| 摘要 |
<p>The heat exchanger is composed of a vertical sewer pipe for greywater and of a helical pipe coil (1) for heated water. The helical pipe coil (1) constitutes a metal insert mounted vertically inside the sewer pipe together with a short inner pipe (3), on which the upper part of the pipe coil is wound. The helical line of the pipe coil wound on the short inner pipe (3) has its pitch greater than the pitch of the helical line of the pipe coil below the short inner pipe (3).</p> |
