Gas reacting apparatus and method

Abstract

Gas reacting apparatus and method are described for wet mass transfer of solute gases from a gas stream with a liquid or slurry reacting medium capable of chemisorption of solute gases in the gas stream. The apparatus comprises an elongated conduit defining a primary reaction zone in fluid-flow communication with a fan defining both a secondary reaction zone and a spray coalescence zone, and a plurality of dual-fluid spray nozzles coaxially spaced in series within the conduit and countercurrently or cocurrently directed to the gas stream for spraying the liquid or slurry reacting medium into said conduit to form a plurality of spray contact zones of uniformly-distributed fine droplets wherein intimate contact of high interfacial surface area between the sprayed liquid or slurry and the gas stream is effected to remove solute gases from the gas stream. The fan is operated at a relatively low speed to promote coalescence of droplets through droplet-droplet collisions followed by collection on the fan blades with liquid or slurry layers which, under the action of centrifugal forces, are separated in the form of an attendant annular spray zone of relatively large droplets to trap more of the solute gases. The droplets upon impingement on the fan casing are collected and removed by gravity, while the clean gas stream is exhausted from the fan casing. The apparatus may also include a quenching structure for saturating and cooling the gas stream prior to the removal of solute gases as well as an entrainment separator for further removing entrained droplets not separated by the fan from the clean gas stream.