WO2000019198A1

WO2000019198A1 - Device and method for measurement of process parameters for controlling of metallurgical processes

Info

Publication number: WO2000019198A1
Application number: PCT/SE1999/001590
Authority: WO
Inventors: Jan Hellstenius; Svante ROSÉN
Original assignee: Smte Sweden Ab
Priority date: 1998-09-29
Filing date: 1999-09-13
Publication date: 2000-04-06
Also published as: AU1192000A; SE512620C2; SE9803299L; EP1117994A1; SE9803299D0

Abstract

A metallurgical process is operated in a process container (1). A remotely controlled mobile unit (7) is brought forward from a protected parking position (13) separated from the surroundings (11) of a process container (1) to a stand-by position (14) close to the process container (1) only a short time before a measurement of a process parameter is requested. A probing device (9), movably attached at the mobile unit (7) is brought into the process container (1) for measuring of the process parameter, and is then brought back again. The mobile unit (7) returns thereafter to the parking position (13). The process parameter is transferred wireless to an evaluation unit before or during the return of the mobile unit (7). The mobile unit (7) may preferably be provided with storage for probing devices (9), in order to be able to change probing devices (9) also in the stand-by position (14).

Description

DEVICE AND METHOD FOR MEASUREMENT OF PROCESS PARAMETERS FOR CONTROLLING OF METALLURGICAL PROCESSES

TECHNICAL FIELD

The present invention relates generally to devices and methods used in connection with metallurgical processes, and more specifically devices and methods for measurement of process parameters for control of the metallurgical process.

BACKGROUND ART

At metallurgical processes, a number of process steps are normally performed, which are intended to give rise to a requested composition or quality of the metallic material. During such processes, e.g. raw material and/or alloying substances in solid or liquid state may be added, or gas, such as for example oxygen, argon or nitrogen may be added for refining of the metal. The processes may also consist of heating or cooling of the metallic material to give the final metallic material the right composition and structure. Such processes are often performed according to tested routines to give a good reproducibility, but very small differences in conditions and process parameters may often lead to that the processes take longer time or that the conditions have to be changed somewhat in order to reach the required result. In such cases, measurements of certain critical process parameters, such as temperature, oxygen content, solidification temperature and chemical composition, may serve as guidance for if the process has reached its final goal, or if it should be con- tinued and/or be corrected.

By e.g. steel manufacturing, measurement of temperature and other parameters is normally requested in different furnace processes. If the steel charge has acquired a certain temperature, the next process step can take over, if not any additional elec- trie energy, oxygen gas or other energy type should be provided. In the state of the art, there are a number of ways to perform such temperature measurements. The traditional procedure is to perform the testing manually. A person goes up to the melting furnace, converter, ladle or casting box and introduces a lance with an attached probing device into the liquid metal. This operation is very hazardous. At metallurgical processes, boiling-out or similar things may happen. At collapses in furnaces, explosion-like courses may arise. Despite protecting clothing or other encapsulation, a man in the vicinity of the furnace would in such cases not be absolutely safe.

To set aside such elements of danger for the personnel at metallurgical establish- ments, but also to increase the productivity, a number of fully automated systems have been developed. In the Japanese patent document JP60-141814, a robot for automatic operation of electric arc furnaces is described. A carriage on wheels supports a number of lances for supply of additives, gas supply, burner and measurement and sample collecting lances. Such an equipment is present at the furnace during the entire process for recurrently providing introduction of additives, measurements, sample collection, oxygen gas supply, slag control etc.

Badische Stahl-Engineering GmbH has presented a BSE Temp-Samp manipulator, which uses equipment for oxygen gas supply, fixed at the furnace, to be used to in- troduce a measurement/sample collection lance into the furnace, when requested.

Further equipment, e.g. where a temperature measurement lance is introduced vertically into a melting furnace with a permanently arranged manipulator is also used in metallurgical connections.

SUMMARY OF THE INVENTION

The equipment according to the state of the art described above discloses a number of disadvantages and problems. Serious problems are the risk for damages on the equipment and that the equipment is obstructing at furnace changes and similar actions. The closest surrounding around the process containers is extremely inhospitable. High temperatures, combined with large and ungainly mechanical construe- tions, aggressive chemical environment and above all the risk of melted metal and slag spattering around, implies that all equipment has to be protected with care. Measurement equipment, independent of whether it measures the temperature of the charge, oxygen content, solidification temperature or any other process pa- rameters, is generally a sensitive apparatus, which has to be protected particularly well against the high temperatures, possible mechanical damage and aggressive environment for to function reliably. In all the above described devices, the meas- . urement equipment is positioned at the spot in front of the furnace during a large portion of the process and is running the risk of being damaged. The measurement equipment may to a large extent be protected by heating screens, mechanical protections etc., but at the same time, the availability is then obstructed.

Another disadvantage with the above described devices is that one and the same manipulator is used to serve several purposes. Normally, e.g. an oxygen gas lance may be inserted into the process container to support e.g. a refining process. For to measure the temperature, this lance has to be drawn back and the lance is may be changed for a temperature measurement lance. Thereafter, the direction of the manipulator has to be adjusted for allowing the temperature measurement lance to be inserted in the right direction. All these procedures take time, which both increases the process time and also introduces many mechanical operations that may be disturbed by the inhospitable environment.

An object of the present invention is thus to provide a method and a device, eliminating personnel risks and reduces the risk for damages from the environment on the probing devices and which requires only very short or no interruptions in the metallurgical process. Another object of the present invention is to simplify the used mechanical parts, in order to reduce the risk for mechanical faults. A further object of the present invention is to introduce a system, which is not obstructing within the physical labour area.

The above objects are achieved by a method and a device according to the enclosed claims. A remotely controlled mobile unit is brought from a protected parking position, separated from the area surrounding the process container, to a stand-by position in the vicinity of the process container only a short time before the measurement of the process parameter is requested. A probing device, movably attached to the mobile unit, is brought into the process container for measuring of the process parameter, and is subsequently brought back again. Thereafter, the mobile unit returns to the parking position. By the short exposure time at the process container, the risks for damages on the probing device is reduced. By using a separate mobile unit for the measurement of the process parameter, the actual measuring operation may be prepared and the interruption in the metallurgical process can be reduced.

DESCRIPTION OF THE DRAWINGS

In order to better understand the invention, a number of embodiments of the present invention are described here below in connection with the enclosed drawings, in which:

Fig. 1 is a sketch of principle of the device and method according to the present invention;

Fig. 2 is a flow diagram of a method according to prior art;

Fig. 3 is a flow diagram of a method according to an embodiment of the present invention;

Fig. 4 is a flow diagram of a method according to an alternative embodiment of the present invention;

Fig. 5 is a part flow diagram of a method according to a further embodiment of the present invention;

Fig. 6a is a sketch of a device according to the present invention, with caterpillar tracks; Fig. 6b is a sketch of a device according to the present invention, with wheels;

Fig. 7a is a sketch of an embodiment of a part device for introduction of a probing device into a process container according to the present invention, at the original position;

Fig. 7b is a sketch of the part device shown in fig. 7aprobing device, at the final position;

Fig. 7c is a detail sketch of the part device shown in fig. 7a;

Fig. 8a is a sketch of a preferred embodiment of a part device for introduction of a probing device into a process container according to the present invention;

Fig. 8b is a sketch of the part device shown in fig. 8b, with a storage for probing devices;

Fig. 9 is a block diagram of a device according to the present invention; and

Fig. 10 is a flow diagram of an insertion method used for the devices shown in fig. 7a and 8a.

ILLUSTRATIVE EMBODIMENTS

Below, a number of embodiments of the present invention will be described. It is obvious for anyone skilled in the art that there are many modifications and variants, which can be used without deviating from the scope defined by the enclosed claims.

Fig. 1 shows a illustrative sketch of an area in the vicinity of a process container for a metallurgical process. A process container 1 for a metallurgical process has an opening 2, through which the process is possible to influence, e.g. by addition of oxygen gas through a lance 4. A carrier unit 3 comprises a manipulator 5, at which the lance is arranged. The manipulator 5 can be remotely controlled to bring the lance 4 through the opening 2, draw the lance 4 back out and change its angle with respect to the process container 1. In this embodiment, oxygen gas is added to the metallurgical process by the lance 4.

A floor 11 extends around the process container 1. The floor is relatively large, to give space for the bulky equipment required to take care of the metallurgical process. Furthermore, the space around the process container 1 serves as a protection zone for the inhospitable environment in the vicinity of the process container 1. All equipment being present in the vicinity of the process container during operation, such as e.g. the carrier unit 3 and the devices attached to this, are exposed for a large risk to be damaged. The damages are usually caused by mechanical damages from other equipment moving in the area, chemical damages caused by aggressive gas state substances, heat damages as a result of the heat originating from the process container 1 and risk for being hit by liquid metal or slag spattered around.

According to the present invention, a screen device 6 is provided, which is arranged at a substantial distance from the process container 1. The screen device is de- signed for defining a space 12, which is separated from the surroundings of the process container. The screen device preferably comprises walls and ceiling, which protect for mechanical and thermal damages and for spattering metal, and a fan system, keeping the hazardous gas state substances at a satisfying level. The space 12 behind the screen thus constitutes an area, in which sensitive equipment can be stored, prepared, repaired etc.

A mobile unit 7 is during the main part of the progress of the process parked in a parking position 13 in the space 12 behind the screen device 6. Here, there is no or small risk for the equipment of the mobile unit 7 to be damaged. A measurement lance 8 is movably arranged at the mobile unit 7 and a probing device 9 is attached at the front end of the lance 8. In the parking position 13, the probing device 9 can be changed or repaired, even manually, without any risk existing for material or personal damages.

The metallurgical process run in the process container 1 is performed according to predetermined routines to reach a well defined final point of the process. This can be performed in different process steps, during which the conditions may differ somewhat. Depending on the composition of the metallic material, the amount of material and the conditions under which the process is run, an expected final point for, or necessary adjustment of the process or process step can be estimated. A final judgement of the result is performed by effecting measurements of one or several process parameters, such as the temperature of the metal charge, the oxygen content or the temperature of solidification. Such a testing has according to prior art been performed by the methods and devices described under the headline of background art.

In the following, there will be no principal difference made between the process as a whole and process steps of the process, but these will be treated in the samme manner. In fig. 2, a process flow according to the state of the art is described schematically. The process or the process step starts in step 100. In step 102, an esti- mated final point or measurement time of the metallurgical process or process step is determined based on external factors and/or earlier measurements. The metallurgical process or process step is in step 104 run according to the predetermined routines to the estimated measurement time. When the predicted measurement time is reached, a measurement of some process parameter 107 is performed, either manually or by means of any automated device according to the state of the art. From the result of this measurement, it is in step 109 determined whether or not the metallurgical process or process step has reached its true final point. If it has not reached the true final point, the process returns to step 102, where a new estimated final point or measurement time is determined and the process is run further in step 104. If the true final point has been reached, the process or process step is finished in step 112. The method according to the present invention discloses distinguishing operations. Again with reference to fig. 1 , a suitable probing device 9 is arranged at the lance 8 of the mobile unit 7 for carrying out measurement of at least one process parameter. A short time before the estimated final point and/or measurement time of the metal- lurgical process has been reached, the mobile unit 7 is brought from the parking position 13 along a predetermined path 10 over the floor 11 to a stand-by position 14 in close connection to the process container 1. This movement can be performed in different manners and is described in more detail below. The short time period which remains before the metallurgical process has reached the predicted measurement time should be long enough, so that the movement of the mobile unit 7 has time to be performed, but not so long that the mobile unit 7 has to wait in the stand-by position 14 during any longer time periods. When the measurement of the process parameter then is to occur, the mobile unit 7 is present in the stand-by position 14 and the mobile unit 7 moves the lance 8 so that the attached probing device 9 is brought into the process container 1 through the opening 2 and comes into contact with the liquid metal. Subsequently, the probing device 9 is again removed and the mobile unit 7 may then be moved back to the parking position 13 behind the screen device 6.

A flow diagram illustrating this is shown in fig. 3. The process is started in step 100, and an estimated final point and/or measurement time for the metallurgical process is determined based on external factors in step 102. In step 103, the metallurgical process is run until a short period before the estimated measurement time for the metallurgical process is reached, when the mobile unit 7 is transported forward to its stand-by position 14 in step 105, simultaneously as the process is brought to the estimated measurement time. The probing device 9 is in step 106 brought into the process container 1 into contact with the liquid metal and in step 107, at least one process parameter is measured. The probing device 9 is in step 108 brought back out from the process container 1. In step 109 and 110, the mobile unit 7 is brought back to the parking position 13 and it is determined if the actual final point is reached, based on the measured process parameter or parameters. If the actual final point has been reached, the process is finished in step 112, otherwise the pro- cess returns to step 102, where a new estimated final point and/or measurement time is determined. Step 109 and step 110 may of course be performed also in the opposite order, but this will result in that the process time for the metallurgical process increases.

Depending on the metallurgical process and other help equipment, a number of additional steps may be necessary or preferable. Most metallurgical processes require some form of external influence or stimulation, e.g. in the form of heat supply, addition of gas or e.g. alloying substances. In certain cases, the metallurgical process may continue during the testing procedure. However, to perform the required testing, it might in certain other cases be necessary to interrupt the metallurgical process or the stimulation to this totally or in part. Furthermore, it might be necessary, at least to a part, to remove help equipment for running the metallurgical process, such as different lances etc. This might be necessary, partly to protect the equipment from e.g. melting, and partly for enabling the preparation of enough space in the openings 2 to the process container so that the probing device 9 could be brought in without any risk for collision. However, it is often not necessary to fully remove such help equipment, and thereby shorten the time necessary to such movements.

In fig. 4, a flow diagram containing such additional steps is shown. The steps that are the same as in fig. 3 are denoted by the same reference numbers and are not described again. Step 115 implies that the metallurgical process is interrupted, totally or partly, or that the outer stimulation to the metallurgical process, e.g. the blowing of oxygen gas or supply of heat, is interrupted, totally or partly, in step 116, the help equipment that has to be removed to perform the testing is removed from the process container, at least to a part. This means that e.g. a lance for oxygen gas blowing is retracted as far as it leaves a sufficient gap in the opening 2 for the probing device 9 and the lance 8 of the mobile unit 7 to be brought into the process container 1. Step 117 and 118 are performed if the true final point has not been reached and is constituted by that the help equipment are re-entered and that the metallurgical process is fully resumed, respectively. Depending on which probing device and which evaluation method are used, some additional steps may be needed in the process, probing devicelf the temperature of the charge, the solidification temperature or oxygen content is measured, a measurement result can be achieved more or less immediately. To wait for a mechanical movement of the mobile unit 7 back before this measurement result can be analysed results in a long interruption of the process, which in most cases is unacceptable. Thus, the present invention is most suitable for measurement of process parameters, which process parameters are achievable in direct connection with the measurement in the charge. Examples of suitable process parameters are, as mentioned above, the temperature of the charge, the solidification temperature and oxygen content. Since these parameters are the basis for the continued control of the metallurgical process, it is important that the result is readily available for a decision about how the process is to process.

In fig. 5, a part process is illustrated, corresponding to the steps 109 and 110 in fig. 3 and 4. Thus, in figure 5, a process is shown, suitable for a probing device 9, which during or in connection with the end of the measurement transmits signals to a measurement unit 75 (fig. 9) present in the mobile unit. After or in connection with that the probing device 9 is removed from the process container 1 , the measurement result is transmitted 120 from the measurement unit 75 to an evaluation unit 71 (fig. 9), which evaluates the measurement result. The evaluation unit is preferably placed at a protected position, e.g. behind the screen device 6. The decision 109 about whether or not interrupting the metallurgical process finally, can be made at once and the metallurgical process can be resumed during the time the mobile unit 7 is brought back 110 to the parking position 13. The transmission may in the simplest case be performed totally visually, by providing the measurement unit with a display, showing the measurement result. This measurement result is visually read over a certain distance by the operator, which then man run the process or process step further based on this reading.

The above part process is only usable for parameters possible to be recorded or processed in direct connection with the sampling occasion. Obviously, it can not be used for e.g. collection and chemical analysis of small metallic samples, since such an analysis requests apparatuses, which can not be integrated in a simple probing device 9. Neither can the metallic sample be transferred by signals. Therefore, analysis of metallic samples may rather be seen as a verification of the final product than a measurement of parameters for controlling the metallurgical process.

The different functions for the mobile unit 7 may be realised in a multitude of ways. Some variants are shown in the figures 6a and 6b. The driving of the mobile unit 7 is preferably performed by caterpillar tracks 21 , since the floor 11 in many cases pro- vides large unevennesses, cavities, gates, obstructing objects, for example slag lumps etc. The caterpillar tracks 21 should not include any inflammable material such as rubber etc., but should preferably be constructed of metal chains, covered with friction enhancing material, in order to be able to move without problems over different floor materials, such as concrete, metal or slag. Another possibility is to equip the mobile unit 7 with large wheels 22, in order to be insensitive for metal or slag obstacles at the floor. Also here, it is an advantage if the wheels 22 are temperature and/or fire resistant.

A third possibility, as shown in the Japanese patent abstracts JP 60 001558 and JP 61 177305 concerning metal sample collection, is to let the mobile unit be driven on a rail, fixed attached at the floor or in the ceiling. However, this possibility is unsuitable, since the mobile unit 7 in many cases has to pass over e.g. gates in the floor or ceiling. Furthermore, the parts of the rail which are constantly arranged close to the process container 1 are exposed for the inhospitable environment and is easily damaged. A rail device also has the drawback that it limits movements close to the process container.

The driving of the mobile unit 7 may be performed in different ways. An electrical motor, with one or several separate batteries, placed in the mobile unit 7, is to pre- fer. Petrol or diesel driven units are also possible, but not to prefer. The control of the path 10 of the mobile unit 7 over the floor 11 , may be performed in different ways. A number of techniques for AGV trucks (Automated Guided Vehicle) are available, which easily may be adjusted for this purpose. Rocla Oy Robotruck, Finland, uses a laser navigation system, which easily can be modified for use within the metallurgy industry. Furthermore, Netzler & Dahigren Co AB is marketing the laser navigation system NDC Laser Scanner 2.0, which is used in such applications. Different IR navigation systems are also conceivable.

Control by laser or IR navigation systems has many advantages. The most obvious is that stationary mechanical arrangements (such as rails), which extend over floor or ceiling and which may be damaged or obstruct other activities, are avoided. Another advantage is that the predetermined path 10 (fig. ) easily can be modified, if obstructing objects appear in the path of the mobile unit 7. Such obstructing objects may be e.g. another mobile or stationary equipment or larger quantities of thrown- out metal or slag. By laser or IR navigation systems, one may easily define a new predetermined path, which avoids the obstructing object. Such alternative travel paths may be determined in advance, or be established upon need. Stationary control devices, such as rail, lack this flexibility.

Further advantages with flexible control devices arise at plants with more than one process container 1. One and the same mobile unit 7 may then be used for process parameter measurements in several process containers 1. In these cases, the navigation system indicates which of the predetermined paths to be used. If the mobile unit 7 further is provided with possibilities to exchange the probing device 9, which is further discussed below, the mobile unit 7 may furthermore move directly from one process container to another without intermediate visit to the parking position, if needed.

Two types of communication to and from the mobile unit 7 are present. The first type of information is concerned with control of the mobile unit 7, comprising among other the movement of the mobile unit 7 along the predetermined path 10 and control of the introduction of the probing device 9. The other type of information contains measurement results from the probing device 9. The communication can be effected in a number of different ways. The use of cables is not to prefer, since they are easily damaged and may furthermore constitute obstacle to the movement of the mobile unit 7, in particular at use of alternative travel paths. Therefore, the mobile unit 7 is preferably totally physically free from stationary controlling units, and the communication has to be effected in another way than with cables. A preferred way is to use connectionless communication, either by IR or radio links. This connectionless communication may then be connected to the measurement unit 75 (fig. 9) in the mobile unit 7. Heraeus Electro-Nite AB is marketing a product called Digiterm III, which is a temperature measurement unit 75 that is easily modified to communicate via radio links.

Navigation equipment and/or wireless communication devices do not occur in devices in the present technical field according to prior art. The reason for this, is mainly that navigation and communication equipment generally is sensitive equipment, which in devices according to prior art continuously are exposed for large strains. In order to be able to protect such an equipment in a satisfactorily way, the technical solutions become so costly and complicated that this is not any true alternative in practice. Thus, communication according to prior art is more or less exclu- sively performed by cables. With the motion of the mobile unit 7 according to the present invention, the circumstances are suddenly changed. The exposure time for the navigation and communication equipment is reduced to such a large extent that the expected life time becomes satisfactorily long. Additionally, the screen device 6 allows for the equipment to be easily maintained, repaired or exchanged at the parking position. The mobile unit 7 and its pattern of motion thus presents a possibility to use solutions concerning navigation and communication, which has been inconceivable so far.

Fig. 9 shows a sketch of principle for how different units are distributed in a preferred embodiment of the invention. The mobile unit 7 comprises a means 78 for movement of the mobile unit 7. This means 78 comprises preferably a navigation means 79. A measurement unit 75 is connected to the probing device 9 in order to measure process parameters. The measurement unit 75 and the movement means 78 use preferably the same communication system for transmission of signals to and from a control station 80. Furthermore, the mobile unit 7 comprises a means for driving of the mobile unit 76, e.g. one or several electrical motors and at least one battery. The mobile unit also comprises a motion means 77 for the probing device. This means will be described more in detail below.

Fig. 9 also shows a preferred embodiment of the control station 80 behind the screen device. This control station 80 comprises at one hand a communication sys- tem 73 for signal transferring to and from the mobile unit 7 and on the other hand an evaluation unit 71 for processing of the measured data signals. A docking station 72 is preferably also present in this control station 80. The docking station is connected together with the mobile unit 7 in its parking position, and may be equipped in order to e.g. change the probing device 9 and/or to charge the batteries of the mobile unit 7. It is obvious for anyone skilled in the art that many of these parts can be physically positioned at other places and only be electronically related to the physical control station behind the screen device 6.

The mobile unit 7 carries, as described above, a probing device 9, which is brought forward together with the mobile unit 7 and is brought into the process container 1. This introduction operation is one of the critical points during the whole process. As mentioned above, it is important that this introduction is effected reproducible, carefully and with simple equipment. An embodiment of an introduction device is shown in fig. 7a, 7b and 7c, and another preferred embodiment is show,-) in fig. 8a and 8b.

The mobile unit 7 comprises the above mentioned movement means 78, communication system 74, measurement unit 75 etc., which normally are placed on the frame of the mobile unit. In this embodiment, there is also a base portion 51 , which here is constituted by an arm or a framework, and which supports a square beam 52, slop- ing with respect of the horizontal plane. At both sides of the squa, e beam 52, a rail is mounted. This rail device 54 defines a linear track. A wagon 55 is disposed against this rail device 54 with supporting wheels 56, and a motor 62 drives the wagon 55 along the rail device 54, for example via a rack mechanics (not shown). At the wagon 55, a lance 8 is arranged, which is connected at one of the ends (the lower one) with the wagon 55 by a rotatable shaft 58, a first support point. The probing device 9 is connected to the other, upper, end of the lance 8.

On the base portion 51 , also a guiding device is disposed. This guiding device is in this embodiment constituted by a somewhat bent and/or sloping steel bar 60, fixed at the base portion 51. The upper surface of the steel bar 60 defines a path of motion for a second support point 61. The second support point 61 , in this embodiment a wheel, is attached a distance in front of the first support point 58. Thus, the rotatable shaft 58 and the wheel 61 constitues a first and second support point, respectively, for a support device of the lance 8. Since the gravitation force acts on the lance 8 and probing device 9, the wheel 61 is pressed against the upper surface of the steel bar 60, i.e. the lance 8 is kept in place.

In order to move the lance 8, the motor 62 is started and drives the wagon 55 such that it and the first support point 58 moves along the linear track. At the same time, the wheel 61 rolls against the steel bar 60, due to the gravitation. The lance 8 is in this way brought upwards along the square beam 52. By letting t e direction and shape of the steel bar 60 be somewhat different from the square beam 52, whereby it drops at its upper part, the lance 8 will gradually also be tilted somewhat forward in a dipping motion. Starting from the intended stand-by position 14 and design of the process container 1 , the steel bar 60 can be given such a shape that the lance 8 and probing device 9 are brought into the process container 1 with a suitable dipping movement. Fig. 7a shows the lance 8 and the probing device 9 before the introduction begins, and fig. 7b shows the lance 8 and the probing device 9 when the dipping movement is completed. Fig. 7c shows a detail study of the two support points of the support device.

During the dipping movement, the probing device is normally brought through a layer with slag before its tip reaches the metal charge. If this slag layer or the steel bath as such is too stiff or contains large solid particles, the probing device can easily be damaged at the introduction, if the lance rigidly is brought along a predetermined track. This is avoided by the present invention, by holding the lance 8 against the steel bar 60 with substantially the force of the gravitation. If the probing device 9, during the dipping movement, comes across abnormally large mechanical resistance and risks to be damaged, the lance will be lifted off the steel bar 60 by this force. A switch may then easily detect such a lifting and give the introduction means a signal about that the introduction has failed, whereby the measurement rapidly can be interrupted.

A preferred embodiment of the mobile unit 7 according to the present invention is shown in fig. 8a and 8b. The mobile unit 7 comprises the above mentioned movement means 78, communication system 74, measurement unit 7 etc., which normally are placed on the frame 30 of the mobile unit. The mobile unit 7 according to the present embodiment is moved by caterpillar tracks 21. Also in this embodiment, there is a supporting framework 31 , on which a first wagon 32 is rranged. The first wagon 32 is movable on wheels linearly forward and back (to the left and right in fig. 8a), relative to the framework 31 with a motor 33.

An attachment unit 36 is arranged at the first wagon 32 by two st, -its 37, 39. The struts are jointed at their attachments and enable a parallel displacement of the attachment unit 36 in a direction perpendicular to the sheet accord., lg to fig. 8a. A substantially V-shaped dipping arm 35 is by one of its ends turna jly mounted at the attachment unit 36, whereby a rotation around an axis 42 is poss.ole. A support device 43 is in one of its ends jointly attached to the other end of th clipping arm 35, at a first support point 38. At the support device 43 a lance 8 is dis . , ced, so that one of the ends of the lance is tumably connected to the support device 43 close to the other end of the support device. The probing device 9 is connected to the other, upper, end of the lance 8. The support device 43 is at its other end astened to a wire 40, at a second support point 41. The other end of the wire 40 is . , ranged to a part of the attachment unit 36 at an attachment point 44 a distance d om the axis 42. The wire 40 may also be replaced by a tie rod. To the attachment unit 36 is a not shown motor arranged, in order to turn the dipping arm 35 around the axis 42. The first support point 38 will then present a circle arc path 34, illustrated by a broken line in fig. 8a. The lance 8, the probing device 9, the support device 43 and the wire 40 will follow in the turning. The weight of the lance 8 will as a result of the gravitation keep the lance 8 in place in the support device 43 and at the same time stretching the wire 40. The wire 40 presents a rotating motion around the attachment point 44, which results in that the second support point 41 is guided along a path of motion 45, illustrated by a broken line in fig. 8a. In the illustrated case, the wire 40 presents a pure rotating motion, which gives a specific mo- tion of the lance 8. If another motion is desirable, another attachment point 44 may be chosen. Alternatively, one may also change the length of the wire 40 or the distance between the supporting points 38, 41. It is also possible to let e.g. the attachment point 44 move or to change the length of the wire simultaneously with that the dipping arm 35 is rotated.

When the dipping motion is ready, the dipping arm, the wire, the support device, the lance and the probing device are placed as indicated by broken contours at 46 in fig. 8a. In the same way as for the previous embodiment, the lance 8 is kept in place by the action of the gravitation. If an exceptionally large mechanical resistance appears during the dipping motion, the lance 8 will, in a similar way as discussed earlier, be lifted away from the intended introduction path. The support device 43 and the lance 8 will then turn around the first support point 38, so that the second support point 41 is leaving the intended path 45, whereby the wire 40 bends. A mechanical switch may then easily detect such a lifting and give the introduction means a signal about that the introduction has failed, whereby the measurement rapidly can be interrupted.

The above described embodiments may at a first glance seem totally different, but are in fact two embodiment of one and the same basic idea. The lance 8 is attached to two support points 38, 41 and 58, 61 , respectively. One of these support points 38 and 58, respectively, are brought along a stationary path 34 and 54, respectively. The other support point 41 and 61 , respectively, follows and is guided by a guiding device 40, 60 along a certain path. The stationary path is in the first example constituted by a linear path and in the second example by a part of a circular arc.

Fig. 8b illustrates the mobile unit according to fig. 8a, with a storing unit 90 for prob- ing devices. If e.g. a failed measurement has been performed and the probing device is consumed without obtaining a measure, it may take a long time to let the mobile unit 7 return the whole way to the parking position to exchange the probing de-: vice for a new one. In a similar way, if the mobile unit 7 is used for several process containers 1 , it may be time consuming to let the mobile unit 7 return to the parking position every time between the visits, when it is much faster to let the mobile unit move directly to the new position. It may also exist situations, when several types of measurements are requested, but there are no probing devices handling all measurements at the same time. In such cases, the work is facilitated by that the mobile unit 7 is equipped with a storing unit 90 for exchangeable probing devices.

One example of such a storage is shown in fig. 8b. An upright frame 91 is fastened at the framework 31. On the upright frame, a second wagon 92 is mounted, which by motor operation is able to move upwards and downwards along the frame 91. A substantially V-formed plate 94 is mounted at the second wagon 92 by supporting beams 96. The plate 94 is designed to contain a probing device 9. A guiding rail 93 is arranged at the end of the plate to guide the lance 8. At the side, and inclining towards the plate 94 is a storage 95 of probing devices. When the probing device present in the plate 94 is removed, a new probing device will fall down by the force of gravitation.

At exchange of probing device, the old probing device is first loosened, e.g. by letting it scrape against a suitable edge or by blowing it off by compressed air. The used probing device is normally discarded after use and may be dumped in connection with the process container. The first wagon 32 is moved backwards along the mobile unit 7 to the position, illustrated in fig. 8b. The dipping arm 35 is moved to a position, where the probing device attachment of the lance is directed substantially horizontal. The second wagon brings the plate 94 to a position just in front of the front end of the lance, whereupon the first wagon 32 is brought forward and a new probing device is passed onto the lance 8. The first wagon 32 is backed out a short distance again, and then the storing unit 90 is moved away, by lowering the second wagon 92. Now, the mobile unit 7 is again ready for a new measurement.

It is obvious that there are many detailed technical solutions for storing of probing devices. Among other solutions, one may e.g. stack a number of different storages 95 with attached plates 94 above each other, to provide for probing devices of different types at the same time.

The actual dipping procedure can easiest be described by the flow diagram presented in fig. 10. The introduction procedure starts in step 200. The lance is in step 202 brought into the process container. In step 204, it is continuously checked if the mechanical resistance is too large, and in such a case, the introduction is interrupted in step 206. If that is not the case, it is checked in step 208, if the introduction period has taken longer time than normal, whereby the introduction is interrupted. When the probing device 9 has come into right position, either detected by a switch at the dipping device or by an indication from the probing device itself, a signal is sent to the introduction means. In step 210, it is checked if such a ready-sign signal has been detected. If the probing device is present at the right position, the measurement procedure starts in step 212. During the measurement, it is in the steps 214 and 216, checked if a predetermined time period has ended, or if a ready signal from the probing device has been received. If that is the case, the measurement is interrupted and the lance with probing device is brought out in step 218, whereby the procedure is finished in step 220. This above described procedure is a preferred procedure in order to create a maximum security at the testing.

Probing devices, suitable for temperature measurement of the charge temperature and/or solidification temperature and oxygen activity measurement are today com- mercially available by e.g. ElectroNite. The design of those is not the main topics of the present invention and is therefore not described any closer. The above described embodiments of the present invention, constitutes only examples on how the present invention may be realised. These examples should not be considered limiting the scope of the invention, but the scope of the invention is only defined by the enclosed claims. Anyone skilled in the art will understand that many changes and variations may be done, which still falls within the scope of the enclosed claims. For example, a measurement may be combined with a collection of a metallic sample, which is transported back with the mobile unit for a subsequent analysis. The mobile unit may also provide for different additional movements of e.g. the lance, e.g. tilting with respect of the main axis of the mobile unit, in order to fit to different actual situations and process container geometries in an optimal manner.

Claims

1. A method for controlling of metallurgical processes, including the steps of: operating a metallurgical process in a process container (1), during which metallurgical process at least a part of the metallic material is in a liquid state; estimation or determination of a final point of metallurgical process steps, based on external parameters and/or earlier measurements; when the estimated final point has been reached, measuring of at least one process parameter of said liquid metallic material, said process parameter is achiev- able in direct connection with the measurement in said process container (1); determining if said metallurgical process has reached a true final point, based on said measured process parameter; and if the true final point is reached, finishing said metallurgical process step; characterised in that the step of measuring a process parameter in turn comprises the steps of: a short period before the time for the measurement has been reached, moving of a remotely manoeuvrable mobile unit (7) from a parking position (13) totally separated and protected from the surroundings (11) of said process container to a stand-by position (14) in close connection to said process container (1); when the time of measurement has been reached and with said mobile unit

(7) in said stand-by position (14), bringing a probing device (9) attached to said mobile unit (7) into said process container(l), and into contact with said liquid metallic material, whereby said measuring and said determining is enabled; removing said probing device (9) from said process container (1); and moving back said mobile unit (7) from said stand-by position (14) to said parking position (13).

2. The method according to claim 1 , characterised in that said measured process parameter is transferred wireless from said mobile unit (7) to an evaluation unit (71), separated therefrom, before or during said moving back of said mobile unit (7).

3. The method according to claim 1 or 2, characterised in that said measuring of at least one process parameter comprises at least one of the following: measuring of the temperature of said melted metallic material; measuring of the solidification temperature of said metallic material; and measuring of the oxygen activity in said metallic material.

4. The method according to claim 1 , 2 or 3, characterised in that said metallurgical process continues during the introduction of said probing device (9) into said process container (1).

5. The method according to claim 1 , 2 or 3, characterised in that said metallurgical process is interrupted totally or in part, before the introduction of said probing device (9) into said process container (1).

6. The method according to claim 5, characterised in that help equipment (4) for operating said metallurgical process at least to a part is removed from said process container (1) before the introduction of said probing device (9) into said process container (1).

7. The method according to claim 5 or 6, characterised by the step of, if the true final point has not been reached, fully resume said metallurgical process.

8. The method according to any of the preceding claims, characterised in that said introduction of said probing device (9) comprises the steps of: conveying a first support point (38; 58) of a support device attached to a lance (8), to which said probing device (9) is attachedprobing device, along a first track (34; 54); and guiding a second support point (61) of said support deviceprobing device, along a predetermined second track at said mobile unit (7), said second track is ad- justed to give said probing device (9) a suitable introduction path into said process container (1).

9. The method according to claim 8, characterised in that said lance (8) is kept in place by the action of gravitation forces, during conveying the first support point (38; 58).

10. The method according to any of the preceding claims, characterised in that said introduction of said probing device (9) is interrupted if an abnormal mechanical resistance occur at said probing device (9) during said introduction.

11. The method according to any of the preceding claims, characterised in that said removing of said probing device (9) from said process container (1) is started when one of following criteria has been reached: an approved measurement of said process parameter has been received; a certain time period has elapsed since said probing device (9) came into contact with said metallic material; and a certain time period has elapsed since said introduction was started.

12. Device for measurement of process parameters at metallurgical processes in a process container (1) including: a probing device (9) for measurement of process parameters, said process parameters are achievable in direct connection with the measurement in said process container (1); and a remotely controlled mobile unit (7), at which said probing device (9) is attached; characterised in that said mobile unit (7) comprises: means for moving said mobile unit (7) from a parking position (13), totally separated and protected from the surroundings (11) of said process container (1) to a stand-by position (14) in close connection to said process container (1) and for moving back said mobile unit (7) to said parking position (13); and means for motion of said probing device (9) into and out from said process container (1).

13. The device according to claims 12, characterised in that said mobile unit (7) comprises a communication system (73, 74) for controlling the motion of said mobile unit and/or wireless transmission of process parameter information between the mobile unit (7) and an evaluation unit (71).

14. The device according to claim 12 or 13, characterised in that said movement means (78) comprises a navigation means (79) of at least one of the types: .

IR navigation means; and laser navigation means.

15. The device according to any of the claims 12 to 14, characterised in that said means for motion of said probing device (9) into and out from said process container (1) comprises: a lance (8), on which said probing device (9) is fixedly arranged, said lance (8) is connected with said mobile unit (7) via a support device provided with a first support point (38; 58) and a second support point (41 ; 61); a conveying means (35; 55), to which said first support point (38; 58) of said support device is fixedly but rotatably connected; and a guiding means (40; 60), which defines a motion path of said second sup- port point (41; 61) of said support device.

16. The device according to claim 15, characterised in that said guiding means (40; 60) has a shape that, when said conveying means (38; 58) is conveyed along a predetermined track (34; 54), guides said second support point (41 ; 61) of said sup- port device in order to give said lance (8) and said probing device (9) a suitable introduction path into said process container (1).

17. The device according to claim 16, characterised in that said lance (8) is kept in place by means of the gravitational force of said lance (8), along said intro- duction path.

18. The device according to claim 16 or 17, characterised in that said lance (8) is removable from said introduction path by an upwards directed mechanical force applied on said probing device (9).

19. The device according to any of the claims 15 to 18, characterised in that said conveying means (35) conveys the first support point (38) of said support device along a circle arc path (34).

20. The device according to any of the claims 15 to 18, characterised in that said conveying means (55) conveys the first support point (58) of said support device along a linear path (54).

21. The device according to any of the claims 12 to 20, characterised by a docking station (72) at said parking position (13), to which said mobile unit (7) is connectable, said docking station (72) comprises means for charging of batteries, present in said mobile unit, and/or means for change of probing device (9).

22. The device according to any of the claims 12 to 21 , characterised in that said mobile unit (7) further comprises at least one storing unit (90) for probing de- vices (9).

AMENDED CLAIMS

[ received by the International Bureau on 9 February 2000 (09.02.00); original claims 1-22 replaced by new claims 1-20 (5 pages) ]

(7) in said stand-by position (14), bringing a probing device (9) attached to said mobile unit (7) into said process container(l), and into contact with said liquid metallic material, whereby said measuring and said determining is enabled; removing said probing device (9) from said process container (1); moving back said mobile unit (7) from said stand-by position (14) to said parking position (13); and before or during said moving back of said mobile unit (7), wireless transferring said measured process parameter from said mobile unit (7) to an evaluation unit (71), separated therefrom.

2. The method according to claim 1 , characterised in that said measuring of at least one process parameter comprises at least one of the following: measuring of the temperature of said melted metallic material; measuring of the solidification temperature of said metallic material; and measuring of the oxygen activity in said metallic material.

3. The method according to claim 1 or 2, characterised in that said metallurgical process continues during the introduction of said probing device (9) into said process container (1).

4. The method according to claim 1 or 2, characterised in that said metallurgi- cal process is interrupted totally or in part, before the introduction of said probing device (9) into said process container (1).

5. The method according to claim 4, characterised in that help equipment (4) for operating said metallurgical process at least to a part is removed from said precess container (1) before the introduction of said probing device (9) into said process container (1).

6. The method according to claim 4 or 5, characterised by the step of, if the true final point has not been reached, fully resume said metallurgical process.

7. The method according to any of the preceding claims, characterised in that said introduction of said probing device (9) comprises the steps of: conveying a first support point (38; 58) of a support device attached to a lance (8), to which said probing device (9) is attachedprobing device, along a first track (34; 54); and guiding a second support point (61) of said support deviceprobing device, along a predetermined second track at said mobile unit (7), said second track is adjusted to give said probing device (9) a suitable introduction path into said process container (1).

8. The method according to claim 7, characterised in that said lance (8) is kept in place by the action of gravitation forces, during conveying the first support point (38; 58).

9. The method according to any of the preceding claims, characterised in that said introduction of said probing device (9) is interrupted if an abnormal mechanical resistance occur at said probing device (9) during said introduction.

10. The method according to any of the preceding claims, characterised in that said removing of said probing device (9) from said process container (1) is started when one of following criteria has been reached: an approved measurement of said process parameter has been received; a certain time period has elapsed since said probing device (9) came into contact with said metallic material; and a certain time period has elapsed since said introduction was started.

11. Device for measurement of process parameters at metallurgical processes in a process container (1) including: a probing device (9) for measurement of process parameters, said process parameters are achievable in direct connection with the measurement in said process container (1 ); and a remotely controlled mobile unit (7), at which said probing device (9) is attached; characterised in that said mobile unit (7) comprises: means for moving said mobile unit (7) from a parking position (13), totally separated and protected from the surroundings (1 1) of said process container (1) to a stand-by position (14) in close connection to said process container (1) and for moving back said mobile unit (7) to said parking position (13); means for motion of said probing device (9) into and out from said process container (1); and a communication system (73, 74) for controlling the motion of said mobile unit and wireless transmission of process parameter information between the mobile unit (7) and an evaluation unit (71).

12. The device according to claim 11 , characterised in that said movement means (78) comprises a navigation means (79) of at least one of the types: IR navigation means; and laser navigation means.

13. The device according to claim 11 or 12, characterised in that said means for motion of said probing device (9) into and out from said process container (1) comprises: a lance (8), on which said probing device (9) is fixedly arranged, said lance (8) is connected with said mobile unit (7) via a support device provided with a first support point (38; 58) and a second support point (41 ; 61); a conveying means (35; 55), to which said first support point (38; 58) of said support device is fixedly but rotatably connected; and a guiding means (40; 60), which defines a motion path of said second support point (41 ; 61) of said support device.

14. The device according to claim 13, characterised in that said guiding means (40; 60) has a shape that, when said conveying means (38; 58) is conveyed along a predetermined track (34; 54), guides said second support point (41; 61) of said support device in order to give said lance (8) and said probing device (9) a suitable in- troduction path into said process container (1).

15. The device according to claim 14, characterised in that said lance (8) is kept in place by means of the gravitational force of said lance (8), along said introduction path.

16. The device according to claim 14 or 15, characterised in that said lance (8) is removable from said introduction path by an upwards directed mechanical force applied on said probing device (9).

17. The device according to any of the claims 13 to 16, characterised in that said conveying means (35) conveys the first support point (38) of said support device along a circle arc path (34).

18. The device according to any of the claims 13 to 16, characterised in that said conveying means (55) conveys the first support point (58) of said support device along a linear path (54).

19. The device according to any of the claims 11 to 18, characterised by a docking station (72) at said parking position (13), to which said mobile unit (7) is connectable, said docking station (72) comprises means for charging of batteries, present in said mobile unit, and/or means for change of probing device (9).

20. The device according to any of the claims 11 to 19, characterised in that said mobile unit (7) further comprises at least one storing unit (90) for probing de- vices (9).