专业英语(L7-8)

1、Part Mine Safety LESSON 7 Mine Gases教学内容教学内容 IntroductionGeneral properties of gasesGas accumulation and stratificationGases derived from combustion processesGases from explosivesNatural occurrences of gases 教学目的教学目的 要求要求熟记专业词汇熟记专业词汇propane prupein carbon dioxide Stratification Buoyancybinsi Turbule

2、nce Hydrocarbon LESSON 7 Mine Gases丙烷丙烷carbon dioxide二氧化碳二氧化碳分层分层Buoyancy浮力浮力Turbulence湍流湍流Hydrocarbon 碳氢化合物（烃类）碳氢化合物（烃类）propane Stratification 教学目的教学目的 深入理解深入理解introduction、General properties of gases等内容，达到熟等内容，达到熟练阅读和正确、通顺地翻译的程度；练阅读和正确、通顺地翻译的程度；了解了解Gases derived from combustion processes、Gases fro

3、m explosives、Natural occurrences of gases等内容，达到熟等内容，达到熟练阅读和正确、通顺地翻译的程度练阅读和正确、通顺地翻译的程度LESSON 7 Mine Gases教学重点、难点教学重点、难点 General properties of gases 课时安排课时安排 1 credit hour授课方法授课方法 讲授与讨论相结合讲授与讨论相结合LESSON 7 Mine Gases复习旧课复习旧课1回忆回忆junction、barometric、NVP(NVE)专业词汇的中文含义；质量专业词汇的中文含义；质量流量、体积流量的英文表达。流量、体积流量的英

4、文表达。2Please describe Kirchhoffs first law and the Kirchhoffs laws applied in ventilation network in English.LESSON 7 Mine Gases The mass flow entering a junction equals the mass flow leaving that junction; The simplest statement of Kirchhoffs second law applied to ventilation networks is that the al

5、gebraic sum of all pressure drops around a closed path, or mesh, in the network must be zero, having taken into account the effects of fans and ventilating pressures.LESSON 7 Mine Gasesthe mass flow entering a junction equals the mass flow leaving that junction;Kirchhoffs second law applied to venti

6、lation networks is that the algebraic sum of all pressure drops around a closed path, or mesh, in the network must be zero, having taken into account the effects of fans and ventilating pressures.IntroductionIt is generally assumed when referring to gases in the mining environment that the interest

7、is in toxic gases, however, the concentration of nontoxic gases, such as oxygen, can be of importance. LESSON 7 Mine GasesIt is generally assumed when referring to gases in the mining environment that the interest is in toxic gases, however, the concentration of nontoxic gases, such as oxygen, can b

8、e of importance. 一提到矿山环境中的气体，人们一般一提到矿山环境中的气体，人们一般多会关心有毒气体。然而，无毒气体多会关心有毒气体。然而，无毒气体的浓度（例如氧气的浓度）也很重要。的浓度（例如氧气的浓度）也很重要。 Gases in the mine environment come from different sources. The major concern about most gases is their toxicity to workers.If the concentration of and exposure time to a gas are suffic

9、ient, illness or death may result. LESSON 7 Mine Gasestoxicity n.毒性毒性toxin n.生化生化生生毒素毒素Gases in the mine environment come from different sources. The major concern about most gases is their toxicity to workers.矿山中的气体来源很多。人们对大多矿山中的气体来源很多。人们对大多数气体主要关注的是它们对工人产生数气体主要关注的是它们对工人产生的毒性。的毒性。If the concentrati

10、on of and exposure time to a gas are sufficient, illness or death may result.如果某种气体的浓度足够大如果某种气体的浓度足够大，人们暴人们暴露在该气体中的时间足露在该气体中的时间足够够长，长，(多分支多分支共干结构共干结构)就可能导致疾病或者死亡。就可能导致疾病或者死亡。toxicity n.毒性毒性toxin n.生化生化生生毒素毒素 During an emergency when a toxic gas or gases are released into the workplace, the concentra

11、tion of the toxins can exceed normal workplace standards. This situation may pose a short-term or acute risk because of the increased toxicity of the higher concentration. As well, the reduction of oxygen in the air may also pose a risk to life because oxygen is needed to sustain life.LESSON 7 Mine

12、GasesDuring an emergency when a toxic gas or gases are released into the workplace, the concentration of the toxins can exceed normal workplace standards. 当某种或几种有毒气体释放到工作场所当某种或几种有毒气体释放到工作场所这种突发事件发生时，毒素的浓度可能这种突发事件发生时，毒素的浓度可能会超过工作场所的正常标准。会超过工作场所的正常标准。This situation may pose a short-term or acute risk

13、because of the increased toxicity of the higher concentration. 这种情况可能造成短期的或严重的危险，这种情况可能造成短期的或严重的危险，因为高浓度的有毒气体增加了毒性。因为高浓度的有毒气体增加了毒性。As well, the reduction of oxygen in the air may also pose a risk to life because oxygen is needed to sustain life.同时，空气中氧气的减少对生命也形成了同时，空气中氧气的减少对生命也形成了危险，因为氧气是维持生命所必须的。危险

14、，因为氧气是维持生命所必须的。 General properties of gasesThe term gas refers to the physical state of a substance at room temperature and normal atmospheric pressure that, when unconfined, expands to fill the space it occupies. At reduced temperatures or high pressures, a gaseous substance can exist in a differen

15、t physical state. Examples include the liquid propane gas (LPG) and the solid dry ice that, at room temperature would be gaseous propane and carbon dioxide.LESSON 7 Mine GasesThe term gas refers to the physical state of a substance at room temperature and normal atmospheric pressure that, when uncon

16、fined, expands to fill the space it occupies. 气体这一术语指的是某物质在室温和标气体这一术语指的是某物质在室温和标准大气压力下的物理状态，当不受约束准大气压力下的物理状态，当不受约束时，气体能够膨胀，充满它所占的空间。时，气体能够膨胀，充满它所占的空间。At reduced temperatures or high pressures, a gaseous substance can exist in a different physical state. 当温度降低时或者高压下，气态物质能当温度降低时或者高压下，气态物质能够以不同的物理状态存在。

17、够以不同的物理状态存在。Examples include the liquid propane gas (LPG) and the solid dry ice that, at room temperature would be gaseous propane and carbon dioxide.例如液态丙烷和固态干冰在室温下将变成例如液态丙烷和固态干冰在室温下将变成气态丙烷和二氧化碳。气态丙烷和二氧化碳。 Traditionally, mine rescue teaching about gas properties focused on the density of pure gases

18、. However, gases in a workplace in emergency situations are often not pure, but are mixed with air and other gases. Pure gases seldom exist in the workplace. When they do, it is likely that the gas was released from a pressurized vessel discharging uncontrollably. LESSON 7 Mine GasesTraditionally, m

19、ine rescue teaching about gas properties focused on the density of pure gases. 传统上讲，矿山救护在讲授气体性质时传统上讲，矿山救护在讲授气体性质时一般指的是纯气体的浓度。一般指的是纯气体的浓度。However, gases in a workplace in emergency situations are often not pure, but are mixed with air and other gases. Pure gases seldom exist in the workplace. 然而，在突发事

20、件下进入工作地点的气体然而，在突发事件下进入工作地点的气体通常不纯，而是混入了空气和其它气体。通常不纯，而是混入了空气和其它气体。纯净的气体很少在工作场所存在。纯净的气体很少在工作场所存在。When they do, it is likely that the gas was released from a pressurized vessel discharging uncontrollably. 当确实存在时，这种气体很可当确实存在时，这种气体很可能是承压容器失控卸压时释放能是承压容器失控卸压时释放出来的出来的 Even a leak of pure, pressurized gas wi

21、ll not perform like a pure gas as the distance from the leaking vessel and turbulence increases. Eventually, the leaking gas will mix with the surrounding air as it moves away from the source of the leak. LESSON 7 Mine GasesEven a leak of pure, pressurized gas will not perform like a pure gas as the

22、 distance from the leaking vessel and turbulence increases.即使是纯净承压气体的泄漏，随着离即使是纯净承压气体的泄漏，随着离泄漏容器的距离增加，湍流（紊流）泄漏容器的距离增加，湍流（紊流）增强，其行为也不会象纯净的气体那增强，其行为也不会象纯净的气体那样。样。Eventually, the leaking gas will mix with the surrounding air as it moves away from the source of the leak. 最终，当泄漏气体远离泄露地点最终，当泄漏气体远离泄露地点时，它将与

23、周围的空气相混合。时，它将与周围的空气相混合。 Stratification of gases does occur where the gas mixture has a significant difference in density from the surrounding air. A good example is the gases produced during a fire. Because of the heat of combustion, the gases that are released from burning material are hot and less

24、 dense than air at normal conditions. As a result, combustion gases generally rise. LESSON 7 Mine GasesStratification of gases does occur where the gas mixture has a significant difference in density from the surrounding air. 气体分层现象发生在气体混合物的密气体分层现象发生在气体混合物的密度与周围空气的密度有显著差别的地度与周围空气的密度有显著差别的地方方A good e

25、xample is the gases produced during a fire. Because of the heat of combustion, the gases that are released from burning material are hot and less dense than air at normal conditions. As a result, combustion gases generally rise. 一个很好的例子就是在火灾期间产生的气体。一个很好的例子就是在火灾期间产生的气体。由于燃烧产生热，所以从燃烧物质释放的气由于燃烧产生热，所以从燃

26、烧物质释放的气体是灼热的，其密度比标准状态下空气的密体是灼热的，其密度比标准状态下空气的密度小。因此，燃烧气体一般会上升。度小。因此，燃烧气体一般会上升。 This mass of hot gas, or package, has a diffuse boundary and is lighter than the surrounding air. The fact that heated gas responds as an unconfined mass is readily visible from chimney smoke in cooler weather. LESSON 7 Mi

27、ne GasesThis mass of hot gas, or package, has a diffuse boundary and is lighter than the surrounding air. 这种热空气团或束有一个扩这种热空气团或束有一个扩散边界，比周围的空气轻。散边界，比周围的空气轻。The fact that heated gas responds as an unconfined mass is readily visible from chimney smoke in cooler weather. 在寒冷气候下，从烟囱冒出的烟中可在寒冷气候下，从烟囱冒出的烟中可以

28、很容易观察到热空气形成不受约束以很容易观察到热空气形成不受约束的气团这一事实。的气团这一事实。 The smoke has buoyancy and rises until the package of gas has mixed and cooled to the same point as the surrounding air. Because of turbulence and diffusion, the package of gas is diluted to the point where it differs little from air alone. LESSON 7 Mi

29、ne GasesThe smoke has buoyancy and rises until the package of gas has mixed and cooled to the same point as the surrounding air.烟具有浮力，一直上升直到和周围空烟具有浮力，一直上升直到和周围空气混合，并且冷却到和空气同样的温气混合，并且冷却到和空气同样的温度。度。 Because of turbulence and diffusion, the package of gas is diluted to the point where it differs little

30、 from air alone. 由于湍流和扩散作用，气体束被稀释到由于湍流和扩散作用，气体束被稀释到和空气自身差别很小。和空气自身差别很小。 There are other physical properties of gases, such as taste, colour, and odour, that may or may not be helpful as warning properties. For example, the property of colour is often best observed with pure gases. Workers may or may

31、 not be able to smell a gas (depending on its concentration). LESSON 7 Mine GasesThere are other physical properties of gases, such as taste, colour, and odour, that may or may not be helpful as warning properties.气体还有一些其他物理性质，气体还有一些其他物理性质，例如味道、颜色、气味。这些例如味道、颜色、气味。这些性质作为预兆特性可能有用，性质作为预兆特性可能有用，也可能无用。也可

32、能无用。例如颜色特性对于纯净气体最易观察例如颜色特性对于纯净气体最易观察到。工人是否能闻到一种气体，取决到。工人是否能闻到一种气体，取决于该气体的浓度。于该气体的浓度。For example, the property of colour is often best observed with pure gases. Workers may or may not be able to smell a gas (depending on its concentration). Therefore, in an emergency, these properties may serve littl

33、e purpose in understanding the toxic nature of a gas when it has been mixed with mine air.LESSON 7 Mine Gases Therefore, in an emergency, these properties may serve little purpose in understanding the toxic nature of a gas when it has been mixed with mine air.因此，在紧急情况下，当一种气体与矿因此，在紧急情况下，当一种气体与矿山空气混合后

34、，物理性质很少被用来了山空气混合后，物理性质很少被用来了解气体的毒性。解气体的毒性。 Gas accumulation and stratification瓦斯积聚和分层瓦斯积聚和分层Gases can collect in pockets separate from the rest of the mine air. This is especially true where mines lack adequate ventilation. Hot gases from a fire will rise to the back and remain there until the smoke

35、 has time to cool and mix with the air. LESSON 7 Mine GasesThis is especially true where mines lack adequate ventilation.Hot gases from a fire will rise to the back and remain there until the smoke has time to cool and mix with the air. Gases can collect in pockets separate from the rest of the mine

36、 air. Therefore, expect the smoke near a fire to be denser at the back. The smoke will be more uniformly distributed in a drift once it moves away from the fire and is mixed with the mine air by ventilation flows and turbulence.LESSON 7 Mine GasesTherefore, expect the smoke near a fire to be denser

37、at the back. The smoke will be more uniformly distributed in a driftonce it moves away from the fire and is mixed with the mine air by ventilation flows and turbulence. A second example of gas stratification is the distribution of methane in a coal mine. Pure methane has a relative density about one

38、-half that of air and can be produced in massive quantities in an underground coal mine. LESSON 7 Mine GasesA second example of gas stratification is the distribution of methane in a coal mine.Pure methane has a relative density about one-half that of air and can be produced in massive quantities in

39、 an underground coal mine. Such large amounts of methane will physically displace the other mine air. Because of its low density, there may be pockets of methane that will tend to accumulate near the back.LESSON 7 Mine GasesSuch large amounts of methane will physically displace the other mine air. B

40、ecause of its low density, there may be pockets of methane that will tend to accumulate near the back. Small differences between the density of a gas and of air will not cause stratification. For example, oxygen is ten percent more dense than air. However, the oxygen will not be more concentrated ne

41、ar the floor in a room or a stope. It remains thoroughly mixed with the rest of the mine air.LESSON 7 Mine Gasesstope .采矿场采矿场 v.在采矿场采矿在采矿场采矿Small differences between the density of a gas and of air will not cause stratification. For example, oxygen is ten percent more dense than air. However, the ox

42、ygen will not be more concentrated near the floor in a room or a stope.It remains thoroughly mixed with the rest of the mine air.stope .采矿场采矿场 v.在采矿场采矿在采矿场采矿 Gases derived from combustion processesBurning organic material and hydrocarbon fuel results in the formation of carbon monoxide and carbon di

43、oxide. Generally, carbon dioxide (CO2) is produced in larger quantities while carbon monoxide(CO) is produced in smaller amounts where combustion is not 100 percent efficient.LESSON 7 Mine GasesGases derived from combustion processes来自燃烧过程的气体来自燃烧过程的气体Burning organic material and hydrocarbon fuel res

44、ults in the formation of carbon monoxide and carbon dioxide. 燃烧有机物质和烃类燃料生成一燃烧有机物质和烃类燃料生成一氧化碳和二氧化碳。氧化碳和二氧化碳。Generally, carbon dioxide (CO2) is produced in larger quantities while carbon monoxide(CO) is produced in smaller amounts where combustion is not 100 percent efficient.一般来说，二氧化碳生成量较多，而当一般来说，二氧化

45、碳生成量较多，而当燃烧不充分时，产生少量的一氧化碳。燃烧不充分时，产生少量的一氧化碳。 Nitrogen dioxide (NO2) and other oxides of nitrogen, sulphur dioxide (SO2), hydrogen cyanide (HCN) and phosgene (COCI2) may be produced by combustion. Burning various plastic or synthetic materials will result in some production of these gases. LESSON 7 Mi

46、ne Gasescyanidesai,naid n.化化氰化物氰化物Nitrogen dioxide (NO2) and other oxides of nitrogen, sulphur dioxide (SO2), hydrogen cyanide (HCN) and phosgene (COCI2) may be produced by combustion.燃烧可能产生燃烧可能产生NO2和其他氮类氧化物、和其他氮类氧化物、SO2、氰化氢、碳酰氯。、氰化氢、碳酰氯。Burning various plastic or synthetic materials will result in

47、some production of these gases. 燃烧各种各样的塑料和合成物质会燃烧各种各样的塑料和合成物质会产生这些气体。产生这些气体。Phosgene n.化化光气光气, 碳酰氯碳酰氯 Phosgenefzdi:n （carbon oxychloride ksikl:raid） n.化化光气光气, 碳酰氯碳酰氯 cyanide n.化化氰化物氰化物 Base metal mines, such as those that produce copper or zinc, get the metals from sulfide ores. In cases where sulph

48、ide ore catches fire after a production blast, a large quantity of sulphur dioxide will be produced.LESSON 7 Mine Gasesbase metal n.冶冶贱金属贱金属Base metal mines, such as those that produce copper or zinc, get the metals from sulfide ores.贱金属矿山，例如生产铜和锌的矿贱金属矿山，例如生产铜和锌的矿山，从硫化物矿石中获取金属。山，从硫化物矿石中获取金属。In cases

49、 where sulphide ore catches fire after a production blast, a large quantity of sulphur dioxide will be produced.当生产爆破后，硫化物矿石着火时，会当生产爆破后，硫化物矿石着火时，会产生大量的二氧化硫。产生大量的二氧化硫。base metal n.冶冶贱金属贱金属 Gases from explosives来自爆炸的气体来自爆炸的气体The detonation detnein of commercial explosives creates the same gases found

50、from burning fuel. The presence of carbon and nitrogen in commercial explosives makes it likely that carbon monoxidemnksaid , carbon dioxide and nitrogen oxides will be produced from a blastblst .LESSON 7 Mine GasesThe detonation of commercial explosives creates the same gases found from burning fue

51、l. 商用炸药爆炸时，产生的气体和商用炸药爆炸时，产生的气体和燃料燃烧时产生的气体相同。燃料燃烧时产生的气体相同。The presence of carbon and nitrogen in commercial explosives makes it likely that carbon monoxide, carbon dioxide and nitrogen oxides will be produced from a blast.商用炸药中存有碳和氮，这就很可能在爆商用炸药中存有碳和氮，这就很可能在爆炸时产生炸时产生CO、CO2和氧化氮。和氧化氮。 Natural occurrence

52、s of gasesHydrogen sulfide (H2S): Hydrogen sulfide in the mining environment is derived from water. The hydrogen sulfide dissolved in the water originates from bacterial decomposition of solublesljubl sulfate in the water. LESSON 7 Mine Gasessulfateslfeit n.化化 硫酸盐硫酸盐v.以硫酸或硫酸盐处理以硫酸或硫酸盐处理, 使使变为硫酸盐变为硫酸

53、盐sulfaten.化化 硫酸盐硫酸盐v.以硫酸或硫酸盐处以硫酸或硫酸盐处理理, 使变为硫酸盐使变为硫酸盐Natural occurrences of gasesHydrogen sulfide (H2S): Hydrogen sulfide in the mining environment is derived from water.The hydrogen sulfide dissolved in the water originates from bacterial decomposition of soluble sulfate in the water. Once the wate

54、r enters the mine, hydrogen sulfide is released into the mine air in the absence of hydrostatic pressure. The solubility of hydrogen sulfide in water is relatively low at mine atmospheric pressures.LESSON 7 Mine GasesOnce the water enters the mine, hydrogen sulfide is released into the mine air in t

55、he absence of hydrostatic pressure. The solubility of hydrogen sulfide in water is relatively low at mine atmospheric pressures. When the water inflow area has restricted ventilation, hydrogen sulfide will build up in the area of the inflow. Levels of 100 ppm（parts per million）are rare in unventilat

56、ed cavernskvn with water inflows. Although 100 ppm is not an immediately lethalli:lconcentration, extended and unprotected exposure beyond one-half hour can lead to unconsciousnessnknsnis and, ultimately, death.LESSON 7 Mine GasesWhen the water inflow area has restricted ventilation, hydrogen sulfid

57、e will build up in the area of the inflow. Levels of 100 ppm are rare in unventilated caverns with water inflows. Although 100 ppm is not an immediately lethal concentration, extended and unprotected exposure beyond one-half hour can lead to unconsciousness and, ultimately, death. Decomposition of o

58、rganic material such as sewagesju:id can lead to the formation of hydrogen sulfide if sulphur compounds are in the decaying material. Water wells with intakes at the bottom of the reservoir have brought hydrogen sulfide into the pump house with deadly results for workers.LESSON 7 Mine Gases Decompos

59、ition of organic material such as sewage can lead to the formation of hydrogen sulfide if sulphur compounds are in the decaying material. Water wells with intakes at the bottom of the reservoir have brought hydrogen sulfide into the pump house with deadly results for workers. Carbon dioxide (C02 ):

60、Carbon dioxide is a natural metabolite produced in the human body and exhaledeksheil in the respiratoryresprtri process. In sufficient concentration, naturally exhaled carbon dioxide is hazardous. LESSON 7 Mine GasesMetabolite mitblait n. 代谢物代谢物Carbon dioxide (C02 ): Carbon dioxide is a natural meta