This invention relates to injection vessels capable of injecting liquid amendment into contaminated sediment, and in particular to injection vessels capable of operating in shallow salt water and fresh water systems with little environmental impact.
Remediation of contaminated sediment in shallow salt water marshes, tidal flats, or fresh water wetlands, after ecological harm has occurred, should be performed in a manner to minimize the intrusion of the remediation equipment in these ecologically sensitive areas. Sediment remediation techniques that are currently used typically involve dredging, tilling, installing horizontal wells, and manually injecting liquid amendment into the contaminated subsurface sediment. The various types of equipment that are currently used to perform these operations are usually large, bulky, noisy, and polluting, hence the anthropogenic impact of these methods and the equipment used to carry out these methods can be substantial.
Therefore, it would be advantageous to provide an injection vessel that is capable of delivering liquid amendment into the sediment without adversely impacting the ecologically sensitive environment in which it operates.
An injection vessel for injecting liquid amendment into contaminated subsurface sediment in ecologically sensitive areas such as shallow water salt marshes, tidal flats, or fresh water wetlands is disclosed. The injection vessel described herein includes a shallow-draft floating platform that has an injection system mounted thereon. The injection system includes an injection grid containing a plurality of injection syringes that receive liquid amendment from a metering pump. The injection grid is lowered such that the output of the injection syringes is within the contaminated sediment. The metering pump provides the liquid amendment to the injection syringes and a fluid path is established that injects the liquid amendment into the contaminated sediment. A propulsion system mounted on the floating platform provides for locomotive and maneuvering power.
A control system allows the operation of the system either in a semi-autonomous mode in which an on-board controller is programmed to provide the command signals, or in a remote control mode with an operator providing real time command signals through either a wireless or wired controller. The control system provides propulsion commands to the propulsion system and injection commands to the injection system. The propulsion commands include both locomotive commands and maneuvering commands. The injection commands include the lowering and raising of the injection grid and the operation of the metering pump to dispense the predetermined amount of liquid amendment.
In one aspect, the propulsion system of the injection vessel includes a pair of paddle wheels that are mounted on the floating platform and are powered by a pair of electric motors coupled to the controller. In one embodiment, the propulsion commands can be forward or reverse and on and off for each motor.
In another aspect, the controller includes an on-board computer/controller that receives commands from an off-vessel user having a field computer, wherein the field computer and the on-board computer/controller are coupled via a wireless connection, which can be a radio frequency or optical link. The commands can be generated by a user using the field computer via a keyboard, keypad, or controller such as a joystick. In another aspect the on-board computer/controller receives commands from a hardwired controller operated by a user, and wherein the controller can be a joystick. In another aspect, the on-board computer/controller can receive commands programmed and stored in a programmable memory coupled to the on-board computer/controller, or the programmable memory can be coupled to the field computer and transmitted over the wireless link.
Other features, functions, and aspects of the invention will be evident from the Detailed Description of the Invention that follows.
The invention will be more fully understood with reference to the following Detailed Description of the Invention in conjunction with the drawings of which:
In operation, the control system 126 navigates the injection vessel 100 to a predetermined location via control signals sent to the electric motors 124a and 124b. The control system 126 then instructs the raising/lowering mechanism 122 to lower the injection grid assembly 112 containing the injector assembly 114 such that a portion of the injector assembly 114 is inserted into the contaminated subsurface sediment. The metering pump 117 is then signaled to provide the liquid amendment to the injector assembly 114 to inject the liquid amendment into the contaminated subsurface sediment. The raising/lowering mechanism 122 is signaled to raise the injector grid 112, thus raising the injector assembly 114 out of the sediment. The control system 126 then selects the next location to be remediated, and provides control signals to the electric motors 124a and 124b to move the injection vessel 100 to the next selected location.
In the preferred embodiment, the two electric motors are 24 volt DC motors, that are capable of providing rotation in either direction such that the individual paddle wheels can be counter rotated with respect to one another to allow the injection vessel to turn and maneuver. In this embodiment, the swing arms are constructed out of anodized aluminum and the paddle wheels are constructed from fiberglass reinforced plastic.
In the preferred embodiment, the floating platform 102 is a pontoon boat using a plurality of ¼″ thick pontoons held together by anodized aluminum “z-bars” and stainless steel fasteners. A suitable pontoon boat is manufactured by Rettey Corporation, Colchester, Ill.
As depicted in
In particular, in response to movement commands, the on-board controller provides first and second motor control signals 612 and 614 respectively to the first and second electric motors, 124a and 124b, respectively. In the preferred embodiment, the movement commands control forward and reverse operation of each of the pair of paddle wheels, 202a and 202b. In this embodiment, the on-board computer/controller 610 provides forward-reverse and on-off commands to the motors and their associated control electronics to provide for movement and maneuvering of the injection vessel. In another embodiment, the computer/controller 610 can provide fractional power commands to control the speed and direction of each paddle wheel 202a and 202b.
The on-board computer/controller 610 also provides an injection initiation signal 616 to an injection controller 618. The injection controller provides the necessary injection commands 622 to the injection system via line 620 and provides monitoring data to the on-board computer/controller. The injection controller 618 provides the injection commands 622 to the raising/lowering mechanism 122 to lower the injection grid 112, to the metering pump 117 to dispense the predetermined amount of liquid amendment, to the system as a whole to wait a predetermined amount of time for the injected liquid amendment to settle into the sediment, and to the raising/lowering mechanism 122 to raise the injection grid 112.
The control system 126 includes a variety of operational command modes. In one embodiment, an off-vessel operator using a field computer 602 communicates via a wireless connection 607 between a wireless modem 606 coupled to the field computer 602 and a second wireless modem 608 coupled to the on-board computer 610. The off-vessel operator receives data from the on-board computer 610 and provides instructions and commands to the on-board computer 610. In this embodiment, the off-vessel operator interfaces to the field computer 602 via a HyperTerminal that allows direct control over the on-board computer 610. In the preferred embodiment, the wireless connection 607 is a 900 MHz spread spectrum radio signal and the wireless modems are Ewave Super Screamer multi-protocol wireless modems available from Ewave, Inc. of Dallas Tex. Advantageously, by not having an operator onboard the injection vessel, the vessel will draw less water, enabling the injection vessel to have potentially more access to contaminated areas while minimizing the environmental impact on the area. In another embodiment, the wireless connection can be an optical connection, such as using infrared radiation.
In this preferred embodiment, as depicted in
In another embodiment, a joystick or other controller 628 is hardwired into the on-board computer/controller 610 to provide a direct input from the user to the on-board computer/controller 610. In this embodiment, the user may be located on the injection vessel itself or may be off-vessel and tethered to the on-board computer/controller 610 via a cable of sufficient length. Movement commands are based on the position of the joy-stick and the initiation of the injection process is provided by depressing the trigger button of the joystick.
In another embodiment, the movement and injection process initiation commands to the on-board computer/controller 610 can be pre-programmed into a memory 624 and executed autonomously by the on-board computer/controller 610. Navigation, movement and maneuvering, and injection control can be pre-programmed. If an optional global positioning receiver is used, as discussed in more detail below, the injection vessel can be nearly autonomous since the on-board computer/controller will have all the information necessary to carry out a pre-programmed mission. The data can include for example, the starting position of the injection vessel, preselected locations to inject the liquid amendment, the amount of liquid amendment, and the final location. The controller can be programmed with navigation and route selecting algorithms to aid in this process. In this embodiment, it may be desirable for an operator to monitor the injection vessel and to be able to manually override the injection vessel on-board computer/controller 610 in the event of a failure or an emergency. Accordingly, the wireless system described above could be used. In another embodiment, the programmable memory can be coupled to the field computer and commands and data transmitted via the wireless connection between the field computer and the on-board computer/controller.
The on-board computer/controller 610 can also include an on-board global positioning system (GPS) receiver 626 to provide location and velocity data. The GPS receiver 626 can incorporate a differential GPS receiver so that sub-meter positioning can be achieved during injections. The differential GPS receiver can be configured to work with the US Coast Guard correction signal for marine purposes as well as the Wide Angle Augmentation System (WAAS) supported by the Federal Aviation Administration (FAA) such that corrections inland may be achieved as well. In addition, the GPS receiver 626 can be configured to support third-party corrections such as the satellite system by Omni-Star for corrections world wide. A suitable GPS receiver is available from Trimble Navigation Ltd., Sunnyvale, Calif.
In the preferred embodiment, the field computer 602 is a suitable lap-top computer that can be interfaced to a network such as an Ether Net and provide the necessary processing and graphics for the user. A suitable on-board computer/controller is the TEMPERATURE SENSING-2800 SBC DOS based computer/controller available from Technologic Systems, Fountain Hills, Ariz. This computer/controller was selected since it is a completely self contained module and includes a DOS ROM based operating system with full TCP/IP support, 2 PC/AT RS232 serial ports, 8 Mbytes of RAM, 1 Mbyte of FLASH RAM, 24 I/O ports, self-contained time clocks, a lithium battery and battery backed CMOS memory. In the preferred embodiment, the injection controller 618 is a programmable logic controller that is powered using 12 volts and accepts 8 DC inputs and has 6 outputs. Relays or electronic switches then provide the appropriate current to the raising/lowering mechanism 122, which as provided above is preferably a winch and cable system. The interface between the on-board computer/controller 610 and the injection controller 618 is preferably via an Ethernet.
It should be appreciated that other variations to and modifications of the above-described injection vessel may be made without departing from the inventive concepts described herein. Accordingly, the invention should not be viewed as limited except by the scope and spirit of the appended claims.
The work leading to this invention was carried out with United States Government support provided under a grant from the NOAA, Grants No. NA16RG1035, and NA070R0351. Therefore, the U.S. Government has certain rights in this invention.
Number | Name | Date | Kind |
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4069678 | Miura et al. | Jan 1978 | A |
4072017 | Shiraki | Feb 1978 | A |
5127765 | Millgard | Jul 1992 | A |
Number | Date | Country |
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2079345 | Jan 1982 | GB |
57-209318 | Dec 1982 | JP |
57209318 | Dec 1982 | JP |