Abstract:
A portable, collapsible, secondary combustion biomass stove which maintains the environmental and efficiency benefits of a secondary-burn biomass stove while removing the need for the weight and volume of permanent insulation. The stove can be quickly and easily assembled or disassembled without the use of tools for storage and transport. The outer housing of the stove provides stability while shielding the user from the high temperatures of secondary combustion within the chimney and combustion chamber, and collapses for stove transport, insulation may be added to the stove using material indigenous to most campsites, whereby stove operating temperature and efficiency increases while toxic gas release and fuel consumption decrease.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/041,646 titled Collapsible Rocket Stove And Associated Embodiments filed on Aug. 25, 2014, the entire contents of which are incorporated herein by reference. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     Portable camp stoves are a staple item for most backpackers, campers, hikers and survivalists. The most popular current models are propane, butane, or alcohol-fueled stoves. Some of these stoves are compact and lightweight, but each of these invariably requires the transport of fuel to the cooking location. These fuel containers can be bulky and awkward for hiking, camping, and survival applications, for which weight and volume are of considerable importance. These canisters encumber the user and occupy his or her time, since each must be recycled, refilled, or discarded after use. 
     Campfires remove the need for canisters since they are fueled by sticks, logs, or assorted biomass available on the trail, though campfires are not permitted in many campgrounds. Furthermore, like biomass stoves, campfires offer the environmental advantage of being carbon-neutral, since the carbon dioxide released via natural decomposition of the biomass is instead produced by burning the biomass as fuel. However, burning fuel in a campfire or open flame produces toxic byproducts and hydrocarbons due to inefficient fuel consumption. 
     As wood burns in a campfire, flammable wood gas is released in the form of volatile organic compounds. These wood gases usually comprise at least 50% of the potential chemical energy available from the wood fuel. Exothermic reactions (wood burning) begin at approximately 250° C., and wood gases do not ignite until approximately 600° C. The combustion configurations of a fireplace or campfire fail to ignite most of these gases since they do not usually reach sufficient temperatures for wood gas combustion. This unburned fuel cools and condenses when dispersed and forms particulates in the form of smoke. Smoke is wasted fuel. 
     Wood stoves improve on an open fire in that each contains a combustion chamber. In a wood stove the containment of the wood gas within the combustion chamber and chimney apparatus (if one exists) serves to superheat the gas and ignite a “second burn.” This second burn allows a wood stove to produce more heat per unit mass of fuel than a fireplace or campfire. The hotter and longer the burn, the more efficient the wood stove. However, most portable wood stove models currently available often do not reach either sufficient temperature or sufficient burn duration to consume most volatile organic compounds, although these are more energy efficient than an open fire. 
     The “rocket stove,” so named for the “rocket” sound the user hears when the stove produces a muffled roar at its high operating temperature, has been a popular biomass stove with wood stove enthusiasts and survivalists in recent decades. The rocket sieve design offers a more efficient use of biomass consumption than many other wood stoves. The rocket stove concept involves a flow of air drawn towards the combustion chamber (a draw) by the partial vacuum created by the high temperatures therein (This relationship is often described quantitatively by either a combination of Charles&#39; Law and Boyle&#39;s Law or the Ideal Gas Law, according to preference). 
     Rocket stoves traditionally utilize an “L-shape” design in order to direct fuel and air into a combustion chamber. Air is channeled horizontally towards the “corner” of the “L-shape” via a fuel and air intake apparatus (the feel and air intake apparatus is often referred to as a wood box or fire box). The channelization of air within the fuel and air intake apparatus prior to combustion preheats the air as it nears the combustion chamber beneath and around the fuel, serving to reduce the convective cooling of the combustion chamber that usually occurs via an uncontrolled interaction of ambient air with the combustion chamber. Rocket stove designs often feature insulation of the combustion chamber and (more often) the chimney apparatus in order to prevent air-cooling of stove surfaces which contain combustion. 
     The channelization of air also serves to pre-heat the wood prior to combustion, allowing the induced draft within the fuel and air intake apparatus to function as an evaporator. This pre-heating of the wood evaporates water from the fuel, drying the wood and preventing much of the energy loss in the combustion chamber normally expended to evaporate water. Live or “green” wood is comprised of approximately 50% of water by weight, while wood properly stored and left to dry is comprised of approximately 20% of water by weight, depending on environmental factors. The teaching contained herein allows a portable means of pre-heating “greener” or more recently felled biomass prior to combustion, evaporating water from the wood as it nears combustion and expanding potential fuel sources. 
     The rocket stove&#39;s numerous advantages are likely responsible for its popularity among wood stove enthusiasts. These advantages include improvements over current biomass camping stoves, campfires, and gas camping stoves in efficiency, safety, and environmental impact. Since the majority of Chinese, Indian, and African households depend on solid fuel consumption for domestic energy production (often in enclosed of poorly ventilated spaces), environmental and safety problems associated with biomass consumption represent a long-felt but unmet need for amelioration. 
     The reduction in both ash and smoke production resulting from a rocket stove burn (upon reaching optimal operating temperatures) both testify to its efficiency. One 2007 study documenting the replacement of traditional wood stoves with rocket stoves in sub-Saharan Africa reflects this efficiency. These stoves were non-collapsible, insulated stoves that were used to produce hundreds of thousands of meals over a period of months or years. The four institutions involved in the field test reported a 57-71% reduction in wood fuel purchases upon the introduction of the stoves ( ProBEC Study on the Impact of the Institutional Rocket Stoves in School Kitchens , August 2007). 
     Numerous types of woodstoves, camping stoves, and survival stoves have been proposed and patented, however none of these combine the efficiency, collapsibility, convenience, and simplicity of the embodied teachings. Numerous collapsible woodstoves have been patented which are bulky when collapsed and do not offer the potential use of indigenous insulation, for example U.S. Pat. No. 4,069,806 to Landry (1978) and U.S. Pat. No. 5,159,799 to Cowen (1992). Furthermore, numerous woodstoves either do not utilize the rocket stove design advantage of the continuous addition of fuel without removal of the pot, or limit added fuel to very small twigs and sticks which will be quickly consumed without removal of the pot, for example U.S. Pat. No. 0,284,047 A1 to Johnson et al. (2011), U.S. Pat. No. 0,083,946 A1 to Cedar et al. (2010), or U.S. Pat. No. 5,842,463 to Hall (1998). 
     Other woodstove or camp stove designs do not use insulation of any kind, do not provide for the potential use of insulation indigenous to the site of use as found in the teachings herein, or by virtue of design make the achievement of sustained temperatures necessary for ignition of most secondary wood gases difficult or impossible, furthermore, these stoves fail to provide the safety benefits of an insulated barrier between combustion surfaces and the user. For example U.S. Pat. No. 8,261,731 B2 to Marsh (2012), U.S. Pat. No. 4,971,045 to Probst (1990), or U.S. Pat. No. 0,204,852 to Boucher (2012). Some woodstoves do utilize the design advantages of the rocket stove concept but do not collapse, for example U.S. Pat. No. 0,258,104, A1 to DeFoort et al. (2010). Many other woodstoves require consumable elements for their operation, with their inherent drawbacks of dependency on electrical sources or store-bought fuel. For example U.S. Pat. No. 0,165,769 A1 utilizes a blower to improve efficiency and fuel consumption, but has the drawback of requiring a power source. Other stoves are very light, portable, or collapsible, but require fuel tablets for operation. U.S. Pat. No. 0,217,657 A1 to Anue (2005) and U.S. Pat. No. 6,851,419 B2 to Reiner (2005) fall into this category. Bach of these stoves has its advantages, but nevertheless none of the stoves heretofore known offer the advantages of the collapsible rocket stove design of the teachings herein. 
     BRIEF SUMMARY OF THE INVENTION 
     Be it known that Frederick Douglas Heuchling, a Citizen of the United States, residing at Green Bay, in the County of Brown and in the State of Wisconsin, have invented a collapsible secondary-burn biomass stove. The invention provides a housing into which stove components are inserted and assembled. The invention separates the operator from immediate contact with the combustion chamber by allowing the operator to construct the combustion chamber via the assembly of the fuel and air intake apparatus and the chimney apparatus within the housing. The invention provides the user a means of insulating the chimney apparatus and fuel and air intake apparatus using materials indigenous to the cook site (such as dirt, rocks, etc.), removing the need for the transport of high-volume or high-weight insulating material. The invention allows a portable means of pre-heating biomass prior to combustion, evaporating water from the wood as it nears combustion, increasing efficiency through higher operating temperature, and expanding potential fuel sources to wetter, “greener” wood. The invention provides a lightweight and high-efficiency biomass stove that preserves the rocket stove concept in a portable, collapsible configuration. 
     One embodiment described herein has achieved temperatures in excess of 1700° Fahrenheit using scrap wood, a temperature well in excess of that necessary to achieve secondary combustion and the ignition of wood gases. Furthermore, the embodiment described herein collapses roughly to the dimensions of a large-screen laptop computer, a storage savings of over 90% of the expanded version. The embodiments herein described also offer advantages in stability over many commercially available rocket stoves, which are often supported by welded legs or a tripod. In addition, the wide, square base of most of the embodiments taught herein is less likely to tip over and dump embers on an unintended area. 
     The improvement in efficiency is a direct consequence of improved combustion, which translates to decreased production of the products of incomplete combustion. These detrimental products include the production of hydrocarbons and carbon monoxide, both of which carry negative health costs upon inhalation. The World Health Organization estimates that 2.7 to 3 million people die each year as a consequence of pollution from solid fuel use. Any decrease in the production of these pollutants will carry positive health implications for the users. 
     The stoves in the African study referred to above, however, like the rocket stoves currently available on the market, are either too heavy or too bulky to serve as an ideal camping, hiking, or survival solution. The smaller of these stoves often weigh at least 15 lbs, and require several square feet of packing space. Furthermore, most rocket stoves currently available and advertised as portable do not allow for insulation of the chimney apparatus and fuel and air intake apparatus, in contrast to embodiments here presented. In contrast to currently available rocket stoves, the embodiments taught herein offer a lighter, more compact solution over currently available rocket stove designs that preserves the rocket stove concept. 
     The enclosed teaching also addresses a long-felt, unmet need in the field of survival applications. In the event of a massive power outage or burst water lines, a sanitary source of water for cooking and hygiene may not be available. In the wake of hurricanes Katrina and Sandy, for example, millions of Americans found themselves without a source of clean water, sometimes for days. Often, there was no shortage of fresh water from local sources, but there was no ready means of sanitizing what water was available, especially in an urban environment where campfires are less practicable. A lightweight, efficient means of burning scrap wood made possible by the embodiments presented herein allow the sanitation of water or cooking of meals without recourse to power or gas. Furthermore, the enclosed combustion chamber of the design herein described would mitigate concerns of accidental secondary fires due to external combustion in an urban environment. 
     The use of a main housing to separate the user from the combustion chamber is an additional safety feature not found in most commercially available, portable rocket stoves. This feature decreases the likelihood of accidental burns during employment of the stove. Furthermore, the embodiments described herein allow for the potential use of insulation indigenous to the campsite, for example and without limitation dirt, rocks, or sand. This insulating material is added inside the main housing around the combustion chamber, fuel and air intake apparatus, and chimney apparatus to achieve higher operating temperatures and efficiency. This allows for the transport weight of the collapsible rocket stove described herein to be considerably less than that of an expanded and insulated rocket stove in the tested versions. This fraction varies depending on the insulating material and the particular dimensions of the rocket stove employed. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  is a perspective view of a first embodiment in assembled configuration. 
         FIG. 2  is a perspective view of a main housing laid flat and folded twice. 
         FIG. 3  is a perspective view of a main housing laid flat and unfolded once. 
         FIG. 4  is a perspective view of a main housing in expanded configuration. 
         FIG. 5  is a perspective view of a rectangular chimney apparatus in expanded configuration. 
         FIG. 6  is a perspective view of a rectangular chimney apparatus in collapsed configuration. 
         FIG. 7  is a perspective view of a rectangular fuel and air intake apparatus in expanded configuration. 
         FIG. 8  is a perspective view of a rectangular fuel and air intake apparatus in collapsed configuration. 
         FIG. 9  is a perspective view of a separator. 
         FIG. 10  is a perspective view of a main housing expanded with fuel and air intake apparatus inserted into main housing. 
         FIG. 11  is a perspective view of a main housing expanded with fuel and air intake apparatus and chimney apparatus inserted into main housing. 
         FIG. 12  is a perspective view of a first embodiment in assembled configuration with closed cook plate surface. 
         FIG. 13  is a perspective view of one embodiment of a main housing composed of non-hinged panels laid flat. 
         FIG. 14  is a perspective view of one embodiment of a main housing composed of non-hinged panels in an expanded configuration. 
         FIG. 15  is a perspective view of a cylindrical main housing with cylindrical fuel and air intake apparatus openings in a rolled configuration. 
         FIG. 16  is a top-down view of a cylindrical main housing with cylindrical fuel and air intake apparatus openings in an unrolled configuration. 
         FIG. 17  is a perspective view of a peg and hole fastener system for cylindrical components. 
         FIG. 18  is a perspective view of a curl and hook fastener system for cylindrical components. 
         FIG. 19  is a top-down view of a cylindrical main housing with a curl and hook fastener system in an unrolled configuration. 
         FIG. 20  is a perspective view of a cylindrical main housing with rectangular fuel and air intake apparatus openings in a rolled configuration. 
         FIG. 21  is a top-down view of a cylindrical main housing with rectangular fuel and air intake apparatus openings in an unrolled configuration. 
         FIG. 22  is a perspective view of a cylindrical chimney apparatus in a rolled configuration. 
         FIG. 23  is a top-down view of a cylindrical chimney apparatus section in an unrolled configuration. 
         FIG. 24  is a perspective view of a cylindrical fuel and air intake apparatus in a rolled configuration. 
         FIG. 25  is a top-down view of a cylindrical fuel and air intake apparatus in an unrolled configuration. 
         FIG. 26  is a perspective view of a triangular main housing with single rear fuel and air intake apparatus opening. 
         FIG. 27  is a perspective view of a triangular main housing with dual rear fuel and air intake apparatus openings. 
         FIG. 28  is a perspective view of a triangular main housing with a folding side panel and a single rear fuel and air intake apparatus window in expanded configuration. 
         FIG. 29  is a perspective view of a triangular main housing with a folding side panel and a single rear fuel and air intake apparatus window in a partially collapsed configuration. 
         FIG. 30  is a perspective view of a fuel and air intake apparatus with a separator plate hingedly attached to one side of a fuel and air intake apparatus and a separator plate catch on a fuel and air intake apparatus side opposite a hinge. 
         FIG. 31  is a top plan view of a fuel and air intake apparatus with a hinged separator plate. 
         FIG. 32  is a perspective view of a main housing in an expanded configuration with a hinged base plate, a hinged base plate catch, a hinged cook surface plate, and a hinged cook surface plate catch. 
         FIG. 33  is a perspective view of one embodiment of a main housing and chimney apparatus in which a stability rod is inserted into a main housing and chimney apparatus sections. 
         FIG. 34  is a perspective view of a fuel and air intake apparatus with vertically configured stability rods. 
         FIG. 35  is a perspective view of a chimney apparatus with front and rear fuel and air intake apparatus openings. 
         FIG. 36  is a perspective view of one embodiment of a fuel and air intake apparatus with hinged separator plates in the front and rear of the fuel and air intake apparatus. 
         FIG. 37  is a perspective view of one embodiment of a fuel and air intake apparatus with a perforated grate section. 
         FIG. 38  is a perspective view of one embodiment of a fuel and air intake apparatus with a perforated grate section with one embodiment of a sliding grate with lever and catch rods for the sliding grate. 
         FIG. 39  is a perspective view of the rectangular main housing with cylindrical fuel and air intake apparatus openings in expanded configuration. 
         FIG. 40  is a perspective view of a rectangular main housing with dual folding side panels in an expanded configuration. 
         FIG. 41  is a perspective view of a rectangular main housing with dual folding side panels in a partially collapsed configuration. 
         FIG. 42  is a perspective view of a cylindrical gravity fed fuel and air intake apparatus. 
         FIG. 43  is a perspective view of a rectangular gravity fed fuel and air intake apparatus. 
         FIG. 44  is a perspective view of a variation of the first embodiment in assembled configuration with a cylindrical gravity fed fuel and air intake apparatus. 
         FIG. 45  is a perspective view of a separator plate with an air vent adjustment rod attached to the lower surface. 
         FIG. 46  is a perspective view of a fuel and air intake apparatus with an air vent adjustment plate hingedly attached to one side of a fuel and air intake apparatus. 
         FIG. 47  is a perspective view of one embodiment of a cylindrical chimney apparatus inserted into a fuel and air intake apparatus with the air vent adjustment plate and separator with an air vent adjustment rod in an assembled configuration. 
         FIG. 48  is a perspective view of one embodiment of a separator plate with a curved end. 
         FIG. 49  is a perspective view of one embodiment of a separator plate with bent legs. 
         FIG. 50  is a perspective view of an assembled configuration with a grill surface including grill support rails, grill tabs, and slots for grill tab insertion. 
         FIG. 51  is a perspective view of one embodiment of a main housing in which main housing panels are hingedly attached to one another and which is assembled using a tab and slot system. 
         FIG. 52  is a perspective view of one embodiment of a cook plate with re-drafter box comprised of a cook plate surface and hinged re-drafter panels assembled via re-drafter wire harness, panel lock catch tabs, and re-drafter wire harness hinge. 
         FIG. 53  is a top-down view of one embodiment, of a re-drafter comprised of a cook plate surface with a re-drafter box to be situated above chimney apparatus. 
         FIG. 54  is a perspective view of one embodiment of a re-drafter comprised of a cook plate surface with a re-drafter box positioned above an assembled collapsible biomass stove. 
         FIG. 55  is a perspective view of one embodiment of a gravity-fed fuel and air intake apparatus and gravity-fed fuel and air intake apparatus catch. 
         FIG. 56  is a perspective view of one embodiment of an assembled rocket stove with a gravity-fed fuel and air intake apparatus, gravity-fed chimney apparatus, separator with air vent adjustment rod, and air vent adjustment plate. 
         FIG. 60  is a perspective view of one embodiment of a removable pin inserted into three interlocking partial curls. 
         FIG. 61  is a perspective view of one embodiment of a rectangular chimney apparatus with chimney apparatus stability legs. 
         FIG. 62  is a perspective view of one embodiment of a fuel and air intake apparatus with holes for chimney apparatus stability legs and separator plate supports. 
     
    
    
     DRAWINGS—REFERENCE NUMERALS 
       101  main housing 
       102  front main housing panel 
       103  left main housing panel 
       104  right main housing panel 
       105  fuel and air intake apparatus window (rectangular) 
       106  separator 
       107  chimney apparatus side panel 
       108  hinge 
       109  chimney apparatus front panel 
       110  chimney apparatus (rectangular) 
       111  chimney apparatus rear panel 
       112  chimney apparatus separator slot 
       113  fuel and air intake apparatus side panel 
       114  fuel and air intake apparatus (rectangular) 
       115  fuel and air intake apparatus top panel 
       116  fuel and air intake apparatus separator slot 
       117  fuel and air intake apparatus bottom panel 
       118  rectangular main housing with cylinder fuel and air intake apparatus openings 
       119  hinge for chimney apparatus and fuel and air intake apparatus 
       120  cylinder fuel and air intake apparatus opening (rectangular) 
       121  rear main housing panel 
       124  cylindrical main housing with cylindrical fuel and air intake apparatus openings 
       125  curl-hook fastener 
       126  front cylinder fuel and air intake apparatus opening 
       128  rear cylinder fuel and air intake apparatus opening 
       130  peg fastener 
       132  hole for peg fastener 
       134  cylindrical main housing with rectangular fuel and air intake apparatus openings 
       136  front rectangular fuel and air intake apparatus opening 
       138  rear rectangular fuel and air intake apparatus opening 
       140  cylindrical chimney apparatus 
       142  cylindrical chimney apparatus separator slot 
       144  cylindrical chimney apparatus fuel and air intake apparatus opening 
       146  cylindrical fuel and air intake apparatus 
       148  cylindrical fuel and air intake apparatus separator slot 
       150  cylindrical fuel and air intake apparatus chimney apparatus opening 
       152  fuel and air intake apparatus separator catch bar 
       154  housing hinge for housing base plate 
       156  housing base plate 
       157  housing base plate hinge 
       158  catch bar for housing base plate 
       160  hinge for cook surface plate 
       162  catch bar for housing cook surface plate 
       164  hinged cook surface plate 
       166  stability rod 
       168  holes for stability rod 
       170  guide rails for chimney apparatus 
       171  groove for non-hinged front/rear panel 
       172  non-hinged front/rear main housing panel 
       173  tongue for non-hinged side panel 
       174  non-hinged side main housing panel 
       176  chimney apparatus with front and rear fuel and air intake apparatus openings 
       178  fuel and air intake apparatus separator hinge 
       179  fuel and air intake apparatus with hinged separator plate 
       180  fuel and air intake apparatus hinged separator plate 
       182  sliding grate for fuel and air intake apparatus 
       184  sliding grate lever for fuel and air intake apparatus 
       186  catch rod for sliding grate 
       187  perforated grate section 
       188  fuel and air intake apparatus with perforated grate section 
       189  dual separator fuel and air intake apparatus 
       190  triangular main housing with dual fuel and air intake apparatus windows 
       191  triangular main housing with single fuel and air intake apparatus window 
       192  triangular main housing right rear panel with single fuel and air intake apparatus window 
       193  triangular main housing left rear panel with single fuel and air intake apparatus window 
       194  triangular main housing left rear hall-panel 
       195  triangular main housing left front half-panel 
       196  triangular main housing right rear panel with dual fuel and air intake apparatus windows 
       197  triangular main housing with folding half-panels 
       198  triangular main housing left rear panel with dual fuel and air intake apparatus windows 
       200  cylindrical main housing with curl-hook fasteners 
       213  rectangular main housing with hinged side half-panels 
       214  main housing hinged half-panel 
       216  auxiliary cylindrical gravity-fed fuel and air intake apparatus 
       217  auxiliary rectangular gravity-fed fuel and air intake apparatus 
       218  main housing panel opening for auxiliary gravity-fed fuel and air intake apparatus 
       220  chimney apparatus opening for auxiliary gravity-fed fuel and air intake apparatus 
       222  fuel and air intake apparatus opening for auxiliary gravity-fed fuel and air intake apparatus 
       224  removable pin in partial curl hinge system 
       226  interlocking partial curl 
       228  gravity-fed fuel and air intake apparatus catch 
       234  separator with parabolic edge 
       235  fuel and air intake apparatus with adjustable air vent 
       236  separator with air vent adjustment rod 
       238  air vent adjustment rod 
       240  slide tube for air vent adjustment rod 
       242  air vent adjustment plate 
       244  hinge for air vent adjustment plate 
       246  hole catch for air vent adjustment rod 
       248  hinged cook surface grate 
       250  holes for hinged cook surface grate tabs 
       252  hinged cook surface tabs 
       254  grill support rods 
       256  tab for tab/slot assembly 
       258  slot for tab/slot assembly 
       260  folding panel main housing with tab/slot assembly system 
       262  re-drafter box with cook plate attachment 
       264  re-drafter vent hole 
       266  re-drafter wire harness 
       268  wire harness catch tab 
       270  hinged re-drafter panel 
       272  re-drafter wire harness hinge 
       274  gravity-fed fuel and air intake apparatus 
       276  gravity-fed cylindrical chimney apparatus 
       278  gravity-fed main housing 
       280  separator plate with legs 
       282  hole for chimney apparatus stability leg 
       284  chimney apparatus stability leg 
       286  separator plate supports 
       288  chimney apparatus with stability legs 
       291  fuel and air intake apparatus with holes for chimney apparatus stability legs 
     DETAILED DESCRIPTION OF THE INVENTION 
     Description 1 st  Embodiment (FIGS.  1 - 12 ) 
     The following detailed description comprises several contemplated modes of carrying out the numerous exemplary embodiments of the invention. The description that follows is not to be taken in a limiting sense, but rather is offered for the purpose of illustrating the general principles of the invention. Generally speaking, the collapsible rocket stove embodiments taught herein provide a simple, portable, high-efficiency cooking solution across camping, hiking, and survival applications. 
     In reference to  FIGS. 1 through 10 , a collapsible rocket stove according to one present embodiment is described in detail. The expanded and completed structure of this embodiment is seen in  FIG. 1 . The interior of this embodiment contains a chimney apparatus  110  and a fuel and air intake apparatus  114  inserted into a main housing  103 . A separator  106  is inserted into the fuel and air intake apparatus  114  and chimney apparatus  110 . A hinged cook surface plate  164  is seen in an open configuration. The hinged cook surface plate  164  is hingedly attached to the right main housing panel  104  and is advantageously movable between a closed and open position. 
     I presently contemplate that the chimney apparatus  110 , fuel and air intake apparatus  114 , and hinged cook surface plate  164  components of this embodiment are composed of type  304  stainless steel, while the main housing is composed of aluminum. Each component, however, may be comprised of a variety of materials suitable for the purpose, such as high-carbon steel, titanium, polycarbonate, ceramic, brick or any combination of materials resistant to high temperature. 
       FIG. 2  details a present embodiment of a main housing  101  in a collapsed and folded configuration. Main housing  101  is preferably but not necessarily comprised of four walls, and preferably but not necessarily of a planar geometry.  FIG. 3  details the main housing  101  in a collapsed configuration and unfolded once. A side main housing panel  104  hingedly attaches to a front main housing panel  102  via three hinges  108  in this embodiment. Another side main housing panel  103  hingedly attaches to the other side of the front main housing panel  102  via three hinges  108 . Likewise a rear main housing panel  121  hingedly attaches to the left main housing panel  103  and right main housing panel  104  via three hinges  108  on each opposing side. The front main housing panel  102  and rear main housing panel  121  each have a fuel and air intake apparatus window  105 . To enable folding of the main housing panels, either the side main housing panel  104  or side main housing panel  103  may be slightly wider than the other to accommodate the thickness of the hinge and width of the panels. Likewise, either the front main housing panel  102  or rear main housing panel  121  may be slightly wider than the other to accommodate the thickness of the hinge and width of the panels when folding. The degree of difference in the width of these panels is determined by the type of hinge employed and thickness of the main housing panels. 
       FIG. 4  details the expanded main housing  101 .  FIG. 5  details one embodiment of the chimney apparatus  110  in which the chimney apparatus  110  is advantageously movable between an expanded configuration and a collapsed configuration, detailed in  FIG. 6 . A chimney apparatus front panel  109  is hingedly attached to two chimney apparatus side panels  107  by hinges  119 . The chimney apparatus side panels  107  in this embodiment are likewise hingedly attached to a chimney apparatus rear panel  111  via hinges  119 . Those skilled in the art will note that any number or length of hinges  119  may be used to hingedly connect the chimney apparatus side panels  107  to the chimney apparatus front panel and to the chimney apparatus rear panel  111 . The chimney apparatus side panels  107  each feature a chimney apparatus separator slot  112  in this embodiment. 
       FIG. 7  details fuel and air intake apparatus  114 , in which fuel and air intake apparatus side panels  113  are hingedly attached to fuel and air intake apparatus top panels  115  and a fuel and air intake apparatus-bottom panel  117 . The fuel and air intake apparatus  114  is advantageously movable between an expanded configuration in  FIG. 7  and a collapsed configuration as in  FIG. 8 . The fuel and air intake apparatus  114  is configured to accept the insertion of the separator plate  106  into fuel and air intake apparatus separator plate slots  116  within each of the fuel and air intake apparatus side panels  113 . The separator plate is seen in  FIG. 9 . 
     It will be apparent to those of ordinary skill in the art that the fuel and air intake apparatus  114  need not feature the chimney apparatus opening at the midpoint of the top of the fuel and air intake apparatus, as detailed in  FIG. 7  and in most figures to follow. That is, the fuel and air intake apparatus top panels  115  need not be of identical length, and the fuel and air intake apparatus  114  could be configured such that the chimney apparatus inserted either towards or away from the “front” or “fuel-feeding” section of the feel and air intake apparatus  114 . An embodiment in which the chimney apparatus was located further away from the “front” of the fuel and air intake apparatus, for example, would permit a longer distance and therefore longer duration of pre-heating the fuel before entry into the combustion chamber. 
       FIG. 10  details the fuel and air intake apparatus  114  inserted into a fuel and air intake apparatus window  105  in the front main housing panels  102  and rear main housing panel  121 .  FIG. 11  details the chimney apparatus  110  inserted into the fuel and air intake apparatus  114 .  FIG. 12  details the completed folding rocket stove configuration with the hinged cook surface plate  164  in a closed configuration with separator  106  inserted into fuel and air intake apparatus  114  and chimney apparatus  110 . In this embodiment, the separator plate fits within the fuel and air intake apparatus separator plate slots  116  and the chimney apparatus separator plate slots  112 . 
     Alternate Component Configurations—1 st  Embodiment (FIGS.  1  to  12 ) 
     Those skilled in the art will note that any number of hinges  108  may be used to connect the side main housing panel  103  and side main housing panel  104  to the front main housing panel  102  and rear main housing panel  121 . Likewise those skilled in the art will note that hinge  108  may be replaced by a single continuous hinge  160 , a rod and a series of cylinders or approximately cylindrical elements either continuous with or attached to the sides of the component panels. Likewise any number of hinges or hinge substitutes attaching hinged cook surface plate  164  to right main housing side panel  104  may be employed. Those skilled in the art will note that any individual hinge  108  or continuous hinge  160  throughout the collapsible rocket stove may likewise be replaced with any number of hinges, with a continuous hinge, or with another attaching mechanism functioning as a hinge (e.g. a rod and with a threaded end running through a series of cylinders, loops, wires, etc. and attaching to a threaded apparatus or nut at the opposite end). Likewise, coiled wires, rolled steel cylinders, or approximately cylindrical elements may also be substituted for hinges, whereby these elements are permanently affixed to adjacent elements in a manner clear to those skilled in the art. These hinge  108  substitutions or continuous hinge  160  substitutions may be applied to any other hingedly connected elements discussed herein. In addition, three of the four main housing panels may be hinged, while the fourth is attached via tab and slot attachments or another means of attachment achieving the same purpose. 
     Variously, hinges may be omitted entirely, utilising permanently expanded components for chimney apparatus  110  and fuel and air intake apparatus  114  while retaining the structure of the rocket stove. As with the embodiment discussed with collapsible components, the permanent or non-hinged components are assembled utilizing an outer housing and interior components advantageously inserted into the outer housing for cooking, or disassembled for cleaning, storage, or transport. For example, a main housing  101  may be collapsible in the manner described, while non-hinged/non-collapsible components are inserted and assembled within the housing. Such an embodiment would retain some of the ad vantages of reducing storage and transport volume of a rocket stove constructed out of entirely collapsible components while omitting complications and high construction costs associated with the use of hinges or components functioning as hinges. Such an embodiment would also retain the advantage of potential use of indigenous insulating material, such as dirt, rocks, etc. utilized at the site of use, and discarded without adverse environmental consequence upon disassembly. 
     Alternatively, an embodiment of the collapsible rocket stove in which one or more components consist entirely or partially of panels inserted into appropriate slots in the main housing is possible. This configuration could omit the use of some or all hinges, saving on cost, weight, and complexity. For example, the fuel and air intake apparatus  114  could be constructed of a bottom plate and hinged side panels, and inserted into the main housing in a “U” configuration. The top plate then consists of a panel overlaid upon the open top of the fuel and air intake apparatus after fuel and air intake apparatus insertion. The side panels may be inserted into slots maintaining the expanded position of the “U” shaped bottom, and side portion of the fuel and air intake apparatus. The top panel may then be overlaid upon the fuel and air intake apparatus (held in place via overhanging bends in the top panel or some alternate means of attachment). 
     A further alternate embodiment in which any or all component panels are embossed, ribbed, or otherwise altered for rigidity is envisioned. That is, in order to preclude warping and increase component rigidity, a pattern of either a purely functional or decorative nature is pressed, embossed, or otherwise imparted so as to change the section modulus of the component. This change enables the components to better withstand the extreme anisotropic heating and cooling involved in prolonged rocket stove operation without component deformation. 
     Operation—1 st  Embodiment (FIGS.  1  to  12 ) 
     The operation of the first embodiment detailed in  FIGS. 1 to 12  is described below. The main housing  101  in collapsed configuration ( FIG. 2 ) is unfolded as in  FIG. 3  and expanded as in  FIG. 4 . The chimney apparatus  110  in collapsed configuration as in  FIG. 6  is expanded as in  FIG. 5 . The fuel and air intake apparatus  114  in collapsed configuration as in  FIG. 8  is expanded as in  FIG. 7 . The collapsible configuration for the main housing  101 , chimney apparatus  110 , and fuel and air intake apparatus  114  reduces the volume the user must commit to storage and transport of the rocket stove. 
     The fuel and air intake apparatus  114  inserts into the main housing window  105  in the front housing panel  102 . In this embodiment, the fuel and air intake apparatus rests partially extruding from the front main housing panel  102  and rear main housing panel  121 , forming a bridge between the housing panels as seen in  FIG. 10 . The “bridge” formed by the insertion of the fuel and air intake apparatus into the main housing serves to elevate the combustion chamber from both the ground and the main housing  101 . The chimney apparatus  110  is inserted into fuel and air intake apparatus  114  as seen in  FIG. 11 . The separator plate  106  is inserted into the fuel and air intake apparatus separator plate slots  116  and chimney apparatus separator plate slots  112  as seen in  FIG. 12 . It will be clear to those skilled in the art that the fuel and air intake apparatus  114  could also rest upon the ground, whereby the fuel and air intake apparatus windows  105  would likewise be continuous or nearly continuous with the bottom edge of the front main housing panel  102  and rear main housing panel  121 . 
     The insertion of the separator plate  106  serves to divide the fuel and air intake apparatus  114  into two sections. The volume within fuel and air intake apparatus  114  above separator plate  106  functions as the solid fuel intake of the rocket stove. The user may insert twigs, sticks, and assorted biomass into this section of the fuel and air intake apparatus  114 . The volume within fuel and air intake apparatus  114  beneath the separator plate  106  functions as the air intake for the rocket stove, which will serve to supply oxygen into the combustion chamber. The combustion chamber is substantially located within the volume contained within both the chimney apparatus  110  and the fuel and air intake apparatus  114 . 
     At this point several alternate configurations may be employed in operation of this embodiment of the collapsible rocket stove. Insulation may be added after the rocket stove is expanded and assembled within the main housing  101  around the fuel and air intake apparatus  114  and chimney apparatus  110 . This serves to elevate the operating temperature of the stove and reduce connective losses due to ambient air contact with the outer chimney apparatus  110  and fuel and air intake apparatus  114  panel walls. This insulation may be indigenous to a campsite or cook site, for example but not limited to earth, small stones, clay or sand. Alternatively, vermiculite, kitty litter, or any insulating material available may be employed as desired. The added insulation will increase the efficiency of the embodiment by raising the temperature of the fuel and air intake apparatus  114 , chimney apparatus  110 , and combustion chamber. The higher temperature will allow for a more complete “re-burn” of the hydrocarbons released during the burning of the biomass normally lost as smoke. Likewise, it will be apparent to those of ordinary skill in the art that the chimney apparatus  110  or fuel and air intake apparatus  114  may be insulated from within by an appropriate material inserted into the chimney apparatus  110  or fuel and air intake apparatus  114 , either slid into place upon expansion or fixedly attached to any or all of the component panel walls. Such an insulation could be comprised of tile, ceramic, high-temperature ceramic fiber insulating cloth, or any material suitable for the purpose. 
     Sticks, twigs, or assorted biomass are then inserted into the combustion chamber, along with tinder, kindling, or paper according to preference. The fire is then kindled, and the high temperature of the ignited biomass in the combustion chamber creates a low pressure region. This pressure gradient draws air into the fuel and air intake sections of the fuel and air intake apparatus  114 . The confined combustion within the high temperature combustion chamber and chimney apparatus  110  serves to contain and prolong the combustion of fuel, leading to a more complete consumption of available hydrocarbons and highly efficient fuel consumption. This high temperature environment is further assisted by another well-known feature of the rocket stove concept. That is, a pre-heating of the air and fuel due to the confinement of the draft to the fuel and air intake apparatus  114 , where the air and fuel are heated along their path to the combustion chamber. 
     As the draft then continues up the chimney apparatus  110 , secondary combustion continues as the heat and combustion products are channeled and expelled towards the cook surface. The hinged cook surface plate  164  is now closed. In this embodiment, the cook surface plate  164  attaches to the right main housing panel  104  via the hinge for cook surface plate  160 . The side of the cook surface plate  164  opposite the hinge for cook surface plate  160  rests upon the catch bar for housing cook surface plate  162 . Fuel can now be fed into the fuel and air intake apparatus for continuous cooking in any pot, pan, or cooking instrument placed on the hinged cook surface plate  164 . Temperature can be partially controlled by limiting the available biomass in the fuel and air intake apparatus  114 . 
     The addition of insulation will also provide a heat source for a greater duration than an air-insulated cook, allowing heat trapped in the insulation to release its energy gradually as the insulating material cools. Either variation will provide a highly efficient portable biomass stove, and the particular choice of insulation, if any, will vary according to preference and available material. 
     Description and Operation—2 nd  Embodiment (FIGS.  13  to  14 ) 
       FIG. 13  details an alternate embodiment of the main housing, in which non-hinged panels comprise the main housing and are assembled via a tongue and groove. In this embodiment, a tongue for non-hinged side panel  173  within a non-hinged side main housing panels  174  fits into a groove for non-hinged front/rear main housing panel  171  within non-hinged front/rear main housing panels  172  as seen in  FIG. 14 . This configuration may be preferable in some instances where cost and weight are of principle concern, as this embodiment omits the need for the cost and weight of main housing hinges. Operation of the 2 nd  Embodiment then proceeds identically to the 1 st  Embodiment. 
     Description and Operation—Cylindrical Configurations (FIGS.  15  to  27 ) 
       FIG. 13  details an alternate embodiment of the main housing, in which a cylindrical main housing  124  is employed and seen in a rolled or expanded configuration. This embodiment is envisioned to consist of a single sheet with circular fuel and air intake apparatus openings  126  and  128  opposite one another when the sheet is rolled into a cylinder.  FIG. 16  details the cylindrical main housing embodiment  124  in an unrolled configuration. 
     This configuration is assembled using peg fasteners  130  and holes for peg fasteners  132 , in which the side of the sheet with peg fasteners  130  is pulled beneath the side of the sheet with holes for peg fasteners  132 . The peg fasteners  130  insert into the holes for peg fasteners  132  as detailed in  FIG. 17 . 
       FIG. 18  details a perspective view of the means of attaching a cylindrical main housing with curl-hook fasteners  200  in which the opposite ends are pulled inward and connected via curl-hook fasteners  125 , similar to that employed in ductwork for heating/cooling applications. Cylindrical fuel and air intake apparatus openings  126  and  128  are featured and will receive opposite ends of the fuel and air intake apparatus upon assembly.  FIG. 19  details the cylindrical main housing embodiment with curl-hook fasteners  200  in an unrolled configuration. 
       FIG. 20  details an alternate embodiment in which a cylindrical main housing  134  is employed with rectangular fuel and air intake apparatus openings  136  and  138  situated opposite one another when the sheet comprising the cylindrical main housing  134  is rolled into a cylinder.  FIG. 21  details the cylindrical main housing  134  in an unrolled configuration. 
       FIG. 22  details an alternate chimney apparatus embodiment in which a cylindrical chimney apparatus  140  is employed. The cylindrical chimney apparatus fuel and air intake apparatus opening  144  is configured to accept the separator  106  within the separator slots  142 . This chimney apparatus is constructed by fastening opposing ends of the unrolled configuration seen in  FIG. 23 . Both  FIGS. 22 and 23  feature an opening for cylindrical fuel and air intake apparatus  144  as well as slots for a separator plate  142 . 
     It will be apparent to those of ordinary skill in the art that this opening for cylindrical fuel and air intake apparatus  144  may or may not be symmetric, and may rather be configured to limit or direct air flow or fuel into the combustion chamber as desired. Likewise, it will be apparent to those of ordinary skill in the art that the cylindrical chimney apparatus  140  may be insulated by an appropriate material inserted into the cylindrical chimney apparatus  140  upon expansion or fixedly attached to the cylindrical chimney apparatus  140  wall. 
       FIG. 24  is a perspective view of the cylindrical fuel and air intake apparatus  146  in a rolled configuration. This is constructed via the fastening of opposite ends of the unrolled configuration seen in  FIG. 25 . Both  FIGS. 24 and 25  feature separator plate slots  148  as well as an opening for cylindrical chimney apparatus  150 . The cylindrical fuel and air intake apparatus  146  and cylindrical chimney apparatus  140  assemble in a similar fashion to the non-cylindrical counterparts. That is, the cylindrical feel and air intake apparatus  146  is inserted into a cylindrical main housing with cylindrical fuel and air intake apparatus openings  124 . The cylindrical chimney apparatus  140  is then inserted into the cylindrical fuel and air in take apparatus via the opening for the cylindrical chimney apparatus  150 . The cylindrically configured embodiment is then operated in a manner identical to the 1 st  and 2 nd  embodiments. 
     Description and Operation—4 th  Embodiment (FIGS.  26  to  29 ) 
       FIG. 26  details the triangular main housing with a single rear fuel and air intake apparatus opening  191 . This housing is comprised of triangular main housing right rear panel with single fuel and air intake apparatus window  192  hingedly connected to front main housing panel  102 . Front main housing panel  102  is also hingedly connected to triangular main housing left rear panel with single fuel and air intake apparatus window  193 . The triangular main housing side panels  192  and  193  may be advantageously maneuvered into either a collapsed or expanded configurations according to preference. In this embodiment, the triangular main housing side panels  192  and  193  are attached to one another via a removable pin  224  through the top and down the length of a series of interlocking partial curls  226  at the panel edge. One embodiment of this mechanism is seen in  FIGS. 57 to 60 . 
     Those skilled in the art will note that any number of means of interlocking the two triangular main housing side panels  192  and  193  may be variously employed to secure the sides. These include interlocking loops or partial curls in the panel, attached bolts or spacers, or a series of interlocking slots and tabs in any number of configurations which mechanically join the triangular main housing side panels  192  and  193 . Likewise those skilled in the art will note that removable pin  224  may consist a rod and a series of cylinders or approximately cylindrical elements either continuous with or attached to the sides of the component panels and joined by some rod, bolt, screw, or similarly functioning mechanism. 
     Another embodiment of the invention is the triangular main housing with dual fuel and air intake apparatus windows  190  seen in  FIG. 27 . Triangular main housing right rear panel with dual fuel and air intake apparatus windows  196  and triangular main housing left rear panel with dual fuel and air intake apparatus windows  198  are both hingedly attached in this embodiment to the front main housing panel  102 . In a manner similar to the embodiment shown in  FIG. 26 , the rear panels are attached to one another via a removable pin  224  inserted through the top and extending down the length of a series of interlocking partial curls  226  at the panel edges of the triangular main hosing right and left rear panels with dual fuel and air intake apparatus windows  196  and  198 . One embodiment of this mechanism is seen in  FIGS. 57 to 60 . 
     Alternately,  FIGS. 28 and 29  depict another embodiment of the triangular main housing design, namely a triangular main housing with folding half-panels. In this embodiment, one of the two rear side panels of  FIG. 26  is replaced with two panels, triangular main housing rear half-panel  194  and triangular main housing front half-panel  195  hingedly attached to one another and both the front main housing panel  102  and a triangular rear main housing panel either  192  or  193 , depending on which rear panel is replaced with the hinged panels. This embodiment enables the user to expand and construct the main housing structure from a collapsed configuration depicted in  FIG. 29 . This embodiment is advantageously movable between expanded or collapsed configurations as desired. The triangular main housing embodiments depicted in  FIGS. 26 to 29  are then operated in a manner identical to the 1 st , 2 nd , and 3 rd  embodiments. 
     Alternate Component and Main Housing Configurations Description and Operation (FIGS.  30  to  62 ) 
     A fuel and air intake apparatus with hinged separator plate  179  is seen in  FIGS. 30 to 31 . In this embodiment, the separator plate  180  is hingedly attached to one side of the fuel and air intake apparatus via a hinge for separator plate  178 . This configuration omits the need for separate insertion of a separator plate, and instead utilizes a separator plate catch  152  to stabilize the separator plate  180  on the side of the fuel and air intake apparatus opposite the hingedly connected side. The expanded perspective view is seen in  FIG. 30 , while the end-on view of the expanded fuel and air intake apparatus with hinged separator plate  180  is seen in  FIG. 31 . This embodiment can be advantageously expanded and collapsed according to preference. 
     An alternate main housing embodiment is detailed in  FIG. 32 . In this embodiment, a hinged base plate  156  is hingedly attached to a side panel of the main housing via a housing base plate hinge  157 . A base plate catch  158  is located opposite the hinged side of the hinged base plate in this embodiment. It will be apparent to those of ordinary skill in the art that the base plate may be attached to the main housing by way of any number of means, including a tab and slot system in a manner similar to those seen in  FIG. 52 , tongues and grooves in a manner similar to those seen in  FIG. 13 , or by any means achieving the same purpose. 
     The attachment of a hinged base plate  156  to the main housing  101  serves several functions. The base plate allows for an insulated version of the stove to be transported from one location to another without requiring re-insulation. That is, the fuel and air intake apparatus  114  and chimney apparatus  110  can be insulated with dirt, rocks, etc., and this insulation will not fall out of the bottom of the stove during transport. 
       FIG. 33  details one embodiment of a means of stabilizing the chimney apparatus within the main housing. In this embodiment, a stability rod  166  is inserted through both the main housing  101  and the chimney apparatus  110  via a series of holes for stability rod  168 . It will be apparent to those of ordinary skill in the art that stability rod may be oriented in any direction, may be one rod or numerous rods, or may be replaced with a wire harness or similar implement, to effectively achieve the same purpose. 
       FIG. 34  details one embodiment of another means of stabilizing the chimney apparatus within the main housing. In this embodiment, a series of stability guide rails  170  are situated vertically within the fuel and air intake apparatus  114  which serve to effectively limit the range of motion available to the chimney apparatus  110  upon insertion into the fuel and air intake apparatus  114 . It will be apparent to those of ordinary skill in the art that stability guide rails  170  may consist of stainless steel rounds, thin strips of stainless steel, ceramic rods or any alternate material suitable for the high temperature conditions in close proximity to the combustion chamber. These may be oriented vertically within the fuel and air intake apparatus  114  at the four corners where the fuel and air intake apparatus  114  meets the chimney apparatus  110  as depicted in  FIG. 34 . Similarly, it will be apparent to those of ordinary skill in the art that these may be oriented vertically within the fuel and air intake apparatus  114  and correspond to slits or cuts in the lower chimney apparatus section which serve to vertically align and maintain the chimney apparatus  110  orientation relative to the fuel and air intake apparatus  114 . 
       FIG. 35  details one embodiment of a chimney apparatus with front and rear fuel and air intake apparatus openings  176 . This embodiment differs from chimney apparatus  110  in that the chimney apparatus rear panel  111  is replaced with another chimney apparatus front panel  109 . The panels comprising the walls of the chimney apparatus with front and rear fuel and air intake apparatus openings  176  are hingedly attached to one another in manner similar to the original chimney apparatus  110  embodiment. This embodiment would require dual separator plates of any embodiment, to enable two-sided rocket stove operation. Furthermore, it will be apparent to those of ordinary skill in the art that one side or some portion of one side of the chimney apparatus front panel  109  may extend further down the length of the chimney apparatus, creating an asymmetrical opening in to the chimney apparatus for fuel and air from the fuel and air intake apparatus. 
       FIG. 36  offers a perspective view of a fuel and air intake apparatus with dual separators  189  with two hinged separator plates  180 , two hinges for separator plates  178 , and two separator plate catches  152 . It will be apparent to those of ordinary skill in the art that the dual separator fuel and air intake apparatus  189  could be comprised of dual separator plates  106  with accompanying fuel and air intake apparatus separator slots  116 . Furthermore, it will be apparent to those of ordinary skill in the art that the dual separator plates  106  in this embodiment, as with any separator embodiment, could be comprised of a separator plate supported not by slots but by approximately 90° turns in opposing ends of the separator plate which act as legs or supports for the plate. One such embodiment is depicted as separator plate with legs  228  in  FIG. 49 . 
       FIG. 37  describes an alternate fuel and air intake apparatus embodiment, depicting a fuel and air intake apparatus with perforated grate section  188 . In this depiction, two catch rods for sliding grate  186  are depicted running parallel to the bottom panel and attached to the side panels of the fuel and air intake apparatus with perforated grate section  188 .  FIG. 38  depicts the embodiment with the sliding grate for fuel and air intake apparatus  182  inserted. The operation of this embodiment involves the sliding grate lever for fuel and air intake apparatus  184 , which may be moved advantageously towards or away from the front of the fuel and air intake apparatus with perforated grate section  188 . This movement may be perforated such that any ash or debris that may collect upon the sliding grate for fuel and air intake apparatus  182  can be either dropped or shaken through the aligned holes in the perforated grate section  188  and sliding grate for fuel and air intake apparatus  182 . 
     It will be apparent to those of ordinary skill in the art that the perforated grate may be constructed out of hardware cloth or expanded steel welded to the stainless steel base plate of the fuel and air intake apparatus with perforated grate section  188 . Similarly, it will be apparent to those of ordinary skill in the art that the perforated grate may consist merely of a plurality of holes drilled in the center of the lower (bottom) plate of the fuel and air intake apparatus with perforated grate section  188 . The sliding grate lever for fuel and air intake apparatus  184  may be comprised of a rod composed of stainless steel or any material sufficient to withstand the temperatures involved with the stove&#39;s operation. Furthermore, the sliding grate lever for fuel and air intake apparatus  184  may end in a loop for ease of use as depicted in  FIG. 38 , or it may otherwise end in any shape suitable for the purpose of facilitating movement of the sliding grate for fuel and air intake apparatus  182 . It will be apparent to those of ordinary skill in the art that the sliding grate for fuel and air intake apparatus  182  may extend the length of the lower panel of the fuel and air intake apparatus with perforated grate section  188  and may or may not be terminated with a sliding grate lever for fuel and air intake apparatus  184 . 
       FIG. 39  depicts one embodiment of a rectangular main housing with cylindrical fuel and air intake apparatus openings  118 . This embodiment maintains the hingedly collapsible main housing while allowing for a cylindrical fuel and air intake apparatus  146  to be inserted into either of the cylindrical fuel and air intake apparatus openings  120 . It will be apparent to those of ordinary skill in the art that the rectangular main-housing with cylindrical fuel and air intake apparatus openings  118  may be connected by several hinges in as in  FIG. 39 , or variously with continuous hinges, sections of continuous (aka piano) hinges, or implements serving the function of hinges. 
     Another embodiment of a rectangular main housing allows for the collapse of the main housing without the need for a second fold utilized in the main housing  101  and depleted in  FIG. 40 . This embodiment depicts a rectangular main housing with dual folding side panels  213 . This embodiment employs a bifurcation of the side panels of the main housing  101 , in which said main housing hinged half-panel  214  is hingedly connected to both another main housing hinged half-panel and either a front or rear main housing panel  102 . It will be apparent to those of ordinary skill in the art that the main housing hinged half-panels may be connected by several hinges in as in  FIG. 39 , or variously with continuous hinges, sections of continuous (aka piano) hinges, or implements serving the function of hinges. A partially collapsed depiction for the rectangular main housing with dual folding side panels  213  is seen in  FIG. 41 . 
     Another alternate embodiment of the folding rocket stove concept involves an auxiliary fuel and air intake apparatus which augments the main fuel and air intake apparatus  114  by providing another means of fuel delivery to the combustion chamber. In this embodiment, the auxiliary gravity-fed fuel and air intake apparatus may be either cylindrical or rectangular. The auxiliary cylindrical gravity-fed fuel and air intake apparatus  216  is depicted in  FIG. 42 , while the auxiliary rectangular gravity-fed fuel and air intake apparatus  217  is depicted in  FIG. 43 . One embodiment of the employment of these auxiliary gravity-fed fuel and air intake apparatus is depicted in  FIG. 44 . In this embodiment, a cylindrical auxiliary gravity-fed fuel and air intake apparatus is depleted as protruding from the top right side of the main housing via the main housing gravity fuel and air intake apparatus cylinder opening  218 . Similarly, the auxiliary cylindrical gravity-fed feel and air intake apparatus  216  passes through both the fuel and air intake apparatus opening for auxiliary gravity-fed feel and air intake apparatus  218  and the chimney apparatus opening for auxiliary gravity-led fuel and air intake apparatus  222  in this embodiment. 
     It will be apparent to those of ordinary skill in the art that the embodiment depicted in  FIG. 44  may be composed of rectangular rather than oval openings to fit the auxiliary rectangular gravity-fed fuel and air intake apparatus  217  in place of the auxiliary cylindrical gravity-fed fuel and air intake apparatus  216 . Likewise, it will be apparent to those of ordinary skill in the art that the embodiment depicted in  FIG. 44  may contain an auxiliary gravity-fed fuel and air intake apparatus oriented in any direction. That is, the auxiliary cylindrical gravity-led feel and air intake apparatus  216  depicted in  FIG. 44  may be oriented to the left, to the front, or to the rear of the main feel and air intake apparatus  114  rather than the right. Likewise, it will be apparent to those skilled in the art that there may be one or several auxiliary gravity-fed fuel and air intake apparatuses, with accompanying openings in the main housing  101 , chimney apparatus  110 , and fuel and air intake apparatus  114 . 
     In  FIGS. 45, 46, and 47  an alternate embodiment of a separator and fuel and air intake apparatus that enables preferential limitation of the air draft through the fuel and air intake apparatus is provided.  FIG. 45  depicts a separator with air vent adjustment rod  236 . This embodiment provides an air vent adjustment rod  238  as well as a slide tube for air vent adjustment rod  240 . This slide tube provides the means of attachment of the air vent adjustment rod  238  to the separator  106 .  FIG. 46  provides an embodiment of a fuel and air intake apparatus with adjustable air vent  235  with an air vent adjustment plate  242  hingedly attached to the fuel and air intake apparatus with adjustable air vent  235  via a continuous hinge for air vent adjustment plate  244  and hole catch for air vent adjustment rod  246 . 
       FIG. 47  depicts the insertion of the air vent adjustment rod  238  into the hole catch for air vent adjustment rod  246 , whereby the air vent adjustment rod  238  may be advantageously moved towards and away from the operator by passing through the slide tube for air vent adjustment rod  240 , an action which will correspondingly move the air vent adjustment plate  242  towards and away from the operator. This movement, limits or expands the available space for the air draft past the air vent adjustment plate  242  during stove operation. 
     It will be apparent to those of ordinary skill in the art that the embodiment depicted in  FIGS. 45 through 47  may utilize a weld to attach the slide tube for air vent adjustment rod to the separator plate  106 , although any number of alternate means of attachment may be employed, including a strip of metal and screws directed through the separator plate and metal fastening strip, a series of such fastening strips, or any similar means achieving the same end. 
       FIGS. 48 and 49  depict alternate separator embodiments.  FIG. 48  depicts a separator plate with parabolic edge  234 . Such an embodiment inserts into the fuel and air intake apparatus separator slot  116  as well, as the chimney apparatus separator slot  112  as taught in earlier embodiments, but recedes from the combustion chamber in a concave manner to allow for earlier direct contact between air from the bottom section of the fuel and air intake apparatus  114  and the fuel.  FIG. 49  depicts an alternate embodiment of a separator plate in which the plate is bent at the edges parallel to the walls of the fuel and air intake apparatus  114  to form legs upon which the separator rests. This embodiment obviates the need for a chimney apparatus separator slot  112  and fuel and air intake apparatus separator slot  116 , although what this design gains in simplicity it sacrifices somewhat for volume, since the legs are not collapsible. 
     An alternate depiction of a cook surface is depicted in  FIG. 50 , in which a hinged cook surface grate  248  is hingedly attached to a main housing  101  via a hinge for cook surface plate  160 . In this embodiment, the hinged cook surface grate  248  is supported by a pair of grill support rods  254 . Furthermore, this embodiment features a pair of holes and tabs locking the hinged cook surface grate  248  into the main housing  101 . In this embodiment, the hinged cook surface tabs  252  insert into the holes for hinged cook surface grate tabs  250 . 
     It will be apparent to those of ordinary skill in the art that any number of holes and tabs may be employed in any or all of the remaining main housing panels, rather than the two depicted in the opposite panel as depicted in  FIG. 50 . Likewise, it will be apparent to those of ordinary skill in the art that the hinged cook surface grate  248  may be supported by any number of possible variants of this design, to include tabs or posts extending from the hinged cook surface grate  248  and resting on the top of the main housing panels  102 ,  103 ,  104 , or  121 . 
     An alternate main housing configuration is depicted in  FIG. 51 , in which a folding panel main housing with tab/slot assembly system  260  are hingedly connected as shown. The panels assemble via a tab and slot system, whereby the tabs for tab/slot assembly  256  are inserted into the slots for tab/slot assembly  258  by folding each panel at right angles to form a right rectangular parallelepiped. 
     It will be apparent to those of ordinary skill in the art that any number of tabs and slots may be employed in place of those depicted in  FIG. 51  for any or all of the main housing panels, requiring either tabs or slots in any number or configuration. Furthermore, it will be apparent to those of ordinary skill in the art that any geometrical configuration of tab or slot that serves the noted purpose can be substituted for the particular embodiment taught in  FIG. 51 . 
     An alternate embodiment involving the cook surface and/or the space between the chimney apparatus and the cook surface is seen in  FIG. 52 . In this embodiment, the cook plate with re-drafter box  262  is comprised of preferably four approximately planar plates, preferably comprised of austenitic steel to better withstand the stove operating temperatures, hingedly attached to the underside of a cook plate, these four hinged re-drafter panels  270  may be advantageously moved between a collapsed and expanded configurations. The expanded configuration of hinged re-drafter panels  278  is maintained, in this embodiment, by way of a re-drafter wire harness  266  and a series of wire harness catch tabs  268  positioned along the hinged re-drafter panels  270  in such a manner as to enable the re-drafter wire harness  266  to securely maintain the re-drafter box  262  in an expanded configuration. This may be accomplished via a friction hold between the wire harness and the tab. Alternately, the wire harness catch tabs  268  may be configured in such a manner as to enable a tension hold between the two hinged re-drafter panels  270  adjacent to the hinged re-drafter panel  270  with the re-drafter wire harness hinge  272  and the hinged re-drafter panel  270  opposite the hinged re-drafter panel  270  with the re-drafter wire harness hinge  272 . 
     This embodiment of the re-drafter box with cook plate attachment  262  is intended to be placed upon the collapsible rocket stove after the stove has reached operating temperature. At this point, the re-drafter box with cook plate attachment  262  will be constructed in an expanded configuration using the re-drafter wire harness  266  and the wire harness catch tabs  268 . The re-drafter box with cook plate attachment  262  is then placed on top of the main housing  101 , centered on the center of the chimney apparatus  110  in this embodiment. The relative positions of the re-drafter box with cook plate attachment  262  and the main housing  101  of a constructed collapsible rocket stove is depicted in  FIG. 54 . 
     Once the re-drafter box with cook plate attachment  262  is lowered onto the rocket stove at operational temperatures, rising air and smoke from the combustion chamber will be re-directed down by the re-drafter box with cook plate attachment  262 , delaying the interaction of the smoke and rising air with cooler ambient air. This will prolong the “secondary-burn” of the wood gases released by the fuel, enabling a more complete burn of volatile organic molecules, increasing the stove efficiency and decreasing smoke production. The exhaust from the stove will then pass beneath the skirt of the re-drafter box with cook plate attachment  262  and rise to escape through re-drafter vent holes  264  and into the ambient environment. 
     It will be apparent to those of ordinary skill in tire art that any number of re-drafter vent holes  264  may be employed in any orientation to permit passing of the stove exhaust into the ambient environment. Furthermore, it will be apparent to those of ordinary skill in the art that the hinged re-drafter panels  270  may be assembled via tabs and slots in a manner similar to that depicted in  FIG. 51 , pins and partial curls in a manner similar to those seen in  FIGS. 57 to 60 , or by means of any attachment mechanism suited for the purpose. Likewise, it will be apparent to those of ordinary skill in the art that the re-drafter box with cook plate attachment  262  may not be hinged at all but rather a permanently configured optional component to a collapsible rocket stove, though this attachment in a non-collapsible embodiment would have to trade simplicity of construction (without hinges) for inconvenience of transport, as a non-hinged version would not be collapsible. It will also be apparent to those of ordinary skill in the art that the re-drafter panels may be continuous and impermeable, or may rather be perforated with holes or “windows” through which the re-drafted exhaust may escape. 
     It will furthermore be apparent to those of ordinary skill in the art that the re-drafter box may be free-standing, designed to maintain its position upon either the ground or upon some interior insulation via several legs or via the extension of the hinged re-drafter panel  270 . The re-drafter box with cook plate attachment  262  may likewise be employed with a chimney apparatus featuring vents along the upper walls of the chimney apparatus, allowing exhaust to escape the chimney apparatus from the upper sides of the chimney apparatus either in addition to or in place of exhaust exclusively through the top of the chimney apparatus  110  as detailed in other embodiments herein described. 
     Another embodiment of the fuel and air intake apparatus component is seen in  FIG. 55 . In this embodiment, a fuel and air intake apparatus similar to the fuel, and air intake apparatus detailed in  FIGS. 7 and 8 , but of greater length, with an elongated chimney apparatus opening, and with gravity fuel and air intake apparatus catches  228  is detailed. This embodiment is the gravity-fed fuel and air intake apparatus  274 . As with previous rectangular configurations, the gravity-fed fuel and air intake apparatus  274  is preferentially composed of planar or roughly planar panels hingedly attached to one another. The gravity-fed fuel and air intake apparatus can then be advantageously expanded or collapsed for use or transport according to preference. Likewise, it will be apparent to those of ordinary skill in the art that the gravity fuel and air intake apparatus catch  274  could be utilized with a fuel and air intake apparatus  114  for purposes of component stability. 
     For this embodiment, a gravity-fed main housing  278  would be required, which would accommodate the gravity-fed fuel and air intake apparatus  274  and is detailed generally in  FIG. 56 . This embodiment would entail fuel and air intake apparatus openings to be offset from one another relative to the resting surface, with the fuel and air intake apparatus opening of higher elevation representing the opening into which the expanded configuration of the gravity-fed fuel and air intake apparatus  274  is inserted. The gravity-fed fuel and air intake apparatus  274  is then, fed into the gravity-fed main housing  278  until the gravity-fed fuel and air intake apparatus has passed through the lower fuel and air intake apparatus opening, and then caught upon outer surface of the gravity-fed main housing  278  by way of the two gravity-fed fuel and air intake apparatus catches  228  in this embodiment. 
     It will be apparent to those of ordinary skill in the art that the gravity-fed fuel and air intake apparatus may be oriented in any direction and through a wide array of angles relative to the ground, according to preference. It will be furthermore apparent to those of ordinary skill in the art that the gravity-fed fuel and air intake apparatus  274  may be comprised of geometries similar to those described for alterations upon the first described embodiment. That is, a cross section of the gravity-fed fuel and air intake apparatus  274  may be of a square, rectangular, triangular, oval, or circular geometry. Likewise, any number and orientation of gravity-fed fuel and air intake apparatus catches  228  may be alternately employed to accomplish a similar purpose. 
       FIGS. 57 to 60  detail possible embodiments of panel edges curled upon themselves to form interlocking partial curls  226 . A cross-sectional view of one such embodiment is seen in  FIG. 57 . It will be apparent to those of ordinary skill in the art that this type of interlocking mechanism may be substituted for any or all hinge components seen in the various embodiments of the invention. This embodiment of a “hinging” mechanism is preferentially continuous with, or otherwise physically attached to, the panels of the varied components of the invention. Panels to be joined would then be comprised of offset interlocking partial curls  226 . 
     A cross-section of two overlaid interlocking partial curls  226  are seen in  FIG. 58 . One embodiment of a removable pin  224  which would be inserted along the overlapping axis of the interlocking partial curls  226  is seen in  FIG. 59 . The affect of interlocking partial curls  226  continuous with adjacent, joined panels is seen in  FIG. 60 . 
     Alternate embodiments of a chimney apparatus with stability legs  288  is depicted in  FIG. 61 . In this embodiment, the chimney apparatus stability legs  284  insert into the holes for chimney apparatus stability legs  282  located in the bottom plate of the fuel and air intake apparatus with holes for chimney apparatus stability legs  290 , as depicted in  FIG. 62 .  FIG. 62  also depicts the addition of rails, rods, or narrow plates serving as separator plate supports  286 , which enables the use of a separator plate without the need for inserting the plate into slots in the chimney apparatus  288  and/or fuel and air intake apparatus. 
     It will be apparent to those of ordinary skill in the art that alternative embodiments, including any number of substituted arrangements of the component embodiments described in the above teaching, may be produced given the foregoing description. As such, any variations, combinations, and alternative embodiments are accordingly considered within the scope of the present invention. 
     Any directional references (e.g. upper, lower, above, below, left, right, top, bottom, above, below, etc.) are used exclusively for identification purposes as an aid to understanding of the embodiments provided, and do not create limitations, particularly as to the position, orientation, or the use of the invention. Joinder references do not necessarily imply direct, contact, and are to be construed broadly and may include components interspersed between elements described as attached or connected in the described embodiments. 
     It is intended that all matter contained in the above description or accompanying drawings would be interpreted as exclusively illustrative and not exhaustive. That is, the description is in no way intended to limit the invention, to the embodiments specifically described. Any arrangement of portable, independent rocket stove components assembled within an outer housing calculated to form a similar structure and achieve a similar purpose could be substituted for the specific examples shown. Changes in structure, material, or detail may be made without departing from the spirit of the invention. This application is intended to cover such changes.