Drum Pulper Systems for Kraft Liner OCC Processing: Continuous Pulping at Industrial Scale

The Pulping Bottleneck in High-Volume Kraft Liner Mills

Kraft liner mills processing 500+ TPD of OCC furnish face a common constraint: batch pulpers limit throughput and create consistency swings that propagate through the entire stock preparation line. Continuous drum pulping addresses this bottleneck by combining defibering and coarse screening in a single rotating drum, delivering stable high-consistency output to downstream cleaners and screens.

Working Principle and Technical Parameters

A drum pulper operates as a two-zone system. The pulping zone rotates at 12-18 rpm, lifting and dropping the stock at 14-18% consistency so fibers separate through friction rather than cutting force. The screening zone then washes accepted fibers through 8-14 mm perforated plates while rejects such as plastics, tapes and wet-strength fragments discharge continuously from the drum end. Typical industrial specifications:

• Capacity: 300-1200 TPD per unit
• Pulping consistency: 14-18%, versus 4-6% in conventional hydrapulpers
• Installed power: 160-630 kW depending on drum diameter
• Specific energy consumption: 8-12 kWh per ton, roughly 30-40% lower than batch pulping at equivalent capacity

Energy and Fiber Quality Data

Because contaminants remain largely intact instead of being shredded, downstream screening load drops measurably: pressure screen reject rates fall by 2-4 percentage points and slotted basket wear life extends by 20-30%. Industry operating data for 600 TPD OCC lines shows combined pulping-plus-screening electricity of 18-22 kWh/t against 26-30 kWh/t for hydrapulper-based systems, an annual saving of roughly USD 45,000-60,000 at USD 0.09/kWh on a 350-day operating schedule. Fiber freeness after drum pulping typically holds 20-40 mL CSF higher, preserving tear index for the liner ply.

Maintenance Planning

Key wear items include riding ring surfaces, support roller bearings and trommel screen plates. Bearing lubrication intervals run 2,000 operating hours; screen plate inspection is recommended every 4-6 weeks under abrasive OCC furnish, with typical plate life of 10-14 months. The absence of a high-speed rotor eliminates the rotor and bedplate rebuilds that batch pulpers require every 12-18 months, reducing both spare parts cost and planned downtime.

Specify the Right Pulping System

Leizhan Technology supplies complete OCC pulping lines, including drum pulpers, D-type hydrapulpers, high density cleaners and pressure screens, engineered as matched systems for kraft liner production from 100 to 1200 TPD. Share furnish composition and target capacity for a line configuration proposal.

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