| 摘要 |
<p>A metallurgical lance comprises a fibre optic (40) housed within the lance or in a tube mounted thereon, the fibre optic being protected against the heat and arranged to view the flame at the lance tip (50) to provide a signal for flame detection purposes. The fibre optic may as shown be located within a central fuel gas passage (10) of the lance which is surrounded by an oxygen air passage (15) itself enclosed in a cooling jacket (20). The output of the fibre optic may pass through a lens and may be applied to a system to discriminate signals in the range 200-600 Hertz. <IMAGE></p> |
