| 摘要 |
An aerator comprising a support member in the form of a flat plate which is adapted, when the aerator is in use, to lie in a horizontal plane and to be rotated about its central vertical axis, a plurality of angularly spaced blades secured to the underside of said plate and each extending radially from a central region thereof towards its periphery, each said blade having a maximum depth beneath a horizontal datum at a position intermediate its ends, and being provided with a plate secured to its lower edge and extending on both sides of the blade along at least a portion of that part of the length of the blade between its outer end and the position of maximum depth.
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