The wind separator is the core equipment for dry classification of quartz
sand, which separates sand particles of different sizes (such as fine powder and
coarse sand below 200 mesh) through airflow. If there is poor grading accuracy
(pass rate of qualified particle size is less than 85%) and excessive fine
powder carryover (the proportion of fine powder in coarse sand exceeds 10%), it
will lead to substandard product quality and increased workload in subsequent
processes. Based on practical experience, summarize a three-step troubleshooting
method to quickly restore graded performance.
Step 1: Check the airflow system and ducts - airflow stability is the basis
for grading
The abnormal wind pressure and air volume of the fan, as well as the sealing
of the air duct, are the main reasons for poor accuracy.
Inappropriate wind pressure and volume: When the wind pressure is below 3kPa,
fine powder is difficult to be carried up by the airflow, and the grading is not
thorough; Over 5kPa, coarse sand is easily carried by airflow, and the
proportion of fine powder exceeds the standard; The air volume fluctuates by
more than 10%, and the grading effect is unstable. Use a wind pressure and air
volume tester to test and adjust the fan frequency converter to control the wind
pressure between 3.5-4.5kPa and stabilize the air volume within ± 5% of the
equipment's rated value, ensuring that the airflow passes through the selection
chamber at a constant speed.
Leakage or dust accumulation in the air duct: aging of sealing components at
the connection of the air duct (such as cracking of rubber pads), infiltration
of external air, and damage to the airflow field; Dust accumulation on the inner
wall of the air duct exceeds 5mm, narrowing of the airflow channel and uneven
flow velocity. Replace the wear-resistant sealing gasket and reinforce the
connection with sealant; Clean the dust accumulation in the air duct with a
high-pressure air gun (0.6MPa) every week to ensure that the air duct is
unobstructed.
Step 2: Calibrate core components and parameters - component
adaptation+precise parameters are key
The sorting impeller, guide plate status, and feed parameters directly affect
the grading effect.
Sorting impeller speed or blade wear: low speed (below 800r/min),
insufficient centrifugal force, difficult separation of fine powder; Excessive
speed (over 1200r/min) can cause coarse sand to be easily swept into the fine
powder channel; The blade wear exceeds 1/3 of the original thickness, and the
airflow direction is disordered. Use a tachometer to check and adjust to
900-1100r/min (choose high speed for fine sand grading and low speed for coarse
sand grading); Replace the high chromium alloy blades and ensure that they are
perpendicular to the impeller disc after installation, with a deviation of ≤
1mm.
Improper angle or feeding rate of the guide plate: If the angle of the guide
plate is less than 15 °, the airflow will be dispersed and the grading accuracy
will decrease; Greater than 30 °, the airflow is concentrated and prone to
carrying coarse sand. Adjust the angle to 20 ° -25 °, fix it with bolts and
calibrate it. The feed rate exceeds the rated value (e.g. rated 20t/h, actual
25t/h), causing material accumulation in the sorting chamber and preventing
airflow from penetrating; Uneven feeding and local overload. Use an electronic
belt scale to control the amount and maintain it at 80% -90% of the rated value.
Install a screw feeder to achieve uniform feeding.
Step 3: Adaptation of Materials and Daily Maintenance - Raw Material
Characteristics+Proper Maintenance to Prevent Malfunctions
The lack of material status and equipment maintenance will exacerbate the
grading problem.
High moisture content or impurities in materials: If the moisture content
exceeds 6%, sand particles are prone to clumping, fine powder is wrapped in
coarse sand, and difficult to separate by airflow; Mixing large impurities (over
10mm) can block the feed inlet and disrupt the airflow field. Drying process
(reducing moisture to below 4%) and screening process (removing large
impurities) need to be added before air selection; When the agglomeration is
severe, a dispersing device should be installed at the feed inlet to crush the
agglomerated sand particles.
Maintenance deficiency: Bearing oil shortage or impeller imbalance, unstable
impeller speed; Motor vibration exceeding 0.1mm affects airflow stability. Check
the bearing temperature daily (≤ 65 ℃) and add high-temperature lubricating
grease every week; Calibrate the impeller with a dynamic balance meter every
month (deviation ≤ 0.3g · m), tighten the fixing bolts of the impeller to avoid
shaking during operation.
By following the above three steps, the classification accuracy of quartz
sand can be improved to over 95%, and the fine powder carryover can be reduced
to below 5%. If there are still problems, it is recommended to contact the
manufacturer to test the compatibility between the sorting chamber and the
material, ensuring that the equipment is accurately matched with the quartz sand
particle size grading requirements.