Outer ring fire cap and burner

Abstract

An outer ring fire cover and a burner, the outer ring fire cover comprising: a fire cover body having a ring-shaped top wall, an inner ring wall, and an outer ring wall, and a ring-shaped gas mixing cavity being formed between the ring-shaped top wall, the inner ring wall, and the outer ring wall; the ring-shaped top wall being provided with fire outlet holes which are distributed in a circumferential direction and are in communication with the ring-shaped gas mixing cavity; the distance between a single fire outlet hole and the nearest adjacent fire outlet hole being L, the sum of the fire outlet areas of the two adjacent fire outlet holes forming the distance being S, and the ratio of L / S being 0.4-1, and the ratio of L / S of the fire outlet holes in the inner fire outlet area being greater than that of the fire outlet holes in the outer fire outlet area, and the ratio of the number of the fire outlet holes with the ratio of L / S being 0.4-1 to the total number of the fire outlet holes being ≥70%. Compared with the prior art, the present application can ensure the secondary air supplement of the inner ring fire outlet holes.

Description

Technical Field

[0001] This invention belongs to the field of household stove technology, specifically relating to an outer ring burner cap and a burner for stoves. Background Technology

[0002] To avoid nozzle clogging caused by overflow, the top-inlet burner adopts a nozzle-top design. The ejector tube is placed horizontally at the bottom of the burner, and its length is limited by the outer diameter of the burner, making it shorter than the length of a conventional ejector tube. Therefore, the ejector performance of the ejector structure is weaker than that of a conventional bottom-inlet structure.

[0003] To compensate for the insufficient primary air in the top-intake burner, the applicant adopted a multi-hole sheet metal structure on the top wall of the outer ring burner, as shown in the invention patent application "A Fully Top-Intake Burner" (application publication number CN112240548A) with application number 201910647362.2. The flame holes formed by its thin sheet metal structure have the advantage of low air outlet resistance. In addition, the multi-hole burner has the advantages of small individual flame hole diameter and large total flame area, thus alleviating the problem of insufficient primary air in the top-intake burner.

[0004] However, in actual use, the secondary air inside the outer ring burner and outside the inner ring burner needs to be supplied to both the inner and outer ring burners simultaneously, resulting in insufficient secondary air supply at the burner holes on the inner ring of the outer ring burner (i.e., the burner holes relatively close to the inner ring burner) in the aforementioned patent application. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide an outer ring flame cap in order to ensure the secondary air supply of its inner ring flame holes, in light of the current state of the prior art.

[0006] The second technical problem to be solved by the present invention is to provide a burner having the above-mentioned outer ring flame cap.

[0007] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: an outer ring flame cap, comprising:

[0008] The flame cap body has an annular top wall, an inner annular wall extending downward from the inner edge of the annular top wall, and an outer annular wall extending downward from the outer edge of the annular top wall. An annular mixing chamber is formed between the annular top wall, the inner annular wall, and the outer annular wall. The annular top wall is provided with flame outlet holes that are spaced apart circumferentially and communicate with the annular mixing chamber. Each of the circumferentially spaced flame outlet holes forms a flame outlet area, and there are at least three groups of them, which are radially spaced apart inside and outside the annular top wall.

[0009] Its features are:

[0010] Let L be the distance between a single flame outlet and its nearest adjacent flame outlet, and let S be the sum of the flame outlet areas of the two adjacent flame outlets forming this distance. The ratio of the two satisfies the following: L / S is 0.4 to 1, and the above ratio of flame outlets in the inner flame outlet area is greater than the above ratio of flame outlets in the outer flame outlet area. The ratio of the number of flame outlets with a ratio L / S of 0.4 to 1 to the total number of flame outlets is ≥70%.

[0011] The aforementioned spacing refers to the distance between the edges of the two firing holes.

[0012] The aforementioned fire-emitting area is composed of fire-emitting holes spaced apart in the circumferential direction. The fire-emitting holes in the same fire-emitting area can be equally spaced along the circumferential direction, or the spacing can be different.

[0013] The two adjacent fire outlets mentioned above can be adjacent in the circumferential direction or in the radial direction.

[0014] The terms "inner side" and "outer side" refer to a relative positional relationship, and are not limited to the innermost and outermost sides. Furthermore, the L / S ratio of the flame outlet holes in the inner flame outlet region is greater than that in the outer flame outlet region.

[0015] The ratio of the number of flare holes with a ratio L / S between 0.4 and 1 to the total number of flare holes is preferably ≥93%.

[0016] Thus, compared to the flame holes in the outer flame area, the sum of the flame areas of the flame holes in the inner flame area is smaller or the spacing between them is larger. When the spacing between the flame holes in the inner flame area is larger, secondary air can flow smoothly along the spacing, thus ensuring sufficient secondary air around the flame holes in the inner flame area. The secondary air is smoothly replenished from the edges of the flame holes, thereby reducing the smoke generated during combustion and improving combustion efficiency. When the sum of the flame areas of the flame holes in the inner flame area is smaller, less secondary air is required for combustion, and the secondary air from the outside is sufficient to replenish the flame holes in the inner flame area, thereby reducing the smoke generated during combustion and improving combustion efficiency.

[0017] Furthermore, when the ratio L / S is less than 0.4, it indicates that the spacing between the flame holes is too small or the area of ​​a single flame hole is too large. When the spacing between the flame holes is too small, the secondary air passage is too small and insufficient to support the replenishment of secondary air around the flame holes during combustion. When the area of ​​a single flame hole is too large, there is too much secondary air required for combustion, which will also cause the problem of insufficient secondary air replenishment.

[0018] When the ratio L / S is greater than 1, it indicates that the spacing between the flame outlets is too large or the area of ​​a single flame outlet is too small. When the spacing between the flame outlets is too large, it will result in an excessively large flame spacing, which will lead to unstable combustion, dispersed flames, excessive heat dissipation, and reduced combustion efficiency. When the area of ​​a single flame outlet is too small, it will result in a smaller flame and a tendency for flameout.

[0019] In this invention, when the ratio of the number of flame outlets with a ratio L / S of 0.4 to 1 to the total number of flame outlets is less than 70%, that is, more than 30% of the flame outlets do not meet this requirement, the air flowing to the inside of the burner cap will not meet the requirements for sufficient combustion of the inner flame outlets, resulting in incomplete combustion.

[0020] In summary, the present invention can ensure that there is sufficient secondary air around the flame outlet, especially the flame outlet located in the inner flame outlet area, thereby reducing the smoke generated during combustion and improving combustion efficiency.

[0021] Preferably, the annular top wall slopes downwards from the inside out. The sloped annular top wall has the following technical advantages: First, with a fixed burner cap diameter, the sloped annular top wall allows for more flame outlets compared to a planar annular top wall, ensuring a sufficiently large flame area; second, the lower height of the outer edge of the annular top wall reduces the overall height of the burner; third, as heated air flows upwards, the sloped annular top wall facilitates the flow of secondary air from the outside in, resulting in smoother secondary air replenishment at the flame outlets on the inner ring of the outer burner cap and the inner burner cap, leading to higher combustion efficiency.

[0022] Preferably, the angle between the annular top wall and the horizontal plane is 20 to 45°.

[0023] Furthermore, the annular top wall is shaped like the side wall of a frustum, wider at the bottom and narrower at the top. This means that each flame outlet is located on the side surface of the same frustum, ensuring that each flame outlet can have good contact with secondary air and increasing the contact area between the flame and the secondary air.

[0024] To further increase the contact area between the flame and the secondary air, preferably, the axis of the flame outlet is perpendicular to the annular top wall.

[0025] Furthermore, the angle between the axis of the fire outlet and the horizontal plane is 45° to 70°.

[0026] To ensure sufficient secondary air supply while preventing flame detachment, preferably, at least 15 flame outlets arranged continuously in the circumferential direction are grouped into 4 to 7 groups, radially spaced along the annular top wall, with a spacing of 1 to 2 mm between adjacent flame outlets in each group. This achieves the following technical effects: 1. The number and distribution of flame outlets in this invention create a porous structure with densely distributed flame outlets on the annular top wall, resulting in a large flame area and uniform gas output and heating; 2. By designing the spacing between adjacent flame outlets to be 1 to 2 mm, sufficient secondary air supply is ensured while flame propagation is achieved; 3. The number and distribution of flame outlets in this invention prevent excessively fast gas flow from each outlet, ensuring stable combustion; and the flame at each outlet effectively holds the flame of adjacent outlets, achieving a self-stabilizing flame.

[0027] In the above embodiments, preferably, the flame outlet is located on the inner side of the annular top wall in the radial direction to form a flame zone, while the outer side of the annular top wall forms a ring of flameless zones without flame outlets. During use, the entire flame cap is at a high temperature, and the temperature of the outer flameless zone is very high. When secondary air flows from the flameless zone to the flame zone, it can be adequately guided and preheated.

[0028] If the size of the non-flame-out zone is too large, too much gas will remain under the outer ring of the burner cap when the flame is turned off, resulting in a popping sound when the flame is turned off. Furthermore, if the size of the non-flame-out zone is too large, the temperature of the outermost area of ​​the burner cap will be relatively low, and the combustion stability will be relatively poor. Therefore, the flame outlets located on the outer ring are prone to flame lift-off. If the size of the non-flame-out zone is too small, the secondary air cannot be preheated well. Therefore, in order to overcome the above technical problems, preferably, the radial width of the non-flame-out zone projected on the horizontal plane accounts for 12 to 62% of the radial width of the annular top wall projected on the horizontal plane. Therefore, firstly, it avoids the phenomenon of excessive gas accumulation below the no-flame zone and subsequent popping during flameout caused by an excessively large no-flame zone size; secondly, it allows secondary air to flow radially along the no-flame zone during replenishment, resulting in better airflow guidance and preheating. If the no-flame zone size is too small, it cannot achieve good preheating and airflow guidance during secondary air replenishment; thirdly, for top-intake burners, the outlet end of the injector generally extends horizontally into the mixing chamber below the outer ring burner cap, and to ensure uniform mixing, the outlet end of the injector is not opposite to the flame outlet, so that the gas output from the injector and air can be uniformly mixed in the mixing chamber. The no-flame zone design in this invention provides space for the mixing of gas and air, thereby improving the uniformity of mixing, and the size design of the no-flame zone allows for an increase in the length of the portion of the injector extending into the mixing chamber (i.e., the no-flame zone can block the top of the injector), thereby extending the overall length of the injector; fourthly, it ensures a high overall temperature of the burner cap and prevents flame lift-off.

[0029] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a burner, characterized by having an outer ring flame cap as described above.

[0030] Preferably, the burner further comprises an inner ring flame cap disposed within the inner ring wall of the outer ring flame cap, and the inner ring flame cap has a vertically extending peripheral wall opposite to the inner ring wall of the outer ring flame cap, and is provided with inner ring main flame holes at circumferential intervals, wherein the diameter of the inner ring main flame holes is greater than or equal to 1.8 mm, and the upper limit of the diameter value of the inner ring main flame holes is 3 mm.

[0031] Preferably, at least the upper part of the inner ring wall of the outer ring flame cap slopes inward from top to bottom to form a guide wall, and the upper edge of the guide wall engages with the inner edge of the annular top wall. The guide wall can guide the secondary air located in the inner ring of the outer ring flame cap, so that the secondary air can flow more smoothly to the flame outlet.

[0032] To further prevent the flame at the inner ring fire hole from burning the guide wall, preferably, the lower edge of the inner ring fire hole is at a higher height than the lower edge of the guide wall.

[0033] The angle between the axis of the inner ring flame hole and the horizontal plane is greater than the angle between the guide wall and the horizontal plane. This further prevents the flame at the inner ring flame hole from burning the guide wall.

[0034] Preferably, the burner is used in a stove.

[0035] The burner is preferably an upper air intake burner. Of course, the burner can also be a lower air intake burner.

[0036] Compared with the prior art, the advantages of the present invention are as follows: By designing the ratio L / S between the distance L between two adjacent flame holes to the sum of the flame areas S of the two adjacent flame holes forming the distance to be 0.4 to 1, and the ratio of flame holes in the inner flame area is greater than that in the outer flame area, that is, compared with the flame holes in the outer flame area, the sum of the flame areas of the flame holes in the inner flame area is smaller or the spacing between the holes is larger. When the spacing between the flame holes in the inner flame area is larger, the secondary air can flow smoothly along the spacing, thereby ensuring that there is sufficient secondary air around the flame holes in the inner flame area. The secondary air is smoothly replenished from the edges of the flame holes, thereby reducing the smoke generated during combustion and improving the combustion efficiency. When the sum of the flame areas of the flame holes in the inner flame area is smaller, less secondary air is required for combustion, and the secondary air from the outside is sufficient to replenish the flame holes in the inner flame area, thereby reducing the smoke generated during combustion and improving the combustion efficiency.

[0037] Furthermore, when the ratio L / S is less than 0.4, it indicates that the spacing between the flame holes is too small or the area of ​​a single flame hole is too large. When the spacing between the flame holes is too small, the secondary air passage is too small and insufficient to support the replenishment of secondary air around the flame holes during combustion. When the area of ​​a single flame hole is too large, there is too much secondary air required for combustion, which will also cause the problem of insufficient secondary air replenishment.

[0038] When the ratio L / S is greater than 1, it indicates that the spacing between the flame outlets is too large or the area of ​​a single flame outlet is too small. When the spacing between the flame outlets is too large, it will result in an excessively large flame spacing, which will lead to unstable combustion, dispersed flames, excessive heat dissipation, and reduced combustion efficiency. When the area of ​​a single flame outlet is too small, it will result in a smaller flame and a tendency for flameout.

[0039] In this invention, when the ratio of the number of flame outlets with a ratio L / S of 0.4 to 1 to the total number of flame outlets is less than 70%, that is, more than 30% of the flame outlets do not meet this requirement, the air flowing to the inside of the burner cap will not meet the requirements for sufficient combustion of the inner flame outlets, resulting in incomplete combustion.

[0040] In summary, the present invention can ensure that there is sufficient secondary air around the flame outlet, especially the flame outlet located in the inner flame outlet area, thereby reducing the smoke generated during combustion and improving combustion efficiency. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the burner structure in Embodiment 1 of the present invention;

[0042] Figure 2 This is a cross-sectional view of the burner in Embodiment 1 of the present invention;

[0043] Figure 3 This is a top view of the outer ring flame cap in Embodiment 1 of the present invention;

[0044] Figure 4 This is a cross-sectional view of the outer ring flame cap in Embodiment 1 of the present invention;

[0045] Figure 5 This is a schematic diagram of the outer ring fire cap in Embodiment 2 of the present invention. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] Example 1:

[0048] like Figures 1-4 As shown, this is a preferred embodiment of the outer ring burner and burner of the present invention. The burner is for top-intake combustion in stoves and includes a base 3, an outer ring burner and an inner ring burner 2.

[0049] The base 3 is a prior art technology, having an inner ring mixing chamber 31 with its opening facing upwards and an outer ring mixing chamber 32 located circumferentially around the inner ring mixing chamber 31.

[0050] The inner ring burner cap 2 is installed on the inner ring mixing chamber 31 and has a vertically extending peripheral wall 21. The peripheral wall 21 is provided with inner ring main burner holes 210 at intervals along the circumference. The diameter of a single inner ring main burner hole 210 is 1.8 to 3 mm (the diameter of a single inner ring main burner hole 210 can be any value of 1.8 to 3 mm, such as 1.8 mm, 2 mm or 3 mm).

[0051] An outer ring flame cap is mounted on an outer ring mixing chamber 32 and includes a flame cap body 1. The flame cap body 1 has an annular top wall 11, an inner ring wall 12 extending downward from the inner edge of the annular top wall 11, and an outer ring wall 13 extending downward from the outer edge of the annular top wall 11. An annular mixing chamber 10 with a downward opening is formed between the annular top wall 11, the inner ring wall 12, and the outer ring wall 13. In this embodiment, the annular top wall 11 of the outer ring flame cap slopes downward from the inside to the outside, and the angle between the annular top wall 11 and the horizontal plane is 20° to 45° (the angle can be any value between 20° and 45°, such as 20°, 30°, or 45°). The annular top wall 11 is generally shaped like a frustum with a smaller top and a larger bottom. The inner ring wall 12 of the outer ring flame cap is located outside the peripheral wall 21 of the inner ring flame cap 2 and is spaced apart from the peripheral wall 21. Furthermore, the upper part of the inner ring wall 12 slopes inward from top to bottom to form a guide wall 121, and the angle between the guide wall 121 and the horizontal plane is smaller than the angle between the axis of the inner ring main flame hole 210 and the horizontal plane. Simultaneously, the upper edge of the guide wall 121 engages with the inner edge of the annular top wall 11. The lower edge of the guide wall 121 is at a lower height than the lower edge of the inner ring main flame hole 210. This prevents the flame at the inner ring main flame hole 210 from burning the guide wall 121.

[0052] Simultaneously, the inner radial portion of the annular top wall 11 is provided with circumferentially spaced flame outlets 110 that connect to the annular mixing chamber 10, forming a flame zone 11a. The outer portion of the annular top wall 11 forms a ring of flameless zones 11b without flame outlets. The radial width of the flameless zone 11b projected onto the horizontal plane accounts for 12% to 62% of the radial width of the annular top wall 11 projected onto the horizontal plane (the width percentage of the flameless zone 11b can be any value from 12% to 62%, such as 12%, 20%, 40%, 50%, or 62%). Thus, during secondary air replenishment, it can flow radially along the flameless zone 11b to the flame zone 11a and receive sufficient preheating. The axis of each flame outlet 110 within the flame zone 11a is perpendicular to the annular top wall 11. Furthermore, each group consists of at least 15 flaming holes 110 spaced circumferentially, forming a flaming zone. There are 4 to 7 such groups, radially spaced along the annular top wall 11. Figure 3In the enlarged view, multiple flame outlets 110 located on the same circumferentially extending dotted line 100 constitute the aforementioned flame outlet area (there are 6 groups of flame outlet areas); the interval between two adjacent flame outlets 110 in each group is 1-2 mm, and the distance between a single flame outlet and its nearest radially adjacent flame outlet is L. The sum of the flame outlet areas of the two adjacent flame outlets forming this distance is S, and the ratio of the two satisfies: L / S is 0.4-1 (the ratio L / S can be any value from 0.4 to 1, such as 0.4, 0.6, or 0.8). The ratio of the number of flame outlets 110 with a ratio L / S between 0.4 and 1 to the total number of all flame outlets 110 is ≥70%. Meanwhile, the distance between a single flame outlet in the inner flame outlet region and the distance between a flame outlet radially adjacent to it is greater than the distance between a single flame outlet in the outer flame outlet region and the distance between a flame outlet radially adjacent to it. This results in the aforementioned ratio of flame outlets in the inner flame outlet region being greater than the aforementioned ratio of flame outlets in the outer flame outlet region. This ensures sufficient secondary air around the flame outlets, especially those located in the inner ring, thereby reducing the amount of smoke generated during combustion and improving combustion efficiency.

[0053] Example 2:

[0054] like Figure 5 As shown, this is a preferred embodiment of the outer ring burner and burner of the present invention. This embodiment is basically the same as the first embodiment, except that the flame area of ​​a single flame hole in the inner flame area is smaller than that of a single flame hole in the outer flame area, so that the ratio of the flame holes in the inner flame area is greater than that in the outer flame area.

[0055] The specification and claims of this invention use terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," to describe various exemplary structural parts and elements of the invention. However, these terms are used herein merely for ease of explanation and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0056] The term "vertical" is also used in the specification and claims of this invention, meaning basically along the up and down direction, and is not limited to just the vertical direction, but can also be slightly deviated from the vertical direction.

[0057] The term "radial" is also used in the specification and claims of this invention, meaning essentially along the inside-out direction, and is not limited to the radial direction that passes through the center of the circle, but can also be slightly deviated from the radial direction.

Claims

1. An outer ring flame cap, comprising: The flame cap body (1) has an annular top wall (11), an inner annular wall (12), and an outer annular wall (13). An annular mixing chamber (10) is formed between the annular top wall (11), the inner annular wall (12), and the outer annular wall (13). The annular top wall (11) is provided with flame outlet holes (110) that are spaced apart in the circumferential direction and connected to the annular mixing chamber (10). The flame outlet holes (110) spaced apart in the circumferential direction form a flame outlet area, and there are at least three groups, which are spaced apart in the radial direction of the annular top wall (11). Its features are: Let L be the distance between a single flame outlet and the nearest adjacent flame outlet, and let S be the sum of the flame outlet areas of the two adjacent flame outlets forming this distance. The ratio of the two satisfies the following: L / S is 0.4 to 1, and the above ratio of flame outlets in the inner flame outlet area is greater than the above ratio of flame outlets in the outer flame outlet area. The ratio of the number of flame outlets (110) with a ratio L / S of 0.4 to 1 to the total number of flame outlets (110) is ≥70%.

2. The outer ring flame cap according to claim 1, characterized in that: The annular top wall (11) slopes downward from the inside to the outside; Furthermore, the angle between the annular top wall (11) and the horizontal plane is 20 to 45°.

3. The outer ring flame cap according to claim 2, characterized in that: The annular top wall (11) is generally shaped like the side wall of a frustum, which is smaller at the top and larger at the bottom.

4. The outer ring flame cap according to claim 2, characterized in that: The axis of the fire outlet (110) is perpendicular to the annular top wall (11).

5. The outer ring flame cap according to claim 1, characterized in that: The angle between the axis of the fire outlet (110) and the horizontal plane is 45-70°.

6. The outer ring flame cap according to any one of claims 1 to 5, characterized in that: There are 4 to 7 groups of at least 15 fire outlet holes (110) arranged continuously in the circumferential direction, distributed radially at intervals along the annular top wall (11), and the distance between two adjacent fire outlet holes (110) in each group is 1 to 2 mm.

7. The outer ring flame cap according to claim 6, characterized in that: The flame outlet (110) is located on the inner side of the annular top wall (11) in the radial direction to form a flame zone (11a), and the outer side of the annular top wall (11) forms a ring of flameless zone (11b) without flame outlets.

8. The outer ring flame cap according to claim 7, characterized in that: The radial width of the non-flame zone (11b) projected onto the horizontal plane is 12 to 62% of the radial width of the annular top wall (11) projected onto the horizontal plane.

9. A burner, characterized in that... It has an outer ring fire cap as described in any one of claims 1 to 8.

10. The burner according to claim 9, characterized in that: It also has an inner ring flame cap (2) located in the inner circumference of the inner ring wall (12), and the inner ring flame cap (2) has a vertically extending peripheral wall (21), the peripheral wall (21) is opposite to the inner ring wall (12), and is provided with inner ring main flame holes (210) at intervals along the circumference, the diameter of the inner ring main flame holes (210) is 1.8 to 3 mm.

11. The burner according to claim 10, characterized in that: The inner ring wall (12) extends downward from the inner edge of the annular top wall (11), and at least the upper part of the inner ring wall (12) is inclined inward from top to bottom to form a guide wall (121), and the upper edge of the guide wall (121) is joined to the inner edge of the annular top wall (11).

12. The burner according to claim 11, characterized in that: The lower edge of the inner ring main fire hole (210) is at a higher height than the lower edge of the guide wall (121); The angle between the axis of the inner ring main fire hole (210) and the horizontal plane is greater than the angle between the guide wall (121) and the horizontal plane.

13. The burner according to claim 9, characterized in that: The burner is an upward-intake burner and is used in stoves.

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