Design optimization of a novel screw conveyor based system to scoop oil sludge from floor of storage tanks

Abstract

• Novel screw conveyor system for online sludge scooping from the oil storage tank floor without having to empty it. • Mathematical model results approximated the optimal set of screw design parameters for optimum scooping sludge volume. • In the CFD package, rheological material behavior is simulated to visualize the flow of particles in different screw designs. • Experimentally quantified the maximum amount of sludge scooped at a given speed for a certain range of radius and pitch ratio. This paper presents the design optimization and testing of a novel screw conveyor based system to scoop crude oil sludge from the floor of oil storage tanks. This proposed new system consists of a screw conveyor mounted on a ‘C’ shaped casing with a bearing on both sides driven by a waterproof motor through a worm drive. A novel mathematical model is developed to help the design of a screw conveyor for a maximum amount of sludge scooping per turn, and numerical simulations are performed using computational fluid dynamics to visualize the flow of material particles in various possible designs of the system. The proposed mechanism was 3D printed, and laboratory tests were conducted to quantify the amount of sludge removal by the different designs of the screw. Optimized design of a mechanism screw with a radius ratio of 0.40 and a pitch ratio of 0.15 scoops up to a maximum of 5.88 kg hr of material at 110 rev min .