Rectangular Spiral Aeration Units
Engineered for a variety of aeration basin geometries, Mapal’s rectangular spiral aeration unit delivers uniform oxygen distribution and effective mixing across the basin. The spiral layout supports consistent biological treatment performance with stable operating conditions. Its geometry is optimised for efficient shipment in a 20-foot container, simplifying logistics and site handling. Available in stationary (floor-sitting) and floating configurations with tubular or disc diffusers, the unit features a robust stainless-steel design that supports drop-in deployment without draining.
Available Configurations
Stationary Rectangular Spiral Tubular Diffuser
Designed for retrofit applications and operating reactors where flexibility and minimal downtime are critical, Mapal’s floor-resting rectangular spiral-configured aeration unit is suitable for a wide range of basin geometries. It is engineered to deliver uniform oxygen distribution and effective mixing across the basin, supporting stable and efficient biological treatment performance.
This configuration incorporates PP/PE inner tubes with fine-bubble membrane sleeves.
The unit features a marine-grade stainless steel (304/316) structure for durability and long service life. It is crane-installed (drop-in), fully retrievable, and suitable for installation in live reactors without draining, minimising downtime and operational disruption.
Technical Snapshot
| Parameter | Description |
| Disc quantity range per unit | 30–100 pcs |
| Airflow per single disc diffuser | 2–8 m³/h |
| Configuration | Floor-resting spiral |
| Diffuser Type | Disc (EPDM, Silicone, PU) |
| Structure Material | Stainless Steel 304 / 316 |
| Installation Method | Crane-installed / drop-in |
| Maintenance | Fully retrievable |
| Retrofit Compatibility | Excellent |
Floating Rectangular Spiral Tubular Diffuser
Designed for retrofit applications and operating reactors where flexibility and minimal downtime are critical, Mapal’s floating rectangular spiral-configured aeration unit is suitable for a wide range of basin geometries. It is engineered to deliver uniform oxygen distribution and effective mixing across the entire basin, supporting stable and efficient biological treatment performance.
This configuration incorporates PP/PE inner tubes with fine-bubble membrane sleeves, and a stabilising system of UV-resistant polypropylene floats. The unit is secured in place to ensure stable operation under varying conditions.
The unit features a marine-grade stainless steel (304/316) structure, ensuring durability and long service life. It is crane-installed (drop-in), fully retrievable, and suitable for installation in live reactors without draining, minimising downtime and operational disruption.
Operational Flexibility
The floating unit can provide a complete aeration solution, operate over existing fixed-floor diffusers, work alongside surface aerators for supplemental oxygen, or replace malfunctioning equipment.
Technical Snapshot
| Parameter | Description |
|---|---|
| Diffuser length range | 2000-4500 mm |
| Airflow per 1 m tubular diffuser | 4-12 m³/h |
| Configuration | Floating |
| Diffuser Type | Tubular (EPDM, Silicone, PU) |
| Structure Material | Stainless Steel 304 / 316 |
| Installation Method | Crane-installed (drop-in) in live reactors |
| Maintenance | Fully retrievable |
| Retrofit Compatibility | Excellent |
| Floating Configuration Feature | Incorporates a balancing system of UV-resistant polypropylene floats and is harnessed in place for stable operation. |
Stationary Rectangular Spiral Disc Diffuser
Designed for retrofit applications and operating reactors where flexibility and minimal downtime are critical, Mapal’s floor-resting rectangular spiral aeration unit equipped with disc diffusers is designed for a wide range of basin geometries. It delivers high oxygen transfer efficiency and uniform performance across the basin, supporting stable biological treatment.
Mapal’s rectangular spiral aeration units equipped with disc diffusers are compatible with disc diffusers from any manufacturer.
The unit features a marine-grade stainless steel (304/316) structure, ensuring durability and long service life. It is crane-installed (drop-in), fully retrievable, and suitable for installation in live reactors without draining, minimising downtime and operational disruption.
Technical Snapshot
| Parameter | Description |
|---|---|
| Diffuser length range | 2000-4500 mm |
| Airflow per 1 m tubular diffuser | 4-12 m³/h |
| Configuration | Floating |
| Diffuser Type | Tubular (EPDM, Silicone, PU) |
| Structure Material | Stainless Steel 304 / 316 |
| Installation Method | Crane-installed (drop-in) in live reactors |
| Maintenance | Fully retrievable |
| Retrofit Compatibility | Excellent |
| Floating Configuration Feature | Incorporates a balancing system of UV-resistant polypropylene floats and is harnessed in place for stable operation. |
Floating Rectangular Spiral Disc Diffuser
Designed for retrofit applications and operating reactors where flexibility and minimal downtime are critical, Mapal’s floating rectangular spiral aeration unit equipped with disc diffusers is suitable for a wide range of basin geometries. It delivers high oxygen transfer efficiency, uniform oxygen distribution, and effective mixing across the basin, supporting stable and efficient biological treatment performance.
Designed to maintain optimal diffuser submergence under variable water levels, it is particularly suitable for lagoons and basins where draining or civil works are not feasible, where the floor is uneven, or where access to the tank floor is restricted. Its relatively compact dimensions make it especially suitable for emergency and temporary aeration applications.
The unit incorporates a stabilising system of UV-resistant polypropylene floats and is secured in place to ensure stable operation. It is compatible with disc diffusers from any manufacturer.
The unit features a marine-grade stainless steel (304/316) structure, is crane-installed (drop-in), fully retrievable, and suitable for installation in live reactors without draining, minimising downtime and simplifying long-term maintenance.
Operational Flexibility
The floating unit can provide a complete aeration solution, operate over existing fixed-floor diffusers, work alongside surface aerators for supplemental oxygen, or replace malfunctioning equipment.
Technical Snapshot
| Parameter | Description |
|---|---|
| Disc quantity range per unit | 30-100 pcs |
| Airflow per single disc diffuser | 2-8 m³/h |
| Configuration | Floating |
| Diffuser Type | Disc (EPDM, Silicone, PU) |
| Structure Material | Stainless Steel 304 / 316 |
| Installation Method | Crane-installed (drop-in) in live reactors |
| Maintenance | Fully retrievable |
| Retrofit Compatibility | Excellent |
| Floating Configuration Feature | Incorporates a balancing system of UV-resistant polypropylene floats and is harnessed in place for stable operation. |
Where This Unit
Performs Best
Rectangular spiral aeration units are particularly well suited for:
Retrofit Projects Without Shutdown Windows
Drop-in installation enables deployment in live basins without draining, reducing risk and minimising operational disruption.
A Variety of Basin Geometries
The rectangular spiral configuration supports uniform oxygen distribution and effective mixing across a wide range of basin layouts, helping maintain stable process performance.
Aging Diffuser System Replacement
Replaces failing diffuser systems without requiring major civil modifications or extended outages
Plants Operating Near Capacity Limits
Supports improved oxygen transfer efficiency and consistent process performance under high loading conditions.
Facilities Seeking Long-Term Reliability
Marine-grade stainless steel construction ensures durability and dependable long-term operation.
Engineered For Efficient Shipping And Site Handling
The rectangular spiral aeration unit is optimised for efficient shipment in a 20-foot container, simplifying logistics, handling, and deployment.
Loading rectangular spiral aeration units into 20’ container being shipped to winery in Santiago, Chile.
Rectangular spiral aeration units delivered in a shipping container, assembled on site, and deployed in operation.
Typical Applications
Municipal Wastewater Treatment Plants
Industrial Wastewater Treatment
Retrofit Upgrades of Aging Aeration Systems
Why Mapal
Drop-In, Retrievable Solutions
No-Downtime Installation
Proven Global Installations
Municipal Wastewater Treatment Plants
Planning an Upgrade or Retrofit?
Let our engineering team evaluate your basin and recommend the optimal aeration configuration for your process requirements.