The fluid produced from oil and gas wells is usually two-phase, which due to the need to maximize the efficiency of two-phase separators, achieving accurate design of separator dimensions is essential. But one of the main problems in the country is the impossibility of accurate design of the dimensions of industrial two-phase separators. Therefore, one of the most important issues in the field of oil and gas industry is to achieve a reliable way to design the dimensions of separators that have the best operational efficiency in the process of separating the production fluid. In this study, a review of classical methods of designing two-phase separators based on theoretical and semi-experimental methods was performed. Then, in order to evaluate the two-phase separators in the laboratory, the laboratory pilot design of the separators was performed. Therefore, one of the main problems in this field, namely the lack of a suitable laboratory pilot to experimentally evaluate the performance of two-phase separators, was solved, and it was possible to determine the standard dimensions for accurate design of industrial separators. According to the results of experiments performed in different operating conditions and comparison with the classical design, a correction factor (α) was proposed to modify the classical relations. Finally, the dimensional analysis method was introduced to design the dimensions of the industrial separator using laboratory results. In order to validate the dimensional analysis method, standard dimensions for separating liquid droplets larger than 750μm in the produced fluid by one of the wells in South Pars field were presented and compared with the actual separator dimensions. It should be noted that the design error of industrial separator dimensions compared to the dimensions of separators used in industry, has been less than 4 percent.

In this study, the turbulent gas-particles multi-phase flow through the helical coil separator has been simulated by CFD techniques. Eulerian-Eulerian approach was used for multi-phase flow simulation. For validation, the friction coefficient gaining from CFD simulation was compared with experimental values. The results showed that the RSM and RNG k-e turbulence model and wall function model and second upwind method for solving partial differential equations are most appropriate method for simulating two-phase flow through ahelical channel. Finally, the influence of solid load in the gas flow, particle size and flow rate on the separation efficiency and pressure drop were investigated. The results showed with increasing of solid loading, the efficiency of cyclone decreases. The simulations have been done for particle size up to 16 micron, the results present the variation of efficiency is not significant (close to 100%) for particle size bigger than 6 micron. Also it was observed the appropriate inlet velocity for efficient performance of cyclone is between 5-10 m/s.

The Gas-Liquid Cylindrical Cyclone (GLCC) separators have proven themselves in laboratory and field, as a well alternative to the conventional gravity-based gas/liquid separator. This study presents investigation of the effect of changes in physical aspects on GLCC performance. These changes are including increases in outlet length and reduction in gas body column length, inlet, body column, liquid and gas outlet diameter. In addition, results show that reduction of inlet diameter enhances the GLCC performance but any reduction in diameter of body column and liquid outlet has negative effect on that. Also, changes in gas outlet diameter does not have any effects on the GLCC flowrates domain. Finally, any increase in length of outlets rises the friction force and diminishes the performance of separator.

Several theoretical approaches for predicting performance parameters (collection efficiency, pressure drop, and velocities) of cyclone separators have been developed due to their extensive use in particle handling industries. Expensive and time-consuming experiments to analyze the swirling flow inside the cyclone separators could be avoided with reliable theoretical approaches. However, there are only a limited number of cyclone theory evaluations in the literature. This study investigated the accuracy of cyclone theories by comparing experimental and numerical data at a particle loading rate of 1. 0 g. m-3 operating at 5 and 10 m. s-1. General agreements between the theories were revealed by Muschelknautz’s theory for collection efficiency and Shepherd and Lapple’s theory for pressure variations at low solid loading conditions, disagreements were found to be due to the theories’ insensitivity to influences from the particle phase and the frictional wall effect inside cyclone separators.

Vane plates are considered as one of the most efficient devices in industry which are widely used to eliminate liquid droplets from gas flows. In this study, the two-phase flow of gas-liquid between the wavy plates of a type of vane separator was simulated using Computational Fluid Dynamics (CFD) technique and influences of three independent factors of inlet gas velocity, vane spacing and vane angle on the separation efficiency were investigated. To model the liquid-gas flow, Eurelian-Lagrangian approach was applied and separator efficiency was evaluated within a velocity range of 3-8m/s while mass fraction of liquid droplets in the gas flow was 0.089. The liquid film breakup phenomenon was considered in these simulations. Having compared simulation results with experimental data, we realized that there was an average error about 0.9% in simulations. Regarding the simulation results, vane separation efficiency depends on inlet gas velocity and geometrical parameters of the vanes.

Separation of thallium isotopes (203Tl , 205Tl ) have been carried out by a 180o electromagnetic isotope separator. Thallium iodide as the charge material is used in a graphite crucible of calutron ion source. Under the pressure of 1 × 10-5 torr, thallium ions are extracted, accelerated and focused by the electrical lenses. The ions then traverse the main vacuum tank in circular paths, entering the magnetic field of 2547 Gauss and finally reach the collector. A number of chemical procedures have been employed for recovery and purification of the collected ions from the copper pockets. The final isotopic products have been characterized by a x-ray diffractometer, inductively coupled plasma-atomic emission spectrometer (ICP-AES) and a mass spectrometer. High pure thallium trioxide (Tl203 ) with 95.91% isotopic abundance for 203Tl has been confirmed.