Method and apparatus for treating soot

Abstract

This invention belongs to the field of additive manufacturing and relates to a method and equipment for treating fume. The method involves passing the metal fume to be treated through an inert compound in a low-oxygen or oxygen-free environment for physical bonding. This promotes contact between the inert compound and the metal particles in the fume, forming a physically bonded mixture, thereby reducing the concentration of metal particles in the fume. The metal fume originates from the additive manufacturing process. This invention provides a fume treatment method and equipment that is highly safe, easy to operate, and improves forming efficiency.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing and relates to a method and equipment for treating dust, particularly a method and equipment for treating dust generated during metal additive manufacturing. Background Technology

[0002] In the process of metal additive manufacturing, metal fumes containing metal powder particles and / or metal condensates (black slag) generated during the process are often produced. These fumes have a very low minimum ignition energy and are highly flammable. Therefore, special dust removal equipment is required to remove, collect, transfer, or store the dust in a safe environment.

[0003] Conventional dust removal methods primarily utilize an inert gas atmosphere to prevent dust from reacting with oxygen, thus preventing combustion by isolating the air. However, this type of dust removal device presents challenges in maintenance, including difficulties and hazards. Additionally, some dust removal methods work by simply filtering metal fumes to separate metal powder particles and / or metal condensates (black slag) generated during the process from the gas. However, this method is prone to incomplete separation and low separation efficiency.

[0004] In addition, there is a dust removal method that uses liquid passivation, which involves filling the dust collection bin / filter box with liquid such as water for passivation before proceeding with other maintenance steps. However, this method requires a lot of manpower and material resources and is not suitable for aluminum / aluminum alloy powder. Alternatively, natural incineration is also a common method, which involves placing the dust collection bin / filter box in a safe area and allowing it to react fully with oxygen to generate low-activity oxide dust. However, this method is highly dangerous, requires specific site conditions, is environmentally unfriendly, and results in the filter / dust collection bin being unusable or having a reduced lifespan. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems in the background art, the present invention provides a dust treatment method and equipment that is safe, easy to operate and can improve forming efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for treating fume, characterized in that: the fume treatment method involves passing the metal fume to be treated into an inert compound in a low-oxygen or oxygen-free environment for physical bonding, thereby promoting contact between the inert compound and the metal particles of the fume and forming a physically bonded mixture, thereby reducing the concentration of metal particles in the fume; the metal fume originates from an additive manufacturing process.

[0008] The specific implementation method of the above-mentioned fume treatment method is as follows: the metal fume to be treated is continuously introduced into the inert material in a low-oxygen or oxygen-free environment to increase the probability of contact between the metal fume to be treated and the inert material, so as to promote the full physical combination of the metal particles of the metal fume to be treated and the inert material to form a physically combined mixture, thereby reducing the concentration of metal particles in the metal fume.

[0009] The above-mentioned methods to increase the probability of contact between the metal fumes to be treated and the inerting agent are any one or a combination of the following methods:

[0010] Method 1: The metal fumes to be treated directly impact the inert material with short-distance impact, which promotes the dispersion of the inert material and increases the probability of contact between the metal fumes to be treated and the inert material;

[0011] Method 2: The metal fumes to be treated are guided to directly impact the inert material, promoting the dispersion of the inert material and increasing the probability of contact between the metal fumes and the inert material; preferably, the guide is a guide plate and / or a guide duct;

[0012] Method 3: The metal fumes to be treated are directly introduced into the inert compound, impacting the inert compound and causing it to disperse, increasing the probability of contact between the metal fumes to be treated and the inert compound;

[0013] Method 4: The metal fumes to be treated are directly introduced into the inertite, and the inertite is dispersed by a fluidized bed formed by the air distribution equipment, which increases the probability of contact between the metal fumes to be treated and the inertite;

[0014] Method 5: A fluidized bed is formed by introducing airflow to disperse the inert material, increasing the probability of contact between the metal fumes and the inert material; preferably, the introduced airflow is a clean inert airflow or purified dust gas; preferably, the direction of the introduced airflow is not the same as the direction of the metal fumes.

[0015] The above-mentioned dust treatment method further includes a step of filtering the physically bound mixture; preferably, the filtering method is filtration and / or cyclone separation.

[0016] The above-mentioned fume treatment method further includes a physical separation step; the physical separation step is a step of physically separating the metal fumes to be treated before physical bonding and / or a step of physically separating the metal fumes whose metal particle concentration has been reduced after filtering the physically bonded mixture; the physical separation method is filtration and / or cyclone separation; preferably, the filtration is a filter element and / or a filter screen; the cyclone separation is cyclone separation and / or a mechanical labyrinth; the inerting agent is calcium carbonate powder.

[0017] A fume treatment device for implementing the fume treatment method described above is characterized in that: the fume treatment device includes at least a physical bonding device capable of physically bonding with the metal particles of the metal fume to be treated; the physical bonding device includes a reaction chamber loaded with inert material; the interior of the reaction chamber is in a low-oxygen or oxygen-free environment; the reaction chamber is provided with a fume inlet and an exhaust outlet, as well as a feed inlet and a slag discharge outlet, which communicate with the reaction chamber; the metal fume to be treated enters the reaction chamber through the fume inlet and directly impacts or is introduced into the inert material to physically bond with the inert material; the purified metal fume is discharged through the exhaust outlet.

[0018] The aforementioned physical bonding device also includes a dispersion device placed inside the reaction chamber; the dispersion device is an air guiding device, an air distribution device, and / or an aeration device; the metal fume to be treated enters the reaction chamber through the fume inlet and then undergoes physical bonding with the inert material through the dispersion device.

[0019] When the above-mentioned dust dispersion device is an air-guided device, the air-guided device is placed on the inner wall of the reaction chamber and extends towards the surface of the inert material; the metal dust to be treated enters the reaction chamber through the dust inlet and is guided by the air-guided device to impact and disperse the inert material, and the inert material is physically bonded to the inert material; preferably, the air-guided device is a guide plate and / or a guide duct;

[0020] When the dust dispersion device is an air distribution device, the air distribution device is installed in the reaction chamber, and the inert material is placed on the upper part of the air distribution device; the metal dust to be treated enters the reaction chamber through the dust inlet, is diverted by the air distribution device, and then impacts or is introduced into the inert material to form a fluidized bed and physically combine with the inert material; preferably, the air distribution device is an air distribution plate, and the air distribution plate is provided with air distribution holes penetrating the air distribution plate; preferably, there are multiple air distribution holes, which are evenly or non-evenly distributed on the air distribution plate; preferably, when the air distribution holes are non-evenly distributed on the air distribution plate, the density of air distribution holes at the center of the air distribution plate is greater than the density of air distribution holes at the non-center of the air distribution plate;

[0021] When the dust dispersion device is an aeration device, the aeration device includes an aeration pipe and a fan connected to the aeration pipe; the aeration pipe extends into the reaction chamber; the fan blows clean inert gas or purified dust gas through the aeration pipe to form an impact airflow; the impact airflow enters the inert material to form a fluidized bed; the metal dust to be treated enters the reaction chamber through the dust inlet and then physically combines with the inert material in the fluidized bed; preferably, the direction of the impact airflow is not the same as the direction of the metal dust to be treated entering the reaction chamber through the dust inlet; or, the metal dust to be treated directly impacts the inert material through the fan and the aeration pipe to form a fluidized bed and physically combines with the inert material.

[0022] The aforementioned physical bonding device also includes a filtration device placed inside the reaction chamber, through which the mixture generated after the metal fumes to be treated physically bond with the inert substance is intercepted; the purified metal fumes are discharged through the filtration device and the exhaust port; preferably, the filtration device is a filter screen, a filter element and / or a cyclone separator.

[0023] The reaction chamber described above is either an integral structure or a split structure; when the reaction chamber is a split structure, the reaction chamber includes a fixing component and a detachable component movably connected to the fixing component; the filtration device is placed in the fixing component.

[0024] The aforementioned dust treatment equipment also includes a physical separation device connected to the physical combination device; the physical separation device is a front-end separation device and / or a back-end separation device.

[0025] Preferably, when the physical separation device is a front-end separation device, the metal fumes to be treated are physically separated by the front-end separation device and then injected into the physical bonding device; when the physical separation device is a back-end separation device, the purified metal fumes discharged from the physical bonding device are injected into the back-end separation device for physical separation; when the physical separation device consists of both a front-end separation device and a back-end separation device, the metal fumes to be treated are initially physically separated by the front-end separation device and then injected into the physical bonding device, and the purified metal fumes discharged from the physical bonding device are injected into the back-end separation device for final physical separation.

[0026] The aforementioned physical separation equipment includes filter elements, filter screens, cyclone separators, and / or mechanical labyrinths.

[0027] The advantages of this invention are:

[0028] This invention provides a method and apparatus for treating fume extraction. The method involves passing the metal fume to be treated into an inert compound in a low-oxygen or oxygen-free environment for physical bonding. This promotes contact between the inert compound and the metal particles in the fume, forming a physically bonded mixture, thereby reducing the concentration of metal particles in the fume. The metal fume originates from additive manufacturing processes. This invention directly replaces the existing method of attaching inert compounds to the filter surface and frequent backflushing with directly passing the metal fume to be treated into the inert compound, especially continuously. This increases the contact probability between the metal fume and the inert compound, allowing for thorough bonding and avoiding downtime caused by insufficient inert compound or frequent backflushing. This directly improves fume treatment efficiency, enhances part printing quality, and increases printing efficiency. Simultaneously, the thorough bonding between the metal fume and the inert compound significantly reduces the reactivity of the metal fume, making the resulting mixture of metal fume and inert compound less flammable in air, thus increasing safety. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the dust treatment equipment (top-blown type) provided by the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the dust treatment equipment (top-guided type) provided by the present invention;

[0031] Figure 3 This is a schematic diagram of the structure of the dust treatment equipment (bottom-blown type) provided by the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the dust treatment equipment (top-supply and diversion type) provided by the present invention;

[0033] Figure 5 This is a top view of the air distribution plate used in this invention.

[0034] Figure 6 This is a schematic diagram of the structure of the dust treatment equipment (clean airflow aeration type) provided by the present invention;

[0035] Figure 7 This is a schematic diagram of the structure of the dust treatment equipment (purified airflow aeration type) provided by the present invention;

[0036] Figure 8 This is a schematic diagram of the structure of the dust treatment equipment (preferred embodiment) provided by the present invention;

[0037] Figure 9 This is a schematic diagram of a preferred structure of the dust treatment equipment provided by the present invention;

[0038] Figure 10 This is a structural schematic diagram of the dust treatment equipment (simple top-supply type) provided by the present invention;

[0039] in:

[0040] 1-Reaction chamber; 2-Inerting agent; 3-Fume inlet; 4-Exhaust outlet; 5-Filtration equipment; 6-Feeding port; 7-Slag discharge port; 8-Second differential pressure gauge; 9-First differential pressure gauge; 10-Slag discharge valve; 11-Slag collection bucket; 12-Guide plate; 13-Air distribution plate; 14-Air distribution hole; 15-Aeration pipe; 16-Fan; 17-External fan; 18-Forming chamber; 19-Cyclone separator; 20-Filter cartridge box; 21-Separation filter cartridge. Detailed Implementation

[0041] This invention provides a method for treating fume extraction. The method involves introducing the metal fume to be treated into an inert compound in a low-oxygen or oxygen-free environment for physical bonding. This promotes contact between the inert compound and the metal particles in the fume, forming a physically bonded mixture, thereby reducing the concentration of metal particles in the fume. The metal fume originates from additive manufacturing processes. This invention directly replaces the existing method of attaching inert compounds to the filter surface and frequent backflushing with a method that continuously introduces the metal fume to be treated into the inert compound. In particular, continuous introduction increases the probability of contact between the metal fume and the inert compound, ensuring thorough bonding and avoiding downtime caused by insufficient inert compound or frequent backflushing. This directly improves fume treatment efficiency, enhances part printing quality, and increases printing efficiency.

[0042] Specifically, the way to increase the probability of contact between the metal fume to be treated and the inert compound is any one or a combination of the methods described below. Regardless of the method or combination, the purpose is to promote the full combination of the metal fume to be treated and the inert compound, thereby improving the fume treatment effect.

[0043] Method 1: The metal fumes to be treated are directly impacted by short-distance impact on the inert material. For example, see [link to example]. Figure 10 The metal fumes to be treated are directly introduced into the reaction chamber 1 from the waist or below and directly impact the inert material 2 inside the reaction chamber 1, especially the upper surface of the inert material 2. This method can reduce the running distance of the metal fumes to be treated in the reaction chamber 1, directly promote the dispersion of the inert material 2, and increase the probability of contact between the metal fumes to be treated and the inert material.

[0044] Method 2: The metal fumes to be treated are guided to directly impact the inert material. For example, see [link to example]. Figure 2 The metal fumes to be treated can be introduced into the reaction chamber 1 from the top or above the waist through the air guide plate and / or air guide pipe, and directly impact the inert material 2 inside the reaction chamber 1, especially the upper surface of the inert material 2. Similarly, this method can reduce the running distance of the metal fumes to be treated in the reaction chamber 1, directly promote the dispersion of the inert material 2, and increase the probability of contact between the metal fumes to be treated and the inert material.

[0045] Method 3: The metal fumes to be treated are directly introduced into the inert compound. For example, see [link to example]. Figure 1 The metal fumes to be treated are introduced into the reaction chamber 1 from the side and directly into the inert material 2 inside the reaction chamber 1. This causes the inert material 2 to move under the impact of the metal fumes to be treated, directly causing the inert material 2 to disperse and increasing the probability of contact between the metal fumes to be treated and the inert material.

[0046] Method 4: The metal fumes to be treated are directly introduced into the inert compound, and a fluidized bed is formed by the air distribution equipment to disperse the inert compound, increasing the probability of contact between the metal fumes and the inert compound; for example, see Figure 3 The metal fumes to be treated are introduced into the reaction chamber 1 from the bottom. As the metal fumes rise, they are dispersed by multiple airflows formed by the air distribution device, impacting and dispersing the inert material 2, thus forming a fluidized bed and increasing the probability of contact between the metal fumes and the inert material. For example, see also... Figure 4 The metal fumes to be treated are introduced into the reaction chamber 1 from the side and extend directly to and through the air distribution device at the bottom of the inertite 2. After rebounding through the cavity at the bottom of the reaction chamber 1, the metal fumes to be treated rise continuously and form multiple airflows through the air distribution device. These airflows then impact and disperse the inertite 2, thereby forming a fluidized bed and increasing the probability of contact between the metal fumes to be treated and the inertite.

[0047] Method 5: A fluidized bed is formed by introducing airflow to disperse the inert material, increasing the probability of contact between the metal fumes and the inert material; preferably, the introduced airflow is a clean inert airflow (exemplary, such as...). Figure 6 (as shown) or purified dust (exemplary, such as...) Figure 7 (as shown); Preferably, the direction of the introduced airflow is not the same as the direction of the metal fume flow. In this case, the introduced airflow collides with the metal fume to be treated, accelerating the dispersion of the inert material.

[0048] After the metal fumes to be treated are thoroughly mixed with the inerting agent, a physically bonded mixture is formed. At this time, the fume treatment method provided by the present invention further includes a step of filtering the physically bonded mixture. For example, the filtering method can be filtration and / or cyclone separation.

[0049] The fume treatment method provided by this invention, based on the aforementioned physical bonding, further includes a physical separation step; the physical separation step is a step of physically separating the metal fume to be treated before physical bonding and / or a step of physically separating the metal fume with reduced metal particle concentration after filtering the physically bonded mixture; the physical separation method is filtration and / or cyclone separation; preferably, filtration is a filter element and / or filter screen; cyclone separation is cyclone separation and / or mechanical labyrinth; the inerting agent 2 includes, but is not limited to, calcium carbonate powder, and can be other powders, as long as they can be mixed with the metal particles of the metal fume and reduce safety hazards, they are all objects selected by this invention.

[0050] To achieve the aforementioned method, the present invention provides a dust treatment device for implementing the dust treatment method, see [link to relevant documentation]. Figure 1The fume treatment equipment includes at least a physical bonding device capable of physically bonding with the metal particles of the metal fume to be treated. The overall structure is an upward-blowing type. The physical bonding device includes a reaction chamber 1 containing inert material 2. The reaction chamber 1 is located in a low-oxygen or oxygen-free environment. The reaction chamber 1 is equipped with a fume inlet 3 and an exhaust outlet 4 that communicate with it. The metal fume to be treated enters the reaction chamber 1 through the fume inlet 3 and directly impacts or is introduced into the inert material 2 to physically bond with it. The purified metal fume is then discharged through the exhaust outlet 4. In use, the fume treatment equipment provided by this invention fills the reaction chamber 1 with an excess or sufficient amount of inert material 2. When the metal fume to be treated enters the reaction chamber 1 through the fume inlet 3, it can fully mix with the inert material 2 in the reaction chamber 1, forming a physically bonded mixture. Under the action of gravity, the physically bonded mixture gradually sinks and accumulates at the bottom of the reaction chamber 1. The purified metal fume is then discharged through the exhaust outlet 4 or recycled. Please continue to see... Figure 1 The physical bonding device also includes a first differential pressure gauge 9 for monitoring the pressure difference between the slag-gas mixture inlet pipe and the gas outlet pipe, and a second differential pressure gauge 8 for monitoring the pressure difference between the treatment zone and the treated zone. The second differential pressure gauge 8 detects the pressure difference across the filter element. When this pressure difference is too large, the filter element needs to be cleaned by air blowing, ultrasound, vibration motor, or mechanical vibration. The first differential pressure gauge 9 monitors the pressure difference between the slag-gas mixture inlet pipe and the gas outlet pipe, and controls the fan speed to ensure minimal pressure changes at the inlet and outlet of the dust removal device, thus achieving a stable flow field in the forming chamber. For example, the shape of the reaction chamber 1 is not limited; it can be square or circular, and may or may not have internal baffles. It should be noted that the metal fumes to be treated flow using an inert gas carrier, powered by a fan or air pump.

[0051] In order to fully mix the metal fumes to be treated with the inert material 2 in the reaction chamber 1, the physical bonding device provided by the present invention also includes a dispersion device placed inside the reaction chamber 1; the dispersion device is a wind guide device, a wind distribution device and / or an aeration device; the metal fumes to be treated enter the reaction chamber 1 through the fumes inlet 3 and then physically bond with the inert material 2 through the dispersion device.

[0052] When the fume dispersion device is an air-guided device, the air-guided device is placed on the inner wall of the reaction chamber 1 and extends towards the surface of the inert material 2; the metal fume to be treated enters the reaction chamber 1 through the fume inlet 3 and is guided by the air-guided device to the inert material 2, impacting and dispersing it to physically bond with the inert material 2; preferably, the air-guided device is a guide plate 12 and / or a guide duct. For example, when the air-guided device uses a guide plate 12 (the setting and working principle of the guide duct and guide plate 12 are the same, and will not be described again), see [link to relevant documentation]. Figure 2The overall structure is an upper-guided airflow design. A baffle plate 12 is placed on the inner wall of the reaction chamber 1 and extends towards the surface of the inert material 2. The metal fumes to be treated are introduced into the reaction chamber 1 from the top or near the top, and after passing through the fume inlet 3, are guided by the baffle plate 12 to the inert material 2, where they physically combine with it. The baffle plate 12 can be multiple parallel plate-like structures, parallel tubular structures, or flared openings with a flared bottom. Multiple baffle plates 12 divert the metal fumes to be treated, thus creating a dispersed state. The flared opening also encourages the metal fumes to extend outwards, creating a dispersed state, which in turn impacts the inert material 2 and further disperses it, increasing the probability of contact between the metal fumes and the inert material.

[0053] When the dust dispersion device is an air distribution device, the air distribution device is installed in the reaction chamber 1, and the inerting material 2 is placed on the upper part of the air distribution device; the metal dust to be treated enters the reaction chamber 1 through the dust inlet 3, is divided by the air distribution device, and then impacts or is introduced into the inerting material 2, forming a fluidized bed and physically bonding with the inerting material 2. When the air distribution device is an air distribution plate 13, see, for example. Figure 3 (The overall structure features bottom-ventilated design) and Figure 4 (The overall structure is an upper-supply, diverting airflow design). The air distribution plate 13 is laid flat in the reaction chamber 1, and the inerting agent 2 is placed on top of the air distribution plate 13. The air distribution plate 13 has air distribution holes 14 that penetrate it. The metal fumes to be treated enter the reaction chamber 1 through the fume inlet 3, are diverted by the air distribution holes 14, and then impact or pass into the inerting agent 2, where they physically combine with the inerting agent 2. See also... Figure 3 The metal fumes to be treated flow into the reaction chamber 1 from the bottom. As the fumes rise, they are blocked and dispersed by the air distribution plate 13 within the reaction chamber 1, and then react fully with the inert material 2 on the air distribution plate 13. See also Figure 4 The metal fumes to be treated are introduced into the inert material 2 through the side wall of the reaction chamber 1, first penetrating the air distribution plate 13. The metal fumes then flow back from the bottom of the reaction chamber 1 and rise to the air distribution plate 13. After being blocked and diverted by the air distribution plate 13, they form a dispersed state and then fully react with the inert material 2 on the air distribution plate 13. For example, in order to fully disperse the metal fumes to be treated, the present invention uses multiple air distribution holes 14, which are evenly or non-evenly distributed on the air distribution plate 13. See [link to other documentation] Figure 5 As a preferred implementation, when the air distribution holes 14 are arranged non-uniformly on the air distribution plate 13, the density of the air distribution holes 14 located at the center of the air distribution plate 13 is greater than the density of the air distribution holes 14 located at the non-center position of the air distribution plate 13. Preferably, the air distribution holes 14 are eccentrically distributed, thereby causing the inerting material 2 to flow periodically.

[0054] For example, the air distribution plate 13 is preferably a perforated plate, used to evenly distribute the incoming metal fumes to be treated at the bottom of the inertite 2 for uniform fluidization. The structure of the air distribution plate 13 is not limited; it can also be an array of elongated openings or a pipe with an internal flow channel, as long as it can control the airflow direction and divert the flow. The air distribution holes 14 on the air distribution plate 13 can also be asymmetrical, so that the air acting on the bottom of the inertite 2 is appropriately deflected to one side, so as to generate swirling flow in the inertite 2, causing the inertite and additives to flow periodically, thereby improving the uniformity of fume mixing. The air distribution plate 13 can also be used with a filter screen, i.e., a filter screen is superimposed on the upper / lower side of the air distribution plate 13 to prevent the inertite from falling below the air distribution plate 13, thereby reducing the airflow pressure drop and making the fluidization effect more uniform. For example, in addition to the inerting material 2, auxiliary filter additives and auxiliary filter element cleaning additives, such as plastic filter media and lightweight coarse particles, can also be added to the air distribution plate 13 to improve the adsorption capacity of the metal fumes to be treated, and to a certain extent clean the filter element by means of friction from the additives. Obviously, the present invention lays the inerting material 2 on the air distribution plate 13 to form a fluidized bed, thereby achieving the purpose of real-time inerting.

[0055] When the dust dispersion device is an aeration device, the aeration device includes an aeration pipe 15 and a blower 16 connected to the aeration pipe 15; the aeration pipe 15 extends into the reaction chamber 1; the blower 16 delivers a clean, inert airflow (such as...) Figure 6 As shown, the overall structure is a clean airflow aeration type) or purified dust gas (such as... Figure 7 As shown, the overall structure is a purified airflow aeration type. An impact airflow is formed through the aeration pipe 15; the impact airflow enters the inertite 2, forming a fluidized bed; the metal dust to be treated enters the reaction chamber 1 through the dust inlet 3 and physically combines with the inertite 2 in the fluidized bed. Preferably, to fully disperse the inertite 2, the direction of the impact airflow is not the same as the direction of the metal dust to be treated entering the reaction chamber 1 through the dust inlet 3; or, the metal dust to be treated directly impacts the inertite 2 through the fan 16 and aeration pipe 15, forming a fluidized bed and physically combining with the inertite 2. Alternatively, the metal dust to be treated directly impacts the inertite 2 through the fan 16 and aeration pipe 15, forming a dispersed state and simultaneously physically combining with the dispersed inertite 2. This method can omit the clean airflow or other auxiliary methods. For example, using... Figure 6 Taking the structure shown as an example, a wind distribution plate 13 is also provided inside the reaction chamber 1 (the structure is as described above and will not be repeated here). The fan 16 will form an impact airflow by passing the clean inert gas flow or the purified dust gas through the aeration pipe 15. After the impact airflow is blocked and diverted by the wind distribution plate 13, it will form a dispersed state, which can accelerate the dispersion of the inert material 2 on the wind distribution plate 13, making it a fluidized bed, and further increasing the probability of contact between the metal dust to be treated and the inert material.

[0056] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 as well as Figure 7 The physical bonding device provided by this invention also includes a filter device 5 placed inside the reaction chamber 1. The mixture generated after the metal fumes to be treated and the inerting agent 2 physically bond is intercepted by the filter device 5; the purified metal fumes are discharged through the filter device 5 and the exhaust port 4. For example, the filter device 5 can be a filter screen, filter element and / or cyclone separator, but regardless of the structure, any conventional or non-standard device that can separate the airflow and the mixture generated after physical bonding can be selected.

[0057] by Figure 2 Taking the structure shown as an example, the working method of the physical bonding device provided by the present invention will be described as follows: See Figure 2 Inertite 2 is pre-stored in reaction chamber 1. Before physical bonding, the circulating air is activated. The circulating air enters from the dust inlet 3 at a lower speed than during operation, is guided by the guide plate 12, and blown along the inner wall of reaction chamber 1 towards inertite 2. The inertite 2 is then rolled up (blown away) and blown towards the filter device 5. After a layer of inertite 2 covers the filter device 5, operation begins. That is, the metal dust to be treated is introduced into reaction chamber 1 through dust inlet 3 and guided by the guide plate 12. The metal dust to be treated, together with the inertite 2 inside reaction chamber 1, is blown onto the filter device 5. Under certain conditions (the filter device 5 is saturated, or the reaction chamber 1 is filled with inertite 2), the process continues. Once the inertium 2 is completely blown away, or the inertium 2 in the reaction chamber 1 has been completely blown away for a period of time, and a layer of pure dust adheres to the filter device 5, but the dust is not enough to penetrate deep into the filter device 5, the metal dust to be treated is stopped from entering through the dust inlet 3, and the filter device 5 is cleaned (the filter device 5 is back-blown, that is, a strong airflow is used to back-blown the filter device 5 to make the adhering material on the filter device 5 fall off, or other means such as mechanical scraping, mechanical vibration, etc. can be used), so that the mixture formed by the inertium 2 on the filter device 5 and the metal particles in the metal dust to be treated falls back into the reaction chamber 1. After the mixture formed by the inertite 2 on the filter device 5 and the metal particles in the metal fume to be treated is cleaned back into the reaction chamber 1, the metal fume to be treated is reintroduced through the fume inlet 3, and the aforementioned process is repeated until the inertite 2 is fully utilized or completely combined with the metal particles in the metal fume to be treated. Then, the mixture formed by the inertite 2 and the metal particles in the metal fume to be treated is removed, and new pure inertite 2 is added to start a new round of purification work for the metal fume to be treated.

[0058] by Figure 3 , Figure 4 as well as Figure 5 Taking the structure shown as an example, the working method of the physical bonding device provided by the present invention will be described as follows: See Figure 3 , Figure 4 as well as Figure 5 Inertite 2 is added into reaction chamber 1. Preferably, additional additives may also be added to inertite 2. Before physical bonding, the circulating air is started with a speed higher than the working speed. The circulating air enters through the dust inlet 3 and uses the high speed to blow inertite 2 onto the surface of filter equipment 5 or to disperse inertite 2, so that the surface of filter equipment 5 is covered with a layer of inertite to protect filter equipment 5. After a layer of inertite covers filter equipment 5, the filter equipment is started. The metal dust to be treated continuously passes through inertite 2. At this time, most of the metal particles in the metal dust are adsorbed and left by the dispersed inertite 2. Some metal dust and the rolled-up or dispersed inertite 2 are blown onto filter equipment 5 and adhere to filter equipment 5. Once certain conditions are met (the filter device 5 is saturated, or the inerting agent 2 in the reaction chamber 1 has been completely blown away for a period of time, and a layer of pure dust adheres to the filter device 5, but the dust is not yet deep enough to penetrate the filter device 5), the metal dust to be treated is stopped from entering the dust inlet 3, and the filter device 5 is cleaned (for example, the filter device 5 is backflushed, that is, a strong airflow is used to blow the filter device 5 in the opposite direction to make the adhering material on the filter device 5 fall off; other methods such as mechanical scraping or mechanical vibration can also be used), the inerting agent 2 on the filter device 5 mixes with the metal particles in the metal dust and falls back to the bottom of the reaction chamber 1. It should be noted that the cleaning of the filter device 5 will not interrupt the purification process of the metal dust, avoiding problems such as machine shutdown caused by insufficient inerting agent or frequent backflushing, and can directly improve the dust treatment efficiency, improve the printing quality of parts and printing efficiency. After the mixture formed by the inerting agent 2 on the filter device 5 and the metal particles in the fumes to be treated is cleaned back into the reaction chamber 1, the fumes to be treated are reintroduced through the fume inlet 3, and the aforementioned process is repeated until the inerting agent 2 is fully utilized or completely combined with the metal particles in the fumes to be treated. Then, the mixture formed by the inerting agent 2 and the metal particles in the fumes to be treated is removed, and new pure inerting agent 2 is introduced to start a new round of fumes purification. It should be noted that if the cleaning method of the filter device 5 is mechanical scraping or other methods that do not affect the circulating air, the circulating air can continue to circulate, and mechanical scraping can be performed during continuous operation. Figure 3 as well as Figure 4 The structure shown utilizes the filtration and adsorption effects of a fluidized bed to significantly reduce the amount of dust reaching the filtration device 5, thereby reducing the burden on the filtration device 5 and extending the filter element's lifespan. The fluidized bed's mixing capacity ensures uniform mixing of dust and inert materials; it requires no additional power source or moving parts.

[0059] The reaction chamber 1 used in this invention can be a one-piece structure or a split structure. Figure 1 as well as Figure 3 Taking the structure shown as an example, when the reaction chamber 1 used in this invention is an integral structure, the reaction chamber 1 is respectively provided with a feeding port 6 and a slag discharge port 7 that communicate with the interior of the reaction chamber 1. Inert material 2 can be added to the reaction chamber 1 through the feeding port 6, and at the same time, the mixture generated after physical bonding can be discharged through the slag discharge port 7. Exemplarily, the slag discharge port 7 can also be replaced with a slag collection bucket 11 at the bottom of the reaction chamber 1. A slag discharge valve 10 is provided between the slag collection bucket 11 and the reaction chamber 1. By opening and closing the slag discharge valve 10, the mixture generated after physical bonding can be discharged into the slag collection bucket 11, and then transferred or processed. Obviously, the discharge method of the mixture generated after physical bonding is not unique. That is, it can be discharged through the slag discharge port 7; or the mixture generated after physical bonding can be collected in the slag collection bucket 11, and then the slag collection bucket 11 can be replaced as a whole.

[0060] When the reaction chamber 1 is a split structure, the reaction chamber 1 includes a fixed part and a detachable part that is movably connected to the fixed part; the filter device is placed in the fixed part. Before physical bonding, the detachable part is disassembled and an appropriate amount of inert material 2 is filled into the detachable part. When physical bonding is completed, the detachable part containing the mixture generated after physical bonding is transferred or cleaned in an oxygen-free or low-oxygen environment.

[0061] Dust treatment equipment also includes physical separation equipment connected to physical separation equipment; physical separation equipment is front-end separation equipment and / or back-end separation equipment, and physical separation equipment can be common or non-standard equipment such as filter elements, filter screens, cyclone separators and / or mechanical labyrinths.

[0062] When the physical separation device is a front-end separation device, the metal fumes to be treated are physically separated by the front-end separation device and then injected into the physical bonding device. For example, see... Figure 8 The front-end separation equipment includes a cyclone separator 19, which first physically separates the metal fumes to be treated, filtering out large particles in the metal fumes. Then, it is injected into the physical bonding equipment to physically bond with inert materials 2. The final purified metal fumes (generally only inert gas) are pumped into the forming chamber 18 by an external fan 17 for reuse.

[0063] When the physical separation device is a back-end separation device, the purified metal fumes discharged from the physical bonding device are injected into the back-end separation device for physical separation. For example, see... Figure 9The back-end separation equipment includes a filter box 20, which contains a separation filter 21. The metal fumes purified by the physical bonding equipment are then physically separated by the back-end separation equipment. The metal fumes purified by the physical bonding equipment are further purified so that they are cleaner when pumped into the forming chamber 18 by the external fan 17 for reuse.

[0064] When the physical separation equipment consists of a front-end separation unit and a back-end separation unit, the metal fumes to be treated undergo initial physical separation in the front-end separation unit and are then injected into a physical bonding unit. The purified metal fumes discharged from the physical bonding unit are then injected into the back-end separation unit for final physical separation. For example, see [link to example]. Figure 9 The metal fumes to be treated are first physically separated by the cyclone separator 19, and large particles in the metal fumes are filtered out. Then, they are injected into the physical bonding device to physically bond with the inerting agent 2. The metal fumes purified by the physical bonding device are then physically separated by the downstream separation device. The metal fumes purified by the physical bonding device are further purified so that they are even cleaner when pumped into the forming chamber 18 by the external fan 17 for reuse.

[0065] by Figure 1 For example, the dust treatment equipment provided by this invention can be used without stopping the machine. As long as there is metal dust to be treated input, the metal particles (black slag) in the metal dust to be treated can be treated in a timely and effective manner.

Claims

1. A method for treating smoke and dust, characterized in that: The fume treatment method involves passing the metal fume to be treated into an inert compound in a low-oxygen or oxygen-free environment for physical bonding, thereby promoting contact between the inert compound and the metal particles of the fume and forming a physically bonded mixture, thus reducing the concentration of metal particles in the fume; the metal fume originates from the additive manufacturing process.

2. The method for treating smoke and dust according to claim 1, characterized in that: The specific implementation of the fume treatment method is as follows: the metal fume to be treated is continuously introduced into the inert material in a low-oxygen or oxygen-free environment to increase the probability of contact between the metal fume to be treated and the inert material, so as to promote the full physical combination of the metal particles of the metal fume to be treated and the inert material to form a physically combined mixture, thereby reducing the concentration of metal particles in the metal fume.

3. The method for treating smoke and dust according to claim 2, characterized in that: The method of increasing the probability of contact between the metal fume to be treated and the inert compound is any one or a combination of the following methods: Method 1: The metal fumes to be treated directly impact the inert material with short-distance impact, which promotes the dispersion of the inert material and increases the probability of contact between the metal fumes to be treated and the inert material; Method 2: The metal fumes to be treated are guided to directly impact the inert material, promoting the dispersion of the inert material and increasing the probability of contact between the metal fumes and the inert material; preferably, the guide is a guide plate and / or a guide duct; Method 3: The metal fumes to be treated are directly introduced into the inert compound, impacting the inert compound and causing it to disperse, increasing the probability of contact between the metal fumes to be treated and the inert compound; Method 4: The metal fumes to be treated are directly introduced into the inertite, and the inertite is dispersed by a fluidized bed formed by the air distribution equipment, which increases the probability of contact between the metal fumes to be treated and the inertite; Method 5: A fluidized bed is formed by introducing airflow to disperse the inert material, increasing the probability of contact between the metal fumes and the inert material; preferably, the introduced airflow is a clean inert airflow or purified dust gas; preferably, the direction of the introduced airflow is not the same as the direction of the metal fumes.

4. The method for treating smoke and dust according to claim 1, 2, or 3, characterized in that: The dust treatment method further includes a step of filtering the physically bound mixture; preferably, the filtering method is filtration and / or cyclone separation.

5. The method for treating smoke and dust according to claim 4, characterized in that: The fume treatment method further includes a physical separation step; the physical separation step is a step of physically separating the metal fumes to be treated before physical bonding and / or a step of physically separating the metal fumes whose metal particle concentration has been reduced after filtering the physically bonded mixture; the physical separation method is filtration and / or cyclone separation; preferably, the filtration is a filter element and / or a filter screen; the cyclone separation is cyclone separation and / or a mechanical labyrinth.

6. A dust treatment apparatus for implementing the dust treatment method according to any one of claims 1-5, characterized in that: The fume treatment equipment includes at least a physical bonding device capable of physically bonding with the metal particles of the metal fume to be treated; the physical bonding device includes a reaction chamber (1) loaded with inertite (2); the reaction chamber (1) is in a low-oxygen or oxygen-free environment; the reaction chamber (1) is provided with a fume inlet (3) and an exhaust outlet (4) communicating with the reaction chamber (1), as well as a feed inlet (6) and a slag outlet (7); the metal fume to be treated enters the reaction chamber (1) through the fume inlet (3) and directly impacts or is introduced into the inertite (2) to physically bond with the inertite (2), and the purified metal fume is discharged through the exhaust outlet (4).

7. The dust treatment equipment according to claim 6, characterized in that: The physical bonding device also includes a dispersion device placed inside the reaction chamber (1); the dispersion device is a wind guide device, a wind distribution device and / or an aeration device; the metal dust to be treated enters the reaction chamber (1) through the dust inlet (3) and then undergoes physical bonding with the inerting material (2) through the dispersion device.

8. The dust treatment equipment according to claim 7, characterized in that: When the dust dispersion device is an air guiding device, the air guiding device is placed on the inner wall of the reaction chamber (1) and extends towards the surface of the inert material (2); the metal dust to be treated enters the reaction chamber (1) through the dust inlet (3) and is guided by the air guiding device to the inert material (2) to impact and disperse the inert material (2) and physically combine with the inert material (2); preferably, the air guiding device is a guide plate (12) and / or a guide pipe; When the dust dispersion device is a dust distribution device, the dust distribution device is installed in the reaction chamber (1), and the inert material (2) is placed on the upper part of the dust distribution device; the metal dust to be treated enters the reaction chamber (1) through the dust inlet (3), and after being diverted by the dust distribution device, it impacts or is introduced into the inert material (2) to form a fluidized bed and physically combine with the inert material (2); preferably, the dust distribution device is a dust distribution plate (13), and the dust distribution plate (13) The air distribution plate (13) is provided with air distribution holes (14) that penetrate through it; preferably, there are multiple air distribution holes (14), which are evenly or non-evenly distributed on the air distribution plate (13); preferably, when the air distribution holes (14) are non-evenly distributed on the air distribution plate (13), the density of the air distribution holes (14) located at the center of the air distribution plate (13) is greater than the density of the air distribution holes (14) located at the non-center of the air distribution plate (13); When the dust dispersion device is an aeration device, the aeration device includes an aeration pipe (15) and a blower (16) connected to the aeration pipe (15); the aeration pipe (15) extends into the reaction chamber (1); the blower (16) passes clean inert gas flow or purified dust gas through the aeration pipe (15) to form an impact airflow; the impact airflow enters the inert material (2) to form a fluidized bed; the metal dust to be treated enters the reaction chamber (1) through the dust inlet (3) and then physically combines with the inert material (2) in the fluidized bed; preferably, the direction of the impact airflow is not the same as the direction of the metal dust to be treated entering the reaction chamber (1) through the dust inlet (3); or, the metal dust to be treated directly impacts the inert material (2) through the blower (16) and the aeration pipe (15) to form a fluidized bed and physically combines with the inert material (2).

9. The dust treatment equipment according to any one of claims 6-8, characterized in that: The physical bonding device also includes a filter device (5) placed inside the reaction chamber (1), and the mixture generated after the metal dust to be treated and the inert compound (2) are physically bonded is intercepted by the filter device (5); The purified metal fumes are discharged through a filtration device (5) and an exhaust port (4); preferably, the filtration device (5) is a filter screen, a filter element and / or a cyclone separator.

10. The dust treatment equipment according to claim 9, characterized in that: The reaction chamber (1) is an integral structure or a split structure; when the reaction chamber (1) is a split structure, the reaction chamber (1) includes a fixing member and a detachable member movably connected to the fixing member; the filtration device is placed in the fixing member.

11. The dust treatment equipment according to claim 10, characterized in that: The dust treatment equipment also includes a physical separation device connected to the physical combination device; the physical separation device is a front-end separation device and / or a back-end separation device. Preferably, when the physical separation device is a front-end separation device, the metal fumes to be treated are physically separated by the front-end separation device and then injected into the physical bonding device; when the physical separation device is a back-end separation device, the purified metal fumes discharged from the physical bonding device are injected into the back-end separation device for physical separation; when the physical separation device consists of both a front-end separation device and a back-end separation device, the metal fumes to be treated are initially physically separated by the front-end separation device and then injected into the physical bonding device, and the purified metal fumes discharged from the physical bonding device are injected into the back-end separation device for final physical separation.

12. The dust treatment equipment according to claim 11, characterized in that: The physical separation equipment is a filter element, filter screen, cyclone separator and / or mechanical labyrinth.

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