Storage warehouse of raw material powder for metal 3D printer and storage method of raw material powder for metal 3D printer

Abstract

A storage warehouse for a raw material powder for a metal 3D printer is provided with: a storage warehouse main body having a closed space on the inside thereof and in which one or more storage containers for accommodating a raw material powder for a metal 3D printer can be placed; a purge gas supply path for supplying a purge gas using air as a raw material to the sealed space; and an oxygen and moisture removal device located on the purge gas supply path for removing oxygen and moisture from the air. The storage warehouse can provide a storage environment suitable for the raw material powder for the metal 3D printer under the condition that the storage warehouse is not limited by setting places.

Description

Technical Field

[0001] The invention relates to a storage vault for raw material powder for a metal 3D printer and a storage method for raw material powder for a metal 3D printer.

[0002] This application claims priority based on patent application No. 2022-101704 filed in Japan on June 24, 2022, and its contents are incorporated herein by reference. Background Art

[0003] Additive manufacturing technology (also known as "Additive Manufacturing") can produce structures of any shape in a short period of time, and therefore has attracted attention as a promising technology in cutting-edge technology fields such as the aircraft industry and medicine.

[0004] As an example of a manufacturing device using additive manufacturing technology, a metal 3D printer is known that sintered raw material powder made of metal stored on a molding table using a laser, etc. The metal 3D printer can manufacture metal molded objects with high precision by sequentially stacking sintered metal layers on the molding table.

[0005] As the raw material powder used in the metal 3D printer (hereinafter, sometimes referred to as "raw material powder for metal 3D printer"), there are aluminum alloys, titanium alloys, iron alloys, nickel-based alloys, high entropy alloys, etc. Although these raw material powders are stored in a storage container, if they are stored in the atmosphere, most metal types will be oxidized by the oxygen in the atmosphere. If oxidized raw material powder is used, the amount of oxygen dissolved in the molded object will increase, which will affect the molding characteristics. In addition, the moisture resistance of the storage container is low. For example, within a few days, the raw material powder absorbs moisture to the same extent as in the atmosphere. For example, when using a raw material powder composed of an aluminum alloy, if moisture is present when the metal layer is molded, the molded object will be deformed after the heat treatment process. In addition, when using a raw material powder composed of a titanium alloy, if oxygen and moisture are present when the metal layer is molded, the mechanical properties of the molded object will deteriorate.

[0006] As described above, since the influence of oxygen and moisture present during the molding of the metal layer is caused by the oxygen and moisture attached to the raw material powder, the storage environment is very important for the raw material powder for metal 3D printers. Therefore, it is preferred to store the raw material powder for metal 3D printers in a storage warehouse that can remove oxygen and moisture.

[0007] As a storage tank capable of removing oxygen and moisture, for example, Patent Document 1 is known. Patent Document 1 discloses a technology that uses an inert gas such as nitrogen, helium, or argon as a purge gas, adjusts the moisture concentration and oxygen concentration in the storage tank, and provides a storage environment suitable for raw material powder for a metal 3D printer.

[0008] Patent Document 1: Japanese Patent Publication No. 2021-130870

[0009] However, the storage warehouse disclosed in Patent Document 1 uses an inert gas such as nitrogen, helium, or argon as a purge gas, which requires inert gas supply equipment and supply capacity, and thus has a problem of limited installation location of the storage warehouse. Summary of the invention

[0010] The present invention is proposed in view of the above situation, and its object is to provide a storage warehouse for raw material powder for metal 3D printer and a storage method for raw material powder for metal 3D printer, which can provide a storage environment suitable for raw material powder for metal 3D printer without being restricted by the setting location.

[0011] In order to solve the above-mentioned problems, the present invention has the following configuration.

[0012] [1] A storage tank for raw material powder for a metal 3D printer, comprising:

[0013] A storage vault body, having a closed space inside the storage vault body, and capable of placing one or more storage containers in the closed space, the storage containers being used to contain raw material powder for a metal 3D printer;

[0014] a purge gas supply path for supplying a purge gas made of air to the enclosed space; and

[0015] The oxygen and moisture removal device is located on the purge gas supply path and is used to remove oxygen and moisture from the air.

[0016] [2] The storage warehouse for raw material powder for a metal 3D printer according to [1], wherein the oxygen and moisture removal device is a gas diaphragm or a filling cylinder filled with a gas adsorbent.

[0017] [3] The storage tank for raw material powder for metal 3D printer according to [1] or [2] further comprises:

[0018] a first on-off valve located on the primary side of the oxygen and moisture removal device in the purge gas supply path;

[0019] a first flow regulator located on the secondary side of the oxygen and moisture removal device in the purge gas supply path;

[0020] a bypass path branched from the purge gas supply path on the primary side of the first on-off valve and merged with the purge gas supply path on the secondary side of the first flow rate regulator;

[0021] a second on-off valve, located on the bypass path;

[0022] a second flow regulator, located on the bypass path;

[0023] An oxygen concentration measuring instrument, used to measure the oxygen concentration in the confined space;

[0024] a moisture concentration measuring instrument for measuring the moisture concentration in the enclosed space; and

[0025] The control device can send and receive signals with the first on-off valve, the first flow rate regulator, the second on-off valve, the second flow rate regulator, the oxygen concentration measuring instrument, and the moisture concentration measuring instrument.

[0026] [4] The storage tank for raw material powder for a metal 3D printer according to any one of [1] to [3], further comprising:

[0027] a heater for heating the enclosed space; and

[0028] The temperature measuring instrument is used to measure the temperature of the enclosed space.

[0029] [5] The storage tank for raw material powder for metal 3D printer according to [4], wherein:

[0030] The blow-off port of the purge gas supply path opens below the enclosed space.

[0031] [6] The storage tank for raw material powder for a metal 3D printer according to any one of [3] to [5], further comprising:

[0032] an exhaust path for exhausting the atmosphere gas in the enclosed space as exhaust gas to the outside of the storage tank body,

[0033] At least one or both of the oxygen concentration measuring instrument and the water concentration measuring instrument are provided on the exhaust gas path.

[0034] [7] The storage tank for raw material powder for a metal 3D printer according to any one of [1] to [6], further comprising:

[0035] a third on-off valve located on the secondary side of the oxygen-water removal device in the purge gas supply path; and

[0036] The exhaust path branches from the purge gas supply path on the secondary side of the oxygen moisture removal device and on the primary side of the third on-off valve.

[0037] [8] A method for storing raw material powder for a metal 3D printer, wherein:

[0038] One or more storage containers are placed in the closed space, and the storage containers are used to contain raw material powder for the metal 3D printer.

[0039] A purge gas made of air and obtained by removing oxygen from the air is supplied to the closed space.

[0040] [9] The method for storing raw material powder for a metal 3D printer according to [8], wherein:

[0041] After the moisture concentration and the oxygen concentration in the enclosed space are lower than desired threshold values, the supply of the purge gas is stopped.

[0042]

[10] The method for storing raw material powder for a metal 3D printer according to [9], wherein:

[0043] After the supply of the purge gas is stopped, the purge gas is supplied into the closed space every time a required time elapses, and the moisture concentration and the oxygen concentration of the closed space are measured.

[0044]

[11] The method for storing raw material powder for a metal 3D printer according to

[10] , wherein:

[0045] When at least one of the moisture concentration and the oxygen concentration in the closed space exceeds a threshold value, supply of the purge gas is restarted.

[0046]

[12] The method for storing raw material powder for a metal 3D printer according to any one of [8] to

[11] , wherein:

[0047] The temperature of the enclosed space is set to a desired temperature.

[0048]

[13] The method for storing raw material powder for a metal 3D printer according to any one of [8] to

[12] , wherein:

[0049] The oxygen concentration in the enclosed space is maintained below 3% by volume,

[0050] The dew point temperature of the enclosed space is maintained below -40°C.

[0051]

[14] A storage tank for raw material powder for a metal 3D printer, comprising:

[0052] A storage vault body, wherein the storage vault body has a closed space inside, and one or more storage containers can be placed in the closed space, wherein the storage containers are used to contain raw material powder for a metal 3D printer;

[0053] a purge gas supply path for supplying a purge gas made of air into the enclosed space;

[0054] an oxygen and moisture removal device, located on the purge gas supply path, for removing oxygen and moisture from the air;

[0055] a first on-off valve located on the primary side of the oxygen and moisture removal device in the purge gas supply path;

[0056] a first flow regulator located on the secondary side of the oxygen and moisture removal device in the purge gas supply path;

[0057] a bypass path branched from the purge gas supply path on the primary side of the first on-off valve and merged with the purge gas supply path on the secondary side of the first flow rate regulator;

[0058] a second on-off valve, located on the bypass path;

[0059] a second flow regulator, located on the bypass path;

[0060] An oxygen concentration measuring instrument, used to measure the oxygen concentration in the confined space;

[0061] a moisture concentration measuring instrument for measuring the moisture concentration in the enclosed space; and

[0062] The control device can send and receive signals with the first on-off valve, the first flow rate regulator, the second on-off valve, the second flow rate regulator, the oxygen concentration measuring instrument, and the moisture concentration measuring instrument.

[0063]

[15] A storage tank for raw material powder for a metal 3D printer, comprising:

[0064] A storage vault body, wherein the storage vault body has a closed space inside, and one or more storage containers can be placed in the closed space, wherein the storage containers are used to contain raw material powder for a metal 3D printer;

[0065] a purge gas supply path for supplying a purge gas made of air into the enclosed space;

[0066] an oxygen and moisture removal device, located on the purge gas supply path, for removing oxygen and moisture from the air;

[0067] a third on-off valve located on the secondary side of the oxygen-water removal device in the purge gas supply path; and

[0068] The exhaust path branches from the purge gas supply path on the secondary side of the oxygen moisture removal device and on the primary side of the third on-off valve, and includes an on-off valve.

[0069]

[16] A storage tank for raw material powder for a metal 3D printer, comprising:

[0070] A storage vault body, wherein the storage vault body has a closed space inside, and one or more storage containers can be placed in the closed space, wherein the storage containers are used to contain raw material powder for a metal 3D printer;

[0071] a purge gas supply path for supplying a purge gas made of air into the enclosed space;

[0072] an oxygen and moisture removal device, located on the purge gas supply path, for removing oxygen and moisture from the air;

[0073] a third on-off valve located on the secondary side of the oxygen and moisture removal device in the purge gas supply path;

[0074] a discharge path branching from the purge gas supply path on the secondary side of the oxygen and moisture removal device and on the primary side of the third on-off valve;

[0075] a first on-off valve located on the primary side of the oxygen and moisture removal device in the purge gas supply path;

[0076] a first flow regulator located on the secondary side of the oxygen and moisture removal device in the purge gas supply path;

[0077] a bypass path branched from the purge gas supply path on the primary side of the first on-off valve and merged with the purge gas supply path on the secondary side of the first flow rate regulator;

[0078] a second on-off valve, located on the bypass path;

[0079] a second flow regulator, located on the bypass path;

[0080] An oxygen concentration measuring instrument, used to measure the oxygen concentration in the confined space;

[0081] a moisture concentration measuring instrument for measuring the moisture concentration in the enclosed space; and

[0082] The control device can send and receive signals with the first on-off valve, the first flow rate regulator, the second on-off valve, the second flow rate regulator, the oxygen concentration measuring instrument, and the moisture concentration measuring instrument.

[0083]

[17] A storage tank for raw material powder for a metal 3D printer according to any one of

[14] to

[16] , wherein:

[0084] The oxygen and moisture removal device is a gas diaphragm or a filling cylinder filled with a gas adsorbent.

[0085]

[18] The storage tank for raw material powder for a metal 3D printer according to any one of

[14] to

[16] , further comprising:

[0086] a heater for heating the enclosed space; and

[0087] The temperature measuring instrument is used to measure the temperature of the enclosed space.

[0088]

[19] A storage tank for raw material powder for a metal 3D printer according to

[18] , wherein:

[0089] The blow-off port of the purge gas supply path opens below the enclosed space.

[0090]

[20] The storage tank for raw material powder for a metal 3D printer according to any one of

[14] to

[16] further comprises:

[0091] an exhaust path for exhausting the atmosphere gas in the enclosed space as exhaust gas to the outside of the storage tank body,

[0092] At least one or both of the oxygen concentration measuring instrument and the water concentration measuring instrument are provided on the exhaust gas path.

[0093]

[21] A method for storing raw material powder for a metal 3D printer, using the storage vault for raw material powder for a metal 3D printer described in any one of

[14] to

[16] ,

[0094] One or more storage containers are placed in the sealed space inside the storage body, and the storage containers are used to store raw material powder for metal 3D printers.

[0095] A purge gas made of air and obtained by removing oxygen and moisture from the air is supplied to the closed space.

[0096]

[22] The method for storing raw material powder for a metal 3D printer according to

[21] , wherein:

[0097] After the moisture concentration and the oxygen concentration in the enclosed space are lower than desired threshold values, the supply of the purge gas is stopped.

[0098]

[23] The method for storing raw material powder for a metal 3D printer according to

[22] , wherein:

[0099] After the supply of the purge gas is stopped, the purge gas is supplied into the closed space every time a required time elapses, and the moisture concentration and the oxygen concentration of the closed space are measured.

[0100]

[24] The method for storing raw material powder for a metal 3D printer according to

[23] , wherein:

[0101] When at least one of the moisture concentration and the oxygen concentration in the closed space exceeds a threshold value, supply of the purge gas is restarted.

[0102]

[25] The method for storing raw material powder for a metal 3D printer according to any one of

[21] to

[24] , wherein:

[0103] The temperature of the enclosed space is set to a desired temperature.

[0104]

[26] The method for storing raw material powder for a metal 3D printer according to any one of

[21] to

[25] , wherein:

[0105] The oxygen concentration in the enclosed space is maintained below 3% by volume,

[0106] The dew point temperature of the enclosed space is maintained below -40°C.

[0107] According to the storage warehouse for raw material powder for metal 3D printer and the storage method for raw material powder for metal 3D printer of the present invention, it is possible to provide a storage environment suitable for raw material powder for metal 3D printer without being restricted by the installation location. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] Figure 1 This is a schematic diagram showing an example of a storage structure of raw material powder for a metal 3D printer as one embodiment to which the present invention is applied.

[0109] Figure 2 This is a diagram showing an example of a control device configuration applicable to a storage facility according to the present embodiment.

[0110] Figure 3 This is a flowchart of an example of a method for storing raw material powder for a metal 3D printer as one embodiment to which the present invention is applied.

[0111] Figure 4 This is a schematic diagram showing a modified example of the storage structure of the raw material powder for the metal 3D printer as one embodiment to which the present invention is applied. DETAILED DESCRIPTION

[0112] Hereinafter, a storage vault for raw material powder for a metal 3D printer to which an embodiment of the present invention is applied will be described in detail together with a storage method for raw material powder for a metal 3D printer using the storage vault with reference to the accompanying drawings. In addition, with respect to the drawings used in the following description, in order to facilitate understanding of the features, sometimes the features are enlarged for convenience, and the dimensional ratios of the various structural elements are not limited to be the same as the actual ones.

[0113] <Storage of raw material powder for metal 3D printers>

[0114] First, a storage structure of raw material powder for a metal 3D printer as one embodiment to which the present invention is applied will be described. Figure 1 This is a schematic diagram showing an example of a storage structure of raw material powder for a metal 3D printer as one embodiment to which the present invention is applied. Figure 2 This is a diagram showing an example of a control device configuration applicable to a storage facility according to the present embodiment.

[0115] like Figure 1 and Figure 2 As shown, the storage tank for raw material powder for metal 3D printer of this embodiment (hereinafter sometimes referred to as "storage tank") 1 is roughly constructed to include a shell (storage tank body) 2, a heater 3, a temperature measuring instrument 4, a purge gas supply path L1, an exhaust path L2, a bypass path L3, an opening and closing valve (a first opening and closing valve) 5, an oxygen and moisture removal device 6, an opening and closing valve (a third opening and closing valve) 7, a flow regulator (a first flow regulator) 8, an oxygen concentration measuring instrument 9, a moisture concentration measuring instrument 10, an opening and closing valve (a second opening and closing valve) 11, a flow regulator (a second flow regulator) 12 and a control device 13.

[0116] like Figure 1 As shown, the storage 1 of this embodiment stores raw material powder for metal 3D printer (hereinafter sometimes referred to as "raw material powder") in an environment maintaining appropriate oxygen concentration and water concentration. And, during molding in the metal 3D printer, the raw material powder is taken out from the storage 1 for use.

[0117] The raw material powder to be stored is not particularly limited as long as it can be used in a metal 3D printer. Examples of such raw material powder include aluminum alloys, titanium alloys, iron alloys, nickel-based alloys, and high entropy alloys.

[0118] The raw material powder is stored in a storage container S. Here, the storage container S is composed of a container body made of resin or metal and a lid made of resin or metal. The raw material powder is stored in the container body and can be stored with or without the lid on.

[0119] The housing (storage body) 2 is a rectangular storage room having a sealed space 2A inside. The structure of the housing 2 is not particularly limited. As the housing 2, a housing having a back plate, a top plate, a bottom plate, a pair of side surfaces, and an opening and closing door can be used. A plurality of shelves 2B of different heights are arranged in the vertical direction in the sealed space 2A (in Figure 1The enclosed space 2A is divided by a plurality of shelves 2B. On each shelf 2B of the housing 2, one or more storage containers S can be placed, and the storage containers S are used to contain raw material powder.

[0120] The opening and closing door is not particularly limited as long as it can form an opening in the enclosed space 2A that allows the storage container S for storing the raw material powder to be taken in and out. Examples of the opening and closing door include single-side opening, double-leaf opening, and sliding types.

[0121] It is preferred that the opening and closing door be sealed (sealed) to such an extent that oxygen and moisture do not penetrate into the closed space 2A from the environment in which the storage warehouse 1 is installed when the opening and closing door is closed.

[0122] In addition, it is preferable to provide a sensor on the opening and closing door so as to send a signal when the door is opened.

[0123] The capacity of the housing 2 (in other words, the volume of the enclosed space 2A) is not particularly limited, and can be appropriately selected according to the storage amount of the storage container S. The capacity of the housing 2 can be 100 to 2000 L, and is preferably 300 to 1500 L, and more preferably 600 to 1200 L from the perspective of practicality and carrying out and carrying in the powder container.

[0124] The material of the housing 2 is not particularly limited as long as it has heat insulation and thermal insulation effects. Examples of the material of the housing 2 include iron-based materials and resin materials. Among them, from the perspectives of load resistance and electrical conductivity, a laminated structure of a metal plate such as stainless steel or steel and a heat insulating material such as polyurethane resin is preferably used.

[0125] The heater 3 is used to heat the enclosed space 2A of the housing 2 to a desired temperature or to keep it warm at a desired temperature. The heater 3 is located on the entire surface of the back plate. Here, the position where the heater 3 is set is not particularly limited as long as it is a position facing the enclosed space 2A. As such a position, for example, a top plate, a bottom plate, a pair of side surfaces, and an opening and closing door not shown in the figure can be cited. In addition, the heater 3 can be set at more than two places such as the back plate and a pair of side surfaces, or it can be set only at a part of the back plate instead of the entire surface of the back plate.

[0126] The heater 3 is not particularly limited as long as it can heat the enclosed space 2A to a desired temperature or keep it warm at a desired temperature. As the heater 3, for example, a rubber heater, a sheath type heater, etc. can be cited. Among them, from the viewpoint of easy installation on the back plate or the safety of the operator, it is preferred to use a rubber heater.

[0127] A heater cover (contact prevention plate) is preferably provided on the surface of the heater 3 . This can prevent the operator from accidentally touching the heater 3 when storing the storage container S in the storage warehouse 1 or when taking the storage container S out of the storage warehouse 1 .

[0128] like Figure 1 As shown, the temperature measuring instrument 4 is arranged in the housing 2 to measure the temperature of the enclosed space 2A. Specifically, it is arranged near the mounting surface of the shelf 2B. In addition, the number of the temperature measuring instruments 4 is not particularly limited. By arranging a plurality of temperature measuring instruments 4 in the housing 2, the temperature distribution of the enclosed space 2A can be measured. Thus, the temperature distribution in the enclosed space 2A can be appropriately adjusted.

[0129] The temperature measuring instrument 4 is not particularly limited as long as it can measure the temperature of the enclosed space 2A. Examples of the temperature measuring instrument 4 include a K-type thermocouple manufactured by Yamazato Sangyo Co., Ltd.

[0130] like Figure 2 As shown, the heater 3 and the temperature measuring instrument 4 are connected to the control device 13 via a wired or wireless signal line. Thus, the control device 13 receives the measured value of the temperature of the enclosed space 2A from the temperature measuring instrument 4 in the form of an electrical signal, and sends a control signal to the heater 3 to heat or keep the enclosed space 2A warm based on the received measured value.

[0131] like Figure 1 As shown, the purge gas supply path L1 is a gas supply pipe for supplying the purge gas to the closed space 2A in the casing 2 .

[0132] The storage warehouse 1 of the present embodiment uses a purge gas made of air. In other words, the storage warehouse 1 of the present embodiment uses air as a raw material of the purge gas.

[0133] The raw material air is preferably compressed air pressurized by an air compressor. In addition, the raw material air is preferably dry air after the water is removed. Furthermore, the raw material air is preferably high-purity air (clean air) after the tiny impurities (particles) are removed.

[0134] Specifically, when a gas membrane module is used as the oxygen moisture removal device 6 described later, it is preferable to use clean dry air (CDA) as the raw air. As a result, particles included in the raw air are removed, so that the performance degradation of the gas membrane can be suppressed and the gas membrane module can be used for a long time. Furthermore, since the moisture concentration of the raw air is low, the moisture concentration of the purge gas (inert gas) obtained by the gas membrane module can be reduced.

[0135] The purge gas supply path L1 has outlets L1a and L1b that open below the closed space 2A.

[0136] The blow-out ports L1a and L1b are arranged at a predetermined interval below (near the bottom) the enclosed space 2A. By introducing the purge gas near the bottom of the enclosed space 2A, the atmosphere of the enclosed space 2A can be convected from the bottom to the top. In other words, the atmosphere of the enclosed space 2A can be stirred.

[0137] The blowing ports L1a and L1b are adjusted in a direction in which the blown purge gas contacts the heater 3 disposed on the back plate. By blowing the purge gas toward the heater 3, the heated purge gas can be supplied into the closed space 2A.

[0138] On the secondary side of the branch point P of the purge gas supply path L1 and on the primary side of the confluence point Q, an on-off valve (first on-off valve) 5, an oxygen and moisture removal device 6, an on-off valve (third on-off valve) 7 and a flow regulator (first flow regulator) 8 are arranged in sequence.

[0139] The on-off valve (first on-off valve) 5 is located on the primary side of the oxygen-water removal device 6 on the purge gas supply path L1, and selects the open state or the closed state of the flow path of the purge gas supply path L1. By setting the on-off valve 5 to the open state, the raw air can be supplied to the oxygen-water removal device 6 on the secondary side of the on-off valve 5. On the other hand, by setting the on-off valve 5 to the closed state, the supply of raw air to the secondary side of the on-off valve 5 can be stopped. The on-off valve 5 is not particularly limited as long as the open and closed state of the flow path can be selected. As the on-off valve 5, for example, a solenoid valve can be applied.

[0140] The oxygen and moisture removal device 6 is located on the purge gas supply path L1 and can output nitrogen gas obtained by removing oxygen and moisture from the introduced raw material air as purge gas. In other words, the oxygen and moisture removal device 6 is a device for producing purge gas using air as raw material.

[0141] The oxygen and moisture removal device 6 is not particularly limited as long as it can remove oxygen and moisture from the raw air. As the oxygen and moisture removal device 6, for example, a gas diaphragm module having a gas diaphragm and a filling cylinder filled with a gas adsorbent can be cited. Among them, a gas diaphragm module and a filling cylinder filled with a gas adsorbent that can remove oxygen from the raw air without using a power supply are preferred. The oxygen and moisture removal device 6 can also be a structure in which a gas diaphragm module is combined in the front section and a filling cylinder filled with a gas adsorbent is combined in the rear section.

[0142] Examples of the gas membrane include a hollow fiber membrane made of a polyimide resin and a carbon membrane.

[0143] In addition, as the above-mentioned gas membrane module having a gas membrane, for example, "NM-C07F" manufactured by Ube Industries, Ltd. (Ube Industries, Ltd.) can be cited.

[0144] Examples of oxygen gas adsorbents include potassium permanganate, Cu-Zu-based or Mn-based gas adsorbents, and specifically, "N-112" manufactured by Nikko Catalyst Co., Ltd. and "Ni3288E" manufactured by NE CHEMCAT. Examples of moisture gas adsorbents include silica gel, and specifically, "NKHD24" manufactured by Sumika Alchem ​​Co., Ltd. and "ZEOLUM F9, ZEOLUM F9HA, ZEOLUM A3" manufactured by Tosoh Corporation.

[0145] From the viewpoint of suppressing oxidation of the raw material powder, the purge gas derived from the oxygen and moisture removal device 6 preferably has a lower oxygen content and moisture content (lower oxygen concentration and dew point temperature). Specifically, the oxygen concentration of the purge gas is preferably 3% by volume or less, more preferably 1% by volume or less. As the purge gas applied to the storage warehouse 1 of the present embodiment, nitrogen having an oxygen concentration of 3% by volume or less is preferred. The dew point temperature of the purge gas is preferably below -50°C, more preferably below -60°C. As the purge gas applied to the storage warehouse 1 of the present embodiment, nitrogen having a dew point temperature of -50°C or less is preferred.

[0146] The on-off valve (third on-off valve) 7 is located on the secondary side of the oxygen and moisture removal device 6 on the purge gas supply path L1, and selects the open state or closed state of the flow path of the purge gas supply path L1. By setting the on-off valve 7 to the open state, the purge gas can be supplied to the purge gas supply path L1 on the secondary side of the on-off valve 7. On the other hand, by setting the on-off valve 7 to the closed state, the supply of the purge gas to the secondary side of the on-off valve 7 can be stopped. The on-off valve 7 is not particularly limited as long as the open and closed state of the flow path can be selected. The on-off valve 7 can be applied to the solenoid valve in the same manner as the above-mentioned on-off valve 5.

[0147] The flow rate regulator (first flow rate regulator) 8 is located on the secondary side of the oxygen and moisture removal device 6 on the purge gas supply path L1, and regulates the flow rate of the purge gas to the closed space 2A. The flow rate regulator 8 is not particularly limited as long as it can regulate the flow rate of the purge gas. As the flow rate regulator 8, for example, a mass flow controller manufactured by Fujikin Co., Ltd. can be cited.

[0148] like Figure 2 As shown, the on-off valve 5, the on-off valve 7 and the flow regulator 8 located on the purge gas supply path L1 are electrically connected to the control device 13 via a wired or wireless signal line. Thus, control signals can be sent and received between the on-off valve 5, the on-off valve 7 and the flow regulator 8 and the control device 13 via the signal line.

[0149] like Figure 1 As shown, the exhaust path L2 is an exhaust duct that is connected to the enclosed space 2A and discharges the atmosphere gas in the enclosed space 2A as exhaust gas to the outside of the shell 2. The connection position of the exhaust path L2 is close to the upper part of the shell 2. Therefore, the exhaust path L2 is located on the side opposite to the blowout ports L1a and L1b arranged in the enclosed space 2A across the enclosed space 2A, so that the convection of the atmosphere gas in the enclosed space 2A from the lower side to the upper side can be promoted.

[0150] The oxygen concentration measuring instrument 9 is located on the exhaust path L2 and measures the oxygen concentration in the atmosphere gas exhausted from the enclosed space 2A to the exhaust path L2. In other words, the oxygen concentration measuring instrument 9 indirectly measures the oxygen concentration in the enclosed space 2A by measuring the oxygen concentration in the atmosphere gas exhausted from the enclosed space 2A to the exhaust path L2.

[0151] The oxygen concentration measuring device 9 is not particularly limited as long as it can measure the oxygen concentration. Examples of the oxygen concentration measuring device 9 include an oxygen concentration meter manufactured by Michell Corporation.

[0152] The moisture concentration measuring instrument 10 is located on the exhaust path L2 and measures the moisture concentration in the atmosphere gas exhausted from the enclosed space 2A to the exhaust path L2. In other words, the moisture concentration measuring instrument 10 indirectly measures the moisture concentration in the enclosed space 2A by measuring the moisture concentration in the atmosphere gas exhausted from the enclosed space 2A to the exhaust path L2.

[0153] The water concentration measuring instrument 10 is not particularly limited as long as it can measure water concentration. Examples of the water concentration measuring instrument 10 include a dew point meter manufactured by Michell Corporation.

[0154] like Figure 2 As shown, the oxygen concentration measuring instrument 9 and the water concentration measuring instrument 10 are connected to the control device 13 via a wired or wireless signal line. Thus, the oxygen concentration measuring instrument 9 and the water concentration measuring instrument 10 and the control device 13 can transmit and receive the measured values ​​of the oxygen concentration and the water concentration of the enclosed space 2A in the form of electrical signals.

[0155] like Figure 1 As shown, the bypass path L3 is a gas supply pipeline that branches from the purge gas supply path L1 at the branch point P on the primary side of the on-off valve 5 and merges with the purge gas supply path L1 at the confluence point Q on the secondary side of the flow regulator 8. In other words, the bypass path L3 is a gas supply pipeline that allows the raw air flowing in the purge gas supply path L1 to bypass (bypass) the oxygen and moisture removal device 6 and be supplied to the secondary side of the oxygen and moisture removal device 6. According to the bypass path L3, the purge gas including the raw air can be supplied to the enclosed space 2A in the housing 2.

[0156] On the secondary side of the branch point P and the primary side of the junction Q on the bypass path L3, an on-off valve (second on-off valve) 11 and a flow rate regulator (second flow rate regulator) 12 are provided in this order.

[0157] The on-off valve 11 is located on the bypass path L3, and selects the open state or the closed state of the flow path of the bypass path L3. By setting the on-off valve 11 to the open state, the raw air can be supplied to the secondary side of the on-off valve 11. On the other hand, by setting the on-off valve 11 to the closed state, the supply of raw air to the secondary side of the on-off valve 11 can be stopped. The on-off valve 11 is not particularly limited as long as the open and closed state of the flow path can be selected. As the on-off valve 11, for example, a solenoid valve can be applied.

[0158] The flow rate regulator 12 is located on the bypass path L3, and adjusts the flow rate of the raw air supplied to the purge gas supply path L1 via the bypass path L3. In other words, the flow rate of the purge gas to the enclosed space 2A is adjusted. The flow rate regulator 12 is not particularly limited as long as it can adjust the flow rate of the raw air. As the flow rate regulator 12, for example, a mass flow controller manufactured by Fujikin Co., Ltd. can be cited.

[0159] like Figure 2 As shown, the on-off valve 11 and the flow regulator 12 on the bypass path L3 are electrically connected to the control device 13 via a wired or wireless signal line. Thus, control signals can be sent and received between the on-off valve 11 and the flow regulator 12 and the control device 13 via the signal line.

[0160] like Figure 1 As shown, in the storage vault 1 of the present embodiment, from the viewpoint of removing moisture contained in the raw material powder, the purge gas introduced into the closed space 2A in the housing 2 is preferably dry and has a low moisture content. Specifically, the dew point of the purge gas is preferably -50°C or less, and more preferably -60°C or less. As the purge gas used in the storage vault 1 of the present embodiment, nitrogen having a dew point of -50°C or less is preferably used.

[0161] like Figure 2 As shown, the control device 13 is electrically connected to the heater 3, the temperature measuring instrument 4, the on-off valve 5, the on-off valve 7, the flow regulator 8, the oxygen concentration measuring instrument 9, the moisture concentration measuring instrument 10, the on-off valve 11 and the flow regulator 12 through a wired or wireless signal line.

[0162] Thus, the measured values ​​of the temperature, oxygen concentration, and water concentration of the enclosed space 2A can be sent and received in the form of electrical signals between the control device 13 and the temperature measuring instrument 4, the oxygen concentration measuring instrument 9, and the water concentration measuring instrument 10. In addition, the control signal can be sent and received in the form of electrical signals between the control device 13 and the heater 3, the on-off valve 5, the on-off valve 7, the flow regulator 8, the on-off valve 11, and the flow regulator 12.

[0163] The control device 13 is not particularly limited as long as it has the above-mentioned transmission and reception function. As the control device 13, a PLC (Programmable Logic Controller), a PC, a portable terminal such as a tablet computer, etc. can be applied.

[0164] In summary, the storage warehouse 1 of the present embodiment can control the flow rate of the purge gas supplied to the enclosed space 2A and the composition (oxygen concentration) of the purge gas based on the measured values ​​of the oxygen concentration and the water concentration in the enclosed space 2A.

[0165] Furthermore, the storage warehouse 1 of the present embodiment can control the output of the heater 3 located in the enclosed space 2A based on the measured values ​​of the water concentration and the temperature of the enclosed space 2A.

[0166] <How to store raw material powder for metal 3D printer>

[0167] Next, a method for storing raw material powder for a metal 3D printer as one embodiment to which the present invention is applied will be described. Figure 3 This is a flowchart showing an example of a method for storing raw material powder for a metal 3D printer as one embodiment to which the present invention is applied.

[0168] The method for storing raw material powder for a metal 3D printer according to the present embodiment (hereinafter, sometimes simply referred to as “storage method”) is performed using the storage chamber 1 described above.

[0169] In the storage method of this embodiment, one or more storage containers S for containing raw material powder are placed in the closed space 2A inside the shell 2, and a purge gas made of air as a raw material and from which oxygen and moisture are removed is supplied to the closed space 2A at a specified flow rate from the purge gas supply path L1.

[0170] Below, refer to Figure 3 The storage method of this embodiment will be described in detail.

[0171] like Figure 3 As shown, the operation of storage warehouse 1 is started (START).

[0172] First, as shown in step S1, raw material powder is put into or taken out of the warehouse.

[0173] Specifically, when the raw material powder is put into the storage, the door of the housing 2 is opened, and one or more storage containers S are placed on the loading surface of any shelf 2B. On the other hand, when the raw material powder is taken out of the storage, the door of the housing 2 is opened, and one or more storage containers S placed on any shelf 2B are taken out from the storage 1.

[0174] Furthermore, when the opening and closing door of the housing 2 is opened while the raw material powder is already stored, the purge gas in the enclosed space 2A flows out, and the operator may suffer from hypoxia. In this case, it is preferred to set the opening and closing valve 11 of the bypass path L3 to an open state, and control the flow regulator 12 to supply the raw material air to the purge gas supply path L1, and supply it as purge gas to the enclosed space 2A of the storage 1. Thus, when the storage 1 is opened, the raw material air also flows out together with the purge gas, so that the operator can be prevented from suffering from hypoxia.

[0175] Next, as shown in step S2 , a purge gas is supplied to the sealed space 2A of the storage warehouse 1 .

[0176] Specifically, after closing the opening and closing door of the housing 2, the opening and closing valves 5 and 7 are set to an open state, and the opening and closing valve 11 is set to a closed state, and the purge gas is supplied to the enclosed space 2A from the purge gas supply path L1. In addition, the purge gas is supplied while controlling the supply amount through the flow regulator 8. At the same time, the atmosphere gas in the enclosed space 2A is discharged to the outside of the housing 2 from the exhaust path L2.

[0177] Next, as shown in step S3, it is determined whether the water concentration and the oxygen concentration in the closed space 2A of the storage warehouse 1 are equal to or lower than a required threshold value.

[0178] Specifically, when the ambient gas is discharged from the exhaust path L2, the oxygen concentration in the ambient gas is measured by the oxygen concentration measuring instrument 9, and the moisture concentration in the ambient gas is measured by the moisture concentration measuring instrument 10, and it is determined whether the moisture concentration and oxygen concentration in the enclosed space 2A are below the required threshold value.

[0179] As a result of determination, when any one of the water concentration and the oxygen concentration in the closed space 2A is greater than the required threshold value (determination of "No"), the process returns to step S2 to control the supply amount of the purge gas.

[0180] Here, in step S2, the supply amount of the purge gas may be changed according to the measured value of the water concentration. For example, when the water concentration in the enclosed space 2A is higher than the required threshold value, the flow rate of the purge gas is preferably a high flow rate that can completely replace the atmosphere gas in the enclosed space 2A of the storage vault 1 within 1 to 60 minutes. By supplying a high flow rate of purge gas, the water present in the enclosed space 2A of the storage vault 1, especially the water adsorbed on the surface of the raw material powder, can be quickly removed.

[0181] Thus, by controlling the flow rate and composition ratio (oxygen concentration) of the purge gas supplied to the enclosed space 2A of the storage warehouse 1 based on the measured value of the impurity concentration in the enclosed space 2A, the atmosphere in the enclosed space 2A of the storage warehouse 1 can be brought to a desired state as quickly as possible.

[0182] The oxygen concentration in the sealed space 2A may be 6 vol% or less, preferably 3 vol% or less, and more preferably 1 vol% or less. By setting the oxygen concentration in the sealed space 2A to 3 vol% or less, oxidation of the raw material powder during storage can be suppressed.

[0183] The water concentration in the enclosed space 2A may be below the dew point temperature of -40°C, preferably below -50°C, and more preferably below -60°C. By setting the water concentration in the enclosed space 2A below the dew point temperature of -40°C, the effect of removing the water from the raw material powder after moisture absorption and the effect of suppressing moisture absorption can be obtained.

[0184] On the other hand, if the measured values ​​of the water concentration and oxygen concentration of the confined space 2A are below the required threshold values ​​(judged as "yes") as a result of the judgment in step S3, the process proceeds to step S4 to stop the supply of the purge gas. Specifically, the on-off valves 5, 7, and 11 are set to a closed state. Thus, according to the storage method of this embodiment, energy consumption can be reduced. In addition, the load on the oxygen moisture removal device 6 can be reduced, so the life of the oxygen moisture removal device 6 can be extended.

[0185] Next, as shown in step S5, after a desired time has passed, the purge gas is supplied to the sealed space 2A, and at the same time, the atmosphere in the sealed space 2A is exhausted as exhaust gas from the exhaust path L2 to the outside of the housing 2.

[0186] Here, the supply amount of the purge gas is preferably a flow rate that can completely replace the atmosphere gas in the closed space 2A of the storage warehouse 1 within 1 to 60 minutes. From the viewpoint of measuring the oxygen concentration and water concentration in the warehouse in a short time, it is more preferably a flow rate that can completely replace the atmosphere gas in the closed space 2A of the storage warehouse 1 within 1 to 10 minutes.

[0187] The purge gas is preferably supplied to the enclosed space 2A from a plurality of outlets L1a and L1b opened below the enclosed space 2A. This allows wide-area stirring in the enclosed space 2A of the storage warehouse 1, so that stable water concentration and oxygen concentration measurement values ​​can be obtained in step S6 described later.

[0188] Next, as shown in step S6, it is determined whether the water concentration and the oxygen concentration in the enclosed space 2A of the storage warehouse 1 are equal to or lower than the required threshold values.

[0189] Specifically, similar to the above-mentioned step S3, when the ambient gas is discharged from the exhaust path L2, the oxygen concentration in the ambient gas is measured by the oxygen concentration measuring instrument 9, and the moisture concentration in the ambient gas is measured by the moisture concentration measuring instrument 10, and it is determined whether the moisture concentration and oxygen concentration in the enclosed space 2A are below the required threshold value.

[0190] As a result of determination, when any one of the water concentration and the oxygen concentration in the closed space 2A is greater than the required threshold value (determination of "No"), the process returns to step S2 and the supply of the purge gas is restarted.

[0191] On the other hand, if the measured values ​​of the water concentration and oxygen concentration of the confined space 2A are below the required threshold value (judged as "yes"), the supply of the purge gas is stopped. Specifically, the on-off valves 5, 7, and 11 are set to a closed state. Thus, the energy consumption can be reduced. In addition, the load on the oxygen moisture removal device 6 is reduced, so the life of the oxygen moisture removal device 6 can be extended.

[0192] Next, as shown in step S7, it is determined whether the operation of the storage room 1 is stopped.

[0193] If the result of the judgment shows that the operation of the storage warehouse 1 is continued without stopping (judgment is "No"), return to step S5, after stopping the supply of the purge gas, the purge gas is supplied to the enclosed space 2A again after the required time, and the moisture concentration and oxygen concentration of the enclosed space 2A are measured.

[0194] According to the storage method of this embodiment, when the impurity concentration in the enclosed space 2A of the storage warehouse 1 is below the required threshold value, the supply of the purge gas is stopped, and the purge gas is supplied to the enclosed space 2A every time a required time has passed, and the water concentration and oxygen concentration in the enclosed space 2A are measured, thereby reducing the energy consumption of the storage warehouse 1 and maintaining a suitable storage environment for the raw material powder. In addition, the load on the oxygen and moisture removal device 6 can be reduced, so the life of the oxygen and moisture removal device 6 can be extended.

[0195] In addition, according to the storage method of the present embodiment, since the oxygen concentration measuring instrument 9 and the moisture concentration measuring instrument 10 are both located on the exhaust path L2, if the supply of purge gas to the enclosed space 2A is stopped, it may not be possible to accurately measure the impurity concentration of the enclosed space 2A of the storage warehouse 1 due to the lack of flow of exhaust gas. However, by supplying the purge gas to the enclosed space 2A every time the required time has passed, the impurity concentration of the enclosed space 2A of the storage warehouse 1 can be accurately measured.

[0196] The supply interval of the purge gas for measuring the impurity concentration in the storage tank after the supply of the purge gas is stopped is not particularly limited and can be appropriately selected according to the sealing performance and volume of the storage tank 1 .

[0197] On the other hand, if the result of determination in step S7 is that the operation of the storage warehouse 1 is stopped (determination: YES), the operation of the storage warehouse 1 is ended (END).

[0198] (Variant 1)

[0199] In the storage method of the present invention, when supplying the purge gas in step S2, the purge gas may be supplied while heating the sealed space 2A of the storage container 1 only during a period when the water concentration is higher than a required threshold value.

[0200] The heating of the enclosed space 2A of the storage warehouse 1 by the heater 3 is stopped when the water concentration becomes equal to or lower than a required threshold value.

[0201] Furthermore, from the viewpoint of maintaining the storage environment of the raw material powder, during the above-mentioned steps S5 to S7, the sealed space 2A of the storage chamber 1 may be heated by the heater 3 as needed in order to maintain the temperature of the sealed space 2A of the storage chamber 1.

[0202] According to variation 1 of the storage method of the present embodiment, when supplying the purge gas in step S2, the purge gas is supplied in a state where the enclosed space 2A of the storage chamber 1 is heated only during the period when the moisture concentration is higher than the required threshold value, thereby promoting the separation and removal of moisture from the raw material powder.

[0203] Furthermore, during the supply of the purge gas in step S2, when the water concentration is equal to or less than a required threshold value, the output of the heater 3 can be reduced, thereby reducing the energy consumption during storage of the raw material powder.

[0204] As described above, according to the storage vault 1 and the storage method of this embodiment, since the purge gas using air as the raw material is used, a storage environment suitable for the raw material powder for metal 3D printer can be provided without being restricted by the installation location. In particular, even in the case where practical equipment for supplying inert gas cannot be provided due to the provisions of the High-Pressure Gas Safety Act, a storage environment suitable for the raw material powder for metal 3D printer can be provided.

[0205] Furthermore, according to the storage vault 1 and the storage method of the present embodiment, since the raw material powder can be stored in an optimal atmosphere, the quality of the raw material powder used in the metal 3D printer can be maintained, which helps maintain the performance of the molded product.

[0206] According to the storage vault 1 and the storage method of this embodiment, since the raw material powder can be stored in an optimal atmosphere, oxidation of the raw material powder can be suppressed. Thus, the amount of discarded raw material powder can be reduced. In addition, according to the storage vault 1 and the storage method of this embodiment, the hygroscopic raw material powder can be dried by storing it in the storage vault 1. This helps maintain the performance of the molded product produced by the metal 3D printer.

[0207] According to the storage vault 1 and the storage method of this embodiment, since the supply amount of the purge gas can be optimized by controlling the flow rate of the purge gas, the amount of purge gas used can be reduced. In addition, since the purge gas using air as the raw material is used, an inert gas supply source such as nitrogen or argon is not required, thereby reducing the running cost when storing the raw material powder.

[0208] In addition, the technical scope of the present invention is not limited to the above-mentioned embodiment, and various changes can be made without departing from the scope of the present invention. For example, according to the storage tank 1 of the above-mentioned embodiment, the structure in which the opening and closing valves 5 and 7 are respectively provided on the primary side and the secondary side of the oxygen and moisture removal device 6 is described as an example, but it is not limited to this. For example, Figure 4 As shown, the storage tank 21 may be configured such that the discharge path L4 branches off from the branch point R of the purge gas supply path L1 on the secondary side of the oxygen moisture removal device 6 and the primary side of the on-off valve 7 .

[0209] In the case of the storage vault 1 of the above embodiment, when the purge gas supply is stopped in the above step S4, the gas flows out from the exhaust path (not shown) for exhausting the gas containing a large amount of oxygen and moisture from the oxygen and moisture removal device 6 (gas membrane module), so the pressure in the oxygen and moisture removal device 6 decreases, and there is a case where the atmosphere is drawn into the oxygen and moisture removal device 6. As a result, when the purge gas supply is restarted, the purge gas with a high oxygen concentration may be supplied to the storage vault 21.

[0210] according to Figure 4 The storage reservoir 21 shown in the figure has a discharge path L4 having an on-off valve 14 on the secondary side of the oxygen-water removal device 6. Therefore, when the purge gas supply is stopped in the above step S4, the on-off valve 7 can be closed and the on-off valve 14 can be set to an open state. Thus, in order to suppress the air from being drawn into the oxygen-water removal device 6, the purge gas derived from the oxygen-water removal device 6 can be discharged from the discharge path L4 for a predetermined period of time and purged. Therefore, according to the storage reservoir 21, when the purge gas supply is restarted, only the clean purge gas can be supplied to the storage reservoir 21.

[0211] In addition, in the storage room 1 of the above-mentioned embodiment, the heater 3 is provided as a mechanism for heating the enclosed space 2A in the housing 2, and the structure in which the purge gas is supplied while being blown onto the surface of the heater 3 is described as an example, but the present invention is not limited thereto. For example, a heater for heating the purge gas may be provided on the purge gas supply path L1. In addition, a structure in which the enclosed space 2A in the housing 2 is heated by supplying a high-temperature purge gas and the enclosed space 2A is kept warm by the heater 3 may also be provided.

[0212] In addition, in the storage warehouse 1 of the present embodiment, the case where clean dry air (CDA) is used as the raw air of the purge gas is described as an example, but the present invention is not limited to this. For example, in the case where there is no clean dry air supply equipment in the installation environment of the storage warehouse 1, an air compressor for compressing the raw air and supplying it, a filter for removing particles in the air, and a moisture removal device for removing moisture in the air may be provided on the purge gas supply path L1.

[0213] In addition, in the storage warehouse 1 of the present embodiment, a structure in which an oxygen-water removal device 6 is provided on the purge gas supply path L1 as a purge gas generating device is described as an example, but the present invention is not limited thereto. For example, the purge gas supply path L1 may be branched into two or more and an oxygen-water removal device 6 may be provided on each of the branched paths. By providing a plurality of oxygen-water removal devices 6 in parallel in this manner, when the function of the oxygen-water removal device 6 in use decreases, the storage warehouse 1 may be continuously operated by switching to a reserved oxygen-water removal device 6.

[0214] In addition, in the storage vault 1 of the present embodiment, the bypass path L3 capable of supplying raw material air as a part of the purge gas to the closed space 2A of the storage vault 1 is described as an example, but the present invention is not limited to this. For example, the bypass path L3 may be directly connected to the closed space 2A of the storage vault 1 without merging with the purge gas supply path L1 after branching from the purge gas supply path L1. Furthermore, the bypass path L3 may not be branched from the purge gas supply path L1 but may be a path parallel to the purge gas supply path L1 from the beginning.

[0215] In the storage warehouse 1 of the present embodiment, the oxygen concentration meter 9 and the water concentration meter 10 are located on the exhaust path L2 as an example, but the present invention is not limited thereto. The oxygen concentration meter 9 and the water concentration meter 10 may be located in the closed space 2A of the storage warehouse 1.

[0216] In the storage 1 of the present embodiment, the function of transmitting and receiving measured values ​​and control signals is concentrated in the control device 13 as an example, but the function may be divided into two or more elements or positions.

[0217] Furthermore, in the storage warehouse 1 of the present embodiment, when the heater 3, the on-off valve 5, the on-off valve 7, the flow regulator 8, the on-off valve 11 and the flow regulator 12 have the function of directly sending and receiving signals between them and the temperature measuring meter 4, the oxygen concentration measuring meter 9 and the moisture concentration measuring meter 10, the structure can also be constructed to omit the control device 13.

[0218] Description of Reference Numerals

[0219] 1 Storage warehouse for raw material powder for metal 3D printer (storage warehouse)

[0220] 2 Shell (main body of storage room)

[0221] 2A Confined Space

[0222] 3 Heater

[0223] 4 Temperature measuring instrument

[0224] 5. On-off valve (first on-off valve)

[0225] 6 Oxygen and moisture removal device

[0226] 7 On-off valve (third on-off valve)

[0227] 8 Flow regulator (first flow regulator)

[0228] 9 Oxygen concentration measuring instrument

[0229] 10 Moisture concentration measuring instrument

[0230] 11 On-off valve (second on-off valve)

[0231] 12 Flow regulator (second flow regulator)

[0232] L1 Purge gas supply path

[0233] L2 exhaust path

[0234] L3 bypass path

[0235] L4 discharge path

[0236] S Storage Container

Claims

1. A storage room for raw material powder for metal 3D printer, comprising: A storage vault body, having a closed space inside the storage vault body, and capable of placing one or more storage containers in the closed space, the storage containers being used to contain raw material powder for a metal 3D printer; a purge gas supply path for supplying a purge gas made of air to the enclosed space; and The oxygen and moisture removal device is located on the purge gas supply path and is used to remove oxygen and moisture from the air.

2. The storage of raw material powder for metal 3D printer according to claim 1, wherein: The oxygen and moisture removal device is a gas diaphragm or a filling cylinder filled with a gas adsorbent.

3. The storage tank for raw material powder for metal 3D printer according to claim 1 further comprises: a first on-off valve located on the primary side of the oxygen and moisture removal device in the purge gas supply path; a first flow regulator located on the secondary side of the oxygen and moisture removal device in the purge gas supply path; a bypass path branched from the purge gas supply path on the primary side of the first on-off valve and merged with the purge gas supply path on the secondary side of the first flow rate regulator; a second on-off valve, located on the bypass path; a second flow regulator, located on the bypass path; An oxygen concentration measuring instrument, used to measure the oxygen concentration in the confined space; A moisture concentration measuring instrument, used to measure the moisture concentration in the enclosed space; and The control device can send and receive signals with the first on-off valve, the first flow rate regulator, the second on-off valve, the second flow rate regulator, the oxygen concentration measuring instrument, and the moisture concentration measuring instrument.

4. The storage tank for raw material powder for metal 3D printer according to claim 1, further comprising: a heater for heating the enclosed space; and The temperature measuring instrument is used to measure the temperature of the enclosed space.

5. The storage warehouse for raw material powder for metal 3D printer according to claim 4, wherein: The blow-off port of the purge gas supply path opens below the enclosed space.

6. The storage of raw material powder for metal 3D printer according to claim 3, further comprising: an exhaust path for exhausting the atmosphere gas in the enclosed space as exhaust gas to the outside of the storage tank body, At least one or both of the oxygen concentration measuring instrument and the water concentration measuring instrument are provided on the exhaust gas path.

7. The storage of raw material powder for metal 3D printer according to claim 1, further comprising: a third on-off valve located on the secondary side of the oxygen-water removal device in the purge gas supply path; and The exhaust path branches from the purge gas supply path on the secondary side of the oxygen moisture removal device and on the primary side of the third on-off valve.

8. A method for storing raw material powder for a metal 3D printer, wherein: One or more storage containers are placed in the closed space, and the storage containers are used to contain raw material powder for the metal 3D printer. A purge gas made of air and obtained by removing oxygen and moisture from the air is supplied to the closed space.

9. The method for storing raw material powder for a metal 3D printer according to claim 8, wherein: After the moisture concentration and the oxygen concentration in the enclosed space are lower than desired threshold values, the supply of the purge gas is stopped.

10. The method for storing raw material powder for a metal 3D printer according to claim 9, wherein: After the supply of the purge gas is stopped, the purge gas is supplied into the closed space every time a required time elapses, and the moisture concentration and the oxygen concentration of the closed space are measured.

11. The method for storing raw material powder for a metal 3D printer according to claim 10, wherein: When at least one of the moisture concentration and the oxygen concentration in the closed space exceeds a threshold value, supply of the purge gas is restarted.

12. The method for storing raw material powder for a metal 3D printer according to any one of claims 8 to 11, wherein: The temperature of the enclosed space is set to a desired temperature.

13. The method for storing raw material powder for a metal 3D printer according to any one of claims 8 to 11, wherein: The oxygen concentration in the enclosed space is maintained below 3% by volume, The dew point temperature of the enclosed space is maintained below -40°C.

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