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To address uneven particle size distribution in Hydraulic Double Roller Crusher processing quartz stone, a systematic approach is required. Below are targeted solutions addressing mechanical, operational, and material-specific factors:

I. Hydraulic Double Roller Crusher Inspection and Repair

1. Roll Parallelism Calibration

• Symptom: Misaligned roll axes result in inconsistent gaps (e.g., 8mm on one end, 12mm on the other).
• Inspection:
  • Use a laser alignment tool to measure axial deviation (tolerance ≤0.1mm/m).
  • Manual method: Measure the gap at three points (both ends and center) with feeler gauges (max deviation ≤0.5mm).
• Correction:
  1. Loosen bearing housing bolts.
  2. Adjust shims or hydraulic rods to realign rolls.
  3. Validate parallelism by feeding 10mm calibration blocks during a no-load test.

2. Roll Surface Wear Repair

• Wear Patterns:
  • Grooves/wavelike deformations in high-pressure zones (e.g., feed end).
  • Critical wear threshold: ≥3mm depth.
• Solutions:
  • In-situ Hardfacing: Apply TDL-65 flux-cored wire (high-chromium cast iron) to rebuild surfaces (3–5mm thickness).
  • Replace Roll Sleeves: Use bimetal composite sleeves (42CrMo base + WC-12Co coating) for 3–5x longer lifespan.

3. Hydraulic Double Roller Crusher Drive System Maintenance

• Gear Inspection:
  • Apply Prussian blue to check tooth contact ratio (≥85% required).
  • Gear backlash: 0.25–0.40mm for modules ≥20.
• Universal Joint Service:
  • Replenish grease (NLGI 2# lithium-based) every 500 hours.
  • Replace if bearing clearance exceeds 0.3mm.

II. Process Parameter Optimization

1. Feed Size Control

• Two-Stage Prescreening:
  • Upper deck: Aperture ≤0.8x roll gap (e.g., 8mm sieve for 10mm target gap).
  • Lower deck: Remove fines (<3mm) to minimize over-crushing.
• Example: For 50–80mm quartz, use a jaw crusher (50mm discharge) + vibrating screen (30mm aperture) upfront.

2. Speed and Linear Velocity

• Formula$V = \frac{π \times D \times n}{60}$ (D = roll diameter, n = RPM).
• Recommended:
  • Φ750mm rolls: 40–50 RPM (1.57–1.96 m/s).
  • Φ1200mm rolls: 25–35 RPM (1.57–2.20 m/s).

3. Hydraulic Pressure Settings

• Constant-Pressure Mode:
  • Preload: 60–70% of rated pressure (e.g., 21–25MPa for 35MPa systems).
  • Tramp iron protection: Instantaneous peak ≤110% rated pressure.

III. Material-Specific Adjustments

1. Moisture Management

• Drying Process:
  • For feed moisture >3%, use a rotary dryer (200–300°C) to reduce to ≤1.5%.
  • Install humidity sensors on feed conveyors for real-time monitoring.

2. Hardness Sorting

• Online Hardness Detection:
  • Deploy near-infrared analyzers (e.g., ASD TerraSpec) to monitor Mohs hardness.
  • Divert high-hardness quartz (Mohs >6.5) to cone crushers.

3. Feed Distribution Improvement

• Matrix Feeder:
  • Use 6–8 individually controlled gates to balance material flow.
  • Cross-roll thickness variation ≤5%.

By systematically addressing mechanical alignment, process tuning, and intelligent control, the particle size uniformity (D90/D10 ratio) for quartz crushing can be improved from 3–5 to 2–2.5, meeting high-spec aggregate standards. Quarterly precision audits are advised to sustain long-term performance.