Vertical feed stick wood fuel burning furnace system

A new and improved stove or furnace for efficient combustion of wood fuel in the form of sticks, logs or other elongate pieces of wood, or wood in a vertical stack, and for extraction of heat from the hot gaseous end products of combustion comprising:

• combustion chamber means with substantially vertical axis forming an upright column, said combustion chamber means comprising a base portion of refractory material forming the locus of wood fuel combustion, and water jacket means defining at least a major portion of said upright column positioned over the combustion chamber base portion and forming a substantially air tight enclosure over the base portion, said combustion chamber refractory base portion and said water jacket means in combination defining a vertical feed combustion chamber for receiving elongate pieces of wood or wood in a vertical stack with the bottom of the wood fuel resting in the refractory base portion so that the wood fuel is gravity fed into the locus of wood fuel combustion by burning progressively from the bottom;
• heat exchange means for receiving and conducting the hot gases of wood fuel combustion for heat exchange from the hot flue gases to a heat transfer medium circulating through the heat exchange means;
• a channel bounded by refractory material extending laterally from the refractory base portion of the combustion chamber means to the heat exchange means;
• means for inducing a draft from the vertical feed combustion chamber refractory base portion through the laterally extending refractory channel for directing the products of wood fuel combustion through the refractory channel means;
• means for admitting air into the combustion chamber refractory base portion to effect turbulent mixing and swirling of air with the gaseous products of combustion and so that a turbulent mixture of air and fuel gas follows the draft from the refractory base portion of the combustion chamber means through the laterally directed refractory channel;
• said refractory channel affording a high temperature environment and delayed propagation of the flue gas and air mixture sufficient to afford efficient and substantially complete secondary burning of the gaseous products of combustion with the turbulent air admitted into the combustion chamber base portion, prior to heat transfer in the heat exchange means;
• means for coupling said combustion chamber water jacket means to a source of water or other heat transfer medium for at least convection driven circulation of the water or medium;
• said water jacket means over the combustion chamber base portion and said laterally directed draft from the combustion chamber base portion combining to confine the locus of wood fuel combustion to the refractory base portion of the chamber means and the bottom of the elongate pieces of wood or wood stack supported generally vertically in the combustion chamber means thereby preventing the burn from ascending into the upright column of the chamber means.

A new and improved furnace for efficient combustion of wood fuel and extraction of heat comprising:

• combustion chamber means with substantially vertical axis forming an upright column, said combustion chamber means comprising a base portion of refractory material forming the locus of wood fuel combustion, and water jacket means in a configuration forming a major portion of the walls of said upright column positioned over the combustion chamber base portion and formed with substantially air tight cover means over the column, said combustion chamber refractory base portion and said water jacket means in combination defining a substantially vertical feed combustion chamber for receiving elongate pieces of wood or stacks of wood fuel with the bottom of the elongate pieces or stacks of wood fuel resting in the refractory base portion so that wood fuel is gravity fed into the locus of combustion while burning progressively from the bottom;
• heat exchange means comprising a base portion of refractory material for receiving and insulating the hot gases of wood burning, and a heat exchanger positioned over the refractory base portion for receiving and conducting the hot gases of wood fuel combustion for heat exchange from the hot flue gas to water or other heat exchange receiving fluid circulating through the heat exchanger;
• channel means bounded by refractory material extending laterally from the refractory base portion of the combustion chamber means to the refractory base portion of the heat exchange means;
• means for inducing a draft from the vertical feed combustion chamber refractory base portion through the laterally extending refractory channel, refractory heat exchange means base portion and heat exchanger for directing the products of wood fuel combustion through the refractory base portions of the furnace;
• means for admitting air at high velocity into the combustion chamber refractory base portion to effect turbulent mixing and swirling of air with the gaseous products of wood fuel combustion and so that a turbulent mixture of air and fuel follows the draft from the refractory base portion of the combustion chamber through the laterally directed refractory channel to the base portion of the heat exchange means;
• said refractory channel affording a high temperature environment and delayed propagation of the flue gas and air mixture sufficient to afford efficient and substantially complete secondary burning of the gaseous products of wood burning with the turbulent air forced into the combustion chamber base portion, and prior to heat transfer in the heat exchange means;
• means for coupling said combustion chamber water jacket means to a source of water or other heat transfer fluid for at least convection driven circulation of water or fluid between the water jacket means and the source of water or fluid;
• said water jacket means over the combustion chamber base portion and said laterally directed draft from the chamber base portion combining to confine and restrict the locus of wood fuel combustion to the refractory base portion of the combustion chamber means and to the bottom of elongate pieces or stacks of wood fuel supported in the chamber means thereby preventing the burn from ascending into the upright column of the combustion chamber means.

A new and improved furnace for efficient combustion of wood fuel and extraction of heat comprising:

• a refractory base portion including a combustion chamber base of refractory material forming the locus of wood fuel combustion, a channel bounded by refractory material extending laterally away from the combustion chamber base, and a heat exchanger base of refractory material for supporting heat exchange means and receiving and insulating the hot exhaust gas of wood fuel combustion from the refractory channel for delivery to the heat exchange means;
• combustion chamber water jacket means forming at least a major portion of the walls of a substantially vertical column positioned over the combustion chamber base and formed with a substantially air tight cover means over the column, said substantially vertical column water jacket means and combustion chamber base in combination defining a substantially vertical feed combustion chamber for receiving through the air tight cover elongate pieces of wood fuel or wood in a vertical stack and for supporting said wood fuel in a vertical attitude with the bottom of the wood fuel resting in the refractory combustion chamber base whereby elongate pieces of wood or wood in a vertical stack are gravity fed into the locus of wood fuel combustion in the chamber refractory base while burned progressively from the bottom;
• heat exchanger means positioned over the heat exchanger base for receiving and conducting the hot gases of wood fuel combustion, said heat exchanger means comprising extended flue gas passageway means defining extended surface area for heat exchange from the hot flue gas to water or other heat receiving medium circulating through the heat exchanger means;
• means for coupling said combustion chamber water jacket means to a source of water or other heat transfer fluid for at least convection driven circulation of the water or fluid between the water jacket means and the source of water or fluid;
• means for coupling said heat exchanger means to a source of water or other heat transfer medium for circulation of the water or other medium between the heat exchanger means and the source of water or other medium;
• means for establishing a draft from the vertical feed combustion chamber through the laterally extending refractory channel, refractory heat exchanger base, and heat exchanger for directing the products of wood fuel combustion through the refractory portion of the furnace;
• means for forcing air into the combustion chamber refractory base at relatively high velocity to effect turbulent mixing and swirling of air with the gaseous products of primary wood burning whereby said turbulent fuel gas and air mixture follows the draft from the combustion chamber refractory base through the laterally directed refractory channel to the base of the heat exchanger;
• said refractory channel affording a high temperature environment and delayed propagation of the flue gas and air mixture sufficient to afford highly efficient and substantially complete secondary burning of the gaseous products of wood fuel combustion with the turbulent air forced into the combustion chamber base;
• said vertical column water jacket means over the combustion chamber base, and laterally directed draft away from the combustion chamber base combining to confine and restrict the locus of wood fuel combustion to the refractory base portion of the combustion chamber, thereby preventing the burn from ascending vertically into the column of the combustion chamber.

A new and improved furnace system for high efficiency combustion of wood or other solid fuel and high efficiency energy recovery from the end products of combustion comprising:

• a substantially vertical column combustion chamber, the major upper portion of said vertical column comprising a water jacket for at least convection circulation of water or other heat transfer fluid, the base portion of said combustion chamber comprised of refractory material forming the locus of combustion, said combustion chamber adapted to receive and support elongate pieces of fuel in a vertical attitude or fuel pieces in a vertical stack and confine combustion to the chamber base by the quenching action of the water jacket, said combustion chamber formed with a draft outlet at the base of the chamber;
• said combustion chamber base and locus of combustion forming part of a furnace sequence in a refractory high temperature environment, said furnace sequence comprising in order from upstream to downstream in the air and flue gas flow as follows:
• means for forcing air at relatively high pressure above ambient pressure and at high velocity through restricted orifice means into the combustion chamber for jet stirring and turbulent mixing,
• low resistance air entry means into said combustion chamber and means for controlling said air entry means,
• said combustion chamber refractory base portion as enumerated above,
• flue gas propagation delay channel means bounded by refractory material for maintaining a high temperature environment, for directing flue gas away from the base of the combustion chamber, and for increased retention time of the flue gas and forced air mixture in the high temperature environment for completion of combustion chemical reactions prior to heat extraction from the flue gas,
• refractory insulated manifold means for receiving the hot end products of combustion and for distribution of the hot gases over heat exchange means;
• heat exchange means coupled to said refractory manifold and refractory furnace sequence output downstream from the delay channel means for recovering energy from the hot gaseous end products of combustion;
• and means for inducing draft and establishing a low pressure gradient in the furnace sequence.

A new and improved furnace for efficient combustion of wood fuel in the form of sticks, logs or other elongate pieces of wood or wood pieces in a vertical stack, and for extraction of heat from the hot gaseous end products of combustion comprising:

• vertical feed combustion chamber means forming an upright column for receiving and supporting wood fuel in a substantially vertical attitude or stack, said combustion chamber means being substantially air tight and formed with a laterally directed draft outlet at the base of the combustion chamber means, a major upper portion of the combustion chamber means comprising water jacket means with means for coupling said water jacket means to a source of water or other heat transfer fluid for at least convection circulation of water or fluid through the water jacket means for confining the locus of wood fuel combustion to the base of the vertical feed combustion chamber means, the lower portion of said combustion chamber means comprised of refractory heat confining material to provide high temperature and efficient combustion, said combustion chamber means formed with combustion air inlet means;
• high temperature refractory flue gas channel means extending from the laterally directed draft outlet of the vertical feed combustion chamber means affording delayed propagation of flue gas in a high temperature environment sufficient to afford substantially complete secondary burning of the gaseous products and constituents of primary combustion with combustion air;
• and heat exchange means coupled to the delayed propagation channel means for transferring heat from gaseous end products of substantially complete wood fuel combustion.