| 摘要 |
<p>A one-piece substrate (20) has an external holder (201) with an inner grid (21) forming openings (22). The basic grid cross section is triangular, forming angled surfaces (210) on the air entry side, whilst the rear (211) is flat. All surfaces of the synthetic substrate are completely coated with a layer of infrared emitter, made from an infrared-emitting ceramic powder. Several grids of this type are connected together, the grids being mutually-offset in rotation. Air flows over the angled surfaces and into the interspaces left between grids.</p> |
