A stacked double-stage spiral screening device

Abstract

This invention discloses a stacked double-stage spiral screening device, belonging to the technical field of wet screening equipment. The device includes a frame, an upper screen cylinder assembly and a lower screen cylinder assembly stacked vertically. The discharge port of the upper screen cylinder assembly is directly connected to the feed port of the lower screen cylinder assembly, creating a continuous two-stage screening path for the material. The device uses only one drive motor, which simultaneously drives the upper and lower screening screws through the same synchronous transmission mechanism to complete fine and coarse material separation sequentially within the same device. Furthermore, the device is equipped with a quick-release screen module and can be configured with a water spray device and a roller brush cleaning device to achieve rapid screen replacement and online anti-clogging cleaning. Through this structure, the invention reduces the footprint of the screening equipment, lowers drive energy consumption, improves the continuity and stability of the two-stage screening process, and enhances the ease of equipment maintenance, making it suitable for continuous screening of wet and sticky materials.

Description

Technical Field

[0001] This invention relates to the field of material screening equipment technology, and in particular to a screening device that combines screening and conveying. Specifically, it relates to a double-stage spiral screening device with upper and lower stacking, which is suitable for multi-stage continuous particle size classification of materials under wet screening conditions. It can be applied to the screening of wet granular or slurry materials in industries such as chemical, building materials, and metallurgy. Background Technology

[0002] This technology relates to the field of material screening equipment, and in particular to a multi-stage particle size classification device suitable for wet screening conditions. It can be applied to the screening of wet granular materials, slurry materials or liquid-solid mixtures in industries such as chemical, building materials, and metallurgy.

[0003] In chemical and related industrial production processes, it is often necessary to classify granular or slurry materials by particle size to remove excessively small fine particles and excessively large coarse particles, thereby obtaining materials with intermediate particle sizes that meet process requirements. Depending on the material's state, screening methods are generally divided into dry screening and wet screening. For materials with high moisture content, prone to agglomeration, easy adhesion, or containing fine powder impurities, wet screening utilizes a liquid medium to wet, disperse, and wash the material, which helps reduce dust, minimize particle agglomeration, and improve the continuity of the screening process.

[0004] Existing wet screening equipment typically includes vibrating screens, drum screens, and screening equipment with spiral guide structures. Vibrating screens mainly rely on screen vibration to promote material dispersion and screening, and are characterized by relatively simple structure and high screening accuracy. However, when processing materials with high moisture content or high viscosity, wet and sticky materials are prone to adhering to the screen surface or clogging the screen holes, resulting in a decrease in screening efficiency. At the same time, vibrating screens are usually fixed by multiple fasteners, and replacing screens with different mesh sizes or performing cleaning and maintenance requires disassembling many parts, which is cumbersome and results in long downtime.

[0005] Rotary drum screens typically use the rotation of the drum to agitate materials and separate particles using the screen openings on the drum. This type of equipment has a large processing capacity and is adaptable to some wet materials, but it occupies a large space and has a long screening path. When two-stage or multi-stage screening is required, it is often necessary to increase the drum length, set up multiple screening zones, or use multiple machines in series, resulting in complex equipment layout and increased floor space. Furthermore, the high degree of internal enclosure of the rotary drum screen makes cleaning difficult after the screen becomes clogged, and the efficiency of screen replacement and maintenance is low.

[0006] For applications requiring the simultaneous removal of both excessively fine and excessively coarse materials, existing solutions typically employ two screening devices connected in series: the first device removes the fine material, and the second device removes the coarse material. While this method achieves two-stage grading, it has significant drawbacks. First, the horizontal series arrangement of the two devices significantly increases the production line length and equipment footprint, which is unfavorable for space-constrained plant layouts. Second, an intermediate conveying device, chute, or pipeline transition structure is usually required between the two stages of equipment. Wet and sticky materials are prone to stagnation, bridging, secondary agglomeration, or blockage during transfer, affecting the stability of continuous production. Third, the two devices are usually equipped with separate drive motors and control systems, which not only increases equipment manufacturing costs and operating energy consumption but also complicates the matching of conveying cycle time and material flow between the two stages of screening.

[0007] Furthermore, existing wet screening equipment still has room for improvement in terms of screen maintenance and anti-clogging. For production scenarios involving multiple varieties, small batches, or frequent changes in particle size, screens need frequent replacement or cleaning; if the fixed structure of the screen is inconvenient to disassemble and assemble, it will directly affect production efficiency. When processing wet and sticky materials, relying solely on vibration, rolling, or the material's own flow is insufficient to maintain unobstructed screen openings in the long term, and problems such as material adhering to the screen surface, screen clogging, and fluctuations in screening efficiency may still occur.

[0008] Therefore, there is an urgent need for a screening device that is compact in structure, can achieve two-stage continuous screening in the same equipment, has a simplified drive system, allows for quick and easy disassembly and assembly of the screen, and is suitable for anti-clogging screening of wet and sticky materials. This would solve the problems of existing wet screening equipment, such as large footprint, the need for equipment to be connected in series for multi-stage screening, complex drive control, inconvenient screen maintenance, and easy clogging of screens by wet and sticky materials. Summary of the Invention

[0009] In view of this, the purpose of the present invention is to provide a double-stage spiral screening device with upper and lower stacking, so as to solve the problems of existing wet screening equipment in achieving two-stage screening, such as large equipment footprint, need for multiple devices to be connected in series, complex drive system, high energy consumption, inconvenient screen replacement, and easy clogging by wet and sticky materials.

[0010] To achieve the above objectives, the present invention provides the following technical solution: In one possible implementation, a stacked double-stage spiral screening device is provided, comprising: a frame, an upper screen cylinder assembly, and a lower screen cylinder assembly; the upper screen cylinder assembly is disposed above the lower screen cylinder assembly, and the two overlap at least partially in the vertical projection direction; the upper screen cylinder assembly is provided with an upper screening screw, and has an upper screen cylinder inlet, an oversize discharge outlet, and an undersize discharge outlet; the lower screen cylinder assembly is provided with a lower screening screw, and has a lower screen cylinder inlet, a coarse material outlet, and a fine material outlet that are directly connected to the oversize discharge outlet; wherein, the device is provided with only one drive motor, and the drive motor is simultaneously connected to the upper screening screw and the lower screening screw through the same synchronous transmission mechanism to drive the upper screening screw and the lower screening screw to rotate synchronously; The transmission arrangement of the synchronous transmission mechanism is matched with the spiral rotation direction of the upper and lower screening screws, so that the upper and lower screening screws form matching material conveying directions when rotating synchronously. This allows the material to form a continuous conveying path within the upper and lower screen cylinder assemblies, and to complete two-stage continuous screening of fine and coarse materials in the same equipment.

[0011] In one possible implementation, the synchronous transmission mechanism includes a driving transmission wheel, an upper driven transmission wheel, a lower driven transmission wheel, and a synchronous transmission member; the driving transmission wheel is disposed on the output shaft of the drive motor, the upper driven transmission wheel is disposed on the shaft end of the upper screening screw, and the lower driven transmission wheel is disposed on the shaft end of the lower screening screw; the synchronous transmission member is simultaneously wound around the driving transmission wheel, the upper driven transmission wheel, and the lower driven transmission wheel.

[0012] In one possible implementation, the synchronous transmission component is a synchronous belt or a double-row chain; when the synchronous transmission component is a synchronous belt, the driving drive wheel, the upper driven drive wheel, and the lower driven drive wheel are all pulleys; when the synchronous transmission component is a double-row chain, the driving drive wheel, the upper driven drive wheel, and the lower driven drive wheel are all sprockets.

[0013] In one possible implementation, the upper driven drive wheel and the lower driven drive wheel are located on the same side of the frame and are arranged adjacent to each other in the vertical direction to shorten the transmission path of the synchronous transmission member.

[0014] In one possible implementation, a direct material discharge channel is formed between the upper screen cylinder assembly and the lower screen cylinder assembly, so that the material from the upper screen cylinder assembly directly enters the lower screen cylinder assembly under at least the action of gravity, or under the combined action of gravity and liquid medium flow, without the provision of an intermediate transfer mechanism.

[0015] In one possible implementation, a quick-release screen module is also included, the quick-release screen module comprising a screen frame and a quick-locking mechanism, the screen frame being detachably mounted at the mounting port on the cylinder wall of the upper screen cylinder assembly and / or the lower screen cylinder assembly.

[0016] In one possible implementation, the quick-locking mechanism includes a protruding rib disposed on the screen frame, a fixed seat disposed on the outside of the screen cylinder mounting port, a long pressure plate disposed on the fixed seat, a slot disposed on the inside of the long pressure plate, and a locking bolt; the slot engages with the protruding rib to form a multi-point pressing structure; the cross-section of the protruding rib is rectangular, semi-circular, trapezoidal, triangular, or other shape that can engage with the slot.

[0017] In one possible implementation, the quick-locking mechanism includes a wedge-shaped slider disposed on the side of the screen frame, a guide rod disposed on the side of the screen cylinder mounting port, a fixing buckle disposed on the guide rod, and a drive screw connected to the fixing buckle; by rotating the drive screw, the fixing buckle is driven to press the wedge-shaped slider, so that the screen frame achieves self-locking through wedge compression.

[0018] In one possible implementation, the device further includes an online anti-clogging and cleaning device, which includes a water spraying device and a roller brush cleaning device. The water spraying device is disposed above the upper screen cylinder assembly and / or the lower screen cylinder assembly and is used to spray water onto the screen surface. The roller brush cleaning device is disposed outside the upper screen cylinder assembly and / or the lower screen cylinder assembly and is used to clean the screen surface online. The device also includes a protective cover disposed outside the upper screen cylinder assembly and the lower screen cylinder assembly to prevent material or liquid from splashing out.

[0019] In one possible implementation, the lead of the upper screening screw 21 and the lead of the lower screening screw 31 can be configured differently according to the material propulsion speed and screening residence time of the corresponding screening stage. With this configuration, even when the upper screening screw 21 and the lower screening screw 31 are synchronously driven by the same drive motor, it is still possible to achieve different or matching propulsion speeds and screening residence times for the material within the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3.

[0020] In a preferred embodiment, the lead H1 of the upper screening screw 21 and the lead H2 of the lower screening screw 31 can be set according to the material viscosity, throughput, and screening accuracy requirements. For example, H1 / H2 can be set to 1 to 2; the ratio of the lead of the upper screening screw 21 and / or the lower screening screw 31 to the corresponding screw outer diameter can be set to 0.2 to 1. The above parameters are only preferred ranges and do not constitute a limitation on the scope of protection of the claims of this invention.

[0021] In one possible implementation, a two-stage spiral screening method based on the above-mentioned equipment is also provided, comprising the following steps: feeding the material to be screened into the upper screen cylinder assembly from the upper screen cylinder inlet; performing a first-stage screening under the pushing action of the upper screening screw, causing materials with particle sizes smaller than the upper screen mesh aperture to be discharged from the undersize outlet, and causing the oversize material with particle sizes not smaller than the upper screen mesh aperture to be output through the oversize outlet; allowing the oversize material to pass through a direct communication channel between the oversize outlet and the lower screen cylinder inlet, at least under the action of gravity, or Under the combined action of gravity and liquid medium flow, the material enters the lower screen cylinder assembly. The material undergoes a second-stage screening under the pushing action of the lower screening screw, causing materials with a particle size smaller than the lower screen mesh size to be discharged from the fine material outlet, and materials with a particle size not smaller than the lower screen mesh size to be discharged from the coarse material outlet. The upper and lower screening screws are synchronously driven by the same drive motor through the same synchronous transmission mechanism, and the transmission arrangement of the synchronous transmission mechanism, in conjunction with the screw rotation direction, forms a continuously matched material conveying path.

[0022] Based on the above technical solution, the superimposed double-stage spiral screening equipment of the present invention is not simply a superposition of two screening units, but rather takes the continuous material transfer, drive synchronization, screening residence time matching and screen maintenance efficiency in the two-stage screening process as the overall design object, forming an integrated screening structure that works together.

[0023] Specifically, this invention arranges the upper and lower screen cylinder assemblies vertically, ensuring at least partial overlap in their vertical projection direction. This eliminates the need for the two screening units to be connected horizontally, significantly reducing the horizontal footprint of the equipment and improving plant space utilization. Simultaneously, a direct discharge channel is formed between the discharge port of the upper screen cylinder assembly and the feed port of the lower screen cylinder assembly. This allows the oversize material from the first screening stage to directly enter the second screening area, either under gravity or through a combination of gravity and liquid flow, eliminating the need for intermediate conveying equipment, chute transfer mechanisms, or pipeline transition structures. This reduces the risk of material stagnation, bridging, secondary agglomeration, and blockage during intermediate transfer, improving the continuity and stability of the two-stage screening process.

[0024] Furthermore, this invention uses only one drive motor, which simultaneously drives the upper and lower screening screws to operate synchronously via a synchronous transmission mechanism. This structure does not simply reduce the number of motors; rather, it utilizes the spatial proximity of the drive ends of the upper and lower screen cylinder assemblies to reliably connect the driving wheel, upper driven wheel, and lower driven wheel via the same synchronous transmission component. This achieves synchronous drive of the two-stage screening screws without the need for a long drive shaft, intermediate support, or a dual-motor synchronous control system. Therefore, this invention simultaneously reduces energy consumption, simplifies the control structure, and improves the stability of material flow matching during the two-stage screening process.

[0025] This invention utilizes a synchronous transmission mechanism arranged in conjunction with the spiral directions of the upper and lower screening screws to create a material conveying relationship suitable for connecting the upper and lower screening stages under the same drive source. Thus, after the material completes the first stage of screening in the upper screen cylinder assembly, it can smoothly enter the lower screen cylinder assembly through a direct connection between the oversize discharge port and the lower screen cylinder inlet, where it continues to undergo the second stage of screening. This avoids material accumulation, backflow, or poor transfer caused by a mismatch between the screw conveying direction and the transfer paths of the upper and lower stages. Furthermore, in a preferred embodiment, the upper and lower screening screws can form opposite or coordinated axial conveying directions, ensuring that the axial reaction forces generated during operation are at least partially offset within the frame. This reduces end support load and overall machine vibration, improving the stability of the equipment during long-term continuous operation.

[0026] This invention employs a differentiated lead design for the upper and lower screening screws under synchronous drive conditions. This allows the two screws to achieve different material propulsion speeds and screening residence times even at the same rotational speed through lead differences. Therefore, instead of relying on complex dual-motor speed control to separately adjust the two-stage screening process, this invention achieves matched control of the two-stage screening residence times at the mechanical structure level, enabling the first stage (removing fine materials) and the second stage (removing coarse materials) to adapt to different screening requirements.

[0027] Furthermore, this invention features a quick-release screen module, and achieves rapid locking and releasing of the screen frame through a long pressure plate multi-groove meshing structure or a wedge slider self-locking structure. This structure ensures stable fixation of the screen frame while reducing the disassembly and assembly operations required by traditional multi-bolt fixing methods, enabling rapid completion of screen replacement, cleaning, and mesh size switching, thereby reducing downtime and adapting to the screening needs of multiple batches and multiple particle size specifications in chemical production.

[0028] Furthermore, the present invention can also be combined with a water spraying device and a roller brush cleaning device to perform online rinsing and mechanical cleaning of the screen surface during the screening process. The water spraying device can reduce the adhesion of wet materials and rinse the screen holes, while the roller brush cleaning device can remove the adhering substances on the screen surface. Together with the spiral pushing screening process, they form an anti-clogging mechanism that combines continuous conveying, rinsing, and cleaning, thereby improving the continuity and stability of screening under wet and sticky material conditions.

[0029] The technical features in this invention are not set in isolation, but are designed collaboratively around the continuous flow path of the material in the two-stage screening process, the matching of the conveying cycle and the requirements for anti-blocking, thereby forming a systematic and holistic technical solution.

[0030] In summary, this invention combines several technical features, including a stacked double-stage screening structure, a directly connected material feeding path, a single-motor synchronous drive, screw conveyor direction matching, differential lead control, a quick-release screen module, and an online anti-clogging and cleaning device. These features enable the various structures to work synergistically around continuous feeding and discharging, matching conveying rhythm, anti-clogging cleaning, and convenient maintenance during the two-stage screening process. This solves the problems of existing wet screening equipment, such as large footprint, the need for multiple devices to be connected in series for multi-stage screening, complex drive control, inconvenient screen replacement, and easy clogging by wet and sticky materials. The invention achieves a comprehensive technical effect of compact equipment layout, low energy consumption operation, continuous two-stage screening, stable anti-clogging, and convenient maintenance. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the superimposed double-stage spiral screening equipment of the present invention. It mainly shows the superimposed arrangement of the frame, the upper screen cylinder assembly and the lower screen cylinder assembly, as well as the relative positional relationship of each inlet and outlet.

[0032] Figure 2 for Figure 1 The side view of the device shown mainly illustrates the arrangement of the drive motor driving the upper and lower screening screws simultaneously through a synchronous transmission mechanism.

[0033] Figure 3 This is a schematic diagram of the multi-groove meshing structure of the long pressure plate of the quick-release screen module in an embodiment of the present invention, mainly showing the cooperation relationship between the protruding ribs, the fixed seat, the long pressure plate, the slots and the locking bolts.

[0034] Figure 4 This is a schematic diagram of the wedge slider self-locking structure of the quick-release screen module in an embodiment of the present invention, mainly showing the cooperation relationship between the wedge slider, guide rod, fixing buckle and drive screw.

[0035] in: 1—Rack; 2—Upper screen cylinder assembly; 21—Upper screening screw; 22—Upper screen cylinder inlet; 23—Oversize discharge outlet; 24—Undersize discharge outlet; 3—Lower screen cylinder assembly; 31—Lower screening screw; 32—Lower screen cylinder inlet; 33—Coarse material outlet; 34—Fine material outlet; 4—Drive motor; 5—Synchronous transmission mechanism; 51—Driving transmission wheel, which is a driving pulley in the illustrated embodiment; 52—Upper driven transmission wheel, which is an upper driven pulley in the illustrated embodiment; 53—Lower driven transmission wheel, which is a lower driven pulley in the illustrated embodiment; 54—Synchronous transmission component, which is a synchronous belt in the illustrated embodiment; 6—Quick-release screen module; 61—Screen frame; 7—Quick locking mechanism; 71—Protruding rib; 72—Fixed seat; 73—Long pressure plate; 74—Slot; 75—Locking bolt; 76—Wedge-shaped slider; 77—Guide rod; 78—Fixing buckle; 79—Drive screw; 8—Water spray device; 9—Roller brush cleaning device; 10—Protective shield. Detailed Implementation

[0036] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the specific embodiments of this invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0037] This invention addresses the problems of existing wet screening equipment, such as large footprint, the need for multiple devices connected in series for two-stage screening, complex drive systems, inconvenient screen replacement, and easy clogging by wet and sticky materials. It proposes a stacked double-stage spiral screening device. This device integrates the upper and lower screen cylinder components vertically, and combines them with a single motor synchronous drive, quick-release screen modules, and an online anti-clogging structure to achieve continuous completion of two-stage screening within the same device.

[0038] The following will combine Figures 1 to 4 This invention will be specifically described from aspects such as overall structure, drive system, quick-release screen module, auxiliary structure, key parameter design, working principle and implementation effect summary.

[0039] I. Overall Structure like Figure 1As shown, the present invention provides a stacked double-stage spiral screening device, including a frame 1, an upper screen cylinder assembly 2 and a lower screen cylinder assembly 3 mounted on the frame 1. The frame 1 serves as the load-bearing foundation structure of the entire machine, supporting the upper screen cylinder assembly 2, the lower screen cylinder assembly 3, and related drive and auxiliary components. All components are fixed or connected to the frame 1, thereby forming a stable overall structure.

[0040] The upper screen cylinder assembly 2 is positioned above the lower screen cylinder assembly 3, with the two stacked vertically and overlapping at least partially in the vertical projection direction. This spatial layout integrates the two screening units, which would normally be arranged in series horizontally, vertically, thereby significantly reducing the horizontal length of the equipment and improving space utilization while ensuring screening functionality.

[0041] Furthermore, the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3 are directly connected. Specifically, one end of the upper screen cylinder assembly 2 is provided with an oversize discharge port 23, and the lower screen cylinder assembly 3 is provided with a lower screen cylinder inlet 32 ​​at a position corresponding to the oversize discharge port 23. The oversize discharge port 23 and the lower screen cylinder inlet 32 ​​are connected to form a directly connected material discharge channel between them. Thus, the oversize material after the first stage screening can directly enter the lower screen cylinder assembly 3 under at least the action of gravity, or under the combined action of gravity and liquid medium flow, without the need for intermediate conveying devices, chute transfer mechanisms, or pipeline transition structures. This shortens the material transfer path between the two stages of screening, reduces the risk of wet and sticky materials stagnating, bridging, secondary agglomeration, and blockage during the transfer process, and improves the continuity and stability of the two-stage screening process.

[0042] An upper screening screw 21 is axially inserted inside the upper screen cylinder assembly 2. One end of the upper screen cylinder assembly 2 is provided with an upper screen cylinder inlet 22 for introducing the material to be screened; the other end is provided with an oversize discharge outlet 23 and an undersize discharge outlet 24 respectively. The undersize discharge outlet 24 is used to discharge materials with a particle size smaller than the upper screen mesh size, while the oversize discharge outlet 23 is used to discharge materials with a particle size larger than the upper screen mesh size and introduce them into the lower screen cylinder assembly 3.

[0043] The lower screen cylinder assembly 3 also has a lower screening screw 31 running through it along the axial direction. One end of the lower screen cylinder assembly 3 is provided with a lower screen cylinder inlet 32 ​​for receiving the oversize material from the upper screen cylinder assembly 2. The other end is provided with a coarse material outlet 33 and a fine material outlet 34, where the fine material outlet 34 is used to discharge materials with a particle size smaller than the lower screen mesh size, and the coarse material outlet 33 is used to discharge materials with a particle size larger than the lower screen mesh size.

[0044] Through the above structural arrangement, the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3 form a continuous two-stage screening channel within the same equipment, allowing the material to sequentially complete the first-stage screening process of removing fine materials and the second-stage screening process of removing coarse materials, thereby achieving particle size classification. Simultaneously, since the two-stage screening units are directly connected and integrated on the same frame 1, the problems of large footprint, complex connections, and unstable operation caused by multiple devices connected in series in traditional solutions are avoided.

[0045] II. Drive System like Figure 1 and Figure 2 As shown, the drive system of the present invention is mounted on the frame 1 and is used to provide power to the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3, realizing the synchronous operation of the two-stage screening process. This drive system adopts a single-motor centralized drive structure, mainly including a drive motor 4 and a synchronous transmission mechanism 5. The following description uses a synchronous belt as an example to illustrate the specific structure and operation of the synchronous transmission mechanism 5.

[0046] Specifically, the drive motor 4 is mounted on one side of the frame 1, and a drive pulley 51 is fixedly mounted on its output shaft. One end of the upper screening screw 21 extends out of the upper screen cylinder assembly 2 and is connected to the upper driven pulley 52; one end of the lower screening screw 31 extends out of the lower screen cylinder assembly 3 and is connected to the lower driven pulley 53. The drive pulley 51, the upper driven pulley 52, and the lower driven pulley 53 are interconnected by a synchronous belt 54, thereby forming a synchronous transmission mechanism 5.

[0047] With the above structure, when the drive motor 4 starts, its output shaft drives the drive pulley 51 to rotate, which in turn drives the upper driven pulley 52 and the lower driven pulley 53 to rotate simultaneously via the synchronous belt 54, so that the upper screening screw 21 and the lower screening screw 31 rotate synchronously. Therefore, only one drive motor 4 is needed to drive both stages of the screening unit simultaneously, avoiding the problems of structural complexity, control difficulties, and increased energy consumption associated with traditional two-stage screening equipment that uses two separate motors.

[0048] Furthermore, since the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3 are arranged in a stacked manner, their corresponding upper driven pulley 52 and lower driven pulley 53 are located on the same side and close to each other in space. This results in a shorter transmission path for the synchronous belt 54, eliminating the need for a long-distance transmission shaft or intermediate support structure, thereby improving transmission efficiency and reducing mechanical losses. Simultaneously, this arrangement helps ensure the consistency of rotational speed between the two screening screws, avoiding torsional deformation or asynchrony caused by an excessively long transmission chain.

[0049] Furthermore, in the embodiment where the synchronous transmission component 54 is a synchronous belt, the winding direction of the synchronous belt can be designed so that the upper driven pulley 52 and the lower driven pulley 53 form the same or different rotation directions. Simultaneously, by configuring the upper screening screw 21 and the lower screening screw 31 with left-hand or right-hand helical structures, they can form axial conveying directions that match the upper and lower screening paths respectively when rotating synchronously. Since the helical conveying direction is determined by both the screw rotation direction and the helical direction, this invention does not simply rely on the reverse rotation of the upper and lower screening screws to achieve material conveying. Instead, through the coordination of the synchronous belt winding method and the screw rotation direction, the material can smoothly enter the lower screening cylinder assembly 3 after completing the first stage of screening in the upper screening cylinder assembly 2, and continue to complete the second stage of screening in the lower screening cylinder assembly 3, thereby meeting the process requirement of continuous connection between the upper and lower screening stages.

[0050] Furthermore, when the synchronous transmission component 54 adopts a meshing synchronous transmission component such as a synchronous belt or double-row chain, compared with the friction-based transmission method of ordinary V-belts or flat belts, slippage is less likely to occur. It can maintain the predetermined transmission ratio and synchronization relationship between the upper screening screw 21 and the lower screening screw 31 under fluctuating material load, ensuring the stability of the two-stage screening process. Especially when processing wet and sticky materials, when local resistance changes or material accumulation occur, the aforementioned meshing synchronous transmission component can reduce speed deviation caused by transmission slippage, thereby reducing the risk of material accumulation, blockage, or poor transport within the screen cylinder.

[0051] Among them, synchronous belt drive can be preferred for working conditions with low operating noise requirements and high maintenance convenience requirements; double-row chain drive can be preferred for working conditions with large loads or significant impact loads.

[0052] In summary, this invention, through the design of a drive system consisting of a single motor and a synchronous transmission mechanism, enables reliable synchronous driving of the two-stage screening units while maintaining a compact structure. This not only reduces equipment energy consumption and manufacturing costs but also improves operational stability, providing a reliable guarantee for achieving efficient and continuous two-stage screening.

[0053] III. Quick-release screen module like Figure 3 and Figure 4 As shown, the present invention provides a quick-release screen module 6 on the cylinder wall of the upper screen cylinder assembly 2 and / or the lower screen cylinder assembly 3 for quick installation and removal of the screen. The quick-release screen module 6 mainly includes a screen frame 61 and a quick-locking mechanism 7 for fixing the screen frame 61 to the screen cylinder.

[0054] The screen frame 61 is used to support the screen body. Its external dimensions match the mounting port on the screen cylinder assembly and it can be embedded in the mounting opening on the screen cylinder wall, so that the screen frame 61 and the screen cylinder form a sealed fit structure, thereby ensuring that the material can only be graded through the screen aperture during the screening process.

[0055] To improve screen replacement efficiency while ensuring locking reliability, this invention provides two optional quick-locking structure forms.

[0056] (a) Long pressure plate multi-groove interlocking structure like Figure 3 As shown, in one embodiment, the quick-locking mechanism 7 includes a protruding rib 71 disposed on the screen frame 61, a fixed seat 72 disposed on the outside of the screen cylinder mounting port, a long pressure plate 73 supported by the fixed seat 72, a slot 74 disposed on the side of the long pressure plate 73 facing the screen frame 61, and a locking bolt 75 for locking.

[0057] Specifically, taking one side edge of the screen frame 61 as an example, the protruding rib 71 is disposed at the edge of the screen frame 61 to be pressed and extends along the length direction of the edge; the protruding rib 71 can be one or more, preferably multiple spaced and parallel, and its cross-section can be rectangular, semi-circular, trapezoidal or triangular. The fixing seat 72 is fixedly disposed on the outside of the screen cylinder mounting port and located on the outside of the corresponding edge of the screen frame 61; the long pressure plate 73 is detachably installed on the fixing seat 72, and its length direction is basically consistent with the extension direction of the protruding rib 71. The long pressure plate 73 has a groove 74 corresponding to the protruding rib 71 on the side facing the screen frame 61. The locking bolt 75 passes through the long pressure plate 73 and is threadedly connected to the fixing seat 72; when the locking bolt 75 is tightened, the long pressure plate 73 moves toward the screen frame 61 and presses it, so that the slot 74 engages with the protruding rib 71, thereby pressing and fixing the screen frame 61 to the screen cylinder installation port.

[0058] During installation, the screen frame 61 is placed inside the screen cylinder mounting opening, with the protruding rib 71 facing the side of the long pressure plate 73. Then, the long pressure plate 73 is installed on the fixing base 72, and the slot 74 is aligned with the protruding rib 71. By tightening the locking bolt 75, the long pressure plate 73 is pressed towards the screen frame 61, thereby gradually engaging the slot 74 with the protruding rib 71 and pressing the screen frame 61 against the sealing mating surface around the screen cylinder mounting opening, achieving uniform locking.

[0059] During disassembly, simply loosen the locking bolts 75 and remove the long pressure plate 73 to disengage the slot 74 from the protruding rib 71, thereby quickly removing the screen frame 61.

[0060] This structure forms multi-point clamping through the meshing of the slot 74 and the protruding rib 71, making the screen frame 61 more evenly stressed. It has the advantages of reliable locking, good vibration resistance and convenient assembly and disassembly.

[0061] (ii) Wedge slider self-locking structure like Figure 4 As shown, in another embodiment, the quick locking mechanism 7 includes a wedge-shaped slider 76 disposed on the side of the screen frame 61, a guide rod 77 disposed on the side of the screen cylinder mounting port, a fixing buckle 78 disposed on the guide rod 77, and a drive screw 79 connected to the fixing buckle 78.

[0062] The wedge-shaped slider 76 is located on the side of the screen frame 61, and its outer surface is inclined. The guide rod 77 is fixed to the side wall of the screen cylinder and is used to guide the movement direction of the fixing buckle 78. The fixing buckle 78 is sleeved on the guide rod 77 and can move axially along the guide rod 77. The drive screw 79 passes through the fixing buckle 78 and is threaded to it. Its end can be equipped with a handwheel or an internal hexagonal structure for operation.

[0063] During installation, the screen frame 61 is placed into the screen cylinder installation opening, so that the wedge slider 76 is within the range of action of the fixing buckle 78; by rotating the drive screw 79, the fixing buckle 78 moves along the guide rod 77 and gradually presses the wedge slider 76; under the action of the inclined plane, the wedge slider 76 drives the screen frame 61 to press against the screen cylinder wall, thereby achieving reliable locking.

[0064] During disassembly, the drive screw 79 is rotated in the opposite direction to loosen the wedge-shaped slider 76 by the fixing buckle 78, thereby releasing the locking state and removing the screen frame 61.

[0065] This structure utilizes the principle of inclined plane force amplification, which can generate a large locking force under a small operating force, and also has self-locking characteristics, making it suitable for working conditions with large vibrations or impacts.

[0066] With the aforementioned quick-release screen module 6, the installation and removal of the screen can be completed with minimal operations, eliminating the need to disassemble numerous fasteners. This significantly shortens screen replacement time and reduces equipment downtime. Furthermore, while ensuring reliable screen fixation, this structure enhances the equipment's adaptability to different particle size screening requirements, making it particularly suitable for continuous production scenarios involving multiple batches of materials of varying specifications.

[0067] IV. Auxiliary Structures like Figure 1 As shown, in order to further improve the operational stability and screening efficiency of the equipment under wet screening conditions, the present invention also provides several auxiliary structures on the basis of the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3, mainly including a water spraying device 8, a roller brush cleaning device 9 and a protective cover 10.

[0068] (a) Water spraying device The water spraying device 8 is positioned above the upper screen cylinder assembly 2 and / or the lower screen cylinder assembly 3, with its spray direction directed towards the working area of ​​the screen. The water spraying device 8 is used to spray a liquid medium (preferably water) onto the screen surface and the material surface during the screening process, thereby wetting and rinsing the material.

[0069] In actual operation, the water spray device 8 effectively reduces the adhesion of wet and sticky materials, making them easier to disperse on the screen surface and promoting the smooth passage of fine particles through the screen holes. Simultaneously, the sprayed liquid washes the screen holes, reducing particle retention and thus lowering the risk of clogging.

[0070] Furthermore, the water spraying device 8 can be started / stopped or its flow rate adjusted according to the material characteristics and screening requirements to adapt to screening requirements under different working conditions.

[0071] (ii) Roller brush cleaning device The roller brush cleaning device 9 is located on the outside of the upper screen cylinder assembly 2 and / or the lower screen cylinder assembly 3, with its brush body corresponding to the outer surface of the screen. The roller brush cleaning device 9 is used to mechanically clean the screen surface during equipment operation.

[0072] In operation, the roller brush cleaning device 9 can contact the outer surface of the screen along the axial or circumferential direction of the screen cylinder. Through the rotation or relative movement of the roller brush, the particulate material attached to the screen surface is brushed off in time, thereby preventing the material from forming a layer on the screen surface or clogging the screen holes.

[0073] When used in conjunction with the water spray device 8, the roller brush cleaning device 9 can further remove the residual material after brushing, thus forming a synergistic mechanism of "liquid flushing + mechanical cleaning" and significantly improving the self-cleaning ability of the screen.

[0074] (iii) Protective shield The protective cover 10 is disposed outside the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3, and completely covers the screening area. The protective cover 10 is used to form a relatively enclosed working space during the screening process.

[0075] By installing the protective cover 10, material particles and sprayed liquid can be effectively prevented from splashing outwards during the screening process, thereby reducing environmental pollution and improving the operating environment. At the same time, the protective cover 10 can also reduce the noise generated during equipment operation to a certain extent, improve equipment safety, and prevent operators from direct contact with moving parts.

[0076] (iv) Explanation of Synergistic Effects By setting the above-mentioned auxiliary structure, the present invention can improve the screen anti-clogging ability and equipment operation safety in the wet screening process.

[0077] The water spraying device 8 sprays liquid medium onto the screen surface and material surface to reduce the adhesion of wet and sticky materials and to rinse clogged or semi-clogged screen holes. The roller brush cleaning device 9 mechanically scrapes the screen surface to remove the wet material layer or residual particles adhering to the screen surface. The water spraying device 8 and the roller brush cleaning device 9 can work synchronously or alternately according to the material characteristics and screening conditions, thus forming an online anti-clogging screening mechanism that combines wetting and dispersion, hydraulic rinsing and mechanical cleaning. It is especially suitable for screening high-viscosity, easily agglomerated wet and sticky materials.

[0078] The protective cover 10 is installed on the outside of the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3. It is mainly used to prevent material particles or liquid media from splashing outward during the screening process and to form an isolation and protection for the moving parts, thereby improving the working environment around the equipment and enhancing operational safety.

[0079] Therefore, the present invention, through the cooperation of the water spray device 8 and the roller brush cleaning device 9, enables the screen to maintain a good unobstructed state during continuous operation, reducing the risk of screen hole blockage; at the same time, the protective cover 10 protects and isolates the screening area, enabling the equipment to operate more stably and safely for a long time under wet screening conditions.

[0080] V. Key Parameter Design To enable this invention to adapt to materials with different properties and screening process requirements, and to improve the matching and stability of the two-stage screening process, several preferred parameter designs are described below. It should be noted that the parameter ranges described below are exemplary ranges in the preferred embodiments and do not constitute a limitation on the scope of protection of the claims of this invention.

[0081] Firstly, in a preferred embodiment, the leads of the upper screening screw 21 and the lower screening screw 31 can be differentiated according to the material propulsion speed and screening residence time in the two-stage screening process. Specifically, the lead of the upper screening screw 21 is H1, and the lead of the lower screening screw 31 is H2, with H1 / H2 potentially set to 1 to 2. This range is merely a preferred example. With the above configuration, even when the upper screening screw 21 and the lower screening screw 31 are synchronously driven by the same drive motor 4 and maintain the same rotational speed, the axial propulsion speed and residence time of the material in the two-stage screening areas can still be adjusted by the difference in lead, thereby improving the matching of the two-stage screening process.

[0082] Specifically, when H1 / H2 is a larger value, the upper screening screw 21 advances at a relatively faster speed, which facilitates the rapid passage of material through the first-stage screening zone and reduces material retention within the upper screen cylinder assembly 2, thereby lowering the risk of accumulation or blockage of high-viscosity materials. Simultaneously, the lower screening screw 31 has a relatively smaller lead, which extends the residence time of material in the second-stage screening zone, thus improving the adequacy of coarse particle classification. Conversely, when H1 / H2 is a smaller value, the residence times of the two screening processes become more similar, making it suitable for applications with narrow particle size distributions and high screening accuracy requirements.

[0083] Furthermore, the ratio of screw lead to screw outer diameter is controlled within the range of 0.2 to 1. This parameter range comprehensively considers the balance between conveying capacity and screening efficiency: when the ratio is small, the screw conveying speed is low, which helps to prolong the residence time of the material in the screen area, thereby improving screening accuracy; when the ratio is large, the screw conveying capacity is enhanced, which helps to increase the throughput and reduce the risk of clogging. Therefore, by reasonably selecting this ratio, adjustments can be made between different throughput and screening accuracy requirements.

[0084] Furthermore, the aperture combination relationship between the screens in the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3 can be set according to actual screening requirements. Preferably, the aperture of the upper screen is smaller than that of the lower screen to achieve a two-stage screening process path of "removing fine materials first and then removing coarse materials"; or it can be set as a graded combination of different particle size ranges according to specific application scenarios to meet the particle size requirements of various products.

[0085] Furthermore, the rotational speeds of the upper screening screw 21 and the lower screening screw 31 are determined by the same drive motor 4. In practical applications, the overall processing capacity can be adjusted by regulating the speed of the drive motor. Preferably, the rotational speeds of the two screws are kept consistent to ensure flow matching of materials during the two-stage screening process, avoiding upstream accumulation or downstream idling.

[0086] In summary, by coordinating the design of key parameters such as screw lead ratio, lead-to-outer diameter ratio, screen aperture combination, and overall rotational speed, this invention enables the matching and control of a two-stage screening process under a single drive condition. This not only improves screening efficiency and accuracy but also enhances the equipment's adaptability to materials with different characteristics.

[0087] VI. Working Principle like Figure 1 As shown, the superimposed double-stage spiral screening device of the present invention achieves two-stage sequential screening of materials within the same device through the continuous arrangement of the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3. Its specific working process is as follows: First, the material to be processed (such as a chemical suspension or wet granular material) enters the upper screen cylinder assembly 2 through the feed inlet 22. Driven by the drive motor 4, the upper screening screw 21 begins to rotate, exerting an axial pushing effect on the incoming material, causing the material to move forward along the axial direction of the upper screen cylinder assembly 2. During this conveying process, the material makes full contact with the screen under the combined action of the screw driving force, its own weight, and the screen structure.

[0088] In the first stage of screening, materials with a particle size smaller than the upper screen mesh size (including liquids and fine particles) pass through the screen under the action of gravity and fluid and are discharged from the undersize outlet 24; particles with a particle size larger than the upper screen mesh size cannot pass through the screen holes and continue to be conveyed forward as the oversize material under the push of the upper screening screw 21, and are finally discharged from the oversize outlet 23.

[0089] Subsequently, the material discharged from the oversize discharge port 23, at least under the action of gravity, or under the combined action of gravity and liquid medium flow, enters the lower screen cylinder inlet 32 ​​of the lower screen cylinder assembly 3 via a directly connected drop channel. Since the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3 are directly connected, the material can be transferred without going through an additional conveying path, thereby reducing the retention and accumulation of material during the transfer process.

[0090] After entering the lower screen cylinder assembly 3, the material continues to move axially under the action of the lower screening screw 31, entering the second-stage screening process. In this process, the material with a particle size smaller than the lower screen mesh size passes through the screen and is discharged from the fine material outlet 34, while the particles with a particle size larger than the lower screen mesh size are treated as coarse material and are discharged from the coarse material outlet 33 under the continuous pushing of the lower screening screw 31.

[0091] Throughout the screening process, the upper screening screw 21 and the lower screening screw 31 are driven synchronously by the same drive motor 4 through the synchronous transmission mechanism 5, so that the two-stage screening process is carried out continuously at the same beat, thereby ensuring the flow matching of materials between the upper and lower screening stages and avoiding upstream accumulation or downstream material interruption.

[0092] Furthermore, under wet screening conditions, the water spraying device 8 continuously sprays liquid onto the screen surface to wet and wash the material, thereby reducing the material viscosity and decreasing the adhesion between particles. Simultaneously, the roller brush cleaning device 9 mechanically cleans the outer surface of the screen, promptly removing particles adhering to it. These two functions work together to keep the screen unobstructed during operation, effectively preventing screen clogging.

[0093] Furthermore, since the upper screening screw 21 and the lower screening screw 31 can achieve different lead parameters in their structural design, they can form different material propulsion speeds under the same rotation speed conditions, thereby enabling the material to have different residence times in the two-stage screening areas, thus achieving matching optimization of the first-stage screening and the second-stage screening process.

[0094] The present invention enables the material to form a stable flow path and screening rhythm inside the equipment through the above-mentioned continuous screening process, thereby avoiding the material imbalance and fluctuation problems existing in traditional multi-equipment series systems.

[0095] Through the above working process, the present invention realizes a continuous screening process from material feeding to two-stage classification output in a single device, completing the classification treatment of "removing fineness" and "removing coarseness" of materials, while ensuring the stability and efficiency of the screening process.

[0096] VII. Summary of Implementation Results As can be seen from the above structural design and working process, this invention is not a simple improvement on existing screening equipment, but a systematic optimization of key issues in wet screening such as "multi-stage grading, space utilization, drive coordination, and anti-clogging maintenance." Its implementation effect is mainly reflected in the following aspects: Firstly, in terms of structural layout, by stacking the upper screen cylinder assembly 2 and the lower screen cylinder assembly 3 vertically, the two-stage screening units are spatially integrated on the same frame 1. Compared with the traditional horizontal series arrangement, this significantly shortens the horizontal length of the equipment and improves the utilization rate of factory space, making it particularly suitable for production environments with limited space.

[0097] Secondly, in terms of screening process, by setting the first-stage screening and second-stage screening channels in the same equipment, the material can complete the two-stage continuous grading process of "removing fine materials" and "removing coarse materials" in one feeding process, avoiding the problems of process complexity, unstable connection and material transfer loss caused by multiple equipment connected in series, thereby improving the overall screening efficiency and process stability.

[0098] Furthermore, in terms of the driving method, by adopting a structure of a single drive motor 4 combined with a synchronous transmission mechanism 5, the upper screening screw 21 and the lower screening screw 31 are driven synchronously. While reducing the number of drive units, it ensures that the material conveying rhythm is consistent in the two-stage screening process, avoiding material accumulation or flow interruption caused by mismatched speeds, thereby improving the reliability of equipment operation and reducing energy consumption.

[0099] Furthermore, in terms of screening matching, by differentiating the lead parameters of the upper and lower screening screws, the residence time of the material in the two screening areas can be adjusted under the same rotation speed, thereby taking into account the screening needs of different particle size ranges and improving screening accuracy and grading effect.

[0100] In addition, in terms of maintenance and adaptability, the quick-release screen module 6 makes the installation and replacement of the screen more convenient, and the operation can be completed without disassembling a large number of fasteners, thereby significantly shortening the equipment downtime and improving the equipment's adaptability under various production conditions.

[0101] Meanwhile, in terms of anti-clogging and stable operation, the water spray device 8 and the roller brush cleaning device 9 work together to continuously flush and clean the screen during the screening process, reduce the adhesion of materials and remove attached particles in time, effectively prevent screen hole blockage, and thus ensure that the equipment can maintain high screening efficiency and continuous operation capability when processing wet and sticky materials.

[0102] In summary, through the synergistic design of multiple structures and functions, this invention has achieved significant technical effects in terms of equipment compactness, two-stage continuous screening, simplified drive, optimized screening matching, and anti-clogging maintenance, providing a solid foundation for the further development of subsequent specific implementation methods.

[0103] The technical solution of the present invention has been described in detail above with reference to the accompanying drawings. Those skilled in the art should understand that various modifications, equivalent substitutions or improvements can be made to the above embodiments without departing from the technical concept and core principles of the present invention, and such modifications, equivalent substitutions or improvements should all fall within the protection scope of the present invention.

[0104] It should be noted that the specific embodiments described in the specification are only used to explain the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements or combinations made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0105] Furthermore, the various technical features involved in the specification and claims can be arbitrarily combined to form new embodiments, provided that they do not contradict each other, and all of these should be regarded as the content disclosed in this invention.

[0106] The scope of protection of this invention shall be determined by the claims. The description and drawings are only used for interpreting and explaining the claims.

Claims

1. A stacked double-stage spiral screening device, characterized in that, include: The frame (1), the upper screen cylinder assembly (2), and the lower screen cylinder assembly (3); The upper screen cylinder assembly (2) is disposed above the lower screen cylinder assembly (3), and the two overlap at least partially in the vertical projection direction; The upper screen cylinder assembly (2) is provided with an upper screening screw (21), and is also provided with an upper screen cylinder inlet (22), an oversize outlet (23), and an undersize outlet (24). The lower screen cylinder assembly (3) is provided with a lower screening screw (31), and is provided with a lower screen cylinder inlet (32), a coarse material outlet (33) and a fine material outlet (34) that are directly connected to the screen material outlet (23). The device is equipped with only one drive motor (4), which is connected to the upper screening screw (21) and the lower screening screw (31) through the same synchronous transmission mechanism (5) to drive the upper screening screw (21) and the lower screening screw (31) to rotate synchronously. The transmission arrangement of the synchronous transmission mechanism (5) is matched with the spiral rotation direction of the upper screening screw (21) and the lower screening screw (31), so that the upper screening screw (21) and the lower screening screw (31) form matching material conveying directions when rotating synchronously, thereby forming a continuous conveying path for the material in the upper screen cylinder assembly (2) and the lower screen cylinder assembly (3), and completing two-stage continuous screening of fine material separation and coarse material separation in the same equipment.

2. The superimposed double-stage spiral screening device according to claim 1, characterized in that, The synchronous transmission mechanism (5) includes a driving transmission wheel (51), an upper driven transmission wheel (52), a lower driven transmission wheel (53), and a synchronous transmission component (54). The active drive wheel (51) is mounted on the output shaft of the drive motor (4), the upper driven drive wheel (52) is mounted on the shaft end of the upper screening screw (21), and the lower driven drive wheel (53) is mounted on the shaft end of the lower screening screw (31). The synchronous transmission element (54) is simultaneously wound around the active transmission wheel (51), the upper driven transmission wheel (52) and the lower driven transmission wheel (53).

3. The superimposed double-stage spiral screening device according to claim 2, characterized in that, The synchronous transmission component (54) is a synchronous belt or a double-row chain; When the synchronous transmission component (54) is a synchronous belt, the driving transmission wheel (51), the upper driven transmission wheel (52) and the lower driven transmission wheel (53) are pulleys respectively; When the synchronous transmission component (54) is a double-row chain, the driving transmission wheel (51), the upper driven transmission wheel (52) and the lower driven transmission wheel (53) are sprockets.

4. The superimposed double-stage spiral screening device according to claim 2, characterized in that, The upper driven drive wheel (52) and the lower driven drive wheel (53) are located on the same side of the frame (1) and are arranged adjacent to each other in the vertical direction to shorten the transmission path of the synchronous transmission member (54).

5. The superimposed double-stage spiral screening device according to claim 1, characterized in that, The upper screen cylinder assembly (2) and the lower screen cylinder assembly (3) form a direct material discharge channel, so that the material from the upper screen cylinder assembly (2) can directly enter the lower screen cylinder assembly (3) under the action of gravity, or under the combined action of gravity and liquid medium flow, without setting an intermediate transfer mechanism.

6. The superimposed double-stage spiral screening device according to claim 1, characterized in that, It also includes a quick-release screen module (6), which includes a screen frame (61) and a quick-locking mechanism (7). The screen frame (61) is detachably installed at the cylinder wall mounting port of the upper screen cylinder assembly (2) and / or the lower screen cylinder assembly (3).

7. The superimposed double-stage spiral screening device according to claim 6, characterized in that, The quick locking mechanism (7) includes a protruding rib (71) on the screen frame (61), a fixed seat (72) on the outside of the screen cylinder mounting port, a long pressure plate (73) on the fixed seat (72), a slot (74) on the inside of the long pressure plate (73), and a locking bolt (75). The slot (74) engages with the protruding rib (71) to form a multi-point pressing structure; The cross-section of the protruding rib (71) is rectangular, semi-circular, trapezoidal, triangular, or other shape that can engage with the slot (74).

8. The superimposed double-stage spiral screening device according to claim 6, characterized in that, The quick locking mechanism (7) includes a wedge-shaped slider (76) disposed on the side of the screen frame (61), a guide rod (77) disposed on the side of the screen cylinder mounting port, a fixing buckle (78) disposed on the guide rod (77), and a drive screw (79) connected to the fixing buckle (78). By rotating the drive screw (79), the fixing buckle (78) is driven to press the wedge-shaped slider (76), so that the screen frame (61) achieves self-locking through wedge extrusion.

9. The superimposed double-stage spiral screening device according to claim 1, characterized in that, The equipment also includes an online anti-clogging and screen cleaning device, which includes a water spray device (8) and a roller brush screen cleaning device (9). The water spraying device (8) is located above the upper screen cylinder assembly (2) and / or the lower screen cylinder assembly (3) and is used to spray water onto the screen surface. The roller brush cleaning device (9) is located on the outside of the upper screen cylinder assembly (2) and / or the lower screen cylinder assembly (3) for online cleaning of the screen surface; The device also includes a protective cover (10), which covers the outside of the upper screen cylinder assembly (2) and the lower screen cylinder assembly (3) to prevent material or liquid from splashing out.

10. The superimposed double-stage spiral screening device according to claim 1, characterized in that, The lead of the upper screening screw (21) is different from that of the lower screening screw (31) so that the material forms different propulsion speeds and screening residence times in the upper screen cylinder assembly (2) and the lower screen cylinder assembly (3).

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