HK1052055A - Measurement of the wear of the fireproof lining of a metallurgical vessel - Google Patents

Description

Wear measurement of refractory lining of metallurgical furnace

The invention relates to a method for identifying and determining the position of an object, in particular a metallurgical furnace, in the measurement of the wear of its refractory lining.

In order to achieve an increase in the efficiency and a higher operational safety of refractory-lined metallurgical furnaces, it is necessary to obtain as much as possible the wear on the lining in the use of the furnace (so-called "voyage").

In which it is of particular importance to know precisely the thickness of the refractory lining, also called "residual brick thickness", since this makes it possible to use the refractory lining effectively until it is completely worn, without the risk of the outer metal wall of the metallurgical furnace being melted through.

There have been many efforts over the long term to develop measurement methods to accurately measure metallurgical furnaces. For time and cost reasons, these methods should not require furnace cooling, but can be carried out in a high temperature furnace. Thus, and also due to the inaccessibility of many metallurgical furnaces, the above-mentioned measurements are excluded from the outset.

Ferrotron electronics, ltd, discloses a different measurement method for determining the wear of the lining than the above method, in which the inner surface is scanned by a laser beam and the surface structure of the refractory lining can be mapped by distance and angle measurements. The residual brick thickness can be determined by comparison with a reference measurement made on the metallurgical furnace before the voyage.

The wear measurement of the refractory lining of a metallurgical furnace by means of the above-mentioned method is based on the premise that the position of the object coordinate system of the metallurgical furnace under test is determined relative to the device coordinate system of the measuring device used for the measurement, so that the measuring device and the furnace can be brought into the same coordinate system by coordinate transformation.

In order to be able to reconstruct the object coordinate system used in reference measurements made before the voyage when finishing the wear measurements, for example US-PS4025192 discloses an optical method for measuring the refractory lining of a metallurgical furnace. The first step in this method is to determine the coordinates of three reference points around the metallurgical furnace taphole by angle and distance measurements with a theodolite and to measure the refractory lining also by angle-and distance measurements at the individual points.

After the furnace has been used, the reference point and the lining are remeasured, the actual position of the object coordinate system relative to the apparatus coordinate system is determined by comparing the reference point coordinates measured immediately before with the reference point coordinates measured immediately before, and a position transformation is carried out when calculating the measurement points of the lining. The electromagnetic radiation emitted by the measuring device is manually aligned with the reference point by means of an optical sight.

Although the position and orientation of the furnace can be determined and reconstructed prior to the wear measurement in this way, the disadvantage is that this method is laborious and has a significant probability of error since it is carried out manually.

For this reason, and also because automation of the method is particularly important, DE19614564a1 discloses a method in which a calibration marking system on the outer furnace wall surface is recorded by a camera at the time of the reference measurement and before the wear measurement. The difference between the position and the geometry of the calibration marking system deduces the difference between the position of the furnace in the reference case and the measurement case. Although this method can be automated in principle, it has the disadvantage that the measurement accuracy achievable by this method is limited, on the one hand, due to the small dimensions of the calibration marking system and the small deviations of the individual points of the calibration marking system which occur when the furnace position changes, and on the other hand, due to the two-dimensional reference point position determination. Furthermore, this method assumes that the position of the furnace relative to the measuring device is determined separately and serially, so that the time consumption required for completing the wear measurement increases.

DE19808462a1 discloses a method in which three reference points on a metallurgical furnace are first collected by an identification device and then, after the measuring device has automatically aligned the reference points in succession, the exact position of the reference points in space is determined by means of a measuring device, which may comprise a laser distance measuring device.

Although the measurement accuracy of this method is improved compared to the method disclosed in DE19614564a1, since the three-dimensional information is obtained using the original position measuring device for determining the reference point, it has the disadvantage that the reference measurement needs to be carried out by optical recognition means.

US5212738 discloses another method for determining the position of a metallurgical furnace, in which the furnace is measured from two different positions, the position being determined by superposition of images.

This method has the disadvantage that the mutual position must be determined precisely, which increases the measuring expenditure.

The object of the invention is to provide a method which makes it possible to identify an object, in particular a metallurgical vessel, by identifying a two-dimensional or three-dimensional structure, which can be formed by the vessel itself or by a structure having a defined positional relationship to the vessel and a known geometry, and to determine its position relative to an optical detection device, without a plurality of measurements from different positions being necessary.

The above object is achieved by the invention according to claim 1.

The invention utilizes the following principle: the spatial measurement data measured by a distance measuring device operating with electromagnetic radiation, for example a laser distance scanner, are represented in polar coordinates and are arranged in a grid of angles Φ (m), θ (n) (Δ Φ, Δ θ) and corresponding distances Rad (m, n) relative to the measuring head.

A typical size of the two-dimensional measurement value matrix m × n thus constructed is 450 × 450.

Reference to a "pixel" below refers to a single point of this matrix. The map given by the corresponding distance values Rad (m, n) is referred to as "distance map".

In addition to the distance Rad (m, n), the corresponding intensity value Amp (m, n) of the reflected laser pulse may be detected for each pixel. Similar to the distance map, a so-called amplitude map is given by the intensity values.

It is known from image processing to use matrix operations when representing the measured values in a uniform grid. Wherein the distance values correspond to the grey values of the camera images. There are, however, disadvantages here: this method cannot cope with the fact that the distance between the measuring device and the measuring object changes, which is usually the case when wear measurements are carried out on the refractory lining of a metallurgical furnace: the size of the measured structures varies with the distance Rad (m, n) and the polar angle position (o), so that conventional operators need to scale on a large number so that they can accommodate all the possible measurement situations. This means a large computational overhead and implies a risk of misidentification.

In the method according to the invention, as in the case of image processing, although the entire matrix or a partial region is analyzed in discrete steps according to a defined structure, the measured distance values or the corresponding polar angles are also used for scaling the arithmetic unit. Thus, the measured range values Rab (m, n) and the measured angles (m), θ (n) around any pixel (m, n) during the search first participate in the operator scaling according to a structure of known spatial dimensions. The scaling of the operator here means that it is performed in the pixel coordinate system i: [ -imax, imax, Δ i]，j：[-jmax，jmax，Δj]Range [ imax, jmax ] of]And resolution [ Δ i, Δ j]And the desired values R (m + i, n + j) of the operators are adapted to the measured polar coordinates Rad (m, n), [ phi ], [ theta ] (n). The desired value of the operator is calculated from a known two-dimensional or three-dimensional spaceAnd (5) calculating. The operator delineates the ideal shape of the structure. The graph size of the structure is preferably given by the number of pixels. The resulting value of the operator at position (m, n) can be found from the squared difference between the desired value R and the measured distance Rad as follows:where norm (m, n) normalizes the resulting values by the corresponding number of pixels scanned. The resulting matrix S (m, n) allows the minimum position to be found in a conventional way, from which the spatial coordinates of the object (or objects) to be searched can be calculated.

In applying the method of the invention, it is preferred to carry out the following steps:

1. defining an operator in a two-dimensional or three-dimensional cartesian coordinate space by means of the known shape and size of the structure to be searched;

2. the following steps are repeated circularly:

i) pixel scanning of the matrix Rad (m, n);

ii) by means of an actual scanning coordinate scaling operator, wherein:

a) pixel boundaries in grid polar coordinates

b) The desired distance R (m + i, n + j) is calculated for all the operator pixels on the above calculated boundary.

iii) calculating the square deviation between the expected distance and the measured distance at the scanned position P (m, n)Arithmetic unit of

3. The searched coordinates Rad (m _ opt, n _ opt) or Rad ([ theta ] opt) with the best operator-result value are selected by minimum calculation.

In a first embodiment of the method according to the invention, a ball is used as the structure. It is particularly suitable because the scalable structure of the arithmetic unit depends only on the distance and not on different observation angles. The operator is defined by a known spherical radius and a general spherical geometry. The center point M of the ball is calculated as the resulting coordinate by adding the known ball radius P. This reference point coordinate is used along with other measured reference point coordinates to determine the furnace position in the equipment coordinate system.

In a second preferred embodiment of the method according to the invention, a brightly colored, environmentally placed planar marking is used as the structure. The operator, hereinafter referred to as amplitude operator, is first calibrated by the measured distance values Rad (m, n) and thus the expected marker size is calculated. This signature is then found by applying the well-known correlation method in the amplitude map.

A cross-shaped bright mark can be drawn on the converter body as a measurement mark. If a best matching pixel position is found, its spatial coordinates in the device coordinate system can be calculated from the corresponding distance values Rad (m, n).

In a third embodiment of the method according to the invention, the furnace itself is used as a structure. This alternative is particularly suitable for measuring a furnace with a cylindrical base structure. The computing unit, hereinafter referred to as "V-computing unit", first finds a point on the furnace mouth and, starting from it, the computing unit calculates at least a second point on the furnace mouth and is found for checking at least one point in the furnace body. With this embodiment of the method according to the invention, the position and orientation of the furnace can also be determined roughly in the inclined state. They are necessary for the subsequent calculation, for example, preferably for the precise calculation of the furnace position according to the embodiment of the method according to the invention described below.

The following embodiment of the method according to the invention for the precise calculation of the furnace position uses the furnace mouth as a structure. By means of the rough position found in the preceding step, the distance-and angle values are measured at the furnace opening to points in a search window pointing to the center of the furnace to be found. From this, a vector rad (k) is extracted, on which a line segment of a predetermined length b, which corresponds to the thickness of the taphole ring (in cartesian coordinates), is located by means of a calibrated operator, referred to below as "taphole operator". The tilt position of the furnace measured by the V-operator thus yields the tilt angle γ of the sought line segment.

If this embodiment of the method according to the invention is applied to a plurality of search windows, which cover the entire measured furnace opening region, a large number of furnace opening points are obtained from which the position of the circular furnace opening to be searched can be calculated by approximating a circle.

During operation of a metallurgical furnace, the furnace mouth is so heavily soiled that a point on the furnace mouth cannot be guaranteed to be identified by the V-operator and the tilting position of the furnace cannot be determined.

In this case, an embodiment of the method according to the invention is advantageous, in which a further cylindrical structure of the furnace is involved in the determination of the position, for example a ring or collar which surrounds the furnace on the outside. The tilt angle is determined in this case by means of an inclinometer.

In a further preferred embodiment of the method according to the invention, the transition region between the wall and the floor of the furnace is used as a structure, and an operator, referred to below as "wall-floor operator", is defined by two line segments of length Δ x, Δ z whose end points meet at a point and have a defined angle δ with respect to one another. Similarly to the previously described embodiments of the invention, the curve of the cross section of the furnace in the transition region from the wall to the floor is represented graphically, and this structure is calibrated and located inside a search window which points radially to the roughly determined furnace center. The position of the circular wall-floor transition is determined by a suitably large number of such search operations.

The method according to the invention is particularly suitable for determining the position of a converter, a ladle or an arc furnace relative to a measuring device.

In the case of arc furnaces, which usually comprise a vertical pot-shaped furnace body, the interior of which can only be accessed from above, the method according to the invention can also be used for hot furnaces, since the measurement time is in principle shorter than 20 seconds and the measuring device can be assembled with little expenditure so that it is subjected to the heat acting on it over this time span during the entire measurement process.

Devices particularly suitable for implementing the method of the invention include:

-a transmitting device for emitting a pulsed electromagnetic radiation;

-a receiving device for receiving electromagnetic radiation reflected at an object;

-a time measuring device for measuring the time of flight of the electromagnetic radiation pulse between the instant of emission and the instant of reception of the reflection from the object;

-a deflection device for deflecting the pulsed electromagnetic radiation in two mutually perpendicular directions with a predetermined period;

a data acquisition/processing device for acquiring the angle at which the electromagnetic radiation is emitted in two mutually perpendicular directions and the time of flight, for storing the known or determined spatial structure, and for comparing the spatial structure measured by the acquisition angle and the time of flight with the known or determined spatial structure in order to determine the actual position of the measured structure.

If the device has additional equipment for measuring the amplitude of the electromagnetic radiation reflected at the object, it can be used to map an amplitude map which is similar to a black/white picture in practice. From the amplitude map it is possible to check mainly whether the object (metallurgical furnace) fills the map gap and to perform optical control of the device which results from the method according to the invention.

If a device for measuring the heat radiation emitted at the location of the reflected electromagnetic radiation is added, a thermal profile can be mapped, which can, for example, provide an indication of a particularly strong thermal stress range of the furnace.

The transmitting means preferably comprise a laser diode operating in a pulsed manner, and the receiving means are formed by a photodiode.

As previously described, a grid of measurements is plotted for the completion of the measurement. The periodic deflection of the laser light required for this purpose is preferably effected in the vertical direction by means of a polygon mirror which is rotated about a horizontal axis and in the horizontal direction by a reciprocating movement of the measuring device about a vertical axis.

If the apparatus is mounted on a boom, the boom can be reciprocated between a position away from the metallurgical furnace and a position above or within the open furnace; the device is particularly suitable for the positioning of an electric arc furnace and the subsequent measurement of its refractory lining.

In this case, it is also possible and expedient to provide a device on the support arm in a fixed spatial relationship to the measuring device for applying refractory material to the interior of the furnace body.

The device for applying the refractory material may be, in particular, a device of MINTEQ International under the name MINSCAN^TMThe spraying robot can rotate, incline and lift into the furnace body by the nozzle.

The control of this jetting robot can be done directly with the wear data collected by the device.

By further measuring the interior of the oven body by means of said method, incorrect operation of the spray robot can be collected by visible, imminent incorrect application.

The measuring device and the nozzle are in a fixed spatial relationship to one another on the support arm, so that the actual position of the nozzle in the furnace before the application can be determined by means of the method according to the invention and incorrect application can thus be avoided.

The method according to the invention and a device suitable for carrying out the method are described below with the aid of the figures. In the drawings:

FIG. 1 schematically illustrates an apparatus suitable for carrying out the method of the present invention;

fig. 2 schematically illustrates the principle of pulse-travel measurement for determining distance;

FIGS. 3a-c illustrate, by way of example, a cylindrical furnace, a coordinate system that is decisive in the positioning of an object by means of the method according to the invention;

FIG. 4a shows a longitudinal section of a cylindrical furnace closed at one end in Cartesian coordinates;

FIG. 4b shows a view on the side of the furnace mouth of the same furnace as in FIG. 4a in Cartesian coordinates (view A in FIG. 4 a);

FIG. 5a is a view of the same furnace in polar coordinates corresponding to FIG. 4 a;

FIG. 5b is a view of the same furnace in polar coordinates corresponding to FIG. 4 b;

FIGS. 6a and b schematically show the coordinates of a ball operator in two mutually perpendicular views;

FIGS. 7a and b schematically show the coordinates of a so-called V-operator in two mutually perpendicular views;

FIG. 8 schematically shows the coordinates of a two-dimensional fire door operator;

FIG. 9 schematically shows the coordinates of a two-dimensional "wall-floor-operator";

FIGS. 10a and 10b illustrate the measurement process in Cartesian coordinates or grid polar coordinates with a furnace mouth arithmetic unit as an example to illustrate the following calculation examples;

FIG. 11a schematically illustrates various test positions of a measuring device on an object in a rotating axis system;

FIG. 11b schematically illustrates various tilt positions of the object in the rotating axis system;

fig. 12 shows a data flow diagram of a wear measurement of a converter by means of the method according to the invention.

In carrying out the method according to the invention, a measuring device, indicated as a whole by 100 in fig. 1, is used, which comprises a transmitter 10 for generating laser pulses LP, means for deflecting the laser pulses into a desired spatial direction, and a receiver 11 for detecting the laser pulses reflected from the object 0. The transmitter 10 and the receiver 11 are connected to a time measuring circuit, which determines the time between the emission time of the laser pulse of the transmitter 10 and the time at which the receiver 11 receives the laser pulse LP reflected from the object 0, calculates the distance of the object 0 reflecting the laser light from the measuring device 10 on the basis of the speed of light and stores the respective spatial directions.

One laser diode may be used as the transmitter 10 and one photodiode may be used as the receiver 11. The means for deflecting the laser pulses may comprise a device which is pivotable about an axis X (axis Y in FIG. 3a) perpendicular to its mutually parallel sides₁) A rotating polygonal mirror 12 whose sides with intersecting sharp corners reflect the laser pulses, and a device for rotating the measuring device 10 about an axis Y perpendicular to the axis X (axis Z in FIG. 3a)₁) A means for deflecting. The rotational speed of the polygon mirror 12 is 10 revolutions per second in the shown embodiment, the measuring device being rotated at 2 ° per second. The laser diode emits 20000 pulses per second.

The device shown in fig. 1 achieves a rapid deflection of the laser pulses in the vertical direction by rotation of the polygon mirror 12 (fig. 1 schematically shows the direction of travel of three successive laser pulses, which impinge on the object 0 at the positions 1, 2, 3), and the deflection of the laser pulses in the horizontal direction is achieved by a reciprocal oscillation of the entire measuring device about the axis Y. Since the laser measuring device produces measured values at uniform time intervals and the rotational movement is kept constant, the scanning of the object surface takes place at regular angular steps. The vertical movement is always from top to bottom. While the horizontal movement is alternately clockwise or counter-clockwise. A distance grid is thus depicted with the device 100, which in principle has the structure shown in the sub-diagram ER in fig. 1. This distance grid typically contains about 400 x 400 measurement points (pixels).

The receiver 11 may also have a device for measuring the thermal radiation WS emitted from the same point at which the distance to the object is determined.

As can be seen from fig. 2, the amplitude AM 'of the laser pulse LP' reflected from the object 0 is related to the amplitude of the emitted laser pulse LP and the surface structure, e.g. the finish, at the location of reflection.

The following measured values are determined for each test point with the measuring device 100:

-measuring the distance Rad between the device and the reflection location on the object,

the amplitude of the reflected laser-pulse LP',

-thermal radiation at reflection locations on the object

Horizontal and vertical angles at which the measuring device emits laser-pulses LP.

The horizontal and vertical angles θ are taken as coordinate axes, and the amplitude measurement AM' is plotted as a luminance value at the corresponding angular coordinate, resulting in an amplitude map that is much like a black and white photograph. In the same way, the distance and temperature radiation measurements can be mapped and also encoded on a color scale.

The amplitude diagram has the following meanings for the operator of the measuring device:

a) checking the furnace for a good fill map;

b) the control of the interactive scanogram or the automatic scanogram is performed by means of the gated building blocks (circuits, etc.).

The distance map is the basis for the calculation of the measurement results, the data of which can be used for automated structure search due to its regular grid structure (e.g. furnace mouth, support ring (lugs), wall-floor-transition zone, balls, etc.).

The measured values of the temperature radiation diagram are converted into temperature measured values by means of a calibration device and are plotted in an object coordinate system, which together with the simultaneously measured residual material concentration makes it possible to determine metallurgically useful information about the thermal state (e.g. temperature distribution, heat capacity of the refractory lining).

In order to be able to carry out wear measurements of, for example, the refractory lining of a metallurgical furnace by means of the measuring device 100 in a manner known per se, it is required that the relative positions of the measuring device and the furnace are determined beforehand.

In addition to the unit of measurement, a reference point and a direction relating to the measured value are also given in each spatial position measurement. A point in space can be described by three measured values (coordinates) which are all referenced to a common reference point (origin) and are each in mutually perpendicular directions (coordinate axes). The examples of metallurgical furnaces shown in fig. 3a-c in relation to the method of the invention use different coordinate systems:

1) plant system X₁，Y₁，Z₁: origin and axis are determined by the measuring head-geometry (FIG. 3a)

2) Rotating axis system X₂，Y₂，Z₂: origin being the center of the converter on the axis of rotation, Z-axis (Z)₂) In the direction of 180 DEG rotation angle, Y-axis (Y)₂) Is the axis of rotation (fig. 3 b).

3) Object system X₃，Y₃，Z₃: origin point being the central point of the ring 3, Z-axis (Z)₃) Perpendicular to the ring 3, X-axis (X) of the furnace mouth₃) Perpendicular to the axis of rotation (Y)₂) (FIG. 3 b). A point in the object system may also be represented in the cylindrical coordinate system W, R, Z₃(see fig. 3 c).

Approximately 200000 measurement points after recording a survey scan are in polar coordinates phi, theta, Rad, rather than in the reference device system X₁，Y₁，Z₁On the coordinates of (c). In this form, the surface structure of the object 0, that is, the refractory coordinate X cannot be judged₃，Y₃，Z₃. For this purpose, the measurement points must be represented with reference to an object system (coordinate transformation). Since the position of the measuring device relative to the object is different during each scan, the object system X has to be determined again each time₃，Y₃，Z₃In the equipment system X₁，Y₁，Z₁Of (c) is used. This evaluation value provides as a result the exact position of the object, which calculation is mathematically represented in the form of a transformation matrix.

Using a cylindrical furnace G as an example, a preferred embodiment of the method according to the invention for determining the furnace position is described below with reference to fig. 4 to 12.

The cylindrical furnace G shown in fig. 4a and b has a bottom layer 1, a cylindrical wall 2 and a furnace opening 3. The outer diameter of the snout ring, which in the embodiment shown corresponds to the outer diameter of the wall 2, is d and the thickness of the snout ring is b.

For clarity, in fig. 4a and 5 a-fig. 5a shows the same furnace in polar coordinates in the same view as fig. 4 a-a point inside the furnace is denoted by a, the intersection of the floor and the inner wall 4 is denoted by B, a point on the inner boundary line of the furnace opening 3 is denoted by C, a point approximately in the center of the wall constituting the region of the furnace opening is denoted by D, and a point on a circle constituting the outer edge of the furnace opening is denoted by E.

As shown in fig. 6a and 6b, the ball operator is so open in three mutually perpendicular spatial directions in cartesian coordinates that the origin of the respective cartesian coordinate system coincides with the center point M of the ball.

Correspondingly, the three-dimensional V-operator is at a point D on the furnace mouth approximately in the center between the inner and outer boundaries of the furnace mouth₁，D₂，D₃，D₄And opens between a point a in the furnace.

As shown in FIG. 8, the fire door operator is defined in two-dimensional Cartesian space near a point D approximately centered between the inner and outer boundaries of the fire door and points C and E, which are on the inner or outer boundary of the fire door, respectively.

The two-dimensional wall-floor operator is defined by two line segments of length Δ x, Δ z whose end points intersect at a point and, in the embodiment shown, are at an angle δ of 90 ° to one another. So that the curve of the furnace profile in the transition from the wall to the floor is briefly shown.

The method of the invention will now be described in a window F1 with the coordinate γ being 0 as shown in fig. 5b, using a furnace mouth arithmetic unit as an example with reference to fig. 10a and b.

The port operator extends between points C, D and E and defines the wall of the port and is approximately centered on the wall (see fig. 8). As can be seen from fig. 10, for a distance Z0 from the scanning point D:

(1)Z₀＝Rad_Dsin*_Dwherein Rad_DAnd [ v ] & o_DIs the measurement of the scanned pixel n.

Also visible in FIG. 10a is

(2)X_D=Rad_Dcos*_D，

Thus, the boundary of the furnace mouth arithmetic unit is calculated:

X_C＝X_D-b/2→*_C＝atan(Z₀/X_C)→Kmax＝round[(*_C-*_D)/Δ*]

X_E＝X_D+b/2→*_E=atan(Z₀/X_E)→Kmin＝round[(*_E-*_D)/Δ*]

then, the rated distance r (k) is calculated:

(3)K＝0： R_(K＝0) ：＝Rad_D(*_D)

K＝1： R_(K＝1) ：＝Z₀/5in(*_D+Δ*)

a compound of the general formula:

for K ∈ [ Kmin, Kmax ]

The resulting value at scan position m is then found:

the coordinates of the searched furnace mouth point are then determined by identifying the best matching position as follows.

(5)S_opt＝Min(S(m))→m_opt＝m(S_opt)→

*_opt＝*(m_opt)→Rad_opt＝Rad(m_opt)

The wear measurement process of the refractory lining of a metallurgical furnace, the position of which relative to the measuring device 100 is determined by means of the method according to the invention, will now be described with reference to fig. 11a) and b) and fig. 12.

Three different measurements and the basic ways of their evaluation can be distinguished for this purpose:

1) basic measurement

2) Reference measurement

3) Wear measurement

1) Basic measurement, which is carried out in a clean furnace, measures the spatial position of the following structures in the furnace:

-the position of an always clean structure in the rotating shafting (converter) or in the object system (ladle),

the position of the ring of the tuyeres in the axis of rotation (converter),

this data is stored in a dedicated elementary file. It is necessary to determine the position of the furnace relative to the measuring device before the wear measurement is carried out according to the method of the invention.

2) Reference-measurement refers to a measurement made on a furnace lined with a durable lining or on a furnace (steel shell) which is completely broken, so that it can only be carried out at a specified time (over a period of weeks, months or years). Instead of the reference measurement, a furnace with or without a durable lining or a cross section of a figure can be inferred (reference profile compilation). The reference profile is stored in a reference file.

If the measurement is carried out on the steel shell of the furnace and there is a file containing the reference profile (drawing) of the furnace, a deformation-evaluation is carried out with the aid of a data processing device and a measurement file is formed relating to the real-time steel shell profile. Instead, a corresponding measurement file is created when measuring the inner lining and is determined from the steel jacket profile or, if no measurement is available for it, from the reference profile.

3) Wear-measuring measures a furnace lined with a worn lining and it can be carried out virtually at any time in the furnace being emptied. It is of primary importance here that the total time of measurement is as short as possible, so as not to affect production. The wear profile is also stored in a file.

In most cases, the furnace mouth is dirty in this measurement, so that it must be reconstructed (scanogram) with the aid of its own file before each measurement. This can then be calculated from the real-time profile data and a predetermined amount of steel at the bath level. In order to obtain a real-time brick thickness (residual brick thickness) of the worn lining, a reference profile of the durable lining recorded beforehand is read from a reference file and compared with the actual measured values.

Multiple scans, for example repeat scans, scans under different object tilts or scans from different measurement positions, are made at each measurement (wear, reference or base measurement).

Typically, 450 × 450 measurement points per scan can be optimally stored in one scan-file. Wherein each measurement point may contain 5 measurement values, i.e.

Measuring the distance Rad between the device and the reflection location on the object

Amplitude of the reflected laser-pulse LP

Thermal radiation WS on the reflection location of the object

Horizontal and vertical angles at which the laser pulses LP are emitted by the measuring device.

Since the position of the furnace relative to the measuring device is generally unknown, a position scan is carried out according to the method of the invention, in which a clean outer structure is measured. The measurement position of the unknown measuring device relative to the furnace is then determined. All these scans, together with optionally other test values (for example the converter inclination measured by an inclinometer), constitute the raw data of the measurement.

In the following, converter measurements are taken as an example to show how the measurements consist of individual scans.

After placing the measuring device 100 in the measuring position M (see fig. 11a), the furnace G enters an inclined position 0, the operator records the inclination angle-possibly by using an inclinometer-in real time and registers the position-scan number 1.

The method according to the invention determines the position of the measuring device relative to the furnace G (scanogram) from the raw data.

Each scan evaluation may also be performed after all scans are registered to avoid unnecessary production delays.

The converter G is now brought to the tilting position I, and the operator again records the real-time tilting angle and registers the survey scan number 1. If the position-scan scanogram is complete, the program can now directly calculate the position of the fire hole circle and draw it into the amplitude map. The operator then takes the measurements of survey scan numbers 2 and 3 in the same way at tilt positions II and III.

In order to measure the side upper wall of the converter G at an object angle of 90 °, which in this case is covered by the furnace opening, the operator moves the measuring device 100 into the measuring position L, to measure the exact position of the measuring device 100 in this position, the rotary furnace G is returned to the inclined position 0, and the position scan number 2 is registered. The converter is then rotated to the inclined position II and the survey-scan number 4 is registered. Which position this measurement-scan belongs to-the scan is recorded and displayed to the operator.

To measure the upper furnace side at an object angle of 270 °, the measuring device 100 is placed in the measuring position R, the furnace is rotated again into the inclined position 0, and the position scan number 3 is registered. The furnace was then rotated to position II and measurement-scan number 5 was registered.

The above sequence is expressed in a short way as follows:

1) position-scan number 1M 0

2) Measure-scan number 1M 1

3) measurement-Scan number 2 MII

4) measurement-Scan No. 3 MIII

5) Position-scan number 2L 0

6) measurement-Scan number 4 LII

7) Position-scan number 3R 0

8) measurement-Scan No. 5 RII

The following rules are followed here:

the data processing device performs the numbering of the position scans and the measurement scans in such a way that the numbering is filled in from small to large, one measurement scan corresponding to the position scan performed in the preceding time. One position-scan is always performed as the first scan.

All 8 scan-memories are loaded with scan data and form the original data set. Factory production can continue.

If the scanogram value is not performed directly after each scan, it may be performed later. As a result, the transformation-matrix of all 5 measurement-scans is calculated.

The evaluation is then carried out in the true sense. First, the data processing device transforms the measurement points from the system into the system of objects and simultaneously selects those measurement points which do not belong to the interior of the furnace. The remaining brick thickness is then calculated by comparison with the reference-file. For calculating the data of the measurement file and the diagram of the evaluation values, a program specific to the measurement point is used. The measurement files are stored in increasing numbered order and displayed and printed as a chart. The operator can now calculate the specified length of the furnace by manual assistance if, for example, a particularly thin worn lining is detected at this point. At this point, not only the evaluation but also the measurement is finished.

The determination of the position of the furnace relative to the measuring device and the subsequent furnace measurement have been described above by way of example with a converter. Since the method according to the invention for locating is suitable for any object, the position determination and the subsequent measurement can be carried out in this way for other metallurgical furnaces.

If the furnace is a ladle, it is usually measured laterally.

For this purpose, the well-known wall-floor arithmetic unit is used to determine the coordinate system of the ladle. The position of the inner edge of the substrate without the refractory lining is first measured by the arithmetic unit. The position of other known structures of the ladle is then determined, these positions being reproducible in the wear measurement and being associated with a ring that is almost parallel to the opening, around the side of the ladle shell. The measured positions of the structure are collected and stored in the object coordinate system and later compared with later measured values for position determination.

The main advantage of the method according to the invention is that the determination of the position of the furnace relative to the measuring device is carried out in a short time and, as already mentioned, the individual scanogram values can also be carried out after all scans have been carried out, which in turn reduces the measuring time.

The method of the invention makes it possible for the first time to measure the interior of a pyrometallurgical furnace without the need for a sufficient inclination of the furnace, so that the measuring apparatus outside the furnace is in the high-temperature region during the measuring period.

The resulting extreme temperature loading and the time limitation set for production require very short measurement times.

The main application is an electric arc furnace, where the measuring device can be located approximately centrally above the opening of the furnace according to the principle of reduced shadowing, preferably with the edge of the opening as a known structure for determining the position of the furnace relative to the measuring device, and then the measurement is performed by means of a furnace mouth operator.

Symbol table

1. A bottom layer, a first side layer and a second side layer,

2, the wall of the container is divided into a plurality of walls,

3, a furnace mouth is arranged at the furnace mouth,

4 the inner wall of the inner cavity is provided with a plurality of grooves,

d, the outer diameter of the furnace opening ring,

b, the thickness of the furnace opening ring,

the inner point of the furnace A is arranged,

b a bottom layer/inner wall connection point,

c, a point on the inner boundary of the furnace mouth,

d is at a point approximately in the center between the inner and outer boundaries of the furnace mouth,

E a point on the outer boundary of the furnace mouth,

p-scan the point(s),

the center point of the M circle is,

100 the test of the device is carried out,

10a transmitter is provided, wherein the transmitter is provided with a plurality of emitters,

11a receiver for receiving the signal from the external,

12 a multi-prism lens, and a prism lens,

the LP laser-a pulse-is,

the number of the O objects,

the X-axis of the light beam is parallel to the X-axis,

and the Y axis.

Claims (22)

1. Method for determining and locating an object, in particular a metallurgical vessel, by means of electromagnetic radiation, in particular for measuring the refractory lining thereof, in which an operator is defined on the basis of a two-dimensional or three-dimensional structure of known shape and dimensions, and then the distance values (Rad (m, n)) and the corresponding measurement angles ([ phi ] (m), theta (n)) are determined within the structural range for the scaling of the operator, while the range and resolution (i: [ -imax, imax, deltai ], j: [ -jmax, jmax, deltaj ]) of the operator and the desired values (R (m + j, n + j)) of the operator in the diagram coordinate system are adapted to the measurement polar coordinates (Rad (m, n), [ phi ], theta (n)) for the scaling of the operator in the diagram coordinate system, and the desired values (R (m + i, n + j)) of the operator and the measured values (Rad (m + i, n + j)) find the resulting value (S (m, n)), and the sought structure position is determined from the position of the smallest resulting value.

2. The method of claim 1, comprising the steps of:

-defining an operator in two or three dimensions by means of the known shape and dimensions of the structure sought;

-thereafter cyclically repeating the steps of:

pixel scanning of the matrix (Rad (m, n));

scaling of the operator by means of actual scanning coordinates, wherein

a) The pixel boundaries in the grid polar coordinate map are found, and

b) finding a desired distance (R (m + i, n + j)) for all pixels of the operator on the boundary found previously;

determining operator results at scanned locations (m, n) from variances between desired and measured distances

-selecting the sought coordinates with the best operator-result value by finding the minimum value

Rad (m _ opt, n _ opt) or Rad ([ o ] opt, θ _ opt).

3. Method according to claim 1 or 2, characterized in that the intensity value (Amp (m, n)) of the reflected electromagnetic radiation is measured in addition to the distance value (Rad (m, n)).

4. A method according to claim 1 or 2, characterized in that a ball is used as the structure.

5. A method as claimed in claim 3, characterized in that a brightly colored, environmentally placed planar marker is used as the structure and the operator is scaled in the amplitude map in a correlated manner.

6. Method according to claim 1 or 2, characterized in that the furnace itself is used as a structure and the operator finds a point in the area of the furnace opening and at least two other points around this point are distributed over the furnace opening, while at least one other point inside the furnace is found for inspection.

7. A method according to any one of claims 1, 2 or 6, characterized in that the distance and angle values of points in the search window radially towards the centre of the furnace to be found on the furnace mouth are measured, whereby a vector (Rad (K)) is extracted, on which the distance of the specified length (b), which corresponds approximately to the thickness of the furnace mouth ring, is found by means of a scaled operator.

8. A method according to any one of claims 1 to 7, characterized in that also the tilt angle of the furnace is measured by means of an inclinometer which can be rotationally mapped about an axis perpendicular to its length axis, and this tilt angle is taken into account when the furnace is positioned.

9. A method according to any one of claims 1, 2 or 6, characterized in that the transition zones of the walls and the floor of the furnace are used as structures and in that the operator is defined by two line segments of length (Δ x, Δ z) whose end points intersect at a point and are at a defined angle (δ) to each other.

10. A method as claimed in any one of claims 1 to 9 for determining the position of a rotary kiln.

11. A method according to any one of claims 1 to 9 for determining the position of a ladle.

12. The method of any one of claims 1 to 9, for determining the position of an electric arc furnace.

13. Apparatus for carrying out the method of any one of claims 1 to 9, comprising

-a transmitting device for transmitting pulsed electromagnetic radiation,

-a receiving means for receiving electromagnetic radiation reflected from the object;

-a time measuring device for measuring the time of flight of the electromagnetic radiation pulse between the instant of emission and the reception of the radiation reflected from the object;

a deflection device for periodically deflecting the pulsed electromagnetic radiation in two mutually perpendicular directions;

a data acquisition/processing device for collecting the angles at which the electromagnetic radiation is radiated in mutually perpendicular directions and the travel times, and for storing the known or determined spatial structure and for comparing the spatial structure measured from the measured angles and the travel times with the known or determined spatial structure in order to determine the actual position of the structure under test.

14. The apparatus of claim 13, wherein the receiving means further comprises a device for measuring the amplitude of the electromagnetic radiation reflected from the object.

15. An apparatus according to claim 13 or 14, wherein the receiving means further comprises means for measuring heat radiation emitted at about the location of the reflected electromagnetic radiation.

16. A device as claimed in any one of claims 13 to 15, wherein the emitting means is a laser diode operable in a pulsed state.

17. A device as claimed in any one of claims 13 to 16, wherein the receiving means is a photodiode adapted to the frequency of the radiation emitted by the laser diode.

18. A device according to any one of claims 13 to 17, wherein the deflecting means comprises a polygon (12) rotatable about an axis (X) perpendicular to its mutually parallel sides, the sides whose sharp corners intersect to reflect the electromagnetic radiation.

19. An apparatus according to any one of claims 13 to 18, characterized in that the deflection means comprise a device with which the measuring device (100) can be swung back and forth about an axis (Y) which is approximately perpendicular to the axis (X) of rotation of the polygon mirror (12).

20. An apparatus according to any one of claims 13 to 19, wherein the measuring device is mounted on a support arm such that it can be reciprocally positioned between a position remote from the metallurgical furnace, such as a converter, and a position external or internal to the open metallurgical furnace.

21. The apparatus of claim 20, wherein there is a means for applying refractory material to the interior of the metallurgical furnace in fixed spatial relationship to the measuring device on the support arm.

22. The apparatus of claim 21, wherein the means for applying the refractory material is a spray robot that is currently used to apply the refractory material to the interior of the metallurgical furnace.