FI78406B - FOERFARANDE OCH ANORDNING FOER PRODUKTION AV LAONGA ROERFORMIGA METALLPRODUKTER. - Google Patents

Abstract

Dense, homogeneous tubular metal products (33) such as pipe is cast in long lengths continuously by introducing liquid metal (32) into the lower portion of an annular-shaped casting vessel (11). The liquid metal (32) is withdrawn in the presence of at least one elongated upwardly travelling alternating electromagnetic levitation field and a second inner electromagnetic containment field for maintaining the tubular liquid metal column (26) in a substantially weightless and pressureless condition while solidifying. The resulting solidified tubular metal product (33) is withdrawn from the upper portion of the field, cooled and further processed to result in a desired end product.

Description

78406

This invention relates to a new and improved method and apparatus for the continuous production of tubular metal products, such as pipes.

In particular, this invention relates to the continuous production of tubular metal products, such as pipe, in long lengths by casting in the presence of electromagnetic elevation fields to minimize gravity, friction and adhesion forces acting on the cast tubular metal product while still between the metal and the 15 heat exchangers during solidification.

Tubular metal products in the form of a tube, etc., have previously been produced by a variety of techniques, including casting, which has been described in detail in the published literature in this field. U.S. Patent No. 4,272,470, issued March 23, 1981, lists in its introduction, which appears in columns 1 and 2, for example, a number of prior patents and technical articles describing and processing electromagnetic casting devices suitable for use in the manufacture of tubular metal products such as pipe. disadvantages of these known methods. These prior art publications include U.S. Patent 3,467,166 to Getselev, et al., U.S. Patent 3,605,865 to Getselev, U.S. Patent 4,014,379 to Getselev, and U.S. Patent 4,126,175 to Getselev, which ku-30 require the use of an electromagnetic mold to surround a pool of molten metal within certain dimensions while the pool moves downward and in which the outer, laterally extending portions of the pool solidify. In this process, the expansion of the solidified metal extends longitudinally and the melt 35 is fed either semi-continuously or continuously, by gravitational flow to the upper end of the descending pond, which forms a solidifying ingot. One of the most serious disadvantages of this procedure is the lack of reliability of the previously known vertical casting technique. Thus, in the event of an unexpected power outage, etc., the molten metal may flow out of the downwardly moving molten metal pond instead of merely leaking back, as would be the case in a vertical casting system. In addition, the overflow and rupture potential of molten metal in these known downward casting techniques requires constant careful control of both the molten metal feed rate and the solidified ingot discharge rate, both rates being significantly limited by the heat transfer problem, thus reducing the cost of this continuous casting process.

15 U.S. Patent 3,746,077 to Lohikoski et al. And U.S. Patent 3,872,913 to Lohikoski, both patents to Outokumpu Oy, Finland, describe an upward casting technique in which molten metal is either hydrostatically forced or drawn. by suction upwards to reach an open vertically placed mechanical mold counter-molded. In this procedure, the cooled casting product is immediately removed from physical contact with the upper end of the mechanical mold, into which the molten metal is continuously introduced. This system maintains the desired reliable nature of the vertical casting technique, but only at the expense of significant wear on the external contact mold, which is worn out in too short a time during continuous or semi-continuous operation of the system. Thus, there is a need for an improved continuous casting system for a tubular metal-30 product that avoids the disadvantages of previously known electromagnetic casting systems.

It is therefore a primary object of the present invention to provide a new and improved continuous casting method and apparatus for producing tubular metal products, such as pipe, in continuous long lengths, and which avoids the disadvantages and shortcomings of currently known and used continuous pipe casting techniques and systems. , mentioned above.

This object is achieved by a method according to claim 1 and an apparatus according to claim 9 for producing tubular metal products in long lengths by casting the products in the presence of an upward electromagnetic lifting field so as to minimize gravitational, frictional and adhesive forces acting on the cast tubular metal. maintaining maximum heat transfer between the solidifying tubular metal product and the heat exchanger.

In carrying out the invention, there is provided a method and apparatus for producing tubular metal products comprising means for generating an elongate, upwardly alternating alternating electromagnetic field of excellence within a surrounding annular casting vessel and an equally wide electromagnetic shielding field component directed directly at an upward angle. The second electromagnetic field generating means 20 are formed to form at least a second electromagnetic shielding field component acting in the opposite direction to the former electromagnetic shielding field in the center of the annular casting vessel. The liquid metal is introduced into the lower part of the annular casting vessel and the electromagnetic fields form a tubular molten metal column. The value of the electromagnetic elevation field acting on the tubular molten metal column is provided by suitable means to approximate the hydrostatic pressure of the column to a minimum while maintaining a predetermined sizing ratio between the inner and outer surfaces of the tubular molten metal column and the interior surfaces of the annular casting vessel. The electromagnetic fields acting on the tubular molten metal column are maintained so that the cross-sectional dimension of the tubular molten metal column is large enough to make pressure-free contact, but prevents the formation of a substantial gap between the inner and outer surfaces of the tubular molten metal column 4 78406. net contact and maximum achievable heat transfer between the tubular molten metal column and the 5 casting vessels, while simultaneously minimizing gravitational, frictional and adhesive forces. The tubular molten metal column is moved upwardly through the casting vessel while being raised and solidified in the solidification region surrounded by the heat exchanger, and the solidified tubular metal product is then removed from the top of the casting vessel.

In continuous casting, the liquid metal is continuously introduced into the bottom of the casting vessel and the solidified tubular metal product is continuously removed from the top of the vessel at a tubular metal product production rate determined by adjusting the solidified tubular metal product removal rate from the top of the vessel and the corresponding liquid metal feed rate.

In a preferred embodiment of the invention, the second electromagnetic field component is produced by a means for generating a second upwardly extending electromagnetic elevation field located in the central opening of the annular casting vessel.

When the process is initially started, the parent metal tube is connected to a tubular molten metal column that moves upwardly through the riser by cooling and solidifying the lower end of the tubular liquid metal column within the fields to the lower end of the parent metal tube in the solidification zone. Means are also provided for lifting the outlet lift tube and the associated solidified tubular metal product 30 at a rate that determines the production rate of the tubular metal product. The lifted tubular metal product is precooled as it exits the upper end of the casting vessel and then rolled to the desired final size, if desired, and finally cooled to ambient temperature. Alternatively, if the tubular metal product is initially cast to the desired dimensions as it exits the upper end of the casting vessel, it is precooled and then further cooled to ambient temperature and stored.

These and other objects, features and many advantages of the present invention will become more apparent and better understood upon reading the following detailed description taken in conjunction with the accompanying drawings, in which like parts are designated by the same reference numerals in each drawing.

Fig. 1 is a partial schematic operation diagram 10 of a new and improved tubular metal product casting apparatus according to the invention and shows the important structural parts of the apparatus and their interrelationships in the manufacture of tubular metal products according to the invention; and

Figure 2 is a schematic block diagram of a continuous casting system using the apparatus shown in Figure 1 in accordance with the method of the present invention.

U.S. Patent 4,414,285, issued November 8, 1983 to the invention "Continuous Metal Casting Method, Apparatus and Product," by Hugh R. Lowry and Robet 20 T. Frost, of General Electric Company, discloses a new continuous metal casting method, apparatus and product for casting dense homogeneous solid metal bars in long lengths by conducting liquid metal to the bottom of a casting vessel in the presence of an elongate upwardly varying electromagnetic elevation field. The present invention is an improvement over that disclosed in this U.S. Patent No. 4,414,285 in that it provides a method and apparatus for extending the principle set forth in this U.S. Patent No. 4,414,285 to the manufacture of tubular metal products in the form of tubes, etc.

Figure 1 is a functional schematic diagram of a modified apparatus suitable for making long tubular metal products by continuous casting in accordance with the present invention and using the principles set forth in U.S. Patent 4,414,285. The device shown in Figure 1 consists of an annular molten metal container 10 into which 6 78406 molten metals are fed, from which a tube or other tubular metal product is made. It will be appreciated that the molten metal container 10 should be provided with suitable refractory liner insulation and heating elements to store the molten metal 5 therein in the molten state. An annular combined casting vessel / heat exchanger, generally indicated by reference numeral 11, is located at the upper end of the container 10 with the annular inner cavity of the tubular casting vessel / heat exchanger 11 aligned and communicating with the opening in the lid of the correspondingly shaped molten metal container 10.

The tubular casting vessel / heat exchanger 11 consists of an outer cylindrical ceramic liner 12 which is supported and penetrates the annular passages formed in the lid of the container 10. The inner ceramic liner 13 is formed in the form of an inverted cup disposed over a central opening 14 formed in the center of the annular molten metal container 10. The side walls of the inner ceramic cup liner 13, together with the outer ceramic liner 12, define an elongate annular casting vessel in which molten metal from the container 10 solidifies into the shape of a desired tubular metal product, such as a tube.

An annular heat exchanger 15 is located immediately around the outer ceramic liner 12 in the area above the molten metal container 10, which may be constructed and operate in the same manner as the heat exchanger shown and described in connection with Figure 3 of U.S. Patent 4,414,285, which is incorporated herein by reference. to this application-30 in its entirety. Cooling water is supplied to the heat exchanger 15 through an inlet marked by arrow 16 and heated water is removed from the heat exchanger from an outlet marked by arrow 17. A second internal annular heat exchanger 18 is physically located 35 adjacent the inner surfaces of the inner cup-shaped ceramic liner 13.

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Inside, the heat exchanger 18 is provided with an upper end portion 18A which abuts against the bottom surface of the upside-down ceramic cup liner 13 and supplies cooling water downwardly downwardly through the side portions 18B.

The downwardly hanging side portions 18B are in contact and draw heat from the downwardly hanging side portions of the upside down ceramic cup liner 13, which cup liner 13 together with the outer cylindrical ceramic liner 12 forms an annular casting vessel in which the tubular metal products 10 are to be formed. Cooling water is supplied to the end portion 18A through a central inlet pipe 18C and then branches as shown by arrows 19 and 21 to cool the downwardly hanging wall portions 18B of the inner heat exchanger 18. The entire structure is physically rolled in the central opening 14 of the annular molten metal container 10 with suitable physical supports (not shown).

It will be appreciated that the cooling water is supplied to the inner heat exchanger 18 via the center conductor 18C as indicated by the inlet arrow 19, circulated through the end portion 13A 20 and then discharged through the downwardly hanging cup side portions 13B and outlet lines 18D connected to the side portions 18B.

The multi-turn winding 22 surrounds the outer surface of the circumferential outer heat exchanger 15 as shown in Fig. 1. The multi-turn winding 22, for example, may comprise 12 windings spaced vertically apart around the outer ceramic liner 12 with the plane of the windings arranged substantially perpendicular to the axis of the ceramic liner 12. As more fully described in the aforementioned U.S. Patent 4,414,285, and in particular with reference to Figure 3 thereof, the respective windings of the multi-turn winding 22 are connected in groups to successive stages of a multi-phase power supply, as shown in Figure 2 of the drawings to generate an upward electromagnetic .

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A somewhat similar multi-turn winding, denoted by reference numeral 23, is formed with the individual windings of the multi-turn winding in planes at right angles to the central axis of the inverted cup liner 13 of the inner ceramic 5. The windings of the winding 23 are wound around the inner surface of the side flaps 18B of the circumferentially inverted cup-shaped heat exchanger 18. The supply electric current is supplied to the internal multicircular windings 23 via the supply lines 24. Although the inner, multi-turn windings 23 are preferably magnetized with a multi-phase current to form a second, inner upward electromagnetic field, it is also possible to construct this inner coil as a single-phase winding, as will be described in more detail below. However, in a preferred embodiment of the invention, the inner multi-turn winding 23 is connected as a multi-phase winding which is supplied with a multi-phase current via supply conductors 24. This results in the generation of an upward electromagnetic elevation field that is substantially in phase with the upward elevation field produced by the outer multicast winding 22, but has a shielding field component located at a right angle 22 to the upwardly extending elevation fields and acting opposite to produce relative to the protective field component.

Figure 2 of the drawings shows an outer multi-turn winding 22 connected to a multi-phase power supply and controller 25, which in turn may be frequency independent controlled by a frequency controller 26 and power level 30 independently controlled by a power controller 27, all of which are conventional known structures. Similarly, the inner multi-turn winding 23 of Fig. 1 is connected via supply wires 24 to an inner coil power supply and controller 28 having independent frequency control 29 and independent power control 31 to the frequency value of the supply current (640) supplied by the controller 28 to the inner multi-turn winding 23 controlling. As mentioned above, the multi-turn winding 23 may comprise a multi-phase winding as well as an outer multi-phase winding 22, in which case the current supplied by the controller 28 through the supply conductors 24 would be a multi-phase current capable of producing an upward electromagnetic field. This field is preferably substantially in phase with the upward pitch field produced by the outer multicast winding 22, but has a shielding field component that is substantially at right angles to the upward rise fields and counteracts the shielding field 22 produced by the outer multicycle winding.

In operation, molten metal made in an oven (not shown) is fed to a crucible 10 through an inlet 15 10A from which it is removed upwardly to the lower part of an annular casting vessel defined by the inner surfaces of the outer ceramic liner 12 and the outer surfaces of the inverted ceramic cup liner 13. The arrangement is such that, either by gravity or by pressure from an inert gas shield, molten metal, indicated by reference numeral 25, is caused to rise inside the annular casting vessel formed between the ceramic walls 12 and 13 to a level just outside the outer and inner multilayers. above the lower ends of the windings 22 and 25 23. The furnace feeds the molten metal to the tank 10 either intermittently or continuously as needed during the continuous operation of the process to maintain this initial level of molten metal in the annular casting vessel 12, 13. At this level, the molten metal is subjected to upward electromagnetic fields generated by an external coils 22, as well as electromagnetic field components produced by the inner multi-turn winding 23. This is the field produced by the multi-turn winding 23 then only a 22 with respect to the shielding component of the electromagnetic field.

During the initial start-up, a tubular initial lifting member 5 (not shown) is introduced from the upper end of the tubular casting vessel 12, 13 to contact the upper end of the tubular molten metal column formed by the molten metal rising in the annular casting vessel 12, 13. As the cooling water flows at full speed 10 through the respective heat exchangers 15 and 18, the upper end of the tubular liquid column indicated by reference numeral 26 solidifies in contact with the tubular outlet. The tubular outlet and associated solidified tubular column 26 are then drawn upward from the annular casting vessel 12, 13 by suitable draw rolls as shown in Figure 2. The outlet tube and associated tubular metal column 26 are removed at a rate determined by the solid bar formation rate. casting system production speed. During solidification-20 in the solidification zone, which is substantially defined by the length of the multi-turn coils 22 and 23, the liquid metal column, in both molten and solidified form, is maintained 4,414,285.

During operation, the tubular liquid metal column in the cooling zone and during lifting as mentioned above becomes the subject of a unique and unexpected self-adjusting property. Due to this self-adjusting property, if the tubular liquid metal column is accelerated upward with a lifting force greater than the gravity of the liquid metal column, it produces a decrease in the cross-sectional area of the column. This then results in an auto-35 automatic reduction of the lifting force as a result of the reduction of the cross section of the liquid metal column “78406” causing a higher lifting force. As a result, there is an automatic deceleration in the upward movement of the tubular liquid metal column, so that the system stabilizes itself and becomes self-adjusting.

5 The opposite situation is also possible when the tubular metal column is decelerated due to a decrease in the lifting force, which increases the cross-section of the tubular liquid metal, leading to an increase in the lifting force acting on the column and thus accelerating the upward movement of the tubular liquid metal column. Thus, within the lift zone (i.e., the zone where the upward electromagnetic lift field acts on the tubular metal column in either its molten or solidified state), it is seen that the system is inherently self-regulating as long as it is actuated as described above.

Although the full effect of the electromagnetic elevation field is applied to a large portion of the length of the tubular liquid metal column and to the solidified tubular metal product in the solidification zone, a portion of the column is is supported, respectively, by the pressure produced to raise the liquid column to its initial height and by the lifting force applied through the outlet pipe described previously. Thus, when a tubular molten metal column is provided with a small upward acceleration due to these lower end region lift forces, but when the liquid metal column moves upward so as to be in the center of the lift field, it enters a sufficiently strong field to support the column in a substantially weightless state. that its contact with the walls 12 and 13 of the renal-35 gaseous casting vessel becomes substantially depressurized. By depressurized is meant that there is no substantially continuous pressure contact between the inner and outer surfaces of the liquid metal column 12 and surrounding the annular casting vessel 12, 13, and the tubular liquid metal column is without substantial hydrostatic pressure at critical solidification , frictional and adhesive forces have been reduced to a minimum in this critical zone.

The inner diameter of the outer cylindrical ceramic liner 10 12 and the outer diameter of the cylindrical hanging skirt portion of the inner ceramic cup liner 13 are designed to form a minimal gaseous space between the outer surface of the tubular liquid metal column 25 and the opposite surfaces 15 of the ceramic liners 12,13. This gap, which in reality is not a gap but an occasional open space between the tubular metal column and the outer surfaces of the side walls of the casting vessel, is too small to be seen in the drawings because it is important for good heat transfer to keep the gap dimensions very small. However, in Figures 2 and 3 of the aforementioned U.S. Patent 4,414,285, an attempt is made to illustrate the location where this space occurs, bearing in mind that the representation is schematic and is not intended as a means of actually representing the locations and dimensions. However, the gap appears randomly and irregularly and its existence is evidenced by the outer surface of the resulting solidified tubular metal product having a shiny wavy appearance. The gap, if allowed to become too large due to the upward components of the upward electromagnetic elevation fields, could significantly impair the efficient heat transfer between the tubular liquid metal column and the opposite side surfaces of the ceramic liners 12 and 13 due to the strong inverse dependence of the field -35 Iill. Thus, the strength of the elevation field should be set at the beginning of the casting operation to form the desired non-pressurized 13 78406 contact, as defined above, with minimal gap formation providing good heat transfer. The field strength should then be maintained at this setting and should not be changed during the casting operation even if the removal rate (line speed) of the tubular liquid metal column through the solidification zone is changed.

Referring to Figure 2 of the drawings, it can be seen that the solidified tubular metal product is removed from the upper end of the riser apparatus and passed to the precooling chamber 34 10 and discharge rollers 35 and 36 to two successive hot rolling stations 37 and 38 and then finally cooled and has the correct diameter and finish for use as cast, it is removed from the precooling chamber 34 by the discharge rollers 35 and 36 and fed to the next cooling and winding without further processing.

During operation, the casting speed (i.e., the line speed of the tubular liquid metal column through the heat exchanger / 20 lifting apparatus 11) should be controlled by controlling the drive motors of the rod discharge rollers 35 and 36 synchronized with the rollers 37 and 38 and the winding mechanism 39. The intensity and excitation frequency of the elevation field should be set to a value calculated for the tubular metal to be cast for a given size and resistivity to obtain an elevation ratio in the range of 75-200%. In a practical process and system using the invention, one could start at a lower than normal line speed and a higher than normal lift ratio to ensure start-up reliability. After reaching steady state (within 2-3 minutes), the line speed could then be manually increased stepwise and the elevation field strength reduced stepwise until the maximum casting rate in tons per hour was reached for the molten metal to change to a solidified tubular metal product. The system would then be maintained in this setting during operation, 4 78406. Normally, it would be desirable to monitor the temperature of the exiting solidifying tubular metal product by observing the product in an annular casting vessel, either visually or with a pyrometer, to ensure successful production.

The invention provides a new method and apparatus for the continuous casting of tubular metal products, such as pipe, in the presence of electromagnetic lifting fields, which greatly reduces the forces required and the wear of the equipment normally used for casting such products.

After explaining the method and apparatus of the invention and the resulting solidified tubular metal product, it is believed that it will be apparent to those skilled in the art that other modifications and variations of the invention may be presented in light of the above. It is therefore to be understood that changes may be made to the specific embodiments of the invention described which are entirely within the scope of the invention as defined in the appended claims.

Claims (15)

A method of producing long tubular metal products using two electromagnetic fields to form an upwardly directed molten metal tubular column, characterized in that it comprises the steps of: an elongated upwardly alternating electromagnetic raising field (22) is formed in the interior of a surrounding annular mold vessel (11) and an equally extensive electromagnetic protective field component is formed, which is perpendicularly directed relative to the upstanding elevation field (22), at least a second electromagnetic field component 15 (23) is formed. act in an opposite direction relative to the first-mentioned electromagnetic protective field component within the center (14) of the annular casting vessel (11), molten metal is inserted at the lower end (10) of the annular casting vessel (11) and into the the fields for forming a molten metal tubular column, the value of the electromagnetic raising field acting on the molten metal tubular column; It is determined which value reduces the hydrostatic pressure of the pillar to a minimum, while maintaining a predetermined dimensional relationship between the outer and inner surfaces of the tubular molten metal column and the annular molding surface (11) opposite inner surrounding surfaces of the electromagnetic fields. It is maintained that the cross-sectional dimension of the molten metal tubular column is sufficiently large to form a pressure-free contact, but prevents the formation of a substantial gap between the inner and outer surfaces of the molten metal tubular column and the annular mold vessel. (11) opposite inner surrounding surfaces and thus provide a pressureless contact and a maximum achievable heat transfer between the tubular pillar of molten metal1 and the casting vessel (11), while gravitational, frictional and adhesive forces are reduced. to a minimum, the molten metal tubular column is displaced upwardly through the casting vessel ( 11), the metal one solidifies as it moves up through said vessel (11) and said field, and the solidified tubular metal product is removed from the upper portion of the casting vessel (11). The method of claim 1, wherein it is used in a continuous casting method in which molten metal is continuously fed to the lower part (10) of the casting vessel (11) and solidified tubular metal product is continuously removed from said vessel's (11) upper part and the tubular metal product. production rate is determined by controlling the stiffened metal product removal rate from the upper portion of the vessel and by controlling the corresponding feed rate of molten metal in the lower portion (10) of the vessel (11), characterized in that the second electromagnetic field component (23) is formed second upwardly extending electromagnetic elevation field, operating within the central aperture (14) of the annular casting vessel (11). 3. A method according to claim 2, characterized in that the tubular column of molten metal extending through the electromagnetic fields is maintained at a point of gravity, so that it substantially lacks hydrostatic pressure over most of its field located in said field. length and the intensity of the electromagnetic field are installed to maintain a predetermined dimensional relationship between the inner and outer surfaces of the tubular pillar of molten metal and the inner surrounding surfaces of the annular mold vessel (11) so that the cross-sectional dimensions of the tubular metal is maintained at values which substantially prevent a continuous pressure contact between the inner and outer surfaces of the tubular pillar of molten metal and the inner surrounding surfaces of the annular casting vessel (11) and that the column lacks substantial hydrostatic pressure gravitational, frictional and adhesive forces, which act on the solidifying tubular metal column, to a minimum without attenuating the heat transfer between the surrounding cast vessel (11) and the solidifying metal column in the solidification zone. 4. A method according to claim 3, characterized in that, in the initial stage of the process, an starting metal tube is connected to the tubular column of molten metal, which column is displaced up through the fields by cooling the upper end of the tubular column of molten metal and bringing to solidify within the field to the lower end of the output metal tube. 15 5. A method according to claim 1, characterized in that the main part of the length of the molten metal tubular column in the solidification zone is maintained electromagnetically in a predetermined dimensional relationship between the inner and outer surfaces of the molten metal tubular column. and the surrounding surfaces of the casting vessel (11) such that the cross-sectional dimensions of the tubular molar metal column are in a pressureless contact and substantially prevent a continuous pressure contact between the inner and outer surfaces of the molten metal tubular column (11). ) surrounding surfaces and the column lack substantial hydrostatic pressure and thus reduce gravitational, frictional and adhesive forces acting on the solidifying metal column, to a minimum without substantially weakening the heat transfer between the surrounding casting vessel and the solidifying metal column. Method according to claim 5, characterized in that the molten metal tubular column is continuously formed and displaced to the solidification zone and the solidified tubular metal product is continuously removed from said zone by means other than 24 7 8 4. The electromagnetic elevation fields and thus the rate of production of the solidified tubular metal product is regulated. 7. A method as claimed in claim 6, characterized in that the upstanding electromagnetic raising field has a frequency exceeding one kilohertz. 8. A method according to claim 6, characterized in that the intensity of the upturned electromagnetic raising field has instants according to the type and size of the metal to be cast, to form an increase ratio between 75-200% by weight per unit length of the molten metal. . 9. A continuous tubular metal product molding device which uses two electromagnetic fields to form an upwardly directed narrow metal tubular column, characterized in that it comprises an elongated annular tubular molding vessel 20 (11) positioned vertically for receiving molten metal for solidification, a means (10A) for feeding molten metal into the lower portion (10) of the annular vessel (11) and thus forming a tubular column of molten metal, a heat exchange device (15, 18) ), which connects to the vessel (11) for cooling and solidifying the tubular molten metal column therein, a device (35, 36) for removing the solidified tubular metal product from the vessel (11), a device (22) ), which forms a first electromagnetic raising field, which means is placed around the outer surface of the annular casting vessel (11) on a portion of its length, a member (23) forming a second electromagnetic raising field, which is positioned within the center portion of the annular casting vessel (11) to form at least a second electromagnetic protective field component operating in an opposite direction relative to one of the means (22) forming the first electromagnetic raising field, formed electromagnetic protective field component, wherein the means forming the first (22) and the second (23) electromagnetic field reduce the hydrostatic pressure of the column and maintain a predetermined dimensional relationship between the outer and inner surfaces of the molten metal tubular column and the annular molar (11) surrounding surfaces, a means for maintaining the values of the electromagnetic elevation and protection fields such that the cross-sectional dimension of the tubular molten metal column is sufficiently large to prevent the occurrence of a substantial gap between the interiors. and the outer surfaces of the molten metal tubular column and the annular molding vessel (11) surrounding surfaces and thus achieve a maximum achievable heat transfer between the tubular molten metal column and the casting vessel (11), while gravitational, frictional and adhesive forces are reduced to a minimum. a means for displacing the tubular molten metal column eaten up through the casting vessel independently of said means (22, 23) forming the electromagnetic raising and protection field, and a means for removing the solidified metal product from the upper part of the vessel. 10. Device according to claim 9, characterized in that the device (23) forming the second electromagnetic field also comprises a device which forms an electromagnetic raising field and both the first and the second device forming a electromagnetic raising field, comprises several electromagnetic coils connected to successive phases of an electric current source (25) to form an upwardly alternating electromagnetic field. 11. Device according to claim 10, characterized in that it comprises a crucible which contains a molten metal bath and which contacts the lower part of the annular molding vessel (11) and a device which connects attach the crucible to provide a molten metal tubular column and displace it upright in the annular casting vessel (11) in a pane above the at least lower end of the member (22), which forms the first electromagnetic elevation field. 12. Device according to claim 11, characterized in that the multi-phase electric power source is made up of a three-phase generator, whose output power and frequency can be set to produce a smooth and balanced upward electromagnetic raising power according to the type and size of the metal to be cast. Device according to claim 12, characterized in that it comprises a device which functions during the initial start of the device to connect a metallic lift tube to the upper end of the tubular pillar of molten metal by contacting the end of the lift tube 1. The upper end of the molten metal tubular column where it is still in the solidification zone and thereafter by solidifying the tubular metal column at the end of the lift tube and a member to pull the tubular metal column connected to the lift tube with a speed which determines the tubular metal the production rate of the metal product. Device according to claim 9, characterized in that the device (23) forming the second electromagnetic protection field component comprises a device which forms a single-phase electromagnetic protection field for forming a leak-acting electromagnetic protection field acting on the tubular element. of molten metal. Device according to claim 14, characterized in that it comprises a device which functions during the initial start-up phase of the device to connect a metallic lift tube to the end of the tubular column of molten metal by contacting the end of the lift tube.