Doebritz Fine Particle Size Reduction – Official Technical Overview & Datasheet

DOEBRITZ FINE PARTICLE SIZE REDUCTION: EXECUTIVE SUMMARY

Doebritz introduces its advanced Fine Particle Size Reduction system, engineered for the most demanding industrial milling, classifying, and de-agglomeration applications. Leveraging decades of precision machining expertise, this equipment provides consistent, high-efficiency particle size reduction for friable, hygroscopic, and heat-sensitive materials across the chemical, food, pharmaceutical, and mineral processing sectors. The system integrates seamlessly into pneumatic conveying and gravity-fed lines, delivering superior control over particle size distribution (PSD) with minimal fines generation and low specific energy consumption.

HOUSING & ROTOR METALLURGY

The main housing is manufactured from marine-grade cast iron (GGG-40) or 316L stainless steel with an internal mirror finish to prevent material adhesion and facilitate rapid cleaning. The rotor assembly features a proprietary staggered pin or beater plate configuration, hardfaced with tungsten carbide or Stellite alloy for extended service life against abrasive particulates. All contact parts meet FDA and EC 1935/2004 standards for food-contact applications. Rotors are dynamically balanced to ISO 1940-1 Grade G6.3, ensuring vibration-free operation at speeds up to 4500 RPM.

KEY FEATURES
– Precision Rotor Clearances: Adjustable gap settings from 0.2 mm to 2.0 mm for tailoring PSD from d50 = 50 µm to 2000 µm.
– Modular Screening Media: Quick-change perforated screens or wire mesh cassettes (apertures 0.3 mm – 12 mm) enable rapid product changeovers.
– Dual Shaft Sealing: Nitrogen-purged, labyrinth-style or mechanical cartridge seals prevent product migration and maintain pressure differentials up to 3.5 bar(g).
– ATEX 95/2 Compliance: Certified for dust explosion zones 20/21/22 (Gas IIB, Dust IIIC). Optional inert gas injection integrated.
– Low Temperature Rise: Cooling jackets for housing and shaft minimize thermal degradation of heat-sensitive compounds.

COMPLIANCE & SAFETY STANDARDS

Doebritz Fine Particle Size Reduction systems are fully compliant with:
– Machinery Directive 2006/42/EC (CE marked)
– ATEX Directive 2014/34/EU (Category 2D/2G)
– NFPA 652 & 69 (explosion venting and suppression ready)
– ISO 12100:2010 (risk assessment)
– EHEDG guidelines (hygienic design, CIP/SIP compatible)

TECHNICAL SPECIFICATIONS

Operating Principle: High-speed impact / shear milling with integrated classification
Rotor Tip Speed Range: 30 – 120 m/s
Drive Power: 5.5 kW to 250 kW
Throughput Range (dry powder): 10 kg/h to 25,000 kg/h (depending on material density and target fineness)
Maximum Feed Particle Size: Up to 20 mm (friable materials)
Product Temperature Range: -20°C to +150°C (with optional jacket)
Pressure Shock Resistance: 10 barg (design)
Connections: Inlet/Outlet DN150 to DN600, DIN/ANSI mating flanges

INDUSTRIAL DEPLOYMENT

Typical installations include: fine grinding of lactose and APIs in pharma, pulverizing of PVC and masterbatch in plastics, reducing sodium bicarbonate and activated carbon for flue gas treatment, and de-agglomerating milk powder or cocoa presscake in food processing. The system can be configured for batch or continuous operation and is available with PLC integration (Profinet, EtherNet/IP) for full process control, remote diagnostics, and predictive maintenance logging.