Linear vibrating screen is the core equipment for quartz sand grading. If the
screening efficiency is low (the capacity is less than 80% of the rated value)
and the grading accuracy is poor (the grain size deviation of finished product
is more than 10%), the unqualified sand will be mixed into the finished product,
the rework cost will be increased and the whole production line will be slowed
down. As a professional manufacturer of quartz sand equipment, combined with
practical operation experience, the three-step troubleshooting solution is
summarized to quickly recover equipment performance.
Step 1: Calibrate vibration parameters - core parameters are wrong and
sieving must be wrong
The vibration frequency, amplitude and inclination of linear vibrating screen
are the key to the grading, and the deviation of parameters will directly affect
the efficiency.
The vibration frequency is too low (lower than 15Hz), the materials bounce
weakly on the screen surface, and the fine particles are difficult to pass
through the screen; Too high (more than 25Hz), the material is easy to "bounce",
the retention time is short, and the grading is not sufficient. It can be
detected by vibration tester, normally controlled within 18-22Hz, and calibrated
by adjusting motor frequency converter parameters.
Small amplitude (less than 3mm), insufficient material looseness, easy to
block the screen; Relatively large (more than 6mm), coarse grains are easy to
leak with fine grains. Generally, the screening amplitude of quartz sand is
4-5mm, which can be adjusted by increasing or decreasing the weight of motor
eccentric block.
Improper inclination of the screen surface will also affect the efficiency:
the inclination is less than 5 °, the material flows slowly and is easy to
accumulate; If the angle is greater than 15 °, the material slides fast and the
screening time is short. Measure with a protractor. It is suggested to adjust it
to 8-12 ° to ensure that the materials flow at a constant speed.
Step 2: Check the equipment structure - component loss is hidden "stumbling
block"
Loss of screens, vibrating motors, springs and other components is a common
cause of poor efficiency.
Screen blockage or wear is the primary problem: fine powder adheres to the
screen hole (especially when the moisture content of the material exceeds 5%),
or the screen wear causes the pore size to become larger, which will make the
grading failure. Regularly wash the screen with a high pressure water gun,
replace the screen with a screen with abrasion exceeding 1/3 of the original
thickness, and give priority to polyurethane wear-resistant screen, with a
service life 3 times longer than that of ordinary steel screen.
Unbalance of vibrating motor will also lead to uneven screening: lack of oil
in motor bearing and loose eccentric block will make the screen surface vibrate
and deviate, and materials will accumulate in some areas. Check the motor
bearing every week and add high temperature resistant lubricating grease;
Tighten the bolts of eccentric block to ensure that the angles of eccentric
blocks on both sides are the same.
The aging of the support spring (the elastic force drops by more than 30%)
will weaken the vibration transmission, resulting in insufficient amplitude of
the screen surface. Replace the spring every half a year and select manganese
steel to ensure stable vibration.
Step 3: Adaptation of material characteristics - "innate problems" of raw
materials need targeted treatment
The particle size, moisture content and impurities of the material will
directly affect the screening effect. Ignorance will lead to low efficiency.
The particle size difference of materials is too large (such as mixed
0.1-5mm), the fine powder is easy to block the screen, and the coarse particle
is easy to block the screen. It is required to add pre-screening before sieving
to separate the materials according to coarse and fine particle sizes, and then
enter the vibrating screen of corresponding sieves.
Quartz sand with water content more than 8% is easy to agglomerate and adhere
to the screen. Drying or vibrating dehydration process shall be added before
sieving to reduce the water content to below 5%; If there is no condition, add a
dispersing device on the screen surface to break the caking.
Impurities (such as metal blocks and stones) in the materials will block the
screen and even damage the equipment. Grilles and metal detectors shall be
installed at the feed inlet to intercept impurities in advance and reduce
equipment failures.
Routine maintenance is also critical: daily cleaning of screens and equipment
residue, weekly checking of component tightness, monthly calibration of
vibration parameters. By doing so, the linear vibrating screen efficiency can be
increased by over 20%, and the classification accuracy is stable and up to the
standard. If there is still any problem, contact the professional manufacturer
for door-to-door troubleshooting to ensure that the equipment meets the
production requirements.