The Inclined Screen, as a core screening equipment in the coal, mining and metallurgical industries, is capable of handling various production demands and can achieve screening accuracy that meets the requirements of standards such as "Building Gravel and Crushed Stone". However, its performance is entirely dependent on standardized installation and commissioning.
If the installation and commissioning are not done properly, it may result in a 10%-20% decrease in screening efficiency at the minimum, and in the worst case, it can cause premature failure of the exciter bearings, deformation of the screen frame, and other faults, increasing the maintenance cost in the later stage. Therefore, from the initial preparation to the final acceptance, every step must be strictly controlled.
Next, I will break down the practical key points from the aspects of pre-installation preparation, core installation process, and phased debugging, to help everyone successfully complete the installation and commissioning of the Inclined Screen.
Preparation Before Installation Of The Inclined Screen
► Site And Environment Adaptation
The site is the primary guarantee for the stable operation of the equipment. Key aspects to focus on include:
- ① Bearing Capacity: The ground load-bearing capacity should be no less than 1.2 times the self-weight of the equipment to prevent ground subsidence over time and affect the levelness of the equipment.
- ② Flatness Requirement: Use a level gauge for inspection. The ground flatness error should be ≤ 2mm per meter. If the deviation is too large, it is necessary to level it with cement mortar in advance.
- ③ Space Reservation: Both sides and the top of the equipment should reserve ≥ 2 meters of operation space for convenient maintenance in the future; at the same time, space for the connection between the feeding chute and the discharge conveyor belt should be reserved to avoid material transportation obstruction.
In addition, if the equipment is installed in a damp and dusty mine or coal washing plant, it is necessary to deploy dust cover brackets and drainage systems in advance to prevent dust from entering the equipment or water from soaking the foundation components.
► Equipment And Accessories Verification
After the equipment arrives, do not install it directly. Instead, conduct a thorough verification of each component:
- ① Integrity Of Core Components: Check whether the Screen box, exciter, shock absorber spring, Screen plate, and transmission device are complete, and check for any deformation or damage caused by transportation (such as cracks in the Screen plate, dents in the exciter housing).
- ② Quality Of Key Components: Rotate the exciter bearing by hand and ensure there is no sticking sensation and smooth rotation; check whether the opening rate of the Screen plate meets the standard (the opening of the upper perforated Screen plate is 130mm, and the opening of the lower welded steel plate is 50mm), and ensure there are no defects such as burn-through or incomplete fusion in the welds.
- ③ Preparation Of Tools And Materials: Prepare 10.9S grade high-strength bolts (suitable for the tightening requirements of different components), 320 grade gear oil (for lubrication of the exciter), level gauge (precision 0.02mm/m), amplitude measuring instrument, torque wrench, etc. in advance to avoid confusion during installation.
► Study Of Technical Documents
Before installation, it is essential to thoroughly understand the technical documents and focus on the following two points:
- ① Installation Drawing Parameters: Confirm key dimensions such as the centerline position of the foundation, the spacing of the anchor bolts, and the total height of the equipment. In particular, the connection dimensions between the exciter and the screen frame need to be verified, with the deviation controlled within ±1mm.
- ② Instructions For Prohibited Operations: Remember the prohibitions such as "Do not weld the side plates" and "The exciter must be operated without load for trial run". Clearly define the tightening torques for each component (such as 300-500Nm for the crossbeam bolts and 800-1200N·m for the anchor bolts), to avoid damaging the equipment due to improper operation.
Installation Process Of Inclined Screen
● Basic Positioning And Fixation
The basic positioning serves as the "pillar of stability" for equipment installation and requires three steps to be followed:
- ① Centerline Calibration: Use a laser level instrument to locate the centerline of the foundation, with the deviation needing to be ≤ ±1mm; then use a level gauge to adjust the levelness of the foundation, with the error per meter ≤ 5mm.
- ② Installation Of Foundation Bolts: Drill holes according to the drawings, with the verticality error of the bolts ≤ 1°. After installation, use a torque wrench to tighten them according to the specified torque, and install anti-loosening nuts to prevent the bolts from loosening during equipment operation.
- ③ Recheck Of Equipment Positioning: After hoisting the equipment into place, recheck the levelness again - the longitudinal levelness error ≤ 1% and the transverse levelness error ≤ 0.05%; use a square to check the verticality of the side plates, with the deviation per meter ≤ 1mm, to ensure that the equipment is not tilted.
● Assembly Of Core Components
The assembly of the core components of the Inclined Screen should be carried out in the following sequence: "Screen frame → exciter → damping system → Screen plate → transmission device → electrical system". Each step has strict standards:
- ① Installation Of The Screen Frame: The side plates are made of a single piece of Q245R steel plate, without any joints and with a flatness error of ≤ 1mm per square meter; the crossbeam is riveted to the side plate (welding is prohibited), and it is tightened in sections according to the diagonal order to ensure uniform force and avoid deformation of the side plate.
- ② Installation Of The Exciter: The exciter is precisely aligned with the Screen frame using positioning pins, ensuring that the parallelism error of the exciter axis and the center line of the Screen frame is ≤ 1mm; when assembling the bearings, an appropriate amount of lubricating oil should be applied to avoid hard knocking and hammering, and to prevent damage to the bearings.
- ③ Installation Of The Damping System: The damping spring material is 60Si2Mn. During installation, the axis line must be perpendicular to the installation surface; the static compression error of the symmetrical position springs should be ≤ If the error is too large, the springs need to be replaced or the installation height adjusted.
- ④ Assembly Of The Screen Plate: The upper perforated Screen plate and the lower round steel Screen plate need to be fixed in sequence "first in the middle and then on both sides", with the gap between adjacent Screen plates ≤ 1mm; the Screen plate and the support beam need to be closely adhered, and the sides are fixed with polyurethane side pressure strips to prevent the Screen plate from loosening during operation.
- ⑤ Installation Of The Transmission Device: The pulley of the motor and the exciter should ensure parallelism of the axis lines; the tension of the V-belt should be appropriate, with a compression depth of 15-20mm after pressing; the pulley is fixed by expansion sleeve, and after installation, it is necessary to check for no gap to avoid slipping during transmission.
- ⑥ Electrical System Connection: The wiring of the motor should ensure correct phase lines, insulation resistance ≥ 1MΩ, and grounding resistance ≤ 4Ω; the wiring of the sensors (temperature and vibration sensors) needs to be protected by conduit to avoid being worn by the materials.
Debugging Process Of Inclined Screen
No-load Testing
No-load testing is crucial for identifying potential hazards and requires continuous monitoring:
- ① Pre-power-on Inspection: Re-tighten all bolts, rotate the exciter to confirm there is no jamming, and check if the grease level is at 1/2 - 2/3 of the oil gauge.
- ② Parameter Monitoring During Operation: After starting the equipment, use an amplitude measuring instrument to detect the double amplitude. It should be within the range of 8 - 11mm, and the amplitude difference at the symmetrical points on both sides should be ≤ 5mm; use a frequency meter to detect the vibration frequency, and the deviation should be ≤ 2.5% of the specified value (13Hz).
- ③ Key Indicator Monitoring: Use an infrared thermometer to monitor the bearing temperature. The temperature rise should be ≤ 40℃, and the maximum temperature should be ≤ 75℃; use a noise analyzer to detect the noise at 1 meter from the equipment, and the no-load noise should be ≤ 60dB (A); there should be no abnormal vibration or noise during operation, and the fasteners should not be loose.
- ④ Problem Handling: If there is uneven amplitude, check if the counterweight block of the exciter is balanced; if the bearing temperature rise is too high, check if the grease is added adequately or if the model is compatible, and make timely adjustments before re-running the test.
Load Debugging
Load debugging should be carried out in a step-by-step manner to avoid damage to the equipment due to material shock:
- ① Gradual Loading: Start by operating at 30% of the rated processing capacity (for example, a 2000t/h equipment starts with 600t/h of material) for 24 hours. If there are no abnormalities, then increase to 50%, 80%, and finally 100%. The entire process should take 7 days.
- ② Screening Efficiency Verification: Collect the material on the screen and the material below the screen. Test the proportion of particles in the lower layer screen with a diameter of ≤ It should be ≥ 95%; observe if there is any material blockage on the screen surface. If the blockage rate exceeds 5%, adjust the amplitude or clean the screen holes.
- ③ System Coordination Detection: Check if the transmission device is stable, with no V-belt slipping; the vibration spring has no abnormal deformation; the dust cover is well sealed, with no dust leakage; the electrical system has no tripping, and the sensor signals are normal.
- ④Exception Handling: If there is material deviation, adjust the position of the feed chute; if the screen plate leaks material, re-tighten the side pressure strips or replace the sealing rubber strips to ensure the stable operation of the equipment.
Acceptance And Delivery
After the load debugging is completed and deemed qualified, a final acceptance inspection is required:
- ① Continuous Operation Assessment: Run continuously at the rated load for 24 hours, with the cumulative downtime due to faults not exceeding 6 hours, and the processing capacity and screening efficiency meeting the standards.
- ② Indicator Confirmation: Re-examine the amplitude, frequency, bearing temperature rise, noise and other indicators, compare them with the data from the no-load debugging, and there should be no significant deviations, which means it meets the requirements.
- ③ Record And Documentation: Compile the parameters (such as amplitude at each stage, bearing temperature) and the handling of faults during the installation and debugging process into a report, keep it for future reference, and provide a basis for later maintenance.
Common Problems In The Installation And Commissioning Of Inclined Screen
During the installation and debugging process, I have summarized several frequently occurring problems and their solutions for your reference:
- ① Uneven Vibration: This is mostly caused by excessive errors in the damping springs (more than 3mm) or imbalance in the exciter counterweight. Solution: Replace the springs with those that meet the specifications, adjust the eccentric weight of the exciter to ensure consistency on both sides.
- ② Material Leakage From The Screen Plate: Common reasons include excessive gap between the screen plate (more than 1mm) or loose side pressure strips. Solution: Re-adjust the position of the screen plate, tighten the side pressure strips, and add sealing rubber strips if necessary.
- ③ Excessive Bearing Temperature Rise: This may be due to insufficient lubricating grease, incorrect model, or overly tight bearing assembly. Solution: Add the appropriate lubricating grease (320 gear oil), and if the assembly is too tight, disassemble and adjust the bearing clearance.
- ④Transmission Slippage: Mostly caused by insufficient V-belt tension or deviation in the parallelism of the pulleys. Solution: Adjust the position of the motor, increase the tension of the V-belt; if there is a deviation in parallelism, re-calibrate the axis of the pulley.
Precautions After Installation And Commissioning Of The Inclined Screen
Completion of installation and commissioning does not mean everything is settled. Post-installation maintenance is equally important:
- ● Initial Maintenance Focus: Daily check on bolt tightness and oil level of the exciter; weekly cleaning of the screen surface debris, inspection of screen plate wear; monthly replenishment of lubricating grease to ensure the equipment is in good condition.
- ● Regular Maintenance Schedule: Check the thickness of the screen plate every 3 months; if the wear exceeds 30%, replacement is required; disassemble the exciter every 6 months to check for bearing wear and replace if necessary; annually test the elasticity of the shock-absorbing spring; if the elasticity drops by more than 20%, replacement is needed.
- ● Safe Operation Guidelines: Do not touch rotating parts during operation; before maintenance, power must be cut off and a "Do Not Close Switch" sign must be hung; do not start with materials in the screen; before stopping, clear the materials from the screen surface.
- ● Long-term Optimization: Adjust operating parameters based on material characteristics; for materials with high clay content, the amplitude can be appropriately increased; if the processing capacity increases, check if the exciter power is suitable and avoid overloading operation.
This guide covers all the key points of the installation and commissioning process of the Inclined Screen, from the initial preparation to the final maintenance. Every step must be carried out meticulously. I always believe that standardized installation and commissioning is not "extra work", but rather the key to enabling the equipment to perform at its best and extend its lifespan.
I hope everyone can follow the guide for practical operation, avoid common mistakes, and ensure that the Inclined Screen operates stably and continuously in production, helping to reduce costs and increase efficiency for your production line.
If you encounter any difficulties during installation and commissioning - such as being unable to make progress in adjusting the counterweight of the exciter, failing to meet the standard for screening efficiency during load testing, or needing to customize an installation plan to accommodate special materials - please feel free to contact us at any time. Our technical team will provide 1-on-1 on-site guidance or remote technical support based on your actual working conditions, helping you quickly solve the problems and enable the equipment to truly enhance production and create greater value.
