DE102019101948A1 - Device and method for cooling metallic sheet - Google Patents

Abstract

The invention relates to a device for cooling metallic sheet metal, comprising a roller conveyor with at least one transport roller (2a, 2b) which is in contact with the sheet metal (1) in order to move the sheet metal in one direction of movement (B) during cooling , an upper nozzle device (3a) which is arranged downstream of the transport roller (3a) in the direction of movement (B) of the sheet metal, the upper nozzle device (3a) being a housing (4a) with at least one coolant inlet (5a), with a first Has nozzle opening (8a) and with a second nozzle opening (8a`), wherein the nozzle openings (8a, 8a ') in the direction of movement (B) at a distance from each other are directed obliquely towards the top of the sheet, each nozzle opening (8a, 8a') as A gap is formed which extends across the width of the sheet (1) transversely to the direction of movement (B). According to the invention, a first coolant flow channel (6a) runs in the housing (4a) at an angle (α) to the horizontal and a second flow channel (7a) at an angle (β) to the horizontal. The first and second flow channels (6a, 7a) are each formed by an inner side wall (9a, 9a ') and an outer side wall (9c, 9c`), which run plane-parallel and between them the first and second nozzle openings (8a, 8a '). The inner side walls (9a, 9a ') of the first and second flow channels (6a, 7a) can be moved in the vertical direction by means of an adjusting element (11a) in order to adjust the width of the first and second nozzle openings (8a, 8a').

Description

The invention relates to a device for cooling metallic sheet metal, comprising a roller conveyor with at least one transport roller which is in contact with the sheet metal in order to move the sheet metal in one direction of movement during cooling, an upper nozzle device which is downstream in the direction of movement of the sheet metal the transport roller is arranged, wherein the upper nozzle device has a housing with at least one coolant inlet, with a first nozzle opening and with a second nozzle opening, the nozzle openings being directed obliquely at a distance from one another in the direction of movement toward the top of the sheet metal, each nozzle opening as a gap is formed, which extends across the width of the sheet transverse to the direction of passage (D).

The invention further relates to a method for cooling metal sheet in a device with a roller conveyor with at least one transport roller, for moving the sheet during cooling in one direction of movement, the sheet having been heated to a predetermined temperature in an industrial furnace before cooling.

The term “sheet metal” means sheets of different thicknesses, strips or other flat products. The term “metallic” means different types of steel and non-ferrous metals, especially aluminum or brass.

An important area of application for the invention is the heat treatment of heavy steel sheets, which usually have a thickness of 2 mm to 250 mm.

The sheets are heated in an industrial furnace for heat treatment, in particular for hardening in heat treatment plants, and then cooled or quenched in a continuous process. By cooling or quenching heated steel, its mechanical properties, such as hardness or tensile strength in particular, can be specifically changed.

• - Erhitzung und Abkühlung von kohlenstoffhaltigen Stahlblechen zur Einstellung einer martensitischen oder bainitischen Härte;
• - Erhitzung und gezieltes Abkühlen von kohlenstoffhaltigen Stahlblechen mit Verzögerung zum Erreichen eines perlitischen Gefüges;
• - Erhitzung und sanftes Abkühlen von kohlenstoffarmen Stahlblechen zum Erreichen eines ferritischen Gefüges;
• - Erhitzung und gestuftes Abkühlen von höher legierten Blechen aus Stahl, Edelstahl, einer Nickelbasislegierung oder andere Nichteisenmetallen.

Common heat treatment processes are:

• - Heating and cooling of carbon steel sheets to set a martensitic or bainitic hardness;
• - Heating and targeted cooling of carbon-containing steel sheets with a delay to achieve a pearlitic structure;
• - Heating and gentle cooling of low-carbon steel sheets to achieve a ferritic structure;
• - Heating and gradual cooling of higher alloy sheets made of steel, stainless steel, a nickel-based alloy or other non-ferrous metals.

As a rule, the heavy plates have to be cooled very quickly and abruptly as part of heat treatments. For this purpose, cooling devices in the form of slot nozzles are used in particular, which rapidly cool or quench the sheet across its width by means of a liquid coolant, usually water.

For example, a heavy plate, which was initially heated or heated to austenitizing temperature, typically 800 ° C to 950 ° C, is cooled very quickly in a continuous process with a coolant, usually water, using full jet nozzles in order to create a martensitic or bainitic structure produce.

Furnace systems are used for the hardening of heavy plate steel, followed by a continuous quenching device, also known as a continuous quench. During the cooling process, both the top and the bottom of the sheets are usually cooled in the same way. During the cooling, the sheets are continuously moved in the direction of passage through at least one cooling zone by means of a roller conveyor which can have only lower transport rollers or lower and upper transport rollers. The sheet usually runs between upper and lower transport rollers, which are arranged in pairs at a distance from one another in the direction of passage.

Nozzle bodies with a slit-shaped nozzle opening are used for rapid cooling. The slot-shaped nozzle opening is also called the slot nozzle. The nozzle opening can extend over the entire width of the sheet, which can be, for example, 4 m. It is known from practice to use three nozzle openings arranged side by side across the width of the sheet in order to be able to quench the sheet across its width at different speeds or intensities and / or durations.

In order to ensure that no water vapor film can form between the still very hot sheet and the inflowing water when using water as a coolant, the cooling water must act on the sheet to be quenched with a high exit impulse. The cooling water is therefore under increased pressure. A water vapor film would prevent the sheet metal surface from coming into direct contact with the cooling water and would significantly reduce the quenching speeds. This phenomenon is known in the art as the Leidenfrost problem and affects, for example, everyone Quenching operations that are carried out with the help of water basins.

To quench a sheet in a continuous process, its top and bottom must be cooled. Therefore, one nozzle opening or slot nozzle or a plurality of nozzle openings or slot nozzles arranged next to one another over the width of the sheet is or are required on each side of the sheet. At least one nozzle opening that extends across the width of the sheet is directed from above onto the top of the sheet, and a further nozzle opening is directed onto the sheet on the opposite side from below.

In practice it has been shown that there is a need for improvement when cooling relatively thin heavy plates with a single slot nozzle, which is directed in the direction of movement, because a path of undefined water exposure with an undesirable formation of vapor pads forms downstream of the transport roller.

A device of the type mentioned is from WO 2015/075041 A1 known. An upper or lower nozzle device has two nozzle openings spaced apart from one another in the direction of passage. The first nozzle opening in the direction of movement of the sheet is directed in the direction of movement of the sheet. The second nozzle opening is directed against the direction of movement of the sheet, so that both nozzle openings are directed towards each other and produce two mutually directed vortices or a double vortex on the sheet surface. The width of the first or second nozzle openings cannot be changed, so that when the requirements change, the nozzle device must be completely replaced.

The object of the invention is accordingly to provide a possibility of flexibly cooling sheet metal of different thicknesses in the course of different heat treatments in different ways in the continuous process.

An essential aspect of the task is to optimally cool thin sheets in a continuous process.

According to the invention, the object is achieved by claim 1.

The first and second nozzle openings run parallel across the width of the sheet. The impact surface of the two coolant steels is rectangular or linear. A nozzle opening can extend over the entire width of the sheet. Within the scope of the invention, a plurality of nozzle openings can also be provided next to one another across the width of the sheet transverse to its direction of movement.

According to the invention, a first flow channel runs in the housing at a first angle ( α ) to the horizontal and a second flow channel at an angle ( β ) to the horizontal. Each flow channel has an inner side wall and an outer side wall, which run plane-parallel and form the first and second nozzle openings. The passage cross section for the coolant is essentially constant in the flow direction of the coolant from the coolant inlet to the outlet from the nozzle openings. This ensures that the coolant jet cools down a precisely defined impact area in a focused manner and does not hit the sheet metal in an undefined and diversified manner.

The width of the coolant jet emerging from the nozzle openings can be varied as required. The inner side walls of the two flow channels can be moved in the vertical direction by means of an adjusting element in order to adjust the width of the first and second nozzle openings, i.e. H. adjust the width of the coolant jet in the direction of movement of the sheet to the optimum width in a simple manner.

In the context of the invention, a lower nozzle device is provided below the sheet metal, which is of the same design as the upper nozzle device and is arranged in a play-like manner with respect to the upper nozzle device, so that a first and a second nozzle opening of the lower nozzle device are directed towards the underside of the sheet metal. Thus, during cooling from the top and bottom of the sheet, the first and second nozzle openings are directed in mirror image onto the sheet.

A cooling area with high heat transfer and essentially the same cooling conditions is formed on the top and bottom of the sheet. This ensures optimal cooling of the top and bottom of the sheet.

The inner side walls of the first and second flow channels are preferably formed by a distribution element which is detachably connected to the housing by means of the adjusting element. The distribution element is essentially A-shaped in cross section and extends over the width of the housing, which also extends over the width of the upper and lower nozzle device.

An advantageous embodiment is characterized in that there is in the coolant inlet a coolant which is permeable or continuous for the connection of the adjusting element to the housing. The Fastening means, which is located in the coolant inlet, can be designed, for example, as a frame or grid. The adjusting element is arranged centrally in the coolant inlet. The adjusting element is preferably designed as an adjusting screw, the head of which engages the distributing element and the end of which is connected to the fastening means.

A defined bias of a spring element advantageously acts on the adjusting element. In other words, the setting element is floating. The spring element is preferably located between the adjusting actuator and the fastening means. The spring element is preferably designed as a plate spring.

In a preferred embodiment, in the entrance area of the coolant inlet, i.e. a flow straightener arranged upstream of the fastening element. The cross section of the coolant inlet is preferably circular. Other cross-sectional shapes are possible within the scope of the invention. The flow straightener is designed in the form of a grid in cross section or viewed from above. The flow straightener causes the coolant volume flow to be made more uniform across the width and to equalize the distribution of the coolant over the two flow channels. Within the scope of the invention, a plurality of coolant inlets distributed over the width of the nozzle device can be provided for introducing the cooling medium. Together, the passage areas of all coolant inlets correspond to at least the cross-sectional areas of the flow channels.

The length of the first or second flow channel in the flow direction of the coolant is preferably at least 3 times the width of the first or second flow channel, which preferably extends to the coolant inlet. The width of the first or second flow channel corresponds to the width of the first or second nozzle opening, so that the length of the first or second flow channel corresponds to 3 times the width of the first or second nozzle opening.

The width of the first or second flow channel or the width of the first or second nozzle opening is preferably between 0.8 mm and 3 mm.

According to the invention, the first angle is ( α ) or the second angle ( β ), under which the first and second flow channels run to the horizontal, 20 ° and 60 °. The angle ( α ) and the angle ( β ) same size.

A further development of the invention is characterized in that the width of the first or second nozzle opening can be adjusted by means of at least one first or second adjusting screw which engages the inner and the outer side wall of the substantially perpendicular to the first or second flow channel.

With a length of the nozzle openings between approximately 2.0 m and 5.0 m transverse to the direction of movement B For example, several adjusting screws can be provided over the length of the nozzle openings, which are at a distance from one another, which is preferably 0.5 m. The adjusting screws are freely accessible, so that the width of the nozzle openings can be adjusted in a simple manner over the entire length of the nozzle openings, which extend across the entire width of the sheet.

A further advantageous embodiment is characterized in that on the outside of the housing of the upper nozzle device, at least partially parallel to the first flow channel and directed against the direction of flow, at least one deflector element is attached at a predetermined distance from the plate in order to reject the plate from the nozzle openings and the deflecting element extends at least partially across the width of the nozzle device.

The predetermined distance between the deflector element and the sheet must be less than the minimum distance between the first and second nozzle openings and the sheet.

The invention offers the advantageous possibility that the distance between the first and the second nozzle opening from the sheet metal can be adjusted.

According to the invention, the first nozzle opening is against the direction of movement on the sheet metal X the contact of the transport roller with the sheet. The coolant jet, which is directed from the first nozzle opening onto the sheet metal surface, effects the main cooling. The second nozzle opening is directed opposite to the first nozzle opening in the direction of movement of the sheet and, with the emerging coolant jet, causes the area of the sheet which has already been cooled with the coolant jet from the first nozzle opening to be cooled, because the area which has already cooled passes under the second nozzle opening in the direction of movement .

Downstream of the second nozzle opening there is a coolant guide roller which is arranged at a predetermined vertical distance from the top of the plate, so that a gap through which the coolant can flow is formed around at least part of the coolant from the top of the plate in the direction of movement dissipate.

The coolant guide roller can be profiled and have grooves which promote the removal of the coolant, so that at least some of the coolant runs off specifically over the surface of the sheet below a coolant guide roller.

• Verfahren zum Abkühlen von metallischem Blech in einer Einrichtung mit einer Rollenbahn mit mindestens einer Transportrolle, zum Bewegen des Bleches während des Abkühlens in eine Bewegungsrichtung, wobei das Blech vor dem Abkühlen in einem Industrieofen auf eine vorgegebene Temperatur erhitzt worden ist, mit den Schritten,
  • -Einleiten eines Kühlmittels in den Kühlmittel-Einlass im Gehäuse einer oberen Düsenvorrichtung,
  • -Leiten des Kühlmittels durch einen ersten und einen zweiten Strömungskanal zu einer ersten und einer zweiten Düsenöffnung,
  • -Abkühlen der Oberseite des Bleches mittels der oberen Düsenvorrichtung, die in Bewegungsrichtung stromab der Transportrolle angeordnet ist, wobei die obere Düsenvorrichtung ein Gehäuse mit mindestens einem Kühlmittel-Einlass und mit einer ersten Düsenöffnung zum Erzeugen eines ersten KühlmittelStrahls und einer zweiten Düsenöffnung zum Erzeugen eines zweiten Kühlmittelstrahls aufweist, wobei die Kühlmittelstrahlen in Bewegungsrichtung beabstandet voneinander schräg auf die Oberseite des Bleches gerichtet sind, wobei jede Düsenöffnung als Spalt ausgebildet ist, der sich über die Breite des Bleches quer zur Bewegungsrichtung erstreckt, dadurch gekennzeichnet, dass das Kühlmittel im Gehäuse in einem ersten Strömungskanal geführt wird, der unter einem Winkel(α) zur Horizontalen verläuft und in einem zweiten Strömungskanal geführt wird, der unter einem Winkel(β) zur Horizontalen verläuft, dass jeder Strömungskanal eine äußere Seitenwand und eine innere Seitenwand aufweist, die planparallel verlaufen und die erste bzw. zweite Düsenöffnung bilden und dass die inneren Seitenwände des ersten und zweiten Strömungskanals mittels eines Einstellelements in vertikaler Richtung beweglich sind, um die Breite der ersten und zweiten Düsenöffnung einzustellen.

Technically, the task is solved by the following procedure:

• Method for cooling metallic sheet in a device with a roller conveyor with at least one transport roller, for moving the sheet during cooling in one direction of movement, the sheet having been heated to a predetermined temperature in an industrial furnace before cooling, with the steps,
  • Introducing a coolant into the coolant inlet in the housing of an upper nozzle device,
  • Directing the coolant through a first and a second flow channel to a first and a second nozzle opening,
  • Cooling the top of the sheet by means of the upper nozzle device, which is arranged downstream of the transport roller, the upper nozzle device having a housing with at least one coolant inlet and with a first nozzle opening for generating a first coolant jet and a second nozzle opening for generating a second Has coolant jet, wherein the coolant jets are directed at a distance from each other obliquely towards the top of the sheet, each nozzle opening is designed as a gap which extends across the width of the sheet transverse to the direction of movement, characterized in that the coolant in the housing in a first Flow channel is guided, which is at an angle ( α ) runs to the horizontal and is guided in a second flow channel, which is at an angle ( β ) to the horizontal runs that each flow channel has an outer side wall and an inner side wall, which run plane-parallel and form the first and second nozzle openings and that the inner side walls of the first and second flow channels are movable in the vertical direction by means of an adjusting element by the width the first and second nozzle opening.

In the context of the invention, the underside of the sheet is generally also cooled, in that first and second nozzle openings of a lower nozzle device, which has the same structure as the upper nozzle device, are directed onto the underside of the sheet.

The admission pressure of the coolant at the coolant inlet is preferably approximately 2 bar to 8 bar, i.e. it is a high pressure quenching process.

• - Primäres Abkühlen der Oberseite des Bleches, indem der erste Kühlmittelstrahls aus der ersten Düsenöffnung entgegen der Durchlaufrichtung auf die Kontaktstelle (X) der Transportrolle mit dem Blech gerichtet wird,
• - Nachkühlen der Oberseite des Bleches, indem der zweiten Kühlmittelstrahl aus der zweiten Düsenöffnung in Bewegungsrichtung auf die Oberseite des Bleches gerichtet wird, Abführen des Kühlmittels von der Oberseite des Bleches in Bewegungsrichtung mittels einer Kühlmittel-Führungsrolle, die mit vertikalem Abstand zu der Oberseite des Bleches stromab der zweiten Düsenöffnung angeordnet ist.

The following method steps are carried out within the scope of the invention:

• - Primary cooling of the top of the sheet by the first coolant jet from the first nozzle opening against the direction of flow onto the contact point ( X ) the transport roller is straightened with the sheet,
• - After cooling the top of the sheet by directing the second coolant jet from the second nozzle opening in the direction of motion onto the top of the sheet, removing the coolant from the top of the sheet in the direction of motion by means of a coolant guide roller which is at a vertical distance from the top of the sheet is arranged downstream of the second nozzle opening.

The invention is explained in more detail below on the basis of preferred exemplary embodiments in conjunction with the drawings.

• 1 in schematischer Darstellung einen Längsschnitt durch eine erfindungsgemäße Einrichtung mit einer oberen oder unteren Düsenvorrichtung;
• 2 zeigt in schematischer Darstellung einen Längsschnitt durch eine obere Düseneinrichtung.

Show it:

• 1 a schematic representation of a longitudinal section through an inventive device with an upper or lower nozzle device;
• 2nd shows a schematic representation of a longitudinal section through an upper nozzle device.

1 schematically an inventive device for cooling or quenching metal sheet 1 , here a relatively thin heavy plate made of steel in a continuous process. The sheet is heated in an industrial furnace (not shown) before it is cooled for heat treatment, here for hardening.

In 1 and 2nd the same components are provided with the same reference numerals.

A roller conveyor, not shown, has a plurality of transport rollers which are spaced apart from one another in the direction of movement of the sheet. In 1 are only one pair of transport rollers with an upper transport roller 2a and a lower transport roller 2 B shown.

The upper transport roller 2a and the lower transport roller 2 B are in contact with the sheet or lie flush on the spot X on the sheet and move the sheet by means of a rotary movement during cooling in one direction B .

The upper and lower transport rollers ( 2a , 2 B ) are arranged one above the other and lie flush over the entire width of the sheet 1 on this so that no cooling water can flow towards the industrial furnace.

An upper nozzle device 3a is in the direction of movement downstream of the upper transport roller 2a above the sheet 1 arranged. A similarly constructed lower nozzle device is a mirror image of this 3b downstream of the lower transport roller 2a below the sheet 1 arranged. The sheet or the direction of movement of the sheet forms a mirror axis.

The lower nozzle device 3b is identical to the upper nozzle device 3a and pictorial to the upper nozzle device 3a below the sheet 1 arranged. This ensures the same cooling conditions on the top 1a and the bottom 1b of the sheet 1 reached.

The upper and lower nozzle devices form the first coolant application zone for the heavy plate after it has left the industrial furnace.

As in 1 and 2nd is shown, the upper and lower nozzle device 3a , 3b a housing 4a , 4b with a central upper or lower coolant inlet 5a , 5b to provide a coolant. Every coolant inlet 5a , 5b is connected to a coolant line, not shown. Water is used as the coolant. The coolant is under increased pressure, so that it is a high-pressure quench. The pressure of the coolant is increased with at least one pump, not shown. The coolant faces the coolant inlet 5a , 5b a pre-pressure of 2bar to 8bar.

In the housing 4a the upper nozzle device 3a are each a first upper flow channel 6a and a second upper flow channel 7a educated. In the housing 4b the lower nozzle device 3b are each a first lower flow channel 6b and a second lower flow channel 7b educated. The first flow channel 6a , 6b runs at a first angle α to the horizontal and the second flow channel 7a ' , 7b` at a second angle β to the horizontal.

The flow channels 6a , 6b , 7a , 7b are each from an inner side wall 9a , 9a ' , 9b , 9b` and an outer side wall 10a , 10a ' , 10b , 9b ' formed with the inner side wall 9a and the outer side wall 10a of the first flow channel 7a the upper nozzle device 3a run plane-parallel. The same applies accordingly to the other flow channels.

Consequently, the free passage cross section through which the coolant can flow is from each flow channel 6a , 6a ' 6b , 6b ' , 7a , 7a ' , 7b , 7b` constant in the flow direction of the coolant until it emerges.

The inner side wall 9a and the outer side wall 9c of the first flow channel 6a the upper nozzle device 3a form a first nozzle opening at their downstream ends in the flow direction of the coolant 8a , out of which a coolant jet is directed towards R exit. The inner side wall 9a` forms with the outer side wall 9c` the upper second nozzle opening 8a`. The inner side wall 9b forms with the outer side wall 9d the lower first nozzle openings 8b . The inner side wall 9b` forms with the outer side wall 9d ' the lower second nozzle openings 8b ' .

The first nozzle opening 8a and the second nozzle opening 8a` of the upper nozzle device 3a are spaced apart from each other on the top in the direction of flow 1a of the sheet 1 directed. The first nozzle opening 8b and the second nozzle opening 8b that of the lower nozzle device 3b are spaced apart in the direction of movement on the underside 1b of the sheet 1 directed.

The first angle α under which the first flow channel 6a to the horizontal or the second angle β under which the second flow channel 7a to the horizontal and below which the coolant on the top 1a or the bottom 1b of the sheet 1 strikes is between 20 ° and 60 °. The first angle α and the second angle β are the same size. However, the two angles can also differ within the scope of the invention.

The length of the first or second flow channel 6a , 6b , 7a , 7b in the direction of flow of the coolant is at least 3 times the width of the first or second flow channel, which extends as far as possible to the coolant inlet.

The width of the first or second flow channel 6a , 6b , 7a , 7b is usually 0.8mm to 3.0mm. The width of the first or second flow channel corresponds to the width of the first or second nozzle opening.

All nozzle openings 8a , 8a ' , 8b , 8b` are slit-shaped or slit-shaped and run across the width of the nozzle devices 3a , 3b transverse to the direction of movement B of the sheet 1 so that of the nozzle openings 8a , 8a ' , 8b , 8b` each emerging coolant jet has a substantially rectangular shape. Expressed differently, have the nozzle openings 8a , 8a ' , 8b , 8b` each the shape of a line that is perpendicular to the direction of movement B extends over a width which is as large as the width of the sheet 1 . The nozzle openings generally extend over the entire width of the nozzle device, which can be 2 m to 5 m. But there can also be several nozzle openings transverse to the direction of movement B of the sheet can be provided side by side.

The nozzle openings 8a , 8a ' , 8b , 8b` have a predetermined vertical distance of preferably 15mm to 40mm from the sheet 1 on. The vertical distance of the nozzle openings from the sheet can be changed.

The inner side walls 9a , 9a` of the upper first and upper second flow channels 7a and the inner sidewalls 9b , 9b` of the lower first flow channel 6b and the lower second flow channel 7b are each made by an essentially A-shaped distribution element 10a , 10b formed, which in the housing of the upper and lower nozzle device 3a , 3b is arranged. The housing 4a and the distribution element 10a above the sheet 1 are spaced from each other by means of an adjusting element 11a releasably connected. The same applies to the housing 5b and the distribution element 11b below the sheet 1 .

The adjustment element 11a , 11b is designed as a screw, the head of which is on the distributor element 11a , 11b and its end in a fastener 12a , 12b attacks. The adjustment element 11a , 11b is form-fitting with the fastener 12a , 12b connected, which is located in the coolant inlet and through which the coolant can flow. The adjustment element is located centrally in the coolant inlet. The fastening means can be designed as a frame or grid.

In the entrance area of the coolant inlet 5a , 5b is upstream of the fastener 12a , 12b a flow straightener 15a , 15b arranged. The flow straightener causes the coolant volume flow to be made uniform across the width and to equalize the distribution of the coolant over the two flow channels. The admission pressure of the coolant at the coolant inlet is 2bar to 8bar. With a lower inlet pressure, the effect of the flow straightener would be insufficient.

The cross section of the coolant inlet 15a , 15b is circular. The cross section can also have a different shape. The flow straightener 15a , 15b is lattice-shaped. Another embodiment is also possible within the scope of the invention. A nozzle device may have a plurality of coolant inlets for introducing the cooling medium.

On the adjustment element 11a , 11b acts a defined bias of a spring element 13a , 13b , which is between the adjusting actuator 11a , 11b and the fastener 12a , 12b located. In the exemplary embodiment, the spring element is designed as a plate spring.

By means of the setting element 11a , 11b , which engages the housing and the distribution element, is the distance of the distribution element 10a or. 10b in the vertical direction relative to the housing 4a or. 4b adjustable. The distribution element 10a or. 10b and thus the inner sidewalls of the first and second flow channels 6a , 7a or. 6b , 7b by means of the setting element 10a or. 10b moved in the vertical direction. By means of the vertical relative movement of the distribution element 10a or. 10b towards the housing 4a or. 4b becomes the width of the first and second nozzle openings 8a , 8a` or 8b, 8b` easily set at the same time. In other words, the distance of the distribution element from the housing in the vertical direction can be adjusted by means of the adjusting element. At the same time, the width of the first and second flow channels and thus the outlet cross section of the first and second nozzle openings change. This setting option is simple and robust, sufficiently precise and takes as little time as possible.

The width of the first or second nozzle opening 8a , 8a` or 8b, 8b` is by means of a first or second adjusting screw 14a , 14a ' or. 14b , 14b` adjustable, that is, as precisely adjustable as possible The adjustment screws 14a , 14a ' or. 14b , 14b` grab the case 4a or housing 4b and the distribution element 10a or distribution element 10b essentially perpendicular to the first flow channel 6a , 6b or the second flow channel 7a , 7b on.

The nozzle openings extend transversely to the direction of movement of the sheet and can be several meters long. With a length of the nozzle openings between approximately 2.0 m and 5.0 m transverse to the direction of movement B several adjusting screws are provided at a distance from one another over the width of the sheet, the distance preferably being 0.5 m. The adjustment screws are freely accessible so that the width of the nozzle openings can be adjusted across the entire length of the nozzle openings transversely to the direction of movement B is possible in a simple manner.

Outside on the case 4a the upper nozzle device 3a and on the case 4b the lower nozzle device 3b are at least one protection element 16a , 16b attached, the Deflectors 16a , 16b are directed against the direction of flow and are at least partially parallel to the sheet at a defined distance A from the sheet. It is not necessary for the deflecting element to extend over the entire width of the nozzle device. A plurality of deflecting elements can be provided at a distance from one another over the width of the nozzle device, for example a width of 5 m. Within the scope of the invention, however, a single deflecting element can also extend over the entire width.

As a rule, the distance between the first 8a, 8b or second nozzle opening is 8a ' , 8b` to the sheet 1 about between 15mm and 40mm. The minimum distance of 15 mm is relatively small, so that there is a risk that the nozzle openings, in particular the first nozzle opening, will be damaged by an uneven sheet. Therefore, on the transport roll 2a , 2 B facing side of the housing 4a , 4b the repellent element 16a , 16b installed to perform a straightening function on uneven sheets.

The first nozzle opening 8a , 8b is against the direction of movement B on the sheet on the sheet contact point X the transport roller 2a , 2 B directed. The coolant jet from the first nozzle opening 8a , 8b causes the main cooling of the sheet 1 .

The second nozzle opening 8a ' . 8b` is in the direction of movement B of the sheet 1 directed and causes a targeted after-cooling of the already cooled area of the sheet, which is by means of the transport rollers 2a , 2 B continuously in the direction of movement B is moved. The second nozzle opening 8a ' . 8b` is in the opposite direction to the first nozzle opening 8a , 8b directed.

The invention is based on the knowledge that, in particular in the case of thin heavy plates, a targeted cooling of the plate directly behind the pair of transport rollers 2a , 2 B , ie directly downstream of the pair of transport rollers 2a , 2 B with a high heat transfer coefficient is advantageous. This prevents that between the pair of transport rollers 2a , 2 B and the impingement of the water jet from the second nozzle opening upstream of the coolant guide roller pair 17a , 17b on the top 1a or the bottom 1b forms a stretch of undefined water exposure and heat transfer with the formation of steam pads.

After-cooling can take place in a structurally simple manner through the second nozzle opening, which would otherwise have to be carried out with a separate cooling device.

A coolant guide roller is located downstream of the second nozzle opening 17a , 17b with a defined vertical distance 18a , 18b to the top 1a or the bottom 1b of the sheet 1 provided to remove at least a portion of the coolant from the surface of the sheet 1 in the direction of movement B dissipate. The coolant runs specifically through the gap 18a , 18b that is between the top 1a or the bottom 1b of the sheet 1 and the respective coolant guide roller 17a , 17b forms. The diameter of the transport roller 2a , 2 B is larger than the diameter of the coolant guide roller 17a , 17b , so that the coolant is not directed towards the industrial furnace upstream of the transport roller 2a , 2 B can flow.

The embodiments described above are to be understood as examples. Features or method steps that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or method steps of other described exemplary embodiments without leaving the scope of protection of the patent claims.

The features, which are described together with other features, independently of whether they are disclosed in the description, the claims, the figures or otherwise, also individually define essential components of the invention.

Modifications are possible within the scope of the invention without further notice. So the setting element can be designed differently than the exemplary embodiment.

Finally, it is pointed out that the term “having” does not exclude components or elements, that reference signs in the claims do not represent any restriction and that “a” or “a” includes a large number.

Reference list

1

sheet

1a, 1b

Top, bottom of the sheet

2a, 2b

Upper or lower transport roller

3a, 3b

Upper or lower nozzle device

4a, 4b

Upper and lower nozzle housing.

5a, 5b

Coolant inlet of the upper or lower nozzle device

6a, 6b

first flow channel of the upper and lower nozzle device

7a, 7b

second flow channel of the upper and lower nozzle device.

8a, 8a ', 8b, 8b`

first and second nozzle openings of the upper and lower nozzle devices

9a, 9a ', 9b, 9b`

inner side wall of the first and second flow channels of the upper and lower nozzle device

9c, 9c ', 9d, 9d'

outer side wall of the first and second flow channels of the upper and lower nozzle device

10a, 10b

Distribution element of the upper and lower nozzle device

11a, 11b

Adjustment element of the upper or lower nozzle device

12a, 12b

Fastening element of the upper and lower nozzle device Fastening element of the upper and lower nozzle device

13a, 13b

Spring element of the upper and lower nozzle device

14a, 14a ', 14b, 14b'

Adjusting screw of the upper and lower nozzle device

15a, 15b

Flow straightener of the upper and lower nozzle device

16a, 16b

Deflection element of the upper or lower nozzle device

17a, 17b

Coolant guide roller

18a, 18b

Gap between coolant guide roller u. sheet

B

Direction of movement of the sheet

R

Direction of the coolant jet

X

Sheet contact point of the transport roller

α

first angle of the first flow channel

β

second angle of the second flow channel

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2015/075041 A1 [0014]

Claims (15)

Device for cooling metallic sheet metal, comprising a roller conveyor with at least one transport roller (2a, 2b) which is in contact with the sheet metal (1) in order to move the sheet metal in a direction of movement (B) during cooling, an upper nozzle device (3a), which is arranged downstream of the transport roller (3a) in the direction of movement (B) of the sheet metal, the upper nozzle device (3a) being a housing (4a) with at least one coolant inlet (5a) and with a first nozzle opening (8a) and having a second nozzle opening (8a`), the nozzle openings (8a, 8a`) being directed obliquely at a distance from each other in the direction of movement (B) towards the top of the sheet metal, each nozzle opening (8a, 8a ') being designed as a gap, which extends across the width of the sheet (1) transversely to the direction of movement (B), characterized in that in the housing (4a) a first flow channel (6a) for the coolant at an angle (α) to the horizontal and a second flow channel al (7a) for the coolant at an angle (β) to the horizontal that the first and second flow channels (6a, 7a) each have an inner side wall (9a, 9a ') and an outer side wall (9c, 9c') are formed, which run plane-parallel and form the first or second nozzle opening (8a, 8a ') between them and that the inner side walls (9a, 9a') of the first and second flow channels (6a, 7a) by means of an adjusting element (11a) are movable in the vertical direction to adjust the width of the first and second nozzle openings (8a, 8a '). Establishment after Claim 1 , characterized by a lower nozzle device (3b) which is identical to the upper nozzle device (3a) and is arranged in mirror image to the upper nozzle device (3a) below the sheet (1), so that a first nozzle opening (8b) and a second Nozzle opening (8b`) of the lower nozzle device (3b) are directed towards the underside (1b) of the sheet (1). Establishment after Claim 1 or 2nd , characterized in that the inner side walls (9a, 9a ', 9b, 9b`) of the first and second flow channels (6a, 7a, 6b, 6b`) are formed by a distribution element (10a, 10b) which is connected to the housing ( 4a, 4b) is detachably connected by means of the setting element (11a, 11b). Device according to at least one of the preceding claims, characterized in that in the coolant inlet (5a, 5a) in the housing (4a, 4b) of the nozzle device (3a, 3b) there is a fastening means (12a, 12b) which is continuous for the coolant positive connection of the adjusting element (11a, 11b) to the housing (4a, 4b) and / or that the adjusting element (11a, 11b) is designed as an adjusting screw. Device according to at least one of the preceding claims, characterized in that a defined bias of a spring element (13a, 11b) acts on the adjusting element (11a, 11b) and that the spring element (13a, 13b) is preferably designed as a plate spring. Device according to at least one of the preceding claims, that a flow straightener (15a, 15b) is arranged in the entrance area of the coolant inlet (5a, 5b). Device according to at least one of the preceding claims, characterized in that the length of the first or second flow channel (6a, 6b, 7a, 7b) in the flow direction of the coolant is at least 3 times the width of the first or second flow channel. Device according to at least one of the preceding claims, characterized in that the first angle (α) or the second angle (β) at which the first or second flow channel extends to the horizontal is between 20 ° and 60 ° and / or that the angle (α) and the angle (β) are the same size. Device according to at least one of the preceding claims, characterized in that the width of the first nozzle opening (8a, 8b) by means of at least one first adjusting screw (14a, 14b) and the width of the second nozzle opening (8a ', 8b') by means of at least one second adjusting screw (14a ', 14b') is adjustable and that the first and second adjusting screw (14a, 14a ', 14b, 14b`) are each on the inner side wall (9a, 9a', 9b, 9b`) and the outer side wall (9c , 9c ', 9d, 9d`) of the first or second flow channel (6a, 6b, 7a, 7b) acts essentially vertically. Device according to at least one of the preceding claims, characterized in that on the outside of the housing (4a, 4b)) of the nozzle device (3a, 3b) at least partially directed parallel to the first flow channel (6a, 6b) and against the direction of movement (B), at least a deflecting element (16a, 16b) is attached at a predetermined distance from the plate in order to deflect the plate (1) from the nozzle openings (8a, 8a ', 8b, 8b`) and that the deflecting element (16a, 16b) at least partially extends across the width of the nozzle device (3a, 3b). Device according to at least one of the preceding claims, characterized in that the first nozzle opening (8a, 8b) counter the direction of movement (B) is directed towards the sheet metal contact point (X) of the transport roller (2a, 2b) that the second nozzle opening (8a ', 8b') is directed in the direction of movement of the sheet that downstream of the second nozzle opening (8a ' , 8b ') there is a coolant guide roller (17a, 17b) which is arranged at a predetermined vertical distance from the top of the sheet metal, so that a gap (18a, 18b) through which the coolant can flow is formed in order to cover at least part of the Drain coolant from the top of the plate in the direction of movement. Method for cooling metallic sheet in a device with a roller conveyor with at least one transport roller (2a, 2b), for moving the sheet during cooling in one direction of movement (B), the sheet (1) being cooled in an industrial furnace before being cooled predetermined temperature has been heated, with the steps of introducing a coolant into the coolant inlet (5a) in the housing (4a) of an upper nozzle device (3a) which is arranged downstream of the transport roller (2a) in the direction of movement (B), wherein the housing (4a) has a first nozzle opening for generating a first coolant jet and a second nozzle opening for generating a second coolant jet, the coolant jets being directed obliquely at a distance from one another at the top (1a) of the sheet, each nozzle opening (8a, 8a ') is designed as a gap which extends across the width of the sheet transverse to the direction of movement (B) and cooling of the upper ite (1a) of the sheet (1), characterized in that the coolant in the housing (4a) in a first flow channel (8a), which runs at an angle (α) to the horizontal and is guided in a second flow channel (8a`) which runs at an angle (β) to the horizontal that the first and second flow channels (8a, 8a ') are formed by an inner side wall (9a, 9a') and an outer side wall (9c, 9c ') that the inner side wall (9a, 9a`) and the outer side wall (9c, 9c`) run plane-parallel and form the first or second nozzle opening (8a, 8a ') between them and that the inner side walls (9a, 9a') of the first and of the second flow channel (8a, 8a ') can be moved in the vertical direction by means of an adjusting element (11a) in order to adjust the width of the first and second nozzle openings (8a, 8a'). Procedure according to Claim 12 , characterized in that the underside (1b) of the sheet (1) is cooled by a first coolant jet from a first nozzle opening (8b) and a second coolant jet from a second nozzle openings on the underside (1b) of the sheet (1) (8b ') of a lower nozzle device (3b) are directed and that the lower nozzle device (3b) and the upper nozzle device (3a) are of identical design and are each arranged in mirror image to one another above and below the sheet. Method according to at least one of the Claims 12 to 13 , characterized in that the coolant at the coolant inlet (5a, 5b) has a pre-pressure of 2bar to 8bar. Method according to at least one of the Claims 12 to 14 , further with the steps, - primary cooling of the sheet (1) by the first coolant jet directed from the first nozzle opening (8a, 8b) against the direction of movement onto the sheet metal contact point (X) of the transport roller (2a, 2b) - After-cooling of the sheet by directing the second coolant jet from the second nozzle opening (8a ', 8b') in the direction of movement onto the sheet (1), removing at least some of the coolant from the top (1a) or the bottom ( 1b) of the sheet in the direction of movement (B) by means of a coolant guide roller (17a, 17b), which is at a vertical distance from the top (1a) or the underside (1b) of the sheet (1) downstream of the second nozzle opening (8a ', 8b ') is arranged.

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