三、坩埚与支撑砖间的空隙：
Third, the gap between crucible and support brick:
1.坩埚与支撑砖间的空隙太小，坩埚受热膨胀后会受阻裂开，可在坩埚和炉壁顶部支撑砖间直接放置可燃物（插入小木片或纸板），在坩埚加热后，可燃物会燃烧掉从而留下足够的空间。The gap between the crucible and the supporting brick is too small, after the expansion of the heated crucible will be blocked in the crack, crucible and furnace wall top supporting brick directly placing combustibles (insert the small pieces of wood or cardboard), in the crucible after heating, fuel burn down and leave enough space.
2.对于在侧面排废气的炉子，坩埚和炉壁之间可以用保温棉密封，然后用耐高温水泥固定。这样既可以防止因炉顶没有完全密封，而使坩埚顶部氧化而裂开，且在坩埚受热向上膨胀时不会受阻裂开。For exhaust gas in the side of the stove, crucible and furnace wall can be sealed with insulation cotton, and then fixed with high temperature cement. This prevents both the top of the crucible from being oxidized and cracked by the top of the crucible due to incomplete sealing of the furnace roof, and is prevented from cracking when the crucible is heated upwardly.
（注：建议使用炉沿盖来防止坩埚的氧化、顶部开裂和腐蚀。炉沿盖的内边要覆盖住坩埚内表面100mm处，能更好地避免坩埚受到外力撞击和被氧化。）(Note: It is recommended to use the cover to prevent the oxidation
of the crucible furnace top, cracking and corrosion. The inner side of the
furnace cover is covered with the inner surface of the crucible 100mm, so as to
avoid the impact of the external force and the oxidation of the crucible.)
3.在倾转炉中，应该在坩埚一半高度的位置上，有一块或两块支撑砖在浇嘴的下方把坩埚固定。应在坩埚和支撑砖之间放入3~4cm左右的高温棉，以保留足够的空间防止坩埚膨胀时受阻。
In the tilting furnace, one or two supporting bricks should be positioned below the crucible at a height of half the crucible to hold the crucible below the spout. You should be placed between the crucible and support brick around 3 ~ 4cm high temperature cotton, in order to retain enough space to prevent the crucible expansion blocked.
