Patent ID: 8277116

Claim:
A fluid mixing device comprising: a flow duct extending lengthwise along a longitudinal axis, the flow duct having a perimeter extending transversely to and around the longitudinal axis, the flow duct configured to provide a primary flow flowing along the longitudinal axis; and at least one deployable and retractable projection disposed within the flow duct at an angle which is non-perpendicular and non-parallel to the longitudinal axis and configured to, when deployed in a direction away from at least one wall of the flow duct, provide at least one secondary flow flowing transversely to the primary flow, the at least one secondary flow configured to bring fluid from the at least one wall of the flow duct to an inner portion, disposed apart from the at least one wall, of the flow duct and back from the inner portion of the flow duct towards the at least one wall of the flow duct.