SURFACE AERATION IMPELLER

摘要

An impeller which is adapted to be affixed to a rotating shaft is provided for aerating a liquid and includes a support disk having a circular outer edge. The support disk is affixed to the rotating shaft in such a manner that it is maintained in a substantially perpendicular relationship with the shaft. A plurality of impeller blades are affixed to the support disk in such a manner as to be spaced from the shaft and extend above the upper surface of the support disk and below the lower surface of the support disk. The impeller blades further extend radially outwardly from the circular outer edge and have an upper edge which lies in a plane substantially parallel to the support disk and a lower edge which is tapered causing the blades to be widest at the portion closest to the rotating shaft and progressively more narrow as the blades extend radially Outwardly from the support disk. Additionally each of the impeller blades includes a flow inducing fin along the lower edge of the blade, which fins are tapered so as to be widest at the portion closest to the rotating shaft and progressively more narrow as the blade extends radially outwardly from the support disk. A cover means is affixed to the impeller blades and spaced from the upper surface of the support disk for creating an air intake opening above the upper surface of the support disk and for reducing the amount of splashing caused by the rotation of the impeller near the surface of the liquid. In one embodiment the impeller includes means for adjustably securing the impeller blades to the support disk so that the degree of radial extension is adjustable and further includes means for adjustably securing the cover means to the upper edges of the impeller blades.