Prospectus

Return to Table of Contents Volunteer to help write Position Paper

DSP-28 Open Area Effect on Entrainment from Packing Distributors Expected Benefit to Members: Would improve distributor designs while maximizing packing capacity for both random and structured packings. Present Situation and Proposed Research : Little is known about liquid entrainment from distributors. During previous FRI research with high capacity structured packing, considerable entrainment was noted. The entrainment was of two types, large droplets and fine mist. It was impossible to determine if the distributor or packing was the major cause of the entrainment generation. The effect of distributor open area on liquid entrainment would be investigated for trough type distributors. Open area is the area between troughs that is not obstructed by the parting box for vertical upward vapor flow. The objective is to learn how the relative area between the troughs and parting box obstruction influences liquid entrainment from the distributor and the packing. Proposed Internals and Test System: Large size structured packing (50 - 120 m 2 /m 3 ) and up to four different trough distributor designs for the ortho/para xylene system at 100 mm Hg and atmospheric pressure. An entrainment capture device, similar to that used in prior entrainment studies, would be above the distributor. Also, the bubble cap heat transfer tray would be used to supply saturated reflux, to eliminate possible entrainment from droplets forming on a subcooled internal reflux pipe. Changes in measured entrainment would be due to differences in distributor open area. Estimated Unit Time: 5 weeks Estimated Additional Costs (Beyond Unit Time): None Background and Discussion: There has been a large experimental effort to understand the effect of initial liquid distribution on packing performance that has led to a variety of designs to insure an even initial liquid distribution. Some designs sacrifice open area for vapor flow to achieve better initial liquid distribution. There is no clear understanding of the open area tradeoff in distributor design. A poorly designed distributor could have liquid being entrained overhead instead of flowing into the packing. This then becomes a performance limitation. Studying how distributor open area design influences liquid entrainment should lead to better distributor designs. Developmental Research Idea

PROSPECTUS

Page | 20