LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Sher, Farooq; Sajid, Zaman; Tokay, Begum; Martin, Khzouzc; Sadiqd, Hamad (2016)
Publisher: Wiley
Languages: English
Types: Article
Subjects:
This study presents a full operation and optimisation of a mixing unit; an innovative approach is developed to address the behaviour of gas-liquid mixing by using Electrical Resistance Tomography (ERT). The validity of the method is investigated by developing the tomographic images using different numbers of baffles in a mixing unit. This technique provided clear visual evidence of better mixing that took place inside the gasliquid system and the effect of a different number of baffles on mixing characteristics. For optimum gas flow rate (m3/s) and power input (kW), the oxygen absorption rate in water was measured. Dynamic gassingout method was applied for five different gas flow rates and four different power inputs to find out mass transfer coefficient (KLa). The rest of the experiments with one up to four baffles were carried out at these optimum values of power input (2.0 kW) and gas flow rate (8.5×10-4 m3/s). The experimental results and tomography visualisations showed that the gasliquid mixing with standard baffling provided near the optimal process performance and good mechanical stability, as higher mass transfer rates were obtained using a greater number of baffles. The addition of single baffle had a striking effect on mixing efficiency and additions of further baffles significantly decrease mixing time. The energy required for complete mixing was remarkably reduced in the case of four baffles as compared to without any baffle. The process economics study showed that the increased cost of baffles installation accounts for less cost of energy input for agitation. The process economics have also revealed that the optimum numbers of baffles are four in the present mixing unit and the use of an optimum number of baffles reduced the energy input cost by 54%.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Kleerebezem, R. and M.C. van Loosdrecht, Mixed culture biotechnology for bioenergy production. Current opinion in biotechnology, 2007. 18(3): p. 207-212.
    • Paul, E.L., V.A. Atiemo-Obeng, and S.M. Kresta, Handbook of industrial mixing: science and practice. 2004: John Wiley & Sons.
    • Moinfar, S. and M.-R.M. Hosseini, Development of dispersive liquid-liquid microextraction method for the analysis of organophosphorus pesticides in tea. Journal of hazardous materials, 2009. 169(1): p. 907-911.
    • Assirelli, M., et al., Macro-and micromixing studies in an unbaffled vessel agitated by a Rushton turbine. Chemical Engineering Science, 2008. 63(1): p. 35-46.
    • Chemical Engineering Science, 2005. 60(8): p. 2203-2214.
    • Micheletti, M., et al., Fluid mixing in shaken bioreactors: Implications for scale-up predictions from microlitre-scale microbial and mammalian cell cultures. Chemical Engineering Science, 2006. 61(9): p. 2939-2949.
    • Chemical Engineering Research and Design, 2006. 84(3): p. 239-245.
    • Tribe, L., C. Briens, and A. Margaritis, Determination of the volumetric mass transfer coefficient (kLa) using the dynamic “gas out-gas in” method: Analysis of errors caused by dissolved oxygen probes. Biotechnology and bioengineering, 1995. 46(4): p. 388-392.
    • Moutafchieva, D., et al., Experimental determination of the volumetric mass transfer coefficient. Journal of Chemical Technology & Metallurgy, 2013. 48(4).
    • Wang, F. and Z.-S. Mao, Numerical and experimental investigation of liquid-liquid two-phase flow in stirred tanks. Industrial & engineering chemistry research, 2005. 44(15): p. 5776- 5787.
    • Lane, G., M. Schwarz, and G. Evans, Predicting gas-liquid flow in a mechanically stirred tank. Applied Mathematical Modelling, 2002. 26(2): p. 223-235.
    • Yapici, K., et al., Numerical investigation of the effect of the Rushton type turbine design factors on agitated tank flow characteristics. Chemical Engineering and Processing: Process Intensification, 2008. 47(8): p. 1340-1349.
    • Chemical Engineering Science, 1996. 51(5): p. 733-741.
    • Kresta, S.M. and P.E. Wood, The flow field produced by a pitched blade turbine: characterization of the turbulence and estimation of the dissipation rate. Chemical Engineering Science, 1993. 48(10): p. 1761-1774.
    • Adrian, R.J., Twenty years of particle image velocimetry. Experiments in Fluids, 2005. 39(2): p. 159-169.
    • Roehle, I., et al., Recent developments and applications of quantitative laser light sheet measuring techniques in turbomachinery components. Measurement Science and Technology, 2000. 11(7): p. 1023.
    • Schäfer, M., M. Höfken, and F. Durst, Detailed LDV measurements for visualization of the flow field within a stirred-tank reactor equipped with a Rushton turbine. Chemical Engineering Research and Design, 1997. 75(8): p. 729-736.
    • Pettersson, M. and Å.C. Rasmuson, Hydrodynamics of suspensions agitated by pitched‐blade turbine. AIChE journal, 1998. 44(3): p. 513-527.
    • Carletti, C., et al., Analysis of solid concentration distribution in dense solid-liquid stirred tanks by electrical resistance tomography. Chemical Engineering Science, 2014. 119: p. 53- 64.
    • Aw, S.R., et al., Electrical resistance tomography: A review of the application of conducting vessel walls. Powder Technology, 2014. 254: p. 256-264.
    • Yenjaichon, W., et al., Mixing quality in low consistency fibre suspensions downstream of an in-line mechanical mixer measured by electrical resistance tomography. Nordic Pulp and Paper Research Journal, 2014. 29(3): p. 392-400.
    • Abdullah, B., et al., Electrical resistance tomography-assisted analysis of dispersed phase hold-up in a gas-inducing mechanically stirred vessel. Chemical Engineering Science, 2011.
    • 66(22): p. 5648-5662.
    • Yenjaichon, W., et al., Assessment of mixing quality for an industrial pulp mixer using electrical resistance tomography. The Canadian Journal of Chemical Engineering, 2011.
    • 89(5): p. 996-1004.
    • Tahvildarian, P., et al., Using electrical resistance tomography images to characterize the mixing of micron-sized polymeric particles in a slurry reactor. Chemical Engineering Journal, 2011. 172(1): p. 517-525.
    • Hosseini, S., et al., Study of solid-liquid mixing in agitated tanks through electrical resistance tomography. Chemical Engineering Science, 2010. 65(4): p. 1374-1384.
    • Hari-Prajitno, D., et al., Gas-liquid mixing studies with multiple up-and down-pumping hydrofoil impellers: Power characteristics and mixing time. The Canadian Journal of Chemical Engineering, 1998. 76(6): p. 1056-1068.
    • Coulson, J.M., et al., Coulson and Richardson's Chemical Engineering Volume 1 - Fluid Flow, Heat Transfer and Mass Transfer (6th Edition). 1999, Elsevier.
    • Measurement Science and Technology, 1996. 7(3): p. 247.
    • Mann, R., et al. Resistance tomography imaging of stirred vessel mixing at plant scale. in Institution of chemical engineers symposium series. 1996. Hemsphere publishing corporation.
    • Beck, M.S., Process tomography: principles, techniques and applications. 1995: ButterworthHeinemann.
    • Gladden, L., Process Tomography: Principles, Techniques and Applications. Measurement Science and Technology, 1997. 8(4).
    • Mann, R., et al., Application of electrical resistance tomography to interrogate mixing processes at plant scale. Chemical Engineering Science, 1997. 52(13): p. 2087-2097.
    • 2002, New York: McGraw-Hill.
    • Towler, G.P. and R.K. Sinnott, Chemical engineering design: principles, practice, and economics of plant and process design. 2013: Elsevier.
    • Hockey, R. and J. Nouri, Turbulent flow in a baffled vessel stirred by a 60 pitched blade impeller. Chemical Engineering Science, 1996. 51(19): p. 4405-4421.
    • Chem. Eng. Prog, 2002. 98(2): p. 42-47.
    • Wang, M., et al., Measurements of gas-liquid mixing in a stirred vessel using electrical resistance tomography (ERT). Chemical Engineering Journal, 2000. 77(1): p. 93-98.
    • Sardeing, R., et al., Gas-Liquid Mass Transfer: Influence of Sparger Location. Chemical Engineering Research and Design, 2004. 82(9): p. 1161-1168.
    • Nienow, A.W., M.F. EDWARDS, and N. Harnby, Mixing in the process industries. 1997: Butterworth-Heinemann.
    • Nienow, A.W., M.F. Edwards, and N. Harnby, eds. Mixing in the Process Industries. second ed. 1997, Butterworth Heinemann.
    • Gubanov, O. and L. Cortelezzi, On the cost efficiency of mixing optimization. Journal of Fluid Mechanics. 692: p. 112-136.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article