|
Introduction to Mine Ventilation
[教学内容
Introduction、Purposes of Mine Ventilation、Historical Development、Properties of Air [教学目的] 通过该部分学习，要求学生熟记 Mine ventilation、dilute、contaminant、exhaust shaft、colliery、trapper 、moisture content等专业词汇，达到英文与中文相互熟练翻译的程度；深入理解Purposes of Mine Ventilation、Properties of Air等内容，达到熟练阅读和正确、通顺地翻译的程度；了解Historical Development等内容，达到比较熟练和比较通顺翻译的程度。 [教学重点、难点] purposes of Mine Ventilation、Properties of Air [课时安排] 1 [授课方法] 讲授与讨论相结合 Introduction Mine ventilation involves the control of the atmospheric
environment. This requires control of the air quality and air
movement to satisfy the requirements for the health, safety and
comfort of mine workers. Minimum standards are set out in the
various states mines regulation. Some are descriptive,
specifying the standards required (eg. Victoria), and some are
prescriptive, detailing exactly how the standards are to be
achieved (eg. W.A.). set out To lay out systematically and graphically: 生动形象地摆出： set out a terrace. 画出地形 Purposes of Mine Ventilation Properly engineered control of the mine atmosphere is required to: ·provide fresh air (oxygen) for men to breathe ·provide a source of oxygen for internal combustion engines in machinery ·dilute atmospheric contaminants to acceptable levels ·maintain temperature and humidity within acceptable limits ·remove atmospheric contaminants from the mine. engineer vt 设计 The road is very well engineered. 这条路设计得很好。 策划 His enemies engineered his ruin. 敌人图谋毁灭他。 The minister's enemies engineered his ruin. 部长的敌人密谋陷害他。 Historical Development
Mine ventilation is twofold in purpose: first, it maintains life, and secondly it carries off dangerous gases. The historic role of ventilation was to provide a flow of fresh air sufficient to replace the oxygen consumed by the miners working underground. 注：Historic和 historical尽管在意义上有重叠的地方，但用法上有区别。 Historic指历史上有重要意义的：the historic first voyage to outer space而且也用于形容那些因与历史事件或人物有联系而有名或有趣的事物：a historic house. Historical是指不管重要与否而在过去存在的所有事物：a historical character. Historical也指与历史或对过去的研究有关的事物：a historical novel; 但这两个词并不是截然不同的。它们经常可换用。 historic adj.历史上著名的, 有历史性的 historical adj.历史(上)的, 有关历史的 Today's mine ventilation primarily deals with noxious gases (mainly generated by trackless equipment underground). In the past, mining occurred near the surface where natural light and ventilation was available. Fires were used to draw fresh air into the mine and exhaust shafts vented the hot smoke out of the mine. Long before coal was mined in North America,
collieries in Europe were sunk with dual entrances; one through which air flowed into the mine and another through which air flowed out. Initially, mine ventilation was assisted by underground furnaces, which used the practical principle that the updraft of a fire caused a suction which drew air out of the mine and this air was replaced by air which was pulled in to fill the opening. 注：colliery (包括建筑， 设备在内的)煤矿 Canaries are said to have been used to detect gas in coal mines in the early stages of coal mining. This sensitive bird would be taken into the workings and, if it perished, the colliers would immediately leave the mine. 在煤矿开采的早期，人们已用金丝雀来检测瓦斯。这种敏感的鸟带到工作地点，如果发现它死亡了，矿工将立即离开矿井。 file:///C:/Users/cheng/AppData/Local/Temp/ksohtml/wps_clip_image-19564.pngfile:///C:/Users/cheng/AppData/Local/Temp/ksohtml/wps_clip_image-15005.png file:///C:/Users/cheng/AppData/Local/Temp/ksohtml/wps_clip_image-22636.pngfile:///C:/Users/cheng/AppData/Local/Temp/ksohtml/wps_clip_image-3209.png However, before the 1870s, managers and qualified persons were using safety lamps to detect gas. These safety lamps soon replaced oil lamps and open flared candles as a source of working light. Soon, small hand-turned fans were used to blow out gas from working places into main air currents. Trap doors were strategically placed as part of the ventilation system to guide the flow of air to or from selected areas. "Trapper" boys were posted at the busier doors to open them for the passage of coal, materials and men. "Air courses" were frequently cut through coal and rock. In the 1920s the hand-turned fans were replaced with air-powered small turbine fans. Large fans of the suction type were placed on the surface and gradually increased in size. Air from surface compressors was piped into the mine to power machinery and to assist in ventilation. Properties of Air The constituents of air are: | | | | | | | | | | | | Rare Gases (Ar, H2, He, etc.) | | |
Atmospheric Pressure at any point is due to the weight of air
above it, and varies with altitude (which determines the height
of the air column), and air density (which is determined by
temperature and moisture content). Standard atmospheric
pressure is taken as 760mm of Hg, (101.3kPa) at mean sea
level, and it varies by about lkPa for every 90 m increase or
decrease in altitude. Atmospheric temperature is normally given according to the
Celsius scale (°C), but the Kelvin scale (°K) may be used. | | | | | | | (freezing point of water) | | | | |
Air is a colorless,
odorless, tasteless gas mixture which
supports combustion and life. In mine ventilation we are
usually dealing with an air/water vapor mixture which has
different thermodynamic properties to dry air. The density of
dry air is 1.21 kg/m³ at standard atmospheric pressure (101.3kPa) and temperature (15°C). New Words and Expressions Mine ventilation 矿山通风 internal combustion engine 内燃机 dilute冲淡, 变淡, 变弱, 稀释 contaminant 污染物 noxious 有害的 exhaust shaft 出风井 colliery 煤矿 sink 挖掘 suction 吸入, 吸力, 抽气, 抽气机, 抽水泵, 吸引 canary [动金丝雀, 淡黄色 trap door 通风门 trapper设阱捕兽者, [矿矿井风门开关管理 moisture content 湿度 thermodynamic
adj.热力学的, 使用热动力的
| 
雷达卡
发表于 2011-4-3 09:22
提升卡
沉默卡
喧嚣卡
变色卡
抢沙发
显身卡
