MXPA99005761A - Improvements in or relating to underwater excavation apparatus - Google Patents

Abstract

There is disclosed an improved underwater excavation apparatus (300a, b, c). Known apparatus suffer from a number of problems, e.g., efficiency and control of movement. Accordingly, the invention provides an underwater excavation apparatus (300a, b, c) comprising a hollow body (370a, b, c) having at least one inlet (371a, b, c) and at least one outlet (373a, b, c), at least one pair of impellers (335a, b, c), (340a, b, c) coaxially displaced one from the other and rotatably mounted in the hollow body (370a, b, c), and means for driving the impellers in contrary rotating directions. The underwater excavation apparatus (300a, b, c) comprises a pair of horinzontally opposed inlets (371a, b, c) communicating with a single outlet (373a, b, c) the outlet (373a, b, c) being disposed vertically downwards substantially midway between the two inlets, in use. The excavation apparatus (300a, b, c) may, therefore, be substantially"T"or"Y"shaped. The means for driving the impellers (335a, b, c), (340a, b, c) may include at least one drilling motor (310a, b,c).

Description

IMPROVEMENTS IN OR RELATED TO A UNDERWATER EXCAVATION APPARATUS DESCRIPTION OF THE INVENTION This invention relates to an improved digging apparatus, and in particular to an improved underwater excavating apparatus. Underwater excavating apparatuses are known, for example, from GB 2 240 568 (CONSORTIUM RESOURCE et al). In that description is presented, an underwater excavating apparatus comprising a hollow body with an inlet for receiving water and an outlet for discharging water. A propeller is rotatably mounted in the hollow body to draw water through the inlet and supply a flow of water through the outlet. The jets of water at the propeller tips spin the propeller when the water is supplied to the jets. Such rotation causes the water to be drawn into the body through the inlet and expelled from the body as a flow through the outlet. The flow can be used to move the material over the seabed. Underwater excavation apparatuses known from the prior art have a number of problems / disadvantages: (a) low energy efficiency due to, for example, hydrodynamic limitations of fluid jets, thus requiring low energy and large pumps to drive the system; (b) the tendency of the apparatus to rotate in reaction to the rotation of the propeller; (c) difficulty in the direction and placement of the apparatus. It is an object of at least some of the aspects of the present invention to seek to avoid or mitigate one or more of the aforementioned problems of the prior art. Accordingly, a first aspect of the present invention is to provide an underwater excavating apparatus comprising a hollow body having at least one inlet and at least one outlet, at least one pair of propellers rotatably mounted in the hollow body and means for drive the impellers.

Advantageously, the actuator means causes the impellers to be driven in opposite directions of rotation, during use. At least one output can be included at an angle to an axis along which at least one output is provided. Preferably, at least one pair of inputs is provided. Preferably, at least one pair of inputs is substantially symmetrically disposed about an axis extending from the outlet. In one embodiment, the underwater excavating apparatus comprises a pair of horizontally opposed entrances communicating with a single outlet, the outlet being disposed vertically downward substantially at half the distance between the two entrances, during use. In this case, the excavating apparatus, therefore, has a substantially "T" profile shape. In an alternative embodiment, the underwater excavating apparatus comprises a pair of inlets communicating by an individual outlet, the inlets being substantially and symmetrically disposed about an axis extending from the outlet, the outlet being disposed vertically downward substantially in half of the distance between the two entrances, during use. In this case, the excavating apparatus, therefore, has a substantially "Y" profile shape. Advantageously, the outlets are each separated / inclined substantially 45 ° from the axis extending from the outlet. At least one impeller can be provided within / adjacent to each input. The means for driving the / each impeller (s) may include at least one drilling motor. At least one drilling motor may comprise a stator and a rotor rotatably mounted on the stator, the stator being provided with a bar depression and an exhaust port, the rotor being provided with a rotor channel and at least one channel for driving driving fluid from the rotor channel into a chamber between the rotor and the stator; the bar depression being provided with a rod, which, during use, forms a seal between the stator and the rotor.

Although not essential, it is highly desirable that the rotor be provided with a seal for coupling with the stator. Preferably, the seal is made from a material selected from the group consisting of plastic, polyethylethyl ketone, metal, copper alloy and stainless steel materials. Advantageously, the bar is made from a material selected from the group consisting of plastic materials, polyethylethyl ketone, metal, copper alloys and stainless steel. Preferably, the stator is provided with two bar depressions, which are arranged opposite each other, and two exhaust ports, which are arranged opposite each other, each of the bar depressions being provided. with a perspective bar, the rotor having two seals that are arranged opposite each other. The drilling motor advantageously can comprise two drilling motors arranged with their respective rotors connected together each motor comprising a stator and a rotor rotatably mounted on the stator, the stator being provided with a bar depression and an exhaust port, the rotor being provided with a rotor channel and at least one channel for driving the drive fluid from the rotor channel into a chamber between the rotor and the stator, the bar depression being provided with a rod which, during use, forms a seal between the stator and the rotor. Preferably, the drilling motors are connected in parallel, although they can be connected in series if desired. Advantageously, the drilling motors are arranged so that, during use, one drilling motor operates out of phase with the other. Thus, in a preferred embodiment, each drilling motor has two chambers and the chambers in the first drilling motor are 90 ° out of phase with the chambers in the second drilling motor. Similarly, in a modality wherein each drilling motor has four chambers, the chambers in the first drilling motor preferably could be 45 ° out of phase with the chambers in the second drilling motor. This arrangement helps to ensure a moderate exit of energy and inhibits the loss. Alternatively, at least one drilling motor can be a "Moineau" motor, hydraulic, or a suitable electric motor adapted. The impellers can be driven through a gearbox or through the exploitation of the opposite reactive torque in the motor drive body. When the reactive torque on the motor body is used, at least one impeller can be connected to an output arrow of said motor, while at least the other impeller can be connected to the motor body. Alternatively, the impellers can be driven through a pair of motors operating in opposite directions. In each case, said motors and impellers are balanced and equal.

The underwater excavating apparatus may further comprise a stirring device having means of mechanical disturbance and means of fluid flow disorder. The underwater excavating apparatus can be, during use, suspended from a surface container or mounted on a slide of the type currently known for use in underwater excavation operations. According to a second aspect of the present invention, there is provided an underwater apparatus comprising a hollow body having a pair of inputs communicating with an outlet, at least a pair of impellers rotatably mounted on the hollow body and means for driving the impellers , the entrances being substantially and symmetrically arranged around an axis extending from the exit, where the entrances are not horizontally opposed to one another. Now embodiments of the present invention will be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows a cross-sectional side views of a first embodiment of an excavating apparatus according to the present invention: Figure 2 shows a longitudinal cross-sectional view of one embodiment of a drilling apparatus for use in the excavating apparatus of Figure 1 according to the present invention.

Figures 3A-3D are cross-sectional views along line A-A of Figure 2 showing a motor rotor in four different positions; Figures 4A-4D are cross-sectional views along line B-B of Figure 2 showing the rotor in four different positions; Figure 5 shows a transverse side view of a second embodiment of an excavating apparatus according to the present invention; and Figure 6 shows a cross-sectional side view of a third embodiment of an excavating apparatus according to the present invention. Referring to Figure 1, a first embodiment of an underwater excavating apparatus 300a according to the present invention is shown. The apparatus 300a comprises a hollow body 370a formed from a pair of horizontally opposed input ducts 371a and an outlet duct 373a, a driving motor 310a and a pair of impellers 335a, 340a. The apparatus 300a is further provided with deflection baffles 302a within the hollow body 370a, suspension brackets 306a to allow the apparatus 300a to be suspended from a surface container, guide vanes 386a to regulate fluid flow beyond the thrusters 335a, 340a, and safety grids 385a so as to prevent the ingress of solid matter that can damage the thrusters 335a, 340a.

In this first embodiment, the drive motor 310a is provided along an axis common to the opposing horizontally inlet ducts 371a and impellers 335a, 340a. An output shaft 330a of the motor 310a is connected to a first driver 335a, while the second driver 340a is connected to an arrow 342a connected through an oscillator 325a to an external housing of the drive motor 310a. During use, motor fluid is supplied to motor 310a through fluid inlet 308a, which in turn causes output shaft 330a and impeller 335a to rotate. The reactive torque from this rotation causes the outer housing of the drive motor 310a to rotate in a direction opposite to that of the output shaft 330a. This in turn results in the rotation of the second driver 340a. The impellers 335a, 340a are configured such that, despite rotation in opposite directions, each provides an equal flow velocity of water to the hollow body 370a. The water drawn into the hollow body 370a in this way is directed through the deflection baffles 302a via the outlet duct 373a and towards the seabed 400a. The arrow 342a and the oscillator 325a can be, in an alternative embodiment, placed by a second motor that directly drives the driver 340a. as described above with reference to Figure 5. The excavating device 300a can be suspended, for example, from the bow or stern of a surface container, or through a combination apparatus of a dedicated underwater operations vessel. . In an alternative embodiment, the device 300a may be provided on a slide (not shown) of the type currently used for underwater operations. The excavation device 300a may further be provided with a stirring device (not shown) having mechanical distortion means and means for distorting fluid flow. In an advantageous embodiment, the motor 310 comprises a drilling motor, such as that described in W095 / 19488, the content of which is incorporated herein by reference. The drilling motor 310 may comprise a first motor and a second motor 50. The first motor 20 comprises a stator 21 and a rotor 23. An upper portion of the rotor 23 extends through an upper bearing assembly 24, which comprises a thrust bearing 26 and seals 25. The drive fluid, for example water, drilling mud or gas under pressure, flows through a central underwater channel 12 to a central rotor channel 27, and then out through rotor flow channels 28 to action chambers 31 and 32. After a power stroke of the motor, the drive fluid flows through the exhaust ports 33 in the stator 21, and then to down through an annular channel circumjacent the stator 21 and flow channels 35 in a lower bearing assembly 34. A portion 36 of the rotor 23 extends through the lower bearing assembly 34, comprising a thrust bearing 37 and seals 38. The ends of the stator 21 are castellated and the castellations engage in depressions in the upper bearing assembly 24 and the respective lower bearing assembly 34, to inhibit the rotation of the stator 21. The upper bearing assembly 24 and the bearing assembly bottom 34 are in an airtight fit in an outer tubular member 14 and are held against rotation through compression between threaded sleeves 16 and 84. A grooved joint 39 joins an extr emo corrugated of the rotor 23 to a fluted end of the rotor 53 of the second motor 50. The second motor 50 has a stator 51. An upper portion 52 of the rotor 53 extends through an upper bearing assembly 54. Seals 55 are disposed between the upper bearing assembly 54 and the exterior of the upper portion 52 of the rotor 53. The rotor 53 moves on thrust bearings 56 with respect to the upper bearing assembly 54. The driving fluid flows into a central rotor channel 57 from the central rotor channel 27 and then out through the rotor flow channels 58 to the drive chambers 61 and 62. After a motor power stroke, the drive fluid flows through the exhaust ports 63 and the stator 51, and then down through an annular channel circumjacent the stator 51 and flow channels 65 in a lower bearing assembly 64. A portion 66 of the rotor 53 extends through a bearing assembly i lower 64. The rotor 53 moves on thrust bearings 67 with respect to the lower bearing assembly 64 and the seals 68 seal the abutting surface of the bearing-rotor assembly. Also the drive fluid flowing through the flow channels 35 in the lower bearing assembly 34, flows down through the channels 79 in the upper bearing assembly 54, past the stator 51 and through the raceway channels. flow 65 in the lower bearing assembly 64. The upper bearing assembly 54 and the lower bearing assembly 64 are in an airtight fit in an outer tubular member 18 and are maintained against rotation through compression between the threaded sleeve 84 and a lower threaded sleeve (not shown). Figures 2A-2D and 3A-3D illustrate a typical cycle for the first and second engines 20 and 50, respectively, and show the state of the two engines with respect to each other at various times in the cycle. For example, Figure 2C shows an escape period for the first engine 20, while Figure 3C, at that same time, shows a power period for the second engine 50.

As shown in Figure 2A, the drive fluid flows through the rotor flow channels 28 into the drive chambers 31 and 32. Due to the geometry of the chambers (as discussed below) and the resultant forces , the motive fluid moves the rotor in a clockwise direction, as shown in Figure 2B. The drive chamber 31 is sealed at one end through a bearing blade rod 71, which abuts an outer surface 72 of the rotor 23 and a portion 74 of a rod depression 75. At the other end of the chamber 31, a seal 76 on a lobe 77 of the rotor 23 in sealed form abuts an inner surface of the stator 21. As shown in Figure 2B, the rotor 23 has moved to a point near the end of a period of power. As shown in Figure 2C, the drive fluid starts to escape at this point in the engine cycle through the exhaust ports 33. As shown in Figure 2D, the bearing blade bars 71 and the seals 76 have sealed the drive chambers and the motor fluids flowing thereto will rotate the motor 23 until the seals 76 again move past the exhaust ports 33. The second motor 50 operates as the first motor 20 does; but, as is preferred, and as shown in Figures 3A-3D, the two motors are out of phase by 90 °, so that one motor is ejected motor fluid, while the other is providing power. Seals 76 are made, in one embodiment, of polyethylethyl ketone (PEEK). The bearing blade bars 71 are also made from PEEK. The rotors 23, 25 and the stators 21, 51 are preferably made from corrosion resistant materials, such as stainless steel. When a seal 76 on the first motor 20 rotates past an exhaust port 33, the driving fluid that causes the rotation exits i flows downward, then through the channels 79, past the exhaust ports 63 and the flow channels 65. It should be appreciated that although in the embodiment described, the drilling motor 310 comprises two motors 20, 50, with suitable adaptation, the drilling motor 310 may comprise only one motor 20 or 50. Referring now to the Figure 5 shows a second embodiment of an underwater excavating apparatus 300b according to the present invention. Similar parts of the apparatus 300a are identified with numbers used to identify the parts of the apparatus 300a of Figure 1, except that with the subscript "b" instead of "a". The apparatus 300b differs from the apparatus 300a in that the arrow 342a and the oscillator 325a are replaced by a second motor 310'b and a T-shaped coupling 326b. In this way, the impellers 335b, 340b are driven through respective motors 310b , 310'b. During use, the driving fluid is supplied to the engines 310b, 310'ba through a fluid inlet 308b and a T-shaped coupling 326b. Referring now to Figure 6, a second embodiment of an excavating apparatus is shown. underwater 300c according to the present invention. Similar parts of the apparatus 300b are identified by number used to identify the parts of the apparatus 300b of Figure 5, except with the subscript "c" instead of "b". The apparatus 300c differs from the apparatus 300b in that while in the apparatus 300b the inputs 371b are horizontally opposite, in the apparatus 300c the inputs are substantially symmetrically arranged around an axis extending from the outlet 373c, so that the apparatus 300c has a substantially "Y" shape. In this embodiment, therefore, a Y-shaped coupling 326c is provided. The embodiments of the invention so far described are given by way of example only, and are not intended to limit the scope of the invention in any way. It should be particularly appreciated that the drilling motor 310 is suitable for use in any of the described modes.

Claims (25)

1. An underwater excavating apparatus comprising a hollow body having at least one inlet and one outlet, at least one pair of impellers rotatably mounted on the hollow body and means for driving the impellers.

2. An underwater excavating apparatus according to claim 1, wherein the driving means causes the impellers to be driven in opposite directions of rotation.

3. An underwater excavating apparatus according to any of claims 1 or 2, wherein at least one inlet is inclined at an angle to an axis along which at least one outlet is provided.

4. An underwater excavation apparatus according to any of the preceding claims, wherein at least one pair of inputs is provided.

5. An underwater excavating apparatus according to any of the preceding claims, wherein at least one pair of inlets are substantially symmetrically arranged around an axis extending from the outlet.

6. An underwater excavation apparatus according to any of claims 1 to 5, wherein the apparatus comprises a pair of horizontally opposed entrances communicating with an individual outlet, the outlet being arranged vertically downward substantially to half of the distance between the two entrances, during use, so that the excavating apparatus has a substantially profiled shape of

7. - An underwater excavating apparatus according to any of claims 1 to 5, wherein the apparatus comprises a pair of inputs communicating with an individual outlet, the entrances being substantially and symmetrically arranged around an axis extending from the outlet, the outlet being disposed vertically downwards substantially at half the distance between the two entries, during use, so that the excavating apparatus has a substantially "Y" shaped profile.

8. An underwater excavating apparatus according to any of claims 6 or 7, wherein at least one impeller is provided within each inlet.

9. An underwater excavation apparatus according to any of the preceding claims, wherein the means for driving the / each impeller includes at least one drilling motor.

10. An underwater excavating apparatus according to claim 9, wherein at least one drilling motor comprises a stator and a rotor rotatably mounted on the stator, the stator being provided with a bar depression and an exhaust port. , the rotor being provided with a rotor channel and at least one channel for driving the drive fluid from the rotor channel towards a chamber between the rotor and the stator, the bar depression being provided with a rod which, during use, It forms a seal between the stator and the rotor.

11. An underwater excavation apparatus according to claim 10, wherein the rotor is provided with a seal for coupling with the stator.

12. An underwater excavating apparatus according to claim 11, wherein the seal is made from a material selected from the group consisting of plastic materials, polyethylethyl ketone, metal, copper alloys and stainless steel.

13. An underwater excavation apparatus according to any of claims 10 to 12, wherein the rod is made from a material selected from the group consisting of plastic materials, polyethylethyl ketone, metal, copper alloys and stainless steel .

14. An underwater excavation apparatus according to any of claims 10 and 13 wherein the stator is provided with two bar depressions, which are arranged opposite each other, and two exhaust ports, which are arranged in opposite manner to each other, each of the bar depressions being provided with a respective bar, the rotor having two seals, which are arranged opposite each other.

15. An underwater excavating apparatus according to claim 8, wherein at least one drilling motor comprises two drilling motors arranged in their respective rotors connected together, each motor comprising a stator and a rotor rotatably mounted in the stator. , the stator being provided with a bar depression and an exhaust port, the rotor being provided with a rotor channel and at least one channel for driving the drive fluid from the rotor channel to a chamber between the rotor and the stator , the bar depression being provided by a bar which, during use, forms a seal between the stator and the rotor.

16. An underwater excavation apparatus according to claim 15, wherein the drilling motors are connected in parallel or in series.

17. An underwater excavating apparatus according to claim 15 or 16, wherein the drilling motors are arranged so that, during use, one drilling motor operates out of phase with the other.

18. An underwater excavation apparatus according to any of the preceding claims, wherein the impellers are driven through a gearbox or through the operation of the opposite reactive torque on a motor drive body.

19. An underwater excavating apparatus according to claim 18, wherein the reactive torque on the motor body is used, at least one impeller is connected to an output shaft of the motor, while at least the other The impeller can be connected to the motor body.

20. An underwater excavation apparatus according to claim 1, wherein the impellers are driven through the pair of motors operating in opposite directions.

21. An underwater excavation apparatus according to the preceding claims, wherein the underwater excavating apparatus further comprises a stirring device having mechanical distortion means and means for distorting fluid flow.

22. An underwater excavating apparatus according to any of the preceding claims, wherein, during use, the underwater excavating apparatus is suspended from a surface container or mounted on a slide of the type currently known for use in operations of underwater excavation.

23. An underwater excavating apparatus according to claim 7, wherein the outlets are each inclined substantially 45 ° from the axis extending from the outlet.

24. An underwater excavation apparatus comprising a hollow body having a pair of inlets communicating with an outlet, at least one pair of impellers rotatably mounted in the hollow body and means for driving the impellers, the entries being substantially and symmetrically arranged around an axis extending from the outlet, where the inlets are not horizontally opposed to one another.

25. An underwater excavation apparatus as described above with reference to Figure 1 or Figure 5 or Figure 6.