Design and Performance of Slug Damper

A novel flow conditioning device, namely, the slug damper, which can be used upstream of compact separation systems, is investigated theoretically and experimentally. In the experimental part, a 3” ID slug damper facility has been installed in an existing 2” diameter two-phase flow loop. This flow loop includes an upstream slug generator, a Gas-Liquid Cylindrical Cyclone (GLCC© ) attached to the slug damper downstream, and a set of conductance probes for measuring the propagation of the dissipated slug along the damper. Over 200 experimental runs were conducted with artificially generated inlet slugs of 50 ft length (Ls/d = 300) that were dumped into the loop upstream of the slug damper, varying the superficial liquid velocity from 0.5 to 2.5 ft/s and superficial gas velocity between 10 to 40 ft/ (in the 2” inlet pipe) and utilizing segmented orifice opening heights of 1”, 1.5”, 2” and 3”. For each experimental run, the measured data included: propagation of the liquid slug front in the damper, differential pressure across the segmented orifice, GLCC liquid level, GLCC outlet liquid flow and static pressure in the GLCC. The data prove that the slug damper is capable of dissipating long slugs, ensuring fairly constant liquid flow rate into the downstream GLCC. Also, the damper capacity to process large slugs is a strong function of the superficial gas velocity (and mixture velocity). The theoretical part includes the development of a mechanistic model for the prediction of the hydrodynamic flow behavior in the slug damper. The model enables the predictions of the outlet liquid flow rate and the available damping time, and in turn the prediction of the slug damper capacity. Comparison between the model predictions and the acquired data reveals an accuracy of 30% with respect to the available damping time and outlet liquid flow rate. The developed model can be used for design of slug damper units in the field.© 2007 ASME