制冷与空调专业英语第2版 林慧珠 主编 1-3新.pptVIP

Unit One Lesson 1 Air Lesson 2 The Need of Conditioning Lesson 3 The Cleaning of Air Lesson 4 Thermal Storage Lesson 3 The Cleaning of Air New Words Expressions Text Notes to the Text Exercise Lesson 3 Lesson 3 Lesson 3 Text Particles in the atmosphere range in size from less than 10-6 up to the order of magnitude of the dimension of leaves and insects1. The particles exist in all sizes and shapes and generally it is impossible to design one air cleaner that is best for all applications 这些微粒的尺寸，小的数量级达到10-6，大的达到树叶和昆虫的尺寸。微粒的大小和形状各式各样，一般不可能设计一种能很好地适用所有场合的空气净化器。 Different degrees of air cleanliness are required for various applications. Another consideration is the fact that dust particles in the air may damage the conditioned spaces or its furnishings. For example, the walls may be discolored if even the smallest components of the atmospheric dust are not removed. 不同的应用场合需要不同型号的空气净化装置。另外，还要考虑到空气中的尘粒会损害空调空间和其内的家具。例如，即使残留尘粒的最小组分也有可能使墙壁褪色。 Unfortunately the smallest particles cause the most discoloring. Therefore, in this case, electronic air cleaners or high performance dry filters are required. In clean room applications or when radioactive particles are present, extremely high performance filters should be employed. 不幸的是，尘粒越小墙壁褪色越严重。因此，在这种情况下，需要使用电子空气净化器或高性能干燥过滤器。在绝对无尘室或存在放射性微粒时，需要利用极高性能的过滤器。 One of the most effective ways of controlling allergic disorders is to remove the allergens from the air by using high performance filters.2 Of all the characteristics affecting the performance of an air filter, particle size is the most important; however, the cleaning efficiency of a filter is affected to some extent by the velocity of the air stream. 控制由于过敏造成的身体紊乱最有效方法之一，是使用高性能过滤器除掉空气中的过敏源。微粒大小是所有的特征中影响空气过滤器的性能最主要的因素；然而，在某种程度上净化器的净化效率受气流流速的影响。 The major factor influencing filter design and selection is the degree of air cleanliness required. In general the cost of the filter or filter system will increase as