问题 问答题 简答题

造成皮带跑偏的原因及处理措施。

答案

参考答案:

(1)滚筒中心线偏差。应调整滚筒,使各滚筒中心线平行、对中,平行度和平面度均符合要求;

(2)入料位置偏,将皮带“砸”偏。应在皮带机入料口加缓冲板,改变落料位置、减缓物料冲击动能;

(3)头部或改向滚筒上粘结物料,使皮带横向张力不平衡。应清理滚筒上粘结的物料;

(4)调心托辊不起作用,可能是调心托辊支架或调心托辊损坏、调心托辊支架积料卡死而使调心托辊失去调心作用。应清理积料、更换调心托辊支架或调心托辊,使调心托辊恢复正常;

(5)导料槽两侧挡皮磨损不一致,导致皮带两侧运行阻力不均衡。应调整或更换挡皮,尽量使皮带两侧运行阻力均衡;

(6)一侧许多托辊有转动不灵活现象,导致皮带运行时两侧阻力不平衡。应对托辊进行维修或更换,使全部托辊均回转灵活;

(7)配重不均衡,可能是配重箱内配重放置不均衡或配重箱内落入物料。应将配重箱内配重均衡放置,若配重箱内或上部有集料要及时清理;

(8)皮带粘结接头时质量不高,接头横向两侧长短不一致,导致皮带两侧张力不平衡。在粘结接头时应严把质量关,避免出现此种情况,万一出现,在跑偏一侧加装立滚,强制皮带对中运行;

(9)皮带制造时两侧弹性不均衡。应在跑偏一侧加装立滚,强制皮带对中运行,同时将配重有意识的在紧边多放;

一般情况下,运行一段时间后皮带便可消除两侧弹性不均衡现象,这时应及时调整配重使之两侧均衡。

(10)皮带机架安装不规范,平面度差或托辊安装后向一侧倾斜。应在跑偏一侧加装立滚,强制皮带对中运行;

(11)皮带较厚,横向柔韧性小,胶带不能平服的和托辊接触。应加装调心托辊组,在皮带两侧加装立滚强制皮带对中运行。

阅读理解

First Day at School

It was my first day at school in London and I was half-excited and half-frightened. On my way to school I wondered, what questions the other boys would ask me and practiced all the answers: "I am nine years old. I was born here but I haven't lived here since I was two. I was living in Farley. It's about thirty miles away. I came back to London two months ago." I also wondered if it was the rule for boys to fight strangers like me, but I was tall for my age. I hoped they would decide not to risk it.

No one took any notice of me before school. I stood in the center of the playground, expecting someone to say "hello", but no one spoke to me.

My teacher was called Mr. Jones. There were 42 boys in the class, so I didn't stand out there, either, until the first lesson of the afternoon. Mr. Jones was very fond of Charles Dickens, so he asked several boys if they knew Dickens' birthplace, but no one guessed right. A boy called Brian, the biggest in the class, said: "Timbuktu” and Mr. Jones went red in the face. Then he asked me. I said: "Portsmouth” and everyone stared at me because Mr. Jones said I was right. This didn't make me very popular, of course. “He thinks he's clever," I heard Brian say.

After that, we went out to the playground to play football. I was in Brian's team, and he obviously had Dickens in mind because he told me to go in goal. No one ever wanted to be the goalkeeper.

"He's big enough and useless enough;" Brian said when someone asked him why he had chosen me.

As the boy kicked the ball hard along the ground to my right, I threw myself down quickly and saved it. All my team crowded round me. My bare knees were grazed and bleeding. Brian took out a handkerchief and offered it to me.

"Do you want to join my gang (team)?" he said.

At the end of the day, I was no longer a stranger.

小题1: The writer prepared to answer all of the following questions EXCEPT "__________".

A.How old are you?

B.Where are you from?

C.Do you want to join my gang?

D.When did you come back to London?小题2: We can learn from the passage that ___________________.

A.boys were usually unfriendly to new students

B.the writer was not greeted as he expected

C.Brian praised the writer for his cleverness

D.the writer was glad to be a goalkeeper小题3:The underlined part "I didn't stand out" in paragraph 3 means that the writer was not ______.

A.noticeable

B.nervous

C.important

D.outstanding小题4:The writer was offered a handkerchief because _________________.

A.he was in Brian’s team

B.he was no longer a new comer

C.he was beginning to be accepted

D.he pushed a player on the other team

单项选择题