EP0259472B1

EP0259472B1 - Dredger

Info

Publication number: EP0259472B1
Application number: EP19870902092
Authority: EP
Inventors: Martti Kuusisto
Original assignee: Lannen Konepaja Oy
Current assignee: Lannen Konepaja Oy
Priority date: 1986-03-17
Filing date: 1987-03-17
Publication date: 1991-09-25
Also published as: HU201587B; FI81864C; FI861101A; FI81864B; DK156403B; DK156403C; EP0259472A1; WO1987005649A1; DK562687A; FI861101A0; HUT49660A; DK562687D0

Abstract

A suction dredger apparatus. The apparatus includes a scoop (3) mounted on a boom arrangement, and a suction device (4) including a dredger pump (9) mounted on the scoop and a discharge pipe arrangement (10).

Description

The invention relates to a suction dredger apparatus in which the dredger pump is located in a movable boom mounted on a base.
A dredger apparatus of today normally includes a floating base, and a rotating chopper is fastened at the end of a folding boom mounted on the base. the axis of the chopper is essentially vertical. Also a suction pump is located on the base, and the suction end of its suction pipe is located in the vicinity of the chopper. The material loosened by the chopper is sucked up by the pump, and it is led for instance to a barge or on land. One problem in this kind of apparatus is the fact that besides the material to be dredged, a considerable volume of water has to be transferred which impairs the efficiency of the apparatus and makes the separation of solid material more difficult.
Patent publication FI -B- 53 477 discloses also an apparatus in which the chopper is a screw rotating around a horizontal axis and in which a shieldlike plate is placed on the screw in order to lead the loosened material to the mouth of the suction pipe. However, this apparatus is very complicated and expensive but rather limited in its function.
Patent publication US-A- 3 774 323 again discloses dredger apparatus having a base, a movable boom, a pump mounted at the end of the said boom and connected to a discharge pump arrangement and a scoop. The scoop has a lip, sides and a rear plate bent forward at its upper end. However, the suction pump is rigidly fastened to the end of a boom which moves only in vertical direction, such that the suction direction is always parallel to the boom. In addition, there is a hood surrounding the pump at the end of the boom. The driving engine of the pump is located in the vessel. The efficiency of this apparatus is poor and the apparatus is awkward to use and lacks versatility such that when dredging, the vessel has to be moved forward almost continuously. Even in this way, only a very narrow groove can be dredged.
According to the invention there is provided a suction dredger apparatus including a base; a base anchoring equipment, an hydraulic boom arrangement turnable about a vertical axis and mounted on the base; a vertically pivoting scoop fastened to the boom arrangement and having a lip plate, side plates and a rear plate bent forward at its upper part; and a suction device having a discharge pipe arrangement and a dredger pump being a centrifugal pump connected to the discharge pipe arrangement, characterised in that the dredger pump is fixedly mounted on the rear plate of the scoop to be simultaneously rotatable with the scoop relative to the boom arrangement in such a way that the suction opening of the pump is inside the scoop and the suction direction is always changed with any movement of the scoop relative to the boom arrangement; the pump inlet passage in the scoop being convergent towards the pump by means of guide plates and the scoop being provided with water-tight air containers.
In the apparatus now invented, the dredger pump is located in a scoop movably mounted at the end of a boom arrangement, the suction opening being inside the scoop. In this way, the suction direction of the pump is always changed with any movement of the scoop, relative to the boom arrangement, and unnecessary pumping of water can be avoided.
The boom arrangement is preferably a folding boom arrangement so that a fairly long area can be dredged from one anchoring site forward. When the boom arrangement is preferably still laterally movable, a fairly wide sectorlike area can be dredged from one anchoring site.
The driving motor of the pump is preferably a hydraulic motor which is located with the pump in the scoop.
The apparatus now invented can reach good efficiency but still the apparatus is very simple. The apparatus is also flexible in use; it can easily be modified according to different dredging tasks, and also other tools can be connected to it.
Some embodiments of the invention will be described in detail in the following. In the drawings connected to the description, Fig. 1 shows a side view of a dredger vessel, Figs. 2 and 3 show a front view and top view of the scoop of the apparatus, Figs. 6 and 7 show the scoop of Figs. 4 and 5 modified into a hoe scoop, and Fig. 8 shows a dredger excavator.
The main parts of the apparatus of Fig. 1 are a floating base 1, a hydraulic boom arrangement 2 mounted on it, a vertically pivoting scoop 3 placed at the end of the hydraulic boom arrangement, and a suction device 4 connected to the scoop. A motor as a power source and necessary controlling and steering devices have been placed in the vessel. The base has a turnable propeller, by means of which it can be moved and steered.
At the other end (rear end) of the vessel, on the sides of the vessel, there are two anchoring poles 5 to be thrusted into the bottom. During transportation, the anchoring poles can be placed lying on the deck. Near the opposite end of the vessel, on the sides of the vessel, there is a pair of support legs 6. The support legs are mounted to the barge pivoting vertically. When lowered to the bottom, the support legs give sufficient support to the functioning of the apparatus. Containers increasing the buoyancy can be arranged in the support legs so that it is easier to lift the legs from the bottom mud.
The anchoring poles 5 and the support legs 6 are hydraulically driven, and together they form anchoring equipment.
The anchoring poles 5 and the support legs 6 together with the excavating device can also be used for moving the vessel. On land, the vessel lifts itself up on the support legs so that a transport base can be driven directly under the vessel or away from under the vessel. From the loading site, the vessel moves into water and away from water utilizing its support legs and the excavating device.
The boom arrangement is folding, and it can be moved both vertically and laterally. In order to move the boom arrangement as far downwards as possible, the front edge 7 of the vessel is made slanting downwards.
The scoop is fastened at the end of the boom arrangement by means of fast couplings 8.
Two centrifugal pumps 9 are mounted on the scoop, horizontally side by side in such a way that the suction openings of the pumps are located inside the scoop. The outlet openings of the pumps are connected to a discharge pipe 10.
Fig. 2 shows a front view of the scoop and suction device of Fig. 1, and Fig. 3 shows a top view.
The scoop is formed by a rear plate 11, a lip plate 12 and two side plates 13. The rear plate and lip plate form a sharp angle inside the scoop. The upper edge 14 of the rear plate is bent forward. The upper part of the scoop is provided with fastening lugs 15 for fastening the scoop to the boom arrangement. Pumps 9 driven by hydraulic motors 16 are placed in the rear plate of the scoop so that the suction openings are directed forwards.
A side guide plate 17 is placed in each corner formed by the side plate 13, lip plate 12 and rear plate 11, and centre guide plates 18 are placed in the middle of the scoop, between the lip plate, rear plate and the upper edge 14 of the rear plate in such a way that a convergent inlet passage is formed in front of each pump. The space remaining behind the guide plates is made water-tight. In this way, the buoyancy applied to the scoop has been increased which reduces the force required for moving the scoop in the water.
The front edge of the lip plate 12 is provided with claws 19.
The pumps 9 are provided in front of their suction openings with shredding blades 20 rotating with rotors.
The scoop shown in Figs. 4 and 5 is formed by a rear plate 21, side plates 22 and a lip plate 23. The upper edge 24 of the rear plate is bent forwards and downwards in such a way that a kind of hood is formed. Pumps 25 are similar to the ones in the scoop of Fig. 2 but they are placed in the upper part of the rear plate so that the suction opening is directed downwards, towards the lip plate.
Immediately below the front edge 24 of the rear plate, a horizontal shaft 26, parallel to the width of the scoop, is journalled in the side plates 22. A pivoting screen, having the same width as the scoop and provided at its upper part with a guide plate 27 and at its lower part a grate 28, is fasted on the shart 26. The grate is formed by bars fastened at equal spacings in the guide plate and curving forward.
Side guide plates 29 are placed in the corners between the rear plate 21 and the side plates 22, and centre guide plates 30 are placed in the middle of the scoop in such a way that converging inlet passages are formed in front of the pumps. Water-tight spaces remain behind the guide plates and act as float containers.
Figs. 6 and 7 show the working of a scoop of the type shown in Figs. 4 and 5, arranged as a hoe scoop. In this case, the side plates 22 are still provided with a front stopper 31 and rear stopper 32 which respectively define the front limit and the rear limit of the movement of the plate 27 and grate 28.
In the working step (Fig. 6), the guide plate 27 and grate 28 are at the rear position. The guide plate prevents the direct flow of water into the suction openings of the pumps 25. The grate again prevents big stones and other pieces from entering the pump. The grate also cuts and disintegrates ground material. In order to make this more efficient, the front edge can be formed sharp. When the grate is desired to be emptied from the material sticking to it, the scoop is turned into an emptying position (Fig. 7), so that the guide plate and the grate are turned into their front position where the tips of the bars of the grate point directly downwards. In this way, the material remaining on the grate falls easily off.
A hoe scoop is particularly suitable for dredging relatively hard ground material. A dipper shovel again is particularly suitable for removing soft or loose material.
When using the apparatus, it is transported to the site and anchored firmly by means of the anchoring poles 5. The apparatus can be turned around either one of the poles 5, and in this way a sector with a desired area can be dredged from one point. By means of the turning, folding boom arrangement, it is also possible to dredge a fairly wide sector at one position of the support legs 6.
When dredging, the scoop is moved with a suitable speed so that the material loosened by the scoop and disintergrated by the claws 19 and the grate 28 is carried to the pumps 9, 25, and further via the discharge pipe 10 to a desired place. The shredding device 20 of the pump disintegrates the material, particularly water plants and the like in it so that no blockages or disturbances are formed in the pump.
The bent upper edge 14, 24 of the rear plate of the scoop, and the possible guide plate 27 of the screen prevent pure water from flowing directly to the pumps 9, 25 which makes the suction effect more efficient and improves the efficiency of the dredging.
By means of the scoop, fairly large hindrances on the bottom, such as stones, tree trunks and the like, can easily be moved aside. In addition, the apparatus can be used for conventional excavating if the material to be removed is too dense for pumping.
Due to the fast coupling of the scoop, some other tool, such as a chopper or drill can quickly be changed into the boom arrangement.
The scoop and the suction device can be mounted also on a boom arrangement of an excavator travelling on land. In this way, shore waters or small subjects, such as canals or basings, can conveniently be dredged. Fig. 8 shows such an embodiment. In this case, the base is an excavator 32 travelling on caterpillar bands 31. The boom arrangement 2 corresponds to the one in Fig. 1, and the scoop 3′ and the suction device 4′ correspond to the ones in Figs. 4 and 5.
In the embodiments described in the above, there are two dredger pumps placed side by side so that a practical working width is obtained. However, the scoop can be provided with one pump only, or there can be more than two pumps. The pumps can alse be placed in some other way than side by side.
The size and shape of the scoop can be made different according to the requirements of a specific dredging work in each case.

Claims

1. A suction dredger apparatus including a base (1/32); a base anchoring equipment (5,6/31); an hydraulic boom arrangement (2) turnable about a vertical axis and mounted on the base; a vertically pivoting scoop (3) fastened to the boom arrangement and having a lip plate (17/23), side plates (13/22) and a rear plate (11/21) bent forward at its upper part; and a suction device (4) having a discharge pipe arrangement (10) and a dredger pump (9/25) being a centrifugal pump connected to the discharge pipe arrangement, characterised in that the dredger pump (9/25) is fixedly mounted on the rear plate (11/21) of the scoop (3) to be simultaneously rotatable with the scoop relative to the boom arrangement in such a way that the suction opening of the pump is inside the scoop and the suction direction is always changed with any movement of the scoop relative to the boom arrangement; the pump inlet passage in the scoop being convergent towards the pump by means of guide plates (17/18/29/30) and the scoop being provided with water-tight air containers.

2. An apparatus according to claim 1, characterised in that the pump is mounted on the rear plate (21) so that the suction direction of the pump is essentially downwards.

3. An apparatus according to claim 1 characterised in that the containers are spaces defined by the guide plates (17/18/29/30), the lip plate (17/23), the side plates (13/22) or the rear plate (11/21).

4. An apparatus according to any of the preceding claims, characterised in that the scoop is provided with a screen (27/28) placed above the lip plate and turnable around a shaft (26).

5. An apparatus according to claim 4, characterised in that screen is provided with a guide plate (27) at its upper part.

6. An apparatus according to any of the preceding claims, characterised in that the hydraulic boom arrangement is a folding boom arrangement (2).

7. An apparatus according to any of the preceding claims, characterised in that the hydraulic boom arrangement (2) is laterally turnable.

8. An apparatus according to any of the preceding claims, characterised in that the base (1) is floating and further comprises base anchoring equipment including turnable support legs (6).

9. An apparatus according to claim 8 characterised in that buoyancy containers are arranged in the support legs to make it easier to lift the support legs.