| 摘要 |
Solid blocks are formed from sodium hydroxide solution by supplying molten lye by gravity feeding to a vertical cooling shaft and cooling the solution from above in repeated incremental steps while ejecting the solidified extrusion from the shaft downwardly. The cooling and the ejection are carried out by the displaceable downward movement of cooling elements. After each cooling step, the elements are retracted and the shaft is filled up to the original level with the sodium hydroxide solution. During each subsequent step at least a portion of the refill melt present between the solidified extrusion and the cooling elements is solidified by cooling. The apparatus advantageously includes a vertically elongated cooling tower having cutting means associated with the lower end thereof for cutting the extrusion which is ejected through the lower end in desired block size lengths. The cooling elements advantageously comprise one or more fixed cooling elements and one or more elements which move into and out of the tank from above. The elements are tapered conically downwardly in order to facilitate the separation of the elements from the solidified material after it is formed. The shaft is provided with cooling coils adjacent the upper end thereof for aiding in the solidification and also with heating coils directly adjacent the top of the shaft in order to maintain a melted condition or a controlled melted or solid condition in accordance with preferred operating procedures.
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