JP2001173917A - Regenerative burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerative burner which can elongate the life of a heat reservoir. SOLUTION: A regenerative burner comprises, in a burner tile 20 of a combustion furnace, a honeycomb-shaped heat reservoir 4 made of heat resisting metal. The regenerative burner also comprises a suction control means for controlling the suction distribution of an exhaust gas suction rate in a radial direction, so that more exhaust gas is sucked into the central portion of the heat reservoir 4 than into the outer periphery of the heat reservoir.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative burner capable of extending the life of a heat storage body.

[0002]

2. Description of the Related Art Conventionally, in order to save energy in a combustion apparatus such as a heating furnace or a combustion furnace, a burner tile is used to recover heat of exhaust gas burned in the furnace and heat combustion air. A regenerative burner in which a heat storage body is provided is known. In this case, as the heat storage body, a heat-resistant metal such as ceramic or stainless steel in a honeycomb shape is generally used.

Among them, those using a heat-resistant metal as a heat storage element have various advantages such as being lighter and larger than ceramics, having excellent breaking strength, and being low in pressure loss due to being thin. However, there is a limit in the operating temperature conditions (about 1000 ° C. or less) due to the limitation of the heat resistant temperature. In addition, there is also a problem that when used at a temperature exceeding the heat-resistant temperature, it must be replaced in a short period of time due to thermal deformation or thermal destruction. Furthermore, even when the heat storage body is used near the heat-resistant temperature, there is a problem that the thermal damage to the outer peripheral portion of the heat storage body is severe and the expected use period cannot be secured.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and can be reduced in weight and size, has excellent breaking strength, and has a small pressure loss. The object of the present invention is to provide a regenerative burner which can be used continuously for a long period of time without any limitation on the use temperature and without causing thermal deformation or thermal destruction of the heat storage body.

[0005]

Means for Solving the Problems A regenerative burner according to the present invention, which has been made to solve the above-mentioned problems, is a regenerative burner in which a honeycomb-shaped heat storage body made of a heat-resistant metal is provided in a burner tile of a combustion furnace. Suction control means for controlling a radial suction distribution of an exhaust gas suction amount such that exhaust gas sucked into the heat storage body is suctioned more toward the center portion than at the outer peripheral portion of the heat storage body. .

The flow rate control means may be arranged such that a concentric partition is provided in a radial direction of the heat storage body in a flow path of the exhaust gas sucked by the heat storage body. And is divided into a plurality of flow passages following the outer periphery of the heat storage body, and is configured so that exhaust gas is independently sucked into each flow passage. The invention according to claim 2, wherein the radial suction distribution of the exhaust gas suction amount is controlled such that a large amount of the exhaust gas is sucked so that the exhaust gas is sucked more toward the center portion than the outer peripheral portion of the heat storage body. .

The flow control means is a suction control plate provided in a flow path of the exhaust gas supplied to the heat storage body, and the exhaust control device controls the flow direction of the exhaust gas flowing through the outer peripheral portion toward the center by the suction control plate. It is configured to change, and by sucking more exhaust gas into the flow path on the center side, the exhaust gas suction amount is suctioned in the radial direction so that the exhaust gas is sucked more toward the center compared to the outer periphery of the heat storage body. What controls distribution is the invention according to claim 3.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. The drawing shows the switchable regenerative burner incorporated in the preheating and drying equipment of the molten iron pan used for drying and heating the refractory lining of a molten iron pan (eg, a ladle) in a steel mill, or for preheating before receiving steel and before receiving iron. It is shown. In the figure, reference numeral 1 denotes a burner main body mounted in a burner tile 20 of a furnace wall. The burner main body 1 includes a fuel nozzle 2 having a tip facing the furnace and a burner outer cylinder 3 covering the fuel nozzle 2. The front part of the fuel nozzle 2 is inserted into a honeycomb-shaped heat storage body 4 made of a heat-resistant metal typified by stainless steel and mounted in the burner tile 20. The heat storage body 4 is heated when the heat of the exhaust gas burned in the furnace is discharged from the burner outer cylinder 3 and stores the heat. On the other hand, when the valve is switched, the combustion air is sent from the burner outer cylinder 3 into the furnace. In this method, the combustion air is preheated by the stored energy to improve the combustion efficiency of the burner, thereby saving energy.
In addition, the switchable regenerative burner here means a pair of burners installed in the diagonal direction of the furnace, one of which is in a combustion state, and the other is in a state of exhaust gas discharge, and burns for a certain period of time. This is a type in which the discharge state is changed and combustion is performed for a fixed time, and this is alternately switched. FIG. 1 shows one side of the pair.

In the present invention, suction control means for controlling the radial suction distribution of the exhaust gas suction amount so that the exhaust gas sucked into the heat storage body 4 is suctioned more toward the center portion than the outer peripheral portion of the heat storage body 4. Has a characteristic configuration. As a result of the research conducted by the present inventors, it has been found that the exhaust gas flows into the heat storage body 4 in a large amount into the outer peripheral portion and is more likely to be heated than the central portion. It is based on the results of research that the outer circumference is mechanically longer than the center, so the thermal expansion allowance is large and the element that deforms is large. Things. Therefore, when high-temperature exhaust gas is sucked into the burner, the suction control means prevents the large amount of exhaust gas from being sucked into the outer peripheral portion of the heat storage body 4 which is easily damaged by heat. By controlling the exhaust gas to be sucked more, the heat load is applied evenly to the entire heat storage body, preventing the occurrence of local thermal damage on the outer periphery as in the past, and improving the durability It is to plan.

In FIG. 1, the flow control means is provided in the flow path of the exhaust gas sucked through the heat storage unit 4.
A concentric partition 5 is provided in the radial direction of the heat storage body, and is divided into two flow paths, a flow path 6a following the center of the heat storage body 4 and a flow path 6b following the outer periphery of the heat storage body 4. The exhaust gas is independently sucked into each of the flow paths, and the exhaust gas is sucked into the flow path 6a on the inner peripheral side so that the exhaust gas has a central portion compared to the outer peripheral portion of the heat storage body 4. The radial suction distribution of the exhaust gas suction amount is controlled so that a large amount of exhaust gas is sucked. The flow paths 6a and 6b have dampers 7a and 7 for adjusting the amount of exhaust gas sucked, respectively.
b is provided to adjust the degree of opening of the dampers 7a and 7b to arbitrarily change the exhaust gas suction amount. As shown in FIG. 1 (b), the damper 7a is fully opened and the damper 7a is fully opened. By making the opening 7b about half open, more exhaust gas is sucked into the central part of the heat storage body 4, and the temperature rise in the outer peripheral part is suppressed.

In the above, the case of the switching type regenerative burner has been described. However, the present invention can be similarly applied to a self-type regenerative burner. The self-type regenerative burner referred to here is, as shown in FIG.
By rotating the combustion air supply duct connected to the rear end of the heat storage body continuously or intermittently in the circumferential direction of the burner shaft, the combustion air is preheated from the duct via the heat storage area of the heat storage body. A single burner enables preheating and heat storage of the combustion air by a series of operations in which high-temperature exhaust gas passes through the part where the heat is removed from the heat storage body through the passage of the combustion air and stores heat. A type of burner.

Specifically, as shown in FIG. 2, the burner main body 1 has a heat storage body 4 made of a heat-resistant metal around a fuel nozzle 2 having a tip facing the inside of a furnace. A duct 1 which is provided in a built-in manner and communicates with the combustion air supply port 11 of the burner outer cylinder 3 adjacent to the rear end of the heat storage body 4
2 is provided so as to be rotatable in the circumferential direction of the fuel nozzle 2, and an exhaust gas suction port 13 is provided in the burner outer cylinder 3. At the time of combustion heating, fuel is supplied from the fuel supply port 14 of the fuel nozzle 2 to the tip of the fuel nozzle 2, and simultaneously, the combustion air supply port 11 is connected to the duct 1.
2 is supplied to the tip of the fuel nozzle 2 after preheating by supplying combustion air to the regenerator 4 and then burning the fuel, and then injecting the combustion gas into the molten iron pot (furnace) and lining. Heat the refractory. On the other hand, in the molten iron pot after heating (in the furnace)
The high-temperature exhaust gas (combustion gas) passes through a portion of the heat storage body 2 other than the combustion air passage portion, stores the heat therein, and then diffuses to the outside through the exhaust gas suction port 13. Then, duct 1
2 is driven by a motor 15 to rotate in the circumferential direction about the burner axis, and while rotating to the heat storage portion of the heat storage body 4, combustion air passes through the heat storage body 4 from the duct 12, and constantly stable preheated air is supplied to the fuel nozzle On the other hand, the high-temperature exhaust gas passes through the heat storage site where heat is removed by the preheating of the combustion air, and heat is stored. As described above, the duct 5 is rotated continuously or intermittently, and the combustion air is preheated by the heat energy stored in the heat storage body 4 to improve the combustion efficiency of the burner, thereby saving energy. ing.

In this case, the flow control means includes a suction control plate 1 in the flow path 13a of the exhaust gas sucked from the heat storage body 4.
7 is installed, and the exhaust gas flowing through the outer peripheral portion is configured to change its flow direction toward the central portion by the suction control plate 17, and by sucking more exhaust gas into the flow path on the central side, The radial suction distribution of the exhaust gas suction amount is controlled so that the exhaust gas is sucked more toward the central portion than at the outer peripheral portion of the heat storage body.

In the self-type regenerative burner described above, the suction control plate 17 is fixed to the duct 12 which rotates in the circumferential direction of the burner shaft, as shown in FIGS. No. 4 is provided so as to always be applied to a region corresponding to the outer peripheral portion of the exhaust gas suction region (that is, a portion other than the combustion air passage portion). When the suction control plate 17 rotates continuously or intermittently together with the duct 12, the suction control plate 17 supplies the combustion air to the fuel nozzle 2 as preheating air via the heat storage body 4 storing heat, while preheating the combustion air. As a result, the heat stored in the heat storage portion is uniformly stored as a whole by the passage of the exhaust gas sucked into the center by the action of the suction control plate 17.

As the suction control plate 17, it is desirable to use a material having an appropriate ventilation resistance represented by a wire mesh such as expanded metal, but it is also preferable to use a material such as an iron plate that blocks suction. Can be. Further, in FIG. 3, the suction control plate 17 has a structure in which the suction control plate 17 is arranged over the entire periphery of the exhaust gas suction region other than the region occupied by the duct 12, but is not limited thereto. However, for example, as shown in FIG. 5, one arranged in a part in the circumferential direction, or one provided with an inclination such that the width of the suction control plate 17 is not constant but gradually decreases toward the combustion air passage portion For example, any shape can be adopted as long as the shape allows the amount of exhaust gas to pass (the amount of suction) in the outer peripheral portion of the heat storage element 4 to be suppressed and the radial temperature distribution of the heat storage element 4 to be uniform.

In the present invention configured as described above, the heat storage body 4
Is heated when the heat of the exhaust gas burned in the furnace is discharged from the burner outer cylinder 3 and stored. On the other hand, when the combustion air is sent into the furnace, the burned air is preheated by the stored energy. This is basically the same as this type of conventional regenerative burner in that it is operated while saving energy by improving the combustion efficiency of the regenerative burner. In the present invention, suction control means for controlling the radial suction distribution of the exhaust gas suction amount is provided so that the exhaust gas sucked into the heat storage body 4 is sucked more toward the center portion than the outer peripheral portion of the heat storage body 4. Therefore, unlike the related art, only the outer peripheral portion of the heat storage body 4 does not locally rise in temperature. That is, when the exhaust gas flows, only the outer peripheral portion of the heat storage member 4 locally rises in temperature. However, when the high-temperature exhaust gas is sucked, a large amount of heat accumulates on the outer peripheral portion of the heat storage member 4 which is easily damaged by heat. In order to prevent the exhaust gas from being sucked, the suction control means controls the exhaust gas to be suctioned toward the central portion as compared with the outer peripheral portion of the heat storage member 4 so that the heat load is uniformly applied to the entire heat storage member. The temperature distribution should be uniform throughout. As a result, unlike the related art, only the outer peripheral portion does not locally rise in temperature, and the occurrence of thermal damage can be accurately avoided, so that the durability of the heat storage body 4 is greatly improved. According to experiments by the present inventors, it has been confirmed that a continuous use period of 5 years or more can be guaranteed, and a life that is about 10 times as long as that of the related art can be obtained.

[0017]

As is apparent from the above description, the present invention can be reduced in weight and size, has excellent breaking strength, has a small pressure loss, and has no limitation on the operating temperature. Moreover, it can be used continuously for a long period of time without causing thermal deformation or thermal destruction of the heat storage body. Therefore, the present invention greatly contributes to industrial development as a regenerative burner that has eliminated the conventional problems.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a diagram showing a view in the direction of arrow A in FIG. 2;

FIG. 4 is a perspective view showing a flow rate control in FIG. 2;

FIG. 5 is a front view showing another flow control plate.

FIG. 6 is a front view showing another flow control plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner main body 2 Fuel nozzle 3 Burner outer cylinder 4 Heat storage body 5 Concentric partition 6a Flow path leading to the center of heat storage body 6b Flow path leading to the outer periphery of heat storage body 12 Duct 17 Flow control plate 20 Burner tile

Claims (3)

[Claims] In a regenerative burner in which a honeycomb-shaped heat accumulator made of a heat-resistant metal is provided in a burner tile of a combustion furnace, a larger amount of exhaust gas sucked into the heat accumulator is suctioned to a central portion than an outer peripheral portion of the heat accumulator. A regenerative burner provided with suction control means for controlling a radial suction distribution of an exhaust gas suction amount. 2. A flow control system according to claim 1, wherein said suction control means includes a flow path for exhaust gas sucked by said heat storage element, a concentric partition disposed in a radial direction of said heat storage element, and a flow path leading to a central portion of said heat storage element and an outer periphery of said heat storage element. It is divided into a plurality of flow paths following the section, and it is configured so that exhaust gas is sucked into each flow path independently, so that more exhaust gas is sucked into the flow path on the center side 2. The regenerative burner according to claim 1, wherein the exhaust gas suction amount is controlled in the radial suction distribution such that the exhaust gas is sucked more toward the central portion than the outer peripheral portion of the heat storage body. 3. The suction control means is a suction control plate installed in a flow path of the exhaust gas supplied to the heat storage unit, and the exhaust control means controls the direction of flow of the exhaust gas flowing through the outer peripheral portion toward the center. It is configured to change, and by sucking more exhaust gas into the flow path on the center side, the exhaust gas suction amount is suctioned in the radial direction so that the exhaust gas is sucked more toward the center compared to the outer periphery of the heat storage body. The regenerative burner according to claim 1, which controls distribution.