发明名称 |
METHOD AND INDUCTION FURNACE FOR DRAWING LARGE DIAMETER PREFORMS TO OPTICAL FIBRES |
摘要 |
<p>An induction furnace capable of drawing large diameter preforms of up to 130 mm is described, including top and bottom chimneys surrounding the entire preform during operation of the furnace with an inert conditioning gas; the latter is introduced into the top chimney and flows downward through the furnace body and bottom chimney without significant turbulence. A distributor ring inside the top chimney redirects flow from a circumferential direction to a downward direction. The top chimney also includes a resilient seal to releasably hold the top of the preform. The bottom chimney has a smoothly decreasing cross-sectional area preventing turbulence at the furnace exit. The furnace insulation is preferably a rigid self-supporting graphite cylinder. A method of drawing large diameter preforms either to an optical fiber or to a preform of smaller diameter using such a furnace is also claimed and disclosed.</p> |
申请公布号 |
CA2370494(C) |
申请公布日期 |
2008.11.25 |
申请号 |
CA20002370494 |
申请日期 |
2000.05.09 |
申请人 |
PIRELLI CAVI E SISTEMI S.P.A. |
发明人 |
VERONELLI, FRANCO;NUTINI, MASSIMO;ROBA, GIACOMO STEFANO |
分类号 |
C03B37/029;C03B37/012;H05B6/02;H05B6/20 |
主分类号 |
C03B37/029 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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