VORKRISTALLISATOR.

摘要

Melted material undergoes preliminary crystallisation while moving between the inlet and outlet of a horizontal drum with an outer cooling jacket. A motor driven axial shaft carries radially projecting scrapers rotating in close proximity to the inner drum wall from which crystals formed by cooling are detached to act as seeds for further growth. To prevent crystal formation of the scrapers themselves and the hollow shaft, those elements are heated, esp. by internally flowing steam. Hollow support webs at opposite ends of each scraper form a flow circuit loop with the hollow scraper and a bore (tube bend) within the shaft. Melt defelctor surfaces forming the outer contour of the webs may in cross-section be tear shaped or equilateral triangles or form part of pivoted intermediate members.