How to Adjust JCSM-V Shaping Machine Parameters for Calcined Coke D10 D50 D90 Control

JCSM-V is JACAN’s closed-loop circulating spheroidizer, used to round calcined coke after ACM fine grinding. Its core design goal is edge polishing instead of particle crushing. Calcined coke is hard and brittle; improper parameter settings will fracture particles, shift D10/D50/D90 and raise BET. The target feed powder is D50 6–18 μm from upstream ceramic-lined ACM mill. The adjustment objective is to keep D50 nearly unchanged, cap D90 for coarse tail, and protect D10 from dropping due to excessive ultrafine debris.

Key adjustable parameters of JCSM-V

1. Shaping main rotor frequency / speed: controls particle collision & friction intensity
2. Built-in classifier wheel frequency / speed: controls particle cut point (main lever for D90 and fine tail)
3. Screw feeder frequency / feed rate: controls particle residence time and circulating load
4. System airflow (primary air, fine extraction air): carries ultrafines out and stabilizes negative pressure
5. Circulation load / loop time: controls how many times particles circulate inside chamber

Parameter effect rules for calcined coke

Critical rule: JCSM-V should not reduce D50 significantly. Any obvious drop of D50 means over-impact fracture of calcined coke.

1. Main shaping rotor speed

• Increase rotor speed: stronger inter-particle friction; sphericity improves, but brittle calcined coke breaks easily → more ultrafines, D10 decreases, span widens.
• Reduce rotor speed: mild polishing; less fines generation, D10 stable. Sphericity may be insufficient if too low.

Operation principle: Use the minimum rotor speed that meets target sphericity, do not blindly raise speed.

2. Built-in classifier wheel speed (most important for PSD tail control)

• Higher classifier wheel speed: stronger centrifugal interception. Large angular particles are trapped and returned for re-shaping → D90 decreases. More fine debris passes through into fine collection → D10 drops.
• Lower classifier wheel speed: easier for medium particles to pass through → D90 rises; fewer ultrafines extracted, D10 stays higher.

Function split: JCSM-V internal classifier mainly controls D90 (coarse tail); external secondary air classifier handles fine tail to stabilize D10.

3. Quantitative feed rate

• Higher feed rate: higher circulating load, shorter single-pass residence time. Under-shaped coarse particles increase → D90 rises. Less relative impact energy, fewer new fines, D10 tends to be stable.
• Lower feed rate: longer residence time, more repeated rubbing. More edge abrasion fines → D10 decreases.

4. Airflow & fine extraction air

• Increase fine extraction airflow: quickly take away abrasive ultrafine fragments, prevent fines mixing into qualified product → protect D10 from falling.
• Too high airflow: medium-sized qualified particles will be lost into fine fraction and reduce yield.
• Maintain stable negative pressure; pressure fluctuation causes fines back-mixing and unstable D10/D90.

Step-by-step parameter tuning workflow for calcined coke

Step1: Lock incoming feed quality first

Before tuning JCSM-V, confirm ACM outlet powder:

• D50 6–18 μm, Span ≤0.9
• Moisture ≤0.3%
• Pre-remove most ultrafines by upstream classification
  If incoming PSD fluctuates, adjusting JCSM-V cannot stabilize D10/D50/D90.

Step2: Set baseline rotor speed first

Start at low rotor frequency, gradually increase only until sphericity reaches 0.80–0.86.
Stop speed increase once sphericity target is met. For calcined coke, avoid the high rotor speed used for green coke.

Step3: Tune classifier wheel speed to control D90

• If D90 > target: raise classifier wheel speed, return coarse under-rounded particles back to chamber.
• If D90 is too low and yield drops: moderately reduce classifier wheel speed.

Step4: Adjust fine extraction airflow to stabilize D10

• If D10 is too low (too many ultrafines): boost fine extraction airflow to continuously remove abrasive fines. If still poor, slightly reduce main rotor speed to cut fine generation.
• If D10 is higher than specification: reduce fine extraction airflow, or increase rotor speed slightly to get proper edge abrasion.

Step5: Fine-tune feed rate to balance throughput and PSD

• D90 high and coarse tail heavy: reduce feed rate to extend residence time for rounding.
• Excess fines and low D10: increase feed rate properly to reduce single-pass friction time.

Step6: Sampling & closed-loop correction

Take samples after JCSM-V, test laser PSD (D10, D50, D90), tap density and sphericity.
Recommended sampling frequency during commissioning: every 15–30 minutes.
Record parameter matrix for different calcined coke batches (petroleum coke / needle coke).

Typical troubleshooting table for JCSM-V calcined coke shaping

1. D90 too high, D50 slightly coarse, D10 normal
   Root cause: classifier speed too low; feed rate too high; insufficient rounding.
   Adjustment: Raise classifier wheel speed; reduce feeding frequency.
2. D10 too low, BET rises, D50 drifts down
   Root cause: rotor speed excessive; calcined coke particles fractured; fines over-generated.
   Adjustment: Reduce main rotor speed; increase fine extraction airflow; shorten circulation loops.
3. D50 becomes smaller after shaping compared with ACM outlet
   Root cause: over-shaping; particle fracture inside JCSM-V.
   Adjustment: Immediately lower rotor speed and reduce circulation load. Calcined coke PSD should not shrink obviously in shaping stage.
4. D10 unstable batch by batch, span fluctuates
   Root cause: feed moisture >0.3% or unstable negative pressure; fines re-attach on particle surface.
   Adjustment: Re-dry feedstock; inspect fan and filter bags to stabilize negative pressure and airflow balance.

Recommended target specification after JCSM-V shaping

• D50: maintain 6–18 μm (no obvious reduction)
• Sphericity: 0.80–0.86
• Span ≤0.9
• Tap density increased by 12–28% vs ground calcined coke
• Strictly control ultrafine fraction to stabilize D10

For calcined coke on JCSM-V shaping machine, the tuning sequence is: set minimum main rotor speed to hit sphericity → adjust built-in classifier wheel speed to control D90 → tune fine extraction airflow to protect D10 → fine-tune feed rate to balance yield and PSD. JCSM-V is only for edge polishing, not particle grinding. Calcined coke’s brittleness requires lower rotor speed than green coke. Combined with regular laser PSD sampling feedback, operators can lock D10, D50, D90 within target range while keeping good sphericity and tap density for artificial graphite anode precursor.