Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
  • B05C5/02—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
  • B05C5/0295—Floating coating heads or nozzles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C3/00—Apparatus in which the work is brought into contact with a bulk quantity of liquid or other fluent material
  • B05C3/18—Apparatus in which the work is brought into contact with a bulk quantity of liquid or other fluent material only one side of the work coming into contact with the liquid or other fluent material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D1/00—Processes for applying liquids or other fluent materials
  • B05D1/26—Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
• • 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
  • B22D11/008—Continuous casting of metals, i.e. casting in indefinite lengths of clad ingots, i.e. the molten metal being cast against a continuous strip forming part of the cast product
• • 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
  • B22D11/064—Accessories therefor for supplying molten metal

Definitions

• the invention relates to a process for the continuous production of thin layers of liquids as a coating or film, in which a substrate and a pouring point are moved relative to one another and in which during the movement the liquid is poured onto the substrate at the pouring point to form a liquid band, and that infused liquid band is allowed to solidify.
• the invention also relates to a flower which can be used in this method, the flower having a liquid supply channel and an outlet restriction part which, together with the substrate, forms an outlet channel.
• a method for the continuous casting of a metal strip or a metal strip in which a pouring device is used which has a vertical feed channel which is delimited by side walls, the rear side wall to form an outlet channel opposite the front side wall is arranged offset upwards.
• the substrate is moved in a predetermined direction under the pouring device.
• a heating device is provided in front of the pouring device in order to heat the substrate to a temperature which is above the melting point of the metal to be applied.
• an additional heating device for heating the substrate increases the cost of production thin layers.
• the preheating of the substrate can also lead to destruction or deformation of the substrate.
• the applied layer can have a corrugated structure or at least different layer thicknesses.
• the object of the invention is to provide a method and a flow with which an additional preheating device can be largely dispensed with and an improved design of the layer applied to the substrate, in particular with regard to the uniformity of the layer thickness is achieved.
• the method is characterized in that a larger amount of liquid is poured onto the substrate than is required for the formation of the thin layer, and that the excess amount of liquid is removed.
• a high volume flow is thus generated on the substrate, the amount of liquid which is not required for the formation of the thin layer being used to heat the substrate.
• two to ten times the amount is poured onto the substrate, which is required for the formation of the liquid band and thus for the coating.
• the heating of a surface layer of the substrate can thus be controlled via the size of the excess amount, taking into account the heat capacities of the liquid and the substrate.
• the point at which the excess amount of liquid is removed is preferably arranged at a distance from the pouring point.
• the preferably overheated liquid to be applied causes the heating of a surface layer of the substrate, in contrast to separate upstream heating devices, the substrate does not become entire Thickness is heated so that a cooling capacity remains in the substrate.
• the surface temperature rises continuously behind the pouring point and drops again after the excess flow has been separated off.
• the optimum temperature for the formation of the bond between layer and substrate is thus achieved in the area of the flow.
• Another advantage is that the heating by means of the excessive volume flow results in a brief superficial heating of the substrate, so that damage and deformation of the substrate are largely avoided, which in turn also improves the quality of the coating.
• the method according to the invention improves the bond, for example between a metallic sliding layer and a steel substrate.
• the quality of the coating in particular with regard to the constancy of the layer thickness, is significantly improved.
• the improvement is particularly evident when the upper liquid layers of the liquid band facing away from the substrate are discharged as an excess amount of liquid. Behind the pouring point, the poured-on liquid flows in the direction of movement of the substrate on the substrate in the direction of the point where the excess amount of liquid is removed (discharge point). Due to the movement of the substrate, turbulence presumably only occurs in the upper liquid layers, which, however, cannot have a negative effect on the quality of the coating if these upper liquid layers are preferably removed.
• the excess amount of liquid is removed shortly before the solidification front of the liquid band, because this largely prevents the formation of new turbulence behind the discharge point.
• a further improvement in the layer quality is achieved in that the poured-on liquid is conducted as a laminar flow between the pouring point and the discharge point, at least in the substrate / liquid contact area.
• an overpressure is set in the liquid at the pouring point and a negative pressure in relation to the environment at the discharge point. It is advantageous here if the negative pressure is set in such a way that a film-forming meniscus forms immediately behind the discharge point. In this case, the surface of the liquid band behind the discharge point is no longer in contact with components of the pouring device, which could possibly generate further turbulence in the liquid band and thus lead to a different formation of layer thicknesses. Since the materials for forming thin layers are often quite expensive, the excess liquid which is removed is preferably returned and, after heating, is fed back to the substrate, for example in the storage vessel.
• a flow device which, in front of the outlet channel and at a distance from the feed channel, has a discharge channel for removing excess liquid. Between the feed channel and the discharge channel, the underside of the flow is designed together with the substrate to form a flow channel, which at least in sections has a larger cross section than the outlet channel, so that the turbulence which forms in the upper layers of the liquid can be drawn off from the discharge channel.
• the discharge channel extends over the entire width of the flow and is arranged above the flow channel, preferably at an incline, so that the upper liquid layers can get into the discharge channel and be discharged without additional turbulence formation in the branching point flow channel / outlet channel / discharge channel.
• the overpressure provided in the process in the area of the pouring point has the advantage that air pockets between the liquid and the substrate are avoided. However, it must be ensured that the liquid between Entry restriction part and substrate cannot exit against the substrate movement.
• the overpressure is set such that only an overpressure meniscus is formed under the entry restriction part.
• the feed channel and the discharge channel are connected to suitable pressure devices.
• This can be a pump arranged outside the discharge channel, which generates the desired negative pressure in the region of the branch point in the flow.
• a pump can also be provided upstream of the feed channel, and a corresponding arrangement of a storage container above the flow can also ensure the desired pressure conditions.
• Fine-tuning of the pressure conditions in the flow channel can be achieved by structuring the underside of the flow in the area of the flow channel behind the feed channel and in front of the discharge channel.
• the underside of the flow preferably has a flow resistance in the form of a bead running perpendicular to the direction of movement behind the feed channel and in front of the discharge channel.
• the first bead arranged behind the feed channel throttles the liquid flow, so that an overpressure is established at the pouring point.
• the pressure then decreases behind the first bead, the configuration of the second bead arranged in front of the discharge channel being selected such that at the Branching point, the desired negative pressure is present.
• the discharge channel is preferably connected to the supply channel via a return channel, so that the skimmed-off amount of liquid can be used again.
• a particularly simple embodiment of the flow is achieved if a core part is inserted in the interior between the inlet restriction part and the outlet restriction part, which delimits the feed channel, the flow channel and the discharge channel.
• the upper side of the core part can accommodate the return duct or limit.
• the flow can also be open at the top, ie with a free liquid surface. The fluid flow is started by the moving substrate.
• Exit restriction part / surface of the substrate (d 2 ) can be preset, or the flow can rest freely on the substrate, ie float on the liquid, so that d, and d ? adjust according to the flow conditions and the pressures.
• the flow can also be attached to a holding device, wherein it is rotatably mounted either at the front or at the rear end. The flower then takes no parallel position regarding the substrate. To optimize the flow, the flow can also be fastened in such a way that d 2 is variable.
• FIG. 1 a longitudinal section through a flow with liquid and substrate
• FIG. 2 a partial longitudinal section through a flow according to FIG. 1 with a modified flow guide
• FIG. 3 a longitudinal section through a flow machine according to a further embodiment
• FIG. 4 a longitudinal section through a flow in accordance with a further embodiment
• Figure 5 The front view of a flow machine
• FIG. 6 the top view of a flow machine according to FIG. 1,
• Figure 7 A representation of flow profiles in the flow channel
• FIG. 8 The schematic representation of a flow with additional devices.
• a flow 1 is shown in a schematic representation in longitudinal section, under which a ribbon-shaped substrate is moved in the direction of the arrow.
• the front of the flow 1 is formed by an entry restriction part 7, which is arranged inclined at an angle to the front and ends at a distance d above the substrate 30.
• a gap 18 is thus left free between the entry restriction part 7 and the surface of the substrate 30 (see also FIG. 5).
• the feed channel 2 Between the inlet restriction part 7 and the front side 9 of a core part 8 arranged in the interior of the flow 1 there is the feed channel 2 through which the liquid to be applied to the substrate, e.g. a molten metal is fed from above.
• the feed channel 2 is also arranged inclined forward. As can be seen from the top view in FIG. 6, the feed channel 2 extends over the entire width of the flow 1 and is laterally delimited by the side walls 16 and 17.
• the flow channel 3 is formed between the underside 10 of the core part 8 and the substrate 30 and continues at the branching point 33 in the discharge channel 4 and in the outlet channel 5.
• the outlet channel 5 is delimited by the outlet restriction part 6 and the substrate 30.
• the discharge channel 4 is located between the rear 11 of the core part 8 and the outlet restriction part 6 and thus above the Outlet channel 5.
• the discharge channel 4 also extends, as can be seen from FIG. 6, over the entire width of the flow tube 1 and is also laterally delimited by the side walls 16 and 17.
• the liquid intended for the coating is applied through the feed channel 2 from above onto the substrate 30 (pouring point) and, among other things. deflected in the direction of the outlet channel by the moving substrate. A larger amount of liquid is supplied through the feed channel 2 than is necessary for the formation of the liquid band 36.
• the surface of the liquid is exposed and care must be taken at this point that air pockets between the liquid and the substrate surface are avoided. Such air pockets are largely avoided if the liquid is guided with regard to the pressure in such a way that an overpressure meniscus 34 is formed.
• the pressure P 1 and in particular the pressure P- are set such that they are above the ambient pressure, as a result of which the liquid for forming the overpressure meniscus 34 presses slightly into the gap 18.
• the pressure P must not be set so high that the gap 18 is filled with liquid.
• the supplied liquid then enters the flow channel 3 and from there into the discharge channel 4 or the outlet channel 5.
• the excess amount of liquid heats on the way from The feed channel 2 to the discharge channel 4 has the substrate 30 moved under the flower 1, so that the substrate 30 at the branching point 33 or in the region of the outlet channel 5 has the desired temperature for optimally binding the layer on the substrate.
• the cross section of the feed channel 2 and the cross section of the flow channel 3 are adapted to the amount of liquid required for heating the substrate 30 and are larger than the cross section of the outlet channel 5.
• FIG. 7 shows three flow profiles in the flow channel 3, which are identified by I to III.
• q. v corresponds.
• q means the cross section of the flow channel 3
• v the flow velocity of the liquid in the flow channel 3.
• the turbulence which forms on the stationary core underside is discharged through the discharge duct 4 arranged above the outlet duct 5. This ensures that in the outlet channel. 5 a largely turbulence-free flow occurs, so that there are no differences in thickness in the liquid band 36 and thus in the solidified layer 31.
• the film-forming meniscus 35 forms, in front of which a negative pressure must be set in relation to the surroundings in order to achieve a film thickness x which is less than half the height d 2 of the outlet channel 5.
• the pressure P. must therefore be chosen lower than the pressure P.
• the negative pressure in the outlet channel 5 causes a backflow, whereby the film thickness x can be reduced with the same d.
• the position of the film-forming meniscus can either be at the end of the outlet limiting part 6 - as can be seen in FIG. 1 - or at the beginning of the
• AlPblO aluminum alloy
• the speed of the substrate was 1 m / sec.
• the maximum tolerable temperature of lead bronze at the melting temperature of lead is approx. 325 ° C, while the homogenization temperature of the aluminum lead alloy is approx. 1200 ° C.
• the heat capacity of the thin liquid layer is insufficient.
• the layer thickness was 0.2 mm, the
• the position of the film-forming meniscus 35 at the beginning of the outlet channel 5 offers the advantage that it is located on the underside of the
• Outlet restriction part 6 in the outlet channel 5 cannot form new turbulence, which can lead to instabilities of the film-forming meniscus 35 located at the end of the outlet restriction part 6.
• the film-forming meniscus 35 lies directly on the discharge channel 4.
• FIG. 3 shows a pressure-optimized variant of the flow 1, which is characterized, inter alia, in that the edges and transitions are rounded off, in particular in the area of the core part 8.
• a first bead 13 and a second bead 14 are formed on the underside of the core part 10 in order to further influence the pressure profile in the flow channel 3.
• the two beads 13 and 14 extend over the entire width of the flow channel 3.
• the first bead 13 leads to an increase in the pressure P 5 and at the same time to a pressure decrease from P- to P ,.
• the formation of the bead 14 is responsible for the setting of the negative pressure P_ if P 3 also denotes a negative pressure. As can be seen in FIG.
• the feed channel 2 is connected via a feed line 42 to a storage container 40, which can be closed by means of the stopper 41, with which the discharge quantity can also be regulated.
• a storage container 40 which can be closed by means of the stopper 41, with which the discharge quantity can also be regulated.
• the discharge channel 4 is connected to the reservoir 40 via a return line 43.
• a pump 44 is provided which simultaneously transports the excess amount into the storage container 40.
• the excess liquid can also be returned in the flow, as shown in FIG. 4.
• the liquid flow is set in motion by the substrate 30 moved in the direction of the arrow.
• the pressure optimization is carried out exclusively by the cross-sectional design of channels 2, 3, 4 and 15.
• the cross-sectional design is determined exclusively by the shape of the core part 8.
• the core part 8 has on the underside 10 only a bead 14 in the area in front of the discharge duct 4. The first bead is omitted because no flow limiter is required due to the lack of a pressure device.
• the liquid running through the outlet channel 5 should preferably be replaced by adding new liquid in the return channel.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Coating Apparatus (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6441421

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (6)

Citations (5)

Family Cites Families (1)

• 1991
  • 1991-09-25 DE DE4131849A patent/DE4131849C1/de not_active Expired - Fee Related
• 1992
  • 1992-09-23 EP EP92920892A patent/EP0558739B1/de not_active Expired - Lifetime
  • 1992-09-23 DE DE59208496T patent/DE59208496D1/de not_active Expired - Fee Related
  • 1992-09-23 WO PCT/DE1992/000816 patent/WO1993005906A1/de active IP Right Grant
  • 1992-09-23 AT AT92920892T patent/ATE152940T1/de not_active IP Right Cessation

Patent Citations (5)

Also Published As

Similar Documents

Legal Events