Abstract:
The present invention relates to a hand held device for producing large volumes of smoke from a smoke producing solution. The design allows for repeated, fast, and lengthy heating of the heating chamber, and thus is an improvement over prior devices which can only be utilized in short bursts.

Description:
[0001]    This application claims priority of U.S. provisional application No. 61/255,998 filed on Oct. 29, 2009 and is included herein in its entirety by reference. 
     
    
     COPYRIGHT NOTICE 
       [0002]    A portion of the disclosure of this patent contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention relates to aerosol generation and, in particular, to a device that is useful for the production of high volumes of non-toxic simulated smoke for industrial use, military use, and the like. 
         [0005]    2. Description of Related Art 
         [0006]    The generation of a synthetic smoke has been used by the military during combat and training exercises. In addition, it is used by fire departments and police departments for their needs. On the industrial side, theater and motion picture companies frequently use synthetic smoke to simulate smoke for special effects. Typically, these larger uses involve passing a pressurized, smoke producing liquid near a heat source which vaporizes the liquid into a smoke gas. Usually non-toxic, the formulations can be oil or water based depending on the use and the desired effect. The heat source is usually either battery powered or a flame powered by an ignitable gas, such as liquid propane gas (LPG). The smoke producing liquid is usually pressurized by use of some gas that is inert in the process, such as air nitrogen or the like. 
         [0007]    In use, the heating source is heated to a given temperature and then the pressurized, smoke producing liquid passes near the heat source vaporizing before exiting a spray or atomizing nozzle of some sort. Because the vaporization of the smoke producing liquid drains heat energy from the heat source, the problem that exists with these devices is that they can only be used for relatively short bursts since heating the liquid also cools the heat source. This is especially true with battery operated heat sources, and even gas fired heat sources have limited capacity to heat before cooling. In addition, smoke generators typically have limited operational capacity for smoke producing liquid prior to replacing the source or refilling them with additional fluid. An example of a device with such problems is exemplified in U.S. Pat. No. 4,998,479 to Perham et al., issued Mar. 12, 1991 which uses a gas burner in an ignition chamber and discharges the smoke generating gas through a heating coil having about 4 turns. The device has limited capacity for gas generating liquid and is only operable for short bursts before cooling below the vaporization temperature of smoke producing liquids since the heat chamber cools very quickly. In addition, the device cannot generate a dense, thick cloud of smoke as is necessary for many industrial uses. A further problem with this and other devices where an ignition spark ignites a gas, is that ignition is very haphazard and igniting the gas can take several tries leading to a dangerous explosive situation if too much gas accumulates in the ignition chamber before the gases ignite. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    It has been discovered that venting the ignition chamber to the rear of the chamber allows for the chamber to not vent gasses to the side and increases the retention of heat during use. Even further, by including a spark capture tube, ignition is insured on the first try by capturing gas and regulating where the spark is generated. The present device is essentially self contained and maintenance free. The device can be made to be stand alone, dependent external propellant or fuel, or run both ways. 
         [0009]    Accordingly, one embodiment of the invention relates to an aerosol device capable of generating smoke comprising:
       a) a base portion for handling the device during use;   b) a heating chamber for vaporizing a smoke producing solution having an inlet side and a smoke outlet side the chamber comprising a fuel ignition chamber, one or more combustion gas exit pipe vents on the inlet side or exterior side for the release of combustion gas from the heating chamber, the chamber otherwise sealed for the release of the combustion gas and connected to the base portion;   c) a smoke producing solution pressurized by a propellant for the solution, operatively connected to the base and capable of delivering the smoke producing solution to coiled tubing positioned within the heating chamber and around the ignition chamber wherein the coil is operatively connected to an exit nozzle which is capable of dispersing the smoke producing solution once it is vaporized in the heating chamber; and   d) a fuel attached to the base and operably connected to the heating chamber for delivery of the fuel to the ignition chamber for ignition.       
 
         [0014]    Another embodiment relates to an ignition system for lighting a gas fuel in a chamber comprising:
       a) one or more hollow gas collection ignition tubes for positioning within the chamber at least a portion of the side of the tube open to receive gas fuel within the chamber; and   b) an electric spark igniter corresponding to each hollow tube, the tip of each igniter positioned within the open side portion of the corresponding tube.       
 
         [0017]    Yet another embodiment relates to an aerosol device capable of generating smoke comprising:
       a) a base portion for handling the device during use;   b) a heating chamber for vaporizing a smoke producing solution having an inlet side and a smoke outlet side the chamber comprising one or more combustion gas exit vents on the inlet side or the heating chamber side for the release of combustion gas from the heating chamber, the chamber otherwise sealed for the release of the combustion gas and connected to the base portion;   c) a smoke producing solution pressurized by a propellant for the solution, operatively connected to the base and capable of delivering the smoke producing solution to a coiled tubing positioned within the heating chamber wherein the coil is operatively connected to an exit nozzle which is capable of dispersing the smoke producing solution once it is vaporized in the heating chamber; and   d) a heater for heating the heating chamber to a temperature that will vaporize the smoke producing solution in the coil.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a right side elevational view of the aerosol generator and delivery device of the present invention. 
           [0023]      FIG. 2  is a top plan view thereof. 
           [0024]      FIG. 3  is a fragmentary left side elevational view of the generator. 
           [0025]      FIG. 4  is a fragmentary view showing the fuel cutoff valve in the on position. 
           [0026]      FIG. 5  is a top plan view with the frame housing removed and a partial cutaway of the aerosol generation portion of the aerosol generator and delivery device. 
           [0027]      FIG. 6  is a right side elevational view with the frame housing removed and showing a partial cutaway view of the aerosol generation portion of the aerosol generator and delivery device. 
           [0028]      FIG. 7  is an exploded view of the heating chamber that generates the aerosol. 
           [0029]      FIG. 8  is a side elevational view of the aerosol generator and delivery system of the present invention with a ram attachment mounted thereon. 
           [0030]      FIG. 9  is a top plan view of the ram attachment. 
           [0031]      FIG. 10  is a bottom plan view thereof. 
           [0032]      FIG. 11  is a front elevational view of such ram. 
           [0033]      FIG. 12  is a perspective view of backpack mounted propellant, solution and fuel tanks. 
           [0034]      FIG. 13  is a front elevational view of the user of the aerosol generator and delivery system of the present invention with the backpack inlet lines connected to such generator. 
           [0035]      FIG. 14  is a front perspective view of the recharging station used in conjunction with the present invention. 
           [0036]      FIG. 15  is a close-up front perspective view of such stations. 
           [0037]      FIG. 16  is a perspective view of the recharging station with the aerosol generator resting thereon. 
           [0038]      FIG. 17  is a top view of  FIG. 16 . 
           [0039]      FIG. 18  is a front and side perspective view of a spark igniter positioned in a gas collection substitute tube drawing. 
           [0040]      FIGS. 19 ,  19   a ,  19   b  and  19   c  depict an exploded view and assembled view of an exit nozzle having single and multiple exit holes and a check valve. 
           [0041]      FIG. 20  is a perspective view of the air flow channel in larger view than  FIG. 7 . 
           [0042]      FIG. 21  is a view of the ceramic insulators used in the heating chamber. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0043]    While this invention is susceptible to embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure of such embodiments is to be considered as an example of the principles and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of the drawings. This detailed description defines the meaning of the terms used herein and specifically describes embodiments in order for those skilled in the art to practice the invention. 
       DEFINITIONS 
       [0044]    The terms “a” or “an”, as used herein, are defined as one or as more than one. The term “plurality”, as used herein, is defined as two or as more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. 
         [0045]    Reference throughout this document to “one embodiment”, “certain embodiments”, and “an embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments without limitation. 
         [0046]    The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps, or acts are in some way inherently mutually exclusive. 
         [0047]    The drawings featured in the figures are for the purpose of illustrating certain convenient embodiments of the present invention, and are not to be considered as limitation thereto. Term “means” preceding a present participle of an operation indicates a desired function for which there is one or more embodiments, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent in view of the disclosure herein and use of the term “means” is not intended to be limiting. 
         [0048]    As used herein the phrase “aerosol device capable of generating smoke” refers to a device which can atomize or vaporize a liquid to a gaseous state by rapid heating and discharging the atomized gas to the surrounding environment. This type of device is capable of generating smoke by use of a smoke generating liquid which, when atomized or vaporized by flash heating, produces a synthetic smoke. Likewise, any liquid that one is desirous of converting to a vapor phase by flash vaporization could be utilized in such a device. The present invention is very useful in producing smoke, so while the majority of information relates to the production of smoke, it is understood that other products could be vaporized instead of or with the smoke producing liquid that generates smoke in the device. 
         [0049]    As used herein a “smoke producing solution” refers to liquids which, when vaporized in a heat based smoke generating machine, create an artificial smoke. These liquids can be either water or oil based and depending on their particular use can be chosen for their opaqueness, their persistence or lack of persistence or the presence or lack thereof of residual particulate matter. Examples of such liquids (but not limited thereto) include propylene glycol, glycerin, mineral oil, shell ondina oil, and dipropylene glycol. Other ingredients may also be included in the smoke liquids including diluents, such as water, as well as other active ingredients. Secondary ingredients or additives, such as chemicals for dispersion in crowd control (e.g. pepper spray), chemicals for medical treatment or control in a military, other like situations, or for that matter any item to be dispersed quickly in an aerosol manner can be included in the smoke liquid for dispersion by use of the present invention device. One skilled in the art, given this disclosure, could easily select additives for inclusion with the smoke producing liquid in view of the compatibility, dispensability, and the like of the particular additive used in the present invention device. The smoke producing solution can be contained in a canister attached directly to the base, or in other embodiments it can be in a canister or large tank separate from the base, for example, in a backpack or on a floor mounted unit if even larger. It is usually added in a non-pressurized condition so screw fittings and the like can be used to place a cap on the container. 
         [0050]    The smoke procuring solution is delivered to the heating chamber via tubing or the like. Within the heating chamber the tubing is coiled to increase the surface area exposed to heat. In one embodiment, the coil winds are tightly wound (touching) and in other embodiments there are 6 or more, 12 or more, or 18 or more coil turns to the tubing before exiting the heating chamber. The tubing, upon exiting the chamber, makes use of a nozzle fitting to control the exiting vapors. A single hole nozzle is standard in the art for smoke generators. However, in one embodiment a novel nozzle has multiple holes to maximize the pattern and can also be fitted with a check valve to prevent back flow. 
         [0051]    As used herein, the term “fuel” refers to a burnable substance for delivery to the heating chamber for the purpose of burning the fuel and heating the chamber. This can be a solid, liquid or gas type fuel, as desired, and one skilled in the art can deliver either of these to the heating chamber. In one embodiment the fuel is propane (LPG) or natural gas, which under pressure delivers a gas to the heating chamber. It is clear that other heating sources can be used in the heating chamber. In other embodiments the heat is provided by an electrical heating element. This, in some embodiments, is a battery or electric operated metal, ceramic, or the like, which heats up to a desired temperature upon placing an ac or dc current across the element. Typically, the temperature desirable for the heating chamber is from about 800 to about 1600 degrees Fahrenheit. For example, LPG burns at about 1200 degrees F. The fuel can be contained in a canister and in most embodiments is attached to the base wherein the canister can be refilled or replaced as necessary. It could of course be separate from the base as is the case with propellant and smoke producing solutions. 
         [0052]    As used herein, the term “propellant” refers to a gas or other material added to the smoke producing solution so that the solution will travel from where ever it is stored to the heating chamber and out the present invention as smoke. Typical propellants for these solutions include air and nitrogen, though any propellant compatible with the device and the surrounding conditions could be used. In one embodiment the propellant is a vacuum pulling the smoke producing solution to the desired location. Where the fuel needs pressurization, the propellant, either the same or different from the propellant used for the smoke producing solution, could be used to assist the fuel in reaching the heating chamber. The smoke producing solution can be prepressurized, but in one embodiment of the present invention the propellant is in a separate container and delivered to pressurize the smoke producing solution as needed. The propellant can be contained in a canister attached directly to the base or in other embodiments it can be in a canister or large tank separate from the base, for example, in a backpack or on a floor mounted unit if even larger. 
         [0053]    The present invention has two basic parts, a base portion and a heating chamber. The base portion is designed to attach things that need or can be kept cooler and to handle the device during use while the heating chamber side is designed to be brought to a temperature that can vaporize the smoke producing solution delivered to the heating chamber. The “heating chamber” can be either heated by a fuel or an electric heating element as described above. The heating chamber will have an inlet side where the smoke producing solution enters the chamber and an outlet side where the smoke exits. 
         [0054]    A heating chamber has several elements to it. Two elements that will be in the heating chamber, regardless of how the chamber is heated, are any gases generated from the combustion of fuel or the heating process will not be vented directly out the side of the unit, rather out the inlet side or through side tubes. To release the gases in the chamber in this manner, the chamber is essentially sealed in all directions except for the inlet side which comprises one or more exit vents or tubes positioned in the side. The vents can be any type and positioned around the inlet side of the chamber. They can be of mixed types but sufficient to remove venting gas without substantially allowing heat to be released from the chamber (inlet side or side tubes). One type of vent in the inlet side would be a hollow exhaust pipe or a tube stuck on the outside of the inlet side in communication with the interior of the chamber. Yet another type would be a combustion gas tube placed in the chamber to collect combustion gas and then deliver the gas to the inlet side of the chamber and out of the chamber. Both embodiments can be seen in the drawings and examples which follow. A type of side tube can be seen in the drawings for gathering gas and delivering it out the side by creating an indirect pathway, thus trapping heat but releasing gas. The chamber can be sealed by using insulating material the frame tubing used, or any means that substantially seals the chamber except for exhaust vents to the release of the combustion gases. Of course, it must be sealed in a manner that retains the heat in the chamber as best as is possible, as well. Therefore, use of insulators, ceramics, mantles, and the like can be used. One particular embodiment is shown in the drawings which follow, but clearly other embodiments could be designed in view of the disclosure herein for heating the heating chamber. 
         [0055]    Where a fuel is to be ignited in the heating chamber a “spark generator” can be used for igniting the fuel. Spark generators are generally used in the ignition of gasses. Usually they are a metal conductor, sometimes wrapped in a ceramic (a ceramic igniter) and when an electrical current (ac or dc) is applied, a spark travels from the tip of the igniter to a nearby piece of conductive material. An ignition button is positioned on the base portion or elsewhere to engage the igniter for igniting the fuel. In one embodiment there are 2 or more igniters to insure first time ignition especially when used in conjunction with a gas collection ignition tube. Such a gas collection tube is a hollow tube with a portion of the side of the tube removed so that gas can collect within the open side area of the tube. (See the drawings for an example.) The tip of the spark generator can be positioned roughly in the center of the area and since fuel accumulates in the tube open area, it is likely that ignition will occur every time. Once again, a plurality of these tubes can be used to further insure a first time lighting of the fuel. Note where desired, an air inlet including a choke (means to adjust amount of air mixture) may be necessary to ignite the gas. Obviously, while the heating chamber is sealed the air is important to keep the fuel ignited. 
         [0056]    The “base portion” is attached to the heating chamber in a convenient manner. In one embodiment there is an insulating material in-between the base and the heating chamber. It is possible that there is a portion of the heating chamber that exists outside the chamber itself, such as the exit vents, the choke, and the like, for purposes of this invention that is still part of the heating chamber. Note, for example, where the insulator is in the drawings. In one embodiment the insulating material is an alumina silica ceramic, such as Alphabond 2300 from Thermal Ceramics. Other materials could also be used and one skilled in the art could chose those insulators in view of the teaching herein. The base portion is designed for mounting tubing, filters, buttons, valves, handles, on/off buttons, wires, canisters (if small enough), gauges, check valves, over flow valves, inlet valves for filling the device, or any part or means that benefits from being attached to the cool part of the device, or the like. 
         [0057]    It should be noted that in some embodiments the base is made of aluminum and tubing, fittings and the like are made of stainless steel, niconel or the like, however, selection of other heat resistant materials is within the skill in the art in view of this disclosure. 
         [0058]    Now referring to the drawings, the Figures will be discussed collectively since understanding of the invention is aided by referring back and forth to the various perspectives of the present invention. In some drawings, the covers on the base are removed and in others the covers are in place. The aerosol generation (including smoke generation) and delivery device of the present invention, indicated generally at  10 , includes a base  11  formed from a lightweight material, such as aluminum. The base and other parts of the invention can be left natural or colored, such as by aluminum coatings like anodizing. Fixedly mounted on one end of base  11  is a vertically disposed, channel shaped rear guard  12 . An electrical pulse generator  13  is mounted on the rear guard  12  with an ignition button  14  rearwardly projected therefrom as seen clearly in  FIG. 5 . 
         [0059]    A fuel canister  15 , aerosol creating solution canister  16 , and propellant canister  17  are all vertically mounted to the bottom of base  11  and outwardly project therefrom. 
         [0060]    A front base plate  18  is fixedly secured to base  11  by means such as bolts  118 . An upper and two side heating chamber mounting rods  19  are secured to front base plate  18  by nuts  19   a  and outwardly project therefrom. The mounting rods  19  also display heat cooling fins  19   b  which aid in dissipating heat. On the outer end of chamber mounting rods  19  is an outlet side heat chamber cap  20  that is held in place by nuts  19   a . Mounted on the heat chamber mounting rods  19 , intermediate the front base plate  18  and the outlet side heat chamber cap  20 , is inlet side heat chamber cap  21 . 
         [0061]    An igniter  24  passes through inlet side heat chamber cap  21  and is mounted thereon; it is hidden behind igniter heat shield  24   a . It should be noted that two or more igniters can be used to add redundancy to the ignition process. The igniter  24  also passes through inlet side heat chamber cap  21  with the end thereof being disposed in the burner chamber of the heating chamber  160 . The electrical pulse generator  13  is connected to igniter  24  by way of wire  26 . 
         [0062]    When the ignition button  14  is pushed, the electrical pulse generator will send an electrical pulse through wire  26  to the dual ignition  24  which will cause a spark to be created at the tip  25  of both igniters. Since electrical ignition systems of this type are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
         [0063]    Fitting  27  is mounted on base  11  and communicates with the interior of fuel canister  15 . Fuel line  28  is communicatively connected at one end to fitting  27  and at the other end to fuel filter  28   a  (not shown but inside fuel canister is a check valve) and then in turn to fuel cutoff valve  29 , which is also mounted on base  11 . Fuel line  28  is connected between cutoff valve  29  and the inlet side of fitting  30   a  mounted on base  11 . The outlet side of fitting  30   a  is connected to one end of fuel line  31  with the other end being connected to the gas burner, indicated generally at  160 . 
         [0064]    An air mixing orifice housing  33  forms part of the gas burner  160 . An air control sleeve  34  is longitudinally mounted on air mixing orifice housing  33 . A shoulder  34   a  is provided on the rear portion of control sleeve  34  with a coil spring  35  disposed about the exterior of the sleeve between the rear of the front base plate  18  and shoulder  34   a  to bias the sleeve rearwardly. 
         [0065]    An air flow adjuster lever  36  is fixedly secured to the upper portion of sleeve shoulder  34   a  at one end and has a manipulating handle  37  at the opposite end thereof as can clearly be seen in  FIG. 6 . 
         [0066]    A fuel quick connector coupling  38  is mounted on the right side of base  11 . This connector is communicatively connected to fuel line fitting  30  as indicated. 
         [0067]    A propellant quick connector nipple  40  is mounted on elbow  43 . Fitting  41  connects to base  11  and communicates with the interior of propellant canister  17  and with elbow  43 . The inlet end of flexible line  44  is connected to the lower end of a fitting. At the bottom of the loop in flexible line  44  is a solution inlet orifice  45 . A one way check valve  46  is provided in flexible line  44  above orifice  45  to allow propellant and the solution picked up through orifice  45  to pass in the direction of arrow  47  while preventing flow in the opposite direction. 
         [0068]    Flexible line  44  passes from check valve  46  into fitting  48  mounted on base  11 . Fitting  48  operatively connects line  49  to a fitting for further distribution of propellant and solution. 
         [0069]    An internal passage within base  11  communicates between propellant solution and quick connect coupling  57 . A line connects trigger activated valve  54  (with trigger  54   a ). This valve  54  is in turn operatively connected to line  55  at one end with the other end being connected to coil inlet  56 . 
         [0070]    A fuel quick connector nipple  58  is mounted on fitting  58   a  which is mounted on base  11  and communicates with the interior of fuel canister  15 . 
         [0071]    A liquid level gauge  59  is mounted on the left side of base  11  with a tube extending therefrom into the interior of fuel canister  15 . When the canister is being filled through coupling  58  and the liquid level reaches the desired level, this is noted on the gauge  59 . The fueling of the canister can then be stopped. The purpose of this is that safety regulations do not allow the canister to be filled more than 80% full. 
         [0072]    A fuel relief valve  61 , set at preferably 450 psi, is mounted on the left side of base  11  and communicates with the interior of fuel canister  15 . A propellant/solution relief valve  62  is also mounted on the left side of base  11  and communicates with the interior of solution canister  16 . This relief valve is also preferably set at 700 psi. Finally, a propellant relief valve  63  mounted on the left side of base  11  and communicates with the interior of propellant canister  17  and is set at 700 psi. The purpose of the relief valves  61 ,  62  and  63  is to keep the canisters from exceeding a select pressure. Over filling of a cylinder could cause a cylinder to explode, and thus, their presence is a safety factor in using these devices. The pressure relief valves can be fixed pressure or in one embodiment one or more is an adjustable pressure. 
         [0073]    A standard pressure gauge  64  is mounted on base  11  and communicates with the interior of fuel canister  15 . A second pressure gauge  65  is mounted on base  11  and communicates with the interior of propellant canister  16 . 
         [0074]    A screw cap  66  acts as a closer for neck  67  that communicates with the interior of solution canister  16  so that the canister can be filled with solution, such as smoke solution. 
         [0075]    Since the fuel, solution and propellant canisters  15 ,  16  and  17  are of limited capacity, a backpack supply, indicated generally at  68 , is provided in  FIGS. 12 and 13 . A backpack frame  69  has standard adjustable shoulder straps  70  and an adjustable waist strap  71 . Since backpack frames, shoulder straps, and waist straps are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
         [0076]    A propellant tank  72  is mounted on backpack frame  69  by adjustable straps  73 . A standard cut-off valve  74  is mounted on tank  72 . Line  75  communicates between valve  74  and pressure gauge  76 . 
         [0077]    A solution tank  77  is mounted on backpack frame  69  and is held in place by adjustable straps  78 . A valve  79  on solution tank  77  communicates through line  80  to mixing valve  81 . This mixing valve is also connected to line  75  from propellant tank  72 . Mixing valve  81  also communicates with one end of line  82 . The other of this line has a quick connect coupling  83  adapted to be connected to propellant/solution quick connect  57  on the rear portion of base  11  of aerosol generation and delivery device  10 . 
         [0078]    In  FIGS. 14 and 15 , a recharging station, indicated generally at  90 , is used for recharging the pressurized fuel and propellant canisters of the aerosol generation and delivery device  10 . The solution contained within canister  16  is non-pressurized when being filled and the solution is poured into neck  67  after the screw cap  66  has been removed. 
         [0079]    The recharging station  90  includes a horizontal frame  91  with wheels  91   a  rotatively mounted on opposite ends thereof. A vertical frame  92  is secured to horizontal frame  91  at one end with a handle  93  being provided on the other end. 
         [0080]    A propellant tank  94  is mounted on one side of vertical frame  92  and is held in place by adjustable straps  95 . 
         [0081]    A standard tank valve  96  is mounted on propellant tank  94 . One end of line  97  is connected to valve  96  with the other end being connected to a fitting. This fitting communicates with propellant pressure gauge  99 . The fitting is also connected to one end of line  100  with the other end connected to propellant quick connect coupling  101  which can be attached to coupling  40  on generator  10  for filling propellant canisters  16  and  17 . 
         [0082]    Fuel tank  102  is mounted on the opposite side of vertical frame  92  from propellant tank  94  and is held in place by adjustable strap  103 . 
         [0083]    A standard tank cut-off valve  104  is provided on fuel tank  102  and is connected to the LPG connector  105 . One end of fuel line  106  is connected to LPG connector  105  with the other end of the connector being connected to a propane shut-off valve  104 . Line  106  connects to fitting  101  which can connect to nipple  58 . The fitting  101  is out fitted with shut-off valve  110 . Fitting  101 , when connected to fuel quick connect nipple  58 , can be used to fill fuel canister  15  up to 80% when the liquid fuel enters the tube to give a visual reading on site gauge  64 . The refueling process will be stopped at that point. 
         [0084]    The solution canister  16 , which is not pressurized during filling, can be filled through neck  67  after screw cap  66  has been removed as needed. After the solution canister has been filled and the screw cap  66  is replaced, such canister can be charged by the propellant prior to the generation of smoke by the smoke generator  10 . 
         [0085]    A base housing  112  is mounted above base  11  and is secured in place by means such as screws. Exteriorly exposed above base housing  112  is fuel quick connect coupling  58 , fuel pressure gauge  64 , solution filler screw cap  66 , propellant pressure gauge  65 , propellant quick connect coupling  40 , and air flow adjuster lever  36  and its manipulating handle  37  as can clearly be seen in  FIGS. 1 and 2 . 
         [0086]    The air flow adjusting lever  36  passes through longitudinal slot  114  in the base housing  12 . This air flow adjusting lever slot has two L-shaped locking slots  115  and  116  on one side thereof as can clearly be seen in  FIG. 2 . When the air flow adjusting lever  36  is in the position shown in  FIG. 2 , the air control sleeve  34 , against the bias of spring  35 , will be in its most open position relative to the mixing orifice housing  33  of gas burner  160 . When the lever  36  is manipulated by handle  37  and placed in L-shaped slot  115  and is held in place by the bias of spring  35 , sleeve  34  partially closes the air mixing orifice housing  33 . When the lever  36  is in L-shaped slot  116 , the air control sleeve  34  closes off even more of the air mixing orifice housing  33  of burner  160 . 
         [0087]    An insulating plate  117  is mounted between the front base plate  18  and base  11 . The base plate and the insulating plate are held in place by means such as bolts  118  that are threaded into base  11 . 
         [0088]    Insulating plate  117  is made from a material that is commonly referred to as Alphabond 2300 which will eliminate over 70% of the heat that is generated in the heating chamber, indicated generally at  122 , from being transferred to the base  11 . The operation of the heating chamber  122  will hereinafter be described in greater detail. 
         [0089]    In  FIG. 7  we have an exploded view of heating chamber  122  and the air inlet/exit area  150  which is bound by base front plate  18  and inlet side heat chamber cap  21 . 
         [0090]    The area  150  consists of several elements which are visible in other figures but for clarity are shown here in exploded view. Note that this area, among other purposes, is designed to keep the base cool by providing either insulation or cooling function to the heat generated in the heating chamber  122 . It is also designed to be an area for air inlet and for at least some air/heat expulsion. 
         [0091]    The fuel line passes into the air area  150  and reaches the propane orifice  151  where the orifice, modulated by the control sleeve  34 , mixes fuel and air to the desired mixture (note, spring  56  which helps modulate sleeve  34  is not shown but can be seen in  FIGS. 5 and 6 ). This can be valuable when starting the device, i.e. use as a choke mechanism. The fuel line passes through inlet side chamber cap  21  and into the heating chamber  122 . The area  150  is also where combustion gas vent pipes  152  are positioned. The gas vent pipes  152  are positioned in area  150  to aid in removing combustion gases without significantly impacting the heat remaining in the heating chamber  122 . By back venting the gases, the chamber retains more heat than direct side venting (i.e. having a direct side opening for gases to escape), and thus, allows the unit to act more efficiently and retain heat longer. Also, igniter protective housing sleeves  153  insulate and transfer heat away from igniters  24  passing through the sleeves  153  in this area on their way to the heating chamber  122 . 
         [0092]    A mixture of fuel and air are delivered to the heating chamber by mixing orifice  34  and specifically to the inner ignition chamber  160  via opening  34   a . Positioned inside the chamber  160  are gas fuel collection tubes  162 . The gas collection tubes  162 , one for each igniter, help concentrate fuel in opening  163 . By positioning igniter tip  25  in opening  163 , a first time ignition is mostly guaranteed. By utilizing two or more igniters  24 , first time ignition is even further guaranteed. Igniters  24  are left out of  FIG. 7  for clarity, but are shown in  FIG. 18  positioned in a collection tube  162  in larger detail. 
         [0093]    Ignition chamber  160  is then covered with heating mantle  165 . In operation, the air/gas mixture is delivered to ignition chamber  160 , the igniters  24  are engaged and the fuel in the ignition chamber  160  is ignited. Because of mantle  165 , the flame is contained in the chamber  160  as it would be inside a mantle on a gas camping lantern. The mantel  165 , in one embodiment, is a wire mesh made from a material, such as Inconel wire mesh, which will withstand temperatures well above 3000 degrees Fahrenheit. 
         [0094]    Positioned around the ignition chamber  160  is stainless steel coil tubing  170  which contains the propellant/smoke material. It has been found from experience that coils  160  lying in juxtaposition to each other give superior combustion results over coils with fewer turns and/or that are spaced apart. In one embodiment there are 6 coils, in another there are 18 or more coils. 
         [0095]    The heat from the ignition chamber  160  heats the smoke producing liquid to vaporization wherein it exits the coil at  171  before exiting nozzle  173 . Nozzle  173  has an axial opening  174  therein so that smoke created by combustion within coils  170  can be emitted therefrom. (Either single exit port or multiple port, as shown in  FIGS. 19 ,  19   a ,  19   b  and  19   c , can be utilized). In order to further reduce combustion gases, again while minimizing heat loss from heating chamber  122 , exhaust tubes  175  are utilized. The exhaust tubes  175  have exhaust collection ports  176  which are positioned toward the ignition chamber for collecting combustion gas and exit vent  177  for expelling the gas to the atmosphere. As can be seen, a plurality of exhaust tubes  175  are positioned in between the inlet side cap  21  and the outlet side cap  20  at the periphery of those caps. Obviously, the exhaust vent  177  is facing the exterior on a radius with the center of the ignition chamber  160 . These tabs also help retain heat. Also, positioned around the periphery are ceramic panels  182  which then seal the interior of the heating chamber  122  from severe heat loss compared with an open vent to the atmosphere situation. These panels can be made from an inorganic silica binder that will not smoke or produce noxious fumes during initial and subsequent firings. In one embodiment, these panels are made from a material sold under the trade name Alfabond 2300-H, which maintains its structural and mechanical strength and will not burn out. Materials other than ceramic (or other ceramics) could be used if they serve the same function and purpose. In the example of the drawings, 3 pieces of ceramic  182  are utilized and spaced by gas collection tubes  162 , but more or less pieces will be used based on how many, if at all, collection tubes  162  are utilized. Over the ceramic  182  and tubes  175  is placed a heat shield  180 . The shield  180  holds the ceramics  182  in place and further aids in holding heat to prevent or at least slow heat dissipation. The heat shield can be perforated as shown in  FIGS. 1 and 2  in order to allow for combustion gas to escape. The ceramics  182  are shown in  FIG. 21  and left out of  FIG. 7  for clarity purposes. Not shown is an optional heating chamber nozzle burn cover, this over is designed to further retain heat and prevent accidental burns from the heating chamber. In one embodiment, the inner layer is fiber glass insulation, about ¼ to ¾ inches thick, with a center shell of a Kevlar/Nomex material. Other materials could also be utilized and is within the skill in the art. 
         [0096]    Turning back to  FIG. 3  and  FIG. 4 , the fuel valve  29  is shown in the off position in  FIG. 3  while shown in the on position in  FIG. 4 . The fuel valve  29  can also be fitted with a locking means if desired. 
         [0097]    The ram attachment, indicated generally at  137 , as in  FIGS. 8 through 11 , is designed for use in police and military operations to protect the smoke generator during riot control, while flushing fugitives from building enclosures, and the like. 
         [0098]    The ram attachment is composed of a channel member  138  having side walls  139  and a bottom  140 . 
         [0099]    The front of the channel member  138  includes a ring  141  that is secured to the side walls  139  and bottom  140  by means such as weldment. An outwardly projecting concave plate  142  is secured to ring  141  by weldment or other suitable means. This plate has a plurality of openings  143  therein for dissipating heat as well as the upper opening being aligned with the opening  127  in nozzle  125  so that smoke can pass through such plate. 
         [0100]    In the rear portion of the bottom  140  of channel member  138  has a 13-shaped opening  144  therein which allows the propellant canister  15  to project downwardly therethrough as shown particularly clear in  FIG. 10 . 
         [0101]    A plurality of bolts or other suitable securing means  145  pass-through the side walls  139  of channel member  138  as well as through spacers  146  and into base  11  of the smoke generator  10  to firmly hold the ram attachment  137  in place on said generator. 
         [0102]    Finally, a V-shaped canister guard  147  is secured to the bottom  140  of channel member  138  by weldment or other suitable means and downwardly extends therefrom as can clearly be seen in  FIG. 8  and  FIG. 10 . 
         [0103]    The ram attachment  137  can be quickly attached to the smoke generator  10  of the present invention by inserting bolts  145  and tightening the same. The ram attachment can be just as readily removed by simply loosening such bolts and moving the attachment away from the generator. 
         [0104]    To use smoke generator  10  of the present invention as an independent unit, the fuel, propellant and solution canisters must be filled. If the recharging station  90  is used, the canisters  15 ,  16  and  17  are placed on pads as shown in  FIG. 16 . 
         [0105]    The fuel quick connect coupling  101  is placed in operative engagement with fuel quick filling nipple  58 . Valve  104  is opened, as is valve  110 , to allow fuel to flow into fuel canister  15  until it reaches desired full capacity. This is visually seen on site gauge  59 . Valve  110  is then shut off, as is tank valve  104 , and the coupling is disconnected from nipple  58 . 
         [0106]    Screw cap  66  on solution filling neck  67  is removed and liquid solution is poured from a suitable container (not shown) into the neck until the solution canister  16  is full. The screw cap  66  is then replaced. The smoke generator of the present invention is now charged and ready for operation. 
         [0107]    Propellant quick connect coupling  101  is then connected to propellant quick coupling  40  on smoke generator  10 . The propellant tank valve  96  is opened as is valve of coupling  101 . The propellant canister  17  is then filled until the desired pressure is reached. The valves are then closed and coupling  101  disconnected from coupling  40 . 
         [0108]    Handle  37  is adjusted in slot  114  for the proper setting of air control sleeve  34  on the air mixing orifice housing  33  of gas burner  160 . The cut-off valve  29  is now moved to the on position. 
         [0109]    The igniter button  14  is then pushed which will cause the electrical igniter  13  to send an electrical pulse through a wire into igniter  24  which will cause an electrical arc at the tip  25  of the igniter  24 . Since the fuel cut-off valve is open, gas will flow from the canister to the line  28 , to the shut-off valve  29  and then from there through line  31  to burner  160  with the fuel/air mixture coming out the end  33  into burner chamber  160 . At this point the igniter will ignite the fuel in said ignition chamber  160 . 
         [0110]    Due to the size and configuration of the device, within approximately 45 seconds adequate heat buildup will have occurred to combust the smoke solution passing through coils  170 , thus in less than one minute after firing off burner chamber  160 , the smoke generator of the present invention is ready to use. 
         [0111]    The propellant from charged canister  17  passes through line  42  where the pressurized propellant enters flexible line  44  in solution chamber  16 . The pressurized propellant and the solution picked up through orifice  45  passed through check valve  46  and out the fitting  48 . This fitting is connected through line  49  which, through an internal passage, carries the propellant and solution to trigger activated valve  54 . The propellant/solution system is thus, charged and ready to operate. 
         [0112]    Once the burner  160  has reached operating temperature, the user grasps the smoke generator as shown in  FIG. 13 . When desired, the user simply pulls the trigger mechanism  54   a  downwardly with his or her finger which opens valve  54 . Pressurized propellant/solution then passes into coil  170 . As this propellant/solution passes through coil  170 , the solution is combusted. When the combusted solution exits coil outlet  171  through nozzle  173 , heavy non-toxic smoke is emitted therefrom so long as trigger mechanism  54   a  holds valve  54  open. By manipulating said trigger  54   a  short bursts of smoke can be generated or continuous smoke can be generated as desired. 
         [0113]    When the smoke generator  10  is operated as a self contained unit, it can generate smoke for a cumulative time of approximately 45 minutes. This includes the time it is operated during short bursts as well as extended smoke generation. 
         [0114]    Once the smoke generator has exhausted the charges in canisters  15 ,  16 , and  17 , it must be recharged prior to further use. This can be accomplished herein as described above for the initial charging, of such generator at the recharging station  90  or by other suitable recharging arrangements. 
         [0115]    Recharging the smoke generator  10  using the recharging station  90  takes approximately three minutes before the generator is again ready for operation. 
         [0116]    When it is desired to operate the smoke generator of the present invention for extended periods of time, the back pack supply  68  is available. 
         [0117]    The user  136  straps the back pack on, using shoulder straps  70  and waist strap  71  and makes adjustments for a comfortable fit. 
         [0118]    The propellant/solution quick connect coupling  89  on line  88  is operatively connected to propellant/solution quick connect coupling  57  on base  11 . The fuel quick connect coupling on fuel line (not shown) is operatively connected to fuel quick connect nipple  38  mounted on base  11 . The propellant, solution and fuel valves  74  and  79  are then opened, allowing propellant and solution from tanks  72  and  77  to flow to the smoke generator  10  through quick connect nipple  57 . Fuel from tank  102  or other source is allowed to flow to the smoke generator through quick connect nipple  38 . 
         [0119]    The smoke gun  10  is now ready for operation. The fuel can be turned on to burner  160  as herein above described and the ignition button  14  pushed to ignite the fuel in burner chamber  160 . After approximately 45 seconds heat up time, the trigger mechanism  54   a  can be manipulated to produce nontoxic smoke from the tip  174  of nozzle  173  in the same operating manner as herein described above for the generator when used as a self contained unit. The only difference is that, due to the larger capacity of the tanks on the back pack  68 , smoke can be generated for a cumulative time of between 2½ and 3 hours. 
         [0120]    Once the supply in the back pack  68  has been exhausted, the valves can be closed and connectors  83  and  89  disconnected and the back pack removed from the user  136 . A fully charged back pack can then be put on and couplings  83  and  89  reconnected. The smoke generator  10  is now again ready for operation for an extended period of time as herein described above. 
         [0121]    Lastly,  FIGS. 19 through 19   c  depict two different versions of nozzles for use in the present device. Nozzle  173  with single exit  174  is shown on the far right of the picture. This is the nozzle shown in other Figures of the drawings. Nozzle  190  with multiple holes  191  is depicted, which allows for a different dispersal pattern than does nozzle  173 . The nozzle  190  is also fitted with check valve  195  which is two pieces as shown and fits inside nozzle  190 .  FIG. 19   a  and  FIG. 19   b  show a see through version of nozzle  190 , completely assembled and exploded. Connector fitting  195   b  attaches to check valve  195 . It is operated by spring  195   a  and ball bearing  195   c . The entire nozzle is mounted using mounting bracket  195   d  in  FIG. 19   c.    
         [0122]    Regarding trigger  54   a  operation, solution tube  196  supplies smoke solution to the trigger  54   a . Operating trigger  54   a  opens a valve which allows solution to pass to the heating chamber coils. How much solution will pass can be adjusted by set screw  197  which determines how far the trigger can be pulled and thus, how far open the valve can be, Engaging trigger  54   a  is in a forwards and backwards motion, typical for most triggers. In order to resist side-to-side movement by trigger  54   a , trigger guard  198  is utilized which creates a channel for trigger  54   a  to move forward and back with very little ability to move to the side without encountering the guard  198 . 
         [0123]    From the above, it can be seen that the present invention has the advantage of providing a highly efficient smoke generator that can be used for extended periods of time. This generator is readily portable and yet, is highly efficient in producing either large amounts of smoke or bursts of smoke. It is infinitely controllable through the operation of trigger mechanism  54   a . This generator is light weight which adds further to its versatility. 
         [0124]    The present invention can be readily recharged when used as an independent unit or can just as readily be connected to a back pack supply for extended smoke generation. The back pack supply can also be quickly switched to a fresh supply when desired. 
         [0125]    It is clear that the present device can be used with other ingredients added to the smoke for distribution, for example, pepper spray. 
         [0126]    The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of such invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. 
         [0127]    While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.