Residence-time distribution from pulse input

This program is designed to simulate the resulting residence time distributions based on a cascade of 1 to N tanks-in-series. Also, simulations with nth-order reaction can be run and the steady-state conversion obtained. A pulse input disturbance of tracer is programmed here, as in example CSTRPULSE, to obtain the residence time distribution E curve and from this the conversion for first order reaction. 

The extent of gas dispersion can usually be computed from experimentally measured gas residence time distribution. The dual probe detection method followed by least square regression of data in the time domain is effective in eliminating error introduced from the usual pulse technique which could not produce an ideal Delta function input (Wu, 1988). By this method, tracer is injected at a point in the fast bed, and tracer concentration is monitored downstream of the injection point by two sampling probes spaced a given distance apart, which are connected to two individual thermal conductivity cells. The response signal produced by the first probe is taken as the input to the second probe. The difference between the concentration-versus-time curves is used to describe gas mixing. 

A similar analysis for a pulse input would give a response curve of Cpuise vs 0, but this can be obtained more easily by differentiating the J ) curve in Fig. 6-5. From Eq. (6-7), the derivative J B) is proportional to The derivative of the dashed line in Fig. 6-5 will be largest at 0 = 0 and will continually decrease toward zero as 0 increases. Such a distribution curve, given as the dashed line in Fig. 6-6, shows that the most probable [largest J ) d6 residence time is at 0 = 0 for a stirred-tank reactor. 

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