A Study of the Behavior of Rapid Sand Filters Subjected to the High-Velocity Method of Washing

In this paper the writers describe and discuss the development of the high-velocity method of washing rapid sand or mechanical filters, and give a record of a series of experiments obtained in washing a small experimental filter. They also describe the corrosion of a brass wire screen which, in the construction of the filter beds of the Cincinnati, Ohio, Filtration Plant, had been placed between the gravel and sand layers, and for which some other material or some modified form of construction was necessary. Additional observations are given, showing the effect of modifying the depths and sizes of the gravel layers in certain of the Cincinnati filters after removing the brass wire screen.