US20100186940A1 - Method, Device and System for the Heat Treatment of a Moving Metal Strip - Google Patents
Method, Device and System for the Heat Treatment of a Moving Metal Strip Download PDFInfo
- Publication number
- US20100186940A1 US20100186940A1 US12/668,534 US66853408A US2010186940A1 US 20100186940 A1 US20100186940 A1 US 20100186940A1 US 66853408 A US66853408 A US 66853408A US 2010186940 A1 US2010186940 A1 US 2010186940A1
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- Prior art keywords
- strip
- heat
- segment
- metal strip
- roller
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- 238000010438 heat treatment Methods 0.000 title claims abstract description 57
- 239000002184 metal Substances 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000001816 cooling Methods 0.000 claims abstract description 35
- 239000007787 solid Substances 0.000 claims abstract description 16
- 230000005540 biological transmission Effects 0.000 claims abstract description 8
- 238000000137 annealing Methods 0.000 claims description 15
- 238000011144 upstream manufacturing Methods 0.000 claims description 14
- 230000000694 effects Effects 0.000 claims description 4
- 229910000831 Steel Inorganic materials 0.000 description 15
- 239000010959 steel Substances 0.000 description 15
- 239000007789 gas Substances 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 239000003517 fume Substances 0.000 description 4
- 238000009434 installation Methods 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000012809 cooling fluid Substances 0.000 description 3
- 230000000750 progressive effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 230000001172 regenerating effect Effects 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000005097 cold rolling Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 239000000112 cooling gas Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/54—Furnaces for treating strips or wire
- C21D9/56—Continuous furnaces for strip or wire
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
- F27B9/28—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity for treating continuous lengths of work
Definitions
- the present invention relates to a method, device and system for the heat treatment of a moving metal strip.
- One type of heat treatment method is the one known as annealing.
- an annealing method the metal is heated in order to reach temperatures ranging for example from 500° C. to 1100° C. and then cooled in order to modify the crystalline structure of the metal.
- One drawback of such a method, as well as other heat treatment methods, is its high consumption of energy.
- steel production it is frequently necessary to anneal sheets after prior cooling, for example in the case of cold rolling.
- the heating of the sheet is obtained by passing it in front of radiant tubes in which fume gases circulate coming from the combustion of a fuel and air.
- the heat consumed is, despite this recovery, around 1.7 times the heat found in the metal sheet, which corresponds to an efficiency of 60%.
- the cooling gas is blown in a cascade onto the tubes, from one cooling step to the previous one, as described in the international patent application WO 00/25076,
- This method although efficient in theory, cannot be put into industrial practice on sheet-metal annealing lines with a high heating capacity, more than around 40 t/hour. It is in fact impossible to effectively collect the gas flows heated and cooled successively in the various sections of the cascade.
- Such a regenerative method comprises heating of the strip, cooling of the heated strip, and transfer of heat from at least one segment of the strip being cooled to at least one segment of the strip being heated, so as to effect at least some of each of the said cooling and heating of the strip.
- the said heat transfer is effected by circulation of a heat-transfer gas.
- This has the drawbacks of offering only a reduced heat transfer rate and requiring a supplementary addition of energy in order to actuate the circulation of the heat-transfer gas.
- any gain in transfer of heat is more than compensated for by the additional work necessary for making the gas circulate more quickly.
- the problem to be solved is therefore the reduction in the energy consumption in a method of heat treatment of a moving metal strip.
- this problem is solved by effecting the said transfer of heat mainly by conduction.
- the heat is transmitted very effectively without requiring a high supplementary addition of energy in the form of work.
- the transfer heat by conduction is the most effective form of heat transfer.
- the said heat transfer is effected from a plurality of segments of the strip being heated to a plurality of segments of the strip being cooled in reverse order in the direction of travel of the strip.
- the said heat transfer is effected from a plurality of segments of the strip being heated to a plurality of segments of the strip being cooled in reverse order in the direction of travel of the strip.
- the strip is also heated by a source of heat external to the strip.
- a thermal differential serving to impel the said heat transfer is created between the strip being cooled and the strip being heated.
- the said heat transfer is effected by means of at least one heat-conducting solid element in contact with a segment of the strip being heated and a segment of the strip being cooled.
- the heat conduction between the segment of the strip being heated and the segment of the strip being cooled is provided by the said solid element.
- the said at least one heat-conducting solid element is in the form of a roller, preferably metal.
- a roller can provide continuous contact, and therefore good conduction of heat, with the two segments of the moving strip.
- the segment of the strip being cooled is in contact with the said roller at a contact angle of at least 20′, preferably at least 30°. With such a contact angle, it is possible to offer a good contact surface between roller and strip, and therefore good heat transfer.
- the segment of the strip being heated is in contact with the said roller at a contact angle of at least 20°, preferably at least 30°.
- the temperature difference between a segment of metal strip being cooled and a segment of strip being heated between which at least some of the said heat transfer takes place by conduction is at least 200° C. and/or below 500° C. Such a temperature difference would allow effective heat transfer, without causing excessive thermal shock in the metal strip.
- the present invention also relates to a heat transmission device for simultaneously heating a moving metal strip upstream of an additional heating zone and cooling it downstream of the said additional heating zone.
- the device comprises at least one heat-conducting solid element intended to be in contact with the said metal strip both upstream and downstream of the main heating zone, so as to transfer heat by conduction between at least one segment of the metal strip downstream and at least one segment of the metal strip upstream.
- the device comprises a series of several solid heat conducting elements, for example five, for successively contacting the said metal strip both upstream and, in reverse order in the direction of travel of the strip, downstream of the main heating zone, so as to transfer heat by conduction between segments of the metal strip downstream and segments of the metal strip upstream.
- solid heat conducting elements for example five, for successively contacting the said metal strip both upstream and, in reverse order in the direction of travel of the strip, downstream of the main heating zone, so as to transfer heat by conduction between segments of the metal strip downstream and segments of the metal strip upstream.
- the device also comprises at least one deflector roller in order to define a contact angle, preferably at least 20°, between the said metal strip upstream and/or downstream of the furnace and the said heat-conducting solid element in the form of a roller.
- the present invention also relates to a system for the continuous heat treatment, in particular annealing, of a moving metal strip comprising a main heating zone and a heat-transmission device according to the invention.
- FIG. 1 shows a diagram of a prior method
- FIG. 2 shows a diagram of a method according to an embodiment of the invention
- FIG. 3 shows a heat treatment system according to an embodiment of the invention
- FIG. 4 shows a heat treatment system according to an alternative embodiment of the invention
- FIG. 5 shows a heat transmission device according to an embodiment of the invention
- FIG. 6 shows curves for heating and cooling the metal strip that can be obtained with the heat transmission device of FIG. 5 .
- FIG. 1 a conventional method for the continuous annealing of a moving steel strip is illustrated schematically. After cleaning 1 of the strips, the latter is heated from 30° C. to 800° C. in a heating step 2 in a radiant tube furnace. This specifies an energy addition Q of 210 kW per tonne of steel, in the form of natural gas, producing by its combustion 50 kg of CO2 and 80 mg of NOx per tonne of steel.
- FIG. 2 an embodiment of the method of the present invention is shown schematically.
- the steel strip is heated after cleaning 1 .
- the heating is divided into a preheating step 2 a in which the steel strip is preheated from 30° C. to 450° C., and a main heating step 2 b in a radiant-tube furnace, in which the strip is heated from 450° C. to 800° C.
- the heat Q′ transferred to the strip in the preheating strip 2 a comes from the cooling 3 of the same strip from 800° C. to 450° C. and is transmitted by conduction.
- FIG. 3 shows a system 4 for the continuous annealing of a moving steel strip 5 , according to one embodiment of the invention.
- This system 4 comprising a device 6 for transmitting heat by conduction for the preheating 2 a and cooling 3 of the strip 5 , and a furnace 7 with radiant tubes 8 for the additional heating 2 b of the strip 5 .
- the furnace 7 with radiant tubes 8 is of the vertical type.
- the alternative of a horizontal arrangement of the furnace 7 with radiant tubes 8 can also be considered, as illustrated in FIG. 4 .
- the heat-transmission device 6 is illustrated in greater detail in FIG. 5 .
- the strip 5 enters the device 6 through the entry opening 9 and passes through the said device 6 in the direction 10 as far as the furnace 7 while being preheated. After the main heating 2 b, the strip 5 leaves the furnace again and passes through the device 6 in the opposite direction 11 as far as the exit opening 12 while cooling.
- the device 6 comprises an alignment of seven heat-conducting rollers 6 and two alignments of six deflector rollers 14 , one on each side of the alignment of conductive rollers 13 .
- both the conductive rollers 13 and the deflector rollers 14 have a diameter of 800 mm.
- the conductive rollers 13 must have a diameter capable of providing a good contact surface with the strip 5 with a relatively low speed of rotation, while avoiding a plastic deformation of the strip 5 .
- the deflector rollers 14 must also have a diameter avoiding plastic deformation of the strip 5 . According to the geometric and mechanical parameters of the strip 5 , the conductive 13 and deflector 14 rollers may therefore have diameters situated, for example, in a range between 400 and 1600 mm.
- the speed of the strip 5 during cooling is normally greater than its speed during heating.
- the conductive roller 13 could have an angularly variable radius making it possible to adjust the effective radius of the conductive roller 13 to the speed of the strip 5 on each side of the conductive roller 13 .
- Another solution that can be envisaged is that the conductive roller 13 is divided into radial segments, having a certain freedom of angular movement relative to one another.
- each conductive roller 13 thus transfers heat by conduction from a segment 5 b of the strip 5 during cooling to a segment 5 a of the strip during heating.
- the strip 5 contacts the conductive rollers 13 in reverse order in its travel during heating and during cooling.
- Table 1 presents the parameters of an embodiment of the heat treatment method of the invention in the device 6 described above with a strip 5 with a thickness of 1 mm, a width of 1500 mm and a travel speed of 150 m/min for a production of 106 tonnes per hour.
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Thermal Sciences (AREA)
- Physics & Mathematics (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Tunnel Furnaces (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
Abstract
The invention relates to a method for the heat treatment of a running metal strip, which comprises: a heating step for heating the strip; a step for cooling the heated strip; and conductive heat transfer from at least one segment of the strip which is being cooled to at least one segment of the strip which is being heated, so that at least part of each of said cooling and heating steps is carried out on the strip. The invention also relates to a heat transmission device for implementing said method and having at least one thermally conductive solid element, such as for example a roll, and to a system for the heat treatment of a running metal strip that incorporates such a device.
Description
- The present invention relates to a method, device and system for the heat treatment of a moving metal strip.
- In the metallurgical field, it is generally known by persons skilled in the art how to heat treat metal strips in order for example to modify the crystalline structure of the metal to improve its mechanical or other characteristics. Particularly advantageously, such a method can be effected continuously, by circulating the metal strip through a plurality of zones at different temperatures. This makes it possible for example to integrate the heat treatment of the metal strip in a continuous production line, with certain advantages of economic efficiency.
- One type of heat treatment method is the one known as annealing. In an annealing method the metal is heated in order to reach temperatures ranging for example from 500° C. to 1100° C. and then cooled in order to modify the crystalline structure of the metal. One drawback of such a method, as well as other heat treatment methods, is its high consumption of energy. In steel production, it is frequently necessary to anneal sheets after prior cooling, for example in the case of cold rolling. In conventional continuous annealing installations, the heating of the sheet is obtained by passing it in front of radiant tubes in which fume gases circulate coming from the combustion of a fuel and air. In these installations, provision has already been made for recovering heat from the fumes leaving the radiant tubes in order to preheat the combustion air. However, given the losses of heat through the fumes and the leakages in the chamber of the annealing installation, the heat consumed is, despite this recovery, around 1.7 times the heat found in the metal sheet, which corresponds to an efficiency of 60%.
- Typically, for annealing at 800° C., 50 kg of CO2/t of steel is produced, if the fuel gas is methane. Given that, after the thermal cycle, the temperature of the steel returns to its initial temperature, that is to say the one before annealing, the heat consumed is situated entirely in the atmosphere, and/or in the cooling agent.
- Though insulating the hot parts of the installation and improving the efficiency of the fume recuperators makes it possible to improve the global efficiency, it is extremely difficult to radically reduce the energy consumption without affecting the very basis of the heating and cooling system.
- Provision has also been made to improve the efficiency of the cooling of steel objects, such as tubes, subjected to continuous annealing and then cooling in several steps. To do this, the cooling gas is blown in a cascade onto the tubes, from one cooling step to the previous one, as described in the international
patent application WO 00/25076, This method, although efficient in theory, cannot be put into industrial practice on sheet-metal annealing lines with a high heating capacity, more than around 40 t/hour. It is in fact impossible to effectively collect the gas flows heated and cooled successively in the various sections of the cascade. - For this reason, it has also been proposed to use regenerative methods, where at least some of the heat removed from the metal strip during cooling thereof is used for preheating. Such a regenerative method, described in the international application WO 2004/063402 and forming the closest prior art, comprises heating of the strip, cooling of the heated strip, and transfer of heat from at least one segment of the strip being cooled to at least one segment of the strip being heated, so as to effect at least some of each of the said cooling and heating of the strip.
- However, in this prior art, the said heat transfer is effected by circulation of a heat-transfer gas. This has the drawbacks of offering only a reduced heat transfer rate and requiring a supplementary addition of energy in order to actuate the circulation of the heat-transfer gas. By increasing the rate of circulation of the gas beyond a certain point, any gain in transfer of heat is more than compensated for by the additional work necessary for making the gas circulate more quickly.
- The problem to be solved is therefore the reduction in the energy consumption in a method of heat treatment of a moving metal strip.
- In the present invention, this problem is solved by effecting the said transfer of heat mainly by conduction. In this way, the heat is transmitted very effectively without requiring a high supplementary addition of energy in the form of work. The transfer heat by conduction is the most effective form of heat transfer.
- Preferably, the said heat transfer is effected from a plurality of segments of the strip being heated to a plurality of segments of the strip being cooled in reverse order in the direction of travel of the strip. In this way it is possible to effect a high transfer of heat while maintaining moderate temperature gradients, and therefore avoiding internal tensions and deformations in the metal strip.
- Preferably, in the said step of heating the strip, the strip is also heated by a source of heat external to the strip. In this way a thermal differential serving to impel the said heat transfer is created between the strip being cooled and the strip being heated.
- Preferably, the said heat transfer is effected by means of at least one heat-conducting solid element in contact with a segment of the strip being heated and a segment of the strip being cooled. In this way, the heat conduction between the segment of the strip being heated and the segment of the strip being cooled is provided by the said solid element.
- Preferably, the said at least one heat-conducting solid element is in the form of a roller, preferably metal. Such a roller can provide continuous contact, and therefore good conduction of heat, with the two segments of the moving strip.
- Preferably, the segment of the strip being cooled is in contact with the said roller at a contact angle of at least 20′, preferably at least 30°. With such a contact angle, it is possible to offer a good contact surface between roller and strip, and therefore good heat transfer.
- Preferably, the segment of the strip being heated is in contact with the said roller at a contact angle of at least 20°, preferably at least 30°.
- Preferably, the temperature difference between a segment of metal strip being cooled and a segment of strip being heated between which at least some of the said heat transfer takes place by conduction is at least 200° C. and/or below 500° C. Such a temperature difference would allow effective heat transfer, without causing excessive thermal shock in the metal strip.
- The present invention also relates to a heat transmission device for simultaneously heating a moving metal strip upstream of an additional heating zone and cooling it downstream of the said additional heating zone. In order to effect an efficient transfer of heat without requiring significant addition of energy in the form of work, the device comprises at least one heat-conducting solid element intended to be in contact with the said metal strip both upstream and downstream of the main heating zone, so as to transfer heat by conduction between at least one segment of the metal strip downstream and at least one segment of the metal strip upstream.
- Preferably, the device comprises a series of several solid heat conducting elements, for example five, for successively contacting the said metal strip both upstream and, in reverse order in the direction of travel of the strip, downstream of the main heating zone, so as to transfer heat by conduction between segments of the metal strip downstream and segments of the metal strip upstream. In this way it is possible to provide progressive heating of the strip being heated and just as progressive cooling of the strip being cooled, in order to avoid thermal shocks while ensuring significant transfer of heat.
- Preferably, the device also comprises at least one deflector roller in order to define a contact angle, preferably at least 20°, between the said metal strip upstream and/or downstream of the furnace and the said heat-conducting solid element in the form of a roller.
- The present invention also relates to a system for the continuous heat treatment, in particular annealing, of a moving metal strip comprising a main heating zone and a heat-transmission device according to the invention.
- Details concerning the invention are described below, illustratively, but not restrictively, referring to the drawings.
-
FIG. 1 shows a diagram of a prior method, -
FIG. 2 shows a diagram of a method according to an embodiment of the invention, -
FIG. 3 shows a heat treatment system according to an embodiment of the invention, -
FIG. 4 shows a heat treatment system according to an alternative embodiment of the invention, -
FIG. 5 shows a heat transmission device according to an embodiment of the invention, and -
FIG. 6 shows curves for heating and cooling the metal strip that can be obtained with the heat transmission device ofFIG. 5 . - In
FIG. 1 , a conventional method for the continuous annealing of a moving steel strip is illustrated schematically. After cleaning 1 of the strips, the latter is heated from 30° C. to 800° C. in a heating step 2 in a radiant tube furnace. This specifies an energy addition Q of 210 kW per tonne of steel, in the form of natural gas, producing by its combustion 50 kg of CO2 and 80 mg of NOx per tonne of steel. - Next, in order to discharge a heat Q′ in the
cooling 3 of the strip to 450° C., 2 m3 of water per tonne of steel is specified, as well as a supplementary addition of energy W in the form of 20 kW of electricity per tonne of steel in order to circulate the cooling fluid or fluids. - The cost and the environmental impact of this conventional method are therefore not insignificant.
- In
FIG. 2 , an embodiment of the method of the present invention is shown schematically. As in the conventional method inFIG. 1 , the steel strip is heated after cleaning 1. However, in this method, the heating is divided into apreheating step 2 a in which the steel strip is preheated from 30° C. to 450° C., and amain heating step 2 b in a radiant-tube furnace, in which the strip is heated from 450° C. to 800° C. The heat Q′ transferred to the strip in thepreheating strip 2 a comes from thecooling 3 of the same strip from 800° C. to 450° C. and is transmitted by conduction. With this method, an energy addition Q′ in the radiant-tube furnace suffices, reducing the consumption of natural gas to an equivalent of 120 kW per tonne of steel, in this way producing only 30 kg of CO2 and 45 mg of NOx per tonne of steel. Moreover, the cooling can take place without consumption of water and without the need to carry out work for circulating a cooling fluid. The cost and environmental impact of this method according to the invention are therefore substantially less. -
FIG. 3 shows asystem 4 for the continuous annealing of a movingsteel strip 5, according to one embodiment of the invention. Thissystem 4 comprising adevice 6 for transmitting heat by conduction for the preheating 2 a and cooling 3 of thestrip 5, and afurnace 7 withradiant tubes 8 for theadditional heating 2 b of thestrip 5. In the embodiment shown in thisFIG. 3 , thefurnace 7 withradiant tubes 8 is of the vertical type. However, the alternative of a horizontal arrangement of thefurnace 7 withradiant tubes 8 can also be considered, as illustrated inFIG. 4 . - The heat-
transmission device 6 is illustrated in greater detail inFIG. 5 . Thestrip 5 enters thedevice 6 through theentry opening 9 and passes through the saiddevice 6 in thedirection 10 as far as thefurnace 7 while being preheated. After themain heating 2 b, thestrip 5 leaves the furnace again and passes through thedevice 6 in theopposite direction 11 as far as theexit opening 12 while cooling. - The
device 6 comprises an alignment of seven heat-conductingrollers 6 and two alignments of sixdeflector rollers 14, one on each side of the alignment ofconductive rollers 13. In the embodiment illustrated, both theconductive rollers 13 and thedeflector rollers 14 have a diameter of 800 mm. However, alternating diameters for each roller, as well as arrangements with different provisions and numbers of rollers could be envisaged by a person skilled in the art according to circumstances. Theconductive rollers 13 must have a diameter capable of providing a good contact surface with thestrip 5 with a relatively low speed of rotation, while avoiding a plastic deformation of thestrip 5. Thedeflector rollers 14 must also have a diameter avoiding plastic deformation of thestrip 5. According to the geometric and mechanical parameters of thestrip 5, the conductive 13 anddeflector 14 rollers may therefore have diameters situated, for example, in a range between 400 and 1600 mm. - Because of the thermal expansion of the
strip 5, the speed of thestrip 5 during cooling is normally greater than its speed during heating. Several solutions can be envisaged by persons skilled in the art for preventing partial slipping of theband 5 on aconductive roller 13. For example, theconductive roller 13 could have an angularly variable radius making it possible to adjust the effective radius of theconductive roller 13 to the speed of thestrip 5 on each side of theconductive roller 13. Another solution that can be envisaged is that theconductive roller 13 is divided into radial segments, having a certain freedom of angular movement relative to one another. - When a
strip 5 passes through thedevice 6 both during preheating and during cooling, thedeflector rollers 14 hold thesegments 5 a of thestrip 5 during preheating and thesegments 5 b of thestrip 5 during cooling simultaneously in contact with theconductive rollers 13 at contact angles α. Different contact angles α can be envisaged by persons skilled in the art according to circumstances. Eachconductive roller 13 thus transfers heat by conduction from asegment 5 b of thestrip 5 during cooling to asegment 5 a of the strip during heating. As thestrip 5 passes through thedevice 6 inopposite directions strip 5 contacts theconductive rollers 13 in reverse order in its travel during heating and during cooling. This conduction of heat will therefore be effected between thelast segment 5 b of thestrip 5 during cooling and thefirst segment 5 a of thestrip 5 during preheating, between thepenultimate segment 5 b of thestrip 5 during cooling and thesecond segment 5 a of thestrip 5 during preheating, and so on. In this way, the temperatures of thestrip 5 during cooling and during preheating follow respectively thecurves device 6, as illustrated inFIG. 6 . As can be appreciated in this figure, this configuration allows progressive preheating and cooling of thestrip 5. Thestages 17 correspond to the temperatures of theconductive rollers 13, each of them being intermediate to those of thesegments conductive roller 13 is in contact. - Table 1 presents the parameters of an embodiment of the heat treatment method of the invention in the
device 6 described above with astrip 5 with a thickness of 1 mm, a width of 1500 mm and a travel speed of 150 m/min for a production of 106 tonnes per hour. - Although the present invention has been described with reference to specific example embodiments, it is obvious that various modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. Consequently, the description and drawings must be considered in an illustrative rather than restrictive sense.
-
- 1 Cleaning
- 2 Heating
- 2 a Preheating
- 2 b Main heating
- 3 Cooling
- 4 Continuous annealing system
- 5 Steel strip
- 5 a Segment of strip during preheating
- 5 b Segment of strip during cooling
- 6 Heat-transmission device
- 7 Radiant-tube furnace
- 8 Radiant tubes
- 9 Entry opening
- 10 Direction of travel of strip during preheating
- 11 Direction of travel of strip during cooling
- 12 Exit opening
- 13 Conductive roller
- 14 Deflector roller
- 15 Preheating curve
- 16 Cooling curve
- 17 Temperatures of conductive rollers
-
TABLE 1 Operating parameters of the device 6Position of conductive roller 131st 2nd 3rd 4th 5th 6th 7th Contact angle α with segment 5a [°]31.4 62.9 62.9 62.9 62.9 62.9 31.4 Coefficient of contact with segment 5a [%]16.3 16.3 16.3 16.3 16.3 16.3 16.3 Contact surface with segment 5a [m2]0.0358 0.0716 0.0716 0.0716 0.0716 0.0716 0.0358 Contact angle α with segment 5b [°]35.7 71.5 71.5 71.5 71.5 71.5 35.7 Coefficient of contact with segment 5b [%]16.3 16.3 16.3 16.3 16.3 16.3 16.3 Contact surface with segment 5b [m2]0.0407 0.0813 0.0813 0.0813 0.0813 0.0813 0.0407 Initial temperature of segment 5a [° C.]30 64.3 138.1 210.6 286.3 353.8 415.4 Exit temperature of segment 5a [° C.]64.3 138.1 210.6 286.3 353.8 415.4 442.2 Heat transmitted to strip 5 [kcal/h] 425775 914931 898273 880617 840611 805057 363114 Initial temperature of segment 5b [° C.]482.2 549.7 614.2 675.6 730.4 778.7 800.0 Exit temperature of segment 5b [° C.]449.8 482.2 549.7 614.2 675.6 730.4 778.7 Heat received from strip 5 [kcal/h] 453947 973283 953595 927897 886571 847638 384988
Claims (20)
1. A method for the heat treatment of a moving metal strip, comprising:
heating of the strip,
cooling of the heated strip, and
transfer of heat from at least one segment of the strip being cooled to at least one segment of the strip being heated, so as to effect at least part of each of the said cooling and heating of the strip,
and characterised in that the said heat transfer takes place mainly by conduction.
2. A method according to claim 1 , wherein the said heat transfer is effected from a plurality of segments of the strip being heated to a plurality of segments of the strip being cooled in reverse order in the direction of travel of the strip.
3. A method according to claim 1 , wherein, in the said step of heating the strip, the strip is also heated by a heat source external to the strip.
4. A method according to claim 1 , wherein the said heat transfer is effected by means of at least one heat-conducting solid element in contact with a segment of the strip being heated and a segment of the strip being cooled.
5. A method according to claim 4 , wherein the said at least one heat-conductive solid element is in the form of a roller, preferably metal.
6. A method according to claim 5 , wherein the segment of the strip being cooled is in contact with the said roller at a contact angle of at least 20°, preferably at least 30°.
7. A method according to claim 5 , wherein the segment of the strip being heated is in contact with the said roller at a contact angle of at least 20°, preferably at least 30°.
8. A method according to claim 1 , wherein the difference in temperature between a segment of the metal strip being cooled and a segment of the strip being heated between which at least part of the heat transfer takes place by conduction is at least 200° C.
9. A method according to claim 1 , wherein the difference in temperature between a segment of the metal strip being cooled and a segment of the strip being heated between which at least part of the said heat transfer takes place by conduction is below 500° C.
10. A heat transmission device for simultaneously heating a moving metal strip upstream of a main heating zone and cooling it downstream of the said main heating zone, characterised in that it comprises at least one heat-conductive solid element that is in contact with the said metal strip both upstream and downstream of the main heating zone, so as to transfer heat by conduction between at least one segment of the metal strip downstream and at least one segment of the metal strip upstream.
11. A device according to claim 10 , comprising a series of several heat-conductive solid elements for successively contacting the said metal strip upstream and, in reverse order in the direction of travel of the strip, downstream of the main heating zone, so as to transfer heat by conduction between segments of the metal strip downstream and segments of the metal strip upstream.
12. A device according to claim 10 , wherein said at least one heat-conductive solid element is in the form of a roller, preferably metal.
13. A device according to claim 10 , also comprising at least one deflector roller in order to define a contact angle between the said metal strip upstream and/or downstream of the main heating zone and the said heat-conductive solid element in the form of a roller.
14. A system for the continuous heat treatment, in particular annealing, of a moving metal strip, comprising a main heating zone and a heat transmission device according to claim 10 .
15. A method according to claim 6 , wherein the segment of the strip being heated is in contact with the said roller at a contact angle of at least 20°, preferably at least 30°.
16. A device according to claim 11 , wherein said at least one heat-conductive solid element is in the form of a roller, preferably metal.
17. A device according to claim 11 , also comprising at least one deflector roller in order to define a contact angle between the said metal strip upstream and/or downstream of the main heating zone and the said heat-conductive solid element in the form of a roller.
18. A device according to claim 12 , also comprising at least one deflector roller in order to define a contact angle between the said metal strip upstream and/or downstream of the main heating zone and the said heat-conductive solid element in the form of a roller.
19. A system for the continuous heat treatment, in particular annealing, of a moving metal strip, comprising a main heating zone and a heat transmission device according to claim 11 .
20. A system for the continuous heat treatment, in particular annealing, of a moving metal strip, comprising a main heating zone and a heat transmission device according to claim 12 .
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BE2007/0348A BE1017683A3 (en) | 2007-07-12 | 2007-07-12 | METHOD, DEVICE AND SYSTEM FOR THERMALLY TREATING A TILTED METAL STRIP. |
BE2007/0348 | 2007-07-12 | ||
PCT/EP2008/058835 WO2009007362A1 (en) | 2007-07-12 | 2008-07-08 | Method, device and system for the heat treatment of a running metal strip |
Publications (1)
Publication Number | Publication Date |
---|---|
US20100186940A1 true US20100186940A1 (en) | 2010-07-29 |
Family
ID=39025393
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/668,534 Abandoned US20100186940A1 (en) | 2007-07-12 | 2008-07-08 | Method, Device and System for the Heat Treatment of a Moving Metal Strip |
Country Status (9)
Country | Link |
---|---|
US (1) | US20100186940A1 (en) |
EP (1) | EP2171105B1 (en) |
CN (1) | CN101743331B (en) |
AT (1) | ATE488608T1 (en) |
BE (1) | BE1017683A3 (en) |
DE (1) | DE602008003585D1 (en) |
ES (1) | ES2355695T3 (en) |
PL (1) | PL2171105T3 (en) |
WO (1) | WO2009007362A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015533389A (en) * | 2012-10-19 | 2015-11-24 | マシーネンファブリーク・ニーホフ・ゲーエムベーハー・ウント・コー・カーゲー | Apparatus for heat transfer during production of elongated strand shaped material |
US20180153063A1 (en) * | 2015-06-19 | 2018-05-31 | Yamaha Hatsudoki Kabushiki Kaisha | Component mounting device and component mounting method |
US11131001B2 (en) | 2015-08-13 | 2021-09-28 | Ebner Industrieofenbau Gmbh | Oven device for heat-treating a metal blank |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011012257A1 (en) | 2009-07-27 | 2011-02-03 | Corus Technology Bv | Heat pipe assisted strip heat treatment |
PT3181538T (en) | 2015-12-15 | 2024-05-31 | Fertinagro Nutrientes S L | Fertiliser composition including metal ions complexed with amino acids to improve the solubilization of phosphorus by the microorganisms present in the soil |
CN109797278A (en) * | 2019-03-20 | 2019-05-24 | 安徽智磁新材料科技有限公司 | Ultrathin nanometer crystal zone material multistage annealing device |
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US4571274A (en) * | 1982-10-28 | 1986-02-18 | Kawasaki Steel Corporation | Method for continuous annealing of a metal strip |
US4588378A (en) * | 1983-11-18 | 1986-05-13 | Chugai Ro Co., Ltd. | Continuous heat treating furnace for metallic strip |
EP0188659A2 (en) * | 1984-11-27 | 1986-07-30 | Aichelin GmbH | Industrial furnace for the continuous heat treatment of articles |
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CN2224848Y (en) * | 1995-01-27 | 1996-04-17 | 杨兴全 | Thin steel shet qunching and heating apparatus by heat transfering method |
DE19849757A1 (en) * | 1998-10-28 | 2000-05-04 | Vinz Peter | Continuously operated roller hearth furnace with downstream forced-convective annealing cooling |
BE1015309A3 (en) * | 2003-01-14 | 2005-01-11 | Drever Internat S A | Annealing process for sheet metal. |
FR2876709B1 (en) * | 2004-10-14 | 2007-07-27 | Kappa Thermline Soc Par Action | METHOD AND DEVICE FOR QUALITATIVE AND QUANTITATIVE IMPROVEMENT OF PRODUCTION IN A VERTICAL PROCESSING FURNACE FOR STEEL OR ALUMINUM BANDS |
-
2007
- 2007-07-12 BE BE2007/0348A patent/BE1017683A3/en not_active IP Right Cessation
-
2008
- 2008-07-08 EP EP08774880A patent/EP2171105B1/en active Active
- 2008-07-08 DE DE602008003585T patent/DE602008003585D1/en active Active
- 2008-07-08 ES ES08774880T patent/ES2355695T3/en active Active
- 2008-07-08 AT AT08774880T patent/ATE488608T1/en active
- 2008-07-08 CN CN2008800244691A patent/CN101743331B/en not_active Expired - Fee Related
- 2008-07-08 PL PL08774880T patent/PL2171105T3/en unknown
- 2008-07-08 WO PCT/EP2008/058835 patent/WO2009007362A1/en active Application Filing
- 2008-07-08 US US12/668,534 patent/US20100186940A1/en not_active Abandoned
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US4571274A (en) * | 1982-10-28 | 1986-02-18 | Kawasaki Steel Corporation | Method for continuous annealing of a metal strip |
US4588378A (en) * | 1983-11-18 | 1986-05-13 | Chugai Ro Co., Ltd. | Continuous heat treating furnace for metallic strip |
EP0188659A2 (en) * | 1984-11-27 | 1986-07-30 | Aichelin GmbH | Industrial furnace for the continuous heat treatment of articles |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015533389A (en) * | 2012-10-19 | 2015-11-24 | マシーネンファブリーク・ニーホフ・ゲーエムベーハー・ウント・コー・カーゲー | Apparatus for heat transfer during production of elongated strand shaped material |
US20180153063A1 (en) * | 2015-06-19 | 2018-05-31 | Yamaha Hatsudoki Kabushiki Kaisha | Component mounting device and component mounting method |
US11131001B2 (en) | 2015-08-13 | 2021-09-28 | Ebner Industrieofenbau Gmbh | Oven device for heat-treating a metal blank |
Also Published As
Publication number | Publication date |
---|---|
PL2171105T3 (en) | 2011-06-30 |
CN101743331B (en) | 2012-03-28 |
EP2171105A1 (en) | 2010-04-07 |
EP2171105B1 (en) | 2010-11-17 |
BE1017683A3 (en) | 2009-03-03 |
ATE488608T1 (en) | 2010-12-15 |
ES2355695T3 (en) | 2011-03-30 |
WO2009007362A1 (en) | 2009-01-15 |
CN101743331A (en) | 2010-06-16 |
DE602008003585D1 (en) | 2010-12-30 |
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