问题 问答题 简答题

煤磨系统安全要求

答案

参考答案:

①煤磨系统长期停车后开车的安全检查:检查煤粉仓、袋收尘易堵塞部位及输送设备内部有无煤粉及杂物;检查车间内是否有煤或煤粉堆积;

②煤磨系统短期停车后开车时安全检查:确认输送设备内部有无煤粉堵塞及自燃现象;

③排气:为防止开车时发生爆炸,应先启动排风机,将袋收尘及管道中可能产生的易燃易爆气体全部排出;

④磨出口气体温度应保持在合适温度范围内,不能过高,注意煤粉细度及水分,减少过粉磨或过烘干现象,当喂煤量过高或过低时,应严格监视各点工艺操作参数,防止磨出口温度过高等现象发生。

⑤其它设备如袋收尘输送设备等应从温度、压力参数判断是否存在堵塞及煤粉自燃现象。

⑥正常停车:

把煤磨、袋收尘及输送设备等煤粉全部排空后停车;

预计停车时间较长时,原煤仓、煤粉仓要排空,若因故不能排空,要采取铺加生料粉等防护措施;

停车过程中,不得使磨机出口温度太高;

煤磨停车后,应立即停主排风机,关闭袋收尘入口挡板及风机(主排风机)入口挡板。

阅读理解

Reading comprehension.

     When we walk through the city, we all experience a kind of information overload but we pay attention only

to those that are important to us. We don't stop, we keep our faces expressionless and eyes straight ahead, and

in doing so, we are not just protecting ourselves but are avoiding overloading other people as well.

     We make use of stereotypes (刻板的模式) as convenient ways to make quick judgments about situations

and people around us. They may not always be accurate,and they can often be dangerously wrong, but they

are used regularly.

     The problem with the stereotypes is that they restrict experience. By using limited close to provide us with

a rapid opinion of other people or places we may choose to limit our communication. We may decide not to go

to certain places because we believe they will not offer something we enjoy.

     In the city, styles of dress are particularly important with regard to self-presentation. Different groups often

use clearly identifiable styles of clothes so that they can be easily recognized. It is becoming increasingly

common for brand names to be placed on the outside of clothes, and this labeling makes it easy to send out

information about fashion and price instantly, and lets others tell at a distance whether an individual has similar

tastes and is a suitable person to associate with.

     In England, where social grouping or class continues to make social distinctions (区分), clothes, hairstyles,

people's pronunciation and the manner of speaking are all clues to our social group. Class distinctions tend to

be relatively fixed, although in the city where greater variety is permitted, they are more likely to be secondary

determining factors of friendship and association.

1. People walking in cities ignore the surroundings because _____.

A. they do not wish to talk to other people

B. everyone else is expressionless

C. the environment is already familiar to them

D. there is too much information to take in

2. According to the passage,the main disadvantage of using stereotypes is that they _____.

A. are likely to lead us into dangerous situations

B. may make us miss some pleasant experience

C. can rarely be relied on

D. make us mentally lazy

3. From the passage we may conclude that _____.

A. stereotypes can help to understand people fully

B. people are becoming more interested in fashion

C. dressing can send messages about individuals

D. stereotypes can do more harm than good to people

4. It would appear that in England, a person's class _____.

A. might be less important in making friends in a city

B. is mainly determined by his pronunciation

C. plays less of a role than it did in the past

D. is something that can be changed easily

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