JP5382093B2 - Tubular flame burner and radiant tube heating device - Google Patents

Description

  The present invention relates to a tubular flame burner and a radiant tube heating device equipped with the same.

  As a burner attached to a furnace or a combustor, it has a tubular combustion chamber whose tip is open, and a nozzle for blowing a fuel-containing gas and a nozzle for blowing an oxygen-containing gas in the vicinity of the closed end of the rear end of the combustion chamber, Non-premixed tubular flame burners are known that are provided in the tangential direction of the inner peripheral surface of the combustion chamber (see, for example, Patent Documents 1 to 3). Moreover, the radiant tube type heating apparatus carrying the tubular flame burner is disclosed (for example, refer patent document 3).

Since this tubular flame burner forms a flame in a high-speed swirling flow, it can burn with a very high load. In addition, since the combustion amount adjustment range is wide, a single burner can handle a wide range of combustion amounts. Further, since a flame is formed in the burner, a space for combustion is not required in front of the burner, and downsizing of the combustion facility is achieved. In addition, the temperature variation of the combustion exhaust gas is small, the local high temperature region is not formed, and the oxygen supply ratio can be lowered, so there is little generation of harmful gases such as NO _x , soot generation and unburned There is almost no gas discharged as it is, and low pollution of exhaust gas is achieved.

JP-A-11-281015 Japanese Patent Application Laid-Open No. 11-281018 JP 2005-188844 A

  However, the conventional tubular flame burner described in Patent Documents 1 to 3 and the like and the radiant tube heating device equipped with the tubular flame burner have the following technical problems.

  First, there are the following technical problems with the conventional tubular flame burner.

  (1) There is a case where misfire occurs due to a rapid flow rate fluctuation on the supply side of the fuel-containing gas and the oxygen-containing gas. The main reason is that when the flame length of the tubular flame burner is long, a recirculation region useful for flame holding is not formed in the burner. In addition, when a practical burner is assumed, the average superficial velocity in the burner is much higher than the laminar combustion velocity, and it is easy to blow out.

  (2) Hard to ignite. The main reason is that the attachment position of the ignition device is limited to the upstream end (closed end) of the combustion chamber. That is, if the ignition device is protruded from the side wall of the combustion chamber, the swirl flow formed in the combustion chamber is attenuated and the form of the tubular flame is disturbed, which is not preferable. Further, the proper ignition position varies depending on the operating conditions (flow rates of fuel-containing gas and oxygen-containing gas, blowing speed, excess air ratio, etc.).

  Furthermore, the radiant tube type heating device equipped with the conventional tubular flame burner has the following technical problems.

  (3) Since the combustion chamber (radiant tube) is elongated, the ultimate pressure increases due to abnormal combustion (flame propagation), and the tube (radiant tube) may be damaged.

  (4) Since a secondary flow is formed in the curved pipe portion of the radiant tube, mixing of fuel and oxidant proceeds rapidly here, and a flame is formed to the vicinity of the inner wall. A part may be formed and burning trouble may occur.

  (5) In order to ensure the stability of the flame in the combustion chamber, it is necessary to always operate a pilot burner having a large heat capacity. As a result, the consumption of auxiliary fuel increases.

  (6) Since the combustion chamber is elongated and the wall is red-hot, it is difficult for the conventional misfire detector to detect misfire, the valve fully closing operation after misfire is delayed, and there is a risk of abnormal combustion (deflagration).

  (7) Since the combustion chamber is elongated, the rate at which the combustion reaction is frozen in the vicinity of the inner wall is high, and as a result, the exhaust concentration of unburned gas components and particulate matter increases.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a tubular flame burner having high safety and reliability, and a radiant tube heating device equipped with the same. is there.

  In order to solve the above problems, the present invention has the following features.

[1] A tubular combustion chamber having an open tip is provided, each having a nozzle for injecting a fuel-containing gas and a nozzle for injecting an oxygen-containing gas into the combustion chamber, and the injection direction of these nozzles is the circumferential surface of the combustion chamber In a tubular flame burner that is coincident with the tangential direction,
Flow rate fluctuation mitigating means for mitigating rapid flow rate fluctuations of the fuel-containing gas or oxygen-containing gas supplied to each nozzle, and a circular cross section tapered toward the downstream, inserted from the rear end of the combustion chamber into the combustion chamber And a rod-shaped body heating means for maintaining the temperature of the outer surface of the rod-shaped body at or above the ignition temperature of the fuel.

  [2] The tubular flame burner according to [1], wherein the rod-shaped body has an uneven surface.

  [3] The rod-like body according to the above [1] or [1], wherein an axial length of a portion inserted into the combustion chamber is within a range of 2 to 10 times an inner diameter of the combustion chamber. 2] The tubular flame burner described in [2].

  [4] The tubular flame burner according to any one of [1] to [3], wherein the heat source of the rod-shaped body heating means is a burner or an electric heater.

  [5] When the heat source of the rod-shaped body heating means is a burner, the combustion exhaust gas of the burner is used as a drive gas for an ejector for recirculating the combustion exhaust gas of the tubular flame burner. The tubular flame burner according to [4].

  [6] The tubular flame burner according to any one of [1] to [5], wherein the oxygen-containing gas is preheated by combustion exhaust gas from the tubular flame burner.

  [7] The tubular according to any one of [1] to [6], wherein the fuel-containing gas and / or oxygen-containing gas contains combustion exhaust gas from a tubular flame burner. Flame burner.

  [8] A radiant tube heating device, wherein the tubular flame burner according to any one of [1] to [7] is disposed at one or both ends of a radiant tube.

  [9] The radiant tube heating device according to [8], wherein when the tubular flame burner is disposed at both ends of the radiant tube, the tubular flame burner is configured to alternately burn.

  [10] The radiant tube heating device according to [8] or [9] above, wherein an inner diameter of the bent tube portion of the radiant tube is smaller than that of the straight tube portion.

  [11] An automatic operation control device is provided for automatically detecting a differential pressure at both ends of the radiant tube and / or an abnormality in the combustion exhaust gas temperature and automatically performing operations from purging with an inert gas to restarting operation. The radiant tube heating device according to any one of [8] to [10], wherein

  In the present invention, it is possible to achieve stable reduction of exhaust gas pollution over a wide range of fuel flow rates, and to obtain a tubular flame burner and a radiant tube heating device having high safety and reliability.

It is a figure which shows the tubular flame burner which concerns on one Embodiment of this invention. It is a figure which shows the case where a burner is used as a flame holding rod heating means. It is a figure which shows utilization of the waste gas at the time of using a burner as a flame holding rod heating means. In the tubular flame burner concerning one embodiment of the present invention, it is a figure showing that oxygen content gas is preheated with exhaust gas of a tubular flame burner. It is a figure which shows the radiant tube type heating apparatus provided with the tubular flame burner which concerns on one Embodiment of this invention at one end. It is a figure which shows the radiant tube type heating apparatus provided with the tubular flame burner which concerns on one Embodiment of this invention at both ends. It is a figure which shows an example of the radiant tube in one Embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a tubular flame burner according to an embodiment of the present invention, FIG. 1 (a) is a longitudinal sectional view, and FIG. 1 (b) is a view taken along the line AA in FIG. 1 (a). .

  As shown in FIG. 1, a tubular flame burner 10 according to this embodiment has a tubular combustion chamber 11 with an open end 11a, and a fuel-containing gas nozzle 12 for injecting fuel-containing gas (fuel gas) and oxygen. Oxygen-containing gas nozzles 13 for blowing the contained gas (air) are provided on the rear end 11b side of the combustion chamber 11, and the injection directions of these nozzles 12 and 13 coincide with the tangential direction of the inner peripheral surface of the combustion chamber 11. . As a result, a long flame tubular flame 14 is formed in the combustion chamber 11 with a high-speed swirling flow.

  In the tubular flame burner 10, a flow rate fluctuation reducing means 31 for reducing a rapid flow rate fluctuation of the fuel-containing gas is installed in a pipe for supplying the fuel-containing gas to the fuel-containing gas nozzle 12. A flow rate fluctuation mitigating means 41 for mitigating a rapid flow rate fluctuation of the oxygen-containing gas is installed in a pipe that supplies the oxygen-containing gas to the nozzle 13. As the flow rate fluctuation mitigating means 31, 41, a buffer tank, a throttle, a filter (a membrane, a packed bed) or the like is used. 1, 32 and 42 are flow meters, 34 and 43 are flow rate adjusting valves, 34 and 44 are check valves, and 35 and 45 are on-off valves. Here, when a mass flow meter is used as the flow meters 32 and 42, the mass flow meter also has a flow rate fluctuation mitigation function, so that a buffer tank, a throttle, a filter, etc. as the flow rate fluctuation mitigation means 31 and 41 are not installed. Also good.

  Thus, since this tubular flame burner 10 is provided with the flow rate fluctuation mitigating means 31, 41, the rapid flow rate fluctuation of the fuel-containing gas or the oxygen-containing gas is alleviated, so misfire is avoided, Abnormal combustion is prevented, and the safety and reliability are improved in addition to the original low pollution of tubular flames and compatibility with a wide range of heat loads. In addition, the operating rate is improved and the repair cost is reduced, so the operating cost is reduced.

  Furthermore, in this tubular flame burner 10, a circular cross-section rod-like body (here, a hollow truncated cone-like rod-like body) 21 inserted concentrically into the combustion chamber 11 from the rear end 11b of the combustion chamber 11, and its A rod-shaped body heating means (in this case, an electric heater) 24 for maintaining the temperature of the outer surface of the rod-shaped body 21 at or above the ignition temperature of the fuel is provided. A thermocouple 23 is attached to the rod-shaped body 21, and the heater controller 24 adjusts the amount of heat input by the electric heater 22 based on the temperature measurement result by the thermocouple 23.

  Thus, in this tubular flame burner 10, the rod-shaped body 21 is installed concentrically in the combustion chamber 11 from the rear end 11b of the combustion chamber 11, and the temperature of the outer surface of the rod-shaped body 21 is equal to or higher than the ignition temperature of the fuel. Therefore, even if a large flow rate fluctuation occurs for some reason regardless of the operation of the flow rate fluctuation mitigating means 31, 41, the rod-like body 21 in which the surface temperature above the ignition temperature of the fuel is maintained. Can greatly reduce the risk of misfire. Therefore, it is possible to prevent an explosion after a misfire. That is, this rod-shaped body 21 has a function as a flame holding rod.

  Here, the concentric rod-shaped body (flame holding rod) 21 installed in the combustion chamber 11 is that the swirl flow is not easily disturbed by the flame holding rod 21 and the centrifugal force acts on the gas, so that the flame holding rod. Good ignitability and flame-holding property because the gas heated by 21 is difficult to diffuse to the surroundings, and the circumferential velocity decreases as it approaches the flame-holding rod surface, making it difficult for the flame to blow off. Is obtained. Therefore, the present invention is considered to be particularly effective when performing intermittent combustion such as alternating combustion.

  As the form of the outer surface of the flame holding rod 21, even if it is a simple circle, a certain degree of flame holding effect can be expected. However, preferably, the outer surface is provided with irregularities so that the initial flame kernel after ignition is blown away by a swirling flow or the like. It is better not to be. For example, if a plurality of grooves (width 5 mm, depth 5 mm) are arranged on the outer surface of the flame holding rod 21 in the axial direction, a circulation flow is formed in the groove, so the flame holding performance is greatly improved. To do.

  In addition, as for the basic shape of the flame holding rod 21, a certain amount of flame holding effect can be expected even in a cylindrical shape, but preferably from the upstream end (the rear end 11b side of the combustion chamber 11) as shown in FIG. It is better to adopt a tapered truncated cone shape toward the downstream. The main reason is that the tapered shape can reduce the maximum deflection due to the weight of the flame holding rod 21 in terms of material mechanics, and when a tubular flame is formed around the flame holding rod 21, it burns in the downstream. This is because, since the amount of exhaust gas increases, it is desirable to increase the passage cross-sectional area toward the downstream (attenuation of swirling flow can be suppressed).

  Further, regarding the set value of the temperature of the outer surface of the flame holding rod 21, the indicated value of the thermocouple 23 does not necessarily indicate the average temperature of the outer surface of the flame holding rod 21, and the gas accompanying the ignition operation Considering that the flame holding rod 21 is cooled by the flow, etc., it is desirable to set it higher than the ignition temperature of the fuel by about 100 ° C. or more.

  Incidentally, after the ignition operation, when the tubular flame is formed around the flame holding rod 21, the outer surface temperature of the flame holding rod 21 maintains the fuel ignition temperature or higher by the radiation from the flame and the heat transfer by the combustion exhaust gas. Therefore, it is only necessary to apply external energy to the flame holding rod 21 at the initial stage of combustion. Therefore, this method has a larger energy saving effect than the conventional pilot burner method.

  Note that the axial length of the flame holding rod 21 is preferably 2 to 10 times the inner diameter of the combustion chamber 11. If the inner diameter of the combustion chamber 11 is less than twice the inner diameter of the combustion chamber 11, the flame holding property against gas supply fluctuations is extremely deteriorated, making it difficult to prevent abnormal combustion. This is because the amount of deflection due to its own weight becomes excessive, the flame axis target property cannot be maintained, and the outer wall of the flame holding rod 21 and the inner wall of the combustion chamber 11 may be burned out.

  Further, the outer diameter (average outer diameter) of the flame holding rod 21 is preferably 0.4 to 0.6 times the inner diameter of the combustion chamber 11. This is because if the outer diameter of the flame holding rod 21 is too small, the heat transfer area becomes smaller and the flame holding performance is worsened. Conversely, if the outer diameter of the flame holding rod 21 is too large, the space of the combustion chamber 11 becomes smaller. This is because there is a risk that the wall becomes narrower and the flame is too close to burn.

  Similarly, if the flame holding rod 21 is too eccentric with respect to the axis of the combustion chamber 11, the tubular flame may approach the inner wall of the combustion chamber 11 and a burning trouble may occur. In addition, the swirl flow is disturbed by the eccentricity of the flame holding rod 21 and the swirl speed is reduced, so that a tubular flame cannot be formed.

  As described above, since the flame holding performance of the tubular flame burner 10 is greatly improved by installing the flame holding rod 21 in the combustion chamber 11, misfire is avoided and abnormal combustion is prevented. , Safety and reliability are improved. In addition, the operating rate is improved and the repair cost is reduced, so the operating cost is reduced.

  And in this tubular flame burner 10, the combustion exhaust gas of the tubular flame burner 10 is contained in the fuel-containing gas or / and the oxygen-containing gas. That is, as shown in FIG. 1, the combustion exhaust gas of the tubular flame burner 10 is mixed with the fuel gas via the flow meter 36, the flow rate adjustment valve 37, and the check valve 38. Similarly, the flow meter 46, the flow rate adjustment valve 47, mixed with air via a check valve 48.

  As a result, the fuel / oxygen concentration is reduced, the slow combustion is promoted, the local high temperature is avoided, and the emission of NOx, which is an environmental load substance, is reduced. In addition, a high exhaust gas recirculation rate is achieved, and as a result, the excess air ratio can be kept small, which significantly reduces exhaust gas sensible heat and improves thermal efficiency, thus saving fuel consumption. It becomes energy saving.

  In FIG. 1, the electric heater 22 is used as the heating means for the flame holding rod 21, but a burner may be used as the heating means for the flame holding rod 21 as shown in FIG. 2.

  That is, FIG. 2A shows a case where a tubular flame burner is used as a heating means for the flame holding rod 21, and the tubular flame burner is placed in the hollow portion of the flame holding rod 21 (here, a hollow cylindrical rod-like body). 51 is arranged. FIG. 2B shows a case where a commercially available ordinary burner is used as a heating means for the flame holding rod 21, and an inner cylinder 53 is installed in the hollow portion of the flame holding rod 21, and the rear end of the inner cylinder 53 is shown. A commercially available normal burner 52 is attached to (on the upstream end side of the flame holding rod 21).

  When the electric heater 22 is used as the heating means for the flame holding rod 21, precise real-time control can be performed, so that reliability is improved. In addition, the incidental equipment becomes compact and the equipment cost is low.

  On the other hand, when the tubular flame burner 51 is used as a heating means for the flame-holding rod 21, before the combustion starts, heat is supplied from the downstream flame, so that an excess enthalpy flame is formed, Since auxiliary fuel and electricity can be saved, the operating cost is low.

  Further, when a commercially available normal burner 52 is used as a heating means for the flame holding rod 21, the operating cost is reduced.

  In addition, when the tubular flame burner 51 or the normal burner 52 is used as the heating means for the flame holding rod 21, the ejector is driven to recirculate the exhaust gas from the combustion exhaust gas of the tubular flame burner 10 (measures for reducing NOx). It can be used as a gas.

  That is, FIG. 3 is provided with an ejector 57 made of low temperature steam or cold air at a position 1/4 of the tube length from the upstream end, and an ejector 56 made of hot gas at a position 1/4 of the tube length from the downstream end. When the flue gas discharged from the outlet of the combustion equipment (for example, the boiler of the waste incinerator) in which the tubular flame burner 10 is installed is guided to the / 4 wavelength tube (Rijke Tube) 55, the flame holding rod 21 is heated. The exhaust gas from the tubular flame burner 51 or the normal burner 52 is used as the drive gas for the ejector 56.

  As a result, a high-temperature blower for exhaust gas recirculation can be omitted, power consumption can be saved, and equipment costs can be reduced. Further, troubles due to burning of high-temperature blowers and dust adhesion are avoided, safety and reliability are improved, and operating costs are reduced.

  By the way, when the exhaust gas from the waste incinerator is recirculated by a high-temperature induction blower, there are problems such as high equipment costs and troubles caused by dust adhering to the blower impeller (abnormal vibration, impeller damage). .

  Further, in the tubular flame burner 10, the oxygen-containing gas can be preheated by the combustion exhaust gas of the tubular flame burner 10.

  That is, as shown in FIG. 4, a pair of heat accumulators 61 a and 61 b and a switching valve 62 are installed, and the oxygen-containing gas is preheated with the combustion exhaust gas of the tubular flame burner 10 in an alternating manner. 4A shows a state in which the oxygen-containing gas (air) is preheated by the heat storage body 61a and the heat storage body 61b is heated by the combustion exhaust gas of the tubular flame burner 10, and FIG. The state where the heat storage body 61a is heated by the combustion exhaust gas of the tubular flame burner 10 and the oxygen-containing gas (air) is preheated by the heat storage body 61b is shown.

  Thus, by preheating the oxygen-containing gas with the combustion exhaust gas of the tubular flame burner 10, the fuel cost used for the tubular flame burner 10 can be saved, and the operating cost is reduced. Further, the reactivity of the fuel / oxygen-containing gas is improved, misfire is prevented, and abnormal combustion is prevented, so that the repair cost is reduced and the operation cost is reduced. Furthermore, since misfires are prevented, safety and reliability are improved, and the operating rate is improved and the operating cost is reduced.

  FIG. 5 and FIG. 6 show a radiant tube heating device equipped with the tubular flame burner 10 described above. FIG. 5 shows a one-end type radiant tube heating device 71 in which a tubular flame burner 10 is installed at one end of a U-shaped radiant tube 75, and FIG. 6 shows a tubular flame burner at both ends of the U-shaped radiant tube 75. 10 (10a, 10b) is a double-sided radiant tube heating device 72 installed.

  In the radiant tube type heating devices 71 and 72 equipped with such a tubular flame burner 10, a flame is formed in the space along the radiant tube 75, so that the combustion freezing on the inner wall of the radiant tube is avoided and the environmental load is reduced. Emissions of unburned gas and particulate matter are reduced. Moreover, since a stable long flame is formed and a local high temperature is avoided, burning of the inner wall is prevented, repair costs are reduced, and operating costs are reduced. Further, by avoiding local high temperatures, emission of NOx, which is an environmentally hazardous substance, is also reduced. Furthermore, since a stable long flame is formed, the temperature distribution on the outer surface of the radiant tube 75 is averaged, so that the heating efficiency of the heating object (product) is improved, fuel consumption can be saved, and energy can be saved. At the same time, the heating temperature distribution of the product becomes uniform and the quality of the product is improved. In addition, the adjustment range of the heating temperature is expanded and the controllability is improved, so that the facility capacity is improved and the product quality is improved.

  As shown in FIG. 6, in the double-end type radiant tube heating device 72, the tubular flame burner 10 a, the heat storage bodies 76 a and 76 b provided corresponding to the tubular flame burners 10 a and 10 b are used. The alternating combustion is performed while preheating oxygen-containing gas (air) with 10b exhaust gas.

  As a result, the actual flow rate of the oxygen-containing gas is increased, and a longer flame is formed. Therefore, the surface temperature of the radiant tube 75 is averaged, and the heating efficiency is improved. It will be cheaper. In addition, the surface temperature of the flame holding rods 21 provided in the tubular flame burners 10a and 10b is made uniform so that misfires can be prevented more reliably, abnormal combustion is prevented, and repair costs are reduced. In addition, the operating cost is low.

  And as shown in FIG. 7, the radiant tube 75 may make the internal diameter of the curved pipe part 75b thinner than the straight pipe part 75a, and you may make it connect with the taper pipe 75c between them.

  As a result, the turning speed is increased in the curved pipe portion 75b, the tubular flame is stably maintained, reaction freezing and incomplete combustion in the vicinity of the inner wall are avoided, and the discharge of particulate matter is reduced. . Moreover, by maintaining the tubular flame stably, local high temperatures are avoided, heating efficiency is improved, and operating costs are reduced. Furthermore, the discharge of NOx, which is an environmentally hazardous substance, is reduced by avoiding local high temperatures. In addition, since the bent pipe portion 75b of the radiant tube 75 is reduced in weight, the equipment cost is reduced.

  When the inner diameter of the curved pipe portion 75b is made thinner than that of the straight pipe portion 75a, the effect of increasing the turning speed to some extent can be expected by connecting both with a stepped pipe, as shown in FIG. As described above, it is preferable that the connection is smoothly made through the tapered tube 75c (the inner diameter has an opening angle of about 30 ° or less) because the hydrodynamic loss accompanying the generation of vortices and the like can be reduced.

  The radiant tube heating devices 71 and 72 detect the differential pressure at both ends of the radiant tube 75 and / or abnormal combustion exhaust gas temperature, and automatically perform operations from purging with an inert gas to re-operation. An automatic operation control device (not shown) is provided.

  When a flame is formed in the radiant tube 75, the average temperature of the gas in contact with the inner wall of the tube increases, and the viscosity of the gas increases, so that the differential pressure across the radiant tube 75 increases. Therefore, by constantly monitoring the differential pressure at the both ends of the radiant tube 75 and / or the combustion exhaust gas temperature, misfiring can be detected quickly and purged with nitrogen gas or the like to prevent abnormal combustion (deflagration, detonation). Can be prevented.

  That is, the automatic operation control apparatus performs control according to the following procedure.

  (S1) An abnormality in differential pressure at both ends of the radiant tube 75 and / or combustion exhaust gas temperature is detected.

  (S2) The on-off valves 35 and 45 of the tubular flame burner 10 are closed, and the supply of fuel-containing gas and oxygen-containing gas is stopped.

  (S3) The heat load on the flame holding rod 21 is increased.

  (S4) Purge the radiant tube 75 with nitrogen gas. At that time, the amount of nitrogen gas is set to at least 5 times the internal volume of the radiant tube 75.

  (S5) With the on-off valves 35 and 45 of the tubular flame burner 10 opened and the flow rate adjusting valves 33 and 43 opened, the supply of the fuel-containing gas and the oxygen-containing gas is resumed, and the ignition operation is performed.

  (S6) After gradually increasing the opening of the flow rate adjusting valves 33 and 43 to increase the combustion load, the rated operating conditions are set.

  By performing the control as described above, an appropriate measure can be taken immediately after a misfire, abnormal combustion is prevented, repair costs are reduced, and operating costs are reduced. Further, by preventing abnormal combustion, it is possible to minimize the rate of product failure without proper heating.

  As described above, in the tubular flame burner 10 and the radiant tube heating devices 71 and 72 according to this embodiment, the flow rate fluctuation mitigation means 31 and 41 for mitigating rapid flow rate fluctuations of the fuel-containing gas or the oxygen-containing gas. Is installed in the combustion chamber 11 of the tubular flame burner 10, and a flame holding rod 21 having a surface temperature equal to or higher than the ignition temperature of the fuel to be applied is installed. It is not easily affected by this, and flame stability is greatly improved. Therefore, it is possible to obtain excellent effects such as improvement of safety and reliability, inexpensive operation costs and equipment costs, reduction of environmentally hazardous substances (NOx, particulate matter), energy saving, and improvement of product quality.

10, 10a, 10b Tubular flame burner 11 Combustion chamber 11a Front end of combustion chamber 11b Rear end of combustion chamber 12 Fuel-containing gas nozzle 13 Oxygen-containing gas nozzle 14 Tubular flame 21 Rod (flame holding rod)
DESCRIPTION OF SYMBOLS 22 Electric heater 23 Thermocouple 24 Heater controller 31 Flow rate fluctuation relaxation means 32 Flow rate measurement means 33 Flow rate adjustment valve 34 Check valve 35 On-off valve 36 Flow meter 37 Flow rate adjustment valve 38 Check valve 41 Flow rate fluctuation relaxation means 42 Flow rate measurement means 43 Flow control valve 44 Check valve 45 Open / close valve 46 Flow meter 47 Flow control valve 48 Check valve 51 Tubular flame burner 52 Normal burner 53 Inner cylinder 55 1/4 wavelength tube 56, 57 Ejector 61a, 61b Heat storage body 62 Switching valve 71 One-end type radiant tube type heating device 72 Double-end type radiant tube type heating device 75 Radiant tube 75a Straight pipe part 75b Curved pipe part 75c Taper pipes 76a, 76b

Claims (10)

It has a tubular combustion chamber with an open end, and includes a nozzle for injecting a fuel-containing gas into the combustion chamber and a nozzle for injecting an oxygen-containing gas, and the injection direction of each nozzle is a tangential direction of the circumferential surface of the combustion chamber In the matching tubular flame burner,
Flow rate fluctuation mitigating means for mitigating rapid flow rate fluctuations of the fuel-containing gas or oxygen-containing gas supplied to each nozzle, and a circular cross section tapered toward the downstream, inserted from the rear end of the combustion chamber into the combustion chamber A rod-shaped body, and a rod-shaped body heating means for maintaining the temperature of the outer surface of the rod-shaped body equal to or higher than the ignition temperature of the fuel,
A tubular flame burner characterized in that the rod-shaped body has an uneven surface. 2. The tubular flame burner according to claim 1, wherein an axial length of a portion of the rod-like body inserted into the combustion chamber is within a range of 2 to 10 times an inner diameter of the combustion chamber. . The tubular flame burner according to claim 1 or 2 , wherein a heat source of the rod-like body heating means is a burner or an electric heater. If the heat source of the rod-like member heating means is turned from the burner, the combustion exhaust gas of the burner, to claim 3, characterized in that is used as driving gas ejector for recirculating the flue gas of the tubular flame burner The tubular flame burner described. The tubular flame burner according to any one of claims 1 to 4 , wherein the oxygen-containing gas is preheated by combustion exhaust gas of the tubular flame burner. The tubular flame burner according to any one of claims 1 to 5 , wherein the fuel-containing gas and / or the oxygen-containing gas contains a combustion exhaust gas of a tubular flame burner. A radiant tube heating device, wherein the tubular flame burner according to any one of claims 1 to 6 is disposed at one or both ends of a radiant tube. The radiant tube heating device according to claim 7 , wherein when the tubular flame burners are disposed at both ends of the radiant tube, the tubular flame burners are alternately burned. The radiant tube heating device according to claim 7 or 8 , wherein an inner diameter of the bent tube portion of the radiant tube is smaller than that of the straight tube portion. An automatic operation control device is installed to automatically detect the differential pressure at both ends of the radiant tube and / or the abnormality of the combustion exhaust gas temperature and automatically perform the operation from purging with inert gas to re-operation. The radiant tube heating device according to any one of claims 7 to 9 , characterized by the following.

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