Answer Happy

Feedback control system to control the composition of the output stream in a stirred tank blending process is shown in Figure 11.1, page 176 of Textbook (as shown below). 11 V Figure 11.1 Composition control system for a stirred-tank blending process Mass traction of the output stream is the controlled variable, flow rate w 2 of the input stream in the manipulated variable and mass fraction X1 of the other input stream is the disturbance variable. The following data are available: Volume and density are constant. V- 3.2 mp 900 kg/ m3 The process is operating at steady state with w 1-500 kg/min, w 2- 300 kg/min, *104, 2-0.8 GmKm 16 m/(mass fraction). GyKv - 20 kg/min ma The process transfer function GpX'(s)/W 2(1) - K 1/7s+1) where TVp/w and K 1 =(1-x)/W The transfer function relative to the disturbance variable Gd XX)X +(a) =K2/(18+1) where K 2 =W1/W A PI controller is used with K-3 and Tis 1 min The set point for the exit mass fraction is set at the initial steady state value (a) If the disturbance variable x 4 is suddenly decreased to 0.2 from the initial steady state value of 0.4 derive an expression for the response of outlet composition x to this step change [Expression). (6) Calculate the composition of the exit stream (%) 1 minutes after the change. [x-1min] (c) Calculate the composition of the exit stream (X) 2 minutes after the change. IX-2min (d) What is the composition x when a new steady state is reached? (New-SS) (e) What is the offset? [OFFSET
*2 №1 W2 Р. 1/P xm AT (АС х, и 1xsp