Space heating device using solid fuel
United States Patent Kapustin Apr. 1, 1975 [54] SPACE HEATING DEVICE USING SOLID 2,322,016 6/1943 Handeman 126/121 FUEL 2,565,328 8/1951 Stanwycks 126/83 [76] Inventor: Alexander Kapustin 4602 Park Primary E mminer john J Camby Blvd&#34; Oakland 94602 Assistant Examinerl-lenry C. Yuen [22] Fil d; Apr, 11, 1974 Att0rney,Agent, 0r Firm-Warren, Rubin &amp; 21 Appl. No.: 459,925 Chlckermg [57] ABSTRACT [52] [1.8. Cl 126/67, 126/100, 126/76, A space heating d i for use with solid fuels is 126/83 closed including an enclosed chamber divided into a [51] lllt. Cl. F24b 3/00 forward combustion Zone and a rear venting Zone by [58] F&#39;eld of Search 126/67 an internal partition that is sealed against the ceiling 1 10 7446 of the chamber and against the upper portions of the side walls but has open passageways in the lower por- [56] References cued tion thereof, a fire basket having a perforated floor UNITED STATES PATENTS within the combustion zone with a source of fresh, 352.558 11/1886 Moore 126/75 pp rting air suppli d t an ar a n ath 526,780 10/1894 Grindrod 126/76 the perforated floor of the tire basket, a door for sup- 839,354 12/1906 Willett 126/74 plying fuel to the combustion one and a vent from 916,9l5 3/1909 Cope 61. a1. .7 the upper portion of the venting one 1,697,225 1/1929 Cesa 126/67 1,699,433 1/1929 Howell 126/67 8 Claims, 2 Drawing Figures SPACE HEATING DEVICE USING SOLID FUEL BACKGROUND OF THE INVENTION Space heaters which burn solid fuel are notoriously inefficient. A fireplace is the most exaggerated example of inefficiency because the open fire in a fireplace heats only by radiation, and substantially all of the heat pro duced by the combustion of fuel is lost up the chimney. Franklin stoves and a large number of similar space heaters improve on fireplaces by retarding the flow of hot gas from the fuel to the open atmosphere for enough time to extract more heat from it. However. in almost all household space heaters that employ solid fuels, the extraction of heat from the combustion of fuel is so inefficient that most of the energy released by combustion is lost.  
 THE INVENTION This invention is an improvement in devices for space heating which employ solid fuels such as wood, coal, charcoal, coke and the like. The device of this invention is constructed to burn fuel efficiently and to extract heat released from the burning of fuel before it is vented to the atmosphere more efficiently than is accomplished with conventional stoves that burn solid fuels.  
  The device of this invention includes a chamber having front. rear and side walls as well as a floor and ceiling. The chamber is divided by an internal partition between the side walls into a combustion zone and a venting zone. The internal partition is fixed to the chamber to provide for the flow of hot gas from the combustion zone to the venting zone through the lower part of the chamber. preferably by flowing beneath the partition. Open passageways between the combustion zone and the venting zone must always be provided in a lower portion of the chamber, but other passageways may be employed and preferably the partition may also be provided with means to adjust the size, the number or even the location of the passageways between the combus tion zone and the venting zone.  
  The combustion zone is provided with a fire basket which is an element having an open front, a rear wall and side walls extending upwardly into the upper portion of the combustion zone. The rear wall of the fire basket may be formed by the partition. The fire basket has a perforated bottom and a source of fresh air to the zone immediately beneath the perforated bottom; however, the fire basket has side walls and a rear wall that are not perforated. The fresh air may come from the room being heated through a passageway through the front wall or door of the device, or it may be admitted through duct work passing from outside the room being heated. It is preferred that the duct work providing a source of fresh air beneath the perforated floor of the fire basket be held above the floor of the combustion zone.  
  The venting zone is an open chamber having a vent, or a means for conducting combustion gases, from the upper portion of the venting zone to the atmosphere. Typically, the vent will be provided either in the upper portion of the rear wall or through the ceiling of the venting zone with a conventional fixture for connecting to stove pipe.  
  From the foregoing description it is evident that the flames and hot gases produced by the combustion of solid fuel in the fire basket must follow a path wherein the flames or hot gases first pass upwardly over the solid side walls of the fire basket, then downwardly to the floor of the combustion chamber. after which they pass beneath the partition and again upwardly to the vent in the venting zone. The escape of flames and hot gases is not only retarded by following this tortuous path but in following the path the flames and hot gases sweep against the floor, the ceiling, the rear wall and all side walls of the enclosing chamber so that a very large hot surface is made available to radiate heat into the room being heated and to transfer heat by conduction and convection to the room being heated. Since the heat from combustion is employed so efficiently, less fuel need be burned to provide sufficient warmth to make a room comfortable; and not only will less hot gas escape up the chimney, but the temperature of the gas escaping will be lower.  
 DETAILED DESCRIPTION OF THE INVENTION The invention herein may best be described with reference to the accompanying drawings illustrating one suitable embodiment of the invention.  
  FIG. 1 is a sectional front view taken along the line Il of FIG. 2 of a device embodying this invention.  
  FIG. 2 is a sectional side view of the device illustrated in FIG. 1 and taken along the line 22 of FIG. 1.  
  The device illustrated in the figures herein is constructed of a chamber generally designated 10 which is divided by a partition 11 into a forward combustion zone 12 and a rear venting zone 13. The chember is formed of a floor 14, a ceiling 15, side walls 16 and 17, a rear wall 18, and a front wall 19 which includes an opening that is closed by a door 20. The door 20 is illustrated hinged at its side through a hinge 21. An insulating means 20a may be employed to maintain the opening into the combustion zone closed and to insulate the door 20. Other closing arrangements may be employed. The device illustrated in FIGS. 1 and 2 may be adapted so that the upper surface of ceiling 15 is a cooking surface; and if such is the case, an oven 22 shown schematically in broken line representation may be employed.  
  The combustion zone 12 includes a fire basket 23 that is constructed of a perforated floor 24 and solid side walls 25. A particularly preferred embodiment is illustrated in the drawings in that the side walls 25 are provided with bent-over elements 26 which are adapted so that the fire basket 23 may simply hang from the upstanding walls of the air vent 27. In the illustrated embodiment, the fire basket 23 fits snugly against partition 11 so that partition 11 is the rear wall of the fire basket 23 thereby further simplifying the construction of the fire basket.  
  The source of fresh air for supporting combustion is provided through duct 27 which is formed to make a chamber beneath the fire basket 23. In the preferred form as herein illustrated, the duct 27 is formed of a bottom wall 28 spaced from floor 14 and side walls 29 which extend into the upper portion of the combustion zone 12 and provide a support for the fire basket 23. The duct 27 forms a tight seal against partition 11 and against front wall 19. As illustrated, front wall 19 is provided with a large vent 30 that corresponds with a vent 31 in the door 20 so that open communication between the atmosphere and the interior of duct 27 is available. Thus, during combustion and with door 20 closed, the vent 30 and vent 31 superimpose to form a passageway from the room to the duct 27 to supply adequate fresh air to support combustion in fire basket 23. When the door is open, the vent is exposed and it is large enough for removal of ashes that collect on the floor 28 of the duct 27. By maintaining duct 27 above floor 14, the entire area of floor 14 will be available as a hot radiating surface when the device of this invention is in use.  
  A fire maintained in fire basket 23 will produce flames and hot gases discharging from the fire basket upwardly above the solid side walls 25 of the fire basket, sweeping against the portion of the ceiling 15 that is in the combustion zone 12; then reversing direction and passing downwardly sweeping against the side walls 16 and 17 in the combustion Zone 12; then passing beneath the partition 11 and sweeping against the floor 14 which preferably is supported on legs 33; and upon entering the venting zone 13, passing upwardly toward vent 32 and thereby sweeping against the floor 14, the rear wall 18, and that portion of the side walls and ceiling in the venting chamber 13. lt is evident that the tortuous path followed by the flames and hot gases retains them for a prolonged period within the device of this invention and directs their flow so that every radiating and conducting external surface of the device is swept with a continuous flow of hot gas thereby maintaining these surfaces at their maximum temperature.  
  The device of this invention may be modified so that passageways for the passage of hot gases to the venting zone from an intermediate portion of the partition 11 may be provided. A number of vertically aligned holes 34 positioned on one side of duct 27 and another series of vertically aligned holes 35 positioned on the other side of duct 27 provide such intermediately spaced auxiliary passageways for flames and hot gases. To maintain balanced combustion, it is preferred that these holes be symmetric with respect to duct 27. A sliding damper 36 is supported in close contact with partition 11 by suitable supports 37. The sliding damper may be moved horizontally by an operating handle 38 that protrudes through the side wall 17 of venting chamber 13. In the embodiment shown, the sliding damper 36 contains three vertically spaced holes 39 shown in broken lines in FIG. 1. These holes are sized and spaced so that in one position of the sliding damper 38 they superimpose the holes 34 to form open passageways through partition 11 between an intermediate portion of combustion zone 12 and venting zone 13. ln the embodiment illustrated, the distance between the right edge 40 of damper 36 and the left edge of the holes 39 is equal to the distance between the line passing through the centers of the holes 34 and the line passing through the centers of the holes 35. With this arrangement, when operating handle 38 is moved to the left as illustrated in FIG. 1, holes 35 will form open passageways between chambers 12 and 13 as holes 39 and holes 34 superimpose to form open passageways between chambers 12 and 13.  
  As operating handle 38 is moved to the right to the position illustrated in FIG. 1, the right hand edge 40 of damper 36 will cause passageways 35 to close as holes 39 move out of register with holes 34. Holes 34 and holes 35 will be completely closed at precisely the same instant.  
  To make the device of this invention safe but still functional, it may be desirable to place protective screens 41 adjacent the side walls 16 and 17. By suitably selecting screens 41 and connecting them spaced from the side walls, no significant decrease in heat transfer by radiation convection will result. However, the screens 41 will prevent accidental contact with the hot side walls 16 and 17. When the upper surface 15 is not employed as a cooking surface, it may be desirable to protect it with a suitable screen also.  
  It is evident from the foregoing description that this invention is a highly efficient space heater that employs solid fuels effectively and with minimum waste. The device is compact and efficient and may readily be adapted to provide hot, useful cooking surfaces.  
 What is claimed is:  
  l. A space heating device for burning solid fuel comprising:  
 a. a chamber having a floor, a ceiling, front, back and side walls,  
 b. a partition between the side walls of said chamber dividing it into a front combustion zone and a rear venting zone, said partition being substantially sealed against the ceiling of said chamber and the upper portions of the side walls of said chamber and having a lower passageway from said combustion zone to said venting zone,  
 c. a tire basket maintained in said combustion zone above the floor thereof, said fire basket having a perforated bottom, solid side walls extending into the upper portion of said combustion zone but not in contact with the ceiling thereof, a back wall and an open front,  
 d. a passageway from beneath the perforated bottom of the fire basket communicating with a source of fresh air,  
 e. a door for providing fuel to said combustion Zone,  
 and  
 f. a vent for removing combustion products from the upper portion of said venting zone.  
 2. The device of claim 1 wherein said partition is the back wall of said fire basket.  
  3. The device of claim 1 wherein said partition includes a central passageway of variable size.  
  4. The device of claim 3 wherein said partition includes two sets of symmetric, vertically spaced vents and a horizontally slideable damper plate with said damper plate having passageways on one side thereof corresponding in size, number and position to the central passageways in said partition and with said passageways being spaced from the far edge of said plate a distance equal to the horizontal distance between the centers of the passageways in said partition, with said slideable plate being mounted to slide horizontally in a manner such that the passageways in said plate superimpose the passageways in said partition at some position of said plate.  
  5. The device of claim 1 wherein said first basket is positioned symmetrically between the slide walls of said chamber.  
  6. The device of claim 1 wherein an upper surface of said heating device is adapted to be a cooking surface.  
  7. The device of claim 1 wherein said source of fresh air comprises a duct having a floor and two upstanding side walls extending into the upper portion of said combustion zone, and said fire basket is provided with side walls adapted to be suspended from the upper portion of the side walls of said duct.  
  8. The device of claim 7 wherein the floor of said duct is vertically spaced from the floor of said combus-