US Patent 7497562 Re-circulating fluid delivery systems

A re-circulating fluid delivery system includes an air-fluid separator structure, a fluid plenum in fluid communication with the separator structure, and a free fluid reservoir. A fluid re-circulation path fluidically couples the separator structure, the fluid plenum and the free fluid reservoir. A pump structure re-circulates fluid through the re-circulation path during a pump mode, wherein air bubbles may be separated from re-circulated fluid.