| 摘要 |
<p>The drum comprises a vertical set of e.g. coiled boards with a flanged bottom, a plastics cover, and a deformable fine film acting as a casing for the assembly. Pref. the casing is formed by an adhering set of polyester and polythene elements held in place by a plastic support, while the casing is also welded to seal against liquid leaks. This design excludes contamination of the liquid by atmospheric gases.</p> |
