NOVELTY - Apparatus for growing ingots (204), comprises: growth chamber defining enclosure configured to circulate purge gas about growing ingot; crucible (400) provided in chamber to hold molten silicon, heat shield comprising conical body having base and downwardly depending sidewalls extending into chamber and tapering conically to define annular opening to receive ingot drawn from melt/crystal interface; weir supported in crucible, and configured to separate molten silicon into inner growth region surrounding interface from outer region; and inner weir (407) disposed within weir.    USE - For growing ingots drawn from a melt/crystal interface in a quantity of molten silicon replenished by crystalline feedstock; and for a Czochralski (CZ) grower for preventing transport of dust and particles into a crystal growth region and a growing crystal (claimed).    ADVANTAGE - The Czochralski grower is compatible with silicon recycling processes and is capable of using the silicon produced from re-sized bi-product materials. Such an improved CZ grower ideally must be capable of economically processing recycled silicon, such as tops, tails, slabs and pot scrap while eliminating the problem of unmelted particles and dust landing in the growth zone to cause dislocation defects in the growing crystal. By preventing dust particles from causing dislocation defects in the growing ingot, enable direct utilization of recycled sources of silicon as feedstock; and thereby achieve an economic solution for producing high purity silicon wafers for solar cells from recycling tops, tails, slabs and pot scrap bi-product materials.    DETAILED DESCRIPTION - Apparatus for growing ingots (204) by the Czochralski method, where the ingots are drawn from a melt/crystal interface in a quantity of molten silicon replenished by crystalline feedstock, comprises: a growth chamber defining an enclosure configured to circulate a purge gas about the growing ingot; a crucible (400) provided in the growth chamber configured to hold the molten silicon, a heat shield comprising a conical body having a base and downwardly depending sidewalls extending into the growth chamber and tapering conically to define an annular opening configured to receive the ingot drawn from the melt/crystal interface; a weir supported in the crucible, and configured to separate the molten silicon into an inner growth region surrounding the crystal/melt interface from an outer region configured to receive the crystalline feedstock, the weir comprises sidewalls extending vertically and terminating in a peripheral edge adjacent to the sidewalls of the heat shield to define an annular space with respect to the sidewalls of the heat shield, where the annular space is sized to restrict entry of dust into the growth region; and an inner weir (407) disposed within the weir, where the inner weir defines a middle interconnecting region between the inner growth region and the outer region. An INDEPENDENT CLAIM is included for a Czochralski (CZ) grower for preventing transport of dust and particles into a crystal growth region and a growing crystal, comprising: a crucible containing a melt portion defining a central growth region from which a crystal ingot is pulled; a heat shield provided above the crucible having sidewalls depending downward to define an annular opening coextensive with the central growth region, where the annular opening is configured to receive the ingot pulled from the melt portion; a base weir provided in the crucible and extending above a height of a melt in the melt portion, where the base weir is configured to provide a path length for molten silicon feedstock to travel between an outer melting region and the central growth region for melting of solid particles of feedstock, a modular weir provided on the base weir comprising sidewalls extending vertically to define an annular passageway with adjacent downwardly depending sidewalls of the heat shield, where the annular passageway is configured to block transport of dust particles to the crystal growth region.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic sectional view of a double weir arrangement.    Silicon melt (202)    Ingot (204)    Vacuum pump (220)    Crucible (400)    Inner weir (407)    Outer weir (408)