Operating principle, construction and components, membrane pore design, technical parameters and installation notes for the EPDM micro-pore tube aerator.
← Back to Tube AeratorA tube aerator, also called a tube diffuser, is a fine-bubble aeration device used to supply oxygen to municipal sewage and organic industrial wastewater treatment systems. It consists of three main parts: the aeration membrane, the support tube and the air distribution piping. The membrane is stretched over the perforated support tube and fixed at both ends with stainless steel clamps, and the whole assembly is mounted on the air main on the tank floor.
The design is characterised by a simple structure, high oxygen utilisation, reliable performance, pores that do not clog easily, no backflow of wastewater, even loading around the circumference and a long service life, together with quick installation and maintenance and a low system cost.
Air from the distribution main enters the support tube and passes through the pores in its wall. The pressure expands the rubber membrane so that the micro-pores in the membrane open, and the air is released into the water as a uniform curtain of fine bubbles. Because the rubber membrane has good elasticity, the pores open under air pressure and close again when the air supply stops, so the pores stay closed to the water while the blower is off.
This self-closing pore design prevents backflow of wastewater into the air main and keeps the pores free of clogging. The small bubble diameter maintains a high oxygen transfer rate and at the same time provides mixing of the tank contents, so the aerator both oxygenates and stirs the mixed liquor.
The air distribution pipe is made of ABS engineering plastic in a hollow, water-filled form. Filling the pipe with water greatly reduces the buoyancy of the aeration system in the tank, so the diffusers stay stable on the tank floor without heavy anchoring.
The diffuser is assembled from the following parts, counted from the end of the unit:
The rubber membrane is made of EPDM (ethylene propylene diene monomer). It has good heat resistance, ozone resistance and acid-alkali resistance with good chemical stability, and contains no plasticiser, so it keeps its elasticity over a long period without hardening, embrittling or ageing. Compared with general-purpose rubber membranes, this significantly extends service life.
The membrane is perforated with 1.5 mm pores on a 2 × 2.5 mm pitch, and the top of the membrane tube carries a 15 mm unperforated zone. A slit-shaped pore design is also used for this diffuser type: the slit stays closed when no air is supplied and opens under pressure, so the pore has good expandability and closes instantaneously when the air stops. Either way the diffuser releases uniform micro-bubbles 1–3 mm in diameter, which is what gives the high oxygen utilisation of the design.
The support tube is manufactured in ABS or PVC; in the micro-pore version the diffuser uses a UPVC hard tube for the inlet branch and support, with an ABS airflow distributor and ABS fixing and adjusting bracket, and an imported 304 stainless steel clamp. Tube lengths up to 580 mm are formed by extrusion or moulding; lengths above 580 mm are extruded.
| Parameter | Value |
|---|---|
| Outer diameter | 69 mm |
| Standard lengths | 580 mm / 800 mm / 1000 mm |
| Forming method | Up to 580 mm: extruded or moulded; above 580 mm: extruded |
| Membrane material | EPDM micro-pore rubber membrane |
| Membrane perforation | 1.5 mm pores on a 2 × 2.5 mm pitch; 15 mm unperforated zone at the top |
| Bubble diameter | 1–3 mm |
| Oxygen utilisation | 35–42% (reference value for this diffuser design) |
| Support tube | ABS or PVC (UPVC hard tube in the micro-pore version) |
| Air distribution pipe | ABS engineering plastic, hollow water-filled form to reduce buoyancy |
| Clamps | 304 stainless steel |
| Fittings | End cap, connector, gaskets I & II, centre pipe, air distribution pipe, bent plate bracket |
| Connection size & thread | On request — confirmed with the air main design |
| Airflow per unit | On request |
| Service area per unit | On request |
| Recommended water depth | On request |
| Service temperature | On request |
| MOQ / price | On request |
Values are quoted per the reference data for this tube diffuser design. Site-specific oxygen transfer depends on tank depth, airflow rate, diffuser density and layout, so please confirm the final figures against the ordered model and your tank design.
Tube aerators are used for aeration and oxygen supply in municipal domestic sewage and industrial wastewater treatment. Air is supplied through a main pipe and branch distribution pipe to the diffusers, whose expandable membrane pores provide micro-pore aeration with a large service area per unit.
Typical duties include aerobic tanks and aeration basins, activated sludge systems, and the replacement or upgrading of existing aeration systems, where the flat bubble pattern and even loading of the tube design suit long, narrow basins and grid layouts on the tank floor.
Compiled per the manufacturer reference data for this tube diffuser design. Confirm dimensions, connection size and airflow against the ordered model before detailed engineering.