问题 问答题 简答题

乙烯装置化工投油试车前冷区和热区的工艺准备工作是什么?

答案

参考答案:

1.用裂解气压缩机供应的空气按系统分别进行吹扫,以吹出脏物和铁锈。

2.吹扫合格后,向各干燥器、反应器内填装干燥剂和催化剂。

3.用裂解气压缩机供应的空气按各系统综和气密检查要求的不同压力等级进行气密检查。

4.用裂解气压缩机供应的空气,经裂解气干燥器干燥露点降至-60~-70℃,按系统分别进行干燥。

5.在进行系统气密检查、干燥时,裂解气干燥器要进行空气再生。

6.在裂解炉投油前,压缩区,分离系统、燃料气系统应进行氮气置换,使系统氧含量低于0.5%(体)以免在裂解气进入后形成易爆混合物。

7.为使丙烯压缩机在投油前能运行起来,要先自界区外接收粗丙烯,并由丙烯精馏塔进行精制后往丙烯压缩机系统充液。

完形填空

信息匹配题

A. Speak, speak, speak

Practise speaking as often as you can---even speaking to yourself is good practice. Try recording yourself whenever you can. Compare your pronunciation with the master version(版本), see how you can do better and have another go. If you do this several times, you will find that each version is better than the last.

B. Why not learn with someone else?

It helps if you can learn with someone else. If you can persuade a friend or family member to study with you, it will make you keep working. Agree times to meet and set goals for the week. And test each other regularly.

C . Don’t get a shock by a word you don’t know

Practise improvising(即兴的) ways of getting your meaning across when speaking spontaneously(本能地), even if you don’t know the exact words or phrases. Think of things you might want to say whenever you have spare time. A basic example is the use of tenses. If you don’t know the past tense but want to talk about yesterday, use the verb in the present tense and use the word “yesterday”.

Use facial expressions, hand movements, anything to get your meaning across.

Language learning is also about intuition(直觉).

Guesswork is an important strategy in learning a new language. When listening to recorded material, you aren’t expected to understand everything first time round. If you play the same piece several times, you will most probably understand something new each time. Learn to make maximum use of all the clues you can pick up. For example, what do the speakers sound like? happy, angry, calm etc.

E. Build up your vocabulary.

A wide vocabulary is the key to successful language learning but don’t try to learn too much at once. It’s best to study frequently, for short periods of time. Take a maximum of six or seven items of vocabulary and learn them. Put them into sentences to fix them in your mind, then come back to them later. Much of the vocabulary in the course is presented by topic. And above all, have fun!

请阅读以下英语学习者在学习中碰到的困难,然后匹配该学习者应该采取上述五种做法(A、B、C、D、E)中的某一种。

(  ) 72. Jack Anderson. Jack’s vocabulary is very small. He is anxious to improve his English. Therefore, he wants to enlarge his vocabulary in a short time and tries his best to memorize new words as many as possible at a time.

(  ) 73. Margret Lillian. Margret Lillian’s pronunciation is poor. And she doesn’t know how to improve her pronunciation. She is very worried and doesn’t know what to do.

(  ) 74. Alice Fingerhut. Alice has difficulty in understanding the meaning of the English text. So she looks up the new words in the dictionary in order to understand everything.

(  ) 75. Lynne Nagata. Lynne can’t express herself clearly in English because she sometimes forgets some key words and doesn’t know the tenses exactly. What can she do?

单项选择题