| 摘要 |
<p>In various processing or extractive systems it is actual to convey warm substances through subterranean, insulated pipes of such great length that it is required to add heat en route. Preferably this is arranged with the use of concentric pipes with an outer heat insulating coating. Because the temperature in the double pipe may change it has been found necessary to insert in long pipes expensive axial compensators such as U-bent pipe elements. With the invention this is avoided in a simple manner in that the pair of pipes is made of a central pipe (12), about which is mounted a row of pipe elements (2) of the type 'district heating pipe', the inner pipe (4) of which will then form the outer pipe in the pair of concentric pipes, while a surrounding rigid insulation foam (6) and an outer mantle pipe (8) of plastic will serve to anchor the pipe in a self stabilizing manner in the earth, viz. by an earth friction locking effect. The pipe elements (2) may be prepared for mounting in that at one end of the inner pipe (4) there is welded in some inwardly protruding centering rib plates (10) for later welding to the central pipe (12).</p> |
