Pollution characteristics of the generated particles during finishing rolling process and concentration monitoring in the occupied zone

Abstract

In order to explore the pollution characteristics of finishing rolling process in hot rolling mill of the iron and steel industry in China, SEM, laser particle size distribution test and field measurement were used to study the micro morphology, particle size distribution and pollution property of the occupied zone during the finishing rolling process in hot rolling mill of Guangdong province in Summer of 2019, respectively. The results showed that the particles produced by the finishing rolling process had irregular morphology and conglomeration. The particle size was mainly within the range of 2.423~3.519 μm, the uniformity index of the Rosin-Rammler distribution was 1.769, and the characteristic size was 2.932 μm. The results laied a foundation for the numerical simulation and analysis of the cleaning and dust removal of the finishing rolling process. The environmental particle concentration in the occupied zone fluctuated periodically over time. The aforementioned concentration of the environmental measuring points in the finishing rolling zone showed an increasing trend along the rolling direction, and the average concentration ratio of PM2.5/PM10 were 0.807, 0.749 and 0.912 in turn, which indirectly reflected the pollution characteristics of finishing rolling source. Thus, it is suggested that along the rolling direction, the designing ventilation flow rate should be enlarged for each exhaust hood in sequence, so as to achieve the precise control of local environment quality.