The three-dimensional vibration screening instrument (also known as the three-dimensional vibration screen) achieves efficient screening through multi-directional vibration, but it is prone to malfunction due to vibration load, material characteristics, or improper operation during long-term use. The following are common faults, causes, and corresponding solutions, classified by fault type:
1、 Low screening efficiency (poor mesh permeability and incomplete material grading)
Common causes
Improper selection of mesh aperture (small aperture blocking the mesh, or large aperture causing fine material to mix with coarse material);
The high moisture content and viscosity of the material lead to clogging of the sieve mesh;
Unreasonable vibration parameters (too small amplitude, too low frequency, insufficient material jumping on the screen surface);
Insufficient screen tension (loose screen surface, unable to effectively disperse material accumulation);
The feed volume is too large, exceeding the screening surface processing capacity, and the material is "overloaded" and accumulates.
solution
Replace the sieve mesh that matches the particle size of the material (choose large aperture for coarse screening and standard aperture for fine screening to avoid blindly pursuing "fine screening");
If the material is wet and sticky: ① Pre treatment (drying the material until the moisture content is less than 5%); ② Spray anti sticking coating on the screen mesh; ③ Equipped with ultrasonic vibration device (for ultra-fine material blockage);
Adjust vibration parameters: Increase the amplitude (usually 0.5-5mm) or frequency (usually 1500-3000r/min) through a frequency converter to ensure that the material undergoes a "three-dimensional throwing motion" on the screen surface;
Re tighten the screen mesh: Loosen the screen frame pressure strip, tighten the screen mesh evenly (ensure that the screen surface is flat and wrinkle free, and the tension is consistent);
Reduce the feeding speed (controlled by the feeding valve or feeder) to ensure that the material is evenly distributed on the screen surface, with a thickness not exceeding one-third of the screen diameter.
2、 Abnormal equipment vibration (body shaking, abnormal noise, unstable amplitude)
Common causes
Imbalance of vibration motor: ① Inconsistent angle of motor eccentric block; ② The fixing bolt of the eccentric block is loose;
Equipment installation is not horizontal: the contact between the body and the ground is unstable, or the anchor bolts are loose;
Screen frame/screen body deformation: Long term high load vibration causes cracking at the welding of the screen frame, or loosening of the screen mesh pressure strip;
Bearing damage: Vibration motor or spindle bearings lack oil or wear, causing operation to stall;
Material eccentric accumulation: The feed is biased towards one side, resulting in uneven stress on the screen body.
solution
Calibration of eccentric block: After stopping the machine, loosen the bolts of the motor eccentric block, adjust the angles of the eccentric blocks on both sides to be consistent (usually symmetrically set), and then tighten the bolts;
Reinstall and level: ① Use a spirit level to calibrate the body, ensuring that the horizontal error in the front, back, left, and right directions is less than 0.2mm/m; ② Tighten the anchor bolts and, if necessary, place shock-absorbing rubber pads on the bottom seat cushion;
Inspect the screen body: check the welding of the screen frame, and repair the cracked parts with welding; Replace the loose screen pressing strip to ensure a secure connection between the screen body and the vibration source;
Maintenance of bearings: ① Open the bearing end cover, clean the old oil, and add high-temperature resistant grease (such as lithium based grease), with an oil volume of 1/2-2/3 of the bearing chamber; ② If the bearing makes abnormal noise or gets stuck, replace it with a bearing of the same model directly;
Adjust the feeding position: Ensure that the feeding port is facing the center of the screen surface, or install a distributor to avoid material accumulation on one side.
3、 Frequent damage to the screen mesh
Common causes
The mesh material does not match the material (such as using ordinary nylon mesh for hard materials, which is damaged by impact);
The edges of the screen mesh are not firmly fixed, and they rub and wear against the screen frame during vibration;
Mixing metal, stones, and other hard objects into the material, causing impact and scratching of the sieve;
The vibration frequency is too high, and the screen mesh is subjected to high-frequency impact fatigue damage for a long time.
solution
Replace the compatible mesh: choose stainless steel woven mesh/punched mesh for hard materials (such as ore and glass); Select nylon mesh/polyester mesh for fine materials (such as powder);
Strengthen the fixation of the screen mesh: Use specialized pressure strips (such as polyurethane pressure strips) to compact the edges of the screen mesh, ensuring no looseness and reducing friction;
Install pre-treatment device: Add a "impurity removal screen" or magnetic separator before the feed inlet to filter out hard substances in the material;
Reduce vibration frequency: Adjust the frequency according to the hardness of the material (reduce the frequency appropriately for hard materials to avoid excessive impact).
4、 Motor overheating or unable to start
Common causes
Motor overload: Excessive feed volume and clogged screen mesh cause the load to exceed the rated power of the motor;
Power supply issues: unstable voltage (too high/too low), poor circuit contact or phase loss;
Poor motor heat dissipation: damaged fan, blocked heat dissipation holes, or high ambient temperature;
Motor bearing damage: The bearing gets stuck, causing an increase in resistance during motor operation.
solution
Reduce load: Clean the screen blockage, reduce the feed rate, and ensure that the equipment operates within the rated load;
Check the power supply: Use a multimeter to measure the voltage (ensure it meets the rated voltage of the motor ± 5%), tighten the circuit connectors, and troubleshoot phase loss issues (requiring professional electrician operation);
Improve heat dissipation: Clean the dust from the motor's heat dissipation holes, replace damaged heat dissipation fans, and avoid long-term operation of the equipment in environments above 40 ℃;
Maintenance of bearings: If the bearing gets stuck, immediately stop the machine and replace the bearing to prevent the motor from burning out.
5、 Mixing of materials at the discharge outlet (poor grading accuracy)
Common causes
The wear and tear of the sieve aperture increases (deformation and enlargement of the sieve aperture after long-term use);
There is a gap between the sieve and the sieve frame, and fine materials leak into the coarse material area through the gap;
Abnormal vibration direction (three-dimensional vibration becomes unidirectional vibration, material cannot be effectively layered).
solution
Replace the screen mesh with a new one: Regularly check the aperture of the screen mesh and replace it immediately if wear is found (it is recommended to use a spare screen mesh of the same model);
Sealing gap: Install a sealing strip at the contact between the screen mesh and the screen frame, or re press the pressure strip to ensure no leakage gap;
Calibrate vibration direction: Check the installation angle of the vibration motor (usually two motors are symmetrically installed to form a three-dimensional vibration), adjust the motor position or eccentric block angle, and restore the three-dimensional motion of "up and down, left and right, front and back".