Mass transfer enhancement in a three-phase fluidized bed electrochemical reactor

Mass transfer enhancement in a three-phase fluidized bed electrochemical reactor

Gajulapalli V.S.K. Reddy Kasala V. Ramesh 

Department of Chemical Engineering, MVGRCE, Vizianagaram 535005, India

Department of Chemical Engineering, Andhra University, Visakhapatnam 530003, India

Corresponding Author Email: 
kvramesh69@yahoo.com
Page: 
182-188
|
DOI: 
https://doi.org/10.18280/ijht.360124
Received: 
22 October 2017
| |
Accepted: 
18 September 2017
| | Citation

OPEN ACCESS

Abstract: 

An assembly consisting of a string of hemispherical elements arranged concentrically on a rod essentially acted as a displaced augmentative device. This assembly was placed coaxially in a three-phase fluidized bed. Nitrogen gas, an electrolyte and glass spheres were used as gas, liquid and solid phases respectively. Limiting current technique was employed to obtain mass transfer coefficient data. Maximum augmentation realized in the present study was about 18 times in comparison with homogeneous pipe flow. Present investigation revealed that the fluctuations in mass transfer coefficients in axial direction were within ±10%. The mass transfer coefficient increased with superficial gas velocity and particle diameter. The mass transfer coefficient decreased with pitch and characteristic length. Superficial liquid velocity and promoter rod diameter have not shown any noticeable influence on mass transfer coefficient. The entire mass transfer coefficient data obtained in the present study were subjected to least squares regression analysis and a correlation equation has been obtained.

Keywords: 

mass transfer coefficient, fluidized bed, three-phase fluidization, augmentation, turbulent promoter

1. Introduction
2. Experimental Procedure
3. Results and Discussion
4. Conclusions
Nomenclature
  References

[1] Handbook of heat transfer (1998). New York, McGraw Hill 11.1-11.76.  

[2] Sivakumar K, Rajan K. (2015). Experimental analysis of heat transfer enhancement in a circular tube with different twist ratio of twisted tape inserts. International Journal of Heat and Technology 33: 158-162. https://doi.org/ 10.18280/ijht.330324

[3] Kaliakatsos D, Cucumo M, Ferraro V, Mele M, Galloro A, Accorinti F. (2016). CFD analysis of a pipe equipped with twisted tape. International Journal of Heat and Technology 34(2): 172-180. https://doi.org/ 10.18280/ijht.340203

[4] Ramesh KV, Raju GMJ, Murty MSN, Bhaskara Sarma C. (2009). Wall to bed mass transfer in three phase fluidized beds in the absence and presence of a composite promoter. Chemical Engineering Journal 152: 207-211. https://doi.org/10.1016/j.cej.2009.04.048

[5] Murty MSN, Ramesh KV, Venkateswarlu P, Prabhakar G. (2010). Ionic mass transfer in three-phase fluidized beds in the presence of disc promoters. Chemical Engineering Communications 198: 1018. https://doi.org/10.1080/00986445.2011.545302

[6] Subramanyam BS, Murty MSN, Babu BS, Ramesh KV. (2014). Wall-to-bed mass transfer in a three-phase fluidized bed with twisted tape as internal, Journal of The Institution of Engineers (India): Series E 95(1): 49-56. https://doi.org/10.1007/s40034-014-0035-z

[7] Rohini Kumar P, Ashok Kumar K, Murty MSN, Ramesh KV. (2017). Wall-to-bed mass transfer in three-phase fluidized beds in the presence of angled disc promoter. Heat and Mass Transfer 53(10): 3129-3140. https://doi.org/10.1007/s00231-017-2056-x

[8] Rohini Kumar P, Niranjana Rao B, Venkateswarlu P, Ramesh KV. (2018). Wall-to-bed mass transfer in a three-phase fluidized bed with coaxially placed string of spheres internal. Materials Today Proceedings 5: 470-476. https://doi.org/10.1016/j.matpr.2017.11.107

[9] Reddy GVSK, Murthy MSN, Srinivas B, Ramesh KV. (2014). Liquid-wall mass transfer in homogeneous flow with coaxially placed string of hemispheres. Journal of The Institution of Engineers (India): Series E 95(2): 69-74. https://doi.org/10.1007/s40034-014-0040-2

[10] Reddy GVSK. (2016). Wall-to-bed mass transfer in fluidized beds with coaxially placed string of hemispheres. Ph.D. thesis. Dept. of Chemical Engineering, Andhra University, Visakhapatnam, India.

[11] Lin CS, Denton EB, Gaskill HS, Putan CL. (1951). Diffusion controlled electrode reactions. Ind. Eng. Chem. 43: 2136-2143. https://doi.org/ 10.1021/ie50501a045

[12] Harvind Kumar R, Ramesh KV, Sarma GVS, Raju. GJM. (2011). Mass transfer at the confining wall of helically coiled circular tubes in the absence and presence of packed solids. International Communications in Heat and Mass Transfer 38: 319-323. https://doi.org/10.1016/j.icheatmasstransfer.2010.11.008

[13] Jagannadha Raju GJV, Venkata Rao C (1965). Ionic mass transfer in the presence of fluidized solids, Indian Journal of Technology 3(7): 201-205.

[14] Yasunishi A, Fukuma M, Muroyama K. (1988). Wall-to-liquid mass transfer in packed and fluidized beds with gas-liquid counter flow. Journal of Chemical Engineering. of Japan 21: 522-528. https://doi.org/10.1252/jcej.21.522

[15] Venkateswarlu P, Gopichand T, JaganadhaRaju GJV. (2000). Increased mass transfer in a circular column in the presence of disc promoter. Journal of Energy, Heat and Mass Transfer 22: 195-203.

[16] Sarma GVS, Murty MSN, Ramesh KV, Raju GJM. (2011). Wall to bulk mass transfer in gas liquid up flow bubble column with disc promoter. Journal of energy, Heat and Mass Transfer 33: 233-249.