Field of the Invention

[1] This invention relates generally to charcoal making apparatus more particularly, this invention relates to an improved charcoal making kiln.

Summary of the Disclosure

[2] Whereas charcoal making kilns comprise a variety of configurations, there is provided herein and improved charcoal making kiln of a specific configuration conferring various advantages in ease- of-use, portability and/or operation in accordance with various embodiments.

[3] The present improved charcoal making kiln preferably comprises an enclosed domed combustion chamber having a barrel shaped pyrolysis chamber located within an upper region thereof and accessible by way of an access hatch through a front of the combustion chamber.

[4] Combustion material (such as wood) may be burnt atop a fire bed within the combustion chamber for heating pyrolysis feed material (also such as wood) the pyrolysis chamber located thereabove.

[5] The kiln is preferably configured such that substantially an entire exterior surface of the pyrolysis chamber is heated within the combustion chamber. Specifically, the combustion chamber extends a distance above the pyrolysis chamber such that, in this way, a lower region of the exterior surface of the pyrolysis chamber may be heated from direct radiant heat whilst an upper region thereof may be heated by convection.

[6] The combustion chamber may further comprise a front access hatch for feeding the fire therein. In a further embodiment, the combustion chamber may comprise a rear access hatch selectively openable to control air flow into the combustion chamber and therefore the combustion rate of the fire.

[7] The preferred embodiment, the fire bed is substantially planar and coincides generally in elevation with respective front and rear access hatches allowing for the convenient end-to-end cleaning thereof, using brooms, spades, leaf blowers or the like.

[8] In a further preferred embodiment, the kiln comprises an off-gas recycling conduit configured for recycling uncombusted off-gases from an interior of the pyrolysis chamber for ignition by the fire underneath the pyrolysis chamber for additionally heating the pyrolysis chamber. In this way, the fuel requirements of the kiln are reduced by this recycling mechanism. Furthermore, the off-gas recycling conduit provides additional heat until such time that the pyrolysis feedstock is sufficiently pyrolysised. [9] In embodiments, the off-gas recycling conduit may comprise an openable test valve for testing the combustibility of off-gases therein. Furthermore, the off-gas recycling conduit may comprise a removal stopper for removal of tar buildup.

[10] In embodiments, the kiln may comprise a wheeled chassis for the portability thereof.

[11] According to one aspect, there is provided a charcoal making kiln comprising a combustion chamber having a pyrolysis chamber enclosed therein for pyrolytic conversion of pyrolysis feed material above combustion material burning atop a fire bed of the combustion chamber in use, the pyrolysis chamber comprising a substantially airtight hatch accessible via a front of the combustion chamber, the pyrolysis chamber located at an upper region of the combustion chamber and wherein the kiln is configured such that substantially an entire exterior surface of the pyrolysis chamber is exposed within the combustion chamber for heating.

[12] The pyrolytic chamber may comprise a cylindrical midsection enclosed via the airtight hatch at a front thereof.

[13] The airtight hatch may comprise a plurality of peripheral fasteners.

[14] The fasteners may comprise bolt fasteners.

[15] The combustion chamber may enclose the pyrolytic chamber a distance above an upper apex of the pyrolytic chamber.

[16] The combustion chamber may comprise a front access hatch.

[17] The front access hatch may be openable sideways.

[18] The combustion chamber further may comprise a rear access hatch.

[19] The rear access hatch may be upwardly openable.

[20] The rear access hatch may be adjusted to remain open at a particular angle.

[21] The front and rear access hatches may coincide substantially with the surface of the fire bed.

[22] The kiln may further comprise a flue operably coupled to within the combustion chamber.

[23] The flue may be selectively closed with a lid to differing extents.

[24] The combustion chamber may be formed by front and rear planar panels and side panels transitioning over the pyrolysis chamber.

[25] The kiln may further comprise an of gas recycling conduit configured for drawing off-gases from an interior of the pyrolysis chamber for ignition underneath the pyrolysis chamber.

[26] The off-gas recycling conduit may comprise a downpipe leading from an upper region within the pyrolysis chamber to underneath the pyrolysis chamber.

[27] The downpipe may comprise a valve at an upper end thereof.

[28] The downpipe may comprise a release stopper at a bottom end thereof.

[29] The kiln may further comprise a wheeled chassis for supporting the combustion chamber. [30] The fire bed may comprise a mosaic of high-temperature heat bricks.

[31] Other aspects of the invention are also disclosed.

Brief Description of the Drawings

[32] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[33] Figure 1 shows an internal front top perspective view of an improved charcoal making kiln in accordance with an embodiment;

[34] Figure 2 shows a rear top perspective view of the improved charcoal making kiln;

[35] Figure 3 shows a left side elevation view of the kiln including indicative dimensions in accordance with an embodiment;

[36] Figure 4 shows a front elevation view of the kiln including indicative dimensions in accordance with an embodiment; and

[37] Figure 5 shows a right side elevation view of the kiln including indicative dimensions in accordance with an embodiment.

Description of Embodiments

[38] Figure 1 shows an interior top side perspective view of an improved charcoal making kiln 100 and Figure 2 shows a corresponding rear top perspective view thereof.

[39] The kiln 100 comprises a combustion chamber 101 having a front 102 and a rear 103 and a pyrolysis chamber 104 enclosed within the combustion chamber 101 for heating above material burning atop a fire bed 105 of the combustion chamber 101 in use.

[40] The combustion chamber 101 may be enclosed and may be substantially dome-shaped comprising a substantially lower rectangular aspect which tapers slightly towards an upper rounded aspect. The combustion chamber 101 may be manufactured from front and rear planar panels and lateral panels that curve over the top of the combustion chamber 101 to meet at an apex thereof.

[41] The pyrolysis chamber 104 is preferably located within an upper region of the combustion chamber 101 so as to receive heat directly from a fire burning atop the fire bed 105 thereunderneath and be located within the higher convection temperatures of the combustion chamber 101.

[42] The combustion chamber 104 may be cylindrical in shape, similarly comprising a front 102 and a rear 103 corresponding generally in location with the front 102 and rear 103 of the combustion chamber 101. The rear 103 of the pyrolysis chamber 104 may be spaced away from the rear panel of the combustion chamber 101 so as to additionally receive heat therethrough. [43] The interior of the pyrolysis chamber 104 may be accessed by way of access hatch 106 which, in the embodiment shown, comprises peripheral bolt fastening mechanisms 107 for enhancing the seal thereof. In this way, the access hatch 106 seals the pyrolysis chamber 104 in an airtight manner. The access hatch 106 may comprise a hinge mechanism 108 for pivoting the hatch 106 open and closed.

[44] The kiln 100 may be configured such that substantially the entire exterior surface 109 of the pyrolysis chamber 104 is exposed to the interior of the combustion chamber 101. As can be appreciated especially from Figure 1, the side panels 110 of the combustion chamber 101 may extend a distance over above the surface 109 of the pyrolysis chamber 104 such that the pyrolysis chamber 104 is able to be directly heated from all sides within the combustion chamber 101. In this regard, the undersurface of the exterior surface 109 of the pyrolysis chamber 104 may be heated directly from radiant heat from the fire burning thereunderneath whereas an upper surface of the exterior surface 109 may be heated from convected heat thereabove.

[45] The kiln 100 may comprise a flue 111 comprising a pipe 112 selectively closed by lid 113 liftable and rotatable using hinge mechanism 114 comprising a handle 115. In use, the lid 113 may be opened by manipulating the handle 115 for the release of smoke in use and to control the combustion rate.

[46] The combustion chamber 101 may be accessed by way of front hatch 116 and, in a preferred embodiment, a corresponding rear hatch 119.

[47] The front hatch 116 may be locked using a latch 117 and may comprise a hinge 118 at the opposite side thereof to open laterally. Conversely, the rear hatch 119 may comprise upper hinges 120 so as to open upwardly. In embodiments, the rear hatch 119 may comprise a strut (not shown) (or the like) able to hold the rear hatch 119 open at various angles to control air flow into the combustion chamber 101.

[48] Stoking of the kiln 100 may comprise opening the front hatch 116 and inserting combustible feed material (such as wood) therein. The rear hatch 119 may be selectively opened to control the airflow therein and therefore the combustion rate of the combustible material burning atop the fire bed 105. In embodiments shown, the fire bed 105 comprises a mosaic of high-temperature heat bricks 121.

[49] The arrangement of the hatches 116, 117 either side of the planar fire bed 105 may allow for the convenient end-to-end cleaning thereof by inserting a broom, spade or the like thereacross or blowing with a leaf blower or the like to remove spent material via the rear hatch 119. [50] In a preferred embodiment, the kiln 100 comprises off-gas conduit 122 comprising an inlet tube 123 coupled to an interior of the pyrolysis chamber 104 which leads to a downpipe 124 which leads to an outlet tube 125 located beneath the pyrolysis chamber 104 (as is best shown in Figure 5).

[51] The outlet tube 125 may extend some distance underneath the pyrolysis chamber 104 and may further comprise a plurality of vents thereatop and therealong for the release of the off-gases therefrom.

[52] As such, uncombusted off-gases are recycled via the off-gas feed tube arrangement 122 under the pyrolysis chamber 104 which, when released thereunderneath, are ignited by the fire to additionally heat the pyrolysis chamber 104. The off-gas recycling feed tube arrangement 122 reduces the fuel requirements for combustion and furthermore provides additional heat until such time that the wood within the pyrolysis chamber 104 is sufficiently pyrolysed.

[53] In embodiments, the downpipe 124 may comprise a ball valve 126 (or the like) at an upper end thereof which is selectively openable to test the volatility of the off-gases with a pocket lighter or the like so as to test the pyrolysis state of the charcoal feed. Furthermore, the downpipe 124 may comprise a stopper 127 at a lower end thereof selectively releasable to remove tar buildup.

[54] In embodiments shown, the kiln 100 may comprise a wheeled chassis 128 comprising four legs 129 supported atop respective casters 130.

[55] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. Flowever, it will be apparent to one skilled in the art that specific details are not required in order to practice the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed; obviously, many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, they thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.