Your SlideShare is downloading. ×
The effect of geometrical parameters on mixing and parallel jets mixing in a liquid static mixer
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Introducing the official SlideShare app

Stunning, full-screen experience for iPhone and Android

Text the download link to your phone

Standard text messaging rates apply

The effect of geometrical parameters on mixing and parallel jets mixing in a liquid static mixer

229
views

Published on


0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
229
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
3
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. International Journal of Advanced Research in and Technology (IJARET) International Journal of Advanced Research in Engineering Engineering ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEand Technology (IJARET), ISSN 0976 – 6480(Print),ISSN 0976 – 6499(Online) Volume 1, IJARETNumber 1, Sep - Oct (2010), pp. 92-111 © IAEME© IAEME, http://www.iaeme.com/ijaret.html THE EFFECT OF GEOMETRICAL PARAMETERS ON MIXING AND PARALLEL JETS MIXING IN A LIQUID STATIC MIXER D.S.Robinson Smart School of Mechanical Sciences, Karunya University Coimbatore-641 114 E-Mail id: smart@karunya.eduABSTRACT Experimental investigations and computational analysis were carried out topredict the effect of parallel, vertical liquid jets mixing and the geometrical parameterswhich are effecting the mixing in a liquid static mixer. The computer analysis was carriedout by using commercially available CFD software package FLUENT computationalfluid dynamics (CFD) methods [7].An experimental set up was designed andinvestigations were carried out to evaluate the parallel and vertical fluid jets mixing in astatic liquid mixer. Conductivity probe technique was used to evaluate the mixing [3].The results obtained by experimental investigation and computer analysis were comparedand discussed in detail to decide upon the effectiveness of parallel and vertical liquid jetsmixing. The investigations and computer analysis revealed that the mixing efficiencyincreases with the opening of parallel ports and the primary fluid nozzle position reaches50mm with mixing inserts.Keywords: Parallel jets; Liquid mixing; Static mixing1. INTRODUCTION Mixing of two or more ingredients is essential in number of different processindustries such as chemical, pharmaceutical petroleum, plastics, and food processing,water and waste water treatment plants. There are two major types of mixers are availablenamely dynamic and static mixers. The efficiency of mixing depends on the efficient useof energy to generate flow of the components .Stirred tanks perform the mixing by amotor driven agitator. This type of mixer is generally employed when the mixing are 92
  • 2. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEundertaken in successive batches. Static mixers are in-line mixing devices generallyconsisting of mixing elements inserted into a pipe. Mixer of this type is used incontinuous operation, with the energy for mixing being derived from the pressure lossincurred in the process of fluid flow through the elements [7].Over the years there hasbeen increasing emphasis in the process industries towards continuous type of liquidmixing wherever practical or feasible and innovative designs for mixing becameapparent. Hence the process industries are in need of a mixing system, which mixes theliquids, which are having different properties to produce various liquid products with lesspower requirement. In the present work an experimental test facility is designed,developed and the experimental investigations and computational analysis have beencarried out to predict the efficiency of parallel, vertical liquid jets mixing, the effect ofgeometrical parameters such as position of driving nozzle, cone angle of divergentnozzle, position of mixing insert and position of secondary fluid inlet on mixing with aview to optimize them [10].2. EXPERIMENTAL SET UP The experimental set up consists of a centrifugal pump, reservoirs, rotameter, mixingnozzle, four U tube manometers, control valves and conductivity meter . The primaryfluid is stored in a tank. A control valve is used to regulate the primary fluid discharge.A centrifugal pump is used to supply the primary fluid from the tank to the mixer. Figure 1 Experimental set up of parallel and vertical jets mixing nozzle 93
  • 3. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME As the primary fluid passes through the driving nozzle the velocity of flowincreases as the area of flow decreases as it passes through the driving nozzle.Consequently there is a decrease in pressure. This drop in pressure creates a suctionpressure in the converging area and the secondary fluid will be drawn. The suctionpressure at the inlet ports of secondary fluid is measured using the manometers. There arefour sets of secondary fluid ports in the mixing nozzle. The ports which are on the leftside of the converging portion are called parallel ports. Ports on the top of the convergingportion are called top ports and ports on the bottom are called bottom ports. Ports whichare normal to the plane of top and bottom ports are called side ports. The position of thevarious secondary inlet ports is shown in Figure 2.Three suction nozzles (convergent) arefabricated with different cone angle 21deg, 23deg and 25 deg. Top Ports TP1, TP2, TP3, TP4 Parallel Port P1 Side Ports 1,2,3,4 Parallel Port Down Ports Parallel Port P4 Parallel Port P3 Figure 2 Locations of parallel, vertical and circumference secondary fluid ports Two types of inserts are made and it is braced to a long screw in order to movethe insert to the desired location. Conductivity probes are used to measure theconductivity of mixed fluid.EXPERIMENTAL PROCEDURE The aim of the experiment is to find out the extent of mixing of the two fluids byproviding parallel jets, varying the geometrical parameters like, position of the drivingnozzle, position of the insert and position of the secondary suction inlet and to evaluatethe effect in on mixedness of the mixing nozzle. 94
  • 4. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME3.1. Experimentation and mixing efficiency Conductivity or specific conductance is the measure of the ability of the water toconduct an electric current. Conductivity depends upon the number of ions or chargedparticles in water. The specific conductance is measured by passing a current betweentwo electrodes (one centimeter apart) that are placed into a sample of water. In solution,the current flows by ion transport. Therefore, an increasing concentration of ions in thesolution will result in higher conductivity values. The Conductivity Probe is actuallymeasuring in ohms, conductance is measured using the SI unit, siemens (formerly knownas a mho). Since the siemens is a very large unit, aqueous samples are commonlymeasured in micro siemens, or µS. Initially the discharge of primary liquid is kept as 2600 lit/hr by adjustingthe ball valve and the 21º convergent portion is connected with the throat. Parallel port 1is opened and all the other ports are closed. The secondary fluid discharge is obtained bynoting down the time required for the suction of 500 ml of secondary fluid. The suctionpressure is noted down from the manometer. Mixed fluid samples are collected from thesamples points and the average electrical conductivity of the samples is measured. Thisis referred as the mixed fluid conductivity. Standard solution is prepared by taking aproportion of primary and secondary fluids which is having a ratio of the mixed fluid.This proportion of primary and secondary fluid will be well mixed by using a stirrer andthe conductivity of mixed fluid is measured. This is referred as the standard conductivity. The closeness of mixed fluid conductivity with standard conductivity can be takenas a measure of mixing efficiency. Mixing efficiency is calculated as the ratio of mixedfluid conductivity and standard conductivity. The effectiveness of mixing of each port isobtained experimentally by finding out the mixing efficiency (mixingefficiency=Conductivity of mixed fluid /Standard conductivity of mixed fluid). The experiment is repeated by opening the parallel ports P1,P2,P3,P4individually, P1&P3 , P2&P4, P1&P2&P3&P4 combine and the down portsD1,D2,D3,D4 individually & D1&D2&D3&D4 combine .Samples are collected at thepoints 450mm,900mm & 1800mm from the throat entrance . The whole experimentswere repeated by varying the discharge of secondary fluid as 3100lpm & 3600lpm and 95
  • 5. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEthe distance between the tip of the driving nozzle and the throat entrance as 10mm,20mm, 30mm, 40mm & 50mm.5. COMPUTER MODELING AND ANALYSIS5.1. Effect of Voticity and inserts on mixing Different models have been created by varying geometrical parameters such assecondary fluid inlet position, cone angle (convergent) of suction nozzle and drivingnozzle position [5,6]. Similarly Each case has been analyzed by keeping port open andother ports have kept closed and also by varying the position of driving nozzle away fromthe throat entrance. Another set of models have been created by providing an inserts inthe throat of the nozzle. All these models have been created by using a pre-processorcalled ‘Gambit’. The computer analysis is done by exporting the meshed or gridgenerated model form GAMBIT software to the FULENT 6.0 [7]. The Figure 3 shows that the vorticity magnitude reaches the maximum value of9.56(1/s) thus increases the mixedness, when the driving nozzle position DN is 50 mm &all the parallel ports are opened. The value of vorticity magnitude reduces to 8.08(1/s)when all the down ports are opened and leads to less mixing. Figure 3 Contours of vorticity when all the parallel ports are open. It can be observed from the vorticity contours that the vorticity is more when theDN=50 mm and all the down ports are opened. The increase in vorticity leads to moreinteraction of mixing fluids and increasing the mixing efficiency. However near the 96
  • 6. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEinserts the values of vorticity is fluctuating and it is higher near the inserts and lowwithout inserts .Hence the presence of inserts enhances the liquid-liquid mixing in a staticmixing nozzle and the efficiency of mixing can be increased. The Figure 3 shows that the vorticity magnitude reaches the maximum value of9.56(1/s) thus increases the mixedness, when the driving nozzle position DN is 50 mm &all the parallel ports are opened. The value of vorticity magnitude reduces to 8.08(1/s)when all the down ports are opened and leads to less mixing. Also the COV is nearingzero [3] due to more interaction of fluids and more mixing.5.2. Effect of driving nozzle position on vorticity magnitude Figure 4 Comparison of experimental, computational and literature results of Vorticity magnitude when DN=50 mm. Figure 5 Contours of turbulent kinetic energy distribution with inserts (Lobes ). 97
  • 7. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME5.3. Effect of Turbulent kinetic energy Figure 6 Contours of turbulent kinetic energy when parallel ports are opened Figure 7 Contours of Turbulent kinetic energy when all the down ports are open It can be seen that the turbulence kinetic energy is maximum in case when theparallel ports P1 &P2 & P3 & P4 are opened simultaneously and the driving nozzleposition DN is 50mm as it can be observed in Figure 5&6 From the contours of turbulent kinetic energy it is observed that the turbulentkinetic energy is 1.87x10 m2/s2 when the DN=50 mm and all the parallel ports are openedand 1.27x10 m2/s2 when DN=50 mm & down ports are opened. The turbulent kineticenergy is found to be still reducing when any ports is opened individually or combineswith any other port. 98
  • 8. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME The computational analysis of Belovich [25] also proved that ,the parallel jetsmixing is more effective .The increase of turbulent kinetic energy and vorticty areresponsible for good mixing of fluids. Hence the mixing efficiency increases whenDN=50 mm and all the parallel ports are opened.5.4. The effect of DN position & LDNP on mixing efficiency when downports are open. Down Ports VS Efficiency 100 95 D1 open 90 Mixing Efficiency % D2 open 85 D3 open 80 D4 open 75 D1,D2,D3&D4 open 70 65 60 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 LDNP ( Distance between tip of the DN to port side wall ) in mm Figure 8 The effect of DN position & LDNP on mixing efficiency when down ports are open Experiments were conducted as mentioned in the section above by opening theports alternately by changing the distance between the tip of the driving nozzle to theentrance of the throat (DN) as 10 mm, 20 mm, 30 mm, 40 mm & 50 mm. When the DN ischanged the distance between tip of the driving nozzle to side wall entrance which isfacing the entrance of the throat(LDNP) also changes as -40 mm(as it is behind thedriving nozzle), -30 mm, -20 mm, -10mm and 0 respectively. Negative sign indicates thatthe corresponding port is behind the tip of the driving nozzle. 99
  • 9. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME It is clear that the mixing efficiency increases with decrease in LDNP when theD1, D2 opens .Further the LDNP increases and becomes more than 20 mm the mixingefficiency starts reduces. The mixing efficiency is found to reduce when the D3 & D4opens and the LDNP becomes 31 mm ,35mm & 45mm as the chance of interaction ofsecondary fluid with primary fluid becomes very less (since the tip of the driving nozzlebecomes away from the port side wall). When the down ports D1, D2, D3 & D4 are opened simultaneously as the area ofcontact of the secondary with primary fluid becomes more, the mixing efficiency is foundto be more than the efficiency when individual ports are opened. When the driving nozzleposition (DN) is adjusted to at 10mm, only port D4 is partially open and exposed to themain stream of primary fluid, hence the efficiency is found to be low. As the DN isadjusted to 20mm, port D4 is fully exposed to the primary fluid stream and there is anincrease of efficiency. Further there is an increase of mixing efficiency when the DNbecomes 30mm, and the ports D3 and D4 are fully exposed to the primary fluid stream.When the DN is changed to 40mm, efficiency has increased more than above said threeconditions, as the ports D3&D4 are exposed fully and D2 is partially exposed to thestream of primary fluid. The mixing efficiency has reached to 95.4% when the ports D2, D3, D4 are fullyexposed and D1 is partially exposed the stream of the primary fluid and the DN isadjusted to 50mm.From the above analysis it is clear that the mixing efficiency isincreasing when the LDNP is between 0-20mm. 100
  • 10. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME5.5. The effect of driving nozzle position (DN) & LDNP on MixingEfficiency when Parallel ports are open Figure 9 Effect of DN position & LDNP on mixing efficiency when parallel ports are open Parallel ports discharges the secondary fluid, parallel to the primary fluid stream.When the parallel ports P1, P2, P3 & P4 are opened alternately one by one, it wasobserved that the efficiency is all most same. When the distance between the tip of the driving nozzle to exit of the secondaryfluid parallel ports(LDNP) increases the mixing efficiency reduces and it is increasingwith the decrease of LDNP .The increase of efficiency occurring due to the more contactof secondary fluid with the primary fluid in all the four direction when the LDNPdecreases. The mixing efficiency decreases with increase in LDNP as the contact betweenthe primary and secondary fluids getting reduces due the increase of distance between thetip of the driving nozzle to the exit of secondary fluid outlet. Hence the mixingefficiency is inversely proportional to the LDNP. 101
  • 11. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMETable.1. Parallel Port 1(PP1) , 2(PP2), 3(PP3) & 4(PP4)are Open &Driving Nozzleposition, DN=50mm. Discharge Mixing efficiency Mixed fluid conductivity Std DN Q1 ( mS/cm) Conductivity ηm (mm) (lph) (mS/cm) [%] 50 2600 5.45 6.1 89.4 50 3100 6.89 7.3 94.5 50 3600 9.1 9.4 96.7 Table.1 shows that the conductivity of mixed fluid nearing the conductivity ofstandard mixed fluid and which leads to the maximum efficiency when the parallel portsP1, P2, P3&P4 are opened simultaneously when the driving nozzle position DN is50mm.Figure 9 shows that, when the LDNP reduces from 60mm to 12mm the mixingefficiency reaches 96.7 at DN is 50mm.5.6. Effect of driving nozzle position (DN) & LDNP on MixingEfficiency when the down ports, side ports & upper ports are open. Mixing efficiency VS Circumference ports D1,SF1,UP1 95 & SB1 ports open 90 D2,SF2,UP2 M ix in g e f f ic ie n c y % & SB2 ports 85 open D3,SF3,UP3 80 & SB3 ports open 75 D4,SF4,UP4 & SB4 ports 70 open -50 -40 -30 -20 -10 0 10 20 30 40 50 LDNP(Distance between tip of the driving nozzle to side wall of the ports) in mmFigure 10 Effect of driving nozzle position (DN) & LDNP on Mixing Efficiency when the down ports, side ports & upper ports are open. The Figure 10 shows that the mixing efficiency reduces to 94.3% when all thedown ports and the circumference ports are opened. But the efficiency is increasing to 102
  • 12. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME95.4% when all the parallel ports open. Hence it is clear that the parallel jets jets mixingimprove the performance of the static liquid mixer.5.7. Effect of sample location and l/d ratio on mixing. Samples were collected at l/d = 18, l/d = 36 and l/d = 72 i.e. .450mm, 900mm &1800mm from the entrance of the throat during the experiments. The Conductivity ofmixed fluid was found out and the mixing efficiency calculated. Figure 11 shows theresults. Figure 11 Effect of mixing length (l/d ratio or sample point) on mixing efficiency It can be observed that there is only a slight increase as l/d ratio changes [10] from35 to 72 and there is an increase of efficiency only 5% as there is no mechanism availableto increase the energy for mixing or to add the energy for mixing.5.8. Effect of discharge of primary fluid (Q1) on mixing.Figure 12 Effect of primary fluid discharge on mixing efficiency when parallel ports are open 103
  • 13. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEFigure 13 Effect of primary fluid discharge on mixing efficiency when the down ports are open Mixing experiments were conducted by varying primary fluid discharge as2600 lph ,3100 & 3600 lph for various conditions . From the Fig.12 & 13 it is clear thatthe mixing efficiency increases with increase in secondary fluid and primary fluiddischarge (Q1&Q2) as the velocity increases more energy being added to the mixedstream and leads to more mixing and the mixing of fluids take place with greater impact.The experimental analysis of Ahmed [17] also proved that the velocity and dischargeinfluences the mixing of coaxial and parallel liquid jets.5.9. Influence of primary fluid discharge Q1 on Coefficient of variation-Experimentation The mean value and standard deviations are calculated for every set of mixedfluid density values. And the COV calculated (COV=standard deviation of concentrationmeasurements/mean concentration). This is also called the intensity of mixing or degreeof segregation 104
  • 14. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Figure 14 Influence of primary fluid discharge Q1 on Coefficient of variation- Experimentation At least three samples of mixed fluid were collected by changing the primaryfluid discharge Q1, driving nozzle position DN and opening the various ports during theexperiments. Densities of samples were measured. The Figure 14 shows that the mixingefficiency increasing gradually as the COV reducing when the DN=40mm and D3opened=50mm and P2 and P4 are open, all the down ports are opened simultaneously andDN=50mm and opening all the parallel ports. From the experimental result shown in Figure 14 it is clear that COV is a functionof primary fluid discharge Q1[1] and driving nozzle position DN. When the Q1 increasefrom 2600 lph to 3600 lph, DN is 50mm and all the parallel ports are opened, COVdecreases from 0.001169 to 0.000441 as the fluids interacts more and increase inefficiency. Similarly the density distribution found to be more uniform and the COV isnearing zero when the DN=50 mm & all the parallel ports are opened. Hence there is anincrease of mixing efficiency. 105
  • 15. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Figure 15 Influence of primary fluid discharge Q1 on Coefficient of variation & Comparison between experimental and computational results Table 2 Coefficient of variation- COV by computational Opened port DN, mm COV P2 & P4 50 0.0017661 open D1, D2, D3, 50 0.0008814 & D4, open P1, P2, P3 & 50 0.0004417 P4 open Figure 15 and Table 2 shows the comparison of COV obtain by experiment andcomputational .In both the cases it is clear that the COV approaches zero hence increasein mixing efficiency when the parallel ports are opened and parallel jets are gettingmixed. There is a good agreement between COV obtained from the computational andexperimental results.5.10.Effect of mixing insert on mixing efficiency To evaluate the influence and effect of mixing insert on mixing efficiency, helicaland plate type of mixing inserts have been provided at 900 mm (l/d=36 mm) away from 106
  • 16. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEthe entrance of throat and the experiments were repeated for the few best conditionswhich were obtained during the experiments. Driving Nozzle position(DN) VS Mixing efficiency with & with out insert 100 D1 to D4 open & without 95 insert D1 to D4 Mixing efficiency % 90 open & with insert 85 P1 to P4 open & 80 with out insert 75 P1 to P4 open & with insert 70 0 10 20 30 40 50 60 DN position in mm Figure 16 Effect of mixing insert on mixing efficiency The samples are collected at the outlet and whose conductivity was measured.The Figure 15 shows the trend of mixing efficiency with and without inserts. Themixing efficiency is found to be increased by 2 to 3 % by addition of helical type ofmixing insert. Hence it can be concluded that the addition of mixing insert improves themixing efficiency. The sample points can be changed as l/d=18 mm, l/d=36 mm & l/d=72mm (mixing length as 450mm, 900mm & 1800mm). The absence of mixing insert doesnot have much influence on mixing efficiency even though there is an increase of mixinglength (l/d ratio or sample point). By introduction of mixing insert the mixing efficiencyis found to be increase as it adds more energy for mixing when fluid flow through thehelical path of insert. Hui Hu [24] has studied the effect of mixing insert on mixingexperimentally and proved that ,mixing inserts improves the mixing.5.11.Effect of driving nozzle position on vorticity magnitude The Figure 6.10 shows the comparison between the vorticity magnitude obtainedby the computation and literature data’s. The vorticity magnitude reaches the maximumvalue of 9.56(1/s) thus increases the mixedness, when the driving nozzle position DN is50 mm & all the parallel ports are opened and due to the inserts. 107
  • 17. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME Figure 17 Vorticity magnitude when DN=50 mm Also the COV is nearing zero due to more interaction of fluids and more mixingThe value of vorticity magnitude reduces to 8.08(1/s) when all the down ports are openedand leads to less mixing. The results were found agreeing with the literature data.6. FINDINGS AND CONCLUSIONS In the present work a mixing nozzle was designed, fabricated and its performancewas evaluated experimentally. Theoretical analysis is also carried out by using CFDmethod. The influencet of geometrical parameters on mixing and the parallel jets mixingwere evaluated. The mixing efficiency was evaluated by using conductivity which issimple and reliable technique to evaluate the mixing efficiency of the mixing nozzle. Theeffect parallel jets mixing in a static mixing nozzle on various conditions have beenanalyzed and the results are reported. An experimental set up was fabricated and experiments were carried out to predictthe performance on the mixing by varying the locations of secondary fluid inlet to 5mm,15mm, 20mm&40mm, driving nozzle position 10mm, 20mm, 30mm, 40mm&50mm,cone angle of the suction nozzle to 21deg, 23deg & 25deg and the location of the insert to50mm, 100mm&150mm from the entrance of the throat. The investigations revealed that the change in sample point (l/d) does not havemuch effect on mixing efficiency without adding mixing insert. The addition of mixinginsert improves the mixer performance. The mixing efficiency depends on the directionof fluids entry. The increase of primary fluid discharge Q1 influences the suction ofsecondary fluid which in turn has an effect on mixing efficiency. When the driving 108
  • 18. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEMEnozzle was kept at 50mm and the all the parallel ports are opened and the parallel jetsmixing taking place the mixing efficiency was increasing as vorticity magnitude and theturbulent kinetic energy are increasing and the fluids interaction becomes more whichintern increases the mixedness. Computational modeling and the analysis shows that COV is found to beminimum and gives more effective mixing when all the parallel ports ie., P1, P2, P3 & P4are opened at DN = 50 mm. The COV obtained by the experimentation and computationwere compared and found to be in good agreement.7. SCOPE OF FURTHER WORK Further this study can be extended by studying the effect of temperature, viscosityof fluids and twisting angle of inserts on mixing. Mapping methods can be used to studythe distributive mixing processes. Further the standard models can be developed topredict the drop size evolution during the flow in the static mixer.REFERENCES[1] Hiroshige Kumamaru, Takashi Kanada, Kenji Fujith and Naoyuki Sawada, “Mixing of horizontally injected high density solution in vertically upward water flow”, Advances in the fluid modeling and turbulence measurements, proceedings of the 8th International symposium on flow modeling and turbulence, Tokyo, December 2001.[2] T.Sakakaralal and A.Mani, “Experimental Investigations on ejector refrigeration system with ammonia”, International journal of renewable energy, volume 32, Issue 8, pp 1403-1413, 2007.[3] R.Wadley & Mik Dawson, “LIF measurements of blending in static mixers in the turbulent and transitional flow regimes”, Chemical Engineering Science 60 (2005), 2469 – 2478.[4] T.Lemeaned.D.Della Valle, “Droplets formation in turbulent mixing of two immiscible fluids in a new type of static mixer”, Int.Journal of Multiphase flow, 29, 2003, pp813-840. 109
  • 19. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME[5] Riffat S.B & Omer S.A, “CFD modeling and experimental investigation of an ejector refrigeration system using methanol as the working fluid”, International journal of fuel and energy, volume 43, pp 214-214.[6] Kanjanapon Chunnanond, Sath Aphornratna, “An experimental investigation of a steam ejector refrigerator”, Applied thermal engineering 24(2004),pp 311-322.[7] D. M. Hobb and F. J. Muzzio, “Numerical characterization of low Reynolds number flow in Kenics static mixer” chemical engineering sciences, volume 53, no.8, pp 265- 270,1998.[8] Seck Hoe Wong and Patrick Bryant “Investigation of mixing in a cross-shaped micromixer with static mixing elements for reaction kinetics studies” Sensors and Actuators B 95 (2003), 414–424.[9] Hyun-Seob Song and Sang Phil Han “A general correlation for pressure drops in a Kenics static mixer” Chemical Engineering Science 60 (2005), 5696 – 5704.[10] M. A. Abolfadl and M. A. Metwally “Experimental Investigation of Lobed Mixer Performance” journal of propulsion and power Vol. 17, No. 5, September–October 2001.[11] R.Wadley,M.K.Dawson, “LIF measurement of blending in static mixer in the Turbulent and transitional flow regimes” Chemical engineering science, 60,2005, 2469- 2478.[12]. Elizabeth S Mickaily and Philippe Tangui, “Numerical simulations of mixing in an SMRX static mixer”, Chemical Engineering Journal, vol. 63, num. 2, 1996, p. 117-12[13]. Amy L. Ventresca, Qing Cao and Ajay K. Prasad “The Influence of Viscosity Ratio on Mixing Effectiveness in a Two-fluid Laminar Motionless Mixer” The Canadian Journal of Chemical Engineering, Volume 80, August 2002.[[14] Zalc,J.M.,Szalai,E.S., Muzzaio,F.E., and Jaffer.S., “Characterization of flow and mixing in an SMX static mixer”, AIChE.J., 2002,48(3),427-436.[15]. Ying Zheng Liu,Byoung Jae Kim,Hyung Jin Sung., “Two-fluid mixing in a micro channel”, International journal of heat and fluid flow,2004,25,986-995.[16]. Stephen Wiggins.I and Julio M.Ottino, “Foundations of Chaotic mixing”, Trans.R.Soc.Lond, 2004,A 362,pp 937-970. 110
  • 20. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, Sep - Oct (2010), © IAEME[17]. M.R.Ahmed,S.D.Sharma, “Effect of velocity ratio on the turbulent mixing of confined, co-axial jets”, Experimental thermal and fluid science,2000,22,19-33[18]. Harnby, N.Holwards, M.F, “Mixing in the Process Industries”, 2nd coln Butterworth Heinemann, Oxford, 1992.[19]. Arimond .J. and Erwin L, “A Simulation of a motionless mixer”, Chemical Engineering Communications,, 37, 105-126.[20]. W.Prest, Jr., G. Reynolds and C. Hunter, “Thrust Augmentation with mixer/ejector systems”, AIAA Paper 2002-0230, Jan.2002.[21]. S.Casey Jones,A.M.ASCE, “Numerical modeling of helical static mixers for water treatment”, Journal of environmental engineering,Vol.128,No.5.May 1,2002.[22]. Myers, K.J. Bakker, A. and Ryan, D, “Avoiding agitation by selecting static mixers”. Chemical Engineering progress, 1997, 93, 28-38.[23]. Zdzislaw Jaworski and Paulina Painko-Oprycg, “Two phase, laminar flow simulations in a kenics static mixer. The standard Eulerian and Lagrangian approaches”, Chem Eng Technoly,2001,12,276-287.[24]. Hui Hu,Toshio , “Research on the vertical and turbulent structures in the lobed jet flow by using LIF and PIV”, Measurement science and technology, Vol II, No 6,2000,pp.698-711.[25].Belovich,V.M,Samimy.MS.Casey, “Mixing process in a coaxial geometry with a central lobed mixing nozzle”AIAA Journal,Vol.35,No.5,1997,pp838-841. 111