Outlet design optimization based on large-scale nonsmooth DEM simulation
2011 (English)Conference paper, Abstract (Other academic)
We consider the application of a nonsmooth discrete element method (NDEM) [1-3] to geometricdesign optimization of a balling drum outlet used in production of iron ore pellets. The geometricdesign optimization problem is based on the need for spatially and temporally homogeneous flow ofpellets from the balling drum onto a wide belt conveyor feeding a roller sieve. Homogeneous pelletflow makes sieving most efficient and facilitates good control in the hardening furnace. The model ofthe pellet material and balling drum are specified in a NDEM framework. The simulation andanalysis procedure is described. A material flow profile in terms of design parameters is computedfrom simulation data and used for solving the design optimization problem. The solution is comparedwith different designs used in a real production plants. It is demonstrated that the method can clearlydistinguish between the original and improved design in that plant. The uncertainty in the optimaldesign parameters is discussed and put in relation to the assumptions and approximations behind the particular NDEM that is used. Proposal for how to improve and validate the material and ballingdrum model is given.
The particular NDEM is described in more detail in an accompanying paper  where the method isalso contrasted to the more conventional smooth discrete element method (DEM) . The nonsmoothapproach allows for time integration using time-steps much larger than the characteristic elasticresponse time. Given an efficient solver and that the system and application justifies the nonsmoothapproximation a considerable speed-up can be achieved, though it should be recognized that this issignificantly problem dependent. The current paper includes analysis of the computational efficiencyof the NDEM approach to the particular case of balling drum outlet flow analysis with a given errortolerance. Time estimates of a corresponding smooth DEM approach is provided for comparison.
Place, publisher, year, edition, pages
Applied Mechanics Materials Engineering
IdentifiersURN: urn:nbn:se:umu:diva-55938OAI: oai:DiVA.org:umu-55938DiVA: diva2:532468
Particles 2011 – ECCOMAS International Conference on Particle-based Methods, 26-28 October 2011, Barcelona, Spain