WO2013018754A1 - Combustion device and runner cleaning method for vessel for molten metal - Google Patents

Abstract

The problem addressed by the present invention is being able to suitably clean a runner of a vessel for molten metal by efficiently melting and eliminating base metal, which has adhered to the runner of the vessel for molten metal, by a combustion device in a short period of time. The present invention uses a combustion device provided with a plurality of inner flame combustion nozzles (13a), which have a combustion assisting gas ejection nozzle (11a) that can eject a combustion assisting gas at high velocity and a fuel gas ejecting nozzle (12a) that ejects fuel gas, at the center of the tip of a combustion burner (10) and provided with a plurality of outer flame combustion nozzles (13b), which have a combustion assisting gas ejection nozzle (11b) that can eject a combustion assisting gas at high velocity and a fuel gas ejection nozzle (12b) that ejects fuel gas, on the outside periphery of these inner flame combustion nozzles.

Description

Combustion apparatus and runner cleaning method for molten metal container

The present invention relates to a combustion apparatus used to scour ingots attached to a runner of a molten metal container such as a tundish, and to shave ingots attached to a runner of a molten metal container by the combustion apparatus. The present invention relates to a runner cleaning method for a molten metal container that removes the molten metal container to prevent clogging of the molten metal container. In particular, the present invention is characterized in that the metal bar adhering to the runner of the molten metal container is efficiently scraped in a short time so that the runner in the molten metal container can be cleaned appropriately.

Conventionally, in a molten metal container such as a tundish, as shown in Patent Document 1, heat is taken away by a refractory or the like in a portion of the runner through which the molten metal passes, so that the molten metal is solidified and ground in the runway. There was a problem that gold adhered and this caused clogging of the runway. Further, as another form of the runner, there is a pouring spout (tundish upper nozzle) as shown in Patent Document 2, which has the same problem.

For this reason, it has been conventionally performed to remove the metal attached to the runner of the molten metal container and prevent the runner from being clogged in the molten metal container.

In removing the metal from the runner in this way, conventionally, the metal from the runner was heated and melted and removed by a combustion device using a combustion burner. However, there is a problem that it takes a lot of time to melt and remove the metal attached to the runner by heating and melting.

Also, in order to quickly heat and melt the metal attached to the runner, oxygen was blown from the opposite side of the combustion apparatus using an oxygen jet lance.

However, when oxygen is sprayed using an oxygen jet lance in this way, the operator sets the oxygen jet lance at an appropriate position to perform oxygen spraying, which is cumbersome and is difficult to heat and melt the metal. The accompanying smoke, etc., may have an adverse effect on workers.

Conventionally, as shown in Patent Document 2, a seal cover is provided on the outlet side of a tundish pouring port (tundish upper nozzle) that becomes a runner, and adheres to the runner through the seal cover. There has also been proposed a method in which a runner is washed by spraying a plasma jet using a non-oxidizing gas, a reducing gas, or a mixed gas thereof as a raw material gas from a plasma torch.

However, when a seal cover is provided on the outlet side of the pouring spout of the tundish, which becomes a runway, and the above source gas is sprayed from the plasma torch as a plasma jet, the work is troublesome and expensive. At the same time, there was a problem that the metal attached to the runner could not be removed quickly.

JP-A-9-220647 JP 11-138240 A

The object of the present invention is to solve the above-described problems in the case where the bare metal adhering to the runner in a molten metal container such as a tundish is to be scraped.

That is, according to the present invention, when the metal stick attached to the runner of the molten metal container is removed by the combustion device, the metal stick attached to the runner of the molten metal container is efficiently scraped in a short time. It is an object of the present invention to appropriately clean the runner in the molten metal container.

In the combustion apparatus according to the present invention, in order to solve the above-described problems, a combustion nozzle for inner flame is provided at the center of the tip of the combustion burner, and an outer flame is provided on the outer peripheral side of the combustion nozzle for inner flame. A combustion nozzle was provided for controlling the internal flame and the external flame independently.

In such a combustion apparatus, a plurality of combustion nozzles for internal flames having an auxiliary combustion gas discharge nozzle for discharging auxiliary combustion gas and a fuel gas discharge nozzle for discharging fuel gas at the center of the tip of the combustion burner are provided. A plurality of external flame combustion nozzles having an auxiliary combustion gas discharge nozzle for discharging auxiliary combustion gas and a fuel gas discharge nozzle for discharging fuel gas are provided on the outer peripheral side of the combustion nozzle for inner flame. Can be.

Here, in this combustion apparatus, oxygen, air, or the like can be used as the auxiliary combustion gas. However, in order to improve the combustion property of the fuel gas, it is preferable to use oxygen as the auxiliary combustion gas.

Moreover, in this combustion apparatus, in order to discharge the combustion-supporting gas from each of the above-mentioned combustion-supporting gas discharge nozzles, in order to efficiently scrape the bare metal adhering to the runner of the molten metal container in a short time and blow it forward. It is preferable to discharge the combustion-supporting gas from each of the combustion-supporting gas discharge nozzles at a high speed. On the other hand, if the speed at which the combustion-supporting gas is discharged becomes too fast, the flame is lifted and stable combustion cannot be performed. There is a fear. For this reason, it is preferable that the discharge speed of the auxiliary combustion gas discharged from each auxiliary combustion gas discharge nozzle is in the range of 450 to 500 m / s.

In addition, even when the auxiliary combustion gas is discharged from the auxiliary combustion gas discharge nozzle at a high speed as described above, the combustion gas is burned at the tip of each of the combustion nozzles so that the fuel gas is stably burned. It is preferable to provide a concave portion.

In addition, when a plurality of combustion nozzles for inner flame and outer flame are provided at the tip of the combustion burner as described above, the auxiliary combustion gas discharge nozzle and the fuel gas in each combustion nozzle for inner flame and outer flame In order to appropriately supply the auxiliary combustion gas and the fuel gas to the discharge nozzle, respectively, an inner flame auxiliary combustion gas supply pipe for supplying the auxiliary combustion gas to the auxiliary combustion gas discharge nozzle in the inner flame combustion nozzle, , An inner flame fuel gas supply pipe for supplying fuel gas to the fuel gas discharge nozzle in the combustion nozzle for inner flame, and an outer flame for supplying auxiliary combustion gas to the auxiliary combustion gas discharge nozzle in the combustion nozzle for outer flame The auxiliary combustion gas supply pipe and the outer flame fuel gas supply pipe for supplying the fuel gas to the fuel gas discharge nozzle in the combustion nozzle for the outer flame can have a multi-tube structure.

Further, in this combustion apparatus, the adjacent combustion nozzles perform appropriate combustion with each other, and in order to be able to complement the combustion with each other, the inside diameter of the auxiliary combustion gas discharge nozzle is D, and the adjacent combustion nozzles It is preferable to satisfy the condition of 3 ≦ P / D ≦ 5, where P is the interval between the auxiliary combustible gas discharge nozzles.

The combustion device of the present invention is used as a runner cleaning device for a molten metal container. In general, the cross section of the runner of the molten metal container is a circle having a diameter of 50 mm or more and 400 mm or less, or a surface having the same area as the circle.

In the molten metal container runner cleaning method according to the present invention, the above-mentioned combustion apparatus is used to scrape and remove the metal that has adhered to the molten metal container runner.

Here, when removing the metal attached to the runner of the molten metal container by the above-mentioned combustion device, the above-mentioned internal metal It is preferable to make the combustion in the combustion nozzle for flame stronger than the combustion in the combustion nozzle for external flame. Also, in the initial stage of scraping the metal that has adhered to the runner of the molten metal container, only the combustion in the combustion nozzle for the inner flame is performed, and then only the combustion in the combustion nozzle for the outer flame is performed. It can also be.

In the combustion apparatus according to the present invention, a combustion nozzle for inner flame is provided at the center of the tip of the combustion burner, and a combustion nozzle for outer flame is provided on the outer peripheral side of the combustion nozzle for inner flame. When the molten metal container runner is cleaned using this combustion device, the above-mentioned metal is attached to the molten metal container in the initial stage of scraping. The combustion in the combustion nozzle for the inner flame can be made stronger than the combustion in the combustion nozzle for the outer flame. Furthermore, in the initial stage of scraping the metal that has adhered to the runner of the molten metal container, only the combustion in the combustion nozzle for the inner flame is performed, and then only the combustion in the combustion nozzle for the outer flame is performed. It can also be.

Further, in the combustion apparatus according to the present invention, each of the auxiliary combustion gases in the plurality of inner flame combustion nozzles provided at the tip of the combustion burner and the plurality of outer flame combustion nozzles provided on the outer peripheral side thereof. When the auxiliary gas is discharged from the discharge nozzle to burn the fuel gas, the auxiliary gas can be discharged from the auxiliary gas discharge nozzle at a high speed and the fuel gas can be strongly burned, In this way, when the auxiliary combustion gas is discharged from the auxiliary combustion gas discharge nozzle at a high speed, even if the flame in some combustion nozzles becomes unstable, the flame is supplemented by the combustion in the adjacent combustion nozzle. It is possible to perform stable combustion in each combustion nozzle without flying.

When using the combustion apparatus according to the present invention, when removing the bare metal adhering to the runner of the molten metal container by removing the metal, a plurality of combustion nozzles for internal flames provided at the tip of the combustion burner, In the combustion nozzle for external flames, the combustion gas can be burned by discharging the combustion gas from the combustion gas discharge nozzle at a high speed without using an oxygen jet lance as before. Due to the combustion in the combustion nozzles for the inner flame and the combustion nozzles for the outer flame provided at the tip of the burner, the bare metal attached to the runner of the molten metal container is quickly melted. The metal bar attached to the runner of the molten metal container is efficiently scraped and removed in a short time, and the runner in the molten metal container can be cleaned appropriately.

In the combustion device concerning one embodiment of the present invention, it is a schematic front view of the tip side of a combustion burner. FIG. 4 is a cross-sectional explanatory view of a combustion nozzle provided at the tip of a combustion burner in the combustion device in the embodiment. In the combustion apparatus according to the above-described embodiment, the auxiliary combustion gas discharge nozzle in the combustion nozzle for the inner flame provided at the tip of the combustion burner, the auxiliary combustion gas discharge nozzle and the combustion nozzle in the combustion nozzle for the fuel and outer flame, It is a schematic sectional explanatory drawing which showed the structure which supplies auxiliary combustion gas and fuel gas, respectively. In the combustion apparatus in the above embodiment, the amount of auxiliary combustion gas and fuel gas supplied to the combustion nozzle for inner flame is controlled by the control device, and the auxiliary combustion gas and fuel supplied to the combustion nozzle for outer flame are controlled. It is the block diagram which showed the structure which controls the quantity of gas. It is a schematic sectional explanatory view showing the state where the metal which adheres to the runway of the molten metal container using the combustion device in the above-described embodiment is scoured. In the initial stage of scraping off the metal attached to the runner of the molten metal container using the combustion apparatus in the above embodiment, the combustion in the combustion nozzle for the inner flame is stronger than the combustion in the combustion nozzle for the outer flame. It is the schematic explanatory drawing which showed the state which carried out.

Hereinafter, a combustion apparatus according to an embodiment of the present invention and a molten metal container runner cleaning method that uses the combustion apparatus to remove metal that has adhered to the runner of a molten metal container by scouring, based on the attached drawings. This will be specifically described. In addition, the runner cleaning method of the combustion apparatus and molten metal container which concerns on this invention is not limited to what was shown to the following embodiment, In the range which does not change the summary of invention, it can change and implement suitably.

In the combustion apparatus in this embodiment, as shown in FIGS. 1 to 3, a Laval nozzle capable of discharging a combustion-supporting gas composed of oxygen or air at a high speed higher than the sonic speed is used at the center of the tip of the combustion burner 10. A plurality of combustion flame nozzles 13a each having an auxiliary combustion gas discharge nozzle 11a and a fuel gas discharge nozzle 12a for discharging fuel gas are provided, and oxygen is provided on the outer peripheral side of the combustion flame nozzle 13a. A combustion nozzle for an external flame having an auxiliary combustion gas discharge nozzle 11b using a Laval nozzle capable of discharging an auxiliary combustion gas composed of gas and air at a speed higher than the speed of sound, and a fuel gas discharge nozzle 12b for discharging fuel gas A cooling unit 14 for cooling the combustion burner 10 is provided on the outer peripheral side of the combustion nozzle 13b for the external flame. Only to have.

Here, in each of the combustion nozzles 13a and 13b for the inner flame and the outer flame, as shown in FIG. 2, combustion concave portions 15a and 15b are provided at the respective tip portions, and this combustion concave portion 15a. , 15b, the auxiliary gas is discharged from the auxiliary gas discharge nozzles 11a, 11b and the fuel gas is discharged from the fuel gas discharge nozzles 12a, 12b. The fuel gas is discharged from the combustion recesses 15a, 15b. It is made to burn in contact with auxiliary gas.

Further, the auxiliary combustion gas is supplied to the auxiliary combustion gas discharge nozzles 11a and 11b in the combustion nozzles 13a and 13b for the inner flame and the outer flame, and the fuel gas is supplied to the fuel gas discharge nozzles 12a and 12b. In supplying, in this embodiment, as shown in FIG. 3, the auxiliary flame auxiliary gas supply pipe 16a for supplying auxiliary gas to the auxiliary gas discharge nozzle 11a in the inner flame combustion nozzle 13a, A combustion gas is supplied to the fuel gas supply pipe 17a for the inner flame for supplying the fuel gas to the fuel gas discharge nozzle 12a in the combustion nozzle 13a for the inner flame, and to the auxiliary gas discharge nozzle 11b in the combustion nozzle 13b for the outer flame. An external flame fuel gas supply pipe 16b to be supplied, and an external flame fuel gas to supply fuel gas to the fuel gas discharge nozzle 12b in the external flame combustion nozzle 13b. A multi-tube structure in which the supply pipe 17b is concentrically arranged and connected to the nozzle portion 10a at the tip of the combustion burner 10 provided with the combustion nozzles 13a and 13b for inner flame and outer flame as described above. I am letting.

In the combustion apparatus of this embodiment, as shown in FIG. 4, the control device 20 causes the combustion flame nozzle 13 a and the combustion nozzle 13 b for the external flame to be supplied from the auxiliary combustion gas supply device 21. While controlling the quantity of the auxiliary combustion gas supplied to each auxiliary combustion gas discharge nozzle 11a, 11b, each fuel in the combustion nozzle 13a for inner flames and the combustion nozzle 13b for outer flames from the fuel gas supply device 22 The amount of fuel gas supplied to the gas discharge nozzles 12a and 12b is controlled.

Then, as shown in FIG. 5, the base metal 33 attached to the portion of the runner 32 for passing the molten metal provided in the refractory 31 in the molten metal container 30 such as a tundish is used with the combustion apparatus of this embodiment. In the cutting, the front end of the combustion burner 10 is set toward the runner 32, and the combustion recesses in the combustion nozzles 13a and 13b for the inner flame and the outer flame are set. 15a and 15b discharge auxiliary gas from the auxiliary gas discharge nozzles 11a and 11b, and discharge the fuel gas from the fuel gas discharge nozzles 12a and 12b, respectively. The fuel gas is used for combustion for inner flame and outer flame. The metal bar 33 burned in the nozzles 13a and 13b and adhered to the portion of the runner 32 is scraped off.

Here, as described above, the combustion gas is discharged from the combustion gas discharge nozzles 11a and 11b to the combustion recesses 15a and 15b in the combustion nozzles 13a and 13b for the inner flame and the outer flame, and the fuel gas. When the fuel gas is discharged from the discharge nozzles 12a and 12b, the auxiliary combustion gas and the fuel gas collide with each other in the combustion recesses 15a and 15b and are mixed with each other. In 13b, a stable flame can be obtained, and the flame is prevented from flashing back into the combustion burner 10.

Here, if the auxiliary combustion gas is discharged from the auxiliary combustion gas discharge nozzles 11a and 11b provided in the combustion nozzles 13a and 13b for the inner flame and the outer flame, respectively, at the high speed higher than the sonic speed, In addition, due to the high-speed flame in each of the combustion nozzles 13a, 13b for the external flame, the metal 33 attached to the runner 32 is quickly melted, and the metal 33 attached to the runner 32 is quickly It will be scraped.

In addition, when the auxiliary combustion gas is discharged from the auxiliary combustion gas discharge nozzles 11a and 11b at a speed higher than the sound speed as described above, the above-described combustion nozzles 13a and 13b for the inner flame and the outer flame are used. The flame is held in the combustion recesses 15a and 15b, and the flame is not lost by the combustion in the adjacent combustion nozzles 13a and 13b, and the combustion nozzles 13a and 13b are stabilized. Combustion can be performed.

Here, if the discharge speed at which the auxiliary combustion gas is discharged from each of the auxiliary combustion gas discharge nozzles 11a and 11b becomes slow, the molten metal 33 as described above cannot be pushed forward and blown off appropriately. On the other hand, if the discharge speed becomes too fast, the flames at the combustion nozzles 13a and 13b are lifted and the combustion becomes unstable, thereby reducing the combustion efficiency, lowering the melting efficiency and increasing the noise. For this reason, it is preferable that the discharge speed at which the auxiliary combustion gas is discharged from the auxiliary combustion gas discharge nozzles 11a and 11b is in the range of 450 to 500 m / s.

Further, in each of the combustion nozzles 13a, 13b for the inner flame and the outer flame, appropriate combustion is performed in the adjacent combustion nozzles 13a, 13a, 13b, 13b, and the combustion can be complemented with each other. In order to do this, as shown in FIG. 1, the inner diameters of the auxiliary combustion gas discharge nozzles 11a and 11b are D, and the combustion nozzle 13a for the inner flame and the combustion nozzle 13b for the outer flame are adjacent to each other. When the interval between the auxiliary combustion gas discharge nozzles 11a, 11a, 11b, and 11b in 13a, 13a, 13b, and 13b is P, it is preferable to satisfy the condition of 3 ≦ P / D ≦ 5.

As described above, when the fuel gas is burned in the combustion nozzles 13a and 13b for the inner flame and the outer flame, the metal 33 attached to the portion of the runner 32 is subjected to the initial cutting. At this stage, the control device 20 controls the amount of auxiliary combustion gas discharged from the inner flame auxiliary combustion gas discharge nozzle 11a and the amount of fuel gas discharged from the inner flame fuel gas discharge nozzle 12a. The amount of the auxiliary combustion gas discharged from the flame auxiliary combustion gas discharge nozzle 11b and the amount of the fuel gas discharged from the outer flame fuel gas discharge nozzle 12b are larger than those shown in FIG. It is preferable to make the combustion in the combustion nozzle 13a stronger than the combustion in the combustion nozzle 13b for the external flame.

In this way, even if the opening of the runner 32 is reduced by the metal 33 attached to the runner 32, the ground at the center of the runner 32 is caused by the combustion flame in the combustion nozzle 13a for inner flame. The metal 33 is quickly melted, the runner 32 is penetrated, the opening gradually increases, the metal 33 attached to the runner 32 is appropriately welded, and the flame is prevented from backlashing. Will come to be. Moreover, since the surrounding air is prevented from being caught by the external flame by the combustion nozzle 13b for the external flame, the speed of the internal flame is attenuated or the temperature is reduced.

Further, after the metal bar 33 at the center of the runner 32 is sliced in this way to enlarge the through hole in the runner 32 to which the metal bar 33 adheres to a certain extent, the auxiliary combustion gas discharge nozzle 11b for external flame is used. The amount of the auxiliary combustion gas discharged from the outer flame and the amount of the fuel gas discharged from the outer flame fuel gas discharge nozzle 12b are increased to strengthen the combustion in the outer flame combustion nozzle 13b, and the peripheral portion of the runner 32 The ingot 33 attached to the surface is scraped.

In the above-described embodiment, in the initial stage of cutting the metal 33 attached to the runner 32, the combustion in the combustion nozzle 13a for the inner flame is made stronger than the combustion in the combustion nozzle 13b for the outer flame. However, the combustion in the combustion nozzle 13b for the outer flame may be made stronger than the combustion in the combustion nozzle 13a for the inner flame in the later stage of cutting the metal 33 attached to the runner 32.

In addition, after the bare metal 33 attached to the runner 32 is initially scraped, only the combustion in the combustion nozzle 13a for inner flame is performed, and the through hole in the runner 32 to which the bare metal 33 is attached is enlarged to a certain extent. Further, it is possible to perform only the combustion in the combustion nozzle 13b for the external flame.

As described above, in the present invention, the combustion in the combustion nozzle 13a for the inner flame and the combustion in the combustion nozzle 13b for the outer flame are controlled independently, and the ground where the opening of the runner 32 is attached is controlled. When it is reduced by the gold 33, the inner flame caused by the combustion nozzle 13a for the inner flame is made stronger than the outer flame caused by the combustion nozzle 13b for the outer flame, and the metal 33 is melted at the center of the runner 32. Thus, the fuel is concentrated and used to gradually enlarge the opening that penetrates the runner 32. When the opening that penetrates the runner 32 becomes large to some extent, the combustion in the combustion nozzle 13b for the external flame is performed. Is made stronger than the combustion in the combustion nozzle 13a for the internal flame, so that the fuel is concentrated on the opening extending through the runner 32. Therefore, the fuel can be used efficiently, and the runner 32 can be cleaned in a shorter time than before.

DESCRIPTION OF SYMBOLS 10 Combustion burner 11a, 11b Combustion gas discharge nozzle 12a, 12b Fuel gas discharge nozzle 13a, 13b Combustion nozzle 14 Cooling part 15a, 15b Combustion recessed part 16a Inner flame auxiliary gas supply pipe 16b Outer flame auxiliary gas supply Pipe 17a Fuel gas supply pipe for inner flame 17b Fuel gas supply pipe for outer flame 20 Control device 21 Auxiliary gas supply device 22 Fuel gas supply device 30 Molten metal container 31 Refractory material 32 Runway 33 Metal D D Auxiliary gas discharge nozzle Inner diameter P Distance between adjacent auxiliary combustion gas discharge nozzles

Claims (8)

A combustion nozzle for the inner flame is provided at the center of the tip of the combustion burner, and a combustion nozzle for the outer flame is provided on the outer peripheral side of the combustion nozzle for the inner flame so that the inner flame and the outer flame are independent. The combustion apparatus characterized by being able to control. 2. The combustion apparatus according to claim 1, wherein there are a plurality of combustion nozzles for inner flame having an auxiliary combustion gas discharge nozzle for discharging auxiliary combustion gas and a fuel gas discharge nozzle for discharging fuel gas at a central portion of the tip of the combustion burner. A plurality of combustion nozzles for outer flames that are provided and have an auxiliary combustion gas discharge nozzle for discharging auxiliary combustion gas and a fuel gas discharge nozzle for discharging fuel gas on the outer peripheral side of the combustion nozzle for inner flame A combustion apparatus characterized by being provided. The combustion apparatus according to claim 2, wherein a combustion recess is provided at a tip of each combustion nozzle, and the auxiliary combustion gas discharge nozzle and the fuel gas discharge nozzle are provided in the combustion recess. Combustion device characterized by that. The combustion apparatus according to claim 2 or claim 3, wherein an auxiliary flame gas supply pipe for supplying an auxiliary flame to the auxiliary gas discharge nozzle in the inner flame combustion nozzle, and an inner flame auxiliary gas supply pipe. An internal flame fuel gas supply pipe that supplies fuel gas to the fuel gas discharge nozzle in the combustion nozzle, and an external flame auxiliary gas supply that supplies auxiliary gas to the auxiliary gas discharge nozzle in the outer flame combustion nozzle A combustion apparatus, wherein a pipe and an outer flame fuel gas supply pipe for supplying fuel gas to a fuel gas discharge nozzle in an outer flame combustion nozzle have a multi-tube structure. The combustion apparatus according to any one of claims 2 to 4, wherein a discharge speed of the auxiliary combustion gas discharged from the auxiliary combustion gas discharge nozzle is in a range of 450 to 500 m / s. Combustion device. 6. The combustion apparatus according to claim 2, wherein the inner diameter of the auxiliary combustion gas discharge nozzle is D, and the interval between the auxiliary combustion gas discharge nozzles in adjacent combustion nozzles is P. And 3 ≦ P / D ≦ 5 is satisfied. Using the combustion apparatus according to any one of claims 1 to 6, the combustion in the combustion nozzle for the internal flame is performed at an initial stage in which the metal attached to the runner of the molten metal container is scraped. A method for cleaning a molten metal container, characterized in that it is stronger than combustion in a combustion nozzle for external flame. The molten metal container runner cleaning method according to claim 7, wherein at the initial stage of scraping the metal attached to the molten metal container runner, only combustion in the combustion nozzle for the internal flame is performed, and thereafter A method for cleaning a molten metal container, characterized by performing only combustion in a combustion nozzle for external flame.

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