Johnson Screens® designs and manufactures a wide range of vessel internals for media retention. Among these innovative products is a line of internals used in down flow or up flow systems to retain the often-costly media and to provide a collection area for the process flow across the entire vessel diameter or length. Because of their strength, durability and flow characteristics, our support grid and distributor tray systems are widely used in hydrotreaters, desulfurizers, hydrocrackers, molecular sieves, sand filters, gas sweeteners and other absorption systems.

There are multiple advantages in using Johnson® screens for demanding media retention applications:

 

• JOHNSON SCREENS ARE EXTREMELY STRONG

Made of wires and rods welded at every intersection, Johnson screens have exceptional resistance to collapsing or buckling even in operations such as hydrocracking and desulfurizing where screens must withstand loads of 350 kPa or more.

• JOHNSON SCREENS OFFER PRECISE MEDIA RETENTION

Johnson support grids can have slots as narrow as 0.002 in. (0.05 mm) to dependably retain even very small catalyst, resin or molecular sieves. Despite the narrowness of these individual slots, the screen has a much higher total open area than grids using wire mesh on grating. This increased open area translates directly into superior process efficiency.

• JOHNSON SCREENS PROVIDE A STABLE INTERFACE

Unlike wire mesh, Johnson screens directly retain the media without an intermediate layer of inert balls. The smooth surface of the screen also reduces abrasion of the catalyst.

• JOHNSON SCREENS ARE VIRTUALLY MAINTENANCE-FREE

Once installed, the screens equire very little maintenance. Their special slot design virtually eliminates plugging, but if it should ever occur, cleaning with a wire brush is quick and easy and can be done without fear or damage to the screen surface.

• JOHNSON SCREENS HAVE MAXIMUM DESIGN FLEXIBILITY

Johnson support grids are fabricated in a variety of custom shapes and sizes to meet any process or vessel requirements. Made of a variety of materials such as type 304, 316, 316L, 321, 347 and 410S stainless steel and exotic alloys, the grids may also be fabricated in sections and include many ways, dump ports and other features required by vessel or operational constraints.