Studies on Mass and Momentum Transfer at the Outer Wall of a Circular Conduit with Entry Region Spiral Tape Wound on Rod as Turbulence Promoter in Homogeneous Flow

D.N.V. Satyanarayana, M. Venkateswara Rao, K. Nagamalleswara Rao, P. Rajendra Prasad

Abstract


In this study, an experimental investigation is carried out for augmentation of mass transfer coefficients in homogeneous flow by inserting spiral tape wound on rod in a circular conduit. Mass transfer coefficients are evaluated from the limiting current densities and the concentrations of the reacting ions. The variables studied are the geometric parameters of the promoter width, height, pitch of the promoter and the flow rate of the electrolyte, each parameter effect on mass transfer and momentum transfer are investigated. Experiment is conducted for 48 promoters with varying geometric parameters. Reynolds number range covered in the experiment is 4853–14533. Improvement in mass transfer is assessed by comparing the obtained mass transfer coefficient (kL) values with the smooth tube data. It is found that kL increased with increased flow rate. The increase in tape height and width of the promoter resulted in slightly increased mass transfer coefficients. Pitch of the promoter showed marginal effect on kL.

Keywords: Turbulence promoter, spiral tape wound, limiting current densities, turbulence promoter, homogeneous flow

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REFERENCES

Lin et al. Diffusion controlled electrode reactions. Industrial and Engineering Chemistry. 1951; 43(9): 2136–43p.

Chiou JP. Experimental investigation of the augmentation of forced convection heat transfer in a circular tube using spiral spring inserts. Trans. A.S.M.E. 1987; 109: 300–7p.

Prasad RP. Studies on ionic mass transfer with coaxially placed spiral coils as turbulence promoter in homogenous flow and in fluidized beds. Ph.D Thesis. Andhra University, Visakhapatnam, INDIA. 1993.

Sujatha V. Studies on ionic mass transfer with coaxially placed helical tapes on a rod in homogeneous fluid and fluidized beds. Ph. D., Thesis, Andhra University, isakhapatnam, INDIA, 1991.

Rao GR, Sujatha V, Venkateswarlu P. Performance of Helical Tape Promoter in Fluidized Beds. Indian Chem. Engr. Section A. 1997; 39(2).

Sujatha V, Prasad PR, Sarma CB, et al. Studies on ionic mass transfer with insert helical tape promoters in batch fluidized beds. Indian Journal of Chemical Technology. 2003; 10: 694–700p.

Prasad PR, SujathaV, Sarma CB, et al. Studies on ionic mass transfer with coaxially placed spiral coils as turbulence promoter in homogenous flow and in fluidized beds. Chemical Engineering and Processing J. 2004; 43: 1055–62p.

Sujatha V, Sarma CB, et al. Studies on ionic mass transfer with coaxially placed helical and on a rod in forced convection flow. Chemical Engineering and Processing J. 1997; 36(1): 67–73p.

Rao SS. Studies on ionic mass transfer with coaxially placed cones on a rod in homogeneous fluid and fluidized beds. PhD. Thesis, Andhra University, Waltair, India, 1983.

Sitaraman TS. Augmentation of mass transfer with coaxial string of spheres as internals in tubes and fluidized beds. Ph.D. Thesis, University of Madras, India, 1977.

Raju CD. Augmentation of mass transfer at the outer wall of concentric annuli in absence and presence of fluidizing solids effect of wires wound on central rod. Ph.D. Thesis, Andhra University, Visakhapatnam, INDIA, 1984.

Venkateswarlu P. Studies on ionic mass transfer with coaxially placed discs on a rod as turbulence Promoter. Ph.D., Thesis, Andhra University, Visakhapatnam, INDIA, 1987.

Webb RL, Eckert RG, Goldstein RJ. Heat transfer and friction in tubes with repeated-rib roughness. Int. J of Heat and Mass Transfer. 1971; 14(4): 601–17p.

Dawson DA, Trass O. Mass transfer at rough surfaces transfer massique aux surfaces roughnes. Int J of Heat and Mass Transfer. 1972; 15(7): 1317–36p.

Rao VN. Studies on Ionic Mass and Momentum Transfer with co-axially placed twisted tape disc assembly as turbulence promoter in circular conduits. Ph.D. Thesis, Andhra University, Visakhapatnam, INDIA, 2004.

Mohan VM. Studies on mass and momentum transfer with coaxially placed entry region coil, disc assembly as turbulence promoters in circular conduit. Ph. D., Thesis, Andhra University, Visakhapatnam, INDIA, 2008.

Mohan VM, Kumar CS, Sujatha V, et al. Mass transfer correlation development for the presence of entry region coil as swirl promoter in tube. International Journal of Thermal Sciences. 2010; 49: 356–64p.

Rao KN. Studies on mass at the outer wall of a circular conduit with entry region twisted tape as turbulence promoter in homogeneous flow and in fluidized beds, Ph. D., Thesis, Andhra University, Visakhapatnam, INDIA, 2011.

Chang SW, Yang TL. Forced convective flow and heat transfer of upward concurrent air-water slug flow in vertical plain and swirl tubes. Experimental Thermal and Fluid Science. 2009; 33: 1087–99p.

Eiamsa-ard S, Seemawute P, Wongcharee K. Influences of peripherally-cut twisted tape insert on heat transfer and thermal performance characteristics in laminar and turbulent tube flows. Experimental Thermal and Fluid Science. 2010; 34: 711–19p.

Promvonge P, Eiamsa-ard S. Heat transfer augmentation in a circular tube using V-nozzle turbulator inserts and snail entry. Experimental Thermal and Fluid Science. 2007; 32: 332–40p.

Eiamsa-ard S. Study on thermal and fluid flow characteristics in turbulent channel flows with multiple twisted tape vortex generators. International Communications in Heat and Mass Transfer. 2010; 34: 1151–61p.

Gunes S, Ozceyhan V, Buyukalaca O. Heat transfer enhancement in a tube with equilateral triangle cross sectioned coiled wire inserts. Experimental Thermal and Fluid Science. 2010; 34: 684–91p.

Dipprey DF, Sabersky RH. Heat and momentum transfer in smooth and rough tubes at various prandtl numbers. Int. J of Heat and Mass Transfer. 1963; 6(5): 329–32p.

Nikuradse J. Laws of flow in rough pipes. VDI Forsch. 1933; 361p.




DOI: https://doi.org/10.37628/jcep.v1i1.4

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