Drying the feed-grade DCP manufactured by hydrochloric acid process

Based on the theories of chemical thermodynamics and drying dynamics, some problems existing in drying section are analyzed for production of feedgrade DCP by hydrochloric acid prcess. The viewpoint that the calcium chloride in wet material results in lowering the steam pressure of wet material, decreasing the driving force of mass transfer and slowing down the drying rate is stated. The countermeasures, including the increasing wash times to wet material, drying in lower pressure, going down the system pressure and adopting counterflow dryer are recommended.