Gas atomization apparatus

Abstract

To provide a gas atomization apparatus which can simply mount a gas atomization nozzle and connect a gas supply path to the gas atomization nozzle.SOLUTION: A gas atomization apparatus 1 includes a furnace body 2, an atomization unit 3 mounted on the furnace body 2, and a gas piping 4 capable of supplying high pressure gas, wherein the atomization unit 3 has a tundish 31, a gas atomization nozzle 32 fixed to the tundish 31, and a piping connection member 33 connected to the gas piping 4, wherein the gas atomization nozzle 32 includes a molten metal nozzle for discharging molten metal in the tundish 31 and a gas nozzle for jetting the high pressure gas supplied from the gas piping 4 through the piping connection member 33 so as to be integral with each other, the atomization unit 3 is attachable / detachable to / from the furnace body 2 in a state in which the whole atomization unit 3 is integral, and can attach / detach the gas piping 4 to / from the piping connection member 33 by remote operation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas atomizing device, and more particularly to a gas atomizing device equipped with a confined type gas atomizing nozzle. [Background technology]

[0002] There is a high demand for metal powder materials as raw materials for powder metallurgy and additive manufacturing. Gas atomization is widely used as one of the methods for producing metal powder materials. In the gas atomization method, gas is injected from a gas nozzle into molten metal discharged from a molten metal nozzle, and the molten metal is turned into fine droplets, which are solidified to form metal powder. In particular, by using a confined gas atomization nozzle in which a molten metal nozzle and a gas nozzle are integrally provided and the discharge position of the molten metal and the injection position of the gas are close to each other, the crushing energy given to the molten metal by the injected gas can be increased, and fine metal powder can be produced with high efficiency. A gas atomization device equipped with a confined gas atomization nozzle is disclosed in, for example, Patent Document 1 below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-069512 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, when producing fine metal powder by gas atomization, it is preferable to use a confined gas atomization nozzle. The particle size of metal powder produced by gas atomization depends on the gas / metal ratio, which is the ratio of the mass flow rate of gas injected from the gas nozzle to the mass flow rate of molten metal discharged from the molten metal nozzle. The larger the gas / metal ratio, that is, the larger the mass flow rate of gas, the smaller the particle size of the obtained metal powder. Therefore, in order to increase the yield of fine metal powder, it is preferable to supply high-pressure gas, for example, 1 to 10 MPa, to the gas nozzle. However, when constructing a gas atomization device equipped with a confined gas atomization nozzle on a scale capable of mass-producing metal powder, in order to supply high-pressure gas to the gas nozzle, the work required to properly install the gas atomization nozzle and its peripheral members and assemble it into a gas atomization device tends to become complicated. The following two factors can be cited as the main factors.

[0005] The first factor is the need for close contact between the tundish and the gas atomizing nozzle. In gas atomizing equipment, the gas atomizing nozzle is attached to the bottom of the tundish that stores the molten metal, and the molten metal is supplied from the tundish to the molten metal nozzle. However, if a gap is created between the gas atomizing nozzle and the tundish, the high-pressure gas injected from the gas nozzle will leak. To avoid such gas leakage, it is important to attach the gas atomizing nozzle in close contact with the bottom surface of the tundish. However, it is often difficult to attach the gas atomizing nozzle accurately to the specified position on the bottom surface of the tundish.

[0006] The second factor is the complexity of the installation of the gas piping for supplying gas to the gas nozzle of the gas atomizing nozzle. As mentioned above, in order to obtain fine metal powder, it is necessary to inject high-pressure gas from the gas nozzle, and in order to do so, the gas piping for supplying gas from the outside to the gas nozzle must be able to withstand high pressure. This requires that the gas piping be made with a large diameter or that multiple gas piping be installed. The structure of the locations where these gas piping are routed and connected tends to be complicated, and the work of routing and connecting the gas piping tends to be cumbersome.

[0007] In this way, if a gas atomizing device equipped with a confined type gas atomizing nozzle is constructed on a scale capable of mass-producing fine metal powder, the structure around the gas atomizing nozzle becomes complicated, and the work of assembling and connecting the gas atomizing nozzle to the surrounding members also tends to become complicated. This increases the effort and time required to attach and detach the gas atomizing nozzle and the tundish for maintenance, etc. In particular, when the tundish is installed in a melting chamber filled with an inert gas, it is very difficult to perform these operations while maintaining the melting chamber in an inert gas atmosphere.

[0008] An object of the present invention is to provide a gas atomizing device that allows easy installation of a gas atomizing nozzle and easy connection of a gas supply path to the gas atomizing nozzle. [Means for solving the problem]

[0009] In order to solve the above problems, a gas atomizing device according to the present invention has the following configuration. [1] The gas atomizing apparatus of the present invention comprises a furnace body, an atomizing unit attached to the furnace body, and a gas piping capable of supplying high-pressure gas. The atomizing unit comprises a tundish for storing molten metal, a gas atomizing nozzle fixed to the tundish, and a piping connection member connected to the gas piping. The gas atomizing nozzle comprises a molten metal nozzle for discharging the molten metal in the tundish into the inside of the furnace body, and a gas nozzle for injecting the high-pressure gas supplied from the gas piping via the piping connection member into the molten metal discharged from the molten metal nozzle. The atomizing unit is detachable from the furnace body in an integrated state, and the gas piping is detachable from the piping connection member by remote control.

[0010] [2] In the above aspect [1], the furnace body may have a chamber and a hollow cylindrical cylinder whose internal space is interconnected with the chamber, the atomizing unit may be attached to the furnace body at an axial end of the cylinder, and the cylinder may be movable forward and backward relative to the chamber along the axial direction.

[0011] [3] In the above aspect [1] or [2], the gas pipe has a pipe tip member that is detachably connected to the pipe connection member of the atomization unit, the pipe connection member and the pipe tip member are configured as an autocoupler pair, and the gas atomization device further includes an actuator that can move the pipe tip member between a position connected to the pipe connection member and a position away from the pipe connection member by a back and forth motion, and a locking mechanism that can reversibly fix the pipe tip member in a state connected to the pipe connection member.

[0012] [4] In the above aspect [3], the gas atomization apparatus may further have an imaging device that images an area including the pipe tip member and the pipe connection member, and a sensor device that detects the advance / retract position of the actuator.

[0013] [5] In any one of the above aspects [1] to [4], the atomizing unit further has a bottom plate member that is detachable from a bottom surface of the tundish, the piping connection member is attached to the bottom plate member, the molten metal nozzle is fixed to the bottom surface of the tundish, and the gas nozzle is fixed to the bottom plate member, and the bottom surface of the tundish and the bottom plate member are provided with positioning members that can be positioned relative to each other.

[0014] [6] In any one of the above aspects [1] to [5], the gas atomization apparatus further has a melting chamber that accommodates at least a portion of the furnace body to which the atomization unit can be attached and at least a portion of the piping unit that is connected to the piping connection member, and into which the atomization unit can be inserted and removed while maintaining an inert gas atmosphere inside, and a cart that can transport the atomization unit inside the melting chamber, and the atomization unit can be separated from the cart.

[0015] [7] In the embodiment of [2] above, or in any one of the embodiments of [3] to [6] including the configuration of [2] above, the gas atomization apparatus further has an exhaust device capable of exhausting the internal space of the cylinder at a variable pressure, and an exhaust control unit that controls the output of the exhaust device and adjusts the pressure inside the furnace body, and it is preferable that the cross-sectional area of ​​the internal space of the furnace body perpendicular to the axial direction of the cylinder is smaller than that of the chamber in the cylinder.

[0016] [8] In the above aspect [7], the gas atomization apparatus further has a temperature measuring unit that measures the temperature of the molten metal in the tundish and transmits the temperature to the exhaust control unit, and the exhaust control unit controls the pressure in the furnace body to be reduced when the temperature is lower than a reference value. Effect of the Invention

[0017] In the gas atomizing device according to the present invention having the configuration of [1] above, the gas atomizing nozzle is fixed to the tundish to form an atomizing unit, and the atomizing unit can be attached to and detached from the furnace body as a whole. Therefore, if the gas atomizing nozzle is attached to the tundish in advance and then the atomizing unit is attached to the furnace body, or if the atomizing unit is removed from the furnace body as a whole before performing maintenance or other work, the atomizing unit can be easily attached and detached from the furnace body. It is also easy to improve the accuracy of attachment of the gas atomizing nozzle to the tundish, and the adhesion of the gas atomizing nozzle to the bottom surface of the tundish can also be improved.

[0018] Furthermore, the gas pipe that supplies gas to the gas nozzle of the gas atomizing nozzle can be remotely attached and detached to the atomizing unit via the pipe connecting member. If the gas pipe is remotely attached to the pipe connecting member while the atomizing unit is attached to the furnace body, the gas pipe can be connected to the atomizing unit without directly operating the gas pipe or the pipe connecting member, and the gas nozzle can be prepared to be able to supply high-pressure gas. There is no need to operate the gas pipe itself.

[0019] In this way, in the gas atomizing device, the atomizing unit in which the gas atomizing nozzle is fixed to the tundish is made detachable from the furnace body as a unit, and the gas piping is made detachable from the atomizing unit by remote control, so that the gas atomizing nozzle can be attached to a predetermined position with high precision and the gas supply path can be connected to the gas atomizing nozzle easily. Furthermore, by making the gas atomizing nozzle tightly attached to the tundish, it becomes easier to handle gas injection at a large flow rate from the gas nozzle. Furthermore, since the gas piping can be attached to and detached from the gas atomizing nozzle without directly operating the gas piping, the process of attaching and detaching the gas piping is not complicated even if the gas piping has a large diameter or a large number of gas pipings corresponding to the supply of high pressure gas. In this way, the gas atomizing device becomes suitable for injection of gas at a large flow rate, and mass production of fine metal powder can be performed with high efficiency by improving the gas / metal ratio.

[0020] In the above embodiment [2], the furnace body has a chamber and a cylinder, and the cylinder can be advanced and retreated relative to the chamber. The atomizing unit is attached to the furnace body by the cylinder. In this case, the advance and retreat motion of the cylinder can be used to attach the atomizing unit to the furnace body. That is, the atomizing unit can be easily attached to the furnace body by placing the atomizing unit at a predetermined position with the cylinder retreated, and then advancing the cylinder toward the atomizing unit. In addition, by advancing and pressing the cylinder toward the atomizing unit, the adhesion of the cylinder to the atomizing unit can be increased, and the suitability for the injection of a large flow rate of gas from the gas atomizing nozzle can be improved.

[0021] In the above aspect [3], the pipe tip member of the gas pipe and the pipe connection member of the atomizing unit are configured as a set of auto-couplers, and the gas atomizing device further includes an actuator that can move the pipe tip member between a position where it is connected to the pipe connection member and a position away from the pipe tip member, and a locking mechanism that can reversibly fix the pipe tip member in a state where it is connected to the pipe connection member. In this case, the actuator moves the pipe tip member of the gas pipe to a position where it is connected to the pipe connection member of the atomizing unit, and then the pipe tip member and the pipe connection member configured as an auto-coupler are coupled to each other, so that the gas pipe can be automatically connected to the atomizing unit. Furthermore, if the locking mechanism is operated to fix the pipe tip member in a state where it is connected to the pipe connection member, the gas pipe can be stably maintained in such a connected state even when high-pressure gas is supplied from the gas pipe. By configuring the connection point between the gas pipe and the atomizing unit in this way, the gas pipe can be automatically connected to the atomizing unit from a remote location. When removing the gas piping from the atomizing unit, the above steps can be reversed to enable automatic removal from a remote location.

[0022] In the above embodiment [4], the gas atomizing device further includes a photographing device that photographs an area including the pipe tip member and the pipe connection member, and a sensor device that detects the advance / retract position of the actuator. This allows each process associated with the attachment / detachment of the pipe tip member and the pipe connection member to be performed remotely with high reliability while actually checking the state of the pipe tip member, the pipe connection member, the actuator, and the surrounding members. When the attachment / detachment of the pipe tip member and the pipe connection member is performed in a dark place such as inside the melting chamber, a night vision camera may be used as the photographing device.

[0023] In the above embodiment [5], the atomizing unit further has a bottom plate member that is detachable from the bottom surface of the tundish. The piping connection member is attached to the bottom plate member. The molten metal nozzle is fixed to the bottom surface of the tundish, and the gas nozzle is fixed to the bottom plate member. The bottom surface of the tundish and the bottom plate member are provided with positioning members that allow them to be positioned relative to each other. In this case, the atomizing unit that is integrally equipped with the tundish, the gas atomizing nozzle, and the piping connection member can be easily assembled, and the convenience of maintenance of the atomizing unit is increased.

[0024] In the above embodiment [6], at least a part of the furnace body and the gas piping is accommodated in a melting chamber in which the atomizing unit can be put in and taken out while the inside is maintained in an inert gas atmosphere. A carriage capable of transporting the atomizing unit is provided inside the melting chamber, and the atomizing unit is separable from the carriage. By attaching the atomizing unit to the furnace body in the melting chamber maintained in an inert gas atmosphere and performing gas atomization, it is possible to suppress oxidation of the molten metal and produce high-quality metal powder. Even if the atomizing unit is temporarily removed from the melting chamber for maintenance or the like, the atomizing unit can be put into the melting chamber while maintaining the atmosphere in the melting chamber, and then transported to a position where it can be attached to the furnace body using the carriage, and then the atomizing unit is attached to the furnace body and the gas piping is connected, so that the production of metal powder by gas atomization can be resumed under an inert gas atmosphere. Furthermore, since the atomizing unit is separable from the carriage, a plurality of atomizing units, such as three or more, can be sequentially attached and detached and used with maintenance outside the melting chamber in between, by using the common carriage for transportation. Therefore, the time during which metal powder cannot be produced due to maintenance can be kept short, and the operating efficiency of the gas atomizing apparatus can be improved.

[0025] In the above embodiment [7], the gas atomizing apparatus in which the furnace body is provided with a chamber and a cylinder further includes an exhaust device capable of evacuating the internal space of the cylinder at a variable pressure, and an exhaust control unit that controls the output of the exhaust device to adjust the pressure inside the furnace body. The cross-sectional area of ​​the internal space of the furnace body is smaller in the cylinder than in the chamber. Since the cross-sectional area of ​​the internal space of the cylinder is smaller than that of the chamber, the change in pressure in the cylinder when the output of the exhaust device is changed by the exhaust control unit occurs over a wide pressure range and sensitively, compared to when the cross-sectional area of ​​the internal space of the cylinder is as large as the chamber. By changing the pressure inside the cylinder, the discharge speed of the molten metal from the molten metal nozzle of the gas atomizing nozzle changes, and the change in the discharge speed can be used to suppress the clogging of the molten metal nozzle and to control the particle size of the produced metal powder. Since the change in pressure inside the cylinder occurs over a wide pressure range and sensitively, the suppression of the clogging of the molten metal nozzle and the control of the particle size of the produced metal powder can be effectively carried out.

[0026] In the above embodiment [8], the gas atomizing device further includes a temperature measuring unit capable of measuring the temperature of the molten metal in the tundish and transmitting the temperature to the exhaust control unit. When the temperature is lower than a reference value, the exhaust control unit controls the pressure in the furnace body to be lowered. When the temperature of the molten metal in the tundish is lowered, the molten metal nozzle is likely to be blocked due to solidification of the metal nozzle. However, when the pressure in the furnace body, particularly in the cylinder, is lowered by controlling the output of the exhaust control unit, the discharge speed of the molten metal increases, and the molten metal in the molten metal nozzle is rapidly discharged, thereby suppressing the blockage of the molten metal nozzle. The temperature measuring unit used for this control may be of a wired type or a wireless communication type. If the temperature measuring unit is of a wireless communication type, the temperature of the molten metal can be read remotely, and there is no need to connect or disconnect the wiring to the temperature measuring unit when attaching or detaching the atomizing unit to or from the furnace body. [Brief description of the drawings]

[0027] [Figure 1]1 is a schematic diagram showing the overall configuration of a gas atomizing device according to one embodiment of the present invention. [Diagram 2] 1 is a perspective view showing the atomizing unit and the connecting / disconnecting device of the gas atomizing device together with the cylinder of the furnace body, in a state before the atomizing unit is attached to the furnace body. [Diagram 3] This shows the state in which the atomizing unit is attached to the furnace body from the state shown in FIG. 2, and further the pipe end member is connected to the atomizing unit. [Figure 4] FIG. 2 is an enlarged cross-sectional view of an upper part of a furnace body of the gas atomizing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, a gas atomizing device according to one embodiment of the present invention will be described with reference to the drawings.

[0029] [Gas atomization device configuration] FIG. 1 shows a schematic diagram of the overall configuration of a gas atomizing device 1 according to one embodiment of the present invention. In addition, FIGS. 2 and 3 show an atomizing unit 3 and a connection / detachment device 6 of the gas atomizing device 1 together with a cylinder 21 of a furnace body. FIG. 2 shows a state before the atomizing unit is attached to the furnace body, and FIG. 3 shows a state after the atomizing unit is attached to the furnace body and a gas pipe is connected to the atomizing unit. FIG. 4 shows a vertical cross-sectional view of the upper part of the furnace body and the structure in the vicinity thereof. Hereinafter, directions such as up and down shall follow the directions shown in each figure.

[0030] The gas atomizing apparatus 1 according to this embodiment includes a furnace body 2, an atomizing unit 3, and a gas pipe 4. In addition, although optional, the gas atomizing apparatus 1 is also provided with a connection / detachment device 6. It is preferable that at least a part of the furnace body 2 and the gas pipe 4, and the connection / detachment device 6 are housed in a melting chamber 7. The configuration of each component will be described below.

[0031] The furnace body 2 is configured as a hollow container, and an atomizing unit 3 can be attached to the upper part. The detailed structure of the furnace body 2 will be described later, but it is preferable that the furnace body 2 has a chamber 22 and a cylinder 21 whose internal spaces communicate with each other. The cylinder 21 is a hollow cylindrical member, and in the illustrated embodiment, the cylindrical cylinder 21 is attached to the upper part of the hollow chamber 22 with its axial direction facing up and down. The cylinder 21 can move forward and backward (up and down) in the up and down direction relative to the chamber 22.

[0032] An exhaust device 51 is connected to the furnace body 2. The exhaust device 51 exhausts the internal space of the furnace body 2. The exhaust device 51 can change its output, and it is preferable that the internal space of the furnace body 2 including the cylinder 21 can be exhausted at a variable pressure by changing the output. In this case, the exhaust speed can be increased and the pressure in the internal space of the furnace body 2 can be lowered by increasing the output of the exhaust device 51. The output of the exhaust device 51 may be changed by an exhaust control unit (not shown) composed of a calculation and control device such as a CPU. The type of the exhaust device 51 is not particularly limited, and an exhaust blower or the like can be used. In detail, the exhaust device 51 is arranged by branching a path from the bottom of the chamber 22 to a cyclone 52 that classifies the produced metal powder and a hopper 53 that accumulates the classified metal powder.

[0033] The atomizing unit 3 is attached to the furnace body 2, and generates metal powder in the furnace body 2 by gas atomization. The atomizing unit 3 is detachable from the furnace body 2. The atomizing unit 3 includes a gas atomizing nozzle 32 and a tundish 31. The gas atomizing nozzle 32 is configured as a confined type gas atomizing nozzle, and includes a molten metal nozzle 321 and a gas nozzle 322 that are integrally arranged. In the illustrated embodiment, two gas atomizing nozzles 32 are provided. The tundish 31 is configured as a container capable of storing molten metal. The gas atomizing nozzle 32 is fixedly attached to the tundish 31.

[0034] As will be described in detail later, in the atomizing unit 3, when a bottom plate member 37 separable from the tundish 31 is provided below the bottom surface of the tundish 31, the molten metal nozzle 321 of the gas atomizing nozzle 32 is fitted and fixed in a through hole provided in the bottom surface of the tundish 31. Meanwhile, a gas nozzle 322 is fixed to the bottom plate member 37 arranged below the bottom surface of the tundish 31. Then, by joining the tundish 31 and the bottom plate member 37, the gas atomizing nozzle 32 to which the molten metal nozzle 321 and the gas nozzle 322 are joined is assembled and fixed to the composite of the tundish 31 and the bottom plate member 37.

[0035] In the gas atomizing nozzle 32, the molten metal nozzle 321 has a nozzle hole 323 through which the molten metal can pass. The nozzle hole 323 is connected to the space in the tundish 31 at the base end. When the atomizing unit 3 is attached to the furnace body 2, the tip side of the molten metal nozzle 321 protrudes toward the hollow part of the furnace body 2, and the molten metal in the tundish 31 can be discharged from the tip of the molten metal nozzle 321 toward the hollow part of the furnace body 2. The gas nozzle 322 is configured as a member having a gas injection port surrounding the outer periphery of the tip of the molten metal nozzle 321, and can inject an inert gas supplied from the outside at high pressure. The gas injected from the gas nozzle 322 is injected from an oblique upward direction toward the area immediately below the tip of the molten metal nozzle 321.

[0036] The tundish 31 may be provided with a temperature measuring unit (not shown) capable of measuring the temperature of the molten metal in the tundish 31. For example, a thermocouple may be provided in the tundish 31 as the temperature measuring unit. The temperature measuring unit may be either wired or wireless. As an example, a unit capable of wireless communication may be used, and the temperature measured by the temperature measuring unit may be transmitted by wireless communication to an external device such as an exhaust control unit that controls the output of the exhaust device 51, so that the temperature can be read remotely. By reading the temperature with the exhaust control unit, the temperature of the molten metal in the tundish 31 can be used to control the output of the exhaust device 51, as will be described later. In addition, if the temperature measuring unit is wireless communication type, it is not necessary to attach or detach wiring to the temperature measuring unit when the atomizing unit 3 is attached or detached to the furnace body 2.

[0037] In addition to the tundish 31 and the gas atomizing nozzle 32, the atomizing unit 3 is provided with a pipe connection member 33. The pipe connection member 33 is a joint-shaped member that is detachably connected to the gas pipe 4. The pipe connection member 33 is connected to the gas nozzle 322 inside the atomizing unit 3, and the gas introduced from the gas pipe 4 is supplied to the gas nozzle 322 via the pipe connection member 33. In the illustrated embodiment, two pipe connection members 33 are provided.

[0038] The pipe connection member 33 may be directly fixed to the tundish 31, but as shown in the figure, it is preferable that a bottom plate member 37 is provided separately from the tundish 31, and the pipe connection member 33 is attached to the bottom plate member 37 rather than to the tundish 31. The bottom plate member 37 is a detachable plate-like member attached to the lower side of the bottom surface of the tundish 31, and as described above, the gas nozzle 322 of the atomizing nozzle 32 is fixed to the bottom plate member 37. In the illustrated embodiment, a connection portion seat 34 is erected on the bottom plate member 37, and the pipe connection portion 33 is supported by the connection portion seat 34. In a state where the bottom plate member 37 is joined to the bottom surface of the tundish 31, the connection portion seat 34 is disposed on the outer side of the side surface of the tundish 31.

[0039] The atomizing unit 3, including the tundish 31 and gas atomizing nozzle 32 fixed together and the bottom plate member 37 to which the piping connection member 33 is attached, can be attached to and detached from the furnace body 2 as a whole. In other words, the atomizing unit 3 can be attached to and detached from the furnace body 2 as a whole without disassembling and removing the components.

[0040] The gas pipe 4 is a pipe member capable of supplying gas from an external high-pressure gas source (not shown). The gas pipe 4 is composed of a gas pipe 42 as a main body through which high-pressure gas flows. A pressure reducing valve 43 capable of adjusting the gas pressure is appropriately provided on the base end side of the gas pipe 42. The gas pipe 4 is detachable from the pipe connection member 33 provided in the atomizing unit 3 by remote control. Preferably, the gas pipe 42 has a pipe tip member 41 at the tip, and the pipe tip member 41 is detachable from the pipe connection member 33 by remote control. In a state in which the pipe tip member 41 is connected to the pipe connection member 33, high-pressure gas can be supplied from the gas pipe 4 to the gas nozzle 322 of the gas atomizing nozzle 32 through the connection part, and the high-pressure gas can be sprayed from the tip of the gas nozzle 322 into the internal space of the furnace body 2. In the illustrated embodiment, two pipe tip members 41 are also provided corresponding to the pipe connection member 33. 2 and 3, the gas pipe 42 is omitted, and only the pipe end member 41 is shown as the gas pipe 4.

[0041] As a preferred specific example of a configuration in which the pipe end member 41 of the gas pipe 4 can be remotely attached and detached to the pipe connection member 33 of the atomizing unit 3, it is preferable to configure the pipe connection member 33 and the pipe end member 41 as a set of an autocoupler. The autocoupler is a pipe connection member that can remotely connect and disconnect the pipe end member 41 using air or hydraulic pressure.

[0042] Furthermore, the gas atomizing device 1 may be provided with a connection / disconnection device 6 as a device for assisting in the formation and release of the connection between the pipe connection member 33 and the pipe end member 41. The configuration of the connection / disconnection device 6 will be described in detail later, but it is a device that can remotely perform the formation and release of the connection between the pipe connection member 33 composed of a set of autocouplers and the pipe end member 41, as well as the fixing (locking) of them in the connected state and the release of the fixation.

[0043] The melting chamber 7 is configured as a housing chamber capable of maintaining an inert gas atmosphere inside. The melting chamber 7 houses at least the portion of the furnace body 2 where the atomizing unit 3 is attached, that is, at least the upper part of the cylinder 21, and at least the portion of the gas pipe 4 connected to the pipe connection member 33 of the atomizing unit 3, that is, at least the portion including the pipe tip member 41. The connection and detachment device 6 is also housed in the melting chamber 7. In the melting chamber 7, the inside can be filled with an inert gas atmosphere by exhausting the inside with a vacuum pump and introducing an inert gas such as argon through the atmosphere replacement port 71. A rail (not shown) is provided at the bottom of the melting chamber 7 on which the cart 8 carrying the atomizing unit 3 can run. In addition, the melting chamber 7 is connected to a spare chamber 72 whose inside can be evacuated to a vacuum. The melting chamber 7 and the spare chamber 72 are partitioned by an openable and closable shutter 73. When the shutter 73 is closed, the inside of the melting chamber 7 can be kept airtight. The preliminary chamber 72 can accommodate the carriage 8 carrying the atomizing unit 3, and when the shutter 73 is opened, the carriage 8 can be moved between the preliminary chamber 72 and the melting chamber 7. If the preliminary chamber 72 is evacuated to a vacuum in advance with the shutter 73 closed, the carriage 8 can be moved in and out between the preliminary chamber 72 and the melting chamber 7 while the inside of the melting chamber 7 is maintained in an inert gas atmosphere.

[0044] The cart 8 can transport the atomizing unit 3 inside the melting chamber 7 and between the melting chamber 7 and the spare chamber 72. The cart 8 detachably carries the atomizing unit 3, and the atomizing unit 3 transported close to the furnace body 2 inside the melting chamber 7 is attached to the furnace body 2 in a state separated from the cart 8. The atomizing unit 3 can also be separated from the cart 8 and carried out to the outside of the melting chamber 7. A crane device (not shown) that can be remotely operated from outside the melting chamber 7 may be provided in the melting chamber 7 as appropriate to separate the atomizing unit 3 from the cart 8 and move the atomizing unit 3 to an attachment position on the furnace body 2.

[0045] If the atomizing unit 3 is attached to the furnace body 2 in the melting chamber 7 and the gas pipe 4 is connected to the atomizing unit 3, the metal powder can be manufactured by the gas atomization method. At this time, the inner space of the furnace body 2 is first evacuated by the exhaust device 51. Then, molten metal is injected into the tundish 31 from the induction furnace 9 installed in the furnace body 2, and the molten metal is discharged from the molten metal nozzle 321 of the gas atomization nozzle 32 into the inner space of the furnace body 2. At the same time, high-pressure gas is ejected from the gas nozzle 322 and injected into the molten metal discharged from the molten metal nozzle 321. Then, the molten metal is pulverized into fine droplets by the ejected gas. The atomized droplets are cooled and solidified while passing through the cylinder 21, forming fine powder of the metal. The formed metal powder passes through the cylinder 21 to reach the chamber 22, where it is classified by the cyclone 52 connected to the chamber 22 and accumulated in the hopper 53. During the production of metal powder, the exhaust device 51 continues to evacuate the internal space of the chamber 22 and the cylinder 21, and during this time, the output of the exhaust device 51 may be changed by the exhaust control unit, as will be described later.

[0046] [Attaching and detaching the atomizing unit] In the gas atomizing device 1 according to this embodiment, as described above, the gas atomizing nozzle 32, the tundish 31, and the atomizing unit 3 including the piping connection member 33 are assembled as a single unit, and the entire atomizing unit 3 can be attached and detached as a single unit to the furnace body 2. In addition, the gas piping 4 can be attached and detached to and from the piping connection member 33 of the atomizing unit 3 by remote control using the connection and detachment device 6. This allows the gas atomizing nozzle 32 to be attached and detached to and from the furnace body 2, and the gas supply path to the gas atomizing nozzle 32 to be connected and separated easily and in a short time.

[0047] Here, a procedure for mounting the atomizing unit 3 to the furnace body 2 and connecting the gas pipe 4 to the atomizing unit 3 will be described. In the initial state of the description, it is assumed that the atomizing unit 3 is not mounted to the furnace body 2. Also, it is assumed that the inside of the melting chamber 7 is an inert gas atmosphere.

[0048] First, the atomizing unit 3 is assembled in a space outside the melting chamber 7. The assembly of the atomizing unit 3 includes a process of fixing and assembling the gas atomizing nozzle 32 at a predetermined position in the atomizing unit 3. For example, when the atomizing unit 3 includes a bottom plate member 37 in addition to the tundish 31, the molten metal nozzle 321 of the gas atomizing nozzle 32 is fixed to the bottom surface of the tundish 31 in a state in which the tundish 31 and the bottom plate member 37 are separated. Meanwhile, the gas nozzle 322 of the gas atomizing nozzle 32 is fixed to the bottom plate member 37 provided with the pipe connecting member 33, and the pipe connecting member 33 and the gas nozzle 322 are connected so as to be able to supply gas. Then, the tundish 31 and the bottom plate 37 are positioned and joined to each other, and the molten metal nozzle 321 and the gas nozzle 322 are arranged concentrically and integrated, and the atomizing nozzle 32 is assembled. The atomizing unit 3 assembled in this manner is loaded onto a cart 8.

[0049] The carriage 8 carrying the atomizing unit 3 is accommodated in a preliminary chamber 72 isolated from the melting chamber 7 by a shutter 73, and the preliminary chamber 72 is evacuated to a vacuum. After that, the shutter 73 is opened, and the carriage 8 carrying the atomizing unit 3 is moved into the melting chamber 7. When the carriage 8 has finished moving, the shutter 73 is closed, and the melting chamber 7 is replenished with inert gas as necessary. The carriage 8 moves along the rails in the melting chamber 7 and reaches the vicinity of the furnace body 2. In this state, the atomizing unit 3 is separated from the carriage 8, moved to the top of the furnace body 2, and attached to the furnace body 2. The movement of the atomizing unit 3 at this time can be performed by a crane (not shown) or the like. In the case where the furnace body 2 has a cylinder 21 that can be raised and lowered relative to the chamber 22, the cylinder 21 can be further raised and pressed against the bottom surface of the atomizing unit 3, that is, the lower surface of the bottom plate member 37, thereby increasing the airtightness between the atomizing unit 3 and the furnace body 2. The lifting and lowering movement of the cylinder 21 can be driven by an actuator (not shown). After the dolly 8 carrying the atomizing unit 3 is carried into the melting chamber 7, all the processes up to the attachment of the atomizing unit 3 to the furnace body 2 can be performed by remote control from outside the melting chamber 7.

[0050] After the atomizing unit 3 is attached above the furnace body 2 in this manner, the gas pipe 4 is then connected to the atomizing unit 3. At this time, the connection and detachment device 6 connects the pipe tip member 41 of the gas pipe 4 to the pipe connection member 33 protruding outside the atomizing unit 3. The specific configuration and operation of the connection and detachment device 6 will be described in detail later, but the operation of connecting the pipe tip member 41 to the pipe connection member 33 and the operation of removing the pipe tip member 41 connected to the pipe connection member 33 can all be performed by remote control from outside the melting chamber 7.

[0051] In this way, when the installation of the atomizing unit 3 in the furnace body 2 and the connection of the gas pipe 4 to the atomizing unit 3 are completed, the internal space of the furnace body 2 is evacuated by the exhaust device 51, and the production of metal powder by the gas atomization method can be started as described above. When it becomes necessary to take the atomizing unit 3 out of the melting chamber 7 for maintenance or the like, the gas pipe 4 is separated from the atomizing unit 3, the atomizing unit 3 is removed from the furnace body 2, and the atomizing unit 3 is carried out from the melting chamber 7 by following the steps described above in reverse.

[0052] As described above, the atomizing unit 3 is constructed as an integral unit so as to be detachable from the furnace body 2, and the gas pipe 4 is made detachable from the atomizing unit 3 attached to the furnace body 2 by remote control. This allows the gas atomizing nozzle 32 to be attached to a predetermined location and the gas pipe 4 to be attached to and detached from the gas atomizing nozzle 32 easily and in a short time due to at least the following two factors. First, the process of assembling the atomizing unit 3 by connecting the tundish 31, the gas atomizing nozzle 32, and the bottom plate member 37 can be performed by direct work in a large space outside the melting chamber 7. Therefore, the assembly can be performed easily with high accuracy. It also becomes easy to arrange the gas atomizing nozzle 32 in close contact with the bottom surface of the tundish 31. If the gas atomizing nozzle 32 is attached to the furnace body 2 in a state of being in close contact with the bottom surface of the tundish 31, gas leakage from the portion between the gas atomizing nozzle 32 and the tundish 31 is unlikely to occur even when gas is injected at high pressure from the gas nozzle 322 of the gas atomizing nozzle 32, and gas can be easily injected at the intended flow rate. In addition, it becomes easier to control the particle size of metal particles by the gas / metal ratio as intended. In a configuration using a confined type gas atomizing nozzle 32, it is effective to increase the flow rate of gas injected from the gas nozzle 322 in order to refine the generated metal particles.

[0053] Secondly, in the process of attaching the atomizing unit 3 assembled by closely contacting the gas atomizing nozzle 32 to the tundish 31 to the furnace body 2 and the process of connecting the gas pipe 4 to the atomizing unit 3, the atomizing unit 3 can be handled as a whole and each process can be performed by remote control, so there is no need to perform manual work inside the furnace body 2 or complicated work such as operating each component of the atomizing unit 3. There is also no need to perform operations such as routing and connecting the gas pipe 42 to the gas pipe 4 each time it is connected to the atomizing unit 3. Therefore, the preparation of the equipment to a state in which the production of metal powder by the gas atomization method can be performed, including the attachment of the atomizing unit 3 and the connection of the gas pipe 4 to the atomizing unit 3, can be performed easily and in a short time. Furthermore, since each of these processes can be performed while maintaining an inert gas atmosphere inside the melting chamber 7, the time required to attach and detach the atomizing unit 3, which involves moving the atomizing unit 3 in and out of the melting chamber 7 for maintenance of the atomizing unit 3, can be significantly shortened.

[0054] As described above, when using the confined type gas atomizing nozzle 32, increasing the flow rate of the gas to be injected is effective for the refinement of the metal powder, but in order to do so, it is necessary to supply high-pressure gas from the gas pipe 4 to the gas atomizing nozzle 32. In order to make the gas pipe 4 resistant to high pressure, it is necessary to increase the diameter of the gas pipe 42 or the number of gas pipes 42, which tends to cause the configuration of the gas pipe 4 to become complicated and large. However, in the gas atomizing device 1 according to the present embodiment, the connection of the gas pipe 4 to the atomizing unit 3 can be completed by simply connecting the pipe end member 41 to the pipe connecting member 33 without performing any operation on the gas pipe 42 itself, so that the ease of connection and the short time required for connection and disconnection of the gas pipe 4 are maintained even if the gas pipe 4 is made to be compatible with high pressure.

[0055] In the gas atomization device 1, when the type of molten metal that is the raw material of the metal powder is changed or when the constituent members of the atomization unit 3, such as the refractory material of the tundish 31, are worn out, the atomization unit 3 needs to be maintained. However, in the gas atomization device 1 according to the present embodiment, the atomization unit 3 that needs maintenance after use is carried out outside the melting chamber 7 and maintained, and another atomization unit 3 that has been maintained is carried into the melting chamber 7 and attached to the furnace body 2, and metal powder is generated by gas atomization. This shortens the time during which metal powder cannot be generated, and improves the production efficiency in the manufacture of metal powder. In terms of improving the operating efficiency of the gas atomization device 1, the convenience of the maintenance of the atomization unit 3 is also important, and the atomization unit 3 can be carried out as a whole outside the melting chamber 7, and all the work required for maintenance can be performed in a large area away from the melting chamber 7, which improves the ease of maintenance.

[0056] Furthermore, instead of directly fixing and attaching the entire gas atomizing nozzle 32 and the piping connection member 33 to the tundish 31, the gas nozzle 322 and the piping connection member 33 are fixed to the bottom plate member 37, and the tundish 31 is placed on the bottom plate member 37 to which these members 322, 33 are fixed to assemble the atomizing unit 3, which also contributes to improving the maintainability of the atomizing unit 3. This is because a high degree of freedom can be obtained in assembling the atomizing unit 3, including a process of maintaining the tundish 31 itself and a process of connecting pipes so that high-pressure gas can be supplied from the piping connection member 33 to the gas nozzle 322.

[0057] The configuration in which the cart 8 can travel within the melting chamber 7 and the atomizing unit 3 can be transported by the cart 8 also enhances the convenience of attaching and detaching the atomizing unit 3, which involves entering and exiting the melting chamber 7. Furthermore, since the atomizing unit 3 is not fixed integrally to the cart 8 but is detachable from the cart 8, the atomizing unit 3 can be removed from the cart 8 and maintenance can be performed at a position away from the melting chamber 7, which enhances the convenience of maintenance. Furthermore, if a plurality of atomizing units 3, such as three or more, are prepared and can be transported by a common cart 8, a cycle in which some atomizing units 3 are undergoing maintenance while other atomizing units 3 that have been maintained are attached to the furnace body 2 and used can be repeated, with replacement of the atomizing units 3 using the cart 8 in between, so that the operating efficiency of the gas atomizing device 1 can be improved. If the atomizing unit 3 were fixed integrally to the carriage 8, it would be necessary to perform maintenance work while the atomizing unit 3 remains attached to the carriage 8, which would deteriorate the maintainability of the atomizing unit 3. It would also be difficult to prepare multiple (three or more) atomizing units 3 and construct equipment that allows the multiple atomizing units 3 to be attached to the furnace body 2 in sequence with maintenance in between.

[0058] [Specific examples of connection / disconnection devices] The connection and detachment device 6 is not limited to a specific configuration as long as it can remotely connect and release the connection between the pipe connection member 33 and the pipe end member 41. However, when the pipe connection member 33 and the pipe end member 41 are configured as an autocoupler, a connection and detachment device 6 having the following configuration can be suitably used. Here, the connection and detachment device 6 has a push-in actuator 61 and a locking mechanism 62. The connection and detachment device 6 is fixedly installed with respect to the furnace body 2.

[0059] The pushing actuator 61 is a device that can move the pipe tip member 41 between an advanced position where it is connected to the pipe connection member 33 and a retracted position away from the pipe connection member 33. In particular, the pushing actuator 61 is configured as a linear actuator having a rod 611 that can move back and forth, and the tip of the rod 611 is connected to a pipe tip support member 63 fixed to the pipe tip member 41. The pushing actuator 61 is preferably equipped with a sensor device that detects the advanced / retracted position, that is, the position of the tip of the rod 611 in the advanced / retracted direction. As such a sensor device, a cylinder sensor or an encoder that can be attached to the linear actuator may be used.

[0060] The locking mechanism 62 is a mechanism that can reversibly fix the pipe tip member 41 in a state where it is connected to the pipe connection member 33. The locking mechanism 62 has a pair of pressing members 621 provided on the widthwise outer side of the pipe tip member 41. The pressing members 621 extend forward from the pipe tip support member 63 at a position on the widthwise outer side of the pipe tip member 41, and have a claw portion 623 integrally formed at the tip thereof that protrudes toward the widthwise inner side. The pressing members 621 are attached to the pipe tip support member 63 so that the tip side can be opened and closed in the width direction. The locking mechanism 62 further includes a pair of locking actuators 622 that can apply a force to each pressing member 621 to open and close it in the width direction. When the pair of holding members 621 are closed in the width direction by the locking actuator 622 in a state where the pipe end member 41 is connected to the pipe connection member 33, the claws 623 at the ends of the holding members 621 are locked to the connection part pedestal 34 that supports the pipe connection member 33 in the atomizing unit 3. This locking locks the pipe end member 41 from being disconnected from the pipe connection member 33. On the other hand, from this locked state, the holding members 621 are opened in the width direction by the locking actuator 622, and the claws 623 are separated from the connection part pedestal 34, so that the lock can be released. The connection part pedestal 34 may be provided with a locking hole 35 into which the claws 623 can enter and engage. By fixing the pipe end member 41 in a connected state to the pipe connection member 33 by the locking mechanism 62, the connection can be stably maintained even if high-pressure gas passes through the connection point.

[0061] Furthermore, the connection / detachment device 6 may be provided with a positioning member to assist in advancing the piping tip member 41 with the pushing actuator 61 and arranging it in a regular connection position with respect to the piping connection member 33. For example, a positioning pin 64 may be protruded forward from the piping tip support member 63, and a positioning hole 36 into which the positioning pin 64 can enter may be provided in the connection portion base 34 of the atomizing unit 3 when the piping tip member 41 is arranged in a regular connection position with respect to the piping connection member 33.

[0062] The gas atomizing device 1 is preferably provided with a photographing device (not shown) in addition to the connection / detachment device 6. The photographing device is installed near the connection / detachment device 6 so as to photograph the area including the pipe end member 41 and the pipe connection member 33. The photographed image can be confirmed remotely, so that the state of the pipe end member 41 and the pipe connection member 33 can be monitored. Preferably, the photographing device can be used to photograph a wider field of view, such as at least a part of the connection / detachment device 6 and the attachment portion between the atomizing unit 3 and the furnace body 2, so that the photographing device can be used for monitoring the state of a wider range. When the furnace body 2 and the gas pipe 4 are installed in a dark place such as the inside of the melting chamber 7, a night vision camera can be used as the photographing device.

[0063] In a state where the atomizing unit 3 is attached to the furnace body 2, in order to connect the gas pipe 4 to the atomizing unit 3 from a state where the gas pipe 4 is separated from the atomizing unit 3, first, the pushing actuator 61 is operated to advance the rod 611, thereby advancing the pipe end member 41 fixed to the pipe end support member 63 from a retreated position to an advanced position, that is, a position where the pipe end member 41 can be connected to the pipe connection member 33. At this time, it is confirmed that the positioning pin 64 provided on the pipe end support member 63 is inserted into the positioning hole 36 on the atomizing unit 3 side. Next, the compressed air, hydraulic pressure, etc. of the autocoupler are operated to form a connection between the pipe end member 41 and the pipe connection member 33, which are a set of the autocoupler. Furthermore, in the locking mechanism 62, the locking actuator 622 is operated to close the tip of the pressing member 621 in the width direction, and the claw portion 623 is engaged with the connection portion base 34, thereby locking the pipe end member 41 in a connected state to the pipe connection member 33. When the gas pipe 4 is to be disconnected from the atomizing unit 3, the above operations are carried out in reverse.

[0064] In this way, the gas pipe 4 can be attached to and detached from the atomizing unit 3 by the movement of the push-in actuator 61, the formation / release of the connection by the autocoupler, and the movement of the locking actuator 622, all of which can be performed by remote control, that is, without direct human operation. Each operation may be performed automatically. Even if the furnace body 2 and the gas pipe 4 are installed inside the melting chamber 7 filled with an inert gas, the gas pipe 4 can be attached and detached by performing each operation remotely without the need for work inside the melting chamber 7 and without breaking the atmosphere inside the melting chamber 7. Therefore, the gas pipe 4 can be attached and detached from the atomizing unit 3 easily and in a short time. If the advance / retraction position of the push-in actuator 61 is confirmed by a sensor device and the connection point is monitored by a camera device during each operation, each operation can be performed reliably from a remote location.

[0065] [Furnace body configuration details] As described above, the furnace body 2 is preferably composed of the cylinder 21 and the chamber 22. In this case, the atomizing unit 3 is attached to the axial end of the cylinder 21, that is, the upper end of the cylinder 21. The cylinder 21 may be fixed to the chamber 22, but is preferably movable forward and backward relative to the chamber 22 along the axial direction. In other words, the cylinder 21 is preferably connected at its lower end to be movable up and down relative to the chamber 22. In the embodiment shown in FIG. 4, a hollow cylindrical neck 221 having an inner diameter slightly larger than the outer diameter of the cylinder 21 is provided at the upper end of the chamber 22, and a part of the lower end side of the cylinder 21 is inserted into the neck 221 of the chamber 22. An O-ring seal 23 is disposed between the neck 221 of the chamber 22 and the cylinder 21 to seal the gap between the cylinder 21 and the chamber 22. As described above regarding the attachment and detachment of the atomizing unit 3, the atomizing unit 3 is placed on the top of the cylinder 21, and then the cylinder 21 is raised, so that the atomizing unit 3 can be attached in close contact with the cylinder 21. This improves the ease of attachment of the atomizing unit 3, and increases the airtightness of the cylinder 21, so that gas leakage is less likely to occur even when high-pressure gas is sprayed from the gas nozzle 322 of the gas atomizing nozzle 32. In addition, the particle size of the metal powder can be effectively controlled by controlling the gas / metal ratio. An O-ring seal 24 may be appropriately provided between the atomizing unit 3 and the cylinder 21.

[0066] Although the specific shapes and sizes of the cylinder 21 and the chamber 22 are not particularly limited, it is preferable that the cylinder 21 and the chamber 22 have different cross-sectional areas. In other words, in a cross section perpendicular to the axial direction (up-down direction) of the cylinder 21, the cross-sectional area of ​​the internal space of the cylinder 21 is preferably smaller than that of the chamber 22. Although the specific cross-sectional areas of the chamber 22 and the cylinder 21 are not particularly specified, from the viewpoint of fully obtaining the effect of providing the cylinder 21 with a smaller cross-sectional area as described later, it is preferable that the cross-sectional area of ​​the internal space of the cylinder 21 is 0.3% or more and 30% or less of the cross-sectional area of ​​the internal space of the chamber 22. Furthermore, it is preferable that the volume of the cylinder 21 is smaller than the volume of the chamber 22.

[0067] Here, the pressure in the internal space of the cylinder 21 is determined as a balance between the pressure increase due to the ejection of high-pressure gas from the gas nozzle 322 and the pressure decrease due to exhaust by the exhaust device 51. If the exhaust device 51 is capable of changing its output, the higher the output of the exhaust device 51, the lower the pressure in the cylinder 21. Although the internal spaces of the cylinder 21 and the chamber 22 are connected together, the supply of high-pressure gas from the gas nozzle 322 is performed locally at the upper part of the cylinder 21, so the internal pressures of the cylinder 21 and the chamber 22 are not necessarily the same. If the cross-sectional area of ​​the internal space of the furnace body 2 in the cross section perpendicular to the axial direction of the cylinder 21 is smaller in the cylinder 21 than in the chamber 22, the inside of the cylinder 21 is more significantly affected by the pressure increase due to the ejection of high-pressure gas from the gas nozzle 322 and the pressure decrease due to exhaust by the exhaust device 51. As a result, the pressure in the internal space of the cylinder 21 fluctuates over a larger pressure range than when the cylinder 21 is formed with a cross-sectional area as large as that of the chamber 22. Therefore, the pressure inside the cylinder 21 can be changed in a wide range by adjusting the output of the exhaust device 51. In other words, the amount of pressure drop when the output of the exhaust device 51 is increased and the amount of pressure rise when the output of the exhaust device 51 is decreased become large. In addition, by changing the output of the exhaust device 51, the pressure inside the cylinder 21 can be changed sensitively.

[0068] The pressure inside the cylinder 21 affects the discharge speed of the molten metal from the molten metal nozzle 321. The lower the pressure (back pressure) in the internal space of the cylinder 21, the stronger the molten metal is sucked out of the molten metal nozzle 321, and the faster the discharge speed of the molten metal becomes. As explained above, in the gas atomization process, the larger the gas / metal ratio is, the smaller the particle size of the generated metal powder tends to be, and the higher the content of fine powder in the metal powder tends to be. Therefore, by lowering the output of the exhaust device 51, slowing the discharge speed of the molten metal, and increasing the gas / metal ratio, it is possible to produce metal powder with a small particle size.

[0069] For example, the exhaust control unit that controls the output of the exhaust device 51 can be configured to control the output of the exhaust device 51 based on the particle size of the metal powder to be produced. When the particle size of the metal powder to be produced is small, the exhaust control unit reduces the output of the exhaust device 51 and controls to increase the pressure in the internal space of the furnace body 2, thereby optimizing the balance between the yield of the produced metal powder and the production speed.

[0070] In addition, by utilizing the fact that the pressure can be changed over a wide range in the cylinder 21 with a reduced cross-sectional area, control may be performed to suppress clogging of the molten metal nozzle 321. In the confined gas atomizing nozzle 32, high-pressure gas is injected from the gas nozzle 322 at a position immediately adjacent to the tip of the molten metal nozzle 321 to atomize and cool the molten metal, so that the tip of the molten metal nozzle 321 is cooled by the gas. Then, the molten metal may solidify in the molten metal nozzle 321, causing clogging of the molten metal nozzle 321. In particular, inclusions contained in the molten metal are likely to cause clogging of the molten metal nozzle 321. However, in the gas atomizing device 1 according to this embodiment, if the output of the exhaust device 51 is increased and the pressure in the cylinder 21 is reduced when the molten metal nozzle 321 is about to be blocked, the discharge speed of the molten metal from the molten metal nozzle 321 increases. Then, the molten metal is discharged without stagnation at the tip of the molten metal nozzle 321. Furthermore, the supply rate of high-temperature molten metal from the tundish 31 to the molten metal nozzle 321 also increases, and the amount of heat supplied to the tip of the molten metal nozzle 321 increases, so that the metal material that has solidified or is about to solidify at the tip of the molten metal nozzle 321 can be melted and discharged from the tip. By utilizing these phenomena, the progress of blockage of the molten metal nozzle 321 due to an increase in the output of the exhaust device 51 can be suppressed.

[0071] When the temperature of the molten metal in the tundish 31 is low, the molten metal nozzle 321 is likely to be clogged, so the temperature of the molten metal in the tundish 31 is used as an index to suppress the clogging of the molten metal nozzle 321 by increasing the output of the exhaust device 51. In other words, the exhaust control unit may control the output of the exhaust device 51 based on the temperature of the molten metal in the tundish 31 measured by the temperature measuring unit and transmitted to the exhaust control unit. For example, when the temperature measured by the temperature measuring unit becomes lower than a predetermined reference value, the exhaust control unit may increase the output of the exhaust device 51 and perform control to reduce the pressure in the internal space of the furnace body 2. As a result, the pressure inside the cylinder 21 is significantly reduced, and the discharge speed of the molten metal increases, thereby suppressing the progress of the clogging of the molten metal nozzle 321. In addition, immediately after the start of the production of metal powder, the temperature of the molten metal discharged from the molten metal nozzle 321 is low, so the discharge speed of the molten metal is kept low, and the molten metal nozzle 321 is likely to be clogged. Therefore, after starting to discharge the molten metal, the output of the exhaust device 51 is increased for a while to reduce the pressure inside the cylinder 21, while the output of the exhaust device 51 is reduced once the molten metal nozzle 321 reaches a sufficiently high temperature.

[0072] In this way, by controlling the output of the exhaust device 51 by the exhaust control unit, it is possible to control at least one of the particle size of the metal powder to be produced and the prevention of clogging of the molten metal nozzle 321. Both controls can be used in combination. For example, in a situation where the temperature of the molten metal in the tundish 31 is low, such as immediately after the start of the gas atomization process, the output of the exhaust device 51 can be increased to prevent clogging of the molten metal nozzle 321. On the other hand, in a state where the molten metal nozzle 321 is unlikely to be clogged, such as a state where the temperature of the molten metal nozzle 321 is sufficiently high, the output of the exhaust device 51 can be adjusted according to the particle size of the metal powder to be produced.

[0073] Although the embodiments of the present invention have been described above, the present invention is not particularly limited to these embodiments and various modifications can be made. [Explanation of symbols]

[0074] 1 Gas atomizing device 2 Furnace body 21 Cylinder 22 Chamber 3 Atomization unit 31 Tundish 32 Gas atomizing nozzle 321 Molten metal nozzle 322 Gas Nozzle 33 Piping connection parts 37 Bottom plate member 4 Gas piping 41 Pipe end parts 42 Gas Pipe 43 Pressure reducing valve 51 Exhaust system 52 Cyclone 53 Hopper 6. Connection and Detachment Device 61 (Pushing) Actuator 62 Locking mechanism 621 Holding member 622 Lock actuator 623 Claw 7 Melting chamber 72 Spare Room 73 Shutter 8 Carts

Claims

1. The furnace body and An atomizing unit attached to the furnace body, It has gas piping capable of supplying high-pressure gas, The atomizing unit is, A tundish for storing molten metal, A gas atomizing nozzle fixed to the aforementioned tundish, It has a pipe connecting member that is connected to the gas pipe, The aforementioned gas atomizing nozzle is A molten metal nozzle for discharging the molten metal in the tundish into the interior of the furnace body, A gas nozzle is integrally arranged with the molten metal discharged from the molten metal nozzle, and the gas nozzle injects the high-pressure gas supplied from the gas piping via the piping connecting member into the molten metal discharged from the molten metal nozzle. The atomizing unit is detachable from the furnace body as a single integrated unit, A gas atomizing device in which the gas piping can be attached to and detached from the piping connection member by remote operation.

2. The aforementioned furnace body is Chamber and, It has a hollow cylindrical cylinder in which the chamber and the internal space are in mutual communication, The atomizing unit is attached to the furnace body at the axial end of the cylinder, The gas atomizing device according to claim 1, wherein the cylinder is movable forward and backward relative to the chamber along the axial direction.

3. The gas piping has a pipe end member that is detachably connected to the pipe connection member of the atomizing unit, The aforementioned pipe connection member and the aforementioned pipe end member are configured as an auto coupler set. The gas atomizing device further, An actuator that can move the pipe end member between a position connected to the pipe connecting member and a position away from the pipe connecting member by an advancing and retracting motion, The gas atomizing device according to claim 1 or claim 2, further comprising a locking mechanism that can reversibly fix the pipe tip member in a state connected to the pipe connecting member.

4. The gas atomizing device further, A camera for photographing the area including the pipe tip member and the pipe connection member, The gas atomizing apparatus according to claim 3, further comprising a sensor device for detecting the forward and backward position of the actuator.

5. The atomizing unit further, The tundish has a removable bottom plate member attached to the bottom surface, The aforementioned pipe connection member is attached to the bottom plate member, The molten metal nozzle is fixed to the bottom surface of the tundish, and the gas nozzle is fixed to the bottom plate member. The gas atomizing apparatus according to claim 1 or claim 2, wherein the bottom surface of the tundish and the bottom plate member are provided with positioning members that can be positioned relative to each other.

6. The gas atomizing device further, A melting chamber is provided which houses at least a portion of the furnace body to which the atomizing unit can be attached, and at least a portion of the gas piping connected to the piping connection member, and which allows the atomizing unit to be inserted into and removed while maintaining an inert gas atmosphere inside, The melting chamber has a trolley capable of transporting the atomizing unit inside it. The gas atomizing apparatus according to claim 1 or claim 2, wherein the atomizing unit is separable from the trolley.

7. The gas atomizing device further, An exhaust device capable of exhausting the internal space of the cylinder at a variable pressure, It has an exhaust control unit that controls the output of the exhaust device and adjusts the pressure inside the furnace body, The gas atomizing apparatus according to claim 2, wherein the cross-sectional area of ​​the internal space of the furnace body perpendicular to the axial direction of the cylinder is smaller than that of the chamber in the cylinder.

8. The gas atomizing device further, The tundish has a temperature measuring unit that can measure the temperature of the molten metal in the tundish and transmit it to the exhaust control unit, The gas atomizing apparatus according to claim 7, wherein the exhaust control unit controls the pressure inside the furnace body to be lowered when the temperature is lower than a reference value.

Images