| 摘要 |
<p>Lamp glass partic. for a miners lamp is annealed by preheating this to a specific temp. and quenching it in a sand bath and while this is covered by the sand, immersing it in a cooling liquid such as water but without allowing the water to come into direct contact with it. The preheating is progressive up to ca. 670 degrees C and the hot lamp glass is subjected to a vertical drop to eliminate any deformation when it is placed in the annealing mould.</p> |
