EP2336695B1 - Metallurgical assembly - Google Patents

Description

The invention relates to a metallurgical plant having a contact area for hot material, wherein in the metallurgical plant at least one functional element is arranged, which is supplied by a power supply element with electrical energy, wherein the power supply element is designed as a thermoelectric generator, which is connected to the contact area for hot material and is thermally connected to a colder area of the metallurgical plant.

In metallurgical plants, such as in converters, sensors are used to be informed of the operating parameters during operation of the plant. The temperature, pressure or forces prevailing in the system can be interesting.

Conventional measuring technology is only used to a limited extent in steel and rolling mill technology. Due to the extreme environmental conditions with regard to temperature, magnetic fields, dust, steam and water, energy supply and measuring signal dissipation as well as all electrical or electronic components must be protected from environmental influences in a particularly complex manner. Fixed cabling on moving components also requires cable loops, tow traps with and without tow bar equipment, or special costly rotary joints for connection to the sensing-receiving data acquisition systems.

Fixed cabling also complicates the rotational and additional replacement of plant assemblies, such as continuous casting segments. A large number of measuring points increases the installation and maintenance costs considerably. Therefore, the instrumentation is usually limited to the essentials. However, increasing demands on product quality and efficiency require greater process and process transparency, which in turn requires higher point density.

As a result, wireless sensors are frequently used in the meantime, especially where wired systems are too expensive, too susceptible or otherwise unattainable. This is especially true for metallurgical vessels.

In order to interrogate the data measured by the sensors wirelessly, the sensor communicates with a transmitter, which transmits the data to a monitoring station. For this purpose, the transmitter must be powered by a power source with energy.

It is known to use batteries as an energy source. These have the disadvantage that they must be periodically replaced in order to maintain the functionality of the system. Furthermore, there is a risk of explosion when using batteries in the very hot environment.

Another way of supplying energy is to transfer the energy via electromagnetic radiation, eg. B. via microwaves. However, such systems are very complex and therefore expensive.

A generic plant is from the DE 198 48 162 C1 known. Similar solutions show the WO 03/027334 A1 , the WO 99/50629 A1 , the WO-A 2009/082534 , and the CA 2 456 360 A1 ,

The present invention is therefore based on the object, for example, to equip a metallurgical plant of the type mentioned above in such a way that it is possible in an improved manner to supply energy to functional elements which have a transmitting device for measured sensor data. Ie. It is intended to provide electrical energy for the local operation of a functional element, the electrical Energy is required, provided reliably and in sufficient quantity, without the need for electrical supply or discharge.

The solution of this object by the invention is characterized in that between the contact area for hot material and a side portion of the thermoelectric generator, a heat transfer element in the form of a heat pipe (heat pipe) is arranged, wherein the functional element comprises a sensor and a transmitter for one from the sensor measured signal comprises.

The thermoelectric generator is designed in particular as a Peltier element. It usually comprises a plate of semiconductor material.

The sensor may be a temperature, pressure or force sensor.

The heat transfer element may be at least partially surrounded by a thermal and / or electrical insulation element.

The functional element and the energy supply element can be housed in a common housing, wherein the housing preferably has a cylindrical basic shape. The housing may be part of a fastener of the metallurgical plant, in particular an expansion screw. In the housing, a functional element in the form of a sensor, in particular a temperature sensor is arranged with a transmitter. The metallurgical system can be designed to make contact with liquid metal. It is also possible that the metallurgical plant is designed to make contact with hot, solid metal (eg during hot rolling).

Preferably, it is designed as a vessel for liquid metal. Here is intended, for example, to a converter or a lance.

Thus, the invention is based on the idea to install a thermogenerator in a suitable area of a metallurgical plant, for example in a wall of the metallurgical plant, and by means of this electrical energy to gain that the temperature difference between a hot and a colder area of the plant is being used. With the electrical energy thus obtained then sensors and / or transmitting elements and other functional elements can be supplied with electricity.

The invention can be used in all plants for the production and treatment of hot metals, in particular of liquid metals, wherein, for example, steel, copper or aluminum can be processed. What is needed in the system is merely a region whose surface on the side facing the hot metal, in particular the liquid metal, at least temporarily has a higher temperature than the region which faces away from the hot metal.

The characteristic of said metallurgical aggregates temperature differences between different sides of the system (internal hot area and external cold area) are thus used selectively to provide the desired electrical energy by means of a thermogenerator.

The technology of the thermoelectric generator is known as such. The direct conversion of heat into electrical energy is possible with such. For this purpose, semiconductor materials are used. Common materials are Bi ₂ Te ₃ , PbTe, SiGe, BiSb or FeSi ₂ . This can achieve efficiencies between three and eight percent. In order to obtain sufficiently high voltages, several elements can be connected in series between the cold and the hot side. Details are in the WO 2004/090998 A2 described. Various applications of thermoelectric generators are in the EP 0 717 332 A1 , in the WO 2008/025701 A2 and in the JP 60071816 A described.

The thermoelectric conversion is based on the Peltier effect, according to which a current flow through a semiconductor device can produce a temperature difference or conversely at a temperature difference, a current flow can be generated. The basis for this is the contact of two semiconductors, which have a different energy level (either p- or n-type) of the conduction bands. If a current is conducted through two contact points of these materials, thermal energy must be absorbed at one contact point so that the electron enters the higher energy conduction band of the adjacent semiconductor material. This causes it to cool down. At the other contact point, the electron falls from a higher to a lower energy level, so that energy is given off here in the form of heat. The inverse of the Peltier effect is the Seebeck effect. By this it is possible to generate electrical current by establishing a temperature difference between the two sides of a Peltier element, as it is used in the context of this invention.

Thus, according to the basic idea of the present invention, natural temperature differences on the walls of a metallurgical plant can be used to produce and process in particular liquid metals in order to generate electrical energy by means of the thermogenerator.

As a thermogenerator preferably a thin plate of semiconductor material is used, the top is heated and the bottom is cooled. The energy flow through the thermogenerator is made by thermal conduction. The thermogenerator is z in the existing wall. B. a metallurgical vessel installed, for. B. in the water-cooled cooling panel of an electric arc furnace. The thermocouple is clamped for example between two round copper cylinder. To maximize the heat flow, the heat pipes are insulated with a suitable material.

High and low temperatures from the respective hot or cold side of the wall to the poles (sides) of the thermal generator can be brought by means of good heat-conducting elements or good insulating materials. In this way, the direction of the heat flow can be influenced and thus the maximum possible temperature difference can be set. These highly thermally conductive elements consist of adapted heat pipes which have a very high thermal conductivity. The heat-conducting element should be thermally insulated from the surroundings perpendicular to the heat flow, so that the heat flows perpendicular to the heat-conducting element do not reduce the temperature difference at the thermogenerator.

The possible fields of application of the thermal generators include all plant areas of metallurgical process and process engineering, such. As converters or blow lances, which also have hot and cold spots and are difficult to access for wired sensors.

Thus, by means of the thermogenerator a permanent autonomous operation of wireless sensor technology on the walls of plants for the production and treatment of hot, especially liquid metals possible.

The sensors used are preferably integrated in the system components so that they are protected by the components themselves and preferably require no additional protection.

Several sensors can be connected to form a network, which are connected via a gateway to the process control system of the metallurgical plant.

Furthermore, the sensors or sensor modules are equipped with microcontrollers, which can take over a data processing in a timely manner. In this way, evaluation results or only these can be transmitted to the process control system in addition to the raw data.

Accordingly, the assemblies include measuring sensors (with or without microcontroller), a radio module and an energy supplier in autonomous execution, d. H. network-independent.

Corresponding sensors for measuring mass, temperature, pressure, velocity, acceleration, mass or volume flow, distance or position, force, strain, sound, vibration, angular mass, humidity, density and dust in components or assemblies can be provided.

The wireless radio module with at least one transmitting unit and / or receiving unit is suitable for data transmission to another sensor and / or to a higher-level receiving unit. The receiving unit is preferably located at a protected location at an adequate distance from the sensors.

In principle, the invention proposal in assemblies of any metallurgical plant components, individual plants or plant complexes can be used, such. Eg in iron and steel production plants (blast furnace, converter, EAF, Concarc), secondary metallurgical plants (LF, RH, VD), continuous casting plants (slab, thin slab, thin strip, billet, billet, beamblank), kiln plants (hood, pusher furnace, tunnel kiln) , Rolling mills (cold, hot rolling mill) and strip lines.

Overall, an energy self-sufficient and wireless monitoring is possible, which is networkable, self-organized and allows a local data analysis.

There may be a reduction of the piping, cable management and cooling, which requires a corresponding lower cabling and maintenance costs. The costs for mechanics and electrics can be reduced. In mold monitoring, a fieldbus module can be provided on the mainland be, not per mold. The availability of the system is high. An automatic assignment of measuring location and thermocouple is possible. The data volume can be reduced, it can be worked with a telegram traffic.

With regard to the bearing force measurement in a continuous casting plant, the number of measuring points can be better realized. An additional process and plant monitoring can take place, which results in a higher process reliability. This results in a safe operation of the system. It is a permanent measurement possible, in particular as regards the Strangerstarrungszustand in the continuous casting and the condition of the bearing.

Fig. 1

schematisch den Schnitt durch die Wandung eines Lichtbogenofens mit Kühlpanel, wobei die Wandung mit einem Thermogenerator versehen ist,

Fig. 2

den Schnitt durch einen Konverter, der ebenfalls mit einem Thermogenerator in einer Wandung versehen ist,

Fig. 3

die Einzelheit "X" gemäß Fig. 2,

Fig. 4

eine zu Fig. 1 alternative Ausgestaltung des in die Wandung eingebauten Thermogenerators,

Fig. 5

den Schnitt durch eine Blaslanze, die mit einem Thermogenerator in einer Wandung versehen ist,

Fig. 6

ein Blockschaltbild einer Anlage zur Messung und drahtlosen Übertragung eines gemessenen Parameters,

Fig. 7

die Seitenansicht eines Befestigungselements einer metallurgischen Anlage in Form einer Kokille,

Fig. 8

den Schnitt A-B gemäß Fig. 7 durch das Befestigungselement und

Fig. 9

den Schnitt C-D gemäß Fig. 8 durch das Befestigungselement.

In the drawings, embodiments of the invention are shown. Show it:

Fig. 1

FIG. 2 schematically shows the section through the wall of an arc furnace with cooling panel, wherein the wall is provided with a thermogenerator, FIG.

Fig. 2

the section through a converter, which is also provided with a thermogenerator in a wall,

Fig. 3

the detail "X" according to Fig. 2 .

Fig. 4

one too Fig. 1 alternative embodiment of the built-in wall thermogenerator,

Fig. 5

the section through a lance, which is provided with a thermogenerator in a wall,

Fig. 6

a block diagram of a system for measuring and wireless transmission of a measured parameter,

Fig. 7

the side view of a fastener of a metallurgical plant in the form of a mold,

Fig. 8

the section AB according to Fig. 7 through the fastener and

Fig. 9

the cut CD according to Fig. 8 through the fastener.

In Fig. 1 is the section sketched through the wall of an electric arc furnace. The heat input 7 - originating from the liquid metal - takes place in the direction of the arrow in the inner wall 8 made of copper. The liquid metal facing side of the inner wall is the contact area 2 for hot material. The outer wall 9 made of steel, there is a gap that is traversed by cooling water 10.

Between the relatively hot inner wall 8 and the relatively cold outer wall 9 there is a temperature difference, which is used by a power supply element 4 in the form of a thermoelectric generator (thermo generator) 4. For this purpose, the respective temperature of the inner and outer walls is transferred to opposite sides (poles) of the thermogenerator 4 via two heat transfer elements 5, so that different temperatures are applied to the thermogenerator 4. The heat transfer elements 5 together with the thermal generator 4 are embedded in an insulating element 6 and are isolated by this.

Due to the different temperatures applied to the thermogenerator, this generates a voltage which is provided to a functional element 3 via a cable, not shown. The functional element 3 is a transmitter (wireless transmission system) with which measurement data can be transmitted remotely by a sensor (not shown).

This principle is also in the solution according to the FIGS. 2 and 3 realized. Here, a converter 1 is outlined as a metallurgical plant, in whose wall, in turn, a thermogenerator is integrated. Analogous to the solution according to Fig. 1 Here, too, the thermogenerator 4 is installed in the side wall of the converter, wherein heat is transferred from the contact area 2 for hot material via a heat transfer element 5 to the thermogenerator 4. Again, the heat transfer element 5 is thermally insulated by means of an insulating element 6.

The solution according to Fig. 4 is according to the one Fig. 1 similar. Here, only for the application of an electric arc furnace is provided that over a relatively long distance heat is transferred by means of the heat transfer element 5 from the contact area 2 for hot material to the thermal generator 4. The heat transfer element is designed as a heat pipe.

Such a heat pipe is a heat transfer element which, by utilizing heat of vaporization of a substance, enables a high heat flux density, i. H. On small cross-sectional area, large amounts of heat can be transported. To circulate the transport medium heat pipes need no additional auxiliary energy such. B. a circulating pump. This minimizes maintenance and operating costs. There is a distinction between two types of heat pipes, namely between the heat pipe and the two-phase thermosyphon. The mode of operation and design are basically similar.

In Fig. 5 is shown for the application of a lance as part of a metallurgical plant 1, as such can be equipped with the invention. Here again the same components are used as is the case with the previously described embodiments. Shown is now additionally a sensor 3 ', wherein via cable 11 an electrical connection is made both between the sensor 3 'and the thermogenerator 4 and between this and the transmitter 3 ".

In Fig. 6 is a block diagram showing the structure of a complete monitoring device for an operating parameter.

In the metallurgical plant 1 - as described above - the thermogenerator 4 is arranged, which is connected both to the sensor 3 'and to the transmitter 3 "by cable.

A receiver 13 is arranged in a detection and control unit 12, which can receive the signals from the transmitter 3 ", which are forwarded to an evaluation unit 14, which in turn is connected to a control unit 15 of the system metallurgical plant 1 are influenced, which is indicated by the arrow.

In the FIGS. 7 to 9 is sketched out a solution in which the required functional elements including power supply element are housed in a common housing. Specifically, in the figures, a fastener 16 is shown in the form of an expansion screw. A screw head 17 is arranged at one axial end of the fastening element 16. The fastening element 16 comprises as main body a housing 18, which is formed substantially hollow cylindrical.

In this case, the fastening element is formed from two separate and assembled assemblies 19 and 20.

As in the FIGS. 8 and 9 can be seen, a first functional element in the form of a sensor 3 'is arranged concentrically in the first assembly 19. Furthermore, a functional element in the form of a transmitter 3 "is present, specifically integrated in the second module 20. The energy required for the operation of the functional elements 3 ', 3" comes from a thermal generator 4.

Corresponding insulation 6 cause the temperature differences of the metallurgical plant can be optimally used to provide electrical energy by means of the temperature gradient in the thermogenerator can.

In the present case, the fastening element 16 is part of a nut lock nut system which connects a copper plate and a water tank in the rear wall area of a continuous casting mold. It is designed in such a way that the radio adapter 3 "is additionally mounted on the expansion screw and is connected to the temperature measuring device 3 'located inside the expansion screw.

A voltage converter, a measuring transducer and a microcontroller are accommodated in the housing 18 in addition to the radio adapter 3 ", the temperature sensor 3 'and the energy converter 4. The necessary voltage for the active electrical components of the fastening element 16 is provided by the energy converter 4 and the voltage converter ,

The measured temperature values are converted by means of the transducer and transmitted via the radio module to a central measured value acquisition.

But it is also possible - as in the embodiment according to Fig. 7 to 9 provided - that a thermogenerator is used as an energy supply element. In this case, the temperature difference between the water-cooled expansion screw 16 and the process waste heat is used to generate a voltage by means of the thermal generator.

The fastening element 16 consists, as already mentioned, of two subassemblies 19, 20 which are thermally decoupled from one another, wherein a temperature gradient can be established between the two subassemblies, which is used for energy generation by the thermal generator.

The first assembly 19 is connected to the expansion screw, that the highest possible heat transfer is achieved. The second assembly 20 is designed so that the process waste heat is absorbed and forwarded to the thermal generator 4. Both modules are thermally decoupled from each other by insulators 6 that the temperature difference can be largely compensated only via the thermal generators 4.

• Bei einer Pfanne kann ein integrierter, energieautark arbeitender Funkmesssensor der beschriebenen Art eingesetzt werden. Hiermit kann die Gewichts-, Füllstands- bzw. Temperaturmessung des Stahls in der Pfanne erfolgen. Ferner kann die Positions- und Schwingungsüberwachung des Pfannenschiebers vorgesehen werden, wodurch eine Erkennung mitlaufender Schlacke möglich wird. Weiterhin kann eine Temperaturüberwachung der Pfannenausmauerung zur vorbeugenden Instandhaltung bzw. Erkennung von Verschleißschädigungen erfolgen.

The following application examples are given:

• In a pan, an integrated, self-powered radio-measuring sensor of the type described can be used. Hereby, the weight, level or temperature measurement of the steel can be done in the pan. Furthermore, the position and vibration monitoring of the pan slider can be provided, whereby a detection of running slag is possible. Furthermore, a temperature monitoring of Pfannenausmauerung for preventive maintenance or detection of wear damage done.

Even with a distributor, an integrated and energy self-sufficient radio measuring sensor can be used. Hereby, the weight, level or temperature measurement of the steel can be done in the distributor. Furthermore, the position and vibration monitoring of the plug or the distributor slide for monitoring the functionality can be provided. Furthermore, a temperature monitoring of Verteilerausmauerung for preventive maintenance or detection of wear damage done.

Furthermore, in the case of a mold, an integrated and energy self-sufficient radio-measuring sensor can be used. Hereby, the temperature of the mold plates can be monitored. Furthermore, a strain or force measurement in the expansion screws for fixing the mold plates on the water box can be done (see Fig. 7 to 9 ).

Then, a level measurement of the casting mirror can be done. Furthermore, the position, the movement and the conicity of the narrow sides of the mold can be monitored, equally a pressure measurement for monitoring Kokillenklemmung. Furthermore, the position and movement monitoring of Kokillenoszillation can be done by means of displacement and acceleration sensors.

Finally, by way of example, the monitoring of a segment or of a single roller driver of a continuous casting installation by means of an integrated and self-powered radio-measuring sensor may be mentioned. This allows the strain, distance and sound measurement in the bearing blocks to determine the bearing load and bearing monitoring with respect to functionality and preventive maintenance. Furthermore, a temperature, strain or displacement measurement on the segment traverses for monitoring the segment load in the casting operation can take place. Furthermore, a temperature and torque measurement can be made on the continuous casting rolls. Then a measurement of the rotational movement of the rollers for monitoring bearing damage and segment malpositions is possible. Furthermore, a movement or sound measurement on spray nozzles or splash plates for monitoring the nozzle functionality or for preventive maintenance is possible. Finally, it is possible to measure the position and force in the segment cylinders or between the loose side and the fixed side to monitor the jaw width and the spring-back travel, transverse displacements and transverse forces.

LIST OF REFERENCE NUMBERS

1

Metallurgical plant

2

Contact area for hot material

3

functional element

3 '

sensor

3 '

transmitter

4

Energy supply element (thermogenerator)

5

Heat transfer element

6

insulation element

7

heat input

8th

inner wall

9

outer wall

10

cooling water

11

electric wire

12

Detection and control unit

13

receiver

14

evaluation

15

control unit

16

fastener

17

screw head

18

casing

19

first assembly

20

second module

Claims (12)

1. Metallurgical plant (1) comprising a contact region (2) for hot material, wherein at least one functional element (3) supplied with electrical energy by an energy supply element (4) is arranged in the metallurgical plant (1) and wherein the energy supply element (4) is constructed as a thermoelectrical generator thermally connected with the contact region (2) for hot material and with a colder region of the metallurgical plant (1),
   characterised in that
   a thermal transmission element (5) in the form of a heat pipe is arranged between the contact region (2) for hot material and a side region of the thermoelectric generator (4), wherein the functional element (3) comprises sensor (3') and a transmitter (3") for a signal measured by the sensor.
2. Metallurgical plant according to claim 1, characterised in that the thermoelectric generator (4) is constructed as a Peltier element.
3. Metallurgical plant according to claim 1 or 2, characterised in that the thermoelectric generator (4) comprises a plate of semiconductor material.
4. Metallurgical plant according to any one of claims 1 to 3, characterised in that the sensor (3') is a temperature, pressure or force sensor.
5. Metallurgical plant according to any one of claims 1 to 4, characterised in that the thermal transmission element (5) is at least partly surrounded by a thermal and/or electrical insulating element (6).
6. Metallurgical plant according to any one of claims 1 to 6, characterised in that the functional element (3) and the energy supply element (4) are accommodated in a common housing (18), wherein the housing (18) preferably has a cylindrical plan.
7. Metallurgical plant according to claim 6, characterised in that the housing (18) is a component of a fastening element, particularly an expansion screw, of the metallurgical plant.
8. Metallurgical plant according to any one of claims 1 to 7, characterised in that it is constructed for making contact with liquid metal.
9. Metallurgical plant according to any one of claims 1 to 7, characterised in that it is constructed for making contact with hot solid metal.
10. Metallurgical plant according to claim 8, characterised in that it is constructed as a vessel for liquid metal.
11. Metallurgical plant according to claim 10, characterised in that it is constructed as a converter.
12. Metallurgical plant according to any one of claims 1 to 7, characterised in that it is constructed as a blowing lance.

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