The Swirl Reactor—a Reactor Concept for Continuous Gas-Solid Interactions

Abstract

The Swirl reactor is an innovative concept for performing reactions in gas phases or solid and gas phase mixtures. It was developed during the initial boom of the solar cell industry, where the need for more energy- and cost-efficient means of producing high-purity solid silicon became important. The Swirl reactor was designed to fulfil the following requirements: continuous production of high-purity silicon; efficient energy transfer from the reactor to the gas; controlled transport of the Si-fines and the gas formed; the use of silane as feed for silicon. By employing a stainless steel tubular reactor honed on the inside and heated from the outside, and using argon as the carrier gas, the requirements were all shown to be fulfilled. The Swirl reactor throughput can be increased by having more than one injector introducing new swirls. Also, two swirls—each containing reacting agents—may form product where they mix, i.e. along the path where the swirls overlap. Thus, reactions can be controlled but still be run continuously. The possible uses of the Swirl reactor are numerous.

Keywords

• silane
• swirl flow
• amorphous silicon
• photovoltaic silicon
• fines
• cyclone
• downer reactor