RU2477756C2 - Furnace, and device for its cleaning - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, and namely to electric arc furnace and its cleaning device. Electric arc furnace includes outlet channel (2) for removal of liquid metal from furnace, shutoff device (4) for opening and closing of mouth (3) of outlet channel (2), and cleaning device (5, 5', 5") for removal of metal deposited on mouth (3) of outlet channel (2). Cleaning device includes optic recording device (9) for taking the picture of outlet channel (2) and/or its mouth (3).

EFFECT: use of the invention provides improvement of the furnace capacity and safety for service personnel.

9 cl, 6 dwg

Description

The invention relates to a furnace, in particular an electric arc furnace containing an exhaust channel for removing liquid metal from the furnace, a locking device for opening and closing the mouth of the exhaust channel and a cleaning device for removing metal deposited on the mouth of the exhaust channel. In addition, the invention relates to a cleaning device for a furnace according to one of claims. 1-10 of the formula containing a slide with a moving tongue and a scraper located on the tongue.

The invention lies in the field of metallurgy, in particular in the field of metallurgical furnace technology. In a metallurgical furnace, molten metal is smelted or processed. In particular, in an electric arc furnace, scrap metal and / or cast iron, together with other additives, such as lime or coal, are processed into a molten metal of a certain composition. After receiving the metal melt, it is removed from the furnace. This happens, as a rule, through the so-called bottom release. In this case, liquid metal is discharged from the furnace through an exhaust channel in its bottom.

When liquid metal is removed from the furnace, in particular an electric arc furnace, during or after its discharge, a buildup of solidified metal is formed at the mouth of the exhaust channel or in the notch. Before re-closing the mouth of the outlet channel, this growth should be removed. In addition to removing the metal build-up from the mouth of the outlet channel, it is advisable to check the outlet channel for possible damage and / or residues, such as clogging with slag.

The metal outgrowth at the mouth and possible damage and / or residues in the outlet channel are parameters that affect the state of the mouth or the outlet channel itself. Monitoring the state of the mouth of the exhaust channel and / or itself, as well as, if necessary, creating the desired state of the exhaust channel or its mouth are combined under this application under the term "maintenance of the mouth of the exhaust channel or the exhaust channel itself."

Since the maintenance of the outlet channel or its mouth is currently carried out, as a rule, by manual maintenance personnel, a corresponding threat to its health arises. The reason for this when carrying out maintenance activities is, for example, slag coming out of the furnace with a delay or a bucket with liquid metal discharged under the tap hole, etc. In order to eliminate such threats to the health of staff, a relatively long waiting time of up to 1 minute or more is observed at the end of the release before service is performed. A relatively long waiting time, however, leads to an increase in production costs, since the productivity of the furnace is therefore reduced.

A furnace in which manual maintenance is carried out is known, for example, from DE 10034370 A1.

A generic cleaning device is known, for example, from AT 48186 B. Another generic cleaning device is also known from US 4875663, and it is made in the form of a metal brush.

The basis of the invention is the task of improving security for staff and at the same time the productivity of the furnace, in particular the electric arc furnace.

This problem is solved at the furnace of the above kind through the distinctive part of paragraph 1 of the formula. Thanks to the creation of the proposed furnace manual removal of metal growth is no longer required. Due to this, it is possible, in particular, to avoid a long waiting time when servicing the exhaust channel or its mouth. Thus, on the one hand, the safety of personnel is increased, since they are no longer exposed to danger when carrying out maintenance activities. On the other hand, the proposed furnace can increase productivity and reduce costs, because by saving time during maintenance, it is possible to process more than one or two steel melts per day. Such a cleaning device may cause the removal of the metal growth by mechanical, thermal or chemical means. Due to the existing optical recording device, the safety of maintenance personnel is increased, since during inspection of the exhaust channel it does not have to be in close proximity to it. The optical recording device operates primarily in the visible and / or infrared region of the spectrum. For example, a video camera and / or thermal video camera may be used. The optical recording device registers images of the outlet channel and / or its mouth, which are then processed manually or automatically directly on the furnace or in the observation center. Using this information, you can determine whether or not to take, for example, measures to bring the exhaust channel into good condition, for example, to eliminate its partial or complete clogging.

In one preferred embodiment, the cleaning device comprises a wedge-shaped scraper with a scraper edge. In a particular case, the cleaning device itself can be made in the form of a scraper. The scraper can be located, for example, on an existing furnace shut-off device and thereby expand its scope of functions. Retrofitting a furnace with such a scraper is relatively simple.

In particular, it is preferable that the locking device includes a cleaning device. Due to this, it is possible to implement a cleaning and locking device in one common structural unit and, thereby, create a compact device in the form of a combined cleaning and locking device.

In another preferred embodiment of the invention, the cleaning device comprises an adjustment device configured to position and orient the cleaning device relative to the mouth of the outlet channel. Thus, during servicing after each outlet, the condition of the mouth of the outlet can be individually taken into account. The adjusting device can be used both in a separate cleaning device and in a combined cleaning-locking device. The adjusting device can be made, for example, in the form of an eccentric suspension or an adjusting screw.

In another preferred embodiment of the invention, the cleaning device is made in the form of a gate with a moving tongue, and the scraper is located at the end of the tongue. This embodiment of the cleaning device with technically simple means ensures cleaning of the mouth of the outlet channel, despite opposing environmental conditions, in particular high temperatures and a high degree of contamination.

In another preferred embodiment, a cooling device is provided for cooling the cleaning device and / or optical recording device. By cooling the optical recording device or the cleaning device, the long life of the corresponding device is ensured. In particular, if the optical recording device is configured as part of a cleaning device, the cooling device may be combined for the optical recording and cleaning devices. As a cooling medium, for example, water can be used. However, any other cooling medium, such as gas, may also be used. In particular, it is preferable that the cleaning device comprises a housing continuously rinsed with a cooling medium, in particular water, without impairing the function of the cleaning device. Due to this, efficient cooling of the cleaning device can be achieved.

In another preferred embodiment, a device is provided for generating an air stream at least partially flowing around an optical recording device. On the one hand, such an air flow can be used to cool it, and, on the other hand, such an air flow is assigned the function of keeping the optics or field of view of the optical recording device free from contamination. The latter is important, in particular, when the optical recording device “peeks” into the exhaust channel. With this arrangement, severe contamination of the optical recording device or the viewing window by particles exiting the furnace can quickly occur. Consequently, the control of the exhaust channel can only be carried out to a limited extent or can no longer be carried out. Thanks to the device for creating an air flow at least partially flowing around the optical recording device, reliable control of the exhaust channel is possible even in the case of a strongly polluting environment. This is due to the fact that the air flow mainly prevents the deposition of particles, in particular mud particles, along the rays of the optical recording device. The air flow can be created, for example, by compressed air or its guiding device. Alternatively, a gas other than air can also be used.

In one particularly preferred embodiment of the invention, the optical recording device is located on the slide tab. Due to this, a particularly compact cleaning device with a monitoring function can be created. Advantageously, the slide tab is actuated by means of pushing pneumatic cylinders. The compressed air necessary for their operation can be used, for example, also for cooling or cleaning the optics of an optical recording device. In addition, it is preferable that in this embodiment of the cleaning device, the removal of the metal growth and the control of the outlet channel can be carried out for a single translational movement of the slide tab. Advantageously, the slide tab comprises a frame frame, the optical recording device being located between opposite sides of the frame frame.

In another preferred embodiment of the invention, the cleaning device is made in the form of an independent and mobile unit. Thus, it is not permanently located on the furnace, but can be connected to it, for example, for cleaning and control after the release of liquid metal. The cleaning device can be installed for this, for example, on roller elements or mounted on a swivel bracket. Such a mobile cleaning device experiences a lower temperature load than a cleaning device located permanently on the furnace. Lower temperature load, as a rule, has a positive effect on the life of the mobile cleaning device. Also, if necessary, it is possible to reduce the cost of cooling such a cleaning device, or the cooling may completely disappear. If necessary, during operation of the furnace, the cleaning device can be interlocked with it. In particular, it is thus possible to create a counter force to remove the metal growth from the mouth of the outlet channel.

If the cleaning and locking devices are made in the form of structurally independent from each other, mainly constantly located on the furnace devices, it is preferable to orient them in relation to each other so that their longitudinal middle axes enclose, basically, an angle of 90º. This arrangement avoids problems in the discharge of liquid metal from the furnace, in particular the collision of the locking device and / or cleaning device with another technical unit, for example a ladle, when the crucible rotates with the liquid metal inside it.

The objective of the invention is also solved by means of a cleaning device for the furnace according to one of paragraphs. 1-10, containing a gate with a moving tongue and a scraper located on the tongue, as well as an optical recording device for capturing images of the exhaust channel and / or its mouth. The cleaning device can be made in the form of a combined cleaning and locking device. Alternatively, the cleaning device is an additional device independent of the locking device. In particular, when using a locking device and a cleaning device structurally separate from it, a device can be provided to prevent collisions between the components of the locking device and the cleaning device. Determining the risk of collisions using a device to prevent them can be based, for example, on measuring the transit time of ultrasonic signals between potentially colliding components, in particular gates and / or their tongues, locking and cleaning devices. Due to the fact that the cleaning device contains an optical recording device for capturing images of the exhaust channel and / or its mouth, the control of the mouth and the exhaust channel can be carried out in a simple manner, which eliminates the danger to the health of staff. The optical recording device is located mainly on a moving slide tab. This can achieve the fact that the optical recording device can register images of the exhaust channel already during removal of the metal growth. Since its removal and control of the exhaust channel occur at least partially simultaneously, it is possible to further reduce the time spent on servicing the mouth of the exhaust channel or itself, which can further increase the productivity of the furnace.

Preferably, the cleaning device comprises an adjustment device for positioning and orienting the scraper with respect to the mouth of the outlet channel. Due to this, it is possible to guarantee the exact position and / or the exact orientation of the cleaning device relative to the mouth of the exhaust channel. This ensures the best possible removal of the metal growth and, if necessary, the best possible control of the exhaust channel. In particular, the adjusting device is made in the form of several, easily adjustable suspensions, for example eccentric suspensions or adjusting screws. Thus, for example, the housing, the gate and / or its tongue can be adjusted independently from each other or together in three spatial directions in position and orientation relative to the mouth of the outlet channel.

It is further preferred that the cleaning device comprises a cooling device. The latter is made mainly with the possibility of cooling as much as possible of all components of the cleaning device, in particular, however, the optical recording device. Due to this, it is possible to increase the service life of the components of the cleaning device and, thereby, the entire cleaning device.

In particular, it is preferable that the cleaning device comprises a device for creating an air stream at least partially flowing around the optical recording device. Due to this, on the one hand, it is possible to cool the optical recording device, and, on the other hand, it is possible to protect the optics or its field of view from contamination due to the fact that the air stream removes dirt particles.

Other advantages of the invention follow from examples of its implementation, schematically depicted in the accompanying drawings, which represent:

- FIG. 1: section of an electric arc furnace with a cleaning device in a closed state;

- FIG. 2: section of an electric arc furnace with a cleaning device in a partially open state;

- FIG. 3: a top view of the cleaning device in the closed state;

- FIG. 4: a top view of a cleaning device in a partially open state;

- FIG. 5: side view of a cleaning device in a partially open state;

- FIG. 6: a top view of the combined cleaning and locking device.

In FIG. 1 shows a vertical section of a schematic arc electric furnace 1. It contains an outlet channel 2 with a mouth 3. Channel 2 is formed by bricks 3 'with a hole. They are issued, or the mouth 3 is issued for under the furnace 1.

Behind the outlet channel 2 or its mouth 3, a locking device 4 is visible, by means of which the mouth 3 can be opened or closed. In FIG. 1, the mouth 3 is shown in the open state after the removal of liquid metal.

During the removal of liquid metal from the furnace at the mouth 3, metal contaminants are formed, as a rule. Such contamination is performed in FIG. 1 in the form of a growth M solidified from liquid metal. Before closing the mouth 3 again, this growth M should be removed.

For this, a cleaning device 5 'is located on the bottom of the furnace 1. Its longitudinal axis and the longitudinal axis of the locking device 4 enclose a substantially right angle in order to avoid damage to the cleaning device 5 'and / or the locking device 4 in the process of releasing and turning the crucible of the furnace.

The cleaning device 5 'comprises a wedge-shaped scraper 5 with a scraper edge 12. It is located on the tongue 8 of the gate 7. The tongue moves in the longitudinal direction of the cleaning device 5' by means of pneumatic cylinders (not shown). The gate 7 includes pneumatic cylinders and a tongue 8 with a scraper 5.

The gate 7 is located inside the housing 17, cooled by water. A cooling device 10 is provided for this. It includes a supply hole in the housing 17 for supplying cooling water to it and a drain hole in the housing for draining heated water from it.

The optical recording device of FIG. 1 and 2 are not shown for clarity, but are located on a moving tongue 8.

The housing 17 may include, instead of a cooling device 10, a thermally insulating device (not shown). It can be made, for example, in the form of a casting mass that protects against heat, which surrounds the housing at least in separate sections.

The housing 17 by means of the adjusting device 6 is connected to the hearth of the furnace 1. The adjusting device 6 allows you to adjust the housing 17 and, thus, the gate 7 with the tongue 8 and the scraper 5 in all spatial directions relative to the mouth 3. The adjusting device 6 is made in FIG. 1 in the form of several eccentric pendants. It can also be implemented in any other way.

In FIG. 2 depicts basically the same object as in FIG. 1. However, the object of FIG. 2 differs from the object in FIG. 1 in that the tongue 8 of the cleaning device 5 'is extended and used to remove the metal growth M at the mouth 3. For this, the tongue 8 is moved by pushing pneumatic cylinders (not shown) towards the mouth 3, as a result of which the scraper 5 on the tongue 8 removes the metal growth M with its scraper edge 12.

Due to the previous adjustment of the scraper edge 12 relative to the mouth 3, it is possible to remove the metal growth M directly on the mouth 3 and flush with the bricks 3 '.

The cleaning device 5 'comprises an optical recording device (not shown in FIGS. 1 and 2), made in the form of a video camera. With its help, images of the exhaust channel 1 are recorded, which are displayed. Using the images, the maintenance staff decides whether to take measures to bring the exhaust channel 2 in good condition. The control of the exhaust channel 2 can be carried out partially during scraping. As an alternative, the removal of the metal growth from the mouth 3 of the outlet channel 2 and the monitoring of the state of the outlet channel 2 are performed sequentially.

As soon as the service is completed, the tongue 8 is again discharged into the cooled case 17. Then, the mouth 3 is closed using the locking device 4. The exhaust channel 2 is filled at least in some areas, and liquid metal can again be loaded into the furnace 1, or liquid metal may melt again.

Figure 3 shows a top view of the cleaning device 5 'in the closed state. The cleaning device 5 'comprises a housing 17. It is made predominantly double-walled, so that coolant, mainly water, which cannot flow uncontrollably out of it, can circulate between the two walls. Figure 3 also shows a cooling device 10, 16, through which cooling water is supplied to and removed from the housing 17. The housing 17 covers the gate 7.

The gate 7 contains a tongue 8 and pneumatic cylinders 14. On the tongue 8 are an optical recording device 9, a leakage device 11 for cooling and preventing contamination of the optical recording device 9 and a scraper 5 with a scraper edge 12.

Advantageously, overpressure is supplied to the gate 7 by means of compressed air taken, for example, from the pneumatic lines for the pneumatic cylinders 14, as an alternative also supplied via a separate supply line. Excess pressure prevents the contamination of the gate 7. Also, due to the feed, the pistons (not shown) are cooled 14.

In addition, the overpressure in the gate 7 can be used, for example, by the leakage device 11 as an air flow former, which, on the one hand, cools the optical recording device 9, and, on the other hand, flows around it so that the pollution is mainly , do not interfere with the shooting of images, mainly digital images.

The data recorded by the optical recording device 9 via the information line 15 is output from the cleaning device 5 'by it, if necessary, after their processing on the display 18. For this, the tongue 8 contains in FIG. 3 a frame in which the information line 15 runs in separate sections. Display 18, which displays images based on the data recorded by device 9, can be displayed on the display 18 of the surveillance center and / or on the portable display 18. If necessary, images of the optical recording device 9 directly through the information line 15 can be displayed on a display connected directly to it.

The gas outlets on the cleaning device 5 'for the operation of the pushing pneumatic cylinders 14 in FIG. 1-6 are not shown.

The cleaning device 5 'further comprises an adjustment device 6, with which the cleaning device 5', in particular the scraper 5 with the scraper edge 12, can be adjusted relative to the mouth of the outlet channel. In particular, it is preferable that the adjusting device 6 allows the cleaning device 5 'to move around three axes independent of each other.

In FIG. 4 depicted in FIG. 3 in the closed state, the cleaning device 5 'is shown in the open state. This state of his is an example of the state in which maintenance, in particular control, of the exhaust channel of the furnace.

An optical recording device, made, for example, in the form of a video camera, is located outside the housing 17 of the cleaning device 5 'in such a way that its field of view covers the outlet channel or its mouth. The optical recording device 9 includes a protective housing (not shown). It is at least partially permeable to the radiation spectrum recorded by device 9. Advantageously, the protective housing has an inspection window through which the device 9 can look into the exhaust channel.

Depicted in FIG. 4, the leakage device 11 uses the internal space of the gate to create an air stream under overpressure. Due to the pressure difference between the inner space of the gate and the atmosphere, an air stream is generated that is directed through the leak-off device 11. This air stream is supplied to the optical recording device 9. It serves, on the one hand, for cooling, and, on the other hand, for cleaning or preventing contamination of image-relevant components of the cleaning device 5 '. The leakage device 11 divides the air flow into a first part, which is used to prevent contamination of the ray path, and a second part, which is used to cool the optical recording device 9.

Thus, due to one part of the air flow, pollution of the protective housing of the optical recording device is prevented due to the fact that the dirt particles are prevented from deposition, in particular long-term deposition, on the "viewing window" of the protective housing of the optical recording device 9. For this, the "viewing window" is continuously blown. To cool the optical recording device 9, part of the air flow is sent directly to the protective housing in which it is located.

In FIG. 5 is a side view of the cleaning device 5 ′ shown in a plan view of FIG. 4. This image is for clarity only and basically does not differ from the cleaning device 5 'in FIG. four.

In FIG. 6 is a top view of a 5 ″ combination cleaning and locking device. Therefore, no separate locking device is required, indicated for example in FIG. 1 and 2 poses 4. Cleaning and control, as well as opening and closing the mouth of the outlet channel, are carried out by means of the same device.

The combined cleaning and locking device 5 ″ differs from the cleaning devices 5 ’in FIG. 1-5 in that on the tongue 8 is an additional locking element 13.

In addition, the combined cleaning-locking device 5 ″ comprises means for integrated measuring of the path in the pushing cylinder 14. Due to the integrated measuring of the path, the tongue 8 can be purposefully moved to the scraping position, locking position or to the monitoring position.

In the scraping position, the mouth of the outlet can be cleaned. In particular, a buildup of solidified metal can be removed from the mouth. In the locking position of the combined cleaning-locking device, the mouth of the exhaust channel is closed by the locking element 13, and filling of the exhaust channel can be carried out. In the control position, images of the mouth of the outlet channel and / or the outlet channel itself can be recorded.

All the cleaning devices or combined cleaning and locking devices shown in the exemplary embodiments are usually located permanently on the furnace. They are practical and not prone to malfunction.

However, a cleaning device movable relative to the furnace may also be provided, for example, by means of a swing arm or transport device. Such a cleaning device is brought to the furnace only shortly before discharge and is positioned or fixed in such a way that by means of this mobile cleaning device it is possible to service the exhaust channel or its mouth. This provides, for example, the flexible use of a cleaning device in various furnaces.

Claims (9)

1. An electric arc furnace (1) containing an outlet channel (2) for removing liquid metal from an electric furnace (1), a locking device (4) for opening and closing the mouth (3) of the outlet channel (2) and a cleaning device (5, 5 ' , 5``) for removing metal deposited on the mouth (3) of the exhaust channel (2), characterized in that the cleaning device comprises an optical recording device (9) for capturing images of the exhaust channel (2) and / or its mouth (3) and contains an adjustment device (6), which is made for positioning and orientation of the cleaning device (5, 5 ', 5``) relative to the mouth (3) of the exhaust channel (2), as well as the gate (7) with the moving tongue (8), and at the end of the moving tongue (8) there is a scraper (5), at this optical recording device (9) is located on the moving tab (8). 2. The furnace according to claim 1, characterized in that the cleaning device (5, 5 ', 5' ') contains a wedge-shaped scraper (5) with a scraper edge (12). 3. The furnace according to claim 1 or 2, characterized in that the locking device (4) contains a cleaning device (5, 5 ', 5' '). 4. The furnace according to claim 1, characterized in that a cooling device (10) is provided for cooling the cleaning device (5, 5 ', 5' ') and / or the optical recording device (9). 5. The furnace according to claim 1, characterized in that a device (11) is provided for creating an air stream at least partially flowing around the optical recording device (9). 6. The furnace according to claim 1, characterized in that the cleaning device (5, 5 ') is made in the form of an independent and mobile unit. 7. A cleaning device (5, 5 ', 5' ') for an electric arc furnace (1) according to any one of claims 1 to 6, containing a gate (7) with a moving tongue (8), a scraper (5) located at the end of the moving tongue, adjusting device (6) for positioning and orienting the cleaning device relative to the mouth (3) of the exhaust channel (2) and an optical recording device (9) for capturing images of the exhaust channel (2) and / or its mouth (3), while optical a recording device (9) is located on a moving tongue (8). 8. The device according to claim 7, characterized in that it comprises a cooling device (10, 16), in particular, for cooling the optical recording device (9). 9. The device according to claim 7 or 8, characterized in that it comprises a device (11) for creating an air stream at least partially flowing around the optical recording device (9).

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