miller-aluminum / seawater power

rexresearch.com

Timothy MILLER, et al.

Aluminum - Seawater Vortex Combustor

See also : Supercavitation

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=1177213

A Next-Generation AUV Energy System Based on Aluminum-Seawater Combustion

Timothy F. Miller, et al.

[ PDF ]

https://www.scribd.com/doc/149650698/16/Aluminum-Vortex-Combustor

Summary Of The NASA Future Strategic Issues and Warfare Circa 2025 Document

Dennis M. Bushnell - Chief Scientist NASA Langley Research Center -

Warfare Strategy Document - The Future Is Now

http://adjunct.diodon349.com/Kursk-Memorial/Warpdrive_underwater.htm

[ Excerpt -- Supercavitating Torpedoes, &c ]

Warp Drive Underwater

Advanced Propulsion Systems

Most existing and anticipated autonomous supercavitating vehicles rely on rocket-type motors to generate the required thrust. But conventional rockets entail some serious drawbacks - limited range and declining thrust performance with the rise of pressure as depth increases. The first of these problems is being addressed with a new kind of high-energy-density power-plant technology; the second may be circumvented by using a special kind of supercavitating propeller screw technology.
point

NEUTRALIZING MINES. Everyone has seen action-movie heroes avoid fusillades of bullets by diving several feet underwater. The bullets ricochet away or expend their energy surprisingly rapidly as a result of drag and lateral hydrodynamic forces. When the Office of Naval Research was asked to find a cost-effective way to stop thousand-dollar surface mines from damaging or destroying multimillion-dollar ships, they turned to supercavitating projectiles. The result was RAMICS - the Rapid Airborne Mine Clearance System, which is being developed for the U.S. Navy by a team led by Raytheon Naval & Maritime Integrated Systems in Portsmouth, R.I. Operating from helicopters, RAMICS will locate subsurface sea mines with an imaging blue-green lidar (light detection and ranging) system, calculate their exact position despite the bending of light by water refraction, and then shoot them with supercavitating rounds that travel stably in both air and water. The special projectiles contain charges that cause the deflagration, or moderated burning, of the mine's explosive.

"Getting up to supercavitation speeds requires a lot of power," says researcher Savchenko. "For maximum range with rockets, you need to burn high-energy-density fuels that provide the maximum specific impulse." He estimates that a typical solid-rocket motor can achieve a maximum range of several tens of kilometers and a top speed of perhaps 200 meters per second. After considering propulsion systems based on diesel engines, electric motors, atomic power plants, high-speed diesels, and gas turbines, Savchenko concluded that "only high-efficiency gas turbines and jet propulsion systems burning metal fuels (aluminum, magnesium or lithium) and using outboard water as both the fuel oxidizer and coolant of the combustion products have real potential for propelling supercavitating vehicles to high velocities."

Aluminum, which is relatively cheap, is the most energetic of these metal fuels, producing a reaction temperature of up to 10,600 degrees Celsius. "One can accelerate the reaction by fluidizing [melting] the metal and using water vapor," Savchenko explains. In one candidate power-plant design, the heat from the combustion chamber would be used to melt stored aluminum sheets at about 675 degrees C and to vaporize seawater as well. The resulting combustion products turn turbine-driven propeller screws.

This type of system has already been developed in Russia, according to media reports there. The U.S. also has experience with these kinds of systems. Researchers at Penn State's Applied Research Laboratory are operating an aluminum-burning "water ramjet" system, which was developed as an auxiliary power source for a naval surface ship. In the novel American design, powdered aluminum feeds into a whirlpool of seawater occurring in what is called a vortex combustor. The rapid rotation scrapes the particles together, grinding off the inert aluminum oxide film that covers them, which initiates an intense exothermic reaction as the aluminum oxidizes. High-pressure steam from this combustion process expands out a rocket nozzle or drives a turbine that turns a propeller screw.

Tests have shown that prop screws offer the potential to boost thrust by 20 percent compared with that of rockets, although in theory it may be possible for screws to double available thrust, Savchenko says. Designs for a turbo-rotor propeller system with a single supercavitating "hull propeller," or a pair of counterrotating hull props that encircle the outer surface of the craft so they can reach the gas/water boundary, have been tested. He emphasizes, however, that "considerable work remains to be done on how the propeller and cavity must interact" before real progress can be made. ...

http://www.nap.edu/read/9863/chapter/4#15

Assessment of the Office of Naval Research's Undersea Weapons Science and Technology Program

Research is also being conducted using thermal units to provide low-rate energy sources. The thermal conversion activities include the development of a small, closed-cycle Stirling engine coupled to a lithium-sulfur hexaflouride thermal-energy source. A novel wick combustor is being developed for this unit using capillarity to distribute the liquid metal.

High-rate energy sources are being evaluated for potential use in torpedoes and in countermeasure applications. There are two main ONR activities in this field, HYDROX, a hydrogen and oxygen producer and combustor, and an aluminum-water vortex combustor for a water ramjet.

The HYDROX energy system produces gaseous oxygen from liquid lithium perchlorate and hydrogen from the reaction of water and a lithium-aluminum alloy. The gaseous hydrogen and oxygen produced are burned in a combustion chamber to produce steam for a closed Rankine-cycle system. The same gas source could provide the hydrogen and oxygen for a fuel cell. The gases could also be used in a combined system utilizing a low-power unit for low-speed search and a high-power unit for high-speed operations. The innovative wick system to distribute liquid metal is being developed for use in the SCEPS (lithium-sulfur hexafluoride) upgrade.

A novel vortex combustor is being developed for the water ramjet that would propel the high-speed supercavitating vehicle. Aluminum particles are burned in a vortex arrangement in a reaction with water. This unit, although potentially useful as a source of high-density energy for the supercavitating ramjet, could be used in other applications. The production of large volumes of gaseous hydrogen from the aluminum-water reaction could, perhaps, be utilized to increase the energy density.

The high-rate-wick Stirling engine can be employed in torpedoes and manned undersea vehicles and/or UUVs to enhance range, speed, and endurance. The HYDROX system could be used in high-rate, low-rate, or hybrid modes to enable smaller vehicles or superior performance. The aluminum-seawater vortex device could provide very high speed in special applications. These innovative approaches are good examples of revolutionary technology from ONR programs.

Other propulsion S&T efforts include those on electrochemical energy sources, including fuel cells at the Naval Undersea Warfare Center (NUWC), Naval Surface Warfare Center, Carderock Division (NSWC/CD), and several small academic and industrial contractors. The electrochemical area is the largest component of the undersea weapons 6.1 budget ($2 million in FY99). Another effort is that on underwater propellants at the Naval Surface Warfare Center, Indian Head (NSWC/IH).

Finding: The program on propulsion at the Applied Research Laboratory, Pennsylvania State University (ARL/PSU) is exemplary and offers technologies for both weapons and vehicles that could be used in future systems. Closed-cycle engines are among the increasingly attractive options as the importance of stealth and endurance increases...

https://books.google.com/books?id=y5lZnKU5JoIC&pg=PR11&lpg=PR11&dq=aluminum+vortex+combustor&source=bl&ots=L4ty-PPQ0r&sig=SmsUZtC9Z0hb1OrvSjwgcwixmZ0&hl=en&sa=X&ved=0CEMQ6AEwBWoVChMIhLOPornfyAIVxpmICh2bZgI-#v=onepage&q=aluminum%20vortex%20combustor&f=false

Numerical Analysis to Study the Effects of Solid Fuel article Characteristics on Ignition, Burning, and Radiative Emission

by

Thomas A. Marino

https://www.arl.psu.edu/at_esps_tcm.php

Advanced Technology (AT) | technology, concepts & modeling (tcm)

Aluminum Combustor

The Technology, Concepts and Modeling Department (TCM) develops technology for power system modeling, optimization, and integration as well as energy production from a wide range of chemical fuels and oxidizers. TCM advances technologies that enable the development of innovative concepts such as a hybrid unmanned undersea vehicle that geometrically morphs or changes shape in response to a range of requirements for storage, elimination of waste volume, and enhanced mission endurance.

Expertise:

Applied chemistry
Combustor design and testing, including:
   Aluminum-burning vortex combustion research
   Molten alkali alloy combustion research
Turbine design and testing
Computational Fluid Dynamics
Finite Element Analysis and mechanical design
Simulink
Conceptual power plant and system modeling

http://drum.lib.umd.edu/bitstream/handle/1903/7813/umi-umd-5096.pdf;jsessionid=E2CD1475186AE94F4464EA9B1EA26483?sequence=1
drum.lib.umd.edu/bitstream/1903/7813/1/umi-umd-5096.pdf

MODELING OF A HIGH ENERGY DENSITY PROPULSION SYSTEM BASED ON THE COMBUSTION OF ALUMINUM AND STEAM
Walter Ethan Eagle, Master of Science, 2007

1.4 Objectives and Approach
The objective of this thesis is to estimate the power output and overall efficiency of the Rankine Cycle propulsion system outlined in Figure 1.4. It is based on the exothermic reaction of aluminum powder with sea water and a prototype of the system is presently being constructed by ARL for DARPA. The prototype is intended for use in small (10,000lb) Unmanned Underwater Vehicles (UUVs) like the Sea Horse.

The basic operation of the system is as follows : Aluminum powder is suspended in a small flow of gaseous hydrogen and transported to a combustor where it reacts exothermically with steam to form Al2O3(s) and H2. Additional water injected into the reacting flow cools the hot products, producing steam. The combustion products pass through a separator to remove the solid Al2O3. Most of the steam hydrogen mix is then passed to a turbine that drives an alternator. A small fraction of the steam/hydrogen is diverted from the separator, cooled to 900F by a small amount of fresh sea water, compressed, and returned to the entrance of the combustor to sustain the reaction with incoming Aluminum powder. Enthalpy remaining in the flow exiting the turbine is recovered using a heat exchanger and pre-heats the combustor cooling water. The steam is finally condensed and separated from the H2. The water is recycled through a pump which draws in an appropriate amount of fresh water to make up for that spend during combustion. The hydrogen gas is compressed and fed back into the fuel feeder, thus completing the cycle.

The approach taken to estimate the system’s performance is to develop thermodynamic models for each individual component in the system, and then to assemble the individual models to create a model of the entire system. This is accomplished using a specialized software package called Numerical Propulsion System Solver (NPSS) [37], which was originally developed by the NASA Glenn Research Center as a generalized design and analysis tool for developing gas turbine engines although it is equally well-suited for Rankine Cycle analyses. The principal advantage of NPSS is that it takes care of the mathematical difficulties associated with solving systems of interacting thermodynamic components, enabling the focus to be placed on developing appropriate component models.    NPSS creates generalized data structures for passing information between components and implements a Newton-Rhapson solver to find stable operating points.

Other important advantages of NPSS are its graphical user interface with extensive libraries of pre-defined components, the ability to develop new components and add them
to the library, and a very high degree of flexibility in the types of component models that it can accept.    For example, a turbine could be modeled in NPSS either by writing a module in C that incorporates the simple governing equations found in a textbook (with overall efficiency as a parameter), by using a multi-dimensional turbine map, or by linking to an external 3D CFD simulation. It also facilitates the evaluation of many design changes without having to perform an experiment. The solver is capable of incorporating thermodynamic elements in a time-varying or steady state operating mode.

A full description of NPSS and the NPSS system model will be presented in chapter 2 of the thesis.

While the NPSS model is a powerful design tool that can be used to explore a very wide parameter space, this type of modeling effort poses its own challenges and trade-offs. In particular, when combining many different levels of model fidelity among different model elements (combustion, cooling, separation, etc) additional considerations must be made and a “multi-disciplinary design optimization” or MDO should be considered [38].

NPSS allows the user to perform low level ‘sensitivity analyses’ that are a first step in this process. However the present work focuses on the development of the basic NPSS model and only presents results from a very narrow range of the parameter space that is centered around the ARL prototype design. A complete MDO of the propulsion system is a worthy objective but is beyond the scope of this thesis.

US8656724
ALUMINUM COMBUSTION POWER SYSTEM

Inventor(s): CAWLEY THOMAS / LOWERY BRIAN / MILLER TIMOTHY / HERR JOHN / KLANCHAR MARTIN / KIELY DANIEL…

Abstract
An engine that oxidizes aluminum with water to produce electrical and/or mechanical power. The engine can include a fuel made at least partly from aluminum powder that flows like liquid under high pressure. The engine can also include a steam supply system, a combustor, a fuel feed system, a fuel injection system, and a water supply system.

CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of United States Provisional Patent Application Serial No. 61/325,995 filed April 20, 2010 and United States Patent Application Serial No. 13/084,905 filed April 12, 2011, the contents of both are incorporated herein by reference.

GOVERNMENT INTEREST
[0002] This invention was made with government support under Contract No. N0024-02-6604/0031 awarded by the Defense Advanced Research Projects Agency. The Government has certain rights in the invention.

FIELD OF THE INVENTION
[0003] The present invention is related to an aluminum combustion power system, and in particular an aluminum combustion power system that reacts water with aluminum powder to produce molten aluminum oxide droplets, heat, steam, and hydrogen.

BACKGROUND OF THE INVENTION
[0004] The use of internal combustion engines, batteries, jet propulsion, and the like to provide power to underwater vehicles is known. In addition, the use of batteries has exhibited limited success, however the energy density of battery powered systems has been less than desirable.

[0005] As an alternative, the chemical reaction of aluminum with water, fresh or salt, is known to be highly energetic and has been proposed as a basis for an energy producing system. The basic reaction between aluminum and water is

2A1 + 3H20→ A1203 + 3H2 Equation 1 with the products of this reaction exhibiting temperatures up to 3800°F. However, such temperatures and products have heretofore proven to be impractical for power systems that can provide a steady and sustained flow of energy. Therefore, even though the above chemical reaction is extremely energy favorable, the use of aluminum as a fuel to provide a reliable source of energy has proven evasive. Therefore, a power source that reacts aluminum with water and provides reliable power would be desirable.

SUMMARY OF THE INVENTION
[0006] The present invention discloses an engine that reacts aluminum with water to produce electrical and/or mechanical power. The engine can include a fuel made at least partly from aluminum powder that flows like liquid under high pressure. The engine can also include a steam feedback system, a combustor, a fuel feed system, a fuel injection system, and a water supply system.

[0007] The combustor can have an inlet, an outlet, and a combustor wall, and the fuel feed system is operable to pump the fuel from a fuel tank to the combustor. The fuel injection system can mix steam that is fed back or recirculated from the combustor discharge via a small compressor or generated from a recuperator with the fuel and then spray the fuel and the steam mixture into the combustor. The water supply system can spray water into the combustor and the water can react with the aluminum powder to produce molten aluminum oxide droplets, heat, steam, and hydrogen. In addition, the water can solidify the molten aluminum oxide droplets before they contact the combustor wall and thereby prevent clogging of the combustor.

[0008] The aluminum powder can be coated, for example with a film of methysiloxane, such that the coated aluminum powder can be pumped through tubing having a length to diameter ratio of greater than 1000. In addition, the fuel feed system is operable to provide a steady flow of the coated aluminum powder at high pressure to the combustor. The mixture of aluminum powder and steam reacts with water in the combustor to produce the molten aluminum oxide droplets, heat, additional steam, and hydrogen. The water supply system can include a plurality of spray nozzles that can spray water into the combustor and cool the combustor wall. In addition, a high temperature separator downstream from the combustor can separate solidified aluminum oxide particles from an aluminum oxide particle- steam mixture that exits the outlet of the combustor. In this manner, steam without harmful and/or erosive aluminum oxide particles can be provided to a steam turbine to produce electrical and/or mechanical power.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of an aluminum combustion power system according to an embodiment of the present invention;

[0010] Figure 2a is a side cross-sectional view of a combustor for an aluminum combustion power system according to an embodiment of the present invention;

[0011] Figure 2b is an end cross-sectional view of section 2b-2b shown in Figure 2a;

[0012] Figure 3 is a schematic diagram of an aluminum combustion power system that employs the combustor shown in Figure 1 ;

[0013] Figure 4a is a side cross-sectional view of a fuel supply system according to an embodiment of the present invention;

[0014] Figure 4b is an enlarged view of a piston region for the fuel feed system; and

[0015] Figure 5 is another embodiment of a fuel feed system for the aluminum combustion power system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention provides an engine that reacts aluminum with water to produce electrical and/or mechanical power. As such, the present invention has use as a power source.

[0017] The power system can include a combustor that is operable to accept aluminum powder mixed with steam. In addition, the combustor can have water sprayed thereinto, the water reacting with the aluminum powder to form molten aluminum oxide droplets, steam, heat, and hydrogen. In addition, sufficient water can be provided to the combustor such that excess steam is provided and used to drive/power a steam turbine as is known to those skilled in the art.

[0018] The aluminum powder can be coated such that it flows like a liquid and can be provided from a fuel container to the combustor using a fuel line having a length to diameter ratio of greater than 1000. In addition, the aluminum powder can be mixed with the steam prior to entering the combustor such that the mixture expands like a gas upon entering a combustion zone. Aluminum particles can then react with water within the combustion zone via the chemical reaction of Equation 1 and as described in greater detail below. Water can also be introduced into the combustor such that it cools the walls thereof and solidifies molten aluminum oxide droplets formed by the reaction of the aluminum powder with the water. Cooling of the molten aluminum oxide droplets before they come into contact with the combustor wall prevents their accumulation thereon and thus prevents clogging of the combustor. As such, aluminum oxide particles plus steam exit the combustor and enters a high temperature separator that affords for the removal or separation of solidified aluminum oxide particles from the steam. Thereafter, the steam can be provided to a steam turbine which rotates to provide mechanical and/or electrical power. It is appreciated that a recuperator, condenser, low temperature separator, steam compressor, etc., can also be included as part of the power system in order to increase power output, efficiency, safety and the like. [0019] A reaction in which excess water can be included to regulate the product temperature of aluminum reacting with water can be:

2A1 + 3H20 + XH20→ A1203 + 3H2 + XH20 Equation 2 where X moles of excess water can be included to regulate the temperature of a system that burns aluminum in this manner. In some instances, the X moles of excess diluent water can appear in the products as X moles of superheated steam and the steam can be used to provide energy, for example through the use of a steam turbine. It is appreciated that the number of moles of excess water required can depend on the product discharge temperature and the temperature of liquid water added to the reaction. For example, a product temperature in the vicinity of 1500°F will result in a gaseous mixture of 97.5% steam.

[0020] While Equation 2 is relatively simple and energetically favorable, sustaining such a reaction using readily available cold seawater can be difficult. In particular, solid aluminum does not appreciably react with cold water. As such, and as discussed in more detail below, the present invention affords for high temperature steam to be provided to the reaction of aluminum with water. The aluminum can readily react with the high temperature steam in order to provide sufficient heat to maintain the A1203-H20 reaction and drive a steam turbine, preheat cold seawater, and the like. In some instances, more or less than 3 moles of steam might be supplied per every two moles of fuel with evaporating diluent water serving as reactant water if necessary.

[0021] Turning now to Figure 1, a "black box" illustration of an inventive aluminum combustion power system is shown generally at reference numeral 10. The power system 10 can include an input of aluminum 110 and liquid water 120. Reaction of the aluminum 110 with the liquid water 120 results in the production of aluminum oxide 140, hydrogen gas 150, and heat 160. In addition, mechanical or electrical power 170 can be produced from the power system 10, for example through the use of steam to drive a steam turbine.

[0022] It is appreciated that if the system 10 is used underwater, only aluminum 110 is needed to be stored since liquid water 120 can be provided by the environment. Such a system is analogous to a motor vehicle or an airplane carrying a liquid hydrocarbon fuel and using oxygen/air from the surrounding environment.

[0023] In addition to maintaining the reaction of aluminum with water, the aluminum oxide 140 can be formed as molten liquid droplets with a melting/solidification temperature approaching 3800°F. Such droplets can impinge on a surface of the system 10 and cause accelerated corrosion, slagging, and the like. In particular, slagging can result in the buildup of aluminum oxide on internal surfaces of the system 10 and thereby result in clogging of the power system 10.

[0024] Referring now to Figure 2a, an inventive aluminum combustor that can prevent clogging of a power system is shown generally at reference numeral 200. The aluminum combustor 200 can include a combustor can 220 with an injection tube 210. Aluminum 110 and steam 122 can be premixed within the injection tube 210 and allowed to react within the combustor can 220 to provide a stoichiometric combustion cloud 240. The combustor can 220 can have a combustor interior wall 222 which provides a physical barrier to the combustion cloud 240. In order to prevent overheating and/or slagging of the combustor interior wall 222, one or more water sprayers 230 can provide coolant 232, e.g. water, to cool the combustor interior wall 222 and quench aluminum oxide droplets that have formed in the combustion cloud 240. In some instances, the combustor can 220 can be cylindrical shaped with a plurality of sprayers 230 spaced apart and providing liquid spray 232 as shown in Figure 2b.

[0025] For example, and for illustrative purposes only, Figure 2b illustrates a cylindrical combustor can 220 with six liquid sprayers 230 operable to provide liquid spray into the combustor can 220 and thereby cool the combustor interior walls 222 and/or quench liquid aluminum oxide droplets before reaching the interior walls 222. It is appreciated that the liquid spray 232 can also provide water which can be heated and evaporated into steam and thereby provide a steam shroud 250 within the combustor can 220. Additional water spraying nozzles 260 may or may not be provided to enhance the cooling of the combustor interior walls 222 and/or evaporation of water. As shown in the figure, hot gas and fly ash in the form of aluminum oxide particles 280 can exit the combustor can 220 through an exit 270. It is appreciated that the combustor 220 can provide pressurized and/or superheated steam which can be used to power a steam turbine, extract heat therefrom, and the like.

[0026] Turning now to Figure 3, a schematic diagram of an aluminum combustion power system is shown generally at reference numeral 20. In addition to the combustor 200, which can in fact be a compact superheated steam generator, a high-temperature separator 300 can be located downstream from the combustor 200 and afford for separation of more than 99% of the aluminum oxide particles from the oxide particle-steam mixture exiting the combustor 200. In addition, any remaining particles can be less than one-half (0.5) micron in diameter and thereby pass through a turbine 310 safely. The turbine 310 may or may not have a direct drive with a high-speed alternator 320, the alternator 320 operable to generate alternating current which can be rectified and otherwise conditioned to provide a regulated direct current voltage. In some instances, the turbine 310 and alternator 320 can be water cooled and use water lubricated hybrid bearings.

[0027] It is appreciated that exhaust from the turbine 310 can contain considerable energy content and, as such, a recuperator 330 can be used to transfer heat from the turbine exhaust to liquid water in the form of incoming seawater, freshwater and/or water condensed from the exhaust steam. By preheating water supplied to the combustor water sprayers 230, more water can be added to the combustor 200 in order to maintain a desired combustor discharge temperature. The additional water added to the combustor 200 can be converted into steam and thereby increase steam flow from the combustor 200 and through the turbine 310. In this manner, the output power from the turbine 310 and the overall efficiency of the system 20 can be increased. It is appreciated that the hydrogen flowing out of the recuperator represents a considerable potential energy source and in certain instances may be directed to a secondary combustor, electrochemical fuel cell of other conversion system to enhance overall system efficiency.

[0028] Cooler steam leaving the recuperator 330 can be condensed in a condenser 340 to liquid water and thereafter discharged to a low-temperature separator 350. The low-temperature separator 350 can separate gaseous hydrogen which may or may not be pumped overboard with any residual aluminum oxide. In some instances, a portion of hydrogen compressed in the low-temperature separator can be retained for feed system use. In addition, a water pump 360 can pump surrounding seawater, freshwater and/or steam condensate from the low-temperature separator 350 and raise the pressure of the liquid to above the pressure in the combustor 200 for use in the water sprayers 230.

[0029] A steam compressor 400 can also be included and provide high-temperature steam for combustion of the aluminum powder. In some instances, clean steam can be taken from the high-temperature separator 300, passed through the steam compressor 400, and mixed with aluminum powder from the fuel feed system 100. In addition, temperature(s) of the aluminum powder fuel and steam from the steam compressor 400 at the inlet 210 of the combustor 200 can be controlled and/or reduced by addition of liquid water.

[0030] Referring specifically to the flow of the aluminum powder, Figures 4a-4b illustrate an embodiment of the fuel feed system 100. It is appreciated that the flow of aluminum particles under pressure can be an area of concern for an aluminum power system with uneven flow rates, clogging of fuel lines and the like known to be problem areas. However, the fuel feed system 100 having aluminum particles 110 can include treatment of the particles with a silane, e.g. methylethoxysilane, such that polarizable surface groups such as hydroxyl groups can be replaced with siloxane groups or other non-polarizable, hydrophobic terminal groups and result in the: (1) elimination and/or reduction of van der Waals forces; (2) elimination and/or reduction of susceptibility to triboelectric augmentation of cohesion between the particles; and/or (3) suppression of cohesion due to capillary condensation.

[0031] The treatment can include providing a monolayer thick film of siloxane onto the surface of the aluminum particles and placing the particles in the cylinder of a piston-cylinder device. A piston 104 that has a funnel shape on one face and a flat shape on an opposite face can be forced, e.g. by gas pressure, into the fuel 110. The conical face of the piston 104 can then move into the fuel, thereby forcing the fuel to flow through a screen 108. In addition, inert gas can be forced into the fuel 110 through an inlet line 102, and as the piston 104 moves into the fuel 110 and the fuel passes through a fuel line 106, the inert gas in the interstitial spaces of the fuel can expand and provide a dense-phase fluidized particulate flow.

[0032] In some instances, a coiled flexible fuel line 106 having a s-inch diameter with a i6-inch bore can be used to provide aluminum powder to the combustor 200. For example and for illustrative purposes only, such a fuel line 106 can provide sufficient aluminum powder fuel for a 100 hp/75 kW turbine output. In addition, a metal rod can be used to move with the piston 104 so that a position of the piston can be known as a function of time, thereby allowing for a fuel flow rate to be calculated.

[0033] An alternative embodiment of a fuel feed system is shown in Figure 5 at reference numeral 500. The fuel feed system 500 can have a container 505 with a bladder 510 that has aluminum powder fuel 110 therewithin. Pressure can be applied to a back side of bladder 510 in the region 540 and a feeder transport 520 can be used to provide the aluminum powder 110 to an exit orifice 530. In some instances, the feeder transport 520 can have a shaft 524 with an arbor plate 522, the shaft 524 and arbor plate 522 acting as a screw drive to transport the powder 110 from within the bladder 510 to the exit 530. In addition, aluminum oxide particles that exit from the combustor 200 can be separated from the steam/fly ash mixture and placed in the area 540 around the back side of the bladder 510 which was previously occupied by the aluminum powder 110. In this manner, the aluminum oxide particles can be stored on or within an underwater vehicle.

Some Vortex Combustor Patents --

CN203823810
Advanced vortex combustor with flow deflectors
The utility model discloses an advanced vortex combustor with flow deflectors. The advanced vortex combustor consists of a front blunt body, a concave cavity, a back blunt body, the flow deflectors and an air inlet channel, which are arranged in a combustor channel, wherein the front blunt body and the back blunt body are arranged in the combustor channel; the concave cavity is formed by the front blunt body and the back blunt body; the front wall surface of the front blunt body is flush with the channel; the back blunt body has a projecting expansion open structure; two flow deflectors are symmetrically arranged on the upper side and the lower side of the front blunt body; the air inlet channel consists of an upper small channel air inlet and a lower small channel air inlet. The advanced vortex combustor has the beneficial effects that the combustion performance is remarkably superior to the conventional blunt body combustor, the flame holding in the concave cavity and fuel gas blending are facilitated, the combustion efficiency is increased greatly, the outlet temperature distribution is improved, and NO discharge is reduced.

JP2014137151
COMBUSTOR
PROBLEM TO BE SOLVED: To provide a combustor improved in flow rate balance in split air flows.SOLUTION: A combustor 1 in which air flow 10 supplied from the upstream side is split in a damping chamber 21, and the split air flows 10a, 10b are supplied to a combustion chamber 18 from an outer peripheral-side flow channel 16 and an inner peripheral-side flow channel 17, respectively, includes: a pre-diffuser 6 composed of an inner peripheral nozzle plate 6a and an outer peripheral nozzle plate 6b, and supplying the air flow into the damping chamber; suction holes 11 respectively formed on the inner peripheral nozzle plate and the outer peripheral nozzle plate of a speed reducing portion 8 projecting into the damping chamber of the pre-diffuser; a cowl 15 disposed in the damping chamber in opposition to the pre-diffuser and having a convex curved surface; and a plurality of burner nozzles arranged at equal angular pitches and injecting a fuel into the combustion chamber. A part of the air flow colliding with the cowl is separated so that standing vortex is formed in the damping chamber, and a part of the standing vortex is sucked into the speed reducing portion through the suction holes.

CN103672890
Vortex energy-saving combustor
The invention relates to a flat seam vortex energy-saving combustor and belongs to the technical field of domestic gas stoves. According to the flat seam vortex energy-saving combustor, the defects that an air door combustor structure of a traditional domestic gas stove is low in flame temperature and prone to backfire. The flat seam vortex energy-saving combustor is mainly characterized in that the air forms rotation air flow in the gas tangential direction after passing through a flat seam vortex device and is mixed with gas, mixing conditions are better and complete combustion is ensured. The structures of the combustor include the A type structure, the B type structure, the C type structure and the D type structure. The flat seam vortex energy-saving combustor has the prominent advantages of being high in flame temperature, little in waste gas, capable of saving energy and time, convenient to use, safe and sanitary.

EP2933559
Fuel mixing arragement and combustor with such a fuel mixing arrangement
The present application relates to a fuel mixing arrangement (100) for mixing fuel and an oxidizing medium for combustion in a combustor of a gas turbine, with a flute fuel injection system comprising at least two streamline bodies (22) with at least one fuel nozzle wherein the streamline bodies (22) comprise either vortex generators or lobes and at least one body (22) is arranged parallel to the flow direction of the oxidizing medium. A better mixing is achieved by arranging the at least second other streamline body (22) inclined to the first one. A perpendicular arrangement of the streamline bodies (22) is preferred, so that a square arrangement occurs.

JP2013160499
COMBUSTOR ASSEMBLY WITH TRAPPED VORTEX CAVITY
Embodiments of the present application include a combustor assembly (25). The combustor assembly may include an annular trapped vortex cavity (116) located adjacent to a downstream end (106) of a bundle of air/fuel premixing injection tubes (102). The annular trapped vortex cavity (116) may include an opening (124) at a radially inner portion of the annular trapped vortex cavity (116) adjacent to the head end (104) of the bundle of premixing tubes (102). The annular trapped vortex cavity (116) may also include one or more air injection holes (126) and one or more fuel sources (128) disposed about the annular trapped vortex cavity (116) such that the one or more air injection holes (126) and the one or more fuel sources (128) are configured to drive a vortex (130) within the annular trapped vortex cavity (116).

CN103277814
Low-emission trapped-vortex combustor with rich-burn/quick-quench/lean-burn combined with lean pre-mix pre-vaporization
A low-emission trapped-vortex combustor with rich-burn/quick-quench/lean-burn combined with lean pre-mix pre-vaporization comprises a diffuser, casing parts of an aeroengine, a diversion device, a cavity and a combustion liner. Air enters the combustor through the diffuser, the casing parts of the aeroengine comprise an outer casing part of the aeroengine and an inner casing part of the aeroengine, the air is divided into by-pass airflow and main airflow through the diversion device, the cavity comprises an inner annular cavity body and an outer annular cavity body, cavity front wall air inlet holes and cavity rear wall air inlet holes are formed in the cavity, and a plurality of cooling holes and blending holes are formed in the combustion liner.; The low-emission trapped-vortex combustor with rich-burn/quick-quench/lean-burn combined with lean pre-mix pre-vaporization further comprises a main airflow pre-vaporizing device and a flame connecting device, wherein the main airflow pre-vaporizing device is used for pre-vaporizing fuel and stabilizing flames, and the flame connecting device is used for delivering flames. The low-emission trapped-vortex combustor with rich-burn/quick-quench/lean-burn combined with lean pre-mix pre-vaporization further comprises a main burning level fuel manifold and an on-duty level fuel manifold which provide fuel for the inner annular cavity body and the outer annular cavity body.

CN103277812
Rich-burn/quick-quench/lean-burn low-emission trapped-vortex combustor
A rich-burn/quick-quench/lean-burn low-emission trapped-vortex combustor comprises a diffuser, casing parts of an aeroengine, a diversion device, a cavity, a combustion liner, and a quenching device. Air enters the combustor through the diffuser, the casing parts of the aeroengine comprise an outer casing part of the aeroengine and an inner casing part of the aeroengine, the air is divided into by-pass airflow and main airflow through the diversion device, the cavity comprises an inner annular cavity body and an outer annular cavity body, cavity front wall air inlet holes and cavity rear wall air inlet holes are formed in the cavity, and a plurality of cooling holes and blending holes are formed in the combustion liner. The rich-burn/quick-quench/lean-burn low-emission trapped-vortex combustor further comprises a fuel manifold which provides fuel for the cavity and swirl injectors. A part of the by-pass airflow enters the cavity from the cavity front wall air inlet holes and the cavity rear wall air inlet holes and form a tapped vortex to conduct rich burn, the other part of the by-pass airflow enters the combustion liner from the cooling holes and the blending holes of the combustion liner, and the main airflow enters the combustion liner through the flow area of the quenching device.

CN103277811
Single-cavity trapped vortex combustor
A single-cavity trapped vortex combustor comprises a pressure expander, an inner cartridge receiver, an outer cartridge receiver, a flame tube, a flow guide device, a pre-evaporation device, an oil supply system and a high-energy spark plug, wherein airflow at an inlet of the combustor enters the combustor through the pressure expander, the flame tube is of a single-cavity structure, the inner cartridge receiver, the outer cartridge receiver and the flame tube form an inner duct and an outer duct of the combustor, the flow guide device separates the main flow from the air of the outer duct, air is decelerated and pressurized through the pressure expander, is divided into four paths through the flow guide device and the pre-evaporation device, and respectively enters the main flow, the pre-evaporation device, the inner duct and the outer duct, and the high-energy spark plug is arranged at the bottom of the cavity. The combustion area of the single-cavity trapped vortex combustor is divided into a trapped vortex area and a main combustion area, and the single-cavity trapped vortex combustor further comprises a flame joint supporting plate which transmits flames from a cavity to the main flow.

US2013104520
Hydrogen-Rich Gas Combustion Device
A combustion device for hydrogen-rich gas is provided. Before entering a chamber, fuel and air are non-premixed for avoiding flushback. A vortex generator and a fuel sprayer are combined to mix fuel and air for enhancing burning effect. Vortex flame is generated with stabilizing aerodynamics of flow provided through vortex breakdown. A flameholder is formed downstream an injector to maintain stable combustion. Cooling air is introduced from a sheath to cool down a high-temperature gas, which leaves the combustion chamber and drives a turbine for turning a power generator. Thus, the present invention effectively mixes fuel and air, avoids flushback and prevents combustor damage.

CN202647749
Special vortex flame combustor for combustion engine
A special vortex flame combustor for a combustion engine relates to a thermotechnical technology, and comprises a combustion cylinder (1) and a vortex device (2), wherein the vortex device (2) is fixedly arranged in the combustion cylinder (1), and a deflection plate (2-1) is arranged in the vortex device (2). The length of the combustion cylinder (1) is L1, and the diameter of the combustion cylinder (1) is D1; the diameter of the vortex device (2) is D2, the length of the deflecting plate (2-1) is L3, and the deflection angle is X. L1 is equal to 3D1; D2 is equal to the difference between D1 and 1 cm; L3 is equal to D1; and X is equal to 60 degrees. The combustion cylinder (1) is made of special corrosion-resistant metal. The vortex device (2) and the combustion cylinder (1) are welded together by the same composite metal material of the vortex device (2). The special vortex flame combustor has the advantages of simple structure and lower cost, and can completely solve the worldwide problem that alcohol-based fuel can not be fully combusted in the combustion engine, thereby achieving environmentally-friendly emission and high heat utilization rate, and further obtaining favorable environmentally-friendly and energy-saving effects.

US8272219
Gas turbine engine combustor having trapped dual vortex cavity
A gas turbine engine combuslor has a trapped dual vortex cavity defined between aft, forward, and bottom walls. Air injection first holes are positioned in the forward wall. Air injection second holes are positioned in the aft walls. Fuel injection holes in the forward wall are located between the bottom wall and a cavity opening located at a top of the cavity. First angled film cooling apertures are disposed through the bottom wall. Second angled film cooling apertures are located in the forward wall between the fuel injection holes and the bottom wall. Third angled film cooling apertures are located in the forward wall between the fuel injection holes and the cavity opening.

US8464538
TRAPPED VORTEX COMBUSTOR AND METHOD OF OPERATING THE SAME
PROBLEM TO BE SOLVED: To provide a trapped vortex combustor that creates a stable vortex within a trapped vortex cavity and effectively mixes fuel and air. ;SOLUTION: The trapped vortex combustor 14 includes the trapped vortex cavity 40 having a first surface 42 and a second surface 44. A plurality of fluidic mixers 46 are disposed circumferentially along the first surface 42 and the second surface 44 of the trapped vortex cavity 40. At least one fluidic mixer 46 includes a first open end receiving a first fluid stream 48, a coanda profile in the proximity of the first open end, a fuel plenum to discharge a fuel stream over the coanda profile, and a second open end for receiving the mixture of the first fluid stream 48 and the fuel stream and discharging the mixture of the first fluid stream 48 and the fuel stream in the trapped vortex cavity 40. The coanda profile is configured to enable attachment of the fuel stream to the coanda profile to form a boundary layer of the fuel stream and, to entrain the incoming first fluid stream to the boundary layer of the fuel stream to form a mixture of the first fluid stream 48 and the fuel stream. ;

WO2010128964
Vortex combustor for low NOx emissions when burning lean premixed high hydrogen content fuel
A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture, thus allowing use of high hydrogen content fuels. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.