The effect of diameter and height of the inserted rod in a dense medium cyclone to suppress air core

Studies were carried out by suppressing the air core in a 100 mm DMC using a metal rod inserted through the spigot. The effect of the diameter of the inserted rod and its height of insertion on the Ep of the cyclone was studied. A spigot blocking ratio of 0.4 with 60% of free VF clearance gave the best separation efficiency. Multiphase CFD studies showed that the improved performance of the cyclone was because of (i) higher tangential velocity and hence higher centrifugal force acting on the particles (ii) lower radial and axial velocities at the VF reducing misplacement.

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► Different diameters of rods were inserted through the spigot of a 100 mm DMC.
► At the “optimized conditions” of rod insertion: the axial velocity was minimum at the VF tip minimizing misplacement.
► On an average, the tangential was more by 9–16%, in the conical section enhancing separation.
► The solid–liquid boundary was stabler and could “concentrate” light particles.
► The magnitude of the radial velocity was smaller.