Single-Stage Ring Blower | 1 HP & 2 HP Ring Blower for Pond Aeration & Air Knife

A single-stage ring blower is the simplest configuration in the side-channel blower design. One impeller. One motor. One stage of compression. It’s the configuration that covers the widest range of real-world applications — and it’s what most people mean when they say “ring blower.”

We build single-stage units from 0.2 kW up to 7.5 kW, with the 1 HP and 2 HP sizes being far and away our most popular. Those two horsepower ratings sit at the sweet spot where the price is accessible for a small farm or workshop, the air delivery is enough for several ponds or a production line, and the electricity draw won’t double your power bill.

Browse the full ring blower lineup: Ring Blowers overview →

How It Works

One impeller, mounted directly on the motor shaft. No belts. No gears. No coupling that can come out of alignment.

The impeller has dozens of small blades arranged around its circumference. When it spins — typically at 2800 to 3400 rpm, depending on your line frequency — centrifugal force throws air outward into the ring-shaped side channel machined into the housing. The channel guides the air in a spiral path. With each pass through the impeller blades, the air picks up more energy. By the time it reaches the discharge port, the cumulative compression delivers far more pressure than a simple centrifugal fan of the same diameter could produce.

The impeller never touches the housing wall. The clearance is tight, but it’s always there. That means no internal wear and no oil needed anywhere in the air path. The only parts that eventually need replacement are the bearings — and those are Japanese NSK, spec’d for continuous duty in this application, typically good for years before they show any sign of needing attention.

And like any ring blower, this same machine works as a vacuum pump. Connect your process to the inlet. The impeller pulls air out. The outlet vents to atmosphere. No modification needed. No valving to switch. Just a different pipe connection.

Why Single-Stage Ring Blower

The choice between single-stage and double-stage comes down to whether you need flow or pressure more.

A single-stage blower moves more air at a given motor size than its double-stage equivalent. It’s the right choice when you need volume — aerating ponds, blowing off water from bottles, feeding air knives, conveying lightweight material short distances.

A double-stage blower sacrifices some flow to push against higher resistance. It’s the right choice when you’re dealing with deep water, long pipe runs, dense filter media, or any situation where the back-pressure is substantial enough that a single-stage unit would stall.

Most of our customers buy single-stage. If you’re not sure which you need, start here. If a single-stage unit can’t handle the back-pressure in your system, we’ll tell you during the sizing conversation — and we’ll quote the right double-stage model instead.

Not sure which model fits your setup? Request sizing help → Our engineers will recommend the right unit — no charge.

Model Specifications

Table shows single-stage configurations. All models available in 50 Hz and 60 Hz versions. Custom voltage configurations on request. Bold rows = most popular 1 HP and 2 HP models.

→ Download complete spec sheet (PDF)

Popular Models

1 HP Ring Blower

The 1 HP model (approximately 0.75 kW) is our best-seller by a wide margin. It’s the standard choice for:

• 1 to 3 fish or shrimp ponds, each with a couple of diffuser lines
• Small air knife stations on bottling or canning lines
• Vacuum hold-down tables on single CNC routers
• Small dental clinic central suction

At 1 HP, the blower runs on single-phase or three-phase power, depending on the voltage code you select. Most small farms and workshops have single-phase available, making installation straightforward — no three-phase upgrade needed just to run the aerator.

2 HP Ring Blower

The 2 HP model (approximately 1.5 kW) steps up the airflow and pressure for operations that have outgrown a 1 HP. It’s the standard choice for:

• 3 to 8 ponds on a single blower manifold
• Medium air knife systems — multi-nozzle bottle dryers, wider conveyors
• Vacuum conveying of plastic pellets or grain over short distances
• Larger vacuum tables on industrial CNC routers
• Pumping air into biofloc tanks where higher back-pressure from deeper water and dense solids needs more push

Like the 1 HP, available in single-phase or three-phase. If you’re running multiple aerators on a farm, a bank of 2 HP single-stage ring blowers gives you redundancy — if one goes down, the others keep your ponds alive while you swap in a spare.

Larger Models

We build single-stage ring blowers up to 7.5 kW for applications that need high flow at moderate pressure. These tend to go to industrial users — factories running production air knives, central vacuum systems serving multiple workstations, or large aquaculture operations where a single big blower is more efficient than several small ones.

Applications

Aquaculture

The single-stage ring blower dominates small to medium pond aeration. It delivers enough airflow at enough pressure to drive air through diffuser hoses sitting on the pond bottom, in water up to about 1.5 to 2 meters deep. For deeper ponds, or for biofloc systems where the water column is dense with suspended solids, a double-stage model may be necessary.

The 1 HP model covers most smallholder operations — one or two ponds, a few diffusers each. The 2 HP model handles the step up to a small commercial farm. Both run quiet enough that pond-side neighbors won’t complain — a real consideration in densely populated farming areas.

For indoor RAS (recirculating aquaculture systems), the oil-free discharge is essential. No oil mist in the water means no oil film on the biofilter media, which would suffocate the beneficial bacteria that process fish waste.

Air Knife and Drying

After a bottle leaves the filler and before it gets a label, the surface has to be dry. Water droplets under a label cause wrinkles and peeling. An air knife — a narrow slot that blows high-velocity air across the conveyor — strips the water off. Single-stage ring blowers supply the air.

The same principle applies to PCB cleaning lines, food processing conveyors, car wash blow-off stations, and any industrial process where you need to remove water or debris from a moving surface with a curtain of high-speed air.

Vacuum Lifting and Hold-Down

A single-stage ring blower operating as a vacuum pump provides the suction for vacuum workholding tables on CNC routers, for pick-and-place heads on packaging machines, and for sheet-fed printing presses. The continuous-duty rating matters here — these systems run all shift, and the blower needs to keep up without overheating.

Wastewater Treatment

For small treatment plants, package plants, and individual process tanks, a single-stage ring blower provides the aeration air. The maintenance-free aspect is particularly valuable at remote or unmanned sites — there’s no operator to check oil levels or tension belts.

What’s Inside

• Aluminum alloy housing and impeller. Light enough to carry, rigid enough to hold its shape under heat and pressure. Good thermal conductivity pulls heat out of the compression chamber.
• NSK bearings. Japanese-made, double-sealed, packed with high-temperature grease. Rated for continuous duty at the speeds these blowers run.
• Universal voltage motor. The same blower model can be wired for different voltage and frequency configurations. One SKU covers North America (60 Hz), Europe (50 Hz), and most of Asia.
• IP54 protection. Dust and water spray resistant. Suitable for indoor and sheltered outdoor installation.
• Class F insulation. The motor windings handle the heat buildup from continuous operation without degrading.
• CE certified. Compliant with EU health, safety, and environmental standards. ISO 9001 quality management.
• [X]-year warranty. All single-stage ring blowers backed by our factory warranty. Bearings, housing, and impeller covered against manufacturing defects.

→ Download single-stage ring blower catalog (PDF)

Single-Stage vs Double-Stage: Quick Comparison

If your application pushes the limits of a single-stage blower — deep water, long pipe runs, dense filter media — our double-stage ring blower adds the extra compression stage to handle the back-pressure without stalling.

Need help deciding? Contact our engineers → Describe your setup and we’ll tell you whether single-stage or double-stage is the right fit.

Frequently Asked Questions

How many ponds can a 1 HP ring blower aerate?

A 1 HP single-stage ring blower typically handles 1–3 ponds, each with 2–4 diffuser lines, at water depths up to about 1.5 meters. For deeper ponds, more diffusers per pond, or biofloc systems with dense suspended solids, a 2 HP model or a double-stage blower may be needed. Tell us your pond layout, and we’ll confirm the sizing.

Can a 1 HP ring blower run on single-phase power?

Yes. Both the 1 HP and 2 HP single-stage ring blowers are available in single-phase and three-phase configurations. Most small farms and workshops have single-phase power available, making installation straightforward — no three-phase upgrade needed. Specify your power supply when requesting a quote, and we’ll ship the correct configuration.

What is the noise level of a single-stage ring blower?

Slovdson single-stage ring blowers operate at 46–76 dB(A) depending on model size. The 1 HP models typically run at 46–56 dB(A) — comparable to a quiet office. The 7.5 kW models reach approximately 76 dB(A), still significantly quieter than a roots blower of equivalent capacity. This matters for pond-side installations near residential areas and for indoor factory environments.

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How deep can a single-stage ring blower aerate?

Single-stage ring blowers work well for pond depths up to approximately 1.5–2 meters with standard fine-bubble diffusers. Beyond 2 meters, the water column creates back-pressure that starts to reduce airflow significantly. For deeper ponds, biofloc tanks, or any application with elevated back-pressure, our double-stage ring blower maintains full flow at greater depths.

Do I need single-phase or three-phase?

If you’re a small farm or workshop with standard household/commercial power, single-phase is usually available and sufficient for blowers up to 2 HP (1.5 kW). Three-phase is more efficient for larger motors (3 HP / 2.2 kW and above) and is standard in industrial facilities. Our 1 HP and 2 HP models come in both configurations — tell us what power you have, and we’ll match it.

What’s the difference between single-stage and double-stage?

A single-stage ring blower has one impeller — higher flow, moderate pressure (up to ~290 mbar). A double-stage blower has two impellers in series — some sacrifice in maximum flow, but roughly double the pressure (up to 1040 mbar) and deeper vacuum. Choose single-stage for most pond aeration, air knife drying, and vacuum hold-down. Choose double-stage for deep-water aeration, biofloc systems, and long-distance vacuum conveying. Still unsure? See our double-stage ring blower page for detailed guidance, or ask us.