radial slope, which forces all the fluid towards the central hole. In this manner, the fluid flowing straight through the plateau hole encounters fluid that was split by the divergent ring from all 4 directions and is forced through a smaller cross-section.
Description of Figures Related to the Embodiment as Illustrated in
[0076] The labels are common for all further images and represent the specific features of the embodiment as first depicted in
[0086] One aspect of the invention as depicted for the first time
[0087] Another aspect of the embodiment of the invention as depicted in
[0088] One aspect of the embodiment of the invention depicted in
[0089] One important aspect of the embodiment of the invention contained in
[0090] Additional aspects of the embodiment of the invention as depicted in
Description of the Embodiment of the Invention as Depicted in
[0091] Drawing reference to
Description of the Individual Static Mixer Possessing an Axisymmetric Hubcap Consisting of 3 Supporting Limbs as the Structural Element
[0092] A monolith static mixer for mixing multiphase flow comprising an axisymmetric hubcap that splits the flow area, wherein the cap consists of 3 supporting limbs that split the flow region into 3 openings/sections and are eccentric to the pipe central axis. From the cap structure, each opening directs fluid into a U-ramp (which reverses flow direction and causes the fluid to collide with incoming streams. The U-ramp is provided with relief slots, that are just below the hubcap supports. These relief slots provide easy exit paths for fluid and prevent excess back pressure. A common central hole connects the relieve slots and provides an exit channel for the working fluid. Multiple Static mixers can be stacked axially to enhance the mixing and dispersion of the multiphase flow elements. Each successive mixer that is stacked can be oriented with the openings and guide vanes at an angular offset, to enhance the mixing. The U-ramp is provided with a smooth, gradual slope, leading to the circular pipe cross-section.
Description of Flow
[0093] The flow regime initially gets split into the openings between the supports when it encounters the hubcap. The circular flow cross-section is split into 3 smaller pockets by the hubcap and then opens into the U-ramp region. Fluid from each of the openings is forced to reverse its direction and interact with incoming fluid in the central cavity. From this region, the working fluid is pushed out through the relief slots and central hole, where further interaction occurs due to the smaller cross-section area of the holes.
Description of Different Aspects Related to the Embodiment as Illustrated in
[0094] These labels are common for all further images and represent the specific features of the embodiment as first depicted in
[0103] One aspect of the embodiment of the invention as depicted in
[0104] Another aspect of the embodiment of the invention as depicted in
[0105] One important aspect of the embodiment of the invention as depicted in
[0106] One more aspect of the embodiment of the invention as depicted in
[0107] Another aspect of the embodiment of the invention as depicted in
[0108] Additionally 5 embodiments can be realized by the variation of the key aspects of the embodiment as first depicted in
Description of the Embodiment as Depicted in FIG. 5 for the First Time Wherein the Structural Element is a 3 Arch Like Structures Arranged Around the Axis of the Pipe
[0109] Drawing reference to
Description of the Static Mixer Possessing the Structural Element Having 3 Arch Like Structures Arranged Around the Axis of the Pipe Internally
[0110] Each individual Static mixer forming a part of the stacked plurality of static mixers in the conduit for passive mixing of the multiphase flow possesses the structural element consisting of 3 Nozzle like components arranged around the axis of the pipe internally. The mixer element consists of 3 arch like structures that split the flow and then proceed to reduce down to smaller arch like structures. The reduction of the cross-section areas of the arches causes the flow to be squeezed and jet out the exit of the mixer (
Description of Flow
[0111] Description of the flow is explained with the help of
Description of Specific Aspects of the Embodiment of the Invention with 3 Arch Like Structures Arranged Around the Axis of the Pipe as Depicted in
[0112] The flow of fluid happens in the axial direction of the pipe. Dashed lines represent hidden edges that might not be visible in the view. The specific aspects of the embodiment of the invention with 3 arch like structures arranged around the axis of the pipe as depicted for the first time in
[0119] The important aspect of the embodiment of the invention as depicted first time in
[0120] One aspect of the embodiment of the invention as depicted first time in
[0121] One more aspect of the embodiment of the invention as depicted first time in
[0122] Additional embodiments in respect of the embodiment depicted first time in
[0123] Accordingly, the apparatus and the method disclosed herein represent a significant improvement over prior art by providing a method and apparatus that uniquely solve the problems of providing a superior mixing action in a multi-phasic flow ensuring enhanced mass-transfer, heat transfer and improved mixing and dispersion of gas-liquid systems with minimal pressure head loss downstream of the injection site.
[0124] Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for designing other products without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the claims are not to be limited to the specific examples depicted herein. For example, the features of one example disclosed above can be used with the features of another example.
[0125] Furthermore, various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept. For example, the geometric configurations disclosed herein may be altered depending upon the application, as may be the material selection for the components. Thus, the details of these components as set forth in the above-described examples, should not limit the scope of the claims.
[0126] The various embodiments of the invention of Method and apparatus for passive mixing of Multiphase flow are realized in the following examples.
[0127] The apparatus for enhancing the mixing efficiency of a multiphasic flow comprising a stacked plurality of static mixers that possessed specially configured structural elements to effect alternate splitting and combining of the multiphasic flow by way of the structural elements of axisymmetric cap with six-limbs, axisymmetric divergent slope with a four-limbed cap, axisymmetric hubcap consisting of 3 supporting limbs and with 3 arch like structures arranged around the axis of the pipe, on the inner walls of the individual static mixer that formed the stack of the plurality of static mixers in the conduit of the apparatus as described in the invention are produced as per the detailed description as disclosed by the instant invention and are tested to evaluate their mixing efficiency experimentally taking water-acetic acid-toluene system and the results are compared with those obtained from experiments conducted on similar lines in batch mode as well as in a tube reactor. The experimental results are given in the following paragraphs.
[0128] Mass transfer studies are conducted by the Method and Apparatus for passive mixing of multiphase flow or Static mixer reactors (SMRs) as disclosed by the invention to assess and quantify the mixing capabilities of the apparatus or the reactors. Liquid-liquid extraction (LLE) is the physical method employed to ascertain the effective interphase mass transfer in a given system (reactor or mixed vessel or SMRs).
[0129] The liquid-liquid extraction of the ternary system of water-acetic acid-toluene, is studied in a batch system to obtain equilibrium concentration. The same extraction is performed using the apparatus contained in the instant invention to establish their mass transfer efficiency. Similar experiments were conducted in an empty tubular reactor (without the static mixers as disclosed by the instant invention) with a T-joint, to establish the base line mass transfer coefficients without the static mixers. Mass transfer coefficients are evaluated for the liquid-liquid-extraction of water-acetic acid-toluene in a flow system using the apparatus comprising the stacked static mixers with modified geometry as disclosed in the invention. The enhanced efficiency due to the stacked plurality of the static mixers possessing structural elements on their inner walls present inside the apparatus as contained in the instant invention is evaluated by comparing the experimental results.
Example 1
Batch Experiment to Establish the Equilibrium Between Toluene and Water Phase for Acetic Acid (AA) Partition
[0130] Equal volumes (50 ml) of 30 w/w % Acetic Acid in water (feed, raffinate) and Toluene (extractant) are taken in a Round bottom flask. The mixture is kept for stirring at 950 rpm. Samples are collected for every fifteen minutes, and the mixture is transferred to separating funnel where the ternary system gets separated into two definite layers namely, top organic layer which is toluene dominant and the bottom aqueous layer that is water dominant. Acetic acid content in both the layers is analysed by titrating known amount of sample against 1N NaOH. 15 ml of methanol and water are used as solvents for titrating the organic and aqueous layers respectively. The amount of NaOH consumed is used to determine Acetic acid % in both the layers by using equation 1
[0131] Burette reading gives the value for the Vol of NaOH consumed in ml. Samples are collected until repetitive burette readings occur. Content of acetic acid taken as normality is used to calculate Partition coefficient (K.sub.D) and Mass transfer coefficient (K.sub.L) which is given by equation 2 and 3 respectively.
[0132] Where, [AA.sub.org] is the concentration of acetic acid in organic phase and [AAag] implies concentration of acetic acid in aqueous phase. Using the equilibrium concentration and the initial concentration of the solute AA in both the phases the mass transfer coefficient for an interphase mass transfer is calculated according to the equation 3. This will be used in subsequent sections for SMRs.
[0133] Where C.sub.in, C.sub.out are the concentrations of the solute in inlet, outlet of the reactor at time and C* is the equilibrium concentration. The data obtained from batch studies is summarised in table1. From table1, it can be observed that between 75 to 150 min, the concentration of AA in organic phase remained constant which indicated the attainment of the equilibrium between the two layers. The average concentration of AA in Organic (toluene) phase is taken as the equilibrium concentration and it is found to be 0.634N. This is used as C* in the equation 3 to calculate mass transfer coefficient for all the subsequent calculations for the apparatus comprising static mixer reactors (SMRs).
TABLE-US-00001 TABLE 1 Batch study data Concentration of AA in toluene layer as function of time of contact in a batch system [AA], Time wt % AA Normality 0 0.000 0.000 15 2.227 0.371 30 1.565 0.391 45 3.056 0.509 60 3.571 0.595 75 3.881 0.646 90 3.750 0.625 105 3.870 0.644 120 3.853 0.642 135 3.781 0.630 150 3.709 0.618 Equilibrium 0.634N concentration of AA in Toluene organic layer
Example 2
Studies Conducted with the Apparatus Containing Stacked Plurality of Static-Mixers Possessing Structural Elements of Axisymmetric Hubcap Consisting of 3 Supporting Limbs, 3 Arch Like Structures Arranged Around the Axis of the Pipe, Axisymmetric Cap with Six Limbs, Axisymmetric Divergent Slope with a Four-Limbed Cap (Static Mixer Reactors (SMRS) in a Housing and a Tube Reactor with T-Joint
Experimental Setup
[0134] Liquid-liquid extraction procedure was carried out in SMRs to determine mass transfer coefficient by physical method. Two pumps, a separating funnel, and the SMR constituted the experimental setup. Calibrated metering pumps were used to pump known and desired flow of both the solvent and the feed solution. They enter the SMR, get mixed due to the static mixers (SMs) in the reactor and exchange takes place between immiscible organic and aqueous phases. The outlet of the SMR is connected to a separating funnel, where both phases collect and separate immediately, thereby stopping further exchange of mass between the phases. Each sample that was taken was immediately separated, and the solute content of both the layers was determined. This experiment was carried out at six different residence times: 0.25, 0.5, 1, 1.5, 2, 2.5 minutes, by varying the flow rates of the two liquids. The ratio of flow rates of both phases was maintained constant at all time intervals.
Experimental Procedure
[0135] The feed solution (30% Acetic Acid in water) and solvent (Toluene) are pumped into the SMRs. Here they flow concurrently getting intimately mixed due the presence of the novel SMs and resulting in the mass transfer of acetic acid between the two phases. The flowrates of the pumps are fixed according to residence time, which is given by equation 4.
[0136] The collected mixture is left for separation into aqueous and organic layers. Both the layers are analysed for Acetic Acid content by taking 5 gm of sample and titrating it against 1N NaOH as discussed above. Equilibrium concentration is found by conducting batch studies. Mass transfer coefficient is calculated at each time of residence () using equation 3.
[0137] The experimental results and the mass transfer coefficients obtained, for the empty tube reactor, SMRs possessing axisymmetric hubcap consisting of 3 supporting limbs, 3 arch like structures arranged around the axis of the pipe, axisymmetric cap with six limbs, axisymmetric divergent slope with a four-limbed cap as the structural elements are given below in tables 2, 3, 4, 5 & 6 respectively.
TABLE-US-00002 TABLE 2 Estimation of mass transfer coefficients for empty tube with a T-Joint (baseline flow reactor) organic layer aqueous layer 1.0N 1.0N NaOH NaOH Mass Residence wt of titre wt % wt of titre Concetration transfer time sample value, Calculated AA Concetration sample value, Calculated % AA [AA aq] Partition coefficient (min) (gm) ml wt % AA avg [AA org] (N) (gm) ml wt % AA avg (N) coefficient min {circumflex over ()}(1) 0.25 5.03 1.5 1.84 1.79 0.30 5 22.5 27.8 27.84 4.636 0.064 2.501 5.01 1.4 1.73 5.02 22.6 27.8 0.5 5.05 1.7 2.08 2.03 0.34 5.03 22.3 27.4 27.57 4.590 0.074 1.501 5.01 1.6 1.98 5 22.4 27.7 1 5.05 1.9 2.33 2.27 0.38 5.03 22 27.1 27.17 4.524 0.084 0.896 5.01 1.8 2.22 5.01 22.1 27.3 1.5 5.02 1.9 2.34 2.40 0.40 5 21.9 27.1 27.04 4.504 0.089 0.653 5.03 2 2.46 5.04 22 27.0 2 5.01 2.1 2.59 2.59 0.43 5.02 21.8 26.9 26.91 4.482 0.096 0.561 5.01 2.1 2.59 5 21.8 27.0 2.5 5.06 2.2 2.69 2.64 0.44 5.02 21.7 26.7 26.74 4.454 0.099 0.464 5.02 2.1 2.59 5.04 21.8 26.8
[0138] The first column is the residence time set for the articular run. This is for combined flow rates of the liquids and the tube volume is 40 ml. The next 5 columns show the estimation of the concentration of AA in organic layer estimated by titrating the isolated layer with 1N NaOH. Subsequent 5 columns under the Aqueous layer indicate the same estimation for aqueous layer. The column partition coefficient is derived from the equation 2 and the mass transfer concentration is estimated based on equation 3. Equilibrium concentration of AA in organic layer is 0.64N estimated earlier from the batch extraction experiments.
[0139] It is to be noted that for a fixed volume of reactor (here a tube), higher the residence time means lower the flow rates. Lower flow rate means less velocity of the liquids through the reactor. It is established in the science that higher the flow rate, better is the mixing and hence the mass transfer coefficient (m.t.c). The trend of m.t.c with residence time seen in the first and last columns of the above table indicate the same trend. Higher residence time, lower the flow rates, slower the velocity therefore lower the mass transfer coefficient. The trend asymptotically reaches a limit, which can be seen from the above data.
[0140] Tables 3, 4, 5, 6 summarise the data obtained from experiments conducted in SMRs wherein the individual static mixers are possessing the structural elements of axisymmetric hubcap consisting of 3 supporting limbs, 3 arch like structures arranged around the axis of the pipe, axisymmetric cap with six limbs, axisymmetric divergent slope with a four-limbed cap.
TABLE-US-00003 TABLE 3 Experimentally Estimated mass transfer coefficient for different residence times for SMR possessing the structural element of axisymmetric hubcap consisting of 3 supporting limbs. Time, m.t.c min (min (1)) 0.25 4.00 0.5 2.11 1 1.09 1.5 0.88 2 0.65 2.5 0.55
TABLE-US-00004 TABLE 4 Experimentally Estimated mass transfer coefficient for different residence times for SMR possessing structural element of 3 ARCH LIKE STRUCTURES ARRANGED AROUND THE AXIS OF THE PIPE Time, m.t.c min (min (1)) 0.25 3.35 0.5 2.00 1 1.04 1.5 0.79 2 0.60 2.5 0.50
TABLE-US-00005 TABLE 5 Experimentally Estimated mass transfer coefficient for different residence times for SMR possessing the structural element of axisymmetric cap with six limbs Time, m.t.c min (min (1)) 0.25 3.35 0.5 2.10 1 1.09 1.5 0.79 2 0.66 2.5 0.52
TABLE-US-00006 TABLE 6 Experimentally Estimated mass transfer coefficient for different residence times for SMR possessing the structural element of axisymmetric divergent slope with a four-limbed cap. Time, m.t.c min (min (1)) 0.25 4.38 0.5 2.38 1 1.30 1.5 0.95 2 0.79 2.5 0.70
[0141] From tables 3, 4, 5 & 6 it can be concluded that continuous systems with novel split and combine SMRs show higher mass transfer coefficient compared to empty Tubular reactor due to the presence of static mixers possessing structural elements that could enhance the mixing efficiency and in turn mass transfer between the different phases of a multiphasic system. This establishes the utility of the apparatus and method disclosed in the invention for interphase mass transfer devices.
Advantages of the Invention
[0142] The Method and apparatus as disclosed by the instant invention for enhancing mixing efficiency of multi-phasic passive flow herein has the following advantages, [0143] 1. A significant improvement over prior art by providing an apparatus comprising a stacked plurality of static mixers that uniquely solves the problems of providing a superior mixing action in a multi-phasic flow. [0144] 2. The apparatus disclosed herein ensures enhanced mass-transfer, heat-transfer and improved mixing and dispersion of gas-liquid systems with minimal pressure head loss downstream of the injection site. [0145] 3. The apparatus disclosed herein operates by splitting and combining the multiphasic flow due to the presence of limbed structural elements present on the inner walls of the individual static mixers that can be stacked in a conduit axially offering a thorough mixing in multi-phasic systems and can be employed in additive manufacturing; process industries, as is exemplified from the experimental results obtained in the liquid-liquid-extraction studies done with water-acetic acid-toluene system wherein the invention provided better mass-transfer coefficient compared to the same done in a static mixer devoid of such geometrical modifications. [0146] 4. One important embodiment of the invention stresses on the importance of the limbed structural elements that could split the multiphasic flow into various streams and allowing them to get combined thereby ensuring a thorough mixing of the elements of the multiphasic flow which is very essential to obtain products with high purity and in higher amounts especially when there is a considerable difference in the densities of the individual phases of the multiphasic system. [0147] 5. The heat transfer and the mass transfer between the liquid and gaseous phases of the multiphasic fluid is enhanced due to the thorough mixing ensured by the limbed structural elements present in the individual static mixers and this aspect of the invention makes the invention suitable for application in pharmaceutical industries.
Analysis of Novelty, Inventiveness and Utility
[0148] The instant invention of METHOD AND APPARATUS FOR PASSIVE MIXING OF MULTI-PHASE FLOW is novel in the light of the prior art as it provides an apparatus or reactor comprising a stacked plurality of static mixers possessing structural elements or mixing elements on their inner walls, that considerably enhanced the mixing of a multiphasic-flow as is evident from the mass-transfer coefficients obtained from the liquid-liquid extraction studies done using water-acetic acid-toluene system. The inventiveness of the instant invention lies in arriving at the apparatus and a method to enhance the mixing efficiency in multi-phasic flow systems by way of introducing an axisymmetric hubcap consisting of 3 supporting limbs, 3 arch like structures arranged around the axis of the pipe, axisymmetric cap with six limbs, axisymmetric divergent slope with a four-limbed cap as structural elements on the inner walls of the individual static mixers that can be stacked in a conduit, which can be employed successfully in processes to obtain better yields. The various structural elements of the static mixers as illustrated in the various embodiments of the instant invention are indicative of the inventiveness of the instant invention. The utility aspect of the instant invention is realized as the instant invention discloses an apparatus that can provide enhanced mixing efficiency in multi-phase flows and which can be successfully employed in chemical process industries for speciality chemicals, pharmaceutical intermediates and API production, polymer production wherein a thorough mixing of the different phases has a profound effect on the yield and purity of the final product.