| 摘要 |
<p>The box consists of an outer casing provided in its interior with a helical rib supporting an inner casing so that an annular cavity contg. the rib is formed and used as a first circuit (I) for a coolant, e.g. water. The bore of the inner casing is also provided with a helical rib supporting an inner tube and thus forming a second helical path (II) for cooling water. Inside the inner tube is an axial core tube which is monolithic with the inner casing, and is used as an inlet for water flowing through circuit (I); and the annular cavity between the inner tube and the axial core tube is used as an inlet for water flowing through circuit (II). Both the outer and inner casings pref. end in a spherical nose projecting into the refractory lining of the furnace. Only circuit (I) is used initially and, when the nose of the outer casing has worm away, the flow of water through circuit (I) is stopped. But a new circuit (II) can then be used, the result being that the cooling box has a double life.</p> |
