The mixing of large gas streams, an experimental study with reference to the cold shot reactor

Abstract

The mixing of large gas streams in a full scale mixing chamber for a cold shot reactor has been studied at atmospheric pressure with air flow using heat as a tracer. The intensity of segregation with respect to heat has been measured by temperature fluctuations, and the one-dimensional wave number spectrum is obtained by a statistical analogue computer. The experimentally obtained variances are compared with those derived from complete segregation and from Corrsin's analysis of an isotropic turbulent mixer. It is found that the degree of segregation in the outlet is in the order of half a per cent and qualitatively in agreement with Corrsin's predictions of inverse proportionality with the mean residence time and the one third power of the kinetic energy input. The wave number spectra indicate that the energy bearing part is mainly reflecting an unsteady state of the macroscopic flow-pattern, hence giving an integral scale which is not in agreement with the decay rate. The effect of segregation for an ammonia reactor is shown to be in the order of less than 2 per cent reduction of optimum efficiency.