Directional solidification system and method
View Patent ↗The present invention relates to an apparatus and method for purifying materials using a rapid directional solidification. Devices and methods shown provide control over a temperature gradient and cooling rate during directional solidification, which results in a material of higher purity. The apparatus and methods of the present invention can be used to make silicon material for use in solar applications such as solar cells.
1. A system for directional solidification, comprising:
a mold, including:
an outer mold jacket;
at least one insulation layer lining a wall of the outer mold jacket;
at least one heat conducting layer lining a bottom of the outer mold jacket, wherein the at least one heat conducting layer includes a graphite containing layer;
a radially finned metal heat exchanger located on an exterior surface of a bottom of the outer mold jacket, a support structure spacing the mold above a floor surface, and defining a space between the mold and the floor;
an air circulation system to move air within one or more flow pathways in the space.
2. The system of claim 1 , wherein the radially finned metal heat exchanger includes a steel heat exchanger.
3. The system of claim 1 , wherein radially finned metal heat exchanger is removable, and separate from the outer mold jacket.
4. The system of claim 1 , further including a top heater.
5. The system of claim 1 , wherein the air circulation system includes horizontal fan located within the space.
6. The system of claim 1 , further including one or more adjustable baffles to control the flow of air within the space.