Johnson Screens - Shaped Support Grid (SSG)

Insights

The Johnson Screens` Shaped Support Grid (SSG) design performs better than traditional flat surface grid assemblies that are located near the tangent line of the head to shell weld. With traditional flat surface grids designs, the entire volume of the head is a dead area, with no reaction or drying adsorption occurring. 

The Support Grid lies directly on the bottom head surface, allowing for the entire volume to be filled with media. Increased bed volume allows for the conversion of existing vessels to achieve higher process capacity and new vessels to be built shorter in shell length.

During the down flow operation, the tapered design of SSG collects flow from the entire cross section of the vessel and moves it toward the center hub outlet, producing a uniform flow across the entire vessel and better bed utilization up to 30% over traditional bed support systems. 

Away from the vessel centerline, the volumes of catalyst or sieve are much greater. 

The SSG panel matches the configuration shape of the vessel head, collecting flow from all areas uniformly without having to cover the entire cross section of the vessel.