EP2807438B1 - Method for operating an anode furnace and control device - Google Patents

Description

The invention relates to a method for operating an anode furnace and a control device, wherein the anode furnace is formed from a plurality of heating channels and furnace chambers, wherein the furnace chambers for receiving anodes and the heating channels for controlling the temperature of the furnace chambers, wherein the anode furnace comprises at least one furnace unit, wherein the furnace unit comprises a heating zone, a fire zone and a cooling zone, which in turn are formed of at least one furnace chambers section, wherein in a section of the heating zone is arranged a suction ramp and in a section of the fire zone, a burner ramp of the furnace unit, wherein an operation of the ramps is controlled by means of a control device of the furnace unit.

The present method and apparatus find application in the production of anodes needed for fused-salt electrolysis to produce primary aluminum. These anodes are made of petroleum coke with the addition of pitch as a binder in a molding process as so-called "green anodes" or "Rohanoden" which are subsequently sintered in an anode furnace in the molding process.

This sintering process takes place in a defined heat treatment process in which the anodes pass through three phases, namely a heating phase, a sintering phase and a cooling phase. In this case, the raw nodes are in a heating zone of a formed from the heating zone, a fire zone and a cooling zone Anodenbrennofens formed "fire" and are preheated by the originating from the fire zone waste heat of already finished sintered anodes before the pre-heated anodes in the fire zone to the sintering temperature be heated from about 1,200 ° C. According to the prior art, as he, for example, from the EP 1 785 685 A1 is known, while the various so-called zones are defined by a variable continuous arrangement of different units above furnace chambers or heating channels that receive the anodes.

By positioning a burner device or a so-called burner ramp above selected furnace chambers or heating channels, the fire zone is defined, which is arranged between the heating zone and the cooling zone. In the cooling zone are immediately before burned, ie heated to sintering temperature anodes. Above the cooling zone, a blower device or a so-called cooling ramp is arranged, by means of which air is blown into the heating channels of the cooling zone. The air is passed through an above the heating zone arranged suction device or a so-called suction through the heating channels from the cooling zone through the fire zone into the heating zone and from this as a flue gas through a flue gas cleaning system and discharged into the environment. The suction ramp and the burner ramp together with the cooling ramp and the heating channels form a furnace unit.

The abovementioned units are displaced along the heating channels in the direction of the raw anode arranged in the anode furnace at regular time intervals. Thus, it can be provided that an anode baking oven comprises a plurality of oven units whose aggregates are subsequently offset one above the other above the oven chambers or heating channels to subsequent heat treatments of the raw anodes or anodes. In such Anodenbrennöfen, which may be designed in different types as open anode furnaces or anode ring furnaces, in addition to the aforementioned units or ramps regularly still a number of other ramps, such as a measuring ramp, a pressure ramp and several additional cooling and burner ramps are used and functionally compiled. The individual different types of ramps must be in a particular order and spaced apart so that they can operate as a furnace unit in the desired manner. The ramps are in cyclic intervals of z. B. 24 to 26 hours of operators manually or with the help of a crane. For this purpose, an operation of the furnace unit is interrupted and restarted after repositioning the ramps. In particular, when moving the ramps by the operator may lead to a false positioning of the ramps relative to each other or to a list of different types of ramps in a wrong order. This can lead to procedural malfunctions and dangerous operating conditions of the anode furnace with the risk of deflagration, fire or explosion.

It is off EP1742003 For example, it is known to pass information about the respective positions of the ramps by a manual input to a control device of the furnace unit, for example a PLC control. Thus, at least a visual check of the ramp installation takes place. However, the operator can also during the adjustment of the ramp position or when manually entering this information to make a mistake. Therefore, it is still possible that the oven unit can be started even though a ramp is set at a wrong position.

The present invention is therefore based on the object to propose a method and a control device for operating an anode furnace, with or a possibly incorrect installation of a ramp can be safely avoided.

This object is achieved by a method having the features of claim 1 and an apparatus having the features of claim 10.

In the method according to the invention for operating an anode furnace, the anode furnace is formed from a plurality of heating channels and furnace chambers, the furnace chambers for receiving anodes and the heating channels for controlling the temperature of the furnace chambers, wherein the anode furnace comprises at least one furnace unit, wherein the furnace unit comprises a heating zone, a fire zone and a cooling zone, which in turn is formed from at least one furnace chambers section, wherein in a section of the heating zone is arranged a suction and in a section of the fire zone, a burner ramp of the furnace unit, wherein an operation of the ramps controlled by a control device of the furnace unit wherein the ramps each comprise a reading unit, the sections each having at least one stationary transponder unit, the reading units of the ramps communicating with the respective transponder units of the sections in which the ramps are arranged Ind, wherein by means of the control device, an identification of the respective transponder units takes place, and wherein a determination of a respective position of the ramps takes place by an assignment of the ramps to the respective transponder units.

Accordingly, the furnace chambers form sections, each composed of one or more furnace chambers. In each section at least one transponder unit is arranged stationary. Further, in each case a reading unit is mounted on at least one ramp, preferably on all the ramps of the oven unit, which is brought into a local coverage of the ramp in any section with the transponder unit of the section or the transponder unit is so approximated that the Reading unit with the transponder unit can communicate. Each time the furnace unit is moved, an identification of the transponder units of the sections in which ramps have been set up is carried out by means of the control device. Since the transponder units are each individualized, d. H. can not be confused, an assignment of the ramps to the respective transponder units is possible. This presupposes that a position or assignment of the transponder units to the respective sections is stored in the control device. The control device can now determine in which section which ramp has been set up and thus determine the respective position of the ramps. Thus, the control device can easily detect a faulty installation or positioning of a ramp.

It is particularly advantageous if a control unit of the control device responds to the reading units of the ramps after an offset of the furnace unit, wherein the reading units can read information stored by the transponder units assigned to the ramps. The control unit may in particular be a PLC control of the furnace unit. An already existing PLC controller can then be expanded, for example, so that, among other things, the reading units are addressed at a start of the PLC or the control unit. Thus, already in the context of each commissioning of the furnace unit or during operation of the anode furnace that stored in the transponder units Information read out and processed by the PLC control.

The information stored and read out in the transponder units may be displayed by the control unit for inspection. The operator is thus able to check directly on the control unit or on a remote control room a correct installation of the ramps by reviewing the information displayed before the commissioning can be continued by a release of the operating staff. In particular, the operator can compare the displayed information on the position of the ramps with the actual position of the ramps. Furthermore, it is possible for the operator to possibly correct any incorrect information of the transponder units. The operating personnel can therefore correct or replace any incorrectly programmed or defective transponder units and reposition faulty ramps and then continue commissioning.

Regardless of the display of the information from the control unit, the control unit can also take over the control function of the operating personnel. If the information is controlled by the control unit, then a plausibility check of position-independent information can be carried out by the control unit. Accordingly, the control unit can be designed so that the information read out by the transponder units is first checked for plausibility. Thus, possibly defective or incorrectly programmed transponder units can be easily detected by the control unit. The control unit can also automatically interrupt commissioning here.

Also, the information can be corrected by the control unit. For example, the control unit may have a database with frequent errors and possible configurations of a furnace unit include. The control unit can then automatically or automatically correct a detected as faulty information.

When checking the information from the control unit, a plausibility check of position-dependent information can also be carried out, wherein a presupposed position of the ramps can be compared with an actual position of the ramps. In addition to a control of position-independent errors, ie errors that do not relate directly to a faulty installation of the ramps, therefore, the actual position or installation of the ramps can be controlled. This in turn can be done by a comparison of the information read from the transponder units with the information stored in the control unit for a configuration of the oven unit.

Thus, it can further be provided that a startup of the ramps takes place only after a successful check of the position of the ramps. The ramps can then be put into operation only when the control device releases this final step of commissioning. This ensures that all ramps are in the desired position.

From the transponder unit itself, a number of the section of the transponder unit, a number of the anode furnace of the transponder unit and a number of the sections of the anode furnace of the transponder unit can be stored. Thus, each transponder unit, even in an operating system with multiple anode furnaces, can be clearly distinguished from other transponder units and assigned to a defined position in the respective anode kiln. Also, the aforementioned information can be used alone for a plausibility check of the transponder unit. Furthermore, it is possible for a number of other information, such as an identification number, to be stored by the transponder unit. In order to adapt an anode furnace to any changed requirements, it is advantageous if the transponder unit can be programmed with another, portable reader. Thus, the respective assigned transponder units can be individually read by means of the portable reader for checking or reprogramming. This activity can easily be performed manually by the operator.

In the control device according to the invention for operating an anode furnace, the anode furnace is formed from a plurality of heating channels and furnace chambers, wherein the furnace chambers for receiving anodes and the heating channels for controlling the temperature of the furnace chambers, wherein the anode furnace comprises at least one furnace unit, wherein the furnace unit comprises a heating zone, a fire zone and a cooling zone, which in turn are formed from at least one furnace chambers section, wherein in a section of the heating zone is arranged a suction and in a section of the fire zone, a burner ramp of the oven unit, wherein an operation of the ramps controllable by the control device of the oven unit wherein the ramps each comprise a reading unit of the control device, wherein the sections each comprise at least one stationary transponder unit of the control device, wherein the reading units of the ramps with each of the transponder units can communicate the sections in which the ramps are arranged, wherein the control device is designed so that by means of the control device, an identification of the respective transponder units can be carried out, and wherein an assignment of the ramps to the respective transponder units, a determination of a respective position of the ramps can.

For the resulting from the control device according to the invention advantages, reference is made to the above description of the method according to the invention.

The control device may comprise a control unit, wherein the control unit may be a PLC control. PLC controls can be used advantageously for the operation of anode furnaces and easily extended by further functionalities, for example for carrying out the method according to the invention.

Advantageously, the transponder unit may be a passive RFID transponder unit. Passive RFID transponder units do not require their own power supply and are thus essentially maintenance-free. Also, the environmental conditions to an anode furnace, such as heat or contaminants, may not significantly affect communication between the transponder unit and the reader.

Advantageously, the transponder unit can have a range of 15 cm to 45 cm. Thus, the reading unit or the reading device need not be arranged in the immediate vicinity of the transponder unit. Thus, for example, a corresponding distance can be formed between the ramp with the reading unit and the transponder unit. This is advantageous in that anyway the ramp is connected only in the range of Heizkanalöffnungen with the heating channels.

Preferably, the transponder units may be arranged in a regular array in the longitudinal direction of the anode furnace and in unitary positions in the sections. Since the ramps are usually offset in the longitudinal direction of the anode furnace, the reading units of the ramps can thus always coincide with a transponder unit of a series of transponder units. Since the ramps are always arranged in predefined positions in the sections, the transponder units can advantageously be arranged in precisely these positions.

Nevertheless, a position of an antenna of a reading unit on the ramp may be adjustable relative to the position of the transponder unit. So makes it possible to adjust the reading unit relative to the transponder unit so that a trouble-free communication is ensured. Also, any positional tolerances, due to the formation of the respective ramp or arrangement of the transponder units, can be easily compensated.

Furthermore, each section may have two transponder units which are arranged relative to a respective ramp position. If, for example, a ramp can be set up in two different positions in a section, then each of these positions can be detected or controlled by means of the respective transponder unit. Optionally, a section may also have more than two transponder units, depending on the number of possible installation positions.

Advantageously, the transponder unit can be fixedly arranged in an upper installation floor of the anode furnace. In the upper installation floor or a cover of heating channels and furnace chambers may be formed a recess into which the transponder unit is inserted, so that the transponder unit is at least flush with an upper side of the bottom. The transponder unit can also be enclosed in the recess covered with a closure or enveloped with a potting compound. Thus, the transponder unit is particularly effectively protected against adverse environmental influences and mechanical damage.

Further advantageous embodiments of the control device emerge from the feature descriptions of the dependent claims back to the method claim.

Hereinafter, a preferred embodiment of the invention will be explained in more detail with reference to the accompanying drawings.

Fig. 1:

Eine schematische Darstellung einer Ofeneinheit eines Anodenbrennofens in einer Längsschnittansicht;

Fig. 2:

eine Teilschnittansicht eines Aufstellbodens eines Anodenbrennofens mit einer Rampe;

Fig. 3:

ein Ablaufdiagramm für eine Ausführungsform des Verfahrens zum Betrieb eines Anodenbrennofens.

Show it:

Fig. 1:

A schematic representation of a furnace unit of an anode furnace in a longitudinal sectional view;

Fig. 2:

a partial sectional view of a floor of an anode furnace with a ramp;

Fig. 3:

a flowchart for an embodiment of the method for operating an anode furnace.

The Fig. 1 shows a schematic representation of an here only partially illustrated anode furnace 10 with a furnace unit 11. The anode furnace 10 has a plurality of heating channels 12 which extend parallel along intermediate, not shown here furnace chambers. The oven chambers serve to accommodate here also not visible anodes shown. The heating channels 12 extend in a meandering manner in the longitudinal direction of the anode furnace 10 and have at regular intervals Heizkanalöffnungen 13, which are each covered with a Heizkanalabdeckung not shown here. The furnace unit 11 further comprises a suction ramp 14, burner ramps 15 and 16, a cooling ramp 17, and a zero spot ramp 18 and a measuring ramp 19. Their position on the anode kiln 10 defines functionally a heating zone 20, a fire zone 21 and a cooling zone 22. In the course of the production process the anodes, the furnace unit 11 is displaced relative to the furnace chambers or the anodes by moving the ramps 14 to 19 in the longitudinal direction of the anode furnace 10 above the heating channels 12, so that all anodes located in the anode furnace 10 through the zones 20 to 22.

The suction ramp 14 is essentially formed from a collecting channel 23, which is connected via an annular channel, not shown here to an emission control system. The collecting channel 23 is in turn connected in each case via a connecting channel 24 to a heating channel opening 13. Next is a sensor 25 for temperature measurement arranged in each heating channel 12 immediately in front of the collecting channel 23 and connected via a data line 26 with this. The measuring ramp 19 is also equipped with transducers 27. The burner ramps 15 and 16 are each formed from a plurality of burners 28 and transducers 29. The zero point ramp 18 also has transducers 30, and the cooling ramp 17 is formed of a distribution channel 31 with connection channels 32 for the heating channel openings 13.

The ramps 14 to 19 are each arranged in sections 33 to 38, wherein the sections 33 to 38 are each formed in turn from Heizkanalabschnitten 39. At the sections 33 to 38 adjacent sections are not shown here in detail in the sense of simplification of the figure. Within the sections 33 to 38 and also within the sections, not shown, at least one transponder unit, not shown here, is arranged in a set-up floor 40 of the anode furnace 10.

The Fig. 2 shows a partial sectional view of a Aufstellbodens 41 with a recess 42 and a received in the recess 42 transponder unit 43. The recess 42 and the transponder unit 43 is provided with a tight cover 44, so that the transponder unit 43 is protected from environmental influences. The transponder unit 43 here marks an installation position of a ramp 45 shown here in a cross-sectional view. Arranged on the ramp 45 is a reading unit 46, which is formed from an antenna 47 with a reading device 48. The reader 48 is connected via a connecting line 49 to the antenna 47 and via a connecting line 50 with a PLC control, not shown here. The antenna 47 can be mounted on the ramp 45 by means of a mounting device 51 so that it can be arranged directly above the transponder unit 43. Thus, by means of the mounting device 51 inaccuracies in the positioning of +/- 30 cm in the longitudinal direction and +/- 24 cm are compensated in the transverse direction relative to an anode kiln.

With the example in Fig. 3 now shown an automatic check of respective positions of ramps in each commissioning of the furnace unit or during operation of the anode furnace of an anode furnace is possible. With reference to the anode furnaces after the Fig. 1 and 2 Initially, the ramps 14 to 19 are positioned on the set-up floor 40 within the respective sections 33 to 38. By switching on a power supply and thus starting the commissioning, the PLC control and the reading device are started. The PLC controller addresses all readers, which read out the transponder units in the area of ramps 14 to 19 via the antenna. The read-out information is transferred to the PLC control and this verifies the information regarding its consistency. If an inconsistency is detected, a correction can be made, for example an assumed position. This ensures that the transponder units are in the assumed positions. Subsequently, the information is further processed within the PLC control or transferred to a further PLC control, in which case a plausibility check of a position of the ramps 14 to 19 is performed. This is done by comparing a determined position with a presumed position. Should one of the ramps 14 to 19 not be in the preselected position, the oven unit 11 can not be started. Here then a correction of the respective ramp position or a conversion of the respective ramp 14 to 19 is required. If no error is detected during the plausibility check or if this is successful, the oven unit 11 can be completely put into operation by, among other things, igniting the burners 28.

Claims (17)

1. A method for operating an anode furnace (10), wherein the anode furnace is formed from a plurality of heating ducts (12) and furnace chambers, wherein the furnace chambers serve for receiving anodes and the heating ducts serve for controlling the temperature of the furnace chambers, wherein the anode furnace comprises at least one furnace unit (11), wherein the furnace unit comprises a heating zone (20), a firing zone (21) and a cooling zone (22), which are in turn formed from at least one section (33, 34, 35, 36, 37, 38) comprising furnace chambers, wherein a suction ramp (14) is arranged in a section of the heating zone and a burner ramp (15) of the furnace unit is arranged in a section of the firing zone, wherein operation of the ramps (14, 15, 16, 17, 18, 19, 45) is controlled by means of a control apparatus of the furnace unit,
   characterized in that
   the ramps include one reading unit (46) each, wherein the sections include at least one stationary transponder unit (43) each, wherein the reading units of the ramps communicate with the transponder units of the sections in which the ramps are arranged, wherein the respective transponder units are identified by means of the control apparatus, and wherein a respective position of the ramps is determined by allocating the ramps to the respective transponder units.
2. The method according to claim 1,
   characterized in that
   upon initiation of operation, a control unit of the control apparatus activates the reading units (46) of the ramps (14, 15, 16, 17, 18, 19, 45), wherein the reading units read out information stored by the transponder units (43) which are allocated to the ramps.
3. The method according to claim 2,
   characterized in that
   the information is displayed by the control unit for inspection.
4. The method according to claim 2 or 3,
   characterized in that
   the information is inspected by the control unit, wherein a plausibility check of position-independent information is effected.
5. The method according to any one of the claims 2 to 4,
   characterized in that
   the information is corrected by the control unit.
6. The method according to any one of the claims 2 to 5,
   characterized in that
   the information is inspected by the control unit, wherein a plausibility check of position-dependent information is effected, wherein a presupposed position of the ramps (14, 15, 16, 17, 18, 19, 45) is compared to an actual position of the ramps.
7. The method according to any one of the preceding claims,
   characterized in that
   initiation of operation of the ramps (14, 15, 16, 17, 18, 19, 45) is only effected after successfully having checked the position of the ramps.
8. The method according to any one of the preceding claims,
   characterized in that
   a numerical designation of the section (33, 34, 35, 36, 37, 38) of the transponder unit, a numerical designation of the anode furnace (10) of the transponder unit and a total number of the sections (33, 34, 35, 36, 37, 38) of the anode furnace of the transponder unit are stored by the transponder unit (43).
9. The method according to any one of the preceding claims,
   characterized in that
   the transponder unit (43) is programmed by a portable reading instrument.
10. A control apparatus for operating an anode furnace (10), wherein the anode furnace is formed from a plurality of heating ducts (12) and furnace chambers, wherein the furnace chambers serve for receiving anodes and the heating ducts serve for controlling the temperature of the furnace chambers, wherein the anode furnace comprises at least one furnace unit (11), wherein the furnace unit comprises a heating zone (20), a firing zone (21) and a cooling zone (22), which are in turn formed from at least one section (33, 34, 35, 36, 37, 38) comprising furnace chambers, wherein a suction ramp (14) is arranged in a section of the heating zone and a burner ramp (15) of the furnace unit is arranged in a section of the firing zone, wherein operation of the ramps (14, 15, 16, 17, 18, 19, 45) can be controlled by means of the control apparatus of the furnace unit,
    characterized in that
    the ramps include one reading unit (46) of the control apparatus each, wherein the sections include at least one stationary transponder unit (43) of the control apparatus each, wherein the reading units of the ramps can communicate with the transponder units of the sections in which the ramps are arranged, wherein the control apparatus is embodied in such a way that the respective transponder units can be identified by means of the control apparatus, and wherein a respective position of the ramps can be determined by allocating the ramps to the respective transponder units.
11. The control apparatus according to claim 10,
    characterized in that
    the control apparatus includes a control unit, wherein the control unit is a PLC installation.
12. The control apparatus according to claim 10 or 11,
    characterized in that
    the transponder unit (43) is a passive RFID transponder unit.
13. The control apparatus according to any one of the claims 10 to 12,
    characterized in that
    the transponder unit (43) has a transponder range of 15 cm to 45 cm.
14. The control apparatus according to any one of the claims 10 to 13,
    characterized in that
    the transponder units (43) are arranged in regular rows in the longitudinal direction of the anode furnace (10) and in common positions in the sections (33, 34, 35, 36, 37, 38).
15. The control apparatus according to any one of the claims 10 to 14,
    characterized in that
    a position of an antenna (47) of the reading unit (46) at the ramp (14, 15, 16, 17, 18, 19, 45) can be set relative to the position of the transponder unit (43).
16. The control apparatus according to any one of the claims 10 to 15,
    characterized in that
    every section (33, 34, 35, 36, 37, 38) includes two transponder units (43) which are arranged relative to one possible ramp position each.
17. The control apparatus according to any one of the claims 10 to 16,
    characterized in that
    the transponder unit (43) is fixedly arranged in an upper assembly floor (40, 41) of the anode furnace (10).

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