Development of a Model and Computer Code to Describe Solar Grade Silicon Production Processes. Seventh Quarterly Report, April 1-June 30, 1979

摘要

This program aims at developing mathematical models and computer codes based on these models, which allow prediction of the product distribution in chemical reactors for converting gaseous silicon compounds to condensed-phase silicon. The major interest is in collecting silicon as a liquid on the reactor walls and other collection surfaces. Two reactor systems are of major interest, the Westinghouse SiCl sub 4 /Na reactor in which Si(l) is collected on the flow tube reactor walls and the new AeroChem reactor in which Si(l) droplets formed by the SiCl sub 4 /Na reaction are collected by a jet impingement method. During this quarter the following tasks have been accomplished: (1) particle deposition routines have been added to the boundary layer code and (2) Si droplet sizes in SiCl sub 4 /Na reactors at temperatures below the dew point of Si are being calculated. Initial results from the latter show that droplet sizes in such reactors are predominantly in the range 0.2 to 1.0 mu m. Such particles are too small to collect by conventional means (e.g., cyclones) but should be easily collected by very high velocity impaction at reduction pressures such as that being examined by AeroChem. (ERA citation 05:013265)