EP2435588A2

EP2435588A2 - Use of an altitude-compensating nozzle

Info

Publication number: EP2435588A2
Application number: EP10734649A
Authority: EP
Inventors: Ralf Czingon
Original assignee: Saar-Metallwerke GmbH; Saar Metallwerke GmbH
Current assignee: SAAR-METALLWERKE GESELLSCHAFT MIT BESCHRAENKTER HA
Priority date: 2009-05-27
Filing date: 2010-05-26
Publication date: 2012-04-04
Also published as: DE102009025873A1; WO2010136029A2; WO2010136029A3; US20120067983A1; CA2763552A1; ZA201108277B

Abstract

The invention relates to the use of one or more nozzles which are known as "height-compensating" nozzles in aeronautics and astronautics, as outlet nozzles of a feed device for industrial gases to a container during the melting and/or metallurgical treatment of metals.

Description

DESCRIPTION

Use of a height compensating nozzle

The invention relates to the use of a height-compensating nozzle.

The pig iron produced in a blast furnace process contains various undesirable impurities such as carbon, manganese, silicon, phosphorus, sulfur. These can lead to embrittlement, poor forgeability or an unintentionally low melting point.

It is known to introduce into the converter for molten steel blowing lances or fresh lances over which technical gases, in particular oxygen, can be introduced into the molten pig iron. These lances are the basis for various known metallurgical processes, such as the LC or LDAC process. In this process, the unwanted portions of the impurities are "oxidized out" to the desired extent from the melt and bound with the addition of additives, this being achieved by the selective blowing of oxygen in the form of O ₂ onto the metal bath, the oxygen lance setting the oxygen at the desired temperature Depending on the process progress, the lance is lowered vertically into the melt vessel via the melt in process-dependent stages.

The oxygen lance consists essentially of a central O ₂ - gas line with usually two concentrically arranged sheaths. These are used as a supply and discharge of a coolant. The coolant absorbs the heat energy to a large extent, which is mainly absorbed by heat radiation and convection of the lance and lance head, and transports them from the thermally endangered lance head out of the converter. The part of the lance head directly exposed to the thermal energy consists of copper or copper alloys. For a sufficient heat conduction is achieved. The present state of the art corresponding, used coolant is water.

The main purpose of an oxygen lance, and in particular of the lance head, is the directional blowing of the oxygen onto the molten metal and into the molten metal. For this purpose, the Oxygen mass flow according to the method expands to the ambient pressure of the converter, wherein the gas is accelerated within a Laval nozzle or, more rarely, a bell-shaped nozzle to in some cases multiple supersonic speed. By accelerating it is possible to blow the oxygen up and into the melt, where complex metallurgical processes are set in motion.

Since the lance in the converter atmosphere is exposed to extreme conditions, it comes despite the cooling to a wear of the lower portion of the oxygen lance. This affects in particular the nozzles. If the nozzles are not calculated correctly, or if the oxygen lance is not operated according to the design as a result of the process, under- or over-expansion of the oxygen occurs against the converter atmosphere. In one case, there is an uncontrolled behavior of the oxygen jet, which is associated with losses and in the other case to a damage of the nozzle geometry by suction effects and penetration of the converter atmosphere in the inner nozzle geometry.

As characteristic of the quality of lance heads the following are mainly named:

• Long service life or number of head melting operations

• Uniform blowing behavior over the service life to increase process reliability

• Blash hardness adapted to the process

• Tightness of the component to the coolant over all cycles

It is known and state of the art to perform the pressure adjustment of the oxygen against the converter atmosphere by an expansion within the lance head.

This is achieved by passing the O ₂ mass flow through at least one nozzle integrated in the head with a subsequent diffuser. This results in an internal expansion, wherein the nozzle ends without further behind / arranged expansion devices directly in the converter space. The gas thus expands within a predetermined shape within the lance head on an outwardly diverging shape. As a design is in particular the cone-shaped Laval nozzle to call, which has prevailed as a standard. The basis for calculating the nozzles is the ideal case in which the gas introduced into the converter has ambient pressure at the nozzle outlet or shortly thereafter.

By "internally expanding nozzles" is meant analogously nozzles in which the expansion of the gas at the ideal design point (almost) completely within the nozzle geometry runs .. The gas is adjusted at the nozzle exit edge in the theoretically ideal point to the ambient pressure of the diffuser-side system boundary.

In the nozzle, the gas flows through the nozzle, starting from an overpressure volume, to the outside, with an acceleration as well as an adaptation of the gas to the external pressure conditions.

Typical representatives of internally expanding nozzles include, for example: Laval nozzles with rectilinear expansion geometry or "bell nozzles" with rotationally symmetrical, parabolic exit geometries.

Lance-head nozzles with internal expansion - such as the Laval nozzle with conical or parabolic contour - are designed in your mathematical calculation to an assumed, static ambient pressure and an assumed mass flow of the O ₂ or the nozzle form. As a result, there is an inherent optimal operating point that meets these underlying conditions. If these boundary conditions for which the nozzle was designed change, the nozzle is operated outside its specification. Due to unpredictable pressure fluctuations within the converter or due to changes in the O ₂ mass flow according to the process, operating the nozzle outside of the ideal design point is the rule in practice. The changes in the O ₂ mass flow in the current process play a major role in practice.

Since the nozzles of oxygen lances of known types are designed for an idealized, static process, but the real processes are dynamic, over-blowing or under-blowing of the lance nozzles usually occurs during operation. In particular, the application of too little pressure to the nozzles (underblowing) has a considerable influence on the service life, the wear of the lance head, the dimensional stability of the nozzle and thus on the control of the metallurgical processes. Underblowing leads to penetration of the converter atmosphere into the nozzle interior due to premature tearing off of the flow. When tearing off the flow occur undesirable shocks. Here, the gas undergoes a sudden change in conditions such as Mach number, pressure ratio, density and temperature. The Mach number drops, for example, in oxygen from an assumed Mach number of 2.0 to about 0.58. At the compression impacts, a constriction of the flow forms, which then expands again. This results in an undesirable and uncontrolled behavior of the gas jet, which can stand both optimal metallurgical converter processes, as well as reduces the efficiency of the nozzle.

Due to the negative pressure, suction in the area of the nozzle outlet may occur in the unused diffuser areas for the expansion. The converter atmosphere entering the diffuser chamber causes damage. As a result, the nozzles are changed so that forms another strong diffuser diffuser at the end of the original diffuser. This results in many cases to a further impairment and deviation from the desired blowing behavior. Reason is the resulting additional expansion, which additionally affects the oxygen jet uncontrolled and shortens the length of the usable expansion geometry. Due to the damage of the nozzle geometry thus usually results in a permanent deterioration of the blowing behavior of the lance head. This then also applies to the "operating point", which was used as the basis for the calculated design of the nozzle.

If the volume flow is increased beyond the ideal design point (overblowing), the gas can no longer expand completely in the nozzle. Uncontrolled compensation processes can also lead to a "fluttering" of the gas flow.

Although in this case an external expansion of the gas occurs, this expansion is generally neither desirable nor does it correspond to controlled, design compliant states. If the converter pressure is already reached within the nozzle geometry, the flow breaks off before reaching the nozzle orifice and over-expansion occurs. In this case, the atmosphere of the converter can penetrate into the nozzle chamber. This leads to unwanted wear, especially in the mouth region of the nozzle.

The unwanted change of the nozzle geometry has proven to be a particularly harmful factor. This change leads to the fact that the flow of the gas changes after the diffuser exit in an undesirable manner and thus has an influence on the processes in the converter. Therefore, different approaches and ways will be labeled with some great effort to maintain the geometry of the nozzle over a long period of operation and to protect against wear.

These include, for example, improvements in the cooling water supply (DE 696 03 485 T2). This is intended to prevent softening and wear of the material in the mouth areas and thus of the nozzle geometry. Furthermore, by means of the introduction of ceramic rings in the endangered area (DE 101 02 854 C2), the endangered area should be better protected by a suitable selection of materials.

There is also the procedure of designing the nozzle from the beginning to parameters which do not correspond to the nominal specifications. This relinquishes the design to a single optimal operating point. An attempt is made to find a uniform compromise for the operating points in question.

Since oxygen lances are exposed to extreme conditions, in particular the end of the oxygen lance facing the metal bath, this part - the "lance head" - is considered a wear part Lancet head by a stronger wear, such replacement is necessary according to more often.

The ideal case of a controlled process over the entire lifetime of the lance head is opposed by various disturbances. Uncertainties and variable parameters during the blowing process lead to the undesirable effects and the associated effects such as the increased lancet head wear or a suboptimal one Process behavior. Pressure variations and fluctuations, which operate the nozzles outside of the design, play a role here. This leads to the described "underblowing" or "overblowing".

For example, the O ₂ mass flow is reduced during a sublance use. The sublance is used to perform measurements. During measurements of different process parameters by means of a sublance, the oxygen mass flow in practice is often reduced by the converter operator to approx. 50% in order to protect the sublance.

During different processes of refining (blowing oxygen in the converter), there can generally be variable settings in the flow volume of the oxygen.

Since the internally expanding nozzles previously used have a rigid geometry, the processes can not run optimally.

In addition to the process time, energy and raw materials are not used optimally in oxygen blowing lances of known design. These influences result in uncertainties in the metallurgical processes, as well as premature wear of the nozzles. This results in additional costs for maintenance and material.

According to the invention, according to claim 1, the use of one or more nozzles designated as "height compensating" in aerospace engineering as outlet nozzles of a feed device for industrial gases into a container during the melting and / or metallurgical treatment of metals.

These height-compensating nozzles are known from the aerospace industry. Exemplary embodiments of such nozzles are, for example, the so-called aerospike nozzles, "plug nozzles", "single expansion ramp nozzles" or the so-called ED nozzles (expansion-deflection nozzles). because these at different ambient pressures according to the different heights and thus the different external pressure conditions during a flight to ensure sufficient thrust.

Examples of sites where the height-compensating nozzles are explained are given below:

> Liquid rocket thrust chambers: Aspects of modeling, analysis and design, page 437 to page 467

Vigor YANG; Mohammed HABIBALLAH; James HULKA, Michael POPP

ISBN 1-56347-223-6 (2004) published by: American Institute of Aeronautics and Astronautics Inc.

> Rocket Propulsion Elements - An Introduction to the Engineering of Rockets page 70 to page 72

George P. Sutton

ISBN 0-471-52938-9

John Wiley & Sons, Inc. 6th edition (1992)

> Elements of Propulsion: Gas Turbines and Rockets, page 189 to page 213 Pof. Jack D. Mattingly

ISBN 1-56347-779-3 AIAA Published 2006

For the flow behavior at the nozzle outlet, in particular the ratio of the ambient pressure to the pressure of the gas flowing out of the nozzle is important. In aerospace engineering, the ambient pressure over the different heights in a flight has a large span. In contrast, changes in the present application are based primarily on pressure fluctuations of the gas exiting the nozzle and thus the pressure ratio of external pressure to internal pressure.

It has been found that, even with these conditions, the use of the nozzles in the form of the height-compensating nozzles in the aerospace industry makes it possible to stabilize the flow conditions in the sense of at least substantial expansion of the outflowing gas outside the nozzle.

As a rule, these height-compensating nozzles are designed as outwardly expanding nozzles or as internally and externally expanding nozzles (example: stepped nozzle or extended nozzle). In the case of internally and externally expanding nozzles, the gas flow is first pre-expanded through a first nozzle (primary nozzle) (usually via Mach 1) and in the second step either by an outer contour (for example the spike of a Aerospikedüse or at a flow or shock edge (example: ED nozzle)) brought to the design spectrum. This means that, regardless of the mode of operation, the expansion of the technical gas to the ambient pressure takes place at least largely only after leaving the nozzle.

Since this external expansion is a design-related expansion largely outside the nozzle, the height-compensating nozzles are an ordered flow.

In contrast to the described overblowing in the known Laval nozzles, this does not lead to an intrusion of the converter atmosphere into the nozzle.

While in lancet heads of known design, the expansion of the oxygen takes place against the ambient pressure of the converter within at least one inner expanding nozzle, results in the at least one nozzle of the novel lance head characteristic of the blowing behavior expansion of the gas against the ambient pressure to a large extent (!) Outside the lancet head geometry. This means that the gas in the outlet nozzle at most partially expands.

In the embodiment according to claim 2, in the at least one outlet nozzle in the inner region of the outlet opening at least one shaped body is attached, through which the outflowing technical gas is conducted into the edge region of the at least one outlet nozzle.

For this purpose, moldings in the form of additional bodies or additional moldings are used which do not yet lead the gas completely out of the nozzle.

The expansion takes place by the contouring of the moldings according to the design within the converter atmosphere. The adaptation to the respective converter pressure is for the most part thus targeted within the converter and not as in the case of internally expanding nozzles, in particular Laval nozzles or bell nozzles, within the nozzle contour. While the expansion in the converter (that is, after the nozzle exit) corresponds to an operating point at Lanzen previous design, which differs greatly from the nominal operating point of the nozzle design, the inventive nozzle with additional nozzle elements such as deflectors or expansion bodies are designed for the final pressure adjustment to the converter pressure only outside the geometric limits of the oxygen lance.

The designs of lance heads according to the invention can use additional geometries, which bring about a directed deflection of the flowing medium. This also means that the medium is compressed with respect to a nozzle without such additional geometry. The relaxation of the flowing medium is thus targeted and directed outside the nozzle after the discharge of the flowing medium from the nozzle.

The construction of such corresponds to the example of the nozzles, which are used under the name "Aerospike nozzles", "Plug nozzle" and in particular "E-D nozzles" (E-D = Expansion-Deflection), especially in aerospace.

It proves to be particularly advantageous in the present invention and the use of additional geometries in the nozzles in a Sauerstoffblaslanze that results in a self-adaptive behavior of the oxygen to the converter ratios. Due to the design, it is thereby possible to work within a tolerance band with different oxygen pressure ratios, without causing the known effects of overblowing or underblowing. At least, these effects should be reduced in their harmfulness.

In the embodiment according to claim 3, the shaped body protrudes beyond the edge of the outlet nozzle.

This design corresponds to the Aerospike nozzles known from the aerospace industry. In this case, a shaping and orientation of the expanding gas after exiting the nozzle is effected by the shaped body. In the embodiment according to claim 4, the shaped body is mounted so that it can be changed in its position in the outlet direction of the outlet nozzle.

As a result, the flow behavior of the nozzle can advantageously be changed.

The change in position can be done by positioning the molding before the start of the process. Particularly advantageous is an embodiment in which the positioning of the shaped body can also be changed during the ongoing process.

In the embodiment according to claim 5, the shaped body is adjustable by means of an actuating element in its position.

As a result, the shaped body can be changed by means of a control or regulation in its position.

In the embodiment according to claim 6, the molded body is resiliently mounted, wherein the positioning of the shaped body is effected by the resilient mounting of the molded body, the pressure of the flowing technical gas and the ambient pressure.

In this case, no adjusting elements must be provided. The positioning takes place automatically according to the specification by the spring characteristic and otherwise depending on the process parameters.

In the embodiment according to claim 7, the shaped body has at least one passage opening through which a part of the technical gas and / or another gas and / or another substance can be discharged in the outlet direction of the outlet nozzle.

This other substance can also be coal dust, for example, which can be introduced specifically for certain metallurgical processes.

It has been shown that in this embodiment of the molded body, the molded body can be shortened with respect to an aerospike nozzle. The medium exiting through the passage opening acts as a virtual extension of the shaped body for the expanding gas. so that the conditions for the expansion of the gas are substantially identical or at least similar to the ratios to an aerospike nozzle with a usual length of the shaped article (spike). The effect of the virtual extension can be explained by the pressure difference of the resulting medium through the passage to the expanding gas.

The shortening of the shaped body proves to be advantageous insofar as an overhanging shaped body is again closer to the surface of the liquid metal than the outlet opening of the nozzle. This may be problematic because of the temperature conditions and the converter atmosphere. In that regard, the shortening of this shaped body proves to be advantageous.

Advantageously, a conveying channel or a conveying pipe can be connected or connectable to the passage opening, through which specific technical gases or substances, such as coal particles, can be dispensed through the passage opening.

As a result, the materials (substances or gases) which are discharged through the passage opening can advantageously be separated from the materials which are otherwise dispensed from the nozzle.

In the embodiment according to claim 8 the cooling nozzles are associated with the outlet nozzles, which extend outside the nozzles along the outer contour of the outlet nozzles at least substantially transversely to the direction of flow of the outlet nozzles, wherein a coolant is conveyed through the cooling channels, wherein the outer contour of the outlet nozzles not one have axisymmetric but elongated cross section, wherein the longitudinal direction of the cross section is in the flow direction of the coolant.

For this measure of claim 8, the submission of a divisional application is expressly reserved, in which for this feature of the design of the outer contour of the outlet nozzle and regardless of protection is requested that the nozzle is in the aerospace industry as a "height compensating" It can be seen with the measure according to claim 8 by the design of the Outline of the nozzle even with conventional nozzles to achieve an improvement in cooling.

The cooling channels are introduced in the solid material of the outer contour of the outlet nozzles. The adapted outer contour of the outlet nozzles with the extension in the direction of flow of the coolant proves to be advantageous in that a significantly better cooling efficiency is effected. Due to the lower flow resistance, a larger amount of cooling liquid can be conveyed. Furthermore, a more favorable flow of the cooling medium can be realized. In this case, on the one hand, the flow cross-section between the nozzles can be enlarged and streamlined at a nozzle number of at least two nozzles. While the flow velocity between the nozzles in a round design greatly increases, it comes in the flow direction behind the nozzle to a strong reduction in the flow velocity. This considerably reduces the cooling capacity in the slow flow region and may possibly lead to a reduction in the durability of the nozzle shell. In addition, it is possible that at these points water passes into the vapor phase. This can also have undesirable consequences.

The described adaptation of the outer contour of the nozzles allows a larger amount of heat energy to dissipate. By stretched in the flow direction of the water cross-section results in a better flow around the outer contour of the nozzle, since turbulence can be reduced or avoided. This results in a more efficient cooling.

In the embodiment according to claim 9, the molded body in its connection to the material of the outer contour of the outlet nozzle and in its interior at least one cooling channel.

It proves to be advantageous that also the shaped body is cooled. The shaped body has at least one connection to the material of the outer contour of the outlet nozzle, via which the shaped body is fastened in the interior of the outlet nozzle. A cooling channel in this at least one connection and a further design of the cooling channel in the interior of the molded body can advantageously be used for direct cooling of the molded article from the inside. In the embodiment according to claim 10, the shaped body in the extended cross-section of the outlet nozzle on a first connection to the material of the outer contour of the outlet nozzle on the one shorter side of the cross section and a further connection on the opposite side, wherein the cooling channel with a supply line to the molding is guided over the first connection, wherein the derivative of the cooling channel is passed over the further connection.

Advantageously, the cooling channel in the molded body extends with the supply line and with the discharge in the flow direction. This results in turn for the direct cooling of the molded body, a low flow resistance. As a result, the cooling can advantageously be designed with good efficiency.

The present invention is also particularly suitable for use in electric arc furnaces, which are also referred to as EAF (== Elektro Are Furnace) .. There was previously a beam bundling of emerging from the lance gas (usually oxygen) made by the outflowing oxygen a natural gas envelope was issued with. By igniting the natural gas envelope, the expansion of the ignited natural gas causes increased coherence of the oxygen jet. By means of the present invention and the beam bundling associated therewith, a concentration of the kinetic energy and a beam bundling, which causes the technical gas to penetrate into the process space even without such an enveloping gas, take place.

Below follows some explanations to the height-compensating nozzles in the inventive use.

In particular, the design with E-D nozzles offers additional possibilities of optimized lance blowing through adapted "operating modes." E-D nozzles are characterized by two different flow behaviors, which are referred to as "open" and "closed".

In the so-called "closed wake" mode, the outflowing gas fills the entire nozzle and works like a bell-shaped nozzle without pressure compensation. Increases the pressure ratio between the oxygen in the narrowest outlet section and the converter pressure and reaches a certain value - the design point -, the behavior of the expanded gas changes. Here, the gas flow within the nozzle contour is annular and leaves the inner nozzle contour is not fully expanded. At this stage, which is referred to as "open wake", the gas flow receives the already described compensation characteristic, in which the converter pressure itself forms a contour formed from different gas states, at which the expansion can take place. This leads to a nearly ideal expansion behavior over a much larger range in the ratio of internal pressure before the nozzle to the external pressure, compared to previously used nozzles such as the conical Laval nozzles.

As a result, different needs in metal processing converters and other metallurgical (large) vessels can be taken into account over the prior art. The execution of blow lances according to the invention can thus have far-reaching positive effects on the processes in converters and their operation. Processes with different oxygen flows and nevertheless comparatively high efficiency become possible.

By appropriate design of the nozzles can continue to save raw materials and energy, which also has a positive effect on follow-up costs and the environment.

Also advantageous is the use in vacuum processes for steel treatment, which are operated at very low pressure (for example, in the VOD (Vacuum Oxygen Decarburization) method). Since there are some fluctuations in the operating pressure ranges (vacuum, for example 0.01 bar - 0.001 bar), an oxygen head with height-compensating nozzle can greatly contribute to process safety, since the behavior of this type of nozzle is much more tolerant to pressure differences inside / outside.

Due to the large difference in pressure between the internal pressure (in front of the nozzle) and the converter pressure, jet nozzle lengths are also very impractical. This problem does not exist with height-compensating nozzles, because the expansion is at least largely outside of the nozzle geometry. In addition, several nozzles of different design with different flow can be replaced by a single nozzle. The height compensating nozzle shapes are known from experimental space programs. There they are used over a huge range of different external pressure ranges. Examples include SSTO (single stage to orbit) with aerospike nozzles or the STERN (static test expansion deflection rocket nozzle) project using ED nozzles. These nozzles are used because they have a self-adapting characteristic to the external pressure and can handle the most diverse pressure conditions from ground level to the orbit with a single stage.

The present invention is based on the realization of using such nozzles in the field of steelmaking. This ensures that in the steelmaking and especially when refining with oxygen lances nozzles are used in which at least largely an external expansion of the gas takes place.

It can be further advantageous to achieve a compatible connection to existing oxygen lances by a design with external water supply and internal gas flow. This is already mostly the case with currently used oxygen blowing lances. In a necessary replacement of the lance head can then be used in a simple manner, a lance head according to the present invention.

At this time, a coolant flow such as, for example, flows through. Water the lance in the two outer tube areas. In the middle tube, the oxygen is led through the lance tubes to the tube end (the lance head). In this area there is at least one nozzle through which the gas flows into the converter.

However, the arrangement of the cooling water and gas areas may also be different if it allows an advantageous embodiment.

Two embodiments of height-compensating nozzles in connection with the present invention will be described in more detail below by way of example.

1. oxygen lance heads with aerospike (s) Due to the cross-sectional constriction of the conduit from the gas-carrying tube into the inlet of the nozzle with a smaller flow cross-section, the gas is compressed. In the course of the nozzle entry to the narrowest point of the nozzle occurs within an annular contour to a further compression on the limitation of the nozzle hole and the centrically mounted Aerospike body. In this case, the nozzle surrounds the inner part of the aerospike, which is part of the compression cross section.

The attachment of the aerospike can be done in different ways. For example, it can be fastened in the nozzle tubes by means of fastening straps attached to the side or also on another part of the oxygen unit or of the lance head. Practical is also the fixing of the molding on the gas inlet side in a disc with gas passage openings. Another possibility is the Anformung to an existing, belonging to the basic geometries of a lance head component.

At the end of the compression path, the gas is directed at an angle to be determined to the contour of the aerospike. From there, the gas expands into the converter and is directed through the aerospike in the outer area of the lance head. Since an ideal shaped body is too long for a practical operation according to the design, it can be shortened. This reduces the efficiency. However, with reasonable curtailment, the losses are justifiable, as the missing edges are modeled by complex flows as the ideal contour of gas and complex shock layers.

The molded body is divided essentially into an inner and an outer region. In the inner region, the gas is guided according to the design, adapted to the pressure or the exit surface according to the nozzle design and brought to the exit from the lance head. In this case, the mass flow is directed against a nozzle geometry lying outside the lance head, wherein the jet can already be accelerated by an upstream expansion contour to a Mach number greater than 1. The further adaptation of the beam is usually not yet completed. In aerospike nozzles, the point of maximum compression is brought very close to the geometric boundary to the converter space. At a partially external geometry, the gas expands directly against the ambient pressure.

The relaxation over a constructively planned, external contour of the lance head has the advantage that the expansion over a wide range of pressure ratios and closer to the ideal behavior can be performed as is the case with a lance head of known design under the same conditions. In the context of the application according to the present invention, the "height compensation" therefore causes a "self-adaptation" in the sense that a better process behavior is achieved over a larger value range of the process parameters. This also results in a higher efficiency outside the design point.

The outer geometry can have different contours.

In a rotationally symmetrical variant, conical, or optimized, complex parabolic shapes, which are usually determined in numerical / mathematical methods, are to be emphasized as embodiments. The ideal length with only low efficiency losses can also be shortened, resulting in frustoconical geometries.

Despite in some cases severe shortening of the projecting into the converter space geometry, the remaining stumps can be effective because the attributable areas are partially reformed by forming gas flows, these areas themselves act as a continued nozzle contour beyond the end of the nozzle.

The mouth region of the inner nozzle can be formed, for example, as a ring passage or by means of a plurality of directed outlet openings. In the case of a shortening optional flow geometries attached axially to the nozzle may be attached. These flow geometries may be one or more wells that assist in the formation of desired flows. Such an additional nozzle is also referred to as "base bleeding" when the exit is at the center of the geometry.

The attachment of the nozzle geometries, which are required for the inventive design of a lance head, depending on the embodiment directly on the lance head be molded or be multi-part. The nozzle geometries may be attached to a base body by connection techniques such as mating, gluing, or welding to the lance head. In a multi-part design, different materials can be used. For example, copper may be used for the base body, which may include the inner nozzle portion, and ceramic for the tapered outer nozzle portion.

2. oxygen lance heads with E-D nozzle (s)

Oxygen lances with E-D nozzles are characterized by nozzles with a deflector in oxygen flow. The design of an E-D nozzle is similar to a bell nozzle with a centric shaped body to which the deflector is attached. In this case, the deflector usually ends before the nozzle exit edge.

This directs the oxygen flow according to the geometric shape of the centrically mounted molding against the lateral nozzle boundary. Depending on the pressure ratio of the nozzle admission pressure to the converter pressure, two differently usable states can be set, which are referred to as "open wake" or "closed wake". While "open wake" is for the most part externally expanding and compensating for different pressure conditions, "closed wake" is similar to using a nozzle with internal expansion.

In this case, however, an increased gas flow flows on the walls of the nozzle than in the case of an internally expanding nozzle. This is the durability of the nozzle conducive because the aggressive converter atmosphere can not easily damage the trailing edge as in the designs of lance heads with known expansion geometries.

This effect is caused by the deflecting effect of the centrically mounted molding. Due to the special shape of the molded body in the region facing the exit from the nozzle and in particular in the region of the narrowest cross section, nozzles can be developed which take into account the manifold demands on metallurgical processes with regard to different process parameters and durability of the components to a greater extent than in known designs was the case. An embodiment of the invention is shown in the drawing. It shows:

Figures 1 - 4: different views of a lance head with an ED nozzle and a shaped body (pin) in the ED nozzle Figures 5-8: different views of a lance head with an aerospike nozzle and the shaped body (spike) in the Aerospike nozzle .

FIGS. 9-12 show various views of a lance head with a further aerospike nozzle and of the shaped body (spike) in the aerospike nozzle,

Figures 13-16: different views of a lance head with another Aerospike nozzle and the shaped body (spike) in the Aerospike nozzle, Figures 17 - 20: different views of a lance head with another ED nozzle and the molded body (pin) in the ED nozzle, FIGS. 21-25: different views of a lance head with a further ED nozzle and the shaped body (pin) in the ED nozzle,

FIG. 26: the representation of a shaped body (spike) of an aerospike nozzle,

FIG. 27 shows an exemplary embodiment of the use of a nozzle according to the present invention in an electric furnace, FIG. 28 shows a nozzle in a lateral section,

FIG. 29 shows the nozzle according to FIG. 28 in a top view in the flow direction,

FIG. 30 shows another embodiment of a nozzle in a lateral section,

FIG. 31 shows the nozzle according to FIG. 30 in a top view in the flow direction,

Figure 32: a nozzle with a shaped body and cooling channels in a lateral

Section, Figure 33: the representation of the nozzle of Figure 32 in a plan view from below in a section and

Figure 34: a circular arrangement of outlet nozzles with moldings in one

Top view from below.

FIG. 2 shows a lance head 1 with an ED nozzle 201 in a lateral section. FIG. 1 shows the associated top view of the lance head 1 from above. The lance head 1 has in its interior a delivery channel 2, through which the technical gas is conveyed in the direction of the ED nozzle 201 to exit there. Furthermore, flow 3 and return 4 of a cooling circuit can be seen, over which the lance head is to be cooled by the circulation of cooling water in this cooling circuit 3, 4th

It can be seen that in the E-D nozzle 201, a molded body 202 is arranged, which by way of example has three fastening elements 5, 6, 7, which rest on a shoulder of the E-D nozzle 201. In addition, the molded body 202 is held in position.

Figures 3 and 4 show the molded body 202 from different perspectives. The fastener 7 is hidden in this illustration. The fasteners 5 and 6 can be seen.

FIG. 6 shows a lance head 601 with, for example, an aerospike nozzle 602 in a lateral section. FIG. 5 shows the associated top view of the lance head 601 from above.

The lance head 601 has in its interior a delivery channel 603, through which the technical gas is conveyed in the direction of the aerospike nozzle 602 to exit there. Furthermore, flow 3 and return 4 of a cooling circuit can be seen, over which the lance head is to be cooled by the circulation of cooling water in this cooling circuit 3, 4th

It can be seen that in the aerospike nozzle 602, a molded body 604 is arranged, which has three fastening elements 5, 6, 7, which rest on a shoulder of the aerospike nozzle 602. In addition, the molded body 604 is held in position.

FIGS. 7 and 8 show the molded body 604 from different perspectives. The fastener 7 is hidden in this illustration. The fasteners 5 and 6 can be seen.

FIG. 10 shows a lance head 1001 with an aerospike nozzle 1002 in a lateral section. FIG. 9 shows the associated top view of the lance head 1001 from above. The lance head 1001 has in its interior a delivery channel 1003, through which the technical gas is conveyed in the direction of the aerospike nozzle 1002 to exit there. Furthermore, flow 3 and return 4 of a cooling circuit can be seen, over which the lance head is to be cooled by the circulation of cooling water in this cooling circuit 3, 4th

It can be seen that in the aerospike nozzle 1002 a molded body 1004 is arranged, which has three fastening elements 5, 6, 7. By means of these fastening elements 5, 6, 7, this shaped body 1004 is supported in its lower region to the edge of the aerospike nozzle 1002. In addition, a support plate 1005 can be seen, which has passages 1006 for the technical gas. This support plate 1005 rests on a shoulder of the aerospike nozzle 1002. In addition, the molded body 1004 is held in position.

Figures 11 and 12 show the molded body 1004 from different perspectives. The fastening elements 5, 6, 7 are introduced into the illustrated receiving slots 1007, 1008 for these fastening elements 5, 6, 7.

FIG. 14 shows a lance head 1401 with an aerospike nozzle 1402 in a lateral section. FIG. 13 shows the associated top view of the lance head 1401 from above.

The lance head 1401 has in its interior a delivery channel 1403, through which the technical gas is conveyed in the direction of the aerospike nozzle 1402 to exit there. Furthermore, flow 3 and return 4 of a cooling circuit can be seen, over which the lance head is to be cooled by the circulation of cooling water in this cooling circuit 3, 4th

It can be seen that in the aerospike nozzle 1402, a molded body 1404 is arranged, which has three fastening elements 5, 6, 7, which rest on a shoulder of the aerospike nozzle 1402. In addition, the molded body 1404 is held in position.

FIGS. 7 and 8 show the molded body 1404 from different perspectives. The fastening element 7 is concealed in the representation of FIG. The fasteners 5 and 6 can be seen. It can be seen that the molded body 1404 has a passage opening 1405. Through this passage opening 1405, the technical gas can be output, which also emerges from the aerospike nozzle 1402 in the other. Especially with a shaped body 1402 having a reduced length, this passage opening 1405 proves to be advantageous, because thereby the flow behavior of the exiting gas is so infiuated that the gas flows out of the passage opening 1405 after emerging from the aerospike nozzle along this jet. This allows the emerging gas jet with appropriate design in some cases form advantageous.

It is also possible to flow through such a central through opening 1405 in the molded body 1404 and other substances such as other gases, carbon particles, carbon powder or the like. This can be advantageous to influence metallurgical processes.

As can be seen, such a passage opening may also be present in the case of a shaped body of an E-D nozzle.

FIG. 18 shows a lance head 1801 with an E-D nozzle 1802 in a lateral section. FIG. 1 shows the associated top view of the lance head 1801. In contrast to the representation of FIG. 2, this is not a bell nozzle but an embodiment of the basic geometry as a Laval nozzle.

The lance head 1801 has in its interior a delivery channel 1803, through which the technical gas is conveyed in the direction of the E-D nozzle 1802 to exit there. Furthermore, flow 3 and return 4 of a cooling circuit can be seen, over which the lance head is to be cooled by the circulation of cooling water in this cooling circuit 3, 4th

It can be seen that in the ED nozzle 1802, a molded body 1804 is arranged, which has three fastening elements 5, 6, 7, which rest on a shoulder of the ED nozzle 1802. In addition, the molded body 1804 is held in position. Figures 19 and 20 show the molded body 1804 from different perspectives. The fastening element 7 is concealed in the representation of FIG. The fasteners 5 and 6 can be seen.

FIG. 22 shows a lance head 2201 with an E-D nozzle 2202 in a lateral section. FIG. 21 shows the associated top view of the lance head 2201 from above.

The lance head 2201 has in its interior a delivery channel 2203, through which the technical gas is conveyed in the direction of the E-D nozzle 2202 to exit there. Furthermore, flow 3 and return 4 of a cooling circuit can be seen, over which the lance head is to be cooled by the circulation of cooling water in this cooling circuit 3, 4th

It can be seen that in the E-D nozzle 2202, a molded body 2204 is arranged, which has three fastening elements 5, 6, 7, which rest on a shoulder 2206 of the E-D nozzle 2202 via a spring-elastic mounting 2205. In addition, the molded body 2204 is held elastically in position. Due to this resilient mounting, the flow behavior of the E-D nozzle 2202 is advantageously variable.

It can also be seen that the shaped body 2204 again has a passage opening 2207, which has already been explained in connection with FIGS. 13 to 16 for a spike of an aerospike nozzle.

Figures 23, 24 and 25 show the molded body 2204 from different perspectives.

FIG. 26 shows the representation of a shaped article (spike) 2602 of an aerospike nozzle 2601. The dashed extension 2603 shows the full length of the shaped article (spike) 2602. It has been shown that an aerospike nozzle has optimal flow behavior with a full length spike. However, it has also been shown that an approximately optimal flow behavior is still achievable if the spike is shortened accordingly. In the present invention, however, with a corresponding protruding length of the shaped article (spike) 2602, the tip of this shaped article would come close to the metal bath and would thus be exposed to a correspondingly high temperature without the spike being able to be cooled to the tip.

It has been shown to be advantageous, especially in the described application to shorten the molding in its length. Nevertheless, advantageously the shape of the expansion of the exiting gas is largely retained.

Optionally, the molded body 2602 can still be provided with a central passage opening, as has already been explained in connection with the illustration of FIGS. 13 to 16.

Figure 27 shows an embodiment of the use of a nozzle 2701 of the present invention in an electric furnace 2702 with a refractory lining 2703. Such electric furnaces are also referred to as electric arc furnaces or EAF. Steel scrap is melted in these furnaces for reuse in new steels. By a direct current or alternating current arcs are formed between one or more electrodes and the material to be melted.

It can be seen that the nozzle 2701 has a molded body 2704 having a central passage 2705.

Furthermore, the surface 2706 of a metal bath can be seen. From the nozzle 2701 exits a central center jet 2707. Lines 2708 and 2709 describe the envelopes of the gas exiting the nozzle 2701. By the directed discharge of the gas, this can advantageously penetrate through the surface 2706 of the metal bath into the metal bath. The penetration depth advantageously supports metallurgical processes. It can also be a support of the melting process of scrap, which is positioned in front of the nozzle.

The central center jet 2007 consists in the illustrated embodiment of coal particles. The boundary lines 2708 and 2709 indicate that the gas is passing through the Nozzle characteristic compared with the use of previous nozzle concepts characterized by improved coherence. As a result, if applicable, the hitherto customary use of a ignited natural gas / oxygen mixture as envelope gas can be omitted.

FIG. 28 shows a nozzle 2801 in a lateral section. Again, a shaped body 2802 can be seen. Unlike the nozzles shown so far, the nozzle 2801 is only mirror-symmetrical to the central axis, which passes centrally through the molded body 2802. However, the nozzle 2801 is not rotationally symmetric.

FIG. 29 shows the nozzle 2801 according to FIG. 28 in a top view in the flow direction. It can be seen that the nozzle 2801 has a stretched (ie not rotationally symmetrical) profile in the transverse direction. This profile can be rectangular in section. It can be seen from lines 2901 that the edges of this profile can also be rounded.

Basically, in these nozzles with elongated profiles, the cross-sectional profiles along the course axis to the cross-sectional profiles of rotationally symmetrical nozzles may be identical or at least similar. However, the nozzles with the stretched cross-sectional profiles are not rotationally symmetrical.

This proves to be advantageous for the cooling of the nozzle 2801. By the arrow 2902, the flow direction of a coolant (water) is shown, with which the nozzle flows around during operation and is thereby cooled. Due to the profile, which is stretched in the flow direction of the cooling medium, a streamlined profile is achieved and achieved an enlarged flow cross-section. As a result, a better flow behavior of the cooling medium is achieved and thus a more efficient cooling of the nozzle 2801.

It can be seen that this profile of the nozzle can be used not only in the illustrated E-D nozzle but also in aerospike nozzles.

In addition to these types of nozzles in connection with the present invention, this profile is also suitable for conventional nozzles, because also in this case an efficient cooling important is. This was already mentioned in the introductory part of the introduction in connection with the reservation of a separate divisional application directed thereto.

FIG. 30 shows another embodiment of a nozzle 3001 in a lateral section. It can be seen that again a shaped body 3002 is present. Instead of an annular opening of the nozzle, a plurality of openings 3003 are provided, which are located along the outer periphery of the nozzle 3001.

This can be seen again in plan view in the direction of flow of the nozzle in FIG. The dispensed technical gas thus exits through the openings 3003 in this nozzle form. These may, for example, also be embodied as Laval nozzles in order to achieve an "incomplete" pre-expansion, in which case the jet first undergoes its complete and directed expansion at the molded body 3002.

FIG. 32 shows a nozzle 3201 with a shaped body 3202 and cooling channels 3203, 3204 in a lateral section. This can be an outlet nozzle, which is shown in FIG. 33 in a plan view from below. This means that this outlet nozzle is stretched in its outer contour in the flow direction of the cooling channels 3203, 3204. Of this extension is not seen in the representation of Figure 32, since the representation of Figure 32 shows a section transverse to the direction of this stretch.

It can be seen that the cooling channel 3203 extends outside the outlet nozzle 3201 along the outer contour at least substantially transversely to the direction of the flow of the outlet nozzles 3201. This direction of the flow of the outlet nozzles is indicated by the arrow 3205. By this direction is meant the flow direction of the gas or particles emitted via the outlet nozzle 3201. Through the cooling channels 3203, a coolant can be conveyed.

The extension of the outer contour of the outlet nozzles 3201 results in a favorable flow behavior of the coolant.

The molded body 3206 has in its connection to the material of the outer contour of the outlet nozzle 3201 and in its interior at least one cooling channel 3204. In the representation of FIG. 33 in a viewing direction from below, connected with a section, it can be seen that the molded body 3206 has a first connection 3301 to the material of the outer contour of the outlet nozzle 3201, which is arranged on the one shorter side of the cross section. Furthermore, the molded body 3206 has a further connection 3302 on the opposite side. It can be seen that the cooling channel 3204 is guided via the connection 3301 as a feed line to the molded body 3206 and via the further connection 3302 as a discharge of the cooling channel 3204 from the shaped body.

The arrows 3303 show the flow direction of the cooling medium.

This results in advantageous that the cooling channel 3204 is guided in the molding 3206 in the flow direction of the cooling medium. This results in a good flow behavior of the cooling medium in the molded body 3206.

Figure 34 shows a circular arrangement of outlet nozzles 3401 with moldings 3402 in a plan view from below.

In the context of the above-described and described invention, it may also be expedient to protect the shaped body by a metallic or ceramic coating against the hot atmosphere. This may possibly account for a separate active cooling of the molding. This applies to all embodiments described in connection with this application.

Claims

1. The use of one or more nozzles (201, 602, 1002, 1402, 1802, 2202, 260, 2701) designated as "height-compensating" in aerospace engineering as outlet nozzles of a feed device (1, 601, 1001, 1401, 1801, 2201) for technical gases in a container during the melting and / or metallurgical treatment of metals (2706).

2. Use according to claim 1, characterized in that at least one outlet body (202, 604, 1001, 1404, 1804 , 2204, 2602, 2704), through which the outflowing technical gas is conducted into the edge region of the at least one outlet nozzle (201, 602, 1002, 1402, 1802, 2202, 260, 2701).

3. Use according to claim 2, characterized in that the shaped body (604, 1004, 1404, 2602) beyond the edge of the outlet nozzle (602, 1002, 1402, 2601) protrudes.

4. Use according to claim 2 or 3, characterized in that the shaped body (2204) is mounted so that it is changeable in the outlet direction of the outlet nozzle in its position.

5. Use according to claim 4, characterized in that the shaped body is adjustable by means of an actuating element in its position.

6. Use according to claim 4, characterized in that the molded body (2204) is resiliently mounted (2205), wherein the positioning of the shaped body by the resilient mounting (2205) of the shaped body (2204), the pressure of the flowing technical gas and the ambient pressure he follows.

7. Use according to one of claims 2 to 6, characterized in that the shaped body (1404, 2204, 2704) at least one passage opening (1405, 2207, 2705), through which in the outlet direction of the outlet nozzle (1402, 2202, 2701) a Part of the technical gas and / or another gas and / or another substance is ausbringbar.

8. Use according to one of claims 1 to 7, characterized in that the outlet nozzles (3201) associated cooling channels (3203) are present, outside the outlet nozzles (3201) along the outer contour at least substantially transversely to the direction of the flow of the outlet nozzles ( 3201), wherein a coolant can be conveyed through the cooling channels (3203), the outer contour of the outlet nozzles (3201) having a non-axially symmetrical but elongate cross section, the longitudinal direction of the cross section being in the direction of flow of the coolant.

9. Use according to one of claims 2 to 7, characterized in that the shaped body (3206) in its connection (3301, 3302) to the material of the outer contour of the outlet nozzle (3201) and in its interior at least one cooling channel (3204).

10. Use according to claim 8 and 9, characterized in that the shaped body (3206) in the extended cross-section of the outlet nozzle (3201) has a first connection (3301) to the material of the outer contour of the outlet nozzle (3201) on the one shorter side of the cross section and a further connection (3302) on the opposite side, wherein the cooling channel (3204) with a supply line to the molded body (3206) via the first connection (3301) is guided, wherein the derivative of the cooling channel over the further connection (3302) out is.