Vízügyi Közlemények, 1969 (51. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(75) the difficulties arising from the continuous feeding of the tracer dye. This lias been encountered in full-scale experiments. In order to eliminate the above problems a new procedure has been introduced, consisting essentially of the determination of a curve similar to the flow-through curve, without the introduction of a tracer material. Variations in the volume of outflow along the perimeter of the tank are determined instead. The method is illustrated by examples in which the distribution of the time of residence is determined from the distribution of water quantities discharging through individual elements of the series of weirs. In the statistical evaluation of the curve obtained the latter is approximated by a -T-distribution. Experimental results are quoted in support of the theoretical considerations. The relevant observation data have been gained during the tests performed on the presettling tank of the Dorr-system at the Dorog treatment plant. In conclusion suggestions are made concerning the future trends in the hydraulic study of structures of both water- and wastes treatment plants. to*