原文
firefighting foams delivered through portable equipment or from fixed-pipe systems have provided effective fire suppression. In some industries, such as the petroleum industry, these systems, which incorporate hose nozzles, aspirating-type fixed nozzles, or blower-type foam generators, are essential. Despi
te the widespread use of fixed-pipe foam systems, however, potential limitations have emerged. Foam has trouble sticking to vertical surfaces, for example. It isn’t as stable or consistent as is desired for some applications, and its expansion ratios aren’t always as high as needed. The air used to generate foam at the nozzle may contaminate the foam with soot during a fire and plug the screens that generate foam. Concentrations of foaming agents are high, thus increasing costs. And the momentum needed to deliver the foam to the fire is reduced when the foam impinges on the nozzle, thus reducing its ability to penetrate the fire plume to the seat of the fire.
In responding to these issues, researchers have come up with an important innovation in foam system design: fixed-pipe compressed-air foam systems. Compressed-air foam (CAF) is generated by injecting air under pressure into a foam-solution stream. If the process is done correctly, the solution-and-air mixture moves through the hose or piping, forming compressed-air foam created by the combined momentum of the foam-solution and air-injection streams in the hose or piping.
Mobile compressed-air foam systems mounted on fire service vehicles are already used to fight both wild land and structural fires, delivering CAF through manually operated, smooth-bore-type nozzles that release a “rope” of foam with high forward momentum) This type of system has several advantages. For example, the increased momentum allows the foam to penetrate fire plumes and reach the seat of the fire, enabling firefighters to project the foam a considerable distance, and they use water efficiently.
Given these and other benefits, researchers pondered using CAF in a fixed-pipe system. Such a system hadn’t previously been developed due to difficulties in producing and delivering the expanded foam. Not until researchers proved that CAF could be delivered through a fixed pipe did a fixed-pipe system become a real possibility.
翻译文
枪战泡沫递送了过手提式的设备或者已经从固定-管系统提供有效的火抑压.在像合并水管喷嘴的石油业,这些系统这样的一些工业中, 送气发音-类型固定的喷嘴, 或者吹的人-类型起泡沫产生器, 是必要的. Despi
te 广大使用固定的-管泡沫系统, 然而, 限制已经出现的潜能. 泡沫有到垂直的表面麻烦保留, 举例来说. 它是不当做马房或者一致的同样地是对一些申请的渴求, 而且它的扩充比不是总是当做高度当做需要. 空气过去一直在喷嘴产生泡沫可能在火期间用煤烟弄污泡沫而且插入产生泡沫的荧屏. 起泡沫代理人的集中是高的, 如此逐渐增加的费用.而且动力需要递送泡沫给火是缩小的泡沫何时在喷嘴上打击, 如此减少它的能力穿透到火的位子的火羽毛.
在回应这些议题方面, 研究员已经提出泡沫系统设计的一种重要的改革: 固定的-压缩的管-空气起泡沫系统. 被压缩的-空气泡沫 (CAF) 被藉由在压力之下进入一条泡沫-解决的水流之内注射空气产生. 如果程序正确地被做, 解决-和-经过水管或吹笛的空气混合移动, 形成被泡沫的组合动力产生的被压缩-空气泡沫-在水管或吹笛中的解决和空气-注入水流.
被压缩的可动装置-空气泡沫被展开在救火行动车辆上的系统已经用来对抗荒野土地和结构的火灾,穿越递送 CAF 用手操作了, 用高度向前地释放 " 粗绳 " 的泡沫动力的平滑-令人讨厌的人-类型的喷嘴) 这类型的系统有一些利益. 举例来说,增加的动力让泡沫穿透火羽毛而且到达火的位子, 促成消防队员计画泡沫相当多的距离, 和他们有效率地使用水.
提供这些和其他的利益,研究员沉思了使用一个固定-管系统的 CAF . 如此的一个系统不先前被发展由于困难在产生而且递送被扩大的泡沫方面. 不直到研究员证明 CAF 可能被递送过一个固定的管做了一个固定-管系统变成一种真正的可能性.