问题 问答题 简答题

催化蒸馏塔的开工步骤是什么?

答案

参考答案:

催化蒸馏塔的开工步骤如下:

①将经过预反应后的物料进入催化蒸馏塔,使塔釜液面达80%~90%高度。

②给再沸器通入1.0MPa的蒸汽,使塔釜升温,其升温速度为每小时20~30℃。

③塔顶放空阀打开,排放塔内不凝气,当有C4从塔顶排出时,关闭放空阀。

④给冷凝器通冷却水,塔顶压控仪表给定压力参数为0.5~0.8MPa。

⑤当回流罐有回流液面出现时,打开回流罐放空阀,排出回流罐内不凝气,排完不凝气后,关闭放空阀。

⑥当回流罐液面达1/2高度时,启动回流泵向塔顶打回流液。回流量从小到大,视回流罐内液面高度而定。

⑦当塔釜受热后,C4蒸发上升到塔顶,液位降低时,要及时向催化蒸馏塔进预反应后物料,直到塔釜和回流罐都有1/2左右的液位为止。

⑧实行全回流操作。在全回流操作过程中不断调整塔顶压力、反应段床层温度、回流量,使这些参数逐渐达到设计规定值。

⑨在全回流操作平稳4-8小时后,反应段床层温度分布合理,催化剂活性充分发挥后,回流泵出口采样点的物料中异丁烯含量逐渐降低到设计规定值,催化蒸馏塔的转化率达到设计值,塔顶可以出料。

⑩经过全回流操作4-8小时后,塔釜物料中除MTBE外,可能有一定量的甲醇、叔丁醇和水分,如果没有C4或C4量小于0.5%,也可以出料。

⑪.塔顶或塔釜物料合格排出,就要对催化蒸馏塔进料,先按设计进料的60%-70%负荷操作,平稳4-8小时后可满负荷进料、出料,即转入正常运转。

阅读理解

Growing mushrooms(蘑菇) is probably the easiest thing you can do even if you are new to mushroom growing. It is becoming more common because restaurants are starting to create more dishes that include mushrooms.

Mushroom growing is easy. To start, you need to have a space where you are going to grow these mushrooms. It does not have to be a huge space but just enough for you to grow as many mushrooms as you need. When you have found the space perfect for you, you can start researching what kind of mushrooms you want to grow. There are a lot of mushrooms to choose from and not all of them are suitable to eat.

When you decide what kind of mushrooms you want to grow, you can start getting ready to plant the mushrooms. Sometimes you may want to hire some workers to help if you have a large mushroom farm, or if you are trying to start a professional mushroom growing business. Trying to have a business by yourself can be stressful. If you don’t have enough time to spend taking care of everything yourself, dome helpers may be the best choice.

After you have started the mushroom growing, you should regularly check that your mushrooms grow properly and that they are not being attacked by any pesticides(农药) or any other animals or something that could be dangerous to them. That is the worst part of mushroom developing. Protect your mushroom farm well with a fence(围栏) or a gate so that only you and your workers can get in and out.

Mushroom growing is not difficult and it is easy to get stared in the world of farming. You will soon possibly be able to provide some of the great cooks of the world with high quality mushrooms that will be enjoyed by thousands of people all over the world.

小题1:According to the passage, many people begin to plant mushrooms probably ________.

A.because they are in great need.

B.because they look very beautiful

C.because they are healthy food

D.because they are very expensive小题2:Which of the following is the right order of planting mushrooms?

a. Choose suitable mushrooms.

b. Protect your mushrooms well.

c. Find some workers to help you.

d. Start to grow the mushrooms.

e. Find a place to plant your mushrooms.

A.c—a—d—b—e

B.e—a—c—d—b

C.c—a—e—b—d

D.e—a—d—b—c小题3:It can be inferred from the passage that __________.

A.pesticides can be used in mushroom growing

B.anyone can produce high quality mushrooms.

C.after starting, you should always take care of the mushrooms

D.having a mushroom business is not so difficult小题4:The best title of the passage is __________.

A.Healthy mushrooms

B.The value of mushrooms

C.How to choose mushrooms

D.Suggestions on growing mushrooms

单项选择题