JP2014133922A - Profile measurement apparatus for blast furnace charging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a profile measurement apparatus which measures profiles of blast furnace charging materials with high accuracy without influence of the inside conditions of a blast furnace in a high powder dust concentration, reduces the area and thickness of pressure-proof and heat-resistant glass, and facilitates maintenance.SOLUTION: A profile measurement apparatus for blast furnace charging materials includes: a microwave receiver 14 capable of sending and receiving microwaves; an antenna 11 radiating microwaves; a wave guide 13 connecting the receiver 14 to the antenna 11; a reflection plate 12 for reflecting microwaves radiated from the antenna 11 toward the inside of the blast furnace 2; a reflection plate drive device 16 for driving the reflection plate 12; drive shafts 15 connecting the reflection plate 12 to the reflection plate drive device 16; and a pressure-proof and heat-resistant glass 17 transmitting microwaves. The antenna 11, the reflection plate 12, and the pressure-proof and heat-resistant glass 17 are housed in a pressure-proof container 20 which has a furnace side opening 21 directed to the inside of the blast furnace 2. The pressure-proof and heat-resistant glass 17 is fixed to the reflection plate 12 in the reflection direction toward the inside of the blast furnace and, together with the reflection plate 12, rotated around the drive shaft 15.

Description

  The present invention relates to an apparatus for measuring the shape (profile) of the surface of a blast furnace interior.

  In general, blast furnaces in the production of pig iron are alternately charged with sintered ore or lump iron ore (hereinafter simply referred to as iron ore or ore) and coke as a charge from the top of the furnace. As a result, the ore layer and the coke layer are formed in the furnace. The iron ore is heated and reduced (indirect reduction) by the CO gas generated by the reaction between hot air blown from the tuyere below the blast furnace and coke, and part of it is reduced directly by coke and softened and fused. After forming the band, it becomes a droplet. The droplets, that is, the molten iron, pass between the coke layers and accumulate at the bottom of the furnace. The ore layer and coke layer formed in the furnace gradually descend in the furnace.

  In the above process, it is very important to adjust the charge distribution at the top of the furnace formed by the iron ore and coke charged in the blast furnace to obtain an appropriate gas distribution. The profile (surface shape) of the charge at the top of the furnace in the blast furnace is determined by the moving armor in the bell-type charging device and the fall trajectory of the charge through the distribution chute in the bell-less charging device. Usually, the profile of the charge at the top of the furnace has a substantially inverted conical shape with a low center part around the center vertical direction (axial center) of the blast furnace. The profile of the blast furnace interior is important information for the operation of the blast furnace, and conventionally, an apparatus for measuring the profile of the charge charged and deposited in the furnace has been developed and put into practical use.

  For example, Patent Document 1 includes a microwave transmitter, an antenna, a waveguide connecting them, a reflecting plate that reflects microwaves, a reflecting plate driving device, and a drive shaft that connects them. The antenna, the end of the waveguide on the antenna side, the reflecting plate, and the end of the driving shaft on the reflecting plate side are housed in a pressure vessel having an opening toward the furnace of the blast furnace. Is disclosed.

  In such a profile measuring device, conventionally, in order to protect the antenna and the reflector from dusts in the blast furnace, the pressure resistance and heat resistance that allows microwaves to pass through the opening of the pressure vessel (see the furnace inner opening 21 in FIG. 2). Glass is fitted.

JP 2011-145237 A

  However, during the profile measurement, the direction of the reflector is changed, and the microwave reflection direction is changed accordingly. For this reason, when the pressure-resistant and heat-resistant glass is fitted into the opening of the pressure-resistant container, it is necessary to provide the pressure-resistant and heat-resistant glass over the entire range in the reflection direction, and a glass having a large area is required. Furthermore, in order to maintain the performance as a pressure-resistant and heat-resistant glass, the thickness is also required with the area. In addition, there is a problem that maintenance of the pressure and heat resistant glass after installation is extremely difficult.

  An object of the present invention is to reduce the area and reduce the thickness of pressure-resistant and heat-resistant glass in a profile measuring apparatus that can measure the profile of blast furnace interior with high accuracy without being affected by the inside of the blast furnace under high concentration dust. At the same time, it is to make maintenance easy.

  In order to solve the above problems, the present invention is a profile measuring device that is installed at the top of a blast furnace and measures the profile of the blast furnace interior, a microwave transceiver capable of transmitting and receiving microwaves, and An antenna that radiates a microwave transmitted from the microwave transceiver, a waveguide that connects the microwave transceiver and the antenna, and a microwave radiated from the antenna toward the furnace of the blast furnace Reflecting plate, reflecting plate driving device for driving the reflecting plate, driving shaft for connecting the reflecting plate and the reflecting plate driving device, and pressure resistance and heat resistance for transmitting the microwave reflected by the reflecting plate Glass, and the antenna, the reflector, and the pressure-resistant and heat-resistant glass are accommodated in a pressure-resistant container having a furnace inner opening facing the furnace of the blast furnace, Thermal glass is fixed to the reflecting direction toward the furnace of the reflector, characterized in that it rotates about the drive shaft together with the reflector, to provide a profile measuring device of the blast furnace interior container.

  In the blast furnace interior entry profile measuring apparatus, the pressure-resistant and heat-resistant glass and the reflecting plate may be accommodated in a rotating container that rotates about the drive shaft. An upper opening and a lid capable of opening and closing the upper opening may be provided on the top surface of the pressure vessel where the pressure and heat resistant glass is disposed.

  It is preferable that nitrogen gas is blown into the periphery of the pressure-resistant and heat-resistant glass from the outside of the blast furnace at a pressure higher than the furnace pressure in the blast furnace. Further, a valve capable of opening and closing the furnace inner opening may be provided.

  According to the present invention, the pressure-resistant and heat-resistant glass rotates together with the reflecting plate, and the glass is always arranged in the direction of microwave reflection, so that the area and thickness of the glass can be reduced to the minimum. Moreover, maintenance can be easily performed by rotating the pressure-resistant and heat-resistant glass to the upper part.

It is a longitudinal cross-sectional view which shows the example of embodiment of the blast furnace top part provided with the measuring apparatus of this invention. It is a front view which shows the outline of the measuring apparatus concerning embodiment of this invention. It is a longitudinal cross-sectional view of the measuring apparatus seen from the AA line of FIG. It is a top view of the measuring device seen from the BB line of FIG. It is a perspective view which shows the example of a rotation container. It is a longitudinal cross-sectional view which shows the example of the state at the time of non-measurement. It is explanatory drawing of the example of the measuring method using the measuring apparatus concerning this invention, (a) is explanatory drawing which shows the state in a furnace, (b) is a graph which shows correction amount.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example in which a profile measuring device 1 according to the present invention is installed in a blast furnace 2. A bell-less charging device 5 is provided at the furnace port portion of the blast furnace 2, and a charge 4 such as iron ore or coke is charged into the furnace through a distribution chute 6. In the present embodiment, the profile measuring device 1 is installed at two positions symmetrical to the central axis of the furnace body 3 outside the furnace body 3 near the top of the furnace. In addition, you may install the profile measuring apparatus 1 only in one place outside the blast furnace 2 furnace top part.

  2 is an enlarged view of the profile measuring device 1 portion of FIG. 1, FIG. 3 is a longitudinal sectional view of the profile measuring device 1, and FIG. 4 is a plan view of the profile measuring device 1. As shown in FIGS. 3 and 4, the profile measuring apparatus 1 includes an antenna 11 and a reflecting plate 12, a waveguide 13 that supports, drives, and controls the antenna 11 and the reflecting plate 12, a microwave transceiver 14, and a drive. It has a shaft 15, a reflector driving device 16, and a pressure and heat resistant glass 17 that can transmit microwaves. In the profile measuring device 1, a portion excluding the reflector driving device 16 is accommodated in the pressure resistant container 20. The pressure vessel 20 has, on the bottom surface, a furnace inner opening 21 directed into the furnace, and is installed near the top of the blast furnace 2 as shown in FIG.

  The antenna 11 is a parabolic antenna having a diameter of about φ250 to φ360 mm, for example, and is connected to the microwave transceiver 14 via the waveguide 13. The microwave transmitter / receiver 14 generates a microwave whose frequency continuously changes in a certain range and can transmit and receive the microwave. A data processor 18 is connected to the microwave transceiver 14 by a signal line 19.

  A microwave generated in the microwave transmitter / receiver 14 and continuously changing in frequency is radiated from the antenna 11, reflected by the reflector 12, transmitted through the pressure-resistant and heat-resistant glass 17, and is a measurement object in the blast furnace 2. The surface of the charge 4 is irradiated. The irradiated microwave is reflected by the surface of the charge 4, and this reflected wave is received and detected by the microwave transceiver 14. In the data processing unit 18, the round-trip time ΔT of the microwave from the antenna 11 to the measurement target (the surface of the charge 4) is obtained from the change in frequency ΔF from the emission to reception of the microwave at the antenna 11. The distance from the antenna 11 to the measurement target is calculated. This measurement is based on the FMCW (Frequency Modulated Continuous Wave) method (Frequency Modulated Continuous Wave method) that mixes and measures the electrical signal that emits the microwave and the electrical signal that is obtained by receiving the reflected wave from the charged surface. ). A commercially available apparatus may be used for the microwave distance meter of this type. The distance measurement method using microwaves is an example that can be used as an embodiment.

  The transmission frequency band of the microwave used for measurement is 10 GHz or more, preferably about 24 GHz. The higher the frequency, the smaller the antenna 11 can be made. By using the microwave, the profile in the blast furnace 2 can be accurately measured without being affected by the environment such as temperature and dust. Moreover, since the parabolic antenna has high directivity, microwaves can be radiated with high accuracy toward a desired position. Furthermore, since the spread of the microwave at the time of radiation | emission is suppressed, the opening part 21 toward the inside of a furnace can be made small.

  As shown in FIGS. 3 and 4, a drive shaft 15 that connects the reflector 12 and the reflector driving device 16 is provided on the extension of the microwave transmission / reception direction (center axis direction) of the antenna 11. That is, the drive shaft 15 is provided so that the center axis of the drive shaft 15 coincides with the center axis of the antenna 11. As shown in FIG. 3, the reflector 12 is fixed to the drive shaft 15 at an angle of approximately 45 ° with respect to the central axis of the antenna 11. The reflector 12 is made of, for example, a stainless steel plate, and the area viewed from the front side of the antenna 11 is slightly larger than the antenna 11. Although the shape is not limited, a circular shape is preferable in terms of operability. By rotating the drive shaft 15 around its central axis by the reflector driving device 16, the microwave radiated from the antenna 11 in the direction of the central axis is reflected by the reflector 12, for example, as shown in FIG. Reflected toward the inside of the furnace 2 and scanned in the diameter direction of the blast furnace 2. The profile measuring device 1 is preferably arranged so that the microwave passes through the central axis of the furnace.

  The pressure-resistant and heat-resistant glass 17 has a size and a shape that covers the entire projection surface in the reflection direction of the reflecting plate 12, and transmits microwaves. In addition, sufficient pressure resistance is required for the pressure in the blast furnace 2, for example, a pressure resistance design of about 0.3 MPa, a heat resistant temperature of about 200 ° C., a tempered glass of about 40 mm in thickness, a heat resistant temperature of about 1000 ° C., a thickness Quartz glass of about 25 mm is used.

  In the present embodiment, the reflecting plate 12 and the pressure-resistant and heat-resistant glass 17 are accommodated in a cylindrical rotating container 22 in a state where the positional relationship is fixed. For example, as shown in FIG. 5, the rotary container 22 has a rail 22 b on the outer periphery of a cylindrical main body 22 a, and a drive shaft along a rail receiver 23 (FIGS. 3 and 4) fixed in the pressure resistant container 20. Rotate around 15. Therefore, when the reflecting plate 12 rotates in the rotating container 22, the pressure-resistant and heat-resistant glass 17 also rotates in a state of being arranged in the reflecting direction of the reflecting plate 12, so that the pressure-resistant and heat-resistant glass 17 has a minimum area and thickness. The microwave reflected by the reflecting plate 12 can always be transmitted.

  As described above, the area and thickness of the pressure-resistant and heat-resistant glass 17 are reduced to the minimum by rotating together with the reflective plate 12 in a state where the pressure-resistant and heat-resistant glass 17 is always arranged on the projection surface in the reflection direction of the reflective plate 12. Can reduce costs. As an example, in the configuration of the present invention, in the case of a device to which quartz glass having a diameter of 300 mm and a thickness of 25 mm is applied, the conventional configuration requires a glass having a size of about 400 mm × 1200 mm and a thickness of 40 mm.

  The furnace inner opening 21 of the pressure vessel 20 communicates with the furnace of the blast furnace 2. The furnace inner opening 21 is formed so that the microwave reflected by the reflecting plate 12 is irradiated to a predetermined range in the furnace. As shown in FIG. 3, for example, a swing type valve 24 capable of opening and closing the furnace inner opening 21 is provided. The valve 24 is arranged at a position indicated by a two-dot chain line in FIG. 3 to block the furnace inner opening 21 in order to prevent dust and the like from entering the pressure vessel 20 side from the blast furnace 2 except during profile measurement. At the time of profile measurement, as shown by a solid line in FIG. 3, the furnace inner opening 21 is opened by retreating downward. When the profile measurement is not performed, as shown in FIG. 6, the valve 24 is closed and the rotating container 22 is rotated so that the pressure-resistant and heat-resistant glass 17 is arranged on the upper side. Can be protected from etc. The valve 24 may be a partition type.

  Furthermore, the pressure vessel 20 has an upper opening 25 on the top surface where the reflector 12 and the pressure and heat resistant glass 17 are disposed, and a lid 26 for closing the upper opening 25 is provided. As shown in FIG. 6, after the rotating container 22 is rotated until the pressure-resistant and heat-resistant glass 17 is disposed on the upper side, the lid 26 is opened to facilitate inspection, cleaning, or replacement of the pressure-resistant and heat-resistant glass 17. Can do.

  The inner surfaces of the pressure vessel 20 and the rotary vessel 22 are covered with a radio wave absorber 27 corresponding to the transmission frequency band except for the furnace inner opening 21, the upper opening 25, and the reflecting surface side of the reflector 12. Yes. By providing the radio wave absorber 27, measurement noise due to diffused reflection and multiple reflection of microwaves in the pressure resistant vessel 20 is suppressed.

  Further, at the time of measuring the profile, for the purpose of preventing the gas or dust inside the blast furnace 2 from entering the pressure vessel 20 and further preventing the gas inside the blast furnace 2 from leaking to the outside through the pressure vessel 20. The pressure vessel 20 is pressurized with nitrogen gas so that the pressure is, for example, about 1.1 times the furnace pressure. As shown in FIG. 3, nitrogen gas can be blown along the surface of the pressure and heat resistant glass 17 to prevent dust and the like in the furnace from adhering to the surface of the pressure and heat resistant glass 17. Wave attenuation can be prevented. Furthermore, at the time of profile measurement, nitrogen gas is blown from the outside of the blast furnace 2 to the position of the furnace inner opening 21 of the pressure vessel 20 at a pressure slightly higher than the furnace pressure, for example, a furnace pressure +0.4 MPa. . Thereby, even when blowing up of the blast furnace 2 occurs, pressure acts on the inside of the furnace, so that dust or the like in the furnace does not enter and the profile measuring device 1 can be protected. Note that the gas blown into the pressure vessel 20 may be an inert gas other than nitrogen.

  Further, cooling water is allowed to flow from the outside of the blast furnace 2 to the furnace inner opening 21 of the pressure vessel 20, around the microwave transmitter / receiver 14 in the pressure vessel 20, and the profile measuring device 1 is protected from the heat in the furnace. You may do it. In addition, the cooling effect in the heat-resistant container 20 is exhibited also by blowing nitrogen gas.

  Hereinafter, the example of the procedure which measures the profile of a blast furnace interior entrance using the profile measuring apparatus 1 of this invention is demonstrated. The measurement method described below is an example, and the present invention is not limited to this measurement method.

First, the microwave is transmitted from the microwave transmitter / receiver 14 with the direction of the reflector 12 of the profile measuring device 1 directed to the initial position. The microwave is reflected by the reflecting plate 12 through the waveguide 13 and the antenna 11, passes through the pressure-resistant and heat-resistant glass 17 and is irradiated on the blast furnace interior entrance 4, and the distance D to the charge 4 is measured. . Then, the reflector 12 is rotated by the reflector driving device 16 from, for example, an initial position at which the profile directly underneath is measured to a predetermined position, for example, a position at which the opposite side in the inner diameter direction of the furnace is measured. For each angle preset according to the desired spatial resolution, the distance to the charge 4 is measured, the distance data is obtained, and the reflection plate driving device 16 has the scanning angle data at that time as the data processing unit 18. Sent to. Thereafter, the reflecting plate 12 is returned to the initial position side, and the same measurement is performed again at a predetermined time interval T such as 1 minute. The data processing unit 18 calculates a charge profile at each position in the blast furnace based on the input scanning angle data and the distance data at that time. At this time, for example, at an arbitrary position such as a position where the microwave is directed directly below, the descent speed of the blast furnace interior 4 from the first distance data D1 and the second distance data D2 at the same preset scanning angle. V is calculated. The descending speed V is obtained by the following equation.
V = (D2-D1) / T = ΔD / T

Next, a correction amount of the measured distance data is obtained. In this embodiment, the amount of descent due to the time difference during measurement is corrected according to the horizontal distance in the inner diameter direction of the furnace. That is, as shown in FIG. 7 (a), since the charge 4 descends from the time when the initial position is measured until the end of the measurement, the descent correction amount r is as shown in FIG. 7 (b). Furthermore, it decreases as the horizontal distance x of the furnace inner diameter L increases from the initial position, and becomes zero on the opposite side of the initial position. In consideration of the measurement time difference depending on the measurement position, the amount r that descends at the time t is corrected according to the distance in the inner diameter direction of the furnace. That is, the height position of the charge 4 at the time when the opposite side of the initial position is measured is obtained by correction. The descent correction amount r can be obtained by the following equation.
r = V × t

  In this way, by correcting the profile measurement value with the descent correction amount r, a profile of the blast furnace interior 4 that eliminates the influence of the descent of the charge 4 being measured is obtained. In addition, a simple profile can also be calculated | required by making descent speed V constant irrespective of the position in a furnace.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  The present invention can be applied to an apparatus for measuring a surface shape in a furnace in which dust or the like is generated at a high temperature.

DESCRIPTION OF SYMBOLS 1 Profile measuring apparatus 2 Blast furnace 3 Furnace body 4 Charge 5 Bell-less type charging apparatus 6 Distribution chute 11 Antenna 12 Reflector 13 Waveguide 14 Microwave transmitter / receiver 15 Drive shaft 16 Reflector drive 17 Pressure-resistant heat-resistant glass 18 Data Processing unit 20 Pressure vessel 21 Opening inside furnace 22 Rotating vessel 24 Valve 25 Upper opening 26 Lid 27 Radio wave absorber

Claims (5)

A profile measuring device that is installed at the top of the blast furnace and measures the profile of the blast furnace interior,
A microwave transceiver capable of transmitting and receiving microwaves;
An antenna that radiates microwaves transmitted from the microwave transceiver;
A waveguide connecting the microwave transceiver and the antenna;
A reflector that reflects the microwave radiated from the antenna toward the furnace of the blast furnace;
A reflector driving device for driving the reflector;
A drive shaft connecting the reflector and the reflector driving device;
A pressure-resistant and heat-resistant glass that transmits the microwave reflected by the reflector, and
The antenna, the reflector, and the pressure-resistant and heat-resistant glass are accommodated in a pressure-resistant container having a furnace inner opening directed into the furnace of the blast furnace,
The apparatus for measuring a profile of a blast furnace interior, wherein the pressure-resistant and heat-resistant glass is fixed in a reflecting direction toward the furnace of the reflector and rotates around the drive shaft together with the reflector.   The apparatus for measuring a profile of a blast furnace interior according to claim 1, wherein the pressure-resistant and heat-resistant glass and the reflecting plate are accommodated in a rotating container that rotates about the drive shaft.   The top opening of the position where the said pressure-resistant heat-resistant glass is arrange | positioned of the said pressure vessel is provided with the lid | cover which can open and close an upper opening part and the said upper opening part, It is characterized by the above-mentioned. The blast furnace interior entrance profile measurement device described.   The blast furnace interior entrance according to any one of claims 1 to 3, wherein nitrogen gas is blown into the periphery of the pressure and heat resistant glass from the outside of the blast furnace at a pressure higher than the furnace pressure in the blast furnace. Equipment profile measuring device.   The blast furnace interior entrance profile measuring apparatus according to any one of claims 1 to 4, wherein a valve capable of opening and closing the furnace inner opening is provided.

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