JPS60149887A - Repair method through flame spraying - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Field of Industrial Application The present invention relates to a method for repairing damaged parts of various furnace linings by spraying refractory powder by flame spraying.

[Prior art and its problems]

As described in Japanese Unexamined Patent Application Publication No. 118763/1983, in recent years, as a repair method for damaged parts of various kiln linings, 1:
A thermal spray repair method has been developed in which a refractory 15) powder is passed through a 11-temperature flame and heated and melted to form a sprayed layer on the damaged lining layer.

In this thermal spray repair method, the maximum Q, 21 ml of repair refractory particles, is several tens of times faster than the normal thermal spray flame speed.
When flying at m/see, the flame length required to melt in a hot flame of 2400'c is approximately 500 m/see.
It is said to be +im.

On the other hand, in order to obtain a high-temperature flame, propane gas is used as a fuel.
Gaseous fuel such as acetylene gas, liquid fuel such as kerosene double fuel oil, etc. are used alone, and pure oxygen is used as an auxiliary fuel, and the length and temperature of the flame formed vary depending on the type of fuel used. . Generally, when gaseous fuel is used, the length of the high-temperature flame is shorter than that of lrv body fuel, as shown in Figure 1, and the optimal spraying distance of the thermal spray burner is 200 to 800.
It is said to be in the range of +im. On the other hand, in the case of liquid fuel, the surface of oil droplets atomized by the burner tip nozzle gasifies and then burns, so the combustion speed is slow, and the high temperature flame region is End collar 80
0 Dragon~1500m+n, so the optimal spraying distance of the thermal spray burner is 8°O, which is longer than that of gaseous fuel.
It is 1500mm.

For this reason, depending on the area to be repaired, it may be difficult to match the high-temperature flame area of the thermal spray burner with the spraying position, which may limit the use of the thermal spraying repair method. For example, coke oven walls, /8 steel vacuum degassing tank suction pipes, etc. are limited by their shapes and may only be able to spray a spraying distance of several tens of centimeters. In this case, if liquid fuel were used, a sprayed layer would be formed at point a in Figure 2, and the refractory particles would be sprayed unmelted onto the damaged area, resulting in an incompletely melted state. As a result, a porous sprayed layer with insufficient melting is formed, and the strength of the Nj@ portion becomes insufficient.

In addition, for example, when repairing the suction pipe that sucks up molten steel in a vacuum degassing tank, or the lining shrine on the lower wall of the tank, the distance from the thermal spray burner should be approximately 200 to 400 +1 m at the suction pipe part.
The length varies from 400 to 1500 mm at the bottom of the tank side wall.

If conventional single-fuel burners are used for areas where the thermal spray distance changes, it is not possible to place both areas in the same position, and the lance length must be adjusted to the burner lance itself. There is a problem that a proper thermal sprayed body cannot be obtained unless a device capable of changing the temperature is provided.

[Purpose of the invention]

It is an object of the present invention to provide a method for increasing the efficiency of thermal spray repair by generating an optimal flame regardless of the length of the spraying distance from a thermal spray burner to the repaired area and without installing any special equipment in the burner lance. It is in.

[Structure of the invention]

The present invention controls the length of the flame by supplying a plurality of fuels with different flame length characteristics to the flame generating portion.

FIG. 3 is a diagram explaining the present invention in detail. This figure shows the flame characteristics when the gaseous fuel and liquid fuel shown in Figs. Approximately 80mm from the burner end face
A high temperature flame area of 2000°C or more is formed up to the 0 mm position, and a 111i hot flame J and ζ1 area due to liquid combustion 1 is formed at a portion of 800 mm to 1500 mm from the burner end face. In this way, the high temperature flame area is 1
500 parts, and the length of the high-temperature flame formation region is approximately twice as long as when a single fuel is used as in the case of Figures 1 and 2. A high temperature flame area will be formed. This means that the melting capacity of refractory particles passing through a high-temperature flame is doubled, which means that the concentration of particles in the flame can be doubled.

Fig. 4 is a front view showing the arrangement of the jet holes at the tip of a burner suitable for using a combination of gaseous fuel and liquid fuel, and Fig. 5 shows the structure of the burner tip in Fig. 4. A-A
It is a cross section.

As shown in Figure 4, the arrangement of the nozzles at the tip b::i of the burner (1) is as shown in Figure 4. ) vent (
;3), the vents (4a) and (4b) at the end of the fire
, gas combustion! A large number of ejection holes (5) for gases 1' and 1 (for example, a gas prepared by premixing oxygen with propane gas) are arranged in this order.

The structure of the burner (the tip of 11, the so-called nozzle part is the fifth
As shown in the figure, an oxygen nozzle (2') is connected to the oxygen nozzle (2), a liquid fuel nozzle (3') is connected to the liquid fuel nozzle (3), and a non-nozzle hole (4a).

The refractory powder nozzle (4') following (4b), the gaseous fuel nozzle (5'a) that pokes into the gaseous fuel nozzle (5), and the gaseous fuel nozzle (5'a) at the mixing part (5'c). Intersecting oxygen nozzles (5'b) are provided corresponding to each jet hole, respectively.

Each of these nozzles is connected to each supply path in the lance (not shown) at the rear end of the burner fil, and each supply path in the lance is connected to each supply device (including a flow rate adjustment device) installed separately. connected by. Since these lance paralysis supply devices can be easily designed and manufactured by applying known techniques, a detailed explanation will be omitted here.

Now, in the burner with the structure described above, the method of supplying and ejecting gaseous fuel and supplying and ejecting liquid fuel is basically the same as the conventional method of using each fuel individually. In our invention, when the spraying distance is long, we can achieve a long flame by using gaseous fuel and liquid fuel together! ? This method differs from the conventional method in that it allows for Regarding the supply and ejection of the refractory powder, conventional methods such as powder composition, particle size, and general feeding method using a carrier gas (oxygen is used for energization) can be applied as is.

When performing solvent repair using such a burner, the distance from the burner end face to the surface to be repaired must be 800 II11.
If the distance is within the above range, perform thermal spraying with a flame using only gaseous fuel, and if the distance is between 800 am and 1,500 am, use ttv body fuel in addition to gaseous fuel, and perform / 8 tsubukikin & J with a long flame. .

〔Example〕

Using the burner shown in FIGS. 4 and 5, the melted parts of the molten steel vacuum degassing tank were repaired by thermal spraying.

The distance between the burner 6::5 surface and the surface to be repaired varies depending on the /8 loss area, and is 400 + nm for the near area and 1 for the far area.
There are 500 orders.

In this example, the fuel has a calorific value of 24,000 Kcal.
/rn propane gas! ',! 'r Jl 8800
Prepare kerosene of Kcal/R and 1l as thermal spraying material.
j (Fire powder is M, O・Al2 with an average particle size of 110μH1
The O3 powder was delivered with oxygen as a carrier gas.

For areas where the distance to the surface to be repaired is within 800 +u+, use propane gas alone (propane gas 20ONm/H).
Solvent repair with a flame of 100ON m/l1r) of oxygen for premixing, and the distance to the surface to be repaired is 800 m+n.
If the distance exceeds 1;, kerosene is used in addition to the above propane gas, and the amount of kerosene used is increased according to the distance to the surface to be repaired.
/ Ilr.

Combustion supporting oxygen 320ON n? MgO-Al203 refractory powder 12TON/Ilr was successfully sprayed in a completely molten state using 12TON/Ilr (including oxygen as a carrier gas).

Conventionally, the thermal spraying capacity of the propane gas burner was -200N n? /llr, M element-10
0ON n? /Hr flame, Mg0-AQ, z○3
It is possible to spray 3'I'ON/11r/8 refractory powder, and Genura's burner alone has thermal spraying capacity of 170 kerosene.
(H!/llr, oxygen 320ON IT?/11r
With the flame of the above fireproof, the end of 3 TON/llr/
It can be seen that the thermal spraying method of the present invention, which uses propane gas and kerosene in combination, has twice the thermal spraying ability as compared to the sum of each of them alone.

〔Effect of the invention〕

The thermal spray repair method of the present invention, which uses two types of fuel, liquid and gas, allows the length of the high-temperature flame region to be varied by adjusting the flow rates of both fuels, so there is no need to make any special structure of the burnerance itself. It is possible to improve the dissolution efficiency of the anti-spray powder for repair, to adjust the spraying distance, and to greatly expand the range of repair targets by thermal spraying.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing the characteristics of flame when gaseous fuel and liquid fuel are used alone, and Figure 3 is a diagram showing the characteristics of flame generated when gaseous fuel and liquid fuel are used together. show. FIG. 4 is a normal view showing the structure of a burner suitable for carrying out the method of the present invention, and FIG. 5 is a vertical lvi view taken along the line 8-Δ in FIG. (1): Burner (2): Oxygen nozzle (3): Liquid fuel nozzle (4a), (4b): Refractory powder nozzle (5): Gaseous fuel nozzle Patent applicant Nippon Steel Corporation Representative Person hand digging gain (1 idiot) iK I Figure ′−+−High surface force ゛ji’s foot distance Figure 2 Figure 3 8-11 from high surface foot force I Figure 4

Claims (1)

[Claims] 1. When repairing by flame spraying refractory powder, the thermal spray burner is provided with separate gaseous fuel nozzle holes and liquid fuel nozzle holes, and the gaseous fuel flow rate and liquid fuel flow rate can be adjusted separately, and the meteor ratio of both fuels is adjusted. A repair method using flame spraying, characterized in that an arbitrary flame length can be obtained by changing the length of the flame.