Figure W5
7.6. In the two-tank mixing process shown in Fig. P7.6, x varies from 0 lb salt ft3 to 1 lb salt ft3 according to a step function. At what time does the salt concentration in tank 2 reach 0.6 lb salt ft3 The holdup volume of each tank is 6 ft3.
Response Of Firstorder Systems In Series
Very often a physical system can be represented by several first-order processes connected in series. To illustrate this type of system, consider the liquid-level systems shown in Fig. 7.1 in which two tanks are arranged so that the outlet flow from the first tank is the inlet flow to the second tank. Two possible piping arrangements are shown in Fig. 7.1. In Fig. 7. la the outlet flow from tank 1 discharges directly into the atmosphere before spilling into tank 2 and the flow through R depends...
Problems Bcg
6.1. Derive the transfer function H s Q s for the liquid-level system of Fig. P6.1 when a The tank level operates about the steady-state value of hs 1 ft- b The tank level operates about the steady-state value of hs 3 ft. The pump removes water at a constant rate of 10 cfm cubic feet per minute this rate is independent of head. The cross-sectional area of the tank is 1.0 ft2 and the resistance R is 0.5 ft cfm.
Figure P610
6.11. Determine Y 5 if Y s e-3i i 7i 1 . 6.12. Derive the transfer function H Q for the liquid level system shown in Fig. P6.12. The resistances are linear. H and Q are deviation variables. Show clearly how you derived the transfer function. You are expected to give numerical values in the transfer function. 6.13. The liquid-level system shown in Fig. P6.13 is initially at steady state with the inlet flow rate at 1 cfm. At time zero, one ft3 of water is suddenly added to the tank at t 1, one ft...
Index
Absorption, dynamics of, 328-333 ACSL simulation software, 540 Adjoint of matrix, 443 Alarm, process and diagnostic, 549 Amplitude ratio, 202 Analog computer, 517 Analog-to-digital converter, 35 1 Attenuation, 59 Bandwidth, 129 Batch control, 546 Bilinear transformation, 378 Block diagram, 53, 112-113 chemical reactor, 135-141 standard symbols, 143-144 Bode diagram asymptotic approximations, 210-212 controllers, 217-218 definition, 209 first-order system, 209-211 graphical rules, 213...
Problems 1
5.1. A thermometer having a time constant of 0.2 min is placed in a temperature bath, and after the thermometer comes to equilibrium with the bath, the temperature of the bath is increased linearly with time at a rate of l min. What is the difference between the indicated temperature and the bath temperature a 0.1 min, b 1.0 min after the change in temperature begins c What is the maximum deviation between indicated temperature and bath temperature, and when does it occur d Plot the forcing...
Figure 17
link temperature versus time step input for proportional and integral control. This control system is to have two adjustable parameters, Kc and KR. The response of the tank temperature T to a step change in Tj, using a control function described by 1.9 , may be derived by solution of Eqs. 1.3 , 1.6 , 1.7 , and 1.9 . Curves representing this response, which the reader is asked to accept, are given for various values of KR at a fixed value of Kc in Fig. 1.7. The value of Kc is a moderate one, and...