EP0236666A2 - Process for reheating semiproducts from continuous-casting installations or from shaping installations for their introduction into shaping and/or finishing installations - Google Patents

Abstract

Semi-products which have been concast or worked are fed into a heat retaining chamber (9) where groups of semi-products constantly pass by other groups such that heat transfer can take place by radiation, convection and/or direct contact.

Description

The invention relates to a working method for heating semi-finished products cast in continuous casting devices or formed in forming devices for their introduction into forming and / or further processing devices.

Various working methods and devices are known in which semi-finished products, which are transported in the direction of their longitudinal axis or transversely to this, are first fed to a warehouse and from this, according to the needs of the downstream processing device, introduced into heating ovens, heated to the processing temperature and then the corresponding further processing device are supplied. For example, the continuous casting heat of the semi-finished product coming from a continuous casting device is used for further processing. In a known arrangement, this takes place by means of a forming system (semi-finished product line) connected upstream of the further processing device, in such a way that the semi-finished product is not cooled to storage temperature, but rather is fed to the heating furnace of the rolling mill or to a post-heating device arranged in front of it. Since the semifinished product is continuously delivered in paragraphs by the continuous casting device at a fixed speed that does not consistently match the processing speeds and processing times of the downstream forming or Corresponding further processing devices, buffer stores are arranged between the continuous casting device and these or associated heating furnaces, with which the differences in capacity based on the differences in the spreading and further processing speeds are compensated (DE-OS 27 23 626). It is also known to utilize the continuous casting heat of the semi-finished products in such a way that already cooled and still warm semi-finished products are introduced into one and the same heating furnace, resulting in a reduction in the heating-up time to the desired processing temperature, or the warm introduced semi-finished products are shorter Warm oven linger than the cold ones.

This dependent linking of the parts of the overall system connected between the continuous casting device and the further processing device, such as the shaping device, the reheating unit and the buffer store, complicates their adaptation to one another. In practical operation, for example, cold batches often have to be introduced from the warehouse, and the semi-finished products supplied to the forming device (rolling mill) cannot then be removed in the intended number because of necessary batch-related dimensional changes or because of a malfunction. It is also not possible to select different dimensions or qualities within such a batch. Tracking the processing of batches that differ in size or quality requires complex program planning and control of the steelworks themselves, the continuous casting equipment and the downstream processing equipment. Despite such an effort, the overall system is not very flexible if different dimensions and / or qualities are to be produced in more or less large numbers. Another disadvantage is that the individual parts of the Do not allow the entire system to be operated independently of one another in time, but must be operated together, so that considerable idle times are inevitable in some cases. Warehousing itself also requires considerable organizational effort.

Studies have shown that e.g. in a fine steel rolling mill with a conventional rolling program, the use of known working methods with the facilities mentioned enables a more or less direct use of semi-finished products that are warm from casting only 20 to 30% of the total output of the rolling mill.

In addition to these difficulties and disadvantages that result from the use of the known working methods, there is also the need for the semi-finished products to be inspected and, if necessary, cleaned in the course of their processing, rather than in the cooled state on the way to or from the warehouse.

The invention has for its object to improve the generic working methods and the associated systems and devices so that the disadvantages mentioned are eliminated and the difficulties are avoided. This object is achieved in that when casting or during the forming or heating up of one or more groups of semi-finished products, heat introduced into them during the intermediate transport of the semi-finished product groups and / or their storage is transferred to other semi-finished product groups by heat transfer contact. The heat transfer can be effected by radiation, convection and / or direct contact. The heat transfer contact from one or more groups of semi-finished products to the others can be effected during the transport movement of at least one of these groups of semi-finished products, the arrangement can be made so that the cold semi-finished length groups are above the warm ones; If the two semi-finished length groups carry out a transport movement, the heat transfer contact can be brought about in opposite transport movements of the semi-finished product length groups. However, there is also the possibility of moving the semi-finished length groups in the same direction during the heat transfer contact. Further possibilities of the heat transfer contact of both groups of semi-finished products consist in the fact that the transport movements of the groups run transversely to one another. In special cases, the heat transfer contact can also be effected when at least one of the semifinished length groups rests on other semifinished length groups. As the invention further provides, at least one of the semi-finished length groups can be kept at a distance from other semi-finished length groups during the heat transfer contact. The distance between opposing surfaces of the heat-emitting and the heat-absorbing semi-finished length groups can possibly be only a few mm. The semifinished products of at least one of the semifinished product length groups can be rotated about their longitudinal axis before, after or during the transport movement and / or during the thermal contact transmission. As the invention provides, the heat transfer contact can be effected at different speeds of the transport movement of the groups of semi-finished products, and it is further possible that certain groups of semi-finished products are not moved in the process. According to the invention, transport movements of the semi-finished product length groups in a plurality of adjacent transport direction trains and / or in transport planes lying one above the other are advantageous. The transport movements of the heat-absorbing or the heat-emitting semi-finished length groups can advantageously on both sides of the transport movements run towards the heat-emitting or the heat-absorbing semi-finished length groups. As the invention further provides, the non-moving semifinished length groups can form the inventory of intermediate bearings arranged between a continuous casting device and a forming device or between forming devices. The heat transfer contact between the various semifinished product length groups is expediently carried out in a heat insulation chamber surrounding them. In such a thermal insulation chamber, heat-emitting semi-finished length groups can be introduced, which have been introduced from the continuous casting device and / or from one or more forming devices or intermediate stores. The thermal insulation chamber can expediently be equipped with air movement and air guiding devices and, if necessary, with additional heating devices. If the operating conditions so require, several thermal insulation chambers can be arranged one behind the other and / or parallel to one another. The semi-finished product length groups can also perform a rotational movement in at least one of the levels during the heat transfer contact lying in two or more superimposed planes in relation to the semi-finished product length groups in the adjacent planes. The invention also makes it possible to heat the semifinished products used in the shaping system by means of shaping products produced therein.

Devices for carrying out these working methods can consist of two or more support grids arranged next to and / or one above the other and / or pushing, pushing, turning or carrying transport elements, each of which can be driven independently of one another or partially together.

The working method according to the invention brings with it the possibility of completely unlocking the flow of the semi-finished product length groups between the various casting, forming, heating, storage and other further processing devices and thus directing and controlling this flow in accordance with the particular circumstances and requirements that, in addition to the continuity of the flow, there is an optimal utilization of the heat introduced or of the heat newly introduced during the forming and / or heating process. For example, the continuity of the supply of semifinished length groups coming from the continuous casting device to a forming device (rolling mill) can be achieved by heat transfer from this semifinished length group to intermediate, cooled or still warm other semifinished length groups during transport or even when the machine is at a standstill, if necessary using a reheating unit upstream of the forming device. With the appropriate arrangement and design of the systems, this results in e.g. the possibility of supplying semifinished length groups coming from a continuous casting device to the desired processing temperature without stopping, brought directly to the forming device.

Depending on the arrangement and design of the overall system, in these heat transfer processes it is also possible to use groups of semi-finished products or even finished material for heat transfer between the other subordinate or independent shaping devices, which are capable of releasing heat or which also require warming up, e.g. using transverse in accordance with the invention to each other, possibly in different superposed transport tracks.

With the correct design of the working method according to the invention, changes in the respective processing program have just as little effect on the material flow as changes in speed or malfunctions in the further processing system. Lot sizes can be selected and followed up regardless of the size of the batch, the flexibility achieved for the overall system permitting this with relatively simple program planning.

Since the semi-finished products can also be slowly cooled and also slowly heated by the workflow achieved according to the invention, if desired, there are particular advantages in the treatment of stainless steels. The inspection and cleaning work can be carried out on the cooled semi-finished products outside the material flow. The working method according to the invention enables a warm use of the semi-finished products that is considerably higher than the 30% that can be achieved so far.

• Fig. l eine Anlage zur Durchführung des Arbeitsverfah­rens in schematischer Darstellung von oben gesehen,
• Fig. 2 eine andere Ausbildungsform der Anlage nach Fig. l,
• Fig. 3 eine Aufheizeinrichtung mit Tragrosten im Schnitt von der Seite gesehen
• Fig. 4 einen Schnitt nach der Linie A-A durch Fig. 3,
• Fig. 5 eine andere Ausbildungsform der Aufheizeinrich­tung im Schnitt von oben gesehen
• Fig. 6 einen Schnitt nach der Linie B-B durch Fig. 5,
• Fig. 7 eine andere Ausbildungsform der Einrichtung im Schnitt quer zur Transportrichtung.

The invention is explained in more detail using the exemplary embodiments shown in the drawing. Show in the drawing

• 1 shows a plant for carrying out the working process in a schematic representation seen from above,
• 2 shows another embodiment of the system according to FIG. 1,
• Fig. 3 seen a heating device with grids in section from the side
• 4 shows a section along the line AA through FIG. 3,
• Fig. 5 seen another embodiment of the heating device in section from above
• 6 shows a section along the line BB through FIG. 5,
• Fig. 7 shows another embodiment of the device in section transverse to the direction of transport.

As can be seen from Fig. L, the coming from the (not shown) continuous casting St semi-finished lengths in the transport direction one behind the other by means of a roller table R₁ the thermal insulation chamber WK₁ and in this by transverse transport in heat transfer contact with the bearing L₂ coming via a roller table R₃ semi-finished length groups brought and then fed via a roller table R₂ to a warehouse L₁, while the semi-finished length groups heated by this process, as mentioned coming from the warehouse L₂, are fed via a roller table R₄ to a reheating device NW₁, in which the processing temperature is adjusted to the downstream forming device HW (semi-finished rolling mill). are fed. The formed (rolled) lengths of semi-finished products then pass through a roller table R₅ into the thermal insulation chamber WK₂ or via a roller table R₉ into the thermal insulation chamber WK₃. The semi-finished product length groups that entered the thermal insulation chamber WK₂ are brought into heat transfer contact by transverse transport with the semi-finished product length groups coming from the warehouse L₄ via a roller table R₈ and then fed via a roller table R₇ to a warehouse L₃, while the semi-finished product lengths coming from the warehouse L₄ are heated by this process -Groups are fed via the roller table R₆ a pre-heating unit NW₂ upstream of the finishing mill FW₁. In the thermal insulation chamber WK₂ the process runs as in the heat already described insulation chambers WK₁ and WK₂ from. The introduced through the roller table R₉ in the thermal insulation chamber WK₃ semi-finished length groups coming from the warehouse L₆ and brought over the roller table R₁₂ into the thermal insulation chamber semi-finished length groups, which are then fed via the roller table R₁₁ to the finishing mill FW₂ assigned reheating unit NW₃.

Fig. 2 shows an arrangement in which the waste heat of the semi-finished product groups to be cooled is used to preheat the semi-finished product groups to be introduced into the heating furnace. These are fed via a roller table R₁₄ to a thermal insulation chamber WK₄, brought into heat transfer contact by transverse transport with groups of semi-finished products coming from the warehouse L₇ via a roller table R₁₃ and then fed to the warehouse L₈ via a roller table R₁₆, while the heated semi-finished products coming from the warehouse L₇ Groups are fed via a roller table R₁₅ a heating furnace WO.

As can be seen from Fig. 3, two grids lying one above the other take up the positions of the semi-finished lengths. The support grid below, intended for the warm semi-finished lengths HW coming from the continuous casting device (not shown), has grate bars 1 which are arranged at a distance DK from one another, while the overlying grate which receives the semi-finished lengths HK coming from the store only has one here Has a pair of grate beams 2, which rest at a distance DG on the support beam 4 connected to the foundation 3. The lower support grid with the grate bars l is assigned a roller table R 1, which transports the (see FIG. 1) semi-finished lengths HW coming from the continuous casting device ST in the direction of their longitudinal axis. These are then in the direction of arrow P1 by means of the impact beams 6 on the grate beams l postponed and transported in the direction of the second roller table R₂, which feeds the semi-finished lengths HW to a warehouse. At the same time, cold or still warm semi-finished lengths HK are removed from the warehouse and transported over the roller table R₃, which is assigned to the support beam 2 of the upper support grate, and pushed onto this support grate by means of the bumper beam 7 and transported further in the direction of the roller table R₄, which is the semi-finished lengths HK one Processing plant feeds. The hot semifinished product lengths HW on the lower support grate with the grate bars l heat the semifinished product lengths HK that are transported in opposite directions on the grate bars 2 of the upper support grate in the direction of arrow P2 before they are fed to the processing system or a heating furnace. Both support grids are enclosed by a thermal insulation chamber 9. The considerably larger distance DG of the pair of grate beams 2 of the upper support grate is dimensioned such that it leads to a permissible sagging of the overlying semi-finished lengths, but thereby ensures uniform heating of the individual semi-finished lengths HK over their length.

5 and 6, the arrangement is such that the warm semifinished product lengths HW coming from the continuous casting device are carried by the rollers R of a roller table and are transported through the thermal insulation chamber 9 in the direction of the arrows P1 (FIG. 5), while the semi-finished lengths HK coming from the warehouse are carried by an independently driven roller table (not shown) in the direction of arrows P2 in the opposite direction and in each case lying between two warm semi-finished lengths HW and are heated from both sides by the warm semi-finished lengths HW through heat transfer contact. Assign the semi-finished lengths to be treated HW and HK rectangular cross-sections, then they are expediently transported standing and, as can be seen from FIG. 7, held by guide rollers FR arranged above the roller table with the rollers R. There is also the possibility, not shown, of arranging two or more roller tables one above the other, with the transport of the semi-finished lengths either in the manner shown in FIGS. 5 to 7 or in such a way that the semi-finished lengths HW on one roller table and on one above it arranged roller table the semi-finished lengths HK, are expediently transported in opposite directions.

It is also possible to arrange two of the devices described one behind the other in the transport direction, wherein the semi-finished lengths can be turned after they have left the first device in order to achieve a more uniform heating. Several systems can also be arranged side by side in parallel in order to achieve shorter transport lengths.

In the case of large quality lots, such as bulk steel, which do not require an inspection, the hot semi-finished product lengths coming from the continuous casting device can, if necessary, be fed directly to the further processing plant, here the finishing mill, in such a way that the described devices work in circulation in order to compensate for the differences between the Compensate the discharge capacity of the continuous caster and the acceptance capacity of the processing plant.

Claims (24)

1. Working method for heating semifinished products cast in continuous casting devices or formed in forming devices for their introduction into forming and / or further processing devices
characterized,
that the heat introduced during casting or during the forming or heating up of one or more groups of semi-finished products is transferred to other groups of semi-finished products by heat transfer contact during the intermediate transport of the semi-finished product groups and / or their storage. 2. Working method according to claim 1,
characterized,
that the heat transfer is effected by radiation, convection and / or direct contact. 3. Working method according to claims 1 and 2,
characterized,
that the heat transfer contact is effected from one or more groups of semi-finished products to the others during the transport movement of at least one of the groups of semi-finished products. 4. Working method according to one or more of claims 1 to 3,
characterized,
that the cold semi-finished length groups are above the warm ones. 5. Working method according to one or more of claims 1 to 4 with transport movement of both groups of semi-finished products,
characterized,
that the heat transfer contact is effected in opposite transport movements of the semi-finished length groups. 6. Working method according to one or more of claims 1 to 4,
characterized,
that the heat transfer contact is effected in the same direction during transport movement in the semifinished product groups. 7. Working method according to one or more of claims 1 to 4,
characterized,
that the transport movements of the semi-finished length groups are transverse to each other. 8. Working method according to one or more of claims 1 to 7,
characterized,
that the heat transfer contact is effected when at least one of the semifinished length groups rests on other semifinished length groups. 9. Working method according to one or more of claims 1 to 7,
characterized,
that at least one of the semifinished length groups is kept at a distance from other semifinished length groups during the thermal contact transfer. l0. Working method according to claim 9,
characterized,
that the distance between opposing surfaces of heat-emitting and heat-absorbing semi-finished length groups is only a few mm. 11. Working method according to one or more of claims l to l0,
characterized,
that the semifinished products of at least one of the semifinished product groups are rotated about their longitudinal axis before, after or during the transport movement and / or the heat contact transmission. 12. Working method according to one or more of claims 1 to 11,
characterized,
that the heat transfer contact is effected at different speeds of the transport movements of the semi-finished length groups. 13. Working method according to claim l2,
marked by
groups of semi-finished lengths not moved during the heat transfer contact. 14. Working method according to one or more of claims l to l3,
characterized,
that the transport movements of the semi-finished product length groups run in a plurality of transport direction trains running side by side and / or in transport planes lying one above the other. 15. Working method according to claim 14,
characterized,
that the transport movements of the heat-absorbing or heat-emitting semi-finished length groups run on both sides of the transport movements of the heat-emitting or heat-absorbing semi-finished length groups. 16. Working method according to claim l3,
characterized,
that non-moving semifinished length groups form the inventory of intermediate bearings arranged between a continuous casting device and forming devices or between forming devices. 17. Working method according to one or more of claims l to l6,
characterized,
that the heat transfer contact between the semifinished length groups takes place in a thermal insulation chamber (9) enclosing them. 18. Working method according to claim l7,
characterized,
that heat-releasing semi-finished length groups can be introduced into the thermal insulation chamber (9) which have been introduced from a continuous casting device and / or from one or more shaping devices or intermediate stores. 19. Working method according to one or more of claims l to l8,
characterized,
that the semi-finished products used in the forming plant heat the formed products produced in it. 20. Working method according to one or more of claims l to l9,
characterized,
that the semifinished length groups, during the heat transfer contact, lie in two or more superposed planes in at least one of the planes and perform a rotational movement relative to the semifinished products in the adjacent planes. 2l. Thermal insulation chamber for carrying out the working method according to one or more of claims l to l9,
marked by
in the thermal insulation chamber (9) arranged ventilation and air guiding devices. 22. Thermal insulation chamber according to claim 20,
marked by
Additional heaters. 23. Device for carrying out the working method according to one or more of claims 1 to l9,
marked by
two or more support grids arranged next to and / or one above the other and / or pushing, pulling, turning or carrying transport elements for the semi-finished products, each of which can be driven independently of one another or partially together. 24. The device according to claim 23,
characterized,
that the distances DG of the support elements (grating beams) of the support grid or gratings above are greater than the distances (DK) of the support elements of the lower support grate.

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