Lattice type ball mill drum screen

Abstract

The invention relates to the technical field of mining industry screening, in particular to a lattice type ball mill drum screen which comprises a stainless steel winding drum, screen mesh frameworks are fixedly welded in the stainless steel winding drum, and the screen mesh frameworks are evenly distributed and welded between a screen mesh framework fixing steel ring and a screen mesh framework fixing flange plate to form a complete barrel-shaped supporting body. And a screen framework fixing steel ring is fixedly welded to the outer portion of the screen framework, the screen framework fixing steel ring is welded to one side of the hollow shaft connecting flange plate and serves as a supporting foundation of the screen framework, and the hollow shaft connecting flange plate is fixedly connected to one side of the outer portion of the stainless steel winding drum. The problems that due to the fact that a round steel material is adopted, the screen is short in service life and prone to abrasion and failure are solved, operation potential safety hazards such as unsoldering, falling and poor concentricity caused by the fact that a lifting lug is welded to a horn mouth device are eliminated, and the problems that due to a traditional structure, maintenance is complex, replacement is difficult, and downtime is long are solved.

Description

Technical Field

[0001] This invention relates to the field of mineral screening technology, and in particular to a grid-type cylindrical screen for ball mills. Background Technology

[0002] Ball mills are widely used grinding equipment in industries such as cement, building materials, metallurgy, and chemicals. Their core function is to pulverize raw materials to the required fineness through the impact and grinding action of grinding media (such as steel balls) within the mill. Grate-type ball mills are particularly common in mineral processing due to their forced discharge characteristics. In this type of equipment, a cylindrical screen is typically installed at the discharge end to intercept incompletely worn large steel balls, fragments, and metallic impurities, preventing them from entering subsequent processes and causing equipment damage or affecting process stability. However, traditional cylindrical screens are designed as funnel-mouth discharge systems. This system uses round steel welded into a screen mesh, and three lifting lugs are welded to the outside of the screen body and fixed to the funnel-mouth discharge port device at the ball mill's discharge end, allowing the screen body to rotate synchronously with the mill. However, this solution has several significant technical flaws: First, the round steel material has poor wear resistance, and the screen mesh becomes enlarged after about three months of operation, causing large steel balls to leak out, posing a safety hazard; second, the lifting lug structure is prone to wear and weld failure, causing the entire cylindrical screen to fall off and triggering a serious production accident; third, because it is difficult to ensure perfect concentricity during welding and installation, the cylindrical screen has an eccentricity problem during operation, affecting the stability of the equipment; finally, once the screen is damaged, repair requires complete disassembly, which involves a large amount of work and causes the ball mill to be shut down for a long time, seriously affecting the continuity of production.

[0003] To address this, a grid-type cylindrical sieve for ball mills is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a grid-type cylindrical screen for ball mills, which solves the problems of short screen life and easy wear and failure caused by the use of round steel material; eliminates operational safety hazards such as detachment, falling off, and poor concentricity caused by relying on lifting lugs welded to the bell mouth device; overcomes the problems of complex maintenance, difficult replacement, and long downtime caused by traditional structures; solves the process defects of slurry splashing, easy screen clogging, and ineffective recovery of large steel balls during the discharge process; improves the overall stability, safety, and reliability of ball mill operation; reduces unplanned downtime; and ensures efficient and continuous production, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a grid-type ball mill cylindrical screen, comprising a stainless steel drum, wherein a screen mesh frame is welded and fixed inside the stainless steel drum, the screen mesh frame being evenly distributed and welded between a screen mesh frame fixing steel ring and a screen mesh frame fixing flange to form a complete cylindrical support body; a screen mesh frame fixing steel ring is welded and fixed to the outside of the screen mesh frame, the screen mesh frame fixing steel ring being welded to one side of a hollow shaft connecting flange as a supporting foundation for the screen mesh frame; and a hollow shaft connecting flange is fixedly connected to the outer side of the stainless steel drum. A screen frame fixing flange is fixedly connected to the other side of the cylinder. The screen frame fixing flange is located at the other end of the cylindrical screen and corresponds to the screen frame fixing steel ring. Together, they clamp and fix the screen frame. A stainless steel wear-resistant strip is welded and fixed to the inner side of the screen frame. At least six sets of polyurethane screens are welded and fixed on the stainless steel wear-resistant strip. An involute retaining ring is welded and fixed to the inner side of the screen frame below the polyurethane screens. A discharge end receiving ore box body is provided on the lower outer side of the stainless steel drum. A screen anti-clogging device and a steel ball recovery device are installed in the discharge end receiving ore box body.

[0006] Preferably, the screen anti-clogging device includes a flushing water pipe that runs through the ore receiving box body at the discharge end, and a nozzle that is connected and fixed to the flushing water pipe.

[0007] Preferably, the steel ball recycling device includes a screen fixed on the cleaning port, and two discharge ports are opened on the lower side of the outer side of the discharge end receiving the ore box body, with the screen located on the discharge port near the cleaning port.

[0008] Preferably, the cleaning port is hinged with a small sealing door to facilitate the user to open the cleaning port and retrieve the steel ball.

[0009] Compared with the prior art, the beneficial effects of the present invention are: 1. Significantly increased lifespan: Polyurethane screens have far greater wear resistance than round steel, increasing their lifespan by more than 10 times, from the original 3 months to more than 30 months, greatly reducing the frequency of replacement.

[0010] 2. Safe and stable operation: The welding structure of the lifting lugs is eliminated and flange bolt connection is adopted to completely avoid accidents of detachment and falling off, ensure the equipment operates in a concentric manner, and reduce vibration and failure rate.

[0011] 3. Convenient and efficient maintenance: The modular design of the screen means that if it is damaged, there is no need to disassemble the entire cylindrical screen. You only need to open the top to replace the screen, which shortens the maintenance time and reduces downtime losses.

[0012] 4. Functional integration and optimization: It realizes three major additional functions: anti-splashing ore, anti-clogging, and automatic steel ball recycling, thereby improving process integrity and resource utilization.

[0013] 5. Significant economic benefits: After two years of continuous operation following the upgrade, no malfunctions were caused by the cylindrical screen, ensuring the stable, safe, and efficient operation of the ball mill, providing solid support for the company to complete its production tasks, and generating huge indirect economic benefits.

[0014] 6. Balancing environmental protection and safety: The flushing system reduces dust and clogging risks, while the hinged door design allows inspection and recycling operations to be carried out in a safe environment, improving on-site operational safety. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a prior art structural diagram of the present invention; Figure 2 This is a structural view of the grid-type ball mill cylindrical screen of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Hollow shaft connecting flange; 2. Screen frame fixing steel ring; 3. Screen frame; 4. Screen frame fixing flange; 5. Stainless steel drum; 6. Stainless steel wear-resistant strip; 7. Polyurethane screen; 8. Involute retaining ring; 9. Discharge end connection to ore box body; 10. Screen anti-clogging device; 11. Steel ball recovery device. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figures 1 to 2 The present invention provides a technical solution: A grid-type cylindrical screen for ball mills, comprising:

[0020] Hollow Shaft Connecting Flange 1: Hollow shaft connecting flange 1 is a key component for achieving a rigid connection between the entire cylindrical screen assembly and the ball mill discharge end. It is directly fixed to the hollow shaft at the ball mill discharge end using high-strength bolts, replacing the traditional method of relying on lifting lugs welded to the bell mouth. This design ensures that the cylindrical screen remains highly concentric with the main shaft during high-speed rotation, avoiding safety hazards such as vibration, wear, or detachment caused by eccentric operation. Simultaneously, this flange also serves as a mounting base for other screen structures, transmitting torque and supporting the overall screen body.

[0021] Screen frame fixing steel ring 2: The screen frame fixing steel ring 2 is welded to one side of the hollow shaft connecting flange 1, serving as the supporting foundation for the screen frame 3. Its main function is to firmly fix the screen frame 3 to the rotating system, ensuring that the entire screen structure does not loosen or deform during operation. This steel ring is made of high-strength steel, possessing good structural stability and fatigue resistance, and can withstand the alternating loads brought about by long-term rotation.

[0022] Screen frame 3: The screen frame 3 is the core framework structure supporting the polyurethane screen 7. It consists of multiple arc-shaped beams, evenly distributed and welded between the screen frame fixing steel ring 2 and the screen frame fixing flange 4, forming a complete cylindrical support. Its function is to provide a stable installation platform for the polyurethane screen 7, ensuring that the screen does not shift or tear under material impact and water washing. The frame structure is rationally designed, ensuring both strength and ventilation / material permeability.

[0023] Screen frame fixing flange 4: Located at the other end of the cylindrical screen, the screen frame fixing flange 4 corresponds to the screen frame fixing steel ring 2, together clamping and fixing the screen frame 3. This flange is also made of high-strength steel and is connected to the screen frame 3 by welding, forming a closed-loop structure to enhance overall rigidity and stability. Its presence ensures balanced force distribution at both ends of the screen body, preventing twisting or deformation caused by unilateral force.

[0024] Stainless steel drum 5: The stainless steel drum 5 is welded to the outside of the screen frame fixing steel ring 2, wrapping around part of the outer surface of the screen body, mainly used to enhance the overall wear resistance of the cylindrical screen. Because the discharge end of the ball mill is in long-term contact with high-velocity slurry and the impact of steel balls, the outer wall is extremely prone to wear. The introduction of the stainless steel drum 5 effectively extends the service life of the main screen structure. Its material is corrosion-resistant, high-hardness stainless steel, possessing excellent wear resistance.

[0025] Stainless steel wear-resistant strip 6: The stainless steel wear-resistant strip 6 is welded to the inner surface of the screen frame 3, directly facing the friction and impact of the material flow and steel balls. Its main function is to protect the screen frame 3 from rapid wear and extend its service life. The wear-resistant strips are evenly distributed in strip shape, covering vulnerable areas and forming a "protective layer," effectively reducing the risk of overall failure of the frame structure due to localized wear.

[0026] Polyurethane Screen 7: Polyurethane screen 7 is one of the core functional components of this improvement. It consists of six large modules, which are fixed to the screen frame 3 with bolts. Compared with traditional round steel screens, polyurethane material has extremely high wear resistance, tear resistance, and elasticity, increasing its service life by more than 10 times (up to 30 months or more). Its mesh design is a 20×40mm rectangular grid, which can effectively intercept large particles and steel balls while ensuring sufficient ore penetration. The modular design makes replacement extremely convenient; there is no need to disassemble the entire screen body. Only by loosening the bolts can the damaged unit be replaced, significantly shortening maintenance time.

[0027] Involute retaining ring 8: The involute retaining ring 8 is welded to the inner side of the screen frame 3, located below the polyurethane screen 7. Its shape is an involute curve, and its main function is to guide the material to flow smoothly, reducing the accumulation and retention of material inside the screen. This structure helps reduce the risk of clogging, improves discharge efficiency, and provides some support and restraint for the screen, preventing it from sagging or deforming under high-pressure water flow or material impact.

[0028] Discharge end receiving box body 9: The discharge end receiving box body 9 is used to receive qualified fine slurry discharged from the cylindrical screen and guide it to the next process. The box structure is elongated, extending beyond one end of the cylindrical screen to form a closed discharge channel, effectively preventing slurry splashing and improving the on-site working environment. The box body is made of wear-resistant steel plate, which has good impact resistance and corrosion resistance, ensuring long-term stable operation.

[0029] Screen anti-clogging device 10: The screen anti-clogging device 10 consists of an external water source, control valves, a fixed bracket, and a flushing water pipe. The flushing water pipe adopts a "single-row, multi-hole" design and is installed inside the ore receiving box on the side, directly facing the screen surface. Through continuous high-pressure water spraying, it effectively flushes away sticky sludge or fine particles adhering to the screen, preventing screen clogging. This device can be started and stopped manually or automatically via valves, achieving on-demand flushing, saving water, and ensuring continuous screening.

[0030] Steel ball recovery device 11: The steel ball recovery device 11 is integrated at the end of the discharge box and includes a row of screen holes at the bottom, a discharge pipe, and a recovery channel. When the ball mill grate plates wear down, some large steel balls may be discharged with the slurry. This device uses the screen holes to trap the steel balls inside the box, while the slurry flows into the main process through the under-screen discharge pipe. At the same time, the flushing water pipe above cleans the trapped steel balls, removing surface sludge, facilitating subsequent manual or automatic recycling. A hinged door is provided in the middle of the box, allowing operators to regularly check the screen condition, clean blockages, and recover steel balls, improving maintenance safety and convenience.

[0031] 1. This application uses a hollow shaft connecting flange to directly connect the hollow shaft at the discharge end of the ball mill with bolts, replacing the traditional structure of welding the lifting lug to the flared mouth, fundamentally solving the problems of concentricity and risk of detachment.

[0032] 2. This method improves the screen structure and materials: multiple large polyurethane screen sheets are fixed to the screen frame with bolts to achieve a modular, easy-to-replace, and long-life design. The preferred mesh size is a 20×40mm grid structure.

[0033] 3. This method restructures the entire system: breaking away from the traditional model of "flare mouth + lifting lug + round steel screen", it constructs an integrated solution of "flare direct connection + polyurethane screen + flushing + recycling".

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A grid-type ball mill cylindrical screen, comprising a stainless steel drum (5), characterized in that: The stainless steel drum (5) has a screen frame (3) welded and fixed inside. The screen frame (3) is evenly distributed and welded between the screen frame fixing steel ring (2) and the screen frame fixing flange (4) to form a complete cylindrical support. The screen frame (3) has a screen frame fixing steel ring (2) welded and fixed outside. The screen frame fixing steel ring (2) is welded to one side of the hollow shaft connecting flange (1) as the supporting foundation of the screen frame (3). The hollow shaft connecting flange (1) is fixedly connected to one side of the stainless steel drum (5), and the screen frame fixing flange (4) is fixedly connected to the other side of the stainless steel drum (5). The frame fixing flange (4) is located at the other end of the cylindrical screen, corresponding to the screen frame fixing steel ring (2), together clamping and fixing the screen frame (3). The inner side of the screen frame (3) is welded and fixed with stainless steel wear-resistant strips (6). At least six sets of polyurethane screens (7) are welded and fixed on the stainless steel wear-resistant strips (6). The inner side of the screen frame (3) is welded and fixed below the polyurethane screens (7). The lower outer side of the stainless steel drum (5) is provided with a discharge end receiving box body (9). The discharge end receiving box body (9) is equipped with a screen anti-clogging device (10) and a steel ball recycling device (11).

2. The grid-type cylindrical screen for a ball mill according to claim 1, characterized in that: The screen anti-clogging device (10) includes a flushing water pipe that runs through the ore receiving box body (9) at the discharge end, and a nozzle that is connected to and fixed on the flushing water pipe.

3. A grid-type cylindrical screen for a ball mill according to claim 1, characterized in that: The steel ball recycling device (11) includes a screen fixed on the cleaning port. The discharge end of the ore box body (9) has two discharge ports on its lower side. The screen is located on the discharge port near the cleaning port.

4. A grid-type cylindrical screen for a ball mill according to claim 1, characterized in that: The cleaning port is hinged with a small, sealed door to facilitate the user's opening of the cleaning port and the recovery of the steel ball.

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