Performance evaluation of a tubular bowl centrifuge by using laser obscuration method as an online measurement tool

Abstract

ABSTRACT In the nuclear reprocessing plant, after the dissolution of spent fuel, high-speed tubular bowl sedimentation centrifuge is being used to remove the solid particles from the solvent. The performance of the system and extent of clarification of the solvent is ascertained in the chemical laboratory by drawing the sample. A noninvasive methodology, the laser obscuration, is studied for its adaptability as an online measurement tool for determination of clarification status. This would help to manipulate the operation of the centrifuge to achieve desired separation efficiency with minimum time and without interruption. In this context, the performance evaluation of a uniquely designed high-speed tubular centrifuge for reprocessing of fast reactor fuel has been carried out by using laser obscuration method. The light scattering technique has been widely used for the determination of concentration of clarification liquid. In addition, the size distribution is also ascertained in our study, which is useful to determine the grade efficiency of centrifuge system. Two different particulate liquid suspensions namely ferric oxide (Fe2O3) and zirconium molybdate suspended in de-ionized water are used. The tubular bowl centrifuge is tested at the high-speed rotation of the inner bowl (14000–20000 rpm), various throughput of clarifier liquid (30–470 lph) and in half-loaded bowl condition. The laser obscuration method is found to be useful for ascertaining the performance of the centrifuge system and it is recommended as an online tool for monitoring and maintaining separation efficiency by adjusting rotational speed, throughput and to monitor the bowl-loading condition.