3D metal printing explosion-proof dust removal circulation filtration system

Abstract

The present application relates to the field of explosion-proof dust removal technology, and in particular to a 3D metal printing explosion-proof dust removal circulation filtration system, which includes a dust removal chamber, a filter element, an explosion suppression component and a negative pressure discharge part; the dust removal chamber is internally divided into a filter chamber and a maintenance chamber distributed according to the gas flow direction; the filter element is inserted from the maintenance chamber into the filter chamber and is used to filter dust gas; the explosion suppression component is arranged in the maintenance chamber and is used to input explosion suppression gas from the maintenance chamber to the filter chamber when an explosion occurs; the negative pressure discharge part is used to extract the filtered gas from the maintenance chamber and keep the dust removal chamber in a negative pressure state as a whole. The present application can still effectively perform explosion suppression after a dust explosion occurs.

Description

Technical Field

[0001] The present application relates to the field of explosion-proof dust removal technology, and in particular to a 3D metal printing explosion-proof dust removal circulation filtration system. Background Art

[0002] At present, the development and application of metal 3D printing are becoming more and more extensive. It is widely used in various fields. Metal 3D printing mainly uses metal powder to consolidate the three-dimensional structure required by the profile by sintering or bonding. The precision and quality of the workpiece after molding are closely related to the particle size of the metal powder. The smaller the particle size of the metal powder, the better the quality of the workpiece.

[0003] With the development of technology, the particle size of metal powder is getting smaller and smaller. At present, the particle size of metal powder used in 3D metal printing can reach several microns or even micron level, which will not only cause relatively large dust in the manufacturing site. When the concentration of metal powder in the air of the production site is too high, combined with external factors such as static electricity, it is very easy to cause dust explosion safety accidents. Therefore, dust removal equipment needs to be installed in the metal 3D printing workshop to reduce the dust content in the workshop.

[0004] In the prior art, in order to handle dust, it is necessary to filter the dust from the gas at the production site of the metal 3D printing equipment, especially the gas inside the 3D metal printing equipment, before discharging it to the production workshop to avoid the dangerous situation of excessive concentration of dust in the workshop. At the same time, in order to further reduce the probability of dust explosion accidents, inert gas will be mixed into the gas to reduce the oxygen content in the gas, narrow the concentration range of dust explosion, and reduce the explosion pressure and pressure increase rate.

[0005] However, in actual application, not only are preventive measures required before the explosion, but also corresponding responses are required after the explosion occurs. In the past, the commonly used method was to directly extinguish the fire with water, etc., which also had the effect of reducing dust. However, during the 3D metal printing process, the particle size of the metal powder is as small as microns, especially some metal powders will react chemically when in contact with water to produce a large amount of chemical heat, which will further cause an explosion, such as micron-level aluminum, iron and other commonly used 3D metal printing materials. Although inert gas can reduce the oxygen content in the gas in the filter equipment, its suppression effect will be significantly reduced when an explosion occurs. Therefore, how to suppress the explosion of dust when an explosion occurs is an urgent problem that needs to be solved. Summary of the invention

[0006] In order to effectively suppress the explosion of dust when an explosion occurs, the present application provides a 3D metal printing explosion-proof dust removal circulation filtration system.

[0007] The present application provides a 3D metal printing explosion-proof dust removal circulation filtration system, which adopts the following technical solutions:

[0008] A 3D metal printing explosion-proof dust removal circulation filtration system comprises a dust removal chamber, a filter element, an explosion suppression component and a negative pressure discharge component.

[0009] The dust removal chamber is internally divided into a filter chamber and a maintenance chamber distributed according to the gas flow direction; the filter element is inserted from the maintenance chamber into the filter chamber and is used to filter dust gas.

[0010] The explosion suppression component is arranged in the maintenance chamber and is used to input explosion suppression gas from the maintenance chamber toward the filter chamber when an explosion accident occurs.

[0011] The negative pressure exhaust part is used to extract the filtered gas from the maintenance chamber and keep the dust removal chamber as a whole in a negative pressure state.

[0012] By adopting the above technical scheme, after the explosion occurs, on the one hand, the dust removal chamber is in a negative pressure state as a whole due to the negative pressure discharge component, and the negative pressure can suppress the increase of the lower explosion limit before the explosion. On the other hand, after the explosion, due to the existence of negative pressure, the gas of the explosion suppression component can be output and flow from the maintenance chamber into the filter chamber, further increasing the lower explosion limit of the explosion and increasing the difficulty of a secondary explosion, thereby achieving the possibility of suppressing the occurrence of a secondary explosion after the explosion. At the same time, due to the timely injection of explosion suppression gas from the maintenance chamber into the filter chamber, during the explosion, on the one hand, the oxygen content in the confined space can be further reduced to suppress the occurrence of the explosion. On the other hand, in the process of explosion dissipation, the explosion suppression gas can diffuse toward the surrounding side under the fluctuation generated by the explosion and significantly reduce the oxygen content in the air contacted during the explosion diffusion process, thereby achieving the purpose of suppressing the explosion and the occurrence of continuous combustion and explosion after the explosion.

[0013] Optionally, the filter chamber is provided with a first dust collecting assembly for receiving filtered retained dust, the first dust collecting assembly comprising a dust collecting container and two dust collecting valves spaced apart at the inlet of the dust collecting container, the inlet of the dust collecting container being connected to the filter chamber.

[0014] By adopting the above technical scheme, the dust filtered in the filter chamber can fall into the dust collecting container after passing through the two dust collecting valves. Due to the existence of the two dust collecting valves, an intermediate buffer cavity can be formed between the two dust collecting valves. At this time, since the oxygen content in the intermediate cavity is limited, it is in a closed state and the pressure is relatively low, after an explosion occurs, it can also be effectively isolated by the chamber between the two dust collecting valves, thereby reducing the possibility of the explosion affecting the dust in the dust collecting container and causing a more violent secondary explosion.

[0015] Optionally, the explosion suppression assembly includes a gas storage container for storing compressed explosion suppression gas and an exhaust valve arranged in the gas storage container for controlling the release of the explosion suppression gas, and the gas storage container is arranged in the maintenance chamber.

[0016] By adopting the above technical solution, when an explosion occurs, the exhaust valve opens, so that the compressed explosion-suppressing gas is released in the gas storage container and input into the filter chamber.

[0017] Optionally, the filter element is a sintered plate filter element and is formed with a plurality of parallel filter cavities, and the filter cavities are arranged toward the maintenance chamber opening.

[0018] By adopting the above technical solution, multiple parallel filter chambers can make the negative pressure act relatively evenly on the entire filter element during the filtration process, reducing the situation where the gas is concentrated through a certain part of the filter element due to differences in local filter hole diameters or differences in gas passage resistance, thereby causing dust to adhere to a certain part of the filter element under the action of negative pressure, resulting in excessive local dust content.

[0019] Optionally, an explosion relief component for releasing energy when an explosion occurs is arranged outside the filter chamber, and the filter chamber is provided with an explosion relief port which is not connected to the maintenance chamber. The explosion relief component includes an explosion relief plate and an explosion relief duct arranged at the explosion relief port, the inlet of the explosion relief duct is covered on the explosion relief port and the outlet is bent and faces the outer wall of the dust removal chamber, the opening pressure of the explosion relief duct is L1, the remaining inner wall portion of the dust removal chamber is subjected to a pressure of L2, and L1<L2.

[0020] By adopting the above technical solution, after the explosion occurs, the explosion will cause the gas to expand rapidly. At this time, the explosion venting plate can be opened, and the energy generated by the explosion can be released toward a safe area under the action of the explosion venting duct, so as to reduce the probability of direct overall damage to the equipment due to the dust explosion. At the same time, the explosion venting plate can be used to allow the gas with relatively low oxygen content in the filter chamber to be discharged to the outside of the explosion venting duct through the explosion venting duct to reduce the oxygen in the surrounding environment, thereby achieving the purpose of suppressing secondary explosions.

[0021] Optionally, a pre-filter assembly is also included, which includes a cyclone dust collector and a pre-dust collecting component arranged at the discharge end of the cyclone dust collector, and the output end of the cyclone dust collector is connected to the filter chamber.

[0022] By adopting the above technical scheme, in order to avoid excessive frequency of filter element replacement, the cyclone dust collector can, on the one hand, separate gas and dust in advance, effectively reduce the dust content in the gas entering the filter chamber, and allow the separated technical dust to be collected by the pre-dust collector; on the other hand, large particles of dust can be screened out by the cyclone dust collector, so that the filter element is mainly used for filtering tiny fine metal dust to reduce the possibility of the filter element being blocked.

[0023] Optionally, the pre-dust collecting component includes a pre-dust collecting container and two pre-valves installed at intervals at the input end of the pre-dust collecting container, and the input end of the pre-dust collecting container is connected to and fixed to the dust outlet end of the cyclone dust collector through the two pre-valves.

[0024] By adopting the above technical solution, metal dust can be stored in the front dust collecting container through two front valves. On the one hand, it can reduce the impact on the stored metal dust in the event of an explosion. On the other hand, when handling the dust, the two dust collecting valves and the buffer chamber in the middle can significantly reduce the external impact on the inside of the cyclone dust collector, further reducing the possibility of dust explosion.

[0025] Optionally, a post-filter component is also included, which includes a post-filter element for filtering and a post-control valve group, the input end of the post-filter element is connected to the output end of the negative pressure discharge element, and the post-control valve group is arranged on the post-filter element and is used to control the 3D printing exhaust gas filtration or the direct discharge of the filtered gas.

[0026] By adopting the above technical scheme, since in the process of 3D metal printing, not only gas containing metal dust but also tail gas with relatively high temperature is generated, if it is filtered synchronously with the production gas at this time, the risk of dust explosion will be significantly increased. At this time, the tail gas can be filtered by a separate post-filter in cooperation with a post-control valve group. At the same time, the gas after two filtrations can also be filtered by the post-filter for final treatment to avoid the possibility of dust explosion. At the same time, the post-filter simultaneously filters the tail gas and the gas filtered by the filter element for final filtration. On the one hand, the dust content of the gas after the filter element is extremely low, and the content of the tail gas is also relatively low, but the temperature of the tail gas is relatively high, which will make the post-filter element prone to dust explosion after a certain dust accumulation. At this time, the gas after the filter element is filtered can also effectively cool the post-filter element to reduce the lower explosion limit of the dust explosion and reduce the possibility of explosion. On the other hand, the dust content in the gas discharged from the production site can be fully reduced.

[0027] Optionally, an exhaust assembly is provided in the explosion venting and diversion duct, and the exhaust assembly includes a closing plate and an exhaust member arranged on the side of the closing plate away from the explosion venting port, the closing plate closes the inner wall of the explosion venting and diversion duct and its opening pressure is L1, and the explosion venting plate is connected to the explosion venting and diversion duct through the closing plate.

[0028] The exhaust member is used to output carbon dioxide gas toward the surrounding side through the explosion relief conduit after the sealing plate is opened.

[0029] By adopting the above technical solution, since the gas will expand rapidly after the dust explosion, a large amount of heat and flames will be generated at the same time, and due to the limited oxygen content, most of the flames will be extinguished in a very short time, but the generated energy and heat still need to be released. At this time, if they come into contact with external oxygen, a secondary explosion will easily occur and expand the scope of influence; at this time, the closing plate is first opened and carbon dioxide gas is discharged toward the surrounding side through the room, which can significantly reduce the oxygen content around the explosion venting duct, thereby effectively suppressing the possibility of secondary explosion during the energy release process.

[0030] Optionally, a plurality of exhaust ports opening toward the surrounding side are provided at one end of the explosion venting and draining duct away from the explosion venting port, the closing plate is rotatably connected to the inner wall of the explosion venting and draining duct and is closed, the exhaust component includes a storage container for storing compressed carbon dioxide gas and an exhaust valve for controlling the opening or closing of an output end of the storage container, and the opening end of the exhaust valve is located on the rotation path of the closing plate and is triggered by the closing plate.

[0031] By adopting the above technical solution, after the closing plate is opened, the gas in the storage container is first filled into the explosion venting and drainage duct through the exhaust valve, and then discharged toward the surrounding side of the explosion venting and drainage duct through the exhaust port, so as to significantly reduce the oxygen content on the surrounding side and reduce the possibility of secondary explosion during the energy release process.

[0032] In summary, the present application includes at least one of the following beneficial technical effects:

[0033] 1. During filtration, if an explosion occurs, on the one hand, the dust removal chamber as a whole is in a negative pressure state due to the negative pressure discharge component, and the negative pressure can suppress and raise the lower explosion limit before the explosion. On the other hand, after the explosion, due to the existence of negative pressure, the gas of the explosion suppression component can be output and flow from the maintenance chamber into the filter chamber, further raising the lower explosion limit of the explosion and increasing the difficulty of a secondary explosion, thereby achieving the possibility of suppressing the occurrence of a secondary explosion after the explosion. At the same time, due to the timely injection of explosion suppression gas from the maintenance chamber into the filter chamber, during the explosion, on the one hand, the oxygen content in the confined space can be further reduced to suppress the occurrence of the explosion. On the other hand, during the process of explosion dissipation, the explosion suppression gas can diffuse toward the surrounding side under the fluctuations generated by the explosion and significantly reduce the oxygen content in the air contacted during the explosion diffusion process, thereby achieving the purpose of suppressing the explosion and the occurrence of continuous combustion and explosion after the explosion.

[0034] 2. During the release of explosion energy, carbon dioxide gas can be first released into the explosion venting duct and the surrounding side through the exhaust component to reduce the oxygen content of the surrounding gas. As a result, during the energy release process, the oxygen content of the gas contacted by the expanding gas after being discharged from the explosion venting duct is significantly reduced. The oxygen content can be reduced while cooling in the initial stage, thereby effectively suppressing the possibility of a secondary explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural diagram of Example 1 of the present application.

[0036] Figure 2 It is a schematic diagram of the partial cross-sectional structure of Example 1 of the present application after the shell is removed.

[0037] Figure 3 It is a schematic diagram of the structure of the filter element in Example 1 of the present application.

[0038] Figure 4 It is a schematic diagram of the local structure of Example 1 of the present application.

[0039] Figure 5 yes Figure 2 Schematic diagram of the enlarged structure of part A.

[0040] Figure 6 It is a schematic cross-sectional view of the coordination structure between the explosion relief assembly and the exhaust assembly and the top of the dust removal chamber in Example 2 of the present application.

[0041] Explanation of reference numerals: 1. dust removal chamber; 10. dust removal baffle; 11. filter chamber; 111. explosion vent; 112. buckle ring plate; 113. buckle part; 12. maintenance chamber; 121. maintenance door; 13. first dust collection assembly; 131. dust collection container; 132. dust collection valve; 14. fire extinguishing component; 141. dry powder fire extinguisher; 15. bracket; 151. universal wheel; 16. shell; 17. mid-term explosion suppression component; 2. filter element; 21. filter chamber; 3. explosion suppression assembly; 31. gas storage container; 32. exhaust valve; 321. exhaust pipe; 4. negative pressure discharge component; 5. explosion venting assembly; 51. Explosion venting plate; 52, explosion venting duct; 521, venting port; 6, pre-filter assembly; 61, cyclone dust collector; 611, input pipe; 612, input valve; 62, pre-dust collecting part; 621, pre-dust collecting container; 622, pre-valve; 63, dilution container; 7, post-filter assembly; 71, post-filter element; 711, first post-filter; 712, second post-filter; 72, post-control valve group; 721, control valve; 8, exhaust assembly; 81, closing plate; 812, matching part; 82, exhaust part; 821, storage container; 822, exhaust valve. DETAILED DESCRIPTION

[0042] The following is combined with Figure 1-6 This application is described in further detail.

[0043] The embodiment of the present application discloses a 3D metal printing explosion-proof dust removal circulation filtration system.

[0044] Example 1

[0045] Reference Figure 1 and Figure 2 , the 3D metal printing explosion-proof dust removal circulation filtration system includes a dust removal chamber 1, a filter element 2, an explosion suppression component 3 and a negative pressure discharge component 4. The dust removal chamber 1 is a shell with a cavity structure formed inside, and is preferably a shell with a funnel-shaped structure at the bottom, and a first dust collecting component 13 is provided at the bottom of the dust removal chamber 1 to receive the metal dust trapped after filtration. The filter element 2 is arranged in the dust removal chamber 1 to filter the metal dust in the gas, and the explosion suppression component 3 is used to inject explosion suppression gas into the dust removal chamber 1 to suppress the explosion; and the negative pressure discharge component 4 is used to extract the gas in the dust removal chamber 1 so that the gas in the dust removal chamber 1 maintains a negative pressure state.

[0046] Specifically, a vertically arranged dust removal partition 10 is fixedly connected to the inner wall of the dust removal chamber 1 and divides the dust removal chamber 1 into a filter chamber 11 for filtering and a maintenance chamber 12 for maintenance. Of course, in other embodiments, the dust removal partition 10 can also be arranged obliquely, arranged as a folded plate structure, or arranged as an arc-shaped plate structure, and it is only necessary to divide the internal cavity of the dust removal chamber 1 into the filter chamber 11 and the maintenance chamber 12 distributed horizontally.

[0047] Reference Figure 1 and Figure 2 At the same time, the filter chamber 11 and the maintenance chamber 12 are arranged along the direction of gas flow, and the gas first enters the filter chamber 11 through the pipeline, and then enters the maintenance chamber 12. Among them, the filter element 2 enters the filter chamber 11 from the maintenance chamber 12 through the dust removal partition 10.

[0048] Reference Figure 2 and Figure 3 The filter element 2 is preferably a sintered plate filter element in a plate shape, and the filter element 2 is arranged in multiples. In this embodiment 1, six filter elements 2 are selected and arranged vertically side by side. The filter element 2 is formed with a plurality of filter chambers 21 opened toward the maintenance chamber 12, so as to increase the filtering area of ​​the filter element 2 in a limited space, and guide the flow direction of the filtered gas into the maintenance chamber 12, so that in the process of filtering metal dust, the outer wall of the filter element 2 can produce relatively uniform negative pressure adsorption on the gas in the filter chamber 11, so as to make full use of the filtering performance of the filter element 2.

[0049] Refer to 1 and Figure 2 The opening size of the filter chamber 21 is in the range of 50-150mm in width, and any size within the range of 50mm, 80mm, 100mm, 150mm, etc. can be selected, and multiple filter elements 2 are arranged side by side, which can optimize the filtration efficiency and effect, and can also collect dust from multiple filter elements 2, reducing the space required and making the overall structure more compact.

[0050] At the same time, in order to facilitate maintenance, a maintenance port is provided on the outer wall of the maintenance chamber 12 away from the filter chamber 11, and a sealed maintenance door 121 is hinged on the opening edge of the maintenance port, so that the filter element 2 can be pulled out relative to the dust removal partition 10 for replacement during maintenance.

[0051] Among them, the explosion suppression component 3 is used to input explosion suppression gas into the maintenance chamber 12. The explosion suppression gas is carbon dioxide gas and is input into the filter chamber 11 through the filter element 2. In conjunction with the negative pressure discharge component 4, the input explosion suppression gas can be relatively quickly input and filled in the dust removal chamber 1 as a whole, so as to further dilute the oxygen content in the dust removal chamber 1. While suppressing the explosion, it can also increase the lower explosion limit through carbon dioxide gas, increase the difficulty of further occurrence of the explosion, and slow down the formation of turbulent flames inside the dust removal chamber 1, so as to achieve the purpose of sufficient explosion suppression.

[0052] When in use, the explosion limit of dust is affected by the initial temperature, pressure, oxygen content, etc. The negative pressure discharge member 4 can be used to extract the filtered gas in the dust removal chamber 1 on the one hand, and can also keep the filter chamber 11 and the maintenance chamber 12 in a negative pressure state on the other hand, effectively reducing the initial pressure in the dust removal chamber 1, so as to increase the lower explosion limit of dust and increase the difficulty of dust explosion. At the same time, since the metal particle size of 3D metal printing is getting smaller and smaller, even reaching the micron level, on the one hand, it is very easy to react with water to generate heat, and water cannot be used to extinguish or suppress the explosion after the explosion occurs. On the other hand, the lower explosion limit of metal dust decreases with the decrease of dust particle size, and the explosion intensity will also increase with the decrease of particle size. The influx of carbon dioxide can increase the lower explosion limit on the one hand, and can also slow down the formation of cross-flow flames in the filter chamber 11 and reduce the explosion intensity, so that it can not only suppress the occurrence of explosion, but also have a significant inhibitory effect on the explosion after the explosion occurs.

[0053] Reference Figure 2 Specifically, the explosion suppression component 3 includes a gas storage container 31 and an exhaust valve 32. The gas storage container 31 is used to store compressed explosion suppression gas, that is, compressed carbon dioxide gas. Six exhaust valves 32 are provided one by one corresponding to the filter element 2, and the input end of the exhaust valve 32 is fixed and connected to the gas storage container 31. The exhaust end of the exhaust valve 32 is fixed and connected to an exhaust pipe 321 extending along the distribution direction of several filter chambers 21 on the same filter element 2, and the exhaust pipe 321 is provided with at least one exhaust hole corresponding to the filter chamber 21, so as to timely transport the carbon dioxide gas through the filter chamber 21 to the filter chamber 11 one by one for explosion suppression when dust explosion occurs in the dust removal chamber 1.

[0054] In addition, since the bottom of the dust removal chamber 1 is provided with a first dust collecting assembly 13 for storing the metal dust after filtration, if an explosion occurs, the heat of the explosion is very likely to affect the stored metal dust and produce a secondary explosion. In order to reduce the probability of a secondary explosion, the first dust collecting assembly 13 includes a dust collecting container 131 and two dust collecting valves 132, the top of the dust collecting container 131 is an input end, and the top of the dust collecting container 131 is fixed and connected to the bottom of the funnel-shaped structure at the bottom of the filter chamber 11, so as to collect the dust trapped after filtration. At the same time, the two dust collecting valves 132 are arranged at intervals at the top of the dust collecting container 131, so as to open or close the dust collecting container 131, and a section of intermediate buffer cavity is formed between the two dust collecting valves 132. When an explosion occurs, even if the heat breaks through the closure of the first dust collecting valve 132, it can be buffered in the cavity between the two dust collecting valves 132 and isolated by the second dust collecting valve 132, so as to effectively reduce the possibility of a secondary accident when an explosion occurs.

[0055] Reference Figure 2 and Figure 4At the same time, in order to extinguish the fire in time after the explosion, the filter chamber 11 is connected to a fire extinguishing component 14 for injecting fire extinguishing dry powder during the explosion. The fire extinguishing component 14 includes a plurality of dry powder fire extinguishers 141, and the output end of the dry powder fire extinguisher 141 is connected to the filter chamber 11 through a pipeline with a valve, so as to extinguish the open flame after the explosion.

[0056] An explosion relief component 5 for releasing energy when a dust explosion occurs is arranged outside the filter chamber 11 . The explosion relief component 5 is arranged on the upper side of the filter chamber 11 .

[0057] Reference Figure 4 and Figure 5 Specifically, the inner wall of the filter chamber 11 is provided with an explosion vent 111, and the explosion vent 111 and the maintenance chamber 12 are not directly connected to each other. The explosion vent 111 is opened at a position of the filter chamber 11 corresponding to the external contact, which can be a side wall, a bottom wall or a top wall. In the present embodiment 1, the explosion vent 111 is opened at the top wall of the filter chamber 11 to release the energy generated during the explosion. The explosion vent assembly 5 includes an explosion vent plate 51 and an explosion vent duct 52 that are covered and fixed to the explosion vent 111. The inlet of the explosion vent duct 52 is covered with the explosion vent 111 and the explosion vent plate 51, so that the energy generated during the explosion breaks through the explosion vent plate 51 and enters the explosion vent duct 52 to be guided.

[0058] The explosion venting plate 51 can be a conventional commercially available component, which is a prior art and will not be described in detail here. The pressure at which the explosion venting plate 51 is opened relative to the explosion venting port 111 is L1, and the allowable pressure that the inner wall of the dust removal chamber 1 can withstand is L2, and L1<L2, so that when an explosion occurs, the explosion venting plate 51 can be opened in time to release the explosion pressure, and at the same time, carbon dioxide can be input into the filter chamber 11 more promptly.

[0059] Reference Figure 2 and Figure 4 Finally, since the filter chamber 11 is filtered through the filter element 2, in order to reduce the maintenance frequency of the filter element 2 and the possibility of the filter element 2 being blocked, a pre-filter component 6 is also provided on the side of the dust removal chamber 1 to pre-filter the gas in the internal environment of the 3D metal printing production equipment.

[0060] The pre-filter assembly 6 includes a cyclone dust collector 61 and a pre-dust collector 62. The gas inlet end of the cyclone dust collector 61 is fixed and connected to an input pipe 611. The inlet of the input pipe 611 is provided with an input valve 612 for introducing the gas containing metal dust at the 3D printing site. The gas output end of the cyclone dust collector 61 is fixed and connected to the filter chamber 11 through a pipeline for secondary dust removal and filtration of the gas after the cyclone dust removal.

[0061] At the same time, the front dust collecting part 62 is arranged at the lower side of the dust output end of the cyclone dust collector 61, that is, the lower side of the cyclone dust collector 61. The front dust collecting part 62 includes a front dust collecting container 621 and two front valves 622 installed at intervals at the input port of the front dust collecting container 621. The input end of the front dust collecting container 621 is connected and fixed to the dust outlet end of the cyclone dust collector 61 through the two front valves 622, and the part of the input end of the front dust collecting container 621 located between the two front valves 622 forms an intermediate buffer chamber, so that when dust explosion occurs in the cyclone dust collector 61, it has a buffering and fully isolated effect.

[0062] In order to reduce the oxygen content in the circulating gas during the filtering process, the pipeline at the input end of the cyclone dust collector 61 is connected to a dilution container 63 for inputting inert gas. The dilution container 63 is used to store compressed inert gas, so as to reduce the oxygen content of the gas in the circulating process by dilution with inert gas before gas filtering, and improve the lower explosion limit of dust before initial filtering.

[0063] Reference Figure 2 and Figure 4 In addition, in order to further optimize the content of metal dust in the exhaust gas at the production site, a post-filter assembly 7 connected to the maintenance chamber 12 through a negative pressure discharge member 4 is also provided on the side of the dust removal chamber 1 for filtering the gas before discharge. The negative pressure discharge member 4 is a dust suction fan or a dust suction air pump, and its dust removal capacity range, i.e., air volume, is 150-1100 cubic meters per hour. The input end of the negative pressure discharge member 4 is fixed and connected to the maintenance chamber 12 through a pipeline.

[0064] The post-filter assembly 7 includes a post-filter element 71 and a post-control valve group 72. The post-filter element 71 includes a first post-filter 711 and a second post-filter 712 with two input ends, and the post-control valve group 72 includes a plurality of control valves 721. The input end of the first post-filter 711 is fixed through a pipeline and connected to the output end of the negative pressure discharge element 4; at the same time, the first post-filter 711 has two output ends, and one of the output ends of the first post-filter 711 is connected to one of the input ends of the second post-filter 712 through a control valve 721 and a pipeline, so as to filter the gas twice before discharging it. The remaining output end of the first post-filter 711 is directly connected to the air through other control valves 721, and the gas filtered by the first post-filter 711 can be directly discharged at this time, so as to facilitate the enclosure of the first post-filter 711.

[0065] The remaining input end of the second post-filter 712 is also provided with a control valve 721, and is used to directly input the exhaust gas generated during the operation of the 3D printing equipment. The output end of the second post-filter 712 is also provided with a control valve 721 for sealing treatment in the event of an explosion, thereby reducing the possibility of the heat of the explosion being transmitted along the delivery pipeline.

[0066] Reference Figure 1 In addition, in order to reduce the impact of explosions on the surrounding sides during the filtering process, the bottom of the dust removal chamber 1 is fixedly connected to a plurality of universal wheels 151 through a bracket 15, and the dust removal chamber 1 is covered with a shell 16, which covers the first post-filter 711, the second post-filter 712 and the cyclone dust collector 61, and the first post-filter 711, the second post-filter 712 and the cyclone dust collector 61 are integrated on the side of the dust removal chamber 1 away from the maintenance chamber 12, so that the structure is relatively more compact.

[0067] At the same time, in order to make the structure compact and still have a certain explosion suppression effect in a limited space, a mid-term explosion suppression part 17 can also be provided in the housing 16 when the fire extinguishing part 14 is provided or when the fire extinguishing part 14 is not provided. The mid-term explosion suppression part 17 is a container storing inert dust and compressed gas, for example, a mixture of dust such as sodium bicarbonate (baking soda), diammonium phosphate, and Class D fire extinguishing agent and compressed inert gas; or a single gas, such as an inert gas or carbon dioxide gas, which has at least a combustion suppression effect. The mid-term explosion suppression part 17 is connected to the filter chamber 11 through a pipeline provided with an electromagnetic valve, and the dust removal chamber 1 is provided with a sensor for sensing combustion and explosion in the filter chamber 11, such as a temperature sensor, an air pressure sensor, etc., which can sense the explosion information, that is, temperature information and air pressure information. In this embodiment, the sensors are temperature sensors and air pressure sensors, and the temperature sensors and air pressure sensors are both electrically connected to the controller, which is integrated in the explosion-proof box and arranged outside the dust removal chamber 1.

[0068] Specifically, the controller is preset with a temperature threshold and an air pressure threshold. If the temperature in the information received by the controller is higher than the temperature threshold, and the air pressure value is higher than the air pressure threshold, it is determined that an explosion has occurred, and the controller sends a control signal to the solenoid valve to open, so that the inhibitor is released into the filter chamber 11.

[0069] If the temperature is lower than the temperature threshold or the air pressure is lower than the air pressure threshold, it is determined that no explosion has occurred and the controller does not send a control signal, thereby helping to reduce the possibility of an explosion and the possibility of misjudgment.

[0070] That is, if combustion or explosion occurs, the intermediate explosion suppression component 17 directly uses compressed gas to combine the inert dust with the explosion suppression gas output by the explosion suppression component 3 to fully suppress the explosion and combustion, thereby fully reducing the possibility of open flames on the side of the dust removal chamber 1.

[0071] The implementation principle of Example 1 of the present application is as follows: during filtering, the oxygen content is first reduced by mixing inert gas, and at this time the dust content is relatively high, so that the oxygen content is significantly reduced, so that the explosion can be significantly suppressed, and then the dust content in the gas is significantly reduced by the initial screening of the cyclone dust collector 61; then the filter element 2 is used for secondary filtration to significantly reduce the dust content in the gas in the maintenance chamber 12 after filtration by the filter chamber 11; and because the dust content is relatively reduced, the oxygen content is relatively fixed, and the distribution of dust is close to the dust explosion content. At this time, dust explosion is very likely to occur, and due to the existence of negative pressure, the lower explosion limit of the dust will be further increased; at the same time, due to the presence of carbon dioxide gas in the maintenance chamber 12, even if an explosion occurs, the explosion can be significantly suppressed, and because the limited oxygen is consumed, the combination of carbon dioxide gas and the mixed inert gas can significantly suppress the open flame generated by the explosion in the filter chamber 11, thereby achieving the purpose of significantly suppressing the explosion after the explosion.

[0072] Example 2

[0073] Reference Figure 6 The difference from Example 1 is that an exhaust assembly 8 is provided on the side of the explosion venting and drainage duct 52 away from the explosion venting port 111. The exhaust assembly 8 is used to output carbon dioxide gas toward the surrounding side through the explosion venting and drainage duct 52 after the explosion venting plate 51 is opened, and then discharge the gas expanded due to the explosion, so as to improve the gas content on the surrounding side of the dust removal chamber 1, so that carbon dioxide first fills the surrounding side of the dust removal chamber 1, reducing the possibility of secondary explosion and combustion of the gas discharged due to the explosion expansion after contacting oxygen in the external gas.

[0074] Specifically, a buckle ring plate 112 is fixedly connected to the outer wall of the explosion vent 111 on the side facing the explosion vent pipe 52, the explosion vent 111 is located inside the buckle ring plate 112, and the edge of the buckle ring plate 112 is bent outward to form a buckle portion 113. A fireproof sealing strip is fixed to the side of the explosion vent plate 51 facing the explosion vent 111, and the explosion vent plate 51 is arranged inside the buckle ring plate 112 and fits the opening edge of the explosion vent 111.

[0075] At the same time, the exhaust assembly 8 includes a closing plate 81 and an exhaust member 82. The closing plate 81 covers the buckle ring plate 112, and the closing plate 81 is fixedly connected to the explosion venting plate 51 through the connecting ring plate and presses the explosion venting plate 51 to the opening edge of the explosion venting port 111. One side opening edge of the closing plate 81 is hinged to the opening edge of the explosion venting port 111, and the other side edge of the closing plate 81 opposite to the hinged portion is formed with a matching portion 812 for buckling the buckle ring plate 112. The matching portion 812 is buckled to the buckle ring plate 112, and the pressure driving the matching portion 812 to disengage from the buckle ring plate 112 is L1. At the same time, due to the negative pressure extraction of the negative pressure discharge member 4, the explosion venting plate 51 will pull the closing plate 81 to move toward the explosion venting port 111, so that the explosion venting plate 51 and the closing plate 81 can be relatively tightly matched with the opening edge of the explosion venting port 111 during normal operation, significantly reducing the possibility of leakage.

[0076] The end of the explosion relief conduit 52 away from the explosion relief port 111 is provided with a plurality of exhaust ports 521 facing the surrounding side. The exhaust member 82 includes a storage container 821 and an exhaust valve 822. The storage container 821 is used to store compressed carbon dioxide gas, and the storage container 821 is fixedly connected to the inner wall of the explosion relief conduit 52 through a support. The storage container 821 is located on the side of the closing plate 81 away from the explosion relief plate 51. The output end of the storage container 821 is arranged away from the explosion relief plate 51, so that the carbon dioxide gas in the storage container 821 can be output toward the surrounding side through the explosion relief conduit 52.

[0077] The exhaust valve 822 is installed at the output end of the storage container 821, and the opening end of the exhaust valve 822 is set at the tail of the storage container 821 and located at the initial position of the rotation path of the closing plate 81, so that the closing plate 81 can trigger the exhaust valve 822 to open the storage container 821 first when the explosion relief plate 51 is opened, so that the surrounding side of the explosion relief duct 52 is first filled with carbon dioxide gas, and then the explosion relief plate 51 will be fully opened to release the explosion energy. Among them, the exhaust valve 822 can use a solenoid valve or other valve that can be remotely controlled, and the opening end of the exhaust valve 822 is set at the position of the explosion relief port 111 corresponding to the closing plate 81; or a photoelectric switch is used to sense the closing plate 81 to open the exhaust valve 822.

[0078] Finally, in order to enable the closing plate 81 to rotate and fit the inner wall of the explosion-relief duct 52 after being opened, so as to reduce the possibility of the closing plate 81 swinging due to air flow after the explosion-relief duct 51 is opened, a torsion spring is provided at the hinged portion between the closing plate 81 and the inner wall of the explosion-relief duct 52 to tend to keep the closing plate 81 from disengaging from the buckle 113.

[0079] The implementation principle of Example 2 of the present application is as follows: during normal use, since the dust removal chamber 1 is in a negative pressure state, the explosion relief plate 51 will drive the closing plate 81 to fit relatively tightly with the explosion relief port 111, reducing the possibility of leakage. When an explosion occurs in the filter chamber 11, the explosion suppression component 3 will inject carbon dioxide gas into the filter chamber 11, suppressing the explosion in the filter chamber 11. At the same time, the rapidly expanding gas in the filter chamber 11 will prompt the explosion relief plate 51 to drive the closing plate 81 to rotate, and the carbon dioxide gas in the storage container 821 will be quickly released and output toward the surrounding side through the explosion relief duct 52, so as to significantly reduce the oxygen content on the surrounding side of the explosion relief duct 52, so that after the explosion relief plate 51 is opened, it is only used for energy release. At the same time, the carbon dioxide gas pre-filled in the explosion relief duct 52 will also suppress the explosion and the generation of open flames, thereby optimizing the effect of suppressing the explosion after the explosion occurs.

[0080] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A 3D metal printing explosion-proof dust removal circulation filtration system, characterized by: It comprises a dust removal chamber (1), a filter element (2), an explosion suppression component (3) and a negative pressure discharge component (4); A dust removal chamber (1), the interior of which is divided into a filter chamber (11) and a maintenance chamber (12) distributed according to the gas flow direction; The filter element (2) is inserted from the maintenance chamber (12) into the filter chamber (11) and is used to filter dust gas; An explosion suppression component (3) is arranged in the maintenance chamber (12) and is used to input explosion suppression gas from the maintenance chamber (12) toward the filter chamber (11) when an explosion accident occurs; A negative pressure discharge member (4) is used to extract the filtered gas from the maintenance chamber (12) and maintain the dust removal chamber (1) as a whole in a negative pressure state; The filter element (2) is a sintered plate filter element and is formed with a plurality of parallel filter chambers (21), the filter chambers (21) being arranged with an opening facing the maintenance chamber (12); an explosion relief component (5) for releasing energy when an explosion occurs is arranged outside the filter chamber (11), the filter chamber (11) being provided with an explosion relief port (111) not connected to the maintenance chamber (12), the explosion relief component (5) comprising an explosion relief plate (51) and an explosion relief drainage conduit (52) arranged at the explosion relief port (111), the inlet of the explosion relief drainage conduit (52) covering the explosion relief port (111) and the outlet of which is bent and facing the explosion relief conduit (52). The outer wall of the dust chamber (1), the opening pressure of the explosion relief duct (52) is L1, the remaining inner wall portion of the dust removal chamber (1) is subjected to a pressure of L2, and L1<L2; an exhaust assembly (8) is arranged in the explosion relief duct (52), the exhaust assembly (8) comprises a closing plate (81) and an exhaust member (82) arranged on a side of the closing plate (81) away from the explosion relief port (111), the closing plate (81) closes the inner wall of the explosion relief duct (52) and its opening pressure is L1, and the explosion relief plate (51) is connected to the explosion relief duct (52) via the closing plate (81); The exhaust member (82) is used to output carbon dioxide gas toward the surrounding side through the explosion relief duct (52) after the closing plate (81) is opened; a plurality of exhaust ports (521) opening toward the surrounding side are provided at one end of the explosion relief duct (52) away from the explosion relief port (111); the closing plate (81) is rotatably connected to the inner wall of the explosion relief duct (52) and is arranged in a closed manner; the exhaust member (82) comprises a storage container (821) for storing compressed carbon dioxide gas and an exhaust valve (822) for controlling the opening or closing of an output end of the storage container (821); the opening end of the exhaust valve (822) is located on the rotation path of the closing plate (81) and is triggered by the closing plate (81).

2. The 3D metal printing explosion-proof dust removal circulation filtration system according to claim 1 is characterized in that: The filter chamber (11) is provided with a first dust collecting assembly (13) for receiving filtered and retained dust, the first dust collecting assembly (13) comprising a dust collecting container (131) and two dust collecting valves (132) arranged at intervals at the inlet of the dust collecting container (131), the inlet of the dust collecting container (131) being connected to the filter chamber (11).

3. The 3D metal printing explosion-proof dust removal circulation filtration system according to claim 1 is characterized in that: The explosion suppression component (3) comprises a gas storage container (31) for storing compressed explosion suppression gas and an exhaust valve (32) arranged in the gas storage container (31) for controlling the release of the explosion suppression gas. The gas storage container (31) is arranged in the maintenance chamber (12).

4. The 3D metal printing explosion-proof dust removal circulation filtration system according to claim 1, characterized in that: It also includes a pre-filter assembly (6), the pre-filter assembly (6) including a cyclone dust collector (61) and a pre-dust collecting component (62) arranged at the discharge end of the cyclone dust collector (61), the output end of the cyclone dust collector (61) being connected to the filter chamber (11).

5. The 3D metal printing explosion-proof dust removal circulation filtration system according to claim 4 is characterized in that: The front dust collecting component (62) comprises a front dust collecting container (621) and two front valves (622) installed at intervals at the input end of the front dust collecting container (621); the input end of the front dust collecting container (621) is connected to and fixed to the dust outlet end of the cyclone dust collector (61) via the two front valves (622).

6. The 3D metal printing explosion-proof dust removal circulation filtration system according to claim 1, characterized in that: The invention also comprises a post-filter assembly (7), wherein the post-filter assembly (7) comprises a post-filter element (71) for filtering and a post-control valve group (72), wherein the input end of the post-filter element (71) is connected to the output end of the negative pressure discharge element (4), and the post-control valve group (72) is arranged on the post-filter element (71) and is used to control the filtration of 3D printing exhaust gas or the direct discharge of filtered gas.

Images