A variety of support grids are available to support the column packed bed, depending on the specific application and the column diameter. The support grid must be constructed in such a way that it minimally hinders gas and liquid flows.

Particularly between the packed bed and the support grid, the possibility of reduced hydraulic capacity exists.

Support grids must be adapted to:

• type of packing
• bed height
• liquid holdup
• additional weight caused by fouling
• design temperature for specific application

Support grids require a support ring and, depending on the diameter and/or the supporting loads, one or more internal support beams. If high gas velocities, pressure surges or flooding are a possibility, the bed support can be mechanically fastened to the support ring.

Flat Support Grid

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The most straightforward design is the flat support grid which is used for small column diameters. The hydraulic conditions need to be taken into consideration as this type of support grid has a relatively low free cross-section. Flat support grids are available in ceramic and graphite materials in addition to metals and thermoplastics.

Hump Support Grid

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Profile support grids using profile beams, offer a free cross section of 100% in relation to the entire column cross-section. Downcoming liquid flows separately from the up flowing gas stream, thus preventing the possibility of flooding, even at high hydraulic loadings. The height of the profile beams as well as the slot width ar a function of the parameters of a specific application