Arrangement for manufacturing crystalline silicon ingots

An arrangement for manufacturing crystalline silicon ingots by directional solidification, the arrangement comprising:

• at least one compartment with heat insulating side wall(s) configured to house a crucible, the at least one compartment comprising:
• a heating device;
• at least one inlet for supplying purge gas into the compartment;
• one or more outlet(s) for extracting gas from the compartment;
• a gas conduit formed by a continuous peripheral opening between:
• an upper shield element placed at a distance above the crucible and which covers the horizontal cross-section area of the compartment to separate it in two overlaid sub-compartments where the upper sub-compartment has heating means, and
• a lower shield element placed at a distance below the upper shield element and along the outer surface of the crucible, and which covers the cross-section area formed between the outer surface of the crucible and the inner surface of the side heat insulating wall(s) of the compartment;
• and
• a flow constriction located in the gas conduit or the one or more outlet(s), providing a cross-section area, A, in the gas conduit or one or more outlet(s), equal to A=P·d, where P is a perimeter length of an upper edge of the crucible in mm and d is between 0.5 and 50 mm,
• wherein the one or more inlet(s) for supplying purge gas is (are) located above the crucible, and located on the heat insulating side wall(s) of the compartment between the upper and lower shield elements.