JPS6261642B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is intended to investigate the conditions inside a furnace where the contents of the furnace are unloaded during the operation of a blast furnace, shaft furnace, etc.
This invention relates to a technology that makes it possible to detect the internal shape of a softened cohesive zone at 1400 to 1500°C.

(Prior technology) Special Publication No. 57-48621, Publication No. 1986-28678, Publication No. 1986-28678, Publication No. 1987-28678, Publication No. 1987-28678
-28679 discloses a method and device for grasping the situation inside a blast furnace. As far as temperature is concerned, the
48621, a measuring probe with a plurality of temperature sensing parts formed along the length direction of a hard protective tube is placed radially on the surface layer of the raw material input into the blast furnace, and the measuring probe is lowered as the load is unloaded. The temperature is measured at the point reached by the temperature sensor, and the situation inside the furnace is determined based on the measured value. That is, a vertical and horizontal measurement probe is used to measure the temperature distribution within the blast furnace in two dimensions, vertical and horizontal.

(Problems to be Solved by the Invention) The vertical and horizontal probes of the prior art measure temperature by attaching a thermocouple as a temperature sensing section. There are various sheathed thermocouples such as chromel-alumel (CA) and platinum-platinum rhodium (Pt-PtRk), but CA is less expensive because it cannot be reused.
A sheathed thermocouple is used. However, CA thermocouples can only accurately measure temperatures up to about 1200°C, and therefore the shape of the temperature distribution inside the blast furnace can only be known to the outside of the softened cohesive zone.

The present invention can be used not only in the 0-1200℃ range but also in the 1400-1400℃ range.
The purpose of this invention is to provide a means that enables measurement of the internal shape of a softened cohesive zone in the 1500°C range.

(Means, effects, and embodiments for solving the problems) The above object is achieved in the present invention by making it possible to detect the temperature at the melting point by cutting the metal wire. Therefore, a metal whose melting temperature is known is used as the metal wire. Particularly accurate measurement is possible by using a pure metal with a wide range of melting temperatures. The wire metal is selected in consideration of the measurement temperature range.

That is, the method for detecting the inside condition of a blast furnace according to the present invention has a structure in which, in order to detect the inside condition of a blast furnace, a protective measuring probe is placed on the contents in the furnace in the radial direction and lowered as the load is unloaded. A metal wire with a known melting temperature is buried in the filling inside the sheath, folded inside the probe, and housed in the probe. Used as energized from the base end,
The melting temperature of the metal wire is determined to be the temperature at the melting point in the furnace by cutting off the current by fusing the exposed closed end of the metal wire, and the temperature distribution line is obtained by plotting each position in the furnace. It is characterized by detecting the internal situation. In particular, by using a metal wire such as pure nickel and obtaining a temperature distribution line with a melting temperature of 1453°C, it is possible to understand the inside of the softened cohesive zone in the furnace.

Hereinafter, the method of the present invention will be specifically explained based on examples with reference to FIGS. 1 to 6.

One basic form of the temperature measuring element 1 used in the present invention is shown in FIG.

The metal wire 3 is placed in the metal protective sheath 2 with MgO,
It is made by filling it with a heat-resistant and insulating filler 4 such as Al ₂ O ₃ and drawing it. The metal wire 3 is buried in a folded manner in the filling in the protective sheath, one end of which becomes a closed circuit tip 3a to be fused, and the other end becomes an open base end 3b for energization.

For the metal wire 3, select a pure metal whose melting temperature is known and has no or small melting temperature range, an alloy with a eutectic point composition, etc. For example, pure nickel with a melting temperature of 1453°C is selected for the temperature measuring range of the present invention. use. The wire diameter is
Approximately 0.5 to 2 mm is sufficient.

As shown in FIG. 2, the required number of temperature measuring elements 1 are accommodated in a steel pipe 5, and detection holes 6 are provided at predetermined horizontal measurement positions in the length direction of the steel pipe. The closed end 3a of the probe is exposed to form a measurement probe 7.

This measuring probe 7 is placed on the upper surface of the mortar-shaped furnace contents 9 at the top of the blast furnace 8, for example by using an insertion device 10 shown in Japanese Utility Model Publication No. 56-28678, so that the tip is placed in the radial direction. It is placed in the center of the furnace with its base end located near the furnace wall refractories 11, and is placed in a buried state by charging the next charge, and is lowered as the furnace charges are unloaded during operation. to enable vertical detection. In order to follow the descent, the base end 3b of each metal wire 3 is connected to a connecting wire 12, and the connecting wire 12 is guided onto a deck 13 outside the furnace, wound around a drum 14, and detected by a detection device 15.

When a voltage is applied to the open end 3b of the metal wire 3, a current flows through the metal wire 3, and when the closed end 3a melts, the current is cut off, so that the detection device 15 can detect that a wire breakage has occurred. The melting temperature of the metal wire is determined to be the atmospheric temperature at the location in the furnace where the melting occurs.

For example, as shown in FIG. 2, detection holes 6 are provided in the measurement probe 7 at positions corresponding to the center, middle, and periphery of the blast furnace to expose the closed ends 3a, 3a', and 3a'' of pure nickel metal wires, respectively. In this case, under the temperature distributions T, T' and T'' in the three positions shown in Fig. 4 in the height direction, the melting of the closed end of the strand will occur as per the temperature distribution lines T, T' and T''. It occurs at the intersections t, t' and t'' of the 1453°C lines. As shown in Figure 5, the height of the melting point and the plot of the corresponding position indicate that the temperature is 1453℃.
A temperature distribution line X can be obtained.

According to the technique disclosed in Japanese Utility Model Publication No. 60-28678, the temperature distribution inside the blast furnace is measured using a CA thermocouple, and a temperature distribution line Y from room temperature to 1200° C. shown in FIG. 5 can be obtained. The combination of these temperature distribution lines
The overall shape of the softened cohesive zone, which is said to be at ~1450°C, becomes clear. In this case, the measuring probe is the sixth
As shown in the figure, CA thermocouples 16 and 1 are installed in each detection hole 6.
6' and 16'' to the closed wire ends 3a, 3a' and 3
can be exposed along with a″ so that both measurements are taken.

As described above, in the method of the present invention, the type of metal in the metal wire 3 is changed depending on the known temperature range. For example, pure nickel is suitable for determining the shape of the softened cohesive zone in a blast furnace, but in a reducing atmosphere, the melting point temperature changes due to the solid solution of carbon, so a sheath is used as a countermeasure. It is used by coating the metal wire by applying thermal spraying or the like.

(Effects of the Invention) Generally, the gas flow in a blast furnace is affected by the shape of the softened cohesive zone, so in order to control the gas flow in the blast furnace, it is necessary to control the shape of the softened cohesive zone.

According to the conventional technology, the external shape of the softened cohesive zone is 1200
Although it became possible to measure the temperature using the °C temperature distribution line, its internal shape remained unknown. According to the present invention, the internal shape of the softened cohesive zone can be determined from the 1450° C. temperature distribution line, etc., and the overall image of the softened cohesive zone can be grasped. As a result, the shape of the softened cohesive zone can be controlled more easily than before, and the gas flow distribution in the furnace can be controlled.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional side view of one basic type of temperature measuring element used in the method of the present invention, Fig. 2 is a side view of an example of a measuring probe, and Fig. 3 is a furnace showing the state in which the measuring probe is inserted into the blast furnace. A longitudinal cross-sectional side view of the top part, Figure 4 is a chart showing temperature on the horizontal axis and height on the vertical axis, showing the fusing height and position of the closed end of each metal wire, and Figure 5 shows the temperature distribution inside the blast furnace. FIG. 6 is a side view of another example of a measurement probe that uses both a thermocouple and a metal wire. 1... Temperature measuring element, 2... Protective sheath, 3... Metal wire, 3a, 3a', 3a''... End of closed circuit, 3b...
...Open circuit base end, 4...Filling material, 5...Steel pipe, 6...
Detection hole, 7...Measurement probe, 8...Blast furnace, 9...
... Furnace contents, 10 ... Insertion device, 11 ... Furnace wall refractories, 12 ... Connection wire, 13 ... Deck, 14
...Drum, 15...Detection device, 16, 16',
16″……Thermocouple high temperature end, T, T′, T″, X, Y…
...Temperature distribution line, t, t', t''...intersection.

Claims (1)

[Claims] 1. In order to detect the condition inside the blast furnace, a metal wire with a known melting temperature is placed inside a protective sheath as a measurement probe that is placed radially above the contents of the furnace and lowered as the load is unloaded. The metal wire is buried in the filling, folded inside, and housed in the probe, and the closed end of the metal wire is exposed through the detection hole at a predetermined position of the probe, and the open circuit base end is used as a energized state. The melting temperature of the metal wire is determined to be the temperature at the melting point in the furnace by interrupting the current flow due to the melting of the exposed closed end, and the temperature distribution line is obtained by plotting each position in the furnace to determine the situation inside the furnace. A method for detecting the condition inside a blast furnace. 2. Claim 1, wherein pure nickel with a melting temperature of 1453°C is used as the metal wire to detect the internal shape of the softened cohesive zone at 1400 to 1500°C in the inside of the blast furnace. The described method for detecting the condition inside the blast furnace.