Daily Maintenance of the Shot Blasting Machine in the Steel Plate Pre-treatment Line
I. Pre-start Checks (10 minutes before the shift)
1. Shot Circulation System
Check the material level in the bucket elevator; ensure there is sufficient steel shot and no clumping or moisture. Replenish with qualified shot of the same specification if levels are low.
Check the elevator belt/chain for proper tension, tracking issues, or cracking; ensure buckets are not deformed or detached.
Ensure the screw conveyor is free of accumulated rust, slag, or clumps, and that bearings at both ends show no signs of dust leakage or abnormal noise.
Check the shot distributor and directional sleeve for severe wear; ensure no shot is jammed inside the blast wheel unit.
2. Blast Chamber and Roller Conveyor
Ensure all access doors, sealing baffles, and inlet/outlet wear-resistant rubber curtains are intact, with no damage causing shot leakage.
Check internal wear-resistant liners (end and side panels) for extensive perforation or loose bolts.
Ensure rollers are free of steel plate debris or welding slag obstructions; check for severe wear on roller surfaces and ensure smooth rotation without sticking.
Verify that steel plate limit stops and guide wheels are intact to prevent the plate from drifting and striking the chamber body.
3. Dust Removal System
Ensure the dust extraction fan operates without abnormal vibration or noise, and that air ducts are free of damage or air leaks.
Check that the pulse cleaning air pressure is normal (0.4–0.6 MPa) and drain the air receiver tank daily.
Ensure the dust hopper is free of blockages and the discharge valve operates smoothly.
4. Electrical, Pneumatic, and Safety Components
Verify normal current readings for all motors; check cables for damage or overheating.
Test the functionality of access door interlocks, emergency stop buttons, and photoelectric anti-collision switches.
Check air compressors and pneumatic valves for leaks; ensure smooth operation of all pneumatic cylinders.
5. Lubrication
Check oil/grease levels in blast wheel, elevator, and roller conveyor bearings; replenish grease immediately if levels are low.
II. In-operation Inspections (Every 2 hours)
Listen for abnormal noise or excessive vibration from the blast wheel unit, elevator, and fan; shut down the machine immediately if any abnormalities are detected. Monitor for excessive steel shot splashing at the inlet and outlet; stop the machine immediately to replace the curtain if it is damaged.
Check the dust extraction system; ensure no significant dust escapes into the workshop (clogged filter cartridges can cause dust leakage).
Observe the descaling effect on the steel plate surface; if descaling is incomplete in certain areas, check the shot blasting wheel for wear, verify the blast angle, and check the plate feed speed.
Monitor shot recovery: ensure there are no large amounts of scattered shot on the floor and that the recovery screw conveyor is not clogged.
Ensure motor temperature remains below 70°C to prevent burnout due to overheating.
III. End-of-Shift Maintenance (30 minutes after shutdown)
Empty the shot circulation system: run the machine idle for 5–10 minutes to clear all residual shot and scale from the piping and elevator, preventing clumping and rusting.
Clear dust from the dust collector hopper to prevent spontaneous combustion of accumulated dust or blockage of air ducts.
Sweep up scattered shot from around the equipment for recovery and reuse to minimize waste.
Clean scale, welding slag, and burrs from the roller conveyor surface to prevent scratching the steel plates or causing jams.
Inspect all sealing strips and brushes; remove any entangled metal scraps or debris.
Shut off the air and power supplies, and drain condensate from the air receiver tank.
IV. Weekly Maintenance (requires half-day shutdown)
Open the shot blasting wheel housing cover; inspect the wear on blades, the distributor, and the control cage—replace immediately if wear exceeds limits; tighten all impeller bolts.
Thoroughly inspect the liner plates inside the blast chamber; tighten loose bolts and replace any perforated liners.
Clear accumulated rust slag and broken shot from the bottom of the elevator to prevent bucket jams.
Remove the end covers of the screw conveyor and clear out any clumped scale inside.
Inspect dust filter cartridges; manually blow clean or replace cartridges if pulse cleaning is ineffective; clear dust accumulation from air ducts.
Apply grease to all bearings across the machine (prioritize the shot blasting wheel spindle bearings).
Inspect all flange and module joint gaskets; replace rubber seals where shot leakage occurs.
Check roller conveyor alignment (coaxiality) and clear debris from roller bearing housings. Inspect the electrical control cabinet cooling fans and clean out internal dust to prevent short circuits.
V. Monthly In-Depth Maintenance
Disassemble and overhaul the shot blasting unit; calibrate impeller dynamic balance to prevent high-speed vibration.
Inspect the elevator chain/belt for wear and elongation; adjust tension and replace damaged chains.
Thoroughly clean the entire abrasive circulation system (elevator, screw conveyor, separator) to remove broken shot and rust residue.
Inspect the separator screen; replace it promptly if damaged to ensure effective separation of good and bad steel shot.
Clean dust from the fan impeller and calibrate dynamic balance to eliminate fan vibration.
Inspect all anchor bolts and module connection bolts; retighten all of them.
Check the facility foundation for settlement and verify/adjust equipment leveling.
Test all safety interlocks, emergency stops, and audible/visual alarm devices.
Clean air compressor and dryer filter elements; replace lubricating oil.
VI. Quarterly / Annual Maintenance
Quarterly
Inspect the blast chamber steel plates for rust and deformation; apply touch-up paint for corrosion protection.
Check the roller conveyor gearbox lubricant; replace if it has turned black or contains excessive impurities.
Measure dust emission concentration to verify compliance with environmental standards.
Annual Overhaul
Systematic replacement of all wear parts: blades, liners, door curtains, screens, and bearings.
Disassemble the entire roller conveyor; service bearings and replace worn roller shafts.
Remove rust and touch up paint on the entire machine; replace all module joint seals.
Inspect electrical control system wiring and replace aged cables; back up PLC programs.
Perform insulation testing on fan and shot blasting unit motors.
Calibrate roller conveyor speed and shot blasting coverage efficiency; optimize process parameters.
VII. Criteria for Replacing Key Wear Parts
Shot blasting blades: replace immediately if wear exceeds 1/3 of thickness or if notches/cracks appear; replace as a complete set to ensure dynamic balance.
Control cage (directional sleeve): replace if the window opening has enlarged due to wear, the projection angle has shifted, or rust removal is uneven.
Internal liners: replace if perforated, loose, or worn by more than half of their thickness.
Sealing curtains: replace immediately if damaged (causing shot leakage) or hardened/ineffective. Separator screen: replace if mesh is clogged, deformed, or damaged.
Dust collection filter cartridges: replace if heavily caked with dust, damaged, or if exhaust airflow drops significantly.
VIII. Maintenance Prohibitions and Precautions
Do not operate the machine for extended periods while a fault exists; shut down for inspection and repair if the blast wheel makes abnormal noises or if shot clogging occurs.
Do not feed damp steel plates directly into the blast chamber; moisture causes steel shot to clump, which can clog the elevator.
Before maintenance, disconnect power, apply "Lockout/Tagout" procedures, and shut off the air supply to prevent accidental startup and injury.
Do not mix steel shot of different specifications or with significant differences in age/wear, as this accelerates wear on consumable parts.
Do not operate the dust collection system without filter cartridges installed; dust can damage the fan and contaminate the workshop.
For long-term shutdowns (over 7 days): Empty all steel shot, ensure the chamber is dry to prevent rust, and apply anti-rust grease to bearings.
IX. Maintenance Points Specific to Modular Models
Inspect module connection gaskets weekly; replace promptly if shot leakage occurs to prevent shot from wearing down the flanges.
Independent blast wheel modules can be serviced offline and swapped with spares to minimize production line downtime.
Roller conveyor sections can be maintained individually; a fault in one section does not require dismantling the entire line.
Independent dust collection modules can be shut down for cleaning without interrupting short-term production of the main blasting unit.

