%0 Journal Article
	%A Esam Jassim 
	%D 2014
	%J International Journal of Mechanical and Mechatronics Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 86, 2014
	%T Statistical Modeling of Constituents in Ash  Evolved From Pulverized Coal Combustion
	%U https://publications.waset.org/pdf/9997509
	%V 86
	%X Industries using conventional fossil fuels have an 
interest in better understanding the mechanism of particulate 
formation during combustion since such is responsible for emission 
of undesired inorganic elements that directly impact the atmospheric 
pollution level. Fine and ultrafine particulates have tendency to 
escape the flue gas cleaning devices to the atmosphere. They also 
preferentially collect on surfaces in power systems resulting in 
ascending in corrosion inclination, descending in the heat transfer 
thermal unit, and severe impact on human health. This adverseness 
manifests particularly in the regions of world where coal is the 
dominated source of energy for consumption. 
This study highlights the behavior of calcium transformation as 
mineral grains verses organically associated inorganic components 
during pulverized coal combustion. The influence of existing type of 
calcium on the coarse, fine and ultrafine mode formation mechanisms 
is also presented. The impact of two sub-bituminous coals on particle 
size and calcium composition evolution during combustion is to be 
assessed. Three mixed blends named Blends 1, 2, and 3 are selected 
according to the ration of coal A to coal B by weight. Calcium 
percentage in original coal increases as going from Blend 1 to 3. 
A mathematical model and a new approach of describing 
constituent distribution are proposed. Analysis of experiments of 
calcium distribution in ash is also modeled using Poisson distribution. 
A novel parameter, called elemental index λ, is introduced as a 
measuring factor of element distribution. 
Results show that calcium in ash that originally in coal as mineral 
grains has index of 17, whereas organically associated calcium 
transformed to fly ash shown to be best described when elemental 
index λ is 7. 
As an alkaline-earth element, calcium is considered the 
fundamental element responsible for boiler deficiency since it is the 
major player in the mechanism of ash slagging process. The 
mechanism of particle size distribution and mineral species of ash 
particles are presented using CCSEM and size-segregated ash 
characteristics. Conclusions are drawn from the analysis of 
pulverized coal ash generated from a utility-scale boiler.

 

	%P 348 - 352