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1、<p><b>  英文原文</b></p><p>  MINE FIRE</p><p>  1. Introduction</p><p>  The most feared of hazards in underground mines or other subsurface facilities are those of

2、firseand explosions. Like airplane crashes ,these do not occur often but, when they do ,have the potential of causing diaastrous loss of life and property as well as a temporary or permanent sterilization of mineral rese

3、rves. Fuithermore,” near-misses” occur all to frequently .the incidence of min fires appears not to be declining despite greatly improved methods of mine environmental design and hazard c</p><p>  The major

4、ity of deaths arising from mine fires and explosions are caused ,not by burning or blast effects ,but by the inhalation of toxic gases ,in particular ,carbon monoxide. There are two major differences between underground

5、fires and those that occur in suiface strucrures. the firsr concerns the long distances, often seversl kilometers, that personnel might be required to travel in passageways that may be smoke-filed. Secondly, the ventilat

6、ion routes are bounded by the confines of the airwa</p><p>  It is difficult for anyone who has not had the experience, to comprehend the sensations of compete isolstionand disorientation involved in feeling

7、 one’s way through a long smoke-files mine airway and to walk just a few steps ,even without the trauma of a highly polluted atmosphere .</p><p>  It is, therefore, a matter of ongoing importance that all pe

8、rsonnel involved in the design and detection of subsurface fires ,as well as procedies of personnel warning systems ,escapeways , firefighing, toxic gases, training, fire drills and the vital need for prompt resporise to

9、 a fire emergency. these are some of the topic s that are discussed in this chapter.</p><p>  1.1 The fire triangle and the comcuetion process</p><p>  Peihaps the most basic precept in firefig

10、hter training is the fire triangle shown on figure 12.1. this illustrates that the combustion process which we term “fire” requires three comptnents: furs, heat and oxygen. Remove any one of thest and the fire will be ex

11、tinguished. the fuel may be solids, liquids or gases .the liquids and gases might be introduced into the mine environment at ambient temperature by natural or mining processes, or may be produced by heating solid materis

12、ls.</p><p>  Whenever a solid or liquid is heated to a sufficiently high temperature ,it will produce a vapour that is capable of being ignited by a flame, spark or hot surface which has the required concent

13、ration and duiation of thermal energy. Gasoline has a flashpoint of -45 degrees C while most commonly available solids require the application of a flame for them to reach flashpoint theignition temperature of any given

14、 substance is the lowest temperature at which sustsined combustion is initisted. Flami</p><p>  The oxygen which forms the third side of the fire triangle is normally provided by the air. Flammable liquids

15、such as the oil of a flame safety lamp will cease to burn when the oxygen content of the air is reduced to some 16 percent .flaming combustion of all kinds is extinguished at oxygen concentrations below 2 percent .howev

16、er ,some materials may contain sufficient inherent oxygen for slow combustion to continue at wven furthen reduces levels of atmospheric oxygen .coupled tith the low valu</p><p>  1.2 Classification of mine f

17、ires </p><p>  Fires underground can be classified into two broad groups ,open and concealed fires.open fires occur in airways ,faces and other openings that form part of the active ventilation system of t

18、he mine and , hence, affedt the quality of the mine airflows quickly and directly .as the term might imply ,open fires are often accompanied by flaming combustion because of the concealed firesoccur in areas that are dif

19、ficult or impossible to access such as caved or abandoned zones. These are usually, but </p><p>  2. Causes od ignitions</p><p>  The variety of proceduies, processed and materials used in moder

20、n mining provides mang opportunities for the ignition of flammable materials .however ,the most commonly reported causes of fires and ecplosions in mines are lisred in the following subsectiongs.</p><p>  2.

21、1 Mechanized equipment</p><p>  Manchines intended for use underground should be designed to operste tith a high degree of safety in a harsh physical environment, and are subject to legal requirementsand con

22、ditiongs in most mining countries. it is no suiprise, therefore,thst the majority of fires attributable to machines arise out of :</p><p><b>  Misuse </b></p><p>  Lack of proper mai

23、ntenance </p><p>  Removal or bywpassing of safety features such as diagnostic devices, environment monitors or thermal trip switches and</p><p>  Running unattended for long periods of time <

24、;/p><p>  Exhaust systems on diesel equipment should be fitted with scrubbers that nor only reduce airborne pollution ,but also provent the emission of incandescent particles. furthermore, hoses, transmission o

25、r brake fluids and a variety of components made from synthetic materials on modern diesels may be capable of producing toxic gased when ignited. allvehicles or other diesel equipment should be fitted with on-board fire

26、extinguishers .</p><p>  It is particularly importsnt that equipment which contains significant quantities of oil, such as large transformers or air compressors, shoule be safeguarded by thermal trips, press

27、ure relief valves, and other devices necessary for automatic cut-off in the even of any abnormal codition. such devices should be subjected to routine testing and maintenance. wherever possible non-mobile equipment soule

28、 be located within enclosures with fire-resistant roof,floor and walls, and which are ventilated t</p><p>  2.2 Electrical apparatus</p><p>  In assttion to the general comments on mechanized eq

29、uipment made in the preceding suvsection,electrical gear can give rise to incendive hazards from aparking and overheating. awitchgear should be sited such that it is not affected by convergence or falls of roof .this is

30、mosr liable to ovvur close to mneral winning arwas. fuithermore, start switches shoule be protected against accidental operation glancing blows from falling debris or passing traffic. Electrical sub-stations and batter

31、y chargi</p><p>  Cables in airways should be hung in catenary fashion on cradles suspended from the roof. they should be located such that they will not be convergence or the yielding of roof supports nor b

32、e impccted by vehicles.the insulation and type of sheathing must be suitable for the edectrical load and rigours of the under groung environmeng .all such cables shoule be inspected routinely for evidence of physical d

33、amage .</p><p>  Electrical failures should result in immediate isolation of the power by means of overload and earth leakage protective devices.in gassy mines ,all electrical motors and heavy urrent devices

34、 shoule be enclosed within flameproof casings so that any ignition of methane is contained within the equipment ,signaling or other light current apparatus should be certified as intrinsically safe,ie</p><p>

35、;  Incapable of producing sparks of sufficient energy to ignite a methane: air mixture.</p><p>  During non-working shifts, the electrical power supplies to each area of the mine shoule be isolated at the ap

36、propriate highest level control centre or substation .precautions shoule be taken against power suiges caused by lightning strikes on surface power lines, transformers or substations. similarly, particular care shoule be

37、 taken against electrical leakage in the vicinity of explosives or fuel storage areas.</p><p>  2.3 Conveyors</p><p>  Conveyor fires have been subjected to particular study because of the rapi

38、dity of fire propagation along the early rubber-based types of conveyor belting .modern conveyor belting for underground use must be subjected to fire propagation tests .three types of materials are used for mine conveyo

39、r belts, namely, styrene-butadiene rubber ,neoprene and polyvinyl chloride. composites of these materials are also employed. Following ignition of the belt material and removal of the igniting source, the f</p>&l

40、t;p>  Numerous tests have indicated that fire propagation rates along convey or belting are influenced by airspeed. at a relative velocity of 1.5 m/s between the belt surface and the nearby airstream, a phenomenon kno

41、wn as flash over attains its maximum effect this occurs when a flame front from the burning belt reaches forward over an unburned surface with an optimum angle and length such that the radiant effect on that surface reac

42、hes a maximum. this can cause flaming of the top layer of belting and</p><p>  Conveyor fires are most likely to be initiated by friction .if the belt becomes stsked at any point along its length and the dri

43、ve rollers continue to turn, then high temperatures this condition .such devices should be wired to isolate electrical power from the conveyor drive when an alarm confition is detected. Similarly ,a seized idler or retur

44、n roller can become red-hot from the friction of a belt moving over or around it .conveyors should be patrolled during operation in order to detect the </p><p>  In all of these cases, a fire mayy be intiate

45、d when lubricants ,coal dust or flammable debres reach their ignition points .it follows that dust or spollage should not be allowed to accumulate round and ,particularly, underneath conveyors. A clean conveyor road is m

46、ore likely to be a safe one.</p><p>  2.4 Other frictional ignitions</p><p>  The main cause of methance ignitions on the working faces of coal mines is frictional sparking at the pick points of

47、 coal winning machinery .this occurs particularly when the machine cuts through sandstone or pyretic material. two approaches have been taken to reduce this hazard .one is to ensure that there is sufficient ventilation a

48、round the cutting drum to provide rapid dilution of the methane as soon as it is emitted .it is ,of course ,important that the overall airflow at the working face i</p><p>  The second approach to the incend

49、ive streak of aparks that sometimes trails behind a cutter pick is to quench it with water. this technique combines the suppression of both dust and methane ignitions .it is achieved by pick face flushing and ,even more

50、efficiently ,by yet assested cutting .</p><p>  Rope haulage systems have been the cause of some mine fires .care should be taken that all pulleys and return wheels are routinely serviced and lubricated .rop

51、es should not be allowed to rub against solid surfaces such as the roof ,sides or floor of airways and, particularly, timber supports. if haulage ropes must pass through holes in stoppings then again ,the ropes should no

52、t contact the sides of the orifices. fluid couplings and enclosed gearings or direct drives are preferred to mechanical c</p><p><b>  中文譯文</b></p><p><b>  礦井火災(zāi)</b></p&

53、gt;<p><b>  1 引言</b></p><p>  煤礦井下或其他地面最嚴(yán)重的 危險是具有著火,爆炸危險的設(shè)備.這些不經(jīng)常發(fā)生,但是這些可能造成慘重的 生命和財產(chǎn)以不暫時或永久的 礦產(chǎn)儲量的 損失。而且小事故太頻繁。煤礦火災(zāi)事件沒有下降,盡管在煤礦環(huán)境設(shè)計和危險控制方面有了較大的改進(jìn)。這些導(dǎo)致了兩個問題,第一個是各種新型材料進(jìn)入現(xiàn)代煤礦,各種個樣從樹脂和塑料到液體燃

54、料和液壓液。另一個因素是不斷增加的機械化程度,許多機械包含著易燃的液體和物質(zhì),當(dāng)過熱時能產(chǎn)生有毒煙霧。在十八世紀(jì)和十九世紀(jì)期間,煤礦火災(zāi)和爆炸導(dǎo)致了巨大的生產(chǎn)損失,人們關(guān)談于那個世紀(jì)的工程師和科學(xué)家。盡管在二十世紀(jì)80年代煤礦仍是一個迫切需要解決的課題。</p><p>  煤礦火災(zāi)和爆炸中大部分人之死不是由燃燒和爆炸導(dǎo)致的,而是吸入毒氣,特別是一氧化碳。井下和地面建筑產(chǎn)生的火災(zāi)有兩個不同點。第一點是距離長,常常

55、有幾千米,那里的人可能通過充滿煙霧的巷道。第二點是通風(fēng)路線受風(fēng)巷和工作面邊界的限制,風(fēng)流和火的習(xí)性,兩者密切的相互作用。</p><p>  這些對于沒有經(jīng)驗的人是困難的,包括完全隔離的感覺和迷失的方向時憑感覺通過長長的充滿煙霧零可見度的風(fēng)巷。在沒有照明的回風(fēng)巷關(guān)閉礦燈不行是一個很好的訓(xùn)練,即使沒有嚴(yán)重污染空氣的損失。</p><p>  所以,一個正在進(jìn)行的重要事情是地下開采設(shè)計和施工全

56、部人員應(yīng)該有關(guān)于預(yù)防和發(fā)現(xiàn)井下火災(zāi)的知識,以及人員預(yù)警系統(tǒng),逃亡路線,滅火(消防)方案,有毒氣體,培訓(xùn),消防訓(xùn)練和對于火災(zāi)緊急事件迅速反應(yīng)是至關(guān)重要的。在這個章節(jié)有些討論。</p><p>  1.1 火三角和燃燒過程</p><p>  在消防隊員進(jìn)行訓(xùn)練或火災(zāi)燃燒方面最基本的原理就是如圖所示的火三角。這個圖闡述了我們所說的燃燒過程所需要的三要素:燃燒,熱量,和氧氣。去除這其中任一個要素

57、,都可能火熄滅。燃燒可以是固體,液體,或氣體。進(jìn)入礦井的液體和氣體可能是由自燃或采礦過程產(chǎn)生的,或也可能是由加熱固體物質(zhì)而產(chǎn)生的。</p><p>  無論何時當(dāng)一種固體或液體被加熱到一定高的溫度,既所謂的閃點的時候,就會產(chǎn)生水蒸氣,這種蒸汽能夠被火焰,火花,或是有集中,持久熱能的高溫表面點燃。汽油在45度以下時被點燃,但大多數(shù)普通固體需要達(dá)到閃點才能燃燒。任何一種物質(zhì)的點燃溫度就是它維持燃燒的最低溫度。燃燒是蒸

58、汽迅速氧化并伴隨著光和熱的釋放的過程。在自燃中,其熱量若足夠升高暴露面或表面附近范圍內(nèi)的溫度至閃點。然而,這種燃燒能維持在較低的速率進(jìn)行,而正個過程沒有火焰,我們稱之為陰燃。在這種情況下,氧化過程在物體表面持續(xù)進(jìn)行并產(chǎn)生足夠的熱量來維持自身的燃燒,但并不能產(chǎn)生明火燃燒所需要的蒸汽量。</p><p>  火三角的第三條邊氧氣通常是由空氣來提供的。當(dāng)風(fēng)流中的氧含量減少到16%時,可燃燒液體,諸如汽油外面的火焰燈就會

59、停止燃燒。各種明火燃燒在氧濃度為10—12%時就會停止燃燒,而陰燃通常在氧濃度低于2%時才停止。然而,一些富含氧的物質(zhì)在甚至更低的空氣含氧濃度下還可以進(jìn)行緩慢燃燒。具有粉碎的,低熱導(dǎo)率的兩個特性的物質(zhì),在廢棄的區(qū)域能將這種高溫保存較長一段時間,但是當(dāng)有新鮮風(fēng)流共給時,它就會重新燃燒。</p><p>  1.2 礦井火災(zāi)的分類</p><p>  礦井火災(zāi)被分為兩種,外因和內(nèi)因火災(zāi)。外因火

60、災(zāi)發(fā)生在工作面和其他被開采的區(qū)域,這些巷道形成良好的通風(fēng)系統(tǒng),因此,能夠迅速直接影響礦井空氣的質(zhì)量。正像術(shù)語所暗示的那樣,這些明火伴隨著有焰燃燒是因為氧氣充足,并有利于消防隊員直接滅火。相反,內(nèi)因火災(zāi)發(fā)生在難以進(jìn)入或不可能接近的地方,比如冒落區(qū)或采空區(qū)。它經(jīng)常發(fā)生,但不是必然的,作為自燃火災(zāi)的結(jié)果,起因,它能發(fā)生在廢棄地區(qū)的煤或含有硫化物的礦石中,以及外來的有機物如,紙,丟棄的織物例如含油的麻棉紗或采空區(qū)的木材。內(nèi)因火災(zāi)傳播和污染礦井空

61、氣的程度應(yīng)取決于通過影響區(qū)域的泄漏氣的速度。</p><p><b>  2火災(zāi)的原因</b></p><p>  在現(xiàn)代采礦業(yè)中,由于使用不同的步驟工藝過程和材料,使這些可燃物質(zhì)有利于燃燒。然而,礦井中的火災(zāi)和爆炸的原因最常見的報道在以下的內(nèi)容中列出。</p><p><b>  2.1機械設(shè)備</b></p>

62、;<p>  用于井下惡劣環(huán)境當(dāng)中的設(shè)備應(yīng)當(dāng)被設(shè)計成在操作上有較高的安全性,并且應(yīng)符合大多數(shù)采礦業(yè)國家的法律要求。因此,不可否認(rèn),絕大部分的火災(zāi)都是由機械產(chǎn)生的(絕大部分的火災(zāi)應(yīng)當(dāng)歸于機械的出現(xiàn))</p><p><b>  誤操作</b></p><p><b>  缺乏正常的維修</b></p><p>

63、  一些安全裝置如環(huán)境監(jiān)控器,診斷裝置,過熱保護(hù)沒有使用或沒安裝。</p><p><b>  長時間運行無人看管</b></p><p>  內(nèi)燃機設(shè)備的排氣系統(tǒng)應(yīng)該安裝過濾器,這樣不僅能減少空氣污染,而且能防止發(fā)光,發(fā)熱,顆粒排放。而且,在現(xiàn)代內(nèi)燃機上的一些軟器和其他啟動件,制動件由多種材料復(fù)合的復(fù)合材料,在燃燒時會產(chǎn)生有毒氣體,所有的內(nèi)燃機裝置都應(yīng)裝上車載滅火器

64、。</p><p>  這是很重要的,包含有大量油液的設(shè)備如變壓器,空壓機等就應(yīng)該被一些熱熔斷器,安全閥門和其它必要裝置來保護(hù),以防萬一發(fā)生反常情況。這些裝置應(yīng)當(dāng)經(jīng)常測試,維修保養(yǎng)。無論何種有單獨回風(fēng)系統(tǒng)。還有,在相應(yīng)的硐室內(nèi)應(yīng)當(dāng)安裝有滅火器和可被使用的自動滅火系統(tǒng)。在煤礦里,在相鄰的巷道里面要定期撒布巖粉。</p><p><b>  2.2電器設(shè)備</b><

65、/p><p>  除了前面部分所介紹的機械裝置之外,電器傳動裝置也可能引起電器燃燒危險,是由于它們能引起電火花或過熱。這些傳動裝置的開關(guān)應(yīng)該放置在不受到頂板壓力集中影響到的地方。此外,起動開關(guān)應(yīng)該被保護(hù),防止受頂板冒落敲擊或運輸影響造成的誤操作。在變電站和充電室應(yīng)當(dāng)裝無水滅火器。</p><p>  井下巷道中的電纜應(yīng)當(dāng)集中懸吊在頂板的懸鏈上,它們應(yīng)該被放置在不能被頂板支撐變形或壓力集中破壞的

66、地方,也不能被車輛擠壓到的地方。保護(hù)套的類型和絕緣應(yīng)該能適應(yīng)于電力負(fù)載和井下惡劣的環(huán)境。所有這樣的電纜應(yīng)該定期的檢查以防止有機械損傷。</p><p>  出現(xiàn)電器故障時,過載保護(hù)和漏電保護(hù)裝置應(yīng)能直接導(dǎo)致停電。在瓦斯礦井中,所有的電動機和大電流設(shè)備應(yīng)該裝入防火防爆外殼內(nèi),以使瓦斯火焰被限制在設(shè)備內(nèi)。信號或其它光電儀器應(yīng)該是本質(zhì)安全的,即使產(chǎn)生了電火花也沒有足夠的能量點燃瓦斯與空氣的混合物。</p>

67、<p>  在礦井不工作的交接班期間,礦井相對獨立供電的區(qū)域應(yīng)該能通過相應(yīng)的水平中央變電所和變電站斷電。避免雷擊在電力線表面,變壓器和變電站表面引起沖擊,產(chǎn)生著火。同樣的,要特別小心防備在爆炸物或燃料貯存地區(qū)產(chǎn)生反向泄漏電流。</p><p><b>  2.3運輸帶</b></p><p>  傳送帶火災(zāi)已經(jīng)被深入詳細(xì)的研究,因為火焰沿著早期劣質(zhì)的橡膠運

68、輸帶傳播的很快?,F(xiàn)在用于井下的運輸帶必須要做火災(zāi)傳播試驗。用于井下運輸帶的材料有三種,即苯乙烯,丁二烯橡膠,氯乙烯橡膠和聚氯乙烯。這些物質(zhì)的合成材料也被使用。運輸帶點燃后要切除其點火源,來控制火勢傳播或滅法作到這些,應(yīng)當(dāng)減慢傳播速度。然而,被加熱的運輸帶可能出現(xiàn)有害的濃煙,這應(yīng)引起注意。</p><p>  大量的試驗表明了,火焰沿著運輸帶傳播的速度受風(fēng)速影響。在皮帶表面和他附近的氣流相對速度為1.5米/秒時,出

69、現(xiàn)上述影響現(xiàn)象的最大效果。它發(fā)生在燃燒匹敵的火焰前進(jìn)超過部燃燒的表面形成一個最優(yōu)的角度和長度時,以致于皮帶表面發(fā)生的效果達(dá)到最強。這種導(dǎo)致皮帶頂分層的燃燒和沿皮帶表面?zhèn)鞑サ幕鹧嫠俣忍岣摺>幹莆镔|(zhì)的比較深層可能或不能燃燒。SBR皮帶試驗結(jié)果最明確。當(dāng)皮帶表面火焰?zhèn)鞑ニ俣冗_(dá)到大約10米/秒時,傳播速度極限很難增加。氣流形成的渦流強烈的影響火焰沿煤炭傳送帶傳播。因此試驗室皮帶小樣品的試驗?zāi)軒礤e誤的結(jié)果。大比例的通道試驗是更加可靠的。<

70、/p><p>  摩擦最有可能造成皮帶火災(zāi)。如果皮帶在沿它長度方向的某點被卡住而驅(qū)動滾輪繼續(xù)旋轉(zhuǎn),這時將會在機頭處產(chǎn)生高溫。溫度檢測器或張緊傳感器能檢測到這一狀況。當(dāng)發(fā)現(xiàn)報警時,這種設(shè)備應(yīng)該發(fā)出信號切斷電流。同樣的,一個不轉(zhuǎn)的導(dǎo)輪或驅(qū)動滾筒與移動的或環(huán)繞它的皮帶產(chǎn)生的摩擦能變得又紅又熱。傳送帶在工作時應(yīng)該進(jìn)行巡查,以使發(fā)現(xiàn)損壞滾筒的發(fā)展情況。摩擦的軸承可以通過它發(fā)出的噪音和其表面發(fā)熱后產(chǎn)生的氣味也同樣可以。如果傳送帶

71、在生產(chǎn)方向上不成直線,比如,穿輸帶的構(gòu)件或風(fēng)巷偏移,皮帶相對環(huán)繞的皮帶表面產(chǎn)生摩擦,更進(jìn)一步的摩擦能導(dǎo)致危險。</p><p>  這這些全部原因中,當(dāng)皮帶打滑時可能產(chǎn)生火災(zāi),煤塵或可燃物碎片達(dá)到它們的燃點。沿著皮帶擦掉灰塵或清除灑落煤炭,不讓他們積聚在其周圍特別是使傳送帶的下部。一個清潔的皮帶巷道更加可能是安全的。</p><p><b>  2.4其它摩擦著火</b&g

72、t;</p><p>  煤礦工作面點燃瓦斯的原因是采煤機的截齒摩擦的火花。尤其當(dāng)機器切割通過砂巖或黃鐵礦物質(zhì)時,有兩種辦法被用于降低這個危險。一種是確保切割滾筒的周圍有足夠的通風(fēng),當(dāng)瓦斯涌出時能迅速地稀釋。當(dāng)然,系統(tǒng)地設(shè)計使來自采煤地區(qū)的瓦斯最小,以便工作面總體的風(fēng)流能充分的防止瓦斯積聚是中要得。大量的裝置用于增加通過截出和采煤機的空氣流動。遺憾的是,這加劇了除塵的難題,除非于濕式除塵器聯(lián)合使用。</p&

73、gt;<p>  第二種方法是在截齒蹤跡后面用水熄滅有時產(chǎn)生的火花。這時抑制煤塵和瓦斯燃燒兩者的綜合技術(shù)。能達(dá)到?jīng)_洗截齒面,使其更具效率,有利于截割。</p><p>  鋼絲繩拉升設(shè)備是造成許多礦井火災(zāi)的原因。注意對滑車和回天輪定期的維修和注油。繩不允許與固體表面,比如巷道的頂板,地板尤其是木支護(hù)相摩擦。如果拉升繩必須穿過風(fēng)墻上的洞,那么繩不應(yīng)接觸孔壁。對于煤礦機械傳動來說,液力偶合器,齒輪箱與直

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