Inventors: Pearu Praakle, Erik Lidmets, Rasmus Sillamaa, Tarmo Must

FIELD OF INVENTION

This disclosure relates to a method and a device for preventing of fouling in general. In particular, a cleaning device for hulls of underwater surfaces while afloat the device being adapted for being pulled across, or along the underwater surface to be cleaned, e.g. by ropes (B63B2059/087)

PRIOR ART AND BACKGROUND INFORMATION

When an unprotected surface is introduced to sweater and left undisturbed inorganic particles, organic matter, and bacteria may settle on the surface. Depending on the location the hull could be covered with slime within one day.

Fouling increases ship’s hull drag and decreases propeller performance, which increases energy consumption. It may also block seawater intakes and can cause the deterioration of paint systems. These all translate into reduced efficiency and higher expenditures (cost). Attempts to control the accumulation of these unwanted organisms have been made for centuries.

The inventors of the present invention have noted necessity for finding a solution to lightly clean, or‘groom’, commercially available coatings at specific frequencies to maintain the surfaces in a smooth and fouling free condition after hull is thoroughly cleaned or in case of a new ship and doing so during ships movement.

Earlier attempts have been made to counteract the fouling processes without the need to drydock the ship and physically removing the fouling. These include but are not limited to antifouling coatings like biocide-based coatings, copper ablative coatings and fouling release coatings.

Different hull cleaning solutions and processes used are also known from prior art. Generally, ships need to be in drydock or they can’t be moving during cleaning process. The drawback of these solutions, drydocking and or the need for the ship to be stationary during cleaning, is very costly. Alternatively, especially for large ships whose dry-docking would be quite complex, a team of divers carries out underwater cleaning of the hull. Disadvantageously, said procedures are quite complex and expensive, since they require suitable and large equipment for lifting the boat or specialist personnel.

To overcome said disadvantages, patent KR20160105629A uses a robot that cleans the ships hull with rotating bristles while using magnetic wheels to stay in contact with the ship. Also said invention collects all the cleaned material to a collecting tank. Said invention limits the usage of the robot into harbors or it can only be used while the ship is stationary. Similar robot and system is also described in patent CN105752290A.

To overcome said disadvantages, patent KR20150114136A uses a cable driven robot that removes fouling under the ship. Described means in said patent limit the cleaning area to the bottom of the hull.

To overcome said disadvantages, patent W02002096748A1 uses a cable driven mat that can clean both the sides and the bottom of the ship. Said device can only clean very small area at the time.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a device and method to address the flaws in currently existing art.

It is an object of this invention to provide an autonomous or semi-autonomous device and method for removal of fresh biofouling that has not grown for more than three weeks and is thus more easily removable than biofouling that has grown for months. Above mentioned device is used as often as possible during ships cruising period in fully autonomous embodiment of this device the biofouling removal is performed continuously while all the environmental conditions are favorable.

The present invention also provides a device and method that is capable removing biofouling during ships movement at cruising speed and furthermore is capable to use ships movement to power itself. The device uses waterflow over the ship’s hull during ships cruising to rotate itself around its longitudinal axis via fins attached to the device and by doing so rotate bristles or other grooming means attached to the device against the ship’s hull.

The present invention also provides a device that moves the above-mentioned grooming module longitudinally along the ship’s hull. Said device comprising: an underwater section comprising of grooming modules; an above the waterline section comprising of means for moving the cable on both sides of the ship, linear guide means on both sides of the ship; a cable that connects both means for moving the cable and all the grooming modules. Said devices means for moving the cable transfer the grooming modules back and forth along the ship’s hull along the linear guide means attached to the sides of the ship’s hull. Said device also adjusts the length of the connecting cable.

It is still another object of this invention to provide a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause a computerized ships hull cleaning device to at least: a) Adjust the length of the cable connecting the means for moving the cable and grooming modules accordingly to the ship’s hull cross-section to provide the optimal length in said cross-section.

b) Transfer means for moving the cable along ship’s hull in synchrony

c) Adjust the speed for means for moving the cable accordingly to the movement of the ship

d) Notify personnel of incidents and give feedback of current position and progress made.

DESCRIPTION OF DRAWINGS

FIG. 1 shows a perspective view of a ship equipped with device for grooming a ship hull from fouling according to present invention;

FIG. 2 shows a front view of a ship equipped with device according to present invention, where means for moving the cables with underwater grooming module are fixed to the linear guide means on both side of ship hull;

FIG. 3 shows a perspective view of the grooming module according to present invention;

FIG. 4 shows a perspective view of two grooming modules connected together;

FIG. 5 shows a cross-section of two grooming modules connected together and in detail universal joint between the grooming modules;

FIG. 6 shows a perspective view of the device that moves the connecting cable, the device is attached to the linear guide means fixed in the upper part of the ship hull. FIG. 7 shows a cross-section view of the grooming module while in contact with the sips hull to illustrate placement of fins and brushes.

FIG. 8 shows a cross-section view of two grooming modules connected together and in detail swivel joint between the grooming modules.

DETAILED DESCRIPTION OF THE INVENTION

Now referring to the figures, the ship cleaning device according to this invention is constructed of several modules and it comprises an underwater grooming module(s) Fig.3 140, connecting cable Fig.1 130 and Fig.2 130, means for moving the cable

Fig.1 120 and Fig.2 120 and Fig-6, linear guide means Fig.1 110 and Fig.2 110.

The term“underwater” before grooming module should be not taken as limitation because if the ship does not have load some underwater grooming modules can reach out in the water because the ship’s draft is decreased.

Each underwater grooming module 140 has a cylindrical shape and is capable to rotate around its longitudinal axis. The adjacent grooming modules are connected to each other by connecting means. For example grooming modules are connected to each other from ends via a universal joint 190 comprising of a pair of hinges oriented at 90 degrees to each other and connected by a cross shaft, in alternative embodiments underwater grooming modules are connected to each other but not influenced by each other’s motion so that they can move independently from each- other in said embodiment is used a swivel joint Fig 8 230 where one end of the grooming module has a ball swivel and the other end has a casing. The underwater grooming modules are fitted with fins 160 that make the modules spin around its longitudinal axis, the fins are placed such a way that modules always spin in the same direction shown on the Fig 3 160 is one possible embodiment of these fins. Also fitted on the grooming module are brushes or other means of grooming 200 that rotate with the grooming module and come in contact with the hull (not shown). The brush lines are placed alternately with fins, i.e. brush line then fin, then again brush line etc. In fig 7 is shown in the five brush lines and five fins but the number brush lines or fins can be different depending of the design of grooming module.

In the center of the grooming module is an internal enclosed space or internal core 170 filled with compressed buoyant gas such as compressed air, helium or nitrogen or in alternative embodiments the internal core can be made of material that is buoyant (or floating material, material lighter than water) such as polyurethane. The fins 160 are fitted or attached to the internal core 170 or alternatively the fins are as integral part with said core. The cross section of the fins is rectangular shape along the length of the fin or the cross section of the fins alternatively can be curved all along the length of the fin (see fig 3). When ship is moving the water pressure affect the fins and they start to spin with internal core around the longitudinal axis of the underwater grooming module fitted to the connecting cable 130.

Through the (enclosed space) internal core runs a hole 210 which houses the connecting cable (not shown in fig 3). Buoyancy keeps underwater grooming modules pressed against the ship’s hull. At the ends of each grooming module there is a wheel (roller) 180 that keeps the module at a certain distance above the ship’s hull. Said roller rotates independently from the grooming module when connecting cable is by means of moving the cable moving in the linear guide means.

Connecting cable connects both means for moving the cable located on upper part of the left and right side of the ship hull and passes underneath the keel of the ship’s hull. Also, the connecting cable runs through all the underwater grooming modules (see Fig 4 and Fig 5) while it goes around the ship’s hull. The underwater grooming modules have an enclosed inner space or internal core that is an elongated toroidal shape that has a trough hole for the connecting cable. Also, the universal joints 190 have a trough hole 220 for the cable to pass through (see fig 5). In alternative embodiments of the device the connecting cable connects to the first underwater grooming module and then the modules connect to each other until the connecting cable continues the other side of the ship.

The means for moving the cable Fig 6 are placed on each side (left and right side) of the ship’s hull 100 and they move along a linear guide means 110 that are mounted to both sides of the upper part of the ship’s hull 100. At least one of the means for moving the cable must be able to regulate the length of the connecting cable via a winch 230 to provide the optimal length for the current hulls cross section. The winch is rotated by the means of winch motor 240. Both means for moving the cable must be able to move in synchrony with each other and with designated speed. To move the means of moving the cable along the ship’s hull a toothed rack 250 mounted similarly to linear guide means to both sides of the upper part of the ship’s hull (see fig 6), is used accompanied with a pinion (not shown) mounted to a pinion motor 260. All the components of the means for moving the cable are mounted to a common frame 270 forming means for moving the cable.

All movements are controlled by a controller module (not shown) a non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause a computerized device adjust the length of the cable connecting the means for moving the cable and grooming modules accordingly to the ship’s hull cross-section to provide the optimal length in said cross-section, transfer means for moving the cable along ship’s hull in synchrony, adjust the speed for means for moving the cable accordingly to the movement of the ship, and notify personnel of incidents and give feedback of current position and progress made.

AN EXAMPLE OF INTENDED USE

In case of new ship. While the ship has not jet launched to water, linear guide means 110 on both sides of the hull 100 are installed. If needed then in alternative embodiments in addition the toothed rack is installed on both sides of ship’s hull. Connecting cable 130 is installed along with underwater grooming modules 140 under the ship’s hull. Also, means 120 for moving the cable will be installed at this moment. After ships launch, the system will be ready to be use during cruising.

In case of a used ship. When the ship goes to drydock for its next regular maintenance to be cleaned of fouling, linear guide means on both sides of the hull are installed. Connecting cable is installed along with grooming modules under the ship’s hull. Also, means for moving the cable will be installed at this moment. After ships launch (leaves the dry dock) the system will be ready to be use during cruising.

While cruising the means for moving the cable move along the ship’s hull back and forth with designated speed and in synchronicity. At least one of the means for moving the cable can adjust the length of the connecting cable that connects both means for moving the cable to accommodate to the length of the current ship’s cross- section.

As the ship cruises the waterflow over the ship’s hull causes underwater grooming modules, that are mounted to the connecting cable, to rotate itself around its longitudinal axis. This rotational motion also grooms the surface of the hull of fresh fouling via bristles. 100 - ship’s hull

110 - linear guide means

120 - means for moving the cable

130 - connecting cable

140 - underwater grooming module

160 - fins

170 - internal core (internal enclosed space) 180 - rolling means, such as wheel, roller 190 - universal joint

200 - means of grooming, brushes

210 - hole through the enclosed space 220 - trough hole in universal joint

230 - winch

240 - winch motor

250 - toothed rack

260 - pinion motor

270 - common frame

280 - swivel joint