JPS6259163B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for measuring the descending rate, layer thickness, particle size, etc. of blast furnace charges such as iron ore and coke during blast furnace operation.

[Prior art]

During blast furnace operation, the rate of descent of the charge, layer thickness,
It is extremely important to know the condition of the contents in the furnace, such as particle size and thickness of the fused layer.

Conventionally, various detection methods for use in the above-mentioned measurements have been developed in a relatively low temperature range (400° C. or lower). For example, there are detection methods that utilize the difference in magnetic properties between ore and coke, detection methods that utilize the difference in electrical resistance between ore and coke, and the like. However, these methods cannot be used in the low-temperature range mentioned above due to reasons such as magnetic properties disappearing above the Curie point, electrodes deteriorating at high temperatures, and insulation properties deteriorating due to deposits. was limited to the area.

Under these circumstances, the present inventor first conducted research on a measurement method in the high temperature region of the lower part of the blast furnace.
Invented a method for detecting the contents of blast furnaces by utilizing differences in the transmission or reflection characteristics of radio waves, and received a patent application in 1983.
Patent applications were filed as Nos.-135354 and 57-147967.

The methods disclosed in these patent applications are extremely effective as a method for measuring blast furnace charge in high-temperature regions, and if the detection ends are mounted vertically in multiple stages, the layers of the coke layer, ore layer, and cohesive layer can be measured. Thickness, descent speed, etc. can also be measured.

However, in this method, it is necessary to provide a plurality of detection ends in which each of the waveguides for transmitting and receiving radio waves is surrounded by a housing, and the work of attaching each housing to the furnace wall is difficult.

[Purpose of the invention]

The present invention further improves the above-mentioned invention, and is intended to simplify the measurement of the falling rate, layer thickness, particle size, etc. of the contents in the blast furnace, and to perform the measurements with one device.

[Structure and operation of the invention] In order to achieve the above object, the device developed by the present invention includes a housing having at least three built-in waveguides and a cooling mechanism using a cooling fluid. is inserted between the contents of the blast furnace and attached to the wall of the blast furnace, and a microwave radiation opening and a microwave reception opening provided at the tip of the waveguide are respectively placed on opposite sides of the housing. The microwave receiving aperture is arranged at a different height in the vertical direction from the microwave emitting aperture, and a microwave transmitter/receiver is installed in the waveguide provided with the microwave emitting aperture. This is a blast furnace charge measuring device in which microwave receiving devices are connected to waveguides provided with wave receiving openings.

Using the above-mentioned apparatus of the present invention, a casing equipped with a cooling mechanism is attached to the blast furnace wall with its tip inserted between the blast furnace charges, and the casing is inserted into the blast furnace charge layer from the casing. At the same time, the microwaves scattered by the blast furnace charge layer are received at multiple locations in the vertical direction of the housing, and the blast furnace charge layer is identified from the microwaves, and the blast furnace charge layer is identified. It is possible to measure the conditions inside the furnace, such as the rate of descent, layer thickness, particle size, and thickness of the fused layer.

The contents of the present invention will be explained in detail below based on embodiments shown in the drawings.

FIG. 1 is an explanatory diagram showing the appearance of a blast furnace, and 1 is a furnace body. Reference numeral 2 denotes a measuring device which is an embodiment of the present invention, and is attached to the furnace belly. 3 is a tuyere, and 4 is a cohesive zone.

Figure 2a shows an enlarged side view of the measuring device 2.
Figure b shows a sectional view taken along line BB in Figure 2a, and Figure 2c
The figure shows a sectional view taken along the line CC in FIG. 2a. A housing 2' containing waveguides 6 ₁ , 6 ₂ and 6 ₃ is attached to the blast furnace wall 10 . A microwave transceiver 5 is connected to the outside of the furnace of the waveguide 6 ₁ , and microwave receivers 8 and 9 are connected to the outside of the furnace of the waveguides 6 ₂ and 6 ₃ .
connects. Furthermore, the inner side ends of the waveguides 6 ₁ , 6 ₂ , 6 ₃ are connected to openings 7 ₁ , 7 ₂ , 7 provided in the housing 2'.
It is connected to ₃ . Note that, as shown in FIG. 2b, the opening 7 ₁ is provided on the opposite side from the openings 7 ₂ and 7 ₃ . 11 is an inlet of cooling water for cooling the housing 2', and 12 is an outlet. 13 ₁ , 13 ₂ , 13 ₃
is an inlet for purge gas in the waveguides 6 ₁ , 6 ₂ , 6 ₃ . 14 is a coke layer, and 15 is an ore layer. The PRG shown in FIG. 2c is a pressure-resistant quartz glass.

In order to carry out various measurements of the blast furnace charge using the apparatus of the present invention, microwaves (for example, +20 dBm (100 W), 10 GHz) are generated by the microwave transmitter/receiver 5 and are transmitted from the opening 7 ₁ through the waveguide 6 _{1 .} Radiate into the charge layer. The emitted microwaves reach the openings 7 ₂ and 7 ₃ while being scattered within the coke layer 14 or the ore layer 15, so the waveguide 6
₂ and 6 ₃ out of the furnace, and detected and recorded by microwave receivers 8 and 9.

Compared to when there is a space around the opening 7 ₁ , when the area just in front of the opening 7 ₁ is blocked with coke or ore, the microwave is reflected and returns to the microwave transmitter/receiver 5. becomes larger. Therefore, by measuring the intensity of the reflected wave with the microwave transmitter/receiver 5, the particle size d of the charge can be measured as described later.

Examples of recorded signals are shown in Figures 3a and 3b. Figure 3a shows the signals of the scattered waves that have reached the apertures 7 ₂ and 7 ₃ , and C represents the signal due to the coke layer.
is a signal from the ore layer.

FIG. 3b shows the signal of the reflected wave at the aperture ₇₁ through which noise is removed by passing it through a low-pass filter.

As is clear from Figure 3a, the waveform of the scattered wave is
The opening ₇₃ side lags behind the opening ₇₂ side by Δt. This is because the charge comes down from the top of the furnace, whereas the opening ₇₃ is a distance below the opening ₇₂ . Therefore, the signal on the aperture ₇₃ side has a delay Δt proportional to that of the signal on the aperture ₇₂ side. Therefore, the descending speed v of the charge is v=・c/Δt (where c is a correction coefficient determined by the housing shape, etc., and is determined experimentally. In the case of Fig. 2, it is 0.5). You can ask for it.

If the descending speed v is determined, the coke layer thickness Dc
can be obtained from Dc=tc×v (where tc is the duration of the signal of the coke layer), and the ore layer thickness Do is calculated as Do=to×v (where to is the duration of the signal of the ore layer). It can be found by

In addition, as shown in Fig. 3b, the particle size α of the charge is calculated from the interval τ and the falling speed v, since the peak of the reflected wave is detected every time the charge passes the front surface of the opening ₇₁ . , α=τ×v.

Further, the thickness of the fused layer can be determined by attaching the device of the present invention to the morning glory section of the blast furnace and detecting the charge passing through the front surfaces of the openings ₇₂ and ₇₁ . In other words, when there is a coke layer in front of the opening ₇₂ , the received output of a scattered wave with a large output is detected as in the case of _FIG . Once it reaches that point, the received power drops to such an extent that it cannot be detected at all.
The fused layer can be detected from the change in this signal. Further, by confirming from the reflected wave reception signal that the root of the cohesive zone has passed through the front surface of the opening ₇₁ , the thickness of the cohesive layer can be determined.

The reason why the aperture 7 ₁ (transmission side) and the aperture 7 ₂ (reception side) are provided on opposite sides is that if the apertures are provided on the same side, the microwaves emitted from the aperture 7 ₁ will be transmitted to the surface of the housing. This is because the microwaves propagate between the charges and reach the openings ₇₂ and ₇₃ , and this level is higher than the level of the microwaves propagated within the ore layer, making it impossible to accurately detect the layer. In the illustrated example, there is only one transmitting side aperture, but it goes without saying that a plurality of apertures may be provided.

Next, an example of operation using the apparatus of the present invention will be explained.

A casing with dimensions of 2100 mm in length, 70 mm in width, and 300 mm in thickness was attached to the wall of the abdomen of the blast furnace, with its tip protruding 500 mm from the inner surface of the bricks inside the furnace. Further, the distances between the opening ₇₁ and the openings ₇₂ and ₇₃ were each 200 mm. Microwaves of 9.4 GHz and 100 mW (+20 dBm) were generated by the microwave transceiver 5 and radiated into the charged material through the opening ₇₁ . Scattered waves propagated through the charge and were received by the microwave receivers 8 and 9 through the openings ₇₂ and ₇₃ as shown in FIG. 3a. Duration of this received wave
The coke layer and ore layer could be identified from tc and to. The received power level at this time was an average of 10 ^-5 mW (-50 dBm) in the coke layer.
The average power was 10 ^-9 mW (-90 dBm) in the ore layer. In addition, the thickness of the coke layer and ore layer is
They were 0.44m and 0.36m.

Next, an actual example of detecting a state in which a load is not properly lowered will be described. Figures 4a to 4c show examples of such detection, with Figure 4a showing the case where the coke layer has stagnated for a long time, and Figure 4b showing the case where the ore layer has stagnated for a long time. In these cases, it can be seen that the charge is stagnant because the scattered wave signal continues to be the signal of the coke layer or the ore layer, and the reflected wave signal does not change.
Note that FIG. 4c shows a state in which a mixed layer of a coke layer and an ore layer is descending. In this case, the scattered wave signal will be at a level between the coke layer and the ore layer,
In addition, it becomes a signal with large changes including ripples.

FIG. 5 shows an example where this measurement is continued for a long period of time. From around the 5th day of measurement, the ore layer became thicker.
The coke layer thickness began to thin, and from around the 10th day, the turbulence in the falling rate became noticeable, and the falling rate gradually slowed down. 4a from day 13 to day 17
The poor descent state as shown in Figures 4b and 4b continued, and the rate of descent, layer thickness, and grain size could not be measured. This indicates that a local charge stagnation phenomenon has occurred at the installation location of the device of the present invention. From day 35
Until the 45th day, the mixed layer signal continues as shown in Figure 4c. From a few days before that, the average ore particle size tends to become smaller, the ore layer thickness becomes thinner, and the coke layer thickness tends to become thicker. This indicates that the ore entered the coke layer below, creating a mixed layer consisting mainly of coke.

Next, an example will be shown in which the thickness of the adhesive layer is measured according to the present invention. In this case, the casing serving as the detection end is attached to the morning glory part of the blast furnace. Normally, when the root of the cohesive zone descends and reaches the position of the casing, the above-mentioned detection means and signal processing determine the falling speed, thickness of the coke layer, thickness of the cohesive layer, particle size, etc. can be measured.

Figures 6a and 6b are examples of this,
Before time A, the cohesive zone is above the casing, so only the coke layer is detected. At time A, the root of the cohesive zone reached the opening ₇₂ , so the level of the scattered wave reception signal decreased to -100 dBm (a state in which no microwave was received), and the root of the cohesive zone was detected. Also, A
Between time and time B, the signal disappears between the aperture ₇₂ and the aperture ₇₁ , so no signal from the root of the cohesive zone is detected at the aperture ₇₃ . Therefore, the lower end of the root of the cohesive zone has an opening 7.
It can be confirmed that it is between ₁ and ₇₂ . Furthermore, after time B, the root of the cohesive zone has descended to a level below the opening ₇₁ , so that the descending speed, layer thickness, grain size, etc. of the root of the cohesive zone can be accurately measured. By the way, the descending speed at time B is 3m/hour.
Average cohesive layer thickness is 0.2m, average coke particle size is 40m/
It was m. Note that when the fusion layer reaches the opening ₇₁ , a phenomenon in which the reflected signal becomes large and the change becomes small appears conspicuously.

In addition, the location of disappearance of the cohesive zone (lower end of the root of the cohesive zone) can be estimated from the change in the thickness of the cohesive layer ( _{it is thinner when detected at opening 7 1 than} when detected at opening 7 2). is also possible.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible not only to measure the descending speed, layer thickness, particle size, etc. of the charge, but also to store a plurality of waveguides in one housing and to use the same housing. Since it is attached to the blast furnace wall, installation work and furnace wall maintenance of the attachment part are easy, and since the radiation opening and reception opening are provided on opposite sides of the same housing, the above-mentioned detection can be performed accurately. be able to.
Further, according to the present invention, each state of the blast furnace charge can be measured, which is extremely effective in smoothly operating the blast furnace.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the appearance of a blast furnace. Second
Figures a to 2c show the structure of the measuring device of the present invention, and Figure 2a is a partially cutaway side view;
Figure 2b is a sectional view taken along line B-B of Figure 2a,
Figure c is a sectional view taken along line CC in Figure 2a. FIGS. 3a and 3b are graphs showing actual measurement data obtained by detecting coke layers and ore layers and measuring particle sizes using the apparatus of the present invention. 4th a
Figures 4b and 4c are graphs showing actual measurement data for detecting failure of the load to descend using the apparatus of the present invention, and Figure 5 is a graph showing similarly measured data over a long period of time. Figures 6a and 6b are
It is a graph showing measurement data when the thickness of a fusion layer is measured with the apparatus of the present invention. 1: Blast furnace, 2: Measuring device, 2': Housing, 3: Tuyere, 4: Cohesive zone, 5: Microwave transceiver, 6
₁ , 6 ₂ , 6 ₃ : Waveguide, 7 ₁ , 7 ₂ , 7 ₃ : Opening, 8, 9: Microwave receiver, 10: Furnace wall, 1
1: Cooling water inlet, 12: Cooling water outlet, 13
₁ , 13 ₂ , 13 ₃ : Purge gas inlet, 1
4: Coke layer, 15: Ore layer, PRG: Pressure-resistant quartz glass.

Claims (1)

[Claims] 1. Attach a housing equipped with a cooling mechanism that incorporates at least three waveguides and uses a cooling fluid to the blast furnace wall with the housing tip inserted between the contents of the blast furnace, and A microwave radiation aperture provided at the tip of the wave tube and a microwave reception aperture are provided on opposite sides of the housing, and the microwave reception aperture is vertically higher than the microwave radiation aperture. A microwave transmitter/receiver is connected to the waveguide provided with the microwave radiation opening, and a microwave receiver is connected to the waveguide provided with the microwave reception opening. A measuring device for blast furnace charge.