Fine Bubble Disc Diffuser
Disc-shaped membrane diffusers (Disc 270 & Disc 350) screwed onto air distribution grids, with self-cleaning flexure action and high oxygen transfer efficiency.
AIRFIN Fine Bubble Disc Diffusers are disc-shaped membrane diffusers designed for efficient oxygen transfer in wastewater aeration tanks. Available in two sizes — Disc 270 (9") and Disc 350 (12") — they screw directly onto air distribution grids via a 3/4" NPT Male threaded connection.
Each diffuser features an EPDM, Silicon, Viton, or PTFE Layered EPDM membrane that produces fine bubbles of 0.8–1.9 mm for high SOTE — up to 18% at 3 m water depth. The membrane’s self-cleaning flexure action keeps perforations clear during on/off cycling, reducing maintenance.
Rated for tank depths up to 7.5 m and a maximum air pressure of 1.5 kg/cm², the disc diffusers are lightweight (0.7–1.5 kg) and easy to install or replace on existing grids.
Key features
- EPDM / Silicon / Viton / PTFE Layered EPDM membrane options
- Self-cleaning membrane flexure action prevents clogging
- 3/4" Inches NPT Male threaded connection for easy installation
- Fine bubble size of 0.8–1.9 mm for high oxygen transfer
- Max permissible tank depth of 7.5 m
- Max allowable air pressure of 1.5 kg/cm²
- Available in 9" (Disc 270) and 12" (Disc 350) sizes
- Lightweight design — 0.7 kg (270) and 1.5 kg (350)
Outcomes
- Up to 18% SOTE at 3 m water depth (Disc 350)
- Up to 3.5 kg O₂/kWh aeration efficiency
- Air flow range from 1 to 20 m³/hr across both models
- Active surface area up to 0.065 m² per diffuser
Who it's for
Municipal and industrial wastewater treatment plants, sewage treatment plants, activated sludge systems, aerated lagoons, oxidation ponds, aerobic digesters, and process industries including pharmaceutical, food & beverage, chemical, textile, leather, and aquaculture.
Models & variants
Two disc fine-bubble diffuser models — 9" (Disc 270) and 12" (Disc 350) — for different aeration loads.
270 mm (9") disc fine-bubble diffuser for standard and compact aeration duties.
| Spec | Value |
|---|---|
| Airflow range | 1–12 m³/hr |
| Standard design flow | 2.5–5 m³/hr |
| Perforated area | 0.0375 m² |
| No. of perforations | 6,600 nos. |
| Active surface area | 0.038 m² |
| Perforation size | 1 mm |
| Bubble size | 0.8–1.9 mm |
| Area of influence | 0.2–1 m²/pcs |
| SOTE @ 3 m (1 mm perforation) | 12% |
| Typical standard aeration efficiency | 2.5–1.5 kg O₂/kWh |
| Max allowable air pressure | 1.5 kg/cm² |
| Connection | 3/4" Inches NPT Male |
| Max permissible tank depth | 7.5 m |
| Weight | 0.7 kg |
Performance envelope
Operating range across Disc 270 and Disc 350, rated at 3 m water depth with 1 mm perforation.
| Metric | Min | Max | Unit |
|---|---|---|---|
| Airflow range (Disc 270: 1–12 · Disc 350: 2–20) | 1 | 20 | m³/hr |
| Standard design flow (Disc 270: 2.5–5 · Disc 350: 4–8.5) | 2.5 | 8.5 | m³/hr |
| SOTE @ 3 m (1 mm perforation) (Disc 270: 12% · Disc 350: 18%) | 12 | 18 | % |
| Aeration efficiency | 1.5 | 3.5 | kg O₂/kWh |
| Active surface area | 0.038 | 0.065 | m² |
| Area of influence | 0.2 | 1.5 | m²/pcs |
| Weight | 0.7 | 1.5 | kg |
Common construction
Specifications shared across Disc 270 and Disc 350 models.
| Specification | Value |
|---|---|
| Membrane material | EPDM / Silicon / Viton / PTFE Layered EPDM |
| Perforation size | 1 mm |
| Bubble size | 0.8–1.9 mm |
| Max allowable air pressure | 1.5 kg/cm² |
| Connection | 3/4" Inches NPT Male |
| Max permissible tank depth | 7.5 m |
Applications
Activated sludge systems
Fine-bubble aeration for conventional and extended-aeration activated sludge processes.
Municipal STPs & sewage treatment
Oxygen transfer for municipal sewage and wastewater treatment plants.
Industrial ETPs
Process aeration for pharmaceutical, chemical, textile, food & beverage, and leather effluent treatment.
Aerated lagoons & oxidation ponds
Aeration for stabilisation ponds and lagoon-based treatment systems.
Aquaculture
Dissolved oxygen supply for aquaculture process water.
Focus areas
- Waste Water Treatment