问题 问答题 简答题

简述离心泵的轴封装置有几种形式及其作用是什么?

答案

参考答案:

离心泵轴封装置的形式有填料密封和机械密封两种。水厂(供水站)所用离心泵多为填料密封装置,它由填料、填料环(或水封环)填料压盖、填料箱、水封管等组成。轴封装置的作用是用来密封泵轴和泵轴穿出泵壳处的缝隙,防止水从内漏出和空气透入泵内,同时还可以起部分支承转子以及引水润滑、冷却泵轴的作用。

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    Fifteen is such an awful (糟糕的) age, I should know. I really wish I were eighteen. If you are an
adult, you can be your own boss. People like my parents and my teachers are always telling me what
to do. You know what I mean. "It's time for bed, Sandy." Or "Sandy, you've watched too much TV
for one night." "Sandy, stand up straight." "Sandy, you must improve your handwriting." Sandy this,
Sandy that. No one tells adults when they go to bed or not to watch TV. Besides, adults get to wear
what they like. Now it's going to be great to be an adult. Don't you agree?

     I'm Sandy's mother. Having a fifteen-year-old daughter isn't always easy. Right now, we've got
a problem. Our neighhour, Mrs White, wants Sandy to look after her pet dog for one week. Sandy
really wants to do it, but (I                          ). She's too young and inexperienced. Well, I will
never be able to relax knowing she is all alone with a dog. I've tried to explain my feelings to her,
but she won't listen. She keeps telling me that the Whites live very near, so she can ask for help.
She insists that Mrs White won't ask her to look after her pet dog if she doesn't think Sandy is old
enough. She says I'm "babying" her and I hate to see her mad at me. What should I do?
1. Sandy is fifteen years old and she wishes to be her own _______.
2. Sandy thinks her parents and her teachers are always telling her what to do. Give an example.
                                                                                                                                        
3. 将文中括号内的英文句子补充完整。
4. 将划线句子She says I'm "babying" her and I hate to see her mad at me. 译成汉语。 
                                                                                                                                         
5. Should Sandy look after Mrs White's pet dog? Why or why not? 
                                                                                                                                         
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