EP4316691A2 - Apparatus and process for producing metal bars through continuous casting - Google Patents
Apparatus and process for producing metal bars through continuous casting Download PDFInfo
- Publication number
- EP4316691A2 EP4316691A2 EP23208638.9A EP23208638A EP4316691A2 EP 4316691 A2 EP4316691 A2 EP 4316691A2 EP 23208638 A EP23208638 A EP 23208638A EP 4316691 A2 EP4316691 A2 EP 4316691A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- casting
- stretch
- die halves
- lower die
- nozzles
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002184 metal Substances 0.000 title claims abstract description 114
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 114
- 238000009749 continuous casting Methods 0.000 title claims abstract description 74
- 238000000034 method Methods 0.000 title claims description 8
- 230000008569 process Effects 0.000 title claims description 8
- 238000005266 casting Methods 0.000 claims abstract description 296
- 230000008859 change Effects 0.000 claims abstract description 66
- 238000001816 cooling Methods 0.000 claims abstract description 36
- 239000000112 cooling gas Substances 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- 238000004140 cleaning Methods 0.000 claims description 15
- 239000007788 liquid Substances 0.000 claims description 15
- 238000011144 upstream manufacturing Methods 0.000 claims description 11
- 239000007769 metal material Substances 0.000 claims description 7
- 229910045601 alloy Inorganic materials 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 6
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 239000004411 aluminium Substances 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 6
- 239000007789 gas Substances 0.000 claims description 4
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 3
- 239000000110 cooling liquid Substances 0.000 claims description 2
- 238000011010 flushing procedure Methods 0.000 claims description 2
- 238000005520 cutting process Methods 0.000 description 41
- 238000005096 rolling process Methods 0.000 description 21
- 238000010008 shearing Methods 0.000 description 20
- 238000003825 pressing Methods 0.000 description 18
- 230000000284 resting effect Effects 0.000 description 14
- 238000005406 washing Methods 0.000 description 10
- 238000012423 maintenance Methods 0.000 description 7
- 230000002829 reductive effect Effects 0.000 description 6
- 230000014509 gene expression Effects 0.000 description 4
- 229910001338 liquidmetal Inorganic materials 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- -1 ferrous metals Chemical class 0.000 description 3
- 229910001092 metal group alloy Inorganic materials 0.000 description 3
- 230000035939 shock Effects 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000000670 limiting effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000011179 visual inspection Methods 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- 101150106709 ARC1 gene Proteins 0.000 description 1
- 101150046212 ARC2 gene Proteins 0.000 description 1
- 101100013575 Arabidopsis thaliana FTSHI1 gene Proteins 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0602—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by a casting wheel and belt, e.g. Properzi-process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
- B22D11/003—Aluminium alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0605—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two belts, e.g. Hazelett-process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0608—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by caterpillars
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0631—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by a travelling straight surface, e.g. through-like moulds, a belt
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0637—Accessories therefor
- B22D11/0677—Accessories therefor for guiding, supporting or tensioning the casting belts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0637—Accessories therefor
- B22D11/068—Accessories therefor for cooling the cast product during its passage through the mould surfaces
- B22D11/0685—Accessories therefor for cooling the cast product during its passage through the mould surfaces by cooling the casting belts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0637—Accessories therefor
- B22D11/068—Accessories therefor for cooling the cast product during its passage through the mould surfaces
- B22D11/0688—Accessories therefor for cooling the cast product during its passage through the mould surfaces by cooling the caterpillars
Definitions
- the present invention relates to an apparatus and a process for producing metal bars through continuous casting, particularly suitable for producing bars of aluminium and alloys thereof and other non-ferrous metals.
- Machines for producing bars of non-ferrous metals through continuous casting in which the casting die is formed by a chain of lower die halves closed at the top by a metal belt are currently known.
- the closure belt undergoes considerable mechanical stresses, in particular to fatigue, since the rollers on which it slides have a small diameter.
- the casting channel In the zone closest to the crucible, the casting channel is closed with poor tightness, which causes leakages of molten metal between the lower die halves 4 and the die-closing belt 3.
- the problems of tightness between the belt 3 and the lower die halves 4 also occur in the central stretches of the casting channel.
- Another object of the present invention is to provide an apparatus for producing metal bars through continuous casting, the die-closing belt of which is less stressed and subject to wear and failures.
- one or more first nozzles (14) can possibly have the features according to claim 14 or 15; yet in that case such apparatus 10 can possibly be provided with one or more second nozzles (43) having the features according to claim 15.
- the apparatus for producing metal bars through continuous casting comprises a belt-pressing system (21) configured for pressing the die-closing belt (9) against the open flanks of the lower die halves (3) at least in correspondence with at least part of the casting stretch (13) and comprising at least a first direction change support (23) located at or near the casting zone (11) and configured for resting against the die-closing belt (9) and to guide it along the first direction change stretch so that at the exit from the latter it advances in a direction different from that in which it enters the first direction change stretch, wherein the points of rest of the die-closing belt (9) against the first direction change support lie substantially along a resting surface having an average radius of curvature (RC 1 , RC 2 ) equal to or greater than 0.5 metres and which is substantially tangent to the path followed by the die-closing belt (9) along the casting stretch (13).
- a belt-pressing system (21) configured for pressing the die-closing belt (9) against the open flanks of the lower die halves (3) at least in
- the first direction change support (23) comprises a pulley, wheel or roller which are configured to rest against the die-closing belt (9) during normal operation of the continuous casting apparatus (10) and having a diameter of one meter or more.
- the apparatus (10) comprises a second direction change support (25) for deviating the die-closing belt (9) in a second stretch of its path, wherein the second direction change support (25) may comprise, for example, a pulley, wheel or roller.
- the die-closing belt (9) is configured for advancing by travelling along the second roller conveyor stretch (TR 2 ) after having travelled the first roller conveyor stretch (TR 1 ).
- the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave can possibly extend for a length equal to or greater than half the overall length of the casting stretch (13); in this case the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave can possibly extend for a length equal to or greater than three quarters, four fifths, nine tenths of the overall length of the casting stretch (13) or it can extend over the entire overall length of the casting stretch (13).
- the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave extends for a length equal to or greater than 5 metres, or equal to or greater than 6 metres, 7 metres, 8 metres, 9 metres; in this case, the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave may extend for a length equal to or lower than 15 metres, or 12 metres, 10 metres, 8 metres.
- one or more of the first nozzles (41) is/are configured for striking with a jet of air or other cooling and/or cleaning gas the die halves (3) at least at a first part of the casting stretch (13) at or near the casting zone (11).
- one or more of the second nozzles (43) is/are configured for strike with a jet of water or other cooling and/or cleaning liquid the die halves (3) and/or the die-closing belt (9) at least at a second part of the casting stretch (13) downstream of the first part of the stretch of the casting channel (13) .
- the apparatus (10) comprises one or more third nozzles (45), each of which is configured for striking with a jet of water or other cooling and/or washing liquid a part of the lower die halves (3) at the return stretch.
- this object is achieved with a process having the features according to claim 12.
- Figures 1-7 , 8 relate to an apparatus for producing metal bars through continuous casting according to a first particular embodiment of the invention, indicated with the overall reference 10.
- top, bottom, above, below, horizontal, vertical when not otherwise specified refer to a condition of normal installation and operation of the casting apparatus 10.
- the continuous casting apparatus 10 can be configured for casting bars of non-ferrous metals, such as aluminium and alloys thereof, the cross-sections of which have a height ranging, for example, between 10-100 millimetres, and a width ranging, for example, between 10-250 millimetres.
- the apparatus 10 comprises a continuous casting die 1 in turn comprising a plurality of lower die halves 3 arranged in succession the one after the other and an upper closure system 5.
- Each lower die half 3 forms the bottom 70 and the flanks 71 of a casting channel stretch 7, is open on the flank opposite to the side of the bottom of the respective casting channel stretch 7 and at the ends adjacent to the die halves 3 immediately preceding and following the die half 3 considered.
- the casting channel 7 can be substantially inclined with respect to the horizontal ( Figures 1 , 1 A , 2 , 7 ) or can also be substantially horizontal.
- Each lower die half 3 is preferably made of copper, AISI steel or other stainless steel.
- each lower die half 3 is adapted to contain from 0.5 kg or 0.7 kg to 16 kg or 20 kg of aluminium, preferably from 3 to 7 kg, even more preferably substantially 5 kg.
- the lower die halves 3 can have a substantially H-shaped ( Figure 3 ) or U-shaped cross-section.
- the lower die halves 3 are preferably arranged one after the other so as to form a chain preferably closed on itself, which in turn forms the casting channel 7 formed by the succession of recesses of each lower die half 3.
- the molten metal coming for example from a crucible 28, 28' can then be cast in the casting channel 7.
- Two consecutive lower die halves 3 are preferably fixed together so as to be articulated and to be able to rotate the one with respect to the other.
- the closed chain formed by the lower die halves 3 is configured for sliding by making the plurality of lower die halves 3 advance along a path closed on itself.
- This closed path preferably downstream of the crucible 28, 28' or other casting zone 11, forms a casting stretch 13 with a shape for example rectilinear in which the casting channel stretches 7 of at least part of the lower die halves 3 are aligned along a common casting axis, that is for example - but as explained below, not necessarily - substantially rectilinear ( Figure 1 , 2 ).
- the molten metal material is cast into the casting die 1.
- the casting zone 11 may also not comprise the crucible 28, 28' but for example comprise only a nozzle, spout or other adapter fed from a crucible not shown and outside the casting apparatus 10.
- the path of the lower die halves 3 downstream of the casting stretch 13, for example rectilinear, changes direction so as to detach, in a preferably progressive manner, the lower die halves 3 from a metal bar formed by the metal that has solidified in the casting for example rectilinear stretch 13.
- the apparatus 10 comprises a first 15 and a second die advancing wheel 17, against which the chain formed by the lower die halves 3 rests or around which the chain is wound.
- the wheels 15, 17 are preferably arranged at or near a respective end of the casting for example rectilinear stretch 13 so that at the end of the casting for example rectilinear stretch 13, the chain of lower die halves 3 changes direction around the first die advancing wheel 15, and changes direction again at the second die advancing wheel 17 where it will reach the casting zone 11.
- Each link of the chain of the lower die halves 3 preferably comprises a lower die half 3 and a pair of connecting bars 30, preferably substantially parallel to each other and with respect to the casting channel stretch 7 and each fixed on a flank of the respective lower die half 3 ( Figure 4 ).
- the connecting bars 30 are fixed the one to the other preferably by means of a plurality of lateral pins 4 so as to form two chains arranged side by side and parallel to each other.
- Each lateral pin 4 fixes two connecting bars 30 and two adjacent lower die halves 3 one to another, articulating them and allowing the connecting bars to rotate with respect to each other and the lower die halves to rotate with respect to each other, thus forming the aforesaid chain of die halves 3.
- the apparatus 10 preferably further comprises a load-bearing frame 27, 27' comprising, for example, a plurality of steel bars and/or plates welded together.
- the load-bearing frame 27, 27' is preferably configured for resting on a floor or on a suitable foundation plinth, possibly made of PRM concrete ( Figure 9 ).
- the load-bearing frame 27, 27' may comprise, for example, two or more uprights 29, 31, 270 and two or more crosspieces 38, 100, 101 which extend in a more or less horizontal direction, connect two or more of said uprights and are fixed thereto, for example welded or bolted ( Figure 1 , 1B , 9 ).
- the concavity of the die halves 3 forming the casting channel 7 is preferably turned upwards ( Figure 4 ).
- the continuous casting apparatus 10 further comprises an upper closure system 20 in turn comprising a die-closing belt 9 made of metal material, for example of steel, and closed on itself.
- the die-closing belt 9 can have a width ranging, for example, between 5-25 centimetres or between 16-18 centimetres.
- the die-closing belt 9 closes a part of the lower die halves 3 on the side opposite to their bottoms of the respective stretches of the casting channel, so as to ensure the tightness of the molten metal during its travel in the casting channel.
- the die-closing belt 9 in the more upstream stretch of the casting for example rectilinear stretch 13, or at or near the casting zone 11, describes a first direction change stretch.
- the closure system 20 further comprises a belt pressing system 21, shown in Figure 1 , configured for pressing the die-closing belt 9 against the open flanks of the lower die halves 3 at least part of the casting for example rectilinear stretch 13.
- the apparatus 10 is provided with a first direction change support 23 placed at the first direction change stretch of the die-closing belt 9 and at or near the casting zone.
- the support 23 is configured for resting against the die-closing belt 9 and guide it along the first direction change stretch so that, at the exit of the latter, it advances in a direction different from that in which it advances at the entry to the first direction change stretch.
- the first direction change support 23 is arranged so that the directions with which the die-closing belt 9 reaches and leaves the first support 23 form between them an angle ⁇ [alpha] preferably equal to or lower than 120°, more preferably equal to or lower than 90°, more preferably equal to or lower than 60°, more preferably equal to or lower than 30°, and even more preferably substantially equal to 0° ( Figure 7 A ).
- the closure system 20 further comprises a second direction change support 25 for deviating the die-closing belt 9 in a second stretch of its path.
- This second direction change support 25 is preferably a wheel ( Figure 1 ), pulley or roller.
- the second direction change support 25 is arranged so that the directions with which the die-closing belt 9 reaches and leaves the second support 25 form between them an angle ⁇ [beta] preferably equal to or lower than 120°, more preferably equal to or lower than 90°, more preferably equal to or lower than 60°, more preferably equal to or lower than 30°, and even more preferably substantially equal to 0° ( Figure 7 B ).
- the die-closing belt 9 rests and winds around the first direction change support 23, then runs toward the second direction change support 25 around which it winds itself, afterwards it runs again toward the first support 23, closing its own path on itself.
- the apparatus 10 is configured for causing the chain of the lower die halves 3 and the die-closing belt 9 to advance one integral with another and without mutual sliding, at least along the casting stretch 13.
- the points of rest of the die-closing belt 9 against the first direction change support 23 - and preferably also against the second direction change support 25- lie substantially along a surface having a finite minimum radius of curvature; this surface is preferably and substantially with single curvature.
- This minimum radius of curvature is preferably equal to or lower than 1.5 metres, 1 meter, 0.8 metres or 0.6 metres.
- This minimum radius of curvature is preferably equal to or greater than 0.3 metres, or 0.5 metres or 0.6 metres.
- the points of rest of the die-closing belt 9 against the first direction change support 23 - and preferably also against the second direction change support 25- lie substantially along a surface preferably with a single curvature having a minimum radius of curvature preferably equal to or greater than 0.5 metres and which is substantially tangent to the path followed by the die-closing belt along the casting for example rectilinear stretch.
- the rotation axes of the rollers or other rolling bodies of the first 23 - and preferably also against the second direction change support 25- can lie substantially in a surface preferably with single curvature having a minimum finite radius of curvature, preferably equal to or greater than 0.5 metres and which is substantially tangent to the path followed by the die-closing belt along the casting stretch 13.
- This minimum radius of curvature is preferably equal to or lower than 1.5 metres, 1 meter, 0.8 metres or 0.6 metres.
- This minimum radius of curvature is preferably equal to or greater than 0.3 metres, or 0.5 metres or 0.6 metres.
- the rotation axes of the rollers or other rolling bodies of the first 23 - and preferably also against the second direction change support 25- can lie substantially in a surface with an overall arched shape ( Figure 1 A ), possibly in the form of a spiral arc.
- first 23 and/or the second direction change support 25 each comprise a pulley, a wheel or roller which is configured for resting against the die-closing belt 9 during normal operation of the continuous casting apparatus 1 and having a diameter equal to or greater than one metre.
- the first direction change support 23 advantageously comprises a roller conveyor in turn comprising at least three direction change rolling bodies 108 configured for rest against the die-closing belt 9 during normal operation of the continuous casting apparatus 1, wherein such rolling bodies may be, for example, wheels, pulleys or rollers ( Figure 1 A ).
- the rolling bodies 108 are arranged so that a same point of the die-closing belt 9, when advancing, rests in succession and not simultaneously against the first, then against the second and then against the third of said rolling bodies 108, and more generally, rests in succession and not simultaneously against only one of said rolling bodies 108 at a time.
- the rotation axes of the various rolling bodies 108 are preferably parallel or in any case placed side by side with each other,/ preferably parallel or in any case placed side by side with the surface of the belt 9 and perpendicular, or in any case transverse, to the trajectory of the belt 9.
- Each rolling body 108 has a diameter preferably equal to or greater than 5 centimetres, and more preferably equal to or greater than 8 centimetres and for example ranging between 5-40 centimetres, between 7-20 centimetres, between 8-15 centimetres or equal for example to 8 centimetres.
- the roller conveyor 23 is preferably provided with at least 5 rolling bodies 108 for each metre of length of the stretch of belt that rests against the same roller conveyor, more preferably it is provided with at least 8 rolling bodies 108 /metre and even more preferably it is provided with at least 10 rolling bodies 108 /metre.
- the roller conveyor 23 is preferably provided with about 8-20 rolling bodies 108 /metre or with 10-15 or with 10-13 rolling bodies 108 /metre.
- the roller conveyor 23 allows to apply a greater and more uniform pressure on the die-closing belt 9 so as to push it against the edges of the lower die halves 3, improving the tightness between the belt 9 and the lower die halves 3, near the casting zone 11, in which zone the pressure of the molten metal is greater and therefore the risk of leakages thereof from the casting die through slits or other zones with imperfect tightness is greater.
- roller conveyor 23 allows the belt closing rollers to rest along the casting channel 7 immediately downstream of the roller conveyor 23.
- roller conveyor 23 or other first direction change support 23 is configured for pressing the die-closing belt 9 against the lower die halves 3 so as to close the casting channel 7 at the top along the casting stretch 13.
- roller conveyor 23 is fixed to the load-bearing frame 27, 27' - for example to the upright 29 formed by this frame - so as to be able to adjust its height above the die-closing belt 9 by varying the force with which it presses the latter.
- the rolling bodies 108 are preferably mounted on a respective support, fixed to the load-bearing frame 27, 27' so as preferably to be able to adjust their position with respect thereto.
- the roller conveyor 23 can be possibly fixed to the load-bearing frame 27, 27' - for example to the upright 29 - so as to be able to adjust its horizontal position, for example to adjust the tension of the die-closing belt 9.
- the roller conveyor 23 is preferably configured for guide the die-closing belt 9 along a first stretch TR 1 having a first minimum radius of roller conveyor curvature RC1 and a second stretch TR 2 , travelled by the belt 9 directed toward the casting zone 11 after having travelled the first stretch TR 1 , having a second minimum radius of curvature RC 2 substantially lower than the first radius of roller conveyor curvature, for example equal to or lower than 0.9 times or 0.8 times the radius of curvature RC 2 .
- the first radius of curvature RC 1 can be about 0.6 metres whereas the second radius of curvature RC 2 can be about equal to 0.5 metres.
- the radius of curvature of the die-closing belt 9 is kept high over a longer length of its path, reducing it only where necessary, for example for reasons of encumbrance; the mechanical stress to which the die-closing belt 9 is subjected during operation is thus further reduced, reducing the risks of breakage, wear and tear thereof and extending its operating life in general.
- the second direction change support 25 is fixed to the load-bearing frame 27, 27' - for example, to the upright 270 formed by said frame - preferably but not necessarily so as to be able to adjust its horizontal position, for example to adjust the tension of the die-closing belt 9, and/or its height above the die-closing belt 9 for example to vary the force with which it presses the latter downwards.
- the continuous casting apparatus 10 can be provided with a rotating arm 250 - possibly fixed to the upright 270 or more generally to the load-bearing frame 27, 27'- and with an actuator 252 - such as for example a hydraulic or pneumatic cylinder -, the second direction change support 25 can be fixed to the rotating arm 250 and the latter can be actuated by the actuator 252.
- a rotating arm 250 possibly fixed to the upright 270 or more generally to the load-bearing frame 27, 27'- and with an actuator 252 - such as for example a hydraulic or pneumatic cylinder -
- the second direction change support 25 can be fixed to the rotating arm 250 and the latter can be actuated by the actuator 252.
- first 23 and the second direction change support 25 are fixed to the load-bearing frame 27, 27' so as to be able to adjust their horizontal and/or vertical position independently of each other, in particular, they are not mechanically rigidly constrained the one to the other or made integral the one to the other.
- first 23 and the second direction change support 25 can adjust their position relative to the load-bearing frame 27, 27' and/or between them by moving with respective degrees of freedom substantially that are independent of each other.
- first 23 and the second direction change support 25 are not fixed to the same common beam.
- the second support 25 is configured for adjusting its position - for example its horizontal position - with respect to the first support 23, so as to adjust the tension of the die-closing belt 9 and thus close the casting channel 7 with better tightness and reduce the mechanical and fatigue stresses of the belt 9.
- the apparatus 10 is provided with a liquid and gas cooling system 40, for example air and water.
- a liquid and gas cooling system 40 for example air and water.
- This cooling system 40 comprises one or more first nozzles 41, each of which is configured for striking with a jet of air or other cooling gas, cooling them, the lower die halves 3 at at least one portion of the casting for example rectilinear stretch 13.
- the first nozzles 41 are preferably configured for flushing with a jet of air or other cooling gas the lower die halves 3 at the more upstream portion of the casting for example rectilinear stretch 13 ( Figure 7 ).
- This more upstream portion preferably comprises or coincides with the so-called hypercritical stretch of the casting channel, i.e. with the stretch of the casting channel 7 in which the treated metal is still in the molten state ( Figure 7 ).
- Hypercritical stretch means, in the present definition, the most upstream casting channel stretch in which a metal skin that is thick enough to render a cooling with jets of water at high pressure unadvisable has not solidified outside the bar of the cast metal yet; such jets could in fact break the skin and the water could penetrate in the molten metal creating various drawbacks, among which micro- and macroexplosions which then leave small craters and voids in the solidified metal bar.
- hypercritical stretch refers to the most upstream stretch of the casting channel in which a metal skin whose thickness is equal to or lower than 0.2 millimetres, more preferably equal to or lower than 0.3 millimetres, more preferably equal to or lower than 0.5 millimetres, more preferably equal to or lower than 1 millimetre has not solidified outside the bar of the cast metal yet.
- hypercritical stretch can be understood in the present description as the more upstream stretch of the casting stretch having a length ranging between 0.3-1 metre or between 0.3-0.8 metres or between 0.3-0.6 metres.
- the nozzles 41 are arranged so as to strike the lower die halves 3 from the bottom and from both sides, right and left with respect to the casting axis.
- the air emitted by the nozzles 41 can be for example at room temperature or colder than room temperature, for example 10-20 °C lower than room temperature.
- Air cooling at or near the casting zone 11 is advantageous compared to water cooling, since in this zone it is particularly difficult to tightly close the casting channel 7, and water that has penetrated into it might adversely affect the casting of molten metal in the casting die.
- the preventive cooling by air or other cooling gas allows to reduce the thermal shock of lower die halves 3, allowing in general a better control of their temperature.
- the cooling system preferably further comprises one or more second nozzles 43, each of which is configured for striking with water or other cooling and/or cleaning liquid a part of the lower die halves 3 and/or the die-closing belt 9 at at least the casting for example rectilinear stretch 13.
- the second nozzles 43 are arranged so as to strike with jets of water or other cooling and/or cleaning liquid the lower die halves 3 at least at the casting for example rectilinear stretch 13, downstream of the first nozzles 41 and/or in such a way as to strike with water jets - preferably from above - the die-closing belt 9.
- the second nozzles 43 are preferably arranged so as to strike with jets of water or other cooling and/or cleaning liquid the face of the die-closing belt 9 turned towards the outside of the casting channel 7.
- the lower die halves 3 are preferably flushed with water or other cooling and/or cleaning liquid from the bottom and from both flanks, right and left, with respect to the casting direction.
- the second nozzles 43 are arranged so as to flush with water or other cooling and/or cleaning liquid the die-closing belt 9 along at least 70% of the casting for example rectilinear stretch.
- the second nozzles 43 flush the mould-pressing belt 9 in the hypercritical stretch with water substantially at room pressure - for example because it simply drips onto the belt 9- or with water at relatively low pressure, for example equal to or lower than 2 relative bars, more preferably equal to or lower than 1 relative bars or 0.5 relative bars, thus reducing the risk of water infiltration in the molten or in any case hot metal.
- the second nozzles 43 spray or in any case flush the mould-pressing belt 9 outside the hypercritical stretch with water substantially at high pressure, for example at a pressure equal to or greater than 3 relative bars or 4 relative bars, so as to cool more effectively not only the belt but also the metal bar cast underneath it.
- These second nozzles 43 are arranged so as to strike with a jet of water or other cooling and/or cleaning liquid the lower die halves 3 along at least 300 or 400 of the casting for example rectilinear stretch, or in any case the lower die halves 3 which are not in the hypercritical stretch of the casting stretch 13.
- said second nozzles 43 strike the lower die halves 3 along at least 600 of the casting for example rectilinear stretch.
- the first nozzles 41 is configured for cooling the lower die halves 3 by means of air jets, bringing them to a temperature preferably ranging between 10-60 °C, more preferably ranging between 10-40 °C, or between 15-25 °C and even more preferably between 25-28 °C at least in the half - and more preferably at least in the fourth - of the casting stretch 13 closest to the casting zone 11.
- the apparatus 10 preferably further comprises a plurality of fixed sliding supports 8 fixed to the load-bearing frame 27, 27' so as to preferably form two rows substantially parallel to each other or in any case placed side by side.
- These fixed sliding supports can be fixed, for example, to two beams or crosspieces 47, placed side by side and parallel the one to the other, which can extend along the casting channel 7 between the first 15 and the second die advancing wheel 17 ( Figure 3 , 4 ).
- Each fixed sliding support 8 may comprise, for example, a roller such as, for example, a bush 80 fitted on a pin 82 so as to be able to rotate thereon ( Figures 4, 5 ), possibly with the interposition of a ball bearing (not shown).
- Each bush 80 is configured for rotating about itself about an axis perpendicular to the direction of advancement of the die halves 3.
- the concavity of the die halves 3 which form the casting channel 7 is preferably turned upwards ( Figure 4 ).
- the chain of the lower die halves 3 comprises a plurality of advancement projections 6, each of which is configured for engaging with the first 15 and/or the second die advancing wheel 17, preferably engaging with suitable recesses and/or with suitable teeth obtained on the wheels 15, 17.
- Each advancement projection 6 preferably comprises a bush 60 fitted on a pin 62 so as to be able to rotate thereon ( Figures 4, 5 ), possibly with the interposition of a ball bearing (not shown).
- Each bush 60 is configured for rotating about itself about an axis perpendicular to the direction of advancement of the die halves 3.
- At least one of the wheels 15, 17 is preferably a drive wheel.
- Each advancement projection 6 is preferably arranged at or near half the length of a respective connecting bar 30 ( Figures 3 , 4 ), although in an embodiment not shown it can also be arranged at or near an end of such a connecting bar 30.
- advancement projections 6 and the fixed sliding supports 8 are arranged on and project from both the right and left flanks, with reference to the casting axis, of the chain of the lower die halves 3.
- Each pair of advancement projections 6 and of fixed sliding supports 8 is advantageously obtained from two respective pins which do not extend over the whole width of the respective lower die half 3 or over the whole width of the relative chain link of the die halves 3 ( Figures 5 , 6 ).
- each pair of advancement projections 6 and of fixed sliding supports 8 is not, for example, obtained from a single through pin which passes through the entire width of the respective lower die half 3 or the entire width of the relative chain link of the die halves 3.
- each die half 3 - with reference to the orientation in space that said die half 3 has in the casting stretch 13- it is possible to obtain a longitudinal groove 110, even quite deep, which can face directly onto the nozzles 41, 43 and be struck with greater power by the air and water jets emitted therefrom, without being partially sheltered by the aforesaid through pins, improving the effectiveness of cooling and washing of the die halves 3 ( Figure 5 , 6 ).
- the stretch of the chain of the die halves 3 below the casting stretch 13, i.e. the stretch of the chain of the die halves 3 which extends from the end of the casting channel 7 to the casting zone 11, is conventionally referred to, in the present description, as the so-called return stretch 32 of the chain of the die halves 3.
- the chain formed by the lower die halves 3 advantageously follows a convex path - for example in the form of a catenary curve - the convexity of which is turned downwards ( Figure 1 ), so as to open and widen - for example, by opening them substantially into a V - the slits formed by the ends of the pairs of die halves 3 adjacent to each other, causing any scraps and incrustations of molten material outflown from said slits to fall down and allowing a better washing of said ends of the die halves 3.
- This washing can be made, for example, by means of fluid - for example water or air - at high pressure.
- the chain of the die halves 3 - preferably the advancement projections thereof 6 - rest on and slide along a pair of sliding guides (not shown) preferably fixed to and integral with the load-bearing frame 27, 27'.
- These sliding guides preferably have a shape so that the chain of the die halves follows the aforementioned convex path.
- the belt-presser 21 of the closure system 20 comprises a plurality of pressers 35, 35', each of which is configured for resting against the die-closing belt 9 and press it against the lower die halves 3 at least in the casting stretch 13 so as to close the casting channel 7 ( Figure 1 A , 5 , 6 , 7 ).
- Each presser 35, 35' may comprise a skid or more preferably a rolling element such as for example a wheel or a roller ( Figure 1 A , 15 , 15A ).
- a rolling element runs with less friction on the die-closing belt 9, tends to jam less and raise the belt 9 less, generally creating less drawbacks than a belt-presser skid.
- the belt-presser 21 of the closure system 20 further comprises a plurality of mechanical arms 37, 37' to each of which a respective presser 35, and possibly one or more respective pressers 35, 35', is fixed so as to be able to move it/them.
- Each mechanical arm 37, 37' advantageously comprises an articulated quadrilateral or pantograph kinematic mechanism 374, 374', which allows the relative presser 35, 35' or the relative pressers 35, 35' be raised and simultaneously moved laterally outside the vertical of the belt 9, to allow operators to access the zone below the pressers ( Figure 1 B , 9 , 15 ).
- This feature is extremely useful when carrying out maintenance, belt disassembly and cleaning, or even simply for allowing a visual inspection of the status of the components.
- This visual inspection and maintenance interventions can be carried out directly on the casting stretch 13 of the chain of the die halves with no need to carry them out on the return stretch 32, therefore outside the pit 52 which is usually located below the continuous casting apparatus 10, thus keeping operators in a much safer and more comfortable position and allowing a faster maintenance.
- the pit 52 can be arranged, for example, to collect the washing or cooling wastewater, lubricating oil and dirt that has come off the apparatus 10, 10'.
- Each mechanical arm 37, 37' - in particular its articulated quadrilateral - can be driven by a respective actuator 39, for example by a pneumatic or hydraulic cylinder.
- all the mechanical arms 37, 37' are fixed to a same substantially rigid element of the load-bearing frame 27, 27', as shown for example in Figures 1 , 1 B , 9 .
- all the articulated quadrilaterals or pantographs of the arms 37, 37' can be fixed on a same first beam 38 and all the respective actuators 39 to a second beam 100.
- the first beam 38 and the second beam 100 preferably extend substantially horizontally and/or parallel or longitudinally to the casting channel 7 in the casting stretch 13.
- Each mechanical arm 37' advantageously comprises one or more first roller holder supports 370, to each of which three pressure rollers 35' are fixed.
- rollers 35' are preferably fixed on a respective support 370 so that, when the mechanical arm 37' is lowered or in any case presses against the die-closing belt 9, one of these rollers 35' can rest near and/or at a first edge of the die-closing belt 9, while the other two rollers 35' can rest near and/or at the second edge of the die-closing belt 9.
- one of said rollers 35' is advantageously configured for pressing the first edge of the die-closing belt 9 against the upper edge of a first flank 71 of a casting channel stretch 7, while the other two rollers 35' are advantageously configured for pressing the second edge of the die-closing belt 9 against the upper edge of the second flank 71 of the same casting channel stretch, wherein the first and second flank 71 extend parallel or in any case side by side with each other.
- Each mechanical arm 37' advantageously comprises one or more second roller holder supports 372, to each of which a plurality of first roller holder supports 370 is fixed so that the latter are aligned according to the direction of the blankholder belt 9.
- Each second roller holder support 372 may have, for example, the more or less approximate shape of a crosspiece ( Figure 15 , 15A ).
- Each second roller holder support 372 is preferably fixed to and actuated by a relative articulated quadrilateral or pantograph kinematic mechanism 374, 374' so as to move the rollers 35' close to and away from the belt 9 according to a predetermined direction, for example according to a vertical direction ( Figure 15 , 15A ).
- each first roller holder support 370 is fixed to the relative second roller holder support 372 by means of a flexible joint 376, which allows the first support 370 to vary its inclination and orientation in space with respect to the second roller holder support 372: this allows each set of three rollers 35' of a first roller holder support 370 to rest against the blankholder belt 9 contacting and pressing all the three against the belt 9, thus better pressing the belt 9 against the row of lower die halves 3 and thus avoiding the leakage of molten metal between the belt 9 and the die halves 3 or in any case greatly reducing the risk thereof, thus considerably increasing the tightness.
- the flexible joint 376 may be, for example, a ball joint.
- each flexible joint 376 is provided with a shock absorber in turn provided with a guide rod 3760 and with an elastic element 3762, such as for example a helical spring ( Figure 15A ).
- the guide rod 3760 is configured for constraining the relative movements between the first 370 and the second roller holder support 372, for example limiting this movement substantially to a translation.
- the elastic element 3762 is configured for transmitting and dampen the thrust of the first roller holder support 370 on the second roller holder support 372 and the contrary reaction thrust preventing the rollers 35' from hitting or pressing with excessive force the belt 9, damaging it.
- the apparatus 10, 10' is advantageously provided with a downstream belt presser indicated with the overall reference 54 ( Figure 9 A ).
- the downstream belt presser 54 preferably comprises a carriage 540 provided with wheels or rollers with which it presses the die-closing belt 9 by rolling thereon.
- the carriage 540 is positioned near the wheel, pulley or roller 25.
- the carriage 540 can be fixed to one or more levers 542, 543 or other kinematic mechanisms and from said lever, levers or kinematic mechanisms pressed against the belt 9.
- the levers 542, 543 are preferably actuated by one or more suitable actuators 544, 546.
- one or more of said levers 542, 543 is/are hinged to the rotation axis of the wheel, pulley or roller 25.
- the continuous casting apparatus 10 can be advantageously arranged so that the lower die halves 3 travel, in the casting stretch 13, along a substantially concave casting path TRC with concavity turned downwards; the casting path TRC is indicated by a dotted line in Figures 10, 11 .
- the casting path TRC advantageously comprises an arc of circumference ( Figures 10, 11 ).
- the casting path TRC in the casting stretch 13 may be, for example, exclusively concave.
- the casting path TRC of the die halves 3 in the casting stretch 13 may comprise a more central stretch in the form of an arc of circle or in any case more generally concave, and one or two convex ( Figure 10 ) and/or rectilinear ( Figure 11 ) end stretches.
- the arc or in any case concave path TRC extends preferably along the whole casting stretch 13, that is preferably from the point of the path of the die halves 3 immediately downstream of the crucible 28, 28' or other casting zone 11 to the point of the path of the die halves 3 in which the now solidified casting of molten metal starts to peel off from the die halves 3.
- the concave stretch of the casting path TRC may extend, for example, from the point of the path of the die halves 3 immediately downstream of the crucible 28 or other casting zone 11 and a point placed before that in which the now solidified casting of molten metal begins to peel off from the die halves 3.
- the concave stretch of the casting path TRC may extend, for example, from a point of the path of the die halves 3 not immediately downstream of the crucible 28, 28' or other casting zone 11 and the point in which the now solidified casting of molten metal starts to peel off from the die halves 3.
- the position of fixed sliding supports 8 can be suitably selected and/or adjusted to realise these shapes of the casting path TRC; in particular, for this purpose, the rollers or other fixed sliding supports 8 are advantageously mounted so as to be able to adjust in height the position of their rotation axes.
- the maximum depth PRTMAX of the concavity of the casting path TRC is meant to indicate the maximum distance of a point of the casting path TRC from a tangent straight line TGT - indicated by a dashed line and two dots in Figure 10 - to the casting path TRC at the ends of the casting stretch, wherein this distance PRTMAX is measured perpendicularly to the straight line TGT ( Figure 10 ).
- the distance along the straight line TGT of its two points of tangency with the casting path TRC is instead conventionally defined as the length LTR of the casting path TRC.
- the maximum depth PRTMAX is comprised between 0.5-10 millimetres or between 1-6 millimetres, between 2-4 millimetres or between 3-4 millimetres.
- the maximum depth PRTMAX is comprised between 0.0001-0.0015 times the length LTR, and more preferably it is comprised between 0.0002-0.0008 times, between 0.0004-0.0006 times or between 0.0003-0.0005 times the length LTR.
- the length LTR can be for example comprised between 3-10 metres, between 5-9 metres, between 6-8 metres or between 7-8,5 metres.
- the casting path TRC of the die halves 3 in the casting stretch 13 can comprise a more central stretch in the form of an arc of circle, this arc has a radius preferably ranging between 2000-8000 metres, more preferably between 3000-5000 metres or between 3500-4000 metres or between 3800-4200 metres.
- the concavity of the casting path TRC of the die halves 3 tends to rotate slightly the various lower die halves 3 around the lateral pins 4, closing at least partially and considerably reducing - indicatively up to half of their through section - the slits 302 present between the end faces 300 that are facing and opposed of two adjacent die halves 3, and consequently considerably reducing the leakage of molten metal between consecutive die halves 3 and the dimensions of the ribs formed by them on the flanks of the bars or ingots of the cast and then solidified metal ( Figure 12 ) .
- This relative rotation of two lower die halves 3, one with respect to another, caused by the concavity of the casting path TRC, can be all the more reduced the more the clearances of the chain of the die halves 3 are reduced, for example, a rotation ⁇ [gamma] of less than 0.3-0.2 sexagesimal degrees, a sexagesimal degree, 0.07-0.04 sexagesimal degrees or 0.06-0.04 sexagesimal degrees may be sufficient.
- the curvature of the casting path TRC and the rotation ⁇ [gamma] are such as to bring one or more pairs of end faces 300 that are facing and opposed, into mutual contact, for example in their upper zone.
- the concavity of the casting path TRC exploits the self-weight of the lower die halves 3 to close or at least reduce the slits therebetween.
- This measure is very important because it allows the closed chain formed by the lower die halves 3 to slide, dragging and tensioning its casting stretch 13, for example by means of one or more motors and/or one or more drive pulleys or drive rollers, in particular, for example, by means of the first die advancing wheel 15 alone, while the second wheel 17 can be, for example, idle and dragged by the chain of the die halves 3.
- the compression of the casting stretch 13 tended to deform the chain of the die halves 13 in all the directions of the space, bending it horizontally and vertically and twisting it, making it very difficult if not impossible the control and driving thereof and causing frequent failures, machine downtime and generally requiring a more frequent maintenance, as well as considerably increasing the leakage of molten metal through the slits between the die halves 3.
- the casting channel 7 is generally inclined downwards ( Figures 1 , 2 , 7 , 10 ) ; for example, if it is rectilinear - that is, if the casting path TRC is a straight line - it is preferably inclined by an angle ⁇ [theta] approximately equal to 1-10 sexagesimal degrees or 5-7 sexagesimal degrees with respect to the horizontal, so as to favour the outflow of the molten metal.
- the relative tangent straight line TGT is preferably inclined with respect to the horizontal, for example, by about 1-10 sexagesimal degrees or by 5-7 sexagesimal degrees.
- the continuous casting apparatus 10 is advantageously configured for moving or adjusting, through a suitable actuator, the position of the rotation axis of the first 15 and/or of the second die advancing wheel 17, making it perform for example one or more of the following movements:
- the continuous casting apparatus 10 may optionally be provided with a system for controlling the rotation speed of the drive wheel(s) which drag(s) the chain of the die halves 3, for example for controlling the rotation speed of the first 15 and/or of the second advancing wheel 17 so as to keep the chain always under tension and not under compression.
- the apparatus 10 comprises a zone for washing the lower die halves 3, which is preferably located at at least part of the return stretch 32, and third nozzles 45 are configured for striking the lower die halves 3 with a jet of water or other high-pressure liquid so that they are washed from metal residue and/or other incrustations or dirt ( Figure 8 ).
- the third nozzles 45 are directed toward the side of the lower die halves 3 on which the respective casting channel stretch 7 is obtained by effectively cleaning it from the remains of molten metal and other dirt, in general the removal of which could be more difficult with only the nozzles 43 of the casting stretch 13, where the casting channel 7 is closed at the top by the die-closing belt 9.
- the apparatus 10 also comprises a system for supplying lubricating and/or detaching oil 50, at the direction change supports and/or the rotary elements.
- the so-called return stretch 32 and the washing zone - are enclosed by one or more casings 102, 104 - preferably for example metal - preferably provided with doors which allow access to the chain of the die halves 3 for example for inspection or maintenance and at the same time retain inside the apparatus 10 and allow to recover more easily the dirty water or other exhausted washing liquid which drips from the machine, avoid soiling the surrounding environment ( Figure 1 ).
- the apparatus 10 further comprises a cutting station 106 configured for cutting the cast bar solidified into segments at the desired length ( Figures 2 , 14 ).
- This cutting station 106 is arranged, for example, downstream of the casting channel 7.
- This cutting station 106 can be configured for cutting the bar of solidified metal into ingots or other segments by blanking or fracture, substantially without chip removal, and for example can be a shearing machine ( Figure 2 , 14 ).
- the shearing machine 106 is advantageously provided with a pair of shearing rotors 1060, 1062 placed substantially side by side, configured for rotating about themselves about rotation axes ARC 1 , ARC 2 that are parallel or in any case longitudinal the one to the other ( Figure 14 ).
- the shearing rotors 1060, 1062 are moreover suitably spaced apart so as to allow the metal bar to be cut BRR to pass between them ( Figure 14 ).
- one of the two rotors 1060 can be arranged substantially above the other 1062 ( Figure 14 ) .
- Each shearing rotor 1060, 1062 is preferably provided with one or more blades or cutting edges 1064, more preferably with a pair of cutting edges 1064 arranged in diametrically opposite positions the one with respect to the other that is, angularly offset by about 180° the one from the other ( Figure 14 ).
- the shear 106 is configured for allowing the adjustment of the radial position of the blades 1064, i.e. to vary the radial distances of the respective cutting edges from the rotation axes of the respective shearing rotors 1060, 1062, that is, to make them project radially more or less with respect to the rest of the respective shearing rotors 1060, 1062.
- the shear 106 is configured for rotating the two shearing rotors 1060, 1062 at speeds which may be different from each other by varying each rotation speed, possibly independently of the other.
- the shear 106 is advantageously provided with two actuating motors 1066, 1068, for example electric motors with variable speed, each of which is configured for actuating a respective shearing rotor 1060, 1062.
- the rotation speed of the two motors 1066, 1068 can be varied and controlled independently of that of the other motor 1068, 1066.
- the shear 106 is configured for varying the angle of attack of the cutting edges 1064 and their offset, for example based on the type of metal alloy to be cut.
- the rotation speeds of the two shearing rotors 1060, 1062 and the radial distances of the respective cutting edges from their rotation axes may be different from each other and chosen in such a way as to ensure that, at the end of their metal incision stroke, the two cutting edges meet or in any case are at or near the shear center.
- the shear center according to structural engineering and the theory of elasticity in solids is defined as the point of a cross-section of the bar or ingot through which the straight line of action of the shearing stress must pass so that substantially no twisting moment is produced on the section.
- the rotation speeds of the two shearing rotors 1060, 1062 and the radial distances of the respective cutting edges from their rotation axes can be different from each other and chosen in such a way as to ensure that, at the end of their metal cutting stroke, i.e. when two cutting edges are at the minimum distance from each other, each cutting edge is at a distance equal to or lower than 25 millimetres from the shear center, more preferably at a distance from the shear center equal to or lower than 20 millimetres, 15 millimetres, 10 millimetres or 5 millimetres, two millimetres, one millimetre, 0.86 millimetres or 0.5 millimetres.
- the ingots cut with the known shearing machines have ends with very rough and irregular, chipped surfaces; moreover, during cutting the blades make the ingot raise, with the risk of causing damage to people and things around.
- the apparatus 10 is advantageously provided with or connectable to a logic unit (not shown) configured for storing, for example through a database, the various angles of attack and offset of the cutting edges 1062 that are the most suitable for cutting each metal alloy cast by the apparatus 10.
- the logic unit can then automatically set the shearing machine 106 based on the type, or the composition or recipe, of metal alloy chosen for the next casting to be made.
- the blades or cutting edges 1064 instead of on shearing rotors 1060, 1062 which rotate on themselves can be fixed to or in any case actuated by respective translating jaws which grip the metal bar until it is cut off.
- the crucible 28, 28' may comprise a collection tank 280 and a channel 282, 282' configured for pouring the molten metal coming from the collection tank 280 into the casting die 1 - preferably in the more upstream part of the casting stretch 13- ( Figures 16 , 17, 18 ).
- the collection tank 280 can be, for example, open at the top ( Figures 16 , 17, 18 ).
- the channel 282, 282' preferably has a tubular shape, with preferably rectangular cross ( Figures 16 , 17, 18 ), square or possibly, for example, also polygonal, circular, oval or elliptical sections.
- the channel 282, 282' ends downstream with an outlet mouth 284, 284' which is advantageously inclined with respect to the longitudinal axis of the channel 282, 282'.
- the channel 282, 282' extends generally horizontally or moderately inclined with respect to the horizontal, so that for example its longitudinal axis has an inclination ⁇ [phi] with respect to the horizontal ORZ equal to or lower than 45°, or 30°, or 15° or 5°.
- the axis of the channel 282, 282' and the axis of the casting channel stretch 7 into which the channel 282, 282' introduces the molten metal are substantially parallel or longitudinal to each other.
- outlet mouth 284, 284' is substantially inclined with respect to the longitudinal axis of the channel 282, 282', for example substantially inclined with respect to the stretch that is more downstream of the longitudinal axis of the channel 282, 282' ( Figure 18 , 19 , 20) and is not instead substantially perpendicular with respect to said longitudinal axis.
- outlet mouth 284, 284' is substantially inclined in the form of a drip cone ( Figures 16 , 17, 18 ).
- the outlet mouth 284, 284' can be substantially turned toward the bottom of the casting channel ( Figure 16 , 17 ) or turned in a direction away from the bottom of the casting channel ( Figure 18 ), with an inclination ⁇ [psi] with respect to the axis of the channel 282, 282' in absolute value for example ranging between 5-80°, or between 10-70°, between 30-50°, between 40-50°.
- the longitudinal axis of the channel 282, 282' can be, for example, substantially rectilinear ( Figures 16 , 17, 18 ).
- some outer walls of the channel 282, 282' can mate with some inner walls of the casting channel 7 and have shapes that are for example, complementary to each other, that is, some inner walls of the casting channel 7 can be substantially a negative copy of some outer walls of the channel 282, 282'.
- the drip cone shape of the outlet mouth 284, 284' makes this expansion less fast, thus also reducing turbulence in the molten metal which might cause slag in the casting and loss of level.
- the outlet mouth 284, 284' turned in a direction away from the bottom of the casting channel ( Figure 18 ) is particularly effective in reducing turbulence in the molten metal and making the variation of the passage sections gradual.
- the chain of the lower die halves 3 and the die-closing belt 9 are made to advance preferably so that in the casting stretch 13 they have the same speed with respect for example to the load-bearing frame 27, 27' and therefore slide substantially at the same speed the one with respect to the other.
- the molten metal preferably aluminium or the alloys thereof or other non-ferrous metal - is cast from the crucible 28, 28' - or in any case at the casting zone 11- into the casting die 1, while the movement of the rotatory elements 15 and 17 is active.
- the metal casting can enter the casting die 1 at the zone in which the roller conveyor 23 or other first direction change support 23 firmly presses the die-closing belt 9 against the chain of lower die halves 3, closing the casting channel 7 at the top.
- the metal is cooled by the first nozzles 41, which cool for example with air jets each lower die half 3 from the three lower, right and left, sides with reference to the direction of advancement of the casting, and by the second nozzles 43 which cool, for example, with jets of water or other cooling liquid - preferably directed from the top downwards - the die-closing belt 9.
- the metal material is cooled by jets of water from all sides.
- the metal bar now solidified continues its rectilinear advancement, progressively exiting from the casting die, thanks to the change of direction of the chain of lower die halves 3, which deviates from the rectilinear path resting and winding around the wheel, roller or pulley 15, and also thanks to the change of direction of the die-closing belt 9 which also deviates from the rectilinear path resting and winding around the wheel, roller or pulley 25.
- the bar of solidified metal can then be transported to a cutting station 106, where it will be cut in such a way as to divide it into a plurality of ingots or in any case segments of the desired length.
- the die halves 3 are advantageously washed by the first 41, by the second 43 and by the third nozzles 45.
- the third nozzles 45 contribute considerably to washing also the inside of the casting channel 7, since they are either facing or in any case turned toward it; for example, in the return stretch 32 if the die halves 3 advance with the stretches of the casting channel turned downwards, the third nozzles 45 are preferably turned upwards.
- the continuous casting apparatus 10 described above allows to close better, in particular with a better tightness against leakage of liquid metal, the casting channel 7 by means of the die-closing belt 9 at or near the casting zone 11, thus stressing and damaging less the die-closing belt 9, imposing it greater radii of curvature at the first 23 and at the possible second direction change support 25.
- the decoupling between the adjustment movements of the first 23 and of the second direction change support 25 as well as the pressers 35 and of the relative fastenings 38, 100 to the load-bearing frame 27, 27' further contributes to reducing the mechanical and fatigue stresses in the die-closing belt 9 and to extending the operating life thereof, and further contributes to improving the tightness against molten metal leakage over the entire length of the casting channel.
- the apparatus 10 also allows to bring the lower die halves 3 back to a lower temperature - when appropriate
- the present invention relates to an apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5), and wherein:
- the present invention relates to an apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5), and wherein:
- the casting path (TRC) forms a substantially rectilinear casting axis.
- the casting stretch (13) is substantially rectilinear.
- the casting stretch (13) is configured for containing and solidifying the molten metal.
- the casting path (TRC) is substantially concave having the concavity turned downwards.
- the casting path (TRC) comprises an arc of circumference.
- the lower die halves (3) are fixed one after the other so as to substantially form a chain closed on itself, the chain of the lower die halves (3) forms the casting stretch (13) and a return stretch (32), by travelling along said return stretch the lower die halves (3) move from the more downstream end of the casting stretch (13) to the casting zone ( 11 ), in at least part of the return stretch (32) the chain of the lower die halves (3) possibly follows a convex path the convexity of which is turned downwards.
- an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention is configured for making the lower die halves (3) advance by tensioning the chain formed by them at least in the casting stretch (13).
- an apparatus (10) for producing metal bars through continuous casting comprises a first die advancing wheel (15) arranged at or near the downstream end of the casting stretch (13), and the apparatus (10) is configured for tensioning the chain formed by the lower die halves (3) by dragging said chain through the first die advancing wheel (15).
- the first direction change support (23) comprises a roller conveyor in turn comprising at least three direction change rolling bodies (108) configured for resting against the die-closing belt (9) during normal operation of the continuous casting apparatus (10), wherein said rolling bodies (108) may be, for example, wheels, pulleys or rollers.
- the roller conveyor of the first direction change support ( 23 ) is provided with at least five, and possibly at least ten direction change rolling bodies ( 108 ), for each meter of length of the linear development of the stretch of the die-closing belt ( 9 ) which rests against the roller conveyor ( 23 ).
- the roller conveyor of the first direction change support ( 23 ) is configured for guide the die-closing belt ( 9 ) along a first roller conveyor stretch (TR 1 ) of its path having a first average radius of roller conveyor curvature (RC 1 ), and a second roller conveyor stretch (TR 2 ) having a second average radius of roller conveyor curvature (RC 2 ) substantially lower than the first radius of roller conveyor curvature (RC 1 ).
- an apparatus ( 10 ) for producing metal bars through continuous casting comprises a load-bearing frame ( 27, 27') configured for resting on a floor, and wherein the first direction change support ( 23 ) is fixed to the load-bearing frame ( 27, 27' ) so as to be able to vary its position with respect to the latter by adjusting the pressure with which said first support ( 23 ) presses the die-closing belt ( 9 ) against the lower die halves ( 3 ) by closing the casting channel at the top at least at or near the casting zone ( 11 ), the second direction change support ( 25) is fixed to the load-bearing frame ( 27, 27' ) so as to be able to adjust the tension of the die-closing belt ( 9 ) and to vary its position with respect to the latter with movements that are substantially independent with respect to those of the first direction change support ( 23) , and/or moving according to one or more degrees of freedom that are substantially independent of the one or more degrees of freedom according to which the
- the present invention relates to the use of an apparatus ( 10 ) having the features according to the fifth aspect of the present invention, for producing bars of a non-ferrous metal, such as aluminium or alloys thereof, through continuous casting.
- the present invention relates to a process for producing metal bars through continuous casting, comprising the following operations:
- the present invention relates to an apparatus ( 10 ) for producing metal bars through continuous casting, comprising a continuous casting die ( 1 ) in turn comprising a casting zone ( 11 ) configured for receiving molten metal, a plurality of lower die halves ( 3 ) arranged in succession the one after the other and an upper closure system ( 5 ), and wherein:
- the present invention relates to an apparatus ( 10 ) for producing metal bars through continuous casting, comprising a continuous casting die ( 1 ) in turn comprising a casting zone ( 11 ) configured for receiving molten metal, a plurality of lower die halves ( 3 ) arranged in succession the one after the other and an upper closure system ( 5 ) and a crucible ( 28, 28' ), and wherein:
- the concave path TRC of the lower die halves 3 in the casting stretch 13 may have a shape tolerance TLR the absolute and overall value thereof is, for example, equal to PRTMAX/2, or PRTMAX/4 to PRTMAX/8 or to PRTMAX/10; the band defined by this shape tolerance and within which the shape of the casting path TRC may vary is schematically indicated by the dashed band of Figure 13 .
- the present invention relates to a cutting station ( 106 ) configured for shearing or blanking metal bars and ingots, for example the bars and the ingots produced by the casting die ( 1 ), and comprising at least one pair of cutting blades
- the cutting station ( 106 ) configured for ending the cutting strokes of the pair of cutting blades (1064) substantially at or near the shear center of the cross sections of the bar or ingot to be cut.
- the present invention relates to a cutting station ( 106 ) configured for shearing or blanking metal bars and ingots, for example the bars and ingots produced by the casting die ( 1 ), and comprising at least one pair of cutting blades ( 1064 ) configured for cutting the bar or ingot by pressing in substantially mutually opposite or opposed directions, and a pair of actuators ( 1066, 1068 ) each of which is configured for actuating a respective cutting blade ( 1064 ), and each actuator ( 1066, 1068 ) can impose on its respective cutting blade ( 1064 ) cutting movements and trajectories that are substantially independent of those imposed by the other actuator ( 1068, 1066 ) on its cutting blade ( 1064 ).
- actuators ( 1066, 1068 ) may be rotary electric motors, each of which is arranged or in any case adapted to rotate the respective cutting blade ( 1064 ) with rotations that are substantially independent of the rotations imposed by the other motor, for example, rotations at a speed substantially different from that of the other motor and/or by suitably phase shifting the rotations of the two blades ( 1064 ), and/or by making sure that one comes into contact with the bar or ingot to be cut before the other.
- the cutting blades ( 1064 ) can cut the bars or ingots by translating or roto-translating with respect to the bars and with respect to the ingots and not only by rotating.
- the materials used, and the dimensions may be any according to the technical requirements.
- references to a "first, second, third, ... n-th entity" have the sole aim of distinguishing them from one another but the indication of the n-th entity does not necessarily imply the existence of the first, second ... (n- 1 )th entity.
Abstract
Description
- The present invention relates to an apparatus and a process for producing metal bars through continuous casting, particularly suitable for producing bars of aluminium and alloys thereof and other non-ferrous metals.
- Machines for producing bars of non-ferrous metals through continuous casting, in which the casting die is formed by a chain of lower die halves closed at the top by a metal belt are currently known.
- An example of such continuous casting machines is described in the Japanese patent application No.
JP58020356 in the name of Mitsubishi Heavy Ind LTD reference number 4 indicates each of the die halves that are connected to form a chain closed on itself, and thereference number 3 indicates the belt closed on itself which closes the casting channel in the casting stretch at the top. - According to the authors of the present invention, this type of continuous casting machine has however several drawbacks.
- The closure belt undergoes considerable mechanical stresses, in particular to fatigue, since the rollers on which it slides have a small diameter.
- This causes premature belt wear and breakage, making machine maintenance and operating costs worse.
- In the zone closest to the crucible, the casting channel is closed with poor tightness, which causes leakages of molten metal between the
lower die halves 4 and the die-closing belt 3. - These leakages in turn encrust and generally foul the machine, cause misalignment of the
lower die halves 4 and malfunctions in general. - In some examples and models of this type of continuous casting machine, the problems of tightness between the
belt 3 and thelower die halves 4 also occur in the central stretches of the casting channel. - It is an object of the present invention to obviate the above-mentioned drawbacks of the prior art and in particular to provide an apparatus for producing metal bars through continuous casting having an improved tightness against leakages of molten metal.
- Another object of the present invention is to provide an apparatus for producing metal bars through continuous casting, the die-closing belt of which is less stressed and subject to wear and failures.
- This object is achieved, according to a first aspect of the present invention, with an apparatus having the features according to
claim 1. - In that case one or more first nozzles (14) can possibly have the features according to
claim 14 or 15; yet in that casesuch apparatus 10 can possibly be provided with one or more second nozzles (43) having the features according toclaim 15. - In a particular embodiment, the apparatus for producing metal bars through continuous casting according to the invention comprises a belt-pressing system (21) configured for pressing the die-closing belt (9) against the open flanks of the lower die halves (3) at least in correspondence with at least part of the casting stretch (13) and comprising at least a first direction change support (23) located at or near the casting zone (11) and configured for resting against the die-closing belt (9) and to guide it along the first direction change stretch so that at the exit from the latter it advances in a direction different from that in which it enters the first direction change stretch, wherein the points of rest of the die-closing belt (9) against the first direction change support lie substantially along a resting surface having an average radius of curvature (RC1, RC2) equal to or greater than 0.5 metres and which is substantially tangent to the path followed by the die-closing belt (9) along the casting stretch (13).
- In a particular embodiment of an apparatus for producing metal bars through continuous casting according to the invention, the first direction change support (23) comprises a pulley, wheel or roller which are configured to rest against the die-closing belt (9) during normal operation of the continuous casting apparatus (10) and having a diameter of one meter or more.
- In a particular embodiment of the invention, the apparatus (10) comprises a second direction change support (25) for deviating the die-closing belt (9) in a second stretch of its path, wherein the second direction change support (25) may comprise, for example, a pulley, wheel or roller.
- In a particular embodiment of an apparatus for producing metal bars through continuous casting according to the invention, the die-closing belt (9) is configured for advancing by travelling along the second roller conveyor stretch (TR2) after having travelled the first roller conveyor stretch (TR1).
- In a particular embodiment of an apparatus for producing metal bars through continuous casting according to the invention, the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave can possibly extend for a length equal to or greater than half the overall length of the casting stretch (13); in this case the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave can possibly extend for a length equal to or greater than three quarters, four fifths, nine tenths of the overall length of the casting stretch (13) or it can extend over the entire overall length of the casting stretch (13).
- In a particular embodiment of an apparatus for producing metal bars through continuous casting according to the invention, the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave extends for a length equal to or greater than 5 metres, or equal to or greater than 6 metres, 7 metres, 8 metres, 9 metres; in this case, the portion of the casting stretch (13) in which the casting path (TRC) is substantially concave may extend for a length equal to or lower than 15 metres, or 12 metres, 10 metres, 8 metres.
- In a particular embodiment of an apparatus for producing metal bars through continuous casting according to the invention, one or more of the first nozzles (41) is/are configured for striking with a jet of air or other cooling and/or cleaning gas the die halves (3) at least at a first part of the casting stretch (13) at or near the casting zone (11).
- In a particular embodiment of an apparatus for producing metal bars through continuous casting according to the invention, one or more of the second nozzles (43) is/are configured for strike with a jet of water or other cooling and/or cleaning liquid the die halves (3) and/or the die-closing belt (9) at least at a second part of the casting stretch (13) downstream of the first part of the stretch of the casting channel (13).
- In a particular embodiment of the invention, the apparatus (10) comprises one or more third nozzles (45), each of which is configured for striking with a jet of water or other cooling and/or washing liquid a part of the lower die halves (3) at the return stretch.
- In a second aspect of the invention, this object is achieved by using said apparatus having the features according to
claim 11. - In a third aspect of the invention, this object is achieved with a process having the features according to claim 12.
- Further features of the invention are the subject matter of the dependent claims.
- The advantages attainable with the present invention shall become more readily apparent, to the person skilled in the art, from the following detailed description of some particular, non-limiting examples of embodiments, illustrated with reference to the following schematic figures.
-
-
Figure 1 shows a first perspective view of an apparatus for producing metal bars through continuous casting according to a first particular embodiment of the present invention; -
Figure 1A shows a side view of the first direction change support of the apparatus ofFigure 1 ; -
Figure 1B shows a perspective view of a detail of the belt-presser of the apparatus ofFigure 1 ; -
Figure 2 shows a second perspective view of the apparatus ofFigure 1 ; -
Figure 3 shows a perspective view of a stretch of the chain of the lower die halves and of the casting stretch of the apparatus ofFigure 1 ; -
Figure 4 shows a side view of the stretch of the chain of the lower die halves and of the casting stretch ofFigure 3 ; -
Figure 5 shows a section of the casting stretch of the apparatus ofFigure 1 , according to the sectional plane V-V; -
Figure 6 shows a section of the casting stretch of the apparatus ofFigure 1 , according to the sectional plane V-V; -
Figure 7 shows a schematic side view of the cooling system and possibly also washing system of the apparatus ofFigure 1 ; -
Figure 7A shows a schematic side view of a detail of an apparatus for producing metal bars through continuous casting according to a second particular embodiment of the present invention; -
Figure 7B shows a schematic side view of a detail of an apparatus for producing metal bars through continuous casting according to a third particular embodiment of the present invention; -
Figure 8 shows a partially sectional view, taken along the sectional plane VIII-VIII, of a point of the return stretch of the chain of the lower die halves of the continuous casting apparatus ofFigure 1 ; -
Figure 9 shows a front view of an apparatus for producing metal bars through continuous casting according to a fourth embodiment of the present invention; -
Figure 9A shows a front view of the downstream belt-presser of the continuous casting apparatus ofFigure 9 ; -
Figure 9B shows an enlarged detail of the casting die of the continuous casting apparatus ofFigure 9 ; -
Figure 10 shows a front view of the system for reducing the leakages through the chain of lower die halves of an apparatus for producing metal bars through continuous casting according to a fifth particular embodiment of the present invention; -
Figure 11 shows a front view of the system for reducing the leakages through the chain of lower die halves of an apparatus for producing metal bars through continuous casting according to a sixth particular embodiment of the present invention; -
Figure 12 shows a front view with a detail of the leakage reduction system ofFigure 11 or12 ; -
Figure 13 shows a front view with an indication of the geometric tolerances of the trajectory of the chain of the die halves in the casting stretch in the leakage reduction system ofFigure 11 or12 ; -
Figure 14 shows a perspective view of the cutting station of the apparatus ofFigure 1 ; -
Figure 15 shows a perspective view of a mechanical belt-presser arm of the apparatus ofFigure 9 ; -
Figure 15A shows a side view, partially in section, of the mechanical arm ofFigure 15 ; -
Figure 16 shows a partially exploded perspective view of a first example of a crucible usable in the continuous casting apparatus ofFigures 1 ,2 or9 ; -
Figure 17 shows a side view of the crucible ofFigure 16 , according to a normal direction of observation to the casting axis; -
Figure 18 shows a side view, according to a normal direction of observation to the casting axis, of a second example of crucible usable in the continuous casting apparatus ofFigures 1 ,2 or9 . -
Figures 1-7 ,8 relate to an apparatus for producing metal bars through continuous casting according to a first particular embodiment of the invention, indicated with theoverall reference 10. - In the present description, the terms "top, bottom, above, below, horizontal, vertical" when not otherwise specified refer to a condition of normal installation and operation of the
casting apparatus 10. - The
continuous casting apparatus 10 can be configured for casting bars of non-ferrous metals, such as aluminium and alloys thereof, the cross-sections of which have a height ranging, for example, between 10-100 millimetres, and a width ranging, for example, between 10-250 millimetres. - The
apparatus 10 comprises acontinuous casting die 1 in turn comprising a plurality oflower die halves 3 arranged in succession the one after the other and an upper closure system 5. - Each
lower die half 3 forms thebottom 70 and theflanks 71 of acasting channel stretch 7, is open on the flank opposite to the side of the bottom of the respectivecasting channel stretch 7 and at the ends adjacent to thedie halves 3 immediately preceding and following the die half 3 considered. - The
casting channel 7 can be substantially inclined with respect to the horizontal (Figures 1 ,1A ,2 ,7 ) or can also be substantially horizontal. - Each
lower die half 3 is preferably made of copper, AISI steel or other stainless steel. - Preferably, each
lower die half 3 is adapted to contain from 0.5 kg or 0.7 kg to 16 kg or 20 kg of aluminium, preferably from 3 to 7 kg, even more preferably substantially 5 kg. - As shown in the accompanying
figures 2 ,4 and 5 , thelower die halves 3 can have a substantially H-shaped (Figure 3 ) or U-shaped cross-section. - The
lower die halves 3 are preferably arranged one after the other so as to form a chain preferably closed on itself, which in turn forms the castingchannel 7 formed by the succession of recesses of eachlower die half 3. - The molten metal coming for example from a
crucible 28, 28' can then be cast in thecasting channel 7. - Two consecutive lower die
halves 3 are preferably fixed together so as to be articulated and to be able to rotate the one with respect to the other. - The closed chain formed by the
lower die halves 3 is configured for sliding by making the plurality oflower die halves 3 advance along a path closed on itself. - This closed path, preferably downstream of the
crucible 28, 28' orother casting zone 11, forms acasting stretch 13 with a shape for example rectilinear in which the casting channel stretches 7 of at least part of thelower die halves 3 are aligned along a common casting axis, that is for example - but as explained below, not necessarily - substantially rectilinear (Figure 1 ,2 ). - In the
casting zone 11 the molten metal material is cast into the casting die 1. - The casting
zone 11 may also not comprise thecrucible 28, 28' but for example comprise only a nozzle, spout or other adapter fed from a crucible not shown and outside thecasting apparatus 10. - The path of the
lower die halves 3 downstream of thecasting stretch 13, for example rectilinear, changes direction so as to detach, in a preferably progressive manner, thelower die halves 3 from a metal bar formed by the metal that has solidified in the casting for examplerectilinear stretch 13. - As is visible in
Figure 1 , theapparatus 10 comprises a first 15 and a seconddie advancing wheel 17, against which the chain formed by thelower die halves 3 rests or around which the chain is wound. - The
wheels rectilinear stretch 13 so that at the end of the casting for examplerectilinear stretch 13, the chain oflower die halves 3 changes direction around the firstdie advancing wheel 15, and changes direction again at the seconddie advancing wheel 17 where it will reach thecasting zone 11. - Each link of the chain of the
lower die halves 3 preferably comprises alower die half 3 and a pair of connectingbars 30, preferably substantially parallel to each other and with respect to thecasting channel stretch 7 and each fixed on a flank of the respective lower die half 3 (Figure 4 ). - The connecting bars 30 are fixed the one to the other preferably by means of a plurality of
lateral pins 4 so as to form two chains arranged side by side and parallel to each other. - Each
lateral pin 4 fixes two connectingbars 30 and two adjacentlower die halves 3 one to another, articulating them and allowing the connecting bars to rotate with respect to each other and the lower die halves to rotate with respect to each other, thus forming the aforesaid chain of die halves 3. - The
apparatus 10 preferably further comprises a load-bearing frame 27, 27' comprising, for example, a plurality of steel bars and/or plates welded together. - The load-
bearing frame 27, 27' is preferably configured for resting on a floor or on a suitable foundation plinth, possibly made of PRM concrete (Figure 9 ). - The load-
bearing frame 27, 27' may comprise, for example, two or more uprights 29, 31, 270 and two ormore crosspieces Figure 1 ,1B ,9 ). - At least along the
casting stretch 13, the concavity of the die halves 3 forming the castingchannel 7 is preferably turned upwards (Figure 4 ). - The
continuous casting apparatus 10 further comprises anupper closure system 20 in turn comprising a die-closingbelt 9 made of metal material, for example of steel, and closed on itself. - The die-closing
belt 9 can have a width ranging, for example, between 5-25 centimetres or between 16-18 centimetres. - At the casting for example
rectilinear stretch 13, the die-closingbelt 9 closes a part of thelower die halves 3 on the side opposite to their bottoms of the respective stretches of the casting channel, so as to ensure the tightness of the molten metal during its travel in the casting channel. - The die-closing
belt 9 in the more upstream stretch of the casting for examplerectilinear stretch 13, or at or near the castingzone 11, describes a first direction change stretch. - The
closure system 20 further comprises abelt pressing system 21, shown inFigure 1 , configured for pressing the die-closingbelt 9 against the open flanks of thelower die halves 3 at least part of the casting for examplerectilinear stretch 13. - The
apparatus 10 is provided with a firstdirection change support 23 placed at the first direction change stretch of the die-closingbelt 9 and at or near the casting zone. - The
support 23 is configured for resting against the die-closingbelt 9 and guide it along the first direction change stretch so that, at the exit of the latter, it advances in a direction different from that in which it advances at the entry to the first direction change stretch. - The first
direction change support 23 is arranged so that the directions with which the die-closingbelt 9 reaches and leaves thefirst support 23 form between them an angle α [alpha] preferably equal to or lower than 120°, more preferably equal to or lower than 90°, more preferably equal to or lower than 60°, more preferably equal to or lower than 30°, and even more preferably substantially equal to 0° (Figure 7A ). - Preferably, the
closure system 20 further comprises a seconddirection change support 25 for deviating the die-closingbelt 9 in a second stretch of its path. - This second
direction change support 25 is preferably a wheel (Figure 1 ), pulley or roller. - The second
direction change support 25 is arranged so that the directions with which the die-closingbelt 9 reaches and leaves thesecond support 25 form between them an angle β [beta] preferably equal to or lower than 120°, more preferably equal to or lower than 90°, more preferably equal to or lower than 60°, more preferably equal to or lower than 30°, and even more preferably substantially equal to 0° (Figure 7B ). - Preferably along its trajectory, the die-closing
belt 9 rests and winds around the firstdirection change support 23, then runs toward the seconddirection change support 25 around which it winds itself, afterwards it runs again toward thefirst support 23, closing its own path on itself. - Preferably, the
apparatus 10 is configured for causing the chain of thelower die halves 3 and the die-closingbelt 9 to advance one integral with another and without mutual sliding, at least along thecasting stretch 13. - The points of rest of the die-closing
belt 9 against the first direction change support 23 - and preferably also against the second direction change support 25- lie substantially along a surface having a finite minimum radius of curvature; this surface is preferably and substantially with single curvature. - This minimum radius of curvature is preferably equal to or lower than 1.5 metres, 1 meter, 0.8 metres or 0.6 metres.
- This minimum radius of curvature is preferably equal to or greater than 0.3 metres, or 0.5 metres or 0.6 metres.
- The points of rest of the die-closing
belt 9 against the first direction change support 23 - and preferably also against the second direction change support 25- lie substantially along a surface preferably with a single curvature having a minimum radius of curvature preferably equal to or greater than 0.5 metres and which is substantially tangent to the path followed by the die-closing belt along the casting for example rectilinear stretch. - As an alternative or in combination with the above, the rotation axes of the rollers or other rolling bodies of the first 23 - and preferably also against the second direction change support 25- can lie substantially in a surface preferably with single curvature having a minimum finite radius of curvature, preferably equal to or greater than 0.5 metres and which is substantially tangent to the path followed by the die-closing belt along the
casting stretch 13. - This minimum radius of curvature is preferably equal to or lower than 1.5 metres, 1 meter, 0.8 metres or 0.6 metres.
- This minimum radius of curvature is preferably equal to or greater than 0.3 metres, or 0.5 metres or 0.6 metres.
- As an alternative or in combination with the above, the rotation axes of the rollers or other rolling bodies of the first 23 - and preferably also against the second direction change support 25- can lie substantially in a surface with an overall arched shape (
Figure 1A ), possibly in the form of a spiral arc. - Thanks to these wide radii of curvature, the mechanical stress to which the die-closing
belt 9 is subjected during operation is reduced, reducing the risks of mechanical stress, breakage, wear and tear thereof and extending its operating life in general. - In a particular embodiment, the first 23 and/or the second
direction change support 25 each comprise a pulley, a wheel or roller which is configured for resting against the die-closingbelt 9 during normal operation of thecontinuous casting apparatus 1 and having a diameter equal to or greater than one metre. - Like for example shown in
Figures 1 and6 , the firstdirection change support 23 advantageously comprises a roller conveyor in turn comprising at least three directionchange rolling bodies 108 configured for rest against the die-closingbelt 9 during normal operation of thecontinuous casting apparatus 1, wherein such rolling bodies may be, for example, wheels, pulleys or rollers (Figure 1A ). - The rolling
bodies 108 are arranged so that a same point of the die-closingbelt 9, when advancing, rests in succession and not simultaneously against the first, then against the second and then against the third of said rollingbodies 108, and more generally, rests in succession and not simultaneously against only one of said rollingbodies 108 at a time. - The rotation axes of the various rolling
bodies 108 are preferably parallel or in any case placed side by side with each other,/ preferably parallel or in any case placed side by side with the surface of thebelt 9 and perpendicular, or in any case transverse, to the trajectory of thebelt 9. - Each rolling
body 108 has a diameter preferably equal to or greater than 5 centimetres, and more preferably equal to or greater than 8 centimetres and for example ranging between 5-40 centimetres, between 7-20 centimetres, between 8-15 centimetres or equal for example to 8 centimetres. - The
roller conveyor 23 is preferably provided with at least 5 rollingbodies 108 for each metre of length of the stretch of belt that rests against the same roller conveyor, more preferably it is provided with at least 8 rollingbodies 108/metre and even more preferably it is provided with at least 10 rollingbodies 108/metre. - The
roller conveyor 23 is preferably provided with about 8-20rolling bodies 108/metre or with 10-15 or with 10-13rolling bodies 108/metre. - The
roller conveyor 23 allows to apply a greater and more uniform pressure on the die-closingbelt 9 so as to push it against the edges of thelower die halves 3, improving the tightness between thebelt 9 and thelower die halves 3, near the castingzone 11, in which zone the pressure of the molten metal is greater and therefore the risk of leakages thereof from the casting die through slits or other zones with imperfect tightness is greater. - In addition, the
roller conveyor 23 allows the belt closing rollers to rest along the castingchannel 7 immediately downstream of theroller conveyor 23. - Advantageously, the
roller conveyor 23 or other firstdirection change support 23 is configured for pressing the die-closingbelt 9 against thelower die halves 3 so as to close the castingchannel 7 at the top along thecasting stretch 13. - For this purpose the
roller conveyor 23 is fixed to the load-bearing frame 27, 27' - for example to the upright 29 formed by this frame - so as to be able to adjust its height above the die-closingbelt 9 by varying the force with which it presses the latter. - For this purpose, the rolling
bodies 108 are preferably mounted on a respective support, fixed to the load-bearing frame 27, 27' so as preferably to be able to adjust their position with respect thereto. - The
roller conveyor 23 can be possibly fixed to the load-bearing frame 27, 27' - for example to the upright 29 - so as to be able to adjust its horizontal position, for example to adjust the tension of the die-closingbelt 9. - The
roller conveyor 23 is preferably configured for guide the die-closingbelt 9 along a first stretch TR1 having a first minimum radius of roller conveyor curvature RC1 and a second stretch TR2, travelled by thebelt 9 directed toward the castingzone 11 after having travelled the first stretch TR1, having a second minimum radius of curvature RC2 substantially lower than the first radius of roller conveyor curvature, for example equal to or lower than 0.9 times or 0.8 times the radius of curvature RC2. - For example, the first radius of curvature RC1 can be about 0.6 metres whereas the second radius of curvature RC2 can be about equal to 0.5 metres.
- In this way the radius of curvature of the die-closing
belt 9 is kept high over a longer length of its path, reducing it only where necessary, for example for reasons of encumbrance; the mechanical stress to which the die-closingbelt 9 is subjected during operation is thus further reduced, reducing the risks of breakage, wear and tear thereof and extending its operating life in general. - Advantageously, the second
direction change support 25 is fixed to the load-bearing frame 27, 27' - for example, to the upright 270 formed by said frame - preferably but not necessarily so as to be able to adjust its horizontal position, for example to adjust the tension of the die-closingbelt 9, and/or its height above the die-closingbelt 9 for example to vary the force with which it presses the latter downwards. - For this purpose, the
continuous casting apparatus 10 can be provided with a rotating arm 250 - possibly fixed to the upright 270 or more generally to the load-bearing frame 27, 27'- and with an actuator 252 - such as for example a hydraulic or pneumatic cylinder -, the seconddirection change support 25 can be fixed to therotating arm 250 and the latter can be actuated by theactuator 252. - Advantageously, the first 23 and the second
direction change support 25 are fixed to the load-bearing frame 27, 27' so as to be able to adjust their horizontal and/or vertical position independently of each other, in particular, they are not mechanically rigidly constrained the one to the other or made integral the one to the other. - In other words, the first 23 and the second
direction change support 25 can adjust their position relative to the load-bearing frame 27, 27' and/or between them by moving with respective degrees of freedom substantially that are independent of each other. - In particular, the first 23 and the second
direction change support 25 are not fixed to the same common beam. - More generally, preferably the
second support 25 is configured for adjusting its position - for example its horizontal position - with respect to thefirst support 23, so as to adjust the tension of the die-closingbelt 9 and thus close the castingchannel 7 with better tightness and reduce the mechanical and fatigue stresses of thebelt 9. - Advantageously, the
apparatus 10 is provided with a liquid and gas cooling system 40, for example air and water. - This cooling system 40, schematically illustrated in
Figure 5-7 , comprises one or morefirst nozzles 41, each of which is configured for striking with a jet of air or other cooling gas, cooling them, thelower die halves 3 at at least one portion of the casting for examplerectilinear stretch 13. - The
first nozzles 41 are preferably configured for flushing with a jet of air or other cooling gas thelower die halves 3 at the more upstream portion of the casting for example rectilinear stretch 13 (Figure 7 ). - This more upstream portion preferably comprises or coincides with the so-called hypercritical stretch of the casting channel, i.e. with the stretch of the casting
channel 7 in which the treated metal is still in the molten state (Figure 7 ). - Hypercritical stretch means, in the present definition, the most upstream casting channel stretch in which a metal skin that is thick enough to render a cooling with jets of water at high pressure unadvisable has not solidified outside the bar of the cast metal yet; such jets could in fact break the skin and the water could penetrate in the molten metal creating various drawbacks, among which micro- and macroexplosions which then leave small craters and voids in the solidified metal bar.
- More precisely, the expression hypercritical stretch refers to the most upstream stretch of the casting channel in which a metal skin whose thickness is equal to or lower than 0.2 millimetres, more preferably equal to or lower than 0.3 millimetres, more preferably equal to or lower than 0.5 millimetres, more preferably equal to or lower than 1 millimetre has not solidified outside the bar of the cast metal yet.
- In combination with or as an alternative to the previous definition, hypercritical stretch can be understood in the present description as the more upstream stretch of the casting stretch having a length ranging between 0.3-1 metre or between 0.3-0.8 metres or between 0.3-0.6 metres.
- The
nozzles 41 are arranged so as to strike the lower diehalves 3 from the bottom and from both sides, right and left with respect to the casting axis. - The air emitted by the
nozzles 41 can be for example at room temperature or colder than room temperature, for example 10-20°C lower than room temperature. - Air cooling at or near the casting
zone 11 is advantageous compared to water cooling, since in this zone it is particularly difficult to tightly close the castingchannel 7, and water that has penetrated into it might adversely affect the casting of molten metal in the casting die. - The preventive cooling by air or other cooling gas allows to reduce the thermal shock of
lower die halves 3, allowing in general a better control of their temperature. - The cooling system preferably further comprises one or more
second nozzles 43, each of which is configured for striking with water or other cooling and/or cleaning liquid a part of thelower die halves 3 and/or the die-closingbelt 9 at at least the casting for examplerectilinear stretch 13. - In particular, the
second nozzles 43 are arranged so as to strike with jets of water or other cooling and/or cleaning liquid thelower die halves 3 at least at the casting for examplerectilinear stretch 13, downstream of thefirst nozzles 41 and/or in such a way as to strike with water jets - preferably from above - the die-closingbelt 9. - The
second nozzles 43 are preferably arranged so as to strike with jets of water or other cooling and/or cleaning liquid the face of the die-closingbelt 9 turned towards the outside of the castingchannel 7. - The
lower die halves 3 are preferably flushed with water or other cooling and/or cleaning liquid from the bottom and from both flanks, right and left, with respect to the casting direction. - Preferably, the
second nozzles 43 are arranged so as to flush with water or other cooling and/or cleaning liquid the die-closingbelt 9 along at least 70% of the casting for example rectilinear stretch. - More preferably they strike the
belt 9 along at least 90% of the casting for example rectilinear stretch, and even more preferably along the entire casting stretch. - Preferably, the
second nozzles 43 flush the mould-pressingbelt 9 in the hypercritical stretch with water substantially at room pressure - for example because it simply drips onto the belt 9- or with water at relatively low pressure, for example equal to or lower than 2 relative bars, more preferably equal to or lower than 1 relative bars or 0.5 relative bars, thus reducing the risk of water infiltration in the molten or in any case hot metal. - Advantageously, the
second nozzles 43 spray or in any case flush the mould-pressingbelt 9 outside the hypercritical stretch with water substantially at high pressure, for example at a pressure equal to or greater than 3 relative bars or 4 relative bars, so as to cool more effectively not only the belt but also the metal bar cast underneath it. - These
second nozzles 43 are arranged so as to strike with a jet of water or other cooling and/or cleaning liquid thelower die halves 3 along at least 300 or 400 of the casting for example rectilinear stretch, or in any case thelower die halves 3 which are not in the hypercritical stretch of thecasting stretch 13. - More preferably, said
second nozzles 43 strike the lower diehalves 3 along at least 600 of the casting for example rectilinear stretch. - Preferably, the
first nozzles 41, and more generally theapparatus 10, is configured for cooling thelower die halves 3 by means of air jets, bringing them to a temperature preferably ranging between 10-60°C, more preferably ranging between 10-40°C, or between 15-25°C and even more preferably between 25-28°C at least in the half - and more preferably at least in the fourth - of thecasting stretch 13 closest to thecasting zone 11. - The
apparatus 10 preferably further comprises a plurality of fixed slidingsupports 8 fixed to the load-bearing frame 27, 27' so as to preferably form two rows substantially parallel to each other or in any case placed side by side. - These fixed sliding supports can be fixed, for example, to two beams or
crosspieces 47, placed side by side and parallel the one to the other, which can extend along the castingchannel 7 between the first 15 and the second die advancing wheel 17 (Figure 3 ,4 ). - Along these fixed sliding
supports 8 the chain of thelower die halves 3 can slide and can rest thereon, at least in thecasting stretch 13. - Each fixed sliding
support 8 may comprise, for example, a roller such as, for example, a bush 80 fitted on apin 82 so as to be able to rotate thereon (Figures 4, 5 ), possibly with the interposition of a ball bearing (not shown). - Each bush 80 is configured for rotating about itself about an axis perpendicular to the direction of advancement of the die halves 3.
- Preferably, at least along the
casting stretch 13, the lower die halves 3 - and more preferably the respective pair of connecting bars 30- rest on and slide along the fixed sliding supports 8. - This makes maintenance easier and improves efficiency. In fact, carrying out the necessary check operations on a limited number of bushes will be easier and can be scheduled, thus guaranteeing the efficiency of the sliding plane between
supports 8 and links 30. - At least along the
casting stretch 13, the concavity of the die halves 3 which form thecasting channel 7 is preferably turned upwards (Figure 4 ). - Advantageously, the chain of the
lower die halves 3 comprises a plurality ofadvancement projections 6, each of which is configured for engaging with the first 15 and/or the seconddie advancing wheel 17, preferably engaging with suitable recesses and/or with suitable teeth obtained on thewheels - Each
advancement projection 6 preferably comprises abush 60 fitted on apin 62 so as to be able to rotate thereon (Figures 4, 5 ), possibly with the interposition of a ball bearing (not shown). - Each
bush 60 is configured for rotating about itself about an axis perpendicular to the direction of advancement of the die halves 3. - For this purpose at least one of the
wheels - Again for this purpose, preferably even if not necessarily only one of the
wheels other wheel - Each
advancement projection 6 is preferably arranged at or near half the length of a respective connecting bar 30 (Figures 3 ,4 ), although in an embodiment not shown it can also be arranged at or near an end of such a connectingbar 30. - The advantage of this arrangement is twofold, kinematic and functional.
- Kinematic because it reduces the motion irregularity by 50% (arc meshing on a circle); functional because even if also the
advancement projection 6 wears, there are no problems of meshing on thewheels - Preferably, the
advancement projections 6 and the fixed slidingsupports 8 are arranged on and project from both the right and left flanks, with reference to the casting axis, of the chain of the lower die halves 3. - Each pair of
advancement projections 6 and of fixed slidingsupports 8 is advantageously obtained from two respective pins which do not extend over the whole width of the respective lower diehalf 3 or over the whole width of the relative chain link of the die halves 3 (Figures 5 ,6 ). - For this purpose, each pair of
advancement projections 6 and of fixed slidingsupports 8 is not, for example, obtained from a single through pin which passes through the entire width of the respective lower diehalf 3 or the entire width of the relative chain link of the die halves 3. - In this way, on the lower face of each die half 3 - with reference to the orientation in space that said
die half 3 has in the casting stretch 13- it is possible to obtain alongitudinal groove 110, even quite deep, which can face directly onto thenozzles Figure 5 ,6 ). - The stretch of the chain of the die halves 3 below the
casting stretch 13, i.e. the stretch of the chain of the die halves 3 which extends from the end of the castingchannel 7 to thecasting zone 11, is conventionally referred to, in the present description, as the so-calledreturn stretch 32 of the chain of the die halves 3. - In the
return stretch 32, the chain formed by thelower die halves 3 advantageously follows a convex path - for example in the form of a catenary curve - the convexity of which is turned downwards (Figure 1 ), so as to open and widen - for example, by opening them substantially into a V - the slits formed by the ends of the pairs ofdie halves 3 adjacent to each other, causing any scraps and incrustations of molten material outflown from said slits to fall down and allowing a better washing of said ends of the die halves 3. - This washing can be made, for example, by means of fluid - for example water or air - at high pressure.
- Advantageously along this
return stretch 32 the chain of the die halves 3 - preferably the advancement projections thereof 6 - rest on and slide along a pair of sliding guides (not shown) preferably fixed to and integral with the load-bearing frame 27, 27'. - Since these sliding guides support most of the weight of the chain of the die halves 3, they allow to size said chain so that it has a lower tensile strength and therefore a lower weight.
- These sliding guides preferably have a shape so that the chain of the die halves follows the aforementioned convex path.
- Preferably, the belt-
presser 21 of theclosure system 20 comprises a plurality ofpressers 35, 35', each of which is configured for resting against the die-closingbelt 9 and press it against thelower die halves 3 at least in thecasting stretch 13 so as to close the casting channel 7 (Figure 1A ,5 ,6, 7 ). - Each
presser 35, 35' may comprise a skid or more preferably a rolling element such as for example a wheel or a roller (Figure 1A ,15 ,15A ). - In fact, a rolling element runs with less friction on the die-closing
belt 9, tends to jam less and raise thebelt 9 less, generally creating less drawbacks than a belt-presser skid. - Preferably, the belt-
presser 21 of theclosure system 20 further comprises a plurality ofmechanical arms respective presser 35, and possibly one or morerespective pressers 35, 35', is fixed so as to be able to move it/them. - Each
mechanical arm pantograph kinematic mechanism 374, 374', which allows therelative presser 35, 35' or therelative pressers 35, 35' be raised and simultaneously moved laterally outside the vertical of thebelt 9, to allow operators to access the zone below the pressers (Figure 1B ,9 ,15 ). - This feature is extremely useful when carrying out maintenance, belt disassembly and cleaning, or even simply for allowing a visual inspection of the status of the components.
- This visual inspection and maintenance interventions can be carried out directly on the
casting stretch 13 of the chain of the die halves with no need to carry them out on thereturn stretch 32, therefore outside thepit 52 which is usually located below thecontinuous casting apparatus 10, thus keeping operators in a much safer and more comfortable position and allowing a faster maintenance. - The
pit 52 can be arranged, for example, to collect the washing or cooling wastewater, lubricating oil and dirt that has come off theapparatus 10, 10'. - Each
mechanical arm respective actuator 39, for example by a pneumatic or hydraulic cylinder. - Preferably, all the
mechanical arms bearing frame 27, 27', as shown for example inFigures 1 ,1B ,9 . - For this purpose, all the articulated quadrilaterals or pantographs of the
arms first beam 38 and all therespective actuators 39 to asecond beam 100. - The
first beam 38 and thesecond beam 100 preferably extend substantially horizontally and/or parallel or longitudinally to thecasting channel 7 in thecasting stretch 13. - Each
mechanical arm 37' advantageously comprises one or more first roller holder supports 370, to each of which three pressure rollers 35' are fixed. - These rollers 35' are preferably fixed on a
respective support 370 so that, when themechanical arm 37' is lowered or in any case presses against the die-closingbelt 9, one of these rollers 35' can rest near and/or at a first edge of the die-closingbelt 9, while the other two rollers 35' can rest near and/or at the second edge of the die-closingbelt 9. - More particularly, one of said rollers 35' is advantageously configured for pressing the first edge of the die-closing
belt 9 against the upper edge of afirst flank 71 of acasting channel stretch 7, while the other two rollers 35' are advantageously configured for pressing the second edge of the die-closingbelt 9 against the upper edge of thesecond flank 71 of the same casting channel stretch, wherein the first andsecond flank 71 extend parallel or in any case side by side with each other. - Each
mechanical arm 37' advantageously comprises one or more second roller holder supports 372, to each of which a plurality of first roller holder supports 370 is fixed so that the latter are aligned according to the direction of theblankholder belt 9. - Each second
roller holder support 372 may have, for example, the more or less approximate shape of a crosspiece (Figure 15 ,15A ). - Each second
roller holder support 372 is preferably fixed to and actuated by a relative articulated quadrilateral orpantograph kinematic mechanism 374, 374' so as to move the rollers 35' close to and away from thebelt 9 according to a predetermined direction, for example according to a vertical direction (Figure 15 ,15A ). - Advantageously, each first
roller holder support 370 is fixed to the relative secondroller holder support 372 by means of a flexible joint 376, which allows thefirst support 370 to vary its inclination and orientation in space with respect to the second roller holder support 372: this allows each set of three rollers 35' of a firstroller holder support 370 to rest against theblankholder belt 9 contacting and pressing all the three against thebelt 9, thus better pressing thebelt 9 against the row oflower die halves 3 and thus avoiding the leakage of molten metal between thebelt 9 and the die halves 3 or in any case greatly reducing the risk thereof, thus considerably increasing the tightness. - The flexible joint 376 may be, for example, a ball joint.
- Advantageously, each flexible joint 376 is provided with a shock absorber in turn provided with a guide rod 3760 and with an
elastic element 3762, such as for example a helical spring (Figure 15A ). - The guide rod 3760 is configured for constraining the relative movements between the first 370 and the second
roller holder support 372, for example limiting this movement substantially to a translation. - The
elastic element 3762 is configured for transmitting and dampen the thrust of the firstroller holder support 370 on the secondroller holder support 372 and the contrary reaction thrust preventing the rollers 35' from hitting or pressing with excessive force thebelt 9, damaging it. - In order to eliminate or in any case reduce the leakage of liquid metal between the die-closing
belt 9 and the die halves 3, theapparatus 10, 10' is advantageously provided with a downstream belt presser indicated with the overall reference 54 (Figure 9A ). - The
downstream belt presser 54 preferably comprises acarriage 540 provided with wheels or rollers with which it presses the die-closingbelt 9 by rolling thereon. - The
carriage 540 is positioned near the wheel, pulley orroller 25. - The
carriage 540 can be fixed to one ormore levers belt 9. - The
levers suitable actuators - Advantageously, one or more of said
levers roller 25. - This allows the
carriage 540 to be arranged very close to the wheel, pulley orroller 25, improving the tightness between thebelt 9 and the die halves 3 also near the wheel, pulley orroller 25. - In order to eliminate or in any case reduce the leakage of liquid metal between the slits that are present between two adjacent
lower die halves 3 along the casting channel, thecontinuous casting apparatus 10 can be advantageously arranged so that thelower die halves 3 travel, in thecasting stretch 13, along a substantially concave casting path TRC with concavity turned downwards; the casting path TRC is indicated by a dotted line inFigures 10, 11 . - The casting path TRC advantageously comprises an arc of circumference (
Figures 10, 11 ). - The casting path TRC in the
casting stretch 13 may be, for example, exclusively concave. - Alternatively, the casting path TRC of the die halves 3 in the
casting stretch 13 may comprise a more central stretch in the form of an arc of circle or in any case more generally concave, and one or two convex (Figure 10 ) and/or rectilinear (Figure 11 ) end stretches. - The arc or in any case concave path TRC extends preferably along the
whole casting stretch 13, that is preferably from the point of the path of the die halves 3 immediately downstream of thecrucible 28, 28' orother casting zone 11 to the point of the path of the die halves 3 in which the now solidified casting of molten metal starts to peel off from the die halves 3. - Alternatively, the concave stretch of the casting path TRC may extend, for example, from the point of the path of the die halves 3 immediately downstream of the
crucible 28 orother casting zone 11 and a point placed before that in which the now solidified casting of molten metal begins to peel off from the die halves 3. - In a further alternative, the concave stretch of the casting path TRC may extend, for example, from a point of the path of the die halves 3 not immediately downstream of the
crucible 28, 28' orother casting zone 11 and the point in which the now solidified casting of molten metal starts to peel off from the die halves 3. - The position of fixed sliding
supports 8 can be suitably selected and/or adjusted to realise these shapes of the casting path TRC; in particular, for this purpose, the rollers or other fixed slidingsupports 8 are advantageously mounted so as to be able to adjust in height the position of their rotation axes. - Conventionally, in the present description, the maximum depth PRTMAX of the concavity of the casting path TRC is meant to indicate the maximum distance of a point of the casting path TRC from a tangent straight line TGT - indicated by a dashed line and two dots in
Figure 10 - to the casting path TRC at the ends of the casting stretch, wherein this distance PRTMAX is measured perpendicularly to the straight line TGT (Figure 10 ). - The distance along the straight line TGT of its two points of tangency with the casting path TRC is instead conventionally defined as the length LTR of the casting path TRC.
- Preferably during normal operation the maximum depth PRTMAX is comprised between 0.5-10 millimetres or between 1-6 millimetres, between 2-4 millimetres or between 3-4 millimetres.
- Preferably the maximum depth PRTMAX is comprised between 0.0001-0.0015 times the length LTR, and more preferably it is comprised between 0.0002-0.0008 times, between 0.0004-0.0006 times or between 0.0003-0.0005 times the length LTR.
- The length LTR can be for example comprised between 3-10 metres, between 5-9 metres, between 6-8 metres or between 7-8,5 metres.
- When the casting path TRC of the die halves 3 in the
casting stretch 13 can comprise a more central stretch in the form of an arc of circle, this arc has a radius preferably ranging between 2000-8000 metres, more preferably between 3000-5000 metres or between 3500-4000 metres or between 3800-4200 metres. - The concavity of the casting path TRC of the die halves 3 tends to rotate slightly the various lower die
halves 3 around the lateral pins 4, closing at least partially and considerably reducing - indicatively up to half of their through section - theslits 302 present between the end faces 300 that are facing and opposed of twoadjacent die halves 3, and consequently considerably reducing the leakage of molten metal between consecutivedie halves 3 and the dimensions of the ribs formed by them on the flanks of the bars or ingots of the cast and then solidified metal (Figure 12 ). - These
slits 302, designed with very marked dimensions and not to scale inFigure 12 , are present because of the clearances of the chain formed by the lower die halves 3. - This relative rotation of two
lower die halves 3, one with respect to another, caused by the concavity of the casting path TRC, can be all the more reduced the more the clearances of the chain of the die halves 3 are reduced, for example, a rotation γ [gamma] of less than 0.3-0.2 sexagesimal degrees, a sexagesimal degree, 0.07-0.04 sexagesimal degrees or 0.06-0.04 sexagesimal degrees may be sufficient. - Preferably, the curvature of the casting path TRC and the rotation γ [gamma] are such as to bring one or more pairs of end faces 300 that are facing and opposed, into mutual contact, for example in their upper zone.
- Basically, the concavity of the casting path TRC exploits the self-weight of the
lower die halves 3 to close or at least reduce the slits therebetween. - This measure is very important because it allows the closed chain formed by the
lower die halves 3 to slide, dragging and tensioning itscasting stretch 13, for example by means of one or more motors and/or one or more drive pulleys or drive rollers, in particular, for example, by means of the firstdie advancing wheel 15 alone, while thesecond wheel 17 can be, for example, idle and dragged by the chain of the die halves 3. - The tensioning of the
casting stretch 13 on one side tends to widen the slits present between the end faces 300 of the die halves 3 - but as has already been explained, this drawback can be considerably reduced when it is not completely eliminated by the curved shape of the casting path TRC- but on the other hand it keeps thecasting stretch 13 of the chain ofdie halves 3 well straight and considerably facilitates the control and movement thereof, avoiding for example the drawbacks of some known continuous casting machines in which thecasting stretch 13 of the chain ofdie halves 3 was made to operate compressed, for example by means of a pair of drive wheels rotating at different speeds. - The compression of the
casting stretch 13 tended to deform the chain of the die halves 13 in all the directions of the space, bending it horizontally and vertically and twisting it, making it very difficult if not impossible the control and driving thereof and causing frequent failures, machine downtime and generally requiring a more frequent maintenance, as well as considerably increasing the leakage of molten metal through the slits between the die halves 3. - As already stated, preferably the
casting channel 7 is generally inclined downwards (Figures 1 ,2 ,7 ,10 ) ; for example, if it is rectilinear - that is, if the casting path TRC is a straight line - it is preferably inclined by an angle θ [theta] approximately equal to 1-10 sexagesimal degrees or 5-7 sexagesimal degrees with respect to the horizontal, so as to favour the outflow of the molten metal. - If the casting channel 7 - and correspondingly the casting path TRC- has a concave shape, as has already been said, the relative tangent straight line TGT is preferably inclined with respect to the horizontal, for example, by about 1-10 sexagesimal degrees or by 5-7 sexagesimal degrees.
- In order to maintain the
casting stretch 13 of the chain of the die halves 3 in a suitable tension, thecontinuous casting apparatus 10 is advantageously configured for moving or adjusting, through a suitable actuator, the position of the rotation axis of the first 15 and/or of the seconddie advancing wheel 17, making it perform for example one or more of the following movements: - a displacement which moves the rotation axes of the
first wheel 15 and of thesecond wheel 17 away from or toward each other; - a movement having a non-zero horizontal component of the rotation axis of the first 15 and/or of the
second wheel 17. - Again in order to control the tension of the
casting stretch 13 of the chain ofdie halves 3, thecontinuous casting apparatus 10 may optionally be provided with a system for controlling the rotation speed of the drive wheel(s) which drag(s) the chain of the die halves 3, for example for controlling the rotation speed of the first 15 and/or of the second advancingwheel 17 so as to keep the chain always under tension and not under compression. - Advantageously, the
apparatus 10 comprises a zone for washing thelower die halves 3, which is preferably located at at least part of thereturn stretch 32, andthird nozzles 45 are configured for striking thelower die halves 3 with a jet of water or other high-pressure liquid so that they are washed from metal residue and/or other incrustations or dirt (Figure 8 ). - Advantageously, the
third nozzles 45 are directed toward the side of thelower die halves 3 on which the respectivecasting channel stretch 7 is obtained by effectively cleaning it from the remains of molten metal and other dirt, in general the removal of which could be more difficult with only thenozzles 43 of thecasting stretch 13, where the castingchannel 7 is closed at the top by the die-closingbelt 9. - Advantageously, the
apparatus 10 also comprises a system for supplying lubricating and/or detachingoil 50, at the direction change supports and/or the rotary elements. - Preferably, the so-called
return stretch 32 and the washing zone - are enclosed by one ormore casings 102, 104 - preferably for example metal - preferably provided with doors which allow access to the chain of the die halves 3 for example for inspection or maintenance and at the same time retain inside theapparatus 10 and allow to recover more easily the dirty water or other exhausted washing liquid which drips from the machine, avoid soiling the surrounding environment (Figure 1 ). - Advantageously, the
apparatus 10 further comprises a cuttingstation 106 configured for cutting the cast bar solidified into segments at the desired length (Figures 2 ,14 ). - This cutting
station 106 is arranged, for example, downstream of the castingchannel 7. - This cutting
station 106 can be configured for cutting the bar of solidified metal into ingots or other segments by blanking or fracture, substantially without chip removal, and for example can be a shearing machine (Figure 2 ,14 ). - In this case the shearing
machine 106 is advantageously provided with a pair ofshearing rotors Figure 14 ). - The
shearing rotors Figure 14 ). - For this purpose one of the two
rotors 1060 can be arranged substantially above the other 1062 (Figure 14 ) . - Each
shearing rotor edges 1064, more preferably with a pair of cuttingedges 1064 arranged in diametrically opposite positions the one with respect to the other that is, angularly offset by about 180° the one from the other (Figure 14 ). - Advantageously, the
shear 106 is configured for allowing the adjustment of the radial position of theblades 1064, i.e. to vary the radial distances of the respective cutting edges from the rotation axes of therespective shearing rotors respective shearing rotors - Advantageously, the
shear 106 is configured for rotating the twoshearing rotors - For this purpose, the
shear 106 is advantageously provided with two actuatingmotors respective shearing rotor - Advantageously, the rotation speed of the two
motors other motor - Advantageously, the
shear 106 is configured for varying the angle of attack of thecutting edges 1064 and their offset, for example based on the type of metal alloy to be cut. - In other words, the rotation speeds of the two
shearing rotors - The shear center according to structural engineering and the theory of elasticity in solids is defined as the point of a cross-section of the bar or ingot through which the straight line of action of the shearing stress must pass so that substantially no twisting moment is produced on the section.
- More generally, the rotation speeds of the two
shearing rotors - In this way the cutting quality by shearing or blanking increases considerably with respect to that obtained with known shearing machines, in which at the end of the cutting strokes the cutting edges meet or touch at or near half the height of the cross sections of the bar or ingot to be cut.
- The ingots cut with the known shearing machines have ends with very rough and irregular, chipped surfaces; moreover, during cutting the blades make the ingot raise, with the risk of causing damage to people and things around.
- Again for this purpose, the
apparatus 10 is advantageously provided with or connectable to a logic unit (not shown) configured for storing, for example through a database, the various angles of attack and offset of thecutting edges 1062 that are the most suitable for cutting each metal alloy cast by theapparatus 10. - The logic unit can then automatically set the shearing
machine 106 based on the type, or the composition or recipe, of metal alloy chosen for the next casting to be made. - The use of a shearing unit rather than a sawing machine or other cutting unit with chip removal allows to eliminate the considerable waste of recast metal which would form the cutting chips.
- In an embodiment not shown, the blades or cutting
edges 1064 instead of onshearing rotors - The
crucible 28, 28' may comprise acollection tank 280 and achannel 282, 282' configured for pouring the molten metal coming from thecollection tank 280 into the casting die 1 - preferably in the more upstream part of the casting stretch 13- (Figures 16 ,17, 18 ). - The
collection tank 280 can be, for example, open at the top (Figures 16 ,17, 18 ). - The
channel 282, 282' preferably has a tubular shape, with preferably rectangular cross (Figures 16 ,17, 18 ), square or possibly, for example, also polygonal, circular, oval or elliptical sections. - In any case the
channel 282, 282' ends downstream with anoutlet mouth 284, 284' which is advantageously inclined with respect to the longitudinal axis of thechannel 282, 282'. - During normal operation of the apparatus for producing metal bars through
continuous casting 10, thechannel 282, 282' extends generally horizontally or moderately inclined with respect to the horizontal, so that for example its longitudinal axis has an inclination ϕ [phi] with respect to the horizontal ORZ equal to or lower than 45°, or 30°, or 15° or 5°. - Preferably, during normal operation, the axis of the
channel 282, 282' and the axis of the castingchannel stretch 7 into which thechannel 282, 282' introduces the molten metal are substantially parallel or longitudinal to each other. - Advantageously during normal operation the
outlet mouth 284, 284' is substantially inclined with respect to the longitudinal axis of thechannel 282, 282', for example substantially inclined with respect to the stretch that is more downstream of the longitudinal axis of thechannel 282, 282' (Figure 18 , 19, 20) and is not instead substantially perpendicular with respect to said longitudinal axis. - In other words, the
outlet mouth 284, 284' is substantially inclined in the form of a drip cone (Figures 16 ,17, 18 ). - During normal operation, the
outlet mouth 284, 284' can be substantially turned toward the bottom of the casting channel (Figure 16 ,17 ) or turned in a direction away from the bottom of the casting channel (Figure 18 ), with an inclination ψ [psi] with respect to the axis of thechannel 282, 282' in absolute value for example ranging between 5-80°, or between 10-70°, between 30-50°, between 40-50°. - The longitudinal axis of the
channel 282, 282' can be, for example, substantially rectilinear (Figures 16 ,17, 18 ). - During operation at least one stretch of the
channel 282, 282' is at least partially inserted in the casting channel (Figures 16 ,17, 18 ). - For this purpose, some outer walls of the
channel 282, 282' can mate with some inner walls of the castingchannel 7 and have shapes that are for example, complementary to each other, that is, some inner walls of the castingchannel 7 can be substantially a negative copy of some outer walls of thechannel 282, 282'. - Due to the not negligible thickness of the walls of the
channel 282, 282', the molten metal outflowing therefrom rapidly expands due to the sudden variation of the passage sections of the conduit in which it flows. - The drip cone shape of the
outlet mouth 284, 284' makes this expansion less fast, thus also reducing turbulence in the molten metal which might cause slag in the casting and loss of level. - The
outlet mouth 284, 284' turned in a direction away from the bottom of the casting channel (Figure 18 ) is particularly effective in reducing turbulence in the molten metal and making the variation of the passage sections gradual. - An example of possible operation and use of the
continuous casting apparatus 10 is now described. - By rotating the first 15, the second
die advancing wheel 17 and the wheel, pulley orroller 25 or other direction changesupport 25, the chain of thelower die halves 3 and the die-closingbelt 9 are made to advance preferably so that in thecasting stretch 13 they have the same speed with respect for example to the load-bearing frame 27, 27' and therefore slide substantially at the same speed the one with respect to the other. - The molten metal, preferably aluminium or the alloys thereof or other non-ferrous metal - is cast from the
crucible 28, 28' - or in any case at the casting zone 11- into the casting die 1, while the movement of therotatory elements - The metal casting can enter the casting die 1 at the zone in which the
roller conveyor 23 or other firstdirection change support 23 firmly presses the die-closingbelt 9 against the chain oflower die halves 3, closing thecasting channel 7 at the top. - In a first part that is more upstream of the
rectilinear casting stretch 13 the metal is cooled by thefirst nozzles 41, which cool for example with air jets each lower diehalf 3 from the three lower, right and left, sides with reference to the direction of advancement of the casting, and by thesecond nozzles 43 which cool, for example, with jets of water or other cooling liquid - preferably directed from the top downwards - the die-closingbelt 9. - Preliminary cooling by air or other cooling gas offers the following advantages:
- a smaller quantity of water is used - at least 50 less
- by exploiting the thermal inertia of the
lower die halves 3; - a softer cooling is obtained, avoiding the immediate return of the liquid metal inside the very first stretch of the casting channel, which causes potential problems in the solidification step.
- problems of surface quality are avoided if particularly fluid alloys are cast which inevitably have micro-leakages in the initial zone of the casting channel;
- in general, the thermal shock of the materials of the various components is reduced.
- In a second part of the optionally
rectilinear casting zone 13 the metal material is cooled by jets of water from all sides. - Once the casting zone, possibly but not necessarily rectilinear, has been completed, the metal bar now solidified continues its rectilinear advancement, progressively exiting from the casting die, thanks to the change of direction of the chain of
lower die halves 3, which deviates from the rectilinear path resting and winding around the wheel, roller orpulley 15, and also thanks to the change of direction of the die-closingbelt 9 which also deviates from the rectilinear path resting and winding around the wheel, roller orpulley 25. - The bar of solidified metal can then be transported to a cutting
station 106, where it will be cut in such a way as to divide it into a plurality of ingots or in any case segments of the desired length. - During their path, in addition to cooling, the die halves 3 are advantageously washed by the first 41, by the second 43 and by the
third nozzles 45. - In particular, the
third nozzles 45 contribute considerably to washing also the inside of the castingchannel 7, since they are either facing or in any case turned toward it; for example, in thereturn stretch 32 if the die halves 3 advance with the stretches of the casting channel turned downwards, thethird nozzles 45 are preferably turned upwards. - From the previous description it is clear that the
continuous casting apparatus 10 described above allows to close better, in particular with a better tightness against leakage of liquid metal, the castingchannel 7 by means of the die-closingbelt 9 at or near the castingzone 11, thus stressing and damaging less the die-closingbelt 9, imposing it greater radii of curvature at the first 23 and at the possible seconddirection change support 25. - The decoupling between the adjustment movements of the first 23 and of the second
direction change support 25 as well as thepressers 35 and of therelative fastenings bearing frame 27, 27' further contributes to reducing the mechanical and fatigue stresses in the die-closingbelt 9 and to extending the operating life thereof, and further contributes to improving the tightness against molten metal leakage over the entire length of the casting channel. - Thanks to the cooling system by air or other gas, the
apparatus 10 also allows to bring thelower die halves 3 back to a lower temperature - when appropriate - in the
casting zone 11, at the same time reducing the contaminations of the molten metal caused by the cooling water and cooling the molten metal in a softer and more gradual manner in thecasting zone 11. - In its
return stretch 32 the chain oflower die halves 3 can be firmly supported by guides on which theadvancement projections 6 slide. - Again in its
return stretch 32 the chain oflower die halves 3 can be effectively washed by means of further nozzles not shown. - The embodiments previously described are subject to different modifications and variations without departing from the scope of protection of the present invention.
- For example, in a fourth aspect thereof, the present invention relates to an apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5), and wherein:
- each lower die half (3) forms the bottom (70) and the flanks (71) of a casting channel stretch (7), is open on the flank opposite to the side of the bottom (70) of the respective casting channel stretch (7) and at the ends adjacent to the die halves (3) immediately preceding and following the lower die half (3) considered;
- the plurality of lower die halves (3) is configured for advancing along a path that downstream of the casting zone (11) forms a casting for example rectilinear stretch (13) in which the casting channel stretches (7) of at least part of the lower die halves (3) are aligned along a common casting, for example substantially rectilinear axis;
- the path of the lower die halves (3) downstream of the casting for example rectilinear stretch (13), changes direction so as to detach the lower die halves (3) from a metal bar formed by the metal that has solidified in the casting for example rectilinear stretch (13);
- the upper closure system (5) comprises:
- a die-closing belt (9) made of metal material and closed on itself which, at the casting for example rectilinear stretch (13), closes a part of the lower die halves (3) on the side opposite to their bottoms (70) of the stretches of the casting channel (7), which die-closing belt (9) at or near the casting zone (11) forms a first direction change stretch;
- a belt-pressing system (21) configured for pressing the die-closing belt (9) against the open flanks of the lower die halves (3) at least in correspondence with at least part of the casting for example rectilinear stretch (13) and comprising at least a first direction change support (23) located at or near the casting zone (11) and configured for resting against the die-closing belt (9) and to guide it along the first direction change stretch so that at the exit from the latter it advances in a direction different from that in which it enters the first direction change stretch;
- In a fifth aspect thereof, the present invention relates to an apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5), and wherein:
- each lower die half (3) forms the bottom (70) and the flanks (71) of a casting channel stretch (7), is open on the flank opposite to the side of the bottom (70) of the respective casting channel stretch (7) and at the ends adjacent to the die halves (3) immediately preceding and following the lower die half (3) considered;
- the plurality of lower die halves (3) is configured for advancing along a path that downstream of the casting zone (11) forms a casting for example rectilinear stretch (13) in which the casting channel stretches (7) of at least part of the lower die halves (3) are aligned along a common casting path (TRC), for example substantially rectilinear axis;
- the path of the lower die halves (3) downstream of the casting for example rectilinear stretch (13), changes direction so as to detach the lower die halves (3) from a metal bar formed by the metal that has solidified in the casting for example rectilinear stretch (13);
- the upper closure system (5) comprises:
- a die-closing belt (9) made of metal material and closed on itself which, at the casting for example rectilinear stretch (13), closes a part of the lower die halves (3) on the side opposite to their bottoms (70) of the stretches of the casting channel (7), which die-closing belt (9) at or near the casting zone (11) forms a first direction change stretch;
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the casting path (TRC) forms a substantially rectilinear casting axis.
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the casting stretch (13) is substantially rectilinear.
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the casting stretch (13) is configured for containing and solidifying the molten metal.
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, in the casting stretch (13) the casting path (TRC) is substantially concave having the concavity turned downwards.
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, in the casting stretch (13) the casting path (TRC) comprises an arc of circumference.
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the lower die halves (3) are fixed one after the other so as to substantially form a chain closed on itself, the chain of the lower die halves (3) forms the casting stretch (13) and a return stretch (32), by travelling along said return stretch the lower die halves (3) move from the more downstream end of the casting stretch (13) to the casting zone (11), in at least part of the return stretch (32) the chain of the lower die halves (3) possibly follows a convex path the convexity of which is turned downwards.
- In a particular embodiment, an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention is configured for making the lower die halves (3) advance by tensioning the chain formed by them at least in the casting stretch (13).
- In a particular embodiment, an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention comprises a first die advancing wheel (15) arranged at or near the downstream end of the casting stretch (13), and the apparatus (10) is configured for tensioning the chain formed by the lower die halves (3) by dragging said chain through the first die advancing wheel (15).
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the first direction change support (23) comprises a roller conveyor in turn comprising at least three direction change rolling bodies (108) configured for resting against the die-closing belt (9) during normal operation of the continuous casting apparatus (10), wherein said rolling bodies (108) may be, for example, wheels, pulleys or rollers.
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the roller conveyor of the first direction change support (23) is provided with at least five, and possibly at least ten direction change rolling bodies (108), for each meter of length of the linear development of the stretch of the die-closing belt (9) which rests against the roller conveyor (23).
- In a particular embodiment of an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention, the roller conveyor of the first direction change support (23) is configured for guide the die-closing belt (9) along a first roller conveyor stretch (TR1) of its path having a first average radius of roller conveyor curvature (RC1), and a second roller conveyor stretch (TR2) having a second average radius of roller conveyor curvature (RC2) substantially lower than the first radius of roller conveyor curvature (RC1).
- In a particular embodiment, an apparatus (10) for producing metal bars through continuous casting according the fifth aspect of the present invention comprises a load-bearing frame (27, 27') configured for resting on a floor, and wherein the first direction change support (23) is fixed to the load-bearing frame (27, 27') so as to be able to vary its position with respect to the latter by adjusting the pressure with which said first support (23) presses the die-closing belt (9) against the lower die halves (3) by closing the casting channel at the top at least at or near the casting zone (11), the second direction change support (25) is fixed to the load-bearing frame (27, 27') so as to be able to adjust the tension of the die-closing belt (9) and to vary its position with respect to the latter with movements that are substantially independent with respect to those of the first direction change support (23), and/or moving according to one or more degrees of freedom that are substantially independent of the one or more degrees of freedom according to which the first direction change support (23) moves.
- In a sixth aspect thereof, the present invention relates to the use of an apparatus (10) having the features according to the fifth aspect of the present invention, for producing bars of a non-ferrous metal, such as aluminium or alloys thereof, through continuous casting.
- In a seventh aspect thereof, the present invention relates to a process for producing metal bars through continuous casting, comprising the following operations:
- providing an apparatus (10) for producing metal bars through continuous casting having the features according to the fifth aspect of the present invention;
- by means of the one or more first nozzles (41), bringing or maintaining the temperature of one or more lower die halves (3) in an interval of about 10-40 degrees centigrade.
- In an eigth aspect thereof, the present invention relates to an apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5), and wherein:
- each lower die half (3) forms the bottom (70) and the flanks (71) of a casting channel stretch (7), is open on the flank opposite to the side of the bottom (70) of the respective casting channel stretch (7) and at the ends adjacent to the die halves (3) immediately preceding and following the lower die half (3) considered;
- the plurality of lower die halves (3) is configured for advancing along a path that downstream of the casting zone (11) forms a casting for example rectilinear stretch (13) in which the casting channel stretches (7) of at least part of the lower die halves (3) are aligned along a common casting, for example substantially rectilinear axis;
- the path of the lower die halves (3) downstream of the casting for example rectilinear stretch (13), changes direction so as to detach the lower die halves (3) from a metal bar formed by the metal that has solidified in the casting for example rectilinear stretch (13);
- the upper closure system (5) comprises a die-closing belt (9) made of metal material and closed on itself which, at the casting for example rectilinear stretch (13), closes a part of the lower die halves (3) on the side opposite to their bottoms (70) of the stretches of the casting channel (7), which die-closing belt (9) at or near the casting zone (11) forms a first direction change stretch;
- in the casting stretch (13) the casting path (TRC) is substantially concave with concavity turned downwards.
- In a ninth aspect thereof, the present invention relates to an apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5) and a crucible (28, 28'), and wherein:
- each lower die half (3) forms the bottom (70) and the flanks (71) of a casting channel stretch (7), is open on the flank opposite to the side of the bottom (70) of the respective casting channel stretch (7) and at the ends adjacent to the die halves (3) immediately preceding and following the lower die half (3) considered;
- the plurality of lower die halves (3) is configured for advancing along a path that downstream of the casting zone (11) forms a casting for example rectilinear stretch (13) in which the casting channel stretches (7) of at least part of the lower die halves (3) are aligned along a common casting, for example substantially rectilinear axis;
- the upper closure system (5), at the casting for example rectilinear stretch (13), is configured for closing a part of the lower die halves (3) on the side opposite to their bottoms (70) of the stretches of the casting channel (7);
- the crucible (28, 28') is configured for cast molten metal into the casting channel (7) and comprises a channel (282, 282') configured for being inserted at least partially in the casting channel (7) and to introduce the molten metal therein;
- the channel (282, 282') ends with an outlet mouth (284, 284') which is advantageously inclined with respect to the longitudinal axis of the channel (282, 282').
- The concave path TRC of the
lower die halves 3 in thecasting stretch 13 may have a shape tolerance TLR the absolute and overall value thereof is, for example, equal to PRTMAX/2, or PRTMAX/4 to PRTMAX/8 or to PRTMAX/10; the band defined by this shape tolerance and within which the shape of the casting path TRC may vary is schematically indicated by the dashed band ofFigure 13 . - In a tenth aspect thereof, the present invention relates to a cutting station (106) configured for shearing or blanking metal bars and ingots, for example the bars and the ingots produced by the casting die (1), and comprising at least one pair of cutting blades
- (1064) configured for cutting the bar or ingot by pressing in substantially opposite or opposed directions, wherein the cutting station (106) is configured for ending the cutting strokes of the pair of cutting blades (1064) substantially at or near the shear center of the cross sections of the bar or ingot to be cut.
- In an eleventh aspect thereof, the present invention relates to a cutting station (106) configured for shearing or blanking metal bars and ingots, for example the bars and ingots produced by the casting die (1), and comprising at least one pair of cutting blades (1064) configured for cutting the bar or ingot by pressing in substantially mutually opposite or opposed directions, and a pair of actuators (1066, 1068) each of which is configured for actuating a respective cutting blade (1064), and each actuator (1066, 1068) can impose on its respective cutting blade (1064) cutting movements and trajectories that are substantially independent of those imposed by the other actuator (1068, 1066) on its cutting blade (1064).
- These actuators (1066, 1068) may be rotary electric motors, each of which is arranged or in any case adapted to rotate the respective cutting blade (1064) with rotations that are substantially independent of the rotations imposed by the other motor, for example, rotations at a speed substantially different from that of the other motor and/or by suitably phase shifting the rotations of the two blades (1064), and/or by making sure that one comes into contact with the bar or ingot to be cut before the other.
- In a variant embodiment not shown, the cutting blades (1064) can cut the bars or ingots by translating or roto-translating with respect to the bars and with respect to the ingots and not only by rotating.
- Every reference in this description to "an embodiment", "an example of embodiment" means that a particular feature or structure described in relation to such embodiment is comprised in at least one embodiment of the invention and in particular in a particular variant of the invention as defined in a main claim.
- The fact that such expressions appear in various steps of the description does not imply that they necessarily only refer to the same embodiment.
- Furthermore, when a feature, element or structure is described in relation to a particular embodiment, it is observed that it falls within the skills of the average person skilled in the art to apply such feature, element or structure to other embodiments.
- Numerical references that only differ in terms of
different superscripts 21', 21", 21 III unless specified otherwise indicate different variants of an element with the same name. - Moreover, all details may be replaced with other technically equivalent elements.
- For example, the materials used, and the dimensions, may be any according to the technical requirements.
- It is to be understood that an expression of the type "A comprises B, C, D" or "A is formed by B, C, D" also comprises and describes the special case in which "A is comprised of B, C, D".
- The expression "A comprises an element B" unless specified otherwise can be interpreted as "A comprises one or more elements B".
- References to a "first, second, third, ... n-th entity" have the sole aim of distinguishing them from one another but the indication of the n-th entity does not necessarily imply the existence of the first, second ... (n-1)th entity.
- The examples and lists of possible variations of this application are to be considered as non-exhaustive lists.
Claims (15)
- Apparatus (10) for producing metal bars through continuous casting, comprising a continuous casting die (1) in turn comprising a casting zone (11) configured for receiving molten metal, a plurality of lower die halves (3) arranged in succession the one after the other and an upper closure system (5), and wherein:- each lower die half (3) forms the bottom (70) and the flanks (71) of a casting channel stretch (7), is open on the flank opposite to the bottom side (70) of the respective casting channel stretch (7) and at the ends adjacent to the die halves (3) immediately preceding and following the lower die half (3) considered;- the plurality of lower die halves (3) is configured for advancing along a path that downstream of the casting zone (11) forms a casting stretch (13) in which the casting channel stretches (7) of at least part of the lower die halves (3) are aligned along a common casting axis (TRC);- the path of the lower die halves (3) downstream of the casting stretch (13), changes direction so as to detach the lower die halves (3) from a metal bar formed by the metal that has solidified in the casting stretch (13);- the upper closure system (5) comprises:wherein the apparatus (10) further comprises a cooling system (40) comprising one or more first nozzles (41) each of which is configured for striking the die halves (3) with a jet of air or other cooling gas at least at part of the casting stretch (13), so as to cool the casting.- a die-closing belt (9) made of metallic material and closed on itself which, at the casting stretch (13), closes a part of the lower die halves (3) on the side opposite to their bottoms (70) of the stretches of the casting channel (7), which die-closing belt (9) at or near the casting zone (11) forms a first direction change stretch;
- Apparatus (10) according to claim 1, comprising a cooling system (40) comprising one or more first nozzles (41) each of which is configured for striking with a jet of air or other cooling gas the die halves (3) at least at part of the casting stretch (13), so as to cool said part.
- Apparatus (10) at least according to claim 2, wherein the cooling system (40) comprises one or more second nozzles (43) each of which is configured for striking with a jet of water or other cooling liquid the die halves (3) and/or the die-closing belt (9) at least at part of the casting stretch (13), so as to cool them.
- Apparatus (10) according to one or more of the preceding claims, wherein one or more of the first nozzles (41) is/are configured for striking with a jet of air or other cooling and/or cleaning gas the die halves (3) at least at a first part of the casting stretch (13) at or near the casting zone (11).
- Apparatus (10) at least according to claim 3, wherein one or more of the second nozzles (43) is/are configured for strike with a jet of water or other cooling and/or cleaning liquid the die halves (3) and/or the die-closing belt (9) at least at a second part of the casting stretch (13) downstream of the first part of the stretch of the casting channel (13).
- Apparatus (10) according to one or more of the preceding claims, wherein the first nozzles (41) are configured for flushing with a jet of air or other cooling gas the lower die halves (3) at the most upstream portion of the casting stretch (13), which stretch is for example rectilinear.
- Apparatus (10) according to one or more of the preceding claims, wherein the first nozzles (41) are arranged so as to strike the lower die halves (3) from the bottom and from both sides, right and left sides, with respect to the casting axis.
- Apparatus (10) according to claim 3 and/or 5, wherein the second nozzles (43) are arranged so as to strike with jets of water or other cooling and/or cleaning liquid the lower die halves (3) at least at the casting stretch (13), which stretch is for example rectilinear, downstream of the first nozzles (41) and/or in such a way as to strike with water jets the die-closing belt (9).
- Apparatus (10) according to claim 3 and/or 5, wherein the second nozzles (43) are arranged so as to strike with jets of water or other cooling and/or cleaning liquid the face of the die-closing belt (9) turned towards the outside of the casting channel (7).
- Apparatus (10) according to claim 3, 5, 8, 9 wherein the second nozzles (43) are arranged so as to flush with water or other cooling and/or cleaning liquid the die-closing belt (9) along at least 70% of the casting stretch, which stretch is for example rectilinear.
- Use of an apparatus (10) having the features according to one or more of the preceding claims, for producing bars of a non-ferrous metal, such as aluminium or alloys thereof, through continuous casting.
- Process for producing metal bars through continuous casting, comprising the following steps:- providing an apparatus (10) for producing metal bars through continuous casting having the features at least according to claim 2 or 3;- by means of the one or more first nozzles (41), bringing or maintaining the temperature of one or more lower die halves (3) in an interval of about 10-40 degrees centigrade.
- Process according to claim 12, comprising the following steps:S.13.1) providing an apparatus (10) for producing metal bars through continuous casting having the features according to claim 7;S.13.2) through one or more first nozzles (41) of said cooling system (40) striking the lower die halves (3), so as to cool them, with a jet of air or other cooling gas at least at the most upstream portion of the casting stretch (13), wherein said most upstream portion comprises or coincides with the hypercritical stretch of the casting channel.
- Process according to claim 12 or 13, wherein the first nozzles (41) emit air having one or more of the following features:- it is at room temperature;- it is by 10-20°C colder than room temperature.
- Process according to one or more claims from 12 to 14, wherein the apparatus (10) for producing metal bars through continuous casting cools the lower die halves (3) by means of air jets, bringing the lower die halves (3) to a temperature comprised between 10-60°C at least in the half of the casting stretch (13) closest to the casting zone (11).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT102020000000457A IT202000000457A1 (en) | 2020-01-13 | 2020-01-13 | DEVICE AND PROCEDURE FOR PRODUCING METAL BARS BY CONTINUOUS CASTING |
EP21151431.0A EP3848133B1 (en) | 2020-01-13 | 2021-01-13 | Apparatus and process for producing metal bars through continuous casting |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP21151431.0A Division EP3848133B1 (en) | 2020-01-13 | 2021-01-13 | Apparatus and process for producing metal bars through continuous casting |
EP21151431.0A Division-Into EP3848133B1 (en) | 2020-01-13 | 2021-01-13 | Apparatus and process for producing metal bars through continuous casting |
Publications (2)
Publication Number | Publication Date |
---|---|
EP4316691A2 true EP4316691A2 (en) | 2024-02-07 |
EP4316691A3 EP4316691A3 (en) | 2024-03-13 |
Family
ID=70295730
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP23208638.9A Pending EP4316691A3 (en) | 2020-01-13 | 2021-01-13 | Apparatus and process for producing metal bars through continuous casting |
EP21151431.0A Active EP3848133B1 (en) | 2020-01-13 | 2021-01-13 | Apparatus and process for producing metal bars through continuous casting |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP21151431.0A Active EP3848133B1 (en) | 2020-01-13 | 2021-01-13 | Apparatus and process for producing metal bars through continuous casting |
Country Status (2)
Country | Link |
---|---|
EP (2) | EP4316691A3 (en) |
IT (1) | IT202000000457A1 (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5820356B2 (en) | 1979-06-20 | 1983-04-22 | 昭和ロツク株式会社 | cylinder lock |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4061177A (en) * | 1975-04-15 | 1977-12-06 | Alcan Research And Development Limited | Apparatus and procedure for the belt casting of metal |
US4331195A (en) * | 1978-08-08 | 1982-05-25 | Webber C Eugene | Continuous casting machine |
JPS6120648A (en) * | 1984-07-09 | 1986-01-29 | Nippon Kokan Kk <Nkk> | Synchronous type horizontal and continuous casting device |
JPH01309764A (en) * | 1988-06-08 | 1989-12-14 | Ishikawajima Harima Heavy Ind Co Ltd | Caterpillar type continuous casting machine |
US5964276A (en) * | 1998-07-24 | 1999-10-12 | Hazelett Strip-Casting Corporation | Edge-DAM blocks having abuttable upstream and downstream faces meshing with each other in mating relationship for continuous casting of molten metals--methods and apparatus |
ITUB20160568A1 (en) * | 2016-02-08 | 2017-08-08 | Giulio Properzi | MACHINE FOR PRODUCTION, USING CONTINUOUS CASTING, OF NON-FERROUS METAL BARS. |
-
2020
- 2020-01-13 IT IT102020000000457A patent/IT202000000457A1/en unknown
-
2021
- 2021-01-13 EP EP23208638.9A patent/EP4316691A3/en active Pending
- 2021-01-13 EP EP21151431.0A patent/EP3848133B1/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5820356B2 (en) | 1979-06-20 | 1983-04-22 | 昭和ロツク株式会社 | cylinder lock |
Also Published As
Publication number | Publication date |
---|---|
IT202000000457A1 (en) | 2021-07-13 |
EP3848133A1 (en) | 2021-07-14 |
EP4316691A3 (en) | 2024-03-13 |
EP3848133B1 (en) | 2023-12-20 |
EP3848133C0 (en) | 2023-12-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN104379270B (en) | Method for the injection apparatus of rolling equipment and for removing from mill stand/inserting the system in mill stand the system | |
KR20140037205A (en) | Locking bolt and method for manufacturing same | |
EP4316691A2 (en) | Apparatus and process for producing metal bars through continuous casting | |
CN105473746A (en) | System for thermal treatment of rails | |
JP4287572B2 (en) | Rotary hearth furnace | |
EP2505284A2 (en) | Twin roll casting machine | |
CN112658051A (en) | Wire drawing device is used in cable processing with protection is kick-backed in fracture | |
US20110083486A1 (en) | Bush widening apparatus and process for forging a bush blank | |
CN104768678B (en) | Mold conveyer | |
CN201326006Y (en) | Auto-cleaning device for the lip mouth of air knife | |
JP4814814B2 (en) | Die lubricator for forging press | |
JP2005528218A (en) | Equipment for cooling the rolling material inside the cooling section of the rolling equipment | |
JP5639369B2 (en) | Continuous casting method and apparatus for producing rough profiles, in particular double T-shaped rough profiles | |
JPH11254111A (en) | Steel continuous casting equipment provided with deburring device for cut-off burr of slab, bloom and billet | |
KR20120107344A (en) | Duburrer | |
CN214735866U (en) | Drill rod moving bracket device of tapping machine | |
CN211360590U (en) | Adjustable front guide of withdrawal and straightening machine | |
CN211564122U (en) | Forming vertical roller assembly for circular tube forming | |
US3822738A (en) | Apparatus for guiding an oscillating continuous casting mold at a continuous casting installation with curved path of travel of the strand | |
CN110814310B (en) | Front-mounted guiding device of tension leveler | |
CA2015120A1 (en) | Arc-type plant for continuously casting steel strands, with an oscillatory continuous casting mould | |
RU45947U1 (en) | DEVICE FOR SCALE REMOVAL IN THE CONTINUOUS STEEL MILLING MACHINE | |
KR20080097610A (en) | Apparatus for lifting weir of meniscus shield in the twin roll type strip caster | |
CN211757638U (en) | Water-immersed square billet cooling bed | |
CN219597946U (en) | Flying shear for section steel |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED |
|
AC | Divisional application: reference to earlier application |
Ref document number: 3848133 Country of ref document: EP Kind code of ref document: P |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R079 Free format text: PREVIOUS MAIN CLASS: B22D0011060000 Ipc: B22D0011000000 |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: B22D 11/06 20060101ALI20240207BHEP Ipc: B22D 11/00 20060101AFI20240207BHEP |