Twin Lobe vs Tri Lobe Roots Blower: Engineering Comparison

Rotary lobe positive displacement blowers are primarily manufactured with two rotor profiles: Twin Lobe (2-Lobe) and Tri Lobe (3-Lobe). Understanding their differences helps select the optimal machine for your plant.

1. Pressure Pulsations & Vibration

• Twin Lobe: Discharges air 4 times per shaft revolution. Generates higher backpressure pulsations and higher mechanical vibration.
• Tri Lobe: Discharges air 6 times per revolution. Reduces discharge pressure pulsations by up to 50%, resulting in minimal piping vibration.

2. Acoustic Noise Levels

Because tri-lobe rotors smooth out airflow pulses, a Tri Lobe Roots Blower operates 3 to 5 dB(A) quieter than a twin-lobe unit of equal capacity.

3. Mechanical Bearing & Gear Life

Lower pressure pulsations mean less shock loading on timing gears and shaft bearings, leading to extended bearing service life in tri-lobe models.

4. Cost & Volumetric Displacement

Twin Lobe Roots Blowers have slightly higher displacement per frame size and lower manufacturing cost, making them ideal for budget-conscious heavy industrial projects.

Comparison Summary Matrix

Feature	Twin Lobe	Tri Lobe
Discharge Pulses/Rev	4	6
Noise Level	Standard	Low (-5 dB)
Piping Vibration	Moderate	Very Low
Capital Cost	Lower	Slightly Higher

Discuss your application with our Gujarat engineering team.