专业外语增加翻译部分

LESSON 1

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.).

说明

矿山通风涉及到对大气环境的控制。这需要控制空气的质量和运动，以满足矿工的健康、安全和舒适性要求。许多州的矿山条例中都提出了（关于空气的质量和运动方面的）最低标准。有些是叙述性的，指明必需的标准（例如，维多利亚加拿大港市)。有些是说明性的，详细严密地叙述如何达到这些标准（例如）

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.

矿山通风的目标

从工程技术来讲，正确控制矿山空气需要：

提供新鲜的空气（氧气）工，供人呼吸

提供氧气来源，供给各种机械上的内燃机。

稀释空气中的污染物，以达到允许标准

保持空气的温度和湿度在容许的界限内

除去空气当中来自矿山的污染物。

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.

历史发展

矿山通风的目标有两部分内容：首先，维持生命；其次，带走有毒的气体。矿山通风在历史上重要的角色是提供足量的新鲜空气，以代替井下工作的矿工所消耗的氧气。

Today's mine ventilation primarily deals with noxious gases (mainly generated by trackless equipment underground).

现今，矿山通风主要对付有害的气体（主要由无轨设备产生）。

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.

过去，采矿业产生在地表附近，可利用自然光和通风。人们用火驱动新鲜空气进入井下，出风井把烟排出井外。

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.

在北美州开始采煤的很早以前，欧洲的煤矿都挖掘两个入口：一个用来流入空气，一个用来流出空气。最初，人们用地下的炉子帮助矿山通风。这利用的实际原理是：火的上升气流产生一种吸力，驱动空气排出井外，从而在原来位置产生空缺，然后驱动另外空气填充空缺。

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。

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. 然而，在19世纪70年代以前，管理人员和有资格的人员一直用安全灯来检测瓦斯。这些安全灯很快代替油灯和裸露燃烧的蜡烛作为工作照明的工具。

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.

很快，人们用手工转动的风机把来自于工作地点的瓦斯吹到主风流当中。通气门被放置在通风系统中，以引导风流流入或流出选定的区域，这具有战略意义。矿井风门开关管理员被安排在过往较频繁的风门，当煤、材料和人员通过时，打开风门。通风巷道经常穿过煤层和岩层。

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.

20世纪20年代，手工转动的风机被小型的空气动力涡轮风机所取代。大型的抽出式风机安置在地表，并且其尺寸在逐渐增加。地面的压缩机把风流通过管道压入矿井中，供给动力机械和辅助通风。

Properties of Air

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.

任何地点的大气压力是由于其上面的空气柱的重量所产生的，随着高度（决定空气柱的高度）和空气密度（由温度和湿度所决定）发生变化。标准大气压力在平均海平面下为760毫米汞柱，高度每增加或减少90米，压力变化1kPa。

Atmospheric temperature is normally given according to the Celsius scale (°C), but the Kelvin scale (°K) may be used.

大气温度通常以摄氏度的形式给出，然而开氏温标也被使用。

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).

空气是无色、无嗅、无味的混合气体，维持燃烧和生命。矿井通风当中，我们通常讨论空气和水蒸汽的混合物，这和干空气的热力性质不同。标准大气压力和温度下，干空气的密度是1.21kg/m3。

LESSON 2

Energy Changes in Fluid Flow

流体流动的能量变化

Mine Ventilation is normally an example of a steady flow process, that is, one in which none of the variables of flow changes with time. Transition and loss in energy are involved in such a process, and it is important to understand their nature and to be able to express them mathematically. Energy changes are basic to the calculation of the mine quantity and head, one of the ultimate objectives of mine-ventilation engineering. An expression relating the energy variables may be developed as follows.

正常情况下，矿山通风是稳定流动过程中的一种，也就是说，流动过程中所有流动变量不随时间发生变化。能量转换和能量损失包含在这个过程中，重要的是：我们应了解它们的性质，并能够用数学形式描述出来。能量变化是计算矿山风量和压力的基础，而计算矿山风量和压力是矿山通风工程的一个最终目标。一个与能量的变量相关联的式子将在下面阐述。

The total energy at any section in a moving as fluid consists of the sum of the internal static, velocity, potential, and heat energies at that section. Assume a real fluid moving in a conduit, and consider the energy changes that occur between any two sections in the system. The heat changes is generally negligible compared to the other terms, except in deep mines or ones naturally ventilated, and the addition of mechanical energy is usually considered separately. Omitting these terms for now, the total energy at section 1equals the total energy at section 2, plus the flow energy losses occurring between 1 and 2, or

流体在流动过程中，其任何区域的总能量由该区域固有的静压能、动压能、位能和热能组成。假定真实流体在管道中流动，并且考虑系统中任两区域之间的能量变化。同其他形式的能量相比，热能常常忽略，除了深部矿井和自然通风的矿井之外。机械能之和常常单独考虑。暂且忽略热能，那么区域1的总能量等于区域2的总能量加上1和2之间的流动能量损失，即：

These versions of the Bernoulli energy equation (Eq.2 and 4) are both basic and general and the most useful to employ in mine ventilation. In relating the static velocity, potential, and total heads plus the losses flow, the energy equation permits writing of an expression encompassing all flow variables between any two points in the ventilation system. These points may be selected at the beginning and end of the system (the entrance and discharge of mine for the air circuit), enabling the calculation of the characteristics for the entire system (the mine heads).

伯努力方程的这些形式不仅是基本的、普遍的，而且是最有用的应用于矿山通风的手段。能量方程式与流体的静压、速压、位压、总压头加上流动损失相关联，能够表示成包含通风任两点的所有流动参数的形式。这些点可以选在系统的开始和结束处（矿山空气环路的进口和出口），从而能够计算整个系统的特性（矿山压头）。

LESSON 3

Face Ventilation

工作面通风

Unless the air is properly distributed to the face, the mine ventilation system is not performing its primary function . While it has always been recognized that this last part of ventilation is the most import, it is also the most difficult to achieve.

除非给工作面分配了合适的风量，否则矿井通风系统就没有完成它的主要任务。虽然人们普遍认识到通风的这个最终任务是极其重要的，但是要完成这个任务也是极其困难的。

There are basically two methods of ventilating the blind entries ahead of the last open crosscut: the use of line brattices or the installation of auxiliary fans. Each technique has its defenders as well as its outspoken critics.

对最后一个连通石门前的独头平巷进行通风，有两种主要方法：使用纵向风障和安装局部通风机。每一种方法都有它的优点和缺点。

Line Brattices

The line brattice is essentially a space divider or temporary partition made of an impervious material that is installed and maintained very carefully and kept as close to the face as possible. Its purpose is to guide the airflow through the face area and last open crosscut and into the return. Brattices were formerly (and to some extent still are) made of untreated jute, but nylon reinforced plastics and similar materials are more commonly used in them today. While the more effective material is invariably higher in initial cost, it results in lower overall expense in that it allows for greater reuse and less air leakage.

纵向风障实际上是一种用不透风材料制成的间隔物即临时隔板，它要细心安置、精心维护，并使其尽可能接近工作面。纵向风障的用途是引导风流流经工作面区域和最后连通石门后，进入到回风流中。以前，纵向风障是由未经加工的黄麻制成的（现在仍多少使用这种材料），但是，现在人们普遍使用尼龙加固塑料和类似的材料来制成风障。虽然这种效果较好的材料使初期成本总是较高，但是它导致总体费用下降，这是因为考虑到它能够多次重复使用，并且漏风较少。

The line brattice is installed so as to split the heading longitudinally and thus provides an inlet as well as a return from the face to the last open crosscut. Since the mining machine must have room to maneuver on one side of the brattice, it is not practical to split the entry evenly, so a wide side is provided for the machine. The air may be brought up the narrow side and, after it sweeps by the face , returned on the wide side, as in the blowing system or it may be forced in the reverse direction as shown in the exhaust system. Since the blowing system produces a high velocity of air at the face, it achieves superior gas dilution, but the air, now contaminated with gas and dust, returns over the machine and its operator. As a result, this system is rarely used today. The more commonly employed exhaust system, with intake air coming in on the wide side of the brattice and returning on the narrow side, eliminates this problem because the fresh air passes over the machine operator before it reached the face. However, since the air velocity provided at the face by the exhausted system is low, it does a less effective job of diluting the gas there. In fact, the corner of the face opposite the end of the brattice can easily gas up, so it is imperative that the end of the brattice be maintained no farther than 3 m from the face.

安装纵向风障使得平巷沿纵向分割，从而形成一进风通道和一从工作面到达最后连通石门的回风道。采矿机械要在风障的一侧运行，必须留有空间，因此等分入口安装是不符合实际的，应在采煤机的一侧留出较多的空间。在压入式系统中，风流从窄的一侧流入，在清扫工作面后，从宽的一侧排出，而在抽出式系统中风流方向反向。由于压入式系统在工作面附近提供了的风速较高，因此瓦斯能够得到很好的稀释。但是，由于含有瓦斯和粉尘的污浊风流流经机器和操作人员，所以现在很少采用这种系统。现在，广泛采用的是抽出式系统，在这个系统中，风流从风障较宽的一侧流入，从较窄的一侧排出，由于新鲜风流首先流经采煤机的操作人员，然后才到达工作面，所以消除了压入式系统产生的问题。然而，因为抽出式系统在工作面附近提供的风速较低，因此，它的瓦斯稀释效果不好。事实上，工作面对应于风障端部的角落，容易得到瓦斯聚集，所以规定风障端部与工作面之间的距离不能大于3m。

Auxiliary Fans

While auxiliary fans have not achieved the popularity they deserve in coal mines, they are not necessarily panacea for face ventilation. As a concept, the idea of hanging tubing out of the way while providing an adequate flow of air to the face appears very attractive. However, when one begins to calculate the pressure and horsepower required by an auxiliary fan, one soon realizes that the tubing needs to be much larger than originally visualize. Also, it must be very carefully installed and maintained to minimize leakage and kept close to the face. However, it may be easier to keep the tubing closer to the face than it is with a line brattice.

当局部通风机在煤矿开采中没有得到应有的普及时，它们未必是工作面通风的万能灵药。从原理上来说，将管道悬吊于巷道旁巡而为工作面供应足够风量的思想似乎是很有吸引力的。但是，当我们开始计算局部通风机所需的压力和功率时，就会很快意识到管道所需的尺寸比原先想象的大得多。同时，局部通风机应细心安置，精心维护以减少漏风量，并使其接近工作面。不过局部通风机管道比纵向风障更容易靠近工作面。

A blower system can be installed as shown in Fig. 1 (A). There is no problem in delivering more than 1 416 L/s of air through 30 m of 45 cm-diam tubing with reasonable pressure and horsepower. Even with the end of the tubing as far as 10.6 m from the face, adequate dilution can be achieved with methane liberations of as much as 9.4 L/s. The disadvantage of such a blower system is that dust-and gas-laden air passes over the machine operator, and a methane buildup can occur out by

the machine. Because of the difficulty of controlling dust, this technique is seldom used today.

压入式系统的安装如图18.1（A）所示。该系统释放超过1416升／秒的具有适度压力和功率的风流，流经长度为30米、直径为45厘米的管道，这不存在任何问题。甚至当管道距离工作面有10.6米远，该系统也能够充分稀释释放量为9.4升／秒的瓦斯。压入式系统的缺点是含有粉尘和瓦斯的污浊风流流经采掘机操作人员，并且在采煤机附近能够产生瓦斯聚集。由于很难控制粉尘，这种方法目前很少使用。

The exhaust system shown in Fig. 1(B) eliminates the passage of contaminated air over the machine operator, and effectively removes the dust from the working environment. However, even when an airflow of 2630 L/s is maintained through an 45cm tubing 30 m long and ending within 2.1 m of the face, it is not uncommon to have the far corner gas up. When the tubing is allowed to lag back from the face 4.5 to 6 m, it is not uncommon for the entire face to gas up. By this time, the operator is between the end of the tubing and the face and is exposed to contaminated air, so this is a situation that must not be allowed to occur.

图18.1（B）所示的抽出式系统消除了污浊空气流经采掘机操作人员的通道，有效地除去工作环境中的粉尘。不过，即使当2630升／秒的风流流经直径为45厘米，长度为30米，端部距离工作面在2.1米以内的管道时，远而偏的隅角仍有瓦斯聚集。当管道滞后于工作面4.5到6米时，整个工作面都会有瓦斯聚集。这时，在管道端部和工作面之间的操作人员暴露在污浊气流中，因此这种情况不允许发生。

The combination of a diffuser fan mounted on the mining machine and an exhaust fan as sown in Fig. 2 achieves optimal results without the inconvenience installing and maintaining two lines of vent tubing. A small, hydrau lically driven, centrifugal fan powered by the miner’s hydraulic system is mounted directly on the machine. With as little as 306.8 L/s of air from 15 cm-diam tubing directed toward the face, it is possible to provide an air flow of 1005 m/min in the far corner of the face and effectively force contaminated air into the larger air volume circulated by the exhausted fan. By circulating 1888 L/s through a 30 m length of 90 cm tubing, methane liberation of up to 18.9 L/s have been safely handled. With this system, recirculation can occur during normal operation if the exhaust tubing is allowed to lag behind, and thus the end of the tubing should always be kept well ahead of the inlet to the diffuser fan. Also, if the exhaust fan stops for any reason, and the machine continues to operate, recirculation will occur around the diffuser fan with possibly a dangerous accumulation of gas.

如图18.2所示，将装在采煤机上的扩散式辅助扇风机和抽出式风机联合能获得最佳效果，又无安装和维修两条管道之麻烦。一小型的、由采煤机液压系统驱动的离心式风扇直接安装在采煤机上。该系统在直径15厘米的管道中产生的306.8L／s风流直接流向工作面，这就可能使工作面远而偏的隅角处风流速度达到1005 米／分，有效地迫使污浊空气流入到由抽出式风扇循环的体积较大的气流中。使1888 升／秒的风流循环流经长度为30米，直径为90厘米的管道，释放量达到18.9 升／秒的瓦斯得到了安全处理。如果抽出式风扇风筒滞后，使用该系统，在正常生产期间可能会形成循环风流，因此应经常保持抽出式风筒入口超过稀释风机进风口。同时，如果抽出式风扇由于某种故障停止运行，并且采煤机继续在运行，那么就会在扩散式风机附近产生循环风，并可能产生瓦斯聚集，这是很危险的。

LESSON 4

Mechanical Ventilation

The application of fans to induce airflow is common in the mining industry. The majority of modern mine fans are the axial-flow type. However, many centrifugal fans still are in use and may be preferred for some applications. The general fan laws are the same for either axial-flow or centrifugal fans. The only differences are in the individual characteristics of power, pressure and air volumes.

在采矿业中，普遍应用风机产生风流。矿上的新式风机大多数都是轴流式的。然而，许多离心式风机仍在使用中，它们也许是一些应用的首选。不论是轴流式扇风机还是离心式扇风机，其一般规律都是相同的。它们的不同处仅仅是功率、压力和风量的个体特性。

Fan Laws---- These are as follows:

风机的规律如下：

1. Air quantity varies directly as fan speed. Quantity is independent of air density (twice the volume requires twice the speed).

1. 风量和风机转速成正比。风量和风流的密度无关（风量要增大到两倍需要转速增大到两倍）。

2. Pressures induced vary directly as fan speed squared, and directly as density (twice the volume develops four times the pressure).

2．产生的压力和风机转速平方成正比，与密度成正比（风量增大到两倍引起压力增大到四倍）。

3. The fan power-input varies directly as the fan speed cubed and directly as the air density (twice the volume requires eight time the power).

3. 风机输入功率和风机转速的立方成正比，与密度成正比（风量增大到两倍需要功率增大到八倍）。

4. The mechanical efficiency of the fan is independent of fan speed and air density.

4．风机的机械效率与风机转速和风流密度无关。

Selection of Fans----The performance of a fan in a ventilating system is determined by its characteristic curve and the mine resistance if acting alone on the system, and by its characteristic curve, characteristic of other pressure sources, and the resistance of individual zones of influence if acting in combination with other pressure sources. Fan characteristics are a matter of design, which is controlled by the manufacturer. The resistance of the mine is a matter of layout and maintenance of the ventilating network, and is controlled by the mine operator.

在通风系统中，如果一台风机单独运行，那么该风机的性能决定于它的特性曲线和矿井的阻力；如果风机和其它压力源联合运行，那么该风机的性能决定于它的特性曲线、其它压力源的特性和自身影响区域的阻力。风机特性与设计有关，这由制造厂家所控制。矿井阻力与通风网络的布置和维护有关，这由矿上人员所控制。

The amount of airflow induce in a mine will depend on fan characteristic and mine resistance. The

pressure (H) required to pass a quantity (Q) through a mine or segment of a mine is expressed by the common formula H=RQ2, where R , the resistance factor, may be calculated from known pressure losses or from the common formula.

在矿井中所产生的风量依赖于风机特性和矿井阻力。通过矿井或矿井区段的风量所需的风压H是通过公式H=RQ2表示的。公式中的R为阻力因数，可以由已知的压力损失计算得出，也可以由通用的公式计算得出。

Mine fans are available to suit most conditions of mine resistance and desired volume relationships. Modern axial-flow fans are built with variable-pitch blades that permit a wide range of application for the single fan. The various blade settings permit the same fan to operate through a wide range of mine-resistance relationships.

矿井可用的风机能够满足大多数矿井阻力条件和所需风量间的关系。新式轴流式风机安装有可变安装角的叶片，这就使单个风机的应用范围更为广泛。不同的叶片设置可使同一风机能够运行在矿井阻力关系变化大的情况下运行。

All fan-performance data are based upon a standard density of 0.075 pcf. At altitudes where the air density is substantially less than standard, corrections must be applied on the basis of the true density.

所有性能的数据是以建立在标准密度为0.075磅的基础上的。在某一高度，当空气的密度远低于该标准时，必须以真实密度为基础对数据进行修正。

The efficiency of the fan is power output divided by power input. The power input is the actual horsepower used to drive the fan rotor and equals the measured motor horsepower, less any shaft or belt losses . The power output of the fan is measured in air horsepower, which is the total fan pressure (P) in pounds per square foot times the air quantity in cubic feet per minute, divided by 33 000. Since 33 000 ft 1b equals 1 hp, air horsepower equals (P×q)/33 000. For convenience, since most measurements are in inches of water, the pressure P is changed to H (pressure in inches of water); and since H=P/5.2, P=H×5.2. Substituting this in the formula, air horsepower=(H×5.2×q )/33 000. Simplifying it further, air horsepower=(H×q)/6 350 for practical applications.

风机的效率指的是风机输出功率除以输入功率。风机的输入功率指的是用以启动风机转子所需的实际马力，它等于所测出电动机马力减去轴损失或皮带带动损失。风机的输出功率是以空气的马力来度量的，它等于压力（P，单位为磅／平方英尺）乘以风量（单位为立方英尺／分），再除以33000。因为33000英尺＊磅等于1马力，所以风流的马力等于P×q/33000. 因为大多数压力是以水柱英寸数度量的，所以为方便起见，压力P变为H（以水柱英寸数为单位的压力）。由于H＝P／5.2，所以P＝H×5.2，将此代入公式，空气马力＝(H×5.2×q )/33 000。将其进一步简化，空气马力在实际中应用的公式为H×q／6350。

Fan in series----Fan operating in series are those operating on the same flow circuit, each handling the total flow of the circuit and each generating a part of the total pressure required to balance the pressure losses of circuit. Any number of fans can be used. The advantage of fans in series is that where resistance to flow is high more efficient distribution and better operating conditions may be obtained.

串联风机——串联运行的风机指的是运行在同一风路中的风机，每个扇风机通过风路中的整

个流量并产生需要的一部分总分压以补偿风路压力的损失。使用风机的数目可以是任意的。串联风机的优点是风路阻力高的地方能够得到有效的阻力分布和较好的运行条件。

The flow conditions for series operations are determined by mine resistance and the combined pressure characteristic of the fans, obtained by plotting the sum of the pressure for the same quantity.

串联运行的流动条件决定于矿井阻力和风机的联合压力特性（通过连接同风量下压力之和的点得到）。

Unless the two fans are properly selected for the work to be done in series operation, they will not operate together at maximum efficiency and the results will be disappointing. The mine-resistance curve must intercept the combined characteristic curve of both fans.

除非对运行在串联中的两台风机进行适当地选择，否则它们联合运行的效率将没有达到最大，运行结果将令人失望。矿井阻力曲线必须与两台风机联合运行的特性曲线相交。

Fans in Parallel----Fans may be used in parallel to increase the air volume against changed mine resistance. As a mine is developed and more air is needed, a common practice is to install an available fan in parallel with the operating fan.

并联风机——风机可并联使用以便在矿井阻力变化时增大风量。当矿井扩建和需要更多风量时，通常做法安装一个可用风机使其与运行风机成并联形式。

Fans may be placed together to operate on the same airway or they may be on separate airways. When operating on the same airway, they act together on the total flow. The primary condition is that the pressure generated by each fan must equal the pressure loss sustained by the total volume they produce. The combined performance characteristic of fans acting in parallel at the same point in the system is obtained by plotting sum of the quantities handled at the same pressures against the pressures. The intersection of the system and the combined fan characteristics determine the pressure and, since the pressure must be the same for both fans, this pressure determines the relative quantities that each fan will produce.

风机可以安置在一起在同一风路中运行（集中并联），或者风机也可以在各自的风路中运行（对角并联）。当风机在同一风路中运行时，它们共同作用于总流量。主要条件每台风机产生的压力必须等于它们产生的总风量所维持的阻力损失。并联工作的风机在同一点的联合工况特征可以通过连接在相同风压下风量之和的点获得。系统和风机联合特性曲线的交叉点确定了压力，又因为两台风机的压力必须相等，所以这个压力就确定了每台通风机将产生的相应风量。

If the mine-resistance curve does not intersect the combined characteristics, the higher pressure fan will handle more air alone than the two fans together, and if an attempt is made to operate them in parallel the high-pressure fan will reserve air through the low-pressure fan.

如果矿井阻力曲线与风机联合特性曲线不相交，那么高压风扇单独产生的风量多于两台风扇共同产生的风量，如果企图使风扇并联工作，高压扇风机将使风流反向流过低压扇风机。

A common method of installing fans in parallel is to place them on separate airways. Where the resistances of the separate airways are comparatively large, little operating trouble is experienced.

However, when the separate airway resistance is small, it is difficult to determine the resistance against which the fans must operate. Consequently, the characteristics of the separate, as well as of the combined, airways must be considered.

并联风机安装的普遍做法是把它们置于各自的风路中。当各自的风路阻力相当大时，不会导致大的工作故障。然而，当各自风路阻力小时，难于确定扇风机必须克服的阻力。因此，风机的单独特性和联合特性必须考虑风路。

LESSON 5

Mine Ventilation Systems

Figure 1 depicts the essential elements of a ventilation system in an underground mine or other subsurface facility. Fresh air enters the system through one or more downcast shafts, drifts (slopes, adits), or other connections to surface. The air flows along intake airways to the working areas or places where the majority of pollutants are added to the air. These include dust and a combination of many other potential hazards including toxic or flammable gases, heat, humidity, and radiation. The contaminated air passes back through the system along return airways. In most cases, the concentration of contaminants is not allowed to exceed mandatory threshold limits imposed by law and safe for the entry of personnel into all parts of the ventilation system including return airways. The intake and return airways are often referred to simply as intakes and returns respectively. The return air eventually passes back to the surface via one or more upcast shafts, or through inclined or level drifts.

图1描述了地下矿山或其他地下设施中通风系统的基本要素。新鲜空气通过一个或多个进风竖井、巷道（斜井、平硐）或其他与地面相连的线路进入系统中。空气流经进风巷道，到达工作区域或地点，那里大部分污染物混入到风流当中。这些污染物包括粉尘和许多其他具有潜在危险的物质组成的混合物（包括有毒或可燃气体、热、湿气和辐射）。污浊风流沿着回风巷道流经系统。大多数情况下，污染物的浓度不允许超过法规规定的强制性的极限范围，对包括回风在内的通风系统各部分的人员来说是安全的。进风巷道和回风巷道通常被简化为进风和回风。回风通过一个或多个回风竖井、倾斜或水平巷道排出到地面。

Fans

The primary means of producing and controlling the airflow are also illustrated on Figure 1. Main fans, either singly or in combination, handle all of the air that passes through the entire system. These are usually, but not necessarily, located on surface, either exhausting air through the system as shown on Figure 1 or, alternatively, connected to downcast shafts or main intakes and forcing air into and through the system. Because of the additional hazards of gases and dust that may both be explosive, legislation governing the ventilation of coal mines is stricter than for most other underground facilities. In many countries, the main ventilation fans for coal mines are required, by law, to be placed on surface and may also be subject to other restrictions such as being located out of line with the connected shaft or drift and equipped with "blow-out" panels to help protect the fan in case of a mine explosion.

风机

图1也表示出了产生和控制风流的主要方法。主要通风机，单独或联合运行，控制流经整个系统的所有风流。主要通风机通常（但不是必须的）安置在地面，或者如图1所示的那样抽

出风流流过系统，或者与进风竖井或主要进风道相连，压入风流进入和流经系统。由于煤矿瓦斯和粉尘都可能爆炸，这是其他地下设施所不具有的危害，所以煤矿的保障通风的法规比其他地下设施要严格。许多国家的法规规定，煤矿中的主要通风机必须安置在地面，并且还有其他一些限制，例如不安装在和竖井或巷道呈直线的位置，配备冲击板（防爆门）以在煤矿发生爆炸时，起到保护风机的作用。

Stoppings and Seals

In developing a mine, connections are necessarily made between intakes and returns. When these are no longer required for access or ventilation, they should be blocked by stoppings in order to prevent short-circuiting of the airflow. Stoppings can be constructed from masonry, concrete blocks or fireproofed timber blocks. Prefabricated steel stoppings may also be employed. Stoppings should be well keyed into the roof, floor and sides, particularly if the strata are weak or in coal mines liable to spontaneous combustion. Leakage can be reduced by coating the high pressure face of the stopping with a sealant material and particular attention paid to the perimeter. Here again, in weak or chemically active strata, such coatings may be extended to the rock surfaces for a few metres back from the stopping. In cases where the airways are liable to convergence, precautions should be taken to protect stoppings against premature failure or cracking. These measures can vary from "crush pads" located at the top of the stopping to sliding or deformable panels on prefabricated stoppings. In all cases, components of stoppings should be fireproof and should not produce toxic fumes when heated.

风墙和密闭

矿山在开采过程中，进风和回风之间需要一些连接设施。当巷道不再需要通过或通风，那么应用风墙封闭，以防止风流短路。构筑风墙的材料为砖石、混凝土或耐火木材。另外，也使用预先制成的钢制风墙。风墙应充分楔入顶板、地板和四周，尤其当岩层松软或者煤矿易发生自燃的情况下。在风墙压力高的一面涂上一层密封剂，并特别注意其周界，那么漏风会减少。这里同样，在松软和化学活性强的岩层中，这种涂层应延伸到岩层表面距风墙后面几米处。在风路易于集中的情况下，应采取预防措施来保护风墙，以避免过早出现故障或者破裂。这些措施从在风墙的顶部安置压垫到在预制风墙上安置滑动的或可变形的面板。在所有情况下，风墙的组成成分是防火的，当加热时不应产生有毒烟气。

As a short term measure, fire-resistant brattice curtains may be tacked to roof, sides and floor to provide temporary stoppings where pressure differentials are low such as in locations close to the working areas.

作为一种短期措施，风障帘被固定在顶板、四周和底板，形成一种临时密闭，这用于压差小的地方，例如开采区域的附近位置。

Where abandoned areas of a mine are to be isolated from the current ventilation infrastructure, seals should be constructed at the entrances of the connecting airways. If required to be explosion-proof, these consist of two or more stoppings, 5 to 10 metres apart, with the intervening space occupied by sand, stone dust, compacted non-flammable rock waste, cement-based fill or other manufactured material. Steel girders, laced between roof and floor add structural strength. Grouting the surrounding strata adds to the integrity of the seal in weak ground. In coal mines, mining law or prudent regard for safety may require seals to be explosion-proof.

当矿井报废区域需要同现有基本通风结构隔离，应在连接风道的入口处构造密闭。如果要求

密闭具有防爆性，它们应由两个或多个间距为5~10米的风墙组成，在风墙之间的区域填充沙、石粉、紧密的不燃岩石废料、以水泥为基础的填充物或其他人造材料。钢梁架在顶板和底板之间，以增加结构强度。用薄灰浆填塞岩层周围，增加了松软地面上密闭的完整性。煤矿中，矿业法规或谨慎的安全考虑可能要求密闭为防爆的。

Doors and airlocks

Where access must remain available between an intake and a return airway, a stopping may be fitted with a ventilation door. In its simplest form, this is merely a wooden or steel door hinged such that it opens towards the higher air pressure. This self-closing feature is supplemented by angling the hinges so that the door lifts slightly when opened and closes under its own weight. It is also advisable to fit doors with latches to prevent their opening in cases of emergency when the direction of pressure differentials may be reversed. Contoured flexible strips attached along the bottom of the door assist in reducing leakage, particularly when the airway is fitted with rail track. 风门和风闸

当进风和回风之间必须通行时，在风墙上应安装一个通风门。最简单的形式是装有铰链的木制或钢制风门，能够在风流压力大的一侧开启。使铰链形成角度补充了这种半关闭特性，从而使风门打开时有轻微地提升，在自身的重力下关闭。建议在风门上安装插销，以防止在压差方向反向的紧急情况下，风门被打开。沿着风门的底部缚上具有特定断面形状的柔韧性条带，有助于减少漏风，尤其当风路上铺有轨道时。

Ventilation doors located between main intakes and returns are usually built as a set of two or more to form an airlock. This prevents short-circuiting when one door is opened for passage of vehicles or personnel. The distance between doors should be capable of accommodating the longest train of vehicles required to pass through the airlock. For higher pressure differentials, multiple doors also allow the pressure break to be shared between doors.

安设在主要进风和回风之间的通风门通常构建为两道或多道，形成了风闸。这防止了当一道风门打开让车辆和人员通行时风流短路。风门之间的距离应能够容纳需通过风闸的交通工具中的最长列车。压差高时，多层风门也使压力突变均分到各风门上。

Mechanized doors, opened by pneumatic or electrical means are particularly convenient for the passage of vehicular traffic or where the size of the door or air pressure would make manual operation difficult. Mechanically operated doors may, again, be side-hinged or take the form of rollup or concertina devices. They may be activated manually by a pull-rope or automatic sensing of an approaching vehicle or person. Large doors may be fitted with smaller hinged openings for access by personnel. Man-doors exposed to the higher pressure differentials may be difficult to open manually. In such cases, a sliding panel may be fitted in order to reduce that pressure differential temporarily while the door is opened. Interlock devices can also be employed on an airlock to prevent all doors from being opened simultaneously.

机械风门由气动力或电力开启，这对于车辆通行尤其方便，对于由于风门尺寸小或空气压力造成手动操作困难的情况下很便利的。机械操作风门也可以是一侧装铰链的形式，还可以呈手工卷制的雪茄烟或六角手风琴形式。它们可以通过拖绳人工操作，也可以自动感觉接近的车辆或人员。大型风门安装有带铰链的小门供人员通行。暴露在较高压差下的人门人工开启可能困难。这种情况下，安装一滑动面板，当风门打开时能暂时减小压差。在风闸上也应采用互锁装置，以阻止所有风门同时被打开。

（翻译增加部分）

Regulators

风窗

A passive regulator is simply a door fitted with one or more adjustable orifices. Its purpose is to reduce the airflow to a desired value in a given airway or section of the mine. The most elementary passive regulator is a rectangular orifice cut in the door and partially closed by a sliding panel. The airflow may be modified by adjusting the position of the sliding panel manually. Louvre regulators can also be employed. Another form of regulator is a rigid duct passing through an airlock. This may be fitted with a damper, louvres or butterfly valve to provide a passive regulator or a fan may be located within the duct to produce an active regulator. Passive regulators may be actuated by motors, either to facilitate their manual adjustment or to react automatically to monitored changes in the quantity or quality of any given airflow.

When the airflow in a section of the mine must be increased to a magnitude beyond that obtainable from the system then this may be achieved by active regulation. This implies the use of a booster fan to enhance the airflow through that part of the mine. Section 9.6 deals with the subject of booster fans in more detail. Where booster fans are employed, they should be designed into the system such that they help control leakage without causing undesired recirculation in either normal or emergency situations. In some countries, coal mine legislation prohibits the use of booster fans.

可调节风窗就是一个简单的门与一个或多个可调节孔组成的装置。其目的是在矿山给定的风巷或区域中降低气流使其达到理想的期望值。最基本的调节风窗是一个矩形的口门，嵌入在门里而且部分滑动面板的附近。可以通过手动调整滑动面板的位置来调整风流。也可采用百叶窗式调整装置。另一种调节装置的形式是穿过风闸严密的管道。这可能是装有阻尼器，百叶窗或蝶阀提供可调节风窗或有风扇可能位于管道内产生一个自动调节风窗。可调节风窗可能会由电动机驱动，或者以方便他们手动调整或自动作出反应，在任何特定的风流数量或质量中监测气流的变化。

当在一个矿井区段气流需要增大并且超出了从系统时，那么这部分的获取可能通过自动调节风窗来实现。这意味着通过使用一个增压风机，以提高通过该矿山部分的气流。第9.6节增压风机的主题将会讲述。当使用增压风机时，也应设计到系统中，例如，他们帮助，控制泄漏而不会引起在正常或紧急情况下意外再循环。在一些国家，煤矿立法禁止使用增压风机。

（翻译增加部分）

Air crossings

Where intake and return airways are required to cross over each other then leakage between the two must be controlled by the use of an air crossing. The sturdiest form is a natural air crossing in which the horizon of one of the airways is elevated above the other to leave a sill of strata between the two, perhaps reinforced by roof bolts, girders or timber boards. A more usual method is to intersect the two airways during construction, then to heighten the roof of one of them and/or excavate additional material from the floor of the other. The two airstreams can then be separated by horizontal girders and concrete blocks, or a steel structure with metal or timber shuttering. Sealants may be applied on the high pressure side. Control of the airway gradients approaching the air crossing reduces the shock losses caused by any sudden change of airflow direction.

Man-doors can be fitted into the air-crossing for access.

Completely fabricated air crossings may be purchased or manufactured locally. These can take the form of a stiffened metal tunnel. Such devices may offer high resistance to airflow and should be sized for the flow they are required to pass. They are often employed for conveyor crossings. Another type of air crossing used mainly for lower airflows and which requires no additional excavation is to course one of the airstreams through one or more ducts that intersect a stopping on either side of the junction. An advantage of this technique is that the ducted airflow may be further restricted by passive regulators or up-rated by fans in the ducts.

In all cases, the materials used in the construction of air crossings should be fireproof and capable of maintaining their integrity in case of fire. Neither aluminium nor any other low melting-point or combustible material should be employed in an air crossing.

风桥

当进风巷和回风巷需要相互穿越对方时，两者之间必须使用风桥来控制的风流的泄漏。最坚固的形式是一个自然风桥，其中的一个风巷地平线高于另一个上面，两个阶层之间的留有基石，可能由顶板螺栓，大梁或木制板加强。更常用的方法是在施工期间交叉两个风巷，然后提高对其中一个顶板或从另一个顶板的挖掘额外材料。这样两股风流就可以沿着水平大梁和混凝土块进行分流，或用合金钢结构以及木制板分流。密封剂可应用于高压侧。进入风桥的风流量的控制可降低因风流方向的突然变化造成的损失，人行门口可安装到风桥中用于过人。完全焊接而成的的风桥可在当地购买或制造。这些风桥可以采取强化合金金属隧道形式。这种装置可能提高了风流的阻力，应该为他们设计需要通过风量的大小。他们往往采用传输通道。另一种主要用于低风流和不需要额外的挖掘过程中引导风流通过一个或多个管道，管道在枢纽点每一面交叉于风墙。这种技术的优点是，管道气流可能会进一步被被动调整器控制，或在管道中用风机加强。在所有情况下，在风桥建设中使用的材料应当防火和火警发生时维持其完整性。无论是铝或任何其他低融点或可燃材料应才风桥中使用。

LESSON 6

Fundamentals of Ventilation Network Analysis

通风网络分析的基本原理

Any integrated ventilation system can be represented as a schematic diagram in which each line (branch) denotes either a single airway or a group of openings that are connected such that they behave effectively as a single airway. Only those airways that contribute to the flow of air through the system appear on the network schematic. Hence, sealed-off areas of insignificant leakage, stagnant dead-ends and headings that are ventilated locally by ducts and auxiliary fans need not be represented in the network. On the other hand, the tops of shafts or other openings to surface are connected to each other through the pressure sink of the surface atmosphere. The points at which branches connect are known simply as junctions or nodes.

任何一个完整的通风系统都可以用一个示意图来表示，在该示意图中每条线（分支）不是代表一个单独的风道就是代表一组连接在一起的巷道（其行为实际上可视为一条单独巷道）。仅仅那些流过系统风流的风道显示在网络示意图中。因此，漏风可忽略的密闭区域、风流停

滞的独头巷道和通过管道和辅助通风机进行局部通风的巷道不需要在网络中表示。另一方面，立井的顶端或者其他通向地面的巷道连接起来，压力为地面大气压。分支相连接的点简称为交叉点或者节点。

（翻译增加部分）

Computer programs have been developed for compressible flow networks. These require input data (pressures, temperatures, elevations and air quality parameters) from which variations in air density and natural ventilation effects may be calculated. On the other hand, where compressibility and natural ventilating effects need to be taken into account, there are means by which these can be simulated to an acceptable accuracy by an incompressible flow network program. For these reasons, the great majority of subsurface ventilation planning employ the simpler and faster incompressible flow programs. The more sophisticated and demanding compressible flow programs are required for compressed air (or gas) networks or for specialized applications in subsurface ventilation systems.

计算机程序已经研发出可压缩流动网络系统。这些都需要输入数据（压力，温度，海拔高度和空气质量参数），并从空气密度的变化和自然通风的影响中计算出来。另一方面，压缩率和自然通风的效果需要加以考虑，也有些可以由不可压缩流的网络程序模拟成一个可接受的准确性。基于这些原因，绝大多数地下通风规划采用简单，更快速的不可压缩流程序。压缩空气（或气体）网络或在地下通风系统应用的专业应用需要更复杂的且高要求的可压缩流的程序.

LESSON 7

Mine Gases

矿井气体

Introduction

It 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 be of importance. 引言

一提到矿山环境中的气体，人们一般相当然地关心有毒气体。然而，无毒气体的浓度，例如氧气，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 sufficient, illness or death may result.

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的毒性。如果某种气体的浓度足够大，人们暴露在该气体中的时间足够长，就可能导致疾病或者死亡的产生。

During an emergency when a toxic gas or gases are released into the workplace, the concentration 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.

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，毒素的浓度会超过工作场所的正常标准。这种情况可能造成短期或严重的危险，因为它产生了高浓度的毒性物质。同时，空气中氧气的减少对生命形成了危险，因为氧气是维持生命所必须的。

General properties of gases

The 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 different 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.

瓦斯的一般性质

术语气体指的是某物质在室温和标准大气压力下的物理状态，当不受约束时，气体能够膨胀，充满它所占的空间。当温度降低或者压力升高时，气态物质能够以不同的物理状态存在。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。

Traditionally, mine rescue teaching about gas properties focused on the density of pure gases. 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. Even a leak of pure, pressurized gas will 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.

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。然而，在突发事件下进入工作地点的气体通常不纯，而混入空气或者其他气体。纯净的气体很少在工作面存在。当确实存在时，很可能是气体从受压容器在失控卸压时释放出来。即使纯的受压气体的泄露，随着离泄露容器的距离增加，涡流的程度增强，其行为也不象纯的气体那样。最终，当泄露气体移离泄露地点时，它将混入周围的空气。

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 dense than air at normal conditions. As a result, combustion gases generally rise. 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. 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.

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方。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。这种热空气团或束有一个扩散边界，比周围的空气轻。热空气形成不受约束的团状这种事实在较冷的气候时，从烟囱冒出的烟中可以很容易观察到。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度。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。

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 not be able to smell a gas (depending on its concentration). 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.

气体还有一些其他物理性质，例如味道、颜色、气味。这些性质作为预兆特性可能有用，也可能无用。例如颜色特性通常最能观察道纯净气体。工人可能够闻到气体，也可能够闻不到气体，这取决于气体的浓度。因此，在紧急情况下，这些特性作为了解混入矿山空气中气体的毒性意义不大。

Gas accumulation and stratification

瓦斯积聚和分层

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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 has time to cool and mix with the 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.

A 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 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.

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 near the floor in a room or a stope. It remains thoroughly mixed with the rest of the mine air.

瓦斯可以用袋子收集与其他矿井空气分开。当缺乏足够的通风的煤矿，这一点尤其如此。从发生火灾的热气体将上升至背面和保持在那里，直到烟尘有时间冷却下来和空气混合一起。因此，预计火灾附近的烟雾将会浓度加强。一旦烟雾从火源移动，那么将更加均匀的分布在竖井中，并通过通风流和湍流与矿井空气混合。瓦斯分层的第二个例子是甲烷在煤矿中的分布。纯甲烷约是空气相对密度的一半，可在地下煤矿中大批量生产。这种大量的甲烷将物理上的取代其他矿井空气。由于其密度低，有可能是甲烷聚集区，趋向于在背部附近聚集。瓦斯与空气的密度的微小差异不会导致分层。例如，氧气比空气重百分之十以上。然而，氧气不会更多的在一个房间或者回采场附近集聚。它仍然完全与其他矿井空气混合。

Gases derived from combustion processes

来自燃烧过程的气体

Burning organic material and hydrocarbon fuel results in the formation of carbon monoxide and

carbon dioxide. 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.

燃烧有机物质和烃类燃料生成一氧化碳和二氧化碳。一般来说，二氧化碳生成量较多，而当燃烧不充分时，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. Base metal mines, such as those that produce copper or zinc, get the metals from sulfide ores. In cases where sulphide ore catches fire after a production blast, a large quantity of sulphur dioxide will be produced.

燃烧可能产生NO2和其他氮类氧化物、SO2、氰化氢、碳酰氯。燃烧各种各样的塑料和合成物质会产生这些气体。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。当产物爆炸后，硫化物矿石着火时，会产生大量的二氧化硫。

Gases from explosives

来自爆炸的气体

The detonation of commercial explosives creates the same gases found from burning fuel. 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.

商用炸药爆炸时，产生的气体和燃料燃烧时产生的气体相同。商用炸药中存有碳和氮，这就很可能在爆炸时产生CO、CO2和氧化氮。

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Natural occurrences of gases

Hydrogen 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 water 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.

When the water inflow area has restricted ventilation, hydrogen sulfide 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 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 ): Carbon dioxide is a natural metabolite produced in the human body and exhaled in the respiratory process. In sufficient concentration, naturally exhaled carbon dioxide is hazardous. The exhalation of carbon dioxide by workers in refuge stations can create hazards. A dead air space is commonly employed for refuge in underground potash mines. Hardrock mines commonly use much smaller refuge stations supplied with compressed air..

Methane (CH4 ) or natural gas: Methane is produced when organic matter decomposes. Methane is also produced when sewage or other organic matter is subject to stagnant conditions and bacterial action. Coal beds may also contain methane and release the gas when the bed is exposed during mining. Methane is very dangerous in underground coal mines where inadequate ventilation can result in concentrations of the gas building to explosive levels.

气体的自然现象

硫化氢（H2S）：氢硫化物在采矿环境来源于水。硫化氢融在水中的来源于水中水溶性硫酸盐的细菌分解。一旦水进入矿井，在液态静压力缺失下硫化氢被释放到空气中的。矿井大气压力下，在水中氢硫化物溶解度相对较低。当进水地区已经限制通风，硫化氢将在进水区聚集。100 ppm的水平在不通风的进水洞穴是罕见的。虽然100 ppm是不是立即致死浓度，长期而又无保护的接触超过半小时可导致昏迷，最终死亡。如果硫磺化合物在腐烂的材料中，如污水，有机物质分解可导致硫化物的形成。与在水库底部取水口水井会带来硫化氢进入泵房从而给工人带来致命的后果。二氧化碳（二氧化碳）：二氧化碳是一种在人体内的呼吸过程中并且呼出的自然产生的代谢物。如浓度过高，自然呼出的二氧化碳是有害的。在庇护站由工人呼出的二氧化碳可产生危险。在碳酸钾矿中一个封闭的气体空间经常用来避难。硬岩石矿常使用更小的避难所并供应压缩空气. 甲烷（CH4）或天然气：甲烷是有机物分解时产生的。甲烷也会在污水或其他有机物受细菌作用的条件下产生。煤层也可能含有甲烷并在开采的过程中释放甲烷气。甲烷在地下煤矿里是非常危险，当通风不足时可能导致的瓦斯聚集的浓度达到爆炸极限，发生爆炸危险。

LESSON 8

Coal seam methane

煤层瓦斯

Methane generation

Methane, carbon dioxide and water are generated as by-products of the coal formation process. The proportions of each gas produced vary during the process.

瓦斯的生成

瓦斯、二氧化碳和水是成煤过程中产生的副产品。成煤过程中生成各气体的比例是不一样的。

Most of the gas and water migrates away from the seam. However some gas is retained within the coal seam. The capacity of coal to retain carbon dioxide is much greater than for methane. However, the large quantities of methane produced during the formation of the high rank bituminous and anthracite coals flushed most of the carbon dioxide away. The bituminous coals of the Sydney and Bowen Basins typically contain gas consisting of over 95 per cent methane with smaller quantities of carbon dioxide, ethane, higher hydrocarbons, nitrogen and inert gases. The seams in some areas of the basins contain very high levels of carbon dioxide. This carbon dioxide was introduced later into the coal measure sequence by igneous activity replacing the methane preferentially.

大多数气体和水蒸气从煤层中散发出来。然而，一些气体保留在煤层当中。煤吸附二氧化碳

的能力比吸附瓦斯的能力强。然而，高品级的烟煤和无烟煤在形成过程中产生大量的瓦斯，把二氧化碳排挤出去。有代表性的例子是悉尼和Bowen盆地的烟煤，其瓦斯含量超过95%，剩下的是少量的二氧化碳、乙烷、高类碳氢化合物、氮气和惰性气体。一些地区的煤层二氧化碳含量非常高。后来，在煤测定工序中，优先使用二氧化碳的火成作用代替瓦斯。

There are three mechanisms by which gas is stored within the coal seams.

气体通过三种途径保存在煤层当中。

About 90 per cent of the gas is absorbed onto the coal surface within the matrix pore structure, the remainder exists as free gas in the natural fracture (cleat) systems of the seams or is dissolved within the seam water.

90%的气体是吸附在煤层表面的微孔矩阵结构中，剩余的气体以自由状态存在于煤层的原生裂隙（节理）当中或者溶解到煤层的水中。

Gas which has migrated away from the seams is often trapped in the fractures and pore spaces within the roof and floor rocks. The capacity of coal to hold gas is dependent on porosity which in turn is related to rank, gas composition and gas pressure. A general relationship has been established that sorptive capacity (and therefore potential total gas content) increases with rank of the coal and with depth. Permeability of coal decreases with depth.

从煤层中散发出来的气体通常被捕获到顶、底板岩石的裂隙和微孔中。煤层保存气体的能力决定于多孔性，这依次与品级、气体组成成分和气体压力有关。一般关系为：煤的品级越高，埋藏深度越深，煤的吸附能力（潜在的总气体含量）越大。埋藏深度越深，渗透性越小。

Methane retention in coal

瓦斯在煤体中的存在状态

Methane exists within coal in two distinct forms, generally referred to as free gas and adsorbed gas. The free gas comprises molecules that are, indeed, free to move within the pores and fracture network. Porosities of coals have been reported from 1 to over 20 percent. However, those values depend upon the chosen definition of porosity and the manner in which it is measured. Absolute (or total) porosity is the total internal voidage divided by the bulk volume of a sample and may be difficult to measure accurately. Effective (or macroscopic) porosity is the ratio of interconnected void space to the bulk volume. The latter definition is more useful in the determination of recoverable gas from a seam.

存在于煤中的瓦斯有两种截然不同的形式，通常称为自由状态瓦斯和吸附状态瓦斯。自由状态瓦斯由分子组成，这些分子实际上能够自由地在微孔中和裂隙网中移动。据报告，煤的孔隙率从1%到20%以上。然而，这些数值的大小倚赖于孔隙率所选择的定义和它测量的方式。绝对（或总）孔隙率指的是样品内部总的孔隙度除以体积；绝对孔隙率可能难以准确测量。有效（或者宏观）孔隙率指的是相互连接空隙与总体积的比率。有效孔隙率在查明煤层中可利用瓦斯时比较有用。

An attractive force exists between the surfaces of some solids and a variety of gases. Coal surfaces attract molecules of methane, carbon dioxide, nitrogen, water vapour and several other gases. Those molecules adhere or are adsorbed onto the coal surface. When the adsorptive bond exceeds the short-distance repulsive force between gas molecules, then the adsorbed molecules will