NL2012302C2

NL2012302C2 - Bottom leveller system.

Info

Publication number: NL2012302C2
Application number: NL2012302A
Authority: NL
Inventors: Wouter Kuijpers
Original assignee: Ihc Holland Ie Bv
Priority date: 2014-02-21
Filing date: 2014-02-21
Publication date: 2015-08-25
Also published as: WO2015126247A1; IL247333B; EP3108069B1; ES2900832T3; EP3108069A1; IL247333A0

Abstract

A method of flat bottom dredging of a bed at least partially covered with liquid from a floating pontoon (12) comprises controllably rotating a ladder (14) with a cutter head (26) toward the bed to set the dredge depth and force with a first hydraulic system (18); adjusting the cutter head position with a second hydraulic system (22) so that it is level with the bed; and continuously adjusting the ladder depth and force and the cutter head position while dredging through a control system (30) which receives sensor signals.

Description

BOTTOM LEVELLER SYSTEM

BACKGROUND

Cutter-suction dredgers (“CSD”) are vessels which can be used to cut and loosen material which is at least partly underwater. CSD’s typically connect the cutter head to the vessel through a rigid ladder. The ladder can extend from the vessel to form a rigid connection between the cutter head and the vessel. The cutter head contacts the water bed and can be rotated to cut and loosen material. This material can then be transported to the vessel or another location, for example, by using a wear-resistant pump such as a centrifugal pump. CSD’s are often used to cut hard surface materials, such as rock, although they may also be used to excavate gravel or sand.

Many dredging systems are designed for use in the ocean, and include complicated systems to keep the cutter head in place despite waves and other water disturbances. For example, U.S. Pat. No. 3,777,376 also discloses a dredging system which is adapted for use in rough water. The ladder is formed by two parts connected together by a link to isolate the two parts and to ensure that the cutter head stays stable despite waves. W02006/089866 also discloses a cutter head which is formed of discshaped bodies and is resiliently connected to the ladder, enabling operation even in bad weather conditions. U.S. Pat. App. Pub. No. 2005/0268499 discloses a dredging system which uses a suction head to remove a layer of material from a contoured bottom. The suction head is connected to a boom which is lowered by a winch and rope. The suction head engages the bottom to dredge the bottom. A leveling device using linkages can be used to maintain the suction head substantially level with the bottom. Each these devices relies on the weight of the ladder and/or cutter head for any downward force of the cutter head into the water bed.

Some areas which require dredging are very shallow, for example salt evaporation ponds. In this case, the ladder can be connected to a floating pontoon, which could also be a dredger. Dredging is required in salt evaporation ponds because of the precipitation of chlorides. In salt evaporation ponds, a very flat profile inhibits the formation and growth of precipitation in the form of salt mushrooms.

SUMMARY A method of flat bottom dredging of a bed at least partially covered with liquid comprises controllably rotating a ladder with a cutter head toward the bed to set the dredge depth and force with a first hydraulic system; adjusting the cutter head position with a second hydraulic system so that it is level with the bed; and continuously adjusting the ladder depth and force and the cutter head position while dredging through a control system which receives sensor signals.

This dredging method allows for very precise and/or continuous adjustment of the position and force of the ladder. This allows for very precise dredging, for example in a shallow and/or hard bed pond requiring a flat bottom profile.

Additional and/or alternative embodiments may include the sensor signals being one or more of ladder depth, ladder upper angle, ladder lower angle, cutter head position, bed conditions, bed depth, draught and liquid conditions; the cutter head comprising a first portion that is conical in shape; and/or the first hydraulic system and/or the second hydraulic system comprising one or more hydraulic cylinders.

According to an embodiment, the method further comprises measuring the position of one or more of the ladder depth, ladder force, ladder upper angle, ladder lower angle, cutter head position, bed conditions, bed depth, draught and liquid conditions with sensors; and sending the sensor signals to the control system.

According to an embodiment, the step of continuously adjusting the ladder depth and force and the cutter head position while dredging through a control system is done automatically. In an alternative embodiment, this step can be done manually or partially automatically and partially manually.

According to an embodiment, the step of controllably rotating a ladder with a cutter head toward the bed to set the dredge depth and force with a first hydraulic system comprises adjusting the first hydraulic system to provide an additional downward force. This allows for the system to provide additional force, for example when in danger of underdredging and/or the liquid bed is very hard.

According to an embodiment, a dredging system for dredging a liquid bed from a floating pontoon comprises a ladder rotatably connected to the pontoon on a first end; a cutter head adjustably connected the ladder on a second end and shaped to enable flat bottom cutting of the water bed; a first hydraulic system to control the movement of the ladder; a second hydraulic system to control the position of the cutter head; a plurality of sensors to sense information regarding positioning and force of the cutter head, ladder, liquid and/or liquid bed; and a control system to receive the information from the sensors and control the movement and force of the ladder and cutter head through the first and second hydraulic systems to ensure that the cutter head is cutting the liquid bed with a flat bottom profile.

Additional and/or alternative embodiments may include the cutter head comprising a structure that is at least partially conical; the control system being an automatic control system; the control system being a manual control system; the cutter head comprising cutting teeth shaped to enable cutting the liquid bed with a flat bottom profile; the control system adjusting the ladder and/or the cutter head relative to the liquid conditions; and/or the first hydraulic system and/or the second hydraulic system comprise one or more hydraulic cylinders.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A shows a dredging system with a cutter ladder in a raised position. FIG. 1B-1C show the dredging system of FIG. 1A in use at different depths. FIG. 2 shows an embodiment of a cutter head for the dredging system of FIG. 1A.

DETAILED DESCRIPTION FIG. 1A shows dredging system 10 connected to floating pontoon 12. In FIG. 1A, dredging system 10 has cutter ladder 14 in a raised position. FIG. 1B-1C show dredging system 10 in use at different depths against bed 15, with cutter ladder 14 in different positions. Floating pontoon 12 can be a dredger.

Dredging system 10 includes ladder 14, first hydraulic system 18, ladder upper angle position sensor 20, second hydraulic system 22, ladder lower position sensor 24, cutter head 26, draught sensor 28 and control system 30. First hydraulic system 18 and/or second hydraulic system 22 can comprise one or more hydraulic cylinders.

Ladder 14 rotatably connects to pontoon 12 at an upper end and the rotated position, or ladder depth is controlled by first hydraulic system 18. Second hydraulic system 22 connects to ladder 14 at a lower end and controls the angle of lower end of ladder 14 and cutter head 26.

Draught sensor 28 can measure the draught relative to the water level. Measurements from the draught sensor 28 and the dredging depth required can be used to determine the ladder upper and lower angle requirements. Upper ladder angle position sensor 20 can, for example, measure the upper ladder angle with a pendulum. Lower ladder angle position sensor 24 can, for example, also measure with a pendulum or with linear position measurement of hydraulic cylinders on the second hydraulic system 22. Measurements can also be taken of the actual dredge draught at ladder 14, dredge angle, pontoon 12 vertical position relative to earth fixed location and other measurements related to ladder 14 position and dredge force.

Upper ladder angle position sensor 20 senses the angle of ladder 14, and sends that information to control system 30. Lower ladder position sensor 24 senses the angle of lower end of ladder 14 and cutter head 26, and sends that information to control system 30. Draught sensor 28 sends draught measurement information to control system 30. The information or signals sent to control system 30 can include information on one or more of ladder depth, ladder upper angle, ladder lower angle, ladder force, cutter head position, bed conditions, bed depth, draught and liquid conditions and can be sent by the sensors shown or others not shown in these figures. The signals can be transmitted to control system 30 via wires or wirelessly.

Control system 30 receives this information, and can use it to maintain a realtime, position measurement and control system with a high level of accuracy to maintain a cutting profile horizontally at a set depth. This accuracy can, for example, be a sub-decimeter or centimeter accuracy. Control system 30 is typically a real-time programmable logic controller “PLC” or programmable controller “PC” control system which measures actual system geometry and compares these measurements with a user set depth. The user provided depth settings can be dredge master real time input or can be depth data, stored by a dredge operator in a bathymetry data system. Set depth will generally vary depending on actual position of the dredge and dredge angle. Control system, through PLC/PC, can control first hydraulic system 18 and second hydraulic system 22, to adjust cylinder lengths therefore rotating ladder 14 and dredge to a desired depth and pressure. Control system 30 can continuously adjust the ladder force, depth and position during a dredging operation to ensure that the dredging stays at the desired conditions and depth. Control system 30 can be automatic, manual or both, depending on system requirements.

In operation, ladder 14 begins from a horizontal position as shown in FIG. 1A. Control system 30 uses information from sensors to adjust first hydraulic system 18 and/or second hydraulic system 22 to rotate ladder 14 and place cutter head 26 at the desired location against bed 15 (see FIGS. 1B-1C). First hydraulic system 18 and/or second hydraulic system 22 can additionally be used to adjust the pressure of cutter head 26 against bed, for example, to put additional downward force on ladder 14 and cutter head 26 when bed 15 is very hard. FIG. IB shows dredging system 10 in use in a pond with a medium depth. First hydraulic system 18 extends to rotate ladder 14 downward. In this figure, second hydraulic system 22 is extended very little, as ladder 14 does not need very much lower rotation to allow cutter head 26 to cut a flat bottom profile. FIG. 1C shows dredging system 10 in use in a very shallow pond. In this figure, first hydraulic system 18 is extended very little, and second hydraulic system 22 is extended more to rotate lower end of ladder 14 toward bed 15. Control system 30 can adjust upper hydraulic system 18 and/or lower hydraulic system 22 to provide more or less force as required during the dredging operation.

As discussed above, salt evaporation ponds require dredging due to the precipitation of chlorides. These salt evaporation ponds are often very shallow and can have very hard beds. The dredging must be done to have a very flat profile to inhibit the formation and growth of precipitation in the form of salt mushrooms. Dredging system 10 is able to dredge a very flat profile and in a hard liquid bed 15 due to the use of first and second hydraulic systems 18, 22 and control system 30 with sensors 20, 24, 28 to continuously monitor and control the position and force of ladder 14 and cutter head 26.

Previous dredging systems typically suspended a ladder from a dredging vessel with a cable or a rope. The dredging force was limited by the weight of the ladder, and the control of the ladder and thus the cutter head was limited. Dredging system 10 allows for a precise profile, even in shallow ponds or liquid bodies with a hard bed by using first and second hydraulic system 18, 22 and control system 30 with a variety of sensors 20, 24, 28 to monitor and continuously adjust the position and force of ladder and cutter head for high levels of dredging accuracy. Previous systems could only control overdredging by removing force from the ladder with the rope or cable. Dredging system 10 is able to control both overdredging and underdredging by being able to add or remove force from ladder 14 due to the use of first and second hydraulic systems 18, 22 for controlling ladder 14.

Additionally, due to the sensors and control system 30, dredging system 10 does not rely on the profile of bed 15 when attempting to cut a flat profile. Control system 30, sensors 20, 24, 28 and first and second hydraulic system 18, 22 allow for the controlled flat bed cutting solely through measurements obtained, resulting in an extremely flat bottom where the appearance of precipitations is prevented as long as possible. FIG. 2 shows and embodiment of a cutter head 26 for dredging system 10. Cutter head 26 has a first portion 32 that is conical in shaped and formed by arms extending from a base ring 34 to the central hub 36. In the embodiment shown, cutter arms include cutter teeth.

Cutter head 26 can be used with dredging system 10 to cut a flat bottom profile for a liquid bed 15. The conical shaped of first portion 32 of cutter head 26 allows for first and second hydraulic systems 18, 22 to lay conical portion flat against liquid bed 15 to enable flat profile cutting.

In summary, dredging system 10 uses first and second hydraulic systems 18, 22, control system 30 with sensors and cutter head to enable a more precise dredge, particularly in systems which require a flat bottom profile and/or have very hard beds 15. Control system 30 and hydraulic systems 18, 22 allow for the real-time, continuous control and adjustment of the position and force with which ladder 14 dredges. Control system 30 and sensors provide signals for the continuous adjustment of ladder position and force without relying on the liquid bed for leveling. Cutter head 26 can additionally be shaped, for example with a partial conical shape, to enable easier and more precise cutting of a flat bottom profile. Cutter head 26 can also include teeth which makes the flat profile dredging easier.

While sensors 20, 24, 28 have been shown, more or fewer sensors could be used with the embodiment shown in FIGS. 1A-1C or other embodiments to measure ladder depth, ladder force, ladder upper angle, ladder lower angle, cutter head position, bed conditions, bed depth, draught, liquid conditions and other related parameters. Additionally, these and other parameters could be sensed with other types of devices and/or sensors. Furthermore, the sensor and control system locations are shown for example purposes only, and these or other sensors or systems could be located at different positions.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. Werkwijze voor vlakke-bodembaggeren van een bedding dat tenminste gedeeltelijk is bedekt met vloeistof, waarbij de werkwijze omvat: het regelbaar roteren van een ladder met een snij kop naar de bedding om de baggerdiepte en -kracht te bepalen met een eerste hydraulisch systeem; het aanpassen van de snij koppositie met een tweede hydraulisch systeem zodat het gelijk is met de bedding; en het continu aanpassen van de ladderdiepte en -kracht en de snij koppositie tijdens het baggeren, door middel van een regelsysteem dat sensorsignalen ontvangt.A method for flat-bottom dredging of a bed that is at least partially covered with liquid, the method comprising: controllably rotating a ladder with a cutting head to the bed to determine the dredging depth and force with a first hydraulic system; adjusting the cutting head position with a second hydraulic system so that it is flush with the bed; and continuously adjusting the ladder depth and force and the cutting head position during dredging, by means of a control system that receives sensor signals.

2. Werkwijze volgens conclusie 1, waarbij de sensorsignalen een of meer zijn van de ladderdiepte, ladderb ovenhoek, ladder onderhoek, snij koppositie, beddingconditie, beddingdiepte, diepgang en vloeistofconditie.A method according to claim 1, wherein the sensor signals are one or more of the ladder depth, ladder oven angle, bottom ladder angle, cutting head position, bed condition, bed depth, draft and fluid condition.

3. Werkwijze volgens een der voorgaande conclusies, waarbij de snijkop een eerste deel omvat, welke conisch van vorm is.3. Method as claimed in any of the foregoing claims, wherein the cutting head comprises a first part, which is conical in shape.

4. Werkwijze volgens een der voorgaande conclusies, verder omvattende: het meten van de positie van een of meer van de ladderdiepte, ladderbovenhoek, ladderonderhoek, snij koppositie, beddingconditie, beddingdiepte, diepgang en vloeistofcondities met sensoren; en het zenden van sensorsignalen naar het regelsysteem.A method according to any one of the preceding claims, further comprising: measuring the position of one or more of the ladder depth, ladder upper corner, ladder lower corner, cutting head position, bed condition, bed depth, draft and fluid conditions with sensors; and sending sensor signals to the control system.

5. Werkwijze volgens een der voorgaande conclusies, waarbij de stap van het continu aanpassen van de ladderdiepte en -kracht en de snij koppositie onderwijl het baggeren door middel van een regelsysteem automatisch plaatsvindt.A method according to any one of the preceding claims, wherein the step of continuously adjusting the ladder depth and force and the cutting head position, while dredging by means of a control system, takes place automatically.

6. Werkwijze volgens conclusies 1-4, waarbij de stap van het continu aanpassen van de ladderdiepte en -kracht en de snij koppositie onderwijl het baggeren door middel van een regelsysteem handmatig plaatsvindt.Method according to claims 1-4, wherein the step of continuously adjusting the ladder depth and force and the cutting head position while manual dredging takes place by means of a control system.

7. Werkwijze volgens een der voorgaande conclusies, waarbij de stap van het regelbaar roteren van een ladder met een snij kop naar de bedding om de baggerdiepte en -kracht te bepalen met een eerste hydraulisch systeem omvat het aanpassen van het eerste hydraulische systeem om een verdere neerwaartse kracht te voorzien.A method according to any preceding claim, wherein the step of controllably rotating a ladder with a cutting head to the bed to determine the dredging depth and force with a first hydraulic system comprises adjusting the first hydraulic system to a further provide downward force.

8. Werkwijze volgens een der voorgaande conclusies, waarbij het eerste hydraulische systeem en/of het tweede hydraulische systeem een of meer hydraulische cilinders omvat.A method according to any one of the preceding claims, wherein the first hydraulic system and / or the second hydraulic system comprises one or more hydraulic cylinders.

9. Baggersysteem voor het baggeren van een vloeistofbedding vanaf een drijvend vaartuig, het baggersysteem omvattende: een ladder roteerbaar verbonden aan het vaartuig aan een eerste einde; een snij kop aanpasbaar verbonden met de ladder aan een tweede einde; een eerste hydraulisch systeem voor het regelen van de beweging van de ladder; een tweede hydraulisch systeem voor het regelen van de positie van de snijkop; en een meervoud van sensoren voor het opvangen van informatie betreffende het positioneren van en de kracht van de snijkop, ladder, diepgang, vloeistof en/of vloeistofbedding.A dredging system for dredging a fluid bed from a floating vessel, the dredging system comprising: a ladder rotatably connected to the vessel at a first end; a cutting head adaptably connected to the ladder at a second end; a first hydraulic system for controlling the movement of the ladder; a second hydraulic system for controlling the position of the cutting head; and a plurality of sensors for receiving information regarding the positioning and the force of the cutter head, ladder, draft, fluid and / or fluid bed.

10. Baggersysteem volgens conclusie 9, verder omvattende: een regelsysteem voor het ontvangen van de informatie van de sensoren en het regelen van de beweging en kracht van de ladder en snijkop door de eerste en tweede hydraulische systemen ter zekering dat de snijkop het vloeistofbedding snijd met een vlakke-bodemprofiel.The dredging system of claim 9, further comprising: a control system for receiving the information from the sensors and controlling the movement and force of the ladder and cutter by the first and second hydraulic systems to ensure that the cutter is cutting the fluid bed with a flat bottom profile.

11. Baggersysteem volgens conclusie 10, waarbij het regelsysteem een automatisch regelsysteem is.The dredging system of claim 10, wherein the control system is an automatic control system.

12. Baggersysteem volgens conclusie 10, waarbij het regelsysteem een handmatig regelsysteem is.The dredging system of claim 10, wherein the control system is a manual control system.

13. Baggersysteem volgens een der conclusies 9-12, waarbij de snijkop snijtanden omvat.A dredging system according to any of claims 9-12, wherein the cutting head comprises cutting teeth.

14. Baggersysteem volgens een der conclusies 10-13, waarbij het regelsysteem de ladder en/of snijkop aanpast ten opzichte van de vloeistofcondities.A dredging system according to any of claims 10-13, wherein the control system adjusts the ladder and / or cutting head relative to the fluid conditions.

15. Baggersysteem volgens een der conclusies 9-14, waarbij het eerste hydraulische systeem en/of het tweede hydraulische systeem een of meer hydraulische cilinders omvat.A dredging system according to any one of claims 9-14, wherein the first hydraulic system and / or the second hydraulic system comprises one or more hydraulic cylinders.

16. Baggersysteem volgens een der conclusies 9-15, waarbij de drijvende vaartuig een baggeraar is.A dredging system according to any one of claims 9-15, wherein the floating vessel is a dredging vessel.

17. Baggersysteem volgens een der conclusies 9-16, waarbij de snijkop is gevormd voor vlakkebodemsnijding van het waterbedding.A dredging system according to any one of claims 9-16, wherein the cutting head is formed for flat bottom cutting of the water bed.

18. Baggersysteem volgens een der conclusies 9-17, waarbij de snijkop een structuur omvat die ten minste gedeeltelijk conisch is.A dredging system according to any one of claims 9-17, wherein the cutting head comprises a structure that is at least partially conical.