
1.10 A holding tank serves as an effective way of smoothing variations in the flow of a liquid. For
example, suppose the liquid flow rate from an upstream process is
F
1
(t) ¼
(
F þ f sin
2pt
T
, t 0
where
(
F is an average flow
f is the fluctuation about the average flow
T is the period of the fluctuations
Nominal parameter values for the input flow rate are
F ¼250 ft
3
=min, f ¼50 ft
3
=min, and
T ¼15 min.
A holding tank is placed between the source F
1
(t) and a downstream process that requires a
more constant input flow rate, F
0
(t), as shown in Figure E1.10. The downstream process
requires that the sustained fluctuations in the flow F
0
(t) be no larger than 10 ft
3
=min. ...