JP6447470B2 - Charge distribution control method in blast furnace - Google Patents

Description

  The present invention relates to a charge distribution control method for appropriately controlling a charge distribution in a furnace in a blast furnace in which a raw material is charged into the furnace by a bell-less charging apparatus having a turning chute.

Generally, in the blast furnace, ore (which may be mixed with the coke) and coke are charged alternately from the top of the furnace, and ore layers and coke layers are alternately deposited in the furnace. The raw material is filled in the state.
In blast furnace operation, it is important to maintain an appropriate charge distribution at the top of the furnace. If the charge distribution is not appropriate, the gas flow distribution becomes uneven, the gas permeability decreases, and the reduction efficiency. As a result, the productivity will decrease and the blast furnace operation will become unstable.
As a means for charging the raw material from the top of the furnace, a bell-less charging device equipped with a turning chute (distribution chute) is widely used. In this charging device, the tilt angle and the number of turns of the turning chute are selected. The distribution of the charged material is controlled by adjusting the dropping position of the raw material and the deposition amount in the furnace radial direction.

  On the other hand, in order to grasp the charge distribution, it is necessary to measure the profile of the furnace interior entrance surface (raw material deposition surface). As a method of measuring the profile of the furnace interior entrance surface, a detection wave such as a microwave is transmitted toward the furnace interior entrance surface, and the detection wave reflected by the furnace interior entrance surface is received to receive the furnace interior entrance. The distance to the surface is measured, and the profile of the furnace interior entrance surface is obtained based on the measured distance. As a specific method, a measurement lance provided with a detection wave antenna is connected to the furnace port. The method of inserting from the side toward the furnace center is the mainstream (for example, Patent Documents 1 and 2).

JP-A-7-34107 JP 2002-115008 A

In order to accurately control the charge distribution in the blast furnace, it is necessary to accurately and quickly grasp the profile of the furnace interior charge surface. In addition to being time consuming and not being able to make a quick measurement, there is a problem that the measurement frequency becomes low because the measurement lance has to be withdrawn from the furnace body when the raw material is charged. For this reason, the information obtained from the measurement results cannot be quickly reflected in the actual operation. Furthermore, even if a specific action (charge distribution control) is taken based on the measurement result, the result cannot be confirmed immediately. That is, with the conventional measurement method, it is substantially difficult to perform the measurement while reflecting and confirming the profile measurement result of the furnace interior entrance surface in the charge distribution control.
In addition, since the furnace interior inclusion deposition surface cannot be measured when the raw material is charged, the raw material deposition process cannot be grasped. For this reason, it is difficult to determine which process of raw material deposition has a problem, and it is difficult to improve the accuracy of charge distribution control.

  Therefore, the object of the present invention is to accurately and quickly grasp the charge distribution in the blast furnace, so that the charge distribution can be appropriately controlled, thereby obtaining a high reduction efficiency of the ore and the blast furnace. The object is to provide a charge distribution control method capable of stabilizing the operation.

The gist of the present invention for solving the above problems is as follows.
[1] By means of a bell-less charging device equipped with a swivel chute, ores (including mixed raw materials in which a portion of coke and / or auxiliary materials are mixed with ore) and coke are alternately charged into the blast furnace. In addition, the raw material charging in which the ore layer (however, including the mixed raw material layer by the mixed raw material) and the coke layer are alternately laminated is performed, and the charging of the ore and the coke in one charge is performed in a plurality of batches. In doing so,
This is a profile measuring device for the furnace interior entrance surface installed at the top of the blast furnace. The distance to the furnace interior entrance surface is measured with a radio-type distance meter, and the detected wave radiation direction of the distance meter is Using a profile measuring device that measures the profile of the furnace interior entrance surface based on the distance data to the furnace interior entrance surface obtained by scanning in the radial direction, the furnace interior entrance after at least each batch is charged. The profile of the surface is measured, and the distribution of the ore and coke charged in each batch is obtained based on the profile. Based on this distribution, the ore layer thickness ratio at the top of the furnace interior layer [Lo / (Lc + Lo)] (where Lo: ore layer thickness, Lc: coke layer thickness) has a charging distribution that satisfies the following conditions (a) to (d). Swivel chute notch in at least one batch during charging or And burden distribution control method in a blast furnace, characterized in that adjusting the number of turns.
(A) Average value of the first region: less than 0.5 (b) Average value of the second region: 0.6 or more and less than 0.9 (c) Average value of the third region: 0.4 or more and less than 0.8 (D) Average value of the first region <Average value of the third region <Average value of the second region However, the distance from the furnace center in the furnace radial direction is r (m), and the furnace radius at the furnace port is Rt In the case of (m), the in-furnace region in the furnace radial direction is, in order from the furnace center side, r / Rt ≦ 0.20: first region, 0.20 <r / Rt ≦ 0.80: second region 0.80 <r / Rt: The third region.

[2] In the charge distribution control method of [1] above, the ore charge closest to the furnace wall in at least one batch so as to obtain a charge distribution that satisfies the conditions (a) to (d). A charge distribution control method in a blast furnace, wherein the position is shifted to the furnace center side by at least one notch.
[3] In the charge distribution control method of [2] above, when ore charging is performed in two batches, the ore charging position closest to the furnace wall in the first batch and the second batch is determined. , A charge distribution control method in a blast furnace, characterized by shifting to the center side of the furnace by at least one notch.
[4] In the charge distribution control method according to any one of [1] to [3] above, in at least one batch, r so as to obtain a charge distribution that satisfies the conditions (a) to (d). / Rt: Ore layer thickness ratio in the region of r / Rt: 0.7-0.8 by increasing the number of turns of the turning chute at the notch where the region near 0.8 is the ore charging position A charge distribution control method in a blast furnace, characterized by increasing an average value of [Lo / (Lc + Lo)].
[5] In the charge distribution control method of [4] above, when ore charging is performed in two batches in one charge, in the first batch, the area near r / Rt: 0.8 is ore charging. By increasing the number of turns of the turning chute at the notch at the position, the average value of the ore layer thickness ratio [Lo / (Lc + Lo)] in the region of r / Rt: 0.7-0.8 A charge distribution control method in a blast furnace characterized by increasing the amount.

  According to the present invention, it is possible to accurately and quickly grasp the charge distribution in the blast furnace and appropriately control the charge distribution. For this reason, high reduction efficiency of ore can be obtained, and stabilization of blast furnace operation can be achieved.

The longitudinal cross-sectional view which shows typically one Embodiment of the profile measuring apparatus of the furnace interior entrance surface used by this invention method Fig. 1 shows an installation example of the profile measuring device on the furnace interior entrance surface of Fig. 1 and is a longitudinal sectional view of the top of the blast furnace furnace where the profile measuring device is installed Drawing showing charging distribution (coke and ore charging distribution in one charge) in the uppermost layer in the furnace interior before applying the method of the present invention Drawing showing the ore layer thickness ratio [Lo / (Lc + Lo)] in the furnace radial direction at the top of the furnace interior in Fig. 3 The ore layer thickness ratio [Lo / (Lc + Lo)] in the furnace radial direction at the top of the furnace interior layer after charging the raw material by the action (1) to which the present invention method is applied is shown in FIG. Drawing shown in comparison with thickness ratio [Lo / (Lc + Lo)] The gas utilization rate ηCO (horizontal sonde ηCO) in the furnace radial direction after charging the raw material by the action (1) to which the present invention method is applied is compared with the gas utilization rate ηCO in the furnace radial direction in the charging distribution of FIG. Drawing The ore layer thickness ratio [Lo / (Lc + Lo)] in the furnace radial direction at the top of the furnace interior layer after charging the raw material by the action (2) to which the present invention method is applied is shown in FIG. Drawing shown in comparison with thickness ratio [Lo / (Lc + Lo)] FIG. 6 shows the gas utilization rate ηCO (horizontal sonde ηCO) in the furnace radial direction after raw material charging by the action (2) to which the present invention method is applied in comparison with the gas utilization rate ηCO of FIG. In actual operation, the method of the present invention was carried out from the middle of the operation as shown in FIGS. 3 and 4, and the raw material charging and the charge distribution corresponding to action (2) were performed. Drawing that shows the operation results before and after the implementation of the method of the present invention in the case of operation

  According to the method of the present invention, ores (including a mixed raw material in which a part of coke and / or a secondary raw material is mixed with ore) and coke are alternately placed in a blast furnace by a bell-less charging device equipped with a turning chute. The raw material charging is performed by alternately laminating the ore layer (including the mixed raw material layer by the mixed raw material) and the coke layer, and plural chargings of the ore and the coke in each charge are performed. When performing in batch, using a specific furnace interior entry surface profile measuring device, measure the profile of the furnace interior entry surface after charging at least in each batch, and based on this profile, it was charged in each batch Obtain the distribution of ore and coke, and based on this distribution, the ratio of the ore layer thickness [Lo / (Lc + Lo)] at the top of the furnace interior layer (Lo: ore layer thickness, Lc: thickness of coke layer) So that satisfactory charging distribution and adjusts the notch and / or number of turns of the swivel chute at least one batch of charging ore.

In the present invention, ore means one or more of iron ore, such as sintered ore, massive ore, and pellets.
For the purpose of improving the reducibility of the ore layer, a mixed raw material in which a part of coke is mixed with ore (ore coke mixed charging method) or a mixed raw material in which auxiliary materials are mixed with ore are charged. In the present invention, charging ore into the blast furnace in the present invention refers to a case where a mixed raw material in which a part of coke and / or auxiliary materials are mixed into the ore as described above. Therefore, the ore layer includes the case of a mixed raw material layer (coke and / or auxiliary raw material mixed ore layer) by such a mixed raw material.
Here, the auxiliary raw material is a raw material used for adjusting CaO, SiO ₂ , MgO components, etc. of slag, and is mixed with ore and charged (however, one of sintered ore and pellets). Examples of the excluding auxiliary materials included as part include limestone, quartzite, and serpentine.

In blast furnace raw material charging, a series of charging to form laminated coke layer and ore layer is one charge, and charging of ore and coke at one charge is performed in one batch or multiple batches, respectively. In the invention, charging of ore and coke in one charge is performed in a plurality of batches.
In a bell-less charging device equipped with a turning chute, raw materials (ores, coke, etc.) are supplied to the turning chute from the furnace top bunker, and the turning chute turns to charge the raw material. The turning chute can be tilted with respect to the central axis (perpendicular) of the blast furnace, and the raw material dropping position in the furnace radial direction can be selected by adjusting the tilt angle. Usually, the tilt angle of the turning chute is changed in a plurality of stages with one batch of raw material charging, and the turning chute is turned at least once at each tilt angle. The tilt angle to be changed in a plurality of stages is represented by a notch No., for example, notch No. 1: tilt angle 55 °, notch No. 2: tilt angle 53 °... Notch No. 19: tilt angle 19 ° notch No. 20: The tilt angle is set to 17 °. Therefore, it is possible to control the charge distribution by adjusting the notch of the turning chute or / and the number of turns in each batch.

The profile measuring device for the furnace interior entrance surface used in the method of the present invention is a measurement device installed at the top of the furnace of the blast furnace, and measures the distance to the furnace interior entrance surface with a radio wave type distance meter, The profile of the furnace interior entrance surface is measured based on the distance data to the furnace interior entrance surface obtained by scanning the detection wave radiation direction of the distance meter in the furnace radial direction.
This profile measuring device is not limited in its configuration as long as it can continuously measure the distance to the furnace interior entrance surface by scanning the detection wave radiation direction of the radio distance meter in the furnace radial direction. In particular, the following embodiments are preferable.

  FIG. 1 and FIG. 2 show an embodiment of a profile measuring device for a furnace interior entrance surface used in the method of the present invention and an installation example thereof. FIG. 1 is a longitudinal sectional view schematically showing the profile measuring device. 2 is a longitudinal sectional view of the top of the blast furnace furnace in which the profile measuring device of FIG. 1 is installed. In the figure, 20 is a furnace body, 21 is a turning chute (distribution chute) of a bell-less charging device, and raw materials such as iron stone and coke put in a furnace top bunker (not shown) are passed through this turning chute 21. Charged into the furnace. In FIG. 2, θ is the tilt angle of the turning chute 21.

  The profile measuring apparatus shown in FIGS. 1 and 2 includes a detection wave transmitter / receiver 1 in which a radio wave type distance meter transmits / receives a detection wave such as a millimeter wave or a microwave, and a waveguide 4 is connected to the detection wave transmitter / receiver 1. And a detection wave reflector 3 having a variable reflection angle provided opposite to the antenna 2, and is transmitted from the detection wave transmitter / receiver 1 and radiated from the antenna 2. The detection wave is reflected by the detection wave reflector 3 and incident on the furnace interior entrance surface, and the detection wave reflected by the furnace interior entrance surface is received by the detection wave transceiver 1 via the detection wave reflector 3 and the antenna 2. Thus, the distance to the furnace interior entrance surface is measured, and the reflection angle of the detection wave reflection plate 3 is adjusted to scan the detection wave radiation direction in the furnace radial direction.

A window hole 5 is formed in the furnace body portion at the top of the furnace at a position where a furnace interior entrance surface (deposition surface) can be seen downward or obliquely downward, and the window hole 5 is formed outside the furnace body portion. A casing 6 having a predetermined pressure resistance is attached and fixed so as to cover. The inside of the casing 6 constitutes a storage chamber 7, and the storage chamber 7 opens into the furnace space through the window hole 5.
The antenna 2 is disposed in the storage chamber 7, and the detection wave transceiver 1 is disposed outside the storage chamber 7 (outside the furnace body 20). A waveguide 4 connecting the detection wave transmitter / receiver 1 and the antenna 2 passes through the casing 6, and the antenna 2 is supported at the tip thereof.
Further, the detection wave reflection plate 3 is disposed in the storage chamber 7 so as to face the antenna 2. A drive device 8 for rotating the detection wave reflecting plate 3 is disposed outside the storage chamber 7 (outside the furnace body 20), and the rotation drive shaft 9 passes through the casing 6 and reflects the detection wave at the tip thereof. A plate 3 is supported.

Here, the positional relationship among the antenna 2, the detection wave reflection plate 3 and its driving device 8, and the opening 12 of the storage chamber 7 is as follows: (Ii) the detection wave reflector 3 can be rotated by being fixed to the rotational drive shaft 9 of the drive device 8, and (iii) the antenna 2 and the detection wave reflector 3 are The detection wave transmitted from the antenna 2 and reflected by the detection wave reflection plate 3 is provided such that the detection wave is arranged with respect to the opening 12 so as to be guided into the furnace through the opening 12.
In order to prevent the reflected raw material 13 from being damaged by the blown-up raw material hitting the detection wave reflecting plate 3 when the furnace interior material is blown through, the detection wave reflecting plate 3 is not connected to the rear surface when not measuring. It can be stopped at a rotational position such that the side (opposite the reflecting surface 13) faces the opening 12.

The detection wave transmitter / receiver 1 generates a detection wave (millimeter wave, microwave, etc.) whose frequency continuously changes in a certain range, and can transmit and receive the detection wave.
As the antenna 2, a parabolic antenna, a horn antenna, or the like can be used. Among these, a horn antenna with a lens is particularly preferable because it has excellent directivity characteristics.
The detection wave reflecting plate 3 is made of, for example, a metal material such as stainless steel and is not limited in shape, but is usually circular. By rotating the detection wave reflecting plate 3 with the rotation drive shaft 9 of the driving device 8, the radiation direction of the detection wave transmitted from the antenna 2 in the central axis direction and reflected by the detection wave reflecting plate 3 is scanned in the furnace radial direction. Can be made.

  A gate valve 10 that shuts off the storage chamber 7 from the furnace space is provided between the detection wave reflection plate 3 and the opening 12 in the storage chamber 7 (in the vicinity of the opening 12 in this embodiment) so as to be opened and closed. It has been. An opening / closing drive unit 11 for the gate valve 10 is installed outside the storage chamber 7 (outside the furnace body 20), and the gate valve 10 is slid by the opening / closing drive unit 11 to be opened and closed. The gate valve 10 is opened at the time of profile measurement, and is closed at other times.

Further, in order to prevent in-furnace gas and dust from entering the storage chamber 7 during measurement, and to prevent the in-furnace gas from leaking from the casing 6 to the outside, the casing 6 has a purge gas supply gas. A supply pipe 14 is connected, and a purge gas (usually nitrogen gas) having a predetermined pressure is supplied into the storage chamber 7 through the gas supply pipe 14.
This profile measuring device calculates the distance from the antenna 2 to the furnace interior entrance surface based on the data received and detected by the detection wave transmitter / receiver 1, and further obtains the profile of the furnace interior entrance surface from this distance data. A data processing unit 15 is included.

  In the profile measuring apparatus as described above, a detection wave having a continuously changing frequency generated by the detection wave transmitter / receiver 1 is transmitted from the antenna 2 and radiated toward the furnace interior entrance surface through the detection wave reflector 3. The The detection wave (reflected wave) reflected by the furnace interior entrance surface is received by the detection wave transceiver 1 via the detection wave reflector 3. In the detection of the furnace interior entrance surface by such a detection wave, the detection wave reflection direction is changed as shown in FIG. 2 by changing the reflection angle of the detection wave by rotating the detection wave reflector 3 by the driving device 8. Scan in the radial direction of the furnace. In the data processing unit 15, the round trip time of the detection wave from the antenna 2 to the furnace interior entrance surface is usually obtained by the FMCW method (frequency modulation continuous wave system), and the distance from the antenna 2 to the furnace interior entrance surface is calculated. Is done. Then, the profile of the furnace interior entrance surface is obtained from the distance data obtained by scanning the detection wave radiation direction in the furnace radial direction as described above.

In the method of the present invention, using the profile measuring device, at least the profile of the furnace interior entrance surface after charging in each batch is measured, and charging of ore and coke charged in each batch is based on this profile. Find the distribution. Then, charge distribution control (action) is performed based on this charge distribution. In this charge distribution control, (i) in order to improve the air permeability of the furnace center and ensure a stable gas flow. In addition, O (Ore) / C (Coke) in the center of the furnace is kept low (that is, the ratio of coke is increased), (ii) The gas flow rate in the periphery of the furnace is increased, and the heat level is maintained at a high level. In order to suppress the growth of zinc deposits on the furnace wall, the O / C around the furnace is kept low (that is, the coke ratio is increased), and (iii) the furnace is improved in order to improve the reduction efficiency of the entire furnace. Maintain O / C in the middle part (region between the furnace center and the furnace periphery in the furnace radial direction) at a high level, (iv) non-uniform gas flow distribution due to local deterioration of air permeability, ore rise From the viewpoint of suppressing the occurrence of local high O / C to prevent delay in temperature reduction Ore layer thickness ratio [Lo / (Lc + Lo)] (where Lo: ore layer thickness, Lc: coke layer thickness) at the top of the furnace interior layer is the following conditions (a) to (d) To adjust the notch or / and the number of turns of the turning chute in at least one batch in the charging of the ore. Here, when the distance from the furnace center in the furnace radial direction is r (m) and the in-furnace radius at the furnace port is Rt (m), the in-furnace area in the furnace radial direction is sequentially from the furnace center side. , R / Rt ≦ 0.20: first region (furnace center), 0.20 <r / Rt ≦ 0.80: second region (furnace middle), 0.80 <r / Rt: third region (Furnace periphery).
(A) Average value of the first region: less than 0.5 (b) Average value of the second region: 0.6 or more and less than 0.9 (c) Average value of the third region: 0.4 or more and less than 0.8 (D) Average value of the first region <Average value of the third region <Average value of the second region Note that in the following description, the ore layer thickness ratio in the furnace radial direction at the top of the furnace interior layer [ Lo / (Lc + Lo)] is simply referred to as “[Lo / (Lc + Lo)]”.

  That is, the condition (a) is defined from the viewpoint (i), the condition (c) is defined from the viewpoint (ii), and the condition (b) is defined from the viewpoints (iii) and (iv). Is done. The condition (d) is that the average value of the ore layer thickness ratio [Lo / (Lc + Lo)] in the furnace periphery (third region) is the center of the furnace (first Is less than or equal to (region), the gas flow velocity around the furnace becomes too high, and the amount of heat removed from the furnace body increases, which may lead to problems such as increased heat loss. The

In the present invention, when adjusting the notch of the turning chute or / and the number of turns in at least one batch in the charging of the ore so as to obtain a charging distribution that satisfies the conditions (a) to (d) above, For example, the following embodiments can be adopted.
(I) The ore charging position closest to the furnace wall in at least one batch is shifted to the furnace center side by at least one notch. For example, when ore charging with one charge is performed in two batches, the ore charging position closest to the furnace wall in the first batch and the second batch is shifted to the furnace center side by at least one notch.
(Ii) In at least one batch, by increasing the number of turns of the turning chute at the notch where the region near r / Rt = 0.8 is the ore charging position, r / Rt = 0.7-0. The average value of [Lo / (Lc + Lo)] in the region of 8 is increased. For example, when ore charging with one charge is performed in two batches, in the first batch, the number of turns of the turning chute at the notch where the region near r / Rt = 0.8 is the ore charging position is increased. Thus, the average value of [Lo / (Lc + Lo)] in the region of r / Rt = 0.7 to 0.8 is increased.

Hereinafter, an operation example in which the charge distribution control is performed by the method of the present invention using the profile measuring device for the furnace interior entrance surface as shown in FIGS. 1 and 2 will be described.
In this operation example, the profile of the furnace interior entrance surface was measured with a profile measuring device for each turn of the turning chute in each batch of raw material (ore ore, coke) charging.
FIG. 3 shows the charging distribution (coke and ore charging distribution in one charge) at the top of the furnace inner layer before applying the method of the present invention, and FIG. [Lo / (Lc + Lo)] in the furnace radial direction at the top of the layer is shown.
3 and 4 show the profile of the furnace interior charge surface after charging in each batch using the profile measuring apparatus described above, and the ore and coke charging in each batch based on this profile. The distribution is calculated. This also applies to each drawing of the operation example described later.

In this example, C1 and C2 indicate coke charging, and O1 and O2 indicate ore charging. In one charge, coke charging and ore charging are performed in two batches respectively, and C1 (first coke batch) → C2 (second batch of coke) → O1 (first batch of ore) → O2 (second batch of ore). In addition, the vertical axis of FIG. 3 sets the reference height to “0” (the position of the reference height “0” is the (downward) tip position of the turning chute when the tilt angle θ of the turning chute is 0 °). The position in the furnace height direction (mm), and the horizontal axis is the position in the furnace radial direction (mm) with the furnace center being “0”. The “base O2” is the charging surface of the precharged O2.
In this example, a raw material charging apparatus capable of changing the tilt angle of the turning chute in 25 stages (notches No. 1 to 25) was used.

In FIG. 4, the target [Lo / (Lc + Lo)] is indicated by a solid line, and r in the second region (furnace intermediate portion) with respect to the target [Lo / (Lc + Lo)]. [Lo / (Lc + Lo)] is too small in the region of /Rt=0.25 and r / Rt = 0.7 to 0.8, while in the region of r / Rt = 0.5, Lo / (Lc + Lo)] is excessive. In addition, [Lo / (Lc + Lo)] in the third region (furnace peripheral portion) as a whole is too small. Therefore, it was considered appropriate to increase or decrease [Lo / (Lc + Lo)] in the direction indicated by the arrow in the figure.
Compared with the charging distribution shown in Fig. 3, the O2 charging position for each turn and the estimated raw material falling position are compared, and the ore of O2 is generally deposited in a wide range toward the furnace center starting from the estimated raw material falling position. I found out. Since the dropping position was too biased toward the furnace periphery, the inclination angle toward the furnace center became large, and it was judged that the flow of the raw material after dropping was excessive.

  Therefore, the following adjustments were made for ore charging as action (1) in order to reduce the inclination angle and make it flat by reducing the amount of ore charging to the furnace periphery. In other words, the ore charging position closest to the furnace wall at O1 is 1 notch, and the ore charging position closest to the furnace wall at O2 is 2 notches, relative to the operation schedule of the raw material charging apparatus so far. Ore charging (coke charging was not changed) was carried out with the operation schedule shifted to the furnace center. Specifically, according to the previous operation schedule, the ore charging position closest to the furnace wall at O1 is due to Notch No. 5, and the ore charging position closest to the furnace wall at O2 is due to Notch No. 4. On the other hand, in the operation schedule of action (1), the ore charging position closest to the furnace wall at O1 and O2 was determined by Notch No.6.

When the profile of the furnace interior entrance surface after charging the raw material by this action (1) was measured with a profile measuring device, the deviation of the ore falling position toward the furnace periphery was improved, and as a result, toward the furnace center The inclination angle was reduced.
FIG. 5 shows [Lo / (Lc + Lo)] in the furnace radial direction after charging the raw material by this action (1) in comparison with [Lo / (Lc + Lo)] in FIG. . FIG. 6 compares the gas utilization rate ηCO (horizontal sonde ηCO) in the furnace radial direction after charging the raw material by action (1) with the gas utilization rate ηCO in the furnace radial direction in the charging distribution of FIG. As shown. 5 and FIG. 6, “base” means [Lo / (Lc + Lo)] and gas utilization rate ηCO in the charging distribution of FIG. 3 and FIG.
According to FIG. 5, [Lo / (Lc + Lo)] after the action (1) is r in the second region (furnace middle part) compared with [Lo / (Lc + Lo)] in FIG. [Lo / (Lc + Lo)] increases around /Rt=0.25 and r / Rt = 0.7 to 0.8, while [Lo / (Lc + Lo)] increases around [R / Rt = 0.5]. / (Lc + Lo)] decreases, and [Lo / (Lc + Lo)] in the third region (furnace periphery) increases as a whole. As a result, as shown in FIG. 6, the gas utilization rate ηCO in the furnace periphery is improved.

  [Lo / (Lc + Lo)] after action (1) shown in FIG. 5 is [Lo / (Lc) in the region of r / Rt = 0.7 to 0.8 in the second region (furnace intermediate portion). + Lo)] could be further improved (increased), so action (2) was made to increase [Lo / (Lc + Lo)] in this area as shown by the dashed arrows in FIG. The following adjustments were made for ore charging. That is, considering the relationship between the region of r / Rt = 0.7 to 0.8 where [Lo / (Lc + Lo)] is to be increased, the ore charging position of O1 and the estimated raw material falling position, the above action (1 ), The ore charging (coke charging) is performed with the driving schedule in which the number of turns of the turning chute at the notch where the area near r / Rt = 0.8 is the ore charging position in O1 is increased. No change). Specifically, in the operation schedule of action (1), the number of turns of the turning chute at notches No. 11 and 13 in which the region near r / Rt = 0.8 is the ore charging position in O1 is 1. On the other hand, in the operation schedule of action (2), the number of turns of the turning chute in No. 11 and 13 was set to 2.

When the profile of the furnace interior entrance surface after charging the raw material by this action (2) was measured with a profile measuring device, the thickness of the ore layer in the middle of the furnace increased.
FIG. 7 shows [Lo / (Lc + Lo)] in the furnace radial direction after raw material charging by this action (2), and [Lo / (Lc + Lo)] (after action (1) in FIG. [Lo / (Lc + Lo)]). 8 shows the gas utilization rate ηCO (horizontal sonde ηCO) in the radial direction of the furnace after charging the raw material by action (2), and the gas utilization rate ηCO (gas utilization rate ηCO after action (1) in FIG. ).
According to FIG. 7, [Lo / (Lc + Lo)] after action (2) is the second region (furnace middle) compared to [Lo / (Lc + Lo)] after action (1). [Lo / (Lc + Lo)] in the region of r / Rt = 0.7 to 0.8 increases, and the target [Lo / (Lc + Lo)] as shown by the solid line in the figure I was able to approach. As a result, as shown in FIG. 8, the gas utilization rate ηCO in the furnace middle portion is improved.

  In actual operation, the method of the present invention was carried out from the middle of the operation as shown in FIGS. 3 and 4 and the raw material charging and the charge distribution corresponding to the above action (2). Operated. The operation results before and after the implementation of the method of the present invention are shown in FIG. 9, and the coke ratio could be reduced by 2 kg / t by implementing the method of the present invention.

DESCRIPTION OF SYMBOLS 1 Detection wave transmitter / receiver 2 Antenna 3 Detection wave reflector 4 Waveguide 5 Window hole 6 Casing 7 Storage chamber 8 Drive device 9 Rotation drive shaft 10 Gate valve 11 Opening / closing drive part 12 Opening part 13 Reflecting surface 14 Gas supply pipe 15 Data Processing unit 20 Furnace 21 Turning chute

Claims (1)

By means of a bell-less charging device equipped with a swirl chute, ore is charged alternately in the blast furnace (including mixed raw materials in which a portion of coke and / or auxiliary materials are mixed with ore) and coke. When performing raw material charging for alternately laminating layers (however, including the mixed raw material layer by the mixed raw material) and coke layers, and charging ore and coke in one charge in multiple batches,
This is a profile measuring device for the furnace interior entrance surface installed at the top of the blast furnace. The distance to the furnace interior entrance surface is measured with a radio-type distance meter, and the detected wave radiation direction of the distance meter is Using a profile measuring device that measures the profile of the furnace interior entrance surface based on the distance data to the furnace interior entrance surface obtained by scanning in the radial direction, the furnace interior entrance after at least each batch is charged. Measure the profile of the object surface, find the distribution of ore and coke charged in each batch based on the profile, and based on this distribution of the ore layer thickness ratio at the top of the furnace interior layer [Lo / (Lc + Lo)] (where Lo: ore layer thickness, Lc: coke layer thickness) has a charging distribution that satisfies the following conditions (a) to (d). Swivel chute notch in at least one batch during charging or And burden distribution control method in a blast furnace, characterized in that adjusting the number of turns.
(A) Average value of the first region: less than 0.5 (b) Average value of the second region: 0.6 or more and less than 0.9 (c) Average value of the third region: 0.4 or more and less than 0.8 (D) Average value of the first region <Average value of the third region <Average value of the second region However, the distance from the furnace center in the furnace radial direction is r (m), and the furnace radius at the furnace port is Rt In the case of (m), the in-furnace region in the furnace radial direction is, in order from the furnace center side, r / Rt ≦ 0.20: first region, 0.20 <r / Rt ≦ 0.80: second region 0.80 <r / Rt: The third region.

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