| 摘要 |
<p>A centering spacer includes a component (230) comprising a material of low thermal conductivity covered by a plastic polymer envelope (232). - The low conductivity material is an aerogel with an inorganic basis. The component comprises two semi-circular halves (236, 238); the free ends (240, 242) are designed for attachment by fasteners (254, 256, 258). A particularly abrasion-resistant plastic covering is used. The component has a compressive resistance exceeding 10 MPa. The annular void between spacers contains a material of low thermal conductivity. Spacers are separated by up to 5 m. The mean coefficient of thermal transfer is less than 11/10 of that of a portion of tubing in the annular section which contains material of low thermal conductivity. - An INDEPENDENT CLAIM is included for a corresponding jacketed pipe.</p> |
