Abstract:
Apparatus and method to produce point-of-use compressed superheated steam for a wide variety of uses including, but not limited to, cleaning, heating, drying, surface preparation, sterilization, pest control and elimination, degreasing and food preparation. The apparatus produces and compresses superheated steam without the hazards and problems associated with the current state of the art where steam is generated, compressed and stored in potentially dangerous and maintenance intensive boilers and associated piping and fixtures. The in-line steam generator of the present application produces superheated steam at one atmosphere which is immediately pressurized using a compression means and then immediately utilized through application employing a nozzle or a storage tank or other such device.

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application Ser. No. 61/446,533 filed Feb. 25, 2011 and International application PCT/US12/25334 filed Feb. 16 2012 by the present applicants. This application incorporates the apparatus and method disclosed in U.S. patent application Ser. No. 11/682,107 published as US2007/0145038 on Jun. 28, 2007 and Ser. No. 12/514,516 published as US2010/0129157 on May 27, 2010, which are incorporated herein in their entirety by reference. 
    
    
     BACKGROUND 
     1. Field 
     The present application relates to the generation of superheated steam at one atmosphere and subsequent pressurization for a wide variety of uses including, but not limited to, cleaning, heating, drying, surface preparation, sterilization, pest control and elimination, degreasing and food preparation. 
     2. Prior Art 
     For industrial and non-industrial applications, steam is currently often produced by the heating of water in a boiler or other vessel. Generally, for these applications, saturated steam is produced and is then pressurized to a desired level by the continued application of heat. The pressurized steam generated by this process is then piped from the vessel for use. Saturated steam, having high moisture content, will readily condense in piping and upon application to surfaces. Such systems have several obvious disadvantages including expense, maintenance, efficiency, safety and dimensional constraints. 
     Common boiler systems can be expensive to install due to the required strength of materials and adequate fabrication needed to meet safety standards. The high temperatures and pressures associated with boilers are very hazardous and need to be compensated for with appropriate engineering design and advanced materials. Required inspection, maintenance, training and insurance costs add to the expense of such systems. Elaborate and expensive piping, gauging and monitoring equipment may also be called for, further adding to the overall expense. 
     Boiler systems use large amounts of clean water on initial start-up to produce steam. If water is in short supply, operation of such systems would be costly if at all possible. Leaks and condensation in such systems also result in water wastage, corrosion, damage and clean-up. Large amounts of costly and environmentally unfriendly fuel are required to heat the masses of water required in boilers to needed temperatures and pressures. If proper insulation is not installed on piping and other fixtures, which would add to cost, an amount of heat and energy would be lost from the process. For these and other reasons present boiler systems may be very inefficient for their intended purposes. Boiler operators need to be well trained in the operation of their equipment as well as focused, observant and skilled in their duties. Costs and work-place hazards could be minimized with a system that requires less training due to higher safety and easier operation than is the case with current methods for the pressurization of steam. 
     In many cases, due to their size and weight, current methods of pressurized steam production are limited to industrial or other settings where space is not an issue. In other cases, where space is limited, a boiler system would be too bulky. A smaller, lighter and portable method for providing pressurized steam is needed and is provided for by the present application. 
     The greatest concern in regards to the generation of pressurized steam is safety. Boilers and other pressure vessels can be extremely dangerous when not designed, built, operated or maintained properly. Pressurized steam lines running from the vessel are hazardous as well. In the vessel, large amounts of very hot pressurized steam are contained in a relatively small volume, creating the possibility of catastrophic rupture and explosion. The failures of steam pressure vessels are common and often deadly. To decrease the chances for such failures, boiler systems must be carefully designed, operated, maintained and inspected, which, as stated above, add to the overall cost of such systems. 
     SUMMARY 
     This application presents an apparatus and method for the in-line, point-of-use generation of superheated steam at one atmosphere and the immediate pressurization of the superheated steam. An in-line, point-of use system here is defined as a compact and portable, if desired, system that can quickly, almost as needed, generate superheated steam at one atmosphere and then pressurize the steam to desired levels. The superheated temperature of the steam is maintained during pressurization, which eliminates the disadvantages, associated with the present state of the art. The best mode and other embodiments included in the present application offer a safe, efficient, less costly and portable apparatus and method to supply pressurized superheated steam for a variety of uses. 
     Described are a point-of-use steam generation and pressurization apparatus and method that solve existing problems associated with current steam pressurization methods which often employ dangerous, maintenance intensive and inefficient boilers and piping. Here, water is quickly and efficiently converted to high temperature steam and then immediately compressed or pressurized with a compressor or other means. The compressed steam may then be contained, projected or otherwise employed for the desired application by the user. 
     In one embodiment superheated steam is generated at one atmosphere and then compressed utilizing a means of pressurization such as a compressor. In a further embodiment the means of pressurization of the superheated steam is a succession of pressure vessels and check valves that increase steam pressure to desired levels in steps. In all embodiments, the unique properties of superheated steam, such as higher internal energy, higher enthalpy, higher specific volume and higher temperatures attainable at lower pressures, are relied upon to produce a novel and improved and apparatus and method for the safe and economic application of superheated steam for many industrial and non-industrial uses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the pressurized point-of-use superheated steam generation apparatus showing a superheated steam assembly, composed of a superheated steam generator inside a housing, connected to a means of pressurization which, in turn, is connected to a means of application. 
         FIG. 2  is a perspective view of the pressurized point-of-use superheated steam generation apparatus depicting the means of pressurization as a compressor and the means of application as a hose and nozzle. 
         FIG. 3  is a perspective view of the pressurized point-of-use superheated steam generation apparatus depicting the means of pressurization as a compressor and the means of application as a pressure vessel. 
         FIG. 4  is an embodiment of the heater contained within the superheated steam generator of the present application. 
         FIG. 5  is an exploded view of the heater contained within the superheated steam generator. 
         FIG. 6  is a cross sectional view of the heater contained within the superheated steam generator. 
         FIG. 7  is a view of the heating coils contained within the heater. 
         FIG. 8  is an embodiment of the superheated steam generator utilized in the present application. 
         FIG. 9  is a further embodiment of the superheated steam generator utilized in the present application. 
         FIG. 10  is a schematic of an embodiment of a pressurized superheated steam apparatus wherein superheated steam pressure is increased to desired levels through the employment of a succession of pressure vessels and check valves. 
         FIG. 11  is an embodiment of a pressurized superheated steam apparatus wherein superheated steam pressure is increased to desired levels through the employment of a succession of pressure vessels and check valves. 
         FIG. 12  is a further embodiment of a pressurized superheated steam apparatus wherein superheated steam pressure is increased to desired levels through the employment of a succession of pressure vessels and check valves. 
         FIG. 13  is a plot showing the behavior of superheated steam in reference to P sat  and T sat . 
     
    
    
     
       
         
               
             
               
               
               
               
             
           
               
                   
               
               
                 DRAWINGS-Reference Numerals 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. 
                 pressurized superheated 
                  2. 
                 superheated steam 
               
               
                   
                 steamer 
                   
                 assembly 
               
               
                  3. 
                 low-pressure piping 
                  4. 
                 means of pressurization 
               
               
                  5. 
                 piston-type compressor 
                  6. 
                 high-pressure piping 
               
               
                  7. 
                 means of application 
                  8. 
                 hose and nozzle 
               
               
                   
                   
                   
                 assembly 
               
               
                  9. 
                 pressure vessel 
                  9-1. 
                 P1 pressure vessel 
               
               
                  9-2. 
                 P2 pressure vessel 
                  9-3. 
                 Pn pressure vessel 
               
               
                  10. 
                 industrial gas heater 
                  11. 
                 steam generator housing 
               
               
                  12. 
                 cylindrical tubular 
                  13. 
                 one-way check valve 
               
               
                   
                 housing 
               
               
                  13a. 
                 one atmosphere one-way 
                  13-1. 
                 P1 one-way valve 
               
               
                   
                 valve 
               
               
                  13-2. 
                 P2 one-way valve 
                  13-3. 
                 Application control valve 
               
               
                  14. 
                 gas entry port 
                  16. 
                 gas exit port 
               
               
                  18. 
                 open end 
                  20. 
                 end cap 
               
               
                  22. 
                 annular sidewall 
                  24. 
                 end wall 
               
               
                  26. 
                 stepped passage 
                  28. 
                 inner helical coil 
               
               
                  28a. 
                 generally continuous 
                  28b. 
                 gap 
               
               
                   
                 wire 
               
               
                  28c. 
                 adjacent turn 
                  28d. 
                 terminal lead wire 
               
               
                  28e. 
                 flow path 
                  28f. 
                 bare wire cross section 
               
               
                  30. 
                 outer helical coil 
                  30a. 
                 generally continuous 
               
               
                   
                   
                   
                 wire 
               
               
                  30b. 
                 gap 
                  30c. 
                 adjacent turn 
               
               
                  30d. 
                 terminal lead wire 
                  30e. 
                 flow path 
               
               
                  30f. 
                 bare wire cross section 
                  34. 
                 spacer 
               
               
                 200. 
                 superheated steam 
                 202. 
                 gas inlet source 
               
               
                   
                 generator 
               
               
                 204. 
                 power cord grip 
                 206. 
                 gas inlet 
               
               
                 208. 
                 manifold housing 
                 210. 
                 casing 
               
               
                 212. 
                 delivery tube 
                 214. 
                 end plate 
               
               
                 216. 
                 fluid reservoir 
                 218. 
                 feed line 
               
               
                 220. 
                 needle valve 
                 222. 
                 reactor vessel 
               
               
                 224. 
                 porous medium 
                 226. 
                 exit nozzle 
               
               
                 228. 
                 diffuser 
                 300. 
                 superheated steam 
               
               
                   
                   
                   
                 generator 
               
               
                 302. 
                 pump 
                 304. 
                 fluid reservoir 
               
               
                 305. 
                 valving 
                 306. 
                 outer jacket housing 
               
               
                 308. 
                 chamber 
                 310. 
                 inlet 
               
               
                 312. 
                 conduit 
                 314. 
                 outlet 
               
               
                 400. 
                 pressurized superheated 
                 450. 
                 external heater 
               
               
                   
                 steamer 
               
               
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION 
     Presented is a new apparatus and method for the point-of-use generation at one atmosphere of superheated steam and its subsequent pressurization for a variety of applications. Such apparatus and method as described here are safer, more versatile, more efficient and less costly than the current technology which often utilizes boilers for the pressurization of steam. Steam generated in any manner may be compressed and pressurized as described in this application, but specific embodiments will be discussed in greater detail. 
     Superheated steam generators of the type, for example, produced by MHI-Inc. with patents pending and published internationally as WO2008/061139 A2 and in the United States national phase as US2010/0129157 A1 are envisioned as the means for the production of superheated steam at one atmosphere in this application. Such generators rely on a flow of gas through and across electrically heated coils contained within the body of the generator. The gas is intended to exit the gas exit port at temperatures between 500° C. and 1500° C. and at a rate in the range of about 1 cubic foot per minute (CFM) to about 1000 CFM. The generators typically have, as depicted in  FIGS. 4 ,  8  and  9 , tubular housings which contain the heating coils and through which the gas passes. 
     The generation of steam can be accomplished by the introduction of water, or possibly other fluids, to the heated gas flow, which commonly is air. The water is almost instantaneously converted to superheated steam and then mixed with the gas flow. The introduction of the water and the mixing of the water vapor with the gas flow may take place outside of the exit port ( FIG. 8 ) or within the tubular enclosure of the generator ( FIG. 9 ). After the water is converted to super heated steam and mixed within the gas flow it is then compressed by use of a compressor or other means of pressurization. Superheated steam may also be compressed by the use of a series of pressure vessels and one-check valves which together increase the pressure to desired levels ( FIG. 10 ). 
     In part, the unique characteristics of superheated steam allow the improvements over the prior art to be realized in the present application. Superheated steam is drier than standard steam allowing for use in applications were condensation is problematical. Steam traps to collect condensation are not needed with superheated steam systems as they are with current systems that use saturated steam. With superheated steam being dry, condensation and resulting corrosion are less of a concern when superheated steam is generated and piped and contained or when it is applied to surfaces. Superheated steam can reach higher temperatures at lower pressures than normal steam (See  FIG. 13 ) and superheated steam has higher internal energy and enthalpy than normal steam. Due to the above characteristics, the superheated steam produced by the embodiments presented in the present application can be used for sanitizing, surface cleaning, sterilizing, antimicrobial applications, and various other uses from heat treatment to drying. 
     Superheated steam is different than saturated steam as it is decoupled from, and does not follow, the P sat  (saturated pressure)/T sat  (saturated temperature) curve that saturated steam follows. It is well known in the art that even when labeled “saturated”, the steam (gas) may hold water vapor (See: Advanced Thermodynamics, Third Edition, Adrian Bejan, John Wiley &amp; Sons, pg. 282). This wet vapor could be, for example, condensed water droplets. In some applications, such as sterilizing, these condensed droplets can defeat the intended use. When water is phase separated into saturated steam, following  FIG. 13 , water droplets may still be present by phase separation/spinodal-like behavior. The line of  FIG. 13  acts more like a band rather than a line, allowing for droplets of water to be mixed within the steam. The higher temperatures of superheated steam allow it to contain less moisture and not condense at pressures lower than saturated steam. Superheated steam is in a vapor region and not a liquid vapor region that saturated steam is found in and is therefore drier, containing less moisture, than saturated steam. Thus, less corrosion and other damage associated with wet conditions will occur in connection with the apparatus equipment or to the items to which the superheated steam is applied. 
       FIG. 13  shows the relationship between saturation pressure and saturation temperature for saturated steam. The plot indicates at what temperature saturated steam is generated at an existing pressure. For example, at one atmosphere (around 100 kPa) saturated stem can be generated at 100° C. Superheated steam, however, exists below and to the right of the saturated steam curve, meaning that at one atmosphere, superheated steam can reach temperature well in excess of 100° C. These facts indicate that superheated steam can reach high temperatures without pressurization which suggests safer and more energy efficient apparatuses and procedures of high temperature steam generation and application. 
     It has been determined through experiment at MHI that superheated steam produced by the novel technology represented by  FIGS. 4-9  can be compressed by a pump or other means of pressurization while retaining a superheated temperature. The superheated steam generator presented in US2007/0145038 and US2010/0129157 and shown in  FIGS. 8 and 9 , in general, consists of an industrial gas heater having a tubular enclosure with a gas entry port spaced from a gas exit port. The industrial gas heater, in various embodiments, includes an inner helical coil contained within the tubular enclosure and an outer helical coil also contained with in the tubular enclosure and surrounding the inner coil to define a substantially unobstructed annular space between the coils. Each coil is electrically heated to convectively heat a gas entering the tubular enclosure via the gas entry port, passing through the annular space between the coils and exiting the tubular enclosure via the gas exit port. 
     In various other embodiments the inner and outer coils are each right circular helical coils arranged concentrically. The inner and outer coils may be wound in opposite directions from each other or in the same direction. The individual coils may be formed from a generally continuous bare wire concentrically wound into a right circular helical coil. The inner and outer coils may be formed together of one generally continuous bare wire, thereby constituting a single electric circuit in series. In other embodiments the inner and outer coils may have different configurations from each other. A spacer may be positioned within the tubular enclosure proximate to the gas exit port and adjacent distal ends of the inner and outer coils to minimize deformation of the coils. 
     The tubular enclosure may be a housing in the form of a right circular cylinder having an open end proximate to the gas entry part and an end cap closing the open end of the housing. In various embodiments the outer coil is positioned in close proximity to, or in contact with, an inner surface of the tubular enclosure to minimize gas flow between the outer coil and the inner surface of the tubular enclosure and to maximize heat transfer to the gas. The coils are designed to heat the gas flowing through the annular space and exiting the gas exit port to a temperature in the range of 500° C. to 1500° C. and at a rate in the range of about 1 cubic foot per minute (CFM) to about 1000 CFM. 
     An embodiment of this industrial heater allows the apparatus to be a superheated steam generator. In this embodiment, the heater, as described above, includes a fluid reservoir adapted to contain a working fluid, a mixing device in fluid communication with the fluid reservoir and the heater and a reactor vessel in fluid communication with the mixing device to receive a fluid and heated gas mixture to produce superheated steam exiting the reactor vessel. The mixing device may be a venturi mixing apparatus. The heater heats a gas to a temperature above the saturation temperature of water such that when the water is combined with the heated gas, a mixture of superheated steam and gas is produced. The generation of the superheated steam-gas mixture is done at approximately one atmosphere of pressure. The temperature of the superheated steam-gas mixture may be between the saturation temperature of water at about one atmosphere of pressure (e.g., about 100° C.) and 1500° C. 
       FIG. 8  shows water being introduced to the heated gas flow at the exit port of the heater.  FIG. 9  shows an alternate embodiment where water is introduced in a sleeve around the heater which keeps the water from direct contact from the heater or gas flow while still allowing it to be in thermal communication therewith. A further embodiment anticipates the introduction of water though a rear entrance port without the need for a separate gas input into the housing of the heater, where the water would be instantly converted to superheated steam. The introduction of other fluids, in place of water, is anticipated as well. Gasses other than air to be heated by the heating unit are also anticipated. 
     The resulting high pressure superheated steam would then be applied for a variety of uses including, but not limited to, killing of micro-organisms, sterilization, surface preparation, decontamination, cleaning and degreasing. Multiple delivery means are envisioned for the application of the pressurized steam. The steam could be applied directly to desired work-pieces through the use of hoses and nozzles ( FIG. 2 ). The pressurized steam could also be piped into a closed container or pressure vessel for sterilizing, preparation or decontamination of objects and surfaces ( FIG. 3 ). The pressurization will allow the superheated steam to penetrate more deeply and completely both general and hard-to-reach surfaces and features. The high temperature of the superheated steam will be able to destroy a wide variety of bacteria and other microorganisms and also permit the treatment and preparation of surfaces where higher temperatures are required, but are not provided for by the present state of the art. 
     The system described has great utility and is very adaptable for a variety of uses. Its size is scalable and portable and in-place embodiments are anticipated. Smaller steam generation and pressurization units are envisioned as being able to be transported to where needed, while larger units could be installed permanently in place in an industrial setting. Wherever the application may be, there will be no need for expensive and space-taking piping and fixturing. A portable unit could be plugged in to any convenient electrical outlet and operated. Larger units could be hard-wired into a power source. Great flexibility is thus provided which, in turn, reduces expenses. 
       FIGS. 1-3  show an apparatus for in-line point-of-use superheated steam generation and pressurization  1 .  FIG. 1  depicts an apparatus for in-line point-of-use superheated steam generation at one atmosphere and subsequent pressurization featuring a superheated steam assembly  2 , consisting of a superheated steam generator  200  or  300  held within a steam generator housing  11 , attached to a means of pressurization  4  which is coupled to a means of applying  7  the pressurized superheated steam. The superheated steam assembly  2  produces superheated steam at one atmosphere that immediately flows through low-pressure piping  3  to the means of pressurization  4 . The superheated steam is pressurized by the means of pressurization and can then be passed through piping  6  to a means of application  7  and projected on to a work-piece. When necessary, a one-way check valve  13  may be positioned at the junction of the low pressure piping  4  and the means of pressurization  3  to prevent the flow of high pressure steam back into the superheated steam generator  200  or  300 . Likewise, a one-way check valve  13  may be positioned at the junction of the piping  6  and the means of application  7  to prevent flow-back into the means of pressurization  4 . 
     In one embodiment, presented in  FIG. 2 , the means of pressurization is a piston-type compressor  5  with the means of application being a hose and nozzle assembly  8 .  FIG. 3  shows another embodiment where the means of application is a pressure vessel  9  in which objects are placed to be treated with the compressed superheated steam. In all embodiments the steam is superheated at one atmosphere. Superheated steam is dryer than other forms of steam resulting in less condensation on various components in the system such as piping and compressors. Superheated steam is different than saturated steam as it is decoupled from and does not follow the P sat  (saturated pressure)/T sat  (saturated temperature) curve that saturated steam follows. The higher temperatures of superheated steam allow it to contain less moisture and not condense at pressures lower than saturated steam. Superheated steam is in a vapor region and not a liquid vapor region that saturated steam is found in and is therefore drier, containing less moisture, than saturated steam. Thus, less oxidation and other damage associated with wet conditions will occur in connection with the apparatus equipment or to the items to which the, compressed and applied quickly with no boilers and little piping. 
     Referring to  FIGS. 4-6 , an exemplary embodiment of an industrial gas heater  10  according to this invention is shown. The heater  10  includes a generally right circular cylindrical tubular housing  12  having a gas entry port  14  at a first end of the housing  12  spaced from a gas exit port  16  at an opposite end of the housing  14 . The housing  14  may be a monolithic ceramic tube or other material such as a metallic enclosure. However, we have found that the temperature of the gas heated within the assembly is increased anywhere from 25-200° C. when a ceramic housing is utilized. 
     The gas entry port  14  is proximate to an open end  18  of the housing  14  and is selectively closed by an end cap  20  mounted on the open end  18  of the housing  14 . The end cap  20  may be made from a ceramic of approximately 90 percent aluminum oxide. The cap  20  includes an annular sidewall  22  and an end wall  24 . The end cap  20  is a partially open end cap and according to various embodiments of this invention, the end cap  20  can be fully or partially open with additional openings for electrical feed-throughs and thermocouple feed-throughs. A stepped passage  26  is formed on the interior of the sidewall  22  and the gas entry port  14  is on the end wall  24 . The opening diameter of the gas entry port  14  to the gas exit port  16  may be at a ratio of about 2:1. 
     The gas heater  10  includes an inner helical coil  28  and an outer helical coil  30  contained within the tubular housing  12 . The inner and outer coils  28 ,  30  are coaxially aligned and concentrically arranged as right circular helical coils within the housing  12  to define a substantially unobstructed annular space  32  for passage of gas through the housing  12  from the gas entry port  14  to the gas exit port  16 . In one embodiment, each coil  28 ,  30  is formed from a generally continuous wire  28   a ,  30   a , respectively, concentrically wound into right circular helical coils. A diameter of the wire  28   a ,  30   a  for each coil may range from about 0.1 mm to about 6 mm A gap  28   b ,  30   b  between the adjacent turns  28   c ,  30   c  of each coil  28 ,  30  may range from about 0.01 mm to about 85 mm. The gap or pitch of each coil  28 , may increase adjacent to the entry port  14  and terminal lead wires  28   d ,  30   d.    
     We have found that where the outer coil  30  is in close proximity to and/or in contact with the inside face of the tubular housing  12 , the gas processed in the heater is heated approximately 25° to 200° C. higher than if the outer coil  30  is not in such a configuration relative to the housing  12 . Additionally, a spacer  34  which may be ceramic is positioned at the distal end of the coils  28 ,  30  proximate the gas exit port  16 . The spacer  34  increases the useful life of the coils  28 ,  30  and minimizes coil deformation over extended periods of use. 
     Among the advantages provided by a gas heater  10  according to this invention is the increased contact between the gas flowing from the entry port  14  to the exit port  16  with the coils  28 ,  30 . For example, the coils  28 ,  30  may be similarly wound or wound in opposite directions as shown in  FIG. 7 . Gas flowing through the housing  12  passes between the coils  28  and  30 . Additionally, gas flowing between the adjacent turns  28   c ,  30   c  of the respective coils  28 ,  30  flows in a riffling or spiraling configuration as schematically shown in  FIG. 7  with flow paths  28   e  and  30   e . The wire of the coils  28  and  30  are composed of bare wire which can be defined otherwise as having a solid or monolithic cross section or as being unclad or having no coating or insulation. Such composition is illustrated by wire cross sections  28   f  and  30   f  in  FIG. 7 . The bare wire of the coils  28  and  30  is generally continuous forming one circuit operating in series. The coils  28  and  30  are wound in a round configuration as opposed to an oval or non-round shape found in the prior art. With the windings of the respective coils  28 ,  30  being in opposite direction, increased mixing of the gas with the coils  28 ,  30  is provided to obtain a more turbulent gas flow. This arrangement provides for increased thermal transfer from the heated coils  28 ,  30  to the gas relative to prior art industrial gas heating systems. 
     The range of gap spacing between the adjacent turns  28   c ,  30   c  of the wires  28   a ,  30   a  in the coils  28 ,  30  is between about 35 mm and about 85 mm with the presently preferred being about 40 mm for the inner coil  28  and about 65 mm for the outer coil  30 . 
     A further embodiment of an industrial heater  10  according to this invention is shown in  FIG. 8  and is adapted to generate super heated steam. Traditionally, boiling water at high pressure and then heating the steam at high pressure have produced super heated steam. The embodiment of  FIG. 8  provides a device where the flow of hot air over an orifice causes a super saturated steam jet. Components of the industrial heater and steam generator  200  shown in  FIG. 8  that are the same or similar to corresponding components of the heater  10  as shown in  FIGS. 4-6  are labeled in a similar manner. The words “superheated”, “supersaturated” and variations thereof are interchangeable. Superheated steam for the purposes of this specification is steam at less than 100° C. at 1 atmosphere or at high pressures greater than 1 atmosphere. It also encompasses H 2 O in the form of gas at any temperature. Although we use the word steam to illustrate making H 2 O gas or vapor we anticipate with this word any embodiment for the conversion of any fluid to a gaseous state with our apparatus and method. The word supersaturated steam is used to indicate H 2 O or other materials in the form of gas at temperatures above 100° C. at pressures of about 1 atmosphere and/or higher. By supersaturated steam we also infer H 2 O in the form of vapor. One objective of this aspect of this invention is to make supersaturated steam at 1 atmosphere; whereas, it normally takes high pressure to make supersaturated steam. Although we use the word steam to illustrate making H 2 O gas or vapor we anticipate with this word any embodiment for the conversion of any fluid to a gaseous state with our apparatus and method. We also intend to use the words superheated and supersaturated interchangeably. 
     The superheated steam generator  200  includes a gas inlet source  202 , which may be pressurized or unpressurized, and a power cord grip  204  proximate a gas inlet  206  of the device. A manifold housing  208  is mounted on the gas entry end of a casing  210  that is generally a right circular tube. An industrial gas heater  10  according to a variety of embodiments according to this invention such as those shown in  FIGS. 4-6  is mounted within the casing  210 . 
     Proximate the gas exit port  16  of the industrial gas heater  10 , a delivery tube  212  is mounted to an end plate  214  of the casing  210 . The delivery tube  212  is in communication with a fluid reservoir or cup  216  which may be a polycarbonate reservoir. The delivery tube  212  advantageously includes a venturi assembly therein. A supply or feed line  218  from the reservoir  216  is regulated by a needle valve  220 , the operation of which is well known by those of ordinary skill in the art. The valve  220  may be either mechanical, electromechanical, semiconductor, nano valve, needle valve, self regulation condition by water level or any other commonly understood regulating device with or without feedback. The feed line  218  is coupled to the delivery tube  212  as shown in  FIG. 8 . The supply feed line  218  may be stainless steel piping or other appropriate material. The delivery tube  212  feeds into a reactor vessel  222  having a generally bulbous configuration. Contained within the reactor vessel  222  is a porous medium  224  such as steel wool or other generally non-dissolvable media; however, a dissolvable media may be utilized within the reactor vessel  222 , if appropriate. The porous medium  224  may be made of metallic, ceramic, polymer, intermetallic, nano-materials, or composite materials or combinations and mixtures thereof. The porosity may be reticulated or well defined. The porosity may be even or uneven and may vary from nanometer-size to centimeter sized pores. An exit nozzle  226  is provided on the reactor vessel  222  and may include a diffuser  228 . 
     The liquid to be heated into super saturated steam is contained within the reservoir  216  and fed to the venturi tube through the inlet pipe as regulated by the needle valve. The gas heated by the gas heater passes into the delivery or venturi tube  212  that is connected to the liquid reservoir  216 . As the hot gas passes through the venturi tube  212 , it draws the liquid from the reservoir  216 . The liquid flow as previously stated is controlled by the needle valve  220 . The liquid is atomized in the venturi tube  212  and the liquid/gas mixture enters the reactor vessel  222  where the liquid is vaporized. The unique design of the reactor vessel  222  provides for total vaporization of the liquid. The vaporized fluid exiting the reactor vessel  222  may be re-circulated through the superheated steam generator  200  and introduced into the gas inlet  202 . Furthermore, the apparatus and method of this invention may produce steam by the addition of H 2 O through one or both of the coils in the gas heater  10 . This introduction of the H 2 O may be at the inlet, outlet or in-between the gas passage and the H 2 O may be added in the form of a liquid, gas or mist. 
     We have noted that the position of the valve  220  influences the air steam mixture. For example, at 100 ml of water in 462 seconds, a high 40% specific humidity value at 375° C. at about 1.3 cfm of hot air is generated. The relative humidity is estimated to be about 40% at this temperature assuming full compositional scale ideal gas mixing with no mixing enthalpy. Further, at 375° C., a pressure of 22 MPa (i.e., approximately 220 times atmospheric pressure) is needed to initiate condensation of the mixture. Alternatively, cooling the gas to about 110° C. at one atmosphere may be required to initiate condensation on account of high surface energy. Thus, under cooling and nucleation may be problems that are overcome by the use of superheated steam presented in this application. Specific humidity is defined as the mass of H 2 O divided by the mass of air. 
     Steam temperature depends on the water valve  220  setting and air inflow setting. Typical settings at a full power of 1 kW for the gas heater to are as follows: gas at 1.45 CFM and water at 200 ml in 45 minutes yields steam air temperature of approximately 350° C. Gas at 1.4 CFM and water at 200 ml in 20 minutes yields steam air temperature of about 250° C. Further, gas at 1.8 CFM and water at 200 ml in 20 minutes yield steam air temperature of about 150° C. The above examples utilize a gas inlet temperature at approximately 30° C. and the water inlet temperature at approximately 30° C. 
     A superheated steam generator  300  in accordance with another embodiment of the invention is illustrated in  FIG. 9 . The superheated steam generator  300  is similar to the superheated steam generator  200 , and thus only the differences between the two will be described in detail. Similar reference numerals will refer to similar features as shown in  FIG. 8 . In this embodiment, the use of a venturi to draw the working fluid from fluid reservoir  216 , and the use of the reactor vessel  222  may be eliminated. Instead, and in one embodiment, a pump  302  may be used to actively supply the working fluid to the superheated steam generator  300  from a fluid reservoir  304 . For example, the pump  302  may be a peristaltic pump having the necessary controls for selectively metering the flow rate of the working fluid (e.g., water) to the superheated steam generator  300 . Such peristaltic pumps are commercially available. Other arrangements for supplying the working fluid to the superheated steam generator  300  are also within the scope of the invention. By way of example, a passive arrangement (shown in phantom in  FIG. 9 ) may be utilized wherein the fluid reservoir  304  (e.g., water bag, cartridge, etc.) supplies the working fluid to the heater and steam generator  300  through gravity, for example, or other passive means. In such an embodiment, the reservoir  304  may include appropriate valving  305  (e.g., drip chambers, clips, etc.) for metering the flow of the working fluid to the superheated steam generator  300 . Another modification to superheated steam generator  300  is the inclusion of an outer jacket housing  306  that defines a chamber  308  about at least a portion of the casing  210  having an inlet  310  for receiving the working fluid from pump  302  via a suitable conduit  312 , and an outlet  314  in fluid communication with delivery tube  212 . While the outer jacket housing  306  is shown adjacent the outlet side of the superheated steam generator  300 , the housing  306  may be located along other portions of the heater and steam generator. 
     In operation, the pump  302  or other active or passive supply device supplies the working fluid from the reservoir  304  through conduit  312 , through inlet  310 , and into the chamber  308  defined by housing  306 . The heater  10  heats the casing  210  sufficiently to preheat the working fluid contained in chamber  308  to near or at its saturation temperature (e.g., boiling point). Thus, saturated liquid, saturated vapor or both may be present in chamber  308 . Similar to the previous embodiment, the fluid in chamber  308  then flows into the delivery tube  212  where it mixes with the heated gas exiting gas heater  10 . The heat from the gas causes the working fluid introduced from chamber  308  to become superheated. In one embodiment, the working fluid is water and the superheated steam generator  300  generates superheated steam. Other working fluids, however, may be used in accordance with aspects of the invention as mentioned above. The end of the delivery tube  212  may include a threaded portion for coupling to various exit nozzles  228  that facilitate directing the superheated vapor-gas mixture (e.g., steam-air mixture) toward various items  230 . 
       FIG. 10  describes an alternative embodiment of the pressurized point-of-use superheated steamer  400  of the present application. The means of pressurization for this embodiment comprises a series of steps, with each step comprising a pressure vessel and a one-way valve, rather than an apparatus such as a compressor. The generation of superheated steam, and the kinetic energy contained therein, are used themselves to increase the pressure of the superheated steam to desired levels for application. This embodiment comprises a superheated steam assembly  2  and a series of pressure vessels  9  and one-way check valves  13  that step-by-step build up the pressure of the steam. A water supply (not pictured) supplies water or other liquids directly to the superheated steam generator  200  or  300  found in the superheated steam assembly  2  for this and all other embodiments. Also, for all embodiments it is envisioned that the superheated steam generator  200  or  300  may be employed without being contained within a steam generator housing  11 . 
     The embodiments of  FIGS. 10-12  comprise a superheated steam assembly  2 , which generates steam at one atmosphere, connected to a one atmosphere one-way valve  13   a  which in turn is connected to a P1 pressure vessel  9 - 1  designed to contain a pressure P1 which is greater than one atmosphere. The P1 pressure vessel  9 - 1  is connected to a P1 one-way valve  13 - 1  that is connected to a P2 pressure vessel  9 - 2  which is designed to contain a pressure of P2, which is greater than P1. The P2 pressure vessel  9 - 2  is then connected to a P2 one-way valve  13 - 2  which in turn is connected to a Pn pressure vessel  9 - 3  with the pressure Pn being greater than P2. Vessel  9 - 3  terminates in an application control valve  13 - 3  and is the last of the pressure vessels, and holds the greatest pressure in the series of vessels and valves. Each pressure vessel and the following one-way check valve represent a step in a series designed to incrementally increase the pressure of superheated steam using the heat and kinetic energy of the superheated steam itself. 
     In this application, a pressure above 1 atmosphere is represented by the letter P. The number following P indicates a level of pressure, with a higher number indicating a higher pressure and the highest pressure being represented by the lower case letter n (Ex.: P1, P2, P3 . . . Pn, where P1 is the lowest pressure and Pn is the highest). 
     Each of the one-way valves acts as a check valve allowing a specific lower pressure from upstream to enter a pressure vessel but preventing higher pressure located downstream from flowing back into a lower pressure chamber. For example, superheated steam generated by the superheated steam assembly  2  would be permitted to enter the P1 pressure vessel  9 - 1  through valve  13   a . However, the valve  13   a  would prevent P1 pressure steam in vessel  9 - 1  from flowing back into the superheated steam assembly  2 . Steam in vessel  9 - 1  could flow through valve  13 - 1  only when the steam reaches a pressure of P2 and valve  13 - 1  allows it to pass. This process is repeated for each successive step-up in pressure as the steam passes through the series of one-way valves and pressure vessels until a desired steam pressure is reached and the steam is applied. 
     A means of application  7  is connected to the application control valve  13 - 3 , with such valve permitting the steam to flow to the means of application  7 , allowing for the application of superheated steam. The means of application may be a hose and nozzle assembly  8  or a pressure vessel  9 , but is not to be limited by these examples. An external heat supply  450  may be optionally used with any or all of the pressure vessels to maintain or increase the temperature of the superheated steam if needed. It is anticipated that more or fewer pressure vessels and one-way check valves may be used, depending on the level of pressure that is desired. It is also anticipated that the pressure vessels and one-way check valves may be in any increment needed for the specific application. It is further anticipated that the superheated steam may be generated by the superheated steam generators  200  or  300  which utilize the coil-in-coil industrial gas heater  10  described in the present application, but not limited to generation by them. Other means to generate superheated steam are thereby anticipated as well. 
     In operation this embodiment  400  works as follows: One atmosphere superheated steam is generated by a superheated steam assembly  2 . The one atmosphere superheated steam contains high internal energies, including kinetic energy which moves the one atmosphere steam through the one atmosphere one-way valve  13   a  and into the P1 atmosphere pressure vessel  9 - 1 . As more one atmosphere steam enters the vessel  9 - 1  the pressure in it increases until it reaches a pressure of P1. The P1 steam seeks an exit, and since the valve  13   a  prevents the steam from flowing back through it upstream, the superheated steam exits through the P1 one-way valve  13 - 1  and enters the P2 pressure vessel  9 - 2 . As before, superheated steam accumulates in the vessel  9 - 2  until a pressure of Pn is reached. When Pn is attained the steam passes through valve  13 - 2  into the Pn pressure vessel  9 - 3  where, in turn, the superheated steam accumulates at the final pressure of Pn. After accumulating to a usable amount at pressure Pn, the Pn one-way valve allows the superheated steam to be released to a means of application  7  and directed to desired surfaces and objects. It is also envisioned that the superheated steam could be released and applied immediately from vessel  9 - 3  at pressure Pn via a means of application  7  rather than allowing the steam to accumulate in vessel  9 - 3 . Likewise, vessel  9 - 3  could act as the pressure vessel  9  used as a means of application in which items are placed for superheated steam treatment. Such an apparatus and process may be used with more or fewer one-way valves and pressure vessels or one-way valves and pressure vessels rated at lower or higher pressures. The step-ups in pressure could therefore be fewer or greater and could have different incremental values depending on the needs of the application. 
     During this process the superheated steam assembly  2  is generating and providing to the series of valves and vessels a constant flow of superheated steam that allows the steam to accumulate in the various pressure vessels and build up to the desired pressures. If, during this process, external heat is needed to keep the superheated steam at desired temperatures an optional external heat supply  450  may be used at any location in the series of pressure vessels. The step-up in pressure can be accomplished under the P sat /T sat  curve. This would represent a savings in power necessary to attain desired pressures. 
     As with previous embodiments, this embodiment is safer, more efficient and more economical than the prior art Minimal piping is required between the superheated steam generator, pressure vessels, valves and means of application requiring less maintenance. The materials and design need only be sufficient for safety at particular stages for particular pressures. An expensive high pressure system need not be fabricated for the entire apparatus. A safer method of pressurizing steam is provided due to constant pressure relief through the valves and an initial generation of superheated steam at one atmosphere. Less water and power is needed making the apparatus more economical and efficient. Such a device also takes up less space and could be portable. Ease of use would require less training for operators as well. 
     Other features are contemplated with all embodiments described in the application and may be added when needed. These features include, but are not limited to pressure relief valves, pressure gauges or sensors, drains, integral water source, integral power source, power cut-off switch, water supply piping, heat shielding and insulation. Also, the embodiments will be able to use different combinations of fluids (not only water) to produce superheated and pressurized vapor. 
     Also, it is anticipated that with all embodiments various assemblies and parts of these assemblies such as pressure vessels, means of pressurization, air compressors and parts including piston rings, valves, piping and means of application could be coated or comprised of antimicrobial and/or enhanced emissivity materials or nanostructures when desired. Such materials are described in U.S. patent application Ser. Nos. 12/516,183 and 12/092,923, which are both incorporated by reference in their entireties, wherein the materials are composed of nanoparticles which comprise at least one of: silver, tungsten, iron, carbon, aluminum, copper, nickel, iron, SiC, SiO 2 , an oxide of at least one of nickel, iron, tungsten, or chromium, Cu, Ag, Au, Pt, Pd, Ir, a rare earth metal, a semiconductor, B, Si, Ge, As, La, Sb, Te, Po, an iron oxide, a tungsten oxide, a chromium oxide, V 2 0 5 , Fe 2 0 3 , FeOx, Fe 3 0 4 , aluminum oxide, NiO, zinc oxide, tin oxide, hafnium carbide, tungsten carbide, MnO 2 , SiO 2 , MoO 3 , HfO 2 , WO 3 , TiB 2 , CrO 3 , Nb 2 O 5 , Al 2 Zr, B 4 C, SiO x , ZrSi04, B 2 0 3 , CdS, MnS, MoS 2 , MoSi 2 , MoSi x , NaN 3 , NaCN, Si 2 N 4 , Si 3 N 4 , PbO, PbO 2 , WO 2 , BaO 2 , SiO 2 , NiFe y O x , MoS x , Fe z NO x , and a further defect compound, where x, y, and z represent non-integer values, or at least one of an oxide, a carbide, a nitride, an aluminide, a boride, a silicide, or a halide of at least one of Cu, Ag, Au, Fe, Si, Ti, Hf, Pt, Pd, or Ir. Coatings of these materials could reduce the antimicrobial levels in the water used and the steam produced reducing the possibility of corrosion and bacterial, biofilm and other undesirable microbial growth. The emissivity of the pressure vessels could be improved by a coating of the materials described in Ser. No. 12/092,923 allowing them to be heated externally with greater efficiency. 
     The above descriptions provide examples of specifics of possible embodiments of the pressurized point-of-use superheated steam generation apparatus and should not be used to limit the scope of all possible embodiments. Thus the scope of the embodiments should not be limited by the examples and descriptions give, but should be determined from the claims and their legal equivalents.