# GATE2013-23

A batch bioreactor is to be scaled up from $\text{10 to 10,000}$ liters. The diameter of the large bioreactor is $10$ times that of the small bioreactor. The agitator speed in the small bioreactor is $\text{450 rpm}$. Determine the agitator speed (rpm) of the large bioreactor with same impeller tip speed as that of the small bioreactor. ____________

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## Related questions

1
A solution was prepared by dissolving $\text{100 mg}$ of protein $X$ in $\text{100 ml}$ of water. Molecular weight of protein $X$ is $\text{15,000 Da};$ Avogadro’s number = $6.022\times 10^{23}$. Calculate the molarity$(\mu M)$ of the resulting solution. $66.6$ $6.6$ $0.67$ $0.067$
2
A fed batch culture was operated with intermittent addition of glucose solution at a flow rate of $\text{200 ml h}^{-1}$. The values of $K_s,\: \mu_m$ and $D$ are $\text{0.3 g l}^{-1}, 0.4\:h^{-1}$ and $\text{0.1 h}^{-1}$, respectively. Determine the concentration of growth limiting substrate $(gl^{-1})$ in the reactor at quasi-steady state. ______________
The maximum cell concentration $(\text{g l}^{-1})$ expected in a bioreactor with initial cell concentration of $\text{1.75 g l}^{-1}$ and an initial glucose concentration of $\text{125 g l}^{-1}$ is ($Y_{X/S} = 0.6\:g\:cell/g$ substrate) ____________.
A chemostat is operated at a dilution rate of $0.6\; h^{-1}$. At steady state, the biomass concentration in the exit stream was found to be $30\; gl^{-1}$The biomass productivity $(g\; l^{-1}h^{-1})$ after $3h$ of steady state operation will be ___________.