泡沫消防系統(tǒng)外文翻譯-wenkub
2023-05-18 22:21:23 本頁(yè)面
【正文】 泡沫比例車或裝在拖車上的裝置生產(chǎn)泡沫溶液。固定系統(tǒng)應(yīng)用在設(shè)有大型儲(chǔ)罐的地方，如大型海上轉(zhuǎn)輸站或散裝儲(chǔ)油庫(kù)。例如，改變吸入水流中的泡沫計(jì)量將影響膨脹率、剪切應(yīng)力和析水率，并能通過(guò)選擇泡沫劑的分子式來(lái)生產(chǎn)低（ 6～ 7），中（ 8～ 12）會(huì)或高（ 12～16）膨脹率的泡沫。 泡沫覆蓋層的隔熱性能與泡沫層的穩(wěn)定性及水在泡沫中的存留量有關(guān)?！傲鲃?dòng)性差”的泡沫剪切應(yīng)力約為 1000 達(dá)因 /厘米 2 ，而普通泡沫槍 生成的泡沫的剪切應(yīng)力在 150～ 250達(dá)因 /厘米 2 范圍內(nèi)。 有效地使用泡沫要求泡沫以一種穩(wěn)定的覆蓋層覆蓋在燃燒液體的表面。在壓力下通過(guò)管道或軟管的水用內(nèi)部孔板來(lái)調(diào)節(jié)比例。 水成膜泡沫時(shí)美國(guó)海軍為撲滅突發(fā)性火災(zāi)而開發(fā)的，對(duì)流散火災(zāi)非常有效。以下是某些基本定義： ：一種于水混合后能充氣并膨脹生成泡沫的化學(xué)劑。 壓力不夠時(shí)，就要安裝消防泵。水霧僅對(duì)水霧覆蓋范圍內(nèi)的粘性油或高閃點(diǎn)油有效。切斷燃料或空氣通常就能滅火?；馂?zāi)的發(fā)生必須三個(gè)基本條件： (1)燃料必須以分散狀態(tài)存在，如蒸氣。oating on the water surface may actually spread the fire. Water is of assistance in keeping adjacent tanks and buildings cool. Water fog,a finely divided spray, is useful in shutting off air from burning oil surface and cooling it below ignition fog is effective on viscous oils or high flash oils in areas that are within the range of the spray. A standard fire stream is rated at about 250 gpm using a in. nozzle and in. smooth rubber lined hose. This standard stream will require a nozzle pressure of about 45 psi with a hydrant pressure of 105 psi using 400 feet of hose between hydrant snd nozzle. A main distribution pressure of 125 psi for hose streams and foam generation is adequate. When pressure is inadequate, fire pumps are installed. Pumps in the 500 to 1500 gpm are normally used. Standby pumps, usually diesel engine driven are provided for use in large facilities or when electrical power may be lost during a fire. Fire Fighting Systems The principal of foam application is to cover a burning oil surface with abblanket that will exclude air and smother the. Here are some basic definitions. (1)Foam Concentratea chemical which when mixed with water can be acrated and expanded to form foam. (2)Foam Solutionthe mixture of foam concentrate and water in proper proportions, usually about 310% foam concentrate. (3)Foam – the aerated mixture of foam solution that is made up of air filled bubbles that form a blanket to smother fire. The most pertinent developments with respect to types of foam include the following: (1)protein foam concentrate (2)fluoroprotein foam (3)aqueous film forming foams(AFFF) AFFF was developed by the . navy for crash fires and is very effctive on spill AFFF is bined with dry chemcial powder (Purple K) it is very effective in extinguishing spill fires. Mechanical foam is made when its three parts: water, air and foam concentrate (chemical pound) are brought together in proportionate and thoroughly and turbulently mixed. The basic method of bining thr
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