In a conclusion, the experimental data shows that microbubble improves the airlift reactor efficiency. In addition, bubble size is an important parameter in the design of an ALB rather than only the physical parameters of the ALB. Chapter 6: Effects of the Draft Tube on Liquid Flow Velocity in ALB 6.1 Introduction The design of vessel significantly influences the performance of airlift reactor, in particularly, the tube and draft tube diameter ratio, the distance between the upper edge of the draft tube to the dispersion surface (CT) and the distance between the lower edge of the draft tube to the aerator surface (CB). Over last decade, there have been lot of studies on the column diameters to draft tube diameter ratio. However, the effect of the top and bottom clearance on the performance of the ALB and the effect of the position of the draft tube on the flow behaviour in the ALB have not been studied to such an extent. Weiland (1984) and Chisti, et al. (1989) reported that that there is a certain range of top clearance affecting the ALB performance and the effects of the bottom clearance was neglected. Sandiani (2012) and Al-azzi & Al-kuffe (2010) neglected the bubble size which affects the flow velocity in the ALB. Sandiani (2012) and Al-azzi & Al-kuffe (2010) varied the clearance distance by changing the water height. Therefore, after completing the previous chapter, illustrating the importance of bubble size on the performance of the ALB, it is necessary to investigate the effect of the draft tube geometry on the ALB performance, with maintaining a consistent bubble size. Therefore, this chapter presents the effects of CT (the distance between the top of
In a conclusion, the experimental data shows that microbubble improves the airlift reactor efficiency. In addition, bubble size is an important parameter in the design of an ALB rather than only the physical parameters of the ALB. Chapter 6: Effects of the Draft Tube on Liquid Flow Velocity in ALB 6.1 Introduction The design of vessel significantly influences the performance of airlift reactor, in particularly, the tube and draft tube diameter ratio, the distance between the upper edge of the draft tube to the dispersion surface (CT) and the distance between the lower edge of the draft tube to the aerator surface (CB). Over last decade, there have been lot of studies on the column diameters to draft tube diameter ratio. However, the effect of the top and bottom clearance on the performance of the ALB and the effect of the position of the draft tube on the flow behaviour in the ALB have not been studied to such an extent. Weiland (1984) and Chisti, et al. (1989) reported that that there is a certain range of top clearance affecting the ALB performance and the effects of the bottom clearance was neglected. Sandiani (2012) and Al-azzi & Al-kuffe (2010) neglected the bubble size which affects the flow velocity in the ALB. Sandiani (2012) and Al-azzi & Al-kuffe (2010) varied the clearance distance by changing the water height. Therefore, after completing the previous chapter, illustrating the importance of bubble size on the performance of the ALB, it is necessary to investigate the effect of the draft tube geometry on the ALB performance, with maintaining a consistent bubble size. Therefore, this chapter presents the effects of CT (the distance between the top of
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