Experimental characterization ofscrubber internals at low andelevated pressures

Abstract

Two typical scrubber internals are studied in this thesis, inlet vane and wire mesh pads. A total of 8 wire mesh pads were studied at low and high pressure conditions. The inlet vane was studied at high pressure. The measurements performed at elevated pressures were performed at 20, 50 and 85 bars for a N2/Exxsol system as well as a synthetic natural gas mix.

The mesh pads studied varied in height, specific surface area, wire packing density, wire diameter as well as porosity. Liquid holdup measurements were made at five vertical positions and in addition pressure drop and separation efficiency were measured. The results show variations in holdup profile depending on liquid load, pad geometry, running time, measuring position and interfacial properties. Droplet size measurements were also made for all wire mesh pads below and at flooding of the wire mesh pads. A new equation was developed that qualitatively describes aspects of wire mesh pad design and was used for developing correlations. A novel method for measuring flooding point was developed and flooding points for several inlet pipe liquid volume fractions were made. A correlation predicting flooding points in wire mesh pads at both low and high pressure was developed. Dry pressure drop for all wire mesh pads was also determined. A correlation predicting dry pressure drop for spiral wound pads was developed.

A novel method for measuring scrubber efficiency above a inlet vane at varying vertical positions was developed. The separation efficiency was measured at five different vertical positions in a scrubber column with an inner diameter of 252 mm. In addition a column of 150 mm was investigated at one position. Liquid fraction measurements were made at two vertical positions to asses flow distribution. Droplet size measurements were also performed 127.5 mm above the inlet vane.