Method and milling device for removing a soil layer

Abstract

The invention relates to a method and a milling device for removing a layer of soil from the bottom of a body of water, with a milling device which is placed on the bottom of the body of water, wherein the milling device has a mobile carrier device and at least one milling unit mounted on the carrier device, which is guided displaceably by means of at least one linear guide device.According to the invention, after being placed on the bottom of the water body, the milling device is brought into a substantially horizontal position and aligned, with the at least one milling unit forming a substantially horizontal, flat initial surface, wherein the at least one milling unit is inserted into the ground substantially vertically along the linear guide device for milling off soil material, the milling device is moved onto the initial surface formed and, starting from the flat initial surface, soil is removed by vertically moving the milling unit into the ground and horizontally moving the carrier device.

Description

[0001] The invention relates to a method for removing a layer of soil from the bottom of a body of water according to claim 1.

[0002] The invention further relates to a milling device for removing a layer of soil from the bottom of a body of water, comprising a mobile carrier unit which has drive units for movement on the ground, and at least one linear guide device which is arranged on the carrier unit and is designed for slidably guiding at least one milling unit which can be inserted into the ground substantially vertically along the linear guide device for milling soil material, according to the preamble of claim 9.

[0003] Milling devices have long been used in specialist foundation engineering, particularly in the construction of so-called diaphragm walls in the ground. These milling devices are usually used on a prepared, level building site.

[0004] It is also known that such milling devices are used in the extraction of mineral resources in different types of terrain.

[0005] From EP 3 805 465 A1, an underwater extraction device for mining raw materials on a body of water is known. This device comprises an extraction unit which is guided on a base frame so as to be displaceable in a horizontal direction in order to assume different extraction positions. Another underwater extraction device is known from CN 114 542 075.

[0006] Furthermore, underwater mining systems are described in WO 2015 / 178854 A1 and WO 2015 / 178853 A1. These systems employ several mobile mining units, from which excavated soil material is transported to floating containers located underwater between the mining units and a supply vessel.

[0007] The invention is based on the TaskThe basis is to specify a method and a milling device with which efficient removal of a soil layer on the bottom of a body of water is made possible.

[0008] The problem is solved according to the invention by a method with the features of claim 1 and a milling device with the features of claim 9. Preferred embodiments of the invention are specified in the dependent claims.

[0009] The invention comprises a method for removing a layer of soil from the bottom of a body of water using a milling device which is placed on the bottom of the body of water, wherein the milling device has a mobile carrier device and at least one milling unit mounted on the carrier device which is guided slidably by means of at least one linear guide device.According to the invention, after being placed on the bottom of the water body, the milling device is brought into a substantially horizontal position and aligned, with the at least one milling unit forming a substantially horizontal, flat initial surface, also called the planum, wherein the at least one milling unit is inserted into the ground substantially vertically along the linear guide device for milling off soil material, the milling device is moved onto the formed initial surface and, starting from the flat initial surface, soil is removed by vertically moving the milling unit into the ground and horizontally moving the carrier device.

[0010] A fundamental aspect of the invention is the ability to use and reliably operate a milling device, particularly a so-called diaphragm wall cutter, with a mobile carrier vehicle even on uneven terrain, especially stepped terrain. This is achieved by placing the milling device on the waterbed and aligning it into a substantially horizontal position. Then, the at least one milling unit is used to create a substantially horizontal, level initial surface. The milling device is then moved onto this initial surface, and soil is removed by vertically moving the milling unit into the ground and horizontally moving the carrier vehicle, starting from this level surface. This allows for further, safe soil removal even in uneven and / or largely unknown underwater terrain.

[0011] A preferred embodiment of the invention consists in the mobile carrier device having propulsion units, each of which is adjustable in a vertical direction. After being lowered onto the riverbed, the propulsion units are adjusted vertically in a defined manner until the desired horizontal orientation of the milling device is achieved. The propulsion units serve to move the milling device. First, the milling device is aligned horizontally. Then, targeted excavation and repositioning / displacing of the milling device can take place. The propulsion units can have a wheeled chassis, a tracked chassis, and / or a walking mechanism.

[0012] According to a further development of the invention, it is preferred that, after the creation of the horizontal initial surface, the drive units are adjusted to approximately the same position. The vertical adjustment can be achieved via suitable actuators, in particular vertical actuating cylinders. After creating an initial surface with drive units extended to different positions to compensate for uneven terrain, the drive units can again be arranged at the same height.

[0013] According to a further development of the invention, an advantageous method variant consists in forming a milling slot with a milling width that is equal to or greater than the width of the carrier device of the milling unit, and in moving the milling unit stepwise into the formed milling slot. This method enables the efficient removal and excavation of near-surface soil layers.

[0014] Another preferred embodiment of the invention involves the milling device removing the soil layer in a step-like and / or meandering pattern. Starting from the initial surface, a large area of ​​soil layer can thus be efficiently removed. With a limited stroke of the drive units in a vertical direction, deeper soil layers can be removed by working downwards in a step-like manner. The milling device can also ascend again in a step-like pattern. By using a meandering removal pattern, adjacent soil areas can be removed in rows.

[0015] In principle, the carrier device can only be equipped with a single milling unit for removing soil. According to one embodiment of the invention, a particularly efficient removal of a soil layer is achieved by having the soil removed by several milling units, which are mounted vertically and adjustable side-by-side on the carrier device.

[0016] Depending on the design and number of milling units used, which may include several pairs of milling wheels with horizontally oriented milling wheel axes, ridges or grooves may form on the surface due to the milling process, impairing the flatness of the removed area. To counteract this, a preferred embodiment of the invention provides for at least one additional removal unit to be used to remove any ridges left behind by the milling unit. This additional removal unit is positioned behind the carrier unit and set back from the milling unit. In the simplest case, the removal unit can be a squeegee-like removal element or cutting element that removes smaller remaining ridges and thus flattens the milled surface. However, the additional removal unit can also be a milling unit itself with one or more driven milling wheels.Preferably, one or more milling wheel axes can be vertically oriented, so that a flat surface is produced by a correspondingly flat end face of the milling wheel. One or more additional removal units can be arranged. The additional removal unit can preferably be mounted to be displaceable in a transverse direction in order to cover the entire milling width by shifting it. Removing soil strata also has the advantage that additional valuable material is recovered during mineral extraction.

[0017] According to one embodiment of the invention, for the efficient extraction of mineral resources, it is advantageous to convey the excavated soil material to a container. The container itself can be located underwater or above water. If the container is underwater, it can be emptied or replaced with an empty one at specific times.

[0018] The milling device according to the invention is characterized in that the drive units are each adjustable in a vertical direction on a chassis of the carrier device and that the drive units are each adjustable in the vertical direction via an actuator.

[0019] A fundamental aspect of the invention is that the drive units are mounted on a chassis of the carrier vehicle in a vertically adjustable manner and can be vertically adjusted by means of an actuator. In this way, a milling device, in particular a so-called diaphragm wall cutter, can be used and reliably operated with a mobile carrier vehicle even on uneven terrain, especially stepped terrain. The milling device according to the invention thus allows for a wider range of applications and ensures a particularly high level of operational safety, especially against tipping on uneven terrain. The linear guide device can, in particular, be a mast along which the milling unit can be moved by means of a carriage along a mast guide.

[0020] The drive units can be mounted and guided along vertical guides on the undercarriage so that they can slide along it. One or more hydraulic cylinders can be used as actuators.

[0021] A preferred embodiment of the invention consists in the carrier device having two longitudinal sides, with at least two longitudinally oriented drive units arranged on each longitudinal side. Thus, two or more drive units are mounted on each longitudinal side, so that differences in terrain along a longitudinal direction of the device can be compensated for by vertical adjustment of the different drive units. In particular, each individual drive unit is individually vertically adjustable.

[0022] According to a further development of the invention, it is preferred that, in addition to the drive units along the longitudinal sides, at least one drive unit is provided on the undercarriage, which is arranged and designed for transverse movement. Preferably, two or more additional drive units are arranged transversely. The transverse drive units can also be vertically adjustable, with a vertical actuator also being provided. The milling device can be moved transversely using the transverse drive units without the need for complex maneuvering. During longitudinal movement, the at least one transverse drive unit can be in a retracted, upward rest position.In a transverse process, one or more transversely directed drive units can be moved downwards and / or the longitudinally directed drive units upwards, so that the longitudinally directed drive units are no longer or not substantially in contact with the ground, thus enabling simplified displacement or movement of the milling device in the transverse direction.

[0023] In principle, the at least one propulsion unit can be configured in any suitable way, in particular with wheels or as a walking mechanism. According to one embodiment of the invention, it is particularly preferred that at least one propulsion unit has a tracked undercarriage. A tracked undercarriage comprises a circulating track and is particularly suitable for off-road use. Furthermore, a tracked undercarriage provides a relatively large contact area, so that even a high machine weight can be distributed over a relatively large contact area, resulting in a relatively low ground pressure. This protects the soil and increases the stability of the machine. The tracked undercarriage can be configured on individual propulsion units or, preferably, on all propulsion units, including the longitudinally and laterally oriented propulsion units. In principle, a combination with other types of propulsion units can also be used.

[0024] A further improvement in driving characteristics can be achieved in one embodiment of the milling device according to the invention by designing at least one drive unit to be rotatable about a vertical axis of rotation. Preferably, rotation through a predetermined angle, for example up to 180 degrees, or a full 360-degree rotation is possible. Particularly in combination with individual height adjustment of the individual drive units, a drive unit can thus be raised and spaced away from the ground, which facilitates rotation in the raised position. With this arrangement, transversely oriented drive units can be omitted.

[0025] A particularly efficient removal of soil material can be achieved according to a further development of the invention by having the milling unit have milling wheels, in particular two pairs of milling wheels, on its underside. Preferably, the milling unit can be a basic component of a generally known diaphragm wall cutter, in which two pairs of milling wheels are arranged on a frame on the underside to form an approximately rectangular milling cross-section. The milling wheels of each pair are rotatably mounted on a common central bearing plate on both sides of the bearing plate.

[0026] A particularly advantageous embodiment of the invention is achieved by arranging several milling units parallel to one another, displaceable along a linear guide. By arranging two, three, or even more milling units, a relatively wide milling slot can be created efficiently. The simultaneous use of adjacent milling units thus reduces the milling time to approximately half. Arranging additional milling units can result in a further corresponding reduction in maintenance time.

[0027] In conventional trench cutters, the removal or trench width is smaller than the width of the mobile carrier unit. According to a preferred embodiment of the milling device according to the invention, the total milling width of the at least one milling unit is equal to or greater than the width of the carrier's undercarriage. This can be particularly advantageous when removing soil material near the surface over larger areas. Specifically, the mobile milling device can perform soil removal in the longitudinal direction, with the carrier unit being advanced step by step after each removal step. In this way, the milling device can independently create a level surface for positioning and moving the milling unit.

[0028] The linear guide device can be designed in virtually any known and suitable manner. In particular, a mast or pole with a linear guide can be provided. According to one embodiment of the invention, it is particularly advantageous for the linear guide device to be box-shaped with at least one guide channel in which a milling unit is slidably guided. The milling unit itself can be provided with a frame-like or box-like milling frame. The milling unit can thus be guided on multiple sides, in particular on two, three, or four sides, within the guide channel by guide surfaces. This enables particularly precise and stable guidance.

[0029] A further increase in flexibility is achieved by mounting the linear guide device on an upper carriage of the carrier device, which is preferably rotatably mounted on the lower carriage about a vertical axis of rotation. This allows the milling device to machine a floor area from all sides.

[0030] According to an advantageous embodiment of the invention, particularly efficient soil removal is achieved by providing a suction device for extracting and conveying the milled soil material. In particular, a suction pump can be arranged on the milling unit or on the carrier vehicle. Through one or more suction openings, preferably located in the area of ​​the milling wheels, the removed soil material, along with any surrounding liquid, can be extracted via a suitable suction line and conveyed away from the processing area by the suction pump. In particular, the material can be conveyed to a collection container and / or to a processing or separation plant.

[0031] The milling device according to the invention can, in principle, be used on land at a ground surface. In such applications, it is preferably advantageous to supply a liquid to the working area, in particular to an excavated trench, in order to facilitate the removal of the excavated soil material, especially by means of a suction device.

[0032] In one embodiment of the invention, a particularly preferred underwater mining arrangement for milling soil from the bottom of a body of water is provided, wherein at least one milling device as described above is arranged. The underwater mining arrangement can be operated autonomously underwater or in conjunction with a supply vessel. In the latter case, the underwater mining arrangement, in particular the milling device, is connected to the supply vessel via a connecting and supply line.

[0033] The milling device according to the invention can be lowered onto the bottom of a body of water with a surface structure that is not precisely known. Due to the vertical adjustability of the drive units, the carrier device with the at least one milling unit can be aligned in a desired manner, in particular brought into a horizontal position, so that a substantially flat removal surface can be created by removing the surface of the water. This surface can be used for further processing of the soil and, in particular, for further extraction using the milling device.

[0034] According to a further development of the invention, it is particularly advantageous that a supply unit is provided which is connected to the at least one milling device for supplying energy and / or removing milled soil material. The supply unit itself can be arranged underwater or on the water surface.

[0035] The invention is further described below with reference to preferred embodiments, which are illustrated in the drawings. The drawings show: Fig. 1 a perspective view of a milling device according to the invention from the rear; Fig. 2 a perspective view of the milling device from Figure 1 from the front; Fig. 3 a perspective view of an underwater mining arrangement according to the invention; Fig. 4 a schematic cross-sectional view of the milling device according to the invention. Figures 1 and 2during the removal of an upper floor area; Fig. 5 an enlarged detail side view of the milling device according to the invention in operation; Fig. 6 a perspective view of the milling device according to the invention during the removal of a sloping floor area; Fig. 7 another perspective view of the milling device according to the invention during the removal of a floor area; Fig. 8 a side view of the milling device according to the invention during the step-like removal of a floor area; Fig. 9 a perspective view of the milling device according to the invention with a machined floor area; Figures 10 to 19 each side views of the milling device according to the invention during the removal of a floor area in successive machining steps; Fig. 20 a perspective view of a milling device according to the invention during the removal of a floor area; Fig. 21 another perspective view of the milling device of Figure 20from the front with a swiveled upper carriage; Fig. 22 a perspective view of the milling device of the Figures 20 and 21 and a further pivoted upper carriage during further removal of a floor area; Fig. 23 a side view of a milling device according to the invention with additional removal unit; Fig. 24 a top view of the milling device of Fig. 23 during the removal of soil in a longitudinal direction; and Fig. 25 a top view of the milling device of Fig. 23 when removing soil in a transverse direction;

[0036] An embodiment of a milling device 10 according to the invention. Figures 1 and 2The carrier unit 12 comprises a chassis 14 and a superstructure 16 rotatably mounted thereon about a vertical axis of rotation. Several drive units 20 are arranged in a row along the longitudinal sides of the preferably rectangular chassis 14. The drive units 20 can each have a crawler track and can be moved vertically by means of an associated actuator 26, as will be explained in more detail later.

[0037] Preferably, the individual longitudinally oriented thrust units 20 can also be rotated about a vertical axis of rotation via the respective actuator 26. In the illustrated embodiment, four thrust units 20 are arranged on each longitudinal side.

[0038] Preferably, two transversely oriented drive units 22 can be arranged on the broad sides of the undercarriage 14, their direction of travel being rotated by 90°, i.e., transverse, to the direction of travel of the longitudinally oriented drive units 20. The transversely oriented drive units 22 can also be vertically adjustable via actuators (not shown in detail). The operation of the transversely oriented drive units 22 is described in more detail below.

[0039] A linear guide device 18 can be arranged on the upper carriage 16. In the illustrated embodiment, this device is box-shaped with three vertically extending guide channels 19. A box-shaped milling unit 30 can be linearly displaceable and driven within each of the guide channels 19. As will be shown in more detail later, the milling units 30 have a box-shaped milling frame with rotating milling wheels on the underside of the frame. By vertically lowering or extending the milling units 30 from the guide channels 19 of the linear guide device 18, soil material located beneath the milling wheels can be removed.

[0040] Via a schematically indicated extraction device 40 with extraction lines 42, milled soil material in the area of ​​the milling wheels can be extracted upwards through the respective milling unit 30 to the upper carriage 16 and from there conveyed via a supply line 68, which may also include a discharge line, from the milling device 10 to a supply unit 60, which will be described in more detail below in connection with the Fig. 3 is described.

[0041] The preferably driverless milling device 10 can be controlled via a control line 74, with which the milling device 10 can be connected to a central control unit 70 to form an underwater mining arrangement 50 according to Fig. 3 is connected.

[0042] Control can also be achieved wirelessly via a suitable radio connection.

[0043] The in Fig. 3The underwater mining arrangement 50 according to the invention comprises at least one milling device 10, which is used underwater on a body of water 1 as a base 2. The milling device 10 can, however, be used on land in a fundamentally identical or similar manner. In the illustration according to Fig. 3 The milling device 10 has already penetrated the ground 2, forming a milling slot 5. The excavated soil material is conveyed via the supply line 68 to a supply unit 60 equipped with a hose winch 66. From the hose winch 66, the excavated soil material is conveyed into a container 64 of the supply unit 60 and stored therein.

[0044] The supply unit 60 can have a base frame 62 with three adjustable feet. A container 64 can preferably be detachably mounted on the base frame 62. The container 64 can be connected to a supply vessel via a conveying line 52 to transport excavated soil material continuously or at specific times. Alternatively or additionally, the container 64 can be detached from the base frame 62 and brought to the surface for emptying. The container 64 can then be replaced by a new, empty container 64.

[0045] A central control unit 70, preferably stationary, can be arranged to control the underwater mining arrangement 50 located on the bottom of a body of water. Furthermore, a mobile unit 72 can be provided, which can perform various tasks. The mobile unit 72 can be equipped with various sensors and probes to explore the bottom of the body of water. The mobile unit 72 can also be designed to pick up and move the central control unit 70.

[0046] The control unit 70 can be connected wirelessly or via a line 73 to the mobile unit. Furthermore, a connection can exist wirelessly or via a control line 74 to the milling device 10 for control purposes. The control unit 70 can also communicate with a supply vessel via another central line 54.

[0047] In Fig. 4The operating principle of the vertically adjustable individual drive units 20 is illustrated. Regardless of the specific embodiments shown, the milling device 10 according to the invention is equipped with a control system that keeps the undercarriage 14 essentially horizontal, even on uneven ground surfaces. To compensate for unevenness, individual drive units 20 can be selectively extended or retracted vertically by means of the respective actuator 26. In such a horizontal position, the individual milling units 30, with a milling frame 32 and lower milling wheels 34, can be extended downwards along the linear guide 18 to mill off soil material. The box-shaped linear guide 18 can itself be mounted so as to be vertically displaceable along a mast 17 on the upper carriage 16.

[0048] As vividly illustrated in Fig. 5As shown, the milling wheels 34 of the respective milling unit 30 can be lowered to a lower edge of the drive units 20, so that a planum 7 is formed in the milling slot 5, which designates an initial surface.

[0049] Furthermore, for near-surface soil removal by milling according to one embodiment of the invention, it is advantageous to provide movable side walls 28 along the linear guide device 18, which can be lowered to the surface of the soil 2 during milling, as clearly shown in Figures 5 and 6. This delineates the milling area from the surroundings, enabling particularly effective extraction of the removed soil material and surrounding liquid. At the same time, it counteracts the spread of turbidity clouds into the environment outside the milling area.

[0050] Due to the dimensions of the milling units 30, which are wider than both the width and length of the approximately rectangular undercarriage 14, a wide milling slot 5 with an approximately horizontal surface, also called the level 7, can be created in uneven ground by progressively advancing the milling device 10. The milling device 10 can then enter the milling slot 5 thus formed. After each milling step, the milling units 30 are raised vertically again until they protrude above the ground surface. The undercarriage 14, with the advance units 20, can then advance one step further into the ground 2, corresponding to the milling width of that step. A further milling step can then be carried out by lowering the milling units 30 to the level of the level 7. This process can be repeated until a desired length of the milling slot 5 is reached.Sufficient removal of soil 2 has taken place.

[0051] The milling slot 5 can be widened according to the illustration. Fig. 7 This can be achieved simply by pivoting the milling units 30 with the upper carriage 16 by 90° relative to the lower carriage 14. The pivoting can be accomplished in particular by raising the milling units 30 with the linear guide 18 above the surface of the floor 2. This allows for particularly easy pivoting.

[0052] A further milling step can then be carried out by lowering the milling units 30 to the level of the subgrade 7. The milling slot 5 can now be advanced in a transverse direction, whereby a transverse advancement can be effected by the transversely directed drive units 22. These can be extended downwards by actuators (not shown) and brought into contact with the ground 2 for this purpose. In this way, a second section of the milling slot 5 can be created, which runs approximately perpendicular to a first section of the milling slot 5.

[0053] Further milling can also be carried out deviating from a level surface 7, for example by gradually lowering milling units 30 to create a stepped floor surface, as can be clearly seen from the Figures 8 and 9 emerges. In Fig. 9In particular, a stepped planum 7 with step-like arranged flat section surfaces is shown.

[0054] As soon as a leveled work surface with a continuous flat planum 7 or a stepped floor surface accordingly Fig. 9 Once formed, further layer-by-layer removal of the soil 2 can be carried out using the milling device 10 according to the invention, as can be clearly seen from the illustrations according to the Figures 10 to 19 can be seen.

[0055] In a first process step, the milling units 30 of the milling device 10 are moved towards the floor 2 by means of the linear guide device 18. To seal off the milling area, side walls 28 are placed on the surface of the floor 2 by the linear guide device 18, thus enclosing the milling area. Then, at least one milling unit 30 is lowered further into the floor 2, with the rotating milling wheels 34 removing soil material. The removed soil material can be extracted via suction lines 42 and conveyed away from the milling device 10.

[0056] After an initial milling step, the milling unit 30 is retracted upwards from the milled slot 5. The milling device 10 is then moved by the feed units 20 by one travel step, corresponding to the width of the milled slot 5, to create a further subsequent milled slot 5, as shown in Fig. 11 is shown.

[0057] For this purpose, the milling device 30 is moved downwards again towards the surface of the base 2 by means of the linear guide device 18, whereby the side walls 28 are again extended to define the milling area. The side wall 28 facing the existing milling slot 5 is extended to the bottom of the existing milling slot 5, as can be clearly seen in Fig. 12 as shown. In this way, the existing milling slot 5 is widened.

[0058] This process step can be repeated as often as desired until a milled slot 5 with a desired slot length is created, as Fig. 13 can be seen from this.

[0059] After the last milling step, the upper carriage 16 of the milling device 10 can be pivoted 180° relative to the lower carriage 14, so that the milling unit 30 with the linear guide device 18 is turned away from the milled slot 5 formed, as shown in the figure. Fig. 14This results in a shift of the center of gravity of the milling device 10 to the half of the milling device 10 that is facing away from the formed milling slot 5.

[0060] This now makes it possible for the milling device 10 to be adjusted accordingly. Fig. 15 with a first partial section, which can correspond to approximately one quarter of the length of the milling device 10, can travel over the formed milling slot 5, as shown in Fig. 15 as shown. In this position, the first drive unit 20 can then be extended downwards with the actuator 26 until the drive unit 20 is supported at the bottom of the milling slot 5, as shown in Fig. 16 This is made clear.

[0061] The milling device 10 can then be moved further towards the milling slot 5 until another feed unit 20 can be lowered into the milling slot 5, as shown in Fig. 17This stepwise insertion of the milling device 10 into the formed milling slot 5 is repeated until the last feed unit 20 has reached the corresponding position. Fig. 18 is lowered into the milling slot 5 and the milling device 10 is completely in the milling slot 5 formed accordingly Fig. 19 The upper carriage 16 can then be pivoted 180° relative to the lower carriage 14, so that the milling unit 30 with the linear guide device 18 faces the milled slot 5. Alternatively, the actuators 26 can be operated to lower the lower carriage 14 again.

[0062] The existing milling slot 5 can now be deepened further with the milling device 10, whereby the milling device 10 can work its way into the ground 2 in a step-like manner, as shown schematically in Fig. 20As shown, the milling slot 5 can be created with a desired length and depth. To further widen the milling slot 5, the upper carriage 16 can be pivoted 90° relative to the lower carriage 14 within the milling slot 5 in order to machine a bottom area transverse to a longitudinal direction of the existing milling slot 5, as shown schematically in Fig. 21 This is illustrated. The transversely directed drive units 22 can be used for this purpose. These are extended vertically downwards so that they come into contact with the bottom of the milling slot 5 and can thus move the milling device 10 in a transverse direction. In this way, the milling device 10 can advance stepwise in a transverse direction to a desired position. The advancement can, in particular, correspond to a width of the milling device 10.

[0063] The upper carriage 16 can then be rotated again by 90° relative to the lower carriage 14, so that, according to the illustration, Fig. 22 The milling device 10 creates a further slot immediately adjacent to the existing milling slot 5, thus widening the existing milling slot 5. In this way, a large area of ​​the soil 2 can be removed or excavated in a row-like fashion using a reversing removal or excavation motion.

[0064] The operation of the milling device 10 within an underwater mining setup 50 has been described previously. However, the milling device 10 according to the invention can also be used on land for the large-scale removal of soil layers. In particular, a milled slot 5 created in the soil 2 can be filled with liquid, which facilitates the suction of the removed soil material.

[0065] Another embodiment of a milling device 10 according to the invention is described in the Figures 23 to 25 The basic structure of this milling device 10 corresponds to the structure of the previously described embodiments. In addition, the milling device 10 is designed according to the Figures 23 to 25 An additional removal unit 46 is arranged between the milling units 30 and the carrier unit 12. This unit is designed for removing, in particular milling, remaining floor ridges or grooves during the removal process by the preceding milling units 30. The additional removal unit 46 can be displaced laterally along a linear guide 48 on the upper carriage 16 of the carrier unit 12. This lateral displacement allows individual longitudinally extending floor ridges or grooves to be removed across the entire milling width. Figure 25 As shown. Vertical adjustability may also be provided for material removal.

[0066] When the upper carriage 16 pivots and soil material is removed in a transverse direction according to Figure 26, the additional removal unit 46 can be designed and arranged in such a way that it reliably removes any remaining soil web or edge during removal by the milling units 30.

Claims

1. A method for removing a soil layer from a bed of a body of water (1) by means of a milling device (10) which is placed on the bed of the body of water (1), wherein the milling device (10) comprises a mobile carrier device (12) and at least one milling unit (30) mounted on the carrier device (12), which milling unit is guided in a displaceable manner by means of at least one linear guide device (18), wherein - the milling device (10), after being placed on the bed of the body of water (1), is brought into an essentially horizontal position and aligned, - an essentially horizontal, planar initial surface is formed by means of the at least one milling unit (30), wherein the at least one milling unit (30) is introduced essentially vertically along the linear guide device (18) into the soil (2) for milling off soil material, - the milling device (10) is moved onto the formed initial surface, and - starting from the planar initial surface (7), soil is removed by vertically displacing the milling unit (30) into the soil (2) and horizontally displacing the carrier device (12).

2. The method according to claim 1, characterized in that propulsion units (20) are arranged on the mobile carrier device (12), each of which is adjustable in a vertical direction, and in that after being placed on the bed of the body of water (1), the propulsion units (20) are adjusted in a defined vertical manner until the desired horizontal alignment of the milling device (10) is achieved.

3. The method according to claim 1 or 2, characterized in that after creating the horizontal initial surface, the propulsion units (20) are adjusted into approximately a same adjustment position.

4. The method according to one of claims 1 to 3, characterized in that a milling slot (5) is formed by means of the at least one milling unit (30) on a processing side of the carrier device (12) with a milling width that is equal to or greater than a width of the carrier device (12) on the processing side, and in that the milling device (10) is moved step by step into the formed milling slot (5).

5. The method according to one of claims 1 to 4, characterized in that the soil layer is removed in a stepped manner and / or in a meandering manner by the milling device (10).

6. The method according to one of claims 1 to 5, characterized in that the soil (2) is removed by several milling units (30), which are mounted parallel next to one another on the carrier device (12) so as to be vertically adjustable .

7. The method according to one of claims 1 to 6, characterized in that at least one additional removal unit (46) is used to remove a soil web remaining during milling by the at least one milling unit (30), which additional removal unit is arranged on the carrier device (12) offset rearward relative to the at least one milling unit (30).

8. The method according to one of claims 1 to 7, characterized in that the removed soil material is conveyed to a container (64).

9. A milling device for removing a soil layer from a bed of a body of water (1), in particular according to a method according to one of claims 1 to 8, comprising - a mobile carrier device (12) which has driven propulsion units (20) for movement on a soil (2), and - at least one linear guide device (18), which is arranged on the carrier device (12) and designed to guide at least one milling unit (30) in a displaceable manner, which milling unit can be introduced essentially vertically along the linear guide device (18) into the soil (2) for milling off soil material, characterized in that - the propulsion units (20) are mounted on an undercarriage (14) of the carrier device so as to be adjustable in a vertical direction, and - in that the propulsion units (20) are each adjustable in the vertical direction by means of an actuator drive (26).

10. The milling device according to claim 9, characterized in that the carrier device (12) has two longitudinal sides, wherein at least two propulsion units (20) oriented in the longitudinal direction are arranged on each longitudinal side.

11. The milling device according to one of claims 9 or 10, characterized in that in addition to the propulsion units (20), at least one propulsion unit (22) is provided on the undercarriage (14) along the longitudinal sides, which propulsion unit is arranged and designed for moving in a transverse direction.

12. The milling device according to one of claims 9 to 11, characterized in that a plurality of milling units (30) are arranged so as to be displaceable parallel to one another along the linear guide device (18).

13. The milling device according to one of claims 9 to 12, characterized in that a total milling width of the at least one milling unit (30) is greater than a width of the undercarriage (14) of the carrier device (12).

14. The milling device according to one of claims 9 to 13, characterized in that the linear guide device (18) is designed in a box-shaped manner with at least one guide shaft (19), in which a milling unit (30) is guided in a displaceable manner.

15. The milling device according to one of claims 9 to 14, characterized in that a suction device (40) for suctioning and discharging the milled soil material is arranged.

16. An underwater excavation arrangement for removing a soil layer from a bed of a body of water, characterized in that at least one milling device (10) according to one of claims 9 to 15 is arranged, and in that a supply unit (60) is provided, which is connected to the at least one milling device (10) for supplying energy and / or discharging milled off soil material.

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