An efficient sand production and screening system

Abstract

The present application relates to the technical field of material screening, and aims to provide a high-efficiency sand production screening system, which comprises a screen cylinder, the screen cylinder comprises a skeleton and a plurality of screen rings arranged uniformly along the length direction of the screen cylinder and arranged on the skeleton, the screen rings can slide along the length direction of the screen cylinder on the skeleton, and the system further comprises a particle size adjusting driving mechanism for driving the screen rings, and the screen cylinder changes the spacing of adjacent screen rings in the axial direction of the screen cylinder through the particle size adjusting driving mechanism to form the adjustment of the screening particle size. The present application adopts a ring gap screening structure, and has the core advantages of flexible and adjustable screening particle size, convenient blockage removal and low comprehensive cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material screening, and in particular to a high-efficiency sand production and screening system. BACKGROUND

[0002] Sand is a basic raw material in the fields of construction, road, water conservancy, etc. Different engineering scenarios have significantly different requirements for sand particle size: 5-10mm fine aggregate is required for high-rise building main structure construction, 20-40mm medium-coarse sand is suitable for road cushion filling, and 50-80mm large gravel is required for river revetment engineering. Sand production lines need to frequently switch the screening particle size to meet the diversified market demand. The drum screen, with its stable operation and large handling capacity, has become the core equipment for sand screening.

[0003] The existing drum screening equipment mostly adopts an axial gap type screening structure (such as fixed screen bars, modular screen segment splicing, etc.). The screening gap of this structure is arranged along the axial direction of the screen drum, and adjacent screen bars or screen segments form an axial long and narrow channel. This not only limits the flexibility of particle size adjustment from the design aspect - the screen bars or screen segments are mostly fixedly connected or modularly rigidly spliced with the screen drum framework, and the size of the screening gap is determined by the size of the components themselves. If the screening particle size needs to be changed, the corresponding size of the screen mesh, screen bar or modular screen segment must be replaced after the machine is stopped, and the gap cannot be dynamically changed through simple structural adjustment, resulting in complicated and time-consuming adjustment operations (usually 1-2 hours, and even dozens of hours for large equipment), which seriously disrupts the production process and is difficult to adapt to the scenario of frequent switching of screening specifications. In addition, the material flow space is limited, which is prone to cause blockage due to material accumulation, high water content or the mixing of large impurities, and it is difficult to clean after blockage, which requires the equipment to be stopped and disassembled, further affecting the production efficiency. At the same time, a single device can only adapt to the screening requirements of a fixed particle size range, and in order to cover a variety of specifications of materials, enterprises need to purchase multiple devices of different types, resulting in a significant increase in equipment purchase cost, site occupation cost and operation complexity.

[0004] Although some existing technologies attempt to optimize the particle size adjustment function by improving the structure, such as using telescopic screen bars or spliced screen segments, they still cannot break through the core limitation of the traditional axial gap: telescopic screen bars are prone to deformation due to axial stress, resulting in poor gap adjustment accuracy and insufficient structural stability; although spliced screen segments can achieve particle size adjustment by replacing modules with different spacings, they still need to be replaced after being stopped and disassembled, and the core problem of long-term interruption of production has not been solved. These improvement schemes have not been able to solve the technical problems of convenient particle size adjustment, efficient unblocking and multi-specification adaptability at the same time, and it is difficult to meet the needs of modern sand production lines for efficient, flexible and low-cost screening. Therefore, an innovative screening structure and adjustment method are needed to overcome the shortcomings of existing technologies. SUMMARY

[0005] The application aims to provide a high-efficiency sand production screening system capable of quickly adjusting the screening gap.

[0006] To achieve the above-mentioned application purposes, the application adopts the following technical scheme: a high-efficiency sand production screening system, comprising a screening cylinder, wherein the screening cylinder comprises a framework and a plurality of screening rings arranged uniformly along the length direction of the screening cylinder and arranged on the framework; the screening rings can slide along the length direction of the screening cylinder on the framework; the system further comprises a particle size adjusting driving mechanism for driving the screening rings; the screening cylinder changes the spacing between adjacent screening rings in the axial direction of the screening cylinder through the particle size adjusting driving mechanism to form the adjustment of the screening particle size.

[0007] Preferably, the framework comprises a full-length steel groove and a driving groove for forming power combination with the screening power mechanism.

[0008] The full-length steel groove is provided with a plurality of full-length steel grooves, the full-length steel grooves extend along the length direction of the screening cylinder, and the plurality of full-length steel grooves are uniformly distributed in a ring shape around the axis of the screening cylinder; the two side walls of the full-length steel groove are provided with first side holes for the screening rings to pass through, and the first side holes extend along the length direction of the full-length steel groove.

[0009] The driving groove is in a ring shape and is provided with at least two driving grooves, and the driving grooves are welded and fixed at the two ends or the middle part of the full-length steel groove.

[0010] The screening ring passes through the first side holes of the plurality of full-length steel grooves and can slide along the first side holes.

[0011] Preferably, a transition cylinder is further arranged in the framework of the screening cylinder near one end of the outlet, the side wall of the transition cylinder is welded on the full-length steel groove, and the outer surface of the transition cylinder abuts against the screening ring; the screening cylinder located in the section covered by the transition cylinder constitutes a transition zone, and the other end constitutes a screening zone.

[0012] Preferably, a sliding block in sliding cooperation with the full-length steel groove is arranged in the full-length steel groove; the sliding block is in one-to-one correspondence with the screening ring and is fixedly connected with the sliding block.

[0013] A supporting elastic member is arranged between adjacent sliding blocks, the particle size adjusting driving mechanism comprises a telescopic extrusion member arranged in the full-length steel groove, the telescopic extrusion member is located at one end of the full-length steel groove opposite to the transition cylinder; the output end of the telescopic extrusion member faces the closest sliding block and is fixedly connected with the sliding block.

[0014] Preferably, the top surface of each sliding block is further provided with two hinge pins, the hinge pins between adjacent two sliding blocks are connected through two groups of connection arms hinged in a V shape, and the left and right extension distances of the V-shaped angle parts of the two groups of connection arms are controlled to form the control of the position of the sliding block.

[0015] The second side hole extending along the length direction of the steel trough is arranged above the first side hole, and the connecting arm group extends into the second side hole; the particle size adjusting drive mechanism further comprises two long clamping plates arranged on both sides of the steel trough and extending along the length direction of the steel trough, a protruding portion is arranged on the long clamping plate at a position opposite to the second side hole, and the protruding portion extends into the second side hole and is in contact with the V-shaped corner of the connecting arm group; the particle size adjusting drive mechanism further comprises a plate driving assembly for driving the long clamping plates to move close to each other or move away from each other.

[0016] Preferably, the top of the steel trough is covered with a cover plate in the shape of U in cross section, the plate driving assembly comprises a screw rod and a screw sleeve, and the middle of the two long clamping plates is provided with two screw rods penetrating through the two side edges of the cover plate, the opposite ends of the two screw rods are sleeved in the screw sleeve, and the screw rod and the screw sleeve are in threaded cooperation.

[0017] Preferably, the supporting elastic member is a butterfly spring or a spiral spring.

[0018] Preferably, the sliding block is composed of two halves, and the screen ring is clamped between the two halves of the sliding block to form fixation.

[0019] Preferably, a plurality of screen cylinders are arranged, and the skeletons of the plurality of screen cylinders are connected to each other; each screen cylinder forms a screening section.

[0020] Preferably, a housing is further included, the plurality of screen cylinders are arranged in the housing, the bottom of the housing is provided with a discharge port corresponding to each screening section, and the top of the housing is provided with an access door.

[0021] The beneficial effects of the present application are mainly embodied in: adopting a ring gap screening structure to realize the core advantages of flexible and adjustable screening particle size, convenient clearing and low comprehensive cost. The working principle and process are as follows: the screen cylinder is composed of a skeleton and a screen ring that can slide axially, breaking through the design limitation of traditional axial gap screening, and a particle size adjusting drive mechanism in the form of manual or automatic (electric, pneumatic, hydraulic drive, etc.) is used to drive the screen rings to slide synchronously; automatic adjustment can quickly change the size of the ring gap formed by adjacent screen rings without stopping the machine, adapt to different screening particle size requirements, and ensure the continuity of production; although manual adjustment needs to stop the machine for operation, it still does not need to disassemble and replace parts, and is more convenient and efficient than traditional equipment adjustment; at the same time, when there is a blockage, the blockage stuck in the ring gap can be quickly removed by adjusting the gap between the screen rings, solving the pain point of difficult cleaning of traditional screening equipment; during screening operation, the screen cylinder rotates to move the sand and stone materials, particles smaller than the ring gap fall through the gap to collect materials, and particles larger than the gap are discharged from the discharge end, realizing accurate screening; the same equipment can cover multiple particle size specifications, greatly reducing the cost of equipment purchase and site occupation, and significantly improving the adaptability and operation efficiency of the sand production line. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Structure diagram of the whole device of the present application;

[0023] Figure 2 Structure diagram of the cross section of the screen cylinder;

[0024] Figure 3 Structure diagram of the cross section of the screen cylinder; Figure 2 Structure diagram of the cross section of the screen cylinder;

[0025] Figure 4 Structure diagram of the screen ring on the steel trough;

[0026] Figure 5 Structure diagram of the cooperation between the connecting arm group and the long clamping plate;

[0027] Reference signs: 1, screen cylinder; 2, skeleton; 3, screen ring; 4, screening power mechanism; 5, steel trough; 6, driving support groove; 7, first side hole; 8, transition cylinder; 9, sliding block; 10, supporting elastic member; 11, telescopic extrusion member; 12, hinged pin; 13, connecting arm group; 14, second side hole; 15, long clamping plate; 16, protruding part; 17, plate driving assembly; 18, cover plate; 19, screw; 20, screw sleeve; 21, cover; 22, discharge port; 23, maintenance door; 24, transition zone; 25, screening zone. DETAILED DESCRIPTION

[0028] The specific embodiments of the present application are described in detail below in combination with the drawings. The embodiments are only used to explain the present application and do not limit the protection scope of the present application.

[0029] I. Overall structure assembly

[0030] As shown in Figs. Figure 1 and Figure 2 , the core components of the high-efficiency sand production screening system include the screen cylinder 1, the particle size adjusting driving mechanism, the transition cylinder 8, the cover 21 and the screening power mechanism 4. The assembly relationship of each component is as follows:

[0031] (I) Assembly of the screen cylinder 1

[0032] The skeleton 2 of the screen cylinder 1 is composed of a through steel groove 5 and a driving groove 6. Six high-strength through steel grooves 5 (material Q355B, yield strength ≥ 355 MPa, to ensure the carrying capacity of the skeleton) are selected, which extend along the length direction of the screen cylinder 1 and are uniformly distributed in a ring shape around the axis of the screen cylinder 1 (the included angle between adjacent through steel grooves 5 is 60°). The groove width of the through steel groove 5 is 80-120 mm, the groove depth is 60-100 mm, and the groove wall thickness is 8-12 mm. The rigid skeleton structure is fixed by integral welding process to ensure the stability of the screen cylinder during rotation. The first side hole 7 extending along the length direction is processed on the side wall of the through steel groove 5. The length of the first side hole 7 is matched with the length of the screen cylinder (3-5 m), and the width is matched with the thickness of the screen ring 3 (the gap is strictly controlled within 0.5-1 mm), which ensures smooth sliding of the screen ring 3 and avoids the problem of uneven gap caused by lateral deviation.

[0033] The driving groove 6 is processed from a ring-shaped steel plate with a thickness of 15-20 mm. The inner diameter is consistent with the distribution circle diameter of the through steel groove 5, and the outer diameter is 100-150 mm larger than the inner diameter. The driving groove 6 is fixed at both ends of the through steel groove 5 by double full welding process. The outer side of the driving groove 6 is processed with a ring gear (modulus 3-5, number of teeth 80-120), which is used to mesh with the output gear of the screening power mechanism 4 (usually motor + reducer + transmission gear set) to realize stable rotation driving of the screen cylinder 1. The transmission efficiency is ≥ 95%. Friction transmission can also be used, and the rubber contact wheel is directly clamped in the driving groove 6 for transmission.

[0034] (2) Assembly of screen ring 3 and sliding block 9

[0035] 1. Structure design of screen ring 3

[0036] Conventional structure: the screen ring 3 is made of ZGMn13 wear-resistant alloy steel (hardness ≥ HRC50, impact toughness ≥ 120 J / cm²). According to the diameter of the screen cylinder 1, the ring structure is processed, the thickness of the screen ring 3 is 10-15 mm, and the ring surface is quenched (quenching hardness HRC55-60) to improve wear resistance.

[0037] Special structure (hollow composite screen ring): the screen ring 3 adopts a hollow composite structure of "outer wear-resistant alloy steel + inner rubber filling", the outer layer selects ZGMn13 alloy steel, the wall thickness is controlled to be 3-5 mm (taking into account the structural strength and lightweight requirements), the inner layer hollow chamber is annular in cross section, the chamber diameter accounts for 1 / 3-1 / 2 of the total thickness of the screen ring (for example, when the total thickness of the screen ring is 12 mm, the chamber diameter is 4-6 mm); the filling material of the inner layer selects high-elasticity wear-resistant natural rubber with a Shore hardness of 60-70HA, 15%-20% of carbon black reinforcing agent and 5%-8% of silane coupling agent are added to the rubber to improve the wear resistance and the bonding force with the metal outer layer, the rubber is filled into the chamber through a 5-8 MPa high-pressure injection process, and the rubber is tightly combined with the metal outer layer (peeling strength ≥3.5 N / mm) after vulcanization treatment at 120°C / 2h, the same material alloy steel end covers (thickness 3-4 mm) are used at both ends to be sealed by argon arc welding and polished flat, and the surface roughness Ra is ≤1.6μm, so that interference or delamination problems during assembly are avoided.

[0038] 2. The slider 9 is connected with the screen ring 3

[0039] Combined Figure 3 and Figure 4 As shown in the drawings, the slider 9 is forged from 45 steel (after quenching and tempering treatment, hardness HRC 28-32), and is composed of two halves, the opposite surfaces of the two halves are processed with arc-shaped grooves (the groove radius is consistent with the outer diameter of the screen ring 3, and the tolerance is ±0.1 mm) matched with the end of the screen ring 3, the inner wall of the groove is paved with wear-resistant rubber pads with a thickness of 2-3 mm to increase the friction with the screen ring 3 and prevent relative sliding. The end of the screen ring 3 is clamped between the two halves of the slider 9, and is symmetrically fastened by 4-6 high-strength bolts (bolt strength grade 8.8) with a pre-tightening torque of 25-35 N·m, to form a firm fixed connection and ensure that the slider 9 and the screen ring 3 move synchronously.

[0040] The slider 9 with the assembled screen ring 3 is embedded into the steel channel 5, the gap between the width of the slider 9 and the groove width of the steel channel 5 is controlled to be 0.3-0.5 mm, and a polyethylene wear-resistant slider (friction coefficient ≤0.15) is installed at the bottom of the slider 9 to reduce the friction when sliding, so that the screen ring 3 passes through the first side hole 7 of each steel channel 5, and the installation of the screen ring 3 on the framework 2 is completed, and the initial gap uniformity error of adjacent screen rings 3 after installation is ≤0.2 mm.

[0041] (Three) installation of the transition cylinder 8

[0042] The transition cylinder 8 is rolled from a stainless steel plate with a thickness of 3-10 mm (material 304 stainless steel, corrosion resistant), the outer diameter of which is matched with the inner diameter of the screen ring 3 (clearance ≤1 mm), the side wall of the transition cylinder 8 is welded to one end of the through steel tank 5 near the outlet of the screen cylinder 1 by an intermittent welding process, the welding seam spacing is 100-150 mm, the welding leg height is 3-4 mm, which ensures the connection strength while avoiding deformation of the transition cylinder. The length of the transition cylinder 8 is 200-300 mm, so that the outer surface of the transition cylinder 8 is closely attached to the screen ring 3, forming a transition zone 24, and the remaining section is a screening zone 25, the inner wall of the transition cylinder 8 is processed with a spiral guide groove (lead 100-150 mm, groove depth 5-8 mm), which can guide the smooth movement of the material and avoid accumulation at the end of the screen ring 3 to cause blockage.

[0043] (Four) Particle size adjusting drive mechanism assembly

[0044] 1. Core transmission assembly installation

[0045] As shown in Figure 4 , the supporting elastic member 10 is selected from a butterfly spring (material 60Si2Mn, elastic modulus 206 GPa) or a spiral spring; the rated bearing capacity of a single butterfly spring is 5-10 kN, and the deformation amount is 5-8 mm; the butterfly spring is installed between adjacent sliding blocks 9; each sliding block is provided with 1-2 groups of butterfly springs on both sides; the sliding blocks 9 are positioned by the spring seat to maintain uniform spacing (spacing error ≤0.2 mm) in the initial state, forming an initial screening gap, and providing a reset elastic force for the sliding of the sliding blocks.

[0046] 2. Multi-type adaptive design of telescopic extrusion and pushing member 11

[0047] The telescopic extrusion and pushing member 11 is a core power component of the automatic adjustment mode, which can be selected from an electric push rod, a hydraulic oil cylinder or a manual jack according to actual working condition requirements, and the installation structure and power coupling mode are designed as follows:

[0048] Type one: electric push rod (preferred scheme, suitable for continuous automatic production)

[0049] An industrial-grade electric push rod with a rated thrust of 5-10 kN, a stroke of 100-200 mm and a positioning accuracy of ±0.1 mm is selected, which is fixed at one end of the through steel tank 5 away from the transition cylinder 8 by a flange, and the output end of the electric push rod is fixedly connected with the closest sliding block 9 by a flange plate (material Q235B), which is fastened by 8 M10-M14 bolts to ensure stable transmission of the thrust. Since the screen cylinder 1 needs to rotate at high speed (30-60 r / min), the circuit coupling of the electric push rod is realized by a conductive slip ring: the structure of the air body can refer to the existing conductive ring scheme to realize power transmission.

[0050] Type two: hydraulic oil cylinder (suitable for large thrust working conditions)

[0051] When the screened material is large-diameter gravel (particle size ≥ 30 mm) or the number of screen rings is large (≥ 20 groups), a double-acting hydraulic cylinder with a rated thrust of 10-20 kN and a stroke of 100-200 mm is selected as the telescopic extrusion piece 11. The hydraulic cylinder is fixed at the end of the lengthwise steel tank 5 through trunnion support, and the cylinder piston rod is connected with the sliding block 9 through a floating joint to compensate for installation errors and movement load deviation. The oil circuit connection is realized through a rotary joint: a hydraulic rotary joint (model HS-G1 / 2, working pressure ≤ 16 MPa) is installed at one end of the screen cylinder, the moving end of the rotary joint rotates synchronously with the screen cylinder, and the static end is fixed on the rack and connected to the hydraulic station. The hydraulic oil pipe is made of high-pressure steel wire braided rubber pipe (working pressure ≥ 25 MPa), which is fixed along the outside of the screen cylinder skeleton through pipe clamps. The connection between the oil pipe and the cylinder and the rotary joint is sealed with a sleeve joint to ensure no leakage under high-pressure working conditions. The hydraulic system is equipped with overflow valves, throttle valves and electromagnetic reversing valves. The telescopic action of the cylinder is realized by controlling the electromagnetic reversing valve through PLC, the sliding block moving speed (0.3-1 mm / s) can be controlled by adjusting the throttle valve, and the safety pressure (10% higher than the working pressure) is set for the overflow valve to prevent overloading and damage to the components.

[0052] Type three: manual jack (adapted to simple working conditions or emergency adjustment)

[0053] For small-scale screening equipment or scenes without power supply, the telescopic extrusion piece 11 can be selected as a screw-type manual jack (rated bearing capacity 5-10 kN, stroke ≥ 100 mm). The jack is fixed at the end of the lengthwise steel tank 5 through a support, and the jack's top rod is in contact with the sliding block 9 through a top block. The surface of the top block is processed with an arc-shaped groove and laid with a wear-resistant rubber pad to increase the contact area and prevent slipping. When manually adjusting, the sliding block 9 is moved by rotating the rocker of the jack, and the gap between the screen rings is measured by a plug gauge. After adjusting to the target value, the position is fixed through the self-locking structure of the jack, without the need for additional locking devices, which is simple to operate and low in cost.

[0054] 3. Long clamping plate and plate driving assembly installation

[0055] The long clamping plate 15 is processed from a steel plate with a thickness of 8-12 mm (material Q355B), and its length is adapted to the lengthwise steel tank 5. A semicircular protruding part 16 (protruding height 10-15 mm, radius adapted to the V-shaped corner part of the connecting arm group 13) is processed at the position opposite to the second side hole 14 of the long clamping plate 15. The surface of the protruding part 16 is polished (roughness Ra ≤ 0.8 μm) to reduce frictional wear with the connecting arm group. Two long clamping plates 15 are arranged on both sides of the lengthwise steel tank 5, with the protruding part 16 extending into the second side hole 14 and tightly contacting with the V-shaped corner part of the connecting arm group 13 (contact pressure 0.3-0.5 MPa).

[0056] The cover plate 18 is made of a U-shaped steel plate (material Q235B, plate thickness 6-8mm), covering the top of the continuous steel channel 5 and fixed to the continuous steel channel 5 by bolts. Two screws 19 with a diameter of 16-20mm (material 45 steel, thread accuracy 6H) are welded to opposite sides of the middle of the long clamping plate 15. The length of the screws 19 is 100-150mm. The screws 19 pass through the two sides of the cover plate 18 (the side is machined with through holes with a diameter matching the screws, and a gap of 0.2-0.3mm). The opposite ends of the two screws 19 are fitted into the screw sleeves 20. The screw sleeves 20 are machined from 45 steel and have bidirectional threads in the inner hole (the threads at both ends turn in opposite directions, with a pitch of 2-3mm). The threads of the two screws 19 and the screw sleeves 20 turn in opposite directions, forming the plate drive assembly 17.

[0057] 4. Manual / Electric Dual-Mode Design of Board Drive Assembly 17

[0058] The board driver assembly 17 supports both manual direct adjustment and motor drive adaptation to meet different operational needs.

[0059] Manual adjustment mode: The outer side of the 20mm threaded insert has a hexagonal structure (24-30mm distance between opposite sides). The insert can be directly rotated with a wrench at a torque of 10-20 N·m to synchronously bring the screws together or apart, thereby adjusting the distance between the long clamps. Locking nuts are installed at both ends of the threaded insert. After adjustment, tighten the locking nuts to prevent vibration from causing the insert to loosen and ensure stable clearance.

[0060] Motor Drive Mode: To improve adjustment efficiency, a driven gear (module 2-3, number of teeth 30-40) can be fitted on the outside of the screw sleeve 20. A micro geared motor (power 50-100W, reduction ratio 50-100:1, output speed 1-2 r / min) is fixed on the cover plate 18 via a motor bracket. A drive gear is installed on the motor output shaft, meshing with the driven gear (transmission ratio 1:1). The motor's circuit layout is shared with the slip ring of the electric push rod. Power is supplied during rotation through the conductive slip ring. The motor is equipped with a forward / reverse controller and limit switches. Adjustment parameters are set via a touch screen. The controller drives the motor to rotate forward or reverse, achieving automatic adjustment of the long clamp. The limit switches prevent excessive movement of the long clamp from damaging the connecting arm assembly, improving operational safety.

[0061] 5. Screen ring gap equalization control mechanism

[0062] Combination Figure 4 and Figure 5As shown, one of the core aspects of this invention is that the double-sided clamping design of the long clamping plate 15 solves the problem of uneven distribution of screen rings that may be caused by a single telescopic extrusion pusher. In actual operation, due to factors such as the friction between the slider 9 and the continuous steel channel 5, and the lateral force generated by the impact of the material, the linkage of the supporting elastic element 10 alone may cause deviations in the sliding displacement of each slider 9, resulting in uneven circumferential gaps between adjacent screen rings 3.

[0063] In this invention, such as Figure 5 As shown, each connecting arm assembly 13 can be considered as two hinged connecting arms. One end of each connecting arm is hinged, and the other end is hinged to a hinge pin 12, forming a V-shaped structure. Two long clamping plates 15 form a rigid clamping constraint on the V-shaped corners of all connecting arm assemblies 13 from both sides of the continuous steel channel 5. When the telescopic pusher 11 pushes the first slider 9 to move, the V-shaped angle of the connecting arm assembly 13 changes, and its corner slides along the protrusion 16 of the long clamping plate 15. The long clamping plate 15 provides a uniform guiding reference, ensuring that the movement trajectory of each connecting arm assembly is consistent, thereby driving all sliders 9 to slide synchronously and uniformly. At the same time, the plate drive assembly 17 can fine-tune the initial position of the connecting arm assembly 13 by adjusting the spacing of the long clamping plates 15, compensating for assembly errors or wear deviations after long-term use, so that the circumferential gap uniformity error of adjacent screen rings 3 is controlled within ±0.1mm, significantly improving the accuracy of the screening particle size.

[0064] (v) Assembly of the multi-screen cylinder and the cover 21

[0065] like Figure 1 As shown, based on the multi-size grading requirements of sand and gravel production, three screen cylinders 1 are set up, each with a length of 3-5m. Each screen cylinder 1 constitutes an independent screening section, and different screening gaps (e.g., 10mm for the first section, 5mm for the second section, and 2mm for the third section) can be set through the particle size adjustment drive mechanism to achieve multi-level grading.

[0066] The assembled multi-sieve cylinder structure is placed in the shell 21, the shell 21 is welded by a steel plate with a thickness of 5-8 mm (material Q235B), and has a cuboid structure, a length that is 50-100 mm shorter than the total length of the multi-sieve cylinder, and a width and a height that are 300-400 mm larger than the outer diameter of the sieve cylinder. A polyurethane sound insulation lining plate with a thickness of 10-15 mm is laid on the inner wall of the shell 21 to reduce the noise during equipment operation (noise ≤85 dBA). Independent discharge ports 22 (with a size of 500×500 mm-800×800 mm) are arranged at the bottom of the shell 21 corresponding to each screening section, and an inclined wear-resistant lining plate (with an inclination angle of 60°-70°) is installed on the inner wall of each discharge port to facilitate the sliding of the material. A chute is arranged below each discharge port and connected to a subsequent conveying device; 2-3 maintenance doors 23 (with a size of 1000×800 mm) or one long large-size maintenance door is arranged at the top of the shell 21, the maintenance door is connected by a hinge and is provided with a sealing rubber strip to facilitate equipment maintenance and fault troubleshooting, and a dust removal interface (with a diameter of 100-150 mm) is further arranged at the top to connect a dust removal device and improve the working environment.

[0067] II. Working process and adjustment mode

[0068] (1) Screening operation process

[0069] The screening power mechanism 4 (a variable frequency motor with a power of 15-30 kW and a rotating speed of 0-1500 r / min is selected, and a hard tooth surface reducer with a reduction ratio of 20-30:1 is matched) is started to drive the ring gear of the drive bracket 6 to mesh with the transmission gear set, thereby driving the sieve cylinder 1 to rotate around the axis at a rotating speed of 30-60 r / min (which can be adjusted according to the characteristics of the material, and a lower rotating speed of 30-40 r / min is selected for viscous material, and a higher rotating speed of 50-60 r / min is selected for dry material).

[0070] The sand and stone material to be screened (with a particle size of 0-50 mm and a water content of ≤15%) is sent into the screening zone 25 from the end of the sieve cylinder 1 away from the transition cylinder 8 through the feeding hopper (with a volume of 1-2 m³), and the feeding speed is controlled at 5-20 m³ / h by the screw feeder to ensure uniform distribution of the material in the sieve cylinder. Under the action of the centrifugal force (centrifugal acceleration 1-2 g) and gravity generated by the rotation of the sieve cylinder 1, the material moves along the length direction of the sieve cylinder 1 to the outlet end, and in the moving process, the particles smaller than the annular gap formed by the adjacent sieve rings 3 fall through the gap to the bottom of the shell 21 and are discharged from the corresponding discharge port 22; the particles larger than the annular gap continue to move forward and are discharged under the guidance of the spiral guide groove of the transition cylinder 8 when passing through the transition zone 24, thereby completing the screening operation.

[0071] When the hollow composite screen ring is used, the elasticity of the inner layer rubber can buffer the impact force generated by the impact of the material (impact absorption amount ≥ 5J), reduce the risk of deformation of the screen ring (deformation amount ≤ 0.1mm), and at the same time, the elastic deformation of the rubber improves the fit of the screen ring and the material, avoiding the fine particle material from being stuck in the gap edge of the screen ring, further improving the screening accuracy (classification error ≤ 0.5mm).

[0072] (II) Screening particle size adjustment method

[0073] 1. Automatic adjustment (no need to stop)

[0074] Electric push rod drive adjustment: start the electric push rod, and the output end pushes the closest slider 9 along the length of the steel groove 5 at a speed of 0.5-1mm / s. The butterfly spring between adjacent sliders 9 is compressed or stretched according to the moving direction of the slider, and the spring force is transmitted to the connecting arm group 13 through the slider, driving the V-shaped angle of the connecting arm group 13 to change synchronously (angle change rate 1-2° / s). Since each slider 9 is linked through the connecting arm group 13, and the long clamping plate 15 forms a rigid constraint to the connecting arm group 13 from both sides, it ensures that all screen rings 3 slide synchronously and uniformly, making the annular gap of adjacent screen rings 3 uniformly increase or decrease (adjustment range 0.5-20mm, adjustment accuracy ±0.1mm), achieving the purpose of accurately adjusting the screening particle size. During the adjustment process, the conductive slip ring ensures continuous communication of the circuit, the screen cylinder 1 keeps rotating, and the material screening operation continues without stopping, and the adjustment response time is ≤10s.

[0075] Hydraulic cylinder drive adjustment: the electromagnetic reversing valve of the hydraulic system is controlled by PLC to make the hydraulic oil enter the rodless cavity of the hydraulic cylinder, push the piston rod to extend, and drive the slider 9 to move; after the reversing valve is switched, the hydraulic oil enters the rod cavity, the piston rod retracts, and the slider resets under the action of the butterfly spring. During the adjustment process, the throttle valve controls the moving speed of the slider, and the pressure sensor monitors the working pressure of the hydraulic cylinder in real time. When the pressure exceeds the set threshold, the relief valve is relieved to protect the equipment from overload damage. The thrust of the hydraulic drive is larger, which is suitable for large particle size material screening or multi-screen ring structure, and has strong adjustment stability, and can realize stable adjustment under high-speed rotation of the screen cylinder.

[0076] 2. Manual adjustment (need to stop or short stop)

[0077] Manual jack adjustment (retractable extrusion push piece): turn off the screening power mechanism 4, and after the screen cylinder is stationary, turn the rocker of the manual jack, push the slider 9 to move along the length of the steel groove 5, and measure the gap between adjacent screen rings point by point through the feeler gauge to ensure that the gap uniformity error is ≤±0.1mm. After adjusting to the target gap, use the self-locking function of the jack to fix the position, tighten the locking nut, and restart the equipment to resume the screening operation. The whole adjustment process takes ≤10min.

[0078] Manual adjustment of the screw (plate drive assembly): turn off the screening power mechanism 4, and turn the screw 20 with a wrench. Since the two screw rods 19 and the screw 20 have opposite screw threads, the screw rotates and synchronously brings the two screw rods closer or further apart, driving the two long clamping plates 15 to move closer or further apart. The protruding part 16 on the long clamping plate pushes the V-shaped corner of the connecting arm group 13 to move, driving the sliders 9 to slide synchronously, and adjusting the gap between the screen rings. After adjustment, tighten the locking nuts at both ends of the screw to prevent the gap from shifting due to vibration.

[0079] Screw motor-driven adjustment (plate drive assembly mode): Set the target gap value through the touch screen, and the control system drives the micro-reduction motor to rotate. The motor drives the screw 20 to rotate through a gear transmission, achieving automatic adjustment of the long clamping plate. During the adjustment process, the displacement sensor collects the movement distance of the long clamping plate in real time and feeds back to the PLC to form a closed-loop control, ensuring an adjustment accuracy of ±0.1 mm. This mode does not require manual operation and has high adjustment efficiency, making it suitable for scenarios that require frequent micro-adjustment of the gap. The motor circuit is powered through a conductive slip ring, which can be shared with the electric push rod, simplifying the circuit layout.

[0080] (Three) Blockage cleaning operation

[0081] When blockage occurs during screening (material is stuck in the circumferential gap between adjacent screen rings 3, usually caused by wet material bonding or large particle material sticking), two cleaning methods can be selected according to actual conditions:

[0082] Automatic adjustment mode (no need to stop): Start the blockage cleaning program through the control system, and the electric push rod or hydraulic cylinder automatically pushes the slider 9, increasing the gap between adjacent screen rings 3 by 30%-50% (for example, from 5 mm to 6.5-7.5 mm). The blockage stuck in the gap falls or is discharged with the material flow under the action of gravity and centrifugal force caused by the rotation of the screen cylinder 1. The cleaning time is 10-20 seconds. After that, the telescopic extrusion piece 11 automatically resets to restore the screen ring 3 gap to the original set value, and the screening operation continues.

[0083] Manual adjustment mode (short-term stop): If the blockage is severe, temporarily turn off the screening power mechanism 4, turn the screw 20 with a wrench or manually adjust the gap with a hand jack, and manually clean the remaining blockage. After restoring the gap, the equipment can be restarted.

[0084] Three, design advantages of key components

[0085] (One) Design advantages of screen ring 3

[0086] Conventional wear-resistant alloy steel screen ring: made of ZGMn13 wear-resistant material, excellent wear resistance after quenching, suitable for screening of high-strength and high-hardness sand and stone materials, with a service life of 8000-10000h, which is more than 50% longer than that of ordinary carbon steel screen rings.

[0087] Special hollow composite screen ring: through the composite structure design of "metal outer layer + rubber inner layer", realize the dual advantages of "strength + elasticity": the metal outer layer guarantees the support strength and wear resistance, the rubber inner layer cushions the impact of the material (reduces the equipment noise by 3-5dB), prevents the deformation of the screen ring, at the same time enhances the adhesion of the material and the screen ring, reduces the phenomenon of sieve leakage and sieve error, the screening accuracy is improved by 10%-15% compared with the conventional screen ring, and the damping effect of the rubber material can absorb vibration, improve the running stability of the screen cylinder.

[0088] (2) Advantages of the connection structure of the screen ring 3 and the sliding block 9

[0089] The upper and lower half sliding blocks 9 clamp and fix the screen ring 3, the connection mode is firm and reliable, which avoids loosening or falling off of the screen ring during high-speed rotation and frequent adjustment; wear-resistant rubber pads are arranged on the contact surface of the sliding block and the screen ring, which not only increases the friction force, but also plays a buffering role to reduce the damage of vibration impact to the connecting bolts; the bolt fastening mode is convenient to disassemble, the screen ring replacement time is ≤30min, which is 80% higher than the replacement efficiency of the traditional welded screen ring, and reduces the maintenance cost.

[0090] (3) Advantages of multiple types of telescopic extrusion pushing pieces and double adjustment modes

[0091] 1. Multiple types of telescopic extrusion pushing pieces: electric push rod for automatic production, hydraulic oil cylinder for large thrust working conditions, manual jack for simple scenes, three types can be flexibly selected according to user needs, improving the versatility and application range of the equipment; each type is equipped with corresponding power coupling components (conductive slip ring, hydraulic rotary joint), which ensures stable power transmission when the screen cylinder rotates at high speed, without winding, leakage and other problems.

[0092] 2. Double mode adjustment of plate driving assembly: manual adjustment structure is simple and reliable, without power supply, suitable for emergency scenes; motor-driven adjustment is efficient and accurate, suitable for automatic production needs, the two modes are complementary, further improving the operation flexibility of the equipment.

[0093] 3. Precise and uniform gap adjustment: the core innovation of the long clamping plate 15 double-sided clamping design provides a unified guide reference for the connecting arm group 13, effectively offsets the influence of factors such as friction force and lateral force, ensures synchronous sliding of all screen rings, and the uniformity error of the gap between adjacent screen rings is ≤±0.1mm, which is much better than the traditional single drive structure (error 1-2mm), and the screening particle size accuracy is significantly improved.

[0094] 4. Wide and stable adjustment range: the screening gap adjustment range is 0.5-20mm, which can meet the screening needs of different particle size sand and gravel materials (from fine sand to coarse gravel); the support elastic element 10 selects a butterfly spring, which has stable elastic reset, and the spring force attenuation rate is ≤5% after long-term use, which ensures the consistency and stability of the gap adjustment.

[0095] (Four) Transition cylinder 8 design advantage

[0096] The transition cylinder 8 is closely attached to the screen ring 3, effectively avoiding the blockage caused by the material accumulation at the end of the screen ring, ensuring smooth material conveying; the spiral guide groove on the inner wall of the transition cylinder guides the orderly movement of the material, reduces the residence time of the material in the transition zone, and improves the processing efficiency; at the same time, the transition cylinder supports and guides the screen ring, preventing the screen ring from deviating horizontally during sliding, and further improving the uniformity of the screen ring gap.

[0097] (Five) Multi-sieve cylinder and shell 21 structure advantage

[0098] 1. Multi-screen section improves screening efficiency: three independent screening sections can be set to different screening gaps, realizing one-time feeding and multi-stage classification (such as separating fine sand, medium sand, coarse sand and gravel at the same time), without the need to configure multiple devices in series, reducing the equipment footprint by 40%-50%, and improving the production efficiency by more than 30%.

[0099] 2. Shell function integration: the shell effectively prevents material splashing and dust dispersion, and can realize dust concentration ≤10mg / m³ when matched with dust removal equipment, meeting environmental protection requirements; multiple independent discharge ports at the bottom facilitate classified material collection, directly docking with subsequent conveying equipment, simplifying the production process; the top maintenance door facilitates equipment maintenance and fault troubleshooting, improving the convenience of operation and maintenance.

Claims

1. A high-efficiency sand and gravel production screening system, comprising a screen cylinder (1), characterized in that: The sieve cylinder (1) includes a frame (2) and a plurality of sieve rings (3) evenly arranged along the length of the sieve cylinder (1) on the frame (2); the sieve rings (3) can slide on the frame (2) of the sieve cylinder (1) along the length of the sieve cylinder (1), and also includes a particle size adjustment drive mechanism for driving the sieve rings (3). The sieve cylinder (1) adjusts the sieve particle size by changing the spacing of adjacent sieve rings (3) in the axial direction of the sieve cylinder (1) through the particle size adjustment drive mechanism. The frame (2) includes a continuous steel trough (5) and a drive tray (6) for forming a power connection with the screening power mechanism (4); The continuous steel trough (5) is provided with multiple troughs, which extend along the length of the screen cylinder (1) and are evenly distributed in a ring around the axis of the screen cylinder (1); the two side walls of the continuous steel trough (5) are provided with first side holes (7) for the screen ring (3) to pass through, and the first side holes (7) extend along the length of the continuous steel trough (5). The drive bracket (6) is annular and at least two are provided. The drive bracket (6) is welded and fixed to both ends or the middle of the continuous steel channel (5). The screen ring (3) passes through the first side hole (7) of multiple through steel grooves (5) and can slide along the first side hole (7); The screen cylinder (1) is also provided with a transition cylinder (8) in the frame (2) near the outlet end. The side wall of the transition cylinder (8) is welded to the continuous steel channel (5), and the outer surface of the transition cylinder (8) is in contact with the screen ring (3). The section of the screen cylinder (1) covered by the transition cylinder (8) constitutes the transition zone (24), and the other end constitutes the screening zone (25). The through-length steel trough (5) is provided with a slider (9) that is in sliding fit with the through-length steel trough (5); the slider (9) corresponds one-to-one with the screen ring (3) and is fixedly connected to the slider (9); A supporting elastic element (10) is provided between adjacent sliders (9). The particle size adjustment drive mechanism includes a telescopic extrusion member (11) provided in the through steel channel (5). The telescopic extrusion member (11) is located at one end of the through steel channel (5) opposite to the transition cylinder (8). The output end of the telescopic extrusion member (11) faces the closest slider (9) and is fixedly connected to the slider (9). Each slider (9) is also provided with two hinge pins (12) on its top surface. The hinge pins (12) of two adjacent sliders (9) are connected by two sets of V-shaped connecting arm groups (13). The position of the slider (9) is controlled by controlling the left and right extension distance of the corner of the V-shape of the two sets of connecting arm groups (13). The continuous steel channel (5) is provided with a second side hole (14) extending along the length direction of the continuous steel channel (5) above the first side hole (7), and the connecting arm assembly (13) extends into the second side hole (14); the particle size adjustment drive mechanism also includes two long clamping plates (15) extending along the length direction of the continuous steel channel (5) on both sides of the continuous steel channel (5), and a protrusion (16) is provided on the long clamping plate (15) at a position opposite to the second side hole (14), and the protrusion (16) extends into the second side hole (14) and contacts the V-shaped corner of the connecting arm assembly (13); the particle size adjustment drive mechanism also includes a plate drive assembly (17) for driving the long clamping plates (15) to move closer or separate.

2. The high-efficiency sand and gravel production screening system according to claim 1, characterized in that: The top of the continuous steel channel (5) is covered with a cover plate (18) with a U-shaped cross-section. The plate drive assembly (17) includes a screw (19) and a screw sleeve (20). Two screws (19) are provided on opposite sides of the middle of the two long clamping plates (15), passing through the two sides of the cover plate (18). The opposite ends of the two screws (19) are fitted into the screw sleeve (20) and form a threaded engagement with the screw sleeve (20). The threaded engagement directions of the two screws (19) and the screw sleeve (20) are opposite.

3. The high-efficiency sand and gravel production screening system according to any one of claims 1-2, characterized in that: The supporting elastic element (10) is a butterfly spring or a helical spring.

4. The high-efficiency sand and gravel production screening system according to any one of claims 1-2, characterized in that: The slider (9) is composed of upper and lower halves, and the screen ring (3) is sandwiched between the two halves of the slider (9) to form a fixed structure.

5. The high-efficiency sand and gravel production screening system according to claim 1, characterized in that: The sieve cylinder (1) is provided in multiple ways, and the skeletons (2) of the multiple sieve cylinders (1) are connected to each other; each sieve cylinder (1) constitutes a sieving section.

6. The high-efficiency sand and gravel production screening system according to claim 5, characterized in that: It also includes a cover (21), and multiple screen cylinders (1) are arranged inside the cover (21). The bottom of the cover (21) is provided with a discharge port (22) corresponding to each screening section; the top of the cover (21) is provided with an inspection door (23).

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