In order to maintain a clean working environment within the Hivox Plant, an extraction system was supplied to extract the ammonia fumes after the bag filters. The fumes extracted downstream of the bag filters are passed through a packed bed gas scrubber before being vented via a stack. The gas flow is approximately 16000 Am³/hr.
The ammonia is scrubbed from the extracted gas by a scrub solution containing ammonium sulphate continuously circulating through the column. The scrub liquor is pumped by a circulating pump from the holding tank to the top of the column, where the ammonia gas is adsorbed into the scrub liquor in a counter current manner. Any carryover of particulates are also recovered from the gas flow and drain with the scrub liquor back into a holding tank.
Periodically, the liquor is returned to the client for re-use and a new batch of scrub liquor is made up. The plant is fully automated and operates on a continuous basis with minimal operator input.