| 摘要 |
<p>PURPOSE:To prevent acid corrosion of a boiler and to improve the thermal efficiency thereof by using a heat transfer pipe made of glass, a synthetic resin or the like as a heat transfer element. CONSTITUTION:The low temperature air preheater comprises a combustion gas heat transfer section 1 and an air heat transfer section 2. The combustion gas heat transfer section 1 is disposed at the lower side of the preheater and the air heat transfer section 2 is disposed at the upper part thereof. Each heat transfer tube is made of a glass tube (or an acid-proof synthetic resin tube), and the upper part and lower part of each heat transfer tube are connected by means of headers. The lower headers 7 of the air heat transfer section and the upper headers 5 are connected to each other by means of a downcomer 3 in each block. Also, the upper header 6 of the combustion gas heat transfer section and the upper header 8 of the air heat transfer section are connected to each other by means of a riser tube 4. In the inner part of each heat transfer tube and each connecting tube, water circulates in the state of a vapor and a liquid while varying in accordance with the heating side and cooling side.</p> |
