PROCESS DYNAMICS FOR OVERFLOW DEVICES OF RECTANGULAR, CIRCULAR, PARABOLIC AND TRIANGULAR SHAPE - LOSS PREVENTION APPLICATIONS

The problem of unsteady-state liquid flow across overflow devices of v arious shapes has been investigated. Dimensionless efflux times to eva cuate a given amount of liquid from an upstream vessel or basin throug h an overflow conduit or weir as a function of dimensionless height of the liquid crest were computed for four specific overflow device shap es: rectangular, circular, parabolic and triangular. Analytical expres sions were developed for this purpose in all cases except circular. Ge neralized comparison charts were developed for the cases of (1) equal flow areas of the overflow devices and (2) equal maximum flow capaciti es. Two examples illustrating application of the equations and charts developed in this paper to loss prevention scenarios are also presente d. (C) 1997 Elsevier Science Ltd. All rights reserved.