Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The process in Figure 21 vaporizes liquid butane and mixes the vapor with compre

ID: 718097 • Letter: T

Question

The process in Figure 21 vaporizes liquid butane and mixes the vapor with compressed air The mixture flows to a packed bed reactor 21 Identfy at least three controlled variables, which must be measured (6) 22 Identify at least one manipulated variable for each of the controlled variables Hint these must be valves 23 Identify at least three disturbance variables For each, determine which controlled variable is influenced, ie , disturbed F2 outane F4 Ft compresscr A1 vt F3 T1 condensate Pale uDuT reactors with cookrng P2 Figure 2 1

Explanation / Answer

2.1) Control variables: variables that have to be maintained at set point and controlled by the controller to keep the process stable

L1: Level of butane in the condenser

T1: temperature of the fluid in condenser

PC 3: Composition of overhead product 3

2.2) manipulated variables: Variables that can adjusted to control the control variables

Manipulated variable for L1: the valve v1

Manipulated variable for T1: the valve v3

Manipulated variable for PC3: the valve v5

These valves either increase or decrease the flowrates of the streams to control the control variables based on the signal from the controller

2.3) Disturbance variable: Those variable which is affected by some external factors causing changes in the control variable.

Disturbance variable for L1: The flowrate F1 from tank

Disturbance variable for T1: The flowarte F1 from tank and flowrate F3

Disturbance variable for PC3: Composition of product P2 from separator