| 摘要 |
<p>VINCENZO SOLIGNO I- 27058 VOGHERA A supporting grid for tubes comprising a central reticular structure formed of main and secondary intersecting strips, an inner annular frame formed in the same material as the strips and so designed as to receive with a tight fit the ends of said strip therein, said inner frame being higher than the reticular structure so that upper and lower proyecting portions are created togheter with cleaning ducts, and an external annular frame formed of a different material and consisting of an external box ring and of a external cover ring capable of receiving and containing therein said projecting portions of the inner frame, axially extending and inwardly facing dogs being provided at the inner portion of said external frame; the inner frame and the external frame being assembled so that at room temperature said dogs of the external frame fit tightly to the inner cylindrical surface of said projecting portions while play exists between the external cylindrical surface of the inner frame and the internal cylindrical surface of the external frame for free thermal expansion of the two materials.</p> |
