The discharge particle size in a double-roll crusher is controlled by adjusting the gap between the two rolls. Below are detailed steps and considerations:

I. Adjustment Principle

• Core Mechanism: The minimum gap between the rolls (discharge opening) determines the maximum allowable particle size (e.g., a 10mm gap ensures 95% of output ≤10mm).
• Compression Crushing: Quartz is crushed by the rotating rolls; particles smaller than the gap fall through, while oversized fragments undergo repeated compression.

II. Adjustment Steps

1. Pre-Adjustment Preparation

• Power off and lock out the machine.
• Clear residual quartz particles from roll surfaces to prevent interference.
• Check adjustment mechanisms (screws, hydraulic cylinders) for flexibility and lubrication.

2. Double-Roll Crushers Measure Current Gap

• Method 1: Use feeler gauges or calipers to measure the narrowest point between rolls.
• Method 2: Insert calibration blocks (e.g., 10mm steel plate) to test roll pass-through.

3. Gap Adjustment Methods

Depending on the crusher design:

• Screw-Spring System:
  1. Loosen locknuts.
  2. Rotate adjustment screws (clockwise to reduce gap, counterclockwise to increase).
  3. Adjust both sides synchronously to maintain parallel roll axes (verify symmetry with calipers).
  4. Tighten locknuts and manually rotate rolls to check for jamming.
• Hydraulic System:
  1. Activate the hydraulic station, monitoring pressure (≤70% of rated value).
  2. Control hydraulic valves to extend/retract cylinders (single-side or synchronized).
  3. For models with displacement sensors, input target gap directly.
• Shim Adjustment:
  1. Remove bearing housing bolts.
  2. Add/remove shims (typical thickness: 0.5–5mm).
  3. Re-torque bolts evenly to avoid misalignment.

4. Test Run Verification

• Run the Double-Roll Crushers empty to check roll stability.
• Feed a small batch of calibrated quartz samples.
• Analyze discharge particle size distribution using sieves or laser analyzers (focus on oversize content).

Through scientific adjustment and real-time monitoring, the roller crusher can still achieve good particle size control effects when processing quartz stone. However, it is necessary to combine periodic roller surface hardfacing (with hardfacing wire) or replacement of composite roller sleeves (tungsten carbide + steel substrate) to maintain accuracy.