JPS5951858B2 - Thermal spray lance for flame gunning - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a thermal spray lance for flame gunning,
In particular, this is a proposal for a thermal spray lance that is unique in that it is equipped with an ignition nozzle in addition to the spray nozzle.

Conventionally, a dry repair method as described in Japanese Patent Application Laid-Open No. 51-40841 has been known as a method for repairing worn parts of converters and other scouring furnaces and refractory linings.

This dry repair method involves spraying pulverized refractories, solid pulverized fuel, and oxygen from a nozzle at the tip of a lance onto the furnace wall at a high temperature of 1,350 to 1,500°C, for example, immediately after tapping the steel, and the combustion flame This method is called a flame gunning method in which molten or semi-molten refractory lining is sprayed onto the worn parts, bonding the refractories together and repairing them.

An apparatus used in such a flame gunning method is shown in FIG.

This device is constructed by rotatably supporting one end of a lance 2 on a moving truck 1, and the reference numeral 3 in the figure is a pivot pin, 4 is a cylinder, and 5 is a heat shield plate. . A spray nozzle 6 is attached to the tip of the thermal spraying lance 2. For example, when repairing the side wall of the converter 7, the tip of the thermal spraying lance 2 is inserted into the furnace by moving the cart 1 as shown in the figure. Spray repair material from attachment nozzle 6 (refractory material + fine powder of C)
At the same time, a combustion-supporting gas such as 00 is injected together, the refractory material is melted by combustion due to contact between the two, and this is sprayed to repair the furnace wall. Figure 2 shows a conventional thermal spraying lance 2 and a spray nozzle 6 attached to its tip.The thermal spraying lance 2 has a concentric quadruple tube and has a central channel through which the spraying repair material flows using No as a carrier gas. 2a
The thermal spray lance 2 is composed of an inner tube 8 communicating with the thermal spray lance 2 and an outer tube 9 communicating with the annular flow path 2b through which oxygen flows.
It protrudes in the radial direction.

Note that cooling water is made to flow through the outer annular channels 2c and 2d of the thermal spraying lance 2. In short, this conventional thermal spraying lance 2 and nozzle 6 is a repair refractory made by melting and semi-molten fine powder refractory under combustion with fuel and oxygen, spraying it onto the furnace wall, and immediately sintering it. It is used to form a layer on the furnace wall. By the way, in flame gunning, the temperature of the atmosphere in the furnace must be at least 1000° C. in order to melt or semi-molten the fine powder refractory and deposit it on the furnace wall surface. If the ambient temperature is lower than this temperature, the ignition will not ignite, or even if it ignites, the combustion state will be poor, and the fine powder refractory discharged from the spray nozzle 6 will reach the furnace wall without reaching a molten state, resulting in poor adhesion strength. There was a drawback. In order to overcome these drawbacks, the present invention provides an ignition nozzle in addition to the spray nozzle 6 to assist combustion. This paper proposes a thermal spray lance that is suitably used to ensure that the fine powder refractories in the sprayed repair material are melted or semi-molten by providing a separate lance to ensure a good combustion condition at all times.

The details of the configuration of the present invention will be explained below. FIG. 3 shows a preferred embodiment of the thermal spraying lance of the present invention, in which two spray nozzles 6, 6' are arranged in a row with a predetermined interval in between, oriented in the radial direction of the lance body. In addition, an ignition nozzle 10 is placed near each of the spray nozzles 6, 6'.
, 10'.

The above-mentioned spray nozzles 6, 6' are attached so that the inner tube 8 and the outer tube 9 are connected to the central passage 2a and the annular passage 2b of the lance body, respectively.

On the other hand, in the ignition nozzle 10, 10' 2, the inner fuel pipe 11 and the outer oxygen pipe 12 are connected to fuel pipes 1 that are separately piped along the pipe axis direction inside and outside the lance body.
3. It is attached in a state where it is defined respectively from the oxygen gas pipe 14. In this case, the oxygen gas pipe 14 and the annular flow path are not electrically connected. The above-described spray nozzles 6 and ignition nozzles 10 are arranged in pairs on the same generatrix of the lance body, but even if their positional relationship is slightly shifted in the circumferential direction of the lance body, the ignition nozzles 10, 10 ''s original function is not diminished.

The ignition nozzles 10, 10' are used after the thermal spray lance 2 is inserted into the furnace in a high temperature state, and then the spray nozzles 6, 6'
It is used prior to spraying, but it may be discontinued if the temperature of the furnace atmosphere rises thereafter, or it may be continued and used specifically to increase the temperature of the spray material flame flame.

As explained above, according to the thermal spraying lance of the present invention, it is easy to obtain a sufficiently high temperature atmosphere during flame gunning, so the sprayed repair material can be reliably molten or semi-molten, and a strong repair layer can be formed. Effective for forming on walls.

[Brief explanation of drawings]

Fig. 1 is a route diagram of the flame gunning device, Fig. 2 is a sectional view of the tip of a conventional thermal spraying lance, Fig. 3 is a sectional view of the thermal spraying lance of the present invention, and in Fig. A in the diagram
, B, and C. FIG. 2... Thermal spray lance, 6... Spray nozzle, 8... Inner pipe of the spray nozzle, 9...
...Outer tube of the spray nozzle, 10...Ignition nozzle, 11...Inner pipe for fuel of the ignition nozzle, 12
・ ・ ・ ・ ・ ・Outer tube for oxygen of ignition nozzle, 13
...Fuel pipe, 14...Oxygen gas pipe.

Claims (1)

[Claims] 1. For a lance body of concentric multiple pipes provided with a central flow path for spraying repair material flow and an annular flow path for combustion-supporting gas flow, the inner tube communicates with the center flow path and the outer tube connects to the annular flow path. A fuel pipe in which a concentric double-pipe spray nozzle connected to the lance is attached in a direction oriented in the radial direction of the lance, and the fuel pipe is guided through the pipe axis inside or outside the lance body. A thermal spraying lance for flame gunning, characterized in that an ignition nozzle connected to an oxygen gas pipe is arranged near the spray nozzle on the lance body.