(133a) An Innovation in Advanced Mass Transfer Technology: The Combination of a High Performance Tray and a Novel Downcomer Distributor for Optimal Performance

The deviation from ideal flow pattern on standard commercial trays can be caused by the recycling of liquid on the tray or by the existence of stagnant regions of liquid. In order to eliminate these issues, a ?Downcomer Distributor?¹ was invented and developed.

The Downcomer Distributor, along with a standard and another proprietary downcomer design, was tested in 2007. It was found experimentally that specific advantages are achieved with the Downcomer Distributor at a wide range of vapor and liquid flow rates, including the elimination of stagnant regions above the tray decks and the reduction of back-flow, thus enabling effective utilization of the entire tray deck for mass transfer. Compared with standard and other proprietary downcomer designs, the distribution of volumetric liquid flow across the tray deck is essentially similar for all paths along which that liquid flows. Thus, the Downcomer Distributor results in improved efficiency.

A successful commercial application of the high performance trays with Downcomer Distributors is field-proven with the de-bottleneck of a commercial-scale gas plant in June 2008. ADV Pinnacle Performance Trays with Downcomer Distributors were installed in both the LPG and Depropanizer Columns. Compared to the prior columns' performance, it was determined during the performance test run period that the columns after revamp are able to handle a greater throughput, the on-spec propane and butane product rates are greater, and thus the calculated incremental production rates significantly exceed the Project targeted incremental production rates. After revamp the tray efficiencies of the LPG and Depropanizer Columns were increased, which results in substantial improvements in column energy consumption, product purities and recoveries, and operation flexibility.

¹The Downcomer Distributor is patent-pending.

KEYWORDS: downcomer distributor, high-performance tray, downcomer, mass transfer