Abstract:
A method and system for generating high pressure superheated steam on demand that uses nano-sized aluminum particles to allow oxidation and heat generation using photonic initiation. This invention uses the unique properties of nano-sized aluminum either alone or with other energetics to provide the needed heat to quickly vaporize and superheat water directly in either a flowing water or static water environment to produce steam as needed. Due to its compact design it can be used in new or existing steam applications. This steam use may be any application that needs an on demand high pressure steam supply. Applications include steam catapults, boost steam for turbines, steam cleaners, surge power for powerplant turbines and any other use.

Description:
RELATED APPLICATION DATA 
       [0001]    This application is related to Provisional Patent Application Ser. No. 61/339,252 filed on Mar. 2, 2010, and priority is claimed for this earlier filing under 35 U.S.C. §119(e). The Provisional Patent Application is also incorporated by reference into this patent application. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    A steam generator cycle heat uses nano-energetic particles as heat source. 
       BACKGROUND AND PRIOR ART OF THE INVENTION 
       [0003]    The safe generation of steam was the driving force for the formation of the American Society of Mechanical Engineers. Many different designs and methods exist for the production of steam. The primary method involves the use of an external heat source providing heat through a boiler wall to water and or steam to vaporize the water and possibly superheat the produced steam. 
         [0004]    This method is in wide use with a variety of heat sources including, oil, natural gas, coal, biomass, nuclear and solar energy as heat sources. External heating provides separation of heating from the water/steam but is limited by the thermal and mechanical properties of the boiler walls. Such boilers have lengthy startup periods and an inability to adjust to short term transient events. 
         [0005]    Some boilers have been devised to use chemical heat reactions within the boiler to provide additional energy to assist with the generation of steam. Typically reactants such as Magnesium oxide and other similar materials can react with already heated steam to provide additional energy. 
         [0006]    The maximum efficiency of a process using steam can be modeled using the Carnot cycle, but maximum efficiency is never reached due to pumping friction losses and heat transfer losses of the boiler and other heat exchangers. An improved new method of rapid generation of high pressure steam would allow steam to be produced to meet our difficult and growing power needs. 
       SUMMARY OF THE INVENTION 
       [0007]    The steam generator cycle of the present invention uses discrete packets of a mixture of nano-particle sized aluminum particles, a source of oxygen and other optional oxidizable fuels to directly heat the water-packet mixture. Two fundamentally different methods can be used with the present invention. The first method uses a pump to provide pressurized water to a mixing chamber to generate larger quantities of steam, and the second method uses a fixed volume of water and energetic packets in a container which becomes pressurized as steam is generated. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0008]      FIG. 1  shows a prospective view of the steam generator practicing the claimed invention; 
           [0009]      FIGS. 2 and 2A  show cut-away view of the energetic nano-particle capsule. 
           [0010]      FIG. 3  shows a fixed water short duration generator; and, 
           [0011]      FIG. 4  shows a prospective view of the steam generator practicing the claimed invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0012]    The pumped process begins with water being pressurized to the desired steam pressure and delivered to a packet metering device where a desired number of packets are inserted into the water stream. When steam production is needed, a high intensity light source such as a strobe, laser or other suitable light shines on the water and packet mixture sufficiently to initiate oxidation of the nano-sized aluminum particles through the optically clear outer packet lining. 
         [0013]    As the nano-aluminum oxidizes it initiates the other materials in the packet and directly heats the surrounding water as the mixture flows towards the steam use point. If the steam use requires clean dry steam the boiling water mixture can travel through a cyclonic steam separator to separate the steam from the aluminum oxide particles and other combustion byproducts. As the heat source is mixed with the water, heat transfer is unimpeded and the water can quickly be converted to superheated steam in a very short travel distance. The production of supercritical steam offers great efficiency to power many processes. 
         [0014]    The use of nano-sized aluminum particles to initiate oxidation allows the process to be initiated by means of a high intensity light burst without physical contact between the light source and the nano-particle. Particles smaller than the wavelength of light can absorb light energy but are unable to reradiate it, causing the light energy to remain inside the particle. 
         [0015]    Because these particles have enormous surface area relative to their mass, the heating is sufficient to melt the particle. This allows a passivated aluminum particle to expose pure aluminum to its environment and rapidly oxidize when any oxygen is present, regardless of whether it is free oxygen or bound to hydrogen. The heat energy released by the nano-sized aluminum can be used to further initiate oxidation in larger close proximity aluminum particles and or other fuels. These reactions generate light energy that will set of other packets within a short distance in line of sight through water or air. Using small packets located inside the water to be converted allows very rapid heating, and boiling of the water and possible superheating of the produced steam to occur at the point of desired use. The choice of a fixed water volume steam generator or the pressurized water inline steam generator is tied to the intended use of the discharged steam mixture. 
         [0016]      FIG. 1  shows a pressurized water feed steam generator  100  with cyclonic steam separator/superheat chamber  105 . To safely contain very high pressures of superheated steam, it is desirable to use small internal diameter vessels. Furthermore as the properties of steel are diminished or exceeded at continuous elevated temperatures, the steam separator/superheater chamber  105  has an insulating ceramic liner  106  to keep the high heat of the discharge steam exiting from discharge pipe  150  away from the pressure bearing outer vessel wall  101 . Pressurized water flows in through inlet pipe  120  and enters the pre-heat chamber  107  between wall  101  and cyclone wall  105  to absorb any heat traveling thru the insulating ceramic liner  106  and outer wall of the cyclone  105 . 
         [0017]    The preheated pressurized water now leaves pre-heat chamber  107  and travels through transfer pipe  110  to the energetic packet metering assembly  130 . Additional heat exchange and cooling of system components may be done by the pressurized water before and after it enters metering assembly  130  to increase cycle efficiency and material durability. Inside metering assembly  130  a pressure balanced rotary metering hub  135  places the energetic packets  145  into the water stream at the desired rate to produce the steam needed. The water and energetic packet mixture travels past the controlled high intensity light source  140  which provides the light energy to initiate oxidation of the energetic particles as they travel through tube  115 . 
         [0018]    Tube  115  is designed with a reflective inner coating  116  to ensure complete initiation and prevent absorption of the generated thermal energy as the initiated packet  145  travels through tube  115  and enters the cyclone  105  in a tangential trajectory. The discharge from tube  115  is guided downward by helical internal vanes  155  as the mixture oxidizes and superheated steam is produced. The velocity of the water increases as it heats and begins to convert to steam. 
         [0019]    This rapid increase in velocity and the centrifugal forces created by the circular motion of the cyclone increases the separation of the mixture keeping the heavier oxidizing particles and water toward the cyclone wall and causing the produced steam to move to the center of the cyclone  105 . The clean superheated steam travels inward and exits up steam delivery pipe  150  to the desired use. The heavier oxidation byproducts and unboiled water continue to be forced outward and downward in a decreasing, spiraling radius until exiting the cyclone discharge pipe  125 . 
         [0020]    Cyclone  105  can be made of an abrasion resistant ceramic that does not need to withstand high steam pressures because of the pressure balance between the supply water on the outside of the cyclone  105  and the steam mixture on the inside. The aluminum oxide and any other solids are separated from the steam exiting pipe  150  and can be removed either with some steam or without through a solids discharge pipe  125 . 
         [0021]    This steam generator offers capabilities that have been largely unavailable previously and can be configured in many variations to meet a wide variety of applications. The configuration of  FIG. 1  is intended to generate superheated clean steam suitable for providing high power output on very short notice to power such devices as high force long travel catapults for aircraft, a rocket or projectile launch, rail gun electric power generators, laser power generators or other power applications. The use of pressurized feed water allows the steam generator  100  to operate for long periods of time without heating the pressure vessel walls  101 , substantially even when producing very high temperature steam. 
         [0022]    The steam generator  100  of  FIG. 1  can be designed without the separation cyclone  105  to provide a steam and aluminum oxide discharge for cleaning and cutting purposes. Very high pressure and temperature discharge can be produced providing unprecedented erosive cutting ability with the addition of a higher concentration of energetic packets  145 . In some applications compressed air or oxygen can be used instead of water to produce even higher temperatures when desired. 
         [0023]      FIG. 2  and  FIG. 2A  is a cut-away of an energetic packet. The clear outer casing  210  holds the mixture  205  of nano Al particles  220  in a water or water hydrogen peroxide slurry mixture  205 . Suspended in the mixture  205  can be additional fuels such as larger aluminum particles  215 , and other fuels. A thin filmed sealed aluminum capsule  230  can be used that may have nano Al initiators  235  along its length, to ignite it and the hydrocarbon and oxygen mixture  240  that is contained inside. One end of the aluminum capsule  230  can have a combustible plug  225  that has a dual purpose to seal the opening and facilitate the filling of capsule  230  with mixture  240 . 
         [0024]    The combustible plug  225  can be designed to burn more quickly than the initiators  235  or instead of them in applications where it is desired to have capsule  230  move out of the initial combustion area before it is completely oxidized. Many different capsule  230  configurations can be used with different mixtures  240  and designs to meet usage goals. Capsules such as  230  offer a longer burn time in larger engines such as might be used in a lighter than air vessel, which operates at a low airspeed, or during high power operations. The use of different composition packets  200  to meet the needed power level allows very rapid thrust changes. 
         [0025]    It will be understood that this example energetic packet does not restrict the variations that are needed to fully implement the advantages of this fuel delivery system component of the invention. Furthermore in some below freezing applications the use of frozen water and nano Al as an outer casing may offer advantages in high altitude aircraft where packets may be fabricated as used with differing compositions. Likewise an outer casing  210  may have a similar design to capsule  230  with an oxidizable metallic shell. 
         [0026]      FIG. 3  shows a cutaway of a fixed water short duration steam generator. Canister  300  is a short duration steam burst generator capable of generating high pressure superheated steam discharge rapidly. Outer housing  305  is constructed of material capable of handling the desired pressure safely such as steel, composite materials, or other metals. The inner bore  310  can be lined with a reflective coating  311  or finish to prevent the produced heat from transferring through the outer housing  305  during the steam production phase. 
         [0027]    Energetic Fuel Packets  315  are of a formulation as discussed in  FIG. 2 . The space between the inner bore  310  walls and the EFP  315  can be filled with water to use the heat released by the EFP  315 . In cases where a slightly longer duration of steam production is needed and to slow the rate of EFP packet initiation, a combustible separator plug  320  can be used. This CSP  320  serves to provide a very short break between EFP  315  initiations that allows the produced steam to travel out thru the opening initially blocked by clear entrance plug  325 . 
         [0028]    CEP  325  serves to keep the water in the vessel during storage, transport and prior to steam generation. CEP  325  is designed to break open at a desired pressure to allow the steam to travel to its desired location of use. Many different canister configurations are possible to meet the need to high pressure superheated steam in both existing technology and new inventions made possible by this invention. CSP  325  can be designed so that it not only controls the reaction rate of multiple EFPs  315  in sequential fire but also provides some superheat to the steam that flows thru it. Canister  300  can use only one EFP  315  or multiple as dictated by the use. The steam exhaust can also be cleaned using a cyclonic separator (not shown) such as seen in  FIG. 1 . 
         [0029]    These steam generators offer a great improvement over existing boiler technology to produce very high temperature and pressure superheated steam quickly and efficiently. This will allow a new generation of efficient steam cycle power plants and uses. These include vehicle power, steam catapults, steam cleaners, abrasive cutters, weapons, and other yet to be conceived uses. 
         [0030]      FIG. 4  is a short duration steam generator that uses the steam canister  300  as disclosed in  FIG. 3  is shown attached to a cyclonic Steam separator assembly  400 . In  FIG. 400  the energetic packets  415  are sequentially initiated producing a high pressure steam, particle and water discharge tangential to the interior wall of conical cyclone vessel  420 . The discharge is guided downward by helical internal vanes  410  as the mixture oxidizes and superheated steam is produced. The clean superheated steam travels inward and exits up steam delivery pipe  430  to the desired use. 
         [0031]    The heavier oxidation byproducts and unboiled water are forced outward and downward by the centrifugal forces created by the circular motion of the cyclone, they continue downward in a decreasing radius spiral until exiting the cyclone  420  at the bottom exit  435  and entering the oxidation byproduct receiver  425 . 
         [0032]    The oxidation byproduct receiver  425  can be removable for cleaning. The cyclone  420  and receiver  425  also serve as an accumulator to prolong and soften the steam delivery impulse, as well as cleaning the steam of oxidation byproducts that are unwanted in some steam uses. The assembly  400  can be without the oxidation byproduct receiver to send the combustion byproducts out of the cyclone  420  bottom exit  435  for use in abrasive cutting, while sending the clean steam up steam delivery pipe  430  for other uses. 
         [0033]    It is understood that the invention can be adapted to meet many applications without leaving the inventions disclosure area. While the invention has been particularly shown and described with respect to preferred embodiments, it will be readily understood that minor changes in the details of the invention may be made without departing from the spirit of the invention.