Effect of Solid Bed Height on Pressure Drop in Stationary Liquid Fluidization

S. Kumar^1*, A. Arora², H. Chandra³

¹Research Scholar, Department of Mechanical Engineering, Bhilai Institute of Technology, Durg, Chhattisgarh, India

²Professor, Department of Mechanical Engineering, Bhilai Institute of Technology, Durg, Chhattisgarh, India

³Associate Professor, Department of Mechanical Engineering, Vishwavidyalaya Engineering College, Sarguja University, Ambikapur, Chhattisgarh, India

*Corresponding Author E-mail:saurabhkumar2002@gmail.com

ABSTRACT:

Present investigation is intended to find the effect of increasing static solid bed height on the column pressure drop during gas fluidization of solids in stationary liquid. Researchers already explored the effect of increasing solid bed height for gas-solid fluidization and gas-liquid-solid fluidization but for stationary liquid fluidization this area is almost untouched. Findings suggest that for increasing solid bed height pressure drop across column increases with increasing gas velocity.

KEYWORDS: Bed height, pressure drop, fluidization, stationary liquid, flow rate

INTRODUCTION:

Epstien (1981) categorized the different types of fluidization as concurrent fluidization, counter current fluidization and stationary liquid fluidization. Out of these concurrent fluidization has been always be the first choice of the researchers. Relatively lesser number of works is reported in the field of counter current fluidization. The present investigation is related to the field of stationary liquid fluidization which is now gaining the attention by the recent researchers. The range of studies and parameters selected for the investigation are presented in Table 1.

Table 1:  Range of experimental variables 

LITERATURE REVIEW:

Gabor et al. (1984)initially worked in the field of stationary liquid fluidization. Tang and Fan (1989) investigated the gas-liquid-solid fluidization for investigating the effect of low density solids on fluidization using conductivity probe. Kumar and co-workers (1998) investigated pressure drop and bed expansion for three phase gas-liquid-solid fluidization. They also suggested the use of rod type promoters for enhancing the quality of fluidization. Jena et al. (2008) carried out the pressure drop studies for thee phase fluidized and semi fluidized beds. Moshtari and researchers (2009) investigated the effect of air distributor and its design on the dynamics of fluidization. The effect of particle size on the pressure drop during gas fluidization of solids has been successfully described by the Kumar et al. (2015) during stationary liquid fluidization. Same authors extended their work and reported in year 2017 the effect of variation in solid bed height on the pressure distribution during gas fluidization of solids in stationary liquid.  Dora et al. (2016) investigated the three phase fluidization for describing the pressure drop, expansion ratio and fluctuation ratio.

EXPERIMENTAL SET-UP:

Figure 1: Line diagram of the experimental set-up

Experimental setup consists of one vertical fluidizing column having internal diameter of 90 mm. The material of construction of the column is acrylic and divided into three different sections. The lower section of the fluidizer is connected with the air distributor section. The air is introduced into the column through distributor section using air compressor. At the top of the fluidizer, liquid disengagement section is attached. Liquid and solids can be added or removed from the inlet / outlet ports provided. The pressure drop across column can be measured either using pressure gauge or manometers.

RESULT AND DISCUSSION:

Figure 2: Variation on column pressure drop with increasing air discharge for 2 mm sized peanut in 40 cm turpentine for different solid bed heights

Figure 3: Variation on column pressure drop with increasing air discharge for 2 mm sized peanut in 50 cm kerosene for different solid bed heights

Figure 4: Variation on column pressure drop with increasing air discharge for 2 mm sized peanut in 60 cm water for different solid bed heights

Figure 5: Variation on column pressure drop with increasing air discharge for 2 mm sized stone in 40 cm turpentine for different solid bed heights

Figure 6: Variation on column pressure drop with increasing air discharge for 2 mm sized coal in 60 cm water for different solid bed heights

Analysis of above figures reveals that for increasing gas flow rate pressured drop across column is also increasing. Further, with rise in bed height of the solids in the column, the pressure drop is also rising. With the rise in the height of the solids in the fluidizing column the total mass present on the distributor section also rises up which requires more air to fluidize. This ultimately increases the pressure drop across the column

CONCLUSION:

From the analysis of figures two conclusions can be made. First is that with increasing gas flow rate pressure drop across the column during fluidization is increasing. Second conclusion is that with increase in the solid bed height the pressure drop across column during gas fluidization of solids in stationary liquid also increases. This finding is similar to the finding reported by Padhi et al (2016).

REFERENCES:

1. Epstein, N. (1981). Three-phase fluidization: Some knowledge gaps. The Canadian Journal of Chemical Engineering, 59(6), 649-657. doi:10.1002/cjce.5450590601

2. Gabor, J. D., Cassulo, J. C., Fountain, D., andBingle, J. D. (1984). Gas fludization of solids in stationary liquid.AIChE annual meeting.

3. Tang, W. ‐T, and Fan, L. ‐S. (1989). Hydrodynamics of a three‐phase fluidized bed containing low‐density particles. AIChE Journal, 35(3), 355–364. https://doi.org/10.1002/aic. 690350303

4. Kumar, A., Roy, G. K. and Pattnaik, P. C. (1998). Effect of co-axial rod promoter onthe pressure drop in a batch liquid-solid fluidized bed, Journal of Institution of Engineers (India), 79, 30-33

5. Cui, H., and Grace, J. R. (2007). Fluidization of biomass particles: A review of experimental multiphase flow aspects. Chemical Engineering Science, 62(1-2), 45-55.

6. Jena, H. M., Sahoo, B. K., Roy, G. K., andMeikap, B. C. (2008).Characterization of hydrodynamic properties of a gas-liquid-solid three-phase fluidized bed with regular shape spherical glass bead particles.Chemical Engineering Journal, 145(1), 50–56. https://doi.org/10.1016/j.cej.2008.03.002

7. Moshtari, B., Babakhani, E. G., and Moghaddas, J. S. (2009). Experimental study of gas hold-up and bubble behavior in gas–liquid bubble column. Petroleum and Coal, 51(1), 27-32.

8. S. Kumar, (2012). “Experimental Analysis for Terminal Velocity of Irregular Particles”, International Journal of Technology, Volume 02, Issue 02, 29-32.

9. Kumar, S., Arora, A., and Chandra, H. (2015). Experimental investigations on variation in particle size on pressure drop during gas fluidization of solids in stationary liquid. International Research Journal of Engineering and Technology (IRJET), 2(5), 883-886.

10. Padhi, R., Dora, D., Mohanty, Y., Roy, G., andSarangi, B. (2016). Prediction of bed pressure drop, fluctuation and expansion ratios for three-phase fluidization of ternary mixtures of dolomite in a conical conduit. Cogent Engineering, 3(1). doi:10.1080/23311916.2016.1181821

11. Kumar, S., Arora, A., and Chandra, H. (2017).Effect of variation in solid bed height on the pressure distribution during gas fluidization of solids. , Research Journal of Engineering Sciences, 6(7), 7-13.

Received on 26.03.2018            Accepted on 09.04.2018           

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Int. J. Tech. 2018; 8(1): 06-10

DOI:10.5958/2231-3915.2018.00002.0