Rotary lobe blower package DEFENDER™

rotarypositive-displacementlow-noise

Overview The HOFFMAN DEFENDER™ Series comprises positive-displacement rotary lobe blower packages engineered for municipal wastewater and environmental applications. These compact, integrated packages convey air and neutral gases at low pressure, are driven by an electric motor via belt drive, incorporate a low-pulse system to reduce residual pressure pulsation, and are delivered with necessary accessories.

Key benefits

• Improved efficiency - Patented rotor geometry reduces required revolutions and improves the capacity-to-pressure ratio.
• Reduced noise - High-efficiency internal compression, silencers, and a noise-reducing enclosure lower sound emissions.
• Straightforward installation - Designed for simple configuration and commissioning.
• Operational flexibility - Configurable to operate near the point of best efficiency.
• Maintenance-friendly design - Accessible components and simplified procedures reduce service time.

System components and features

• Smart Oil System
  • External oil level indicator visible from outside (all models except frame 1).
  • Improved reliability of oil-level readings.
  • Simplified oil filling procedure.
  • Reduced oil top-up time and lower maintenance costs.
• New performance cooling fan
  • Enhanced air circulation inside the noise enclosure.
  • Extended operating-range capacity and improved reliability.
  • Terminal board for simplified electrical connection.
  • Lower internal enclosure temperature for better overall efficiency.
• Easy maintenance
  • Simplified access — maintenance tasks performed from the front by removing front panels or opening the upper panel with gas springs.
  • Accessible soundproof filter (SPF) — serviceable via the upper or front panel.
  • Instant oil-level check — external indicator accessible while blower is running.
  • Front oil change — fill and drain hoses accessible from the front panel.
  • Automatic belt tensioning — motor suspension preserves correct belt tension, reducing bearing loads.
  • Front-access belt replacement — possible without additional equipment thanks to the automatic tensioning device.

Technical specifications

• Model / Series: HOFFMAN DEFENDER™ Series.
• Capacity: up to 6,121 cfm (≈10,400 m3/h).
• Application: Oil-free conveyance of air and neutral gases; intended for municipal wastewater and environmental uses.
• Drive: Electric motor via belt drive.
• Pulsation control: Low-pulse system to reduce residual pressure pulsation.
• Operating temperature range: 104 °F to -13 °F (40 °C to -25 °C).
• Noise control: High-efficiency internal compression, silencers, and noise-reducing enclosure.
• Maintenance features: Smart Oil System (external level), front-access oil change, automatic belt tensioning, simplified front and upper-panel access with gas springs.
• Cooling: New performance cooling fan improving internal airflow and extending the operating range.
• Package: Integrated positive-displacement blower package supplied with accessories; compact and service-oriented design.