Patent Application
20250093036
The subject matter described herein relates to a combustible fuel burning fire pit with a radiant heat opening. The fire pit has particular but not exclusive utility for portable backyard fire pits.
Portable wood burning fire pits may be used in a variety of applications and environments, including being used in camping and in residential backyards for recreation. Fire pits may be used to provide outdoor heating, to support cooking, to create an ambiance, or for other desirable purposes.
Large fire pits are generally fueled by piles of logs or other combustible materials. Heat from the fire pit rises mostly upward with relatively minimal lateral radiation of heat. As a result, surfaces surrounding the fire pit closer to the ground, including the lower extremities of people sitting around the fire pit, receive little to no heat. One solution known in the art is to place a heat deflector over the fire pit to increase the lateral radiation of heat from the fire pit so that the people sitting around the fire pit can receive some of the heat. Conventional heat deflectors, however, can be large, heavy, challenging to move, and can reduce the efficiency of the fire pit.
It is therefore to be appreciated that systems and methods for lateral distribution of heat from a fire pit could be improved. Accordingly, a need exists for systems and methods that improve the performance and efficiency of fire pits with respect to lateral heat distribution.
Illustrative embodiments of the present disclosure will be described with reference to the accompanying drawings, of which:
In accordance with one or more embodiments of the present disclosure, a combustion fire pit is provided with a radiant heat opening that includes novel structural features to facilitate safe lateral emission of radiant energy. The disclosed radiant heat opening also includes air flow features conducive to supplying the combustion fire pit with air used to burn fuel.
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It is nevertheless understood that no limitation to the scope of the disclosure is intended. Any alterations and further modifications to the described devices, systems, and methods, and any further application of the principles of the present disclosure are fully contemplated and included within the present disclosure as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately.
These descriptions are provided for exemplary purposes only and should not be considered to limit the scope of the radiant heat opening or the fire pit. Certain features may be added, removed, or modified without departing from the spirit of the claimed subject matter.
Referring to
Referring to
A burn chamber 140 (or “cavity”) is defined by an interior surface 142 of the inner body 125. A removable fuel grate 145 and a removable ash pan 150 are adapted to be received and positioned within the burn chamber 140. In one or more embodiments, the bottom of the burn chamber 140 is defined by the fuel grate 145. The fire pit 100 further includes a top lip 155 attached to or integrally formed as a single piece with either the inner body 125 or the outer body 130.
The fire pit 100 further includes a plurality of inner ventilation holes 160 located in the top portion 110 of the inner body 125. In the intermediate portion 120 of the fire pit 100, the inner body 125 terminates in an upward-facing rollover 165 (or “support lip”) into which the fuel grate 145 fits, or upon which the fuel grate 145 rests. The fire pit 100 further includes a base plate 170 attached to the outer body 130, a bracing tray 175 supported by stands 180 projecting upward from the base plate 170, and the removable ash pan 150 supported by stands or fect projecting downward from the ash pan 150 into a receiving feature of the bracing tray 175.
When assembled as described above, the bracing tray 175 is separated from the outer body 130 by an air gap 185, the ash pan 150 is separated from the outer body 130 and the bracing tray 175 by an air gap 190, and the inner body 125 is separated from the outer body 130 by an air gap 195. In an example embodiment, air gaps 190 and 195 are both about 50 mm, while air gap 185 is about 100 mm, although other air gaps may be employed that have the advantageous effects disclosed herein. The bracing tray 175 has a circular air gap 200 at the center of the bracing tray 175. The air gap 190 and the air gap 185 are in fluid communication via the air gap 200. In one or more embodiments, an air gap may refer to a gap, a channel, a passageway, or a chamber. In one or more embodiments, the fuel grate 145 may define an air chamber axially below the fuel grate 145. In one or more embodiments, an air chamber may be defined between the fuel grate 145 and the bracing tray 175.
The cavity or burn chamber 140 is in fluid communication with the air gap 195 via the inner ventilation holes 160, and with air gaps 185, 190, and 200 via the fuel grate 145. The air gaps 185, 190, 195, and 200 are in fluid communication with ambient air via the radiant opening 105, such that ambient air (or “an ambient air stream”) may be drawn in through the radiant opening 105 and heated by combustion of a fuel 205 as the ambient air travels through the various air gaps described above. The heated ambient air is then communicated to the burn chamber 140 via the various air gaps and the inner ventilation holes 160 to facilitate improved combustion of the fuel 205.
As shown in
In the embodiment shown, the outer body 130 and the inner body 125 extend vertically upward, substantially perpendicular to the surface on which the fire pit 100 rests and parallel to each other. The vertical orientation of the outer body 130 and the inner body 125 promotes lateral emission of radiant energy. If the fire pit 100 were bowl shaped like fire pits of the prior art, the radiant energy would be emitted downward into the ground as opposed to laterally outward toward objects surrounding the fire pit 100.
Because the purpose of the radiant opening 105 is not only to facilitate intake of air, but also to facilitate lateral heat distribution to surrounding targets, the radiant opening 105 may be sized larger than a conventional air intake opening. In one or more embodiments, the radiant opening is sized in a range of about 4 square inches to about 2500 square inches, although other sizes are contemplated. Further, when multiple adjacent openings are utilized for radiant heat, the size of any single opening may be smaller, but the aggregate should permit sufficient radiant heat transfer outside the fire pit to, for example, increase the comfort of users. In one or more embodiments, the radiant opening 105 may also promote additional heat transfer to users and objects surrounding the fire pit 100 via convective heating by heating the ambient air regions on the lateral sides of the fire pit 100.
In one or more embodiments, the fuel grate 145, ash pan 150, and other structure(s) of the fire pit 100 are made of stainless-steel plates having a thickness within a range of between about 0.5 mm and about 2.5 mm thick. In one or more embodiments, the fuel grate 145, ash pan 150, and the fire pit 100 are formed of 1.0 mm to 2.0 mm thick stainless steel, and in some embodiments are formed of 1.5 mm thick stainless steel. Both thicker and thinner materials are contemplated, including other metals. In one or more embodiments, the fuel grate 145 weighs approximately 48-lb. (21.8 kg), although weights of between about 9 oz and about 88-lb. may be provided.
In one or more embodiments, the fuel grate 145 supports a nominal weight of 100-1b. (45.4 kg) during normal operation, although nominal capacities of between about 5-1b. and about 190-1b. may be provided. During normal operation, the fuel grate 145, or portions thereof, is also heated to between about 700° F. (371° C.) and about 1350° F. (732° C.) by the combustion of the fuel 205, for a time period of between 1 hour and 12 hours, and also at ambient temperatures as low as −40° F. (−40° C.). In one or more embodiments, during normal operation over a period of years, with repeated cycling (e.g., one hundred cycles) between ambient and operational temperatures, the fuel grate 145 exhibits little or no warping that would detrimentally affect its aesthetic appearance, its performance, or its fit within the fire pit 100.
In one or more embodiments, the fuel 205 combusts into ash, which falls through the fuel grate 145 into the ash pan 150. To facilitate cleaning and ash removal, the fuel grate 145 can be removed from the fire pit 100 by lifting the fuel grate 145 vertically upward, in a direction parallel to the longitudinal extension of the fire pit 100, through the burn chamber 140. This permits user access to the ash pan 150, which can then also be removed from the fire pit by lifting vertically through the cavity or burn chamber 140. The ash pan 150 may then be emptied and cleaned as necessary. The fuel grate 145 may also be cleaned as necessary, and then the ash pan 150 and fuel grate 145 can be reassembled within the fire pit 100 as shown in
In one or more embodiments, the air gap 190 between the lip of the ash pan 150 and the side of the bracing tray 175 is large enough to admit human fingers, thus enabling a user to grab the ash pan 150 when it is cool and remove it from the fire pit 100. The ash pan 150 may be lifted upward in a direction parallel to the longitudinal extension of the fire pit 100, same as the fuel grate 145, in order to remove the ash pan 150 from the fire pit 100.
The primary load carried by the fuel grate 145 is applied downward, in a direction parallel to the longitudinal extension of the fire pit 100, by the weight of the fuel 205 piled on the fuel grate 145, which is supported by the upward-facing lip or rollover 165 of the inner body 125.
The primary combustion air 215 flows down into the bottom portion 115 of the fire pit 100 within air gap 185 between the outer body 130 and the inner body 125 and is drawn radially between the bracing tray 175 and the base plate 170. The primary combustion air 215 then rises up through the air gap 200 in the center of the bracing tray 175 and is drawn radially outward along the bottom of the ash pan 150 between the ash pan 150 and the bracing tray 175. The primary combustion air 215 is then drawn upward around the edges of the ash pan 150 through air gap 190 and radially inward along the top of the ash pan 150. The primary combustion air 215 is then drawn upward into the burn chamber 140 through a plurality of ventilation holes 225 in the fuel grate 145. In the burn chamber 140, the primary combustion air 215 interacts with and facilitates combustion of the fuel 205.
As will be shown and described in more detail with respect to
The flow of the secondary combustion air 220 between the inner body 125 and outer body 130 may serve to cool both the inner body 125 and outer body 130, even as the secondary combustion air 220 increases in temperature. The flow of the primary combustion air 215 toward the air gap 200 of the bracing tray 175 may serve to cool the base plate 170 and bracing tray 175. The flow of the primary combustion air 215 between the bracing tray 175 and ash pan 150 may serve to cool both the bracing tray 175 and the ash pan 150. Thus, the wall of the outer body 130 is insulated by a layer of moving air, and the base plate 170 is insulated by three separate layers of moving air. This enables the exterior portions of the fire pit 100 (e.g., the outer body 130 and the base plate 170) to be cooler than the burn chamber 140 or fuel grate 145, thus improving the safety of the fire pit 100 and decreasing the chance of accidental burning of people, animals, or objects that may contact the exterior of the fire pit 100.
Additionally, the large flow of primary combustion air 215 through the fire pit 100 helps to ensure that the fuel 205 is well oxygenated and thus burns at high temperature. This in turn maximizes the heat generated by a given quantity of fuel, while simultaneously minimizing the amount of smoke generated by the combustion.
Referring to
In the embodiment shown in
In the embodiment shown in
As shown in more detail in
Each opening of the plurality of openings 240 is small enough to prevent body appendages (e.g., hands, fingers, feet, and toes of people, and paws of animals) and other foreign objects from extending through the plurality of openings 240 and contacting the hot inner body 125. The ratio of the surface area of the wireframe body 235 to the surface area of the plurality of openings 240 may be optimized in an effort to maximize the amount of infrared radiant energy able to be emitted laterally away from the exposed portion of the inner body 125 adjacent the radiant opening 105 through the screen 230 and the radiant opening 105, and also to maximize the amount of cool ambient air 210 able to be received within the fire pit 100 through the screen 230 and the radiant opening 105. The ratio of the surface area of the wireframe body 235 to the surface area of the plurality of openings 240 may be 1:3. In one or more embodiments, the surface area of the plurality of openings 240 is 65 percent to 70 percent, 70 percent to 75 percent, 75 percent to 80 percent, 80 percent to 85 percent, or 85 percent to 90 percent of the surface area of the screen 230.
In one or more embodiments, the radiant opening 105 extends radially through the intermediate portion 120 of the outer body 130 around a portion of the circumference of the outer body 130. In one or more embodiments, the radiant opening 105 includes a plurality of openings equally distributed about the circumference of the outer body 130. The surface area of the plurality of openings of the radiant opening 105 is optimized to maximize lateral emission of radiant energy from the inner body 125 through the radiant opening 105 and to maximize the amount of cool ambient air 210 received within the fire pit 100 through the radiant opening 105 while maintaining a sufficient amount of material of the outer body 130 within the radiant opening 105 to ensure structural rigidity of the fire pit 100. In such embodiments, the size of each of the plurality of openings of the radiant opening 105 is also optimized to ensure the safety of users and their pets. In such embodiments, the plurality of openings of the radiant opening 105 are small enough to prevent body appendages (e.g., hands, fingers, feet, and toes of people, and paws of animals) and other foreign objects from extending through the radiant opening 105 and contacting the hot inner body 125.
In such embodiments, the ratio of the surface area of the unremoved material of the intermediate portion 120 of the outer body 130 to the surface area of the plurality of openings may be 1:3. In one or more embodiments, the surface area of the plurality of openings of the radiant opening 105 is 65 percent to 70 percent, 70 percent to 75 percent, 75 percent to 80 percent, 80 percent to 85 percent, or 85 percent to 90 percent of the surface area of the radiant opening 105.
In such embodiments, where the radiant opening 105 includes a plurality of openings, the fire pit 100 may not include the screen 230 since the plurality of openings surrounded by the unremoved material of the outer body 130 effectively serves as a screen that allows heat out, air in, and prevents people and animals from being burned by the hot inner body 125. In one or more embodiments, the plurality of openings 240 of the screen 230, or the plurality of openings of the radiant opening 105, may be of any shape, design, or pattern as desired for the particular application. In one or more embodiments, the plurality of openings of the radiant opening 105 may have the shape of a circle, square, triangle, star, heart, cloud, leaf, paw, or any other shape desired.
In one or more embodiments, one or more structural ribs (not shown) extend vertically between and connect the top portion 110 of the outer body 130 and the bottom portion 115 of the outer body 130 to provide structural rigidity to the outer body 130. In such embodiments, the one or more vertically extending structural ribs interrupt or intersect the radiant opening 105 around the circumference of the outer body 130.
With continued reference to
In one or more embodiments, the axial height of the radiant opening 105 may be 30 percent to 35 percent, 35 percent to 40 percent, 40 percent to 45 percent, 45 percent to 50 percent, 50 percent to 55 percent, or 55 percent to 60 percent of the axial height of the outer body 130 of the fire pit 100.
In one or more embodiments, the axial height of the air gap 195 above the radiant opening 105 may be 25 percent to 30 percent, 30 percent to 35 percent, 35 percent to 40 percent, 40 percent to 45 percent, or 45 percent to 50 percent of the axial height of the outer body 130 of the fire pit.
In one or more embodiments, the axial height of the air gap 195 above the radiant opening 105 may be 50 percent to 55 percent, 55 percent to 60 percent, 60 percent to 65 percent, 65 percent to 70 percent, 70 percent to 75 percent, 75 percent to 80 percent, 80 percent to 85 percent, 85 percent to 90 percent, 90 percent to 95 percent, 95 percent to 100 percent, 100 percent to 105 percent, 105 percent to 110 percent, 110 percent to 115 percent, 115 percent to 120 percent, or 120 percent to 125 percent of the axial height of the radiant opening 105 or of the portion of the inner body 125 exposed by the radiant opening 105.
In one or more embodiments, the axial height of the air gap 195 of the top portion 110 may be directly related to the radial width of the air gap 195. If the radial width of the air gap 195 is larger, there will be a greater amount of secondary combustion air 220 flowing up through the air gap 195 at a greater radial distance away from the hot inner body 125. In such embodiments, the axial height of the air gap 195 of the top portion 110 would need to be greater to ensure the secondary combustion air 220 reaches the desired temperature before entering the burn chamber 140. In the alternative, if the radial width of the air gap 195 is smaller, the axial height of the top portion 110 and of the air gap 195 does not need to be as great in order for the secondary combustion air 220 to reach the desired temperature range. In one or more embodiments, the radial width of the air gap 195 may be 15 percent to 20 percent, 20 percent to 25 percent, 25 percent to 30 percent, 30 percent to 35 percent, 35 percent to 40 percent, 40 percent to 45 percent, or 45 percent to 50 percent of the axial height of the air gap 195 of the top portion 110 of the outer body 130 above the radiant opening 105.
As shown in
In one or more embodiments, the fire pit 100 may have a heat directing feature, such as, for example, a rotatable door, a sleeve, a hinged panel, or some other feature, which extends circumferentially about the outer body 130 and covers at least a portion of the radiant opening 105. The heat directing feature may have an axial height equal to the axial height of the radiant opening 105. The heat directing feature may be rotatably received within a groove located proximate the top edge of the bottom portion 115 of the outer body 130. The heat directing feature may be rotated about the circumference of the fire pit 100 within the groove to selectively expose a portion of the inner wall to allow radiant heat out of the radiant opening. In one or more embodiments, the heat directing feature may have one or more openings through which radiant energy from the exposed portion of the inner body 125 may be emitted. By rotating the heat directing feature about the circumference of the fire pit 100, the one or more openings of the heat directing feature can be positioned about the fire pit 100 relative to the radiant opening 105 to emit heat in the direction desired by the user.
In one or more embodiments, the heat directing feature may include one or more panels slidably received between the outer body 130 and the inner body 125. The one or more panels may be slid up or down within the space between the outer body 130 and the inner body 125 to cover or uncover desired portions of the radiant opening 105 and desired portions of the inner body 125 in order to direct heat in the direction desired by the user.
In one or more embodiments, the radiant opening 105 may only extend partway around the circumference of the fire pit 100 such that more radiant heat may be emitted in a desired direction, while less radiant heat may be emitted in less desired directions. In such embodiments, the radiant opening 105 may extend in a range of about 30 degrees to about 330 degrees about the circumference of the fire pit 100. In one or more embodiments, the radiant opening 105 may extend partway around the fire pit 100 in similar ranges even where the fire pit is oval, rectangular (including square), or having three or more than four sides. In some implementations, the radiant opening 105 is disposed to radiate heat on only one side of the fire pit 100. This may be adjustable by physically positioning the fire pit in a desired orientation or by using a heat directing feature such as those described above.
In one or more embodiments, an interior surface 252 of the outer body 130 may include a mirror finish. The mirror finish promotes reflection of the infrared radiation from the inner body 125 that does not exit through the radiant opening 105 back to the inner body 125, which increases the energy and temperature of the inner body 125, or at least helps to maintain said energy and temperature levels, and promotes a more even heat profile on the inner body 125. In so doing, the mirror finish promotes increased emission of heat from the inner body 125 through the radiant opening 105 because the inner body 125 is able to maintain higher energy and temperature levels. In one or more embodiments, the interior surface 252 of the outer body 130 may include other types of reflective finishes or high emissivity coatings known in the art.
In one or more embodiments, the portion of the inner body 125 exposed by the radiant opening 105, which is the portion of the inner body 125 adjacent the radiant opening 105 and in one or more embodiments is the intermediate portion 120 of the inner body 125, includes a high emissivity coating. The high emissivity coating on the exterior surface 208 of the inner body 125 promotes increased emission of radiant energy from the inner body 125 laterally outward away from the fire pit 100 through the radiant opening 105. There are many high emissivity coatings commercially available and known in the art. In some embodiments, a matte finish ceramic coating may also be used on the exterior surface 208 of the inner body 125 to promote emission of radiant energy.
In one or more embodiments, the portion of the inner body 125 adjacent the radiant opening 105 includes surface waviness or undulations that increase the surface area of the portion of the inner body 125 adjacent the radiant opening 105. In other embodiments, the entire inner body 125 may include surface waviness or undulations. Surface area has a direct impact on the amount of radiant energy able to be emitting from a material. Thus, increasing the surface area of the exterior surface 208 of the inner body 125, particularly the portion of the inner body 125 adjacent the radiant opening 105, increases the amount of radiant energy the inner body 125 is able to emit laterally outward away from the fire pit 100 through the radiant opening 105.
Referring to
In the embodiment shown in
Referring to
In one or more embodiments, the ambient air 210 that enters the fire pit 100 via the outer ventilation holes 265 supplements the flow of primary combustion air 215 that flows from the ambient air 210 that enters the fire pit 100 via the radiant opening 105.
In one or more embodiments, the outer body 130 and the inner body 125 are connected at the bottom end 245 of the radiant opening 105 around the entire circumference of the fire pit 100 such that the radiant opening 105 and the plurality of outer ventilation holes 265 are isolated from each other and not in fluid communication. In such embodiments, all of the ambient air 210 that enters the fire pit 100 via the radiant opening 105 rises up as secondary combustion air 220 and enters the burn chamber 140 via the plurality of inner ventilation holes 160 in the top portion 110 of the inner body 125. Furthermore, in such embodiments where the radiant opening 105 and the plurality of outer ventilation holes 265 are isolated from each other, all of the ambient air 210 that enters the fire pit 100 via the plurality of outer ventilation holes 265 flows through the air gap 200 of the bracing tray 175 as primary combustion air 220 and enters the burn chamber 140 via the ventilation holes 225 in the fuel grate 145.
The plurality of outer ventilation holes 265 may be evenly distributed around at least a portion of the circumference of the bottom portion 115 of the outer body 130. In one or more embodiments, the plurality of outer ventilation holes 265 may be evenly distributed around the entire circumference of the bottom portion 115 of the outer body 130. In one or more embodiments, the plurality of outer ventilation holes 265 are axially aligned with the air gap 200 of the bracing tray 175. In one or more embodiments, the outer ventilation holes 265 are at least partially, or are entirely, located below the air gap 200. In one or more embodiments, the outer ventilation holes 265 are at least partially, or are entirely, located above the air gap 200. The design, shape, number, and size of the plurality of outer ventilation holes 265 may vary depending on the requirements or preferences of the application. In one or more embodiments, the plurality of outer ventilation holes 265 may have the shape of a circle, square, triangle, star, heart, cloud, leaf, paw, or any other shape desired. In one or more embodiments, the size of the plurality of outer ventilation holes 265 may be greater than, less than, or equal to the size of the plurality of inner ventilation holes 160.
In one or more embodiments, it is contemplated that the fire pit 100 may not include secondary combustion. In such embodiments, the inner body 125 would not include the inner ventilation holes 160 and would not communicate secondary combustion air 220 to the burn chamber 140 at the top portion 110 of the fire pit 100. The fire pit 100 would maintain the outer body 130, the inner body 125, and the radiant opening 105, but all of the ambient air 210 entering the fire pit 100 through the radiant opening 105 would flow to the bottom portion 115 of the fire pit 100 and enter the burn chamber 140 via the ventilation holes 225 in the fuel grate 145. The radiant opening 105 would still allow radiant heat emitted from the exposed inner body 123 to exit the fire pit 100 via the radiant opening 105 and provide heat to users and objects surround the fire pit 100.
Accordingly, the present disclosure is directed to various aspects, including a fire pit comprising: an inner wall having an interior surface and an exterior surface; a burn chamber defined by the interior surface of the inner wall and a fuel grate; an outer wall surrounding and spaced apart from the inner wall; and a radiant opening extending through the outer wall and exposing a portion of the exterior surface of the inner wall proximate the opening to provide radiant heat to the area outside the fire pit laterally adjacent the outer wall.
In some aspects, the fire pit includes a screen positioned within the opening in the outer wall, the screen having a plurality of openings, each of the plurality of openings of the frame being smaller in size than the opening in the outer wall.
In some aspects, the portion of the exterior surface of the inner wall proximate the opening in the outer wall includes a high emissivity coating adapted to promoted emission of radiant energy from the inner wall.
In some aspects, at least the exposed portion of the exterior surface of the inner wall includes surface undulations that increase the surface area of the exposed portion of the exterior surface of the inner wall.
In some aspects, the disclosure is directed to a fire pit comprising: an outer wall; an inner wall surrounded by the outer wall and being spaced apart from the outer wall to form an air passage therebetween, the inner wall having an interior surface and an exterior surface, the interior surface of the inner wall forming a part of a burn chamber adapted to receive a combustible fuel; a fuel grate forming a part of the burn chamber and defining an air chamber; a bracing tray disposed below the fuel grate; and a radiant opening extending through an intermediate portion the outer wall and exposing a portion of the exterior surface of the inner wall proximate the opening, the opening defining axially opposing first and second ends and extending about the intermediate portion of the outer wall through at least a portion of the perimeter of the outer wall, the first end of the opening being axially spaced apart from both the bracing tray and the fuel grate, the opening being in fluid communication with the air passage and the air chamber.
In some aspects, the opening is entirely axially spaced apart from the bracing tray and the fuel grate.
In some aspects, the fuel grate is positioned axially between the first and second ends of the opening.
The present disclosure may include aspects such as a fire pit comprising: an inner wall having an interior surface defining at least a part of a burn chamber; an outer wall extending circumferentially about, and radially spaced apart from, the inner wall to form an air passage therebetween; a radiant opening in fluid communication with the air passage, the opening extending radially through an intermediate portion of the outer wall and extending through at least a portion of the circumference of the outer wall, the opening defining axially opposing first and second ends, which are spaced apart an axial height that is greater than an axial height of a portion of the air passage above the opening, and the opening exposing a portion of an exterior surface of the inner wall proximate the opening of the outer wall, the portion of the exterior surface of the inner wall proximate the opening of the outer wall having a high emissivity coating adapted to promote emission of radiant energy from the inner wall; a screen positioned within the opening and connected to the outer wall of the fire pit at the first and second ends of the opening, the screen having a plurality of second openings; and a fuel grate defining a bottom of the burn chamber and positioned axially at an elevation between the first and second ends of the opening in the outer wall, the fuel grate defining an air chamber axially below the fuel grate, the air chamber being in fluid communication with the opening in the outer wall.
In some aspects, at least the exterior surface of the inner wall proximate the opening of the outer wall includes surface undulations that increase the surface area of the exterior surface of the inner wall proximate the opening to promote emission of radiant energy.
The present disclosure may include aspects such as a fire pit comprising: an inner body having an interior surface defining at least a part of a burn chamber, the inner wall having a plurality of inner ventilation holes; a first outer wall portion extending about, and radially spaced apart from, the inner wall to form an air passage therebetween, the first air passage being arranged to draw ambient air during use through a first air intake; a fuel grate cooperating with the inner body to define a burn chamber, the fuel grate having a plurality of ventilation holes formed therein, a second outer wall portion disposed at an elevation lower than the first air intake and having a plurality of outer ventilation holes, the outer ventilation holes in fluid communication with the plurality of ventilation holes in the fuel grate via a second air passage, the second air passage being arranged to draw ambient air during use through a second air intake at an elevation different from the first air intake.
In some aspects, the first air intake comprises a radiant opening having first and second ends spaced apart and exposing a portion of an exterior surface of the inner body, the opening sized to emit radiant heat from the inner body of the fire pit during use.
In some aspects, the portion of the exterior surface of the inner wall comprises a high emissivity coating adapted to promote emission of radiant energy from the inner wall.
In some aspects, the first air passage and the second air passage are isolated from each other.
The present disclosure may include aspects such as a fire pit comprising: an inner body having an interior surface defining at least a part of a burn chamber; a first outer wall portion extending about, and radially spaced apart from, the inner wall to form a first air passage therebetween, an inner ventilation opening from the first air passage into the burn chamber; a first air intake configured to draw ambient air during use into the first air passage; a fuel grate cooperating with the inner body to define the burn chamber, the fuel grate having at least one ventilation hole, a second outer wall portion disposed at an elevation lower than the first air intake; a second air intake in fluid communication with the at least one ventilation hole in the fuel grate via a second air passage, the second air intake configured to draw ambient air into the second air passage at an elevation different from the first air intake.
In some aspects, the first air intake comprises an opening having first and second ends spaced apart and exposing a portion of an exterior surface of the inner body, the opening sized to emit radiant heat from the fire pit during use.
In some aspects, the second air intake comprises a plurality of openings formed in an exterior surface of the second outer wall portion.
A number of variations are possible on the examples and embodiments described herein. For example, the fire pit or components thereof could be made of heavier-gauge material in order to support more weight, or of lighter gauge material in order to become lighter and more portable. The radiant opening could have different sizes, designs, and circumferential orientations. Air gaps may be larger or smaller than shown herein, to optimize air flow through the fire pit, to minimize weight or volume of the fire pit, or for other reasons. The relative lengths, widths, and radii of different components could be different than presented herein. The fire pit or components thereof could be made by different processes, including casting, forging, sintering, milling, or 3D printing. They could be made of different metals, or of nonmetallic materials such as ceramics. The fire pit rim could be noncircular, including such possible shapes as ovals, rectangles, triangles, and rhombuses. The technology described herein may be used to burn firewood, wood chips or pellets, scrap lumber, paper, cardboard, coal, and other combustible materials. It may be employed for example in lamps, stoves, fire pits, fireplaces, furnaces, forges, and boilers, and other combustion heaters. In some implementations, the fire pit or components thereof may comprise several pieces that collectively form a structure like that described herein.
The logical operations making up the embodiments of the technology described herein are referred to variously as operations, steps, objects, elements, components, or modules. Furthermore, it should be understood that these may occur or be performed in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.
All directional references e.g., upper, lower, inner, outer, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, proximal, and distal are only used for identification purposes to aid the reader's understanding of the claimed subject matter, and do not create limitations, particularly as to the position, orientation, or use of the fuel grate, ash pan, or fire pit. Connection references, e.g., attached, coupled, connected, and joined are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other. The term “or” shall be interpreted to mean “and/or” rather than “exclusive or.” Unless otherwise noted in the claims, stated values shall be interpreted as illustrative only and shall not be taken to be limiting.
The above specification, examples and data provide a complete description of the structure and use of example embodiments of the radiant opening, fuel grate, ash pan, and fire pit as defined in the claims. Although various embodiments of the claimed subject matter have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the claimed subject matter. Still other embodiments are contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments and not limiting. Changes in detail or structure may be made without departing from the basic elements of the subject matter as defined in the following claims.
This application claims priority to and the benefit of the filing date of U.S. Provisional Patent Application No. 63/582,608, filed Sep. 14, 2023, the entire disclosure of which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63582608 | Sep 2023 | US |
