Filtering flow guide for hydrothermal crystal growth

Abstract

The present invention is a filtering flow guide for hydrothermal reaction vessels--such as crystal growth apparatus--which improves crystal production efficiency and crystal quality without significantly slowing down flow velocities or crystal growth times. One embodiment of the flow guide fits inside a conventional hydrothermal autoclave for crystal growth, and includes at least one central inlet conduit by which crystal nutrient solution flows from the autoclave's dissolving zone into its growth chamber. A plurality of funnels encircle the inlet conduit, the funnels contiguous with each other along their lateral edges and with the inlet conduit's intake opening at the funnels' innermost edges. Each funnel may be substantially shaped as a hollow, inverted triangular pyramid with a nadir instead of an apex, the nadir opening into a filter-containing outlet. The inlet conduit, plurality of funnels and outlet tubes guide the flow of crystal nutrient solution optimally through the autoclave's dissolving and growth chambers, producing an even flow rate and pattern, and reducing wasteful crystal deposition. The inlet conduit, the funnels, or both elements, may further include optional filters positioned to enhance convective solution flow with minimal flow impedance. The flow guide thereby also filters out contaminants, producing high-purity, high-perfection crystals.