Hydraulic Design of Syphons

Abstract

This paper puts forward anew theory on the operation of syphons. It proposes, and gives proof from test results, that the rising leg of a syphon can be greater than heretofore thought (i.e. it can be greater than atmospheric pressure expressed in feet of the fluid being used minus the friction loss). It also shows that the length of the down leg of a syphon has no limit. Test results are given using heated water in syphons; having residence time near the apex; using water supplied off pumps. Pressures and vacua throughout syphons are also tested.It is shown that hydraulic gradient has no significance because the fluid stores energy in parts of some syphons; this matter is discussed in some detail. Other items discussed are friction factors to be used for syphons using water; noise in syphons; priming flows and parallel operation of syphons. It is shown that model tests for syphons have pitfalls. Lines for further investigation are indicated.