Design of a Mobile Robot to Clean the External Walls of Oil Tanks

Introduction

Robotic systems have been applied to tasks where work by humans has drawbacks like the possibility of making mistakes during repetitive tasks, low levels of precision in tasks calling for rapidity, risks of exposure to hazardous settings, or the completion of work that calls for the application of force.

One specific application of robots is the maintenance of tanks in the industry of oil and oil derivatives. These tanks:

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  Avoid shortages of products necessary in the refining process.

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  Ensure the continuous flow of products in the refining process.

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  Measure the barrels of product processed per day.

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  Allow the sedimentation of water, sludge, and other elements that come with oil that are to be removed during the refining process.

Because of the harsh sun, water, wind, and salt conditions these tanks are exposed to, damage to paint often results, thus reducing usable life. Consequently, these tanks constantly require both internal and external cleaning, wall inspection, and repairs.

This chapter presents the design of a mobile robot for externally cleaning tanks of hydrocarbons and hydrocarbon derivatives by removing paint and corrosion from external tank walls by means of high pressure techniques like sandblasting, hydroblasting and hydrosandblasting.

The vortex method, one existing vacuum generation technique, allows mobile robots to maintain a solid grip by means of a constant airflow that creates a suction that in turn produces negative pressure in this closed area, resulting in the necessary force of attraction between the robots and the wall.

Traction in the four wheels enable this umbilical-cable powered mobile robot to climb walls from the ground, controlled through wireless systems like Xbee.