What Is a Horizontal Axial Flow Pump?
A horizontal axial flow pump is a rotodynamic pump in which the impeller shaft is positioned horizontally, typically with suction and discharge connections arranged in-line or through concrete inlet and outlet canals. The pump operates by using propeller-like blades that generate thrust, pushing liquid along the axis of the shaft rather than relying on centrifugal force.
This design distinguishes itself from the more common vertical axial flow pump configuration. In a horizontal setup, the impeller is generally located above the highest water level, or a valve is provided on the discharge side to prevent backflow during maintenance. This arrangement eliminates the need to dam off or drain canal sections when servicing the rotating assembly.
Key Design Characteristics
Horizontal axial flow pumps are built for exceptionally high flow rates at low heads. According to product specifications from major manufacturers, these pumps can handle flows ranging from 7,000 to over 115,000 m³/h (30,000 to 500,000+ gpm) with heads typically under 8 meters (26 feet).The structural design incorporates several distinctive features:
| Feature | Description |
|---|---|
| Split Casing | The pump casing is divided horizontally, allowing the top half to be removed for direct access to the impeller and rotating assembly |
| Between-Bearing Design | Reduces vibration and deflection at the impeller compared to overhung configurations |
| Self-Lubricating Bearings | Anti-friction bearings designed for extended service life, with options for temperature and vibration monitoring |
| Suction Elbow | Heavy wall steel fabrication with mitered design ensuring smooth flow into the impeller |
The motor and drive components are typically positioned above the flow channel, connected to the pump shaft through a gearbox or direct coupling. This arrangement keeps electrical components away from water contact and improves heat dissipation conditions compared to bulb-type tubular pump designs.
