Answer Happy

Problem 1: Consider a spherical reactor with radius 30 cm and thickness 1 cm filled with propane-air mixture in stoichiometric ratio and initial temperature of 1400K. Assume the sphere sits in a quiescent environment and recall that the Nu = 2.0 for such a situation. Take the kinetics constants for propane combustion from Turns, Table 5.1 and assume homogeneous conditions within the reactor. a. Give two possible choices of material for the reactor wall, with justification, if ignition is to be guaranteed. Use the graphical solution method taught in class. b. Estimate the minimum value of the ignition delay time.
Oxidation of Hydrocarbons Table 5.1 Single-step reaction rate parameters for use with Eqn. 5.2 (Adapted from Ref. (91) Pre-exponential Factor, A Activation Temperature, E_/R, (K) Fuel -0.3 13.10 83. 10 1.1 - 102 8.6. 1011 24.3585 15.0989 15.098 15.098 1.3 1.3 1.65 1.65 7.4 - 10 6.4 101 5.7. 1011 5.1 - 1011 15.098 15,098 15,098 15,098 0.5 0.25 0.25 0.25 1.6 1.5 1.5 1.5 CH, CH, С.Н. CH, CH10 C.H12 CH,4 CH CH: CH CH, CH, CH,OH С,НОН CH, С.Н. CH сн. CH, 4.6 1011 7.2. 1012 4.2. 1011 3.8 1011 15.098 20,1314 15,098 15,098 0.25 0.25 0.25 1.5 1.5 1.5 1.5 0.25 3.2 - 1012 1.5. 1012 2.0. 1011 1.6 - 10 15.098 15.098 15,098 15.098 0.25 0.15 -0.1 -0.1 15 1.6 1.85 1.85 2.0 . 1012 4.2 1011 6.5 . 1012 15,098 15.098 15.098 0.1 -0.1 0.5 1.65 1.85 1.25 "Units of A are consistent with concentrations in Egn. 5.2 expressed in units of gmol/em", i.e., A[=] (gmol/cm)-m-h/s. BE = 48.4 kcal/gmol. "E. = 30 kcal/gmol. E. = 40 kcal/gmol. where the parameters A, E,/R, m, and n. shown in Table 5.1, have been cho- sen to provide best agreement between experimental and predicted flame speeds and flammability limits (see Chapter 8). Note the treatment of units for A in the footnote