Vortex Diodes for dampening pressure oscillations in pump pressure lines

Results from measurements, water hammer calculations and practical advice

Abstract

The transient throttling of vortex chamber diodes has first been modelled using a water hammer program, whereby the mo-del has been calibrated and validated on the basis of experimental data. Building on this, it was possible to analyze the use of vortex chamber diodes as an asymmetric throttling device in place of the previous solution consisting of a throttle with by-pass to damp oscillation and limit pressure within pump pressure lines with pressure vessels for surge protection. The transient system behaviour after a pump switch-off has been computed by means of a water hammer program for three different pump pressure line systems, i. e. for systems without a throttle, with a throttle and by-pass and with different vortex chamber diodes. It was found that vortex chamber diodes rapidly damp the oscillations and also effectively limit the pressure rise within the pipe systems. Finally, a pump failure and the transient throttling of the vortex diodes installed at the Amstetten pumping station of the Landeswasserversorgung has been computed, compared and contrasted to measured values. This paper cont-ains the program code and all parameters required to lay out and compute vortex chamber diodes of different nominal dia-meters and thus paves the way for the practical application in engineering.