Design of a cleaning and homogenization robot for large oil storage tanks

A number of methods are currently employed for cleaning and inspection of large fuel storage tanks. All of these methods require that the tank be first taken out of service, emptied, the present sludge material removed, vented, and cleaned before the inspection process is undertaken. This process is very time consuming, laborious and costly. In addition, there is a great safety concern for people that have to operate the machinery inside the tank. In this paper, the design of a novel robotic system for cleaning large crude and # 6 oil storage tanks through regular homogenization that also prepares the tank surfaces and weld line for in-situ inspection is presented. The developed system is shown to not only reduce the direct and indirect cost of fuel tank cleaning and inspection, but also greatly reduce the amount of solid waste that has to be disposed of at high cost and with potentially high adverse environmental impact. This design solves most of the problems associated with the presently available telerobotic systems for similar operations since it makes it possible for the operator to be in constant visual contact with the robot operating within the tank. This novel design also greatly reduces the logistics problems related to the tether line and its handling within the tank and its entanglement. A prototype of this system is under construction.