Spiral conveyor is the "material conveying link" of quartz sand production
line, responsible for horizontal or inclined conveying of finished sand and raw
sand. If there is a conveyor lag (stopping more than once per hour) or excessive
material residue (residual amount in the machine exceeding 5%), it can lead to
material breakage and waste in the production line, and may also cause equipment
failure due to residual compaction. Based on practical experience, summarize the
three-step troubleshooting method to quickly restore stable transportation.
Step 1: Check the spiral blades and barrel - the conveying core determines
the smoothness
Abnormal blade structure and barrel clearance are the main causes of material
jamming and residue.
Blade wear or uneven pitch: The blade edge wear exceeds 1/3 of the original
thickness, the pushing force decreases, and the material is prone to
accumulation; The pitch deviation exceeds 10mm (such as the standard pitch of
200mm, but the actual pitch is 180mm), the conveying rhythm is disrupted, and
there is local jamming. High chromium alloy spiral blades need to be replaced,
and the pitch should be calibrated with a caliper during installation to ensure
consistent pitch throughout the entire section; The gap between the blades and
the inner wall of the barrel should be controlled at 5-8mm. If it is too large,
it is prone to residue, and if it is too small, it is prone to friction and
jamming.
Scale formation or improper inclination angle on the inner wall of the
barrel: When the mud content of quartz sand is high, the inner wall of the
barrel is prone to scale formation (thickness exceeding 10mm), reducing the
conveying space; The inclination angle exceeds 20 °, the downward force of the
material is greater than the pushing force, and the stacking is stuck. Rinse the
inner wall of the machine barrel with a high-pressure water gun (0.7MPa) every
week, and clean it with a scraper when scaling is severe; Adjust the inclination
angle of the conveyor to below 15 °. If large angle conveying is required,
install anti backflow baffles.
Step 2: Calibrate the drive system and operating parameters - power matching
is key
Improper setting of motor and reducer status and speed directly affects
conveying efficiency.
Insufficient motor power or gearbox failure: A 11kW motor is required for a
conveying capacity of 50t/h, but 7.5kW is actually used. Insufficient power
leads to lagging; Gear wear of the reducer (mesh clearance exceeding 0.5mm),
unstable output speed. Replace the matching power motor, inspect the reducer,
replace worn gears, and ensure that the output speed deviation is ≤ 2r/min.
Spiral speed too fast or too slow: If the speed exceeds 60r/min, the material
is prone to "shake off" the blades and residue increases; Below 30r/min,
insufficient pushing force and frequent jamming. Use a tachometer to check and
adjust to 40-50r/min. Choose high speed for fine sand conveying and low speed
for coarse sand conveying; Realize stepless speed regulation through a frequency
converter to adapt to materials of different particle sizes.
Step 3: Adapt materials and seal maintenance - Raw material
characteristics+proper protection to prevent malfunctions
The lack of material status, equipment sealing, and maintenance can
exacerbate transportation issues.
High moisture content or large impurities in the material: if the moisture
content exceeds 12%, quartz sand is prone to clumping and sticking to the
leaves; Mixing large impurities exceeding 50mm can block the spiral shaft.
Drying process (reducing moisture to below 8%) and screening process (removing
large impurities) need to be added before feeding; Install a grille (aperture ≤
30mm) at the feed inlet to prevent hard objects from entering the barrel.
Sealing failure or bearing oil shortage: aging of seals at both ends of the
barrel (such as oil seal cracking), dust infiltration into the bearings; The
lack of oil in the bearing causes the operation to stall and the screw shaft to
shift. Replace the fluororubber seal and install a dust ring; Check the bearing
temperature daily (≤ 70 ℃) and add lithium based grease every week; Tighten the
bolts of the spiral shaft coupling every month and calibrate the verticality of
the shaft with a level, with a deviation of ≤ 1mm.
By following the above three steps, the frequency of conveyor lag can be
reduced to less than once a week, and the residual amount inside the machine can
be controlled within 2%. If there are still problems, it is recommended to
contact the manufacturer to test the compatibility between the spiral diameter
and the conveying capacity, to ensure accurate matching between the equipment
and the quartz sand conveying requirements.