正做-專業(yè)英語(L11)

1、Part Mine Safety LESSON 11 Methods of Dust Control 教學(xué)內(nèi)容教學(xué)內(nèi)容 Introduction VentilationWater spraysDust collectors LESSON 11 Methods of Dust Control 教學(xué)目的教學(xué)目的 要求學(xué)生要求學(xué)生熟記專業(yè)詞匯熟記專業(yè)詞匯，達(dá)到，達(dá)到英文與中文相英文與中文相互熟練翻譯互熟練翻譯的程度的程度aerosol rsl Microflora ,maikrufl:r respiratory resprtri abrasion brein boring extraction lo

2、ngwall shearer aerosol 浮質(zhì)浮質(zhì)(氣體中的懸浮微粒氣體中的懸浮微粒,如煙如煙,霧霧等等)microflora 微植物群微植物群respiratory 呼吸的呼吸的abrasion磨損磨損boring 打眼；鉆進(jìn)；鉆探打眼；鉆進(jìn)；鉆探extraction開采開采longwall長壁開采法長壁開采法shearer（滾筒式）采煤機(jī)（滾筒式）采煤機(jī) 教學(xué)目的教學(xué)目的 深入理解深入理解Ventilation、Water sprays等等內(nèi)容，達(dá)到熟練閱讀和正確、通順地內(nèi)容，達(dá)到熟練閱讀和正確、通順地翻譯的程度；了解翻譯的程度；了解Dust collectors等等內(nèi)容，達(dá)到比較熟練

3、和比較通順翻譯內(nèi)容，達(dá)到比較熟練和比較通順翻譯的程度。的程度。 LESSON 11 Methods of Dust Control 教學(xué)重點(diǎn)、難點(diǎn)教學(xué)重點(diǎn)、難點(diǎn) Ventilation 課時(shí)安排課時(shí)安排 1.5 credit hour授課方法授課方法 講授與討論相結(jié)合講授與討論相結(jié)合LESSON 11 Methods of Dust Control 復(fù)習(xí)舊課復(fù)習(xí)舊課1回憶回憶SHT 、chemisorption（化學(xué)吸附（化學(xué)吸附作用）專業(yè)詞匯的中文含義；氧化作用作用）專業(yè)詞匯的中文含義；氧化作用（oxidation）、采空區(qū)（）、采空區(qū)（goaf or gob）、）、自燃傾向性自燃傾向性su

4、sceptibility to spontaneous combustion英文表達(dá)。英文表達(dá)。2Please describe the primary dangers of concealed fires. (the evolution of carbon monoxide, the ignition of methane and combustion progressing into airways to produce open fires)LESSON 11 Methods of Dust Control The natural atmosphere that we breathe c

5、ontains not only its gaseous constituents but also large numbers of liquid and solid particles. These are known by the generic dinerik name aerosols rsl. They arise from a combination of natural and industrial sources including condensation(,kndensein壓縮；凝結(jié)；冷壓縮；凝結(jié)；冷凝凝) , smokes, volcanic activity, so

6、ils and sands, and microflora. LESSON 11 Methods of Dust Control generic name 通用名通用名 類屬名類屬名 aerosol 浮質(zhì)浮質(zhì)(氣體中的懸浮微粒氣體中的懸浮微粒,如煙如煙,霧霧) microflora 微植物群微植物群 The natural atmosphere that we breathe contains not only its gaseous constituents but also large numbers of liquid and solid particles. These are kno

7、wn by the generic name aerosols. 我們呼吸的自然大氣中，不僅包含氣態(tài)成我們呼吸的自然大氣中，不僅包含氣態(tài)成分，而且還包含大量的液體和固體微粒。分，而且還包含大量的液體和固體微粒。它們統(tǒng)一名稱為懸浮微粒。它們統(tǒng)一名稱為懸浮微粒。They arise from a combination of natural and industrial sources including condensation, smokes, volcanic activity, soils and sands, and microflora. 懸浮微粒的產(chǎn)生有自然方面又有工業(yè)懸浮微粒的產(chǎn)生

8、有自然方面又有工業(yè)方面的原因，這包括：凝結(jié)、煙氣、方面的原因，這包括：凝結(jié)、煙氣、火山活動(dòng)、沙土和微植物群?；鹕交顒?dòng)、沙土和微植物群。Most of the particles are small enough to be invisible to the naked eye. Dust is the term we use in reference to the solid particles. The physiologies of air-breathing creatures have evolved to be able to deal efficiently with most o

9、f the aerosols that occur naturally. LESSON 11 Methods of Dust Control physiology ,fizildi 生理學(xué)生理學(xué) Most of the particles are small enough to be invisible to the naked eye. Dust is the term we use in reference to the solid particles.大部分微粒足夠小，以至于肉眼大部分微粒足夠小，以至于肉眼看不到。我們使用粉塵這個(gè)術(shù)語看不到。我們使用粉塵這個(gè)術(shù)語特指這種固體顆粒。特指這種

10、固體顆粒。The physiologies(,fizildi生理學(xué)生理學(xué),生理機(jī)生理機(jī)能能)of air-breathing creatures have evolved to be able to deal efficiently with most of the aerosols that occur naturally.呼吸空氣的生物的生理機(jī)能已進(jìn)化為能呼吸空氣的生物的生理機(jī)能已進(jìn)化為能夠有效地對(duì)付自然情況下產(chǎn)生的懸浮顆夠有效地對(duì)付自然情況下產(chǎn)生的懸浮顆粒。粒。However, within closed industrial environments, concentrations o

11、f airborne particulates may reach levels that exceed the ability of the human respiratory system to expel them in a timelytaimli manner. In particular, mineral dusts are formed whenever rock is broken by impact, abrasion, crushing, cutting, grinding or explosives. LESSON 11 Methods of Dust Control H

12、owever, within closed industrial environments, concentrations of airborne particulates may reach levels that exceed the ability of the human respiratory system to expel them in a timely manner. 然而，在封閉的工業(yè)環(huán)境內(nèi)，懸浮空然而，在封閉的工業(yè)環(huán)境內(nèi)，懸浮空氣中的微粒濃度可能超過人類呼吸系氣中的微粒濃度可能超過人類呼吸系統(tǒng)能及時(shí)排除它們的程度。統(tǒng)能及時(shí)排除它們的程度。In particular, min

13、eral dusts are formed whenever rock is broken by impact, abrasionbrein , crushing, cutting, grinding raindi or explosives尤其是，只要巖石受撞擊、磨損、破尤其是，只要巖石受撞擊、磨損、破碎、切割、研磨或者爆破碎裂時(shí)，就碎、切割、研磨或者爆破碎裂時(shí)，就能形成礦塵。能形成礦塵。The fragments that are formed are usually irregular in shape. The large total surface area of dust part

14、icles may render(rend致使致使)them more active physically, chemically and biologically than the parent material. This has an important bearing on the ability of certain dusts to produce lungl diseases.LESSON 11 Methods of Dust Control have a bearing on upon 關(guān)系到關(guān)系到., 影響到影響到.render assistance. 給予給予(提供提供)援

15、助援助The fragments that are formed are usually irregular in shape. 形成的碎片通常在形狀上是不規(guī)則形成的碎片通常在形狀上是不規(guī)則的。的。The large total surface area of dust particles may render them more active physically, chemically and biologically than the parent material. 物質(zhì)破碎后形成的塵?？偙砻娣e增大，從物質(zhì)破碎后形成的塵粒總表面積增大，從而在物理、化學(xué)和生物方面活性增強(qiáng)。而在物理、化學(xué)

16、和生物方面活性增強(qiáng)。This has an important bearing on the ability of certain dusts to produce lung diseases.這使某些粉塵能夠引起肺病。這使某些粉塵能夠引起肺病。The three major control methods used to reduce airborne dust in tunnels and underground mines: ventilation, water, and dust collectors.LESSON 11 Methods of Dust Control dust col

17、lector 吸塵器吸塵器dry centrifugalsentrifjul collector 干式離心除塵器干式離心除塵器The three major control methods used to reduce airborne dust in tunnels and underground mines: ventilation, water, and dust collectors.減少隧道內(nèi)和地下礦山中的懸減少隧道內(nèi)和地下礦山中的懸浮粉塵，有三種主要控制方法：浮粉塵，有三種主要控制方法：通風(fēng)、水和集塵器。通風(fēng)、水和集塵器。VentilationVentilation air red

18、uces dust through both dilution and displacement. The dilution mechanism operates when workers are surrounded by a dust cloud and additional air serves to reduce the dust concentration by diluting the cloud. LESSON 11 Methods of Dust Control Ventilation air reduces dust through both dilution and dis

19、placement. 通風(fēng)氣流通過稀釋和置換減少通風(fēng)氣流通過稀釋和置換減少粉塵粉塵The dilution mechanism operates when workers are surrounded by a dust cloud and additional air serves to reduce the dust concentration by dilutinge：dailju:t the cloud.當(dāng)工人處于粉塵云的包圍中，稀釋過程當(dāng)工人處于粉塵云的包圍中，稀釋過程起作用，附加的氣流通過稀釋塵云，減起作用，附加的氣流通過稀釋塵云，減少粉塵的濃度。少粉塵的濃度。The displa

20、cement mechanism operates when workers are upwind of dust sources and the air velocity is high enough to reliably keep the dust downwind.LESSON 11 Methods of Dust Control The displacement mechanism operates when workers are upwind of dust sources and the air velocity is high enough to reliably keep

21、the dust downwind.當(dāng)工人位于塵源的上風(fēng)方向，而且當(dāng)工人位于塵源的上風(fēng)方向，而且氣流速度足夠高，使之能夠可靠地氣流速度足夠高，使之能夠可靠地保持粉塵處在下風(fēng)方向時(shí)，置換過保持粉塵處在下風(fēng)方向時(shí)，置換過程起作用。程起作用。 Dilution Ventilation. The basic principle behind dilution ventilation is to provide more air and dilute the dust. Most of the time the dust is reduced roughly in proportion to the i

22、ncrease in airflow, but not always. The cost of and technical barriers to increased airflow can be substantial, particularly where air already moves through ventilation ductwork or shafts at velocities of 3,000 ft/min or more. Substantial (相當(dāng)相當(dāng))大的大的 ductwork n. 管道系統(tǒng)管道系統(tǒng) LESSON 11 Methods of Dust Con

23、trol 1) Dilution Ventilation. The basic principle behind dilution ventilation is to provide more air and dilute the dust. 1）稀釋通風(fēng)）稀釋通風(fēng) 稀釋通風(fēng)的基本原稀釋通風(fēng)的基本原理是提供更多的空氣來稀釋粉塵。理是提供更多的空氣來稀釋粉塵。Most of the time the dust is reduced roughly in proportion to the increase in airflow, but not always. 大多數(shù)情況下，減少的粉塵與增大多數(shù)

24、情況下，減少的粉塵與增加的風(fēng)量大致成比例，但并不總加的風(fēng)量大致成比例，但并不總是這樣。是這樣。The cost of and technical barriers to increased airflow can be substantial, particularly where air already moves through ventilation ductwork or shafts at velocities of 3,000 ft/min or more.增加風(fēng)量的費(fèi)用和技術(shù)障礙可能是關(guān)鍵，尤其增加風(fēng)量的費(fèi)用和技術(shù)障礙可能是關(guān)鍵，尤其是在流過通風(fēng)管道或井筒的氣流速度已達(dá)到是在流過

25、通風(fēng)管道或井筒的氣流速度已達(dá)到3000英尺英尺/分（分（914.4m/min）以上的礦井，更）以上的礦井，更是如此。是如此。2) Displacement Ventilation. The basic principle behind displacement ventilation is to use the airflow in a way that confinesknfain the dust source and keeps it away from workers by putting dust downwind of the workers. LESSON 11 Methods

26、of Dust Control 2) Displacement Ventilation. 2）置換通風(fēng)）置換通風(fēng)The basic principle behind displacement ventilation is to use the airflow in a way that confines the dust source and keeps it away from workers by putting dust downwind of the workers. 置換通風(fēng)的基本原理是利用風(fēng)流置換通風(fēng)的基本原理是利用風(fēng)流約束塵源，使粉塵處在下風(fēng)位置，約束塵源，使粉塵處在下風(fēng)位置，從

27、而遠(yuǎn)離工人。從而遠(yuǎn)離工人。Every tunnel or mine passage with an airflow direction that puts dust downwind of workers uses displacement ventilation. In mines, continuous miner faces or tunnel boring machines on exhaust ventilation use displacement ventilation. LESSON 11 Methods of Dust Control continuous miner fac

28、es: 連續(xù)采煤機(jī)工作面連續(xù)采煤機(jī)工作面tunnel boring machines: 隧道掘進(jìn)機(jī)隧道掘進(jìn)機(jī)Every tunnel or mine passage with an airflow direction that puts dust downwind of workers uses displacement ventilation.任一隧道或礦山通道中，如風(fēng)流方任一隧道或礦山通道中，如風(fēng)流方向使粉塵處在下風(fēng)方向，使用的就向使粉塵處在下風(fēng)方向，使用的就是置換通風(fēng)。是置換通風(fēng)。In mines, continuous miner faces or tunnel boring mach

29、ines on exhaust ventilation use displacement ventilation. 在礦山中，連續(xù)采煤機(jī)工作面或隧在礦山中，連續(xù)采煤機(jī)工作面或隧道掘進(jìn)機(jī)的回風(fēng)系統(tǒng)，使用的是置道掘進(jìn)機(jī)的回風(fēng)系統(tǒng)，使用的是置換通風(fēng)換通風(fēng)Enclosure of a dust source, such as a conveyor belt transfer point, along with extraction of dusty air from the enclosure, is another example of displacement ventilation. Displ

30、acement ventilation can be hard to implement. LESSON 11 Methods of Dust Control implement vt 貫徹貫徹 執(zhí)行執(zhí)行Enclosure of a dust source, such as a conveyor belt transfer point, along with extraction of dusty air from the enclosure, is another example of displacement ventilation. 在塵源附近，例如運(yùn)輸皮帶轉(zhuǎn)在塵源附近，例如運(yùn)輸皮帶轉(zhuǎn)載

31、點(diǎn)，將塵源連同周圍多塵空載點(diǎn)，將塵源連同周圍多塵空氣一起抽出去，是置換通風(fēng)的氣一起抽出去，是置換通風(fēng)的另一個(gè)例子。另一個(gè)例子。Displacement ventilation can be hard to implement. 置換通風(fēng)很難實(shí)現(xiàn)置換通風(fēng)很難實(shí)現(xiàn)However, if done well, it is the most effective dust control technique available, and it is worth considerable effort to get it right. The difficulty is that when workers

32、 are near a dust source, say, 10 to 20 ft from the source, keeping them upwind requires a substantial air velocity, typically between 60 and 150 ft/min. There is not always enough air available to achieve these velocities.LESSON 11 Methods of Dust Control However, if done well, it is the most effect

33、ive dust control technique available, and it is worth considerable effort to get it right. 然而，如果做得好，置換通風(fēng)是能利用的然而，如果做得好，置換通風(fēng)是能利用的最有效的粉塵控制技術(shù)，值得付出大量的最有效的粉塵控制技術(shù)，值得付出大量的努力，使其運(yùn)行良好。努力，使其運(yùn)行良好。The difficulty is that when workers are near a dust source, say, 10 to 20 ft from the source, keeping them upwind req

34、uires a substantial air velocity, typically between 60 and 150 ft/min. 困難之處在于：當(dāng)工人處在塵源附近困難之處在于：當(dāng)工人處在塵源附近時(shí)，比方說時(shí)，比方說1020英尺，使他們位于英尺，使他們位于上風(fēng)處需要相當(dāng)大的風(fēng)速（一般要上風(fēng)處需要相當(dāng)大的風(fēng)速（一般要60150英尺英尺/分）。分）。There is not always enough air available to achieve these velocities.并不總有足夠的風(fēng)量能達(dá)到這么大的風(fēng)并不總有足夠的風(fēng)量能達(dá)到這么大的風(fēng)速。速。Water spraysTh

35、e role of water sprays in mining is a dualdju:l one: (1) wetting of the broken material being transported and (2) airborne capture. Of the two, wetting of the broken material is far more effective.LESSON 11 Methods of Dust Control The role of water sprays in mining is a dual one: (1) wetting of the

36、broken material being transported and (2) airborne capture. Of the two, wetting of the broken material is far more effective.開采中噴水的作用是雙重的：（開采中噴水的作用是雙重的：（1）濕）濕潤正被運(yùn)輸?shù)姆鬯榈奈镔|(zhì)；（潤正被運(yùn)輸?shù)姆鬯榈奈镔|(zhì)；（2）空中）空中捕獲。這兩個(gè)作用中，濕潤粉碎物質(zhì)捕獲。這兩個(gè)作用中，濕潤粉碎物質(zhì)更加有效。更加有效。Adequate wetting is extremely important for dust control. The vast

37、majority of dust particles created during breakage are not released into the air, but stay attached to the surface of the broken material. Wetting this broken material ensures that the dust particles stay attached. LESSON 11 Methods of Dust Control Adequate wetting is extremely important for dust co

38、ntrol. The vast majority of dust particles created during breakage are not released into the air, but stay attached to the surface of the broken material. 適度的濕潤對(duì)于粉塵控制非常重要。在粉適度的濕潤對(duì)于粉塵控制非常重要。在粉碎過程中產(chǎn)生的粉塵顆粒大部分沒有釋放碎過程中產(chǎn)生的粉塵顆粒大部分沒有釋放到空氣中，而是附著在粉碎物的表面。到空氣中，而是附著在粉碎物的表面。Wetting this broken material ensures th

39、at the dust particles stay attached. 濕潤破碎物能夠確保粉塵顆粒保持附著濕潤破碎物能夠確保粉塵顆粒保持附著狀態(tài)。狀態(tài)。As a result, adding more water can usually (but not always) be counted on to reduce dust. For example, coal mine operators have been able to reduce the dust from higher longwall production levels by raising the shearer wate

40、r flow rate to an average of 100gpm. LESSON 11 Methods of Dust Control As a result, adding more water can usually (but not always) be counted on to reduce dust. 因此，通常加水越多越能降因此，通常加水越多越能降低粉塵（但并不總是如此）。低粉塵（但并不總是如此）。For example, coal mine operators have been able to reduce the dust from higher longwall p

41、roduction levels by raising the shearer water flow rate to an average of 100gpm例如，煤礦經(jīng)營員已能夠通過提高例如，煤礦經(jīng)營員已能夠通過提高（滾筒式）采煤機(jī)的水流速度平均達(dá)（滾筒式）采煤機(jī)的水流速度平均達(dá)到到100 gpm (每分鐘每分鐘100加侖加侖)，來減，來減少生產(chǎn)水平較高的長壁開采工作面的少生產(chǎn)水平較高的長壁開采工作面的粉塵。粉塵。Compared to the amount of coal mined, on a weight basis, this 100gpm is equivalent to 1.9%

42、 added moisture from the shearer alone. Unfortunately, excessive moisture levels can also result in a host of materials handling problems, operational headaches, and product quality issues, so an upper limit on water use is sometimes reached rather quickly. LESSON 11 Methods of Dust Control Compared

43、 to the amount of coal mined, on a weight basis, this 100gpm is equivalent to 1.9% added moisture from the shearer alone. 與開采煤的數(shù)量相比，以重量為基礎(chǔ)，由與開采煤的數(shù)量相比，以重量為基礎(chǔ)，由采煤機(jī)每分鐘單獨(dú)加入的采煤機(jī)每分鐘單獨(dú)加入的100加侖水分等于加侖水分等于開采煤量的開采煤量的1.9%。Unfortunately, excessive moisture levels can also result in a host of materials handling p

44、roblems, operational headaches, and product quality issues, so an upper limit on water use is sometimes reached rather quickly. 可惜的是，過高的水分也能導(dǎo)致許多材料可惜的是，過高的水分也能導(dǎo)致許多材料的處理問題、操作上的不便和產(chǎn)品質(zhì)量問的處理問題、操作上的不便和產(chǎn)品質(zhì)量問題，所以，用水的上限有時(shí)能很快達(dá)到。題，所以，用水的上限有時(shí)能很快達(dá)到。As a result, an alternative to simply adding more water is to en

45、sure that the broken material is being wetted uniformly.LESSON 11 Methods of Dust Control As a result, an alternative to simply adding more water is to ensure that the broken material is being wetted uniformly.因而，確保粉碎的物質(zhì)能夠得到均因而，確保粉碎的物質(zhì)能夠得到均勻加濕是替代僅靠增加水量降塵的勻加濕是替代僅靠增加水量降塵的另一種方法。另一種方法。Under actual minin

46、g conditions, the typical water spray operating at 100 psi and 1-2 gpm gives no more than 30% airborne capture of respirable dust. This is not as good as lab tests would lead one to believe. In lab tests, sprays were usually confined in a duct, and all of the dust was forced to pass through the spra

47、y. LESSON 11 Methods of Dust Control psi:Pounds per Square Inch. 磅磅/平方英尺平方英尺gpm: Gallons Per Minute Under actual mining conditions, the typical water spray operating at 100 psi（pounds per square inch）and 1-2 gpm gives no more than 30% airborne capture of respirable dust.This is not as good as lab te

48、sts would lead one to believe. In lab tests, sprays were usually confined in a duct, and all of the dust was forced to pass through the spray. 這并不與實(shí)驗(yàn)室試驗(yàn)的結(jié)果完全一樣。這并不與實(shí)驗(yàn)室試驗(yàn)的結(jié)果完全一樣。在實(shí)際開采條件下，以在實(shí)際開采條件下，以100psi和和1-2gpm實(shí)施典型的水噴霧，最多能捕獲實(shí)施典型的水噴霧，最多能捕獲30%的風(fēng)載可吸入粉塵。的風(fēng)載可吸入粉塵。在實(shí)驗(yàn)室的試驗(yàn)中，水噴霧通常限定在管在實(shí)驗(yàn)室的試驗(yàn)中，水噴霧通常限定在管道中，所

49、有的道中，所有的 粉塵被迫穿過水噴霧。粉塵被迫穿過水噴霧。However, under actual mining conditions, dust clouds are unconfined. In all sprays, the moving droplets exert iz:t dragdr on the adjacent (deisnt鄰鄰近的近的) air; thus, sprays act to move the air. Because of this air entrainment effect, if a spray is aimed at an unconfined du

50、st cloud, it will carry in air that spreads the cloud, thus making capture by the spray less efficient. LESSON 11 Methods of Dust Control Entrainment n. 帶走帶走,夾帶夾帶 However, under actual mining conditions, dust clouds are unconfined. In all sprays, the moving droplets exert drag on the adjacent air; t

51、hus, sprays act to move the air. Because of this air entrainment effect, if a spray is aimed at an unconfined dust cloud, it will carry(被攜帶被攜帶) in air that spreads the cloud, thus making capture by the spray less efficient. Attempts to improve the airborne capture efficiency of sprays have not met w

52、ith practical success. One approach has been to reduce droplet size, based on the notion that capture by smaller droplets is more efficient.LESSON 11 Methods of Dust Control Notionnun n.概念概念, 觀念觀念, 想法想法, 意見意見, 打算打算, Attempts to improve the airborne capture efficiency of sprays have not met with prac

53、tical success.One approach has been to reduce droplet size, based on the notion that capture by smaller droplets is more efficient.Dust collectorsDust collectors can play a valuable role in dust reductionif space is available to locate the collector and if the collector efficiency is high. Dust coll

54、ectors range from low-volume filtration filtrein systems used in the cabs kb of mining equipment to high-volume wet collectors used on continuous miners in coal mines.LESSON 11 Methods of Dust Control Dust collectors can play a valuable role in dust reductionif space is available to locate the colle

55、ctor and if the collector efficiency is high. Dust collectors range from low-volume filtration systems used in the cabs of mining equipment to high-volume wet collectors used on continuous miners in coal mines.It is important to recognize that the efficiency of a dust collector is the filtration eff

56、iciency of the unit times the capture efficiency of its inlet inlet . For collectors properly designed to trap respirable dust, the filtration efficiency is usually quite high, in the 90%-95% range. LESSON 11 Methods of Dust Control It is important to recognize that the efficiency of a dust collector is the filtration efficiency of