Concentric shaft dual power vertical sand mill

Abstract

The application discloses a concentric shaft double-power vertical sand mill, an inner shaft of which extends downward into a main shaft and passes through a grinding working part to enter a stirring cavity, and a separation turbine is communicated with a discharging channel upward or downward on the middle shaft; the concentric shaft double-power vertical sand mill provided by the application is free of mechanical seal and can reduce maintenance by more than 90% through the arrangement of a feeding bin and an outer threaded sleeve; the outer threaded sleeve generates downward driving force to downwardly convey slurry in the feeding bin, reduces the proportion of upward escaping of the slurry in the stirring cavity barrel, also increases the pressure in the stirring cavity barrel, and guarantees smooth vertical discharging; the main shaft and the inner shaft are vertically installed and concentrically arranged, are uniformly stressed in the circumferential direction, have extremely small vibration and jumping, are stably operated, the probability of instantaneous opening of micro cracks of a support structure due to vibration is greatly reduced, the probability of grinding medium fragments and powder particles entering a sealing surface of the support structure is reduced, and the service life is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of dual-power sand mills, and particularly to a concentric shaft dual-power vertical sand mill. Background Technology

[0002] In existing technology, media mills mainly consist of a cylinder, a stirring device installed inside the cylinder, and a stirring shaft that drives the stirring device. Conventional media mills typically separate the material from the stirring medium using a screen; some improved mills utilize centrifugal principles and a separating turbine. The power for the separating turbine can share the power of the stirring shaft or be connected to a separate drive shaft. Mills with their own drive shaft (also called separating shaft) are generally called dual-power mills. In horizontal dual-power mills, the stirring shaft and separating shaft are located at opposite ends of the stirring chamber and are each driven by a separate motor. The stirring rotor is suspended on the horizontal stirring shaft, and the separating turbine is suspended on the horizontal separating shaft. Therefore, the forces (gravity, etc.) are unbalanced, resulting in poor dynamic balance, large vibrations, and high noise. Before starting the horizontal mill, the grinding media settles and accumulates around the mechanical seal under gravity, easily entering the gaps in the mechanical seal spring structure. This affects the spring's clamping action, the compensation for runout and wear on the sealing surface, and ultimately, seal failure (leakage). Furthermore, due to the unbalanced force and large vibration of the horizontal sand mill, the sealing surfaces of the dynamic and static rings of the mechanical seal are prone to momentary slight opening when the machine vibrates. Particles in the slurry or broken grinding media particles enter the sealing surfaces of the dynamic and static rings, which will roughen and wear the sealing surfaces of the dynamic and static rings, thus causing leakage of the sealing surfaces. The existing vertical dual-power structure features a cylindrical grinding chamber mounted vertically. The separator shaft, driving the separator turbine, is vertically mounted above the grinding chamber, extending into the chamber and fitting with the turbine. A mechanical seal is installed between the separator shaft and the upper cover of the grinding chamber. A pulley is mounted on the upper end of the separator shaft, and the separator motor drives the shaft via a belt. A belt drive connects the pulley to the motor shaft's pulley. A transmission seat with two bearings connects the pulley to the mechanical seal, housing the transmission shaft for power transmission. The stirring shaft, driving the stirring rotor, is mounted below the grinding chamber, extending to its bottom. The stirring rotor is mounted on the upper end of the shaft, and a pulley is mounted on the lower end. The grinding motor drives the stirring shaft via a belt. A mechanical seal is installed between the stirring shaft and the lower cover of the grinding chamber. A transmission seat with two bearings between the pulley and the mechanical seal secures the main shaft and transmits power.

[0003] The mechanical seal of the agitator shaft is installed at the bottom of the grinding chamber. When the machine is stopped, all the grinding media sinks and accumulates around the mechanical seal. After the machine starts, ultrafine grinding media and relatively coarse powder particles can easily enter the gaps in the mechanical seal structure, jamming the spring's extension and contraction. This prevents the spring from compressing and compensating for wear, leading to mechanical seal leakage. The mechanical seal has a very high maintenance rate and high operating costs. The agitator shaft, its mechanical seal, and the transmission device are installed at the bottom of the grinding chamber, close to the ground, making installation, disassembly, discharge of grinding media, slurry discharge, and maintenance very difficult. Furthermore, the overall large size of the sand mill, its large space occupation, complex structure, and numerous parts also increase costs. Summary of the Invention

[0004] The main objective of this invention is to provide a concentric shaft dual-power vertical sand mill, which aims to solve the problems of large footprint, unstable working part, and easy sealing failure in current dual-power sand mills.

[0005] To achieve the above objectives, the present invention provides a concentric shaft dual-power vertical sand mill, comprising: Base; A stirring chamber is installed on the base, and the interior of the stirring chamber is a stirring chamber. A feeding hopper is connected to the top of the mixing chamber and leads to the mixing chamber. A feeding port is provided on the outer wall of the feeding hopper, and a columnar feeding channel is provided at the connection between the feeding hopper and the mixing chamber. A tubular main shaft is rotatably mounted on the base via bearings. The main shaft passes downward through the feed hopper and extends into the mixing chamber. The outer end of the main shaft is the power input end, while the inner end is connected to the grinding working part. An external threaded sleeve is connected to the inner wall of the main shaft and corresponds to the position of the feeding channel. The outer periphery of the external threaded sleeve is provided with a driving thread. The inner shaft extends downward into the main shaft and passes through the grinding working part to enter the mixing chamber. The inner shaft is rotatably mounted on the base and / or the main shaft via bearings. The outer end of the inner shaft is the power input end, while the inner end is connected to a cylindrical separation turbine. The separation turbine has a discharge channel that is connected upward or downward on the central shaft. A support structure is provided between the inner shaft and the main shaft to provide support while ensuring the smooth rotation of the inner shaft and the main shaft.

[0006] Furthermore, the inner shaft is tubular and connects to the separating turbine, and the central space of the tubular inner shaft forms the discharge channel.

[0007] Furthermore, the concentric shaft dual-power vertical sand mill also includes a discharge pipe, which extends from below the mixing chamber into the separating turbine, and the central axis of the discharge pipe forms the discharge channel.

[0008] Furthermore, the upper and lower ends of the separating turbine are respectively provided with an upper sealing plate and a lower sealing plate. The thickness direction of the upper sealing plate and the lower end of the inner shaft together form a separation cavity corresponding to the discharge pipe. The discharge pipe extends into the separation cavity. The outer periphery of the discharge pipe and the inner periphery of the separation cavity, as well as the upper end of the discharge pipe and the upper end of the separation cavity, are all clearance fit.

[0009] Furthermore, the upper and lower ends of the separating turbine are respectively provided with an upper sealing plate and a lower sealing plate. A separation cavity corresponding to the discharge pipe is formed on the upper sealing plate. The discharge pipe extends into the separation cavity. The outer periphery of the discharge pipe and the inner periphery of the separation cavity, as well as the upper end of the discharge pipe and the upper end of the separation cavity, are all clearance fit.

[0010] Furthermore, the support structure is positioned above the top of the feed hopper.

[0011] Furthermore, a cover plate is provided on the top of the feed hopper, and a mechanical seal is provided between the cover plate and the main shaft.

[0012] Furthermore, the concentric shaft dual-power vertical sand mill also includes a pneumatic system, which is introduced into the upper part of the feed hopper.

[0013] Furthermore, the feed hopper is equipped with a liquid level sensor for detecting and outputting liquid level information.

[0014] Furthermore, the grinding working part has a downward-opening barrel-shaped structure, and an inner stator is provided at the bottom of the stirring chamber corresponding to the grinding working part, and a driving thread structure is provided on the outer periphery of the inner stator.

[0015] Compared with the prior art, the beneficial effects of the present invention are: The concentric shaft dual-power vertical sand mill provided by this invention eliminates the need for sealing between the main shaft and the mixing chamber by using a feed hopper and an external threaded sleeve. This eliminates the need for a mechanical seal, reducing maintenance by more than 90%. The external threaded sleeve generates a downward driving force, conveying the slurry in the feed hopper downwards, reducing the proportion of slurry escaping upwards from the mixing chamber, and increasing the pressure in the mixing chamber, ensuring smooth vertical discharge. The vertically installed and concentrically arranged main shaft and inner shaft significantly reduce the space dimensions, resulting in uniform force distribution in the 360-degree circumferential direction, minimal vibration and runout, and stable operation. This also significantly reduces the probability of the support structure momentarily opening micro-slits due to vibration, and the probability of grinding media fragments and powder particles entering the sealing surface of the support structure, thus greatly extending its lifespan. When the mill stops, the grinding media sinks to the bottom of the mixing chamber, away from the support structure. When the mill starts, there are no grinding media around the support structure that could harm the mechanical seal, improving the working stability of the support structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram (first perspective) of the first embodiment of the concentric shaft dual-power vertical sand mill of the present invention. Figure 2 This is a schematic diagram (second perspective) of the first embodiment of the concentric shaft dual-power vertical sand mill of the present invention. Figure 3 yes Figure 2 A local magnification; Figure 4 This is an assembly diagram of the main shaft and inner shaft in the concentric shaft dual-power vertical sand mill of the first embodiment of the present invention; Figure 5 This is a schematic diagram of the second embodiment of the concentric shaft dual-power vertical sand mill of the present invention; Figure 6 This is a schematic diagram of the third embodiment of the present invention: a concentric shaft dual-power vertical sand mill. Detailed Implementation

[0017] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0018] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, units, modules, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, units, modules, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connection or wireless coupling. The term “and / or” as used herein includes all or any of the units and all combinations of one or more associated listed items.

[0019] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0020] Reference Figures 1 to 6 In one embodiment of the present invention, a concentric shaft dual-power vertical sand mill includes: Base 100; A stirring chamber 200 is installed on the base 100, and the interior of the stirring chamber 200 is a stirring chamber 210; A feeding hopper 300 is connected to the top of the mixing chamber 200 and leads to the mixing chamber 210. A feeding port 320 is provided on the outer wall of the feeding hopper 300. A columnar feeding channel 310 is provided at the connection between the feeding hopper 300 and the mixing chamber 200. A tubular main shaft 400 is rotatably mounted on the base 100 via bearings. The main shaft 400 passes downward through the feed bin 300 and extends into the mixing chamber 200. The outer end of the main shaft 400 is the power input end, while the inner end is connected to the grinding working part 410. An external threaded sleeve 500 is connected to the inner wall of the main shaft 400 and corresponds to the position of the feeding channel 310. The outer periphery of the external threaded sleeve 500 is provided with a driving thread. An inner shaft 600 extends downward into the main shaft 400 and passes through the grinding working part 410 to enter the stirring chamber 210. The inner shaft 600 is rotatably mounted on the base 100 and / or the main shaft 400 via bearings. The outer end of the inner shaft 600 is the power input end, while the inner end is connected to a cylindrical separating turbine 610. The separating turbine 610 has a discharge channel that is connected upward or downward on the central shaft. The support structure 700 is disposed between the inner shaft 600 and the main shaft 400 to provide support while ensuring the smooth rotation of the inner shaft 600 and the main shaft 400.

[0021] In the existing technology, the mechanical seal of the stirring shaft is installed at the bottom of the grinding chamber. The mechanical seal has a very high maintenance rate and high operating cost. At the same time, the large height of the entire sand mill, the large space it occupies, the complex structure and the many parts also increase the cost.

[0022] The concentric shaft dual-power vertical sand mill provided by the present invention has a base 100 that can be an integral structure or a split structure, which is not limited here, and is used to provide support for the entire sand mill.

[0023] The mixing chamber 200 is mounted on the base 100 and has an internal mixing chamber 210. The mixing chamber 200 serves as a container for materials and mixing media, thereby completing the grinding action. The installation structure of the mixing chamber 200 is not limited, and both the top and bottom of the mixing chamber 200 can be detachable.

[0024] The feed hopper 300 is connected to the top of the mixing chamber 200 and leads to the mixing chamber 210. A columnar feeding channel 310 is provided at the connection between the feed hopper 300 and the mixing chamber 200. A feed inlet 320 is provided on the outer wall of the feed hopper 300, and a cover plate 330 is provided on the top. The feed inlet 320 can be connected to a pumping system to complete the feeding action. The feed hopper 300 can be funnel-shaped, etc., serving the functions of feeding and storing materials. The columnar feeding channel 310 is provided at the connection between the feed hopper 300 and the mixing chamber 200. The feeding channel 310 can be formed in the feed hopper 300 and / or the mixing chamber 200, specifically achieved through machining at corresponding positions in the feed hopper 300 and / or the mixing chamber 200. Alternatively, the feeding channel 310 can be implemented by a component independent of the feeding bin 300 and the mixing chamber 200. For example, a profile tube can be provided at the connection between the feeding bin 300 and the mixing chamber 200 to form the feeding channel 310.

[0025] A tubular main shaft 400 is rotatably mounted on a base 100 via multiple bearings. The main shaft 400 is generally tubular, but not limited to a precise circular tube. The main shaft 400 is vertically mounted, passing through a feed hopper 300 and entering the mixing chamber 200 of the vertical sand mill. The outer end of the main shaft 400 is connected to an external grinding motor 010, such as a rotary motor, enabling high-speed rotation. The inner end of the main shaft 400 is connected to a grinding working section 410, the shape of which is designed according to actual grinding requirements. A pulley or similar device can be mounted on the outer end of the main shaft 400 to provide a foundation for the power output of the grinding motor 010.

[0026] The external threaded sleeve 500 is connected to the inner wall of the main shaft 400 at a position corresponding to the feeding channel 310. A drive thread is provided on the outer circumference of the external threaded sleeve 500. When the main shaft 400 rotates, the external threaded sleeve 500 rotates accordingly, and the drive thread generates a downward driving force. This force conveys the slurry in the feed hopper 300 downwards and reduces the proportion of slurry escaping upwards from the mixing chamber 200. The external threaded sleeve 500 provides the downward force for the slurry in the feed hopper 300 and also provides the force for the slurry to exit from the mixing chamber 200.

[0027] The inner shaft 600 extends downward into the main shaft 400 and passes through the grinding working part 410 to enter the stirring chamber 210. The main shaft 400 and the inner shaft 600 are fitted together, significantly reducing the spatial dimensions, simplifying coaxial alignment, and improving operational stability. The inner shaft 600 is rotatably mounted on the base 100. For example, one or more bearings are provided on the base 100, and the inner shaft 600 passes through these bearings to achieve rotation. Alternatively, a bearing structure is provided between the inner shaft 600 and the main shaft 400, thus fixing the inner shaft 600 to the main shaft 400. For example, a step is provided inside the main shaft 400, and a bearing is installed on the step, with the inner shaft 600 fixed to the bearing. When the inner shaft 600 is fixed to the main shaft 400, installation convenience is improved, and concentricity is easily achieved and maintained. The outer end of the inner shaft 600 is the power input end, while the inner end is connected to a cylindrical separator turbine 610. A pulley or similar device can be provided at the outer end of the inner shaft 600 to provide a foundation for the power output of the separator motor 020. The separating turbine 610 has a discharge channel connected upwards or downwards on its central shaft. The central shaft of the separating turbine 610 also refers to the central shaft of the main shaft 400, the mixing chamber 200, and the inner shaft 600. The inner shaft 600 can be solid or tubular. When the inner shaft 600 is solid, the discharge direction of the concentric shaft dual-power vertical sand mill is downwards, and the discharge channel is separately provided, as detailed in subsequent embodiments. When the inner shaft 600 is tubular, the concentric shaft dual-power vertical sand mill discharges material upwards through the inner shaft 600, and the discharge channel is formed in the middle of the inner shaft 600, as detailed in subsequent embodiments.

[0028] A support structure 700 is positioned between the inner shaft 600 and the main shaft 400 to provide support. Since the inner shaft 600 is inserted at the upper end of the main shaft 400, its stability at the lower end is relatively weak; the support structure 700 provides supplementary support. The support structure 700 can take various forms, such as various types of rotary bearings, with the specific model designed according to the structure at the mating point of the inner shaft 600 and the main shaft 400. The support structure 700 can be positioned at the middle and / or lower part of the inner shaft 600 in the height direction.

[0029] During operation, the slurry in the feed hopper 300 flows downward into the mixing chamber 200, and the grinding unit 410 grinds the slurry. Under the action of various driving forces (the feed pressure provided by the external threaded sleeve 500 and the negative pressure of the discharge device, etc.), the slurry enters the separation turbine 610 under pressure. Since the mass and size of a single grinding media are much larger than the mass and size of the material particles, the high-speed rotation of the separation turbine 610 achieves the separation of the grinding media and the material particles.

[0030] In summary, the use of the feed hopper 300 and the external threaded sleeve 500 eliminates the need for a seal between the main shaft 400 and the mixing chamber 200, thus reducing maintenance by over 90% by eliminating the need for a mechanical seal. The external threaded sleeve 500 generates a downward driving force, conveying the slurry in the feed hopper 300 downwards, reducing the proportion of slurry escaping upwards from the mixing chamber 200, and increasing the pressure in the mixing chamber 200, ensuring smooth vertical discharge. The vertically installed and concentrically positioned main shaft 400 and inner shaft 600 minimize space constraints. With a significant reduction in size, the force is evenly distributed in the 360-degree circumferential direction, resulting in minimal vibration and jumping. While ensuring stable operation, the probability of the support structure 700 momentarily opening micro-slits due to vibration is greatly reduced, as is the probability of grinding media fragments and powder particles entering the sealing surface of the support structure 700, thus significantly increasing its lifespan. When the machine is stopped, the grinding media sinks to the bottom of the mixing chamber 200, away from the support structure 700. When the sand mill is started, there are no grinding media around the support structure 700 that are detrimental to the mechanical seal, improving the working stability of the support structure 700.

[0031] Reference Figures 1 to 4 In one embodiment, the inner shaft 600 is tubular and connected to the separating turbine 610, and the central space of the tubular inner shaft 600 forms the discharge channel.

[0032] In this embodiment, the inner shaft 600 is used to complete the discharge, eliminating the need for a separate discharge structure. The inner shaft 600 is generally tubular, but is not limited to a precise circular tube. The separating turbine 610 can be a cylindrical shape with closed top and bottom. The inner shaft 600 leads from the top into the separating turbine 610, and multiple penetrating turbine grooves are provided on the peripheral wall of the separating turbine 610 to improve the separation effect. During operation, the slurry in the feed bin 300 enters the mixing chamber 200 downwards, and the grinding working part 410 completes the grinding of the slurry. Under the action of various driving forces (the feed pressure provided by the external threaded sleeve 500 and the negative pressure of the discharge device, etc.), the slurry enters the separating turbine 610 under pressure. Since the mass and size of a single grinding media are much larger than the mass and size of the material particles, the high-speed rotation of the separating turbine 610 achieves the separation of the grinding media and the material particles. The discharge channel is located at the central shaft of the separating turbine 610. Due to centrifugal force, the grinding media at this location is essentially non-existent, and the slurry is discharged outside the concentric shaft dual-power vertical sand mill through the inner shaft 600. When the machine stops, the grinding media settles under gravity and will not abnormally remain in the inner shaft 600.

[0033] Reference Figure 5 In one embodiment, the concentric shaft dual-power vertical sand mill further includes a discharge pipe 800, which extends from below the mixing chamber 200 into the separating turbine 610, and the central axis of the discharge pipe 800 forms the discharge channel.

[0034] In this embodiment, a discharge channel is formed by adding a discharge pipe 800. In this case, the concentric shaft dual-power vertical sand mill uses a bottom discharge method, reducing operational difficulty and eliminating the rotary joint problem associated with top discharge. The separating turbine 610 has an upper sealing plate and a lower sealing plate at its upper and lower ends, respectively. The discharge pipe 800 passes through the lower sealing plate and extends into the separating turbine 610. The specific structural form can vary and will be described in detail in subsequent embodiments. The inner end of the discharge pipe 800 is located at the central shaft of the separating turbine 610. Due to centrifugal force, the grinding media at this location is essentially nonexistent, and the slurry is discharged outside the concentric shaft dual-power vertical sand mill through the inner shaft 600.

[0035] Reference Figure 6 In one embodiment, the upper and lower ends of the separating turbine 610 are respectively provided with an upper sealing plate and a lower sealing plate. The upper sealing plate and the lower end of the inner shaft 600 together form a separating cavity 620 corresponding to the discharge pipe 800. The discharge pipe 800 extends into the separating cavity 620. The outer periphery of the discharge pipe 800 and the inner periphery of the separating cavity 620, as well as the upper end of the discharge pipe 800 and the upper end of the separating cavity 620, are all clearance fit.

[0036] In this embodiment, the upper sealing plate has a through hole, and the lower end of the inner shaft 600 has a blind hole, together forming the separation chamber 620. The discharge pipe 800 passes through the lower sealing plate and extends into the separation turbine 610, further entering the separation chamber 620, with both the circumferential and upper ends of the discharge pipe 800 forming a clearance fit with the separation chamber 620. The slurry entering the separation turbine 610 further passes through the gap between the outer circumference of the discharge pipe 800 and the inner circumference of the separation chamber 620, entering the upper end of the discharge pipe 800, and finally entering the discharge pipe 800. During this process, the gap between the discharge pipe 800 and the separation chamber 620 serves as the entry point for the slurry and can also exclude the grinding media, further reducing the possibility of grinding media entering the discharge pipe 800. The size of the gap is designed according to the size of the grinding media, for example, selected between 0.05 mm and 2 mm. When the size of the grinding media is extremely small, the size of the gap can be less than 0.05 mm. The inner end of the discharge pipe 800 is at the central shaft of the separating turbine 610. Under the action of centrifugal force, the grinding media at this position is basically gone, and the slurry is discharged out of the concentric shaft dual-power vertical sand mill through the inner shaft 600.

[0037] In one embodiment, the separating turbine 610 is provided with an upper sealing plate and a lower sealing plate at its upper and lower ends, respectively. A separating cavity 620 corresponding to the discharge pipe is formed on the upper sealing plate. The discharge pipe 800 extends into the separating cavity 620. The outer periphery of the discharge pipe 800 and the inner periphery of the separating cavity 620, as well as the upper end of the discharge pipe 800 and the upper end of the separating cavity 620, are all clearance fit.

[0038] In this embodiment, the discharge pipe 800 passes through the lower sealing plate and extends into the separating turbine 610, further entering the separating chamber 620. The circumferential and upper ends of the discharge pipe 800 form a clearance fit with the separating chamber 620. The slurry entering the separating turbine 610 further passes through the gap between the outer circumference of the discharge pipe 800 and the inner circumference of the separating chamber 620, entering the upper end of the discharge pipe 800 and finally entering the discharge pipe 800. During this process, the gap between the discharge pipe 800 and the separating chamber 620 serves as the entry point for the slurry and also excludes the grinding media, further reducing the likelihood of grinding media entering the discharge pipe 800. The size of this gap is designed according to the size of the grinding media, for example, between 0.05 mm and 2 mm. If the grinding media size is extremely small, the gap size can be less than 0.05 mm. Since the separating chamber 620 is only formed in the upper sealing plate, the operating parameters can be adjusted by replacing the separating turbine 610 or the upper sealing plate.

[0039] Reference Figure 6 In one embodiment, the support structure 700 is positioned above the top of the feed hopper 300.

[0040] In this embodiment, with top discharge, the position of the support structure 700 is raised above the top of the feed hopper 300. In this case, the slurry level in the concentric shaft dual-power vertical sand mill will not be higher than the support structure 700, which greatly reduces the possibility of abnormality in the support structure 700.

[0041] Reference Figure 6 In one embodiment, a cover plate 330 is provided on the top of the feed hopper 300, and a mechanical seal 340 is provided between the cover plate 330 and the main shaft 400.

[0042] In this embodiment, the connection between the cover plate 330 and the feed hopper 300 can be via clamps or similar means, which are not the focus of this application. The mechanical seal 340 provides a seal between the feed hopper 300 and the main shaft 400, reducing gas leakage from the feed hopper 300 and significantly improving operational safety under volatile conditions. The static sealing ring is fixed to the cover plate 330, while the dynamic sealing ring moves with the inner shaft 600. An elastic compensation structure can be provided on the free end face of the dynamic sealing ring to ensure that the opposing end faces of the static and dynamic sealing rings fit together. The static sealing ring is connected to a cooling system to cool both the dynamic and static sealing rings. The structure of the cooling system can be varied; common structural forms are referenced, but are not the focus of this application.

[0043] In one embodiment, the concentric shaft dual-power vertical sand mill further includes a pneumatic system, which is introduced into the upper part of the feed hopper 300.

[0044] In this embodiment, a pneumatic system is added to the feed hopper 300 to provide air pressure and atmosphere to the space above the liquid surface in the feed hopper 300. This ensures the working pressure while also providing a protective atmosphere as needed. For example, the pneumatic system includes a pneumatic pump, an air source, and a pressure sensor. The pneumatic pump pumps the air source into the feed hopper 300, while the pressure sensor detects the air pressure in the upper space of the feed hopper 300 and controls the air pressure through the control of the pneumatic pump. The air source can be air, nitrogen, or an inert gas, etc.

[0045] Reference Figure 6 In one embodiment, a level sensor 350 for detecting and outputting liquid level information is provided inside the feed hopper 300.

[0046] In this embodiment, the liquid level in the feed hopper 300 is monitored by a liquid level sensor 350 to provide indication for slurry delivery. The operating type of the liquid level sensor 350 is not limited, as long as it can detect liquid level information.

[0047] Reference Figure 6 In one embodiment, the grinding working part 410 has a downward-opening barrel-shaped structure, and the bottom of the stirring chamber barrel 200 is provided with an inner stator 420 corresponding to the grinding working part 410. The outer periphery of the inner stator 420 is provided with a driving thread structure.

[0048] In this embodiment, due to the setting of the inner stator 420, during the rotation of the grinding working part 410, the slurry is driven to rotate due to the viscosity and is driven on the outer periphery of the inner stator 420.

[0049] In summary, the concentric shaft dual-power vertical sand mill provided by this invention, through the setting of the feed hopper 300 and the external threaded sleeve 500, eliminates the need for sealing between the main shaft 400 and the mixing chamber 200, thus eliminating the need for a mechanical seal and reducing maintenance by more than 90%. The external threaded sleeve 500 generates a downward driving force, conveying the slurry in the feed hopper 300 downwards, reducing the proportion of slurry escaping upwards from the mixing chamber 200, and also increasing the pressure in the mixing chamber 200, ensuring smooth vertical discharge. The vertically installed and concentrically set main shaft 400... With the inner shaft 600, the spatial dimensions are significantly reduced, resulting in uniform force distribution in the 360-degree circumferential direction, minimal vibration and jumping, and stable operation. At the same time, the probability of the support structure 700 momentarily opening micro-slits due to vibration is greatly reduced, as is the probability of grinding media fragments and powder particles entering the sealing surface of the support structure 700, thus significantly increasing its service life. When the machine is stopped, the grinding media sinks to the bottom of the mixing chamber 200, away from the support structure 700. When the sand mill is started, there are no grinding media around the support structure 700 that are detrimental to the mechanical seal, improving the working stability of the support structure 700.

[0050] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A concentric shaft dual-power vertical sand mill, characterized in that, include: Base (100); A stirring chamber (200) is installed on the base (100), and the interior of the stirring chamber (200) is a stirring chamber (210). A feeding hopper (300) is connected to the top of the mixing chamber (200) and leads to the mixing chamber (210). A feeding port (320) is provided on the outer wall of the feeding hopper (300). A columnar feeding channel (310) is provided at the connection between the feeding hopper (300) and the mixing chamber (200). A tubular main shaft (400) is rotatably mounted on the base (100) via bearings. The main shaft (400) passes downward through the feed bin (300) and extends into the mixing chamber (200). The outer end of the main shaft (400) is the power input end, while the inner end is connected to the grinding working part (410). An external threaded sleeve (500) is connected to the inner wall of the main shaft (400) and corresponds to the position of the feeding channel (310). The outer periphery of the external threaded sleeve (500) is provided with a driving thread. An inner shaft (600) extends downward into the main shaft (400) and passes through the grinding working part (410) to enter the stirring chamber (210). The inner shaft (600) is rotatably mounted on the base (100) and / or the main shaft (400) via bearings. The outer end of the inner shaft (600) is the power input end, while the inner end is connected to a cylindrical separating turbine (610). The separating turbine (610) has a discharge channel that is connected upward or downward on the central shaft. A support structure (700) is disposed between the inner shaft (600) and the main shaft (400) to provide support while ensuring the smooth rotation of the inner shaft (600) and the main shaft (400).

2. The concentric shaft dual-power vertical sand mill according to claim 1, characterized in that, The inner shaft (600) is tubular and leads to the separating turbine (610), and the central space of the tubular inner shaft (600) forms the discharge channel.

3. The concentric shaft dual-power vertical sand mill according to claim 1, characterized in that, The concentric shaft dual-power vertical sand mill also includes a discharge pipe (800), which extends from below the mixing chamber (200) into the separation turbine (610), and the central axis of the discharge pipe (800) forms the discharge channel.

4. The concentric shaft dual-power vertical sand mill according to claim 3, characterized in that, The separating turbine (610) is provided with an upper sealing plate and a lower sealing plate at its upper and lower ends, respectively. The upper sealing plate and the lower end of the inner shaft (600) together form a separating cavity (620) corresponding to the discharge pipe (800). The discharge pipe (800) extends into the separating cavity (620). The outer periphery of the discharge pipe (800) and the inner periphery of the separating cavity (620) and the upper end of the discharge pipe (800) and the upper end of the separating cavity (620) are all clearance fit.

5. The concentric shaft dual-power vertical sand mill according to claim 3, characterized in that, The separating turbine (610) is provided with an upper sealing plate and a lower sealing plate at its upper and lower ends, respectively. A separating cavity (620) corresponding to the discharge pipe is formed on the upper sealing plate. The discharge pipe (800) extends into the separating cavity (620). The outer periphery of the discharge pipe (800) and the inner periphery of the separating cavity (620), as well as the upper end of the discharge pipe (800) and the upper end of the separating cavity (620) are all clearance fit.

6. The concentric shaft dual-power vertical sand mill according to claim 3, characterized in that, The support structure (700) is positioned above the top of the feed hopper (300).

7. The concentric shaft dual-power vertical sand mill according to any one of claims 1 to 6, characterized in that, The top of the feed hopper (300) is provided with a cover plate (330), and a mechanical seal (340) is provided between the cover plate (330) and the main shaft (400).

8. The concentric shaft dual-power vertical sand mill according to claim 7, characterized in that, The concentric shaft dual-power vertical sand mill also includes a pneumatic system, which is introduced into the upper part of the feed hopper (300).

9. The concentric shaft dual-power vertical sand mill according to any one of claims 1 to 6, characterized in that, The feed hopper (300) is equipped with a level sensor (350) for detecting and outputting liquid level information.

10. The concentric shaft dual-power vertical sand mill according to any one of claims 1 to 6, characterized in that, The grinding working part (410) has a downward-opening barrel-shaped structure. The bottom of the stirring chamber (200) is provided with an inner stator (420) corresponding to the grinding working part (410). The outer periphery of the inner stator (420) is provided with a driving thread structure.

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