JP2007518959A - Flexible co-current burner with gas swirl chamber - Google Patents

Abstract

An apparatus and method for a burner is disclosed. In an embodiment of an apparatus of the present invention, the burner includes a combustion gas tube with a first gas inlet line coupled to the combustion gas tube and an oxygen-containing gas tube with a second gas inlet line coupled to the oxygen-containing gas tube. A swirl chamber is disposed between either the first gas inlet line and the combustion gas tube or between the second gas inlet line and the oxygen-containing gas tube. In accordance with an embodiment of a method of the present invention, the method includes controlling a flow of a combustion gas to the combustion gas tube and controlling a flow of an oxygen-containing gas to the oxygen-containing gas tube. The combustion gas or the oxygen-containing gas is swirled in a swirl chamber and the combustion gas and the oxygen-containing gas is supplied to a burner.

Description

  The present invention includes a burner head, at least one fuel gas pipe, and at least one oxygen-containing gas pipe. The external of the type in which the gas from the fuel gas pipe and the gas from the oxygen-containing gas pipe are fed into the burner head. It relates to a mixed burner. The invention also relates to a method of operating an externally mixed burner that feeds fuel gas and oxygen-containing gas to the burner head through at least one fuel gas tube and at least one oxygen-containing gas tube.

  External mixed burners are used for various purposes. For example, many differently configured burners are used to heat and melt metals and glass. Finding a burner that fits every stage of the melting process and the various loading forms of the melting furnace is a challenge.

  The object of the present invention is therefore to provide a burner that can be advantageously adapted to most stages of use in many fields of use.

  The problem is that the externally mixed burner of the type described at the beginning is equipped with respective gas supply pipes for fuel gas and oxygen-containing gas, and these gas supply pipes are respectively supplied for fuel gas or oxygen-containing gas. And at least one gas supply pipe is connected to the gas swirl chamber in an eccentric manner, and the gas swirl chamber is connected between one gas supply pipe and the fuel gas pipe and / or the other gas supply pipe and oxygen. It solves by arrange | positioning between containing gas pipes.

  In this case, at least one of the gas supply pipes is divided into two branch pipes upstream of the gas swirl chamber, one branch pipe communicates with the gas swirl chamber eccentrically, and the other branch pipe is a fuel gas pipe or oxygen-containing It is preferable to communicate directly with the gas pipe.

  In addition, valves are provided in each gas supply pipe, or valves are provided in portions where each gas supply pipe is already divided into branch pipes, and the opening degree of these valves is adjusted so that the flame shape of the burner can be adjusted. It is particularly preferred that a control mechanism or adjusting mechanism for controlling or adjusting is provided.

  Each valve is preferably configured as an electromagnetically operated valve. With these valves, the flame shape can be changed and adjusted stepwise, for example. If more precise adjustment is required, some or all of these electromagnetically operated valves can be replaced with electromagnetically operated flow control valves. The flow control valve can continuously change and adjust the flame shape.

  The gas swirl chamber preferably has a circular cross section in a plane perpendicular to the axis of the fuel gas pipe. In this case, it is preferable that at least one gas supply pipe communicates with the gas swirl chamber in a tangential direction. With these configurations, the fluid friction resistance against the swirling flow can be reduced, and the entire burner can be downsized.

  Regarding the operation method of the burner, when the external mixing type burner of the type described at the beginning is operated, the fuel gas and / or the oxygen-containing gas is eccentrically introduced into the gas swirl chamber and the fuel gas or This is solved by giving a swirl flow to the oxygen-containing gas and supplying the fuel gas or oxygen-containing gas after passing through the gas swirl chamber to the fuel gas pipe or oxygen-containing gas pipe.

  In this case, the supply amount per unit time of the fuel gas and the oxygen-containing gas supplied to the burner without going through the gas swirl chamber or without going through the gas swirl chamber is adjusted stepwise and / or continuously. When supplying fuel gas and oxygen-containing gas through valves, the degree of opening of these valves is adjusted stepwise and / or continuously so as to produce a flame with the required shape adjustable by the burner It is preferable to adjust or control via

  For example, as a combustion burner in an industrial melting furnace for melting metal or glass, in many cases, a co-current burner is used in which fuel gas and oxygen are mixed and supplied outside the burner head. When fuel gas is burned using air as an oxidant, nitrogen, which is the main component in the air, substantially acts as a ballast gas. Therefore, in recent years, as a measure for reducing the amount of exhaust gas, there is a shift to operating a burner using oxygen-enriched air having an oxygen content higher than that of air as an oxidizing agent. The advantage of this measure is that the nitrogen content of the oxidizer is less than in the case of air, so the flame temperature is increased and the heat content in the exhaust gas is reduced, thereby achieving higher thermal efficiency and The generation of harmful nitric oxide is reduced.

  In the present invention, not only air but also oxygen-enriched air having an oxygen content higher than the oxygen content of air can be suitably used as the oxidant. The advantage of using normal air is that it is available permanently and free of charge. The advantages of using oxygen-enriched air with an increased oxygen content are as already described above.

  Therefore, according to one embodiment of the present invention, air is used as the oxygen-containing gas. Air is always available free of charge anywhere on Earth.

  According to another embodiment of the invention, oxygen-enriched air is used as the oxygen-containing gas. The advantage obtained in this case is that this main oxygen-enriched air is still affordable and potentially has the advantages of using oxygen as a combustion oxidant, ie compared to normal air. Low nitrogen content and high achievable combustion temperatures.

  According to a preferred embodiment of the invention, a gas having an oxygen content greater than that of normal air, in particular an oxygen content greater than 30% by volume, is used as the oxygen-containing gas. The above advantages of utilizing oxygen as a combustion oxidant are even more pronounced in this embodiment.

  According to one particularly preferred embodiment of the invention, a gas having an oxygen content greater than 70% by volume, in particular greater than 99.5% by volume, is used as the oxygen-containing gas. In this case, the above-mentioned advantages of using oxygen as a combustion oxidant are maximized, but the oxidant cost increases accordingly, so in reality, what is the oxygen content is technically desirable. Or, it should be considered for each application whether it is necessary and economically acceptable.

  It is preferable to impart a swirl to the fuel gas, which provides the advantage that good mixing of fuel and oxygen occurs in a slightly shortened flame.

  According to another advantageous embodiment of the invention, a swirling flow is imparted to the oxygen-containing gas. The reason this is advantageous is that in this case too, the flame is somewhat shortened and the burner can be made somewhat simple in construction.

  According to a particularly preferred embodiment of the invention, both are provided with a swirl flow in the same swirl direction. In this case, the advantage is obtained that the flame is very short and small.

  According to yet another embodiment of the present invention, swirl flows in opposite swirl directions are imparted to both the fuel gas and the oxygen-containing gas. This can be recommended when an extremely short and wide strong flame is required.

  The main advantage of the present invention is that the flame length can be changed almost steplessly without changing the amount of fuel during operation of the burner. For example, there is no need to change the burner, such as replacing the burner nozzle. The flame length can be shortened to 1/3 of its maximum length as required.

  The present invention is particularly suitable for industrial processes in which a solid material is heated and melted to form a liquid material. The reason is that in such a melting process, the molten material changes its shape and the flame shape can be adapted to this changed material shape.

  Another significant advantage of the present invention is that the change in flame length is substantially eliminated without having to deactivate the burner, or without requiring any structural changes such as, for example, replacing a conventional swivel disk. In this case, the swirl flow can be started during the operation of the burner, or can be terminated again. The flame shape is changed by changing the flow rate of at least one of the fuel gas and the oxygen-containing gas only by adjusting the opening of each valve provided in the burner. The opening of these valves is adjusted by the burner of the present invention. This is done via an attached stepwise adjustment mechanism or continuous control mechanism.

  The externally mixed burner according to the present invention is particularly suitable for use in melting metal or glass.

  The features and advantages of the present invention will be described in detail with reference to the illustrated embodiment as follows.

  The burner 1 shown in detail in the figure includes a burner head 2, an oxygen-containing gas pipe 4, and a fuel gas pipe 3 (not shown in FIG. 1). Both gas pipes are arranged coaxially. Specifically, the fuel gas pipe 3 is coaxially attached to the inside of the oxygen-containing gas pipe 4. The burner 1 having such a configuration is also called a co-current burner. For example, natural gas is used as the fuel gas.

  The operation of the burner 1 will be described as follows for an embodiment in which the fuel gas and the oxygen-containing gas are swirling in the same direction. First, when the valve 10 is opened, natural gas from a supply source (not shown) flows into the gas swirl chamber 8 from the gas supply pipe 6 via the one branch pipe 6a, where the natural gas flow is turned into a swirl flow. At this time, the valve 11 of the other branch pipe remains closed.

  On the other hand, the oxygen-enriched air is sent to the gas swirl chamber 9 via the gas supply pipe 7 and one of the branch pipes 7a, where the oxygen-enriched air flow is turned into the swirl flow in the same swirling direction as the natural gas flow. . At this time, the valve 12 is opened and the valve 13 remains closed.

  The oxygen-enriched air stream flows from the gas swirl chamber 9 into the oxygen-containing gas pipe 4, and the natural gas stream flows from the gas swirl chamber 8 into the fuel gas pipe 3.

  In the burner head 2, both gas flows sent in are mixed and a characteristic flame is generated. The shape of the flame generated directly depends on the adjustment opening of the valves 10, 11, 12, 13.

  For example, when the fuel gas is supplied with the valve 11 opened and the valve 10 closed, that is, when the swirl flow is not applied to the natural gas, the flame becomes elongated. In other words, the flame in this case becomes longer than the flame length when the swirl flow is applied to both gas flows.

  Similarly, only natural gas can be used as a swirl flow, and the oxygen-containing gas flow can be supplied to the oxygen-containing gas pipe 4 via the valve 13 opened from the branch pipe 7b without swirling.

  By configuring the valves 10, 11, 12 and / or 13 as stepped control valves or continuous control valves, it is possible to provide intermediate opening positions of these valves, i.e. a plurality of adjustable throttle openings. Thereby, the flame length can be adjusted almost or completely in a stepless manner. The actual flame shape can be changed without any problem by a stepwise adjustment mechanism or a continuous control mechanism in which the valves 10, 11, 12, 13 are opened / closed and the opening is adjusted preferably by electromagnetic operation during operation of the burner 1. .

  The supply amount of fuel gas and oxygen-containing gas per unit time must be interpreted as a flame-shaped boundary condition. Once selected, the feed rate remains constant during burner operation. By simply selecting the opening / closing position or the opening position of the valves 10, 11, 12, and 13, it is possible to generate almost continuously from a short and strong wide flame to a long and thin flame.

It is a side view which shows the burner which concerns on this invention. It is AA arrow sectional drawing of FIG. It is a BB line arrow directional cross-sectional view of FIG.

Claims (17)

A burner head (2), at least one fuel gas pipe (3), and at least one oxygen-containing gas pipe (4) are provided, and the burner head (2) contains gas and oxygen from the fuel gas pipe (3). In the external mixing type burner (1) in which the gas from the gas pipe (4) is fed, the gas supply pipes (6, 7) are provided for the fuel gas and the oxygen-containing gas, respectively. Connected to each supply source for fuel gas or oxygen-containing gas, at least one gas supply pipe (6, 7) is eccentrically communicated with the gas swirl chamber (8, 9). The burner is disposed between the gas supply pipe (6) and the fuel gas pipe (3) and / or between the other gas supply pipe (7) and the oxygen-containing gas pipe (4). . At least one gas supply pipe (6, 7) is divided into two branch pipes (6a, 6b, 7a, 7b) on the upstream side of the gas swirl chamber (8, 9), and one branch pipe (6a, 7a) is divided. It is eccentrically connected to the gas swirl chamber (8, 9), and the other branch pipe (6b, 7b) is directly connected to the fuel gas pipe (3) or the oxygen-containing gas pipe (4). The burner according to claim 1. Each gas supply pipe (6, 7) is provided with a valve (10, 11, 12, 13), or each gas supply pipe (6, 7) is already divided into branch pipes (6a, 6b, 7a, 7b). Stepped adjustment to change the opening of the valve (10, 11, 12, 13) so that the flame shape of the burner (1) can be adjusted. A burner according to claim 1 or 2, characterized in that it is equipped with a mechanism or a continuous control mechanism. The burner according to any one of claims 1 to 3, characterized in that the valve (10, 11, 12, 13) is configured as an electromagnetically operated valve (10, 11, 12, 13). The burner according to any one of claims 1 to 4, wherein the gas swirl chamber (8, 9) has a circular cross-sectional shape in a plane perpendicular to the axis of the fuel gas pipe (3). 6. The burner according to claim 5, wherein at least one of the gas supply pipes (6, 7, 6a, 7a) communicates in a tangential direction with the gas swirl chamber (8, 9). A method of operating an externally mixed burner (1) for sending fuel gas and oxygen-containing gas to a burner head (2) through at least one fuel gas pipe (3) and at least one oxygen-containing gas pipe (4), The fuel gas and / or the oxygen-containing gas is eccentrically introduced into the gas swirl chamber (8, 9), and the swirl flow is given to the fuel gas or the oxygen-containing gas inside the gas swirl chamber, so that the gas swirl chamber (8, 9) A burner operation method characterized by supplying the fuel gas or oxygen-containing gas after passing through the fuel gas pipe (3) or oxygen-containing gas pipe (4). The supply amount per unit time of the fuel gas and the oxygen-containing gas supplied to the burner (1) without going through the gas swirl chamber (8, 9) or without going through the gas swirl chamber (8, 9) is stepwise. And / or continuously adjusting fuel gas and oxygen-containing gas through valves (10, 11, 12, 13), and the burner (1) can adjust the opening of these valves. The burner operating method according to claim 7, wherein the burner is adjusted or controlled through a stepwise adjustment mechanism and / or a continuous control mechanism so as to generate a flame having a required shape. The burner operation method according to claim 7 or 8, wherein air is used as the oxygen-containing gas. The burner operation method according to claim 7 or 8, wherein oxygen-enriched air is used as the oxygen-containing gas. 9. The burner operation method according to claim 7, wherein a gas having an oxygen content larger than that of ordinary air, particularly a gas having an oxygen content larger than 30% by volume, is used as the oxygen-containing gas. . 12. The burner operating method according to claim 11, wherein a gas having an oxygen content greater than 70% by volume, in particular greater than 99.5% by volume, is used as the oxygen-containing gas. The burner operation method according to any one of claims 7 to 12, wherein a swirl flow is imparted to the fuel gas. The burner operating method according to any one of claims 7 to 13, wherein a swirl flow is imparted to the oxygen-containing gas. The burner operation method according to any one of claims 7 to 14, wherein swirling flows in the same swirling direction are applied to both the fuel gas and the oxygen-containing gas. The burner operation method according to any one of claims 7 to 14, wherein a swirl flow in swirl directions opposite to each other is applied to both the fuel gas and the oxygen-containing gas. Use of an external mixing burner (1) according to any one of claims 1 to 6 in melting metal or glass.

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