Continuous extraction equipment and method for 3D printing sand
By using a 3D-printed sand continuous extraction equipment for crushing, heating, regenerating, and screening sand, the problem of difficult recycling of old sand has been solved, achieving efficient and automated processing and resource reuse of old sand, and reducing environmental pollution and production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-04
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, the waste sand generated by 3D printing is difficult to recycle effectively, resulting in environmental pollution and high recycling costs, and failing to achieve efficient resource reuse.
The 3D-printed continuous sand extraction equipment includes a sand crushing device, a heating device, and a secondary screening mechanism. Through vibration crushing, heating regeneration, and screening processes, it achieves automated processing and effective separation of old sand.
It achieves efficient recycling of old sand, reduces labor costs and environmental pollution, reduces dependence on new sand, meets the requirements of sustainable development, and has significant economic and environmental benefits.
Smart Images
Figure CN121820538A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of waste sand processing for 3D printing, and in particular to a continuous extraction device and method for 3D printing sand. Background Technology
[0002] The working principle of sand mold 3D printing is to first mix the casting raw sand with the curing agent, then spread a layer of sand on the printing platform, and then spray resin adhesive on the sand layer according to the contour characteristics of the sand core. This process of spreading sand and spraying resin is repeated layer by layer to eventually form the desired sand core. After it hardens at room temperature, it can be taken out of the working box, and the surface loose sand can be cleaned before it can be used for casting production.
[0003] Originally, the foundry sand is white or yellow with a pure surface. However, after 3D printing, the sand particles harden due to the cross-linking reaction of the printing resin and curing agent, becoming sand blocks. During the subsequent casting process, the surface of the sand mold in contact with the high-temperature molten metal is burned, resulting in the production of substances and the presence of metallic impurities left over from the casting process. Furthermore, due to the shape and quantity of the printed sand core, the sand in the printing chamber cannot be fully utilized to create sand cores. This portion of sand that was not coated with resin is cleaned away during the removal of the finished sand core, becoming "used sand."
[0004] Such waste sand is often dumped in wilderness areas without treatment, which may pollute the soil and water environment; or it is recycled and treated as industrial waste by professional cleaning agencies at high cost, which avoids direct environmental pollution, but is very expensive. Summary of the Invention
[0005] To achieve low-cost recycling of used sand, this application provides a 3D-printed sand continuous extraction device and method.
[0006] Firstly, this application provides a continuous extraction device for 3D printed sand, which adopts the following technical solution: A continuous sand extraction device for 3D printing includes: a sand crushing device, comprising a sand crushing cylinder, a vibration component, and a primary screening mechanism, wherein the vibration component is installed at the bottom of the crushing cylinder, and the output end of the vibration component is assembled with the crushing cylinder for vibrating and crushing sand blocks stored in the crushing cylinder; the primary screening mechanism is installed in the middle of the cylinder for separating fine sand and small clumps. A heating device includes a rotating inner liner, a rotating drive assembly, and a heating outer shell. The rotating inner liner is inclinedly disposed inside the heating outer shell, and the rotating drive assembly is disposed outside the rotating inner liner. The rotating drive assembly is assembled with the rotating inner liner to drive the rotating inner liner to rotate. The secondary screening mechanism is located at the output end of the rotating inner tank and is used to carry and screen finished sand and large-particle sand.
[0007] By adopting the above technical solution, the sand crushing device can vibrate and crush sand blocks and perform preliminary screening, breaking the sand blocks into fine sand and small lumps, providing suitable raw material particle size for subsequent processing; the rotary drive component drives the rotation of the rotating inner tank, and the heating shell provides heat energy to the entire rotating inner tank. With the cooperation of the stirring rod and stirring paddle, the fine sand can be fully heated during the heating process, ensuring uniform combustion of the fine sand and improving the effect of thermal regeneration; the secondary screening mechanism can screen the processed white sand into finished sand and large-particle sand, realizing effective separation and collection of sand.
[0008] The various components of this equipment work closely together and employ a continuous extraction method to automate the entire process of used sand processing. This improves the efficiency and continuity of used sand processing, and the entire process requires minimal human intervention, reducing labor costs and intensity. Compared with existing technologies, the high-temperature thermal regeneration process can centrally process used sand, reducing waste sand dumping and thus protecting the soil and water environment, which aligns with the concept of sustainable development. At the same time, it enables the effective recycling of used sand, thereby reducing the reliance on new sand in casting production and helping to save significant raw material costs.
[0009] Preferably, a stirring rod is provided in the middle of the rotating inner liner, the extension direction of the stirring rod is consistent with the extension direction of the rotating inner liner, and multiple stirring paddles are provided on the outer wall of the stirring rod.
[0010] Preferably, a reinforcing member is provided between the end of the stirring rod and the rotating inner liner, and the two are fixedly connected by the reinforcing member.
[0011] By adopting the above technical solution, during the heating process, the reinforcement is fixedly connected to the stirring rod and the rotating inner liner, ensuring the stability and reliability of the stirring structure. During equipment operation, the stirring paddle can fully stir the fine sand inside the rotating inner liner as it rotates, allowing the fine sand to fully contact the heating surface of the inner wall of the rotating inner liner, further improving the heating uniformity of the fine sand. At the same time, the stirring paddle continuously tumbles the fine sand, enabling the fine sand to form a good flow state within the rotating inner liner, which helps oxygen to contact the fine sand more fully. This allows the fine sand to burn more completely during the high-temperature thermal regeneration process, and also facilitates the subsequent discharge of sand, improving the quality and efficiency of old sand regeneration.
[0012] Preferably, the rotary drive assembly includes a rotary drive component and a drive gear. The drive gear is assembled with the rotary drive component via a shaft. A driven gear is fixed to the end of the rotary inner liner that extends out of the rotary inner liner. The driven gear meshes with the drive gear.
[0013] By adopting the above technical solution, the rotary drive component drives the active gear to rotate through the shaft. The meshing of the active gear and the driven gear can transmit the power of the rotary drive component to the stirring rod, thereby driving the rotating inner liner to rotate. The gear transmission method has the characteristics of high transmission accuracy and good stability, which can ensure that the rotating inner liner rotates at a stable speed, making the movement of fine sand in the rotating inner liner more regular, which is conducive to improving the heating and combustion effect.
[0014] Preferably, a support wheel is fixed near the driven gear in the rotating inner liner, the support wheel is coaxial with the driven gear, and an auxiliary wheel is installed on the heating outer shell, the auxiliary wheel rotates by friction with the support wheel.
[0015] The two auxiliary wheels are located at the bottom of both of the supporting wheels, so that the two auxiliary wheels rotate with the supporting wheel simultaneously through friction, and the three are arranged in a triangular distribution.
[0016] By adopting the above technical solution, the triangular distribution structure of the support roller and auxiliary roller provides more stable support for the stirring rod and rotating inner tank. During the rotation of the inner tank, the frictional rotation of the support roller and auxiliary roller effectively reduces the shaking of the stirring rod and rotating inner tank, ensuring the smooth operation of the equipment. Moreover, the frictional rotation of the auxiliary roller and support roller also plays a certain buffering role. When small fluctuations occur during the power transmission of the rotary drive component, the friction between the auxiliary roller and support roller can absorb these fluctuations, avoiding excessive impact on the rotating inner tank and stirring rod, and ensuring the safety and stability of the equipment operation. Especially in the high-temperature thermal regeneration process, stable equipment operation is crucial for the complete combustion and uniform heating of fine sand, ensuring that the sand particles are thoroughly burned into white sand, and further ensuring the safety of the production environment.
[0017] Preferably, a hopper is provided on the outside of the rotating inner liner, the bottom of the hopper is connected to the input end of the rotating inner liner, and a discharge component is provided inside the hopper to speed up the discharge speed.
[0018] The discharge component includes a discharge auger shaft, a discharge driven sprocket, a discharge driving sprocket, a discharge chain, and a discharge motor. The discharge chain meshes with both the discharge driving sprocket and the discharge driven sprocket. The discharge auger shaft is rotatably mounted in the middle of the hopper. The discharge driven sprocket is fixed to the end of the discharge auger shaft that extends out of the hopper. The discharge driving sprocket is connected to the discharge motor via a shaft.
[0019] By adopting the above technical solution, the discharge motor drives the discharge drive sprocket to rotate via its shaft. The discharge chain transmits the power of the discharge drive sprocket to the discharge driven sprocket, which in turn causes the discharge screw shaft to rotate inside the hopper. The rotation of the discharge screw shaft accelerates the discharge of fine sand from the hopper, ensuring that the fine sand can enter the rotating inner tank in a timely and stable manner, preventing the fine sand from accumulating in the hopper, improving the overall feeding efficiency of the equipment, and ensuring the continuity of the old sand processing process. At the same time, by controlling the speed of the discharge motor, the discharge speed can be flexibly adjusted to adapt to different production scales and processing requirements. Preferably, the heating outer casing includes a base outer box, a heating rotary kiln, and a connector. The rotating inner liner is fixed in the middle of the heating rotary kiln by the connector. The heating rotary kiln is rotatably installed in the middle of the base outer box. The outer wall of the base outer box also includes a heat dissipation component. The heating rotary kiln heats the rotating inner liner, and the heat generated is discharged to the outside through the heat dissipation component.
[0020] By adopting the above technical solution, the connecting parts ensure that the relative positions of the rotating inner tank and the heating rotary kiln are fixed, and both are installed inside the base outer box. Under the action of the rotating drive, the rotating inner tank and the heating rotary kiln will rotate synchronously. The heating rotary kiln can provide a stable heat source for the rotating inner tank, ensuring the temperature conditions required for the high-temperature thermal regeneration of fine sand inside the rotating inner tank. The heat dissipation parts can effectively control the temperature of the base outer box, prevent the equipment from being damaged due to overheating, and ensure the safety of the production environment.
[0021] Firstly, this application provides a continuous extraction method for 3D printed sand, which uses a continuous extraction device for 3D printed sand to process used sand, and adopts the following technical solution: A continuous extraction method for 3D printing sand includes: sand block crushing: finely crushing the sand block using a sand crushing device; Primary screening particle size: The crushed sand blocks are separated into fine sand and small lumps by vibrating screen and discharged separately; High-temperature thermal regeneration: Fine sand is put into a heating device and heated to the ignition point of the fine sand. Oxygen is supplied to the heating device at the same time, and the fine sand continues to burn: the amount of fine sand is proportional to the combustion time, until the sand particles of the fine sand are burned through and turn into white sand. The generated waste gas is centrally treated. Low-temperature simmering: After the heating of the white sand is stopped, the white sand is simmered in the heating device using the residual heat until the white sand cools down to room temperature; Cooling and secondary screening particle size: White sand is discharged from the heating device to the secondary screening mechanism, where it is separated into finished sand and coarse sand, and the finished sand and coarse sand are collected separately.
[0022] By adopting the above technical solution, the sand block crushing step processes the sand blocks into suitable particle sizes; the primary screening separates the sand initially; the high-temperature thermal regeneration method uses high temperature and oxygen to burn the fine sand, remove impurities, and convert the fine sand into white sand, while simultaneously treating the waste gas centrally to reduce environmental pollution; the low-temperature smoldering utilizes the residual heat to further process the white sand, making its performance more stable; the cooling secondary screening separates the white sand into finished sand and large-particle sand, realizing the effective recycling and reuse of sand.
[0023] The continuous extraction method provided in this application integrates all steps, improving the efficiency and continuity of used sand processing while reducing labor costs and intensity. Compared with traditional methods, it reduces environmental pollution from waste sand dumping, achieves efficient recycling of used sand, and lowers the dependence of casting production on new sand, thereby significantly saving raw material costs. This aligns with the requirements of sustainable development and yields substantial economic and environmental benefits.
[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. The sand crushing device can vibrate and crush sand blocks and perform preliminary screening, breaking the sand blocks into fine sand and small lumps, providing suitable raw material particle size for subsequent processing; the rotary drive component drives the rotation of the rotating inner tank, and the heating shell provides heat energy to the entire rotating inner tank. With the cooperation of the stirring rod and stirring paddle, the fine sand can be fully heated during the heating process, ensuring uniform combustion of the fine sand and improving the effect of thermal regeneration. The secondary screening mechanism can screen the processed white sand into finished sand and large-particle sand, realizing effective separation and collection of sand. 2. During the heating process, the reinforcement components are fixedly connected to the stirring rod and the rotating inner liner to ensure the stability and reliability of the stirring structure. When the equipment is running, the stirring paddle can fully stir the fine sand inside the rotating inner liner during its rotation, allowing the fine sand to fully contact the heated surface of the inner wall of the rotating inner liner, further improving the heating uniformity of the fine sand. At the same time, the stirring paddle continuously turns the fine sand, which can create a good flow state in the rotating inner liner, which helps oxygen to contact the fine sand more fully. This allows the fine sand to burn more completely during the high-temperature thermal regeneration process, and also facilitates the subsequent discharge of sand, improving the quality and efficiency of old sand regeneration. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the overall structure of the sand crushing device in the embodiments of this application.
[0026] Figure 2 This is a schematic diagram of the structure of the sand crushing cylinder in the embodiments of this application.
[0027] Figure 3 This is a schematic diagram showing the cooperation between the heating device and the secondary screening mechanism in an embodiment of this application.
[0028] Figure 4 This is a schematic diagram of the cooperation between the hopper and the discharge component in an embodiment of this application.
[0029] Figure 5 yes Figure 3 Full sectional view.
[0030] Figure 6 yes Figure 3 Another sectional view.
[0031] Figure 7 This is a schematic diagram of the secondary screening mechanism in the embodiments of this application.
[0032] Explanation of reference numerals in the attached drawings: 1. Sand crushing device; 2. Sand crushing cylinder; 3. Vibration assembly; 31. Vibration motor; 32. Buffer component; 4. Primary screening mechanism; 41. Primary screening screen; 42. Storage tray; 5. Heating device; 51. Rotating inner tank; 511. Stirring rod; 512. Stirring paddle; 513. Driven gear; 514. Support roller; 52. Rotary drive assembly; 521. Rotary drive component; 522. Drive gear; 5 3. Heating shell; 531. Basic outer casing; 532. Heat dissipation components; 533. Connecting components; 534. Auxiliary wheels; 535. Heating rotary kiln; 6. Secondary screening mechanism; 61. Screening box; 62. Secondary screening screen; 63. Vibrating components; 7. Feed hopper; 8. Discharge components; 81. Discharge screw shaft; 82. Discharge driven sprocket; 83. Discharge driving sprocket; 84. Discharge chain; 85. Discharge motor; 9. Discharge hopper. Detailed Implementation
[0033] The following is in conjunction with the appendix Figure 1-7 This application will be described in further detail.
[0034] In a first aspect, embodiments of this application disclose a continuous extraction device for 3D printed sand.
[0035] Reference Figure 1 and Figure 3 A continuous sand extraction device for 3D printing includes a sand crushing device 1, a heating device 5, and a secondary screening mechanism 6. The sand crushing device 1, the heating device 5, and the secondary screening mechanism 6 work in sequence to process the waste sand generated by sand mold 3D printing and extract the finished sand that can be reused.
[0036] Specifically, refer to Figure 1 and Figure 2The sand crushing device 1 includes a sand crushing cylinder 2, a vibrating assembly 3, and a primary screening mechanism 4. The sand crushing cylinder 2 is a container for storing sand blocks. Its structure is usually a cylindrical structure with a certain volume. The material can be a sturdy and durable metal or a high-strength plastic material. It is required that it cannot chemically react with the old sand, ensuring that the old sand only undergoes physical changes in the sand crushing cylinder 2. The vibrating assembly 3 is installed on the working surface at the bottom of the crushing cylinder. Specifically, the vibrating assembly 3 can be composed of a vibrating motor 31, a vibration transmission component, and a buffer component 32. The vibration transmission component is assembled with both the sand crushing cylinder 2 and the output end of the vibrating motor 31. The vibrating motor 31 is the power source of the vibration, which can convert electrical energy into mechanical vibration energy. The vibration transmission component transmits the vibration generated by the vibrating motor 31 to the sand crushing cylinder 2. The buffer component 32 is set between the sand crushing cylinder 2 and the working surface, ensuring that the contraction direction of the buffer component 32 is consistent with the vibration direction. Its function is to buffer the impact of vibration on the working surface and reduce the noise and impact on the surrounding environment during equipment operation. In alternative solutions, in addition to the vibration motor 31, an electromagnetic vibrator or the like can also be used as the vibration source.
[0037] The primary screening mechanism 4 is installed in the middle of the crushing sand cylinder 2. It can adopt a screen structure. The aperture of the screen is determined according to the required fine sand particle size. The crushing sand cylinder 2 has at least two outlets and one inlet. The inlet is the opening of the crushing sand cylinder 2 from top to bottom, which is directly connected to the screen structure. The primary screening mechanism 4 includes at least a primary screening screen 41 and a storage tray 42. The primary screening screen 41 and the storage tray 42 are stacked in two layers with a certain distance between them. The two outlets are staggered and opened on the outer wall of the crushing sand cylinder 2, so that one outlet is connected to the primary screening screen 41 and the other outlet is connected to the storage tray 42.
[0038] During application, sand blocks are fed into the inlet. Under the action of the vibration component 3, the sand blocks are broken. Fine sand falls through the screen, while small clumps remain on the screen, thus achieving the separation of fine sand and small clumps. The fine sand is required to be in a flowing sand state with a particle size of 50-200 mesh. At this time, the sand particles are still all black granules, and the surface is covered with curing agent and resin after the cross-linking reaction. With continuous vibration, the storage pan 42 for carrying fine sand and the primary screen for carrying small clumps will be discharged through their respective outlets. The fine sand enters the subsequent heating device 5 for processing, while the small clumps can be further crushed or treated in other ways depending on the actual situation.
[0039] Reference Figures 3 to 5 The heating device 5 includes a rotating inner liner 51, a rotating drive assembly 52, and a heating outer shell 53. The rotating inner liner 51 is inclinedly disposed inside the heating outer shell 53. The rotating drive assembly 52 is disposed outside the rotating inner liner 51 and is assembled with the rotating inner liner 51 to drive the rotating inner liner 51 to rotate.
[0040] Specifically, the heating outer casing 53 includes a basic outer box 531, a heating rotary kiln 535, and a connecting member 533. The basic outer box 531 is a rectangular box, and the outer wall of the basic outer box 531 also includes a heat dissipation member 532. The heat dissipation member 532 can be a heat dissipation vent opened on the side wall of the basic outer box 531, or a heat dissipation fin or a cooling fan can be added on this basis. By setting a temperature sensor on the inner wall of the basic outer box 531, and electrically connecting the temperature sensor to the heat dissipation member 532, the preset temperature triggers the automatic temperature control function, and the heat dissipation member 532 can autonomously balance the temperature of the basic outer box 531.
[0041] The rotating inner liner 51 can be made of stainless steel and is a continuous cylindrical structure with feeding at one end and discharging at the other. It is a continuous heating structure and is placed at an angle in the middle of the rotating kiln 535. The rotating kiln 535 is an electrically heated rotary kiln, its shape adapted to the rotating inner liner 51, and it is required to completely enclose the inner liner 51. The base outer casing 531 provides support and protection for the rotating kiln 535, but it is required that the rotating kiln 535 can rotate 360° within the base outer casing 531. The rotating inner liner 51 and the rotating kiln 535 are connected by connector 533. When fixing, the connector 533 can be a connecting wing between the two. An auxiliary wheel 534 is provided on the base outer box 531, and a support wheel 514 is fixed to the end of the rotating inner liner 51. Two auxiliary wheels 534 are set at the bottom of the two support wheels 514, so that the two auxiliary wheels 534 rotate with the support wheel 514 at the same time. The three are arranged in a triangular distribution. Furthermore, multiple connecting wings are evenly distributed along the inner wall of the support wheel 514. Each connecting wing is fixed at one end to the rotating inner liner 51 and at the other end to the support wheel 514. The support wheel 514 is also welded and fixed to the side of the heating rotary kiln 535.
[0042] In this application, both ends of the heating rotary kiln 535 are equipped with support rollers 514. These two support rollers 514, together with corresponding auxiliary rollers 534 on the base outer casing 531, form a stable support structure. This design allows the rotating inner liner 51 and the heating rotary kiln 535 to rotate more smoothly under the drive of the rotary drive assembly 52. During operation, the synchronous rotation of the rotating inner liner 51 and the heating rotary kiln 535 ensures a more regular trajectory for the fine sand within the rotating inner liner 51. As the rotating inner liner 51 rotates, the fine sand continuously tumbles within it, making full contact with the heating surface of the inner wall of the rotating inner liner 51, allowing the fine sand to be heated evenly, which is beneficial for improving heating and combustion efficiency.
[0043] Furthermore, referring to Figure 5 and Figure 6A stirring rod 511 is provided in the middle of the rotating inner liner 51. The extension direction of the stirring rod 511 is consistent with the extension direction of the rotating inner liner 51. Multiple stirring paddles 512 are also provided on the outer wall of the stirring rod 511. A reinforcing member is provided between the end of the stirring rod 511 and the rotating inner liner 51, and the two are fixedly connected by the reinforcing member. The reinforcing member can be a connecting plate, which is connected to the stirring rod 511 and the rotating inner liner 51 by welding or bolting. Its function is to enhance the connection stability between the stirring rod 511 and the rotating inner liner 51 and prevent the stirring rod 511 from loosening during rotation. This application requires that the stirring rod 511 is always centered in the rotating inner liner 51, and the two are coaxially distributed. Both ends of the stirring rod 511 protrude from the rotating inner liner 51.
[0044] The rotary drive assembly 52 is located outside the input end of the rotary inner liner 51 and is assembled with the rotary inner liner 51 to drive the rotary inner liner 51 to rotate. The rotary drive assembly 52 includes a rotary drive component 521 and a drive gear 522. The rotary drive component 521 can be a motor or a motor-introduced gearbox combination. The motor drives the drive gear 522 to rotate through a shaft. The drive gear 522 meshes with the driven gear 513 fixed at the end of the rotary inner liner 51, thereby transmitting power to the rotary inner liner 51 to make it rotate.
[0045] Reference Figure 6 and Figure 7 A hopper 7 is provided outside the rotating inner liner 51. The bottom of the hopper 7 is connected to the input end of the rotating inner liner 51. A discharge component 8 is provided inside the hopper 7 to accelerate the discharge speed. The discharge component 8 includes a discharge screw shaft 81, a discharge driven sprocket 82, a discharge driving sprocket 83, a discharge chain 84, and a discharge motor 85. The discharge chain 84 meshes with both the discharge driving sprocket 83 and the discharge driven sprocket 82. The discharge screw shaft 81 is rotatably mounted in the middle of the hopper 7. The discharge driven sprocket 82 is fixed to the end of the discharge screw shaft 81 that extends out of the hopper 7. The discharge driving sprocket 83 is assembled with the discharge motor 85 via a shaft. When the equipment starts, the discharge motor 85 drives the discharge driving sprocket 83 to rotate, and transmits power to the discharge driven sprocket 82 through the discharge chain 84, thereby causing the discharge screw shaft 81 to rotate and accelerating the sand discharge speed.
[0046] The rotating inner liner 51 is equipped with a discharge hopper 9 on its outside. The discharge port of the discharge hopper 9 is connected to the output end of the rotating inner liner 51. The secondary screening mechanism 6 is located below the discharge hopper 9. The secondary screening mechanism 6 includes a screening box 61, a secondary screening screen 62, and a vibrating component 63. The screening box 61 is a rectangular box used to hold the secondary screening screen 62 and the white sand to be screened. The secondary screening screen 62 is installed in the middle of the screening box 61 and also adopts a screen structure. Its aperture size can be adjusted according to the particle size requirements of the finished sand. Vibrating component 63 is installed at the bottom of screening box 61. Vibrating component 63 can adopt the same or similar structure as the above-mentioned vibrating assembly 3. It is also composed of vibrating motor 31, vibration transmission component and buffer 32. Its working principle is similar. The vibrating motor 31 converts electrical energy into mechanical vibration energy, and then the vibration transmission component transmits the vibration to screening box 61, so that the white sand vibrates and rolls continuously on the secondary screening screen 62. The difference between primary screening mechanism 4 and secondary screening mechanism 6 is the size of the screen mesh diameter. The screen mesh diameter of primary screening mechanism 4 is used to separate fine sand with a particle size of 50-200 mesh, while the screen mesh diameter of secondary screening mechanism 6 is precisely set according to the specific particle size requirements of finished sand.
[0047] Furthermore, in an alternative to the vibration component 63, the vibration component 63 consists of a pneumatic vibrator and a vibration transmission rod. The pneumatic vibrator uses compressed air to generate vibration, and the vibration transmission rod transmits the vibration to the crushing sand cylinder 2. The advantage of this vibration component 63 is that the vibration frequency and amplitude can be controlled by adjusting the pressure and flow rate of the compressed air, making it more flexible, convenient, safe, and reliable.
[0048] During the secondary screening process, under the action of the vibrating component 63, fine sand that meets the particle size requirements of the finished sand will fall through the secondary screening screen 62 and into the finished sand collection area at the bottom of the screening box 61; while large sand particles remain on the secondary screening screen 62 and are discharged through the large sand outlet set on the screening box 61, so as to achieve fine screening of white sand and ensure that the quality of the finished sand is uniform and the particle size is consistent.
[0049] In this application, the combination logic of the heating device 5 is as follows: fine sand crushed and screened from the primary screening mechanism 4 is transferred to the feed hopper 7, and the efficiency and input amount of the sand entering the rotating inner liner 51 are controlled by the discharge component 8. The heating rotary kiln 535 heats the rotating inner liner 51, and the rotation drive component 52 drives the rotating inner liner 51 to rotate, so that the sand continuously tumbles inside the rotating inner liner 51. The stirring rod 511 and the stirring paddle 512 further stir the sand, making the sand more evenly heated. Simultaneously, the support roller 514 at the end of the heating rotary kiln 535 cooperates with the auxiliary roller 534 on the base outer box 531 to ensure the stable rotation of the rotating inner liner 51 and the heating rotary kiln 535.
[0050] Inside the rotating inner tank 51, fine sand undergoes thermal regeneration in a high-temperature environment. Oxygen is supplied to burn the fine sand, removing surface impurities and organic matter. As the inner tank 51 rotates, the burned fine sand gradually moves towards the output end and is finally discharged from the discharge hopper 9 to the secondary screening mechanism 6. Throughout the process, the heat dissipation component 532 monitors and adjusts the temperature of the base outer casing 531 in real time to prevent overheating.
[0051] The secondary screening mechanism 6 performs fine screening on the white sand discharged from the heating device 5, collecting the finished sand that meets the particle size requirements, while the large sand can be further processed according to actual needs, such as being crushed again and put back into the processing flow.
[0052] Secondly, this application discloses a continuous extraction method for 3D printed sand, which uses a continuous extraction device for 3D printed sand to process old sand.
[0053] Reference Figures 1 to 7 A continuous extraction method for 3D printing sand includes the following steps: S1, Sand block crushing: The sand block is finely crushed by the sand crushing device 1.
[0054] Specifically, the old sand blocks for 3D printing are fed into the top inlet of the crushing sand cylinder 2. After the vibration component 3 is started, the vibration motor 31 transmits the vibration to the crushing sand cylinder 2 through the transmission component, so that the sand blocks collide and rub against each other in the cylinder to achieve preliminary crushing. At the same time, the buffer component 32 can reduce the impact of vibration on the equipment and reduce noise.
[0055] S2, Primary screening particle size: The crushed sand blocks are separated into fine sand and small lumps by vibrating screen and discharged separately.
[0056] After the sand blocks are crushed in the crushing cylinder 2, the crushed sand particles pass through the primary screening screen 41 under vibration and fall into the storage pan 42 below. Small clumps that do not pass through the screen remain on the primary screening screen 41. The fine sand in the storage pan 42 is discharged through the outlet adjacent to it and then collected with a ton bag. The small clumps are collected through another outlet for subsequent processing.
[0057] S3, High-temperature thermal regeneration: Fine sand is put into heating device 5 and heated to the ignition point of fine sand. Oxygen is supplied to heating device 5 at the same time, and fine sand continues to burn: The amount of fine sand is proportional to the combustion time until the sand particles of fine sand are burned through and turn into white sand. The generated waste gas is centrally treated.
[0058] Specifically, after the fine sand is screened by the sand crushing device 1, it is fed into the hopper 7. After the discharge motor 85 is started, it drives the discharge drive sprocket 83 to rotate. Through the discharge chain 84, it drives the discharge driven sprocket 82 and the discharge spiral shaft 81 to rotate, pushing the fine sand evenly and quantitatively to the input end of the rotating inner liner 51. This can prevent the fine sand from accumulating in the hopper, ensure that the feeding speed matches the subsequent heating treatment, and realize continuous production.
[0059] The heating rotary kiln 535 heats the rotating inner liner 51, raising the internal temperature of the rotating inner liner 51 to between 750-800℃. The rotation drive component 52 drives the inner liner and the stirring rod 511 to rotate synchronously. The stirring paddle 512 continuously tumbles the fine sand, ensuring that it is in full contact with the heated surface of the inner wall of the inner liner.
[0060] Furthermore, the stirring rod 511 of this application adopts a round rod structure with an internal transmission channel. The stirring paddle 512 is actually a hollow lifting plate. The stirring paddle 512 is fixedly connected and internally connected. The heating device 5 is externally equipped with a rotatable blower and a branched air supply pipe, which is connected to the stirring rod 511. During the heating process of the rotating inner liner 51 by the heating rotary kiln 535, the blower simultaneously supplies oxygen to the rotating inner liner 51 and continues to rotate, raising the temperature of the rotating inner liner 51 to the ignition point of fine sand. At high temperature, the black resin surface layer and impurities of the sand particles are burned until the combustion is complete and the black sand turns white. This process takes more than 20 minutes.
[0061] The exhaust gas generated by combustion is collected centrally through a dedicated pipeline, treated by a purification device, and then discharged to avoid environmental pollution. At the same time, the heat sink 532 automatically adjusts the temperature of the base casing 531 based on the feedback from the temperature sensor to prevent the equipment from overheating and being damaged.
[0062] S4, Low-Temperature Firing: After heating the white sand is stopped, it is simmered in the heating device 5 using residual heat until it cools to room temperature. Once the fine sand is completely simmered and turns white, heating of the rotary kiln 535 is stopped, while the inner liner 51 continues to rotate, using residual heat for low-temperature simmering of the white sand. During this period, the high-temperature silica sand naturally undergoes an alpha phase transformation within a fluctuation range of around 570℃, accompanied by a volume expansion of 0.82%, which helps to further remove residual resin film and impurities. This, in turn, reduces the shrinkage and expansion rate of the sand mold in the later use of recycled sand, allowing for more precise control in sand casting. Then, the temperature is slowly reduced to 200-300℃ to further decompose residual organic matter and stabilize the sand particle properties.
[0063] S5, Cooling and Secondary Screening Particle Size: The inclined and rotating inner liner 51, under the combined action of the stirring rod 511 and the stirring paddle 512, discharges from the discharge hopper 9. The white sand falls onto the secondary screening mechanism 6. The vibrating component 63 drives the screening box 61 to vibrate. The sand particles that meet the particle size requirements of the finished sand pass through the secondary screening screen 62 and fall into the finished sand collection area. The large sand particles that do not pass through are discharged through a special outlet and can be returned to the crushing device 1 for reprocessing. Finally, the white sand is divided into finished sand and large sand, and the finished sand and large sand are collected separately.
[0064] In this application, the parameters of each step, such as the vibration frequency of the crushed sand, the heating temperature and time, and the oxygen flow rate, can be flexibly adjusted according to actual production needs and the characteristics of the sand throughout the entire process to achieve the best treatment effect and further improve the quality and efficiency of old sand recycling.
[0065] The above are all preferred embodiments of this application. These embodiments are merely explanations of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of this application should be covered within the scope of protection of this application.
Claims
1. A continuous extraction device for 3D printed sand, characterized in that, include: The sand crushing device (1) includes a sand crushing cylinder (2), a vibration component (3) and a primary screening mechanism (4). The vibration component (3) is installed at the bottom of the crushing cylinder, and the output end of the vibration component (3) is assembled with the crushing cylinder to crush the sand blocks stored in the crushing cylinder. The primary screening mechanism (4) is installed in the middle of the cylinder to separate fine sand and small lumps. The heating device (5) includes a rotating inner liner (51), a rotating drive assembly (52), and a heating outer shell (53). The rotating inner liner (51) is inclinedly disposed inside the heating outer shell (53). The rotating drive assembly (52) is disposed outside the rotating inner liner (51). The rotating drive assembly (52) is assembled with the rotating inner liner (51) to drive the rotating inner liner (51) to rotate. The secondary screening mechanism (6) is located at the output end of the rotating inner liner (51) and is used to carry and screen finished sand and large sand particles.
2. The 3D printing sand continuous extraction device according to claim 1, characterized in that, A stirring rod (511) is provided in the middle of the rotating inner liner (51). The extension direction of the stirring rod (511) is consistent with the extension direction of the rotating inner liner (51). A plurality of stirring paddles (512) are also provided on the outer wall of the stirring rod (511).
3. The 3D printing sand continuous extraction device according to claim 2, characterized in that, A reinforcing member is provided between the end of the stirring rod (511) and the rotating inner liner (51), and the two are fixedly connected by the reinforcing member.
4. The 3D printing sand continuous extraction device according to claim 1, characterized in that, The rotary drive assembly (52) includes a rotary drive member (521) and a drive gear (522). The drive gear (522) is assembled with the rotary drive member (521) via a shaft. A driven gear (513) is fixed to the end of the rotary inner liner (51) that extends out of the rotary inner liner (51). The driven gear (513) meshes with the drive gear (522).
5. The 3D printing sand continuous extraction device according to claim 4, characterized in that, The rotating inner liner (51) is fixed with a support wheel (514) near the driven gear (513). The support wheel (514) is coaxially arranged with the driven gear (513). An auxiliary wheel (534) is installed on the heating outer shell (53). The auxiliary wheel (534) rotates rubbing against the support wheel (514).
6. The 3D printing sand continuous extraction device according to claim 5, characterized in that, The two auxiliary wheels (534) are located at the bottom of the two supporting wheels (514), so that the two auxiliary wheels (534) rotate with the supporting wheel (514) simultaneously, and the three are arranged in a triangular distribution.
7. The 3D printing sand continuous extraction device according to claim 1, characterized in that, The rotating inner liner (51) is provided with a feeding hopper (7) on its outside. The bottom of the feeding hopper (7) is connected to the input end of the rotating inner liner (51). The feeding hopper (7) is provided with a discharge component (8) inside, which is used to speed up the feeding speed of the feeding hopper (7).
8. The 3D printing sand continuous extraction device according to claim 7, characterized in that, The discharge component (8) includes a discharge screw shaft (81), a discharge driven sprocket (82), a discharge driving sprocket (83), a discharge chain (84), and a discharge motor (85). The discharge chain (84) meshes with both the discharge driving sprocket (83) and the discharge driven sprocket (82). The discharge screw shaft (81) is rotatably mounted in the middle of the hopper (7). The discharge driven sprocket (82) is fixed at the end of the discharge screw shaft (81) that extends out of the hopper (7). The discharge driving sprocket (83) is connected to the discharge motor (85) via a shaft.
9. The 3D printing sand continuous extraction device according to claim 1, characterized in that, The heating outer shell (53) includes a base outer box (531), a heating rotary kiln (535), and a connector (533). The rotating inner liner (51) is fixed in the middle of the heating rotary kiln (535) by the connector (533). The heating rotary kiln (535) is rotatably installed in the middle of the base outer box (531). The outer wall of the base outer box (531) also includes a heat dissipation component (532). The heating rotary kiln (535) heats the rotating inner liner (51), and the heat generated is discharged to the outside through the heat dissipation component (532).
10. A continuous extraction method for 3D printing sand, using the continuous extraction equipment for 3D printing sand according to any one of claims 1-9 to process used sand, characterized in that, The processing steps include the following: Sand block crushing: The sand blocks are finely crushed by a sand crushing device (1); Primary screening particle size: The crushed sand blocks are separated into fine sand and small lumps by vibrating screen and discharged separately; High-temperature thermal regeneration: Fine sand is put into the heating device (5) and heated to the ignition point of fine sand. At the same time, oxygen is supplied to the heating device (5) and the fine sand continues to burn: The amount of fine sand is proportional to the burning time until the sand particles of fine sand are burned through and turn into white sand. The generated waste gas is centrally treated. Low-temperature simmering: After the heating of the white sand is stopped, the white sand is simmered in the heating device (5) using the residual heat until the white sand cools down to room temperature; Cooling and secondary screening particle size: White sand is discharged from the heating device (5) to the secondary screening mechanism (6) and is divided into finished sand and large sand, and the finished sand and large sand are collected separately.