WO2021056200A1

WO2021056200A1 - Oxygen delivery apparatus and manufacturing method therefor, and de laval nozzle and manufacturing method therefor

Info

Publication number: WO2021056200A1
Application number: PCT/CN2019/107577
Authority: WO
Inventors: 李长鹏; 张卿卿; 吴琪; 陈国锋
Original assignee: 西门子（中国）有限公司
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2021-04-01
Also published as: CN114144533A; CN114144533B

Abstract

A de Laval nozzle, comprising: a first tube (410), the first tube (410) comprising a first air inlet tube (412) and a plurality of second air outlet tubes (413a-413d), the lower surface of the first air inlet tube (412) being provided with a plurality of air outlet holes (412a-412d), and each of the air outlet holes (412a-412d) being connected to one of the second air outlet tubes (413a-413d); a second tube (420) sleeved on the periphery of the first tube (410), the lower end of the second tube (420) being connected onto the outer wall of the first tube (410); and a third tube (430) sleeved on the periphery of the second tube (420), the lower end of the third tube (430) being connected onto the outer walls of the plurality of second air outlet tubes (413a-413d). The de Laval nozzle further comprises a plurality of guide sheets (440a-440d, 450a-450d, 460a-460d). According to the de Laval nozzle, the design of a cooling water channel is optimized, and thus higher cooling efficiency is achieved. An oxygen delivery apparatus, comprising the de Laval nozzle. A manufacturing method for a de Laval nozzle, in which a de Laval nozzle is manufactured by using the additive manufacturing technology.

Description

Oxygen delivery device and manufacturing method thereof, Laval nozzle and manufacturing method thereof

Technical field

The invention relates to the field of additive manufacturing, in particular to an oxygen delivery device, a Laval nozzle and a manufacturing method thereof.

Background technique

As shown in Figures 1 and 2, the Laval nozzle 220 is a key element of the steelmaking furnace 300. It is arranged at the lower end of the oxygen pipe 210 and is used to remove the molten steel 310 of the steelmaking furnace 300 by spraying out oxygen supplemental blowing. Impurity of carbon, silicon, manganese and phosphorus. Among them, the Laval nozzle 220 as the main element is used as an outlet for oxygen. It has a precisely machined air outlet 222 to obtain the ideal flow rate and parameters. In addition, the Laval nozzle 220 has a first cooling liquid channel 224 and The second cooling liquid channel 226, the first cooling liquid channel 224, and the second cooling liquid channel 226 have circulating cooling liquid to avoid overheating and damage to the Laval nozzle 220. Wherein, the first cooling liquid channel 224 is used to serve as a cooling liquid inlet, and the second cooling liquid channel 226 is used to serve as a cooling liquid outlet.

As shown in the figure, in order to obtain sufficient oxygen outgassing efficiency, the Laval nozzle 220 is usually arranged near the surface of the molten steel 310 whose temperature is greater than 2000 degrees Celsius. Due to the extremely high operating temperature, the cooling liquid inside the Laval nozzle 220 is not sufficient to continuously prevent the nozzle surface from melting or prematurely burning. In addition, due to the difficulty of industrial manufacturing of the Laval nozzle 220, the cooling liquid pipe design cannot be optimized. As shown in Figure 2, due to flow turbulence, there is a region A with a relatively slow flow rate in the Laval nozzle. Although the flow rate of the cooling liquid is very high, it is difficult for the cooling liquid to flow in the region similar to the region A and converge together. A dead water zone is formed, which leads to a lower cooling rate and protection capability. Therefore, the Laval nozzle 220 in the area A is more likely to overheat or even be damaged.

The life of Laval nozzles is very low, and oxygen nozzles are usually damaged and need to be replaced after 100 to 200 furnaces. Nozzle replacement is also very troublesome. The nozzle head that needs to be replaced needs to be cut from the oxygen tube 210 and re-welded with a new nozzle head, which not only causes additional operating costs but also affects the normal production process. In addition, the oxygen tube 210 is made of stainless steel, and the Laval nozzle 220 is made of copper, and the two are connected by welding. The high temperature gradient and different thermal expansion rates of stainless steel and copper can cause cracks along the weld line of the oxygen tube 210 and the Laval nozzle 220, which can lead to premature failure.

Summary of the invention

The first aspect of the present invention provides a Laval nozzle. The Laval nozzle includes: a first pipe including a first air inlet pipe and a plurality of second air outlet pipes, and the lower surface of the first air inlet pipe has a plurality of There are two air outlets, each of which is connected with a second air outlet; the second tube is sleeved on the periphery of the first tube, and the lower end of the second tube is connected to the outer wall of the first tube The first pipe and the second pipe serve as a cooling water inlet channel; the third pipe is sleeved on the periphery of the second pipe, and the lower end of the second pipe is connected to the plurality of second outlets. On the outer wall of the air pipe, between the second pipe and the third pipe is used as a cooling water outlet channel, wherein the Laval nozzle further includes: a plurality of first guide fins, one end of the first guide fins is connected to the On the inner wall of the third pipe, the other end of the first guide piece is connected to the outer wall of the second pipe; a plurality of second guide pieces, one end of the first guide piece is connected to the third pipe On the inner wall of the second guide piece, the other end of the second guide piece is connected to the outer wall of the second tube; a plurality of third guide pieces are arranged between the plurality of second air outlet pipes, and the third guide piece One end is connected to the inner wall of the second tube.

Further, the first guide piece, the second guide piece and the third guide piece are three-dimensional arcs.

Further, the first tube, the second tube and the third tube are coaxial.

Further, the material of the Laval nozzle is copper.

Further, the first pipe and the second pipe serve as a cooling water inlet passage, and the second pipe and the third pipe serve as a cooling water outlet passage.

The second aspect of the present invention provides an oxygen delivery device for passing oxygen into molten steel in a steelmaking furnace, wherein the oxygen delivery device includes an oxygen pipe and a Laval nozzle connected to one end of the oxygen pipe The Laval nozzle includes the Laval nozzle according to the first aspect of the present invention.

Further, the material of the oxygen tube is stainless steel, and the connection area of the oxygen tube and the Laval nozzle is an alloy of stainless steel and copper.

The second aspect of the present invention provides a method for manufacturing a Laval nozzle, wherein the Laval nozzle according to the first aspect of the present invention is manufactured using additive manufacturing technology.

Further, the manufacturing method is performed in a selective laser melting device.

Further, the manufacturing method further includes the following steps: performing laser scanning on the copper metal particles, so that the copper metal particles are melted into the Laval nozzle layer by layer from bottom to top according to a predetermined shape; The copper and stainless steel mixed metal particles are laser scanned, so that the copper metal particles are melted layer by layer from bottom to top according to a predetermined shape into the connection area of the oxygen tube and the Laval nozzle.

Further, the manufacturing method is implemented using a composite additive manufacturing process of laser energy deposition and machining.

Further, the manufacturing method further includes the following steps: performing laser scanning on the copper metal particles provided by the powder injection port, and performing mechanical processing operations at the same time, so that the copper metal particles are melted layer by layer from bottom to top according to a predetermined shape and/ Or mechanical processing is the Laval nozzle; laser scanning is performed on the copper and stainless steel mixed metal particles provided by the powder spray port, and the mechanical processing operation is performed at the same time, so that the copper and stainless steel mixed metal particles are free from a predetermined shape Layer by layer melting and/or mechanical processing from bottom to top becomes the connection area of the oxygen tube and the Laval nozzle.

The oxygen delivery device and its Laval nozzle provided by the present invention optimize the cooling liquid channel and have higher cooling efficiency. Although the structure and layout of the coolant channel are more complicated, the present invention can be easily manufactured through additive manufacturing technology. Among them, the cooling liquid can be guided according to a preset flow rate distribution, and it is avoided that the cooling liquid is difficult to flow in the area surrounding the oxygen channel and the center point of the nozzle and thus converges due to the turbulent flow. The guide piece provided by the present invention can also strengthen the supporting force of the structure, and can obtain a thinner nozzle wall thickness and better cooling capacity. In addition, the guide vanes will also increase the cooling area and increase the additional cooling effect.

Description of the drawings

Figure 1 is a schematic diagram of the oxygen delivery device in the steelmaking furnace;

Figure 2 is a schematic cross-sectional view of a Laval nozzle in the prior art;

Figure 3 is a schematic diagram of the appearance of a Laval nozzle according to a specific embodiment of the present invention;

4a to 4c are schematic cross-sectional structural diagrams of a Laval nozzle according to a specific embodiment of the present invention;

Figure 5 is a schematic diagram of the structure of a selective laser melting device;

Fig. 6 is a schematic diagram of the structure of a composite additive manufacturing process equipment of laser energy deposition and machining.

detailed description

The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

The present invention provides an oxygen delivery device and a manufacturing method thereof, a Laval nozzle and a manufacturing method thereof. The Laval nozzle can be manufactured by a selective laser melting device or a composite additive manufacturing process equipment of laser energy deposition and machining. Among them, the Laval nozzle provided by the present invention has a plurality of cooling liquid guide fins, so as to avoid the situation that the cooling liquid cannot flow due to the turbulent flow, and improve the life of the Laval nozzle.

The first aspect of the present invention provides a Laval nozzle. As shown in FIGS. 3 and 4a, 4b and 4c, the Laval nozzle 400 includes a first tube 410, a second tube 420, and a third tube 430. Specifically, the first pipe 410 includes a first air inlet pipe 412 and a plurality of second

air outlet pipes

413a, 413b, 413c, and 413d. The lower surface of the first air inlet pipe 412 has a plurality of

air outlet holes

412a, 412b, 412c and 412d, a second air outlet pipe is connected to each air outlet. The outlet hole 412a is connected to the second outlet pipe 413a, the outlet hole 412b is connected to the second outlet pipe 413b, the outlet hole 412c is connected to the second outlet pipe 413c, and the outlet hole 412d is connected to the second outlet pipe 413d. The second tube 420 is sleeved on the periphery of the first tube 410, and the lower end of the second tube 420 is connected to the outer wall of the first tube 410. Wherein, the space between the first pipe 410 and the second pipe 420 serves as a cooling water inlet channel. The third tube 430 is sleeved on the periphery of the second tube 420, and the lower end of the second tube 420 is connected to the outer wall of the plurality of second air outlet tubes. Wherein, the space between the second pipe 420 and the third pipe 430 serves as a cooling water outlet channel.

Wherein, the Laval nozzle 400 further includes a plurality of first guide pieces, second guide pieces, and third guide pieces. 4a and 4c, in this embodiment, the Laval nozzle 400 includes four

first guide pieces

440a, 440b, 440c, and 440d, and one end of each first guide piece is connected to the first guide piece. On the inner wall of the third tube 430, the other end of the third tube 430 is connected to the outer wall of the second tube 420. There are four

first guiding pieces

450a, 450b, 450c, and 450d. One end of each first guiding piece is connected to the inner wall of the second tube 420, and the other end is connected to the outer wall of the first tube 410. In this embodiment, the Laval nozzle 400 includes four

third guide pieces

460a, 460b, 460c, and 460d, and each third guide piece is disposed between a plurality of second air outlet pipes. The third guide piece One end of is connected to the inner wall of the second tube 420. One end of the

second guiding piece

440a, 440b, 440c, and 440d is connected to the inner wall of the third tube 430, and the other end of the

second guiding piece

440a, 440b, 440c, and 440d is connected to the second pipe On the outer wall of 420;

Wherein, the first guide piece, the second guide piece and the third guide piece are three-dimensional arc shapes.

Preferably, the first tube 410 and the second tube 420 are coaxial.

Wherein, the material of the Laval nozzle 400 is copper.

Compared with the traditional manufacturing process, the Laval nozzle obtained by the additive manufacturing process has a directionally guided cooling liquid channel. Specifically, the cooling liquid inside the Laval nozzle can be guided by a guide vane with a certain curvature to obtain a predetermined circulating flow direction around the oxygen channel and the center point of the nozzle, thereby optimizing the shape and distance between the guide vanes To achieve the ideal flow velocity distribution. This can improve the fluid dynamics of the cooling liquid, and avoid the slow flow rate of the cooling liquid surrounding the oxygen channel and the center point area of the nozzle due to flow turbulence. In addition, the flow rate distribution of the cooling liquid can be further optimized by adjusting the shape and layout of the guide vanes to further achieve a better cooling rate. In addition, the guide vanes will also act as a strengthening support structure. Increased mechanical strength (increased mechanical stiffness) can achieve a thinner nozzle wall thickness and better cooling capacity. In addition, the guide vanes will also increase the cooling area and increase the additional cooling effect.

The second aspect of the present invention provides an oxygen delivery device for passing oxygen into molten steel in a steelmaking furnace, wherein the oxygen delivery device includes an oxygen pipe and a Laval nozzle connected to one end of the oxygen pipe, so The Laval nozzle is the Laval nozzle described in the first aspect of the present invention.

Preferably, the material of the oxygen tube is stainless steel, and the connection area between the oxygen tube and the Laval nozzle is an alloy of stainless steel and copper.

The third aspect of the present invention provides a method for manufacturing a Laval nozzle, which is characterized in that the Laval nozzle according to the first aspect of the present invention is manufactured using additive manufacturing technology. Optionally, the manufacturing method is performed in a selective laser melting device, or the manufacturing method is performed in a composite additive manufacturing process of laser energy deposition and machining. Among them, selective laser melting equipment is more suitable for manufacturing small parts, and the cost is slightly higher, and the composite additive manufacturing process of laser energy deposition and machining is more suitable for manufacturing large parts, and the cost is lower, so it can be flexibly selected according to different application scenarios.

Among them, the selective laser melting (Selected Laser Melting, SLM) process is a kind of additive manufacturing (Additive manufacturing) technology, which can quickly manufacture the same parts as the CAD model through laser sintering. At present, the selective laser melting process has been widely used. Different from the traditional material removal mechanism, additive manufacturing is based on the completely opposite principle of materials incremental manufacturing (philosophy). Among them, selective laser melting uses high-power lasers to melt metal powder, and inputs layer by layer through 3D CAD. The components/components can be built up to the ground, so that components with complex internal channels can be successfully manufactured. Figure 3 is a schematic diagram of a selective laser melting device. As shown in FIG. 1, the selective laser melting device 100 includes a laser source 110, a mirror scanner 120, a prism 130, a powder feeding cylinder 140, a forming cylinder 150 and a recovery cylinder 160. Wherein, the laser source 110 is arranged above the selective laser melting device 100 and serves as a heating source for the metal powder, that is, the metal powder is melted for additive manufacturing. Among them, there is a first piston (not shown) that can move up and down at the lower part of the powder feeding cylinder 140. A spare metal powder is placed in the cavity space above the first piston of the powder feeding cylinder 140, and it follows the movement of the first piston. The metal powder is sent from the powder feeding cylinder 140 to the forming cylinder 150 by moving up and down. An additive manufacturing part placing table 154 is provided in the forming cylinder 150, an additive manufacturing part is clamped above the placing table 154, and a second piston 152 is fixed below the placing table 154, wherein the second piston 152 and the placing table 154 vertical settings. During the additive manufacturing process, the second piston 152 moves from top to bottom to form a printing space in the forming cylinder 220. The laser source 110 for laser scanning should be set above the forming cylinder 150 of the selective laser melting equipment. The mirror scanner 120 adjusts the position of the laser by adjusting the angle of a prism 130, and the prism 130 is adjusted to determine which area of the laser is melted powder. The powder feeding cylinder 140 further includes a roller (not shown). The metal powder P is stacked on the upper surface of the first piston, and the first piston moves vertically from bottom to top to transfer the metal powder to the upper part of the powder feeding cylinder 140. The selective laser melting device 100 further includes a roller, and the powder for additive manufacturing can be laid on the forming cylinder 220 by the rolling of the roller. The roller may roll on the metal powder P to send the metal powder P to the forming cylinder 150. Thus, the laser scanning is continuously performed on the metal powder to decompose the metal powder into a powder matrix, and the laser scanning of the powder matrix is continued until the powder matrix is sintered from the bottom to the top into a print with a preset shape. In addition, the selective laser melting device 100 further includes a recovery cylinder 160 for recovering the used metal powder in the forming cylinder 150.

Further, the manufacturing method is performed in a selective laser melting device, and the manufacturing method further includes the following steps: laser scanning the copper metal particles, so that the copper metal particles follow a predetermined shape from bottom to top Layer by layer melting into the Laval nozzle; laser scanning is performed on the copper and stainless steel mixed metal particles, so that the copper metal particles are melted into the oxygen tube and the oxygen pipe layer by layer according to a predetermined shape from bottom to top. The connection area of the Laval nozzle. Specifically, the ratio of copper to stainless steel gradually changes from pure stainless steel to pure copper from top to bottom.

Fig. 4 is a schematic diagram of the structure of a composite additive manufacturing process equipment of laser energy deposition and machining. As shown in FIG. 4, the composite additive manufacturing process equipment 200 of laser energy deposition and machining includes a robotic arm 210, a turntable 220 and a machining shaft 230. Wherein, the gripper of the robotic arm 210 is provided with a powder spray port 212, and the powder spray port 212 is used to provide additively manufactured metal powder. The advantage of the composite additive manufacturing process equipment 200 of laser energy deposition and machining is that it does not require intense indoor processing. A placing table 222 is provided on the turntable 220, and the crafted part C of the additive manufacturing is placed on the placing table 222 for manufacturing. Specifically, the powder spray port 212 continues to provide metal powder on the placement table 222, and the laser source continues to perform laser scanning on the metal powder provided by the powder spray port 212, decomposes the metal powder into a powder matrix, and continues to perform laser on the powder matrix. Scanning until the powder matrix is sintered from bottom to top into a printed part C with a preset shape. Compared with the selective laser melting device 100, the laser energy deposition and machining composite additive manufacturing process device 200 performs additive manufacturing with less precision than roughness. Therefore, the machining shaft 230 needs to be mechanically polished and cut at the same time to obtain High-precision print C.

When the manufacturing method is performed using a composite additive manufacturing process of laser energy deposition and machining, the manufacturing method further includes the following steps: laser scanning is performed on the copper metal particles provided by the powder nozzle, and simultaneously performing (or printing several layers) Afterwards, perform a mechanical processing operation, so that the copper metal particles are melted layer by layer from bottom to top according to a predetermined shape and/or mechanically processed into the Laval nozzle; the copper and stainless steel mixed metal provided to the powder nozzle The particles are scanned by laser, and the mechanical processing operations are performed at the same time (or after printing several layers), so that the copper and stainless steel mixed metal particles are melted and/or mechanically processed layer by layer from bottom to top according to a predetermined shape. The connection area of the oxygen pipe and the Laval nozzle. In particular, the ratio of copper to stainless steel gradually changes from pure stainless steel to pure copper from top to bottom.

According to a preferred embodiment of the present invention, from the Laval nozzle to the oxygen pipe connected to it, the composition gradient transitions from pure metallic copper to stainless steel, and the connection area from the Laval nozzle to the oxygen pipe is an alloy of copper and stainless steel. The upper part is welded with a stainless steel oxygen tube, which can ensure better weldability and avoid the temperature rise due to the different thermal expansion coefficients of the Laval nozzle made of copper and the stainless steel oxygen tube.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as limiting the present invention. After those skilled in the art have read the above content, various modifications and alternatives to the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims. In addition, any reference signs in the claims should not be regarded as limiting the involved claims; the word "comprising" does not exclude other claims or devices or steps not listed in the specification; "first", "section Words such as "two" are only used to indicate names, and do not indicate any specific order.

Claims

Laval nozzle, characterized in that, the Laval nozzle comprises:

The first pipe (410) includes a first air inlet pipe (412) and a plurality of second air outlet pipes (413a, 413b, 413c, 413d). The lower surface of the first air inlet pipe (412) has a plurality of outlet pipes. Air holes (412a, 412b, 412c, 412d), each air hole (412a, 412b, 412c, 412d) is connected with a second air outlet pipe (413a, 413b, 413c, 413d);

The second tube (420) is sleeved on the periphery of the first tube (410), and the lower end of the second tube (420) is connected to the outer wall of the first tube (410);

The third tube (430) is sleeved on the periphery of the second tube (420), and the lower end of the second tube (420) is connected to the plurality of second air outlet tubes (413a, 413b, 413c, 413d) ) On the outer wall,

Wherein, the Laval nozzle (400) further includes:

A plurality of first guide pieces (450a, 450b, 450c, 450d), one end of the first guide piece (450a, 450b, 450c, 450d) is connected to the inner wall of the third tube (430), and the first guide piece (450a, 450b, 450c, 450d) is connected to the inner wall of the third tube (430). The other end of a guide piece (450a, 450b, 450c, 450d) is connected to the outer wall of the second tube (420);

A plurality of second guiding pieces (440a, 440b, 440c, 440d), one end of the second guiding piece (440a, 440b, 440c, 440d) is connected to the inner wall of the third tube (430), and the first The other end of the two guide pieces (440a, 440b, 440c, 440d) is connected to the outer wall of the second tube (420);

A plurality of third guiding pieces (460a, 460b, 460c, 460d) are arranged between the plurality of second air outlet pipes (413a, 413b, 413c, 413d), and the third guiding pieces (460a, 460b, 460c, One end of 460d) is connected to the inner wall of the second tube (420).
The Laval nozzle according to claim 1, wherein the first guide piece (450a, 450b, 450c, 450d), the second guide piece (440a, 440b, 440c, 440d) and the The third guide piece (460a, 460b, 460c, 460d) is arc-shaped.
The Laval nozzle according to claim 1, wherein the first tube (410), the second tube (420) and the third tube (430) are coaxial.
The Laval nozzle according to claim 1, wherein the material of the Laval nozzle is copper.
The Laval nozzle according to claim 1, wherein the first pipe (410) and the second pipe (420) serve as a cooling water inlet passage, and the second pipe (420) and the The third pipe (430) serves as a cooling water outlet channel.
An oxygen delivery device for passing oxygen into molten steel in a steelmaking furnace, characterized in that the oxygen delivery device includes an oxygen pipe and a Laval nozzle connected to one end of the oxygen pipe, and the Laval nozzle Including the Laval nozzle according to any one of claims 1 to 5.
The oxygen delivery device according to claim 6, wherein the material of the oxygen pipe is stainless steel, and the connection area between the oxygen pipe and the Laval nozzle is an alloy of stainless steel and copper.
The method for manufacturing a Laval nozzle is characterized in that the Laval nozzle according to any one of claims 1 to 5 is manufactured using an additive manufacturing technology.
The manufacturing method of the Laval nozzle according to claim 8, wherein the manufacturing method is performed in a selective laser melting device.
The manufacturing method of the Laval nozzle according to claim 9, wherein the manufacturing method further comprises the following steps:

Performing laser scanning on the copper metal particles, so that the copper metal particles melt into the Laval nozzle layer by layer from bottom to top according to a predetermined shape;

Laser scanning is performed on the copper and stainless steel mixed metal particles, so that the copper metal particles are melted layer by layer from bottom to top according to a predetermined shape into the connection area of the oxygen tube and the Laval nozzle.
The manufacturing method of the Laval nozzle according to claim 8, wherein the manufacturing method is performed by a composite additive manufacturing process using laser energy deposition and machining.
The manufacturing method of the Laval nozzle according to claim 11, wherein the manufacturing method further comprises the following steps:

Performing laser scanning on the copper metal particles provided by the powder spraying port, while performing a mechanical processing operation, so that the copper metal particles are melted layer by layer from bottom to top according to a predetermined shape and/or mechanically processed into the Laval nozzle;

Perform laser scanning on the copper and stainless steel mixed metal particles provided by the powder nozzle, and perform mechanical processing operations at the same time, so that the copper and stainless steel mixed metal particles are melted layer by layer from bottom to top according to a predetermined shape and/or mechanically It is processed as a connection area between the oxygen pipe and the Laval nozzle.