Two Duct Balloons were supplied on this project to provide auxiliary sealing of the existing inlet and outlet dampers during change out of the SCR catalyst elements. One balloon measured 47’0” (14.3m) wide x 12’0 (3.65m) high x 3’0” (.9m) deep, and the other measured 44’0” (13.4) high x 11’0” (3.35m) wide x 3’0” (.9m) deep. The inlet duct work ran in a vertical up position, so that balloon was installed on top of the existing dampers. The dampers were pinned closed, and the seal air systems were activated. Since a surface temperature of the outlet damper could not be verified, mineral wool insulation was installed on top of the outlet damper and then the balloon was laid down on top of the insulation. Grab handles and “D” rings are sewn into the balloon to help maneuver the balloon in place during inflation. Inflation time for these large balloons was less than ten minutes each.

Two 120V high pressure blowers were supplied on each duct balloon using a “Y” type of inflation tube near the connection point to the blowers. Due to its design, the Duct Balloon cannot become over pressurized by using two blowers simultaneously. In the event of a power loss to the one of the blowers, the Duct Balloon will remain fully inflated by the backup blower, as long each blower is connected to independent circuit breakers.

This Duct Balloon measures 47’0” (14.3m) wide x 12’0 (3.65m) high x 3’0” (.9m) deep

This Duct Balloon measures 44’0” (13.4) high x 11’0” (3.35m) wide x 3’0” (.9m) deep

Note the location of the inflation tube on this large Duct Balloon as it corresponds to the approximate location of the existing access door on the SCR reactor.