Reactor for fluidized bed silane decomposition

An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon

Consolidation of high purity silicon powder

Consolidation of very fine silicon powder into shotted form using heated crucible

Zone heating for fluidized bed silane pyrolysis

An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower reaction zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon

Aerodynamic noise in aircraft and wind tunnels

The modern trend towards high engine power and large13; aeronautical test facilities has resulted in a tremendous13; increase in the generation of noise and consequently the13; problem of noise control in aircraft and wind tunnels has13; become one of increasing importance in recent years. The13; high noise levels are not only a source of annoyance to13; people working, in the vicinity, but also in many cases cause structural damage and malfunctioning of equipment.13; In aviation and aircraft industry the people who are most affected by noise are turbo-jet manufacturers, service crews, occupants of the aircraft, N-wind tunnel operators and communities near, airports and test facilities. The high cost and effort required to provide adequate protection for these people demand a detailed study of the characteristics of various aircraft noise sources, the magnitude of the noise, the nature of the source and the effect of operating conditions on these characteristics, quot;Aerodynamic noisequot; is the noise generated as a byproduct of an unsteady turbulent airflow, or noise produced without participation of solid boundaries. Examples of sources of such noise are* air jets, boundary layers, vortices 9 wakes and related phenomena* Before embarking on a general discussion of these phenomena, some of the basic terms used in acoustic theory and measurement are defined in the next section