Wall rings are a well-known concept for improving the efficiency of SO2 scrubbing.
The spray umbrella of the suspension spray nozzles is less efficient along the walls
of an absorber. Therefore flue gas can "sneak" through the gaps between the spray
cones of spray nozzles and reach to the top rather uncleaned.
Wall rings are installed to prevent that "sneakage" and to direct the flue gas under
the efficient spray umbrellla of the spray headers. The conventional wall rings are
installed on the same level of the spray nozzles and are therefore of limited efficiency.
RPT's concept for wall rings is patent protected. The RPT wall ring is installed below
the spray nozzles - the spray cones are directed on it and are supposed to wetten the
wall ring. The wall ring is a contact surface for the flue gas that passes along the
installation.
The wall ring is built from polypropylene pipes which are installed perpendicular to the
absorber wall and can be dimensioned to any length - in order to balance pressure drop
and scrubbing performance. The pipe segments are installed with spaces between the
pipes so that suspension liquid can drain between them and plugging canot build up
on the wall ring. The combination of redirecting the flue gas under the spray umbrella
of the spray nozzles and the contact surface function of the pipes optimizes the
SO2 scrubbing.