WO1982002368A1

WO1982002368A1 - Ship hull cleaning device

Info

Publication number: WO1982002368A1
Application number: PCT/US1981/001781
Authority: WO
Inventors: Stephen W Oram
Original assignee: Stephen W Oram
Priority date: 1981-01-02
Filing date: 1981-12-31
Publication date: 1982-07-22
Also published as: EP0068022A4; EP0068022A1; JPS58500001U; JPS6340080Y2

Abstract

A cleaning device for removing foulant from the hull (16) of a sea going vessel comprising a carriage (12) a reactor nozzle (40) aligned to produce a reactive force which opposes the force component of the cleaning nozzles (30) which tends to urge the carriage (12) away from the hull of the ship, and control members (24, 26) for displacing the carriage across the hull surface of the vessel Previous devices had problems with controlling movement of a plurality of cleaning nozzles and keeping a carriage against the hull which are overcome by the instant cleaning device.

Description

SHIP HULL CLEANING DEVICE Background of the Invention

I. Field of the Present Invention:

The present invention relates generally to clean¬ ing devices which hydraulicly or mechanically abrade the surface of a ship's hull to remove any accumulated deposits therefrom and more particularly to a carriage for control¬ ling the movement of such cleaning devices across the hull surface of a ship.

II. Description of the Prior Art:

A well-known problem encountered by seagoing ves¬ sels is that foulant such as barnacles, marine plant growth and the like accumulate upon the ship's hull. Such foulant increases the drag as the ship moves through water and therefore increases fuel consumption and reduces the top speed of the ship. Consequently, the hulls must be cleaned periodically to remove the foulant and thus avoid the high cost of inefficient operation of the vessel. In addition to the energy savings, hull cleaning maintains the productivity of each vessel, and as a result, initial fleet investment can be minimized.

A known means for removing the foulant comprises scrapping or chiseling the foulant from the hull surface. However, manual scraping of the hull surface is extremely tedious and time consuming. Moreover, manual scraping is best accomplished in dry dock and, therefore, prolongs the time during which the ship is not available for service.

An improved means for scraping the hull comprises the use of powered rotating brushes which are mounted on a manually guided, wheeled platform. Although such scrubbing devices have been adapted for use below the waterline while the ship is anchored, they are difficult to control. Conse¬ quently, they are typically transported and controlled by a vessel separate from the vessel to be cleaned.

o?.:?ι Another previously known manner for removing fou¬ lant comprises the use of a highly pressurized flow of fluid through a hose and against the foulant on the hull surface. The fluid can be water or a combination of particulate matter and water which is discharged with great force against the foulant. The use of particulate matter as an abrasive medium is disadvantageous in that the particles can pit the surface of the hull and remove the paint from the surface. In addi¬ tion, as the particles are reflected from the surface, they are released into the atmosphere and present undesirable safety and environmental consequences.

Thus, another previously known means for removing foulant comprises the use of only pressurized water. The pressurized water is delivered through a hose having a noz¬ zle at the end which increases the force of the fluid stream discharge.

Moreover, due to the fact that foulant tightly adheres to the surface of the ship's hull, extremely high pressures must be generated in order to blast the foulant from the hull. Thus, although the hose can be manipulated rather easily, and is typically held by a worker who directs the flow against the hull of the ship.

Although the use of high pressure water is highly effective in removing barnacles from the hull of a ship, the flow from the single nozzle contacts only a very limited area of the hull's surface. Thus, the cleaning of large vessels remains extremely time consuming. Although this down time is extremely costly in terms of the service lost as well as storage costs, the necessity for removing the foulant dic¬ tates that the delay be tolerated.

Of course, it would be advantageous to increase the area contacted by the pressurized fluid stream. However, the pressure required to remove the foulant causes a larσe

U __ Λ o:.σι force to be exerted against the hull of the ship which pushes the nozzle away from the hull. Resistance to this pushing force is provided by the worker who handles the nozzle. Because of the magnitude of the force which must be resisted by the worker, it has not been practical or possible for the worker to operate more than one nozzle in order to increase the cleaning swath and thereby decrease cleaning time. More¬ over, the large forces created by nozzles presents a serious risk that two or more workers working together, each operat¬ ing a single nozzle, can cause serious injury to co-workers. Consequently, it has not been practical to utilize more than a single nozzle at one location during the hull cleaning operation.

Summary of the Present Invention The present invention overcomes the above-mentioned disadvantages by providing a cleaning device incorporating a carriage that supports a plurality of cleaning means so that they can be operated and moved across the hull of a ship auto¬ matically. The device includes means for resisting any forces exerted against the hull which tend to push the cleaning means away from the hull surface. The device also includes means for moving the nozzles in a predetermined path along the sur¬ face of the hull.

In one embodiment the device generally comprises a carriage, a plurality of cleaning nozzles facing outwardly from one surface of the carriage and a manifold carried by said carriage to provide a supply of pressurized fluid to the nozzle. The carriage is supported a predetermined distance away from the surface of the hull by a support means such as swiveling casters so that the carriage is easily moved about the surface of the hull. Translational control means for moving the carriage across the hull preferably comprises flexible horizontal and vertical elonσa ed elements such as

OM?I cables. The vertical and horizontal members are secured at one end to the carriage. The other end of each member is secured to an extension/retraction means, such as a winch, which can be mounted in a fixed position with respect^" to the hull. A means for maximizing the tension in the members per¬ mits actuation of the winches to provide accurate displacement of the carriage about a large area of the hull surface in a repetitive pattern.

The means for resisting the force of the cleaning nozzles and thereby maintaining the carriage casters against the hull, preferably comprises a reactor nozzle extending out¬ wardly from the carriage surface opposite to the surface carrying the cleaning nozzles. The reactor nozzle is posi¬ tioned so that the reaction force applied to the carriage by the nozzle directly opposes the effective force vector produced by the plurality of the cleaning nozzles which tends to push the carriage away from the hull. In addition, the reactor nozzle is aligned so as to create a force component which tends to maintain the support members in a tensioned condition. Preferably, the nozzle alignment is adjustable so that the placement of the winch members can be varied.

Thus, the present invention provides a device for controlled cleaning of foulant from the surface of a shi 's hull. The carriage is adapted to carry a plurality of clean¬ ing nozzles so that a wider area of the hull can be cleaned in a given time. The reactor nozzle provides sufficient resistance to the force exerted against the hull by the cleaning nozzles to restrain the cleaning device against the hull of the ship. Moreover, since the carriage is moved across the surface of the ship automatically by remotely secured driving means, workers are not exposed to the risk of injury from the high-pressure cleaning nozzles. In addi¬ tion, the device is especially useful in that it reduces the

O PΓ the amount of time that was previously necessary in order to completely remove the foulant from the hull.

It will be understood that cleaning means other th high-pressure nozzles, such as the previously known rotary brushes, can be advantageously used with this controlled pat¬ tern carriage device. Moreover, it will be understood by those skilled in the art that the device permits cleaning of the hull in dry dock or while the ship is at anchor. In fact with the addition of stabilizing fins on the carriage to maintain positioning, it is possible to accomplish cleaning while the ship is underway.

Brief Description of the Drawing The present invention will be more clearly under¬ stood by reference to the following detailed description of a preferred embodiment of the present invention and the accompanying drawing in which like reference characters refer to like parts throughout the several views and in which:

FIGURE 1 is a perspective view of the cleaning device of the present invention positioned on a ship's hull during the cleaning operation;

FIGURE 2 is a top plan view of the cleaning device of the present invention; and

FIGURE 3 is a sectional elevational view taken substantially along the line 3-3 in FIGURE 2.

Detailed Description of the Present Invention Referring now to FIGURE 1, the present invention 10 is thereshown comprising a carriage 12 mounted on casters 14 for rolling movement along the hull surface 16 of the ship 18. The carriage is secured in position by elongated retaining cables 20 and 22. The cable 20 is secured at one end to the carriage 12 and at its other end to a winch 24 which is se¬ cured to th deck of the ship 18. Means for operating the winch (not shown) permit the cable 20 to be extended and retracted vertically. Likewise, the cable 22 is secured at one end to the carriage 12 and at its other end to the winch 26. The winch 26 is shown secured to a drydock wall 27, although it could also be secured to the bow or deck of the ship 18. Means for controlling the winch 26 (not shown) permit the carriage 12 to be translated in a horizontal direc¬ tion.

As best shown in FIGURES 2 and 3, a plurality of cleaning nozzles 30 extend outwardly from the bottom surface of the carriage 12. The nozzles 30 fluidly communicate with fluid passageways of a manifold 32. The^' inlet passage 34 of the manifold 32 fluidly communicates with the fluid coupling 36 secured to the outside of the carriage 12. A hose 38 is mated with the coupling 36 to provide fluid communication between a remotely positioned fluid source 40 via pump 42 (see FIGURE 1) and the manifold 32.

Although the nozzles 30 can be aligned substantiall normal to the surface 11 of the carriage 12, and thus sub¬ stantially normal to the surface of the hull, in order to permit the full force of the fluid discharged from the nozzle to directly impinge upon the foulant on the surface of the hull, as shown in FIGURE 3, the nozzles 30 are inclined with respect to the surface of the hull for a reason to be herein¬ after described.

Preferably the nozzles 30 are arranged so that a wide path beneath the carriage 12 is cleaned as the carriage moves in an arcuate path along the hull. It is to be under¬ stood that the nozzles 30 are not limited to the particular arrangement disclosed in the drawing, so long as the arrange¬ ment of nozzles provides a cleaning swath beneath a large por¬ tion of the area beneath the carriage 12 as the carriage is displaced along the surface of the hull.

Extending outwardly from the top surface 13 of the carriage 12 is a reactor nozzle 40. A nozzle 40 is secured

by rotatable pivot means 42 to the carriage 12 and in fluid communication with the manifold 32. The rotatable pivot means 42 enables the direction and inclination of the nozzle axis 44 to be selectively adjusted so that the force of the flow stream discharged from the nozzle can be aligned as desired. Preferably, the rotatable pivot means 42 is fixedly secured with respect to the carriage 12 at a point which coin¬ cides with the effective center point of the forces defined by the discharge from the cleaning nozzles 30. Thus, as shown in FIGURE 3, the reaction force component 46 of the fluid dis¬ charged along axis 44 from the nozzle 40 can directly oppose the effective force 47 exerted by the cleaning nozzles 30 in order to maintain the carriage 12 closely adjacent the hull's surface 16.

Referring again to FIGURE 1, the nozzle 40 is shown inclined in a direction which substantially bisects the angle between the retaining cable 20 and retaining cable 22. Thus, one component of the force vector along axis 44 tensions the cables 20 and 22. Consequently, extension or retraction of the cables 20 and 22 by the winches 24 and 26, respectively, causes respective vertical and horizontal translation of the carriage 12 across the hull surface 16. As shown in FIGURE 3, the nozzles 30 are also inclined so as to provide a force vector which enhances the tension force upon the cables 20 and 22.

Having thus described the important structural fea¬ tures of the present invention, the operation of the cleaning device of the present invention is easily explained. The winch 24 is removably secured in a fixed position to the deck of the ship 18. The winch 26 is removably secured to a wall portion of the dry dock at or near the water line on the hull surface 16. The ends of the cables 20 and 22 are secured to the couplings 29 on the carriage 12. The nozzle 40 is then

C...PI aligned so as to substantially intersect the angle between the cables 20 and 22 as shown in FIGURE 1. In this manner, the device is prepared for cleaning the bow portion of the hull 16.

The nozzle 40 is also inclined with respect to the surface 13 of the carriage 12 such that the reaction force component 46 exceeds and directly opposes the sum 47 of the reactive force components from the cleaning nozzles 30. The pump 42 is then activated to provide a pressurized flow of fluid from source 40 through the hose 38 and into the mani¬ fold 32. The manifold 32 thus supplies pressurized fluid to the cleaning nozzles 30 as well as the reactor nozzle 40. As the fluid is discharged from all of these nozzles, the reaction force component 46 from the nozzle 40 slightly exceeds and directly opposes the force component 47 from the cleaning nozzles 30. Thus, the casters 14 are urged against the hull surface 16 and maintain the nozzles 30 sub¬ stantially a predetermined distance above the hull surface 16. Consequently, the carriage 12 follows the contour of the ship's hull as the length of the members 20 and 22 is varied. At the same time, one component of the force vector 44 retains the members 20 and 22 in tension.

The members 20 and 22 are preferably operated so that the carriage 12 moves in a regular pattern across the hull of the ship. For instance, the carriage 12 can be intitially positioned at the water line of the hull 16 as shown in FIGURE 1. The winch 24 is then operated so that the cable 20 extends downwardly to permit the carriage 12 to descend along the hull of the ship. Once the carriage 12 reaches the keel or lowermost portion of the ship, the winch 26 retracts the cable 22 slightly so that a second swath directly adjacent to the first swath traversed can be cleaned. The cable 20 is then retracted by winch 24 so that

O PI the carriage is moved upwardly toward the water line. Upon reaching the top water line again, the cable 22 is again retracted a short distance to displace the carriage adjacent the area just cleaned by the nozzles. The operation is then repeated across the entire underwater surface of the ship. Since both the cables are tensioned by the alignment of the reactor nozzle 40, a substantially regular pattern of carri¬ age movement is provided.

Moreover, it will be understood that the direction of the swath traversed by the carriage can be changed by rearrangement of the winches 24 and 26 and realingment of the nozzle 40. For example, the winches 24 and 26 can be mounted at opposite ends of the deck of the ship. Then by varying the rotational position of the reactor nozzle 40, the respec¬ tive extension and retraction of the cables 20 and 22 causes the carriage to traverse a plurality of patterns which effec¬ tively cover substantially the entire hull surface below the water line on one side of the ship.

On the other hand, as shown in the drawing, the winches are positioned for movement of the carriage across one side of the bow of the ship. It is to be understood that such positioning enables additional winches and carriages to be positioned on the same side of the ship so that other portions of the same side can be cleaned at the same time. Consequently, the hull can be cleaned in substantially less time than was previously possible.

Thus, the present invention provides a hull clean¬ ing device which enables a plurality of high pressure nozzles or other means to be used to remove foulant from the ship's hull. Since the nozzles or other means are mounted to a single carriage, the cleaner permits a wider swath to be cleaned than would be possible using only a single nozzle manually controlled by a worker. Moreover, since the carriaσe

. is remotely controlled, it eliminates the dangers that a worker would be exposed to by the highly pressurized dis¬ charge from the nozzles. Consequently, more than one carriage can be utilized at the same time on a single vessel. In addition, the time during which the ship must be confined to dry dock is substantially reduced.

Having thus described my invention, many modifi¬ cations thereto will become apparent to those skilled in the pertinent art without departing from the scope and spirit of the present invention as defined in the appended claims.

Claims

hat is claimed is:

1. An apparatus for controlled cleaning of fou¬ lant from the hull of a water vessel comprising; a carriage including means for movably supporting the carriage on the hull surface; a plurality of first means for removing foulant mounted on said carriage and aimed toward the hull surface; second means for displacing said carriage across the hull surface; third nozzle means for maintaining said carriage against the hull surface by discharging fluid under pressure away from said hull surface to counteract the force exerted by said first means that tends to separate said carriage from said hull; fourth means for supplying a pressurized cleaning fluid to plurality of high pressure cleaning nozzles and said nozzle means.

2. The invention as defined in claim 1 wherein sai first means comprises nozzle means for discharging a pres¬ surized fluid against the hull surface.

3. The invention as defined in claim 2 wherein the fluid comprises air.

4. The invention as defined in claim 2 wherein said fluid includes particulate matter.

5. The invention as defined in claim 1 wherein the fluid comprises water.

6. The invention as defined in claim 3 wherein said fluid includes particulate matter.

7. The invention as defined in claim 2 wherein said nozzle means comprises means for pivotally and rotat- ably mounting said nozzle to said carriage whereby the inclination and direction of the nozzle discharge are selectively adjustable.

8. The invention as defined in claim 1 and further comprising fins aligned on said carriage whereby when the hull surface to be cleaned is submerged in and moved through a body of water, said carriage is urged toward said hull sur¬ face.

9. The invention as defined in claim 2 wherein said means for movably supporting said carriage comprises means for substantially maintaining said nozzles at a pre¬ determined distance from the hull surface.

10. The invention as defined in claim 9 wherein said last mentioned means comprises casters.

11. The invention as defined in claim 1 wherein fourth cleaning means comprises driven brush or abrasive means.

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