In modern poultry feed production plants, maintaining product quality is paramount. Vibrating screens play a critical role in final stages of production by effectively removing dust and fine particles from finished pellets before packaging or bulk delivery. This comprehensive guide explores essential knowledge for selecting, installing, and maintaining vibrating screens in 1-100 T/H poultry feed production lines, helping you optimize product quality and operational efficiency.
Technical Features of Industrial Vibrating Screens
High-quality vibrating screening machines incorporate several design elements that ensure reliable performance in demanding feed production environments:
Robust Frame Construction: The machine frame is constructed from alloy section bars with precisely calculated dimensions, providing structural integrity and resistance to vibration stress during continuous operation.
Optimized Vibrating Case: The vibrating case is engineered for correct product screening and accommodates screen installation with proper tension devices, ensuring consistent screening performance throughout the production cycle.
Dual Outlet Design: The discharging opening features two separate outlets—one for sieved pellets and another for dust collection—enabling efficient material separation and minimizing product waste.
Precision Elastic Components: Helical springs serve as elastic components, enabling correct functioning of sieve by absorbing vibration energy and maintaining stable operation under varying load conditions.
Adjustable Vibrating Unit: The vibrating unit consists of two vibrating motors with adjustable eccentric mass, allowing operators to modify vibrating movement according to specific material characteristics and production requirements.
Model Selection Criteria
Selecting appropriate vibrating screen model requires careful consideration of multiple factors to ensure optimal performance in your specific production environment:
Material Characteristics: Consider the name, bulk density, viscosity, and temperature of screened material. Different feed formulations may require specific screen configurations to achieve optimal separation efficiency.
Processing Capacity: Determine the required processing volume per hour to match your production line capacity. For high-capacity operations producing 20-30 T/H, ensure the selected screen model can handle peak throughput without compromising screening quality.
Screen Mesh Specifications: Select appropriate mesh number based on desired particle size distribution and dust removal requirements. Fine mesh screens provide superior dust removal but may require more frequent cleaning and maintenance.
Particle Size Ratio: Analyze the particle size ratio of material and required screening accuracy. Materials with wide particle size distribution may benefit from multi-stage screening configurations.
Material Compatibility: Consider acidity and alkalinity of materials when selecting screen construction materials. For corrosive materials, ensure use of 304# stainless steel or 316L stainless steel for extended service life.
Installation Space: Evaluate the available space at the production line site where the vibrating screen will be installed. Consider access for maintenance, material flow patterns, and integration with upstream and downstream equipment.
Installation Guidelines
Proper installation is crucial for optimal performance and longevity of vibrating screening equipment. Follow these essential guidelines during installation process:
Remove Transportation Supports: Since the base of the screen machine and screen frame are connected by springs, the upper part is firmly supported during transportation. After entering the installation site, the transportation support must be removed. It is strictly forbidden to test the machine without removing the transportation support.
Foundation Preparation: The screen machine should be placed on a horizontal foundation during installation. If a foundation is not laid, place a vibration-proof rubber sheet between the workbench and machine base to minimize vibration transmission and protect surrounding equipment.
Electrical Grounding: The vibrating motor and cables in the sieve machine are subjected to severe vibration and must be connected to a standard ground wire for safety. Proper grounding prevents electrical hazards and ensures reliable operation.
Trial Run Procedures
Before putting the vibrating screen into regular production operation, conduct a thorough trial run following these procedures:
Initial Power-On: Turn on the power switch and run the machine for 20-30 minutes. The motor should generally run counterclockwise. If the direction is incorrect, adjust the three-phase power supply connections.
Current Monitoring: Confirm that the vibration motor is running within the rated current. At the beginning of operation, especially in low temperature situations, the current will be slightly higher, but within 20-30 minutes, it should reduce to the rated current value.
Sound Inspection: The vibrating screen must not have any abnormal sound. If any abnormal sound occurs, shut down the machine quickly for inspection. Abnormal sounds are generally caused by loosening of fastening parts, especially during transportation and assembly after disassembly. Pay attention to fastening of each component.
Resonance Zone Awareness: The screen machine has a momentary resonance zone (1-3 seconds) when starting and stopping. During this time, amplitude and noise will increase significantly, which is a normal phenomenon and not cause for concern.
Gradual Feeding: After dry operation, feed a small amount of material through the feed port, then gradually increase to the required and sustainable feeding amount. Adjust the heavy hammer according to discharge situation on the mesh surface to make the screen machine reach optimal efficiency.
Bouncing Ball Device: General materials for this series of screens do not require a bouncing ball device, which can meet screening requirements. Special materials may need a bouncing ball device designed and installed separately. In such cases, no-load noise will increase, which is normal.
Motor Phase Angle Adjustment
Proper adjustment of motor phase angles enables optimization of screening performance for different materials:
Trajectory and Residence Time: Changing the phase angle of the upper and lower heavy hammers can change the movement trajectory and residence time of materials on the screen. To adapt the screening machine to the separation state required by various materials, such as material distribution, processing capacity, separation efficiency, and screen passing rate, adjust to the optimal state.
Motor Rotation Direction: Note that the rotation direction of the two motors is reverse to each other! Both motors can run inwards or outwards at the same time, depending on material characteristics and screening requirements.
Excitation Force Adjustment: When the phase angle of the upper and lower weights decreases or increases, its function is to increase or decrease the excitation force of the screen machine. Adjust the excitation force according to the number of layers of the user's screen machine and the specific gravity of the material. Adjust the motor phase angle of the heavy hammer to achieve the best screening effect. The phase angles of the upper and lower motors must be consistent.
Inclination Angle: The inclination angle of the sieve machine is typically 4°-10°. Sometimes, due to the influence of material's specific gravity, humidity, stacking inclination angle, and other parameters, it may not be possible to successfully adjust the above phases at one time. Users should have sufficient patience to make adjustments to enable the screener to achieve its due high efficiency.
Daily Inspection and Maintenance
Regular maintenance is essential for maximizing equipment lifespan and maintaining consistent screening performance:
Fastener Inspection: Check carefully whether the fastening bolts of each joint of the screen machine are loose. If loose and continued operation occurs, it will damage the screen. Tighten all fasteners regularly according to the maintenance schedule.
Cable Inspection: Check whether the wiring from the vibration motor to the switch is worn. Use neoprene vibration-resistant cables when replacing cables. Operation with missing items is strictly prohibited.
Motor Condition: Check the motor for abnormal sound and abnormal heating. The temperature limit of the motor bearing part is 40°C higher than the ambient temperature. If abnormal, add lubricating oil or replace the bearing. Motor maintenance should be carried out by a technician with professional knowledge.
Screen Condition: Check whether the screen is tensioned and whether the screen surface is damaged. If there is damage, replace the screen in time to maintain screening quality and prevent material contamination.
Cleaning Routine: The inside of the screen must be cleaned after each use to prevent material buildup and cross-contamination between different feed formulations.
Screen Replacement Procedure
When screen damage occurs, follow this replacement procedure to maintain optimal screening performance:
Removal Process: When the screen is found to be damaged and needs replacement, simply loosen the external locking handle to remove the screen grid. Take out the screen frame, remove the rubber seal ring, and loosen the bolts.
Screen Installation: Loosen the screen frame fastening bolts to replace the damaged screen. Then change to a new screen and reinstall it in reverse order. Note: The net must be flat and firm. The lower bolts of the screen frame must be locked first, then the upper bolts. The two outer V-groove bolts must be tightened.
Equipment Maintenance Schedule
Implement a regular maintenance schedule to maximize equipment lifespan and minimize unplanned downtime:
Lubrication: Always add oil when the equipment is in operation, typically twice a week. Regular lubrication reduces wear on moving parts and extends component life.
Minor Maintenance: Conduct minor repair and maintenance every three months. This includes inspection of fasteners, checking for wear on moving parts, and addressing minor issues before they become major problems.
Major Overhaul: Perform a major overhaul in 6-12 months. During the overhaul, check the motor, verify that fasteners are not loose, disassemble the vibrator to clean the bearings and oil seals, and replace worn components as needed.
Cable Replacement: Check cables regularly and change motor leads every three months to prevent electrical issues and ensure safe operation.
