An AODD pump uses two flexible diaphragms connected by a central shaft, alternately pushed and pulled by compressed air (3–8 bar) cycling through an automatic air distribution valve. Each diaphragm acts as both pump and seal displacing 0.01–80 m³/h across 1–50,000 cP at up to 8 bar discharge pressure and suction lift to 7 m. No electricity required; dry-running safe; handles solids up to 12 mm and abrasive slurries without damage.
Compressed air enters the air chamber behind diaphragm 1 pushing it outward and discharging fluid through the outlet check valve. Simultaneously, diaphragm 2 retracts creating suction and drawing fluid through the inlet check valve. The automatic air distribution valve shifts compressed air to the opposite side reversing the stroke and cycling both diaphragms alternately at rates of 10–300 cycles/min. Each diaphragm stroke produces one displacement pulse; combined output gives 2 pulses/cycle.
Challenges
Pulsating Flow (2 Pulses/Cycle)
Alternate diaphragm strokes produce significant pressure pulsation in outlet line.
Check Valve Fouling with Viscous or Fibrous Product
Ball check valves fail to seat properly in high-viscosity or fibrous-containing fluids.
Air Consumption Cost
Compressed air at 5–7 bar represents significant energy cost in continuous high-flow operation.
Diaphragm Fatigue at High Cycling Rate
Above 200 cycles/min, PTFE or rubber diaphragm fatigue life drops below 500 hours.
Icing of Air Exhaust in Cold Environments
Expanding compressed air in exhaust port creates ice that blocks exhaust, causing stall.
Solutions
- Pulsation Dampener (Bladder Type) on Outlet: Reduces pressure variation to ±5% of mean acceptable for all standard applications.
- Flap-Type Check Valves for Viscous/Fibrous Fluids: Flap valves seal reliably across viscous, fibrous, and particle-containing product streams.
- Air-Saving Controller (Pulse-Width Modulation): Reduces air consumption by 30–40% at partial flow without flow rate reduction.
- PTFE-Reinforced Diaphragm with Aramid Fabric Backing: Extends diaphragm life to 2,000–5,000 hours at 200 cycles/min rated operation.
- Exhaust Air Muffler with Anti-Icing Heater: Maintains exhaust port above 0°C in ambient temperatures down to −20°C.
Applications
- Chemical: Acid, alkali, solvent, and hazardous chemical transfer no electricity required, zone-1 ATEX rated.
- Pharmaceutical: API slurry transfer, filter press feed, solvent recovery, and sterile liquid dosing.
- Food & Beverage: Chocolate, jam, tomato paste, yeast, and thick beverage concentrate transfer.
- Wastewater: Sludge and filter cake slurry transfer handles solids up to 12 mm without damage.
- Mining: Abrasive mineral slurry, tailings, and chemical reagent transfer in remote locations.
Product Catalogue & Technical Datasheet
Model | Flow Rate (m³/h) | Air Pressure (bar) | Discharge Pressure (bar) | Viscosity Max (cP) | Solid Particle Max (mm) | Inlet/Outlet Ø (DN) | Suction Lift (m) | L × W × H (mm) | Weight (kg) |
AODD-006 | 0.01–0.6 | 3–8 | Up to 8 | 50,000 | 3 | DN 6 | Up to 7 | 180×120×160 | 4 |
AODD-060 | 0.1–6 | 3–8 | Up to 8 | 50,000 | 6 | DN 15 | Up to 7 | 280×190×240 | 9 |
AODD-200 | 1–20 | 3–8 | Up to 8 | 50,000 | 8 | DN 25 | Up to 7 | 380×280×340 | 18 |
AODD-500 | 5–50 | 4–8 | Up to 8 | 40,000 | 10 | DN 40 | Up to 7 | 520×380×460 | 38 |
AODD-800 | 10–80 | 4–8 | Up to 8 | 30,000 | 12 | DN 65 | Up to 7 | 720×520×620 | 75 |
AODD-1500 | 20–150 | 5–8 | Up to 7 | 20,000 | 12 | DN 80 | Up to 7 | 980×680×800 | 130 |
AODD-2000 | 30–200 | 5–8 | Up to 7 | 15,000 | 12 | DN 100 | Up to 7 | 1,200×840×960 | 200 |
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