Vibration Screener Machine

Vibration Screener Machine

Vibrating screens (also known as vibrating sieves or shredders) are core equipment in fertilizer production processes for the precise grading and screening of granular materials. This equipment uses a vibrating motor as the vibration source, causing the material to be thrown up on the screen mesh while simultaneously moving forward in a straight line (or circle). Through multiple layers of screens, several sizes of oversize and undersize materials are produced, each discharged from its respective outlet. Vibrating screens are the most widely used grading equipment in the compound fertilizer and organic fertilizer industries, used for the grading and screening of finished compound fertilizers and organic fertilizers.

Vibrating screens are characterized by low energy consumption, high output, simple structure, and easy maintenance, making them suitable for production line operations. This equipment can also screen and grade powdery and granular materials, and is widely used in the production operations of fertilizers, abrasives, chemicals, pharmaceuticals, building materials, grains, and carbon industries. In the entire organic fertilizer production line, the application scenarios of vibrating screens are very flexible—they can be installed as grading screens after the granulator to separate finished granules from returned materials; or they can be installed as inspection screens before the packaging machine to perform a final check on products before they enter the warehouse.

Equipment Structure

The vibrating screen mainly consists of the following core components:

(I) Screen Box: This is the main frame of the equipment, used to install the screen mesh and contain materials. The screen box is welded from high-quality steel, resulting in a robust structure. One or more screen meshes are installed inside the screen box.

(II) Screen Mesh: This is the key working component for material grading. The screen mesh is made of woven metal wire square-hole mesh or steel plate mesh, made of materials such as low-carbon steel, brass, and stainless steel. The screen mesh is tightened with a special tensioning plate, making installation, disassembly, and maintenance convenient. When installing multiple screen meshes, the larger mesh size is on top, and the smaller mesh size is on the bottom.

(III) Vibrator (Exciter): This is the core component that generates vibration. The vibrator can be a cylindrical eccentric shaft exciter, with the amplitude adjusted by an eccentric block. Fertilizer screens typically use a dual-shaft inertial exciter, driven by two motors, with the two sets of exciters self-synchronizing and rotating in opposite directions. The vibrating motor acts as the excitation source, directly vibrating the screen mesh and generating periodic inertial forces. (iv) Vibration damping spring device: Used to support the screen body and isolate the transmission of vibration to the foundation. The screen body (vibrating part) is supported by springs under the base frame. The spring device can effectively reduce the impact of equipment vibration on the foundation.

(v) Base frame and support device: This is the supporting structure of the equipment, including the suspension device or support device.

(vii) Transmission and motor: The motor drives the vibrator main shaft to rotate via a V-belt. Due to the centrifugal inertial force of the unbalanced mass on the vibrator, the screen box vibrates.

Application range of equipment

Vibrating screens have a wide range of applications. In fertilizer production, they are a primary piece of equipment for separating finished products from recycled materials and grading products in the production of organic fertilizers, compound fertilizers, and bio-organic fertilizers. In the chemical industry, they are suitable for grading and screening chemical powders and granules. In the pharmaceutical industry, they are used for grading and screening pharmaceutical raw materials and preparations. In the building materials and mining industry, they can be used for grading materials such as sand, gravel, ore, and abrasives. In the grain and food industry, they can be used for screening and removing impurities from grains and feed.

Types of available raw materials

Vibrating screens can handle a wide variety of materials. Fertilizers: organic fertilizer granules, compound fertilizer granules, blended fertilizer granules, bio-organic fertilizer granules, etc. Chemicals: fertilizer raw materials, chemical powders, etc. Minerals: ores, sand, abrasives, etc. Grains: grains, feed, etc. The equipment can adapt to the screening needs of materials with different moisture contents and particle sizes.

Working principle of the equipment

The working principle of a vibrating screen is based on the vibration of a vibrating motor as the vibration source. When the vibrating motor rotates, it generates a periodic inertial force, which, through damping springs and a connecting rod, causes the screen fixed to the connecting rod to vibrate up and down.

For a linear vibrating screen, dual vibrating motors are used. When the two motors rotate synchronously and in opposite directions, the excitation forces generated by the eccentric blocks of the motors cancel each other out in the direction parallel to the motor axis and overlap into a resultant force in the direction perpendicular to the motor axis. Therefore, the running trajectory of the vibrating screen is a straight line. The two motor shafts have an angle relative to the screen surface. Under the combined force of the excitation force and the material's own weight, the material is thrown up and jumps forward in a straight line on the screen surface.

For a circular vibrating screen, the motion trajectory is circular. The centrifugal inertial force of the unbalanced mass on the vibrator causes the screen box to vibrate. The material enters the feed inlet of the screening machine evenly from the feeder, and through multiple layers of screens, several specifications of oversize and undersize materials are produced, which are discharged from their respective outlets.

Equipment operation method

(I) Pre-start Preparation: Before operation, carefully check that all parts of the equipment are intact. Check for any damage to the screen and ensure it is securely fixed. Check that the vibration damping springs are functioning properly. Check that all fastening bolts are tight. The vibrating screen should be started when there is no material on the screen surface.

(II) No-load Start-up: The vibrating screen should be started without material, avoiding starting with material on the screen as much as possible. After starting, observe whether the equipment is operating normally. Material can only be fed after the screen is running smoothly.

(III) Operation Monitoring: Ensure uniform feeding during operation and avoid overloading. Observe the screening effect and adjust the feed rate in a timely manner. Listen carefully for any abnormal noises from the equipment. For sticky and wet fertilizers, it is recommended to increase the screen inclination angle or use a bouncing ball screen cleaning device.

(IV) Shutdown Operation: Stop feeding first, and then disconnect the power supply after all material on the screen surface has been discharged. Maintain accurate equipment usage and maintenance records and complete shift handover procedures.

Equipment maintenance methods

(I) Daily Maintenance: Clean residual materials and dust from the equipment after each shift. Clean the screen residue; compressed air is recommended for blowing. Check the screen for damage; replace it immediately if damaged. Check all fastening bolts for looseness.

(II) Periodic Maintenance: Regularly check the wear of the screen; replace it promptly if severely worn. Regularly check the lubrication of all bearings. Regularly check the damping springs for proper function. Regularly check the excitation force of the vibrating motor for proper function; the amplitude can be adjusted by adjusting the eccentric weight.

(III) Lubrication Management: Add grease to the vibrating screen bearings according to the specified cycle. Regularly inspect the motor and keep it clean.

Equipment troubleshooting

Poor screening effect: Clean clogged screen holes and replace damaged screen surfaces. Adjust the feeding device to ensure uniform feeding. Control the thickness of the material layer on the screen. Retighten the screen mesh. Control the material moisture content within a suitable range.

Weak vibration: Adjust the position of the weight on the flywheel or add counterweight.

Failure to start or insufficient amplitude: Check the electrical wiring, motor, and components for proper functioning. Check for sufficient voltage. Remove accumulated material from the screen surface.

Abnormal noise: Check and tighten loose bolts. Check for damaged bearings and replace them promptly. Check the rigidity of the screen box.

Damaged screen mesh: Replace damaged screen mesh promptly. Install a debris removal device at the feed inlet to prevent hard objects from entering. Adjust the feeding method to reduce impact.