(89b) Reliable Retention of Molecular Sieve Beds

Reliable operation of an Olefin gas/liquid dehydrator requires careful attention to the integrity of the grid supporting the molecular sieve. Problems with retention of the sieve can stem from many points in the design, fabrication, and installation process for these assemblies. Two case studies will demonstrate key details in design of the support grid and sealing arrangements of the grid within the vessel. Metal temperature of the grid verses the vessel wall creates significant thermal expansion problems that must be accounted for in the sizing of components. Properly sealing the grid perimeter requires room for the grid to expand and contract relative to the vessel and still maintain a sieve tight seal. A layer of inert balls does not solve the problem and can make problems more severe. A proven solution for the sealing problems will be presented.

In addition, a proprietary new grid design will be presented that increases usable volume in existing vessels allowing a larger sieve charge, eliminates the sealing problems with the long grid perimeter and handles a wide range of loads.