UBO designs and manufactures a wide range of screens for media retention. Among these innovative products is a line of Johnson Screens flat screens 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 as diameter or length.
Because of their strength, durability and flow characteristics, our Johnson Screens support grid systems are widely used in hydrotreaters, desulfurizers, molecular sieves, gas sweeteners and other adsorption systems.
There are multiple advantages in using our screens for demanding media retention applications:
Extremely strong: made of welded wires and rods, they have exceptional resistance to collapsing or buckling even in operations such as hydrocracking and de-sulfurisers, where screens must withstand loads of 350 kPa or more
Precise media retention: slots can be as narrow as 0.05 mm / 0.002 in to dependably retain even very small size catalyst, resin or molecular sieve. Despite the narrowness of these individual slots, the screen has a much higher total open area than grids using wire mesh on grating
Stable interface: unlike wire mesh, Johnson Screens® support grids directly retain the media without an intermediate layer of inert balls. The smooth surface of the screen reduces abrasion
Comes equipped with support beams, catalyst transfer pipes, manways, rope packing, bolting and all necessary accessories
Arrangement & Installation
A support grid could be made out of parallel or pie shaped segments, each segment just resting on the beams or bolted to or welded to the next one. The joining bars could be flush or project above the screening surface. Support structure can be included for additional strength.
The support grids can be attached to the supporting structure by bolts fixed to the grid or part of the vessel itself
The Packaging and Transportation of the wedge wire screen pipe:
Single with bubble bag and then in wooden case(fumigation certificate). Each case is clearlymarked with:
Name & identification mark of manufacturer
Date of manufacture
Safe heating & application temperature