Abstract:
An ultrasound system is disclosed that includes a tub, a reaction chamber, an ultrasound probe positioned within the reaction chamber, and a cooling jacket surrounding the tub for exchanging heat with the tub.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims benefit of U.S. Provisional Application No. 61/087,651 filed Aug. 8, 2008. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to ultrasound devices, and more particularly, to an ultrasound reaction chamber with temperature control. 
         [0003]    There exist known methods of producing hydrogen. One known method of producing hydrogen may include converting fossil fuels into natural gas which may produce emissions of carbon dioxide and monoxide. 
         [0004]    Another known method may include electrolysis of water which may use a high energy power source requiring relatively large loads of electric energy. 
         [0005]    Another known hydrogen producing methods may involve chemically reacting metal hydrides or may involve reactions between water and alkaline metals such as potassium and sodium, either of which may result in relatively powerful exothermic reactions. 
         [0006]    Methods employing ultrasound have gained interest because ultrasound can produce an improved yield in hydrogen from water however, ultrasonic reactions can produce high temperatures and pressures. 
         [0007]    As can be seen, there is a need for an energy efficient system and method to control temperature in an ultrasonic environment. 
       SUMMARY OF THE INVENTION 
       [0008]    In one aspect of the present invention, an ultrasound system comprises a tub including a reaction chamber; an ultrasound probe positioned at least partially within the reaction chamber; and a cooling jacket disposed around the tub operable to exchange heat between the tub and the cooling jacket. 
         [0009]    In another aspect of the present invention, a gaseous fuel generator comprises an ultrasound tub including a reaction chamber; an ultrasound dome connected to the ultrasound tub; an adjustable ultrasound probe connected to the ultrasound dome; a gas flush port connected to the ultrasound dome; and a cooling jacket circumventing the ultrasound tub. 
         [0010]    In another aspect of the present invention, a method of generating a gaseous fuel in an ultrasonic reaction chamber comprises flushing the ultrasonic reaction chamber with nitrogen or argon gas; removing oxygen present in the reaction chamber with the argon gas; applying an ultrasonic agitation to a bath of chemical reactants; and circulating a coolant through a cooling jacket, wherein the cooling jacket surrounds the reaction chamber. 
         [0011]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  depicts a cut-away front view of an ultrasound system according to an exemplary embodiment of the present invention; and 
           [0013]      FIG. 2  illustrates a series of steps according to an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0015]    Various inventive features are described below that can each be used independently of one another or in combination with other features. 
         [0016]    Broadly, embodiments of the present invention generally provide a jacketed ultrasound device that may produce, for example, hydrogen gas under an improved temperature control environment. In one exemplary use, the ultrasound device may be used as a gaseous fuel generator to produce hydrogen from water by the hydroxylation and oxidation of aluminum. By employment of the jacketed ultrasound device according to exemplary embodiments of the present invention, the temperature within a reaction chamber may be maintained above 32 degrees F. in the 35° F. to 37° F. range. 
         [0017]    Referring to  FIG. 1 , an ultrasound system  100  according to exemplary embodiments of the present invention is shown. The ultrasound system  100  may generally comprise a dome  120 , a tub  125 , ultrasound apparatus  105 , and a double-walled jacket  150 . In one exemplary embodiment, both the dome  120  and the tub  125  may be constructed with stainless steel or other durable materials certified to withstand pressures of 60 psi to 100 psi for use in ultrasonic applications. 
         [0018]    The double-walled jacket  150  may be formed as two concentric walls an outer jacket wall  152  and an inner jacket wall  154  around the tub  125 . The concentric disposition of the outer jacket wall  1   52  and the inner jacket wall  154  may define an inner flow channel  158  and an inner flow channel  156 . The outer flow channel  156  may be defined by a space formed between the outer jacket wall  152  and the inner jacket wall  154 . The inner flow channel  158  may be defined by a space formed between the inner jacket wall  154  and the tub  125 . A fluid entrance connector  153  may be connected to the outer jacket wall  152  for permitting the introduction of a coolant into the outer flow channel  1   56 . A fluid exit connector  1   57  may be connected to the outer wall jacket  1   52  for permitting egress of the fluid from the double-walled jacket  150 . The double-walled jacket  150  may additionally include fluid ports  151 ,  159 , and  155  for circulation of coolant through the double-walled jacket  150 . The fluid port  151  may allow fluid to enter the outer flow channel  156  from the fluid entrance connector  153 . The fluid port  159  may allow fluid to travel between the outer flow channel  156  and the inner flow channel  158 . The fluid port  155  may allow fluid to exit from the inner flow channel  158  into and out of the fluid exit connector  157 . 
         [0019]    The dome  120  may be built according to metallurgic standards as one solid piece. The dome  120  may be composed of several parts. A piezo-electric ultrasound probe  115  may be attached to the dome  120  so that the probe  115  is centered within the dome  120  and passing through a dome lid  122 . The size of the ultrasound probe  115  may vary according to a size of the tub  125 . The dome  120  may also have two side ports; a flush port  140  and a gas port  180 . The flush port  140  may flush the reaction chamber  135  with nitrogen or argon gas. The gas port  180  may provide a conduit for releasing produced hydrogen from the ultrasound system  100 . The gas port  180  may house a temperature probe  184 , a gas analyzer  186 , and a pressure probe  188 . The temperature probe  184  may provide temperature readings of the internal environment of ultrasound system  100 . The gas analyzer  186  may provide a signal detecting the types of gasses being produced inside the ultrasound system  100 . A safety blow-off valve  182  may vent gas from within the dome  120  according to a pressure exceeding a predetermined pressure level as sensed by the pressure probe  188 . 
         [0020]    The tub  125  may be hollow and include a reaction chamber  135  where a chemical reaction may take place. A sleeve  130  may line the interior of the tub  125  disposed between the inner jacket  154  and the reaction chamber  135 . In on embodiment, the sleeve  130  may be made from aluminum. A sealing ring  124 , such as an O-ring, may provide an hermetically sealed connection between the dome  120  and the tub  125  when the dome  120  and the tub  125  are attached to one another. It will be understood that other connections between the dome  120  and the tub  125  are contemplated such as a screw-type connection, a clamp-type connection, or a press-fit connection and that conventional locking mechanisms may be employed. 
         [0021]    The ultrasound apparatus  105  may include an ultrasound head  110  and an ultrasound probe  115 . The ultrasound apparatus may be positioned centered within and passing through the dome  120  and may extend into the tub  125  when the dome  120  and tub  125  are attached. 
         [0022]    An induction magnetic plate  190  may be included within the ultrasound system  100  and positioned outside of the tub  125 . The induction magnetic plate  190  may be connected to a power source (not shown) and when operated, may provide a magnetic field agitating contents held within the reaction chamber  135 . 
         [0023]    Referring now to  FIGS. 1 and 2 , in one exemplary operation, a clean sleeve  130  is positioned within the tub  125  (step  205 ) to hold a bath of chemical reactants  137  (step  210 ). In one exemplary method for producing hydrogen gas, the bath of chemical reactants  137  may comprise non-ionized distilled water, elemental aluminum, and sodium chloride may be placed into the tub  125 . The amounts and ratios of each of the chemical reactants may be based on the chemical equation in mole/grams described by 
         [0000]      i. 3H 2 0+2Al 
         [0000]    where, “H 2 0” represents the non ionized distilled water and “Al” represents aluminum, and the prefix numerals represent the number of moles for reactant. The amount in grams of sodium (NaCl) added to the reaction may be that related to the amount in grams of the two moles of aluminum, defined by an approximate ratio of 1:1. The particle size of the aluminum used may be in the range of 3.5 to 5.5 microns. 
         [0024]    The dome  120  may be connected onto the tub  125  sealing the reaction chamber  135  from the environment (step  215 ). The ultrasound probe  115  may be disposed to contact the bath of chemical reactants  137  upon closing of the dome  120 . It will be understood that the ultrasound apparatus may be in fixed connection to the dome  120  or may be separable and may slide into and out from the dome lid  122  so that the draft of the ultrasound probe  115  in the bath of chemical reactants  137  may be adjusted. The nitrogen or argon gas may be introduced into the ultrasound system  100  through the flush port  140  flushing oxygen from the interior of the ultrasound system  100  (step  220 ). The ultrasound apparatus  105  may be operated causing the ultrasound probe  115  to emit sound waves agitating the bath of chemical reactants  137  (step  225 ). During agitation, sonohydrosis may occur producing OH −  and H +  particles from the water accelerating a chemical reaction with the aluminum resulting in free gas 3H 2  (hydrogen) and aluminum oxide (Al 2 O 3  )as well as aluminum hydroxide among other byproducts. The hydrogen gas may be drawn out of the ultrasound system  100  through the gas port  180  where the temperature probe  184  may measure the current temperature in the ultrasound system  100  (step  230 ), the gas analyzer  186  may analyze the constituency of gasses exiting through the port  180  (step  250 ), and the pressure sensor  188  may measure the current pressure in the ultrasound system  100  (step  235 ). Thus, one may monitor the production quantity and quality of hydrogen gas produced in the ultrasound system  100 . One attribute that may need particular attention is the control of temperature in the ultrasound system  100 . 
         [0025]    Temperature within the ultrasound system  100  may need to be controlled to produce an optimum reaction for the production of hydrogen. One exemplary operation maintains a temperature within the ultrasound system  100  within an approximate range between 35° F. to 37° F. During operation of the ultrasound apparatus  105 , the temperature within the reaction chamber may rise above a desired level caused by energy released from the chemical reactions as well as the heat generated by the energy of the ultrasound waves, which can cause the build-up of pressure in the ultrasound system  100 . 
         [0026]    Temperature within the ultrasound system  100  may be controlled by circulating a coolant through the double-walled jacket  150  (step  245 ). Coolant, such as glycol, may be introduced through the fluid entrance connector  153 . The coolant may circulate through the outer flow channel  156  between the outer jacket  152  and the inner jacket  154  providing a first layer of cooling insulation. The coolant may continue to flow through the outer flow channel  156  and around the tub  125  until the coolant encounters the fluid port  159  allowing the coolant to enter the inner flow channel  158  between the inner jacket  154  and the tub  125  providing a second layer of cooling insulation. The coolant within the inner flow channel  158  may absorb heat from the tub  125  and carry the heated coolant out through fluid port  155  and out the fluid exit connector  157 . It will be understood that the coolant may be circulated in any direction around the tub  125  that may be desired according to the reaction desired in the ultrasound system  1   00 . It will also be understood that circulation of the coolant may be achieved by a pump (not shown) and re-cooling of heated coolant may be achieved by a heat exchanger (not shown) so that the coolant maybe re-circulated into the double-walled jacket  150 . As the temperature within the reaction chamber  135  rises or falls, the coolant flow may be adjusted until the temperature probe  1   84  registers a desirable temperature. Additionally, when the pressure sensor  188  detects a rise in pressure within the reaction chamber  135 , the temperature within the reaction chamber  135  may also rise. Thus pressure may be released from the reaction chamber  135  (step  240 ) through the blow off valve  182  until the pressure sensor  188  and temperature probe  184  register acceptable levels. 
         [0027]    It may be appreciated that NaCl may be included into the reaction to supress passivation. As aluminum reacts with oxygen or with hydroxide (—OH), its by-products inhibit further reaction to occur, therefore stopping it. To facilitate the reaction to continue two things should happen, first increasing the surface area of the aluminum by decreasing the size of the particles (3 to 5 microns) and secondly by adding a salt like NaCl. Experimentation has shown that one preferred molar ratio was 1:1 of NaCl gram weight to the gram weight of aluminum (one mole of aluminum is approximately 54 grams). 
         [0028]    In another exemplary embodiment, the induction magnetic plate  190  may be used to augment agitation of the bath of chemical reactants  137 . Ferrous material may be added to the bath of chemical reactants  137 . Operation of the induction magnetic plate  190  may cause movement of the ferrous material resulting in agitation of the bath of chemical reactants  137 . 
         [0029]    As hydrogen produced by operation of the ultrasound system  100  exits via the gas port  1   80 , the hydrogen may be delivered to a storage tank (not shown), a hydrogen compressor (not shown) or to a fuel cell (not shown). When operation of the ultrasound apparatus  105  is terminated (step  255 ), a hydrogen gas yield may be measured for any gas that continues to be produced after the ultrasound emission stops (step  260 ). The dome  120  may be disconnected from the tub  125  and contents remaining in the reaction chamber  135  may be removed by lifting the sleeve  130  out of the tub  125 . 
         [0030]    Experimentation employing exemplary embodiments demonstrates improved energy efficiency in operation of an ultrasound system  100  according to the present invention. It may be expected that passivation from the byproducts of the reaction between water and aluminum may inhibit the reaction from proceeding forward. In some cases, passivation may contribute to stopping the reaction entirely or slowing the reaction rate to a negligible level after a certain yield is achieved, once the emission of ultrasonic energy is terminated. Yet, experimentation using exemplary embodiments of the ultrasound system  100  has shown that once the reaction begins producing hydrogen, the reaction may become self sustained to the point that no further ultrasound may be needed to stimulate the reaction. The reaction may continue at a relatively slow rate compared to when the ultrasound apparatus  105  is powered yet, may be self sustainable. 
         [0031]    The nature of the reaction may be considered a slow, process relative to some prior art processes. A reaction time of three or more hours under low energy may be expected according to exemplary embodiments of the present invention. Methods according to exemplary embodiments may prefer operating at relatively low energy levels of less than 50 Watts. Higher energy levels that approach the 50 Watt level may result in temperatures at the tip of the ultrasound reaching 5000 degrees Kelvin, which can make aluminum melt. An exemplary processing reaction may include a first phase, which may consist of a period of one hour and a half of processing at an 18-20 watt/Hr level. A second phase may include a half hour of processing at a 34 watt level setting. By this second phase, the concentration of output gas, such as hydrogen, that may be read on the gas analyzer  186  may reach a 9-10% yield concentration. At this point, the emission of ultrasound can optionally be stopped and the reaction may become self-sustainable. Otherwise, the process may continue under a third phase of processing. 
         [0032]    What may be unexpected is that during the third phase of processing, a gas product may react over a four hour period, with yield concentrations of 80% of the gas product, such as hydrogen. This is in comparison to previously known methods that yielded 70% or less of a concentration. After the second phase, the reactants may become more viscose and a change of sound may be heard by an operator. The ultrasound system  100  may register drop in wattage. This may be due to an increase of viscosity in the chemical bath  137 . Thus, in order to maintain the previous energy level, the amplitude of ultrasound waves emitted should be increased (amplitude may be the % of the ultrasound apparatus  105  total output) the watts to be maintained at this point may be in the 8 to 10 Watts range. This phase of processing may be of shorter duration (2:45 to 3:30 hours) than that of the first phase of reaction, but this phase may consume more total energy over the span of the phase. What may also be surprising is that the amount of energy to start the reaction is low in nature, 8 to 10 Watts as compared to the 18-20 Watts used during the first few hours. 
         [0033]    Still yet, what may further be unexpected is that an 80% yield concentration may result even when the ultrasound apparatus  105  is left unpowered after the second phase. During this exemplary embodiment of operation, exemplary embodiments of the ultrasound system  100  may continue reacting without the aid of ultrasonic agitation and may overcome the effects of passivation. For example, when the ultrasound apparatus  105  is powered off after the second phase, the reaction of elements in the chemical bath  137  may continue over several hours (in other words, the duration may typically be longer than 3 hours) and yet yield, for example, an 80% yield of concentration without the need for the additional energy consumed during phase  3 . 
         [0034]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.