Comparison of not modernized and modernized bitumen batch systems of an asphalt mixing plant

Abstract

In the batch type of an asphalt mixing plant (AMP) mass o f the weighted matrix in the all merging batcher’s tanks should correspond in per cents equally in the hot - mix asphalt (HMA) to the designed amount of the job - mix formula (JMF). The bitumen batcher does not always weigh bitumen portions precisely. Their ma ss deviations from the amount determined by JMF and its variation impair HMA composition and performance. The data on statistical evaluation of bitumen batcher’s modernization performed at certain Lithuanian Enterprise are discussed. The differences in str uctures of modernized and not modernized bitumen batching systems (BBS) are analysed and methods of determining modernization effectiveness are presented. Some particular aspects such as the improvement methods of technological parameters for hot bitumen s torage in a pipeline system, transportation and dosed supply to batch AMP are evaluated in this paper. The main objective of this study was to determine the effectiveness of BBS modernization, defining the deviations of bitumen content in subsamples, taken and extracted every day for four seasons (before and after the batcher‘s modernization) of HMA mixture production from the value of JMF and comparing them to the values of tolerances. The analysis of histograms shows that the made modernization helped to increase the precision of supplying the required amount of bitumen to HMA mixture insignificantly. It was also concluded that the process of BBS production became more easily to control, the use of the elements of automatic control helped to make the opera tion of system‘s equipment more precise and effective.