| 摘要 |
PURPOSE:To protect a heat transfer tube from damages, as well as to recover exhaust heat from a high-temperature zone highly efficiently without using a cooling grate or the like, by arranging a heat transfer tube in two stages of upstream side and downstream side, and by interposing a radiation shielding body which prevents radiant heat from being transferred through the heat transfer tube of upstream side and downstream side. CONSTITUTION:The primary heat transfer tube 1 is provided to the upstream side and the secondary heat transfer tube 2 is to the downstream side. The heat transfer tube 1 on the upstream side is made of highly heat-resistant ceramics. The high temperature in exhaust gas is lowered by the heat being absorbed by the heat transfer tube 1, so that a conventional metallic tube is usable for the heat transfer tube on the downstrem side. But ceramics is preferable also for the heat transfer tube 1 on the downstream side. But ceramics is preferable also for the heat transfer tube 2 on the downstream side as same as the tube 1. Between the heat transfer tubes 1 and 2, a shield 3 is provided along the heat transfer tubes 1, 2, in the crosswise direction of a flue A. As for the shield 3, the one in which rods are arranged having specified intervals among them, on arranged in the form of a grate, or a honeycomb plate can be used. As for the material, a heat-resistant ceramics is the best one. |
