上图示出了粘结灰的大致形状。粘结灰不仅在管子背风面形成，更多地在迎风面

上图示出了粘结灰的大致形状。粘结灰不仅在管子背风面形成，更多地在迎风面形成，两侧较少。对这种结灰的成分进行分析，其平均成分仍与飞灰差不多，但仔细分层分析，则发现贴壁一薄层中多升华物成分。例如燃用多碱性金属物质的燃料时，内层多和，呈白色，这是由于有较多的复合硫酸盐。第二层则为结积层，由具有粘性的内层灰捕捉飞灰并再次经过物理化学变化而成。例如对上述燃料，则此层多硫酸盐和氧化铁，呈棕黑（暗红）色。最外层则为飞灰沉积层，成分与飞灰一样。粘结灰最后呈硬结状，像砖瓦一样包在管周上，非常坚实，不易去除，严重时结积速度很高。<br>粘结灰的结积是由开始形成的粘结物在起作用，粘结的成分和程度等和燃料性质及燃烧方法有很大关系，不同燃料和不同燃烧方法中的主要粘结物是不同的。<br>研究较多的是由碱金属的升华（~800℃即可升华）引起的粘结灰。这种灰形成机理大致为：

上图示出了粘结灰的大致形状。 粘结灰不仅在管子背风面形成，更多地在迎风面形成，两侧较少。 对这种结灰的成分进行分析，其平均成分仍与飞灰差不多，但仔细分层分析，则发现贴壁一薄层中多升华物成分。 例如燃用多碱性金属物质的燃料时，内层多和，呈白色，这是由于有较多的复合硫酸盐。 第二层则为结积层，由具有粘性的内层灰捕捉飞灰并再次经过物理化学变化而成。 例如对上述燃料，则此层多硫酸盐和氧化铁，呈棕黑（暗红）色。 最外层则为飞灰沉积层，成分与飞灰一样。 粘结灰最后呈硬结状，像砖瓦一样包在管周上，非常坚实，不易去除，严重时结积速度很高。<br>粘结灰的结积是由开始形成的粘结物在起作用，粘结的成分和程度等和燃料性质及燃烧方法有很大关系，不同燃料和不同燃烧方法中的主要粘结物是不同的。<br>研究较多的是由碱金属的升华（~800℃即可升华）引起的粘结灰。 这种灰形成机理大致为：

The figure above shows the approximate shape of the bond ash. The bond ash is not only formed on the leeward side of the pipe, but also more on the windward side and less on both sides. The average composition of this kind of ash is still similar to that of fly ash, but through careful stratification analysis, it is found that there are many sublimates in a thin layer attached to the wall. For example, when the fuel with multi alkaline metal materials is used, the inner layer is more and more white, which is due to more complex sulfate. The second layer is the accretion layer, which is made up of the inner layer ash with viscosity to catch fly ash and undergo physical and chemical changes again. For example, for the above fuels, this layer of Polysulphate and iron oxide is brown black (dark red). The outermost layer is the fly ash deposit layer with the same composition as the fly ash. At last, the binding ash is hard like bricks and tiles, which are wrapped around the pipe. It is very solid and hard to remove. When it is serious, the deposition speed is very high.<br>The agglomerate of the caking ash is caused by the initial caking material. The composition and degree of caking are closely related to the fuel properties and combustion methods. The main caking materials in different fuels and combustion methods are different.<br>Most of the researches are focused on the bond ash caused by the sublimation of alkali metals (~ 800 ℃). The formation mechanism of the ash is as follows:<br>