| 摘要 |
<p>The heat exchanger, made from two coaxial metal tubes (3, 5) formed into a coil has the inner tube (3) fitted with spacers (9) that maintain the gap (7) between the inner and outer tubes when bent into a curve. The spacers can be in the form of continuous or interrupted radial fins e.g. of flat steel strip, or they can be formed by a coil e.g. of wire or comprise radial needles. The spacers can be made from the same material as the inner tube and relatively malleable so that it follows the shape of the inner tube when it is bent.</p> |
