Patent Document

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a Continuation-in-Part of copending U.S. patent application Ser. No. 12/017,669, filed on Jan. 22, 2008, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     Apparatus and methods for deactivating spent and unspent munitions and incendiary devices, such that its constituents can be recovered/recycled or disposed of responsibly. 
     2. Description of Related Art 
     In the defense of our nation, most projectile weaponry is deployed in a state of readiness, but not actually used. Projectile weaponry includes munitions (ordnance) such as missiles, rockets, grenades, bombs, mines, artillery shells, flares, fireworks, and cartridges (also known as small arms munitions or bullets). All of these munitions and incendiary devices contain high energy materials such as propellants and/or explosives that combust (using self-supplied oxygen) or detonate at a very high rate. 
     In a military conflict, the desired reliability of the munitions is 100 percent. Thus the propellants and/or explosives should always perform their desired functions in the munitions. However, it is known that these high energy chemical materials degrade over time, and thus their reliability decreases to an unacceptable level. The chemical based propellants and/or explosives of the munitions have a specific “shelf life” that is determined by time and ambient physical conditions. When the shelf life or reliability of a given munition is questionable, it is withdrawn from active stock and replaced with a new munition. Furthermore, spent munition casings, although discharged, may contain remnants of energetic material that can pose harm. 
     This results in a problem in that these withdrawn “live” and spent munitions with dangerous high energy materials (“energetics”) and other hazardous materials, such as lead, mercury etc., must be “demilitarized,” i.e. rendered to a state where they are no longer capable of being used as a munition or pose a danger. In order to accomplish this, the energetics must be destroyed, and any remaining munitions materials must be recycled or disposed of in a safe and environmentally responsible manner. It is clearly unacceptable to simply dump munitions that have been withdrawn from service into a landfill, or to sell them and risk their being acquired by criminals or our enemies. 
     In certain embodiments, the present invention is a method and apparatus for the safe and environmentally responsible demilitarization of “conventional” munitions such as missiles, rockets, grenades, bombs, mines, artillery shells, flares, fireworks, and cartridges (also known as small arms munitions or bullets) comprised of casings, high energy materials, and projectiles. In certain embodiments, the present invention is directed to the demilitarization of “small caliber” munitions, i.e. of fifty caliber or less in size. 
     The disposal of conventional munitions has evolved as the technology of munitions has developed. For centuries, aged or defective gunpowder was simply disposed of or ignited. When smokeless gunpowder was developed, it was disposed of in a similar manner. With the advent of more sophisticated energetics contained within large caliber munitions and incendiary devices, such as explosive artillery shells, torpedoes, and the like, the historic method of “open burning” was modified by the use of “booster” explosive charges to become “open detonation.” Open Burn/Open Detonation (OBOD) was for decades considered to be the fastest and cheapest method of munitions disposal. Significant problems with OBOD were operational safety and severe environmental (air, soil and water) contamination. 
     The United States armed forces continued aggressive use of OBOD until the mid-1970&#39;s when regulations of the Environmental Protection Agency (EPA) were promulgated. As the environmental regulations began to impact the use of traditional OBOD, the U.S. Army adapted the use of a rotary kiln incinerator from the hazardous waste disposal industry, which in turn had adapted it from the cement industry. This device was finalized as the APE (Ammunition Peculiar Equipment) 1236, which is currently in use. 
     The APE 1236 has operational shortcomings involving safety, process rates and environmental emissions resulting from incineration. However, it is considered the Best Available Technology (BAT), and is therefore permitted by the Environmental Protection Agency as an incinerator to be operated until it is superseded by an improved process technology. In the last several years, the major suppliers of conventional munitions disposal services to the Department of Defense have each put forward their concepts of the next generation BAT. To the best of the applicant&#39;s knowledge, the best emerging technologies are the Cryogenic Freezing process of the General Atomics Company of San Diego Calif., and the Donovan Blast Chamber technology of the CH2M Hill Company of Denver Colo. These technologies, as well as the APE 1236 technology are all premised on ultimately directly incinerating or detonating the energetic materials contained within the munition. All three technologies have certain disadvantages, including slow rates of processing, energy utilization inefficiencies, highly problematic and costly unintentional detonations with associated safety risks to operating personnel, and/or challenges in meeting federal and state environmental laws and material legacy (hazardous waste) management/disposal issues. 
     Accordingly, there remain operational shortcomings within these new concepts. What is needed is a method and apparatus for the demilitarization of munitions which can be operated in a manner that is safe for operating personnel, environmentally beneficial, that does not result in the generation of gaseous, liquid, or solid pollutants that are discharged to the atmosphere or to waterways or land, and that can be operated with a satisfactory rate of throughput. It is desirable that the demilitarization process results in a maximum amount of recyclable/reusable material and a minimal amount of waste to be discharged, with any such waste being harmless to the environment. 
     SUMMARY 
     The present invention meets this need by providing a non incinerative (“Decineration”) method and apparatus for the demilitarization of conventional munitions. The apparatus is comprised of an elongated tubular munitions conveying chamber having a wall with inner and outer surfaces, an inlet opening, and a discharge opening; a heater in thermal communication with the elongated tubular chamber; and a first discharge barrier obstructing at least a first portion of the discharge opening of the elongated tubular chamber. 
     The apparatus is provided with means for conveying munitions from the inlet opening of the chamber to the discharge opening of the chamber. In one embodiment, the elongated tubular chamber is rotatable around a longitudinal axis thereof and may have a downward incline from the inlet opening to the discharge opening. The elongated tubular chamber is preferably cylindrical in this embodiment, and is rotated about the central axis thereof. The means for conveying munitions in this embodiment is thus comprised of a drive that rotates the cylinder, and a support that may incline the cylinder downwardly from the inlet opening to the discharge opening. In operation, munitions that are delivered into the inlet opening of the chamber thus advances along the wall of the chamber toward the discharge opening of the chamber as the chamber is rotated. 
     The apparatus may include a first inlet barrier obstructing at least a portion of the inlet opening of the elongated tubular chamber and/or a second discharge barrier obstructing a second portion of the discharge opening of the elongated tubular chamber not obstructed by the first discharge barrier. 
     The first discharge barrier may be disposed outside of the elongated tubular chamber and proximate to the discharge opening of the elongated tubular chamber. The first discharge barrier may be formed of a heavy plate of material. Alternatively, the first discharge barrier may be an obstruction grating disposed outside of the elongated tubular chamber and proximate to the discharge opening of the elongated tubular chamber. The obstruction grating may be comprised of a plurality of angle irons joined to a framework. 
     Alternatively or additionally, the first discharge barrier may be comprised of a helical baffle joined to the inner surface of the wall of the elongated tubular chamber, or a plurality of radially inwardly disposed plates joined to the inner surface of the wall of the elongated tubular chamber. In either of these embodiments, the first discharge barrier may also be a part of the means for conveying munitions from the inlet opening of the chamber to the discharge opening of the chamber, with it being unnecessary to provide a downward incline from the inlet opening to the discharge opening. 
     The apparatus may be supplied with munitions to be demilitarized by a material feeding device in communication with the inlet opening of the elongated tubular chamber. The apparatus may also include a material discharge device in communication with the discharge opening of the elongated tubular chamber. A material separator may also be provided to separate the solids discharged from the tubular chamber into separate material streams for maximized recovery/recycling or responsible disposal. 
     The apparatus is preferably further provided with an exhaust for discharge of gases produced by the decomposition (“Decineration”) of the energetic material(s) in the munitions, and an air abatement system for treating any discharged gases, aerosols, soot, or other particulates contained therein. 
     In general, munitions to be demilitarized with the apparatus and method of the present invention are comprised of casing material, at least one energetic material (also referred to herein as an “energetic”), and projectile material. The method of the present invention is comprised of delivering the munitions into an elongated tubular chamber having a wall, an inlet opening, and a discharge opening; providing a first discharge barrier obstructing at least a portion of the discharge opening of the chamber; conveying the munitions along the elongated tubular chamber in a direction from the inlet opening toward the discharge opening; and heating the munitions within the chamber to a temperature sufficient to cause decomposition (“Decineration”) of the energetic material into at least one gas. Where the energetic material of the munition violently decomposes and causes motion of a fragment of the munition, the method further includes obstructing the motion of the fragment with the first discharge barrier. The method may further include providing a first inlet barrier obstructing at least a portion of the inlet opening of the chamber, and obstructing the motion of a fragment with the first inlet barrier. 
     The method may further include discharging the casing material and the projectile material from the discharge opening of the chamber to a discharge device. The casing material and the projectile material may be separated into different streams for different recycling options or disposal processes. The method preferably further includes removing the gas generated by the energetic material decomposition from the tubular chamber through an exhaust, and abating any constituents in the gas with an appropriate abatement device as prescribed by environmental regulations. 
     In accordance with the invention, there is also provided a method of demilitarizing an energetic. The method comprises indirectly heating the energetic in a chamber to a temperature below a combustion temperature of the energetic to at least partially decompose the energetic and substantially preclude combustion of the energetic such that the indirect heating produces a decomposition gas, and separating at least a portion of the decomposition gas from the chamber. The method may further comprise monitoring the decomposition gas and/or passing the separated decomposition gas through an air abatement system. The method may further comprise adjusting at least one of the following: the indirect heating of the energetic, the separating of the decomposition gas, the air abatement system, and a residence time of the energetic in the chamber. The energetic may be a bulk energetic. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described by reference to the following drawings, in which like numerals refer to like elements, and in which: 
         FIG. 1  a schematic illustration of an exemplary apparatus of the present invention for demilitarization of munitions; 
         FIG. 2  is a more detailed schematic illustration of one elongated tubular munitions conveying chamber, and inlet and discharge opening barriers of the apparatus of  FIG. 1 ; 
         FIG. 3A  is an end view of an alternative discharge barrier of the apparatus formed as an obstruction grating; 
         FIG. 3B  is a cross-sectional view of the obstruction grating of  FIG. 3A , taken along line  3 B- 3 B of  FIG. 3A ; 
         FIG. 3C  is a cross-sectional view of the obstruction grating of  FIG. 3B , shown in an inverted position; and 
         FIG. 4  is a lengthwise cross-sectional view of an alternative elongated tubular munitions conveying chamber comprised of a helical baffle joined to the inner surface of the wall thereof. 
     
    
    
     The present invention will be described in connection with a preferred embodiment, however, it will be understood that there is no intent to limit the invention to the embodiment described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements. Standard terminology is widely used in munitions demilitarization art. Accordingly, in describing the present invention, a variety of terms are used in the description. 
     As used herein, the term “caliber” is meant to indicate the interior diameter of the barrel of weapon or a gun (also known as a firearm) in hundredths of an inch or millimeters; the term is also used herein with reference to munitions, and generally refers to the approximate outside diameter of the projectile of the munition, or is meant to indicate munitions that are useable in a particular caliber of weapon. 
     As used herein, the term “cartridge/shell” is meant to indicate an assembled munition that is loadable into a gun or weapon. A cartridge/shell is comprised of a casing, an energetic material, and a projectile. The casing is typically a metallic cylinder open at one end, contains the energetic material. The open end of the casing is sealed to the proximal end of the projectile. The distal end of the projectile is typically of an aerodynamic shape. 
     As used herein, the term “energetics” or “energetic materials” is meant to indicate a material in a munition that contains a large amount of chemical energy and that is either used to propel the projectile of the munition out of the barrel of a gun or weapon or to deliver a destructive end result to its target. The materials are generally classified broadly as “primers,” the highly exothermic decomposition of which is typically set off by the action of a weapon trigger or fuze; propellants, which provide the high energy to separate the projectile from the casing and discharge it from the barrel of the weapon at high velocity; and “main charge” (also known as “filler”, “booster”, “bursting”, etc.) which is what supplies the destructive energy at the target. Munitions or munition components may have any one, two or all three categories of energetics in their assembly. 
     As used herein, the term “demilitarization,” when used with respect to munitions, is meant to indicate actions performed on the munitions to render them inoperative, and thus unsuitable for their original intended purpose and posing no further threat of physical harm. 
       FIG. 1  is a schematic illustration of an exemplary apparatus of the present invention for demilitarization of munitions, and  FIG. 2  is a more detailed schematic illustration of one elongated tubular munitions conveying chamber, and inlet opening barrier and discharge opening barriers of the apparatus of  FIG. 1 . 
     Referring first to  FIG. 1 , apparatus  10  is comprised of an elongated tubular munitions conveying chamber  20  having a wall  22  with an inner surface  21  and an outer surface  23 , an inlet opening  24 , and a discharge opening  26 . A heater  30  is provided in thermal communication with the elongated tubular chamber  20 , for the purpose of heating the space and contents within the chamber  20 . Heater  30  may be an electric heater, or a fuel-fired heater, such as by natural gas or other fuel. Alternatively, heater  30  may be supplied a heated heat transfer fluid from an external source (not shown), with the heat therein being transferred to tubular chamber  20 . By “thermal communication” between heater  30  and tubular chamber  20 , it is meant that heat energy is transferred from heater  30  to tubular chamber  20  by convection and/or conduction and/or radiation. It is not necessary that heater  30  be in direct contact with wall  22  of tubular chamber  20  in order to heat the wall  22  and the contents therein. Additionally, heater  30  may be comprised of a plurality of subzone heaters such as subzone heaters  32 ,  34 , and  36 . Each of subzone heaters may be set at a different temperature for precise control of the overall temperature profile from the inlet opening  24  to the discharge opening  26  of the tubular chamber  20 . Heater  30  is preferably housed within an enclosure  38 , which includes structural walls and thermal insulation (not shown). 
     The apparatus  10  may be further comprised of a first discharge barrier  40  obstructing at least a first portion of the discharge opening  26  of the elongated tubular chamber  20 . The apparatus  10  may also include a first inlet barrier  42  obstructing at least a portion of the inlet opening  24  of the elongated tubular chamber and/or a second discharge barrier  44  obstructing a second portion of the discharge opening  26  of the elongated tubular chamber  20  not obstructed by the first discharge barrier  40 . 
     The first discharge barrier  40  may be disposed outside of the elongated tubular chamber  20  and proximate to the discharge opening  26  of the elongated tubular chamber  20 . The first discharge barrier may be formed of a heavy plate of material as indicated in  FIG. 2 . Alternatively, the first discharge barrier  40  may be an obstruction grating disposed outside of the elongated tubular chamber  20  and proximate to the discharge opening  26  of the elongated tubular chamber  20 . The obstruction grating is formed by a series of rows and/or columns of impact-resistant material such that from any point within the tubular chamber  20 , there is no straight line path out of the tubular chamber. 
       FIGS. 3A-3C  depict one embodiment of a suitable obstruction grating. Referring first to  FIGS. 3A and 3B , the obstruction grating  140  is comprised of a plurality of angle irons  142  joined to a framework  144 . (It is to be understood that the term “angle iron” is not meant to limit the material of elements  142  to being made of iron or steel, but rather to simply indicate a readily available L-shaped structure formed by two flat strips of material intersecting at an apex.) 
     In one embodiment, the obstruction grating may be oriented as shown in  FIG. 3B , with the apices  146  of the angle irons  142  oriented upwardly. Fragments of munitions that impact any of the angle irons  142  will simply fall downwardly and be conveyed onward through the apparatus. In another embodiment, the obstruction grating may be oriented as shown in  FIG. 3C , with the apices of the angle irons  142  oriented downwardly. Some fragments of munitions that impact the angle irons  142  may accumulate in the troughs  148  formed by the angle irons. These accumulated fragments will reduce and eliminate the velocities of subsequent fragments of munitions that impact the obstruction grating  140 , so that they exit the obstruction grating without any velocity. In either case, it can be seen that there is no direct path for fragments of munitions to pass horizontally through the obstruction grating  140  without striking at least one, and likely two angle irons  142 . 
     It will be apparent that the aforementioned first inlet barrier  42  and/or the second discharge barrier  44  may either be plates of material, or obstruction gratings as described above. 
     In an alternative embodiment, the first discharge barrier of the elongated tubular chamber may be comprised of a helical baffle joined to the inner surface of the wall of the elongated tubular chamber.  FIG. 4  is a lengthwise cross-sectional view of a section of such an alternative elongated tubular munitions conveying chamber. The chamber  120  is comprised of a wall  122  with an inner surface  121  and an outer surface  123 , and an inlet and discharge openings not shown, but as described for chamber  20  of  FIG. 1 . The chamber  120  is further comprised of a helical baffle  124  joined to the inner surface of the wall thereof by suitable means such as by welding. The helical baffle  124  is formed as a continuous spiral of material, i.e. portion  124 A continues around the inner surface  121  of the wall  122  and is contiguous with portion  124 B, portion  124 B continues around the inner surface  121  of the wall  122  and is contiguous with portion  124 C, etc. 
     It can be seen that a continuous helical trench is formed between successive portions  124 A,  124 B,  124 C, etc. of the helical baffle  124 . Thus, during munitions processing with the apparatus, when munitions  2  ruptures violently and separates into casings  4 , projectiles  6 , and fragments thereof moving at high velocity, those objects are unable to fly axially along chamber  120  because they are immediately blocked by the helical baffle  124 . Thus the helical baffle  124  functions as a first discharge barrier for the apparatus. 
     In a further embodiment (not shown), the continuous helical trench may be “boxed in,” either by joining a spiral sheet of material to the inner edge of the helical baffle to form a roof over the helical trench, or by providing a cylindrical pipe or rod up through the open center of the tubular chamber, such that the pipe or rod occupies the space of the open center and forms a roof over the helical trench. In this embodiment, the resulting passageway through the elongated tubular chamber is a helical passageway having a rectangular cross-section. In another embodiment (not shown), instead of forming the helical passageway within a cylindrical tube and having a rectangular cross-section, the helical passageway may be made by forming a heavy-walled cylindrical tube into a helical coil or “corkscrew” shape. For either of these embodiments having a helical passageway, when munitions rupture violently in the passageway, the only path for resulting high velocity munitions fragments to advance axially along the passageway is to move in a helical trajectory bounded by the passage walls. The kinetic energy of any such high velocity fragments will quickly be dissipated/eliminated within the passageway. 
     In an alternative embodiment, the first discharge barrier may be comprised of a plurality of radially inwardly disposed plates joined to the inner surface of the wall of the elongated tubular chamber. In this embodiment, instead of having a continuous helical baffle  124 , the chamber may include individual radially inwardly disposed plates  124 A,  124 B,  124 C, etc. The plates may extend along a shorter sector of the inner surface  121  of wall  122  than shown, and may have a lower or higher density and a less ordered arrangement than shown in  FIG. 4 . It is preferable that the plates  124 A,  124 B,  124 C have a pitch with respect to the central axis  99  of the chamber  120 , so that in operation, when chamber  120  is rotated, the munitions will be conveyed axially as indicated by arrow  95 . 
     It is noted that in either of these embodiments, the first discharge barrier formed either by a helical baffle or by pitched radially inwardly disposed plates may also be a part of the means for conveying munitions from the inlet opening of the chamber to the discharge opening of the chamber, with it being unnecessary to provide a downward incline from the inlet opening to the discharge opening. It is also noted that for an added measure of safety, the apparatus may be provided with the previously described plate or obstruction grating barriers at the discharge and/or the inlet openings of the elongated tubular chamber. 
     Referring again to  FIG. 1 , and also to  FIG. 2 , the apparatus  10  is provided with means for conveying munitions from the inlet opening  24  of the chamber  20  to the discharge opening  26  of the chamber  20  during the operation thereof. In one embodiment depicted in  FIG. 1  and  FIG. 2 , the elongated tubular chamber  20  is rotatable around a longitudinal axis  99  thereof and has a downward incline from the inlet opening  24  to the discharge opening  26 . (For clarity of illustration, the relative amount of incline of chamber  20  is exaggerated in  FIG. 2 .) The elongated tubular chamber  20  is preferably cylindrical in this embodiment, and the longitudinal axis of rotation  99  is the central axis of chamber  20 . In this embodiment, the means for conveying the munitions is comprised of a drive gear  28  and motor (not shown) that rotates the cylinder  20 , and a support assembly  50  that supports and inclines the cylinder  20  downwardly from the inlet opening  24  to the discharge opening  26 . 
     Support assembly  50  is comprised of a platform  52  that supports the tubular chamber  20 , the heater enclosure  38 , and other subassemblies of the apparatus  10 . Support assembly  50  is further comprised of a fulcrum base  54 , a fulcrum pin  56 , a level column  58 , and a jack  59 . Jack  59  is extendable and retractable as indicated by bidirectional arrow  98 , such that when jack  59  is extended, the distal end  53  of platform  52  is raised and lowered. Platform  52  and tubular chamber  20  rotate around fulcrum pin  56  as indicated by arcuate arrow  97 , so that when jack  59  is extended upwardly, tubular chamber  20  is moved into an inclined position. In operation, munitions that are delivered into the inlet opening  24  of the chamber  20  thus advances along the wall  22  of the chamber  20  toward the discharge opening  26 , as the chamber  20  is rotated. 
     The apparatus  10  may be supplied with munitions to be demilitarized by a material feeding device  60  in communication with the inlet opening  24  of the elongated tubular chamber  20 . The feeding device  60  is used to deliver the munitions into the tubular chamber  20 . Device  60  can be any material moving device such as an inclined chute, a vibrating feed conveyor or a belt or pan type conveyor. It is desirable that it be metallic and placed at such a location that if any potential fragment of material (e.g. a bullet or casing) exited the inlet opening  24  of the tubular chamber  20 , the trajectory path will impact some portion of the feeding device  60 , hindering the object from exiting and reaching any operator station, if it did not impact the inlet barrier  42 . In the embodiment depicted in  FIG. 1 , which is meant to be illustrative and not limiting, material feeding device  60  is comprised of a hopper  62  for receiving and holding the munitions to be demilitarized, an airlock  64  to prevent escape of decomposition gases during operation, a lower housing  66 , and an inclined chute  68  in communication with the inlet opening  24  of tubular chamber  20 . 
     The apparatus may also include a material discharge device  70  in communication with the discharge opening  26  of the elongated tubular chamber  20 . The discharge device  70  is used to receive the demilitarized munitions from the discharge end  26  of tubular chamber  20 . Material discharge device  70  can be any material moving device such as an inclined chute, a vibrating feed conveyor, or a belt or pan type conveyor. It is preferable that device  70  be metallic in order to withstand the normal physical scouring (wear and tear) of demilitarized munition fragments that are discharged from tubular chamber  20 . It is also preferable that any inclined chute, such as chute  72  of  FIGS. 1 and 2  be placed at such an angle that chute  72  fits through the respective holes or slots  41  and  45  in the blast barriers  40  and  44  at the discharge opening  26  of the tubular chamber  20 . In the embodiment depicted in  FIG. 1 , material discharge device  70  is further comprised of a hopper  74  for receiving the demilitarized munitions and an airlock  76  to prevent escape of decomposition gases during operation. 
     A material separator  80  may also be provided to separate the solids discharged from the tubular chamber  20  into separate material streams for maximized recovery/recycling or responsible disposal. Material separator  80  may be coupled to material discharge device  70  via a flex coupling  82 , which flexes as the incline of tubular chamber  20  is adjusted. Material separator  80  may be used to separate the brass casings, bullets and other materials into different streams  84  and  86  to increase the value of these materials for recycle. If the munition is comprised of ferrous material, (such as bullets with steel jackets) or plastics, paper etc., material separator  80  may include magnetic, eddy current and air separation means (not shown). 
     The apparatus is preferably further provided with an exhaust  90  for removal of gases produced by the decomposition of the energetic material(s) in the munitions from both the apparatus  10 , and from the facility in which the apparatus  10  is installed. Exhaust  90  may be comprised of exhaust ducts  92  and  94 , and exhaust blower  96 . Although exhaust  90  is depicted as being connected to apparatus  10  near the discharge opening  26  of tubular chamber  20 , the connection may also be made near the inlet opening  24 . 
     Exhaust  90  is preferably connected to an air abatement system  100  for treating any regulated exhaust gas streams. It is to be understood that although the products of decomposition of the energetic materials are referred to herein as gases, this is not to be construed as being only materials in the gas phase. The decomposition products may include solid particulates such as soot, and liquid particulates such as aerosol droplets, which are entrained in the exhaust gas stream delivered by exhaust  90 . Accordingly, pollution abatement system  100  may include one or more of a particulate filter, a fume scrubber, an incinerator or thermal oxidizer, a condenser, an adsorbent, an absorbent, (all not shown) and/or other well known separation or destruction means used to abate any regulated gas streams. In general, the gas abatement system  100  enables the demilitarization apparatus  10  to meet the requirements of federal, state, and local environmental laws and regulations, but is not required for the functioning of the apparatus  10 . The relative complexity of the abatement system  100  will depend upon the combination of environmental laws and regulations to be satisfied. 
     In general, and referring to  FIG. 2 , munitions  2  to be demilitarized with the apparatus and method of the present invention are comprised of casing material, at least one energetic material, and projectile material. Referring again to both  FIGS. 1 and 2 , the method of the present invention is comprised of delivering the munitions into an elongated tubular chamber  20  having a wall  22 , an inlet opening  24 , and a discharge opening  26 ; providing a first discharge barrier  40  obstructing at least a portion of the discharge opening  26  of the chamber  20  (or a first discharge barrier  124  internal to the elongated tubular chamber  120  of  FIG. 4  as described previously herein); conveying the munitions  2  along the elongated tubular chamber  20  in a direction from the inlet opening  24  toward the discharge opening  26  as indicated by arrow  95 ; and heating the munitions within the chamber to a temperature sufficient to cause decomposition (Decineration) of the energetic material into at least one gas. The placement of the munitions  2  onto the inclined chute  68  or other feed device may be done either by hand, or by an automated device such as material feed device  60  described previously herein. 
     Where the energetic material of the munitions violently decomposes as indicated by ruptures  93  and causes motion of whole cartridges  3 , casings  4 , projectiles  6 , or fragments  8  thereof, the method further includes obstructing the motion of the fragments  8  with the first discharge barrier  40  or the first discharge barrier  124  of  FIG. 4 . The method may further include providing a first inlet barrier  42  obstructing at least a portion of the inlet opening  24  of the chamber  20 , and obstructing the motion of a fragment  7  with the first inlet barrier  42 . Because the motion of separated casings, projectiles, and fragments thereof resulting from violent decompositions of energetic material is somewhat random, on some occasions, a fragment  9  may be ejected through the discharge hole  41  in first discharge barrier  40 . Because of the potential danger posed by such a high energy ejected fragment  9 , a second discharge barrier  44  is provided to obstruct the motion of ejected fragment  9 . Second discharge barrier  44  is positioned such that it obstructs a second portion of the discharge opening  26  of the elongated tubular chamber  20  not obstructed by the first discharge barrier  40 . 
     The method of the present invention preferably further includes discharging the casings  4 , projectiles  6 , and fragments of material thereof from the discharge opening  26  of the chamber  20  to a discharge device  70 , as indicated by arrow  91 . The casing material and the projectile material may be separated into different streams  84  and  86  for different recycling or disposal processes by material separator  80 . The method preferably further includes removing the gas generated by the energetic material decomposition from the tubular chamber  20  through an exhaust  90 , and abating any constituents in the gas with an air abatement device  100  as prescribed by environmental regulations. 
     More specific preferred attributes and operational details of the applicant&#39;s apparatus and method will now be described. 
     It is desirable that the munitions that has been fed into tubular chamber  20  is aligned as shown in  FIG. 2  in its general direction of travel and parallel to the longitudinal axis  99  of the chamber  20 , and is disposed in a fairly uniform distribution along on the wall  22  of tubular chamber  20 . For most efficient operation, the feed rate to the tubular chamber  20  should be continuous and at a uniform level but that is not required for the applicant&#39;s method to work satisfactorily. The tubular chamber  20  should be preheated and maintained at a temperature of between about 350 and about 1,000 degrees Fahrenheit at a point about midway along the length of the tubular chamber  20  prior to the start of processing munitions. 
     In operating the applicant&#39;s apparatus, the residence time of the munitions and the temperature in the tubular chamber  20  are adjusted to particular values depending upon the caliber of the munitions, the munitions temperature to be attained and maintained, and the type of energetic material inside the munitions, in order to ensure complete decomposition of the energetic and demilitarization thereof. The temperature within the chamber  20  is precisely zone controlled by controlling the power delivered to the heater  30 . The residence time of the munitions within chamber  20  of the apparatus  10  may be controlled by controlling the rotational speed and the degree of incline of chamber  20 . For an apparatus with a tubular chamber  120  that includes a helical baffle  124  as shown in  FIG. 4  and described previously herein, the residence time of the munitions within the chamber  120  is a function of only the rotational speed of the chamber and the pitch of the helical baffle  124  (except for a few random pieces of munitions that may be displaced a short distance forward or rearward in the chamber by violent decomposition therein.) For an apparatus with an alternative munitions conveying means, similar speed-related operational control parameters will be apparent. 
     Complete demilitarization is defined as there being no remaining residual energetic in or on the dis-assembled munitions shells/cartridges, or fragments thereof, in the discharge stream that exits the discharge end  26  of tubular chamber  20 . The discharge stream should contain only shells, cartridge casings, projectiles, and fragments thereof, i.e. “cartridge brass and bullets.” If assembled cartridges and or energetic remains are exiting the tubular chamber, either the munitions residence time, the temperature, or both should be increased. 
     It is anticipated that a portion of the energy released from the decomposition of the energetic contained in a munition will be absorbed by the munitions and/or munition components adjacent to that munition within the elongated tubular chamber  20 . A portion of the undecomposed munitions proximate to the decomposing munitions that still contain their energetic will gain sympathetic heat from the decomposing munitions, which will aid in the needed temperature rise of the adjacent undecomposed munition. In that manner, the thermal energy released by the demilitarization of the munitions in the proposed equipment should have the desired effect of lowering the heat demanded from the heater  30 , thereby making the applicant&#39;s apparatus and method more energy efficient. 
     The applicant&#39;s apparatus and method are advantageous with respect to those of the prior art in other aspects as well. In contrast to the aforementioned prior art methods, the applicant&#39;s method is directed to the controlled decomposition (“Decineration) of the propellant and primer energetic materials contained in the munitions, performed in a manner that meets the requirements of federal and state regulations, and that can result in the total recycling of remaining components. The controlled decomposition (“Decineration”) of the energetic materials results in increased operator safety, complete capture and abatement of all regulated resulting gas streams and full recovery/recycling of remaining materials. 
     The applicant&#39;s preferred apparatus and method differs from the aforementioned APE 1236 apparatus and method in that the applicant&#39;s apparatus and method utilize “rotary furnace” technology, while APE 1236 used “rotary kiln” technology. In a rotary kiln, heat is supplied thereto by the combustion of a fuel. The fuel combustion gases are blown into the kiln and are in direct contact during the firing of the contents therein. These combustion gases place an additional load on the air handling system supplying the furnace and the pollution control equipment abating any emissions therefrom. The direct impingement of the flame front on the material being processed leads to undesired chemical compounds being formed, as 1) there is no way to control the decomposition chemistry of the energetic and solids once the material reaches combustion temperatures and 2) the material approaches the temperature of the flame at which point uncontrolled and unwanted chemical and metal reactions take place. This makes it highly difficult to meet government emissions laws and regulations at acceptable material throughput rates. In contrast, the applicant&#39;s apparatus and method uses the main component of a rotary furnace, which is an elongated tubular chamber that is heated externally with no direct heat source contact on the munitions materials. The tubular chamber is preferably comprised of a very heavy alloy steel tube. Because of this design, low temperature and lack of direct heat contact with the materials, the air abatement equipment that is connected to the applicant&#39;s apparatus operates much more efficiently and handles only the gases produced by the decomposition of the energetic material of the munitions passing through the rotary furnace, and not the larger and more toxic volume of combustion gas that the APE 1236 system produces and must handle. Additionally, because the heating occurs on the exterior of the tubular chamber within the applicant&#39;s apparatus, the temperature can be controlled precisely to assure complete decomposition (“Decineration”) of munitions at temperatures significantly lower than in the APE 1236 rotary kiln. This also results in a more efficient process operation while enabling the meeting of all government environmental emissions regulations. 
     The following example of one embodiment of the applicant&#39;s apparatus is meant to be illustrative and not limiting. Referring again to  FIG. 1 , apparatus  10  may be made by performing modifications to a commercially available rotary furnace, such as a multiple zone electric or gas fired rotary tube furnace manufactured by the Harper International Corporation of Lancaster, N.Y. To adapt this furnace for use in the present application, the unit may be ordered with the features of an internal material feed screw (i.e. helical baffle), a variable incline adjustor, a multi zone heating and entry and exit rotary locks. To this unit, one or both of the inlet blast barrier  42  and discharge blast barriers  40  and  44  may be joined to structural members within the furnace such that they function to block any potential ejected munitions fragments as described previously herein. 
     Within this rotary furnace, both the temperature and residence time may be precisely monitored and controlled independently. This, along with the ability to control the feed rate of products being fed to the furnace enables the complete demilitarization of the munitions. In one embodiment, the temperature within the tubular chamber of the furnace may be maintained between about 350 and about 1000° F., with the residence time of the munitions passing therethrough being around 30 seconds. The tubular chamber of the furnace may have an inside diameter of about twenty (20) to thirty six (36) inches, a wall thickness of about three (3) to four (4) inches, and a length of about twenty (20) to thirty (30) feet. The inside diameter and length are selected for operational considerations (i.e. processing rate and size of munitions) and are not critical for the operability of the invention. The wall thickness is selected for operator safety considerations and is determined by the standard penetration tables established within the munitions community. 
     A complete emissions monitoring and process control package may be added to the outlet of the furnace which incorporates carbon monoxide and oxygen monitoring as well as automatic feed stream control/shut-off. The exhaust from the furnace may be fed into a specifically designed multi-stage air abatement control system. This system is designed to meet government emissions laws and regulations. The unique design of the system allows the air abatement control equipment to operate more efficiently and at significantly lower temperatures than any competing technology known to the applicant. The system may be operated in a continuous, steady state mode, and may be operated at a significantly lower temperature as compared to the APE 1236 system, thus reducing the production of undesired energetic and metal material decomposition byproducts during processing. The applicant&#39;s preferred apparatus also reduces gas volume to be processed by the air on abatement system  100  by several orders of magnitude. 
     It is to be understood that although the applicant&#39;s apparatus and method described herein are directed to the demilitarization of small caliber munitions, with scaling to a larger apparatus, the apparatus and method are adaptable to larger caliber munitions, aerial bombs, torpedoes, mines, rocket warheads, hand grenades, incendiary devices, etc. Thus any dimensions and related scaling of the apparatus recited herein are to be construed as exemplary and not limiting. 
     It is, therefore, apparent that there has been provided, in accordance with the present invention, a method and apparatus for the demilitarization of conventional munitions and incendiary devices containing energetics. While this invention has been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

Technology Category: f