| 摘要 |
<p>A thin metal sheet is bent to form a circular tube possessing a longitudinal slot and forming an outer sheath. Inside the sheath is the material, e.g. an alloying addn., which is surrounded at least partially by a foil below 100 um in thickness; the foil is made of a synthetic organic material or metal. The foil may completely surround the addn. and have overlapping longitudinal edges, the overlap being located below the slot in the outer metal sheath. Alternatively, the foil may be semicircular and located under the slot in the sheath, esp. using a self-adhesive foil. The foil is esp. one which shrinks when exposed to heat. The tube has a very low wt. but can carry a large amt. of an addn., which can thus be fed at high speed into the melt. The addn. is e.g. CaSi fed into molten steel.</p> |
