Lesson9MarineBoilers.doc

Lesson 9 Marine Boilers 第9课 船用锅炉 1. Boilers are used on board ship for producing steam. This steam may be used for driving the main engines, when steam turbines are fitted, or for driving auxiliary machinery such as the windlass. There are two basic types of boiler in use in ships: the fire-tube boiler the （terms “smoke tube” and “donkey boiler” are also in use), and the water-tube boiler. Both are illustrated in Fig. 9-1 船用锅炉用来产生蒸汽。蒸汽在装有蒸汽轮机的船上可用于驱动主机，也可用于驱动辅助机械，如锚机。船用锅炉有两种基本类型：火管锅炉（也使用“烟管锅炉”和“辅锅炉”这两个术语）和水管锅炉。分别图示如下9-1。 2. Now if you look at the diagram of the fire-tube boiler you will see that it consists of a cylindrical steel shell, which contains a furnace at the bottom. Two or more furnaces may be fitted, depending on the size of the boiler. The furnace is connected to a combustion chamber, situated in the middle part of the boiler. Leading from this combustion chamber to a smoke box are a large number of horizontal tubes. Some of these are used for supporting the middle section of the boiler and the combustion chamber. Connected to the smoke box are the uptakes for the waste gases. The furnace, the combustion chamber and the tubes are all surrounded by water. 在火管锅炉的图中可以看到，它由一个圆筒形的钢外壳构成，其底部有炉膛。根据锅炉的大小，可以安装两个或更多的炉膛。炉膛和位于锅炉中间位置的燃烧室相通。燃烧室和烟箱之间设有许多水平烟管。一部分烟管用来支撑锅炉中部和燃烧室。与烟箱相连的是废气的上升烟道。炉膛、燃烧室和烟管都被水包围着。 3. The fire-tube boiler is usually of both riveted and welded construction. It is strong and is capable of operating with poor quality feed water. But there are more efficient types of boiler, which can generate more power; therefore fire-tube boilers are now mainly chosen for low-pressure steam production on vessels requiring steam for auxiliary purposes. 火管锅炉一般为铆接和焊接结构，结构坚固，能够使用劣质给水工作。但是，有些类型的锅炉效率更高，能够产生更大量的蒸汽；因此，苏格兰式锅炉(火管锅炉)现在主要为需要蒸汽驱动辅助机械的船舶提供低压蒸汽。 4. Water-tube boilers have replaced fire-tube boilers for generating high-pressure, high-temperature, high-capacity steam for main engines or cargo pump turbines. From the diagram you will see that they have a steam dr