Flame-spraying lance

Abstract

To provide a flame-spraying lance capable of gas-cooling a tip side lance when the tip side land is independently inserted first in a split-type lance.SOLUTION: A flame-spraying lance A is used for a flame-spraying device for forming a refractory composition by injecting and combusting a mixture C formed by mixing raw material powder containing refractory powder and combustible powder with combustion-supporting carrier gas. The flame-spraying lance A includes a tip side lance 1 having an injection part 11 for injecting the mixture C on a tip side, and a base end side lance 2 detachably connected to a base end of the tip side lance 1. The tip side lance 1 includes an inner pipe 12 for flowing the mixture C, and an outer pipe 13 positioned outside the inner pipe 12. In this constitution, gas G for cooling the tip side lance 1 is introduced to a gap 14 between the inner pipe 12 and the outer pipe 13 from the base end of the tip side lance 1 or its vicinity.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a spraying lance used in a spraying device that forms a refractory composition by spraying and burning a mixture of a raw material powder containing a refractory powder and a combustible powder and a supporting combustion carrier gas. In this specification, the "spraying lance" is also simply referred to as a "lance".

Background Art

[0002] Such a spraying device is widely used for repairing the furnace walls of kilns such as coke ovens. By the way, for example, in repairing the furnace wall of the carbonization chamber of a coke oven, when repairing the back side (the central part of the carbonization chamber) from the kiln mouth, it is necessary to use a long lance corresponding to the distance from the kiln mouth to the central part of the carbonization chamber (for example, 6 to 10 m). However, when using such a long lance to repair the central part of the carbonization chamber from the kiln mouth, most of the lance is inserted into the carbonization chamber of the coke oven, and in particular, the tip side of the lance is heated by the furnace heat in the central part of the carbonization chamber. When the tip side of the lance is abnormally heated, the risk of flashback (a phenomenon in which ignition progresses in the direction opposite to the conveying direction of the mixture) increases. Therefore, in particular, gas-cooled lances are often used for coke oven repair lances.

[0003] Conventionally, as a gas-cooled lance, it has a double-tube structure including an inner tube for flowing the mixture and an outer tube located outside the inner tube, and cooling gas is introduced from the base end of the double tube into the gap between the inner tube and the outer tube. A lance composed of a single double tube (a single piece) is disclosed in Patent Document 1. In addition, in Patent Document 2, in recognition of the problem that a single-piece lance is inconvenient for carrying to the coke oven, which is the repair location, and storage when not in use, a split-type lance that divides the lance in the longitudinal direction and reconnects it during spraying work is disclosed.

[0004] However, since the split lance disclosed in Patent Document 2 is configured to introduce cooling gas from its base end, there is a problem that when the tip-side lance of the two-split lance is inserted first alone, the tip-side lance cannot be gas-cooled. That is, in the split lance of Patent Document 2, the tip-side lance cannot be gas-cooled unless the two-split lances (the tip-side lance and the base-end side lance) are reconnected. Therefore, when the tip-side lance is inserted first alone, the tip-side lance may be abnormally heated and backfire may occur.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved by the present invention is to provide a spraying lance capable of gas-cooling the tip-side lance when the tip-side lance is inserted first alone in a split lance.

Means for Solving the Problems

[0007] According to one aspect of the present invention, the following spraying lance is provided. A spraying lance used in a spraying apparatus for forming a refractory composition by spraying and burning a mixture of a raw material powder containing a refractory powder and a combustible powder and a supporting combustion carrier gas, including a tip-side lance having an injection part for injecting the mixture at the tip side, and a base-end side lance removably connected to the base end of the tip-side lance, wherein the tip-side lance includes an inner tube for flowing the mixture and an outer tube located outside the inner tube. A spraying lance, characterized in that a gas for cooling the tip-side lance is introduced into the gap between the inner pipe and the outer pipe from the base end portion of the tip-side lance or the vicinity thereof.

Advantages of the Invention

[0008] According to the present invention, since a gas for cooling the tip-side lance is introduced from the base end portion of the tip-side lance or the vicinity thereof, the tip-side lance can be gas-cooled when the tip-side lance is inserted first alone.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] FIG. 1 conceptually shows the usage state of a spraying lance according to an embodiment of the present invention. The spraying lance A shown in the figure is used for a spraying device for repairing the furnace wall of the carbonization chamber B of a coke oven, and includes a tip-side lance 1 and a base-end side lance 2 removably connected to the base end portion of the tip-side lance 1. A mixture supply hose D for supplying a mixture C obtained by mixing a raw material powder containing a refractory powder and a combustible powder (for example, a metal powder) and a supporting combustion carrier gas (oxygen gas) is connected to the base end portion of the base-end side lance 2. Further, the tip-side lance 1 has an injection portion 11 for injecting the mixture C at the tip side. Then, the mixture C injected from the injection portion 11 burns and melts, adheres to the furnace wall of the carbonization chamber B, and a refractory composition is formed.

[0011] In this embodiment, the tip-side lance 1 has a double-tube structure including an inner tube 12 for flowing the mixture C and an outer tube 13 located outside the inner tube 12. On the other hand, the base-side lance 2 has a single-tube structure consisting of a single tube for flowing the mixture C. And the base end portion of the tip-side lance 1 and the tip end portion of the base-side lance 2 are removably connected via a connection portion 3.

[0012] FIG. 2 shows a configuration example of the connection portion 3. The connection portion 3 shown in the figure is a camlock mechanism. As shown in FIG. 2(a), the adapter 31 of the camlock mechanism is attached to the base end portion of the tip-side lance 1 (inner tube 12), and the coupler 32 of the camlock mechanism is attached to the tip end portion of the base-side lance 2. After connection, as shown in FIG. 2(b), the tip-side lance 1 (inner tube 12) and the base-side lance 2 communicate with each other via the connection portion 3, and the mixture C is conveyed from the base-side lance 2 to the inner tube 12 of the tip-side lance 1.

[0013] As shown in FIGS. 1 and 2, near the base end portion of the tip-side lance 1, a gas introduction portion 15 for introducing a gas (air in this embodiment) G for cooling the tip-side lance 1 into the gap 14 between the inner tube 12 and the outer tube 13 is provided, and a gas supply hose E is connected to the gas introduction portion 15. In other words, in this embodiment, the gas (air) G for cooling the tip-side lance 1 is introduced into the gap 14 between the inner tube 12 and the outer tube 13 from near the base end portion of the tip-side lance 1. In the present invention, the gas for cooling the tip-side lance is introduced from the "base end portion or its vicinity of the tip-side lance", and the range of "vicinity" may be determined based on common technical knowledge in view of the purpose of cooling the tip-side lance inserted first into a repair location such as the carbonization chamber of a coke oven.

[0014] Next, the method of using the spraying lance A will be described. The actual spraying operation using the spraying lance A is performed with the tip-side lance 1 and the base-side lance 2 connected as shown in FIG. 1. However, since the spraying lance A is long, it is often difficult to insert it into the carbonization chamber B of the coke oven with the tip-side lance 1 and the base-side lance 2 connected due to restrictions on the working space and other circumstances. Therefore, in this embodiment, the tip-side lance 1 is inserted first alone. When the tip-side lance 1 is inserted first alone in this way, as described above, there is a risk that the tip-side lance 1 will be abnormally heated and backfire will occur. However, in this embodiment, gas (air) G is introduced from the gas introduction part 15 near the base end part of the tip-side lance 1 into the gap 14 between the inner pipe 12 and the outer pipe 13, so the tip-side lance 1 is gas-cooled. Therefore, it is possible to suppress the tip-side lance 1 from being abnormally heated. Subsequently, as shown in FIG. 1, the tip part of the base-side lance 2 is connected to the base end part of the tip-side lance 1. Then, the mixture C is supplied from the mixture supply hose D to the base end part of the base-side lance 2, and the spraying operation is performed. In FIG. 1, the reference symbol F is a support roller used when advancing and retreating the tip-side lance 1 in the carbonization chamber B.

[0015] Here, regarding the preferable configuration of the spraying lance A, the length of the base-side lance 2 is preferably 0.5 m or more and 5 m or less from the viewpoint of the operability of the spraying lance A and the like. Also, the total length of the spraying lance A when the tip-side lance 1 is connected is preferably more than 5 m and 11 m or less from the viewpoint of applicability to the coke oven and the like. As an example, in this embodiment, the length of the tip-side lance 1 is 6 m, the length of the base-side lance 2 is 3 m, and the total length is 9 m. Also, the wall thickness T2 (see FIG. 2) of the base-side lance 2 is preferably 1 time or more and 9 times or less the wall thickness T1 (see FIG. 2) of the inner pipe 12 of the tip-side lance 1. By setting such a wall thickness ratio, it is possible to ensure the strength of the base-side lance 2 and also ensure the workability of the spraying operation.

[0016] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in this embodiment, the tip-side lance 1 has a double-tube structure composed of an inner tube 12 and an outer tube 13, but a protective tube may be further provided outside the outer tube 13 to form a triple-tube structure. Also in this case, the gas for cooling the tip-side lance 1 is introduced into the gap 14 between the inner tube 12 and the outer tube 13, but it may also be introduced into the gap between the outer tube 13 and the protective tube. In addition, in this embodiment, the base-end side lance 2 has a single-tube structure, but it can also have a double-tube structure. In this case, the inner tube of the base-end side lance is connected so as to communicate with the inner tube 12 of the tip-side lance 1. Also, when the base-end side lance has a double-tube structure, the wall thickness of the base-end side lance refers to the wall thickness of its inner tube. Furthermore, in this embodiment, a camlock mechanism is adopted as the connection part 3, but other known connection mechanisms may be adopted.

Explanation of Reference Numerals

[0017] A Lance for Spraying B Carbonization Chamber of Coke Oven C Mixture D Mixture Supply Hose E Gas Supply Hose F Support Roller G Gas (Air) 1 Tip-Side Lance 11 Injection Part 12 Inner Tube 13 Outer Tube 14 Gap 15 Gas Introduction Part 2 Base-End Side Lance 3 Connection Part (Camlock Mechanism) 31 Adapter 32 Coupler

Claims

1. A spraying lance used in a spraying device for forming a refractory composition by spraying and burning a mixture obtained by mixing a raw material powder containing a refractory powder and a combustible powder with a supporting combustion carrier gas, comprising a tip-side lance having a spraying portion for spraying the mixture on the tip side, and a base-side lance removably connected to the base end portion of the tip-side lance, wherein the tip-side lance includes an inner tube for flowing the mixture and an outer tube located outside the inner tube, and a gas for cooling the tip-side lance is introduced into a gap between the inner tube and the outer tube from the base end portion or the vicinity thereof of the tip-side lance. The spraying lance is characterized by this.

2. The spraying lance according to claim 1, wherein the wall thickness of the base-side lance is 1 time or more and 9 times or less the wall thickness of the inner tube of the tip-side lance.

3. The spraying lance according to claim 1 or 2, wherein the length of the base-side lance is 0.5 m or more and 5 m or less, and the total length when the tip-side lance is connected is more than 5 m and 11 m or less.

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