Sparger region

Case 1. The pressure drop across the liquid sparger is very much less than that caused by its acceleration over the gas sparger region. This case... 

Perforated plates are defined by a critical flow rate above which the orifice operation is asynchronous and the liquid flow in the sparger region is relatively unstable. As the hole spacing decreases, the critical flow rate decreases as well. At the same time, perforated plates require a minimum pressure drop in order to achieve uniform orifice activity. In other words, a critical flow rate is also created at the lower end such that a lower flow rate would lead to instability as well (Kang et al., 1999 Ruzicka et al., 2003 Su and Heindel, 2005a). This effect would produce additional complications in making comparative analysis between research works using different open area ratio adjustment methods. 

High turbulence is required for efficient mixing this is created by the vortex field which forms behind the blades. For all the gas to flow through this region it must enter the vessel close to and preferably underneath the disk hence it is recommended that spargers should always be nearer, about a distance of DJ2 below the agitator, where D( is the impeller diameter. 

On the other hand animal cells are especially sensitive as regards sparging. Obviously the cells are adsorbed at the gas liquid boundary layer and subjected to the most stress in the region of bubble formation at the sparger and bubble bursting at the liquid surface. 

Intensified turbulence can destroy the stability of large bubbles, which leads to smaller bubbles, and increase the frequency of bubble coalescence and breakup, which improves the surface renewal frequency of bubbles [17,18]. Intensified turbulence can be achieved by changing the gas sparger to decrease the initial bubble size and improve its radial distribution, but the effective region of the gas sparger is only limited to a certain height above the distributor [19]. 

Region without agitation effect. At a very low impeller rotational speed, up to a certain minimum impeller rotational speed, the transfer rate does not improve with stirring. In this region, the mass transfer rate depends on the gas load and type of sparger but is independent of the impeller rotation speed. 

Eles. For porous-carbon media, the manufacturer suggests that the est dispersion performance will result if the broken e regions of Fig. 14-96 are avoided. For porous stainless-steel spargers, which... 

In a recirculation boiler system, see Figure 12.2, the feedwater is normally fed through sparge pipes into the steam drum, where the downward-pointing spargers encourage the formation of a subcooled region. A mixture of subcooled and saturated water is then drawn... 

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