Patent ID: 6152336
Filing Date: 2000-11-28
Classification: B22D

Abstract:
A dip pipe for feeding by gravity, a molten metal or alloy (2) from a ladle (3) having a nearly constant head, into a thin mould to thereby form a slab (4) from a bath with a top surface (17) in the thin mould (5), the mould (5) comprising first, second, third and fourth cooling walls extending in a substantially vertical direction, with a horizontal cross-section of the mould (5) formed by the first and second walls opposing each other and having a length much greater than the third and fourth walls which oppose each other; the dip pipe (1) comprising a vertical upper tube (6) for communication with the upper ladle (3) and, a diffuser (8) connected to the upper tube (6), the diffuser 8 including a partition baffle (14) forming two distinct passages (16, 16') with discharge holes (9, 9'), respectively, at a lower end of the diffuser (8) opening under the top surface (17) of the slab (4) at a given distance from the mould (5) walls, wherein an upper end of the diffuser (8) has a cross sectional area (10) which is smaller than a cross sectional area (11) of the upper tube (6); said diffuser (8) having inner side walls (12, 12') facing the third and fourth walls of the mould (5), said diffuser inner side walls (12, 12') symmetrically diverging downwardly away from a vertical axis (13) extending through the upper tube (6) and diffuser (8) at an angle .alpha..ltoreq.7.5.degree. with respect to said axis; and a lower portion of the partition baffle (14) having side walls (15, 15') that symmetrically converge downward toward the vertical axis (13) at an angle .beta..ltoreq.7.5.degree. with respect to the vertical axis (13) and extend away from the inner side walls (12, 12') toward the discharge openings (9, 9'), respectively, wherein flow of the molten metal or alloy is gradually reduced in the diffuser (8) toward the discharge holes (9, 9') to thereby produce two diverging, dynamically stable symmetric flows that discharge into the bath below the top surface (17).