The major drawbacks of coal combustion are connected with the large emission of particulate matter. This paper deals with the experimental investigation of ultrafine (D100nm) and nano (D10nm) ashes formed during conventional high temperature pulverized coal combustion on a laboratory-scale reactor. The reactor consists of an atmospheric pressure laminar premixed flame homogeneously doped with pulverized coal particles, monodisperse in size. It allows the investigation of the early stage of ash formation. Generated aerosols, sampled using high dilution probes, are conveyed into high resolution Differential Mobility Analyzers (DMA) to perform on-line measurements of the size distribution function of ultrafine ashes. Two DMA systems are used: the first is equipped with a Faraday cup electrometer detector and identifies particles as small as 1nm, and the second is equipped with a condensation nucleus counter and exhibits 3nm lower detection limit. Measurements have been performed at several dilution ratios to understand the nature and behavior of detected particles. Results indicate that nanosized coal ashes are formed during pulverized coal combustion. They are the most abundant in number and also a significant fraction of ultrafine ash mass, implying they should be detected at the exhaust of pulverized coal furnaces.
Size distribution functions of ultrafine ashes from pulverized coal combustion / Carbone, Francesco; F., Beretta; D'Anna, Andrea. - In: COMBUSTION SCIENCE AND TECHNOLOGY. - ISSN 0010-2202. - STAMPA. - 182:(2010), pp. 668-682. [10.1080/00102200903466491]
Size distribution functions of ultrafine ashes from pulverized coal combustion
CARBONE, FRANCESCO;D'ANNA, ANDREA
2010
Abstract
The major drawbacks of coal combustion are connected with the large emission of particulate matter. This paper deals with the experimental investigation of ultrafine (D100nm) and nano (D10nm) ashes formed during conventional high temperature pulverized coal combustion on a laboratory-scale reactor. The reactor consists of an atmospheric pressure laminar premixed flame homogeneously doped with pulverized coal particles, monodisperse in size. It allows the investigation of the early stage of ash formation. Generated aerosols, sampled using high dilution probes, are conveyed into high resolution Differential Mobility Analyzers (DMA) to perform on-line measurements of the size distribution function of ultrafine ashes. Two DMA systems are used: the first is equipped with a Faraday cup electrometer detector and identifies particles as small as 1nm, and the second is equipped with a condensation nucleus counter and exhibits 3nm lower detection limit. Measurements have been performed at several dilution ratios to understand the nature and behavior of detected particles. Results indicate that nanosized coal ashes are formed during pulverized coal combustion. They are the most abundant in number and also a significant fraction of ultrafine ash mass, implying they should be detected at the exhaust of pulverized coal furnaces.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.