CN110173688B

CN110173688B - Burner for stove

Info

Publication number: CN110173688B
Application number: CN201910113600.1A
Authority: CN
Inventors: 佐藤裕康; 武田和也
Original assignee: Rinnai Corp
Current assignee: Rinnai Corp
Priority date: 2018-02-20
Filing date: 2019-02-14
Publication date: 2023-02-24
Anticipated expiration: 2039-02-14
Also published as: CN110173688A

Abstract

The present invention relates to a burner for a cookstove, which is provided with upper and lower 2-layer flame ports opening on the outer peripheral surface of a burner head, the burner head is arranged on a burner body, and comprises a lower head part and an upper head part, the burner head can freely switch between a state of supplying gas to only the lower-layer flame ports and a state of supplying gas to the upper-layer flame ports, when the gas supply to the upper-layer flame ports is started, the burner can extend from the lower-layer flame ports to the upper-layer flame ports, the burner can not cause the enlargement of the burner, and the backfire can be inhibited when the gas extends to the upper-layer flame ports. The upper flame hole is divided into upper and lower 2 portions, i.e., a lower flame hole portion formed by a groove formed in an annular wall provided upright on the lower head member and an upper flame hole portion formed by a groove formed in an annular wall provided perpendicular to the upper head member. The upper flame port portion and the lower flame port portion are arranged in a staggered manner with a circumferentially staggered position.

Description

Burner for stove

Technical Field

The present invention relates to a burner for a cookstove, which includes upper and lower 2-layer flame ports that are open on the outer peripheral surface of a burner head provided on a burner body.

Background

Conventionally, as such a burner for a stove, there is known a burner having: the gas supply device can be freely switched between a state of supplying gas to only the lower flame ports and a state of supplying gas to the upper flame ports, and when gas supply to the upper flame ports is started, the gas is spread from the lower flame ports to the upper flame ports. This structure has the following advantages: the heating power can be adjusted in a wide range from a weak flame that burns only in the lower flame ports to a strong flame that burns in both the lower and upper flame ports.

In general, the burner body has an inner and outer 3-fold cylinder including an outer cylinder, an intermediate cylinder, and an inner cylinder, and the burner head includes: an annular lower head member having a cylindrical portion vertically provided on an inner peripheral portion thereof and fitted into the intermediate cylinder of the burner body; and an annular upper head member having a cylindrical portion vertically provided on an inner peripheral portion thereof to be fitted into the inner cylinder of the burner body. Further, a lower flame port is defined between the outer cylinder of the burner body and the lower head member, and an upper flame port is defined between the lower head member and the upper head member. Specifically, an annular wall is provided upright on an outer peripheral portion of an upper surface of the lower head member, the upper head member is seated on the annular wall, and a plurality of grooves are formed in the annular wall at circumferentially spaced intervals, the grooves being recessed downward from an upper end of the annular wall to serve as upper flame ports.

Here, the groove to be the upper flame hole formed in the annular wall is formed in a trapezoidal shape with a draft angle for pulling out the groove molding die upward, that is, a trapezoidal shape having a small lower bottom width and a large upper bottom width. The width of the lower bottom side of the molding die of the groove needs to be set to a dimension of a degree necessary to ensure strength. Therefore, the width of the lower base of the trapezoid of the groove shape cannot be set to a considerably smaller size than the flame-extinguishing distance, and thus the width of the upper base, i.e., the width of the upper end of the upper flame ports, is larger than the flame-extinguishing distance. In the burner for a cookstove of this type, if the vertical distance between the upper flame ports and the lower flame ports is short, backfire tends to occur in the upper flame ports when the flame is propagated from the lower flame ports to the upper flame ports. The reason for this is as follows. That is, after the supply of the gas to the upper flame ports is started, a certain amount of time is required until the gas spouting velocity at which the gas is spouted from the upper flame ports exceeds the combustion velocity. On the other hand, if the vertical distance between the upper flame ports and the lower flame ports is short, the time from when the gas starts to be supplied to the upper flame ports until the gas reaches the upper flame ports is shortened. Then, the flame is ignited before the gas is ejected from the upper flame ports at a speed higher than the combustion speed, and thereby flashback occurs at the upper end portions of the upper flame ports having a width larger than the flame-out distance.

Therefore, conventionally, a burner for a cookstove is known in which the vertical distance between the upper flame ports and the lower flame ports is extended, according to patent document 1. In this structure, it takes time from the start of gas supply to the upper flame ports until the gas is burned into the upper flame ports. Therefore, the gas is ejected from the upper flame ports at a speed exceeding the combustion speed until the gas reaches the upper flame ports. As a result, it is possible to prevent the occurrence of backfire at the upper end of the upper flame ports having a width larger than the flame-out distance during the flame propagation. However, the burner is enlarged by increasing the vertical distance between the upper flame ports and the lower flame ports.

Patent document 1: japanese patent laid-open No. 2012-127563.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a burner for a cookstove, which can suppress the occurrence of backfire when the burner is extended to the upper flame ports without increasing the size of the burner.

In order to solve the above problems, the present invention is a burner for a cookstove, including upper and lower 2-stage flame ports opened in an outer peripheral surface of a burner head provided in a burner body, the burner head being configured to be freely switched between a state in which gas is supplied only to the lower stage flame ports and a state in which gas is supplied to the upper stage flame ports, and to extend combustion from the lower stage flame ports to the upper stage flame ports when gas supply to the upper stage flame ports is started, the burner body including inner and outer 3-piece cylindrical bodies including an outer cylindrical body, a middle cylindrical body, and an inner cylindrical body, the burner head including: an annular lower head member having a cylindrical portion vertically provided on an inner peripheral portion thereof and fitted into the intermediate cylinder of the burner body; and an annular upper head member having a cylindrical portion vertically provided at an inner peripheral portion thereof so as to be fitted to the inner cylindrical body of the burner body, a lower flame port defined between the outer cylindrical body of the burner body and the lower head member, and an upper flame port defined between the lower head member and the upper head member, wherein a first annular wall is provided upright on an outer peripheral portion of an upper surface of the lower head member, a second annular wall is provided vertically on an outer peripheral portion of a lower surface of the upper head member, the second annular wall is seated on the first annular wall, the upper flame port is divided into upper and lower 2 portions, i.e., an upper flame port portion and a lower flame port portion, a plurality of grooves recessed downward from an upper end of the first annular wall to become the lower flame port portion are formed in the first annular wall at circumferentially spaced intervals, and a plurality of grooves recessed upward from a lower end of the second annular wall to become the upper flame port portion are formed in the second annular wall at circumferentially spaced intervals, and the upper flame ports become circumferentially staggered positions with respect to the upper flame ports.

According to the present invention, since the upper flame ports are divided into the upper and lower 2 portions, i.e., the upper flame port portion and the lower flame port portion, the recessed depth of the grooves formed in each of the first annular wall and the second annular wall is reduced by half as compared with the case where the upper flame ports are not divided into the upper and lower 2 portions. Therefore, the width of the portion of the groove having the largest width, that is, the upper end portion of the groove serving as the lower flame port portion formed in the first annular wall and the lower end portion of the groove serving as the upper flame port portion formed in the second annular wall can be made equal to or less than the flame-extinguishing distance, due to the relationship between the draft angles of the molding die with the groove. Therefore, the vertical distance between the lower flame port portion of the upper flame port and the lower flame port is shortened so as not to cause the burner to be large-sized, and the time required for the flame to extend from the lower flame port to the upper flame port can be shortened, and even if the flame extends before the gas ejection speed of the gas ejected from the lower flame port portion and the upper flame port portion of the upper flame port reaches the combustion speed or more, the backfire can be prevented when the flame extends from the lower flame port portion and the upper flame port portion of the upper flame port. Further, since the upper flame ports and the lower flame ports of the upper flame ports are arranged in a staggered manner, secondary air is sufficiently supplied from the periphery of the gas ejected from the upper flame ports and the lower flame ports. As a result, the flame formed in the upper flame port is shortened, and the flame can be prevented from being blown out to the outside of the pot bottom.

Drawings

Fig. 1 is a perspective view of a burner for a cookstove according to an embodiment of the present invention.

Fig. 2 is a sectional view of the burner for a cookstove according to the embodiment.

Fig. 3 is an enlarged side view of a main part of the burner for a cookstove according to the embodiment.

Fig. 4 is a graph showing changes in the amount of gas supplied to the lower flame ports and the upper flame ports.

Description of the reference numerals

1 … burner, 2 … burner body, 21 … outside cylinder, 22 … middle cylinder, 23 … inside cylinder, 3 … burner head, 31 … lower head, 31a … lower head, 32 … upper head, 32a … upper head, 33 … first annular wall, 34 … second annular wall, 4U 3272 zxft 72 upper flame ports, 4 a … upper flame ports, 4Ub … lower flame ports, 4L … lower flame ports 3284.

Detailed Description

Referring to fig. 1 and 2,1, a burner for a stove according to an embodiment of the present invention is shown. The burner 1 includes a burner main body 2 and a burner head 3 provided on the burner main body 2. A plurality of

flame ports

4U and 4L in the upper and lower 2 stages are opened in the outer peripheral surface of the burner head 3 at circumferentially spaced intervals. In addition, in the portions of the combustion head 3 located at a plurality of circumferential positions in the same direction as the plurality of flame holder claws of the flame holder arranged on the top plate of the burner, in order to prevent incomplete combustion caused by the contact of the flame with the flame holder claws, only the lower flame ports 4L are formed without forming the upper flame ports 4U.

More specifically, the burner main body 2 includes inner and outer 3-fold cylinders, i.e., an outer cylinder 21, an intermediate cylinder 22, and an inner cylinder 23. The outer cylinder 21 is provided with a skirt 21a depending from the outer periphery of the upper end thereof. The burner head 3 is configured to include: an annular lower head member 31 having a cylindrical portion 31a vertically provided on an inner peripheral portion thereof and fitted into the intermediate cylinder 22 of the burner main body 2; and an annular upper head member 32 having a cylindrical portion 32a vertically provided on an inner peripheral portion thereof to be fitted to the inner cylindrical body 23 of the burner main body 2. A lower flame port 4L is defined between the outer cylinder 21 of the burner body 2 and the lower head member 31, and an upper flame port 4U is defined between the lower head member 31 and the upper head member 32.

The upper flame ports 4U are divided into upper and lower portions 2, i.e., upper flame port portions 4Ua and lower flame port portions 4 Ub. Specifically, a first annular wall 33 is provided upright on the outer peripheral portion of the upper surface of the lower head member 31, a second annular wall 34 is provided upright on the outer peripheral portion of the lower surface of the upper head member 32, and the second annular wall 34 is seated on the first annular wall 33. Further, the first annular wall 33 is formed with a plurality of grooves which are recessed downward from the upper end of the first annular wall 33 and which serve as lower flame port portions 4Ub of the upper flame ports 4U, at circumferentially spaced intervals. Further, the second annular wall 34 is formed with a plurality of grooves which are recessed upward from the lower end of the second annular wall 34 and serve as the upper flame port portions 4Ua of the upper flame ports 4U at intervals in the circumferential direction, and the grooves which serve as the upper flame port portions 4Ua are shifted in the circumferential direction with respect to the grooves which serve as the lower flame port portions 4 Ub. Thereby, the upper flame port portions 4Ua and the lower flame port portions 4Ub are arranged in a staggered manner in the circumferential direction with a staggered position.

Referring to fig. 3, the groove formed in the first annular wall 33 to be the lower flame vent portion 4Ub has a trapezoidal shape in which the width of the upper base is larger than the width of the lower base due to the relationship of the draft angle for drawing the groove forming mold upward. The groove formed in the second annular wall 34 to be the upper flame vent portion 4Ua is formed in a trapezoidal shape having a lower bottom width larger than an upper bottom width due to a relationship with a draft for drawing a groove forming mold downward. Here, if the upper flame ports 4U are divided into the upper and lower 2 portions, i.e., the upper flame port portion 4Ua and the lower flame port portion 4Ub, the recessed depth of the grooves formed in the respective

annular walls

33 and 34 of the first and second annular walls is reduced by half as compared with the case where the upper flame ports 4U are not divided into the upper and lower 2 portions. Therefore, the width of the portion of the groove having the largest width, that is, the upper end portion of the groove to be the lower flame port portion 4Ub formed in the first annular wall 33 and the lower end portion of the groove to be the upper flame port portion 4Ua formed in the second annular wall 34 may be set to the flame-out distance (for example, 1.2 mm) or less, depending on the draft of the molding die with the groove.

A third annular wall 35 is provided vertically on the outer peripheral portion of the lower surface of the lower head member 31, and the third annular wall 35 is seated on the upper end portion of the outer cylinder 21 of the burner main body 2. A plurality of grooves which are recessed upward from the lower end of the third annular wall 35 and which serve as the lower flame ports 4L are formed in the third annular wall 35 at circumferentially spaced intervals. Further, a target portion 36 facing an ignition electrode (not shown) is provided to protrude from the lower head member 31 at a position 1 in the circumferential direction, and the lower flame ports 4L are ignited by spark discharge between the ignition electrode and the target portion 36.

Further, the combustor 1 includes: a first mixing pipe 5U for the upper flame ports 4U, which communicates with a space between the intermediate cylinder 22 and the inner cylinder 23 of the burner main body 2; and a 2 nd mixing pipe 5L for the lower flame ports 4L, which communicates with a space between the outer cylinder 21 and the intermediate cylinder 22 of the burner main body 2. The first mixing pipe 5U is supplied with the gas through a first branch 6U branched from the common gas supply passage 6. The gas is supplied to the 2 nd mixing pipe 5L through the 2 nd branch passage 6L branched from the gas supply passage 6. Then, the gas and the primary air sucked into the

mixing pipes

5U and 5L are mixed in the

mixing pipes

5U and 5L of the first mixing pipe and the second mixing pipe, and the mixed gas from the first mixing pipe 5U is ejected from the upper flame ports 4U through the space between the intermediate cylinder 22 and the inner cylinder 23 and the space between the lower head member 31 and the upper head member 32 of the burner body 2. The mixture gas from the 2 nd mixing pipe 5L is ejected from the lower flame ports 4L through the space between the outer cylinder 21 and the intermediate cylinder 22 and the space between the outer cylinder 21 and the lower head member 31 of the burner main body 2.

The gas supply path 6 is provided with a main valve 7, and the main valve 7 is opened at the time of ignition and closed at the time of extinction. The first and

second branch paths

6U and 6L are provided with flow

rate control valves

8U and 8L, respectively, having opening degrees changed in conjunction with an operation member including a lever and a knob for adjusting heating power, which are not shown. The operating member can be operated from the weak fire position to the strong fire position. When the operation member is operated to reach the strong fire position from the weak fire position, the opening degree of the 2 nd flow rate adjustment valve 8L is gradually increased from the minimum opening degree. Further, as shown by the line a in fig. 4, the amount of the supplied gas to the lower flame ports 4L is gradually increased from a prescribed minimum amount QLmin required to prevent flashback at the lower flame ports 4L to a maximum amount QLmax. On the other hand, the first flow rate adjustment valve 8U is not opened until the operation member reaches the predetermined intermediate position, and when the operation member passes over the intermediate position, the first flow rate adjustment valve 8U is rapidly opened to the predetermined opening degree, and the opening degree is gradually increased by the subsequent operation to the strong fire position. Further, when the operation member is operated from the low flame position to the high flame position, as shown by the line b in fig. 4, until the operation member reaches the intermediate position, gas is not supplied to the upper flame ports 4U, and when the operation member passes the intermediate position, the amount of gas supplied to the upper flame ports 4U is sharply increased to a prescribed minimum amount QUmin and then gradually increased to a maximum amount QUmax.

Even when the upper flame ports 4U are burned, the operating member is operated to the strong flame position side to move beyond the intermediate position, and the gas starts to be supplied to the upper flame ports 4U and the flame is spread from the lower flame ports 4L to the upper flame ports 4U. Here, in the present embodiment, as described above, the width of the upper end portion of the groove of the lower flame port portion 4Ub of the upper flame port 4U, which is the portion having the largest width, and the width of the lower end portion of the groove of the upper flame port portion 4Ua of the upper flame port 4U, which is the portion having the largest width, may be set to the flame-out distance or less. In the present embodiment, the vertical distance between the lower flame port portion 4Ub of the upper flame port 4U and the lower flame port 4L is shortened so as not to increase the size of the burner 1. Therefore, the time required for the flame propagation from the lower flame ports 4L to the upper flame ports 4U may be shortened, and the flame propagation may occur before the gas spouting velocity of the gas spouted from the lower flame port portion 4Ub and the upper flame port portion 4Ua of the upper flame ports 4U becomes equal to or higher than the combustion velocity. However, in the present embodiment, as described above, the widths of the upper end portion of the groove that is the portion having the largest width of the lower flame port portion 4Ub and the lower end portion of the groove that is the portion having the largest width of the upper flame port portion 4Ua can be made equal to or less than the flame-out distance, and therefore, even if the flame is delayed until the gas ejection speed at which the gas is ejected from the lower flame port portion 4Ub and the upper flame port portion 4Ua reaches the combustion speed or more, the backfire does not occur at the time of the flame delay at the lower flame port portion 4Ub and the upper flame port portion 4 Ua.

Further, since the upper flame port portions 4Ua and the lower flame port portions 4Ub are arranged in a staggered manner, secondary air is sufficiently supplied from the periphery thereof to the gas ejected from the upper flame port portions 4Ua and the lower flame port portions 4Ub, respectively. As a result, the flame formed in the upper flame ports 4U can be shortened even in a strong flame state, and the flame can be suppressed from being blown out to the outside of the pot bottom.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

Claims

1. A burner for a stove, which comprises upper and lower 2-layer flame ports opened on the outer peripheral surface of a burner head arranged on a burner body, freely switching between a state of supplying gas only to the lower layer flame port and a state of supplying gas to the upper layer flame port, and carrying out flame propagation from the lower layer flame port to the upper layer flame port when the gas supply to the upper layer flame port is started,

the combustor main part has this inside and outside 3 heavy barrels of outside barrel, middle barrel and inboard barrel, and the burning head constitutes and includes: an annular lower head member having a cylindrical portion vertically provided on an inner peripheral portion thereof and fitted into the intermediate cylinder of the burner body; and an annular upper head member having a cylindrical portion vertically provided at an inner peripheral portion thereof to be fitted into the inner cylindrical body of the burner body, a lower flame port defined between the outer cylindrical body of the burner body and the lower head member, and an upper flame port defined between the lower head member and the upper head member,

the burner for a stove is characterized in that,

a first annular wall is provided upright on an outer peripheral portion of an upper surface of the lower head member, and a second annular wall is provided upright on an outer peripheral portion of a lower surface of the upper head member, the second annular wall being seated on the first annular wall,

the upper flame hole is divided into upper and lower 2 parts of upper flame hole part and lower flame hole part, a plurality of grooves which are recessed downwards from the upper end of the first annular wall and become lower flame hole part are formed on the first annular wall at intervals in the circumferential direction, a plurality of grooves which become upper flame hole part are recessed upwards from the lower end of the second annular wall at intervals in the circumferential direction, the grooves which become upper flame hole part are staggered in the circumferential direction relative to the grooves which become lower flame hole part,

the groove formed in the first annular wall and serving as the lower flame vent portion is formed in a trapezoidal shape having an upper base width larger than a lower base width due to the draft of the forming mold with the groove, the groove formed in the second annular wall and serving as the upper flame vent portion is formed in a trapezoidal shape having a lower base width larger than an upper base width due to the draft of the forming mold with the groove,

the width of the portion of the groove having the largest width, i.e., the upper end portion of the groove serving as the lower flame port portion and the lower end portion of the groove serving as the upper flame port portion, is set to be equal to or less than the flame-extinguishing distance, and the upper end portion of the groove serving as the lower flame port portion and the lower end portion of the groove serving as the upper flame port portion are separated in the circumferential direction and do not have an overlapping portion.