Roots Blower | Rotary Blower | Aquaculture Aeration Blower

Working Principle Inside the casing is a pair of three-lobe or two-lobe rotors, driven by timing gears to rotate in opposite directions. There's a small clearance between the rotors and between the rotors and the casing—they don't touch. Gas is drawn in at the inlet, carried around by the rotors to the outlet, and pressure builds up from the resistance downstream. A Roots blower has no internal compression, so pressure depends on system backpressure and airflow stays basically constant. A rotary blower moves air through this same rotary action. For aquaculture aeration, the blower pushes air into bottom diffusers, and the bubbles rise and dissolve oxygen into the water. Application Fields Aquaculture: aerating fish and shrimp ponds to raise dissolved oxygen and prevent fish from gasping at the surface. Wastewater treatment: supplying air to aeration tanks so aerobic microbes can break down organic matter. Pneumatic conveying: moving cement, fly ash, grain, and other powder or granular materials. Chemical and metallurgy: desulfurization oxidation, gas boosting, and material fluidization. FAQ Q1: Are a Roots blower and a rotary blower the same thing? A: A Roots blower is one type of rotary blower. Rotary blowers also include screw and sliding vane types. A Roots blower uses two intermeshing rotors to move air. It's simple, delivers steady airflow, and covers a wide pressure range, which is why it's so common in wastewater treatment and aquaculture. Q2: How do you size airflow and pressure for an aquaculture aeration blower? A: Airflow is estimated from pond area, water depth, and stocking density—usually 1–2 kW per mu. Pressure depends on diffuser depth: about 9.8 kPa per meter of water, plus some margin. Long piping and many elbows add pressure too. Oversizing wastes power; undersizing means not enough dissolved oxygen. Q3: Can the airflow of a Roots blower be adjusted? A: Yes, but not as easily as with a centrifugal blower. Common methods include variable frequency drives, bypass venting, and changing pulley sizes. VFDs save the most energy but cost more upfront. Bypass is simple but wastes energy. With a Roots blower, airflow changes with speed—at constant pressure, halving the speed halves the airflow.