Designing a small scale industrial type vacuum distillation column that based on laboratory and pilot plant studies

Abstract

Rolling oil is used in packaging industry for cooling and lubricating rolling sheets during production process. However, the properties of the rolling oil changes with time and that becomes unsuitable for the use. This study was conducted to find out the applicability of vacuum distillation process for purifying the rolling oil and to design a small scale industrial type vacuum distillation column. At laboratory scale, the oil properties were significantly improved when the used oil was distilled under vacuum. However, it was difficult to investigate the packing material parameters and number of theoretical plates in the laboratory scale vacuum distillation unit. Therefore, a pilot scale vacuum distillation unit was fabricated and tested to identify the number of theoretical plates required to reach the final quality of rolling oil. The optimum purity was reached with a column height of 2800 mm and 25 mm ceramic raschig rings as a packing material. Further increase in the height of the column gave no significant improvement and the number of theoretical plate corresponding to the column height of 2800mm was 5. Data obtained in the pilot study was subsequently used to design a industrial scale plant.