A draft tube for a burner and a burner to which the draft tube is applied

Abstract

The application relates to an ejector for a burner and the burner provided with the ejector. The ejector is divided into a contraction part, a mixing part and a diffusion part according to the change of the cross section along the airflow direction, and is provided with an injector towards the gas inlet end of the contraction part. The ejector is characterized in that a sleeve is arranged on the body of the injector, the first end of the sleeve is connected with the mixing part of the body of the injector, the second end of the sleeve is an open end and is jointly connected with the diffusion part on the base of the burner, the second end of the sleeve and the diffusion part jointly form a make-up air channel for supplying air to the base of the burner, and an opening is arranged on the sleeve and is communicated with the air supply part. Compared with the prior art, the application has the advantages that the make-up air channel combines natural injection and air blowing, can greatly increase the suction amount of the external primary air, and can separate the air blowing and the injector in space, thereby avoiding the influence of the air blowing flow field on the natural injection of the gas.

Description

Technical Field

[0001] This invention relates to burners for gas stoves, and more particularly to an ejector tube for burners. Background Technology

[0002] Currently, there are two main types of gas burners used in kitchen appliances. One type is the ejector-type gas burner, which generally includes a burner cap, an ejector tube, and a nozzle. The ejector tube has a first air inlet at one end corresponding to the nozzle, allowing it to communicate with the outside atmosphere. Gas is injected at high speed from the nozzle into the ejector tube, creating a strong ejection effect. Outside air is drawn into the ejector tube through the air inlet, mixes with the gas inside, and then is delivered to the burner cap for combustion. The advantages of this type of burner are its simple and compact structure and good primary air ejection effect. However, it also has drawbacks. It requires a relatively high gas supply pressure. Furthermore, because the gas is ejected from a nozzle with a small orifice, the jet enters the ejector tube at a very high speed. Under the turbulent diffusion of the jet, some surrounding air is entrained into the ejector tube. However, due to the negative pressure created by the nozzle itself, the amount of primary air introduced is sometimes insufficient, necessitating further improvements. Summary of the Invention

[0003] The first technical problem to be solved by the present invention is to provide an ejector tube that can improve the efficiency of gas combustion, in view of the above-mentioned existing technology.

[0004] The second technical problem to be solved by the present invention is to provide a burner that uses the above-mentioned ejector tube, in view of the current state of the prior art.

[0005] The third technical problem to be solved by the present invention is to provide a burner that improves the success rate of ignition or flame preservation, in light of the above-mentioned existing technology.

[0006] The technical solution adopted by the invention to solve the first technical problem mentioned above is as follows: the ejector tube for the burner, which is divided into a converging part, a mixing part and a diffuser part according to the change of cross-section along the airflow direction, and an injector is provided at the air inlet end of the converging part, characterized in that: it further includes a sleeve sleeved on the body of the ejector, the first end of the sleeve is connected to the mixing part of the body of the ejector, the second end of the sleeve is an open end, and is connected to the base of the burner together with the diffuser part, the second end of the sleeve and the diffuser part together form an air supply channel for supplying air to the base of the burner, and the sleeve has an opening communicating with the air supply part.

[0007] Since the make-up air channel is connected to the burner base, to prevent gas leakage from the burner base, preferably, the sleeve is equipped with a one-way valve in the make-up air channel, allowing only the air supplied by the gas supply unit to flow unidirectionally into the burner base. This one-way valve ensures that the gas supply unit, such as a blower, can only supply the air required for combustion to the burner base in one direction, thus preventing gas leakage from the burner base through the make-up air channel.

[0008] The one-way valve structure can adopt an existing structure. However, to accommodate the structure of the burner's injector and sleeve, and considering structural compatibility, the one-way valve preferably includes a ring body and at least three baffles spaced circumferentially along the ring body. Each baffle has an upper end connected to the ring body and a lower end abutting against the diffuser. Each baffle gradually slopes downwards towards the burner base from its upper end to its lower end. When the gas supply unit is operating, the lower ends of each baffle are blown away from the diffuser, opening the air supply channel and allowing air to be supplied to the burner base. When the gas supply unit stops operating, the lower ends of each baffle re-abut against the diffuser. Because the baffles gradually slope downwards towards the burner base from their upper end to their lower end, and their slope direction is opposite to the direction of gas flow out of the burner base, gas leakage can be avoided. Furthermore, its structure is relatively simple and easy to manufacture.

[0009] In order to facilitate the lower ends of each baffle plate to abut against the diffuser and maintain better sealing with the burner base, preferably, the diffuser extends further into the burner base relative to the second end of the sleeve.

[0010] To address the second technical problem, the present invention also provides a burner comprising a base, wherein the inlet of the gas passage of the base is connected to an ejector tube, characterized in that: the ejector tube is the ejector tube defined in any one of claims 1 to 4 above.

[0011] To ensure even heating of the pot bottom and accommodate both high and low heat settings, the burner cap preferably includes an inner burner cap and an outer burner cap. The ejector tube is divided into a first ejector tube (natural air intake type) and a second ejector tube connected to the gas supply unit. The first ejector tube corresponds to the inner burner cap, while the second ejector tube corresponds to the outer burner cap. Since the combustion load of the inner burner cap in the burner is relatively small, natural ejection is more suitable for injecting the combustion gas and primary air. The outer burner cap combines both forced draft and natural ejection methods to accommodate the larger combustion load of the outer burner cap in the burner.

[0012] Furthermore, the base includes an inner ring wall, an outer ring wall, and a bottom wall connecting the inner ring wall and the outer ring wall, with a cavity formed between the inner ring wall and the outer ring wall;

[0013] A connecting plate covers the cavity, and the connecting plate is also provided with at least two communicating holes communicating with the cavity along the circumferential direction, and the periphery of the communicating holes extends upward with an extension wall;

[0014] The outer ring mixing chamber includes an inner ring wall and an outer ring wall that are arranged in a ring shape and are concentrically spaced apart, as well as a bottom wall connecting the inner ring wall and the outer ring wall. The inner ring wall and the outer ring wall are covered with an outer flame cap. The bottom wall has a through hole that communicates with the extension wall of the connecting hole.

[0015] The diffuser portion of the second ejector tube extends into the base of the burner, and the second end of the sleeve abuts against the base of the burner. The make-up air channel communicates with the cavity.

[0016] The base cavity design creates a cavity similar to a "buffer chamber," which can better mix the air supplied from the make-up air channel with the combustion gas injected through the injector located at the air inlet end of the contraction section and the primary air naturally introduced, thus helping to meet the combustion efficiency requirements of the burner under high-load combustion.

[0017] To address the third technical problem, preferably, the base also has an internal combustion chamber, independent of the recessed cavity, located within the inner circumference of the inner ring wall. The first ejector tube communicates with the internal combustion chamber, and a central combustion pipe for supplying gas to the ignition channel is also provided within the internal combustion chamber. The internal combustion chamber and the central combustion pipe are connected by a gas guide channel. By designing the gas guide channel, the mixture of gas and primary air in the internal combustion chamber is diverted to the central combustion pipe, thereby avoiding the problem of insufficient ignition caused by excessively fast gas output from the ignition orifice, and helping to improve the ignition success rate of the burner.

[0018] To facilitate the installation of the gas guide channel, from a structurally feasible perspective, preferably, the walls between the internal gas chamber and the central gas pipe are connected by connecting ribs, and the gas guide channel is opened on one of the connecting ribs. The internal gas chamber is provided with an inner flame cover, which includes an annular peripheral wall and a top wall covering the annular peripheral wall. An ignition hole and an ignition channel communicating with the ignition hole are opened on the top wall at the position corresponding to the ignition needle. A gas inlet hole communicating with the central gas pipe is opened at the bottom of the top wall corresponding to the ignition channel.

[0019] To facilitate the connection between the ignition channel and the central gas pipe, the ignition channel is preferably arranged in a straight line.

[0020] Compared with the prior art, the advantages of the present invention are as follows: It provides a supplementary air channel that combines natural ejection and forced-air supplementation. Since the first end of the supplementary air channel is the inlet, i.e., the contraction part, which is far away from the natural ejection, the mutual interference between natural ejection and forced-air ejection can be avoided. The air flowing out of the supplementary air channel can be mixed again with the gas and / or primary air flowing out of the diffuser in the ejector tube. On the one hand, it improves the speed and mixing degree of the gas and / or primary air ejected by the ejector tube itself. On the other hand, the ejector tube as a whole has two sources of supplementary air, and their relative positions are also staggered. On the one hand, it can greatly increase the intake of external primary air. On the other hand, it can spatially separate the forced-air and the injector, avoiding the influence of the forced-air flow field on the natural ejection of gas. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the ejector tube in an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A partial sectional view;

[0023] Figure 3 This is a schematic diagram of the burner and ejector tube in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the base structure in an embodiment of the present invention;

[0025] Figure 5 for Figure 4 A sectional view;

[0026] Figure 6 This is a cross-sectional view of the burner from one angle in an embodiment of the present invention;

[0027] Figure 7 This is a cross-sectional view of the burner from another angle in an embodiment of the present invention;

[0028] Figure 8 This is a schematic diagram of the connecting plate in an embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the structure of the bottom wall of the outer ring mixing chamber in an embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram of the one-way valve in an embodiment of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] Example 1

[0033] like Figures 1-10The diagram shows the preferred embodiment of the present invention. In this embodiment, the ejector tube for the burner is divided into a converging section 11, a mixing section 12, and a diffuser section 13 according to the change in cross-section along the airflow direction. An injector 3 is provided at the air inlet end facing the converging section 11. The tube also includes a sleeve 4 sleeved on the body of the ejector. The first end 41 of the sleeve 4 is connected to the mixing section 12 of the ejector body, and the second end 42 of the sleeve 4 is an open end, which is connected to the base 5 of the burner together with the diffuser section 13. The second end 42 of the sleeve 4 and the diffuser section 13 together form an air supply channel 6 for supplying air to the base 5 of the burner. An opening 43 communicating with the air supply section 10 is provided on the sleeve 4. Since the first end 41 of the make-up air channel 6 is the inlet, i.e. the contraction section 11, which is far from the natural ejection, the mutual interference between natural ejection and blower-type ejection can be avoided. The air flowing out of the make-up air channel 6 can be mixed again with the gas and / or primary air flowing out of the diffuser section 13 in the ejector tube. On the one hand, this improves the speed and mixing degree of the gas and / or primary air ejected by the ejector tube itself. On the other hand, the ejector tube as a whole has two sources of make-up air, and their relative positions are also staggered. On the one hand, this can greatly increase the amount of external primary air drawn in. On the other hand, it can separate the blower and the injector 3 in space, avoiding the influence of the blower flow field on the natural ejection of the gas.

[0034] Specifically, the sleeve 4 is equipped with a one-way valve 7 in the air supply channel 6, which only allows the air supplied by the air supply unit 10 to flow unidirectionally to the burner base 5. The one-way valve 7 enables the air supply unit 10, such as a blower, to supply the air required for combustion to the burner base 5 in only one direction, thus preventing the gas in the burner base 5 from leaking out of the air supply channel 6. In addition, since the air supply channel 6 is connected to the burner base 5, in order to prevent the gas in the burner base 5 from leaking out, the one-way valve 7 in this embodiment includes a ring 71 and at least three baffles 72 spaced circumferentially along the ring 71. Each baffle 72 has an upper end 721 connected to the ring 71 and a lower end 722 abutting against the diffuser 13. Each baffle 72 gradually slopes downward toward the burner base 5 from the upper end 721 to the lower end 722. When the air supply unit 10 is in operation... During operation, the lower ends 722 of each baffle 72 are blown away from the diffuser 13, opening the air supply channel 6 and allowing air to be supplied to the burner base 5. When the air supply unit 10 stops working, the lower ends 722 of each baffle 72 re-abut against the diffuser 13. Since each baffle 72 gradually slopes downward toward the burner base 5 from its upper end 721 to its lower end 722, and the direction of this slope is opposite to the direction of gas flow out of the burner base 5, gas leakage can be avoided. In order to facilitate the lower ends 722 of each baffle 72 abutting against the diffuser 13 and to maintain better sealing with the burner base 5, the diffuser 13 extends further into the burner base 5 relative to the second end 42 of the sleeve 4.

[0035] In addition, the present invention also provides a burner using the aforementioned ejector tube. This burner includes a base 5, with the air inlet of the gas passage in the base 5 connected to the ejector tube. The ejector tube is the aforementioned ejector tube with a supplementary air passage 6. To evenly heat the pot bottom and meet the requirements of both large and small flames, the burner cap includes an inner burner cap 8 and an outer burner cap 9. The ejector tube is divided into a first ejector tube 1 with natural air intake and a second ejector tube 2 connected to the gas supply unit 10. The first ejector tube 1 corresponds to the inner burner cap 8, while the second ejector tube 2 corresponds to the outer burner cap 9. Since the combustion load of the inner burner cap 8 in the burner is relatively small, it is more suitable to use natural ejection to eject the gas and primary air. The outer burner cap 9 combines both forced draft and natural ejection methods to eject the gas and primary air, thus adapting to the larger combustion load of the outer burner cap 9 in the burner. The base 5 includes an inner ring wall 51, an outer ring wall 52, and a bottom wall 53 connecting the inner ring wall 51 and the outer ring wall 52. A cavity 54 is formed between the inner ring wall 51 and the outer ring wall 52, and a connecting plate 20 covers the cavity 54. The connecting plate 20 also has at least two communicating holes 201 in the circumferential direction that communicate with the cavity 54, and an extension wall 22 extends upward from the periphery of the communicating holes 201. Correspondingly, the outer ring mixing chamber 30 includes ring-shaped and concentrically spaced components. The inner ring wall 301 and outer ring wall 302, as well as the bottom wall portion 303 connecting the inner ring wall 301 and outer ring wall 302, are covered by an outer flame cap 9. The bottom wall portion 303 has a through hole 304 that communicates with the extension wall 22 of the connecting hole 201. The diffuser portion 13 of the second injector 2 extends into the burner base 5, and the second end 42 of the sleeve 4 abuts against the burner base 5, so that the air supply channel 6 communicates with the cavity 54. Through the design of the cavity 54 of the base 5, a cavity similar to a "buffer cavity" can be formed, which can better mix the air supplied from the air supply channel 6 with the gas injected by the injector 3 that is set towards the air inlet end of the contraction portion 11 and the primary air naturally injected, which helps to meet the combustion efficiency of the burner under high load combustion. Furthermore, the base 5 also has an internal combustion chamber 40, independent of the cavity 54, located within the inner circumference of the inner ring wall 51. The first ejector tube 1 is connected to the internal combustion chamber 40, and a central combustion pipe 50 for supplying gas to the ignition channel 84 is also provided within the internal combustion chamber 40. The internal combustion chamber 40 and the central combustion pipe 50 are connected by a gas guide channel 60. By designing the gas guide channel 60, the mixture of gas and primary air in the internal combustion chamber 40 is diverted to the central combustion pipe 50, thereby avoiding the problem of poor ignition caused by excessively fast gas output from the ignition hole 83, which helps to improve the ignition success rate of the burner.

[0036] To achieve the configuration of the gas guide channel 60, the walls between the internal gas chamber 40 and the central gas pipe 50 in this embodiment are connected by connecting ribs 70. The gas guide channel 60 is opened on one of the connecting ribs 70. An inner flame cover 8 is provided on the internal gas chamber 40. The inner flame cover 8 includes an annular peripheral wall 81 and a top wall 82 covering the annular peripheral wall 81. An ignition hole 83 and an ignition channel 84 communicating with the ignition hole 83 are opened on the top wall 82 at the position corresponding to the ignition needle. A gas inlet hole 85 communicating with the central gas pipe 50 is opened at the bottom of the top wall 82 corresponding to the ignition channel 84. In addition, the ignition channel 84 is designed in a straight line shape, which makes it easier to connect the ignition channel 84 with the central gas pipe 50 in terms of length.

[0037] In summary, this burner combines two ejection methods: natural ejection and natural ejection combined with forced air supply. The air supply unit 10 for forced air supply can be connected to a controller and a matching sensor. The controller can control the air volume of the air supply unit 10 according to the combustion load of the outer burner cap 9 in the outer ring mixing chamber 30 of the burner. When the air supply unit 10 is working, the lower ends 722 of each baffle 72 are blown away from the diffuser 13, thereby opening the air supply channel 6 and supplying air to the base 5 of the burner.

[0038] Example 2

[0039] The structure is basically the same as that of Example 1, the only difference being that: the inner flame cap 8 corresponds to natural injection and forced air replenishment, while the outer flame cap 9 corresponds to natural injection, and the ignition needle is set in the outer flame cap 9 so that the flame emitted from the outer flame cap 9 is a permanent flame.

Claims

1. An ejector tube for a burner, the ejector tube being divided into a converging section (11), a mixing section (12), and a diffuser section (13) according to the change in cross-section along the airflow direction, and an injector (3) is provided toward the air inlet end of the converging section (11), characterized in that: It also includes a sleeve (4) fitted outside the ejector body. The first end (41) of the sleeve (4) is connected to the mixing part (12) of the ejector body. The second end (42) of the sleeve (4) is an open end and is connected to the burner base (5) together with the diffuser part (13). The second end (42) of the sleeve (4) and the diffuser part (13) together form an air supply channel (6) for supplying air to the burner base (5). An opening (43) is provided on the sleeve (4) to communicate with the gas supply part (10). The sleeve (4) is equipped with a one-way valve (7) in the air supply channel (6), which allows the air supplied by the air supply unit (10) to flow unidirectionally to the base (5) of the burner; The one-way valve (7) includes an annulus (71) and at least three baffles (72) spaced circumferentially along the annulus (71). Each baffle (72) has an upper end (721) connected to the annulus (71) and a lower end (722) abutting against the diffuser (13). Each baffle (72) gradually slopes downward toward the base (5) of the burner from the upper end (721) to the lower end (722).

2. The ejector tube for a burner according to claim 1, characterized in that: The diffuser (13) extends further into the burner base (5) relative to the second end (42) of the sleeve (4).

3. A burner comprising a base (5), wherein the inlet of the gas passage of the base (5) is connected to an injector, characterized in that: The ejector tube is the ejector tube described in any one of claims 1 to 2 above.

4. The burner according to claim 3, characterized in that: It also includes a flame cap, which includes an inner flame cap (8) and an outer flame cap (9). The ejector tube is divided into a first ejector tube (1) of natural air intake and a second ejector tube (2) connected to the gas supply unit (10). The first ejector tube (1) corresponds to the inner flame cap (8), while the second ejector tube (2) corresponds to the outer flame cap (9).

5. The burner according to claim 4, characterized in that: The base (5) includes an inner ring wall (51), an outer ring wall (52) and a bottom wall (53) connecting the inner ring wall (51) and the outer ring wall (52), and a cavity (54) is formed between the inner ring wall (51) and the outer ring wall (52). A connecting plate (20) covers the cavity (54). The connecting plate (20) is also provided with at least two connecting holes (201) communicating with the cavity (54) along the circumferential direction. An extension wall (22) extends upward from the periphery of the connecting hole (201). The outer ring mixing chamber (30) includes an inner ring wall (301) and an outer ring wall (302) arranged in a ring and concentrically spaced apart, and a bottom wall portion (303) connecting the inner ring wall (301) and the outer ring wall (302). The inner ring wall (301) and the outer ring wall (302) are covered with an outer flame cap (9). The bottom wall portion (303) has a through hole (304) communicating with the extension wall (22) of the connecting hole (201). The diffuser (13) of the second ejector tube (2) extends into the base (5) of the burner, and the second end (42) of the sleeve (4) abuts against the base (5) of the burner, and the make-up air channel (6) communicates with the cavity (54).

6. The burner according to claim 5, characterized in that: The base (5) also has an internal gas chamber (40) independent of the cavity (54) in the inner periphery of the inner ring wall (51). The first ejector tube (1) is connected to the internal gas chamber (40), and a central gas pipe (50) for supplying gas to the ignition channel (84) is also provided in the internal gas chamber (40). The internal gas chamber (40) and the central gas pipe (50) are connected by a gas guide channel (60).

7. The burner according to claim 6, characterized in that: The walls between the internal gas chamber (40) and the central gas pipe (50) are connected by connecting ribs (70). The gas guide channel (60) is opened on one of the connecting ribs (70). An inner flame cover (8) is provided on the internal gas chamber (40). The inner flame cover (8) includes an annular peripheral wall (81) and a top wall (82) covering the annular peripheral wall (81). An ignition hole (83) and an ignition channel (84) communicating with the ignition hole (83) are opened on the top wall (82) at the position corresponding to the ignition needle. A gas inlet hole (85) communicating with the central gas pipe (50) is opened at the bottom of the top wall (82) corresponding to the ignition channel (84).

8. The burner according to claim 6 or 7, characterized in that: The ignition channel (84) is arranged in a straight line.

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