Johnson Wire Catalyst Support Grid

A Johnson wire catalyst support grid is a structural component used inside chemical reactors, hydrogenation vessels, and adsorption towers. The grid is manufactured from V-shaped stainless steel profile wires resistance-welded to a grid of support beams. The grid is installed at the bottom of the reactor vessel, where it supports the catalyst bed while allowing process gas or liquid to pass through uniformly. The V-shaped slots retain catalyst particles while permitting fluid flow. For large-diameter reactors, the grid is manufactured in multiple segments that are assembled inside the vessel.

The V-shaped slot geometry ensures effective catalyst retention. The slots are narrow at the top surface and wider below, preventing catalyst particles from becoming wedged. Slot openings range from 0.1 mm to 2.0 mm, with common applications using 0.2 mm to 0.5 mm. The slot opening must be smaller than the minimum catalyst particle size. Slot tolerance is held to ±0.03 mm to ±0.05 mm. The open area typically ranges from 15% to 35%, balancing flow capacity with particle retention.

The support grid is constructed with V-shaped profile wires on the top surface and a grid of support beams underneath. For heavy-duty applications, support beams are spaced more closely and larger profile wires are used. Profile wire sizes commonly used include 1.5×3 mm, 2×4 mm, and 3×5 mm. The grid can be a single circular piece for smaller reactors or multiple segments for larger reactors. The segments have locating pins and bolted connections. Materials include stainless steel 304 and 316L, with 2205 duplex, Hastelloy, and titanium available for high-temperature or corrosive applications.