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Abstract-This paper presents a three-dimensional computational fluid dynamics (CFD) modeling study carried out for a rotary cement kiln withal multi-channel burner with swirl and high momentum air components. The simulations are performed using the commercial CFD software ANSYS FLUENT, version 13.0, and are carried out for coal as well as for meat and bone meal (MBM) combustion using the eddy-dissipation model for combustion. Steady-state solutions are obtained using the Lagrangian approach for the particle phase and the Eurasian approach for the continuous phase. The turbulence is modeled by the RNG k-ε model, and gas-phase radiation is modeled by the P1 radiation model. The effect of MBM fuel properties on combustion characteristics such as temperature, fuel devolatilization, volatiles and char burning, in comparison with coal, are presented and discussed. It was found that MBM combustion products temperatureis300K lower than that of coal, and the char burnout of MBM is 83%. This poor burnout is mainly due to bigger MBM particles.Index Terms-CFD, combustion, meat and bone meal, rotary cement kiln.

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The offshore drilling operations generate huge volume of drill cuttings. Rig site transfer of cuttings can be a challenge both if pneumatic conveyors or screw conveyors are used. Especially, wet powder is a challenge since the particles become too sticky for easy handling or too dry for acting like a slurry. This paper presents the preliminary results of a scientific investigation aimed to study transport properties and storage criterion of dry and partially-moist solids drill cuttings. Model materials have been tested in pilot scale pneumatic conveying rigs and CFD simulation on particle conveying has been performed in parallel. The pilot scale tests have been conducted for the sand particles in the size range of 0.1 – 3 mm diameter under the air flow rate of 13-23 ms-1 The simulations were carried out using multiphase particle-in-cell method (MP-PIC) for dry particles that are having particle size distribution in the range of 0.3-3 mm diameter. Pressure drop in a horizontal section is studied and it was observed that at a minimum pressure drop and a minimum specific power requirement is reached when decreasing the superficial air velocity. This region can be considered as the economical region for operation. For the considerd particle size this region was obtained at the air velocity of 16-19 ms-1 for a horizontal pipe section with 81.2 mm diameter. In the simulations, the predicted pressure drops in 15-22 ms-1 velocity range are in good agreement with experimental results. The combination of pilot scale pneumatic conveying tests and simulations of dry drill cuttings provide a platform to evaluate and predict pneumatic conveying parameters for partially-moist drill cuttings.

Drill cuttings generated by offshore drilling operations are handled as a hazardous waste. In sensitive marine environments, the concept of zero discharge of waste is implemented. Hence, the drill cuttings have to be stored within the drilling rig for a short time period until they are transported to the onshore treatment facilities. As the drill cuttings are wet and sticky, conventional single silos may face the problem of blockage and rat holing. This preliminary study focuses on conducting flow property measurements. From the experiments the hopper angle and the required minimum outlet width were calculated. A plane symmetric silo with 25.8° hopper angle is suitable for all the conditions. The viscosity of the fluids is affecting the results significantly.