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High‐Energy Flocculation Units
Author(s) -
Walker J. D.
Publication year - 1968
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1968.tb03670.x
Subject(s) - axial compressor , impeller , reversing , flow (mathematics) , turbulence , brake , reducer , draft tube , horsepower , turbine , rotor (electric) , work (physics) , marine engineering , flow measurement , trailer , flocculation , environmental science , engineering , mechanics , mechanical engineering , automotive engineering , physics , environmental engineering , gas compressor
This article discusses test and comparison work performed on an axial‐flow and a turbine‐type flocculation unit in a plant testing laboratory consisting of a 40‐ft diameter by 15‐ft water depth tank. The units tested were driven by a selective speed reducer gear, Prony brake tested to determine water horsepower. Meter readings were taken at control points in the tank more as a means of back‐checking successive runs than to chart the flow vector regime. The meter does not measure spinning turbulence and may over or under read what actually is happening. It also is apt to miss or under read variable jet streaming; and, it does not read true in a vertical attitude. This article deals primarily with the tested advantages of slow speed, large hub axial‐flow impeller used to circulate and stir a large flocculation reactor. The work reported herein purports that not only is this “special” axial‐flow device adequate for all phases of flocculation, but is actually superior to most reel or bladed radial‐flow devices in the ranges of higher velocity gradients (G = 50‐150/sec). The axial‐flow unit is equally effective installed either on a vertical or horizontal shaft.