Patent Application
20130216966
1. Field of the Invention
The present invention relates in general to alcohol burners. More particularly, the present invention relates to a spill proof alcohol burner that uses liquid alcohol as a fuel source and has an increased burn time, controlled combustion and a smaller footprint.
2. Discussion of the Related Art
Previous alcohol burners were “open reservoir” type alcohol burners. These are still by far the most common type of alcohol fireplace burner sold. In these burners, fuel is stored in a metal container—usually a stainless steel box (square or rectangle)—which holds the alcohol fuel in liquid form. Fire is created by burning liquid alcohol directly from the surface of the liquid fuel in reservoir. The simple design of these open fuel reservoirs allows air, liquid alcohol and alcohol vapor to freely mix in the same contained area without control over the amount of each element present at any given time.
In open reservoir type alcohol burners, there is a high risk of dangerous ignition flare when vapor is first lit, which increases the risk of injury and also a frightening user experience resulting from a momentary flash fire. It is difficult to control flame size in these burners because, as fuel level drops, the amounts of air and vapor in the reservoir become out of balance, i.e., the flame is either too large or too small. This can cause poor flame quality and the flame can be difficult to see, e.g., sometimes there is more flame inside the burner reservoir than is visible on the exterior.
Another problem in these burners is the metal body of the burner reservoir becomes super heated. This creates a risk of injury from touching the metal. There is also a risk of excess vapor production during refueling a hot container.
Other burner designs incorporate materials packed inside the fuel reservoir. Some of these burners used loosely packed steel wool inside the liquid fuel chamber to act as a crude displacement of liquid and to serve as a form of heat catalyst. This approach was not successful and did not resolve the problems from the open reservoir burners.
Some models packed ceramic fiber into the fuel reservoir in a variety of ways. These burners mainly solved only one problem of the open reservoir burners, i.e., they figured out how to use the ceramic fiber to displace vapor and thereby reduce ignition flare problems. These burners also forced the flame to the surface of the burner.
However, there were still a number of issues with alcohol burners that were not addressed. For example, by packing the burner with wool, the air could no longer mix well with the liquid alcohol. Also, the flame on the surface tended to be weak and prone to premature exhaustion. As fuel was consumed, the alcohol vapor was not produced in sufficient volume and the design of the burners prevented alcohol at the bottom of the reservoir from vaporizing and making its way to the top surface of the burner where combustion occurred. The ceramic fiber tended to dry out at the top, while still wet with fuel at the bottom. The result was that the fire would extinguish, or fade down, even when there was abundant fuel stored below. This created yet another user risk because fuel is left trapped and unburned in the container after the fire has died.
Second generation alcohol burners, such as co-owned and co-pending U.S. patent application Ser. No. 13/200,733, the disclosure of which is herein incorporated by reference, were the first to resolve this problem. The second generation burners used a “baffle cage”—a 5-sided basket created by welding together flat sections of perforated stainless steel—that was inserted down into the ceramic fiber packed fuel reservoir. The combustion area was now below the top surface of the burner for the first time. This configuration had several benefits: a) the heat from the flame could now spread deeper and more evenly throughout the fiber fuel reservoir, thus producing greater amounts of vapor and in a controlled ratio that was steady from first ignition to when the fuel level was low; b) through the design of the baffle holes, the optimum balance was created between the amount of vapor allowed to release to the surface at any time, which created a more controlled flame with superior aesthetic qualities; and c) combustion now occurred below the surface of the top plate, but away from the side walls of the fuel reservoir, which eliminated excess heat transfer to the exterior of the burner (reducing risk to user).
Despite the advances made in the second generation burners, these advantages could only be enjoyed in relatively shallow configuration burners. Burners typically needed to be less than 7 cm deep because of the difficulty in spreading heat down into the fuel reservoir. In order to achieve desired length of burn time, the burners had to be wide enough to store the fuel needed, which created challenges for incorporating the burners into compact embodiments desired by consumers. Construction of these flat, shallow pans was also fairly costly with a considerable number of separate parts and welding labor required in assembly. The typical footprint of a second generation burner on the market is 140 square inches with roughly 2-3 hour max burn time. These second generation burners also tend to be difficult to light because the fuel is quickly absorbed into the fiber beneath the baffle, which makes it a challenge to initiate vapor creation initially.
The prior art fails to address these issues. Therefore, there is a need for a new, safer alcohol burner with longer burn times, controlled combustion and a smaller footprint.
The present invention relates to a safer, spill proof alcohol burner that uses liquid alcohol as a fuel source and has an increased burn time, controlled combustion and a smaller footprint. In accordance with certain embodiments, the present invention more than doubles the burn time achieved with half the footprint of prior models. The present invention introduces a system of double stacked baffles with two separate functions. The upper baffle area optimizes controlled combustion, while the lower baffle area optimizes heat transfer from the combustion area down into the fuel storage area. The lower baffle also provides a steady vapor supply to the upper baffle area. By dividing these functions, the burner in accordance with embodiments of the present invention can store fuel vertically, rather than needing to be spread out horizontally. Embodiments of the present invention thus facilitate a wide range of practical configurations for consumer uses not previously possible.
In some embodiments, air is prevented from traveling to the bottom of the apparatus because the lower baffle area is packed with ceramic fiber on all sides. This serves to restrict flame to the controlled combustion area near the top, while still allowing the desired heat to penetrate to the bottom of the fuel areas and spread across both a heat transfer plate and a heat transfer cylinder. The specific design of the weld connections of this burner are important because the challenges of packing this compact fuel cylinder with fuel absorbent wool, while still allowing for heat transfer through the connected metal parts, produces significant challenges of assembly. In some embodiments, the order of welding operations between the top plate, a combustion cylinder, the heat transfer plate and the heat transfer cylinder and the wool packing operations enables the creation of a compact apparatus that produces a sustained, high quality flame from a compact and relatively cost effective construction.
Heat would not transfer deep enough into the fuel storage and unused fuel would settle at the bottom without the continuous connection between the metal parts. Conversely, if the combustion cylinder were to extend further down into the fuel reservoir, fuel would be consumed too rapidly and the size of flame would be undesirably large. In accordance with certain embodiments, the balance between size of combustion area and size of fuel storage area, and the way these are stacked vertically, enable the leap forward in the present invention versus second generation burners that had most of the shallow fuel storage beside the combustion area.
In certain embodiment, the present invention may include an exposed wick, which allows for easy lighting. This solves a challenge that prior alcohol burners faced. When the fiber is completely behind or below the baffle, it is very difficult to ignite and initiate vapor production from the cold liquid fuel stores. Positioning the wick in a large hole in the horizontal heat transfer plate ensures first time ignition will quickly spread heat where it is needed and focuses the fire lighting exercise closest to the main fuel stores connected to this heat transferring plate.
The burner of the present invention is not prone to accidental spill of liquid alcohol because of the shape and assembly of parts that focus on evenly distributed fuel storage.
In accordance with various embodiments, there is minimal risk of unwanted vapor build up beneath the top plate, which is a problem that is still common amongst open reservoir burners and many second generation burners, because the combustion area is contained next to the surface plate. This also reduces risk to the user.
In accordance with some non-limiting embodiments, the burner of the present invention can produce a long flame of high aesthetic quality in an inexpensive apparatus that can be easily accommodated in table top home decor features, compact wall sconce features, outdoor patio lanterns, etc. because it is compact and inexpensive. This was not achievable prior to this invention because previous generation alcohol burners were either too large or too dangerous to be used in these applications. Attempts to make smaller burner versions for these expressed applications typically resulted in unacceptably short fire life and also excessive user risk.
In accordance with some non-limiting embodiments, the burner of the present invention can store one liter of fuel in a cylinder with a footprint of approximately 12 square inches and can burn for approximately four hours on a single filling. No other alcohol burner can come close to this performance, nor match its safety features.
The objects of the present invention may be achieved in connection with an embodiment of the present invention which having a burner comprising a housing including an open first end and a bottom plate; a first cylinder including a body, a first end, a second end, a first opening extending through the body between the first end and the second end and a plurality of openings throughout the body, wherein the first end is configured to abut the bottom plate; a first ceramic fiber ring configured to be positioned between the first cylinder and the housing; a first ceramic fiber column configured to be positioned in the first opening of the first cylinder; a baffle including a first end, a second end and a plurality of holes extending between the first end and the second end, wherein the first end of the baffle is configured to abut the second end of said first cylinder; a second cylinder including a body, a first end, a second end, a first opening extending through the body between the first end and the second end and a plurality of openings throughout the body, wherein the first end of the second cylinder is configured to abut the second end of said baffle; a second ceramic fiber ring configured to be positioned between the second cylinder and the housing; and a top housing plate including an opening and configured to abut the second end of the second cylinder and the first end of the housing, wherein the first ceramic fiber ring, first ceramic fiber column, and the second ceramic fiber ring are configured to store a flammable material.
In some embodiment, the baffle further includes a wick opening extending between the first end and the second end. In other embodiments, the first ceramic fiber column includes a wick configured to be positioned in the wick opening such that an end of the wick protrudes beyond the second end of the baffle. In other embodiments, a number of the plurality of holes in the second cylinder is less than a number of the plurality of holes in the first cylinder. In some embodiments, an area formed by said baffle and said second cylinder is configured to house combustion.
In some embodiments, the first cylinder, the baffle and the second cylinder are made of a material capable of conducting heat.
In other embodiments, the first cylinder includes a first flange at the first end and a second flange at the second end and the second cylinder includes a first flange at a first end and a second flange at a second end. In some embodiments, the first flange of the first cylinder is coupled to the bottom plate of the housing and the second flange of the first cylinder is coupled to the baffle and the first flange of the second cylinder is coupled to said baffle and the second flange of the second cylinder is coupled to the top housing plate.
In other embodiments, a snuffing plate is configured to couple with the top housing plate, wherein when the snuffing plate is coupled with said top housing plate combustion is prevented in the burner.
In other embodiments, the burner includes a surround configured to enclose the housing. The surround can include a channel configured to store oil.
In another aspect, a burner is provided comprising a housing including an open first end and a bottom plate; a first cylinder including a body, a first end, a second end, a first opening extending through the body between the first end and the second end and a plurality of openings throughout the body, wherein the first end is configured to abut the bottom plate; a first ceramic fiber ring configured to be positioned between the first cylinder and the housing; a first ceramic fiber column configured to be positioned in the first opening of the first cylinder; and a second cylinder including tapered sides, a bottom, an open end and a plurality of openings throughout the sides and the bottom, wherein the second cylinder is configured to abut the open end of the housing and the second end of the cylinder; wherein the first ceramic fiber ring, first ceramic fiber column, and the second ceramic fiber ring are configured to store a flammable material.
In some embodiments, the second cylinder further includes a wick opening extending between the first end and the second end. In other embodiments, the first ceramic fiber column includes a wick configured to be positioned in the wick opening such that an end of the wick protrudes beyond the bottom of the second cylinder. In some embodiments, the flammable material is alcohol.
The accompanying drawings help illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements
a is a top view showing an alcohol burner according to an embodiment of the present invention.
b is a perspective view showing an alcohol burner according to an embodiment of the present invention.
a is a perspective view showing an alcohol burner and a surround according to an embodiment of the present invention.
b is an exploded view showing an alcohol burner and a surround according to an embodiment of the present invention.
The present invention relates to an alcohol burner with an extended burn time, controlled combustion and a smaller footprint. The alcohol burner includes a housing, a combustion cylinder, a heat transfer cylinder or lower cylinder and ceramic material configured to retain alcohol. The housing contains the other components of the alcohol burner. The combustion cylinder is configured to allow vaporized alcohol and oxygen to mix such that a sustained and aesthetically desirable fire is formed in the cylinder. The combustion cylinder is heated during combustion, and the heat spreads throughout the burner to vaporize the alcohol retained within the ceramic material. The lower cylinder is configured to conduct heat from the combustion cylinder and facilitate the spread of heat throughout the alcohol burner. This allows for the alcohol burner of the present invention to be larger and deeper than prior burners while still having a controlled, sustained fire and small footprint. The combustion cylinder and the lower cylinder both have a plurality of openings for the vaporized alcohol to travel through. The lower cylinder is in fluid communication with the combustion cylinder, and any vaporized alcohol that enters the lower cylinder travels to the combustion cylinder. The vaporized alcohol enters the combustion cylinder and mixes with oxygen to sustain the combustion. The following is a more detailed description of the alcohol burner in accordance with various embodiments.
a illustrates a top view of an alcohol burner according to an embodiment of the present invention. The alcohol burner 100 includes a housing 102, a combustion chamber 104 and a top plate 106. The housing 102 contains the other components of the alcohol burner, which are described in further detail below. The combustion chamber 104 is the area in which combustion takes place. The top plate 106 covers the top of the alcohol burner 100 and includes an opening configured to be positioned over the combustion chamber 104.
b illustrates a perspective view of an alcohol burner according to an embodiment of the present invention. As can be seen in the non-limiting embodiment of
The lower cylinder 230 is configured to be positioned within the housing 102 and coupled to the bottom plate 200. The lower cylinder 230 is hollow and, in some embodiments, approximately cylindrical. The lower cylinder 230 includes a body 232, a plurality of openings 234 throughout the body 232 and first and second open ends 235 and 236. The first end of the lower cylinder 235 is configured to be coupled with the bottom plate 200. In an embodiment of the present invention, the lower cylinder includes lower flange 237 and upper flange 238. The lower flange 237 can be coupled to the bottom plate 200. The lower cylinder 230 can be composed of steel, aluminum alloy or any other material with a high melting point and good heat conduction properties. The lower retaining ring 220 is configured to be positioned between the lower cylinder 230 and housing 102 and abut the bottom plate 200. The retaining column 240 is configured to be positioned within the lower cylinder 230 and abut the bottom plate 200. The retaining column 240 and the lower retaining ring 220 are configured to retain a flammable material. In an embodiment of the present invention, the retaining column 240 and the lower retaining ring 220 are configured to retain alcohol.
The baffle plate 250 includes a top face 252 and a bottom face 254. The baffle plate 250 is configured to be coupled to the lower cylinder 230, specifically the bottom face of the baffle plate 254 is configured to be coupled to the second end of the lower cylinder 236. In an embodiment of the present invention, the bottom face of the baffle plate 254 is coupled to the upper flange of the lower cylinder 238. The baffle plate 250 is approximately cylindrical. In an embodiment of the present invention, the baffle plate 250 is a cylinder with a circumference approximately equal to the inner circumference of the housing 102, and the baffle plate 250 is positioned such that the exterior of the baffle plate 250 abuts the body of the housing 102. The baffle plate 250 includes a plurality of openings 256 configured to allow vaporized alcohol to pass through. The baffle plate 250 can be composed of steel, aluminum alloy or any other material with a high melting point and good heat conduction properties.
In an embodiment of the invention, the combustion cylinder 270 is hollow and approximately cylindrical. The combustion cylinder includes a body 272, a plurality of openings in the body 274 and first and second open ends 275 and 276. The combustion cylinder 270 is configured to be coupled to the baffle plate 250. Specifically, the first end of the combustion cylinder 275 is configured to be coupled to the top face of the baffle plate 252. In an embodiment of the present invention, the combustion cylinder includes a lower flange 277 and an upper flange 278. The lower flange 277 can be coupled to the top face of the baffle plate 252. The combustion cylinder 270 can be composed of steel, aluminum alloy or any other material with a high melting point and good heat conduction properties.
In an embodiment of the present invention, there are more lower cylinder openings 234 than combustion cylinder openings 274. This allows for the lower cylinder 230 to receive more alcohol vapor to transfer to the combustion cylinder 270. The openings in the combustion cylinder 274 are configured to optimize the amount of alcohol vapor present in the combustion chamber 104.
The upper storage ring 260 is configured to be positioned between the combustion cylinder 270 and the housing 102. The upper storage ring 260 is configured to retain a flammable material, such as alcohol. In one embodiment, the top plate 106 is a circular plate including an opening with a circumference approximately equal to the combustion chamber 270. The circumference of the outside of the top plate is approximately equal to the circumference of the housing 102. The top plate 106 is configured to be positioned on top of the alcohol burner 100. Specifically, the top plate 106 is configured to be coupled to the second end of the housing 214 and the second end of the combustion chamber 276. In an embodiment of the present invention, the top plate 106 is coupled to the upper flange of the combustion cylinder 278.
In an embodiment of the present invention, the burner 100 includes a snuffing plate 280. The snuffing plate 280 is configured to be placed on the top of the burner 100 and enclose the combustion chamber 104. When the snuffing plate 280 is placed on top of the burner 100, the oxygen supply to the combustion cylinder 104 is cut off and any combustion will cease.
In an embodiment of the present invention, the retaining column 240 includes a wick 242 (shown in
In an embodiment of the present invention, the retaining column 240 and wick 242, the lower retaining ring 220 and the upper retaining ring 260 are composed of a temperature resistant porous material, such as silica-alumina ceramic wool or other high temperature-resistance material having low thermal conductivity. The porous material is configured to absorb and store liquid alcohol and facilitate its conversion into vapor to fuel the fire.
The burner of the present invention is safer to operate due to its design and the use of the temperature resistant porous material. For example, the design restricts the flame to the controlled combustion area, thus preventing flames in areas the operator cannot detect. The use of the temperature resistant porous material prevents liquid from freely moving if the burner is tipped over, which allows for safer operation of the burner.
In an embodiment of the present invention, the burner is assembled by connecting the bottom plate 200 to the housing 102 and then to the lower cylinder 230. Next, the baffle plate 250 is connected to the lower cylinder 230 and then to the combustion cylinder 270. Finally, the top plate 106 is connected to the combustion cylinder 270 and then to the second end of the housing 214. In one embodiment, these connections are made by, for example, welding or any other suitable means. The lower retaining ring 220 and retaining column 240 are positioned after the lower cylinder 230 has been connected to the bottom plate 200 and before it is connected to the baffle plate 250. The upper retaining ring 260 is positioned after the combustion cylinder 270 has been connected to the baffle plate 250 and before it is connected to the top plate 106.
In one embodiment, the combustion cylinder 270 and the baffle plate 250 form a combustion chamber 104. The combustion chamber 104 is an open area in which vaporized alcohol and oxygen can mix to create or sustain combustion. The vaporized alcohol enters the combustion chamber 104 through the openings in the baffle plate 250 and the combustion cylinder 270. The oxygen enters the combustion chamber through the second end of the combustion cylinder 276.
In accordance with some non-limiting embodiments, the burner of the present invention can store one liter of fuel in a cylinder with a footprint of approximately 12 square inches and can burn for approximately four hours on a single filling. Other fuel storage capacities and footprints also can be used in connection with embodiments of the present invention.
a and 4b illustrate an alcohol burner and a surround according to an embodiment of the present invention. The alcohol burner 100 can be placed within a surround 400. The surround 400 can be a decorative accessory configured to enhance the appearance of the flame. In an embodiment of the present invention, the surround 400 can include tapered side walls 402 and an opening 404 to view the flame during combustion. The surround 400 can be of any form. For example, it can be a cylinder or a rectangle. Further, the surround 400 can include more than one opening 402 to enhance the appearance of the flame and allow for viewers to see the flame.
As can be seen in
Thus, a number of preferred embodiments have been fully described above with references to the drawing figures. Although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions could be made to the described embodiments within the spirit and scope of the invention.
