In a reactor, velocity profiles across the entire cross-section of the catalyst are unevenly distributed without corrective measures in place. A CRV flow conditioner, installed prior to the 90° elbow induces fluid rotation and works in conjunction with the geometry of pipe to achieve a uniform flow pattern across the entire cross-section at the elbow exit. When installed after the intermediate heater in styrene plants, the CRV has achieved a uniform flow profile to the catalyst in the second dehydrogenation reactor.
Flow velocity at the center of the reactor is much higher in vessels with large expansions prior to the catalyst bed. This creates an unstable and irregular flow pattern throughout the vessel. Developed to correct this problem, the patented Large Angle Diffuser, or LAD consists of a series of overlapping truncated cones arranged with a common focal point. When installed in the area of expansion, the LAD ensures a uniform distribution of flow velocity without creating a substantial pressure drop.
A combination CRV/LAD system has proven effective in nitric acid manufacturing plants. New or retrofitted, when the CRV/LAD system is positioned immediately after the air/ammonia mixer and prior to the catalyst bed, ammonia conversion efficiency increases up to 4% and the useful life of the platinum gauze can increase as much as 10%.
Koch-Glitsch Mixing & Reaction Technology, 4111 East 37th St. North, Wichita, KS 67220. Tel: 316-828-4145; Fax: 316-828-4444.