1、外文翻译翻译部分英文原文Recent Developments and Practices to Control Fire in Undergound Coal MinesS. K. Ray* and R. P. Singh, Central Mining Research Institute, Barwa Road,Dhanbad, Jharkhand 826 001, IndiaPublished online: 6 October 2007Abstract.Coal mine fires cause serious threat to the property and human liv
2、es. Outbreak of fire may be dealt with advanced fire suppression techniques like Infusion of inert gases or liquid nitrogen, Dynamic Balancing of pressure, Reversal of underground mine ventilation, Application of nitrogen foam, Inertisation of Goaf, Water mist etc. The paper addresses all those cont
3、rol techniques in detail. Success story of controlling fires in coal mines of different parts of the world are reported. Results of a recently completed Science & Technology (S&T) project with regard to various fire suppression techniques like Infusion of liquid nitrogen, Injection of high pressure
4、high stability nitrogen foam, and Water mist on open fire are also discussed.Keywords: coal mine fire, infusion of inert gas, dynamic balancing of pressure, reversal of underground mine ventilation, nitrogen foam, inertisation of goaf & water mist1. IntroductionSince inception, mining is considered
5、as a most hazardous and dangerous of peacetime activities. An outbreak of fire in the underground workings of a mine poses a direct threat from the fire itself. Further, an invisible and immediate threat from carbon monoxide poisoning and an explosion, particularly in gassy coal mines is also there.
6、 It affects to both persons working underground at the time of the outbreak and to those involved in the subsequent rescue and fire fighting. It hampers the coal production and sometimes loss of coal winning machinery. Fires in coal mines may be categorised into two groups viz., (a) fires resulting
7、from spontaneous combustion of coal (b) open fires, which are accidental in nature, caused as a result of ignition of combustible materials.In coal mines, fires are generally caused due to several reasons viz., sluggish ventilation, high pressure difference across intake and return airways, loose an
8、d fallen coal in the goaf area, electricity, mechanical friction, blasting, welding , explosions and illicit distillation of liquor.An uncontrolled fire in an underground coal mine frequently can only be attacked by sealing off fire zone or the entire mine in the worse situations, or flooding the en
9、tire mine with water. The intent of sealing is to cut off the oxygen supply and allow the fire to consume available oxygen inside the sealed off area to cease the combustion process.To control fires several techniques have been developed over the years that can be applied in real mining condition de
10、pending upon the site-specific situation. The control of fire may be effected with various methods viz., Infusion of inert gases, Dynamic balancing of pressure, Reversal of underground mine ventilation, Application of High Pressure High Stability nitrogen foam, Inertisation of Goaf, Water mist etc.T
11、o understand the complex dynamic phenomenon of open fires (fires that occur in mine airways usually commence from a single point of ignition) and to study the effectiveness of various fire suppression techniques viz., liquid nitrogen, high pressure high stability nitrogen foam and water mist, recent
12、ly Central Mining Research Institute, Dhanbad, India has designed and constructed a Mine Fire Model Gallery. The model gallery is 65.5 m long; arch in shape with a base of 2.4 m and crown height of 2.7 m. The cross section of the gallery is 5.86m2. The gallery is divided into firing and non-firing z
13、ones. An exhaust type axial flow fan having a capacity to deal with 25 m3/s. of air quantity at 50-mm wg pressure hasbeen installed at its end. The gallery is provided with two sliding doors for quick sealing of the fire and a rolling shutter for regulation of desired airflow. An isometric view of m
14、ine fire model gallery is shown in Figure 1.It is equipped with a state-of-the-art computer aided on-line telemonitoring system. The system consists of 130 sensors (98 temperature, 25 gas, 3 pressure, 2 heat flux, 1 each velocity and Suspended Particulate Matter (SPM) concentration sensor) and instr
15、uments with data logger, computer, computer peripheral etc. for continuous monitoring of various fire parameters like gas concentration (O2, CO2,CO, CH4 & H2), air velocity, pressure across fire zone and fan pressure, temperature, heat flux, dust and particulate matter concentration inside the galle
16、ry.Figure 1. Isometric view of mine fire model gallery.Details of the construction of the gallery and its instrumentation system have been described elsewhere 1.In the experiments inner side of the firing zone of the gallery which is 22 m in length (firing zone starts from 10.5 m from the entry of the gallery) was lined with a thin layer of coal slabs, 810 cm thick, brought from Dobrana seam of New Kenda Colliery. Fixing of coal slabs were effec
