| 摘要 |
<p>The interior of the hollow rotatable roller connects at one end with an annular chamber in which a small quantity of liquid e.g. water is provided and which rotates with roller. The centrifuge effect of rotation forms the liquid into an annulus of greater diameter, than the inner diamter of the roller, and the chamber is heated so that vapour is given off from the inner surface of the liquid annulus and passes into the interior of the roller to heat it. Pref. the inner surface of the roller is conical and has longitudinal grooves so that vapour condensing on the inner surface passes back to the chamber. Pref. the chamber is of a ferromagnetic material and is heated by an induction coil. the roller is used for heating textile yarn. The roller is cheap to produce, economic to operate and the surface is uniformly heated.</p> |
