MXPA98009724A - Lanceta inyectora de chorro cohere - Google Patents

Abstract

The present invention relates to a coherent jet injection lancet comprising: (A) an injector assembly having: (1) a primary passage, an injection space and a convergent / divergent nozzle having an inlet communicating with the injector. primary passage and having an outlet communicating with the injection space; (2) a first secondary passage radially spaced from the primary passage, oriented parallel with the primary passage and communicating the rapid flow of injection space with the outlet of the nozzle and (3) a secondary secondary passage radially spaced from the first secondary passage, oriented parallel with the primary passage and communicating the rapid flow of injection space with the nozzle outlet, and (B) a cover covering the injector assembly. , the cover extends beyond the outlet of the nozzle to define the injection space

Description

COOKING JET INJECTOR LANCET Technical Field This invention relates generally to apparatus for producing a gas flow. The invention is especially useful for producing a gas flow to introduce it into a liquid, such as a molten metal, which creates a rigorous environment for the gas injection device. Background Art It is often desired to establish a gas flow. For example, a gas flow can be injected into a liquid for one or more different reasons. A reactive gas can be injected into a liquid to react with one or more components of the liquid, such as, for example, the injection of oxygen into molten iron to react with carbon inside the molten iron to decarburize the iron and provide heat to the molten iron. . Oxygen can be injected into other molten metals such as copper, lead and zinc for melting purposes. A non-reactive gas, such as an inert gas, can be injected into a liquid to stir the liquid in order to promote, for example, a better temperature distribution or a better distribution of components throughout the liquid. Often the liquid is contained in a container such as a reactor or in a casting vessel where the liquid forms a well inside the container formed at the bottom and at some length of the walls of the container, and having a top surface. When gas is injected into the liquid well, it is desirable to have as much gas flow as possible in the liquid to carry out the attempted gas injection. Consequently, a gas is injected from a gas injection device into the liquid below the surface of the liquid. If the nozzle for a normal gas jet was spaced some distance above the liquid surface, then much of the gas impingement on the surface will be diverted into the liquid surface and will not enter the liquid well. Furthermore, such action will cause splashing of the liquid which can result in loss of material and operational problems. The submerged injection of gas into a liquid using gas injection devices mounted on the bottom or side wall, although they are very effective, have operational problems when the liquid is a corrosive liquid or when it is at a very high temperature, since these are Conditions can cause rapid deterioration of the gas injection device and localized wear of the container liner resulting in both the need for sophisticated external cooling systems and frequent stoppages for maintenance and high operating costs. It is convenient to bring the tip or nozzle of the gas injection device close to the surface of the liquid well avoiding contact with the surface of the liquid and injecting the gas from the gas injection device at a high speed so that a significant portion of the gas to the liquid. However, this convenience is not satisfactory even because the proximity of the tip of the gas injection device to the surface of the liquid can still result in significant damage to this equipment. Furthermore, in cases where the surface of the liquid is not stationary, the nozzle would have to be moved constantly to consider the moving surface for the gas injection to occur at the desired location and for the required distance between the lancet tip and the surface of the bathroom is maintained. For electric arc furnaces, this requires complicated hydraulically driven lancet manipulators which are expensive and require considerable maintenance. Another convenient is to use a tube that is introduced through the surface of the liquid well. For example, chilled waterless tubes are often used to inject oxygen into the molten steel bath in an electric arc furnace. However, this convenience is also unsatisfactory because rapid tube wear requires complicated hydraulically driven tube manipulators as well as tube feeding equipment to compensate for the rapid wear ratio of the tube. further, the loss of tube, which must be continuously replaced, is expensive. These problems can be solved if a coherent stream can be established. A coherent gas jet retains its diameter and velocity, after the injection, beyond what a normal gas jet does. With a coherent jet, the injection tip can be placed significantly farther from the liquid surface while still allowing virtually all of the gas within the coherent gas jet to penetrate the liquid surface. In addition, coherent jets will find use in other applications, such as combustion applications, where gas jets are commonly used.

Accordingly, it is an object of this invention to provide an apparatus for injecting gas into a volume so that the injected gas forms a coherent jet of gas. Summary of the Invention The foregoing and other objectives, which will be apparent to those skilled in the art upon reading this description, are accomplished by the present invention which is: A coherent jet injection lancet comprising: (A) an assembly injector having: (1) a primary passage, an injection space, and a nozzle having an inlet communicating with the primary passage and having an outlet communicating with the injection space; (2) a first secondary passage radially spaced from the primary passage and communicating with the injection space; and (3) a second secondary passage radially spaced from the first secondary passage and communicating with the injection space; and (B) a cover covering the injector assembly, said cover extending beyond the outlet of the nozzle to define the injection space. Brief Description of the Drawings Fig. 1 is a cross-sectional representation of a preferred embodiment of the coherent jet injector lancet of this invention. Fig. 2 is a cross-sectional representation of another preferred embodiment of the coherent jet injector lancet of this invention. Fig. 3 is a simplified cross-sectional representation of a modality of the coherent jet lancet of the invention positioned on a side wall of the container. Fig. 4 is a simplified front view of an embodiment of the coherent jet injector lancet of the invention having additional injection passages in the cover that expel divergent streams. Fig. 5 is a simplified front view of an embodiment of the coherent jet injector lancet of the invention having additional injection passages in the cover that expel convergent streams. The numerals in the Figures are the same for the common elements. Detailed Description The invention will be described in detail with reference to the drawings. Referring now to FIG. 1, the coherent jet injector 1 comprises an injector assembly and an outer cover. The injector assembly includes a primary passage 2 communicating with a primary gas source (not shown). The primary gas can be any gas from which the formation of a coherent jet is desired. Examples of such gases include oxygen, nitrogen, argon, hydrogen, helium, gaseous hydrocarbon fuel and mixtures comprising two or more of these. The primary passage 2 also communicates with the nozzle 3. Preferably, in at least a portion of its length, the nozzle 3 has a diameter that is smaller than the diameter of the primary passage 2 and is smaller than the diameter of the injection space 6. More preferably, as illustrated in Fig. 1, the nozzle 3 is a converging / diverging nozzle. The convergent / divergent nozzle 3 has an inlet 4, which communicates with the primary passage 2, and has an outlet 5 that communicates with the injection space 6. Radially spaced from the primary passage 2 is the first secondary passage 7, and spaced radially of the first secondary passage 7 is the second secondary passage 8. One of the first and second secondary passages communicates with an oxidant source (not shown), and the other of the first and second secondary passages communicates with a fuel source (not shown). When the oxygen is the primary gas the first secondary passage 7 preferably communicates with a fuel source and the second secondary passage 8 communicates with an oxidant source. The oxidant is preferably a fluid containing at least 30 mole percent oxygen, more preferably at least 90 mole percent oxygen. The oxidant can be technically pure oxygen having an oxygen concentration of 99.5 mole percent or more. The fuel can be any fluid fuel such as methane, propane, butylene, natural gas, hydrogen, coke gas for stove or oil. Each of the first and second secondary passages communicates with the injection space 6 preferably, even or aligned with the outlet 5 of the convergent / divergent nozzle 3. Fig. 1 illustrates a preferred embodiment of the invention wherein each of the passages first and second secondaries are converted into a plurality of individual passages so that each of the first and second secondary passages communicate with the injection space 6 as a ring of holes around the exit 5. Alternatively, one or both of the passages The first and second secondary may communicate with the injection space 6 as a circular ring at the outlet 5. The injector assembly is covered by a cover 9 running along the length of the injector assembly and having a cover extension portion. 10 which extends beyond the nozzle outlet 5 to define the injection space 6. The cover extension portion 10 has a length generally of up to 30.5 cm and preferably within the range of 1.27 to 17.8 cm. The extension of the cover does not need to be of the same length around the entire injector assembly and may have a length on one side of the injector assembly that exceeds its length on the other side of the injector assembly. Such an embodiment is illustrated in FIG. 2. Such an embodiment is particularly advantageous when mounted angularly on the side wall of a container. The cover 9 can be cooled by the circulation of refrigerant, e.g. water, in the interior flow passage and coolant 11 and the external flow passage of coolant 12. The injection space or volume 6 formed by the cover extension portion 10 establishes a protective zone that serves to protect the gas streams immediately. above its flows outside the primary and secondary passages. This improves the integrity of the coherent jet by providing an environment conducive to its initial training.

Typically the coherent jet injection lancet of this invention is placed on the wall or ceiling of a container, such as an oven, and is used to inject a gas flow, such as a coherent gas jet, into the container. Fig. 3 illustrates an arrangement such that the coherent jet injection lancet is mounted angularly on the side wall 20 of a container, e.g. an electric arc furnace, for injecting gas into the interior 25 of the container. In Fig. 3 the injector assembly is represented by the dark rectangle 22. In operation, the primary gas is ejected from the lancet 1 and forms the primary gas stream which typically has a velocity of 305 meters per second (mps) or plus. Fuel and oxidant are expelled from the lancet 1 and form annular streams which begin to mix immediately after ejection from the lancet 1 and burn to form a flaming envelope around the primary gas stream. If the invention is employed in a hot environment such as a metal melting furnace, a separate ignition source for the fuel and the oxidant is not required. If the invention is not employed in an environment where the fuel and oxidant self-ignite, an ignition source such as a spark generator will be required. Preferably, the flaming envelope will have a velocity less than the velocity of the primary gas stream and generally within the range of 15 to 305 mps. The flaming envelope forms a shield or fluid barrier around the primary gas stream. This barrier greatly reduces the amount of ambient gases that are entrained in the high velocity primary gas stream, thus serving to keep the gas stream coherent for a significant distance after ejection from the lancet. This allows placement of the lancet so that the tip of the lancet is spaced a greater distance from where the primary gas impacts or otherwise makes contact with another fluid or solid, thus increasing safety and better preservation of the lancet. integrity of the lancet. Generally, the amount of fuel and oxidant provided from the lancet will be sufficient to form a flammable envelope effective for the desired length of the primary gas stream. However, there may be occasions when it is desired that they leave the lancet more fuel and oxidant significantly so that the flaming envelope serves not only to protect the primary gas stream from the ambient gas entrainment, but also serves to provide considerable heat to the container. . That is, the lancet may also function as a burner, in some embodiments of this invention. The cover or jacket of the coherent jet injector lancet of this invention may contain one or more additional passages to provide additional fluid or fluids or to provide one or more streams of solid particles to the container to which the coherent jet of primary gas is injected. This is illustrated in FIG. 3 by the additional passage 21 having an injection aperture 24. The additional passage or passages 21 can be advantageously employed with the coherent jet injection lancet of this invention to provide post-combustion oxygen to a electric arc furnace for carrying out the post-combustion method described and claimed in US, 5,572,444-Mathur et al., although the injector assembly is used to provide oxygen mainly to the molten metal. The additional passage or passages may provide the fluid or additional stream of particles in a stream or streams running parallel to the coherent jet of primary gas or in an eddy current or streams toward or away from the primary coherent gas jet. Fig. 4 illustrates one embodiment of the invention that can be employed to provide two additional divergent currents, and Fig. 5 illustrates one embodiment of the invention that can be employed to provide two additional streams from the lancet such that these two currents intersect downstream of the lancet, that is, the currents are convergent. The axis of a passage or of a gas stream is the imaginary line that runs through the center of the passage or the gas stream along its length. The axis of the primary passage is illustrated in Fig. 1. The following are preferred specifications for the design of the coherent jet injector lancet of this invention. (1) flow ratio through the primary passage: 0.566-4.247 MyiCH to TPN (Normal Temperature and Pressure) Supply Pressure (upstream of the nozzle): 3.52- 21.11 Kg / cra2 Throat Diameter for Convergent-Divergent Nozzle D =? (Q / P) D - Throat Diameter - centimeters Q - MCH to TPN for the primary gas flow ratio. P - Absolute Pressure (Kg / arr) K = 0.03 to 0.04 D = 0.63 to 5.08 c. (2) oxygen to the ring of holes surrounding the nozzle Deq = C ^ DM = Diameter of tube equivalent to the cross-sectional area of the ring of holes. About what_. = Square root of (cross-sectional area of the ring of holes (cm) divided by (Pi / 4)) Q - MCH to TPN for the flow relation of the primary gas. C = 0.013 to 0.16 (3) fuel to the ring of holes surrounding the nozzle Q - MCH to TPN for the primary gas flow ratio. H - Fuel calorific value - Kcal / m - (to TPN) J = 0.4 to 5.0 Now with the use of this invention one can effectively establish a gas flow as a coherent gas jet. Although the invention has been described in detail with reference to certain preferred embodiments, those skilled in the art will recognize that there are other embodiments of the invention within the spirit and scope of the claims.

Claims (9)

1. CLAIMS 1. A coherent jet injector lancet comprising: (A) an injector assembly having: (1) a primary passage, an injection space, and a nozzle having an inlet communicating with the primary passage and having an exit that communicates with the injection space; (2) a first secondary passage radially spaced from the primary passage and communicating with the injection space; and (3) a second secondary passage radially spaced from the first secondary passage and communicating with the injection space; and (B) a cover covering the injector assembly, said cover extending beyond the outlet of the nozzle to define the injection space.
2. 2. The coherent jet injector lancet of claim 1 wherein the nozzle is a convergent / divergent nozzle.
3. 3. The coherent jet injector lancet of claim 1 wherein the cover extends beyond the outlet of the nozzle for a greater distance on one side of the injector assembly compared to the other side of the injector assembly.
4. 4. The coherent jet injector lancet of claim 1 mounted on the side wall of a container.
5. 5. The coherent jet injector lancet of claim 3 mounted angularly on the side wall of a container.
6. 6. The coherent jet injector lancet of claim 1 wherein the cover comprises at least one additional passage for the provision of a stream comprising at least one of fluid or particles.
7. 7. The coherent jet injector lancet of claim 6 wherein at least one additional passage within the cover has an axis which is at an angle to the axis of the primary passage.
8. 8. The coherent jet injector lancet of claim 6 comprising at least two additional passages within the cover which are oriented in such a way that the axes of the fluid streams expelled from said additional passages intersect.
9. 9. The coherent jet injector lancet of claim 6 comprising at least two additional passages within the cover which are oriented in such a way that the axes of the fluid streams expelled from said additional passages diverge. COOLANT JET INJECTOR LANCET SUMMARY A lancet that can be used to establish a "coherent gas jet" that includes a primary passage that has a converging / diverging nozzle, and two secondary passages spaced radially to establish a flaming barrier, each of the passages communicating with an injection space defined by a protective cover.