JPH0717931B2 - Blast furnace furnace interior entrance layer boundary measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of stable operation of a blast furnace at a high level by recognizing the layered state of the interior contents of the furnace in the blast furnace and detecting the position of the cohesive zone from the change in insertion resistance (change in required thrust) when inserting the probe. The present invention relates to a method for measuring the boundary layer of the inner layer of the blast furnace for realizing the above.

The blast furnace is a counter-flow reactor in which iron ore and coke are alternately charged in layers from the upper part of the furnace and hot gas is blown from the lower part of the furnace to produce pig iron. The iron ore layer-wise charged from the upper part of the furnace is reduced by the high-temperature reducing gas as the temperature decreases, and the temperature rises, and finally becomes a softened and fused state. This is called a cohesive zone, and when the reaction proceeds further, it finally melts into hot metal, and drops toward the lower part of the furnace.

The cohesive zone has a very high ventilation resistance and therefore greatly affects the circumferential and radial distributions of the gas flow in the furnace, so its position and shape are recognized as important control items for blast furnace operation. Has been done. The shape of the cohesive zone is determined by the gas flow distribution in the furnace, which is determined by itself, and the thickness of each layer of iron ore and coke in the layered region of coke and the coke layered region (hereinafter referred to as the cohesive zone). The thickness ratio (hereinafter referred to as the layer thickness ratio) is governed by the circumferential and radial distribution states.
Therefore, it is possible to provide important information for the operation of the blast furnace by detecting the layer formation state in the massive zone and by detecting the shape and position of the cohesive zone layer.

One of the methods for measuring the layer thickness and layer thickness ratio in the massive zone is the magnetic layer thickness measuring method and the electrode type layer thickness measuring method that use the difference in the magnetic permeability and the permittivity of iron ore and coke. Only the upper part of the upper furnace and the wall of the furnace can be measured, and the measurement over the entire area of the furnace is virtually impossible.

In addition, the inventors of the present invention have disclosed Japanese Patent Application No. 56-5990 (JP-A-57-1206).
04), Japanese Patent Application No. 56-57832 (Japanese Patent Application Laid-Open No. 57-174405), Japanese Patent Application No. 56-57833 (Japanese Patent Application Laid-Open No. 57-174406), Japanese Patent Application No. 56-104140 (Japanese Patent Application No. 56-104140). By using the apparatus and method proposed in Japanese Laid-Open Patent Publication No. 58-6913), not only can the layer state, the cohesive zone shape, and the position of the entire furnace be detected, but also the particle size of the charge in the massive zone, gas flow, etc. A wide variety of information can be obtained, but since the measurement probe has advanced manufacturing technology, maintenance and adjustment at regular intervals are required, and the measurement equipment is currently expensive, It is not realistic to install a large number in.

However, in order to detect the layer state and the shape and position of the cohesive zone in the cohesive zone, it is necessary to have a large number of detection ends within the blast furnace. It is necessary to reduce the labor required for maintenance and adjustment as much as possible.

Using the measuring device proposed by the present inventors in Japanese Patent Application No. 57-101437 (Japanese Patent Application Laid-Open No. 58-221208), Japanese Patent Application No. 56-5990 (Japanese Patent Application No. 57-120604) discloses According to the proposed optical measurement method, Japanese Patent Application No. 56-57832 (JP-A-57-174405) is used.
Japanese Patent Application No. 56-57833 (Japanese Patent Application Laid-Open No. 57-174406) and Japanese Patent Application No. 56-104140 (Japanese Patent Application Laid-Open No. 58-6913). Then, the inside of the blast furnace is measured and the insertion resistance of the probe is measured by the required thrust, and there is a clear correspondence between the state of formation of the furnace interior charge layer and the required thrust. found.
Further, the insertion resistance when the gas temperature probe, the component measurement probe, the charge sampling probe, or the like was inserted into the furnace using the measuring device was also the same.

The present invention is based on such knowledge, and is characterized in that a probe main body is provided in a probe insertion driving device, and a probe insertion resistance measuring device is provided in the probe insertion driving device. The probe body is inserted into the furnace interior container from the blast furnace side peripheral portion by the probe insertion driving device, the insertion resistance during this insertion is measured by the insertion resistance measuring device, and a change in the measured insertion resistance is detected,
The rising change region is a coke layer, the falling change region is an ore layer, and the irregular fluctuation region is a cohesive zone layer, and the probe tip position at the maximum point when the insertion resistance changes from the rising change region to the falling change region, or the rising change The probe tip position at the minimum point where the region changes to the falling change region is the boundary between the coke layer and the ore layer, and the position where the rising change region or the falling change region changes to the irregular change region is the coke layer or the ore layer and the cohesive zone This is a method of detecting the boundary of layers.

According to the present invention, a probe having a very simple structure is inserted into a furnace, and only the change in insertion resistance (change in insertion thrust) at that time is measured to measure the layer thickness and layer thickness ratio in the massive band, and the position of the fused zone shape is detected. It is possible to improve the accuracy of the blast furnace operation, and to enable the operation of the furnace in a quick and flexible manner in response to changes in the furnace operating conditions and the ironmaking plan.

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment of the present invention.

FIG. 1 shows that the inventors of the present invention have disclosed Japanese Patent Application No. 57-101437 (Japanese Patent Application Laid-Open No. 58-101437).
-221208), a probe driving force measuring device (specifically, a drive motor load ammeter)
And a pressure detecting device at the probe mounting portion is provided as an insertion resistance measuring device (required thrust measuring device), and the furnace state detected by the optical measurement method and the probe insertion resistance (required thrust) measured at that time Shows the correspondence of. The measuring device has an insertion angle of 25 ° downward, and 1 is an iron skin.

From the result of the optical measurement, according to the insertion of the probe 2, it passed through the coke layer 3, then the ore layer 4, further passed through the coke layer 5, the ore layer 6, and the coke layer 7, and entered the cohesive zone 8. I understand. At this time, the insertion resistance of the probe 2, that is, the thrust required for insertion, produces a maximum value 9 at the boundary between the coke layer 3 and the ore layer 4, and a minimum value 10 at the boundary between the ore layer 4 and the coke layer 5. ing. Furthermore, after the similar change, short-period irregular fluctuation starts from the time when it enters the cohesive zone 8.
Sustained 11.

Based on these results, the present inventors have conducted several further experiments and as a result, have shown that the modeling described below is sufficient regardless of the particle size of the charge and the strength of the gas flow in the furnace. Confirmed the reliable measurement method. This point will be described with reference to FIG.

That is, according to the present invention, 1) the region 12 where the thrust is increasing is the coke layer 3. 2) The maximum point 9 of the thrust is the boundary between the coke layer 3 detected in 1) and the ore layer 4 existing below. 3) The area 13 in which the thrust is descending is the ore layer 4. 4) The minimum point 10 of the thrust is the boundary between the ore layer 4 and the coke layer 5 located below. 5) The irregular fluctuation area 11 of the thrust is the cohesive zone 8. Therefore, the point where the irregular fluctuation region 11 starts to occur is the outer surface 14 of the cohesive zone.

When performing the measurement, the length of the probe to be inserted and the insertion angle should be selected according to the situation, depending on the implementation position, purpose and the like. As an example, description will be made with reference to FIG.

In the upper part of the blast furnace 15, the furnace interior charge layer is inclined, and when the probe 16 is inserted horizontally, the coke layer 1
9. Ore layer 20 and coke layer 21 are detected. Probe 17
When the slant is inserted, the coke layer 22 to the ore layer 26 can be detected. Further, if the probe 18 is obliquely inserted, the ore layer 28 to the coke layer 31, the outer surface 14 of the cohesive zone, and the cohesive zone 8 can be detected. For example, when the main purpose is to detect the cohesive zone outer surface 14,
As shown in Japanese Patent Application No. 57-101437 (Japanese Patent Application Laid-Open No. 58-221208) by the present inventors, if the fusion band is inserted at an insertion angle of about 20 ° downward, the fusion zone is close to the minimum length. The outer surface 14 can be detected.

FIG. 4 is an explanatory diagram of a probe necessary to carry out the present invention. It is necessary to devise to transmit the insertion resistance received at the tip of the probe 32 to the probe 32 as much as possible. Therefore, it is desirable to make the flat portion 36 at the tip of the probe 32 as large as possible. For the same reason, it is preferable that the angle θ of the probe tip 35 be as close to 90 ° as possible.

When the outer diameter of the probe 32 is too small, the frictional resistance between the side surface 37 of the probe 32 and the furnace interior container increases as compared with the insertion resistance received by the flat plate portion 36 and the pointed portion 35. , The noise component becomes large. Further, if the outer diameter of the probe 32 is too large, for example, if it is equal to or larger than the thickness of the charging material layer, it becomes impossible to determine. In order to avoid an unnecessary increase in the size of the insertion device, the outer diameter of the probe 32 is preferably about 50 to 150 mm.

Since the residence time of the probe 32 in the furnace is only the time required for insertion and extraction, conditions such as strength and cooling can be simplified within a range that does not hinder the measurement work. If it is carried out in the upper part of the furnace, it is not necessary to cool it with water.
It is also possible to supply inert gas or the like from the introduction hole 33 provided at the rear end of the probe 32 and discharge it into the furnace from the small blow-out hole 34 provided at the tip of the probe 32 so that only cooling and explosion prevention are performed. When the operation is performed in the lower part of the furnace, it is also preferable that the probe 32 has a water cooling structure.

In addition to the structure described above, it is unnecessary to impose special restrictions on the probe, and if necessary, other measurement functions can be added to the probe to perform multiple measurements simultaneously. Is.

FIG. 5 shows another embodiment of the present invention. When the charge layer thickness and the layer thickness ratio in the massive band 38 are measured, the probe 41 is inserted and withdrawn from the upper part of the blast furnace. The insertion length, the circumferential direction, and the number of vertical insertions are determined as necessary.
When the main purpose is to detect the position of the outer surface 14 of the cohesive zone, the probe 39 installed in the middle part of the furnace to the lower part of the furnace is inserted and withdrawn. When detecting the cohesive zone position 42 on the furnace wall, a plurality of probes 40 provided in the vertical direction are sequentially or simultaneously inserted to detect the irregular fluctuation region 11 in FIG. Position is the fusion zone position of the furnace wall
It should be 42.

FIG. 6 shows a schematic view of the insertion device. It has a driving device 43 for driving the probe 32 and an insertion resistance (required thrust) measuring device 44 for carrying out the present invention. The device 44 may be installed, for example, in a case where a strain gauge or the like is attached to the rear end or the holding portion of the probe 32 for detection, or installed in the drive device. When the latter is used, the measuring device 44 is used. -2 needs to be properly selected depending on the type of drive source, for example, a pressure detector is used for hydraulic drive.

As described above, the present invention recognizes and detects the ore layer, the coke layer and their boundaries in the massive zone, and also recognizes and detects the cohesive zone from the change of the insertion resistance (required thrust) at the time of inserting the probe. Detection of the boundary shape between the lumpy zone and the cohesive zone,
Since it can be realized very easily as needed, it will make the measurement over the entire blast furnace a reality and make a great contribution to the stable operation of the blast furnace at a high position.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of measurement results showing the relationship between the state of the contents inside the blast furnace and the probe insertion resistance (required thrust), and FIG. 2 is the method for detecting the state inside the furnace from the probe insertion resistance (required thrust). FIG. 3, FIG. 3 is a schematic diagram in carrying out the present invention, FIG. 4 is an explanatory diagram of a probe, FIG. 5 is an explanatory diagram showing an embodiment of the present invention, and FIG. 6 is a schematic diagram of an insertion device. Is. 1 ... Blast furnace iron crust, 2 ... Probe 3,5,7 ... Coke layer, 4,6 ... Ore layer 8 ... Fused layer, 9 ... Maximum point of insertion thrust 10 ... Minimum point of insertion thrust 11 ... No insertion thrust Regular fluctuation area 12… Increase in insertion thrust 13… Increase in insertion thrust 14… Cohesive zone outer surface, 15… Blast furnace 16,17,18… Probe 19,21,22,24,26,29, 31… Coke layer 20,23,25,27,28,30… Ore layer 32… Probe, 33… Introduction hole 34… Blowout small hole, 35… Spiked head 36… Plate part, 37… Probe side 38… Bulk Band, 39, 40, 41 ... Probe 42 ... Furnace wall fusion zone position, 43 ... Probe drive device 44 ... Insertion thrust detection device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Doi Oita-shi, Oita 1 Nishinosu, Nippon Steel Co., Ltd. Oita Works (72) Inventor Tatsuro Hirata 1 Nishinosu, Oita-shi, Oita New Nippon Steel Co., Ltd. Oita Works

Claims (1)

[Claims] 1. A probe insertion drive device is provided with a probe main body, and a probe insertion resistance measurement device is provided with the probe insertion drive device, and the probe main body is inserted into the furnace interior from a blast furnace side peripheral portion by the probe insertion drive device. Insert inside,
The insertion resistance during the insertion is measured by the insertion resistance measuring device to detect the change in the measured insertion resistance, and the rising change region is the coke layer, the falling change region is the ore layer, and the irregular fluctuation region is the fusion zone. As a layer, the probe tip position at the maximum point when the insertion resistance changes from the rising change region to the falling change region,
Alternatively, the probe tip position at the minimum point where the rising change region changes to the falling change region is the boundary between the coke layer and the ore layer, and the position where the rising change region or the falling change region changes to the irregular fluctuation region is the coke layer or the ore layer. A method for measuring a boundary layer between inner layers of a blast furnace, which is characterized by detecting the boundary of the cohesive zone layer.