JP3129706B2 - How to introduce shock waves into the blast furnace core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blast furnace core for indirectly measuring the temperature and air permeability of a core formed mainly of coke particle deposits formed on the hearth of a blast furnace. And a method for introducing a shock wave into a vehicle.

[0002]

2. Description of the Related Art How to control and stabilize the operation of a blast furnace is an important issue in the steelmaking industry, and various detection ends are provided in a blast furnace body. However, the detection end of the furnace core, which is formed mainly by the accumulation of coke particles above the pool in the hearth of the blast furnace and below the cohesive zone, is widely used as much as the shaft sonde, despite its importance. It has not been done yet.

For example, as proposed in JP-A-61-257405 and JP-A-63-210208, a probe with a cooling mechanism, which incorporates a glass fiber connected to image processing from a tuyere of a blast furnace. There is a direct measurement method such as a method of directly inserting the probe into the furnace core and measuring the temperature, or a method of detecting a sonde insertion resistance into the furnace core. Also, Japanese Unexamined Patent Publication No.
As proposed in Japanese Patent No. 104412, a method of arranging a radiation scanner and a detection group on the outer periphery of a blast furnace to continuously monitor the inside of the furnace and an indirect measurement method are known.

[0004]

The furnace core sonde according to the conventional direct measurement method is a method in which the sonde is directly inserted into the furnace core part through a raceway, which is a high temperature part in the furnace, from a tuyere part. , Equipment and equipment, especially the sealing mechanism becomes large, and the measurement operation itself is dangerous, so it is not easy to measure easily from any tuyeres arranged in the dozens in the circumferential direction of the furnace. It was impossible.

Further, the radiation scanning method related to the indirect measurement method requires equipment for shielding radiation around the casting bed.

Since the blast furnace condition changes every moment, it is desired to detect the core portion in real time and at the same time to detect the balance in the circumferential direction.

[0007] In view of the above problems, the present invention does not directly insert a detection end such as a sonde into the above-mentioned furnace core and does not give a disturbance around the blast furnace. It is intended to provide a method of introducing a shock wave into the core of a blast furnace when indirectly measuring the heat resistance.

[0008]

That is, the gist of the present invention is as follows: (1) A shock wave generated by instantaneous explosive combustion outside a blast furnace is guided into the blast furnace via a waveguide, and The shock wave propagated through the core is received by the receiving sensor, and from the propagation speed or attenuation rate of these shock waves, the temperature of the core of the blast furnace hearth, which is mainly formed by depositing coke particles, or the air permeability A method of introducing a shock wave used for measurement of a furnace core into a blast furnace, wherein a part of a pulverized coal-injected burner installed in a tuyere is used as the waveguide. (2) When the shock wave generated outside the blast furnace is guided into the blast furnace, the pulverized coal flow path is shut off to interrupt the pulverized coal injection, and the furnace core portion according to the above (1), A method to guide the shock wave used for measurement into the blast furnace. It is.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention.

Various vibrations are generated and propagated in the operating blast furnace, and ordinary ultrasonic waves are too large to propagate inside the hearth diameter exceeding 10 m, so that the measurement cannot be performed well. Thus, the present invention focused on shock waves as a result of experiments.

The shock wave referred to in the present invention is a generally referred to as a strong compression wave propagating in a shrinking medium, and specifically includes, for example, instantaneous combustion of gaseous fuel or the like, or instantaneous combustion of explosive or the like. Shock waves generated by using typical combustion can be adopted.

As shown in FIGS. 1 and 2, the shock wave is generated by a shock wave generator 1 provided outside the blast furnace 3. This shock wave generator 1 can generate shock waves intermittently at specific intervals. This shock wave is supplied to the hearth of the blast furnace 3 through the waveguide 2 connected to the generator 1, and is directed from the furnace wall 4 to the furnace core mainly formed of coke particle deposits. . As a connection mode between the shock wave generator 1 and the waveguide 2, as shown in FIG. 1, one shock wave generator 1 is connected to one waveguide 2, or as shown in FIG. There is a method in which a plurality of, for example, four waveguides 2 are connected to a pulse generator 12 that generates a shock wave intermittently. The latter plural waveguides 2
Is connected, it is possible to provide a difference in the length of each waveguide 2, and it is possible to delay the supply timing of the shock wave into the furnace. The tip of the waveguide 2 is provided on the furnace wall 4 so as to face the furnace core as described above. As a characteristic installation mode of the waveguide 2, for example, a part of a burner 6 for blowing pulverized coal installed in the tuyere 5 can be used. When the shock wave generated by this method is supplied into the furnace, the pulverized coal blowing is interrupted, and the shutoff valve 7 in the pulverized coal flow path is closed to promote the propagation of the shock wave to the front of the tuyere 5. . In the case of the tuyere 5 which is not provided with a diversion means such as a pulverized coal injection burner, the dedicated shock wave waveguide 2 is arranged in the same manner as the pulverized coal injection burner.

The number of the waveguides 2 to be installed may be at least three at equal intervals in the furnace circumferential direction, or at four points a, b, c, and d in the cross position in the furnace circumferential direction. As the number of the waveguides 2 increases, the measurement accuracy described later increases.

A plurality of receiving sensors 8 are arranged in the furnace circumferential direction on the furnace wall 4 at substantially the same level as the installation level of the waveguide 2. The receiving sensor 8 is constituted by means for detecting a sound wave, and for example, a pressure-sensitive element can be used. Various modes can be applied as the installation position of the receiving sensor 8. For example, when the receiving sensor 8 is installed inside the furnace of the hearth furnace wall 4, a plurality of the sensors are arranged at equal intervals in the furnace circumferential direction in consideration of heat resistance measures. A method in which the tuyere 5 is installed at the tip of the water-cooling jacket portion, or a method in which a water-cooling probe (not shown) incorporating the receiving sensor 8 is installed in the tuyere 5 or the furnace wall 4 can be adopted. When the receiving sensor 8 is installed outside the hearth furnace wall 4, a method is adopted in which the receiving sensor 8 faces a blow pipe portion or a rearmost viewing window portion arranged at the rear end of the tuyere 5. In this case, the tuyere 5 or the blow pipe functions as a receiving waveguide.

As long as at least eight receiving sensors 8 are installed on the furnace wall facing the waveguide 2, the number of the receiving sensors 8 is acceptable as the measurement accuracy.

When the shock wave generated by the shock wave generator 1 is supplied from the furnace wall through the waveguide 2 into the furnace, the receiving sensor 8 closest to the waveguide 2 that has emitted the shock wave simultaneously emits the shock wave. The other receiving sensor 8 arranged in the furnace circumferential direction receives the shock wave after a delay time corresponding to the part. As shown in FIG. 2, the waveguide 2 and the receiving sensor 8 provided at each tuyere 5 are used, and after the maximum delay time from the emission of the shock wave to the reception thereof, through the waveguide 2 at another portion. By cyclically performing operations of supplying and receiving a shock wave into the furnace, a band where a ripple effect of a shock wave emitted from a specific waveguide 2 with directionality is relatively weak (shock wave emitting waveguide). Are complemented in the next operation, so that a plurality of points in the circumferential direction of the furnace core can be measured.

The shock wave received by the above operation is amplified by the amplifier 9, recorded as a received waveform in the recorder 10, and applied to a calculation display 11 for performing a calculation corresponding to a desired temperature and air permeability to be described later. You.

Each received wave applied to the operation display 11 is C
Data processing is performed by the T scanning method. Specifically, there are a summation method, a convolution method, a least square method, and the like, but the least square method is suitable because the number of data obtained in the circumferential direction is not so large.

For example, when obtaining the temperature distribution of the furnace core,
Generally, the sound velocity v in a gas is given by the following equation.

[0020]

(Equation 1)

Here, κ is a specific heat ratio, R is a gas constant, and T is a gas temperature. If the propagation distance is known, the gas temperature can be known from the propagation time.

Each projection data in CT is transmitted at point A
Divides receiving point B into section n, and within that section the propagation velocity
Is assumed to be constant, the propagation time from transmission to reception
Interval τ _ABIs represented by the following equation.

[0023]

(Equation 2)

Here, l _i : propagation distance in section i, T _i : temperature in section i, v (T _i ): propagation velocity in section i, and u _i : gas velocity in section i.

Conversely, it is assumed that the propagation time from the transmission point B to the reception point A is Z _BA, and that u _i at the core of the blast furnace is sufficiently smaller than v _i , apart from the tuyere tip. From equation (2),

[0026]

(Equation 3)

[0027]

(Equation 4)

## EQU1 ##

From equation (3), the equation representing the temperature distribution in the furnace core is the following multidimensional simultaneous equation.

[0030]

(Equation 5)

In the equation (5), the vector b is the measured value of the propagation time, the matrix A is the distance in the section i, the vector Y is the reciprocal of V _{i in} the section i, and has a relationship between the temperature T _i and the equation (1).

If there are n or more data, based on the equation (5), the least squares method finds the vector Y that minimizes the following equation (6), from which the temperature distribution T _i can be found.

[0033]

(Equation 6)

As described above, various noises are generated in the blast furnace, and nozzles are mixed in the received waveform. However, since the cycle of the temperature change of the furnace core is long, the above-described measurement operation is periodically performed. By repeatedly adding the obtained reception waveforms, S /
The N ratio can be increased. Preferably, the pulse generator 12 generates the shock waves periodically and sequentially.

Although the description has been given based on the calculation example of the temperature, it is needless to say that a theoretical equation corresponding to the characteristic value is developed when the shock wave attenuation rate corresponding to the air permeability is obtained.

[0036]

FIG. 3 shows the results of measurement of the core temperature distribution of an experimental blast furnace using the method of the present invention. Shock waves generated by instantaneous combustion of gaseous fuel are supplied into the furnace at three-second intervals sequentially from the tuyeres 5 at four cross-shaped positions in the circumferential direction of the blast furnace, and are received in 15 tuyeres 5 built-in. The operation of receiving with the sensor 8 was repeated 10 times. This is a result of calculating the furnace core internal temperature by performing arithmetic processing on the obtained reception waveform.

[0037]

According to the present invention, since the temperature distribution and the like of the furnace core can be indirectly measured in a short time during the operation of the blast furnace, the measured physical property information is immediately reflected in the operation, and the result is measured again. Monitoring can be performed, and stable operation can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view of an example of an apparatus according to the present invention.

FIG. 2 is an explanatory horizontal sectional view showing an outline of the present invention.

FIG. 3 is a model diagram showing a temperature distribution of a furnace core in an experimental furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shock wave generator, 2 ... Waveguide 3 ... Blast furnace, 4 ... Furnace wall 5 ... Tuyere 6 ... Pulverized coal blowing burner 7 ... Shutoff valve, 8 ... Reception sensor 9 ... Amplifier, 10 ... Recorder 11 ... Calculation display Vessel, 12 ... pulse generator

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-49-72114 (JP, A) JP-A-60-131906 (JP, A) JP-A-59-22189 (JP, A) 83708 (JP, A) Transactions of the Japan Society of Mechanical Engineers, Vol. 53, No. 489, pp. 1610-1614 (58) Fields investigated (Int. Cl. ⁷ , DB name) C21B 7/24 305 C21B 7/00 310 F27D 21/00 G01K 11/24 F27B 1/28 G01F 23/28

Claims (2)

(57) [Claims] 1. A shock wave generated by an instantaneous explosive combustion outside a blast furnace is guided into a blast furnace through a waveguide, and a shock wave transmitted through a furnace core is received by a receiving sensor, and propagation of these shock waves is performed. One of the pulverized coal blowing burners installed at the tuyere is used to measure the temperature or air permeability of the furnace core formed by depositing mainly coke particles in the hearth of the blast furnace from the speed or the damping rate. A method for guiding a shock wave used for measurement of a furnace core portion into a blast furnace, wherein the portion is the waveguide. 2. The furnace core part according to claim 1, wherein, when a shock wave generated outside the blast furnace is guided into the blast furnace, the pulverized coal passage is interrupted to interrupt pulverized coal injection. A method to guide the shock wave used for measurement into the blast furnace.