JPS5832315B2 - Hot spray repair method and equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot spraying repair method and apparatus that converts changes in the surface temperature of a repaired part of a refractory lining layer into a time axis in advance and controls the moisture content of the sprayed material over time. It is something.

For example, the refractory linings of hot metal ladle, pig iron mixer, pig iron mixer, converter, electric furnace, molten steel ladle, tundish, gutter, etc. are partially and totally worn out with each use.

One of the techniques for hot repairing the worn parts of the refractory lining layer is the dry spraying method disclosed in, for example, Japanese Patent Publication No. 40-22641 or Japanese Patent Application Laid-Open No. 50-17303.

In these dry spraying methods, as shown in the outline of the equipment in Figure 1, powdered refractory material stored in a hopper 1 is fed through a hose 2 using compressed air, and is installed in a spray nozzle 3. The water stored in the tank 5 is pumped into the hydrogenation ring 4 through the hose 6, and the refractory material and water are mixed.
% moisture slurry and sprayed from the spray nozzle 3,
This is a method of forming a spray material layer 10 on the surface 9 of the repaired part of the fireproof lining layer 8.

In the figure, 7 is a water volume adjustment valve.

In such a hot dry spraying method, it is known that there is a correlation between the surface temperature of the repaired part and the moisture content of the spraying material, and that there is a moisture content that is suitable for that temperature.

However, the surface temperature of the repaired area changes when the spraying material comes into contact with it, and the state of the change differs depending on the spraying method. Because the temperature cannot be measured due to the shielding, the moisture content is usually adjusted by the operator's visual judgment (the degree of adhesion).

Therefore, depending on the skill level of the operator, the timing of moisture adjustment may be off, or the amount of moisture may be too high or too low. There was a problem that the adhesion rate was as low as 90% and the variation range of the adhesion rate was wide.

The present inventor conducted various experiments on a method for accurately grasping the surface temperature of the repaired part of the refractory lining layer, and found that changes in the surface temperature of the repaired part of the refractory lining layer were converted into a time axis in advance, and the temperature was measured moment by moment by time measurement. It has been discovered that the change can be estimated with relatively high accuracy, and as a result, it has become possible to control the moisture content of the sprayed material to be suitable for the momentary surface temperature, and the first invention is as follows:
In the method of hot spraying repair by changing the mixing ratio of the sprayed material and moisture in accordance with the surface temperature of the repaired part of the fireproof lining layer, the correspondence between the spraying construction time and the surface temperature of the repaired part is measured in advance, and the spraying is carried out. The relationship between the time and the sprayed refractory material/moisture mixture ratio is established, and the surface temperature of the repaired part is measured or estimated immediately before spraying work, and the spraying work is started with the fireproof material/moisture mixture ratio at that temperature. A hot spraying repair method is characterized in that the mixing ratio of the spraying resistor and water is controlled based on the relationship determined in advance using a time signal, and the second invention thereof is: the surface temperature of the repaired part of the refractory lining layer; a timer that estimates changes in water content, an arithmetic control device that calculates the appropriate moisture content based on the input signal from the timer, a water supply amount adjustment device to the hydrogenation ring that operates based on the signal from the arithmetic and control device, and a spray fireproofing device. A hot spraying repair device is characterized in that it is equipped with a material supply amount adjustment device, and the third invention is: a temperature measuring device that measures the surface temperature of the repaired part before the start of spraying, a spraying time after the start of spraying; clock to measure,
An arithmetic and control device that calculates the appropriate moisture content based on the input signals from the above-mentioned temperature measuring device and timer, a device that adjusts the amount of water supplied to the hydrogenation ring and a device that adjusts the amount of sprayed refractory material that is supplied to the hydrogenation ring that operates based on the signals from the arithmetic and control device. This is a hot spray repair device characterized by comprising:

The present invention will be specifically explained below.

The surface temperature of the repaired portion of the refractory lining layer in the present invention refers to the surface temperature of the repaired portion at the time of spraying, that is, to which the slurry-like spraying material is about to reach.

The surface temperature of such a refractory lining layer depends on its shape characteristics (e.g., crucible-shaped container, etc.) and usage conditions (e.g., steel blowing, etc.)
The surface temperature change of the refractory lining layer is approximately determined by the conditions under which the refractory lining layer is separated from the heat supply source (hot metal, molten steel, etc.), such as by being left in the atmosphere or forced cooling. You can convert it to a time axis by distinguishing which one is placed below.

In response to the shape characteristics of the refractory lining layer, for example, in a converter, the area from the furnace mouth to the furnace bottom is divided in the height direction. By measuring , it is possible to accurately convert to the time axis.

First, since the change in the surface temperature of the refractory lining layer up to the start of the spraying work is based on almost constant cooling, the relationship between elapsed time and temperature should be measured in advance as described above (see 3. (See figure), by measuring the elapsed time until the start of the spraying operation, the surface temperature of the repaired area at the time of the start of the spraying process can be accurately estimated.

The above-mentioned FIG. 3 is a graph of the wall temperature of the trunnion portion immediately after tapping molten steel at 1620° C. in a 100 ton converter.

Before the spraying work starts, there is no obstruction such as spraying material on the surface of the repaired part or its vicinity, so in addition to the method of estimating the surface temperature by time measurement described above, a thermometer is used immediately before the spraying work starts. Alternatively, the surface temperature may be directly measured using a method.

To measure the surface temperature, a known contact or non-contact temperature measuring device such as a thermocouple or a radiation pyrometer can be used.

Next, changes in the surface temperature of the refractory lining layer after the start of the spraying operation are caused by forced cooling by the spraying material.

The degree of temperature change varies depending on the amount of spray material deposited on a specific location and the spray construction method.

Figure 2 shows a typical construction method, and Figure A shows the repair part 9.
(here, the first spray material layer 9 is formed to a predetermined thickness while continuously moving the spray nozzle 3 in the direction of the arrow 10,
Next, the spray nozzle 3 is applied onto the first spray material layer 9 in the same manner as described above.
This is a construction method in which the second spray material layer is formed by moving the spray material.

With this spraying construction method, if the spraying conditions such as the moving speed of the spray nozzle and the spraying amount per unit time are kept constant, the change in the surface temperature of each sprayed area at the stage of forming the first spraying material layer 9 will be reduced. The relationship between the elapsed time and the time and temperature until the second spray material layer is formed on the first spray material layer 9 can be measured in advance.

As described above, when measuring the temperature, if the spraying material in flight acts as a shield, the spraying is interrupted and the temperature is measured.

In Figure 0, a predetermined amount of spray material is continuously sprayed onto a specific part 12 of the repair part 9 to form a spray material layer of a predetermined thickness, and then the spray nozzle 3 is moved to another specific part 12'. This is a construction method that forms a layer of spray material.

With this spraying construction method, the spraying operation is interrupted every time spraying is performed on a specific area 12 for a predetermined period of time, and the surface temperature at that time is measured, thereby determining the relationship between the spraying duration and the surface temperature at each time. be able to.

The present inventors measured the relationship between the surface temperature of the repaired part and time in each of the spraying construction methods described above, and also measured the adhesion rate of the spraying material at each temperature.

Figure 4 compares the relationship between the surface temperature of the repaired area and the moisture content when the adhesion rate shows a value of approximately 70φ or more.
Figure 2 shows the case of the construction method shown in A) and Figure 5 (the case of the construction method shown in Figure 2 A).

In the figure, the dotted line a shows the transition of the surface temperature of the repaired part, and the lines b and b' show the upper and lower limits of the moisture content.

This range of water content becomes narrower as the adhesion rate is increased.

Further, the degree of water damage in the sprayed material may be controlled continuously or stepwise within the range of lines b and b' in accordance with the surface temperature of the repaired part.

However, when using the construction method shown in Figure 2, it is preferable to vertically control sudden changes in the amount of water when changing the spraying area.

As described above, in the hot spray repair method of the present invention, the correspondence between changes in the surface temperature of the repaired area and time is measured in advance, so that the surface temperature of the repaired area determined by time measurement or temperature measurement is Adjust valve 7 to obtain the appropriate moisture ratio.
Spraying is started by setting the opening degree of , and thereafter the amount of water supplied to the hydrogenation ring 4 can be controlled by operating the valve 1 in accordance with the elapse of the spraying time.

When carrying out the above method of the present invention, for example, when a specific type of converter is used under specific operating conditions, the portion of the refractory lining layer worn out during each blowing process is almost determined, and the amount of wear is Can be averaged.

Then, once the spraying conditions such as spraying distance, pressure, and amount of spraying material are fixed, a method is implemented in which the operator operates the valve 7 to the set opening degree that provides the appropriate moisture content in accordance with the spraying time to be measured. can.

As for controlling the water content in the sprayed material, there is a method in which only the amount of sprayed refractory material is adjusted, in addition to a method in which the amount of sprayed refractory material is kept constant and the amount of water supplied is adjusted.

Furthermore, there is a method of adjusting both the spray resistance and water.

If all of these methods are attempted to be carried out manually, there is a risk of erroneous operation; however, the spray repair apparatus shown in FIG. 6 can be recommended as an apparatus for effectively carrying out the method of the present invention.

This device is equipped with a measuring device 13 for measuring the surface temperature before repair, such as a radiation pyrometer and a timer 14.

The temperature measuring device 13 measures the surface temperature of the repaired part immediately before the spraying operation starts.

The temperature measurement data is input to the arithmetic and control device 15, and the device 15
The calculation performed in is set based on an approximate formula that takes into account the type of sprayed refractory material, the distance between the spray nozzle 3 and the repair surface 9, the amount of sprayed material, and the relationship between temperature and moisture shown in Figures 4 and 5. The appropriate moisture content under the spraying conditions is calculated.

The time signal from the clock 14 is input as the surface temperature after the start of spraying.

The control signal for the appropriate moisture ratio determined by the device 15 operates one or both of the water supply amount adjustment device 16 to the hydrogenation ring 4 and the sprayed refractory material supply amount adjustment device 17, and controls the moisture content in the sprayed material. control.

FIG. 7 shows a specific configuration of the water supply amount adjusting device 16, in which a control panel 18 is operated according to a signal from the device 15.
A signal to operate the control valve 7' is transmitted from the control valve 7', and the control valve 7' is opened so that the appropriate amount of water is obtained.

On the other hand, the amount of water flowing through the vibro is measured by a flow meter 19, and this value is converted into an electric signal by a converter 20 and inputted to a control panel 18, so that a loop circuit is constructed.

In the water supply amount adjusting device 16 having the above-described configuration, a mode suitable for adjusting the water supply amount in the state shown in FIG. There is a method in which multiple solenoid valves are installed in parallel and the flow rate is adjusted by changing the number of openings and closings of the electromagnetic valve each time the spraying area is moved.

Although the device 17 for adjusting the supply amount of sprayed refractory material is not particularly shown, it may be possible to control the rotation speed of the drive motor of the refractory material cutting device or the pressure of the compressed air used to forcefully feed the refractory material. This can be implemented by changing the flow rate.

Example l Target container: Oxygen top blowing converter (100 t) Temperature measurement method: Indirect measurement method using an infrared radiation thermometer and measurement of spray duration time Spraying material: Magnesia dolomite Spraying amount: 70 to 100 kg/min (dry spraying Control method: Figures 4 and 5) Automatic control based on the relationship shown (water volume control, constant amount of sprayed material) Moisture control range: 5 l/min to 50 l/min
When carried out under conditions such as n or more, the effects shown in Table 1 were obtained.

Example 2 Target container: Molten steel pot Temperature measurement method: Infrared radiation thermometer Spraying material: Low stone, zircon Spraying amount: 30 to 50 kg/min (dry spraying material amount) Control method: See Figures 4 and 5 Based on the relationship shown, manual control (water amount control, constant amount of sprayed material), moisture range: 2 A/min to 3011 A/min or more was carried out under the following conditions, and the effects shown in Table 2 below were obtained.

As described above, according to the present invention, the relationship between the surface temperature of the repaired part of the refractory lining layer and the spraying time is measured in advance, and the spraying material is sprayed with the moisture content adjusted to suit the temperature. The surface temperature of the repaired area, which changes during application and spraying, is accurately determined by measuring the spraying time, and the spraying material is sprayed with a moisture content controlled to match that temperature.
The adhesion efficiency of the sprayed material can be stabilized and maintained at a high rate.

In addition, the device of the present invention calculates the appropriate moisture percentage for each spraying time according to the spraying method based on the type of sprayed material, spraying distance, pressure, temperature, and moisture percentage, and calculates the amount of water and/or the amount of sprayed refractory material. Since the water content is adjusted, spraying can be carried out based on automatic control of the appropriate moisture content.

[Brief explanation of the drawing]

Figure 1 is a schematic explanatory diagram of a conventional dry spraying device, Figure 2 A,
Figure 3 is a graph showing the relationship between the time from just after the steel is tapped in the converter to the start of blasting and the trunnion wall surface temperature, and Figure 4 is a graph showing the relationship between the trunnion wall surface temperature when using the construction method shown in Figure 2A. A graph showing the relationship between the spraying time, the surface temperature of the repaired area, and the appropriate moisture content range. Figure 5 shows the relationship between the spraying time, the surface temperature of the repaired area, and the appropriate moisture content range when using the construction method shown in Figure 2. The graph and FIG. 6 are explanatory diagrams showing an example of a spraying device according to the present invention, and FIG. 7 is an explanatory diagram showing an example of a water supply amount adjusting device. In the figure: 1...Hopper, 2...Hose, 3...Blowing nozzle, 4...Hydrogenation ring, 5...Water tank, 6...
... Hose, I... Valve, 8... Fireproof lining layer, 9... Repair part, 10... Shot material layer, 11...
Movement direction of spray nozzle 3, 12... Repair local area, 13.
...Temperature meter, 14...Timer, 15...Arithmetic control device, 16...Water supply amount adjustment device, 17...Refractory material supply amount adjustment device, 18...Control panel, 19 ···Flowmeter,
20...Converter.

Claims (1)

[Claims] 1. In a method of hot spraying repair by changing the mixing ratio of sprayed refractory material and moisture in accordance with the surface temperature of the repaired portion of the fireproof lining layer, the correspondence between the spraying construction time and the surface temperature of the repaired portion is determined in advance. Measure and establish the relationship between the spraying time and the sprayed refractory/moisture mixture ratio, estimate the surface temperature of the repaired area immediately before spraying, and perform the spraying with the refractory/moisture mixture ratio at that temperature. After starting,
A hot spraying repair method characterized by controlling the mixing ratio of sprayed refractory material and water based on the relationship determined in advance using a spraying construction time signal. 2. A timer that estimates changes in the surface temperature of the repaired part of the refractory lining layer, an arithmetic control device that calculates the appropriate moisture content based on the input signal from the timer, and a control device that operates based on the signal from the arithmetic and control device. Hot spraying repair device 3 characterized in that it is equipped with a water supply amount adjustment device and a sprayed refractory material supply amount adjustment device.A temperature meter that measures the surface temperature of the repaired part before the start of spraying, and measures the spraying time after the start of spraying. an arithmetic and control device that calculates the appropriate moisture content based on input signals from the temperature measuring device and the timer, a water supply amount adjustment device to the hydrogenation ring that is operated by signals from the arithmetic and control device, and a sprayed refractory material. A hot spraying repair device characterized by being equipped with a supply amount adjustment device.