Isotope and Radiation Application Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
Uranium Extraction Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
Appl Radiat Isot. 2022 Nov;189:110404. doi: 10.1016/j.apradiso.2022.110404. Epub 2022 Aug 10.
Mixer-setters units are widely used in uranium purification processes. For efficient operations of mixer-settler units, it is essential to measure the hydrodynamics parameters of the different phases involved. The residence time distribution (RTD) measurement is commonly used method to estimate the hydrodynamics parameters of process reactors. In the present study, RTD of the aqueous phase was measured in different stages mixer-settler unit (mixers, settlers and mixer-settler units) used for stripping operation using Iodine-131 as a radiotracer. For the RTD measurements, radiotracer was injected as an impulse in aqueous phase feed line and its movement was monitored at different locations in the stripping unit using NaI(Tl) detectors. The mean residence times (MRTs) of the aqueous phase were estimated from measured RTD curves. For quantification of the degree of mixing, suitable flow models were proposed based on design and nature of the measured RTD curves and subsequently used for simulation. Based on the results of the RTD study, the mixing of aqueous phase was characterized and design of the stripping unit and its sub-units were validated. The optimum conditions were identified for efficient for the operation of the stripping unit.
混合-沉降器单元广泛应用于铀纯化过程中。为了使混合-沉降器单元高效运行，测量涉及的不同相的流体动力学参数至关重要。停留时间分布（RTD）测量是常用的方法，用于估算过程反应器的流体动力学参数。在本研究中，使用碘-131 作为示踪剂，在用于汽提操作的不同阶段的混合-沉降器单元（混合器、沉降器和混合-沉降器单元）中测量水相的 RTD。为了进行 RTD 测量，将示踪剂作为脉冲注入水相进料线，并使用 NaI(Tl)探测器在汽提单元的不同位置监测其运动。通过测量的 RTD 曲线估计水相的平均停留时间（MRT）。为了量化混合程度，根据测量的 RTD 曲线的设计和性质提出了合适的流动模型，并随后用于模拟。基于 RTD 研究的结果，对水相的混合进行了表征，并验证了汽提单元及其子单元的设计。确定了最佳条件，以实现汽提单元的高效运行。
