Surface-cleaning device and vehicle

#The invention concerns surface-cleaning devices. More specifically, the invention concerns the cleaning of large submerged surfaces which offer limited availability for conventional cleaning methods, such as a partly submerged hull of a ship. The invention also concerns a remotely operated underwater vehicle for carrying the cleaning devices.

#A ship's hull which is subjected to marine organisms is prone to barnacle growth and general fouling, making the hull surface rough and uneven. This leads to greater friction resistance when the ship is propelled through the water, which in turn means a significant increase in fuel consumption. It is known that a 1% increase in friction causes approximately a 3% fuel consumption increase. Frequent hull cleaning is therefore required, both from economical and environmental points of view.

#Developing suitable and practical cleaning equipment for large surfaces, such as ships' hulls, is a considerable challenge, partly due to the hulls' limited accessibility when submerged in water.

#These and other characteristics of the invention will be clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein:

#FIG. 1 is a perspective view of an embodiment of the cleaning robot according to the invention;

#FIG. 2 is a front view of the cleaning robot illustrated in FIG. 1;

#Referring initially to FIG. 1 and FIG. 2, the cleaning robot 1 in the illustrated embodiment basically comprises a tubular frame 7 carrying a cleaning apparatus 40. The cleaning robot 1 is a neutrally buoyant ROV being remotely controlled by an umbilical 6. The umbilical 6 holds power cables and control cables and extend to power and control units (not shown), located for example on a ship or barge on the water surface. The umbilical 6 also holds power and control cables, as well as liquid supply and return hoses, for operation of the cleaning apparatus 40.

#A coordinate system has been defined for the ROV 1, the axes of which intersect the ROV's centre of gravity (CG; see also FIGS. 20 and 21), and where the x axis defines a roll axis; the y axis defines a pitch axis; and the z axis defined a yaw axis. When floating in the water in the state shown in FIGS. 1 and 2, the z axis points upwards and the ROV has an upper side 5a, to which the umbilical 6 and a lifting padeye 4 are attached, and a lower side 5b where wheels 8a,b (shown also in FIGS. 3 and 4) are attached. The terms “upper” and “lower” are relative terms, as the ROV may assume any orientation in the water. In the following, therefore, the upper side in FIG. 1 is denoted the first side 5a, and the lower side in FIG. 1 is denoted the second side 5b.

#The ROV 1 is furnished with thrusters 2, 3, which is used to control the ROV in the water, in a manner which is well known to the skilled person. These thrusters are electrically powered in the illustrated embodiment, but may also be hydraulically powered, but in a manner and with equipment which are well known in the art. The operation of an ROV per se is well known and will therefore not be discussed further.