JP4826083B2 - Tubular object heating device - Google Patents

Description

  The present invention relates to an apparatus for heating a tubular object from both the inner and outer peripheral surfaces, and more particularly to an apparatus suitable for preheating a dip tube of a degassing furnace (RH furnace) for metal refining.

  The suction type vacuum refining method is a method in which a dip tube is immersed in a molten metal, and the molten steel in the pan is sucked into a vacuum tank and brought into contact with vacuum to perform vacuum refining.

  In the case of the degassing furnace RH method for metal refining, two dip pipes each functioning as a suction pipe and a discharge pipe for circulating the molten steel are used, but preheating is required as a countermeasure against thermal shock from the molten steel at the start of operation. Various methods for heating the dip tube have been studied.

  Patent Document 1 proposes a preheating heating device that enables heating from the outside of the dip tube when the dip tube is heated from the inside and the preheating on the outer surface is not sufficient and cracks and wear of the refractory occur. Yes.

FIG. 5 shows a burner hood 140 that is moved up and down by an electric cylinder 160 attached to a gantry (not shown) of the preheating drying apparatus and covers the dip tubes 120 and 130 of the RH furnace 100, and the dip tube 120 from below the burner hood 140. , 130 is shown, and an internal heating burner 150 for heating them from the inside is shown, and an external heating burner 170 for heating the dip tube from the outside surface is attached to the burner hood 140.
Japanese Patent Laid-Open No. 3-61311

  However, the external heating burner 170 attached to the burner hood 140 by a preheating drying apparatus, a part of which is shown in FIG. 5, is attached so that the jet outlet faces the dip tubes 120, 130. Although the swirl flow is formed by the closed space formed in 140, there is a concern that the heating uniformity from the outer surface is inferior.

  Therefore, the present invention aims to provide a heating device capable of heating a tubular object such as a dip tube almost uniformly over the entire length from both the inside and outside surfaces.

The object of the present invention can be achieved by the following means.
1 A tubular object heating device comprising a plurality of tubular flame burners concentrically so as to heat a tubular object from both the inner surface side and the outer surface side, and of the plurality of tubular flame burners, the tubular object is disposed from the outer surface side. The inner diameter of the combustion flame and / or combustion gas outlet of the tubular flame burner to be heated is larger than the outer diameter of the tubular object, and the inner diameter of the combustion gas outlet of the tubular flame burner that heats the tubular object from the inner surface side is that of the tubular object. The length of the tubular flame burner that is smaller than the inner diameter and that heats the end portion of the tubular object from the outer surface side is longer than the length of the tubular flame burner that is heated from the inner surface side disposed inside the tubular flame burner. Tubular object heating device.

  INDUSTRIAL APPLICABILITY According to the tubular object heating device of the present invention, the inner and outer surfaces of a tubular object such as a dip tube used in an RH degasser can be heated uniformly over the entire length, which is extremely useful industrially.

  The tubular object heating device of the present invention is characterized in that a plurality of tubular flame burners are arranged concentrically so that the tubular object can be heated from the inner and outer surfaces thereof. Hereinafter, it explains in detail using a drawing.

  FIG. 1 is a schematic cross-sectional view showing the structure of a tubular object heating device according to an embodiment of the present invention, and a case where it is applied to a heating device for an RH furnace will be described.

  In the figure, 1 is an RH furnace, 2 is a heating apparatus for an RH furnace constructed by contacting the outer peripheral surfaces of tubular flame burners 13 and 14, 11 and 12 are dip tubes, and 13 and 14 are dip tubes 11 and 12 heated from the outer surface side. The tubular flame burners 15 and 16 are arranged concentrically with respect to the tubular flame burners 13 and 14 and indicate tubular flame burners that heat the dip tubes 11 and 12 from the inner surface side.

Inside diameter d ₀ of the combustion flame and / or combustion gases blow-out port of the tubular flame burner 13 for heating the dip tube 11 from the outer surface side is larger than the outer diameter d ₁ of the dip tube 11, the tubular flame for heating the dip tube 11 from the inner side The inner diameter d ₃ of the combustion gas outlet of the burner 15 is made smaller than the inner diameter d ₂ of the dip tube 11. The dimensional relationship between the dip tube 12 and the tubular flame burners 14 and 16 is the same.

  Each tubular flame burner 13-16 is blown with a fuel gas a and an oxygen-containing gas b or a mixture of these in advance to form a tubular combustion flame. In the combination of the tubular flame burners 13 and 15, 14 and 16 arranged concentrically, the tubular flame burner of the fuel gas a and the oxygen-containing gas b is blown so that the rotation directions of the combustion flame and / or the combustion gas coincide with each other. It is preferable to match the directions.

The length l ₀ of the tubular flame burner 13 (14) is made longer than the length l ₁ of the tubular flame burner 15 (16), and the end of the dip tube 11 (12) is placed in the combustion chamber of the tubular flame burner 13 (14). When inserted, the dip tube 11 (12) can be efficiently heated from the outer surface side, and preferably a multi-stage tubular flame burner can be used.
FIG. 3 schematically shows the structure of a multistage tubular flame burner in which a small diameter tubular flame burner is attached to the end of a large diameter tubular flame burner so that a dip tube can be inserted into the combustion chamber of the large diameter tubular flame burner. explain. 4A is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 4B is a cross-sectional view taken along the line BB in FIG.

  In the figure, 17 is a large-diameter tubular flame burner, 18 is a combustion chamber, 18a is the front end of the combustion chamber, 18b is the rear end of the combustion chamber, 19a and 19c are fuel gas injection nozzles, 19b and 19d are oxygen-containing gas injection nozzles, 20 is a slit, 21 is a small-diameter tubular flame burner, 22 is a combustion chamber of a small-diameter tubular flame burner, 22a is a front end of a combustion chamber of a small-diameter tubular flame burner, 22b is a rear end of a combustion chamber of a small-diameter tubular flame burner, and 23a and 23c. Is a fuel gas blowing nozzle of a small diameter tubular flame burner, 23b and 23d are oxygen containing gas blowing nozzles of the small diameter tubular flame burner, and 24 is a slit of the small diameter tubular flame burner.

  The large-diameter tubular flame burner 17 separately blows combustion gas and oxygen-containing gas into the vicinity of the rear end 18b of the combustion chamber 18 and the tubular combustion chamber 18 whose front end 18a is opened and serves as a combustion gas discharge port. Nozzles 19a-d.

  Among these nozzles 19a to 19d, 19a and 19c are fuel gas injection nozzles, 19b and 19d are oxygen-containing gas injection nozzles, and elongated slits 20 along the tube axis direction as nozzle outlets have the same circumference of the combustion chamber 18. It is formed in the upper four places.

  The ejection directions of the nozzles 19 a to 19 d are provided so as to be tangential to the inner peripheral surface of the combustion chamber 18 and the same rotation direction, and the fuel gas and the oxygen-containing gas blown from the nozzles 19 a to 19 d are within the combustion chamber 18. A swirl flow is formed while being mixed in a region close to the peripheral surface, and when ignited by an ignition device (not shown), a tubular flame is formed in the combustion chamber 18, and the combustion gas flows from the tip 18 a of the combustion chamber 18. Discharged.

  The small-diameter tubular flame burner 21 has a front end portion 22a connected to the rear end 18b of the large-diameter tubular flame burner 18, and combustion gas 22 serving as a combustion gas discharge port and combustion gas near the rear end 22b of the combustion chamber 22 It has nozzles 23a-d for blowing oxygen-containing gas separately.

  Among these nozzles 23a to 23d, 23a and 23c are fuel gas blowing nozzles, 23b and 23d are oxygen-containing gas blowing nozzles, and elongated slits 24 along the tube axis direction serve as nozzle outlets on the same circumference of the combustion chamber 22. It is formed in the upper four places.

  The ejection directions of the nozzles 23 a to 23 d are provided so as to be tangential to the inner peripheral surface of the combustion chamber 22 and the same rotation direction, and the fuel gas and the oxygen-containing gas blown from the nozzles 23 a to 23 d are within the combustion chamber 22. A swirl flow is formed while being mixed in a region close to the peripheral surface, and when ignited by an ignition device (not shown), a tubular flame is formed in the combustion chamber 22, and the combustion gas flows from the tip 22 a of the combustion chamber 22. It is discharged from the tip 18a via the combustion chamber 18 of the large diameter tubular flame burner 17.

  In the above description, the fuel gas and the oxygen-containing gas are blown from separate nozzles, but a mixture previously mixed may be blown.

  FIG. 2 shows a top view of a heating apparatus for an RH furnace according to another embodiment of the present invention. In the figure, 2a is a heating device for the RH furnace, 15a and 16a are tubular flame burners for heating the dip tube from the inner surface side, 13a and 14a are tubular flame burners for heating the dip tube from the outer surface side, 131 and 141 are fuel gases a, An inlet (slit) for blowing the oxygen-containing gas b or a mixture of these in advance into the combustion chamber 151 is shown.

  The RH furnace heating device 2a includes two independent tubular flame burners 15a and 16a for heating the dip tube from the inner surface side, and tubular flame burners 13a and 14a for heating the dip tube from the outer surface side, and the tubular flame burner 13a, 14a forms a combustion chamber 151 comprising one continuous space surrounding the two tubular flame burners 15a, 16a.

  In the combustion chamber 151, the inlet (slit) 131 is disposed so as to form a combustion flame and / or a combustion gas concentric with the combustion flame and / or the combustion gas by the tubular flame burner 15a. The inlet (slit) 141 is also arranged so as to form a combustion flame and / or combustion gas concentric with the combustion flame and / or combustion gas by the tubular flame burner 16a.

The figure which shows one Embodiment of this invention. The figure which shows other embodiment of this invention. The figure which shows the structure of a multistage type tubular flame burner. It is a figure which shows the structure of a multistage tubular flame burner, (a) is an AA arrow directional view of FIG. 3, (b) is a BB arrow directional view of FIG. Preheat drying device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 RH furnace 2, 2a Heating apparatus for RH furnaces 11, 12 Dip tube 13, 13a, 14, 14a, 15, 15a, 16, 16a Tubular flame burner
131, 141 Blowing port 151 Combustion chamber 17 Large diameter tubular flame burner 18 Combustion chamber of large diameter tubular flame burner 18a Front end portion of combustion chamber of large diameter tubular flame burner 18b Rear end of combustion chamber of large diameter tubular flame burner 19a, 19c Large-diameter tubular flame burner fuel gas injection nozzle 19b, 19d Large-diameter tubular flame burner oxygen-containing gas injection nozzle 20, 24 Slit 21 Small-diameter tubular flame burner 22 Small-diameter tubular flame burner combustion chamber 22a Small-diameter tubular flame burner combustion chamber Front end 22b Rear end of combustion chamber of small diameter tubular flame burner 23a, 23c Fuel gas blowing nozzle of small diameter tubular flame burner 23b, 23d Oxygen containing gas blowing nozzle of small diameter tubular flame burner a Fuel gas b Oxygen containing gas 160 Electric cylinder
100 RH furnace
120, 130 Dip tube
140 Burner food
150 Internal heating burner 170 External heating burner

Claims (1)

A tubular object heating apparatus comprising a plurality of tubular flame burners concentrically so as to heat a tubular object from both the inner surface side and the outer surface side , wherein the tubular object is heated from the outer surface side among the plurality of tubular flame burners. The inner diameter of the combustion flame and / or the combustion gas outlet of the tubular flame burner is larger than the outer diameter of the tubular object, and the inner diameter of the combustion gas outlet of the tubular flame burner for heating the tubular object from the inner surface side is the inner diameter of the tubular object The tubular flame burner which is smaller and has a longer length than the tubular flame burner which heats the end of the tubular object from the outer surface side and which is heated from the inner surface side disposed therein. Object heating device.

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