烟气的颜色

Observation of smoke may be helpful in obtaining an indication of the type of the fuel. Smoke color, especially colors other than the neutral white, gray, or black, may give indications of special types of fuel being combusted if they are present in large amounts. Smoke that has an unusual hue, such as red-brown or yellow, may indicate the presence of materials other than conventional building materials and furnishings.

观察烟气可能有助于了解可燃物的类型。烟气颜色，特别是有别于常见的白色、灰色或黑色以外的颜色，能表明有大量特定类型的可燃物参与燃烧。红棕色或黄色等特殊颜色的烟气则表明可能存在常规建材和家具以外的材料。

When complete combustion occurs, most materials produce little or no visible smoke. Under these ideal conditions, all carbon is burned to carbon dioxide, a colorless gas. Incomplete combustion of carbon leads to carbon monoxide, also colorless and odorless but having very toxic properties. Incomplete combustion of carbonaceous materials also produces various highly carbonaceous compounds that are opaque, such as soot, which is largely carbon.

当发生完全燃烧时，多数材料只产生少量的或不可见的烟。在这种理想条件下，所有的碳燃烧生成无色气体二氧化碳。碳的不完全燃烧会产生一氧化碳，也是无色无味的，但具有很强的毒性。含碳物质的不完全燃烧还会产生各种不透明的含碳量高的化合物，如主要成分是碳的烟炱。

Hydrogen, present in all organic materials, burns to water vapor, a major constituent of all combustion gases. It does not contribute to the smoke characteristics, although it may at times be recognized as steam. Other elements often present in organic materials, such as nitrogen, sulfur, and halogens, contribute gases to the combustion products. However, only under very special conditions do these alter the color of the smoke. They may contribute strongly to its odor when present in larger-than-ordinary amounts. Such effects may be encountered in industrial fires but rarely in residential ones.

所有有机材料中都含有氢，氢燃烧产生的水蒸气是燃烧产物的主要成分之一。有时认为产物是蒸汽（vapor，物质的气态形式；steam，水受热蒸发产生的蒸汽），但对烟气的特性没有影响。有机材料中常存在其他元素，如氮、硫和卤素，这增加了燃烧产物中的气体类型。然而，只有在非常特殊的条件下，这些元素才会改变烟气的颜色。当其含量高于正常值时，会产生强烈的气味。这种现象在工业火灾中可能遇到，但很少出现在住宅火灾中。

The color of smoke is almost entirely determined by the character and type of fuel and the availability of oxygen for complete combustion. Most materials, including all hydrocarbons, will never burn completely even in the presence of excess air, without premixing of the fuel with air. This is true of natural gas when burning in large volumes.

烟气的颜色几乎完全由可燃物性质、类型以及氧气供给情况决定。包括所有碳氢化合物在内的大多数材料，如果未与空气预混，即使在空气供给过量的情况下也不会发生完全燃烧。大量天然气燃烧时也是如此。

As the hydrocarbon molecules become larger, such as those in petroleum oils, more air is required, and it becomes more difficult to completely mix the fuel with air. Thus, in an ordinary fire, materials such as petroleum distillates tend to produce a large quantity of dense black smoke. Therefore, the presence of much black smoke may indicate the burning of a highly carbonaceous material like the petroleum products sometimes used as accelerants. Dense black smoke, however, is usually more indicative of the amount of ventilation and the stage of development at which the fire is burning. For example, fire burning in a restricted space without adequate and complete ventilation will always form more smoke and darker smoke than when the same fire is well ventilated.

随着碳氢化合物分子增大，比如石油中的分子，其燃烧需要更多的空气，且可燃物与空气完全混合难度变得更大。因此，一般火灾中，石油馏出物等材料往往产生大量的浓密黑烟（见图1）。因此，出现大量黑烟的现象可能表明燃烧过程中存在含碳量较高的材料，如有时作为助燃剂的石油产品。然而，浓密的黑烟通常更能反映通风状况以及火灾所处的发展阶段。例如，相较于通风良好的火灾，受限空间通风不足，燃烧经常会产生更多颜色更深的烟气。