Stable soil mixing stations are commonly used for mixing materials in lime soil and water stable layers. They do not have high wear shaft end seals for cement mixing machines, but belts, silos, screws, metering, conveying, and mixing pots are prone to sticking and clumping. The maintenance focus is significantly different from that of concrete stations, including pre shift, post shift, weekly, monthly, and special maintenance.
Pre shift startup inspection (before starting work every day)
1. Mixing host (dual axis mixing pot)
Check the inner wall of the pot, mixing blades, and mixing arms for clumps of sticky materials, clean them in advance, and prevent the load from starting and blocking the vehicle;
Check whether the fixing bolts of the blades are loose, whether the blades are worn or deformed, and replace them in a timely manner if the wear is more than half;
Add lubricating grease to the grease fittings on both sides of the bearing seat to prevent soil from entering and damaging the bearings;
Check the sealing rubber and cylinder of the discharge door, and ensure smooth opening and closing without any leakage or air leakage;
Observe the oil level of the gearbox, there is no oil leakage or abnormal noise, and the cooling fan is intact.
2. Aggregate batching bin+vibrating feeder
Internal clumping and arching of various sand, gravel, and soil silos should be loosened in advance to avoid inaccurate proportioning of broken materials;
The wiring of the vibration motor is undamaged, the fixing bolts are tightened, and the shock-absorbing rubber pad is not cracked;
Replace the material blocking rubber under the warehouse door in a timely manner if it is worn or leaking soil;
Check for cracks and deformations in the silo bracket and welds.
3. Belt conveyor system (feeding belt, finished product discharge belt)
Clean the clay on the surface of the drum and roller to prevent the belt from deviating or tearing;
Check if the belt joints and edges are damaged, and if the cleaner and material blocking cover are intact;
Tighten the deviation belt and add butter to the roller and drum bearings;
The guardrail and cleaning baffle of the belt conveyor are intact to prevent the accumulation of scattered materials.
4. Powder system (cement/lime spiral, powder silo)
Powder silo level gauge, high and low level alarm testing;
Check the dust removal bag on the top of the warehouse for any damage or blockage caused by dust accumulation;
The air disc arch breaking device at the bottom of the warehouse ensures smooth ventilation, preventing lime and cement from arching and not being discharged;
Spiral conveyor: no-load test run, listen for no abnormal noise, lubricate the bearings at both ends;
The powder butterfly valve and pneumatic push rod have no powder leakage, and the gas source has no air leakage.
5. Water supply and additive system (some water stabilization stations are equipped with additives)
The water pump and water pipe are unobstructed and leak free, and the filter screen is cleaned;
Clean the silt with a water scale bucket to ensure that there is no load on the measurement;
During winter, drain the pipeline to prevent freezing and cracking due to accumulated water.
6. Measurement system (water stable proportioning core)
Clean the surface of the aggregate belt scale, powder spiral scale, and water scale to remove the adhesive mixture;
The sensor wiring is free from compression or water ingress, and the limit block is not stuck on the scale body;
Zero point reset of the aircraft, timely adjustment of zero drift;
Soft connected canvas with no damage or material leakage.
7. Pneumatic, electrical, and air compressor
The pressure of the air compressor is maintained at 0.6-0.8MPa, and the accumulated water at the bottom of the air storage tank is discharged daily;
Drain the oil-water separator to ensure the compressed air is dry;
Sealing, dustproof and waterproof of control cabinet and motor junction box, emergency stop and limit switch testing;
All motors make abnormal noises when idling, and there is no dust accumulation or blockage in the cooling fan.
Post shift shutdown cleaning (daily mandatory)
Thoroughly clean the mixing pot: add water and rinse the soil mixture in the drum by idling, remove clumps manually, and prohibit accumulation after hardening;
The entire belt, below the ingredient warehouse, and finished product hopper are washed and cleaned, and it is extremely difficult to clean the soil when it is completely dry;
Clean up residual powder and soil from each measuring scale hopper and spiral discharge outlet;
Clean up the equipment platform and the accumulated sand, gravel, and dust on the ground to prevent corrosion of the frame caused by compaction;
Secondary water discharge from the air compressor and storage tank, turn off the main air source and power supply;
The vibration motor for dust removal in the powder silo starts briefly to shake off the accumulated dust in the bag.
Weekly maintenance and upkeep
All lubrication points of the whole machine are uniformly filled with lithium based grease: mixing shaft bearings, rollers, rollers, vibrator pin shafts, and cylinder hinge points;
Fully tighten: all bolts of the silo foundation, mixing pot bracket, belt frame, and blades;
Adjust the tension of the belt, replace the failed cleaner and material stopper;
Disassemble and clean the dust removal bag on the top of the warehouse, and remove any clogged dust;
Complete calibration of measuring equipment, checking for weighing errors of aggregates and cement;
Check the gear oil of the reducer, replace the filter element in advance if it turns black or contains impurities;
Check the shock absorber pads and springs of the vibrating feeder, and replace them promptly if they break;
Check for leaks in the sealing ring of the pneumatic valve and repair the leaking area.
Monthly in-depth maintenance
Sampling and inspection of gearbox gear oil, replacement of gear oil and cleaning of the casing for severe contamination;
Open the maintenance port of the mixing pot, conduct a comprehensive inspection of the wear of the mixing arm and blades, and replace the complete set if the wear exceeds one-third;
Disassemble the bearings at both ends of the screw conveyor and clean the clumped lime and cement inside the pipe;
Replace the air filter and oil filter of the air compressor, and replace the special oil for the air compressor as needed;
Sensors and junction boxes should be wrapped with moisture-proof and waterproof materials, and all wiring terminals should be tightened;
Internal inspection of the powder silo for wall hanging and clumping, and manual cleaning in severe cases;
Rust removal and repainting of the entire machine frame, with a focus on inspecting welds and support legs for cracks;
Calibration of pressure gauges and level alarms to ensure the sensitivity of safety devices.
Quarterly/Annual Overhaul and Maintenance
Replace gear oil uniformly for all reducers;
Disassemble and replace the bearings and sealing kits on both sides of the mixer, thoroughly removing soil erosion;
Replace the drum, idler, and belt with severe wear and tear as a whole;
Third party full set of measurement calibration and retention of calibration records;
Comprehensive maintenance of electrical circuits, replacement of aging cables, contactors, and relays;
Safety inspection of powder silo and pressure pipeline;
Rust removal, anti-corrosion, refurbishment, and painting of the entire machine.
Key points for specialized maintenance of key components
1. Dual axis mixing machine (in areas with severe wear and mud sticking)
Each shift must be washed, as the solidified soil will significantly increase the starting load, burn the motor, and disconnect the mixing arm;
It is strictly prohibited to lack butter, as soil entering the bearing will quickly cause it to lock up;
Prohibit large stones and steel bars from entering the mixing pot to prevent blade breakage.
2. Belt conveyor
Stable soil mixture has high soil viscosity and is prone to sticking to the drum, causing deviation
Clean the adhesive material on the drum daily, and replace the cleaner immediately if it is damaged;
Increase the frequency of flushing during the rainy season to avoid soil accumulation and compaction.
3. Lime/cement screw conveyor
Lime moisture absorption is prone to clumping and pipe blockage:
After daily shutdown, idle for a few minutes to empty the powder in the pipe;
The bottom air disc of the warehouse is regularly ventilated to avoid arching and material breakage affecting the proportioning.
4. Dust removal system
Lime dust is large, and the cloth bag is prone to sticking and clogging:
Clean the cloth bags weekly and increase the frequency of cleaning on rainy days;
Replace the damaged cloth bag in a timely manner to prevent dust leakage and pollution of equipment and motors.
Usage and maintenance taboos
Prohibit starting the mixing machine with heavy loads of materials, as it may burn out the motor and break the mixing arm;
It is strictly prohibited to open the maintenance door of the mixing pot or reach out to clean the inside during operation;
Prohibit excessive feeding to avoid overflowing and burying belts and sensors;
In winter, water pipelines and additive tanks must be insulated, and residual water must be drained daily to prevent freezing;
Cover the control cabinet and sensors during the rainy season to prevent water ingress and short circuits;
Establish a maintenance ledger to record lubrication, calibration, and accessory replacement times, and stock vulnerable parts in advance (blades, liners, belts, bags, sealing strips).
