Abstract:
In a method and system for measuring wear in the lining of a vessel by a laser contouring system having an electromagnetic radiation emitting and receiving device. The laser contouring system references permanent marks and temporary marks positioned outside, on, or within the vessel. The distances and direction from the electromagnetic radiation emitting and receiving device to the fixed and temporary marks is determined during an initial measurement by the electromagnetic radiation emitting and receiving device from a first scanning position. The electromagnetic radiation emitting and receiving device is then moved along a path from the first scanning position to a second scanning position wherein some of the marks which were scanned from the first scanning position are scanned again to determine the relative position of the vessel and points on the internal lining of the vessel to determine the contour of the lining.

Description:
BACKGROUND 
       [0001]    The invention relates to a method for measuring wear in the lining of a metallurgical vessel, for example, a ladle or a basic oxygen furnace. 
         [0002]    It is extremely important to measure wear in the lining of ladles or basic oxygen furnaces or other industrial containers which are used for example in the steel making process. This renders it possible to optimize the service life of the container and to prevent excessive wear in the lining from causing risks pertaining to production or industrial safety. As an example, wear linings of basic oxygen furnaces must be renewed relatively often, as their life time varies, depending on what is melted in the basic oxygen furnace, on the material of which the lining is made, and naturally on the number of melts for which the basic oxygen furnace is used. 
         [0003]    The wear in a lining is measured by a method based on measuring the time of flight or the phase shift of a laser beam. The laser beam is directed to the lining on the inner surface of the basic oxygen furnace, from which it is reflected back to the measuring device. In the method based on measuring the time of flight, the distance between the measuring device and each measured point on the lining to be measured in the coordinate system of the measuring device can be calculated on the basis of the time difference between the emitting time and the return time of the laser beam. The measured points define the wear profile of the lining, which may be output for instance to a display terminal, by which the wear profile measured from a basic oxygen furnace in process can be compared graphically and numerically with the profile that was measured on the safety lining of the container or the working lining before the container was actually brought into use, i.e. before the first melt. 
         [0004]    To measure wear in the lining of three-dimensional objects, such as basic oxygen furnaces, ladles and other containers used in industrial applications, by non-contacting methods, such as laser measurement, requires that the measuring device and the object to be measured are represented in the same coordinate system. Combining the coordinate systems of the measuring device and the object to be measured is called fixing. In other words, the measuring device is positioned or fixed in relation to the object. For fixing it is necessary to use three or more permanent marks, with the laser beam of the measuring device being directed sequentially towards each permanent mark, and the coordinates of each permanent mark are measured in the coordinate system of the measuring device. Even if the measuring device has a fixed position in the vicinity of the container through permanent marks, it is advisable to perform fixing for each lining measurement again, which ensures a change in the ambient conditions and other factors not to cause any errors. 
         [0005]    In the so-called direct method normally used for positioning or fixing, stationary fixing points, also called permanent marks, are part of the object to be measured, or can be mounted to the object, or in the vicinity of the object. By means of the permanent marks the coordinate systems of the object and the measuring device can be mathematically combined. In the direct method, the object to be measured and the measuring device can be included into the same coordinate system by measuring at the same time both the permanent marks and the points to be actually measured. 
         [0006]    In a special case where the object to be measured is supported by a tilt axis, indirect angle measurement fixing can be applied, with the permanent marks being located on the container or outside of the container. An angle measuring device can be mounted, for example, to the tilt axis of the container or can be mounted elsewhere to the container. An example of such measuring device is a so-called inclinometer or tilt sensor. At present, fixing by means of angle measurement is an indirect method which is used when it is difficult to provide the object to be measured with necessary fixing points which are clearly visible and which position can not be recognized otherwise. Angle measurement fixings have been performed using fixing points on the container or on structures outside the object to be measured and using an angle value obtained from the angle measurement device, whereby the coordinate systems could be mathematically combined. The permanent marks are attached to the container or to the frame structures of a factory wall, for example, in vicinity to the basic oxygen furnace. When angle measurements were used in the known methods, the angle measurement device informs the measuring device of the position of the object or container in relationship to the known surroundings. 
         [0007]    In both direct and indirect angle measurement fixing methods, the permanent marks can be, for example, small plates, cylinders, spheres or other regularly shaped objects made from a material which reflects laser radiation. 
         [0008]    EP 1 234 193 B1, which has a counterpart U.S. Pat. No. 6,922,251 to Kirchhoff et al. discloses a method for measuring the refractory lining of a metallurgical container by means of a laser scanner wherein the laser scanner is positioned centrally in front of the container in preparation of the measuring step to establish a precise definition of the position of the laser scanner relative to the container with the aid of permanent marks attached to the said container. Once the container has been emptied, measuring of the interior of the container can be performed in that a laser beam which can be deflected horizontally and vertically scans the inner surface of the container. The laser beams reflected from the refractory lining are received and are processed in accordance with their time of flight. Since also the position of the receiver is well known relative to the laser head and the respective angle position of the laser head has been determined for each individual laser beam, the shape of the surface of the refractory lining can be reconstructed from the data generated. Advantageously the container is not only scanned in its horizontally tilted position, but scanning is also done in two additional tilted positions, for example 20° upwards and approximately 20° downwards to possible scan the entire interior of the vessel. 
         [0009]    After the central scan of the refractory lining, also a left and right scan can be performed in the method known from EP 1 234 193 B1 to also scan the entire side wall near the opening of the vessel by moving the laser scanner into left or right positions with respect to the vessel. The laser scanner has to be moved because the vessel can be tilted about its horizontal axis only but not to the left or right. 
       SUMMARY 
       [0010]    The present invention is directed to a method and a system for measuring the refractory lining of a vessel, e.g. a steel ladle, by means of a laser scanner which comprises a laser head for emitting laser beams which can be deflected in vertical and horizontal directions and a receiving means in the vicinity of the laser head for receiving the laser beams reflected from the refractory lining to determine their directions and their time of flight. 
         [0011]    In the method of the present invention the electromagnetic radiation emitting and receiving device can be a laser scanner and receiving means for receiving electromagnetic radiation reflected by an object. The electromagnetic radiation emitting and receiving device is moved along a predetermined path from a first scanning position to a second scanning position. From the first scanning position the electromagnetic radiation emitting and receiving device scans at least two marks which have a known position in relation to the vessel. The marks can be permanent. The marks used for position determination of the laser scanner can be part of a structure such as the building in which the vessel is located or part of the vessel. The marks can be cylinders, spheres or other unmovable marks which are secured to the building or to the floor of the building. The marks need not be separately positioned or attached bodies as it suffices that they are part of a structure such as the building in which the vessel is located. When the marks are permanent such as marks on a building which does not change its position, the marks can be scanned by the laser beam so that a precise position of the marks can be determined by the laser scanner. 
         [0012]    The marks can be fixed marks positioned in front of the vessel prior to terminating the production process or alternatively, certain incidental structures on or within the container such as slag or funnels or craters formed by nozzles within the refractory lining. From the scanning data, the position of the marks in relationship to the coordinate system of the laser scanner is determined so that the position of the marks can be calculated in the coordinate system of the vessel or vessel tilt axis. 
         [0013]    The precise position and heading of the laser scanner in relation to the coordinate system of the vessel is established by measuring the distance of the laser scanner with respect to the positions of previously installed and defined marks. This initially mapped precise position of the laser scanner will be referred to herein as the first scanning position of the laser scanner or electromagnetic radiation emitting and receiving device. 
         [0014]    From the second scanning position, the refractory lining is scanned by the electromagnetic radiation emitting and receiving device along with at least two marks which were previously scanned during the position scan from the first scanning position. 
         [0015]    Thereafter, when the laser scanner is moved to the second scanning position in front of the vessel by also simultaneously scanning at least two of the marks which were scanned in the first scanning position the new position and heading of the laser scanner from the second scanning position to the coordinate system of the vessel or vessel axis can be calculated. By scanning from the second scanning position the at least two marks which were scanned from the first scanning position, the position of the two rescanned marks within the coordinate system of the laser scanner is simultaneously calculated. From the point data generated by the laser beam scans, the vessel tilt angles, if applicable, and the laser scanner positions, the internal contour of the refractory lining of the vessel is derived. 
         [0016]    In another embodiment of the present invention, from the second scanning position, the refractory lining is scanned by the electromagnetic radiation emitting and receiving device along with at least one mark which was previously scanned during the position scan from the first scanning position. 
         [0017]    Thereafter, when the laser scanner is moved to the second scanning position in front of the vessel by also simultaneously scanning at least one of the marks which were scanned in the first scanning position the new position and heading of the laser scanner from the second scanning position to the coordinate system of the vessel or vessel axis can be calculated. By scanning from the second scanning position the at least one mark which was scanned from the first scanning position, the position of the rescanned mark within the coordinate system of the laser scanner is simultaneously calculated. From the point data generated by the laser beam scans, the vessel tilt angles, if applicable, and the laser scanner positions, the internal contour of the refractory lining of the vessel is derived. In the case in which the vessel is tilted in the time between scanning from the first scanning position and scanning from the second scanning position, measurement of the refractory lining can be made if the vessel tilt angle is determined, for example, by an inclinometer or tilt sensor. 
         [0018]    In another embodiment of the present invention, the electromagnetic radiation emitting and receiving device is moved along the predetermined path to a third, fourth or more scanning positions. From the above-mentioned third, fourth or more scanning positions, the refractory lining is further scanned by the electromagnetic radiation emitting and receiving device. In the case in which the vessel is tilted in the time between scanning from the first scanning position and scanning from any one or more of the second, third, fourth or more scanning positions, measurement of the refractory lining can be made if the vessel tilt angle is determined, for example, by an inclinometer or tilt sensor. 
         [0019]    In an embodiment of the method of the present invention, the production process within the vessel is terminated and the vessel is tilted into a position for measuring whereby the opening of the vessel is facing the laser scanner. The precise position and heading of the laser scanner in relation to the coordinate system of the vessel tilt axis is established by measuring the distance of the laser scanner with respect to the positions of previously installed and defined marks. The vessel is then scanned according to the above described method and the contour of the refractory lining in the coordinate system of the vessel is determined based on tilt angle data from the vessel obtained for example from an inclinometer or tilt sensor and the data from the scanning of the lining. 
         [0020]    In another embodiment of the invention, the vessel can be tilted into two or more additional positions and additional scans of the refractory lining are made at each of the additional positions by repeating the steps described above. 
         [0021]    The present invention also relates to a system for measuring the refractory lining of a vessel comprising an electromagnetic radiation emitting and receiving device for measuring electromagnetic radiation reflected back from a mark and determining the location of the mark in a coordinate system and a means for moving the electromagnetic radiation emitting and receiving device along a predetermined path from a first scanning position in which the electromagnetic radiation emitting and receiving device scans at least two marks or at least three marks of a known position to a second scanning position in which the electromagnetic radiation emitting and receiving device scans at least one of the marks which were scanned from the first scanning position along with a scanning of at least a portion of the refractory lining of the vessel. 
         [0022]    In another embodiment of the invention, the electromagnetic radiation emitting and receiving device is placed in a park position for storage which can be behind a heat shield. The electromagnetic radiation emitting and receiving device is moved along a predetermined path from the park position to the first scanning position. The laser is then moved to the second scanning position and finally after scanning of the vessel, the electromagnetic radiation emitting and receiving device is moved back along the predetermined path to the park or rest position. 
         [0023]    In another embodiment of the invention, the system for measuring wear in the refractory lining of a vessel can have a heat shield which can be selectively placed between the vessel and the electromagnetic radiation emitting and receiving device. When the heat shield is removed from in between the electromagnetic radiation emitting and receiving device and the vessel, the electromagnetic radiation emitting and receiving device can scan from a first scanning position the at least two or at least three marks and determine the initial reference position of the electromagnetic radiation emitting and receiving device and heading electromagnetic radiation emitting and receiving device. The electromagnetic radiation emitting and receiving device is moved along a predetermined path from the first scanning position to the second scanning position and the refractory lining is scanned while the heat shield is not present between the electromagnetic radiation emitting and receiving device and the vessel. 
         [0024]    In another embodiment of the invention the means for moving the electromagnetic radiation emitting and receiving device along a predetermined path from a first scanning position to a second scanning position also moves the electromagnetic radiation emitting and receiving device to and from a park or rest position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention will now be described in connection with the drawings, in which: 
           [0026]      FIG. 1  shows a parallel perspective view of the rear of an embodiment of the system of the present invention for measuring wear in a refractory lining showing the electromagnetic radiation emitting and receiving device or laser in the park position, the first scanning position and the second scanning position, 
           [0027]      FIG. 2  shows a parallel perspective view of the front of the system of  FIG. 1  showing the laser in the park position, the first scanning position and the second scanning position, 
           [0028]      FIG. 3  shows a top view of the system of  FIG. 1  showing the laser in the park position, the first scanning position and finally in the second scanning position during scanning of the refractory lining of the vessel wherein the vessel is shown in a sectional view, 
           [0029]      FIG. 3   a  shows a top view of another embodiment of the system of the present invention for measuring wear in a refractory lining showing the electromagnetic radiation emitting and receiving device or laser in the park position, the first scanning position and the second scanning position, 
           [0030]      FIG. 4  is an elevational view of the front of the system of  FIG. 1  showing the laser in the park position, the first scanning position and the second scanning position, 
           [0031]      FIG. 5  is an elevational view of the rear of the system of  FIG. 1  showing the laser in the park position, the first scanning position and the second scanning position, 
           [0032]      FIG. 6  is a side view of a portion of the rear of the system of  FIG. 1  showing the laser in the park position and behind a heat shield, and 
           [0033]      FIG. 7  is an elevational view of the right side of the system of  FIG. 1 . 
           [0034]      FIG. 8  shows a parallel perspective view of the rear of another embodiment of the system of the present invention for measuring wear in a refractory lining showing the electromagnetic radiation emitting and receiving device or laser in the first scanning position and the second scanning position, 
           [0035]      FIG. 9  shows a parallel perspective view of the front of the system of  FIG. 8  showing the laser in, the first scanning position and the second scanning position, 
           [0036]      FIG. 10  shows a top view of the system of  FIG. 8  showing the laser in the first scanning position and finally in the second scanning position during scanning of the refractory lining of the vessel wherein the vessel is shown in a sectional view, 
           [0037]      FIG. 10   a  shows a top view of another embodiment of the system of the present invention for measuring wear in a refractory lining showing the electromagnetic radiation emitting and receiving device or laser in the first scanning position and the second scanning position, 
           [0038]      FIG. 11  is an elevational view of the front of the system of  FIG. 8  showing the laser in the first scanning position and the second scanning position, 
           [0039]      FIG. 12  is an elevational view of the rear of the system of  FIG. 8  showing the laser the first scanning position and the second scanning position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0040]    It is to be noted that in all figures same parts are provided with the same reference numerals. In particular,  FIG. 1  shows the system of the present invention for measuring wear in a refractory lining showing the electromagnetic radiation emitting and receiving device  2  in the park position A, the first scanning position B and the second scanning position C. The means for moving the electromagnetic radiation emitting and receiving device  2  which can comprise a laser from the park position A to the first scanning position B is a trolley system having a trolley frame  4 , rollers  8 , chain  10  and motor  6 . As the motor  6  drives disc  12  on motor shaft  18  as seen in  FIG. 6  and chain  10  on disc  12  rotates wheel  48  on hanger bar  14  which supports trolley frame  4 . The electromagnetic radiation emitting and receiving device  2  then moves along the predetermined path from the park position A to the first scanning position B and then from the first scanning position B to the second scanning position C. 
         [0041]    The rollers  8  of the trolley system move along rail bar  20  which is supported by cross bars  46 . Mounting bars  50  on frame  42  support cross bars  46 . 
         [0042]    The system can be provided with a means for determining when the electromagnetic radiation emitting and receiving device is located at the park position, the first scanning position and second scanning position such that the means moving the electromagnetic radiation emitting and receiving device stops the electromagnetic radiation emitting and receiving device at the respective park position, first scanning position and second scanning position based on a signal from the means for determining when the electromagnetic radiation emitting and receiving device is located at the park position, the first scanning position and second scanning position. The means for determining when the electromagnetic radiation emitting and receiving device is located at the park position, the first scanning position and second scanning position can be a proximity sensor, encoder or other positioning means. As shown in  FIG. 6 , proximity sensor  16  detects when the electromagnetic radiation emitting and receiving device  2  is positioned at each of the park position A, the first scanning position B and the second scanning position C. The proximity sensors  16  which sense the electromagnetic radiation emitting and receiving device  2  can be located along the rail bar  20  as shown in  FIGS. 1 and 4 . The proximity sensors  16  along the rail bar  20  can serve to stop the movement of the electromagnetic radiation emitting and receiving device  2  along the rail bar  20 . 
         [0043]    The means for determining when the electromagnetic radiation emitting and receiving device  2  is located at the park position, the first scanning position and second scanning position can be encoder  17  in  FIG. 7  which tracks motor  6  movement and thereby the position of the electromagnetic radiation emitting and receiving device  2  along the predetermined path of the electromagnetic radiation emitting and receiving device  2 . 
         [0044]    The means for detecting when the radiation emitting and receiving device  2  is positioned at each of the park position A, the first scanning position B and the second scanning position C can be a mechanical means. Such a mechanical means can be a means for calculating the number of distance units the radiation emitting and receiving device  2  has moved between the park position A, the first scanning position B and the second scanning position C. The mechanical means could track the sum total of the number of mechanical devices, each of which corresponds to a predetermined distance, which were detected by the mechanical means as the radiation emitting and receiving device  2  moved along the predetermined path, for example along rail bar  20 . 
         [0045]    The system for measuring wear in a refractory lining of the present invention can have a heat shield  22  or any other means for protecting the electromagnetic radiation emitting and receiving device  2  from heat or thermal radiation from a hot vessel. 
         [0046]    The system for measuring wear in a refractory lining of the present invention can be provided with a support means for supporting the electromagnetic radiation emitting and receiving device  2  and the means for moving the electromagnetic radiation emitting and receiving device  2  from the first scanning position B to the second scanning position C. The support means can be a frame  42  having members arranged such that the members support the electromagnetic radiation emitting and receiving device  2  and the means for moving the electromagnetic radiation emitting and receiving device  2  from the first scanning position B to the second scanning position C. The members on the frame  42  which provide support can be mounting bars  50  on frame  42  support cross bars  46 . 
         [0047]    In another embodiment of the invention, the system for measuring wear in a refractory lining does not position the electromagnetic radiation emitting and receiving device  2  in a park position. The system for measuring wear in a refractory lining positions the electromagnetic radiation emitting and receiving device  2  in a first scanning position B and a second scanning position C. A moveable heat shield  22  can protect the electromagnetic radiation emitting and receiving device  2  prior to performing scanning from the first scanning position B. Before the electromagnetic radiation emitting and receiving device  2  scans from the first scanning position B the heat shield  22  can be moved out of a position in which the heat shield  22  protects the electromagnetic radiation emitting and receiving device  2  to a position where the electromagnetic radiation emitting and receiving device  2  is able to scan a vessel. 
         [0048]    The electromagnetic radiation emitting and receiving device  2  can be moved along the predetermined path by any other positioning means or device which can be a mechanical device which moves the electromagnetic radiation emitting and receiving device  2  from the first scanning position B to the second scanning position C. 
         [0049]    The system for measuring wear in a refractory lining can have a means for cooling  26  the electromagnetic radiation emitting and receiving device  2 . The means for cooling the electromagnetic radiation emitting and receiving device  2  can be by supplying cooling water and an air supply to the electromagnetic radiation emitting and receiving device  2 . Air can be supplied to the system for measuring wear in a refractory lining from air box  24  which can regulate the supply of air. 
         [0050]    Where conditions make it necessary, other cooling means or methods can be provided such as plant cooling water or other closed loop cooling systems. 
         [0051]    The system for measuring wear in a refractory lining can be provided with a video display  28  for showing the measured contour of the refractory lining  36  or vessel  34 . An image of the contour of the refractory lining  36  can be transmitted to a remote video display. The system for measuring wear can be operated remotely by a high speed Ethernet link. The system for measuring wear in a refractory lining can be operated by a direct hardwired connection. A portion of connection between the operator or operators operating the system can be wireless. 
         [0052]    The vessel which is scanned can be a ladle, a basic oxygen furnace or other industrial lining measurement application. 
         [0053]    The system for measuring wear in a refractory lining of the present invention can be detachably mounted by means of a bolt assembly  30  or any other means for detachably mounting the system to a structure such as a plant floor  44 , concrete pad or any other means for supporting the system. The system for measuring wear in a refractory lining of the present invention can be moved into another position by any means for moving the system such lifting lugs  32  after being detached from the supporting structure for the system. 
         [0054]      FIG. 3  shows a scanning of a vessel  34  using the method for measuring wear in a refractory lining  36  of the present invention. 
         [0055]    In one embodiment of the invention seen in  FIG. 3 , the electromagnetic radiation emitting and receiving device  2  first performs a position scan from a first scanning position B in which at least three marks, i.e. a first mark, PM 1  a second mark PM 2  and a third mark PM 3  are scanned. At least one of the first mark, PM 1  a second mark PM 2  and a third mark PM 3  has a known position in the coordinate system of the vessel  34 . The marks can be permanent or temporary. For example, the marks can be on the trunion  38  or on the trunion block  40 . Other marks in, on or outside of the vessel can be used. The angle α scanned by the electromagnetic radiation emitting and receiving device  2  can be from about 60 degrees to about 120 degrees. In another embodiment, the angle α can be from about 0 degrees to about 360 degrees. 
         [0056]    It is to be noted that two marks can be sufficient for position determination. The electromagnetic radiation emitting and receiving device  2  first performs a position scan from a first scanning position in which at least two marks, i.e. a first mark, PM 1  a second mark PM 2  are scanned. At least one of the first mark, PM 1  and a second mark PM 2  have a known position in the coordinate system of the vessel  34 . 
         [0057]    A means for moving the electromagnetic radiation emitting and receiving device  2  from a first scanning position to a second scanning position such as the trolley system described above then moves the electromagnetic radiation emitting and receiving device  2  from a first scanning position B to a second scanning position C. 
         [0058]    From the second scanning position C the electromagnetic radiation emitting and receiving device  2  scans the refractory lining of the vessel  34 . The angle β scanned by the electromagnetic radiation emitting and receiving device  2  can be from about 20 degrees to about 100 degrees. During the scanning from the second scanning position C, at least two marks such as marks PM 2  and PM 3  which were previously scanned during scanning from the first scanning position B are again scanned from the second scanning position C. The position of the at least two marks which were scanned from the second scanning position C is determined based on the scanning of the at least two marks from the first scanning position B. By scanning at least two marks which were previously scanned in the first scanning position B, the location of the electromagnetic radiation emitting and receiving device  2  can be determined in the coordinate system of the vessel  34 . Therefore, it is not necessary that the location of the electromagnetic radiation emitting and receiving device  2  be determined by reference to any sensors which have a known position on the system for measuring wear in a refractory lining of the present invention. Because the position of the electromagnetic radiation emitting and receiving device  2  in the coordinate system of the vessel  34  is known based on the scanning from the first scanning position B and the second scanning position C, it is not necessary that the position of the electromagnetic radiation emitting and receiving device  2  be determined by reference to any sensors along the predetermined path along which the means for moving the electromagnetic radiation emitting and receiving device  2  moves. 
         [0059]    In another embodiment as seen in  FIG. 3   a,  from the second scanning position C the electromagnetic radiation emitting and receiving device  2  scans the refractory lining of the vessel  34 . The angle β scanned by the electromagnetic radiation emitting and receiving device  2  can be from about 20 degrees to about 100 degrees. During the scanning from the second scanning position C, at least one mark such as mark PM 1  which was previously scanned during scanning from the first scanning position B are again scanned from the second scanning position C. By scanning at least one mark which was previously scanned in the first scanning position B, the location of the electromagnetic radiation emitting and receiving device  2  can be determined in the coordinate system of the vessel  34 . Therefore, it is not necessary that the location of the electromagnetic radiation emitting and receiving device  2  be determined by reference to any sensors which have a known position on the system for measuring wear in a refractory lining of the present invention. Because the position of the electromagnetic radiation emitting and receiving device  2  in the coordinate system of the vessel  34  is known based on the scanning from the first scanning position B and the second scanning position C, it is not necessary that the position of the electromagnetic radiation emitting and receiving device  2  be determined by reference to any sensors along the predetermined path along which the means for moving the electromagnetic radiation emitting and receiving device  2  moves. 
         [0060]    In another embodiment of the method of the present invention, the production process within the vessel  34  is terminated and the vessel  34  is tilted around the tilt axis  54  in the direction of the arrow  52  into a position for measuring whereby the opening of the vessel  34  is facing the electromagnetic radiation emitting and receiving device  2 . The precise position and heading of the electromagnetic radiation emitting and receiving device  2  in relation to the coordinate system of the vessel tilt axis is established by measuring the distance of the electromagnetic radiation emitting and receiving device  2  with respect to the positions of previously installed and defined marks. The vessel  34  is then scanned according to the above described method and the contour of the refractory lining  36  in the coordinate system of the vessel  34  is determined based on angle data from the vessel  34  obtained for example from an inclinometer or tilt sensor if applicable and the data from the scanning of the refractory lining  36 . 
         [0061]    In another embodiment of the invention seen in  FIGS. 8-12  measurement of the wear of the refractory lining  36  is performed without the electromagnetic radiation emitting and receiving device  2  being located at a park position. The electromagnetic radiation emitting and receiving device  2  first performs a position scan from a first scanning position B in which at least three marks, i.e. a first mark, PM 1  a second mark PM 2  and a third mark PM 3  are scanned. At least one of the first mark, PM 1  a second mark PM 2  and a third mark PM 3  has a known position in the coordinate system of the vessel. 
         [0062]    A means for moving the electromagnetic radiation emitting and receiving device  2  from a first scanning position to a second scanning position such as the trolley system described above then moves the electromagnetic radiation emitting and receiving device  2  from a first scanning position B to a second scanning position C. 
         [0063]    From the second scanning position C the electromagnetic radiation emitting and receiving device  2  scans the refractory lining  36  of the vessel  34 . The angle β scanned by the electromagnetic radiation emitting and receiving device  2  can be from about 20 degrees to about 100 degrees. During the scanning from the second scanning position C, at least two marks such as marks PM 2  and PM 3  which were previously scanned during scanning from the first scanning position B are again scanned from the second scanning position C. The position of the at least two marks which were scanned from the second scanning position C is determined based on the scanning of the at least two marks from the first scanning position B. By scanning at least two marks which were previously scanned in the first scanning position B, the location of the electromagnetic radiation emitting and receiving device  2  can be determined in the coordinate system of the vessel  34 . 
         [0064]    The means for cooling the system for measuring wear in a refractory lining can be a Peltier cooler  26  as shown in  FIGS. 8-12  and  2  which is a thermoelectric cooler which uses the Peltier effect. A Peltier cooler is a solid state heat pump which transfers heat from a hot side of a cooler to a cool side with the consumption of electricity. As shown, Peltier cooler  26  is a closed loop system which cycles a cooling media through the electromagnetic radiation emitting and receiving device  2 . 
         [0065]    Where conditions make it necessary, other cooling means or methods can be provided such as plant cooling water or other closed loop cooling systems. 
         [0066]    As seen in  FIG. 8 , the system can be provided with a motor control enclosure  62  which is provided with a video display  28 . Air box  24  can provide an air supply as necessary for any equipment. Also, terminal box  64  can provide any necessary Ethernet or electrical connections. 
         [0067]    In another embodiment as seen in  FIG. 10   a,  from the second scanning position C the electromagnetic radiation emitting and receiving device  2  scans the refractory lining of the vessel  34 . The angle β scanned by the electromagnetic radiation emitting and receiving device  2  can be from about 20 degrees to about 100 degrees. During the scanning from the second scanning position C, at least one mark such as mark PM 1  which was previously scanned during scanning from the first scanning position B are again scanned from the second scanning position C. By scanning at least one mark which was previously scanned in the first scanning position B, the location of the electromagnetic radiation emitting and receiving device  2  can be determined in the coordinate system of the vessel  34 . Therefore, it is not necessary that the location of the electromagnetic radiation emitting and receiving device  2  be determined by reference to any sensors which have a known position on the system for measuring wear in a refractory lining of the present invention. 
         [0068]    The system for measuring wear in a refractory lining can have a movable shield  56  which is opened and closed by air cylinder  58  as seen in  FIG. 8 and 9 . Air cylinder  58  is connected to lug  60  on the interior of shield  56 . 
         [0069]    The method as described in International PCT Publication WO2007064928 which is incorporated by reference in its entirety can be carried out in some embodiments on the present invention. 
         [0070]    Although the invention has been described above with reference to the examples according to the accompanying drawings, it will be obvious that the invention is not restricted thereto but can be modified in many ways within the scope of the inventive concept disclosed in the appended claims.