| 摘要 |
PURPOSE:To prevent the corrosion, the incomplete burning and the reduction in heat exchanging efficiency by coating the heat conductive surface of an aluminum heat exchanger which is exposed to the burning gas with zinc and further coating same with aluminum paste. CONSTITUTION:Zinc electroplating is applied to the surface of a heat transmission section comprising an aluminum drum 1, heat absorbing fins 3 and a heat exchanging tube 2, and, on top of that, a paint obtained by mixing fine powder of aluminum oxide of 180 mesh with silicone resin is applied and baked to complete the coating layer. When the burner in the drum 1 burns, the drum 1 and heat absorbing fins 3 are partially cooled due to the fluid flowing through the heat exchanging tube 2, causing the condensation on their surface, which becomes highly corrosive acid liquid by NOx, SOx, CO2, etc., dissolving and condensed in it. The end of the heat absorbing fins 3 is heated up to 250 deg.C or more. However. since the afore-mentioned coating layer is highly heat- resistant to withstand 400 deg.C and also corrosion resistant to withstand nitric acid, sulfuric acid, etc., there will be no risk of corrosion. |
