Patent Application
20220163199
The present disclosure generally relates to burner assemblies for a cooking appliance such as a cooktop, and more specifically, to burner assemblies that reduce flame lift and flame flashback.
A kitchen appliance sometimes performs a cooking function. Sometimes the kitchen appliance performs the cooking function at a surface that is open to an external environment, such as when the kitchen appliance is a cooktop or a range with a cooktop. The cooktop can utilize one of several methods to produce heat that performs the cooking function. Those methods include combustion of a mixture of air and gaseous fuel, electrical resistance, and induction. When the cooktop relies upon combustion of the mixture of air and gaseous fuel, a burner assembly can be utilized to deliver the mixture of air and gaseous fuel.
However, several problems can arise. First, with some burner assemblies, where the mixture of air and gaseous fuel is converted into a flame at gas outlets, a velocity of the mixture of air and gaseous fuel to the ports exceeds the speed at which the mixture of air and gaseous fuel can combust into the flame, which results in the flame lifting from the burner. This is sometimes referred to as “flame lift.” Second, with some burner assemblies, the flame propagates back upstream into the burner assembly. This is an effect sometimes referred to as “flashback,” and the result can be an audible popping noise.
The present disclosure addresses the flame lifting problem with a spreader for a burner assembly that spreads the mixture of air and gaseous fuel outward toward a plurality of apertures and includes a downward extending ridge that interferes with the flow of the mixture of air and gaseous fuel to the plurality of apertures. The ridge reduces a velocity of the mixture of air and gaseous fuel before the mixture of air and gaseous fuel reaches the plurality of apertures to flow out of the burner assembly and become combusted into the flame. Therefore, the velocity of the mixture of air and gaseous fuel exiting the plurality of apertures does not exceed the speed at which the mixture of air and gaseous fuel combusts into the flame. Thus, the flame does not lift from the burner assembly.
In addition, the present disclosure addresses the flashback problem with a perforated sheet (such as of a perforated metal sheet) that is disposed in fluid communication before a spreader with a plurality of apertures. The mixture of air and gaseous fuel flows through the perforated sheet (that is, through a plurality of apertures through the perforated sheet), and then through the plurality of apertures of the spreader to become combusted into the flame. Should the flame proceed back upstream through the plurality of apertures of the spreader, the perforated sheet quenches the flame. That prevents flashback further into the burner assembly and prevents the generation of noise that further flashback would have caused. The perforated sheet further reduces the velocity of the mixture of air and gaseous fuel before combustion and, thus, also reduces the likelihood of flame lifting.
According to one aspect of the present disclosure, a burner assembly for a cooktop comprises: a spreader comprising (i) a central portion through which an axis extends, the central portion with a bottom surface, (ii) a plurality of apertures through the spreader, the plurality of apertures disposed further away from the axis than the central portion, and (iii) a ridge projecting from the bottom surface, the ridge disposed further from the axis than the central portion but closer to the axis than the plurality of apertures.
In embodiments, the ridge forms a contiguous perimeter around the bottom surface of the central portion. In embodiments, the ridge comprises an inner surface closest to the axis that forms an angle relative to the bottom surface of the central portion that is greater than 90 degrees and less than 120 degrees. In embodiments, the spreader further comprises (i) an outer portion disposed further away from the axis than the plurality of apertures and the ridge, and (ii) a plurality of spaced fingers, each separated by one of the plurality of apertures, bridging the central portion to the outer portion. In embodiments, the spreader comprises a top surface, and the top surface at the central portion is elevated higher than the top surface at the outer portion.
In embodiments, the burner assembly further comprises: a burner cap disposed over the spreader, the burner cap comprising (i) a central portion disposed over the central portion of the spreader, with the axis of the spreader extending through the central portion of the burner cap, (ii) an outer portion disposed further away from the axis than the central portion of the burner cap, the outer portion disposed over the outer portion of the spreader, (iii) a middle portion disposed further away from the axis than the central portion of the burner cap but closer to the axis than the outer portion of the burner cap, the middle portion disposed above the plurality of apertures of the spreader, and (iv) a plurality of apertures through the middle portion. The outer portion of the burner cap assembly comprises a flange that surrounds a lateral edge of the spreader.
In embodiments, the burner assembly further comprises: a venturi comprising (i) an internal surface defining a passageway for a mixture of air and gaseous fuel, (i) an inlet into the passageway in communication with a source of air and a source of gaseous fuel and (ii) an outlet out of the passageway in fluid communication with the plurality of apertures of the spreader. The axis extends through the central portion of the spreader and also extends into the outlet of the venturi. In embodiments, the ridge of the spreader comprises an inner surface that (i) forms an approximately right angle relative to the bottom surface of the central portion and (ii) is at least approximately parallel to the axis, the inner surface disposed at a radius from the axis. The internal surface that defines the passageway at the outlet has a radius from the axis. The radius of the internal surface defining the passageway at the outlet is less than the radius of the inner surface of the ridge of the spreader. The mixture of air and gaseous fuel flows (i) through the passageway of the venturi toward the outlet of the venturi, (ii) out the outlet of the venturi, (iii) and through the plurality of apertures of the spreader. The ridge of the spreader reduces a velocity of the mixture of air and gaseous fuel before the mixture of air and gaseous fuel flows through the plurality of apertures of the spreader. In embodiments, a base is disposed between the spreader and the venturi, and the base comprises (i) a central aperture through which the axis that extends through the central portion of the spreader also extends, the central aperture in fluid communication with the passageway of the venturi, and (ii) an annular ridge at the top around and defining the central aperture, the annular ridge of the base disposed closer to the axis than the ridge projecting from the bottom surface of the spreader.
In embodiments, the burner assembly further comprises: a mixture of air and gaseous fuel flowing (i) through the passageway of the venturi toward the outlet of the venturi, (ii) out the outlet of the venturi, (iii) through the central aperture of the base, (iv) between the annular ridge of the top of the base and the ridge projecting from the bottom surface of the spreader, and (v) through the plurality of apertures of the spreader. The ridge that projects from the bottom surface of the spreader reduces a velocity of the mixture of air and gaseous fuel before the mixture of air and gaseous fuel flows through the plurality of apertures of the spreader.
In embodiments, the base further comprises an inner surface that defines the central aperture, the inner surface being parallel to the axis and having a radius from the axis. The internal surface that defines the passageway at the outlet has a radius from the axis. The radius of the internal surface defining the passageway at the outlet is approximately equal to the radius of the inner surface defining the central aperture of the base.
In embodiments, the base further comprises a second annular ridge at the top of the base that surrounds the annular ridge and, with the annular ridge, defines an annular recess that is planar and perpendicular to the axis. The spreader further comprises a second ridge at a bottom of the spreader that is further away from the axis than the ridge of the spreader, the second ridge disposed over the top of the base and facing the second annular ridge of the base, with the second ridge of the spreader being closer to the axis than the second annular ridge of the base.
According to another aspect of the present disclosure, a burner assembly for a cooktop comprises: (a) a base comprising (i) a tubular wall defining a passageway through which an axis extends, the tubular wall having a first end defining an inlet into the passageway and a second end defining an outlet of the passageway, (ii) a lateral wall extending laterally outward from the tubular wall, and (iii) an outer wall extending upward from the lateral wall and forming a perimeter around the lateral wall, the outer wall is more elevated from the bottom wall than the second end of the tubular wall; (b) a spreader disposed above the tubular wall and the lateral wall of the base, the spreader comprising (i) a central portion through which the axis extends, the central portion disposed above the outlet of the passageway of the base, (ii) an outer portion surrounding the central portion, the outer portion terminating in an edge that defines a lateral perimeter of the spreader away from the axis, with the outer wall of the base surrounding the edge of the outer portion of the spreader, and (iii) a plurality of apertures through the spreader at the outer portion; and (c) a perforated sheet disposed between the base and the spreader, the perforated sheet comprising (i) a central portion through which the axis extends, the central portion disposed between the central portion of the spreader and the tubular wall of the base, (ii) an outer portion further away from the axis than the central portion, the outer portion disposed between the lateral wall of the base and the outer portion of the spreader, the outer portion terminating in an edge, with the outer wall of the base surrounding the edge of the outer portion of the perforated sheet, and (iii) a plurality of apertures through the perforated sheet.
In embodiments, the central portion of the perforated sheet is separated from the tubular wall of the base, and the outer portion of the spreader is separated from the outer portion of the perforated sheet.
In embodiments, a mixture of air and gaseous fuel flows into the inlet of the passageway of the base, through the passageway, out of the outlet of the passageway, through the plurality of apertures of the perforated sheet, and through the plurality of apertures of the spreader. A velocity of the mixture of air and gaseous fuel before the mixture of air and gaseous fuel flows through the plurality of apertures of the perforated sheet is greater than a velocity of the mixture of air and gaseous fuel after the mixture of air and gaseous fuel flows through the plurality of apertures of the perforated sheet.
In embodiments, the apertures of the plurality of apertures through the perforated sheet each have a diameter of 1.9 mm to 2.1 mm. In embodiments, the perforated sheet has a thickness that is 0.8 mm to 1.0 mm.
According to yet another aspect of the present disclosure, a burner assembly comprises: (i) an outlet of a passageway; (ii) a spreader comprising a plurality of apertures; and (iii) a perforated sheet disposed between the outlet of the passageway and the spreader, the perforated sheet comprising a plurality of apertures. The burner assembly is configured to direct a mixture of air and gaseous fuel exiting the outlet of the passageway through the plurality of apertures of the perforated sheet and then through the plurality of apertures of the spreader.
These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.
In the drawings:
The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles described herein.
Referring to
Referring now to
Referring now to
The spreader 34 includes a central portion 42 through which the axis 36 extends. The central portion 42 has a bottom surface 44 at the bottom 40 of the spreader 34. In embodiments, the bottom surface 44 is perpendicular to the axis 36 or approximately perpendicular to the axis 36 (i.e., forming an angle of 70 degrees to 90 degrees relative to the axis 36). The bottom surface 44 of the central portion 42 faces and contacts the mixture of air and gaseous fuel 35 before the mixture of air and gaseous fuel 35 combusts, and spreads the mixture of air and gaseous fuel 35 outward from the axis 36. The central portion 42 has a top surface 46. In embodiments, the top surface 46 is planar. In embodiments, the top surface 46 is perpendicular to the axis 36 or approximately perpendicular to the axis 36 (i.e., forming an angle of 70 degrees to 90 degrees relative to the axis 36).
The spreader 34 further includes a plurality of apertures 48 through the spreader 34. That is, the plurality of apertures 48 extend through the spreader 34 from the bottom 40 to the top 38 of the spreader 34. The plurality of apertures 48 are disposed further away from the axis 36 than the central portion 42. In embodiments, the plurality of apertures 48 are disposed radially around the axis 36. As further discussed below, the mixture of air and gaseous fuel 35 flows through plurality of apertures 48.
In embodiments, the plurality of apertures 48 each have a radial length 50 between a beginning radius 52 and an ending radius 54 from the axis 36. In such embodiments, the plurality of apertures 48 each have a width 56 orthogonal to the radial length 50, and the width 56 is less than the radial length 50. In embodiments, the radial length 50 is 3 to 8 times the width 56.
The spreader 34 further includes a plurality of spaced fingers 58. Each of the plurality of spaced fingers 58 are separated by one of the plurality of apertures 48 (i.e., finger 58, aperture 48, finger 58, aperture 48, in sequence, and so on).
The spreader 34 further includes a ridge 60 at the bottom 40. The ridge 60 projects from the bottom surface 44. The ridge 60 is disposed further away from the axis 36 than the central portion 42 but closer to the axis 36 than the plurality of apertures 48. In embodiments, the ridge 60 is annular, and has a radius 62 from the axis 36 that is constant or approximately constant (e.g., deviation of less than 5% from a median of the radius 62). In embodiments, the ridge 60 separates the central portion 42 from the plurality of apertures 48 at the bottom 40 of the spreader 34. In embodiments, the ridge 60 forms a contiguous perimeter around the bottom surface 44 of the central portion 42.
The ridge 60 includes an inner surface 64 closest to the axis 36. In embodiments, the inner surface 64 forms an angle α that is obtuse (e.g., 90 degrees<angle α<120 degrees) relative to the bottom surface 44. In embodiments, the angle α is right or approximately right (e.g., 85 degrees angle α 95 degrees). In embodiments, the inner surface 64 is parallel to the axis 36 or at least approximately parallel to the axis 36 (i.e., forms an angle of −10 degrees to 10 degrees relative to the axis 36). The inner surface 64 is disposed at, and defines, the radius 62 of the ridge 60 from the axis 36.
In embodiments, the spreader 34 further includes an outer portion 66. The plurality of spaced fingers 58 bridges the central portion 42 to the outer portion 66. The outer portion 66 is disposed further away from the axis 36 than the plurality of apertures 48 and the ridge 60. The outer portion 66 includes a lateral edge 68 that defines a perimeter of the spreader 34 relative to the axis 36. In embodiments, the outer portion 66 includes a top surface 70 that is perpendicular or at least approximately perpendicular to the axis 36 (i.e., forms an angle of 80 degrees to 100 degrees relative to the axis 36). In embodiments, the lateral edge 68 has a radius 72 from the axis 36 that is constant or approximately constant (e.g., deviation of less than 5% from a median of the radius 72). In embodiments, the plurality of spaced fingers 58 project laterally away and downward from the central portion 58, with the result being that top surface 46 of the spreader 34 at the central portion 42 is elevated higher than the top surface 70 of the spreader 34 at the outer portion 66.
In embodiments, the spreader 34 includes a ridge 74 at the top 34 of the spreader 34 that is contiguous with or proximate the edge 68. The ridge 74 extends upward from the top surface 70. In embodiments, the spreader 34 includes apertures 76, 78 through which a temperature sensor 80 (see
In embodiments, the spreader 34 further includes a second ridge 90 at the bottom 40 and at the outer portion 66. The second ridge 90 is disposed further away from the axis 36 than the ridge 60. The second ridge 90 can be annular about the axis 36. The second ridge 90 has an inner surface 92 that faces the axis 36. The inner surface 92 can be parallel to the axis 36 or approximately parallel to the axis 36 (i.e., forming an angle of −10 degrees to 10 degrees relative to the axis 36). The inner surface 92 of the second ridge 90 has a radius 94 that is equal to or approximately equal to the ending radius 54 of the plurality of apertures 48. The second ridge 90 further includes a bottom surface 96 just further away from the axis 36 than the inner surface 92. The bottom surface 96 can be perpendicular to the axis 36 or approximately perpendicular to the axis 36 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 36). The second ridge 90 further includes an outer surface 98 facing away from the axis 36, and further away from the axis 36 than the inner surface 92. The outer surface 98 can be parallel to the axis 36 or approximately parallel to the axis 36 (i.e., forming an angle of −10 degrees to 10 degrees relative to the axis 36).
In embodiments, the burner assembly 12 further includes a burner cap 100 (see particularly
The burner cap 100 includes a central portion 106. The axis 36 extends through the central portion 106. The central portion 106 includes a bottom surface 108 at the bottom 104 that faces the top surface 70 of the spreader 34. In embodiments, the bottom surface 108 is planar and is perpendicular to the axis 36. In embodiments, the top surface 110 is planar and is perpendicular to the axis 36. In embodiments, the bottom surface 108 and the top surface 110 are approximately perpendicular to the axis 36 (i.e., forms an angle of 80 degrees to 100 degrees relative to the axis 36).
The burner cap 100 further includes an outer portion 112. The outer portion 112 is disposed further away from the axis 36 than the central portion 106. The outer portion 112 is disposed over the outer portion 66 of the spreader 34. The outer portion 66 includes a top surface 114 at the top 102, and a bottom surface 116 at the bottom 104 that faces the top surface 70 of the outer portion 66 of the spreader 34. In embodiments, the bottom surface 116 is planar and is perpendicular to the axis 36. In embodiments, the top surface 114 is planar and is perpendicular to the axis 36. In embodiments, the bottom surface 116 and the top surface 114 are approximately perpendicular to the axis 36 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 36).
In embodiments, the outer portion 112 of the burner cap 100 further includes a flange 118. The flange 118 radially surrounds the edge 68 of the spreader 34. The flange 118 includes an inner surface 120. The inner surface 120 faces the edge 68 of the spreader 34. In embodiments, the inner surface 120 is parallel or approximately parallel to the axis 36 (e.g., forms an angle of −10 degrees to 10 degrees relative to the axis 36). Thus, the burner cap 100 partially encases the spreader 34.
In embodiments, the burner assembly 12 further includes one or more gaskets 122 (see particularly
The burner cap 100 further includes a middle portion 128. The middle portion 128 is disposed further away from the axis 36 than the central portion 106 of the burner cap 100 but closer to the axis 36 than the outer portion 112 of the burner cap 100. The middle portion 128 of the burner cap 100 is disposed over the plurality of apertures 48 and plurality of spaced fingers 58 of the spreader 34. The middle portion 128 of the burner cap 100 includes a top surface 130 at the top 102 and a bottom surface 132 at the bottom 104, which faces the spreader 34. In embodiments, the bottom surface 132 of the middle portion 128 forms an obtuse angle α relative to the bottom surface 108 of the central portion 106, such as 135 degrees<angle α<180 degrees. In embodiments, the bottom surface 132 of the middle portion 128 forms a reflex angle β relative to the bottom surface 116 of the outer portion 112 of the burner cap 100, such as 180 degrees<angle β<235 degrees. In embodiments, the top surface 130 of the middle portion 128 forms a reflex angle γ relative to the top surface 110 of the central portion 106, such as 180 degrees<angle γ<235 degrees. In embodiments, the top surface 130 of the middle portion 128 forms an obtuse angle δ relative to the top surface 114 of the outer portion 112 of the burner cap 100, such as 135 degrees<angle δ<180 degrees. Thus, in embodiments, the central portion 106 of the burner cap 100 is elevated higher than the middle portion 128, which is elevated higher than the outer portion 112.
The burner cap 100 further includes a plurality of apertures 134 through the middle portion. The plurality of apertures 134 are open at the top 102 and the bottom 104 of the burner cap 100. As further discussed below, a mixture of air and gaseous fuel 35 flows through the plurality of apertures 134 through the burner cap 100.
In embodiments, the burner assembly 12 further includes a venturi 136 (see particularly
The venturi 136 includes an internal surface 154 that defines the passageway 138. The internal surface 154 at the outlet 146 of the venturi 136 has a radius 156 from the axis 36. In embodiments, the radius 156 of the internal surface 154 is less than the ending radius 54 of the plurality of apertures 48 of the spreader 34. In embodiments, the radius 156 of the internal surface 154 is less than the radius 62 of the inner surface 64 of the ridge 60 of the spreader 34.
In embodiments, the burner assembly 12 further includes a base 158 disposed between the spreader 34 and the venturi 136 (see particularly
The base 158 further includes an annular ridge 166 at the top 160 around and defining the central aperture 164. The annular ridge 166 is disposed closer to the axis 36 than the ridge 60 projecting from the bottom surface 44 of the spreader 34. The base 158 includes an inner surface 168 that defines the central aperture 164. In embodiments, the inner surface 168 is parallel to the axis 36. The inner surface 168 has a radius 170 from the axis 36.
The base 158 is disposed over the venturi 136. The base 158 is attached to the venturi 136. The base 158 includes apertures 172. The venturi 136 includes cooperating apertures 174 at the first piece 148 and the second piece 150, respectively. In embodiments, the radius 170 of the inner surface 168 of the base 158 is approximately equal to the radius 156 of the internal surface 154 of the passageway 138 of the venturi 136 at the outlet 146.
The base 158 further includes an annular ridge 176 at the bottom 162 around and further defining the central aperture 164. The annular ridge 176 sits upon the venturi 136. The base 158 further includes an annular recess 178 at the bottom 162 surrounding the annular ridge 176. The annular recess 178 has a planar surface 180 that is perpendicular to the axis 36 or approximately perpendicular to the axis 36 (i.e., forms an angle of 80 degrees to 100 degrees relative to the axis 36). The base 158 further includes, at the bottom 162, a surface 182 parallel to the axis 36 or approximately parallel to the axis 36 (i.e., forms an angle of −10 degrees to 10 degrees relative to the axis 36) that defines, with the annular ridge 176, the annular recess 178. The surface 182 extends further downward from the planar surface 180 of the annular recess 178 than the annular ridge 176. The surface 182 surrounds the venturi 136 and thus, the base 158 partially encases the venturi 136.
In embodiments, the burner assembly 12 further includes a gasket 184 that is disposed between the base 158 and the venturi 136 (see particularly
The base 158 further includes an annular recess 190 at the top 160 that surrounds the annular ridge 166. The base 158 further includes a second annular ridge 192 that surrounds the annular ridge 166 and, with the annular ridge 166, defines the annular recess 190. The annular recess 190 can be planar and perpendicular to the axis 36. The base 158 further includes an outer portion 194 surrounding the second annular ridge 192. The outer portion 194 has a surface 196 perpendicular to the axis 36. The base 158 further includes a slot 198 in which holds the temperature sensor 80, and a slot 200 in which the ignition electrode 82 is held.
The second ridge 90 disposed at the bottom 40 of the spreader 34 is disposed over, and in embodiments sits upon, the top 160 of the base 158 within the annular recess 190 of the base 158. The second ridge 90 is disposed adjacent to the second annular ridge 192 of the base 158. The second ridge 90 is disposed closer to the axis 36 than the second annular ridge 192 of the base 158. The bottom surface 84 at the outer portion 66 of the spreader 34 is disposed over and can sit upon the second annular ridge 192 of the base 158. The outer surface 98 of the second ridge 90 disposed at the bottom 40 of the spreader 34 faces and, in embodiments abuts, the second annular ridge 192 of the base 158.
In embodiments, the burner assembly 12 includes an injector holder 202 and an injector 204 that the injector holder 202 supports (see particularly
In embodiments, the second end 208 of the injector holder 202 is disposed within the inlet 140 of the venturi 136. In embodiments, the inlet 140 of the venturi 136 includes windows 214 into the passageway 138. In embodiments, the burner assembly 12 includes an air shutter 216. The air shutter 216 is a cylinder that surrounds the inlet 140 of the venturi 136. The air shutter 216 partially covers the windows 214 of the venturi 136 into the passageway 138. Positioning of the air shutter 216 determines how much of the windows 214 are open to draw in air 142 into the passageway 138. Positioning of the air shutter 216 to close more of the windows 214 results in less of the air 142 being drawn into the passageway 138. In contrast, positioning of the air shutter 216 to open more of the windows 214 results in more of the air 142 being drawn into the passageway 138.
In embodiments, the top wall 14 of the cooktop 10 further includes a trim ring portion 218 (see particularly
The trim ring portion 218 of the top wall 14 of the cooktop 10 further includes an outer portion 236. The outer portion 236 surrounds the inner portion 226. The outer portion 236 is disposed further away from the axis 36 than the inner portion 226. The outer portion 236 includes a bottom surface 238 at the bottom 224. The bottom surface 238 is perpendicular to the axis 36 or approximately perpendicular to the axis 36 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 36).
In use, gaseous fuel 144 enters the passageway 210 of the injector holder 202 (see particularly
In a computer model experiment, the velocity of the mixture of air and gaseous fuel 35 exiting the plurality of apertures 134 of the burner cap 100 when the spreader 34 did not include the ridge 60 was measured. In addition, the velocity of the mixture of air and gaseous fuel 35 exiting the plurality of apertures 134 of the burner cap 100 when the spreader 34 did include the ridge 60 was measured. The measured velocities from the two different scenarios (i.e., without the ridge 60 versus with the ridge 60) were then compared. The velocity of the mixture of air and gaseous fuel 35 exiting the plurality of apertures 134 of the burner cap 100 when the spreader 34 did include the ridge 60 was between 10 percent to 13 percent less than the velocity of the mixture of air and gaseous fuel 35 exiting the plurality of apertures 134 of the burner cap 100 when the spreader 34 did not include the ridge 60. The reduced velocity when the ridge 60 is included reduces the likelihood that the flame 22 would lift up from the burner cap 100.
The spreader 34 with the ridge 60 reduces the velocity of the mixture of air and gaseous fuel 35 without reducing the amount of the air 142 that the injection of the gaseous fuel 144 pulls into the passageway 138 of the venturi 136 through the windows 214. In addition, the problem of the flame 22 lifting is sometimes addressed via the number and configuration of the plurality of apertures 48 of the spreader 34, with the number and configuration being different for each of various different types of gaseous fuels (e.g., methane, butane, propane, etc.). The spreader 34 with the ridge 60 addresses the problem in a different way and this allows the spreader 34 to be utilized with any type of gaseous fuel 144. That reduces cost and complexity. The reduction in the flame 22 lifting also increases efficiency of heating and thus is a more efficient use of the gaseous fuel 144.
Referring now to
The base 300 includes a tubular wall 306 (see particularly
The base 300 further includes a lateral wall 326 that extends laterally outward from the tubular wall 306. That is, the lateral wall 326 extends away from the axis 310 in all radial directions from the tubular wall 306. The lateral wall 326 includes a top surface 328 and a bottom surface 330. Both the top surface 328 and the bottom surface 330 can be perpendicular to the axis 310 or approximately perpendicular to the axis 310 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 310).
The base 300 further includes an outer wall 332. The outer wall 332 extends upward from the lateral wall 326 and forms a perimeter around the top surface 238 of the lateral wall 326. The outer wall 332 is present in all radial directions around the axis 310. The outer wall 332 includes an inner surface 334 that faces the axis 310. In embodiments, the inner surface 334 is parallel to the axis 310 or approximately parallel to the interface (i.e., forming an angle of −10 degrees to 10 degrees relative to the axis 310). The inner surface 334 has a radius 336 from the axis 310. The outer wall 332 has a top 338, which is the portion of the outer wall 332 most elevated from the top surface 328 of the lateral wall 326. The top 338 of the outer wall 332 is more elevated from the top surface 328 of the lateral wall 326 and the second end 316 of the tubular wall 306.
As mentioned, the burner assembly 12A further includes the spreader 302 (see particularly
The spreader 302 further includes an outer portion 352 surrounding the central portion 344. The outer portion 352 is further away from the axis 310 than the central portion 344. The outer portion 352 terminates in an edge 354 that defines a lateral perimeter of the spreader 302 away from the axis 310. The edge 354 is at a radius 356 from the axis 310. The radius 356 of the edge 354 is equal to or less than the radius 336 of the inner surface 334 of the outer wall 332 of the base 300. The outer portion 352 has a thickness 358. In embodiments, the thickness 358 decreases as a function of increasing distance from the axis 310. The thickness 358 of the outer portion 352 is greater than the thickness 350 of the central portion 344. A sloped surface 360 transitions between the central portion 344 and the outer portion 352 at the bottom 340 of the spreader 302. The sloped surface 360 forms an acute angle relative to the axis 310 (e.g., 35 degrees to 55 degrees). The sloped surface 360 is radial about the axis 310.
The spreader 302 further includes a plurality of apertures 362. The plurality of apertures 362 extends through the thickness 358 of the outer portion 352 and are open at the top 342 and the bottom 340 of the spreader 302. In embodiments, the plurality of apertures 362 have a slot-like appearance, with a length 364 along a plane perpendicular to the axis 310 that is more than 3 times greater than a width 366 along the plane. In embodiments, a straight-light coincident with the length 364 of the plurality of apertures 362 does not intersect the axis 310.
The spreader 302 sits within the base 300. The outer wall 332 of the base 300 surrounds the edge 354 of the outer portion 352 of the spreader 302, with the inner surface 334 of the outer wall 332 of the base 300 facing the edge 354 of the spreader 302. The bottom surface 346 of the central portion 344 of the spreader 302 is separated from the second end 316 of the tubular wall 306 of the base 300.
In embodiments, the burner assembly 12A further includes a platform 368 for the spreader 302 within the base 300 (see particularly
The platform 368 further includes a top surface 382. In embodiments, the top surface 382 is parallel to the bottom surface 374. In embodiments, the top surface 382 is perpendicular to the axis 310, or approximately perpendicular to the axis 310 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 310). The bottom 340 of the spreader 302 at the outer portion 352 of the spreader 302 sits upon the top surface 382 of the platform 368. The platform 368 has a height 384, which is the distance between the top surface 382 and the bottom surface 374 of the platform 368. The height 384 of the platform 368 thus elevates the bottom 340 of the spreader 302 from the top surface 328 of the lateral wall 326 of the base 300, which separates the bottom surface 346 of the central portion 344 of the spreader 302 from the outlet 318 of the passageway 308 of the base 300.
In embodiments, the platform 368 includes a ledge 386 inset into the platform 368. The ledge 386 includes a surface 388 that is perpendicular to the axis 310 or approximately perpendicular to the axis 310 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 310). The surface 388 can be approximately half-way up the height 384 from the bottom surface 374 of the platform 368.
The ledge 386 further includes a surface 390 that is parallel to the axis 310 or approximately parallel to the axis 310 (i.e., forming an angle of −10 degrees to 10 degrees relative to the axis 310). The surface 390 has a radius 392 from the axis 310. The radius 392 of the surface 390 of the ledge 386 is greater than the radius 372 of the inside surface 370 but less than the radius 378 of the outer surface 376.
It other embodiments of the burner assembly 12A, there is no platform 368 that is separate from the base 300, and the base 300 provides the top surface 382 at the height 384 and the ledge 386 with the surface 388 less elevated from the top surface 328 of the lateral wall 326 of the base 300 than the top surface 382.
As mentioned, the burner assembly 12A further includes the perforated sheet 304 (see particularly
The perforated sheet 304 includes a central portion 398, through the axis 310 extends. The central portion 398 of the perforated sheet 304 is disposed between the central portion 344 of the spreader 302 and the tubular wall 306 of the base 300, including the second end 316 of the tubular wall 306. In embodiments, the central portion 398 is separated from the second end 316 of the tubular wall 306 and separated from the bottom surface 346 of the central portion 344 of the spreader 302.
The perforated sheet 304 further includes an outer portion 400. The outer portion 400 is further away from the axis 310 than the central portion 398. The outer portion 400 terminates in an edge 402 of the perforated sheet 304. The edge 402 fits within an area 404 that is perpendicular to the axis 310, and the area 404 has a distance 406 from the axis 310. The distance 406 of the area 404 is less than the radius 336 of the inner surface 334 of the outer wall 332 of the base 300. The inner surface 334 of the outer wall 332 of the base 300 surrounds edge 402 of the perforated sheet 304. The distance 406 of the area 404 is greater than the radius 372 of the inside surface 370 of the platform 368 (or, in embodiments, the base 300). The outer portion 400 of the perforated sheet 304 is disposed between the lateral wall 326 of the base 300 and the outer portion 352 of the spreader 302, including between the lateral wall 326 of the base 300 and the plurality of apertures 362 of the spreader 302.
The perforated sheet 304 further includes a plurality of apertures 408. The plurality of apertures 408 extends through the perforated sheet 304 and are open at the top 394 and the bottom 396 of the perforated sheet 304.
In embodiments of the burner assembly 12A that include the platform 368, the perforated sheet 304 sits upon the platform 368. In any event, the bottom 396 of the perforated sheet 304 at the edge 402 sits upon the surface 388, either of the ledge 386 of the platform 368 or provided directly by the base 300. The surface 390 of the ledge 386 of the platform 368 (or provided directly by the base 300) faces the edge 402 of the perforated sheet 304.
In embodiments, the perforated sheet 304 can include a sloped portion 410 between the central portion 398 and the outer portion 400. The sloped portion 410 elevates the central portion 398 higher up the axis 310 than the outer portion 400. The central portion 398 is thus separated from the tubular wall 306 of the base 300, i.e., elevated off the second end 316 of the tubular wall 306. In embodiments, the top surface 382 upon which the spreader 302 sits is spaced sufficiently from the surface 388 of the ledge 386 upon which the perforated sheet 304 sits so that the outer portion 352 of spreader 302 is separated from the outer portion 400 of the perforated sheet 304.
In embodiments, the perforated sheet 304 comprises metal. The perforated sheet 304 can be formed from a piece of metal such as steel and machined to be perforated with the plurality of apertures 408. In embodiments, each of the plurality of apertures 408 each have a diameter 412 of 1.9 mm to 2.1 mm. The perforated sheet 304 has a thickness 414, which is the shortest straight-line distance between the bottom 396 and the top 394. In embodiments, the thickness 414 of the perforated sheet 304 is 0.8 mm to 1.0 mm. In embodiments, the plurality of apertures 408 comprises 40 percent to 60 percent of the area 404 within which the edge 402 fits. In embodiments, the plurality of apertures 408 comprises 50 percent to 55 percent of the area 404 within which the edge 402 fits, such as approximately 51 percent.
In embodiments, the burner assembly 12A includes a bottom housing 416 (see particularly
In embodiments, the bottom housing 416 includes a bottom wall 436 and one or more side walls 438 extending upward from the bottom wall 436 and thus forming a perimeter around the bottom wall 436 thus forming an interior chamber 440. The one or more side walls 438 include a top 442. The base 300 is disposed over the bottom housing 416 with the outer wall 332 of the base 300 sitting upon the top 442 of the one or more side walls 438. The ignition electrode 432 and the temperature sensor 434 extend upward through apertures 444, 446, respectively, through the base 300. The outlet 422 of the passageway 418 is open to the interior chamber 440. The axis 310 extends into the outlet 422. The tubular wall 306 of the base 300 extends into the interior chamber 440 of the bottom housing 416. The first end 312 and inlet 314 of the tubular wall 306 are disposed above the injector 426. The first end 312 and the inlet 314 are separated from the bottom wall 436 of the bottom housing 416.
In embodiments, the top wall 14 of the cooktop 10 further includes a trim ring portion 448 (see particularly
In embodiments, the burner assembly 12A further includes a top skirt 464 (see particularly
The top skirt 464 is disposed over the outer wall 332 of the base 300 and the inner portion 458 of the trim ring portion 448. The bottom 474 of the top skirt 464 includes a surface 478 that is perpendicular to the axis 310 or approximately perpendicular to the axis 310 (i.e., forming an angle of 80 degrees to 100 degrees relative to the axis 310). The surface 478 extends most of the way between the inner radius 468 and the outer radius 470. The surface 478 is disposed over the top 338 of the outer wall 332 of the base 300. The top skirt 464 includes projections 480 at the bottom 474 that extend away from the surface 478. The projections 480 are disposed within receivers 482 into the top 338 of the outer wall 332 of the base 300 to limit lateral movement of the top skirt 464. The top skirt 464 further includes apertures 484 through which the temperature sensor 434 and the ignition electrode 432 protrude.
In use, gaseous fuel 424 enters into the inlet 420 of the passageway 418 of the bottom housing 416. The gaseous fuel 424 flows through the passageway 418 to the injector 426. The injector 426 injects the gaseous fuel 424 through the inlet 420 and into the passageway 308 of the base 300 in a direction parallel to the axis 310. The gaseous fuel 424 pulls air 486 from the interior chamber 440 into the passageway 308 of the base 300 as well, thus forming a mixture of air and gaseous fuel 488. The mixture of air and gaseous fuel 488 exits the outlet 318 of the passageway 308 of the base 300. The bottom surface 346 of the central portion 344 of the spreader 302 pushes the mixture of air and gaseous fuel 488 laterally outward from the axis 310, through the plurality of apertures 408 of the perforated sheet 304, and then through the plurality of apertures 362 of the spreader 302. Assuming that the mixture of air and gaseous fuel 488 is combusted, then the mixture of air and gaseous fuel 488 produces a flame 490 above the spreader 302.
The perforated sheet 304 prevents or reduces flashback of the flame 490 beyond the perforated sheet 304. The perforated sheet 304 quenches any such flame 490 attempting to flashback. Without flashback, the flame 490 is more stable. In addition, the perforated sheet 304 eliminates the need to manufacture a different spreader 302 for each of the different kinds of gaseous fuels (butane, methane, propane, etc.). Typically, to address flashback, the size and distribution of the plurality of apertures 362 of the spreader 302 are designed for a particular kind of gaseous fuel. The perforated sheet 304 eliminates any such desire to design and manufacture different spreaders for different types of gaseous fuel, thus reducing expense.
Positioning of the perforated sheet 304 between the spreader 302 and the outlet 318 of the passageway 308 of base 300 does not restrict the amount of the air 486 drawn in from the interior chamber 440 of the bottom housing 416 to create the mixture of air and gaseous fuel 488. The small thickness of the perforated sheet 304 allows the burner assembly 12A to maintain size specifications. The perforated sheet 304 limiting or eliminating the flashback thus limits or eliminates the audible noise that such flashback generates.
Further, the perforated sheet 304 reduces the velocity of the mixture of air and gaseous fuel 488, compared to if the perforated sheet 304 were not present. The reduction in the velocity of the mixture of air and gaseous fuel 488 reduces the likelihood of lifting of the flame 490 off the spreader 302. Thus, the perforated sheet 304 addresses that problem as well.
It will be understood by one having ordinary skill in the art that construction of the described disclosure and other components is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein.
For purposes of this disclosure, the term “coupled” (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated.
It is also important to note that the construction and arrangement of the elements of the disclosure as shown in the exemplary embodiments is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and/or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations.
It will be understood that any described processes or steps within described processes may be combined with other disclosed processes or steps to form structures within the scope of the present disclosure. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting.
