Impellers Inducer

Equation (18-36) is the general expression for impeller-induced nucleation. In a fixed-geometry system in which only the speed of the circulating pump is changed and in which the flow is roughly proportional to the pump speed, Eq. (18-36) may be satisfactorily replaced with... 

Air separator Vow (N-S) Similar shape to hydrocycloue, hut higher included angle. Internal impeller induces recycle within classifier. 0.5 to 7.5 2 mm to 38 im to 2100 4 to 500 Used where solids must be kept dry, such as cement grinding. Air classifiers may be integrated into grinding mill structure. 

Use an impeller inducer. An impeller inducer looks like a corkscrew device that fits onto the center hub of the primary impeller and extends down the suction throat of the pump. It is actually a small axial flow impeller that accelerates the fluid toward the primarv impeller from further down the suctittn throat of the pump. Some inducers bolt onto the impeller and others are cast into the main impeller. The inducer has a low NPSHr for the system feeding it, and it increases the Ha to the primary impeller. 

P Pe PFR <7 Total pressure Peclet number for dispersion Plug flow reactor Heat flux, reaction order, or impeller-induced flow Pa psi... 

Previous works carried out with stirred tank bioreactors reported that the damage of hairy roots by the impeller induced callus formation and consequently reduced the biomass production [65], To overcome this problem the bioreactor configuration was modified. A plastic mesh was placed forming a zigzag arrangement around the baffle in order to increase the surface where the roots could be trapped [28]. 

The conclusions in (2) and (3) were further confirmed for TB/C3 hybridoma by Oh et al. (1989, 1992) who used a high shear Rushton turbine with and without gas sparging. Viability studies in the absence of air sparging showed no noticeable cell damage with a maximum power input of 0.25 W/kg. In contrast, relatively low level of aeration resulted in rapid cell death even at much lower impeller power. These results again prove that impeller-induced shear alone does not result in cell death, whereas the presence of gas bubbles results in significant cell death. 

The helical ribbon impeller is suitable for blending highly viscous media. It comprises a spiral strip attached to the central shaft by supporting struts, as shown in Figure 13.2. In contrast to the propeller, this impeller induces axial flow not by a pressure differential but by positive displacement in the laminar flow range. 

Figure 3 is the assembled model pump. The stemlike projection at the top of the unit was used to afford a magnetic rpm pickup, and mounting, and an extension shaft for motor tests. An exploded view of this model is shown in Figure 4. At the top row are the motor housing, impeller, inducer, volute and inlet bell, all made of a high strength aluminum alloy. Below this, at each side of the rotor, are the ball bearings of 440-C stainless. These used micarta ball separators. At the bottom is the shaft, which was 304 stainless steel.

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