JP2009074776A - Extracting position detecting method and extracting method for heated material in heating furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of detecting an extracting position of a heated material in a heating furnace with high accuracy without impairing an operation. <P>SOLUTION: This invention provides a method of detecting the extracting position of the heated material M conveyed in the direction roughly orthogonal to the longitudinal direction of the heated material M in the heating furnace 100. A plurality of laser distance meters 10 are disposed along the direction orthogonal to the conveying direction at positions separating in the conveying direction from a furnace wall 101 of the heating furnace positioned at a downstream side in the conveying direction of the heated material at an outer portion of the heating furnace, laser beams horizontally projecting from the laser distance meters are applied to the heated material through openings 102 formed on the furnace wall to measure distances from the laser distance meters to the heated material, and the extracting position of the heated material is detected on the basis of the measured distance to the heated material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for detecting an extraction position of a material to be heated in a heating furnace and a method for extracting a material to be heated using the same. In particular, the present invention is a method for accurately detecting the extraction position of the material to be heated in the heating furnace without causing any trouble in operation, and by using this method, the material to be heated can be extracted in a stable state. The present invention relates to a method for extracting a material to be heated.

  Conventionally, a heating furnace for a material to be heated such as slab or steel slab is used to heat the material to be heated to a temperature suitable for rolling when the material to be heated is subjected to partial rolling or hot rolling. It has been.

  The heating furnace generally has a pre-tropical zone, a heating zone, and a soaking zone in order from the charging material charging side. In the case of a so-called walking beam type heating furnace, the material to be heated inserted into the pre-tropical zone from the charging port is placed on the stationary beam and the moving beam alternately, and is substantially orthogonal to the longitudinal direction of the material to be heated. After being heated to a predetermined temperature through a heating zone and a soaking zone, it is extracted from the extraction port on the soaking side to the outside of the furnace.

  When extracting the material to be heated to the outside of the furnace, a plurality of pieces that are installed along the direction (furnace width direction) orthogonal to the conveyance direction (furnace length direction) of the material to be heated and move forward and backward in the conveyance direction of the material to be heated The extractor is used. Specifically, the extractor is advanced to a position corresponding to the position (extraction position) of the heated material placed on the moving beam on the soaking area in plan view, and the extractor is raised at that position. The material to be heated is transferred to the extractor. Next, the extractor is moved backward until the heated material is positioned above the extraction roller installed on the soaking side, and the extractor is lowered at that position, and the heated material is placed on the extraction roller. Finally, the material to be heated is conveyed in the furnace width direction by the extraction roller, and is extracted out of the furnace from the extraction port provided in the furnace wall in the furnace width direction.

  Here, the extraction position of the heated material (the position where the heated material is transferred to the extractor) is not always a fixed position. Specifically, as shown in FIG. 1, the longitudinal direction of the material to be heated M and the transport direction (the direction of the arrow in FIG. 1) are not completely orthogonal (FIG. 1 (a)), The material M may be bent (FIG. 1B). For this reason, when extracting the to-be-heated material M out of the furnace 100, in order to advance each of the extractors 1 to a position corresponding to the extraction position of the to-be-heated material M in plan view, the to-be-heated material It is necessary to detect the extraction position of M by some method. In addition, if the extraction position of the material to be heated M is not detected with high accuracy, the extractor 1 is advanced to the position corresponding to the extraction position of the material to be heated M as shown in FIG. The material to be heated cannot be moved in the direction), and when the material to be heated M is transferred to the extractor 1, there is a possibility that an operation trouble such as the material to be heated M falling from the extractor 1 may occur.

  Conventionally, as a method for detecting the extraction position of a material to be heated, for example, a method has been proposed in which a laser beam generator and a laser beam receiver are installed with a required angle relative to each other in a vertical direction of a heating furnace ( Patent Document 1). More specifically, an appropriate number of pairs of the above laser beam generator and laser beam receiver are arranged in the furnace width direction, and the material to be heated is shielded from the laser beam projected from each laser beam generator. By measuring the elapsed time, it is possible to estimate the extraction position of the material to be heated.

Japanese Utility Model Publication No. 64-1989

  However, in the above conventional method, it is impossible to accurately detect that the material to be heated has blocked the laser beam because the scale is deposited in the vicinity of the laser beam generating device and the laser beam receiving device installed below. As a result, there is a problem that the extraction position of the material to be heated cannot be detected with high accuracy. Patent Document 1 discloses that an air purge is performed on a peep surface made of heat-resistant glass in order to remove scale (page 7, line 16 to line 19 of Patent Document 1). However, it is difficult to remove the scale sufficiently with air purge, and even if the scale can be removed, it may not be possible to accurately detect that the heated material has blocked the laser beam due to contamination on the viewing surface. . For this reason, in order to maintain the detection accuracy of the extraction position of the material to be heated, it is actually necessary to periodically clean the observation window, and there is a problem that the maintainability is very poor. There is also a problem that the oxygen concentration in the furnace rises due to the air purge, and the decarburized layer formed on the surface of the material to be heated easily proceeds. Furthermore, when the laser beam generator and the laser beam receiver are installed in the vertical direction of the heating furnace (up and down the heating furnace), the distance from the furnace wall located above and below the heating furnace to the material to be heated is relatively long. Therefore, in order to improve detection accuracy, it is necessary to install the laser beam generator and the laser beam receiver as close to the furnace wall as possible. For this reason, there is a problem that it is easily affected by heat from the inside of the furnace, and an appropriate apparatus cooling means is required for actual use. Also, when operating a heating furnace with a lower air-fuel ratio in order to improve the basic unit of fuel, smoke is generated in the furnace due to incomplete combustion of the fuel, but the distance that the laser beam passes through the area where the smoke is generated Is relatively long, the detection accuracy may deteriorate.

  As a method for preventing the above-described scale accumulation and the like from becoming a problem, as shown in FIG. 2 of Patent Document 1, a laser light generator and a laser light receiver are installed horizontally in the furnace width direction. Can be considered. However, in this method, as described above, the extraction position of the heated material is accurately detected when the longitudinal direction of the heated material and the conveying direction are not completely orthogonal or when the heated material is bent. I can't do it.

  The present invention has been made to solve such a problem of the prior art, and provides a method capable of accurately detecting the extraction position of the material to be heated in the heating furnace without causing any trouble in operation. Let it be an issue. It is another object of the present invention to provide a method for extracting a material to be heated in a heating furnace that can extract the material to be heated in a stable state without causing any trouble in operation.

  In order to solve the above problems, the present invention is a method for detecting an extraction position of a material to be heated that is conveyed in a direction substantially orthogonal to the longitudinal direction of the material to be heated in a heating furnace, and is provided outside the heating furnace. A plurality of laser distance meters are installed along a direction orthogonal to the transport direction at a position spaced in the transport direction from the furnace wall of the heating furnace located downstream in the transport direction of the material to be heated; The distance from each laser distance meter to the material to be heated is measured by irradiating the material to be heated with the laser light projected in the horizontal direction from each laser distance meter through the opening provided in the furnace wall, and the measurement Provided is a method for detecting an extraction position of a heated material in a heating furnace, wherein the extraction position of the heated material is detected based on the distance to the heated material.

According to the method of the present invention, at a position outside the heating furnace and spaced from the furnace wall of the heating furnace located downstream in the conveying direction of the material to be heated, in the direction orthogonal to the conveying direction. A plurality of laser rangefinders are installed along the line (in other words, along the substantially longitudinal direction of the material to be heated). And the distance from each laser distance meter to a to-be-heated material is measured by irradiating the to-be-heated material with the laser beam projected in the horizontal direction from each laser distance meter through the opening provided in the said furnace wall.
In other words, the method according to the present invention is a method of measuring the distance from the direction facing the conveying direction of the heated material to a plurality of sites along the longitudinal direction of the heated material by each laser distance meter. Even if the longitudinal direction of the material to be heated and the conveying direction are not completely orthogonal or the material to be heated is bent, it is possible to measure the distance without hindrance. In addition, since the laser beam is projected in the horizontal direction, there is no risk that the scale will be deposited on the laser beam projecting / receiving surface of the laser rangefinder and the measurement accuracy will not deteriorate, and it is necessary to perform air purge to remove the scale. Nor. In addition, since the distance from the furnace wall of the heating furnace located downstream in the transport direction to the material to be heated at the extraction position is relatively short, the laser rangefinder is not placed close to the furnace wall and is considerably separated in the transport direction. Even if installed, it is possible to measure the distance with high accuracy. For this reason, it is hard to receive the influence of the heat from the inside of the furnace, and it is not always necessary to provide a cooling means for cooling the laser distance meter. Even if air purge is performed on the laser beam projecting / receiving surface of the laser distance meter, the laser distance meter is installed at a position away from the furnace wall, so there is no risk of purge air entering the furnace, The progress of the decarburized layer formed on the surface of the steel is not affected. Furthermore, when operating a heating furnace with a lower air-fuel ratio in order to improve the basic unit of fuel, smoke is generated in the furnace due to incomplete combustion of the fuel, but the distance from the furnace wall to the heated material at the extraction position Is relatively short (therefore, the distance through which the laser beam passes through the region where smoke is generated is short), so that the measurement accuracy is less likely to deteriorate.
As described above, according to the method according to the present invention, operational troubles (manual maintenance of the apparatus, the decarburized layer of the material to be heated easily progresses, operation with a reduced air-fuel ratio cannot be performed, etc.) The distance from the laser distance meter to the material to be heated can be accurately measured without coming, and based on the measured distance to the material to be heated, the extraction position of the material to be heated (along the longitudinal direction of the material to be heated) It is possible to detect the position of a plurality of parts) with high accuracy.

  In addition, although it is possible to newly provide an opening provided in the furnace wall of the heating furnace located downstream in the conveyance direction of the material to be heated, the oxygen concentration, furnace temperature, and furnace pressure in the furnace are kept constant. From the viewpoint, it is not preferable to provide too many openings in the furnace wall. In general, the heating furnace is often provided with an opening called a site hole for visually confirming the extraction status of the material to be heated. For this reason, it is preferable to use this existing site hole as the opening provided in the furnace wall.

  Moreover, in order to solve the said subject, this invention is installed along the direction orthogonal to the conveyance direction of a to-be-heated material based on the extraction position of the to-be-heated material detected by said detection method, and conveys a to-be-heated material The present invention is also provided as a method for extracting a material to be heated in a heating furnace, in which a plurality of extractors moving forward and backward in the direction are individually driven to extract the material to be heated.

  According to such an invention, based on the extraction position of the heated material accurately detected by the above detection method, the plurality of extractors can be advanced individually to the position corresponding to the extracted position of the heated material with high accuracy. it can. Therefore, it is possible to extract the heated material in a stable state without causing operational troubles such as dropping of the heated material from the extractor when the heated material is transferred to the extractor.

  In the present invention, “individual drive” means that the distance to which each extractor moves forward and backward is set for each extractor.

  According to the method for detecting the extraction position of the material to be heated in the heating furnace according to the present invention, it is possible to accurately detect the extraction position of the material to be heated in the heating furnace without causing any trouble in operation. Moreover, according to the extraction method of the to-be-heated material in the heating furnace which concerns on this invention, it is possible to extract to-be-heated material in the stable state, without producing the trouble on operation.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings as appropriate.
FIG. 3 is a plan view sectional view showing a configuration example of a heating furnace to which the method according to the present invention is applied and an apparatus for carrying out the method according to the present invention. 4 and 5 are cross-sectional views seen from the arrow Y direction of FIG. 3 for explaining the method according to the present invention. FIG. 6 is a plan sectional view for explaining the method according to the present invention.

  A heating furnace (walking beam type heating furnace) 100 to which the method according to the present invention is applied has a pre-tropical zone, a heating zone, and a soaking zone in order from the charging side of the material to be heated (for example, a steel piece) M. FIG. 3 illustrates the vicinity of this soaking zone. As shown in FIG. 3, the heating furnace 100 is installed along a direction (furnace width direction) orthogonal to the conveyance direction of the material to be heated M (the direction indicated by the arrow in FIG. 3, the furnace length direction). A plurality of extractors 1 (1a to 1d) moving forward and backward in the conveying direction of the material M are provided. The extractor 1 is inserted into an opening provided in the furnace wall 101 of the heating furnace 100 located on the downstream side in the conveyance direction of the material to be heated M, and is configured to advance and retreat through the opening. The heating furnace 100 includes a fixed beam 2, a moving beam 3, an extraction roller 4, and an extraction port 5. The material to be heated M charged in the pre-tropical zone of the heating furnace 100 is alternately placed on the fixed beam 2 and the moving beam 3 while being substantially orthogonal to the longitudinal direction of the material to be heated M (furnace length direction). After being heated to a predetermined temperature through a heating zone and a soaking zone, the extractor 1 and the extracting roller 4 extract it from the soaking zone 5 to the outside of the furnace.

  In the method according to the present invention, the position outside the heating furnace 100 having the above-described configuration and spaced from the furnace wall 101 of the heating furnace 100 located downstream in the transport direction of the material to be heated M in the transport direction. , A plurality of laser distance meters 10 (10a to 10d) are installed along a direction (furnace width direction) orthogonal to the transport direction. And the method which concerns on this invention irradiates the to-be-heated material M with the laser beam projected horizontally from each laser rangefinder 10 through the opening 102 provided in the furnace wall 101, From each laser rangefinder 10 The distance to the heated material M is measured, and the extraction position of the heated material M is detected based on the measured distance to the heated material M. Furthermore, the method according to the present invention is characterized in that the heated material M is extracted by individually driving the plurality of extractors 1 based on the detected extraction position of the heated material M.

  As the laser distance meter 10 used in the method according to the present invention, a TOF (Time Of Flight) type distance meter using pulsed laser light is preferably used. That is, the laser distance meter 10 projects pulse laser light toward the measurement object, measures the flight time until the reflected light returning from the measurement object is received, and converts it to the distance to the measurement object. It is preferable to use a distance meter of the type (distance = time of flight / 2 × speed of light).

  Moreover, in this embodiment, the existing site hole for visually confirming the extraction condition of the to-be-heated material M is utilized as the opening 102 provided in the furnace wall 101. This site hole is located above the opening for inserting the extractor 1 described above. For this reason, each laser distance meter 10 is disposed above each extractor 1 and at the same height as the site hole so that the projected and received laser light can pass through the site hole. However, the present invention is not necessarily limited to this, and a new opening 102 can be provided separately from the site hole. In this case, each laser distance meter 10 may be arranged according to the position of the provided opening 102 so that the laser light to be projected and received can pass through the newly provided opening 102.

Hereinafter, the method according to the present invention will be described more specifically with reference to FIGS.
First, as shown in FIG. 4 (a), the extraction position (the position where the heated material M is replaced on the extractor 1). In the present embodiment, the heated material M is most elevated by the moving beam 3 on the soaking area. The laser beam projected from each laser distance meter 10 is irradiated to the material M to be heated at the position. In Fig.4 (a), the irradiation point of the laser beam projected from laser rangefinder 10a-10d is each shown with code | symbol AD. The reflected light from the points A to D is received by the laser distance meters 10a to 10d, and the distances from the laser distance meters 10a to 10d to the heated material M (the distances to the points A to D) are measured. Based on the measured distance to the heated material M, the extraction position of the heated material M is detected.

If it demonstrates more concretely with reference to Fig.6 (a), distance La-Ld from each laser distance meter 10a-10d to the to-be-heated material M will be measured by each laser distance meter 10a-10d. Then, the distance measurement values La to Ld and the distances from the laser distance meters 10a to 10d obtained in advance to the tips of the extractors 1a to 1d at the steady positions (portions on which the material to be heated M is placed). Based on La _{0 to} Ld ₀ , the extraction position of the material to be heated M is detected with reference to the extractors _{1 a} to ₁ d at the steady positions. That is, it is detected that the point A of the heated material M is located at a position spaced apart by La-La _{0 in} a plan view with respect to the distal end portion of the extractor 1a. The same applies to the points B to D of the heated material M.

After detecting the extraction position of the material to be heated M as described above, the extractors 1a to 1d are moved forward and the moving beam 3 is lowered as shown in FIG. Thereby, the to-be-heated material M also falls). At this time, each of the extractors 1a to 1d is individually advanced according to the extraction position of the material to be heated M detected as described above. That is, in this embodiment, the extractor 1a is advanced by La-La ₀ , the extractor 1b is advanced by Lb-Lb ₀ , the extractor 1c is advanced by Lc-Lc ₀ , and the extractor 1d is advanced by Ld-Ld ₀ . Thereby, it becomes possible to move the front-end | tip part of the extractors 1a-1d directly under the to-be-heated material M. FIG.

  As described above, after the tips of the extractors 1a to 1d are moved directly below the material to be heated M, the extractors 1a to 1d are raised as shown in FIG. At this time, the extractors 1 a to 1 d are raised until the upper surfaces of the tips of the extractors 1 a to 1 d are higher than the upper surface of the moving beam 3. Thereby, the to-be-heated material M mounted on the moving beam 3 is mounted on the extractors 1a to 1d.

Next, as shown in FIG. 5 (a) or FIG. 6 (c), the extractors 1a to 1d on which the material to be heated M is placed are placed until the material to be heated M is located immediately above the extraction roller 4 (extracted). The tractors 1a to 1d are moved backward (until the tips of the tractors 1a to 1d are located immediately above the extraction roller 4). At this time, the extractors 1a to 1d are individually retracted in accordance with the advance distances of the extractors 1a to 1d described above. That is, the distance from the leading ends of the extractors 1a to 1d at the normal position to the extraction roller 4 is L (the positions of the extractors 1a to 1d when the leading ends of the extractors 1a to 1d are located immediately above the extracting roller 4). If, and the normal position of the extractor 1 a to 1 d, when the same position in plan view, when L = 0) to, in this embodiment, _La-La 0 -L for extractor 1a, extractor _Lb-Lb 0 -L for 1b, _Lc-Lc 0 -L for extractor 1c, for extractor 1d is retracted by _Ld-Ld 0 -L.

  After the material to be heated M is positioned immediately above the extraction roller 4 as described above, the extract is extracted until it reaches the same height as the steady position (position in FIG. 4A) as shown in FIG. The tractors 1a to 1d are lowered. Since the upper surfaces of the tips of the extractors 1a to 1d after lowering are lower than the upper surface of the extraction roller 4, the heated material M placed on the extractors 1a to 1d is placed on the extraction roller 4. Can be replaced.

  Finally, as shown in FIG. 5C, the heated material M is conveyed in the furnace width direction by the extraction roller 4 and extracted out of the furnace from the extraction port 5 provided in the furnace wall in the furnace width direction.

  According to the method according to the present invention described above, even if the longitudinal direction of the material to be heated M and the conveying direction are not completely orthogonal or the material to be heated M is bent, It is possible to accurately detect the extraction position of the material to be heated M in the heating furnace 100 without causing any trouble. Moreover, it is possible to extract the to-be-heated material M in a stable state without causing operational troubles.

  In the present embodiment, as a preferred mode, the number of laser distance meters 10 to be installed is the same as the number of extractors 1, but the present invention is not necessarily limited to this, and a plurality of laser distance meters 10 (preferably 3 or more) is enough. For example, in FIG. 3, when the laser distance meter 10b is not installed, the distance to point B (see FIG. 6A) is not measured. However, since the distances to the points A, C, and D are measured, an approximate straight line or an approximate curve that passes through the points A, C, and D can be calculated by the least square method using these distance measurements. It is. Based on this approximate line or approximate curve, the distance to point B can be predicted. Therefore, it is possible to drive the extractor 1b appropriately based on this predicted value.

  However, when there is a laser rangefinder 1 that cannot measure the distance among the plurality of installed laser rangefinders 1 or shows an abnormal value whose distance measurement value is clear, an operational trouble is surely avoided. It is not preferable to adopt the same method as described above. That is, an approximate straight line or an approximate curve is calculated by using distance measurement values other than the laser distance meter 1 except the laser distance meter 1 in which distance measurement is impossible or the distance measurement value shows an abnormal value, and the above measurement inability or abnormal value is calculated. It is not preferable to predict the indicated distance. If there is a laser rangefinder 1 that cannot measure the distance or the measured distance value is abnormal, it is heated for some reason (for example, a failure of the laser rangefinder 1 or a failure of the conveying equipment of the heated material M). It is preferable to determine that the extraction position of the material M could not be detected normally and to interrupt the extraction operation of the material M to be heated.

FIG. 1 is a cross-sectional plan view showing an example in which the extraction position of the material to be heated in the heating furnace varies. FIG. 2 is a cross-sectional view in plan view for explaining an example of an operational trouble caused by a change in the extraction position of the material to be heated in the heating furnace. FIG. 3 is a plan view sectional view showing a configuration example of a heating furnace to which the method according to the present invention is applied and an apparatus for carrying out the method according to the present invention. 4 is a cross-sectional view seen from the arrow Y direction of FIG. 3 for explaining the method according to the present invention. 5 is a cross-sectional view seen from the direction of the arrow Y in FIG. 3 for explaining the method according to the present invention. FIG. 6 is a plan sectional view for explaining the method according to the present invention.

Explanation of symbols

1, 1a, 1b, 1c, 1d ... extractor 2 ... fixed beam 3 ... moving beam 4 ... extraction roller 5 ... extraction port 10, 10a, 10b, 10c, 10d ... Laser distance meter 100 ... heating furnace 101 ... furnace wall 102 ... opening M ... material to be heated

Claims (2)

A method of detecting an extraction position of a material to be heated that is conveyed in a direction substantially orthogonal to the longitudinal direction of the material to be heated in a heating furnace,
A plurality of laser distances along the direction orthogonal to the transport direction at a position outside the heating furnace and spaced from the furnace wall of the heating furnace located downstream in the transport direction of the material to be heated. Install a meter,
By irradiating the material to be heated with the laser light projected in a horizontal direction from each laser distance meter through the opening provided in the furnace wall, the distance from each laser distance meter to the material to be heated is measured,
A method for detecting an extraction position of a material to be heated in a heating furnace, wherein the extraction position of the material to be heated is detected based on the measured distance to the material to be heated.   A plurality of extractors installed along a direction orthogonal to the conveying direction of the heated material based on the extraction position of the heated material detected by the detection method according to claim 1 and moving forward and backward in the conveying direction of the heated material A method for extracting a material to be heated in a heating furnace, wherein the material to be heated is extracted individually to extract the material to be heated.

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