JP2018059175A - Level gauge for blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a level gauge for blast furnaces, which requires little installation space; prevents infiltration of not only fine dust from the furnace but also relatively large dust into an apparatus; enables continuous measurement; and enables instantaneous detection of an abnormality in the descent of a charged material.SOLUTION: The level gauge for a blast furnace of the present invention comprises: a vertical portion extending vertically from an opening to the outside of the furnace; a substantially L-shaped cylindrical body extending as a horizontal portion bent from the vertical portion; an antenna disposed at an end of the horizontal portion opposite to the vertical portion; and a reflector having a reflective surface opposing to the opening and the antenna, which is disposed at a bent portion between the vertical portion and the horizontal portion, and inclined at an angle of 45° with respect to the axis of the cylindrical body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a level meter that detects a deposit amount in a blast furnace using a detection wave such as a microwave or a millimeter wave.

In the blast furnace, a level meter is used to manage the amount of charges such as iron ore and coke. As shown in FIG. 3, the conventional blast furnace level meter 1 has an antenna 10 attached outside the opening 101 provided at or near the top of the blast furnace 100, and microwaves from a microwave transceiver 20 are supplied to the furnace. send within this transmission wave M _T is the reflected wave M _R reflected by the surface of the charge 200, such as iron ore and coke received by the transceiver 20, the transmission wave M _T and the reflected wave M _R The accumulation amount of the charge 200 is detected based on the phase difference (see, for example, Patent Documents 1 and 2). Note that reference numeral 30 in the drawing denotes a waveguide connecting the antenna 10 and the transceiver 20.

  However, iron ore or coke dust blows up from the furnace and enters the antenna 10 or the waveguide 30 through the opening 101 to reduce the measurement accuracy. Further, when the waveguide 30 is blocked by dust, microwaves cannot be transmitted / received. Therefore, in Patent Document 3, a branch pipe is provided at an appropriate position of the waveguide 30 to supply an inert gas, or a gas ejection hole is provided to the antenna 10 to supply an inert gas.

Japanese Utility Model Publication No. 62-2807 Japanese Utility Model Publication No. 55-179364 JP 2006-38756 A

  However, the method of supplying an inert gas to the inside of the waveguide 30 and the antenna 10 as in Patent Document 3 is effective for fine powder, but is insufficient for preventing entry of a certain amount of dust. Although it is conceivable to provide a valve valve in the opening 101 and open the valve valve at the time of measurement, it is necessary to open and close the valve valve for each measurement, which not only makes the measurement work complicated, but also increases the measurement interval. When there is an abnormality in the lowering of the charge 200, it cannot be quickly dealt with.

  Moreover, since the antenna 10 is attached in a state of standing vertically from the opening 101, the installation space is also increased.

  The present invention has been made in view of such a situation. In addition to fine powder from the furnace, infiltration of relatively large dust into the apparatus can be prevented more than ever, and continuous measurement is possible. It is an object of the present invention to provide a level meter for a blast furnace that can instantaneously detect an abnormality in the lowering of the charge and further requires less installation space.

In order to solve the above problems, the present invention provides the following blast furnace level meter.
(1) A detection wave from a transmitter / receiver of a detection wave is transmitted into the furnace through an opening near the top of the blast furnace or near the furnace top, and the reflected wave reflected from the surface of the charge in the furnace is transmitted through the opening. In a blast furnace level meter that sends to a transceiver and receives it with the transceiver to detect the state of accumulation of the charge,
A substantially L-shaped cylindrical body comprising a vertical portion extending vertically from the opening to the outside of the furnace, and a horizontal portion extending from the vertical portion;
An antenna installed at an end of the horizontal portion opposite to the vertical portion;
And a reflecting plate disposed at a bent portion between the vertical portion and the horizontal portion, and having a reflecting surface inclined by 45 ° with respect to the axis of the cylindrical body and facing the opening and the antenna. Blast furnace level meter.
(2) The blast furnace level meter according to (1), wherein a bent portion of the cylindrical body is inclined by 45 ° with respect to an axis of the cylindrical body to form the reflecting plate.
(3) Between the reflection plate and the antenna, in order from the reflection plate side, a wire mesh, a woven fabric made of a heat-resistant material that transmits a detection wave, and a non-breathable material made of a heat-resistant material that transmits the detection wave The blast furnace level meter according to (1) or (2) above, wherein a partition wall is provided.
(4) The blast furnace level meter according to (3), wherein an inert gas is supplied between the woven fabric and the partition wall.
(5) In any one of the above (1) to (4), an inclined surface that descends toward the blast furnace is formed in a portion of the cylindrical body that faces the reflector. Blast furnace level meter.

  In the blast furnace level meter of the present invention, dust from the furnace first collides with the reflector, and even if it is relatively large dust, most of it falls into the furnace, greatly increasing the amount of dust entering the antenna side. Can be reduced. Moreover, since it is not necessary to block the opening of the blast furnace and continuous measurement is possible, when there is an abnormality in the descending of the charged material, it is possible to quickly deal with it and to operate the blast furnace stably. Furthermore, since the entire apparatus is substantially L-shaped, the installation space can be reduced as compared with a blast furnace level meter in which the antenna is mounted in a vertical position from the opening.

It is sectional drawing which shows the level meter for blast furnaces of this invention. It is a surface view which shows the wire mesh shown in FIG. It is sectional drawing which shows the conventional level meter for blast furnaces.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the blast furnace level meter 1 of the present invention includes a cylindrical body 40 having a substantially L shape, and an antenna 10 is accommodated at one end thereof, and the other end is connected to an opening 101 of the blast furnace 100. doing. The opening 101 is formed at or near the top of the blast furnace 100.

  The cylindrical body 40 includes a vertical portion 41 that extends vertically from the opening 101 to the outside of the furnace, and a horizontal portion 42 that extends at a right angle from the vertical portion 41 as indicated by a dotted line. The end portion of the horizontal portion 42 is closed, and the antenna 10 is attached to the end surface 43. By attaching the antenna 10 to the end face 43 of the horizontal portion 41, the influence of heat from the opening 101 can be reduced as compared with the case where the antenna 10 is attached vertically to the opening 101 as shown in FIG. .

  A transceiver 20 is connected to the antenna 10 via a waveguide 30, and a detection wave such as a microwave or a millimeter wave is transmitted from the antenna 10. Since the end portion of the horizontal portion 42 is closed and the end face 43 is formed, the transceiver 20 is not substantially affected by heat from the opening 101. As the detection wave, a millimeter wave is preferable, and the diameter of the waveguide 30 is smaller than when a microwave is used, so that it is difficult for dust to enter the waveguide 30.

  The antenna 10 may be a parabolic antenna, and may be a horn antenna with a lens provided with a dielectric lens 11 as shown. In the horn antenna with a lens, the directivity of the detection wave is enhanced by the dielectric lens 11, and the length of the horn can be shortened to shorten the cylindrical body 40.

  A reflecting plate 50 is accommodated in the bent portion 45 of the cylindrical body 40. The reflection plate 50 is inclined by 45 ° with respect to the axis of the cylindrical body 40 so as to face the opening 101 and the antenna 10. Although not shown, a structure in which a support shaft is attached to the center of the back surface (surface opposite to the antenna 10) of the reflection plate 50, and the support shaft is rotated during non-measurement to close the opening 101 with the reflection plate 50. It can also be. By this rotation, it is possible to prevent dust from entering during non-measurement.

  Further, the reflecting plate 50 is not separated as described above, and a portion corresponding to the bent portion 45 of the cylindrical body 40 is formed as an inclined surface inclined by 45 ° so as to face the opening 101 and the antenna 10. It can also be.

By arranging the antenna 10 and the reflecting plate 50 to face each other as described above, a detection wave is transmitted from the antenna 10, propagates through the horizontal portion 42 of the cylindrical body 40, reaches the reflecting plate 50, and the reflecting plate. It is reflected at 50 and sent into the furnace (transmitted wave M _T ). The transmission wave M _T is reflected by the surface of the charge 200, such as iron ore and coke is deposited into the furnace (reflected wave M _R), reaches the reflecting plate 50 through the opening 101, a reflective plate 50 Reflected and received by the transceiver 20. The transceiver 20, calculates the distance to the charge 200 based on the phase difference between the transmitted wave M _T and the reflected wave M _R, determine the amount of accumulated charge 200. Note that the amount of deposit 200 is displayed on a display device (not shown).

  In the furnace, the dust of the charge is blown up and enters the cylinder 40 of the blast furnace level meter 1 through the opening 101. However, there is a reflector 50 immediately above the opening 101, and most of the dust including large-diameter dust collides with the reflector 50 and falls. Therefore, as shown in FIG. 3, the dust traveling to the antenna 10 is greatly reduced as compared with the blast furnace level meter 1 in which the antenna 10 is installed vertically with respect to the opening 101. In addition, since the cylindrical body 40 is substantially L-shaped and the detection wave propagates through the inside, the vertical portion (height portion) of the antenna 10 is eliminated as compared with the blast furnace level meter 1 shown in FIG. Less space is required.

  In addition, fine dust is also included in the dust, and even if this fine float hits the reflector 50, it floats on the horizontal portion 42 of the cylindrical body 40 without falling, and is attached to the antenna 10. There is a risk of reaching. Therefore, it is preferable to install a woven fabric 70 made of a heat-resistant material that transmits the detection wave on the front surface of the antenna 10. As the woven fabric 70, for example, a finely knitted “Tyranno fiber” manufactured by Ube Industries, Ltd. can be used. The Tyranno fiber is a continuous fiber made of silicon, titanium or zirconium, carbon, and oxygen, has heat resistance, and transmits microwaves and millimeter waves that are detection waves.

  However, since fine powder adheres to the woven fabric 70, it is preferable to prevent the adhesion by blowing an inert gas from the antenna side of the woven fabric 70. For this purpose, a non-breathable partition wall 80 (for example, a ceramic plate) made of a heat-resistant material that transmits detection waves is installed between the woven fabric 70 and the antenna 10, and the woven fabric 70 and the partition wall 80. An inert gas such as nitrogen gas is supplied through a gas supply port 90 to the space between the two.

  As described above, dust collides with the reflector 50 and falls, and most of it falls into the furnace from the opening 101, but a part is reflected to the antenna side. As indicated by the dotted line, when the vertical portion 41 and the horizontal portion 42 of the cylindrical body 40 are bent at a right angle, dust accumulates on the bottom surface 46 on the vertical portion side of the horizontal portion 42 to transmit and receive the detection wave. Adversely affect. Therefore, as indicated by a solid line, it is preferable that a portion of the cylindrical body 40 facing the reflecting plate 50 is an inclined surface 47 that descends toward the opening 101. Even if there is dust reflected on the antenna side by the reflecting plate 50, the inclined surface 47 is lowered and falls into the furnace from the opening 101.

  Further, the dust includes large-diameter dust and may be reflected to the antenna side. Therefore, when the woven fabric 70 is installed, there is a possibility that the woven fabric 70 may be damaged by collision of large-diameter dust. Therefore, it is preferable to install the wire mesh 60 on the surface of the woven fabric 70 on the reflecting plate side. The woven fabric 70 and the wire mesh 60 may be arranged with a space therebetween or may be overlapped. FIG. 2 is a front view showing an example of the wire mesh 60, in which a metal horizontal bar 62 and vertical bars 63 are attached to a metal frame 61 by welding or the like in a lattice shape. Moreover, although illustration is abbreviate | omitted, what opened many holes in the metal plate may be sufficient.

  In addition, since the woven fabric 70 and the partition 80 are made of a heat-resistant material, the antenna 10 can be further protected from heat from the opening 101.

  Thus, the blast furnace level meter 1 of the present invention is space-saving, can prevent dust from entering from the furnace even with the opening 101 open, and can perform continuous measurement. Therefore, it is possible to respond immediately when there is an abnormality in the lowering of the charge 200, and stable blast furnace operation is possible.

DESCRIPTION OF SYMBOLS 1 Blast furnace level meter 10 Antenna 20 Transceiver 30 Waveguide 40 Cylindrical body 41 Vertical part 42 Horizontal part 50 Reflector plate 60 Metal mesh 70 Woven cloth 80 Bulkhead 100 Blast furnace 101 Opening 200 Charge

Claims (5)

A detection wave from the transmitter / receiver of the detection wave is transmitted into the furnace through an opening near or at the top of the blast furnace, and a reflected wave reflected from the surface of the charge in the furnace is transmitted to the transmitter / receiver through the opening. In a blast furnace level meter that detects the accumulation state of the charge received by the transceiver,
A substantially L-shaped cylindrical body comprising a vertical portion extending vertically from the opening to the outside of the furnace, and a horizontal portion extending from the vertical portion;
An antenna installed at an end of the horizontal portion opposite to the vertical portion;
And a reflecting plate disposed at a bent portion between the vertical portion and the horizontal portion, and having a reflecting surface inclined by 45 ° with respect to the axis of the cylindrical body and facing the opening and the antenna. Blast furnace level meter.   2. The blast furnace level meter according to claim 1, wherein the bent portion of the cylindrical body is inclined by 45 ° with respect to the axis of the cylindrical body to form the reflecting plate. 3.   Between the reflecting plate and the antenna, in order from the reflecting plate side, a wire mesh, a woven fabric made of a heat-resistant material that transmits the detection wave, and an air-impermeable partition wall made of a heat-resistant material that transmits the detection wave. The level meter for a blast furnace according to claim 1 or 2, wherein the level meter is provided.   The blast furnace level meter according to claim 3, wherein an inert gas is supplied between the woven fabric and the partition wall.   The blast furnace level meter according to any one of claims 1 to 4, wherein an inclined surface that descends toward the blast furnace is formed in a portion of the cylindrical body that faces the reflector.

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