nfcl, mangalore dap/npk plant feasibility study - Environmental ...

6ANNEXURE-IVThe granulator is a carbon steel drum lined with rubber panels and equippedwith an apex scrapper, to minimize product build-up on the supporting beamand the rubber panels.It will be also equipped with a lumps kicker to prevent any lump from remaininginside the drum, disturbing the flow of solids and promoting other lumpsformation. Lumps kicker will make the lumps to jump to an attached grizzly,which will disintegrate them by the rotating action. Rest of product will leavethe granulator by passing through the grizzly bars.Solids leaving granulator, normally with moisture content around 2-3% will begravity fed to dryer, in order to achieve the final requested moisture of 1.0-1.5%.Gases developed into the granulator are sucked up towards the Fumes Pre-Scrubber 3, to recover most of the evolved dust and ammonia losses.DryingIn the rotary drum type Dryer, the solids are lifted and cascaded through a cocurrentflow of hot air from the Combustion Chamber. The dryer is designed formaximum efficiency and minimization of material build-up.The Combustion Chamber is FO fired. Air for combustion is supplied by theCombustion Air Fan. The Quench Air propelled by Fan is used to reduce thetemperature of the combustion gases up to a temperature adequate for thecombustion chamber.The temperature of the hot gases after dilution entering dryer is about 120-180°C (for NPKs with urea) and 130 -250°C (for DAP and NPKs without urea).