Smokeless firepit

Abstract

A smokeless firepit including a first bottom, a second bottom located above the first bottom, an inner wall extending upwardly from the second bottom, an outer wall extending upwardly from the first bottom, and a top plate connecting the inner and outer walls. The second bottom intakes primary combustion air and secondary combustion air. The secondary combustion air is configured to be received at a bottom of the outer wall, pass upward between the inner wall and the outer wall, and enter the burn chamber at a top of the inner wall underneath the top plate when the firepit is in the upright position and burning fuel.

What is claimed is: 
     
         1 . A smokeless firepit comprising:
 a first bottom configured to pass primary combustion air from below the first bottom to above the first bottom when the firepit is in an upright position on a surface and burning fuel;   a second bottom spaced apart from and located above the first bottom, the second bottom configured to pass the primary combustion air from below the second bottom to above the second bottom at a center of the second bottom when the firepit is in the upright position on the surface and burning fuel;   a plurality of feet extending downward from the first bottom and configured to space the first bottom from the surface when the firepit is on the surface in the upright position;   an inner wall extending upwardly from the second bottom, the inner wall and the second bottom defining a burn chamber for retaining and burning fuel therein;   an outer wall extending upwardly from the first bottom and spaced apart from the inner wall; and   a top plate extending inwardly from the outer wall,   wherein secondary combustion air is configured to be received at a bottom of the outer wall, pass upward between the inner wall and the outer wall, and enter the burn chamber at a top of the inner wall underneath the top plate when the firepit is in the upright position and burning fuel.   
     
     
         2 . The smokeless firepit of  claim 1 , further comprising:
 a primary combustion air manifold located about the center of the second bottom; and   the primary combustion air manifold is configured to receive the primary combustion air from below the second bottom and direct the primary combustion air into the burn chamber.   
     
     
         3 . The smokeless firepit of  claim 2 , wherein:
 the primary combustion air manifold comprises an elevated burner which introduces the primary combustion air into the burn chamber above a top surface of the second bottom when the firepit is in the upright position and burning fuel, thus accommodating a buildup of combusted matter on the second bottom without clogging flow of the primary combustion air; and   the elevated burner comprises:
 a riser and extending upwardly from the second bottom, the riser configured to receive the primary combustion air from below the second bottom and direct the primary combustion air into the burn chamber at a top end of the riser; and 
 a cover at a top of the riser, said cover extending beyond an outer perimeter of the riser, said cover configured to prevent fuel and combusted matter from entering the riser and clogging a primary space between the second bottom and the first bottom thus allowing the primary combustion air to freely flow through the primary space, through the riser, and into the burn chamber under the cover. 
   
     
     
         4 . The smokeless firepit of  claim 3 , wherein:
 the riser is connected to the second bottom at a bottom end of the riser;   the cover is connected to the riser at the top end of the riser;   the riser comprises a plurality of primary combustion air outlets at the top end of the riser; and   the plurality of primary combustion air outlets of the riser are each configured to provide primary combustion air from inside the riser to the burn chamber when the firepit is in the upright position and burning fuel.   
     
     
         5 . The smokeless firepit of  claim 1 , wherein:
 the first bottom comprises an outer perimeter connected to the outer wall;   the second bottom comprises an outer perimeter connected to the outer wall; and   the outer wall respectively connects the first bottom to the second bottom about the outer perimeters of the first bottom and the second bottom.   
     
     
         6 . The smokeless firepit of  claim 1 , wherein:
 the second bottom comprises an outer perimeter connected to the outer wall;   the second bottom comprises recesses in the outer perimeter; and   the recesses are circumferentially spaced about the outer perimeter and define air gaps between the outer wall and the second bottom, allowing the secondary combustion air to travel upward from below the second bottom to above the second bottom between the inner wall and the outer wall when the firepit is in the upright position and burning fuel.   
     
     
         7 . The smokeless firepit of  claim 6 , wherein:
 each recess extends inwardly into the second bottom from the outer perimeter which defines an open end adjacent to the outer perimeter and a recess perimeter wall;   each open end is located adjacent to the outer wall;   each recess terminates adjacent to and outwardly of a bottom edge of the inner wall such that each recess perimeter wall is located radially outwardly of the inner wall; and   the secondary combustion air is prevented from entering the burn chamber at the bottom edge of the inner wall and instead passes through each air gap defined by each recess.   
     
     
         8 . The smokeless firepit of  claim 6 , wherein:
 the first bottom comprises an outer perimeter connected to the outer wall;   the first bottom comprises recesses in the outer perimeter;   the recesses of the first bottom are circumferentially spaced about the outer perimeter and define air gaps in between the outer wall and the first bottom; and   the recesses of the first bottom are substantially aligned with the recesses of the second bottom, allowing the secondary combustion air to freely pass respectively through the recesses of the first bottom and the recesses of the second bottom and subsequently in between the outer wall and the inner wall.   
     
     
         9 . The smokeless firepit of  claim 8 , wherein:
 the recesses of the first bottom are identical in shape and size to the recesses of the second bottom, allowing the secondary combustion air to pass through the first bottom and the second bottom without being redirected or otherwise slowed down by the second bottom.   
     
     
         10 . The smokeless firepit of  claim 1 , wherein:
 the second bottom is configured to dually intake the primary combustion air and the secondary combustion air;   the second bottom comprises at least one primary combustion air intake configured to intake the primary combustion air; and   the second bottom comprises at least one secondary combustion air intake configured to intake the secondary combustion air.   
     
     
         11 . The smokeless firepit of  claim 1 , wherein:
 the second bottom comprises a center air intake located at the center of the second bottom;   the second bottom comprises outer perimeter recesses circumferentially spaced about an outer perimeter of the second bottom; and   the second bottom is configured to divert airflow such that the primary combustion air passes through the center air intake and the secondary combustion air passes through the perimeter recesses of the second bottom and subsequently in between the inner wall and the outer wall when the firepit is in the upright position and burning fuel.   
     
     
         12 . The smokeless firepit of  claim 1 , wherein:
 the top plate extends inwardly beyond the inner wall toward a center of the burn chamber; and   the top plate is configured to inwardly direct the secondary combustion air, preventing the secondary combustion air from immediately exiting the burn chamber.   
     
     
         13 . The smokeless firepit of  claim 1 , wherein:
 the top plate extends inwardly beyond the inner wall and at least partially within the burn chamber defining a secondary combustion area within the burn chamber;   the secondary combustion area is located adjacent to an underside of the top plate and the top of the inner wall; and   the top plate is configured to prevent the secondary combustion air from immediately exiting the burn chamber such that the secondary combustion air is forced to temporarily stay within the secondary combustion area adjacent to the underside of the top plate for igniting smoke and gases released by a previous primary combustion of the fuel within the burn chamber.   
     
     
         14 . The smokeless firepit of  claim 1 , wherein:
 the top plate extends inwardly beyond the inner wall and at least partially within the burn chamber defining a secondary combustion area within the burn chamber;   the top plate comprises an inner perimeter and an outer perimeter;   the top plate comprises recesses in the inner perimeter; and   each recess of the top plate is configured to allow combusted matter therethrough.   
     
     
         15 . The smokeless firepit of  claim 1 , wherein:
 the inner wall comprises a plurality of air outlets at the top of the inner wall; and   the plurality of air outlets of the inner wall is configured to allow the secondary combustion air to pass therethrough and enter the burn chamber below the top plate.   
     
     
         16 . The smokeless firepit of  claim 1 , further comprising:
 a primary combustion air manifold located at the center of the second bottom;   a shovel configured to remove combusted matter and comprising a shovel body and a handle extending upwardly from the shovel body;   the handle has a height that is longer than the inner wall;   the shovel body has a width that is less than a distance between the primary combustion air manifold and the inner wall; and   the handle extends at an angle from the shovel body of between 90 and 120 degrees.   
     
     
         17 . The smokeless firepit of  claim 1 , wherein:
 the first bottom has a circular cross-section;   the second bottom has a circular cross-section;   the inner and outer walls each define annular walls; and   the top plate comprises a ring connecting the inner wall and the outer wall together.   
     
     
         18 . The smokeless firepit of  claim 1 , further comprising:
 a support frame located between and connecting the first bottom and the second bottom;   the support frame is configured to support the second bottom and space the second bottom from the first bottom; and   the support frame is configured to guide the primary combustion air from an outer perimeter of the first bottom to the center of the second bottom.   
     
     
         19 . A firepit comprising:
 a first bottom comprising a plurality of air intakes configured to allow air therethrough;   a second bottom elevated above the first bottom, the second bottom comprising a centrally located primary combustion air intake and secondary air intakes, the second bottom configured to divide the air into primary combustion air which passes through the primary combustion air intake and secondary combustion air which passes through the secondary air intakes;   an outer wall extending upwardly from the first bottom;   an inner wall extending upwardly from the second bottom, the inner wall and the second bottom defining a burn chamber for retaining and burning fuel therein, the inner wall being spaced inwardly of the outer wall which defines a secondary space between the outer and inner walls for the secondary combustion air to travel therethrough, and the inner wall comprising a plurality of secondary combustion air outlets located adjacent to a top end of the inner wall; and   a top plate extending inwardly from the outer wall beyond the inner wall,   wherein the secondary combustion air is configured to flow from the second bottom, through the secondary space, through the plurality of secondary combustion air outlets of the inner wall, and into the burn chamber underneath the top plate.   
     
     
         20 . A method comprising:
 providing a firepit comprising a first bottom comprising a plurality of air intakes, a second bottom connected to and elevated above the first bottom, the second bottom comprising a centrally located primary combustion air intake and secondary air intakes, an outer wall extending upwardly from the first bottom, an inner wall extending upwardly from the second bottom, the inner wall and the second bottom defining a burn chamber for retaining and burning fuel therein, the inner wall being spaced inwardly of the outer wall which defines a secondary space between the outer and inner walls for the secondary combustion air to travel therethrough, and the inner wall comprising a plurality of secondary combustion air outlets located adjacent to a top end of the inner wall, and a top plate connecting the inner wall and the outer wall;   initiating a primary combustion of the fuel in the burn chamber;   intaking air, by the first bottom, through the plurality of air intakes in the first bottom;   dividing the air, via the second bottom, into primary combustion air which passes through the primary combustion air intake and secondary combustion air which passes through the secondary air intakes;   preheating, by heat emanating from the second bottom, the primary combustion air;   guiding, by the second bottom, the primary combustion air into the burn chamber;   guiding, by the second bottom, the secondary combustion air into the secondary space between the outer and inner walls;   preheating, by heat emanating from the inner wall, the secondary combustion air which passes through the secondary space;   guiding, by the outer and inner walls and the top plate, the secondary combustion air through the secondary space and toward the plurality of secondary combustion air outlets of the inner wall;   guiding, by the plurality of secondary combustion air outlets of the inner wall, the secondary combustion air from the secondary space into the burn chamber underneath the top plate; and   initiating a secondary combustion by introducing the secondary combustion air into the burn chamber and burning smoke and gases released by the primary combustion of the fuel to reduce smoke outputted by the firepit.