WO2019198095A1

WO2019198095A1 - Method and apparatus for passive mixing of multiphase fluids

Info

Publication number: WO2019198095A1
Application number: PCT/IN2019/050226
Authority: WO
Inventors: Chirag KHALDE; Jitendra SANGWAI; Vivek Ranade
Original assignee: INDIAN INSTITUTE OF TECHNOLOGY MADRAS (IIT Madras); The Queen's University Of Belfast
Priority date: 2018-04-13
Filing date: 2019-03-19
Publication date: 2019-10-17

Abstract

An apparatus for passive mixing of multiphase fluids is provided. The apparatus includes an outer static chamber with a fluid inlet and outlet, and housing at least one mixing element placed concentric to the static chamber. The mixing elements include conical ends and threaded surfaces with thread sets oriented so as to promote mixing. The mixing elements are held in position by a connecting member. The primary fluids enter the chamber through the fluid inlet and passes through a clearance region between the chamber and the mixing element. The surfaces of the static chamber and mixing element may have different wetting capabilities. The connecting member may supply a secondary fluid and also include a temperature control mechanism. The apparatus prevents formation of secondary vortices during operation allowing thoroughly mixed fluids to exit the chamber. Modification of roughness and wetting characteristics of the surfaces may further enhance/control the mixing capabilities.

Description

METHOD AND APPARATUS FOR PASSIVE MIXING OF MULTIPHASE

FLUIDS

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims priority to Indian patent application no. 201841014253 entitled METHOD AND APPARATUS FOR PASSIVE MIXING OF MULTIPHASE FLUIDS, filed on April 13, 2018.

FIELD OF THE INVENTION

[0002] The disclosure relates generally to apparatus for obtaining mixtures and for carrying out chemical reactions and in particular to an apparatus and method for passive mixing of multiphase or multispecies fluids.

DESCRIPTION OF THE RELATED ART

[0003] There is a huge demand for a promising mixer and a mixing mechanism to obtain a thoroughly mixed multi- species fluids and multi- phase fluids with enhanced mixing and heat transfer characteristics. Such mixers may be used for carrying out chemical reactions or for forming a homogenous mixture for controlling the temperature of the fluids. Several such mixer devices have been described earlier including continuous flow stirred-tank reactor (CSTR), a magnetic stirrer, high shear dispersers, or static mixers. The effectiveness or efficiency of the systems where these devices are employed primarily depends on the performance of these mixers. If the efficiency of these mixers is not above a threshold value defined according to the application, it may result in a significant loss in the expected throughput and quality of the product obtained from the process. The limitation of active devices such as CSTR includes a large power input and the possibility of dead zone formation in the edges of the mixer vessel resulting in fluids remaining partially unmixed or unreacted. With improvement in the fundamental understanding of the flow and the related physics, there has been a shift from active devices to passive ones. However, existing passive mixer devices exhibit several limitations. Existing passive mixers require longer length of the channels for achieving mixing such as by creeping structures, folding structures, serpentine channels, etc.

[0004] The US patent publication 201603035271 discloses a fluid mixing device. The device includes a mixing element at one end of the device to mix the fluid that enters the device through an inlet provided. The device is described to reduce the length and provide control of temperature. But the fluid mixing is not even and defects arise in such systems due to the absence of the mixing element along the length of the mixing device. The US patent document 7,484,881 discloses a static mixer for mixing species of liquid reactive multispecies compounds. The mixer includes a container which is pushed by a mandrel over the mixing element to mix the fluid present in the clearance region between the container and the mixing chamber. The mixer also includes boundary elements to secure rotation and displacement of the container and the mixing element. Such mixer systems involve a complex mechanism that is expensive to fabricate and operate. The US patent document 4199263 A discloses a method and apparatus for mixing viscous materials using a rotating mixing element. A rotating mixing element is made to penetrate a fluid containing chamber to obtain a mixed fluid. A rotating chamber may be expensive and also results in an energy loss due to power consumption to rotate the chamber. The rotating mixing element may result in rotation of the apparatus which needs to be avoided. The US patent document 4053141 A describes a static mixer for flowing media includes a mixing member with screw surface. The ends of the mixing elements include a bluff body which may result in the formation of defects in the mixed fluids. The Chinese utility patent document 205740462U discloses a static mixer pipeline device. The device consists of a mixing element which includes a mixing element with a shaft and blades to mix the incoming fluids. The device results in consumption of power to rotate the shaft to enable mixing of the fluid also the process may increase the residence time of the fluid. [0005] The apparatus described above are limited by requirement of specialized equipment increasing the equipment and maintenance costs, inability to be easily scaled up and down, longer length, lack of integration, inability to prevent defects or incomplete mixing through formation of secondary vortices or dead zones. An apparatus for mixing fluids in a cost effective manner thereby eliminating the aforementioned problems is needed.

SUMMARY OF THE INVENTION

[0007] The disclosure relates to an apparatus and a method for mixing fluids, particularly a multiphase, multispecies fluids with enhanced mixing and heat transfer characteristics.

[0008] In various embodiments, an apparatus for a passively mixing multiphase fluids is provided. The apparatus includes a hollow static chamber configured to receive the multiphase fluids. At least one threaded member is coaxially placed within the static chamber thereby forming a clearance region between the threaded member and the hollow static chamber. The threaded member includes a threaded surface with conical edges. The threaded surface includes a plurality of thread sets. The adjacent thread sets have threading in same or opposite direction. The mixer includes at least one connecting member that radially traverses the static chamber and the threaded member. In some embodiments, the apparatus includes a plurality of threaded members and a plurality of connecting members. In one embodiment the adjacent threaded members have threading in same or opposite direction.

[0009] In various embodiments, an apparatus for passive mixing of multiphase fluids is provided. The apparatus includes a hollow static chamber configured to receive the multiphase fluids. The apparatus includes a plurality of threaded members placed coaxially and within the static chamber thereby forming a clearance region between the threaded member and the hollow static chamber. Each threaded member includes a threaded surface with conical edges. The adjacent threaded members have threading in same or opposite direction. In some embodiments, a plurality of connecting members are included such that each connecting member radially traverses the static chamber and a single threaded member. In some embodiments, the apparatus includes a threaded surface which includes a plurality of thread sets. The adjacent thread sets have threads in same or opposite direction. [0010] In many embodiments, the static chamber is formed of a metal, an alloy thereof, a composite thereof, a ceramic, a polymer or any combination thereof. The plurality of threaded members is formed of a metal, an alloy thereof, a composite thereof, a ceramic, a polymer, or any combination thereof. The plurality of connecting members is formed of a metal, an alloy thereof, a ceramic, a polymer, a composite thereof, or any combination thereof. In many embodiments, the threaded surface includes threading selected from acme threads, buttress threads, whitworth threads, knuckle threads, square threads, V-threads, or a combination thereof.

[0011] In various embodiments, the threaded surface comprises a single start thread or a multi-start thread. In various embodiments, a relative roughness defined by a ratio of a measured roughness to a diameter of the static chamber and/or the threaded member is about 10⁵ to about 0.5.

[0012] In various embodiments, surface properties of the threaded elements or the static chamber or combined may be hydrophobic, hydrophilic, or neutral.

[0013] In various embodiments, the multiphase fluids comprise one or more fluids, at least one liquid, at least one gas, or at least one solid. In various embodiments, the static chamber includes at least a first inlet for entry of one or more fluids. In many embodiments, the static chamber is connected through a second inlet with at least one connecting member for entry of one or more fluids in clearance region of the static chamber.

[0014] In one embodiment, at least one threaded member is a solid. In another embodiment, at least one threaded member is hollow. In many embodiments, at least one threaded member is configured to heat or cool the multiphase fluids. In various embodiments, at least one threaded member comprises a resistance heating coil placed within it for heating the multiphase fluids. In many embodiments, at least one connecting member is connected through a third inlet with at least one threaded member. [0015] In various embodiments, at least one connecting member is configured to provide electricity or one or more fluids to the at least one threaded member. In some embodiments, passive mixing is done in batch or continuous modes. In some embodiments, the connecting member holds the threaded member in a fixed position. In many embodiments, the diameter of the threaded member is in the range of 1 mm to 20 m.

[0016] In many embodiments, the length of the threaded member is in the range of 1 mm to 100 m. In various embodiments, depth of the threaded surface is the range of 0.01 mm to 8 m. In some embodiments, adjacent threaded members are placed at a distance in the range of 1 mm to 10 m from one another. In many embodiments, the angle of the conical edges is in the range of 10° to 80°.

[0017] In many embodiments, diameter of the connecting member is in the range of 1 mm to 20 m. In various embodiments, clearance between the static chamber and threaded member is in the range of 0.1 mm to 1 m. In one embodiment, the static chamber may include a second threaded surface formed on the inner walls.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings, in which:

[0020] FIG. 1A depicts a mixer with a single mixing element.

[0021] FIG. 1B depicts a mixer with a plurality of mixing elements.

[0022] FIG. 1C depicts a threaded member including a plurality of thread sets along same direction.

[0023] FIG. 1D depicts a threaded member including a plurality of thread sets along opposite direction.

[0024] FIG. 1E depicts a side view of the mixer.

[0025] FIG. 2 depicts results for 7-channel member, Reynolds number (Re)=200 (a) Path lines colored with tracer mass fraction; (b) Mass fraction contour on inlet; and (c) Mass fraction contour on outlet

[0026] FIG. 3 depicts mixing intensity plots with variation in I_M with Re for different threading configurations

[0027] FIG. 4 depicts mixing intensity plots with variation in I_M along the length of the reactor at different Re. DET AILED DESCRIPTION

[0028] While the invention has been disclosed with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the invention without departing from its scope.

[0029] Throughout the specification and claims, the following terms take the meanings explicitly associated herein unless the context clearly dictates otherwise. The meaning of "a", "an", and "the" include plural references. The meaning of "in" includes "in" and "on." Referring to the drawings, like numbers indicate like parts throughout the views. Additionally, a reference to the singular includes a reference to the plural unless otherwise stated or inconsistent with the disclosure herein.

[0030] In various embodiments, a passive mixer 100 for mixing multiphase and/or multispecies fluids is provided as shown in FIG. 1A. The mixer 100 includes at least a hollow static chamber 101 with a first inlet 103 for receiving incoming fluids and an outlet 105 for collecting the mixed fluids, at least one mixing element or threaded member 110 placed within the chamber. In some embodiments, the mixer includes a single threaded member 110 inserted concentric to the static chamber 101. The mixer may include at least one connecting member 120 radially traversing the static chamber 101 and the threaded member 110.

[0031] In other embodiments, the mixer may include a plurality of such threaded members 110-1,...,110-n, as illustrated in FIG.1B. In various embodiments, the distance between the adjacent mixing elements (110- 1, 110-2, ...,110-n) is in the range of 1 mm to 10 m . [0032] In various embodiments, the one or more threaded member 110 includes a conical nose 113, a conical aft 114, and a threaded surface 111 along the body, as shown in FIG. 1C and 1D. In one embodiment, adjacent threaded surfaces 111 within the mixer are oriented in same or opposite direction. In various embodiments, the threaded surface 111 may include a single or a plurality of thread sets 115. In some embodiments, each threaded surface includes a plurality of thread sets 115-1,.. ,115-n oriented in the same or opposite direction. In other embodiments, the plurality of thread sets 115-1, ..115-n are oriented such that adjacent thread sets are oriented in the same or opposite direction. The threaded surface 111 is configured to impart a shear force to the fluids flowing in the clearance region. The thread sets 115 are configured to reorient flow of the fluids in an opposite direction.

[0033] The threaded surface may be of a single start, double start, triple start, four start, five start, six start, seven start, eight start, nine start or multiple start. The threading may be acme threads, buttress threads, whitworth threads, knuckle threads, square threads or V-threads.

[0034] In some embodiments, the length of the threaded member 110 is in the range of 0.1 m to 100 mm and the depth of the threaded surface 111 on the threaded member 110 is in the range of 0.01 mm to 0.3 mm. In some embodiments, the conical surface 113, 114 of the mixing element 110 has a flat, elliptical or semi-ellipsoidal shape. The conical edges 113 and 114 may be in the form of an acute triangle. The angle of the conical edge 113 and the edge 114 may be in the range of 10° to 80°.

[0035] In various embodiments, the incoming fluids pass through the static chamber 101 such that the passage of the fluids is obstructed by the at least one mixing element 110 placed coaxially within the chamber resulting in flow of the fluids through a clearance region 124 formed between the inner wall of the hollow chamber and the mixing element, as shown in FIG. 1E. The clearance region between the static chamber and threaded member may be in the range of 0.1 mm to 1 m. In some embodiments, the clearance region may include a second threaded surface 125 formed on the inner wall of the static chamber 101. The threaded surface 125 may include a plurality of threaded sets 126 oriented in the same or opposite direction.

[0036] In various embodiments, at least one connecting member 120 radially traverses the static chamber 101 and a single mixing element 110, as shown in FIG. 1A, 1B and 1E. The mixing element 110 is rigidly held by connector 120 which pierces through it. A second inlet 121 is connected to one side of the connecting member 120 which supplies a secondary fluid to enter the static chamber. The secondary fluids may typically enter the clearance region 124 where the thread sets 115 are oriented in the same or opposite direction for enhanced mixing. In some embodiments the diameter of the connecting member 120 is in the range of 0.1 mm to 20 m. In an exemplary embodiment, during a chemical reaction an instant injection of fluids through the main inlet 103 may cause the bulk of the fluids to get untethered and remain non-participatory in the reaction. Also, if the secondary fluid is solid or dense liquid, it may result in deposition in the central part of the mixing element 110. In order to eliminate the aforementioned problems the fluids is introduced in the clearance region with strong shear flow.

[0037] In various embodiments, the temperature control system 127 is configured to regulate the temperature of the fluids within the static chamber 101. Based on physical and chemical properties of the fluids within the static chamber 101, it is heated or cooled. In order, to heat or cool the multiphase fluids a heating or a cooling mechanism is placed within the surface of the threaded member 110. The heating or cooling mechanism is heated or cooled by supplying electricity. Alternatively, a hot or a cold fluid may be supplied through the inlet 123 on the opposite end of the connector member 120, as shown in FIG. 1E. A resistance heating coil placed within the hollow chamber may be utilized for heating the multiphase multispecies fluids. [0038] In various embodiments, the static chamber 101 of the mixer 100 or the threaded member 110 or the connecting member 120 is made of a corrosion resistant material selected from a metal, a metal alloy, a polymer, a composite, or a ceramic. In some embodiments the metal or metal alloy is selected from those based on iron, nickel, cobalt, titanium, platinum, copper, cobalt, nickel, aluminum, or tantalum. In some embodiments the alloy may include any alloy that is resistant to the media being processed within the chamber such as corrosion resistant steel, stainless steel, cobalt alloy or nickel alloy of suitable grade. In some embodiments, the ceramic comprises silica, magnesia, alumina, zirconia, ceria or a combination thereof. In various embodiments, the corrosion resistant materials may be used as coating on the surfaces of the static chamber 101 or the threaded member 110 that are exposed to the working fluids. In various embodiments, suitable materials for the static chamber, threaded member, connecting member, or any other component included herein may include copper, aluminum, steel, stainless steel, mild steel, nickel, cobalt, titanium, platinum, or alloys of these materials. Ceramic comprises silica, glass, magnesia, alumina, zirconia, ceria or a combination thereof. The materials may also include synthetic polymers, natural polymers, biopolymers, rubbers, co-polymers, nano-composites, composite materials of polymers, metals, ceramics, etc. The surface properties of the static chamber and the threaded member may be hydrophobic or hydrophilic or may be coated with material exhibiting such properties.

[0039] In various embodiments, relative roughness as defined by a ratio of a measured roughness to a diameter of the static chamber and/or the threaded member is in the range of about 10⁵ to about 0.5. The roughness of the surface decides the slip and shearing behaviour of the flowing fluids in contact with the solid surface. As for a very smooth surface the fluid will easily slip thereby diminishing the velocity gradients developed near the wall. For a highly rough surface (no slip condition), strong velocity gradients will be developed. These velocity gradients in turn decide the residence of the particles in contact with the wall or in the developed boundary layer region, thereby govern the mixing and heat transfer characteristics. In various embodiments the surface roughness of the surfaces within the static chamber is engineered to a suitable value depending on the mixing and heat transfer characteristics desired in the reactor.

[0040] In various embodiments, surface properties of the threaded elements or the static chamber or combined may be hydrophobic, hydrophilic, or neutral. In various embodiments, wetting characteristics of the surfaces is varied to further improve the mixing capabilities within the mixer.

[0041] In some embodiments, the fluid is a multiphasic and multispecies fluid. In some embodiments, the fluid is one of a solid or a liquid or a gas. In various embodiments, more than one fluid may be mixed in the apparatus. The fluids entering the mixer may include fluids of different phases or multiple fluids of the same phase. For instance the multi-phase includes one of a liquid- gas, gas- gas, solid- gas, liquid- liquid, solid- liquid, solid- solid or a combination thereof.

[0042] In various embodiments, the fluids to be mixed have a residence time in the range of 0.1 s to 240 h. fluids. In various embodiments, a mixing intensity of at least 90 % is obtained.

[0043] In some embodiments, the passive mixing of the multiphase fluids in a mixer 100 is done in a batch mode or continuous mode. The fluid is pumped into the mixer 100 through the inlet 103 and the additional fluids are pumped into the static chamber. A mixed single phase single species fluid is obtained at the outlet 105 in a batch or continuous mode.

[0044] Without being bound to any particular theory, it is suggested herein that a passive mixer is based on the combination of ‘Kutta condition’ and‘Searle principle’. The conical edges 113, 114 at the leading and trailing edge of the member may cause a pinching effect in the near nose region to the flowing fluid. A swirling effect is later experienced in the clearance region 124. Thread sets 115 provided over the threaded member 110 may impart a rotational or shearing effect to the fluid thereby enhancing mixing. In the aft region of the threaded member, the conical tail allows the flow to continue in a swirling path imparted by the threads. There is a smooth change in the direction of swirl in the laminating layers in the region between the two members of opposite threading. The orientation of the thread sets 115 on the threaded surface 111, and the conical edges 113 and 114 eliminates formation of secondary vortices or dead zone or heat zones present in the multiphase outgoing fluids.

[0045] The reactors are easily fabricated tubular reactors with intense mixing, heat and mass transfer capabilities with better control over the residence time distribution for carrying out reactions. They are robust, economical and easily scaled up or scaled down as required. Secondary vortices or dead zones are avoided by the unique combination of swirl, change of directions and pinching effect Absence of secondary vortices and use of shorter length results in reduced power requirement for pumping fluids across the passive mixer-cum-reactor.

[0046] While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt to a particular situation or material the teachings of the invention without departing from its scope. Therefore, the above description and the examples to follow should not be taken as limiting the scope of the invention which is defined by the appended claims.

[0047] EXAMPLES

[0048] Example 1 - Computational analysis of the reactor [0049] The flow and mixing characteristics of the passive reactor, containing two units of modified geometry, has been simulated. Based on initial investigations of mesh sensitivity, highly refined 3D unstructured grids (~27 million cells) were generated in ICEMCFD. The governing equations for steady state incompressible laminar flow were discretized using second order upwind scheme and solved using commercial CFD software ANSYS FFUENT. Water was considered as a working fluid. For mixing study, steady state simulations were carried out using‘species transport’ model using steady state flow solutions obtained earlier. Input of tracer was imposed on the half part of inlet, which has same water properties with mass diffusivity of 2x10 m s . This study was carried out for three threading units at four different values of Reynolds number (Re = lOOx; l< x < 4) to understand their effect on mixing intensity and flow dynamics.

[0050] Results and discussions: After establishing converged flow field, tracer simulations were carried out. A sample of results in the form of contours of tracer mass fraction at the inlet (FIG. 2A) and outlet (FIG. 2B) as well as path lines of fluid particles colored with tracer mass fraction (FIG. 2C) are shown in FIG. 2A-2C. As fluid flows through the mixer, it is forced to follow the helical motion of the fluid streams resulting in enhancement in lamination (in the threaded region) and engulfment (in the region between the members of opposite threading).

[0051] The tracer contours shown in FIG. 2A and 2B clearly indicate the mixing effect and trails of the swirling effect induced in the flow. The swirling effect on the flow is generated not only in the aft, but also in the front side of the member. This effect can be attributed to the tendency of the fluid to divert itself towards the threading direction due to the generated pressure distribution. Thereby, fluid experiences swirling and impinging effect together at the near front nose region. No secondary vortices or dead zones were formed. [0052] Mixing realized in the reactor was quantified by evaluating mixing intensity (IM) profile along the reactor length. The mixing intensity was defined as:

[0053] Extensive simulations were carried out to quantify the influence of key design and operating parameters on mixing performance. The number of channels present in the design plays a pivotal role in deciding the mixing capability. A sample of simulated results is shown in FIG. 2C. Improvement in IM can be realized by increasing the number of channels as shown in FIG. 3. Influence of Reynolds number on IM is more complex because of interaction between residence time and improved mixing rate. Increase in Re improves mixing but reduces residence time thereby providing less time for mixing to occur as shown in FIG. 4. Simulated results were critically analyzed to evolve guidelines for tailoring mixing in the proposed mixer-cum-reactor as desired.

Claims

WE CLAIM:

1. An apparatus (100) for passive mixing of multiphase fluids, the apparatus comprising:

a hollow static chamber (101) configured to receive the multiphase fluids;

at least one threaded member (110) placed coaxially and within the static chamber thereby forming a clearance region (124) between the static chamber and the threaded member, the threaded member comprising a threaded surface (111) with conical edges (113, 114), wherein the threaded surface comprises a plurality of thread sets (115), and wherein adjacent thread sets have threading in same or opposite direction; and

at least one connecting member (120) radially traversing the static chamber and the threaded member.

2. The apparatus of claim 1, comprising:

a plurality of threaded members ; and

a plurality of connecting members.

3. The apparatus of claim 2, wherein adjacent threaded members have threading in same or opposite direction.

4. An apparatus (100) for passive mixing of multiphase fluids, the apparatus comprising:

a hollow static chamber (101) configured to receive the multiphase fluids;

a plurality of threaded members (H0-l,....,l l0-n) placed coaxially and within the static chamber thereby forming clearance regions (124) between the static chamber and each of the plurality of threaded members, each threaded member comprising a threaded surface (111) with conical edges (113, 114), and wherein adjacent threaded members have threading in same or opposite direction; and a plurality of connecting members (120-1,....120-h), each connecting member radially traversing the static chamber and a threaded member.

5. The apparatus of claim 4, wherein the threaded surface comprises a plurality of thread sets (115), and wherein adjacent thread sets have threading in same or opposite direction.

6. The apparatus of claim 1 or 4, wherein the static chamber, the threaded member or the connecting member comprise a metal, a metal alloy, a polymer, a ceramic, or a composite.

7. The apparatus of claim 6, wherein the metal or metal alloy is selected from iron, nickel, cobalt, titanium, platinum, zirconium, aluminum, or tantalum.

8. The apparatus of claim 6, wherein the metal alloy is corrosion resistant steel, stainless steel, cobalt alloy or nickel alloy.

9. The apparatus of claim 6, wherein the ceramic comprises silica, magnesia, alumina, zirconia, ceria or a combination thereof.

10. The apparatus of claim 1 or 4, wherein the threaded surface comprising threading selected from acme threads, buttress threads, whitworth threads, knuckle threads, square threads, V-threads, or a combination thereof.

11. The apparatus of claim 1 or 4, wherein the threaded surface comprises a single start thread or a multi- start thread.

12. The apparatus of claim 1 or 4, wherein the multiphase fluids comprise one or more fluids, at least one liquid, at least one gas, or at least one solid.

13. The apparatus of claim 1 or 4, wherein the static chamber is connected to the connecting member through a second inlet (121) for entry of one or more fluids in clearance region of the static chamber.

14. The apparatus of claim 1 or 4, wherein the threaded member is solid.

15. The apparatus of claim 1 or 4, wherein the threaded member is hollow.

16. The apparatus of claim 15, wherein the threaded member is configured to heat or cool the multiphase fluids.

17. The apparatus of claim 16, wherein the at least one threaded member comprises a resistance heating coil placed within it for heating the multiphase fluids.

18. The apparatus of claim 16, wherein the threaded member is connected to the connecting member through a third inlet (123) for providing electricity or one or more fluids.

19. The apparatus of claim 1 or 4, wherein said passive mixing is done in batch or continuous modes.

20. The apparatus of claim 1 or 4, wherein the connecting member holds the threaded member in a fixed position.

21. The apparatus of claim 1 or 4, wherein the diameter of the threaded member is in the range of 1 mm to 20 m.

22. The apparatus of claim 1 or 4, wherein the length of the threaded member is in the range of 0.1 mm to 100 m.

23. The apparatus of claim 1 or 4, wherein depth of the threaded surface is in the range of 0.01 mm to 8 m.

24. The apparatus of claim 2 or 4, wherein adjacent threaded members are placed at a distance in the range of 1 mm to 10 m from one another.

25. The apparatus of claim 1 or 4, wherein the angle of the conical edges is in the range of 10° to 80°.

26. The apparatus of claim 1 or 4, wherein diameter of the connecting member is in the range of 1 mm to 20 m.

27. The apparatus of claim 1 or 4, wherein clearance between the static chamber and the threaded member is in the range of 0.1 mm to 1 m.

28. The apparatus of claim 1 or 4, further comprising a second threaded surface (125) formed on the inner walls of the static chamber (101).

29. The apparatus of claim 28, wherein the threaded surface, the second threaded surface, or both is hydrophobic or hydrophilic.

30. The apparatus of claim 29, wherein the threaded surface and the second threaded surface have the same or opposite charges.

31. The apparatus of claim 1 or 4, wherein relative roughness of the static chamber, the threaded member, or both is in the range of 10⁵ to 0.5.