Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/0006—Details, accessories not peculiar to any of the following furnaces
  • C21D9/0018—Details, accessories not peculiar to any of the following furnaces for charging, discharging or manipulation of charge
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
  • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
  • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
  • F27B9/22—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace on rails, e.g. under the action of scrapers or pushers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B9/38—Arrangements of devices for charging
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
  • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
  • F27B9/39—Arrangements of devices for discharging
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/18—Door frames; Doors, lids, removable covers
  • F27D1/1858—Doors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/0024—Charging; Discharging; Manipulation of charge of metallic workpieces
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/02—Skids or tracks for heavy objects
  • F27D3/026—Skids or tracks for heavy objects transport or conveyor rolls for furnaces; roller rails
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/04—Ram or pusher apparatus

Definitions

• the object of the invention is a device for the threading and dehorning of billets or other elements, such as tubes or bars, in steel reheating furnaces by means of a revolving door.
• the curling and scraping of the billets that is, the loading and unloading of the billets in the steel reheating furnaces causes air inlets in the oven and, sometimes, this process is carried out using refrigerated equipment located in the oven and causing significant thermal losses that are very detrimental to the heating quality, as well as the total oven performance.
• the air inlets caused by the door openings can also disturb the operation of the burners, in particular by increasing the amount of pollutants in the oven, such as nitrogen oxides, NOx.
• the air inlets caused by the opening of the scrapping door can also increase the amount of scale produced in the oven.
• a second object of the invention is the method that solves the problem described. More specifically, the device object of the invention comprises a revolving door, with a cylindrical profile and adjusted so that it completely separates the interior from the outside of the oven.
• the door comprises a clipped angular sector, where the billet is deposited for its introduction and removal, in such a way that the transfer of the billet between the exterior and the interior of the oven is allowed by the simple rotation of the door.
• the device is completed with a transfer element, which is the only element necessary to move the billet between the feed roller path and the revolving door, as well as between the revolving door and the stringers that are placed inside the oven. That is, the transfer element is responsible and responsible for the movement of loading and unloading between the exterior and the interior of the oven.
• the method object of the invention comprises the transfer of the billet from the outside to the inside of the oven by two simple mechanical movements: a first 90 ° rotation of the revolving door and the linear movement of the element of transfer, so that in these movements the interior and exterior of the oven are completely separated from each other.
• a separation between the inside and outside of the oven is optimized, due precisely to the presence of the revolving door, which reduces the variation of pressures inside and the cold air inlets, saving energy, reducing pollutant emissions (NOx) and reducing heating or surface condition defects that may occur in the product.
• NOx pollutant emissions
• the loading and unloading of high-weight billets is possible; also avoiding sudden movements of the billets, which can affect the loading system.
• FIG. 1 shows a longitudinal section of the furnace illustrating the frontal winding process according to the state of the art.
• FIG. 2 shows a longitudinal section of the furnace illustrating the lateral winding process according to the state of the art.
• FIG. 3 shows a longitudinal section of the furnace, illustrating the lateral winding process according to the state of the art.
• FIG. 4 shows a longitudinal section of the billet reheating furnace equipped with the device of the invention.
• FIG. 5 shows the first sequence of the billet threading in the oven of Figure 4.
• FIG. 6 shows the bilge operation of the billet in the oven of FIG. 4.
• FIG. 7 shows an inlet sequence of the billet in the oven of FIG. 4.
• FIG. 8 shows the oven of FIG. 4 in the billet discharge position.
• FIG. 9 shows a second view of what is indicated in FIG. 8.
• FIG. 10 shows an embodiment of the invention including a translation machine.
• the threading and dehorning of the billets (or of the bars or tubes, if applicable) in a steel furnace is carried out frontally or laterally.
• Figure 1 represents the principle of frontal winding according to the state of the art, while Figures 2 and 3 show the principle of lateral winding.
• Figures 2 and 3 show the principle of lateral winding.
• said embodiments present a series of problems that are solved by the present invention.
• Figure 1 represents a longitudinal section of the furnace (4) composed of a plurality of walls that form an internal enclosure, in which a plurality of stringers (1) supporting the bed of products (2) to be transferred are housed. from the oven inlet (4) to the outlet to ensure overheating to the desired temperature.
• the billet (6) to be enhorn is carried in front of the furnace (4) by means of a roller path (9) that rotate on some pallets (10) moved by motor-reducers (1 1).
• the billet (6) is transferred from the roller path (9) to the rails (1) of the oven by fingers (7) of a pusher, which moves the product from the rollers (9) to the sliders (8) and, on them, towards the stringers (1) to bring the product to the marked position (3).
• the front door (5) of the oven (4) must remain open throughout the width of the oven, which causes a significant variation in the pressure of the internal atmosphere of the oven and constitutes a passage of outside air, which pollutes the atmosphere inside the oven, reducing its temperature inside and, consequently, its overall performance.
• FIG. 2 shows the principle of lateral bilgeing of the billets in an overheating oven.
• the winding door (12) is located on one side of the oven and is smaller in size than the door (5) of a front-loading oven, since it corresponds to the billet section, while the front door (5) corresponds to the length of the billet.
• rollers (9) are located inside the oven (4) and mounted on bearings (10) located outside as well as the motorization (1 1).
• the rollers (9) ensure the transfer of the billet from the outside of the oven to the inside thereof, since the billet is pushed from the roller path (9) onto the stringers (11) by the fingers (7) of a pusher which brings the billet (6) to the loading position, as shown in figure 2.
• the maneuver for front dehorning shown in Figure 1 is identical to the described, that is, the pushing machine comprising the fingers (7) performs a rectangular movement that can collect the product from the stringers (1) of the oven through the opening of the front door (5) and deposit it in the path of rollers (9) that will carry out the evacuation of the billet (6) to the laminator of the later stage in the steel process.
• the devices represented for the removal of the billets have the same type of disadvantages as the enhorizaje, that is to say, the presence of refrigerated mechanical elements that reduce the energy efficiency of the furnace, or the existence of scrap doors that are important entrances to air that reduce the efficiency of the oven and cause additional oxidation in the products, which increases the loss of the material and can cause defects in the finished products during subsequent lamination.
• the drawbacks of the prior art solutions are more critical in that the temperature level inside the oven is much larger than in the sanding and the immediate impact on the product and its quality is greater, since It can cause local cooling in products that will cause problems during subsequent lamination.
• both the oven chamber (4), the stringers (1) supporting the products (2), a roller path (9) for transporting the billet (6) to be screwed in front of the oven are appreciated and on the outside thereof a thrusting pusher provided with a plurality of fingers (7).
• This oven is provided with a revolving door (14) that rotates with respect to an axis (15), which is refrigerated.
• the revolving door (14) is of cylindrical section, with an angular sector (16) cut a certain angle and configured for the introduction of the billet (6) to be screwed. That is, the angular sector (16) is aligned horizontally with the rollers (9) on one of its sides (16a), while the other side (16b) opposite the first, is configured to act as a stop in the introduction of the billets (6).
• the angular sector (16) is approximately 90 °.
• Figure 5 shows the first sequence of the billet threading (6), where the fingers (7) of the pusher move the billet (6) from the roller path (9), on the sliders (13) of the door rotating (14) until it stops with the angular sector (16) trimmed in the door (14) as described.
• Figure 6 shows the bilge threading operation.
• the revolving door (14) has rotated around its axis (15), for example, by the action of one or more hydraulic cylinders not shown in the figure.
• the billet is placed in the interior or chamber of the oven (4), on a slide aligned vertically with the upper plane of the stringers (1) of the oven.
• Figure 7 shows the fingers (7) of the pusher, which, through openings in the revolving door (14), have moved the billet (6) from the sliding door slides (14) to the stringers (1) of the oven, until reaching the maximum position defined by the stroke of the fingers themselves (7), depending on the dimensions of the billet (6) and the desired load of the oven (4). After retraction of the fingers (7), the revolving door (14) returns to the position shown in Figure 4.
• the cylindrical shape of the door (14) is such that it fits perfectly to the oven walls (4), in order to ensure a good air and smoke tightness to perfectly separate the inner atmosphere from the outside of the oven (4) .
• This tightness can be improved, if necessary, with the addition of gaskets or scrapers, for example, manufactured in fibrous type refractory whose flexibility allows to compensate for any possible play between the oven walls and the revolving door (14) in the open or closed position, or during the movement of the door. It is also observed in Figures 4 to 7 that, during periods where the door is locked in loading or unloading position, the tightness of the door is ensured by the coincidence of the external shape of the door (14) with that of the doors. oven walls (4), which can be completed with sealing gaskets.
• Figures 8 and 9 show the door (14) in the discharge position of the billet in the oven (4). As in the cases of figures 4 to 7, it can be seen how the correspondence between the external shape of the door (14) and that of the oven wall (4) ensures the tightness. To further reduce gas leakage, the openings through which the fingers (7) of the pusher pass through the revolving door (14) will be adjusted to the maximum, such that between the fingers (7) and the openings not there is slack, that is, this is the minimum necessary to allow the passage of the fingers (7).
• the transfer of the billet (6) from the outside of the oven (4) to the inside is guaranteed by two simple mechanical movements: the 90 ° rotation of the revolving door (14) and the linear movement of the fingers (7) of the pusher
• the pusher technology is well known to a person skilled in the art, the linear movement of the fingers being obtained hydraulically by means of one or more cylinders, or mechanically, by means of a motor.
• the revolving door (14) can be mounted on two bearings located at the ends or have intermediate support bearings for large doors. It should be mentioned that there is no mechanical equipment that is permanently inside the oven, so that it is not subject to failures created by the high temperature operating conditions. In fact, in the closed position, the door (14) does not expose to the hot atmosphere of the furnace anything other than a surface coated with refractory concrete, which is less sensitive than mechanical equipment such as, for example, the refrigerated rollers described in the state of the art It is clear from the description that the device allows to unscrew a billet in a reheating furnace, significantly reducing heat losses that can occur due to the entry of outside air into the oven or the presence of refrigerated elements inside. The oven's energy balance improves, and the amount of contaminants is reduced.
• Figure 8 shows the stripping sequence according to the invention.
• the last of the products (3) in a first position (6) is transferred by the stringers (1) of the oven (4) to the revolving door (14) in a second position (6 ').
• the product to be undone is in a third position (6 ").
• the arms of the transfer machine belong to the state of the art known to a person skilled in the art, for example with a linear movement of the fingers (17) caused by a gear motor geared with a rack through a pinion, where said rack is jointly attached to a finger (17), and where the lifting movement is controlled by one or more hydraulic cylinders.
• Figure 10 shows a variant of the invention that includes a finger translation machine (17).
• the figure shows how the last billet (6) located on the stringers (1) of the oven (4) is raised by the fingers (17) of the translation machine that moves them by means of a substantially rectangular cycle on the revolving door (14).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Tunnel Furnaces (AREA)
• Heat Treatments In General, Especially Conveying And Cooling (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

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ID=49231798

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Cited By (2)

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Citations (5)

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• 2013
  • 2013-06-12 ES ES201330873A patent/ES2425304B2/es active Active
• 2014
  • 2014-05-14 EP EP14810703.0A patent/EP3009778A4/de not_active Withdrawn
  • 2014-05-14 WO PCT/ES2014/070399 patent/WO2014198977A1/es active Application Filing

Patent Citations (5)

Non-Patent Citations (1)

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